Sample records for maximum precipitation pmp

  1. Probable Maximum Precipitation (PMP) over mountainous region of Cameron Highlands- Batang Padang Catchment of Malaysia

    Sidek, L. M.; Mohd Nor, M. D.; Rakhecha, P. R.; Basri, H.; Jayothisa, W.; Muda, R. S.; Ahmad, M. N.; Razad, A. Z. Abdul


    The Cameron Highland Batang Padang (CHBP) catchment situated on the main mountain range of Peninsular Malaysia is of large economical importance where currently a series of three dams (Sultan Abu Bakar, Jor and Mahang) exist in the development of water resources and hydropower. The prediction of the design storm rainfall values for different return periods including PMP values can be useful to review the adequacy of the current spillway capacities of these dams. In this paper estimates of the design storm rainfalls for various return periods and also the PMP values for rainfall stations in the CHBP catchment have been computed for the three different durations of 1, 3 & 5 days. The maximum values for 1 day, 3 days and 5 days PMP values are found to be 730.08mm, 966.17mm and 969.0mm respectively at Station number 4513033 Gunung Brinchang. The PMP values obtained were compared with previous study results undertaken by NAHRIM. However, the highest ratio of 1 day, 3 day and 5 day PMP to highest observed rainfall are found to be 2.30, 1.94 and 1.82 respectively. This shows that the ratio tend to decrease as the duration increase. Finally, the temporal pattern for 1 day, 3day and 5 days have been developed based on observed extreme rainfall at station 4513033 Gunung Brinchang for the generation of Probable Maximum Flood (PMF) in dam break analysis.

  2. Development of a methodology to evaluate probable maximum precipitation (PMP) under changing climate conditions: Application to southern Quebec, Canada

    Rousseau, Alain N.; Klein, Iris M.; Freudiger, Daphné; Gagnon, Patrick; Frigon, Anne; Ratté-Fortin, Claudie


    Climate change (CC) needs to be accounted for in the estimation of probable maximum floods (PMFs). However, there does not exist a unique way to estimate PMFs and, furthermore the challenge in estimating them is that they should neither be underestimated for safety reasons nor overestimated for economical ones. By estimating PMFs without accounting for CC, the risk of underestimation could be high for Quebec, Canada, since future climate simulations indicate that in all likelihood extreme precipitation events will intensify. In this paper, simulation outputs from the Canadian Regional Climate Model (CRCM) are used to develop a methodology to estimate probable maximum precipitations (PMPs) while accounting for changing climate conditions for the southern region of the Province of Quebec, Canada. The Kénogami and Yamaska watersheds are herein of particular interest, since dam failures could lead to major downstream impacts. Precipitable water (w) represents one of the key variables in the estimation process of PMPs. Results of stationary tests indicate that CC will not only affect precipitation and temperature but also the monthly maximum precipitable water, wmax, and the ensuing maximization ratio used for the estimation of PMPs. An up-to-date computational method is developed to maximize w using a non-stationary frequency analysis, and then calculate the maximization ratios. The ratios estimated this way are deemed reliable since they rarely exceed threshold values set for Quebec, and, therefore, provide consistent PMP estimates. The results show an overall significant increase of the PMPs throughout the current century compared to the recent past.

  3. PMP

    Heldman, Kim


    An up-to-date, concentrated study aide aimed at preparing you for PMP certification The Project Management Professional (PMP) certification is the one of the most desired certification in today's IT marketplace. Candidates are required to have thousands of hours of Project Management experience even before taking the PMP exam. As the ideal reading companion to PMP: Project Management Professional Exam Study Guide, 6th Edition, this essential review gives you that extra preparation you need to approach the grueling PMP exam with confidence. More than 120 review questions, two bonus exams, elect

  4. A probabilistic approach to the concept of Probable Maximum Precipitation

    Papalexiou, S. M.; D. Koutsoyiannis


    International audience; The concept of Probable Maximum Precipitation (PMP) is based on the assumptions that (a) there exists an upper physical limit of the precipitation depth over a given area at a particular geographical location at a certain time of year, and (b) that this limit can be estimated based on deterministic considerations. The most representative and widespread estimation method of PMP is the so-called moisture maximization method. This method maximizes observed storms assuming...

  5. Needs to Update Probable Maximum Precipitation for Critical Infrastructure

    Pathak, C. S.; England, J. F.


    Probable Maximum Precipitation (PMP) is theoretically the greatest depth of precipitation for a given duration that is physically possible over a given size storm area at a particular geographical location at a certain time of the year. It is used to develop inflow flood hydrographs, known as Probable Maximum Flood (PMF), as design standard for high-risk flood-hazard structures, such as dams and nuclear power plants. PMP estimation methodology was developed in the 1930s and 40s when many dams were constructed in the US. The procedures to estimate PMP were later standardized by the World Meteorological Organization (WMO) in 1973 and revised in 1986.In the US, PMP estimates were published in a series of Hydrometeorological Reports (e.g., HMR55A, HMR57, and HMR58/59) by the National Weather Service since 1950s. In these reports, storm data up to 1980s were used to establish the current PMP estimates. Since that time, we have acquired additional meteorological data for 30 to 40 years, including newly available radar and satellite based precipitation data. These data sets are expected to have improved data quality and availability in both time and space. In addition, significant numbers of extreme storms have occurred and selected numbers of these events were even close to or exceeding the current PMP estimates, in some cases. In the last 50 years, climate science has progressed and scientists have better and improved understanding of atmospheric physics of extreme storms. However, applied research in estimation of PMP has been lagging behind. Alternative methods, such as atmospheric numerical modeling, should be investigated for estimating PMP and associated uncertainties. It would be highly desirable if regional atmospheric numerical models could be utilized in the estimation of PMP and their uncertainties, in addition to methods used to originally develop PMP index maps in the existing hydrometeorological reports.

  6. An Integrated Modeling Framework for Probable Maximum Precipitation and Flood

    Gangrade, S.; Rastogi, D.; Kao, S. C.; Ashfaq, M.; Naz, B. S.; Kabela, E.; Anantharaj, V. G.; Singh, N.; Preston, B. L.; Mei, R.


    With the increasing frequency and magnitude of extreme precipitation and flood events projected in the future climate, there is a strong need to enhance our modeling capabilities to assess the potential risks on critical energy-water infrastructures such as major dams and nuclear power plants. In this study, an integrated modeling framework is developed through high performance computing to investigate the climate change effects on probable maximum precipitation (PMP) and probable maximum flood (PMF). Multiple historical storms from 1981-2012 over the Alabama-Coosa-Tallapoosa River Basin near the Atlanta metropolitan area are simulated by the Weather Research and Forecasting (WRF) model using the Climate Forecast System Reanalysis (CFSR) forcings. After further WRF model tuning, these storms are used to simulate PMP through moisture maximization at initial and lateral boundaries. A high resolution hydrological model, Distributed Hydrology-Soil-Vegetation Model, implemented at 90m resolution and calibrated by the U.S. Geological Survey streamflow observations, is then used to simulate the corresponding PMF. In addition to the control simulation that is driven by CFSR, multiple storms from the Community Climate System Model version 4 under the Representative Concentrations Pathway 8.5 emission scenario are used to simulate PMP and PMF in the projected future climate conditions. The multiple PMF scenarios developed through this integrated modeling framework may be utilized to evaluate the vulnerability of existing energy-water infrastructures with various aspects associated PMP and PMF.

  7. Understanding the Role of Reservoir Size on Probable Maximum Precipitation

    Woldemichael, A. T.; Hossain, F.


    This study addresses the question 'Does surface area of an artificial reservoir matter in the estimation of probable maximum precipitation (PMP) for an impounded basin?' The motivation of the study was based on the notion that the stationarity assumption that is implicit in the PMP for dam design can be undermined in the post-dam era due to an enhancement of extreme precipitation patterns by an artificial reservoir. In addition, the study lays the foundation for use of regional atmospheric models as one way to perform life cycle assessment for planned or existing dams to formulate best management practices. The American River Watershed (ARW) with the Folsom dam at the confluence of the American River was selected as the study region and the Dec-Jan 1996-97 storm event was selected for the study period. The numerical atmospheric model used for the study was the Regional Atmospheric Modeling System (RAMS). First, the numerical modeling system, RAMS, was calibrated and validated with selected station and spatially interpolated precipitation data. Best combinations of parameterization schemes in RAMS were accordingly selected. Second, to mimic the standard method of PMP estimation by moisture maximization technique, relative humidity terms in the model were raised to 100% from ground up to the 500mb level. The obtained model-based maximum 72-hr precipitation values were named extreme precipitation (EP) as a distinction from the PMPs obtained by the standard methods. Third, six hypothetical reservoir size scenarios ranging from no-dam (all-dry) to the reservoir submerging half of basin were established to test the influence of reservoir size variation on EP. For the case of the ARW, our study clearly demonstrated that the assumption of stationarity that is implicit the traditional estimation of PMP can be rendered invalid to a large part due to the very presence of the artificial reservoir. Cloud tracking procedures performed on the basin also give indication of the

  8. Site Specific Probable Maximum Precipitation Estimates and Professional Judgement

    Hayes, B. D.; Kao, S. C.; Kanney, J. F.; Quinlan, K. R.; DeNeale, S. T.


    State and federal regulatory authorities currently rely upon the US National Weather Service Hydrometeorological Reports (HMRs) to determine probable maximum precipitation (PMP) estimates (i.e., rainfall depths and durations) for estimating flooding hazards for relatively broad regions in the US. PMP estimates for the contributing watersheds upstream of vulnerable facilities are used to estimate riverine flooding hazards while site-specific estimates for small water sheds are appropriate for individual facilities such as nuclear power plants. The HMRs are often criticized due to their limitations on basin size, questionable applicability in regions affected by orographic effects, their lack of consist methods, and generally by their age. HMR-51 for generalized PMP estimates for the United States east of the 105th meridian, was published in 1978 and is sometimes perceived as overly conservative. The US Nuclear Regulatory Commission (NRC), is currently reviewing several flood hazard evaluation reports that rely on site specific PMP estimates that have been commercially developed. As such, NRC has recently investigated key areas of expert judgement via a generic audit and one in-depth site specific review as they relate to identifying and quantifying actual and potential storm moisture sources, determining storm transposition limits, and adjusting available moisture during storm transposition. Though much of the approach reviewed was considered a logical extension of HMRs, two key points of expert judgement stood out for further in-depth review. The first relates primarily to small storms and the use of a heuristic for storm representative dew point adjustment developed for the Electric Power Research Institute by North American Weather Consultants in 1993 in order to harmonize historic storms for which only 12 hour dew point data was available with more recent storms in a single database. The second issue relates to the use of climatological averages for spatially

  9. Effects of climate change on probable maximum precipitation: A sensitivity study over the Alabama-Coosa-Tallapoosa River Basin

    Rastogi, Deeksha; Kao, Shih-Chieh; Ashfaq, Moetasim; Mei, Rui; Kabela, Erik D.; Gangrade, Sudershan; Naz, Bibi S.; Preston, Benjamin L.; Singh, Nagendra; Anantharaj, Valentine G.


    Probable maximum precipitation (PMP), defined as the largest rainfall depth that could physically occur under a series of adverse atmospheric conditions, has been an important design criterion for critical infrastructures such as dams and nuclear power plants. To understand how PMP may respond to projected future climate forcings, we used a physics-based numerical weather simulation model to estimate PMP across various durations and areas over the Alabama-Coosa-Tallapoosa (ACT) River Basin in the southeastern United States. Six sets of Weather Research and Forecasting (WRF) model experiments driven by both reanalysis and global climate model projections, with a total of 120 storms, were conducted. The depth-area-duration relationship was derived for each set of WRF simulations and compared with the conventional PMP estimates. Our results showed that PMP driven by projected future climate forcings is higher than 1981-2010 baseline values by around 20% in the 2021-2050 near-future and 44% in the 2071-2100 far-future periods. The additional sensitivity simulations of background air temperature warming also showed an enhancement of PMP, suggesting that atmospheric warming could be one important factor controlling the increase in PMP. In light of the projected increase in precipitation extremes under a warming environment, the reasonableness and role of PMP deserve more in-depth examination.

  10. Probable maximum precipitation 24 hours estimation: A case study of Zanjan province of Iran

    Azim Shirdeli


    Full Text Available One of the primary concerns in designing civil structures such as water storage dams and irrigation and drainage networks is to find economic scale based on possibility of natural incidents such as floods, earthquake, etc. Probable maximum precipitation (PMP is one of well known methods, which helps design a civil structure, properly. In this paper, we study the maximum one-day precipitation using 17 to 50 years of information in 13 stations located in province of Zanjan, Iran. The proposed study of this paper uses two Hershfield methods, where the first one yields 18.17 to 18.48 for precipitation where the PMP24 was between 170.14 mm and 255.28 mm. The second method reports precipitation between 2.29 and 4.95 while PMP24 was between 62.33 mm and 92.08 mm. In addition, when the out of range data were deleted from the study of the second method, precipitation rates were calculated between 2.29 and 4.31 while PMP24 was between 76.08 mm and 117.28 mm. The preliminary results indicate that the second Hershfield method provide more stable results than the first one.

  11. Investigation of Atmospheric Modelling Framework for Better Reconstruction on Historical Extreme Precipitation Event in PMP Estimation

    Chen, X.; Hossain, F.; Leung, L. R.


    During May 1-2, 2010, a record-breaking storm hit Nashville, and caused huge humanity and societal loss. It raises the importance of forecasting/reconstructing these types of extreme weather systems once again, in the meanwhile providing an excellent case for such atmospheric modelling studies. However, earlier studies suggest that successful reconstruction of this event depends on and is sensitive to a number of model options, making it difficult to establish a better model framework with more confidence. In this study we employed the Weather Research and Forecast (WRF) model to investigate how this extreme precipitation event is sensitive to the model configuration, and identified options that would produce better results. We tested several combinations of modelling grid sizes together with initial/boundary conditions (IC/BC). At different grid sizes, we conducted a set of tests on various combinations of microphysics (Morrison, new Thompson and WSM5) and cumulus process (Kain-Fristch, Grell-Devenyi and Grell-Freitas) parameterization schemes. The model results were intensively evaluated under bias analysis as well as other metrics (probability of detection, bias, false alerts, HSS, ETS). The evaluation suggests that in general, simulation results benefit from finer model grids (5km). At 5km level, NCEP2 or NAM IC/BCs are more representative for the 2010 Nashville storm. There are no universally good parameterization schemes, but the WSM5 microphysics scheme, Kain-Fristch and Grell-Freitas cumulus schemes are recommended over other tested schemes. These better schemes would help to make better estimation of PMP in the region.

  12. Evaluation of Probable Maximum Precipitation and Flood under Climate Change in the 21st Century

    Gangrade, S.; Kao, S. C.; Rastogi, D.; Ashfaq, M.; Naz, B. S.; Kabela, E.; Anantharaj, V. G.; Singh, N.; Preston, B. L.; Mei, R.


    Critical infrastructures are potentially vulnerable to extreme hydro-climatic events. Under a warming environment, the magnitude and frequency of extreme precipitation and flood are likely to increase enhancing the needs to more accurately quantify the risks due to climate change. In this study, we utilized an integrated modeling framework that includes the Weather Research Forecasting (WRF) model and a high resolution distributed hydrology soil vegetation model (DHSVM) to simulate probable maximum precipitation (PMP) and flood (PMF) events over Alabama-Coosa-Tallapoosa River Basin. A total of 120 storms were selected to simulate moisture maximized PMP under different meteorological forcings, including historical storms driven by Climate Forecast System Reanalysis (CFSR) and baseline (1981-2010), near term future (2021-2050) and long term future (2071-2100) storms driven by Community Climate System Model version 4 (CCSM4) under Representative Concentrations Pathway 8.5 emission scenario. We also analyzed the sensitivity of PMF to various antecedent hydrologic conditions such as initial soil moisture conditions and tested different compulsive approaches. Overall, a statistical significant increase is projected for future PMP and PMF, mainly attributed to the increase of background air temperature. The ensemble of simulated PMP and PMF along with their sensitivity allows us to better quantify the potential risks associated with hydro-climatic extreme events on critical energy-water infrastructures such as major hydropower dams and nuclear power plants.

  13. Estimating the exceedance probability of extreme rainfalls up to the probable maximum precipitation

    Nathan, Rory; Jordan, Phillip; Scorah, Matthew; Lang, Simon; Kuczera, George; Schaefer, Melvin; Weinmann, Erwin


    If risk-based criteria are used in the design of high hazard structures (such as dam spillways and nuclear power stations), then it is necessary to estimate the annual exceedance probability (AEP) of extreme rainfalls up to and including the Probable Maximum Precipitation (PMP). This paper describes the development and application of two largely independent methods to estimate the frequencies of such extreme rainfalls. One method is based on stochastic storm transposition (SST), which combines the "arrival" and "transposition" probabilities of an extreme storm using the total probability theorem. The second method, based on "stochastic storm regression" (SSR), combines frequency curves of point rainfalls with regression estimates of local and transposed areal rainfalls; rainfall maxima are generated by stochastically sampling the independent variates, where the required exceedance probabilities are obtained using the total probability theorem. The methods are applied to two large catchments (with areas of 3550 km2 and 15,280 km2) located in inland southern Australia. Both methods were found to provide similar estimates of the frequency of extreme areal rainfalls for the two study catchments. The best estimates of the AEP of the PMP for the smaller and larger of the catchments were found to be 10-7 and 10-6, respectively, but the uncertainty of these estimates spans one to two orders of magnitude. Additionally, the SST method was applied to a range of locations within a meteorologically homogenous region to investigate the nature of the relationship between the AEP of PMP and catchment area.

  14. On the consideration of scaling properties of extreme rainfall in Madrid (Spain) for developing a generalized intensity-duration-frequency equation and assessing probable maximum precipitation estimates

    Casas-Castillo, M. Carmen; Rodríguez-Solà, Raúl; Navarro, Xavier; Russo, Beniamino; Lastra, Antonio; González, Paula; Redaño, Angel


    The fractal behavior of extreme rainfall intensities registered between 1940 and 2012 by the Retiro Observatory of Madrid (Spain) has been examined, and a simple scaling regime ranging from 25 min to 3 days of duration has been identified. Thus, an intensity-duration-frequency (IDF) master equation of the location has been constructed in terms of the simple scaling formulation. The scaling behavior of probable maximum precipitation (PMP) for durations between 5 min and 24 h has also been verified. For the statistical estimation of the PMP, an envelope curve of the frequency factor (k m ) based on a total of 10,194 station-years of annual maximum rainfall from 258 stations in Spain has been developed. This curve could be useful to estimate suitable values of PMP at any point of the Iberian Peninsula from basic statistical parameters (mean and standard deviation) of its rainfall series.

  15. PMP exam prep

    Mulcahy, Rita


    This book has been FULLY updated to reflect PMI's changes to the PMP exam, and should be used to prepare for all PMP exams delivered on or after July 30th of 2013. Can you imagine valuing a book so much that you send the author a Thank You letter? Hundreds of thousands of project managers know and understand why PMP Exam Prep is a worldwide best-seller. Years of PMP exam preparation experience, endless hours of ongoing research, interviews with project managers who failed the exam to identify gaps in their knowledge, and a razor-sharp focus on making sure project managers don't waste a single minute of their time studying are THE reasons this book is the best-selling PMP exam preparation guide in the world. PMP Exam Prep, Eighth Edition contains hundreds of updates and improvements from previous editions--including new exercises and sample questions never before in print. Offering hundreds of sample questions, critical time-saving tips plus games and activities available nowhere else, this book will help y...

  16. PMP Estimations at Sparsely Controlled Andinian Basins and Climate Change Projections

    Lagos Zúñiga, M. A.; Vargas, X.


    Probable Maximum Precipitation (PMP) estimation implies an extensive review of hydrometeorological data and understandig of precipitation formation processes. There exists different methodology processes that apply for their estimations and all of them require a good spatial and temporal representation of storms. The estimation of hydrometeorological PMP on sparsely controlled basins is a difficult task, specially if the studied area has an important orographic effect due to mountains and the mixed precipitation occurrence in the most several storms time period, the main task of this study is to propose and estimate PMP in a sparsely controlled basin, affected by abrupt topography and mixed hidrology basin; also analyzing statystic uncertainties estimations and possible climate changes effects in its estimation. In this study the PMP estimation under statistical and hydrometeorological aproaches (watershed-based and traditional depth area duration analysis) was done in a semi arid zone at Puclaro dam in north Chile. Due to the lack of good spatial meteorological representation at the study zone, we propose a methodology to consider the orographic effects of Los Andes due to orographic effects patterns based in a RCM PRECIS-DGF and annual isoyetal maps. Estimations were validated with precipitation patterns for given winters, considering snow route and rainfall gauges at the preferencial wind direction, finding good results. The estimations are also compared with the highest areal storms in USA, Australia, India and China and with frequency analysis in local rain gauge stations in order to decide about the most adequate approach for the study zone. Climate change projections were evaluated with ECHAM5 GCM model, due to its good quality representation in the seasonality and the magnitude of meteorological variables. Temperature projections, for 2040-2065 period, show that there would be a rise in the catchment contributing area that would lead to an increase of the

  17. Estimation of probable maximum precipitation at the Kielce Upland (Poland) using meteorological method

    Suligowski, Roman


    Probable Maximum Precipitation based upon the physical mechanisms of precipitation formation at the Kielce Upland. This estimation stems from meteorological analysis of extremely high precipitation events, which occurred in the area between 1961 and 2007 causing serious flooding from rivers that drain the entire Kielce Upland. Meteorological situation has been assessed drawing on the synoptic maps, baric topography charts, satellite and radar images as well as the results of meteorological observations derived from surface weather observation stations. Most significant elements of this research include the comparison between distinctive synoptic situations over Europe and subsequent determination of typical rainfall generating mechanism. This allows the author to identify the source areas of air masses responsible for extremely high precipitation at the Kielce Upland. Analysis of the meteorological situations showed, that the source areas for humid air masses which cause the largest rainfalls at the Kielce Upland are the area of northern Adriatic Sea and the north-eastern coast of the Black Sea. Flood hazard at the Kielce Upland catchments was triggered by daily precipitation of over 60 mm. The highest representative dew point temperature in source areas of warm air masses (these responsible for high precipitation at the Kielce Upland) exceeded 20 degrees Celsius with a maximum of 24.9 degrees Celsius while precipitable water amounted to 80 mm. The value of precipitable water is also used for computation of factors featuring the system, namely the mass transformation factor and the system effectiveness factor. The mass transformation factor is computed based on precipitable water in the feeding mass and precipitable water in the source area. The system effectiveness factor (as the indicator of the maximum inflow velocity and the maximum velocity in the zone of front or ascending currents, forced by orography) is computed from the quotient of precipitable water in

  18. 49 CFR 633.29 - PMP waivers.


    ... 49 Transportation 7 2010-10-01 2010-10-01 false PMP waivers. 633.29 Section 633.29 Transportation... TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.29 PMP waivers. A waiver will be... basis, waive: (a) Any of the PMP elements in § 633.25 of this part if the Administrator determines...

  19. Best fitting distributions for the standard duration annual maximum precipitations in the Aegean Region

    Halil Karahan


    Full Text Available Knowing the properties like amount, duration, intensity, spatial and temporal variation etc… of precipitation which is the primary input of water resources is required for planning, design, construction and operation studies of various sectors like water resources, agriculture, urbanization, drainage, flood control and transportation. For executing the mentioned practices, reliable and realistic estimations based on existing observations should be made. The first step of making a reliable estimation is to test the reliability of existing observations. In this study, Kolmogorov-Smirnov, Anderson-Darling and Chi-Square goodness of distribution fit tests were applied for determining to which distribution the measured standard duration maximum precipitation values (in the years 1929-2005 fit in the meteorological stations operated by the Turkish State Meteorological Service (DMİ which are located in the city and town centers of Aegean Region. While all the observations fit to GEV distribution according to Anderson-Darling test, it was seen that short, mid-term and long duration precipitation observations generally fit to GEV, Gamma and Log-normal distribution according to Kolmogorov-Smirnov and Chi-square tests. To determine the parameters of the chosen probability distribution, maximum likelihood (LN2, LN3, EXP2, Gamma3, probability-weighted distribution (LP3,Gamma2, L-moments (GEV and least squares (Weibull2 methods were used according to different distributions.

  20. An exploratory study of spatial annual maximum of monthly precipitation in the northern region of Portugal

    Prata Gomes, D.; Neves, M. M.; Moreira, E.


    Adequately analyzing and modeling the extreme rainfall events is of great importance because of the effects that their magnitude and frequency can have on human life, agricultural productivity and economic aspects, among others. A single extreme event may affect several locations, and their spatial dependence has to be appropriately taken into account. Classical geostatistics is a well-developed field for dealing with location referenced data, but it is largely based on Gaussian processes and distributions, that are not appropriate for extremes. In this paper, an exploratory study of the annual maximum of monthly precipitation recorded in the northern area of Portugal from 1941 to 2006 at 32 locations is performed. The aim of this paper is to apply max-stable processes, a natural extension of multivariate extremes to the spatial set-up, to briefly describe the models considered and to estimate the required parameters to simulate prediction maps.

  1. Quantifying uncertainty in modelled estimates of annual maximum precipitation: confidence intervals

    Panagoulia, Dionysia; Economou, Polychronis; Caroni, Chrys


    The possible nonstationarity of the GEV distribution fitted to annual maximum precipitation under climate change is a topic of active investigation. Of particular significance is how best to construct confidence intervals for items of interest arising from stationary/nonstationary GEV models.We are usually not only interested in parameter estimates but also in quantiles of the GEV distribution and it might be expected that estimates of extreme upper quantiles are far from being normally distributed even for moderate sample sizes.Therefore, we consider constructing confidence intervals for all quantities of interest by bootstrap methods based on resampling techniques. To this end, we examined three bootstrapping approaches to constructing confidence intervals for parameters and quantiles: random-t resampling, fixed-t resampling and the parametric bootstrap. Each approach was used in combination with the normal approximation method, percentile method, basic bootstrap method and bias-corrected method for constructing confidence intervals. We found that all the confidence intervals for the stationary model parameters have similar coverage and mean length. Confidence intervals for the more extreme quantiles tend to become very wide for all bootstrap methods. For nonstationary GEV models with linear time dependence of location or log-linear time dependence of scale, confidence interval coverage probabilities are reasonably accurate for the parameters. For the extreme percentiles, the bias-corrected and accelerated method is best overall, and the fixed-t method also has good average coverage probabilities. Reference: Panagoulia D., Economou P. and Caroni C., Stationary and non-stationary GEV modeling of extreme precipitation over a mountainous area under climate change, Environmetrics, 25 (1), 29-43, 2014.

  2. Precipitation Isotopes Reveal Intensified Indonesian Monsoon Circulation During the Dry Last Glacial Maximum

    Konecky, B. L.; Russell, J. M.; Vogel, H.; Bijaksana, S.; Huang, Y.


    The Indo-Pacific Warm Pool (IPWP) invigorates the oceanic-atmospheric circulation in the tropics, with far-reaching climate impacts that extend into the high latitudes. A growing number of deglacial proxy reconstructions from the region have revealed the importance of both high- and low-latitude climate processes to IPWP rainfall during the late Pleistocene. Many of these proxies reconstruct the oxygen and hydrogen isotopic composition of rainfall (δ18Oprecip, δDprecip), a powerful tool for understanding changes in climate. However, an increasing number of studies from the region have highlighted the tendency for δ18Oprecip and δDprecip to reflect regional and/or remote circulation processes rather than local rainfall amounts, complicating the reconstruction of IPWP hydroclimate. To better understand high- and low-latitude drivers of late Pleistocene hydroclimate in the IPWP, precipitation isotopic reconstructions must be constrained with both modern observations and independent proxies for rainfall amount. We present a reconstruction of δDprecip using leaf wax compounds preserved in the sediments of Lake Towuti, Sulawesi, from 60,000 years before present to today. We interpret our proxy record with the aid of a new precipitation isotopic dataset from our study site, with daily rainfall isotope measurements to constrain the processes controlling δDprecip. Our Lake Towuti δDwax record is strikingly similar to a speleothem δ18O record from southern Indonesia (Ayliffe et al., 2013) and shares features with other nearby records spanning the Last Glacial Maximum to present. Together, these records indicate that monsoon circulation was intensified in central and southern Indonesia during the glacial period. However, other independent rainfall proxies from Lake Towuti indicate that dry conditions accompanied the intensified monsoon. Regional-scale isotopic depletion during the dry glacial period may have arisen from dynamical and other fractionating processes that

  3. PMP Project Management Professional Exam Study Guide

    Heldman, Kim


    Completely updated for the 2011 version of the PMP exam! If you're preparing for the Project Management Professional (PMP) exam, this thorough book is what you need. Not only does it reflect the very latest version of the exam, it is written by popular project management expert Kim Heldman—author of the five previous editions of this top-selling book—and it also includes a CD with practice exams, exam prep software, electronic flashcards, and over two hours of additional audio review. All exam objectives, as well as essential PMP topics, concepts, and key terms are covered.Prepares

  4. Increased precipitation and weathering across the Paleocene-Eocene Thermal Maximum in central China

    Chen, Zuoling; Ding, Zhongli; Yang, Shiling; Zhang, Chunxia; Wang, Xu


    Global warming during the Paleocene-Eocene Thermal Maximum (PETM) ˜55.5 million years ago (Ma) was associated with a massive release of carbon to the ocean-atmosphere system, as evidenced by a prominent negative carbon isotope excursion (CIE) and widespread dissolution of marine carbonates. The paleohydrologic response to the PETM warming has been studied worldwide; however, relevant records of environmental perturbation in Asia are lacking so far. Here we extend the record of this event in central China, a subtropical paleosetting, through geochemical and mineralogical analyses of lacustrine sediments. Geochemical indicators of authigenic carbonates—including molar Mg/Ca and Sr/Ca ratios—suggest an overall increased precipitation across the PETM, compatible with the disappearance of authigenic dolomite and the appearance of kaolinite in the strata. The relatively humid conditions persisted long after the carbon-cycle perturbation had stopped, implying that the transient hyper-greenhouse warming might have forced the regional climate system into a new climate state that was not easily reversed. Additionally, a gradual increase in chemical index of alteration (CIA) and the appearance of kaolinite are associated with the PETM, indicating an intensified silicate weathering and pedogenesis in the watershed in response to warmer and more humid climate. Our results corroborate the theory that an accelerated continental chemical weathering served as a negative feedback to sequester carbon and lower the atmospheric greenhouse-gas levels during the PETM.

  5. Abrupt change point detection of annual maximum precipitation using fused lasso

    Jeon, Jong-June; Sung, Jang Hyun; Chung, Eun-Sung


    Because the widely used Bayesian change point analysis (BCPA) is generally applied to the normal distribution, it cannot be freely used to the annual maximum precipitations (AMP) in South Korea. Therefore, this study proposed the fused lasso penalty function to detect the change point of AMP which can be generally fitted by using the Generalized Extreme Value (GEV) distribution in South Korea. First, four numerical experiments are conducted to compare the detection performances between BCPA and fused lasso method. As a result, fused lasso shows the superiority of the data generated by GEV distribution having skewness. The fused lasso method is applied to 63 weather stations in South Korea and then 17 stations having any change points from BCPA and the GEV fused lasso are analyzed. Similar to the numerical analyses, the GEV fused lasso method can delicately detect the change point of AMPs. After the change point, the means of AMPs did not go back to the previous. Alternately, BCPA can be stated to find variation points not change points because the means returned to their original values as time progressed. Therefore, it can be concluded that the GEV fused lasso method detects the change points of non-stationary AMPs of South Korea. This study can be extended to more extreme distributions for various meteorological variables.

  6. Prescribers and pharmacists requests for prescription monitoring program (PMP) data: does PMP structure matter?

    Fleming, Marc L; Chandwani, Hitesh; Barner, Jamie C; Weber, Stephanie N; Okoro, Tony T


    Prescription monitoring programs (PMPs) have been purported to be an effective tool to combat prescription drug abuse. However, utilization rates of PMP data by health care providers (e.g., prescribers and pharmacists) is relatively low. The objectives of the study were to describe (1) PMP utilization (e.g., requested reports) by prescribers, pharmacists, and law enforcement for active state PMPs; (2) PMP utilization by health care providers with and without online access; (3) average annual operational costs for PMPs from 2008 to 2009; and (4) PMP requests based on PMP housing authority (law enforcement vs. non-law enforcement [e.g., board of pharmacy]). This was a cross-sectional study employing a Web-based survey. A 16-item questionnaire was e-mailed to the 33 operational state PMP administrators and responses were collected from January to March 2011. Descriptive statistics were used to describe PMP request rates and annual operating costs. The usable survey response rate was 45.5%. Among all authorized users, prescribers had higher mean (±SD) requests per 100,000 population (2198.2 ± 3218.0) compared with pharmacists' requests (268.9 ± 261.2). Online accessibility resulted in higher request rates per 100,000 population (2996.4 ± 3021.5) compared with mail/fax access (14.6 ± 2.8). On average, PMP annual costs were $12,515 ± $14,911 per 100,000 population. In law enforcement-governed PMPs, health care provider utilization was lower compared with PMPs under health or pharmacy boards. Prescriber request rates were higher than pharmacists and online access for providers (e.g., prescribers and pharmacists) resulted in higher request rates per 100,000 population. More research is needed to determine other factors that may be associated with PMP utilization by prescribers and pharmacists.

  7. Precipitation Interpolation by Multivariate Bayesian Maximum Entropy Based on Meteorological Data in Yun- Gui-Guang region, Mainland China

    Wang, Chaolin; Zhong, Shaobo; Zhang, Fushen; Huang, Quanyi


    Precipitation interpolation has been a hot area of research for many years. It had close relation to meteorological factors. In this paper, precipitation from 91 meteorological stations located in and around Yunnan, Guizhou and Guangxi Zhuang provinces (or autonomous region), Mainland China was taken into consideration for spatial interpolation. Multivariate Bayesian maximum entropy (BME) method with auxiliary variables, including mean relative humidity, water vapour pressure, mean temperature, mean wind speed and terrain elevation, was used to get more accurate regional distribution of annual precipitation. The means, standard deviations, skewness and kurtosis of meteorological factors were calculated. Variogram and cross- variogram were fitted between precipitation and auxiliary variables. The results showed that the multivariate BME method was precise with hard and soft data, probability density function. Annual mean precipitation was positively correlated with mean relative humidity, mean water vapour pressure, mean temperature and mean wind speed, negatively correlated with terrain elevation. The results are supposed to provide substantial reference for research of drought and waterlog in the region.

  8. PMP-2 Report: Equatorial Wave Dynamics

    Hirota, I.


    The activities of the pre-MAP project 2 (PMP-2) from 1978 through 1981 are described. The following topics relating to the equatorial middle atmosphere are discussed briefly: (1) the semi-annual oscillation and Kelvin waves; (2) planetary Rossby waves; (3) upper mesospheric waves; and (4) gravity waves.

  9. The promise of post-menopausal pregnancy (PMP).

    Landau, Ruth


    Postmenopausal pregnancy (PMP) is presented as a means of alleviating women's suffering by helping them realize their wish for a child of their "own." The availability of IVF technology and oocyte donation, both necessary for PMP, create the illusion of unlimited female fertility. The aim of this paper is twofold: (1) to examine the psychosocial, health, and ethical aspects of PMP; and (2) to answer the question of whether PMP's promise of unlimited fertility really offers more personal freedom and control for women. The paper concludes that PMP seems to increase, rather than to decrease, human suffering.

  10. Pseudomyxoma peritonei (PMP - a rare entity

    Zaeem Ismail Ebrahim


    Full Text Available Pseudomyxoma peritonei (PMP is a rare complication of mucinous tumours of appendiceal or ovarian origin that results in peritoneal and omental implants. Clinical morbidity and mortality arise from the fact that copious amounts of extracellular and peritoneal mucin result in distortion and loss of function of visceral organs. Therapeutic paracentesis is not possible because of the nature of the mucin. Currently, new techniques are being used to attempt to debulk the mucin volume; none, however, has lead to superior outcome.

  11. PMP practice makes perfect over 1000 PMP practice questions and answers

    Estrella, John A; Zahran, Sami


    A unique learning resource to prepare for the PMP certification exam Without sufficient practice and preparation for taking the Project Management Institute's (PMI's) PMP certification exam, you won't be able to actually put your skills into practice in the real world! To help you achieve your goal of passing the exam, this two-part prep book covers all elements of the brand-new Project Management Professional exam. A team of experts presents you with a solid overview of the exam as well as hundreds of questions, detailed answers, and explanations. In addition, each question is accompa

  12. An application of Hamiltonian neurodynamics using Pontryagin's Maximum (Minimum) Principle.

    Koshizen, T; Fulcher, J


    Classical optimal control methods, notably Pontryagin's Maximum (Minimum) Principle (PMP) can be employed, together with Hamiltonians, to determine optimal system weights in Artificial Neural dynamical systems. A new learning rule based on weight equations derived using PMP is shown to be suitable for both discrete- and continuous-time systems, and moreover, can also be applied to feedback networks. Preliminary testing shows that this PMP learning rule compares favorably with Standard BackPropagations (SBP) on the XOR problem.

  13. Comparison of methods for non-stationary hydrologic frequency analysis: Case study using annual maximum daily precipitation in Taiwan

    Chen, Po-Chun; Wang, Yuan-Heng; You, Gene Jiing-Yun; Wei, Chih-Chiang


    Future climatic conditions likely will not satisfy stationarity assumption. To address this concern, this study applied three methods to analyze non-stationarity in hydrologic conditions. Based on the principle of identifying distribution and trends (IDT) with time-varying moments, we employed the parametric weighted least squares (WLS) estimation in conjunction with the non-parametric discrete wavelet transform (DWT) and ensemble empirical mode decomposition (EEMD). Our aim was to evaluate the applicability of non-parameter approaches, compared with traditional parameter-based methods. In contrast to most previous studies, which analyzed the non-stationarity of first moments, we incorporated second-moment analysis. Through the estimation of long-term risk, we were able to examine the behavior of return periods under two different definitions: the reciprocal of the exceedance probability of occurrence and the expected recurrence time. The proposed framework represents an improvement over stationary frequency analysis for the design of hydraulic systems. A case study was performed using precipitation data from major climate stations in Taiwan to evaluate the non-stationarity of annual maximum daily precipitation. The results demonstrate the applicability of these three methods in the identification of non-stationarity. For most cases, no significant differences were observed with regard to the trends identified using WLS, DWT, and EEMD. According to the results, a linear model should be able to capture time-variance in either the first or second moment while parabolic trends should be used with caution due to their characteristic rapid increases. It is also observed that local variations in precipitation tend to be overemphasized by DWT and EEMD. The two definitions provided for the concept of return period allows for ambiguous interpretation. With the consideration of non-stationarity, the return period is relatively small under the definition of expected

  14. Characterization of human and murine PMP20 peroxisomal proteins that exhibit antioxidant activity in vitro.

    Yamashita, H; Avraham, S; Jiang, S; London, R; Van Veldhoven, P P; Subramani, S; Rogers, R A; Avraham, H


    We have isolated the cDNAs encoding human and mouse homologues of a yeast protein, termed peroxisomal membrane protein 20 (PMP20). Comparison of the amino acid sequences of human (HsPMP20) and mouse (MmPMP20) PMP20 proteins revealed a high degree of identity (93%), whereas resemblance to the yeast Candida boidinii PMP20A and PMP20B (CbPMP20A and CbPMP20B) was less (30% identity). Both HsPMP20 and MmPMP20 lack transmembrane regions, as do CbPMP20A and CbPMP20B. HsPMP20 mRNA expression was low in human fetal tissues, especially in the brain. In adult tissues, HsPMP20 mRNA was expressed in the majority of tissues tested. HsPMP20 and MmPMP20 contained the C-terminal tripeptide sequence Ser-Gln-Leu (SQL), which is similar to the peroxisomal targeting signal 1 utilized for protein import into peroxisomes. HsPMP20 bound directly to the human peroxisomal targeting signal 1 receptor, HsPEX5. Mutagenesis analysis showed that the C-terminal tripeptide sequence, SQL, of HsPMP20 is necessary for its binding to HsPEX5. Subcellular fractionation of HeLa cells, expressing epitope-tagged PMP20, revealed that HsPMP20 is localized in the cytoplasm and in a particulate fraction containing peroxisomes. Double-staining immunofluorescence studies showed colocalization of HsPMP20 and thiolase, a bona fide peroxisomal protein. The amino acid sequence alignment of HsPMP20, MmPMP20, CbPMP20A, and CbPMP20B displayed high similarity to thiol-specific antioxidant proteins. HsPMP20 exerted an inhibitory effect on the inactivation of glutamine synthetase in the thiol metal-catalyzed oxidation system but not in the nonthiol metal-catalyzed oxidation system, suggesting that HsPMP20 possesses thiol-specific antioxidant activity. In addition, HsPMP20 removed hydrogen peroxide by its thiol-peroxidase activity. These results indicate that HsPMP20 is imported into the peroxisomal matrix via PEX5p and may work to protect peroxisomal proteins against oxidative stress. Because some portion of PMP20 might

  15. PMP22 and its related diseases%PMP22及其相关疾病

    郭家松; 李俊


    由基因突变引起的外周神经病统称为Charcot-Marie-Tooth(CMT)病,它是最常见的遗传性神经系统疾病之一,发病率为1/2 500.目前已知有超过53个染色体位点和35个特定基因与CMT有关,但是大部分CMT都是由周围髓鞘蛋白22(PMP22)基因变异所引起的.该文重点对PMP22的生物学及相关疾病的病理生理学进行综述.

  16. Relevance of the correlation between precipitation and the 0 °C isothermal altitude for extreme flood estimation

    Zeimetz, Fraenz; Schaefli, Bettina; Artigue, Guillaume; García Hernández, Javier; Schleiss, Anton J.


    Extreme floods are commonly estimated with the help of design storms and hydrological models. In this paper, we propose a new method to take into account the relationship between precipitation intensity (P) and air temperature (T) to account for potential snow accumulation and melt processes during the elaboration of design storms. The proposed method is based on a detailed analysis of this P-T relationship in the Swiss Alps. The region, no upper precipitation intensity limit is detectable for increasing temperature. However, a relationship between the highest measured temperature before a precipitation event and the duration of the subsequent event could be identified. An explanation for this relationship is proposed here based on the temperature gradient measured before the precipitation events. The relevance of these results is discussed for an example of Probable Maximum Precipitation-Probable Maximum Flood (PMP-PMF) estimation for the high mountainous Mattmark dam catchment in the Swiss Alps. The proposed method to associate a critical air temperature to a PMP is easily transposable to similar alpine settings where meteorological soundings as well as ground temperature and precipitation measurements are available. In the future, the analyses presented here might be further refined by distinguishing between precipitation event types (frontal versus orographic).


    Suresh Kumar Nigam


    Full Text Available Pan masala plain (PMP with or without tobacco (PMT cause testis impairment. Three sets of mice (n = 60, 2% PMP and PMT diet were fed for12 & 13 months. Further six sets of mice in two groups plus control (n=20 received by oral feeding (PO a commercial brand PM (at doses of 8, 40 and 100 mg/kg b.w. in olive 0il by oral administration as a single dose and zarda (PMT too was given same doses and the controls were kept at staple diet only and by oral administration 0.5 ml vehicle for a period of 3 months. The animals were sacrificed (n=10 after 2 weeks and 3 months to study graded dose effects of PM plain and blend on sperm abnormalities. The plain and zarda group showed graded dose related elevated sperm abnormalities compared to control. The damages were high with 100 mg zarda group after 3 months period. The plain and Zarda group when compared, dose-duration wise, at each dose level, and in between two test groups, showed significant structural and functional changes of sperm head and mutilations. The sperm head anomalies were maximum in 12 and 13 months PMP and zarda fed groups in terms of morphology and other abnormalities. The damage is more in 13 months fed mice (p<0.01 and 12 months fed mice (p<0.05 when compared to the control group. Both the groups of PM, showed different types of sperm head abnormalities i.e., banana, beak, hammer shaped, amorphous etc. Testis of 12 and 13 months PMP and PMT groups were processed for histopathology. It was found that PMP and PMT inducts no effects after 2 weeks exposure, whereas caused liver tumor after 56 weeks exposure. PMP and PMT in comparison, and both significantly effect mouse testis showing degenerative changes in seminiferous tubules and interstitial tissue being more prominently effected in PMT group.

  18. Bilateral hand amyotrophy with PMP-22 gene deletion.

    Gochard, A; Guennoc, A M; Praline, J; Malinge, M C; de Toffol, B; Corcia, P


    Hereditary neuropathy with liability to pressure palsies (HNPP) phenotypes are heterogeneous. We report the case of a 52-year-old woman without medical history, who complained of bilateral hand weakness suggestive first of a motor neuron disorder. The presence of a diffuse predominant distal demyelinating neuropathy suggested a deletion of PMP-22 gene, which was confirmed by genetic analysis. This case report underlines a novel phenotype related to the deletion of PMP-22 gene.

  19. Future PMP Estimation in Korea under AR5 RCP 8.5 climate change scenarios and its Changes Cause Analysis

    Kim, S.; Lee, J.; Okjeong, L.; Bogyeong, C.; Park, M. W.


    In this presentation, Korea's probable maximum precipitations (PMPs) which reflects all of the storm data until recently are calculated, and are compared to the existing PMPs which were calculated at 2000. In Korea, abnormal weather phenomena such as typhoon Rusa and Maemi, and the extreme rainfall event occurred on the east coast of the northern region, that can have a significant impact on the PMP estimation, have frequently happened since 2000. After selecting 240 major storm events from 1973 to 2012, new PMPs are proposed with respect to storm areas (25, 100, 225, 400, 900, 2025, 4900, 10000 and 19600 km2) and storm durations (1, 2, 4, 6, 8, 12, 18, 24, 48 and 72 hours) using the Korea hydro-meteorological method. After estimating future PMPs using future rainfall and dew point temperature information under the Korea Meteorological Administration AR5 RCP 8.5, changes in the PMPs under climate change will be investigated by comparison with present and future PMPs. By separating the changes in PMPs under climate change into the changes caused by rainfall and dew point temperature, the relative impact of future rainfall and dew point temperature information under climate change on future PMPs is quantified. This research was supported by a grant 'Development of the Evaluation Technology for Complex Causes of Inundation Vulnerability and the Response Plans in Coastal Urban Areas for Adaptation to Climate Change' [MPSS-NH-2015-77] from the Natural Hazard Mitigation Research Group, Ministry of Public Safety and Security of Korea.

  20. Karakterisasi Enzim Selulase PMP 0126Y dari Limbah Pengolahan Agar

    Ekowati Chasanah


    Full Text Available Hasil penapisan bakteri penghasil enzim selulase terdahulu mendapatkan isolat PMP 0126 sebagai isolat yang berpotensi yang diisolasi dari limbah pengolahan agar skala UKM di Pamengpeuk, Garut. Isolat tersebut ternyata belum merupakan koloni tunggal, terdiri dari 2 isolat bakteri yaitu PMP 0126Y dan PMP 0126W. Isolat PMP 0126Y memiliki kemampuan mendegradasi selulosa yang lebih besar dibanding PMP 0126W. Tujuan dari penelitian ini adalah untuk memproduksi dan mengkarakterisasi enzim selulase dari isolat PMP 0126Y, serta mengidentifikasi isolat tersebut. Hasil penelitian menunjukkan bahwa enzim selulase diproduksi optimum pada hari ke-3 kultivasi menggunakan medium cair berisi  CMC 1%. Enzim kasar yang diperoleh dapat bekerja optimal pada suhu 30 °C dan pH 5, dapat ditingkatkan aktivitasnya dengan ion logam dalam bentuk garam CaCl2 dan ZnCl2 5 mM.. Pemurnian dengan sistem penukar anion dapat meningkatkan aktivitas enzim 15x dengan perolehan 20%. Dari hasil SDS-PAGE terlihat bahwa ada 3 selulase dengan perkiraan berat molekul 39, 30, dan 14 kDa. Enzim kasar ini memiliki kemampuan menghidrolisis limbah pengolahan agar sebaik ketika memecah substrat CMC,  yang mengindikasikan bahwa enzim dari isolat ini berpotensi sebagai kandidat agen sakarifikasi pada produksi bioetanol. Identifikasi bakteri dengan 16S-rDNA menunjukkan bahwa isolat ini memiliki kemiripan 96% dengan bakteri Chryseobacterium indologenes McR-1.

  1. Information Security Pmp Report: August 23, 2013

    Wegener, Henning


    I have to start this brief report with a rueful confession: the PMP did not manage over the last months to complete the work program it had ambitiously laid out in its report of last year. Due to unforeseen circumstances, mainly professional reasons of some long-term members, the Group lost a number of them as active participants, and as a consequence failed to maintain the critical mass required for successful work as a group. However, thanks to the vision and generosity of Professor Zichichi, we were given the opportunity to draw in a number of new high-level cybersecurity experts from a number of countries which not only broadened our collective expertise, but also enhanced geographical distribution. Commensurate with the global nature of cyber affairs, we are now ourselves more global. A panel discussion in this year's plenary on topical issues of cybersecurity under the title "Cybersecurity at the Crossroads: Are We Losing the Battle" allowed some of our new members to display their prowess and expertise. At the same time, we have attempted to weld this new revitalized team into an effective work unit...

  2. Precipitation Extremes: Considerations for Anthropogenically-forced Future Changes

    Kunkel, K.; Young, J.


    The Third National Climate Assessment states that "increases in the frequency and intensity of extreme precipitation events are projected for all U.S. regions". While that general statement was made with high confidence, the practical implications for decision-makers are much less clear. In particular, engineering design needs quantitative estimates of probable maximum precipitation (PMP) and intensity-duration-frequency (IDF) values for the future in order to optimize runoff control structures for future climate conditions. This can be realized by simply analyzing the precipitation data from global climate model simulations of the future. However, confidence in the resulting values suffers from the known issues with GCM simulation of precipitation. In addition, skepticism about the accuracy of climate models negatively affects potential adoption of revised values in the engineering design community. We contend that scientists need a multi-pronged approach to develop PMP/IDF values that can be defended, explained, and promoted in order to maximize societal benefits and avoid catastrophic events. This talk will discuss considerations that could/should form the basis for design values. While global-warming induced increases in atmospheric water vapor content are nearly certain and form the foundation for expected increases in extreme precipitation, they most likely will be modulated by changes in global atmospheric dynamics and the consequent effects on local weather system climatology. This can be seen currently in the unexplained regional variations in recent trends in extreme precipitation frequency and intensity. We need to be able to understand recent trends, when greenhouse gas forcing of the climate systems has been rapidly increasing, in order to produce confident projections of future extreme precipitation.

  3. Land Use Land Cover Impact on Probable Maximum Flood and Sedimentation for Artificial Reservoirs: A Case Study in Western US

    Yigzaw, W. Y.; Hossain, F.


    Unanticipated peak inflows that can exceed the inflow design flood (IDF) for spillways and result in possible storage loss in reservoirs from increased sedimentation rates lead to a greater risk for downstream floods. Probable maximum precipitation (PMP) and probable maximum flood (PMF) are mostly used to determine IDF. Any possible change of PMP and PMF due to future land use and land cover (LULC) change therefore requires a methodical investigation. However, the consequential sediment yield, due to altered precipitation and flow patterns into the reservoir has not been addressed in literature. Thus, this study answers the following question: "What is the combined impact of a modified PMP on PMF and sediment yield for an artificial reservoir? The Owyhee dam of Owyhee River watershed (ORW) in Oregon is selected as a case study area for understanding the impact of LULC change on PMF and sedimentation rates. Variable Infiltration Capacity (VIC) is used for simulating stream flow (PMF) and the Revised Universal Soil Loss Equation (RUSLE) to estimate sediment yield over ORW as a result of change in precipitation intensity and LULC. Scenarios that represent pre-Owyhee dam (Pre-Dam) and post Owyhee dam (Non-Irrigation, Control, 1992, 2001, 2006) are used to simulate PMF's and consequential sediment yield. Peak PMF result for Pre-Dam scenarios is found to increase by 26m3s-1 (1%) and 81m3s-1 (3%) from Non-Irrigation and Control scenario, respectively. Considering only LULC change, sediment yield decreased over ORW due to the transformation of LULC from grassland to shrubland (from Pre-Dam period to the post-Dam years). However, increase in precipitation intensity caused a significant (0.1% storage loss over 21days storm period) increase in sediment yield resulting in largely reservoir sedimentation. This study underscores the need to consider future impact of LULC change on IDF calculation as well as sedimentation rates for more robust reservoir operations and planning.

  4. Real-Time DMB Video Encryption in Recording on PMP

    Seong-Yeon Lee


    Full Text Available At July 2008, the nationwide DMB (Digital Multimedia Broadcasting has got started. As DMB device's volume of sales has been over 12 million already, the development of rapidly changing network systems has increased the dangers of infringing the copyright of DMB contents. For solving this problem, we suggest that real-time encryption algorithm without additional expenses, and implemented that on PMP. We used the SEED algorithm for encryption. As the experimental result, we confirmed that the real-time encryption and decryption of DMB videos were working well. Also confirmed that recorded contents in PMP were not replayed in other devices, and also the contents recorded by other devices were not played in PMP. Suggested algorithms can be useful in the VOD, IPTV or cable TV.

  5. PMP Certification All-In-One Desk Reference For Dummies

    Stackpole, Cynthia Snyder


    Be as prepared as possible to take the PMP certification exam The PMP certification is the most popular project management certification available, but also a very difficult certification to obtain with very demanding requirements. That's where this All-in-One reference comes in. Packed with valuable information for taking the exam, the nine books in one covers everything from the certification process to gathering information for the application and signing up to take the exam, as well as studying for the most pertinent parts of the Project Management Body of Knowledge (PMBOK), and review que

  6. Membrane proteins PmpG and PmpH are major constituents of Chlamydia trachomatis L2 outer membrane complex

    Mygind, Per H; Christiansen, Gunna; Roepstorff, P;


    The outer membrane complex of Chlamydia is involved in the initial adherence and ingestion of Chlamydia by the host cell. In order to identify novel proteins in the outer membrane of Chlamydia trachomatis L2, proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis....... By silver staining of the protein profile, a major protein doublet of 100-110 kDa was detected. In-gel tryptic digestion and matrix-assisted laser desorption/ionization mass spectrometry identified these proteins as the putative outer membrane proteins PmpG and PmpH....

  7. Mother and Child Health Pmp Report: 2011-2012 Activities

    Charpak, Nathalie; Ruiz-Pelaez, Juan G.; de Leon-Mendoza, Socorro



  8. 49 CFR 633.23 - FTA review of PMP.


    ... 49 Transportation 7 2010-10-01 2010-10-01 false FTA review of PMP. 633.23 Section 633.23 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROJECT MANAGEMENT OVERSIGHT Project Management Plans § 633.23 FTA review of...

  9. Aids and Infectious Diseases (aid) Pmp 2013 Report

    Buonaguro, Franco M.


    The AIDS and Infectious Diseases (AID) PMP of the WFS contributed this year with a session on August 22nd to the Plenary Sessions of the International Seminars on Planetary Emergencies and Associated Meetings--46th Session: The Role of Science in the Third Millennium (Erice, 19-24 August 2013). Furthermore a workshop on August 24th was organized...

  10. Regional Analysis of Precipitation by Means of Bivariate Distribution Adjusted by Maximum Entropy; Analisis regional de precipitacion con base en una distribucion bivariada ajustada por maxima entropia

    Escalante Sandoval, Carlos A.; Dominguez Esquivel, Jose Y. [Universidad Nacional Autonoma de Mexico (Mexico)


    The principle of maximum entropy (POME) is used to derive an alternative method of parameter estimation for the bivariate Gumbel distribution. A simple algorithm for this parameter estimation technique is presented. This method is applied to analyze the precipitation in a region of Mexico. Design events are compered with those obtained by the maximum likelihood procedure. According to the results, the proposed technique is a suitable option to be considered when performing frequency analysis of precipitation with small samples. [Spanish] El principio de maxima entropia, conocido como POME, es utilizado para derivar un procedimiento alternativo de estimacion de parametros de la distribucion bivariada de valores extremos con marginales Gumbel. El modelo se aplica al analisis de la precipitacion maxima en 24 horas en una region de Mexico y los eventos de diseno obtenidos son comparados con los proporcionados por la tecnica de maxima verosimilitud. De acuerdo con los resultados obtenidos, se concluye que la tecnica propuesta representa una buena opcion, sobre todo para el caso de muestras pequenas.

  11. Proteolytic cleavage of the Chlamydia pneumoniae major outer membrane protein in the absence of Pmp10

    Juul, Nicolai Stefan; Timmerman, E; Gevaert, K;


    that Pmp10 is differentially expressed in the C. pneumoniae CWL029 isolate. To evaluate whether the absence of Pmp10 in the outer membrane causes further changes to the C. pneumoniae protein profile, we subcloned the CWL029 isolate and selected a clone with minimal Pmp10 expression. Subsequently, we...... compared the proteome of the CWL029 isolate with the proteome of the subcloned strain and identified a specific cleavage of the C-terminal part of the major outer membrane protein (MOMP), which occurred only in the absence of Pmp10. In contrast, when Pmp10 was expressed we predominantly observed full...

  12. Concise and enantioselective synthesis of Fmoc-Pmp(But)2-OH and design of potent Pmp-containing Grb2-SH2 domain antagonists.

    Li, Peng; Zhang, Manchao; Peach, Megan L; Liu, Hongpeng; Yang, Dajun; Roller, Peter P


    [reaction: see text] L-Phosphonomethylphenylalanine (L-Pmp) is an important phosphatase-resistant pTyr analogue. A most concise and stereoselective approach to the synthesis of the suitably protected Fmoc-Pmp(Bu(t))(2)-OH was developed in order to incorporate the functionally significant L-Pmp residue into peptides and peptidomimetics efficiently using standard Fmoc protocol. With this key building block, we are able to efficiently synthesize a series of potent Pmp-containing Grb2-SH2 domain antagonists, which can be used as chemotherapeutic leads for the treatment of erbB2-overexpressed breast cancer.

  13. Effect of precipitation, sorption and stable of isotope on maximum release rates of radionuclides from engineered barrier system (EBS) in deep repository.

    Malekifarsani, A; Skachek, M A


    shown that the concentrations of the following radionuclides are limited by solubility and precipitate around the waste and buffer: U, Np, Ra, Sm, Zr, Se, Tc, and Pd. The Sensitivity of maximum release rates in case precipitation shows that some nuclides such as Cs-135, Nb-94, Nb-93 m, Zr-93, Sn-126, Th-230, Pu-240, Pu-242, Pu-239, Cm-245, Am-243, Cm-245, U-233, Ac-227, Pb-210, Pa-231 and Th-229 are very little changed in case the maximum release rate from EBS corresponding to eliminate precipitation in buffer material. Some nuclides such as Se-79, Tc-99, Pd-107, Th-232, U-236, U-233, Ra-226, Np-237 U-235, U-234, and U-238 are virtually changed in the maximum release rate compared to case that taking account precipitation. In Sensitivity of maximum release rates in case to taking account stable isotopes (according to the table of inventory) there are only some nuclides with their stable isotopes in the vitrified waste. And calculation shows that Pd-107 and Se-79 are very increase in case eliminate stable isotope. The Sensitivity of maximum release rates in case retardation with sorption shows that some nuclides such as Pu-240, Pu-241, Pu-239, Cm-245, Am-241, Cm-246, and Am-243 are increased in some time in case maximum release rate from EBS corresponding to eliminate retardation in buffer material. Some nuclides such as U-235, U-233 and U-236 have a little decrease in case maximum release because their parents have short live and before decay to their daughter will released from the EBS. If the characteristic time taken for a nuclide to diffuse across the buffer exceeds its half-life, then the release rate of that nuclide from the EBS will be attenuated by radioactive decay. Thus, the retardation of the diffusion process due to sorption tends to reduce the release rates of short-lived nuclides more effectively than for the long-lived ones. For example, release rates of Pu-240, Cm-246 and Am-241, which are relatively short-lived and strongly sorbing, are very small

  14. Improved sensitivity of PCR for Chlamydophila using pmp genes.

    Laroucau, K; Souriau, A; Rodolakis, A


    Primers targeting the conserved pmp gene family of Chlamydophila abortus were evaluated for their ability to improve the polymerase chain reaction (PCR) sensitivity. In purified DNA, specific pmp primers (named CpsiA and CpsiB) allowed at least a 10-fold increase of the PCR sensitivity compared to the specific ompA primers for C. abortus, but also for C. psittaci and C. caviae strains. No amplification was observed on C. felis, C. pecorum, C. pneumoniae and Chlamydia trachomatis strains. Tested on contaminated specimens such as genital swabs, the PCR sensitivity observed with CpsiA/CpsiB was also better than with the ompA primers. This study demonstrated that these specific pmp primers could serve as valuable, sensitive and common tools for a specific Chlamydophila diagnosis in ruminant, avian and human diseases. Digestion by AluI of the CpsiA/CpsiB fragments allowed a specific discrimination of the strains in function of their hosts and/or their serotypes.

  15. Functional and comparative genomics analyses of pmp22 in medaka fish

    Kawarabayasi Yutaka


    Full Text Available Abstract Background Pmp22, a member of the junction protein family Claudin/EMP/PMP22, plays an important role in myelin formation. Increase of pmp22 transcription causes peripheral neuropathy, Charcot-Marie-Tooth disease type1A (CMT1A. The pathophysiological phenotype of CMT1A is aberrant axonal myelination which induces a reduction in nerve conduction velocity (NCV. Several CMT1A model rodents have been established by overexpressing pmp22. Thus, it is thought that pmp22 expression must be tightly regulated for correct myelin formation in mammals. Interestingly, the myelin sheath is also present in other jawed vertebrates. The purpose of this study is to analyze the evolutionary conservation of the association between pmp22 transcription level and vertebrate myelin formation, and to find the conserved non-coding sequences for pmp22 regulation by comparative genomics analyses between jawed fishes and mammals. Results A transgenic pmp22 over-expression medaka fish line was established. The transgenic fish had approximately one fifth the peripheral NCV values of controls, and aberrant myelination of transgenic fish in the peripheral nerve system (PNS was observed. We successfully confirmed that medaka fish pmp22 has the same exon-intron structure as mammals, and identified some known conserved regulatory motifs. Furthermore, we found novel conserved sequences in the first intron and 3'UTR. Conclusion Medaka fish undergo abnormalities in the PNS when pmp22 transcription increases. This result indicates that an adequate pmp22 transcription level is necessary for correct myelination of jawed vertebrates. Comparison of pmp22 orthologs between distantly related species identifies evolutionary conserved sequences that contribute to precise regulation of pmp22 expression.

  16. PMP-1 Report: the Fourth Winter of PMP-1, 1981 - 1982: a Winter with Several Interesting Features

    Labitzke, K.


    A synoptic description is given for the fourth winter of pre-MAP project 1 (PMP-1), 1981/82. The main characteristics of this winter are a Canadian warming in the beginning of December, a very strong minor warming in January, and an early final warming in mid-March. The eddy momentum budget, calculated from the daily height and temperature charts, is discussed in terms of the divergence of the Eliassen-Palm-vector.

  17. The Number, Organization, and Size of Polymorphic Membrane Protein Coding Sequences as well as the Most Conserved Pmp Protein Differ within and across Chlamydia Species.

    Van Lent, Sarah; Creasy, Heather Huot; Myers, Garry S A; Vanrompay, Daisy


    Variation is a central trait of the polymorphic membrane protein (Pmp) family. The number of pmp coding sequences differs between Chlamydia species, but it is unknown whether the number of pmp coding sequences is constant within a Chlamydia species. The level of conservation of the Pmp proteins has previously only been determined for Chlamydia trachomatis. As different Pmp proteins might be indispensible for the pathogenesis of different Chlamydia species, this study investigated the conservation of Pmp proteins both within and across C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci. The pmp coding sequences were annotated in 16 C. trachomatis, 6 C. pneumoniae, 2 C. abortus, and 16 C. psittaci genomes. The number and organization of polymorphic membrane coding sequences differed within and across the analyzed Chlamydia species. The length of coding sequences of pmpA,pmpB, and pmpH was conserved among all analyzed genomes, while the length of pmpE/F and pmpG, and remarkably also of the subtype pmpD, differed among the analyzed genomes. PmpD, PmpA, PmpH, and PmpA were the most conserved Pmp in C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci, respectively. PmpB was the most conserved Pmp across the 4 analyzed Chlamydia species.

  18. Head First PMP A Brain-Friendly Guide to Passing the Project Management Professional Exam

    Stellman, Andrew


    Media Reviews "I have been doing project management for over 30 years and am considered a subject matter expert in the PMBOK(r) Guide -Third Edition primarily because I am the Project Manager who led the team that developed this edition. As a consultant I was hired to review and evaluate eight of the top selling PMP Exam Preparation books for their accuracy in following the PMBOK® Guide - Third Edition. I have developed and taught a PMP Exam Prep course for a leading R.E.P., and taught PMP Exam preparation classes for PMI Chapters. I can honestly say that Head First PMP is by far the best P

  19. Estimation of the Probable Maximum Flood for a Small Lowland River in Poland

    Banasik, K.; Hejduk, L.


    The planning, designe and use of hydrotechnical structures often requires the assesment of maximu flood potentials. The most common term applied to this upper limit of flooding is the probable maximum flood (PMF). The PMP/UH (probable maximum precipitation/unit hydrograph) method has been used in the study to predict PMF from a small agricultural lowland river basin of Zagozdzonka (left tributary of Vistula river) in Poland. The river basin, located about 100 km south of Warsaw, with an area - upstream the gauge of Plachty - of 82 km2, has been investigated by Department of Water Engineering and Environmenal Restoration of Warsaw University of Life Sciences - SGGW since 1962. Over 40-year flow record was used in previous investigation for predicting T-year flood discharge (Banasik et al., 2003). The objective here was to estimate the PMF using the PMP/UH method and to compare the results with the 100-year flood. A new relation of depth-duration curve of PMP for the local climatic condition has been developed based on Polish maximum observed rainfall data (Ozga-Zielinska & Ozga-Zielinski, 2003). Exponential formula, with the value of exponent of 0.47, i.e. close to the exponent in formula for world PMP and also in the formula of PMP for Great Britain (Wilson, 1993), gives the rainfall depth about 40% lower than the Wilson's one. The effective rainfall (runoff volume) has been estimated from the PMP of various duration using the CN-method (USDA-SCS, 1986). The CN value as well as parameters of the IUH model (Nash, 1957) have been established from the 27 rainfall-runoff events, recorded in the river basin in the period 1980-2004. Varibility of the parameter values with the size of the events will be discussed in the paper. The results of the analyse have shown that the peak discharge of the PMF is 4.5 times larger then 100-year flood, and volume ratio of the respective direct hydrographs caused by rainfall events of critical duration is 4.0. References 1.Banasik K

  20. Hot topics flashcards for passing the PMP and CAPM exams

    Mulcahy, Rita


    If you are looking for a way to prepare for the PMP or the CAPM exam that fits into your busy schedule, these flashcards are it. Now you can study at the office, on a plane or even in your car with RMC's portable and extremely valuable Hot Topics Exam Flashcards-in hard copy or audio CD format. Over 300 of the most important and difficult to recall PMP® and CAPM® exam-related terms and concepts are now available for study as you drive, fly or take your lunch break. Order them both!

  1. Members of the Pmp protein family of Chlamydia pneumoniae mediate adhesion to human cells via short repetitive peptide motifs.

    Mölleken, Katja; Schmidt, Eleni; Hegemann, Johannes H


    Chlamydiae sp. are obligate intracellular pathogens that cause a variety of diseases in humans. Adhesion of the infectious elementary body to the eukaryotic host cell is a pivotal step in chlamydial pathogenesis. Here we describe the characterization of members of the polymorphic membrane protein family (Pmp), the largest protein family (with up to 21 members) unique to Chlamydiaceae. We show that yeast cells displaying Pmp6, Pmp20 or Pmp21 on their surfaces, or beads coated with the recombinant proteins, adhere to human epithelial cells. A hallmark of the Pmp protein family is the presence of multiple repeats of the tetrapeptide motifs FxxN and GGA(I, L, V) and deletion analysis shows that at least two copies of these motifs are needed for adhesion. Importantly, pre-treatment of human cells with recombinant Pmp6, Pmp20 or Pmp21 protein reduces infectivity upon subsequent challenge with Chlamydia pneumoniae and correlates with diminished attachment of Chlamydiae to target cells. Antibodies specific for Pmp21 can neutralize infection in vitro. Finally, a combination of two different Pmp proteins in infection blockage experiments shows additive effects, possibly suggesting similar functions. Our findings imply that Pmp6, Pmp20 and Pmp21 act as adhesins, are vital during infection and thus represent promising vaccine candidates.

  2. Use of the Pathogen Modeling Program (PMP) and the Predictive Microbiology Information Portal (PMIP)

    The Predictive Microbiology Program,(PMP)is based on the fact that most bacterial behaviors are reproducible and can be quantified by characterizing the environmental factors that affect growth, survival, and inactivation using mathematical modeling. The contents of PMP, a collection of models, are ...

  3. The Standardized 2-Dimensional PMP: A New Assessment Technique in Optometric Credentialing and Education.

    Gross, Leon J.


    A written clinical simulation exercise known as patient management problems (PMP) developed by the National Board of Examiners in Optometry is discussed. The new PMP format is considered standardized in the sense that the "visible" portion of the problem will be identical. (MLW)

  4. Head First PMP A Brain-Friendly Guide to Passing the Project Management Professional Exam

    Greene, Jennifer


    Learn the latest principles and certification objectives in The PMBOK Guide, Fourth Edition, in a unique and inspiring way with Head First PMP . The second edition of this book helps you prepare for the PMP certification exam using a visually rich format designed for the way your brain works. You'll find a full-length sample exam included inside the book. More than just proof of passing a test, a PMP certification means that you have the knowledge to solve most common project problems. But studying for a difficult four-hour exam on project management isn't easy, even for experienced project

  5. Lithium amide assisted asymmetric Mannich-type reactions of menthyl acetate with PMP-aldimines.

    Hata, Seiji; Iguchi, Mayu; Iwasawa, Tetsuo; Yamada, Ken-ichi; Tomioka, Kiyoshi


    A lithium enolate of menthyl acetate added to PMP-imines, in the presence of an equimolar amount of lithium diisopropylamide, affords the Mannich-type addition products in high stereoselectivity. [reaction--see text

  6. Isolation and characterization of maize PMP3 genes involved in salt stress tolerance.

    Jing Fu

    Full Text Available Plasma membrane protein 3 (PMP3, a class of small hydrophobic polypeptides with high sequence similarity, is responsible for salt, drought, cold, and abscisic acid. These small hydrophobic ploypeptides play important roles in maintenance of ion homeostasis. In this study, eight ZmPMP3 genes were cloned from maize and responsive to salt, drought, cold and abscisic acid. The eight ZmPMP3s were membrane proteins and their sequences in trans-membrane regions were highly conserved. Phylogenetic analysis showed that they were categorized into three groups. All members of group II were responsive to ABA. Functional complementation showed that with the exception of ZmPMP3-6, all were capable of maintaining membrane potential, which in turn allows for regulation of intracellular ion homeostasis. This process was independent of the presence of Ca(2+. Lastly, over-expression of ZmPMP3-1 enhanced growth of transgenic Arabidopsis under salt condition. Through expression analysis of deduced downstream genes in transgenic plants, expression levels of three ion transporter genes and four important antioxidant genes in ROS scavenging system were increased significantly in transgenic plants during salt stress. This tolerance was likely achieved through diminishing oxidative stress due to the possibility of ZmPMP3-1's involvement in regulation of ion homeostasis, and suggests that the modulation of these conserved small hydrophobic polypeptides could be an effective way to improve salt tolerance in plants.

  7. Energy Optimal Control Strategy of PHEV Based on PMP Algorithm

    Tiezhou Wu


    Full Text Available Under the global voice of “energy saving” and the current boom in the development of energy storage technology at home and abroad, energy optimal control of the whole hybrid electric vehicle power system, as one of the core technologies of electric vehicles, is bound to become a hot target of “clean energy” vehicle development and research. This paper considers the constraints to the performance of energy storage system in Parallel Hybrid Electric Vehicle (PHEV, from which lithium-ion battery frequently charges/discharges, PHEV largely consumes energy of fuel, and their are difficulty in energy recovery and other issues in a single cycle; the research uses lithium-ion battery combined with super-capacitor (SC, which is hybrid energy storage system (Li-SC HESS, working together with internal combustion engine (ICE to drive PHEV. Combined with PSO-PI controller and Li-SC HESS internal power limited management approach, the research proposes the PHEV energy optimal control strategy. It is based on revised Pontryagin’s minimum principle (PMP algorithm, which establishes the PHEV vehicle simulation model through ADVISOR software and verifies the effectiveness and feasibility. Finally, the results show that the energy optimization control strategy can improve the instantaneity of tracking PHEV minimum fuel consumption track, implement energy saving, and prolong the life of lithium-ion batteries and thereby can improve hybrid energy storage system performance.

  8. Reconstruction of precipitation variability in the Strait of Yucatan associated with latitudinal shifts in the position of the Intertropical Convergence Zone since the Last Glacial Maximum

    Staines-Urías, Francisca; Seidenkrantz, Marit-Solveig; Fischel, Andrea; Kuijpers, Antoon


    The elemental composition of sediments from gravity core HOLOVAR11-03 provides a ca. 40 ka record of past climate variability in the Strait of Yucatan, between the Caribbean Sea and the Gulf of Mexico, a region where precipitation variability is determined by the seasonal position of the Intertropical Convergence Zone (ITCZ). Within this region, sea level pressure decreases and rainfall increases as the ITCZ moves north of the equator in response to increased solar insolation in the Northern Hemisphere during boreal summer. In contrast, as the ITCZ retracts southward towards the equator during boreal winter, rainfall diminishes and the regional sea level pressure gradient strengthens. On interannual, multidecadal and millennial timescales, fluctuations in the average latitudinal position of the ITCZ in response to insolation forcing modulate the intensity and duration of the seasonal regimens, determining average regional precipitation and, ultimately, the elemental composition of the marine sedimentary record. Regionally, higher titanium and iron content in marine sediments reflect greater terrigenous input from inland runoff, indicating greater precipitation, hence a more northerly position of the ITCZ. Correspondingly, Ti and Fe concentration data were used to reconstruct regional rainfall variability since the Last Glacial Maxima (LGM ˜24 cal ka BP). HOLOVAR11-03 age model (based on 4 AMS 14C dates obtained from multi-specific samples of planktic foraminifera) shows stable sedimentation rates in the area throughout the cored period. Nonetheless, higher terrestrial mineral input is observed since the LGM and all through the last glacial termination (24 to 12 cal ka BP), indicating a period of increased precipitation. In contrast, lower Ti and Fe values are typical for the period between 12 and 8 cal ka BP, indicating reduced precipitation. A positive trend characterizes the following interval, showing a return to wetter conditions lasting until 5 cal ka BP

  9. Analysis of Polymorphic Membrane Protein Expression in Cultured Cells Identifies PmpA and PmpH of Chlamydia psittaci as Candidate Factors in Pathogenesis and Immunity to Infection

    Van Lent, Sarah; De Vos, Winnok H.; Huot Creasy, Heather; Marques, Patricia X.; Ravel, Jacques; Vanrompay, Daisy; Bavoil, Patrik; Hsia, Ru-ching


    The polymorphic membrane protein (Pmp) paralogous families of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia abortus are putative targets for Chlamydia vaccine development. To determine whether this is also the case for Pmp family members of C. psittaci, we analyzed transcription levels, protein production and localization of several Pmps of C. psittaci. Pmp expression profiles were characterized using quantitative real-time PCR (RT-qPCR), immunofluorescence (IF) and immuno-electron microscopy (IEM) under normal and stress conditions. We found that PmpA was highly produced in all inclusions as early as 12 hpi in all biological replicates. In addition, PmpA and PmpH appeared to be unusually accessible to antibody as determined by both immunofluorescence and immuno-electron microscopy. Our results suggest an important role for these Pmps in the pathogenesis of C. psittaci, and make them promising candidates in vaccine development. PMID:27631978

  10. The Probability Distribution of the Maximum Amount of Daily Precipitation During 20 Days in Summer of the Huaihe Basins%淮河流域汛期20d内最大日降水量概率分布

    梁莉; 赵琳娜; 巩远发; 包红军; 王成鑫; 王志


    density function of gamma distribution, to a certain extent, overcomes the influence that the random oscillation of the samples caused to the estimation of daily precipitation probability distribution.The probability distribution of maximum daily precipitation in 1 to 20 days derived from gamma distribution function is reasonable. The curve of precipitation probability density of 1 day is monotonically decreasing which takes on the trend of reverse "J". The peak of probability distribution of the maximum daily precipitation in 10 days or 20 days tilts toward the side of large precipitation with the days increased.From the Huaihe Basin's probability distribution of the maximum daily precipitation more than 10 mm, 25 mm, 50 mm in 10 or 20 days, it indicates that the probability of the upper stream of the Huaihe River, the Huaihe River downstream below Hongze Lake, and the Yishu River watershed are evidently higher than the rest regions of the five catchments, which means that the maximum daily precipitation of these areas is more likely to be over 10 mm, 25 mm, 50 mm in 10 or 20 days.The high values of the probability of the maximum daily precipitation over 50 mm in 10 days locates in the eastern part of Yishu River watershed and the upper stream of the Huaihe River, while the high values of the probability of the maximum daily precipitation over 50 mm in 20 days locates in the junction of the downstream of the Huaihe River and eastern of the Hongze Lake, indicating large precipitation are more likely to occur in these areas. This approach can provide practical applications such as decision supports for the management of hydro-meteorological forecasting, agricultural, and water resources management.

  11. Variation Trend of Maximum Daily Precipitation in Recent 50 Years in China%近50年中国最大1 d降水量变化趋势分析

    陆桂华; 陈金明; 吴志勇; 肖恒


    为了解气候变暖对极端降水的影响,根据1960~2009年气象站实测降水量资料,采用Mann-Kendall趋势检验、线性趋势和反映序列持续性的Hurst指数,分析了四李中国西部、北方和南方三个区域最大1d降水量的变化特征,并探讨了20世纪80年代前后中国四季最大1d降水量的变化趋势.结果表明,近50年来西部四季最大1d降水量均呈增加趋势,北方仅冬季呈上升趋势,南方则冬、夏两季增加,春、秋两季减小;相对80年代前,80年代后冬季三大区域、夏季西部和南方及秋季西部最大1d降水量有所增加,春、秋季北方和南方则减少;各区域四季最大1d降水量时间序列具有明显的持续性,即未来最大1d降水量变化趋势将与近50年的变化趋势保持一致,且持续时间西部最长,北方次之,南方最短.%In order to diagnose impacts of climate change on regional extreme precipitation events, the Mann-Kendall test, linear tendency test and Hurst exponent, which reflects the continuity of hydrology series, are applied in this study. Based on the observed precipitation of meteorological stations from 1960 to 2009, seasonal maximum daily precipitation variations in the western, northern and southern part of China are analyzed. Moreover, the changing characteristics of the maximum daily precipitation before and after the 1980s are further analyzed. The results demonstrate that the maximum daily precipitation increases in each season for the western part, increases in winter for the northern part, while increases in winter and summer but decrease in the other two seasons for southern part of China. Compared with the maximum daily precipitation before the 1980s, precipitation increases in winter for whole China, in summer for the western and southern part of China, and in autumn only for the western part of China after the 1980s. The Hurst exponent indicates that the maximum daily precipitation series has characteristics

  12. Regulation of tissue-specific expression of alternative peripheral myelin protein-22 (PMP22) gene transcripts by two promoters

    Patel, P.I.; Schoener-Scott, R.; Lupski, J.R. [Baylor College of Medicine, Houston, TX (United States)] [and others


    Mutations affecting the peripheral myelin protein-22 (PMP22) gene have been shown to be associated with inherited peripheral neuropathies. We have cloned and characterized the human PMP22 gene which spans approximately 40 kilobases and contains four coding exons. Towards developing gene therapy regimens for the associated peripheral neuropathies, we have initiated detailed analysis of the 5{prime} flanking region of the PMP22 gene and identified two alternatively transcribed, but untranslated exons. Mapping of separate PMP22 mRNA transcription initiation sites to each of these exons indicates that PMP22 expression is regulated by two alternatively used promoters. Both putative promoter sequences demonstrated the ability to drive expression of reporter genes in transfection experiments. Furthermore, the structure of the 5{prime} portion of the PMP22 gene appears to be identical in rat and human, supporting the biological significance of the observed arrangement of regulatory regions. The relative expression of the alternative PMP22 transcripts is tissue-specific and high levels of the exon 1A-containing transcript are tightly coupled to myelin formation. In contrast, exon 1B-containing transcripts are predominant in non-neural tissues and in growth-arrested primary fibroblasts. The observed regulation of the PMP22 by a complex molecular mechanism is consistent with the proposed dual role of PMP22 in neural and non-neural tissue.

  13. Development of a Novel PmpD-N ELISA for Chlamydia psittaci Infection

    LIU Shan Shan; CHU Jun; ZHANG Qiang; SUN Wei; ZHANG Tian Yuan; HE Cheng


    ObjectiveChlamydia psittaci is an avian respiratory pathogen and zoonotic agent.The wide prevalence ofC. psittaci poses a threat to the poultry industry and its employees. However, few commercial kits are available for detecting avian antibodies excluding the in-house ELISA kit. In this study, we developed a novel ELISA kit for detecting antibodies againstC. psittaci based on the N-terminal fragment of polymorphic outer membrane protein D (PmpD-N) as the coating antigen. Methods The antigen concentrations, primary antibody, and cut-off value were determined and optimized. The ELISA, designated PmpD-N ELISA, was assessed for sensitivity, specificity, and concordance using sera samples from 48 experimentally infected and 168 uninfected SPF chickens. Results The sensitivity and specificity of PmpD-N ELISA were 97.9%, 100%, respectively, while the concordance was 98.1% as compared to that of MOMP-ELISA. No cross-reaction with positive sera for other avian pathogens was found. Using PmpD-N ELISA, 799/836 clinical samples were positive, including 93.0% and 98.1% positivity in layers and broilers, respectively. Conclusion These data indicate that indirect ELISA with PmpD-N as the antigen candidate is a promising approach for the surveillance ofC. psittaci infection.

  14. Modeling precipitation δ18O variability in East Asia since the Last Glacial Maximum: temperature and amount effects across different timescales

    Wen, Xinyu; Liu, Zhengyu; Chen, Zhongxiao; Brady, Esther; Noone, David; Zhu, Qingzhao; Guan, Jian


    Water isotopes in precipitation have played a key role in the reconstruction of past climate on millennial timescales and longer. However, for midlatitude regions like East Asia with complex terrain, the reliability behind the basic assumptions of the temperature effect and amount effect is based on modern observational data and still remains unclear for past climate. In the present work, we reexamine the two basic effects on seasonal, interannual, and millennial timescales in a set of time slice experiments for the period 22-0 ka using an isotope-enabled atmospheric general circulation model (AGCM). Our study confirms the robustness of the temperature and amount effects on the seasonal cycle over China in the present climatic conditions, with the temperature effect dominating in northern China and the amount effect dominating in the far south of China but no distinct effect in the transition region of central China. However, our analysis shows that neither temperature nor amount effect is significantly dominant over China on millennial and interannual timescales, which is a challenge to those classic assumptions in past climate reconstruction. Our work helps shed light on the interpretation of the proxy record of δ18O from a modeling point of view.

  15. A novel frameshift mutation in PMP22 accounts for hereditary neuropathy with liability to pressure palsies.

    Young, P; Wiebusch, H; Stögbauer, F; Ringelstein, B; Assmann, G; Funke, H


    Peripheral myelin protein PMP22 deficiency is associated with hereditary neuropathy with liability to pressure palsies (HNPP). Most HNPP cases are caused by a 1.5-megabase deletion in chromosome 17p11.2-12, a region that contains the PMP22 gene, whereas point mutations leading to HNPP are extremely rare. We have identified a family with clinical and electrophysiologic features of HNPP,in which all affected members are heterozygous carriers of a single base insertion in codon 94. This mutation is predicted to alter the reading frame and to result in a delayed termination signal. We conclude that the functional consequences of the frameshift are equivalent to those of the PMP22 deletion allele.

  16. [Detection of the PMP22 gene duplication in peripheral neuropathy patients: a study in Mexican population].

    Cortés, Hernán; Hernández-Hernández, Óscar; Bautista-Tirado, Teresa; Escobar-Cedillo, Rosa Elena; Magaña, Jonathan J; Leyva-García, Norberto


    Introduccion. La enfermedad de Charcot-Marie-Tooth (CMT) es una neuropatia que afecta los nervios motores y sensitivos, y la CMT1A es el subtipo mas frecuente en el mundo. La CMT1A se produce por una duplicacion de 1,5 Mb en el locus 17p11.2-p12, donde se localiza el gen PMP22. Para el diagnostico de CMT1A es importante contar con tecnicas moleculares especificas para la determinacion de esta mutacion. Objetivos. Establecer un metodo de uso rutinario para detectar la duplicacion de PMP22 en la poblacion mexicana y estimar su frecuencia en pacientes con caracteristicas clinicas para la CMT. Pacientes y metodos. Se analizaron 157 pacientes mexicanos no relacionados entre si, diagnosticados de CMT por valoracion clinica. La determinacion de la duplicacion de PMP22 se realizo a traves de reaccion en cadena de la polimerasa en tiempo real mediante el metodo comparativo 2–ΔΔCT. Resultados. El metodo 2–ΔΔCT para detectar la duplicacion del gen PMP22 mostro ser sensible y fiable. Los resultados fueron consistentes con los obtenidos mediante la tecnica de hibridacion in situ fluorescente. Se detecto la duplicacion de PMP22 en 79 pacientes (50,3%), con un comportamiento similar a lo comunicado en Estados Unidos, Australia, Finlandia, Suecia y España. Sin embargo, se observo que existen diferencias con otras poblaciones. Conclusiones. La tecnica de reaccion en cadena de la polimerasa cuantitativa se implemento como un diagnostico molecular de CMT1A eficaz y de bajo coste, por lo que puede utilizarse rutinariamente en Mexico. Esto es esencial para el asesoramiento genetico y el tratamiento oportuno de los pacientes con CMT. La frecuencia de la duplicacion del gen PMP22 varia entre regiones geograficas, por lo que es importante estimarla en diferentes poblaciones.

  17. Performance Analysis of QoS in PMP Mode WiMax Networks

    kamboj, Maninder Singh


    IEEE 802.16 standard supports two different topologies: point to multipoint (PMP) and Mesh. In this paper, a QoS mechanism for point to multipoint of IEEE 802.16 and BS scheduler for PMP Mode is proposed. This paper also describes quality of service over WiMAX networks. Average WiMAX delay, Average WiMAX load and Average WiMAX throughput at base station is analyzed and compared by applying different scheduler at Base station and at fixed nodes.

  18. Genetic factors for nerve susceptibility to injuries-lessons from PMP22 deifciency

    Jun Li


    Genetic factors may be learnt from families with gene mutations that render nerve-injury sus-ceptibility even to ordinary physical activities. A typical example is hereditary neuropathy with liability to pressure palsies (HNPP). HNPP is caused by a heterozygous deletion of PMP22 gene. PMP22 deficiency disrupts myelin junctions (such as tight junction and adherens junctions), leading to abnormally increased myelin permeability that explains the nerve susceptibility to injury. This ifnding should motivate investigators to identify additional genetic factors contribut-ing to nerve vulnerability of injury.

  19. Correlation between PMP-22 messenger RNA expression and phenotype in hereditary neuropathy with liability to pressure palsies.

    Schenone, A; Nobbio, L; Caponnetto, C; Abbruzzese, M; Mandich, P; Bellone, E; Ajmar, F; Gherardi, G; Windebank, A J; Mancardi, G


    Hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a deletion in chromosome 17p11.2, which includes the gene for the peripheral myelin protein 22 (PMP-22). A "gene dosage" effect is probably the mechanism underlying HNPP, but the amount of PMP-22 mRNA in sural nerves of HNPP patients is highly variable and the role of PMP-22 underexpression in impairing myelination has yet to be clarified. We have studied 6 genetically proven HNPP patients, to evaluate the relationship between PMP-22 mRNA levels, and clinical, neurophysiological, and neuropathological findings. Underexpression of PMP-22 mRNA correlates with disease severity and with mean axon diameter and g ratio, but not with myelin thickness, number of "tomacula," or nerve conduction parameters. Our findings further confirm that underexpression of PMP-22 is the main pathogenetic mechanism underlying the severity of clinical symptoms and signs in HNPP. Smaller axons in sural nerves of HNPP patients with lower PMP-22 levels suggests that underexpression of PMP-22 may also affect axon development.

  20. Stoichiometric alteration of PMP22 protein determines the phenotype of hereditary neuropathy with liability to pressure palsies.

    Li, Jun; Ghandour, Khaled; Radovanovic, Danijela; Radovanovic, Danuijola; Shy, Rosemary R; Krajewski, Karen M; Shy, Michael E; Nicholson, Garth A


    Hereditary neuropathy with liability to pressure palsies (HNPP) is caused by a 1.4-megabase deletion at chromosome 17p11.2, which bears the PMP22 gene and other genes. However, whether other genes besides PMP22 contribute to the phenotype is unknown. Whether any mutation within the coding region of the PMP22 gene ultimately causes HNPP by reducing the amount of peripheral myelin protein 22 (PMP22) expressed in myelin is also unknown. To determine whether affected patients develop a phenotype identical to that found in HNPP and whether the leucine 7 frameshift (Leu7fs) mutation reduces PMP22 levels in myelin. We evaluated affected family members by neurological examination, electrophysiology, and skin biopsies. We identified a large family with a Leu7fs mutation of PMP22 (11 affected members across 3 generations) that predicts truncation of the protein prematurely and eliminates PMP22 expression from the mutant allele. We found that PMP22 levels were reduced in peripheral nerve myelin in dermal skin biopsies in patients with an Leu7fs mutation. Through clinical and electrophysiological evaluation, we also found that patients with the Leu7fs mutation were indistinguishable from patients with HNPP caused by deletion. We also found that a length-dependent axonal loss became pronounced in elderly patients with Leu7fs mutations, similar to what has been described in heterozygous knockout mice (pmp22 +/-). Taken together, these results confirm that the phenotypic expression is identical in patients with Leu7fs mutation and patients with HNPP caused by chromosome 17p11.2 deletion. They also demonstrate that reduction of PMP22 is sufficient to cause the full HNPP phenotype.

  1. Favorable outcome in a newborn with molybdenum cofactor type A deficiency treated with cPMP

    Hitzert, Marrit M; Bos, Arend F; Bergman, Klasien A.; Veldman, Alex; Schwarz, Guenter; Santamaria-Araujo, José Angel; Heiner-Fokkema, Rebecca; Sival, Deborah A; Lunsing, Roelineke J; Arjune, Sita; Kosterink, Jos G W; van Spronsen, FrancJan


    Molybdenum cofactor deficiency (MoCD) is a lethal autosomal recessive inborn error of metabolism with devastating neurologic manifestations. Currently, experimental treatment with cyclic pyranopterin monophosphate (cPMP) is available for patients with MoCD type A caused by a mutation in the MOCS-1 g

  2. Safe Surgery Trainer Project Management Plan (PMP), Version 1.0


    Methodology including SCRUM (see for more info). Although this Safe Surgery Trainer - PMP Version 1.0 5...3.5  High Level Task Identification and Scheduling Methodology ......................................................................... 8  4...30/2014 Distribution Statement – Approved for Public Release, Distribution is Unlimited. 8 methodology does not specifically describe a life cycle

  3. Expression, processing, and localization of PmpD of Chlamydia trachomatis Serovar L2 during the chlamydial developmental cycle.

    Andrey O Kiselev

    Full Text Available BACKGROUND: While families of polymorphic membrane protein (pmp genes have been identified in several Chlamydia species, their function remains mostly unknown. These proteins are of great interest, however, because of their location in the outer membrane and possible role in chlamydial virulence. METHODOLOGY/PRINCIPAL FINDING: We analyzed the relative transcription of the pmpD gene, a member of the pmp gene family in C. trachomatis serovar L2, and its protein product translation and processing during the chlamydial developmental cycle. By real-time reverse transcription polymerase chain reaction, the pmpD gene was found to be upregulated at 16 to 24 four hours after infection. Using polyclonal antibodies generated against the predicted passenger domain of PmpD, we demonstrated that it is initially localized on the surface of reticulate bodies, followed by its secretion outside Chlamydia starting at 24 hours after infection. In elementary bodies, we found a approximately 157 kDa PmpD only inside the cell. Both events, the upregulation of pmpD gene transcription and PmpD protein processing and secretion, are coincidental with the period of replication and differentiation of RBs into EBs. We also demonstrated that, in the presence of penicillin, the cleavage and secretion of the putative passenger domain was suppressed. CONCLUSION/SIGNIFICANCE: Our results are in agreement with the general concept that PmpD is an autotransporter protein which is post-translationally processed and secreted in the form of the putative passenger domain outside Chlamydia at mid- to- late point after infection, coinciding with the development of RBs into EBs.

  4. The effect of coupling hydrologic and hydrodynamic models on probable maximum flood estimation

    Felder, Guido; Zischg, Andreas; Weingartner, Rolf


    Deterministic rainfall-runoff modelling usually assumes stationary hydrological system, as model parameters are calibrated with and therefore dependant on observed data. However, runoff processes are probably not stationary in the case of a probable maximum flood (PMF) where discharge greatly exceeds observed flood peaks. Developing hydrodynamic models and using them to build coupled hydrologic-hydrodynamic models can potentially improve the plausibility of PMF estimations. This study aims to assess the potential benefits and constraints of coupled modelling compared to standard deterministic hydrologic modelling when it comes to PMF estimation. The two modelling approaches are applied using a set of 100 spatio-temporal probable maximum precipitation (PMP) distribution scenarios. The resulting hydrographs, the resulting peak discharges as well as the reliability and the plausibility of the estimates are evaluated. The discussion of the results shows that coupling hydrologic and hydrodynamic models substantially improves the physical plausibility of PMF modelling, although both modelling approaches lead to PMF estimations for the catchment outlet that fall within a similar range. Using a coupled model is particularly suggested in cases where considerable flood-prone areas are situated within a catchment.

  5. De novo PMP2 mutations in families with type 1 Charcot-Marie-Tooth disease.

    Motley, William W; Palaima, Paulius; Yum, Sabrina W; Gonzalez, Michael A; Tao, Feifei; Wanschitz, Julia V; Strickland, Alleene V; Löscher, Wolfgang N; De Vriendt, Els; Koppi, Stefan; Medne, Livija; Janecke, Andreas R; Jordanova, Albena; Zuchner, Stephan; Scherer, Steven S


    We performed whole exome sequencing on a patient with Charcot-Marie-Tooth disease type 1 and identified a de novo mutation in PMP2, the gene that encodes the myelin P2 protein. This mutation (p.Ile52Thr) was passed from the proband to his one affected son, and segregates with clinical and electrophysiological evidence of demyelinating neuropathy. We then screened a cohort of 136 European probands with uncharacterized genetic cause of Charcot-Marie-Tooth disease and identified another family with Charcot-Marie-Tooth disease type 1 that has a mutation affecting an adjacent amino acid (p.Thr51Pro), which segregates with disease. Our genetic and clinical findings in these kindred demonstrate that dominant PMP2 mutations cause Charcot-Marie-Tooth disease type 1. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email:

  6. Partial Gene Deletions of PMP22 Causing Hereditary Neuropathy with Liability to Pressure Palsies

    Sun-Mi Cho


    Full Text Available Hereditary neuropathy with liability to pressure palsies (HNPP is an autosomal neuropathy that is commonly caused by a reciprocal 1.5 Mb deletion on chromosome 17p11.2, at the site of the peripheral myelin protein 22 (PMP22 gene. Other patients with similar phenotypes have been shown to harbor point mutations or small deletions, although there is some clinical variation across these patients. In this report, we describe a case of HNPP with copy number changes in exon or promoter regions of PMP22. Multiplex ligation-dependent probe analysis revealed an exon 1b deletion in the patient, who had been diagnosed with HNPP in the first decade of life using molecular analysis.

  7. Quantitative reconstruction of precipitation changes on the NE Tibetan Plateau since the Last Glacial Maximum – extending the concept of pollen source-area to pollen-based climate reconstructions from large lakes

    Y. Wang


    Full Text Available Pollen records from large lakes have been used for quantitative palaeoclimate reconstruction but the influences that lake-size (as a result of species-specific variations in pollen dispersal patterns and taphonomy have on these climatic signals have not previously been systematically investigated. We introduce the concept of pollen source-area to pollen-based climate calibration using the climate history of the north-eastern Tibetan Plateau as our study area. We present a pollen data-set collected from large lakes in the arid to semi-arid region of Central Asia. The influences that lake size and the inferred pollen source-areas have on pollen compositions have been investigated through comparisons with pollen assemblages in neighbouring lakes of various sizes. Modern pollen samples collected from different parts of Lake Donggi Cona (in the north-eastern part of the Tibetan Plateau reveal variations in pollen assemblages within this large lake, which are interpreted in terms of the species-specific dispersal and depositional patterns for different types of pollen, and in terms of fluvial input components. We have estimated the pollen source-area for each lake individually and used this information to infer modern climate data with which to then develop a modern calibration data-set, using both the Multivariate Regression Tree (MRT and Weighted-Averaging Partial Least Squares (WA-PLS approaches. Fossil pollen data from Lake Donggi Cona have been used to reconstruct the climate history of the north-eastern part of the Tibetan Plateau since the Last Glacial Maximum (LGM. The mean annual precipitation was quantitatively reconstructed using WA-PLS: extremely dry conditions are found to have dominated the LGM, with annual precipitation of around 100 mm, which is only 32% of present-day precipitation. A gradually increasing trend in moisture conditions during the Late Glacial is terminated by an abrupt reversion to a dry phase that lasts for about 1000

  8. PMP与现代项目管理%PMP and Modern Management



    @@ PMP及其发展状况PMP的英文是Project Management Professional,简称PMP,是美国项目管理学会(Project Management Institute,简称PMI)开展的对项目管理专业人员资格认证.其目的是为了给项目管理人员提供一个行业标准.

  9. PLP and PMP radicals: a new paradigm in coenzyme B6 chemistry.

    Agnihotri, G; Liu, H W


    Enzymes frequently rely on a broad repertoire of cofactors to perform chemically challenging transformations. The B6 coenzymes, composed of pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP), are used by many transaminases, racemases, decarboxylases, and enzymes catalyzing alpha,beta and beta,gamma-eliminations. Despite the variety of reactions catalyzed by B6-dependent enzymes, the mechanism of almost all such enzymes is based on their ability to stabilize high-energy anionic intermediates in their reaction pathways by the pyridinium moiety of PLP/PMP. However, there are two notable exceptions to this model, which are discussed in this article. The first enzyme, lysine 2,3-aminomutase, is a PLP-dependent enzyme that catalyzes the interconversion of L-lysine to L-beta-lysine using a one-electron-based mechanism utilizing a [4Fe-4S] cluster and S-adenosylmethionine. The second enzyme, CDP-6-deoxy-L-threo-D-glycero-4-hexulose-3-dehydrase, is a PMP-dependent enzyme involved in the formation of 3,6-dideoxysugars in bacteria. This enzyme also contains an iron-sulfur cluster and uses a one-electron based mechanism to catalyze removal of a C-3 hydroxy group from a 4-hexulose. In both cases, the participation of free radicals in the reaction pathway has been established, placing these two B6-dependent enzymes in an exclusive class by themselves.

  10. Dual-frequency grating method based research on phase measurement profilometry (PMP) technology

    Wang, Binbin; Liang, Yijun; Deng, Hu


    With more than three decades of development, three-dimensional optical measurement technology has reached a mature stage in commercial applications, meanwhile new ones have continually arisen. Due to the development of Charge Coupled Device (CCD) array camera and digital projection technology, the applications of Phase Measurement Profilometry (PMP) become more and more broad. Among these, dual-frequency grating method has drawn many attentions because of its simplicity in principle and optical path, low requirement of equipment, high accuracy and level of automation comparing with other methods. The phase calculation is one of the key technologies in PMP. However, phase unwrapping algorithm in PMP is a difficult issue. A lot of new algorithm have been proposed, but neither one can solve all the problems, so how to set up new phase unwrapping algorithm becomes urgent. In this chapter, we systematically investigate the phase unwrapping method in dual-frequency grating method, and experimentally set up the system. To verify our method, we experimentally measure a three dimensional object which possesses complicated stair shapes on its surface. The results show that our dual-frequency grating method could achieve phase unwrapping without doing conventional phase unwrapping calculations, and it could also detect the detailed stair shapes on the surface of this three dimensional object automatically.

  11. Costate Estimation of PMP-Based Control Strategy for PHEV Using Legendre Pseudospectral Method

    Hanbing Wei


    Full Text Available Costate value plays a significant role in the application of PMP-based control strategy for PHEV. It is critical for terminal SOC of battery at destination and corresponding equivalent fuel consumption. However, it is not convenient to choose the approximate costate in real driving condition. In the paper, the optimal control problem of PHEV based on PMP has been converted to nonlinear programming problem. By means of KKT condition costate can be approximated as KKT multipliers of NLP divided by the LGL weights. A kind of general costate estimation approach is proposed for predefined driving condition in this way. Dynamic model has been established in Matlab/Simulink in order to prove the effectiveness of the method. Simulation results demonstrate that the method presented in the paper can deduce the closer value of global optimal value than constant initial costate value. This approach can be used for initial costate and jump condition estimation of PMP-based control strategy for PHEV.

  12. Non-parametric frequency analysis of extreme values for integrated disaster management considering probable maximum events

    Takara, K. T.


    This paper describes a non-parametric frequency analysis method for hydrological extreme-value samples with a size larger than 100, verifying the estimation accuracy with a computer intensive statistics (CIS) resampling such as the bootstrap. Probable maximum values are also incorporated into the analysis for extreme events larger than a design level of flood control. Traditional parametric frequency analysis methods of extreme values include the following steps: Step 1: Collecting and checking extreme-value data; Step 2: Enumerating probability distributions that would be fitted well to the data; Step 3: Parameter estimation; Step 4: Testing goodness of fit; Step 5: Checking the variability of quantile (T-year event) estimates by the jackknife resampling method; and Step_6: Selection of the best distribution (final model). The non-parametric method (NPM) proposed here can skip Steps 2, 3, 4 and 6. Comparing traditional parameter methods (PM) with the NPM, this paper shows that PM often underestimates 100-year quantiles for annual maximum rainfall samples with records of more than 100 years. Overestimation examples are also demonstrated. The bootstrap resampling can do bias correction for the NPM and can also give the estimation accuracy as the bootstrap standard error. This NPM has advantages to avoid various difficulties in above-mentioned steps in the traditional PM. Probable maximum events are also incorporated into the NPM as an upper bound of the hydrological variable. Probable maximum precipitation (PMP) and probable maximum flood (PMF) can be a new parameter value combined with the NPM. An idea how to incorporate these values into frequency analysis is proposed for better management of disasters that exceed the design level. The idea stimulates more integrated approach by geoscientists and statisticians as well as encourages practitioners to consider the worst cases of disasters in their disaster management planning and practices.

  13. Solution structure of PMP-C: a new fold in the group of small serine proteinase inhibitors.

    Mer, G; Hietter, H; Kellenberger, C; Renatus, M; Luu, B; Lefèvre, J F


    The solution structure and the disulfide pairings of a 36-residue proteinase inhibitor isolated from the insect Locusta migratoria have been determined using NMR spectroscopy and simulated annealing calculations. The peptide, termed PMP-C, was previously shown to inhibit bovine alpha-chymotrypsin as well as human leukocyte elastase, and was also found to block high-voltage-activated Ca2+ currents in rat sensory neurones. PMP-C has a prolate ellipsoid shape and adopts a tertiary fold hitherto unobserved in the large group of small "canonical" proteinase inhibitors. The over-all fold consists mainly of three strands arranged in a right-handed twisted, antiparallel, beta-sheet that demarcates a cavity, together with a linear amino-terminal segment oriented almost perpendicular to the three strands of the beta-sheet. Inside the cavity a phenyl ring constitutes the centre of a hydrophobic core. The proteinase binding loop is located in the carboxy-terminal part of the molecule, between two cysteine residues involved in disulfide bridges. Its conformation resembles that found in other small canonical proteinase inhibitors. A comparison of PMP-C structure with the recently published solution structure of the related peptide PMP-D2 shows that the most significant differences are complementary changes involved in the stabilization of similar folds. This comparison led us to review the structure of PMP-D2 and to identify two salt bridges in PMP-D2.

  14. Maximum flood hazard assessment for OPG's deep geologic repository for low and intermediate level waste

    Nimmrichter, P.; McClintock, J.; Peng, J. [AMEC plc., Toronto, ON (Canada); Leung, H. [Nuclear Waste Management Organization, Toronto, ON (Canada)


    Ontario Power Generation (OPG) has entered a process to seek Environmental Assessment and licensing approvals to construct a Deep Geologic Repository (DGR) for Low and Intermediate Level Radioactive Waste (L&ILW) near the existing Western Waste Management Facility (WWMF) at the Bruce nuclear site in the Municipality of Kincardine, Ontario. In support of the design of the proposed DGR project, maximum flood stages were estimated for potential flood hazard risks associated with coastal, riverine and direct precipitation flooding. The estimation of lake/coastal flooding for the Bruce nuclear site considered potential extreme water levels in Lake Huron, storm surge and seiche, wind waves, and tsunamis. The riverine flood hazard assessment considered the Probable Maximum Flood (PMF) within the local watersheds, and within local drainage areas that will be directly impacted by the site development. A series of hydraulic models were developed, based on DGR project site grading and ditching, to assess the impact of a Probable Maximum Precipitation (PMP) occurring directly at the DGR site. Overall, this flood assessment concluded there is no potential for lake or riverine based flooding and the DGR area is not affected by tsunamis. However, it was also concluded from the results of this analysis that the PMF in proximity to the critical DGR operational areas and infrastructure would be higher than the proposed elevation of the entrance to the underground works. This paper provides an overview of the assessment of potential flood hazard risks associated with coastal, riverine and direct precipitation flooding that was completed for the DGR development. (author)

  15. PMP-22 expression in the central nervous system of the embryonic mouse defines potential transverse segments and longitudinal columns.

    Parmantier, E; Braun, C; Thomas, J L; Peyron, F; Martinez, S; Zalc, B


    PMP-22, a major constituent of peripheral nervous system (PNS) myelin, is also present in the central nervous system (CNS), in motoneurons of the cranial nerve motor nuclei and spinal cord (Parmantier et al. [1995] Eur. J. Neurosci. 7:1080-1088). The expression of PMP-22 in the CNS during embryonic and early postnatal development was investigated and showed a biphasic spatio-temporal pattern. The expression of PMP-22 started at embryonic day (E)11.5, in restricted longitudinal and transverse domains, in the ventricular zone of the spinal cord, rhombencephalon, mesencephalon and prosencephalon. In the mid- and forebrain, the PMP-22 signal was detectable in a longitudinal domain that followed ventrally the basal/alar boundary but could no longer be detected dorsally at some distance from the roof plate. Along the caudo-rostral axis, the territory in which PMP-22 was detected spanned the mesencephalon and the prosencephalon, extending caudally from the limit between the isthmus and the mesencephalon, and rostrally to the boundary between prosomeres 4 and 5 (p4/p5). In agreement with the prosomeric model of forebrain organization proposed by Puelles and Rubenstein ([1993] TINS 16:472-479), differences in the level of PMP-22 expression in p2, p3, and p4 clearly defined the p2/p3 and p3/p4 neuromeric boundaries. By E17.5, PMP-22 was no longer detected in the ventricular zone, but at E18.5 it began to be expressed in motoneurons of cranial nerve motor nuclei and, after birth, following a rostro-caudal gradient, in the ventral spinal cord.

  16. Polymorphic membrane protein (PMP) 20 and PMP 21 of Chlamydia pneumoniae induce proinflammatory mediators in human endothelial cells in vitro by activation of the nuclear factor-kappaB pathway.

    Niessner, Alexander; Kaun, Christoph; Zorn, Gerlinde; Speidl, Walter; Türel, Zeynep; Christiansen, Gunna; Pedersen, Anna-Sofie; Birkelund, Svend; Simon, Susan; Georgopoulos, Apostolos; Graninger, Wolfgang; de Martin, Rainer; Lipp, Joachim; Binder, Bernd R; Maurer, Gerald; Huber, Kurt; Wojta, Johann


    We tested whether polymorphic membrane proteins (PMPs) of Chlamydia pneumoniae might play a role in triggering an inflammatory response in human endothelial cells. Of 15 purified, recombinant chlamydial PMPs tested, 2 (PMP 20 and PMP 21) dose-dependently increased the production of the inflammatory mediators interleukin (IL)-6 and monocyte chemoattractant protein-1 (MCP-1), in cultured human endothelial cells; production of IL-8 was also increased. When endothelial cells were infected by live C. pneumoniae, an increase in the production of IL-6, IL-8, and MCP-1 was seen. We used adenovirus-induced overexpression of IkappaBalpha-an inhibitor of nuclear factor (NF)-kappaB-to demonstrate that PMP 20 and PMP 21 increase the production of IL-6 and MCP-1 in human endothelial cells by activation of the NF-kappaB pathway, because, in cells overexpressing IkappaBalpha, treatment with the respective PMP did not result in increased production of IL-6 and MCP-1. Thus, C. pneumoniae could, by interactions of its PMPs with the endothelium, contribute to the process of vascular injury during the development and progression of atherosclerotic lesions.

  17. A highly efficient route to enantiomerically pure l-N-Bz-Pmp(t-Bu)2-OH and incorporation into a peptide-based protein tyrosine phosphatase inhibitor.

    Hubbard, Caitlin E; Barrios, Amy M


    Phosphonomethyl phenylalanine (Pmp), a nonhydrolyzable mimic of phosphotyrosine, is an important building block in the development of peptide-based PTP inhibitors. We have designed a novel, efficient synthesis of N-Bz-Pmp(t-Bu)2-OH. A Pmp-containing peptide based on a known biological substrate of the tyrosine phosphatase CD45 (Ac-TEGQ-Pmp-QPQP-NH2) inhibits CD45 with an IC50 value of approximately 100 microM with virtually no inhibition of TCPTP up to concentrations of 120 microM.

  18. Project Manager Street Smarts A Real World Guide to PMP Skills

    Zaval, Linda Kretz


    The perfect workbook for project managers and PMP exam candidates seeking practical experience New project managers and students pursuing the Project Management Professional certification are looking for practical experience to solidify their skills. The step-by-step tasks presented in this book offer them an opportunity to practice the common tasks project managers face in the real world. The authors, both expert project management trainers and consultants, explore each phase of project management: initiation, planning, execution, monitoring and control, and closing the project, with in-depth


    王跃; 翦知湣; 赵平


    teleconnections, especially under glacial conditions( Last Glacial Maximum , LGM ) . However, there are still large uncertainties in the reconstruction of LGM tropical SST, an important boundary condition for the paleoclimate modeling. The new global LGM SST reconstruction from MARGO ( Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface project)provides us a chance to validate the sensitivity of tropical rainfall to SST variations under different climate backgrounds. And more , the SST outputted from the LGM simulations of Atmosphere-Ocean ( AO) coupled model ( CCSM 3 ) can be used to assess the reliability of MARGO SST reconstruction and the two kinds of relationship from modern observations.We used CAM 3, the fifth generation atmospheric general circulation model of the National Center for Atmospheric Research, to study the sensitivity of precipitation in tropical convergence zone ( ITCZ)/summer monsoon regions to local SST anomalies during LGM. Under the T42 resolution ( 2. 8° ×2. 8° horizontally and 26 levels vertically) of CAM 3, we first designed a modern control experiment prescribed with present boundary conditions ( Greenhouse gases ( GHG ) , orbital parameters , Ice sheet , sea level , climatological SST and Sea -Ice ) . then a LGM control case ( CLIMAPLGM ) with glacial conditions ( GHG and orbital parameters of 2lkaB. P. , ICE-5G Ice sheet, -120m sea level, CLIMAP SST and Sea-ice) . The other two LGM sensitive cases were conducted by replacing the SST & Sea-ice in CLIMAPLGM ( MARGOLGM case with tropical SST from MARGO reconstruction and b30. 104wLGM case with global SST & Sea ice from CCSM 3's LGM simulation).By comparing the SST/precipitation differences ( CLIMAPLCM minus modern case , and LGM sensitive cases minus CLIMAPLGM ) ,we suggested that : ( 1) Under glacial conditions , local SST anomalies could largely control the tropical rainfall responses; when SST anomalies extended to the whole tropics, the drastic ITCZ/summer monsoon

  20. Transgenic rice expressing a cassava (Manihot esculenta Crantz) plasma membrane gene MePMP3-2 exhibits enhanced tolerance to salt and drought stresses.

    Yu, Y; Cui, Y C; Ren, C; Rocha, P S C F; Peng, M; Xu, G Y; Wang, M L; Xia, X J


    Plasma membrane proteolipid 3 (PMP3) is a class of small hydrophobic proteins found in many organisms including higher plants. Some plant PMP3 genes have been shown to respond to abiotic stresses and to participate in the processes of plant stress tolerance. In this study, we isolated the cassava (Manihot esculenta Crantz) MePMP3-2 gene and functionally characterized its role in tolerance to abiotic stress by expressing it in rice (Oryza sativa L.). MePMP3-2 encodes a 77-amino acid protein belonging to a subgroup of plant PMP3s that have long hydrophylic C-terminal tails of unknown function. In silico analysis and co-localization studies indicated that MePMP3-2 is a plasma membrane protein with two transmembrane domains, similar to other PMP3s. In cassava leaves, MePMP3-2 expression was up-regulated by salt and drought stresses. Heterologous constitutive expression of MePMP3-2 in rice did not alter plant growth and development but increased tolerance to salt and drought stresses. In addition, under stress conditions MePMP3-2 transgenic plants accumulated less malondialdehyde, had increased levels of proline, and exhibited greater up-regulation of the stress-related genes OsProT and OsP5CS, but led to only minor changes in OsDREB2A and OsLEA3 expression. These findings indicate that MePMP3-2 may play an important role in salt and drought stress tolerance in transgenic rice.

  1. A novel point mutation in PMP22 gene in an Italian family with hereditary neuropathy with liability to pressure palsies.

    Muglia, Maria; Patitucci, Alessandra; Rizzi, Romana; Ungaro, Carmine; Conforti, Francesca Luisa; Gabriele, Anna Lia; Magariello, Angela; Mazzei, Rosalucia; Motti, Luisa; Sabadini, Rossella; Sprovieri, Teresa; Marcello, Norina; Quattrone, Aldo


    Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder characterized by recurrent sensory or motor dysfunction. In 85% of HNPP cases the genetic defect is a 1.4 Mb deletion on chromosome 17p11.2, encompassing the PMP22 gene. Point mutations in the PMP22 gene responsible for HNPP phenotypes are rare. We investigated a 17-years-old girl who led to our detecting a novel mutation in PMP22 gene. The mutation was also detected in her father and corresponded to a deletion of one tymidine at position 11 in exon2 (c.11delT). This novel mutation creates a shift on the reading frame starting at codon 4 and leads to the introduction of a premature stop at codon 6.

  2. Early indication of noise-induced hearing loss from PMP use in adolescents: A cross-sectional analysis

    Diana C Colon


    Full Text Available Context: Distortion product otoacoustic emissions (DPOAEs may indicate preclinical noise-induced hearing loss (NIHL in adolescents from unsafe personal music player (PMP use. Aims: The objective, therefore, was to observe preclinical signs of NIHL in 9th grade adolescents with clinically normal hearing by comparing DPOAE signals between different levels of A-weighted equivalent PMP exposure. Settings and Design: Subjects were recruited from all secondary-level schools located in the city of Regensburg, Germany during two academic years 2009/2010 and 2010/2011. Subjects and Methods: A-weighted equivalent sound pressure levels (SPLs for a 40-hour work week (LAeq,40h were estimated from questionnaire responses on output and duration of PMP use of the previous week. Subjects were then categorized into four levels of exposure: 85 to <90, and ≥90 A-weighted Decibel [dB(A]. DPOAE signals were collected by trained audiological staff, applying a standard optimized protocol, at the Department of Otorhinolaryngology of the University Hospital Regensburg. Statistical Analysis Used: Mean DPOAE signals were compared between levels by unpaired t test. Novel linear regression models adjusting for other leisure noise exposures and with outcome variables DPoutcome and 4 kilo Hertz (kHz DPOAEs estimated effects between levels. Results: A total of 1468 subjects (56% female, mostly aged 15 or 16 years were available for analysis. Comparison of DPOAE means by PMP exposure typically showed no greater than 1 dB difference between groups. In fact, comparisons between ≥90 dB(A and <80 dB(A presented the least differences in magnitude. Both DPoutcome and 4 kHz linear regression models presented a weak association with the 4-level PMP exposure variable. An expected dose-response to PMP exposure was not observed in any analyses. Conclusions: DPOAE signal strength alone cannot indicate preclinical NIHL in adolescents.

  3. PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies


    PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is normal. PMID:24646194

  4. PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies.

    van Paassen, Barbara W; van der Kooi, Anneke J; van Spaendonck-Zwarts, Karin Y; Verhamme, Camiel; Baas, Frank; de Visser, Marianne


    PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is normal.

  5. Maximum Fidelity

    Kinkhabwala, Ali


    The most fundamental problem in statistics is the inference of an unknown probability distribution from a finite number of samples. For a specific observed data set, answers to the following questions would be desirable: (1) Estimation: Which candidate distribution provides the best fit to the observed data?, (2) Goodness-of-fit: How concordant is this distribution with the observed data?, and (3) Uncertainty: How concordant are other candidate distributions with the observed data? A simple unified approach for univariate data that addresses these traditionally distinct statistical notions is presented called "maximum fidelity". Maximum fidelity is a strict frequentist approach that is fundamentally based on model concordance with the observed data. The fidelity statistic is a general information measure based on the coordinate-independent cumulative distribution and critical yet previously neglected symmetry considerations. An approximation for the null distribution of the fidelity allows its direct conversi...

  6. OmpA family proteins and Pmp-like autotransporter: new adhesins of Waddlia chondrophila.

    Kebbi-Beghdadi, Carole; Domröse, Andreas; Becker, Elisabeth; Cisse, Ousmane H; Hegemann, Johannes H; Greub, Gilbert


    Waddlia chondrophila is a obligate intracellular bacterium belonging to the Chlamydiales order, a clade that also includes the well-known classical Chlamydia responsible for a number of severe human and animal diseases. Waddlia is an emerging pathogen associated with adverse pregnancy outcomes in humans and abortion in ruminants. Adhesion to the host cell is an essential prerequisite for survival of every strict intracellular bacteria and, in classical Chlamydia, this step is partially mediated by polymorphic outer membrane proteins (Pmps), a family of highly diverse autotransporters that represent about 15% of the bacterial coding capacity. Waddlia chondrophila genome however only encodes one putative Pmp-like protein. Using a proteomic approach, we identified several bacterial proteins potentially implicated in the adhesion process and we characterized their expression during the replication cycle of the bacteria. In addition, we demonstrated that the Waddlia Pmp-like autotransporter as well as OmpA2 and OmpA3, two members of the extended Waddlia OmpA protein family, exhibit adhesive properties on epithelial cells. We hypothesize that the large diversity of the OmpA protein family is linked to the wide host range of these bacteria that are able to enter and multiply in various host cells ranging from protozoa to mammalian and fish cells.

  7. Enantioselective Synthesis of N-PMP-1,2-dihydropyridines via Formal [4 + 2] Cycloaddition between Aqueous Glutaraldehyde and Imines.

    Ramaraju, Panduga; Mir, Nisar A; Singh, Deepika; Gupta, Vivek K; Kant, Rajni; Kumar, Indresh


    A simple and highly practical one-pot formal [4 + 2] cycloaddition approach for the enantioselective synthesis of N-PMP-1,2-dihydropyridines (DHPs) is described. This chemistry involves an amino-catalytic direct Mannich reaction/cyclization followed by IBX-mediated chemo- and regioselective oxidation sequence between readily available aqueous glutaraldehyde and imines under very mild conditions. A series of N-PMP-1,2-DHPs have been prepared in high yields and excellent enantioselectivity. This method also gives access to both enantiomers of 1,2-DHPs in surplus amount by shifting the catalyst configuration.

  8. Gene expression of PMP22 is an independent prognostic factor for disease-free and overall survival in breast cancer patients

    Schiebel Ingrid


    Full Text Available Abstract Background Gene expression of peripheral myelin protein 22 (PMP22 and the epithelial membrane proteins (EMPs was found to be differentially expressed in invasive and non-invasive breast cell lines in a previous study. We want to evaluate the prognostic impact of the expression of these genes on breast cancer. Methods In a retrospective multicenter study, gene expression of PMP22 and the EMPs was measured in 249 primary breast tumors by real-time PCR. Results were statistically analyzed together with clinical data. Results In univariable Cox regression analyses PMP22 and the EMPs were not associated with disease-free survival or tumor-related mortality. However, multivariable Cox regression revealed that patients with higher than median PMP22 gene expression have a 3.47 times higher risk to die of cancer compared to patients with equal values on clinical covariables but lower PMP22 expression. They also have a 1.77 times higher risk to relapse than those with lower PMP22 expression. The proportion of explained variation in overall survival due to PMP22 gene expression was 6.5% and thus PMP22 contributes equally to prognosis of overall survival as nodal status and estrogen receptor status. Cross validation demonstrates that 5-years survival rates can be refined by incorporating PMP22 into the prediction model. Conclusions PMP22 gene expression is a novel independent prognostic factor for disease-free survival and overall survival for breast cancer patients. Including it into a model with established prognostic factors will increase the accuracy of prognosis.

  9. Characterization of phosphodiesterase 2A in human malignant melanoma PMP cells.

    Morita, Hiroshi; Murata, Taku; Shimizu, Kasumi; Okumura, Kenya; Inui, Madoka; Tagawa, Toshiro


    The prognosis for malignant melanoma is poor; therefore, new diagnostic methods and treatment strategies are urgently needed. Phosphodiesterase 2 (PDE2) is one of 21 phosphodiesterases, which are divided into 11 families (PDE1-PDE11). PDE2 hydrolyzes cyclic AMP (cAMP) and cyclic GMP (cGMP), and its binding to cGMP enhances the hydrolysis of cAMP. We previously reported the expression of PDE1, PDE3 and PDE5 in human malignant melanoma cells. However, the expression of PDE2 in these cells has not been investigated. Herein, we examined the expression of PDE2A and its role in human oral malignant melanoma PMP cells. Sequencing of RT-PCR products revealed that PDE2A2 was the only variant expressed in PMP cells. Four point mutations were detected; one missense mutation at nucleotide position 734 (from C to T) resulted in the substitution of threonine with isoleucine at amino acid position 214. The other three were silent mutations. An in vitro migration assay and a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay revealed that suppressing PDE2 activity with its specific inhibitor, erythro-9-(2-hydroxy-3-nonyl)-adenine (EHNA), had no impact on cell motility or apoptosis. Furthermore, the cytotoxicity of EHNA, assessed using a trypan blue exclusion assay, was negligible. On the other hand, assessment of cell proliferation by BrdU incorporation and cell cycle analysis by flow cytometry revealed that EHNA treatment inhibited DNA synthesis and increased the percentage of G2/M-arrested cells. Furthermore, cyclin A mRNA expression was downregulated, while cyclin E mRNA expression was upregulated in EHNA-treated cells. Our results demonstrated that the PDE2A2 variant carrying point mutations is expressed in PMP cells and may affect cell cycle progression by modulating cyclin A expression. Thus, PDE2A2 is a possible new molecular target for the treatment of malignant melanoma.

  10. PMP22-Related neuropathies and other clinical manifestations in Chinese han patients with charcot-marie-tooth disease type 1.

    Zhan, Yajing; Zi, Xiaohong; Hu, Zhengmao; Peng, Ying; Wu, Lingqian; Li, Xiaobo; Jiang, Mingming; Liu, Lei; Xie, Yongzhi; Xia, Kun; Tang, Beisha; Zhang, Ruxu


    Most cases of Charcot-Marie-Tooth (CMT) disease are caused by mutations in the peripheral myelin protein 22 gene (PMP22), including heterozygous duplications (CMT1A), deletions (HNPP), and point mutations (CMT1E). Single-nucleotide polymorphism (SNP) arrays were used to study PMP22 mutations based on the results of multiplex ligation-dependent probe amplification (MLPA) and polymerase chain reaction-restriction fragment length polymorphism methods in 77 Chinese Han families with CMT1. PMP22 sequencing was performed in MLPA-negative probands. Clinical characteristics were collected for all CMT1A/HNPP probands and their family members. Twenty-one of 77 CMT1 probands (27.3%) carried duplication/deletion (dup/del) copynumber variants. No point mutations were detected. SNP array and MLPA seem to have similar sensitivity. Fifty-seven patients from 19 CMT1A families had the classical CMT phenotype, except for 1 with concomitant CIDP. Two HNPP probands presented with acute ulnar nerve palsy or recurrent sural nerve palsy, respectively. The SNP array has wide coverage, high sensitivity, and high resolution and can be used as a screening tool to detect PMP22 dup/del as shown in this Chinese Han population. © 2014 Wiley Periodicals, Inc.

  11. Assessing the forecasting performance of a generic Bio-Economic farm model calibrated with two different PMP variants

    Kanellopoulos, A.; Berentsen, Paul; Heckelei, T.; Ittersum, van M.K.; Oude Lansink, A.G.J.M.


    Using linear programming in bio-economic farm modelling often results in overspecialised model solutions. The positive mathematical programming (PMP) approach guarantees exact calibration to base year data but the forecasting capacity of the model is affected by necessary but arbitrary assumptions

  12.  Hypertelorism in Charcot-Marie-Tooth disease 1A from the common PMP22 duplication: A Case Report

    Josef Finsterer


    Full Text Available  The 1.4Mb tandem-duplication in the PMP22 gene at 17p11.2 usually manifests as hereditary sensorimotor polyneuropathy with foot deformity, sensorineural hearing-loss, moderate developmental delay, and gait disturbance. Hypertelorism and marked phenotypic variability within a single family has not been reported. In a single family, the PMP22 tandem-duplication manifested as short stature, sensorimotor polyneuropathy, tremor, ataxia, sensorineural hearing-loss, and hypothyroidism in the 27 years-old index case, as mild facial dysmorphism, muscle cramps, tinnitus, intention tremor, bradydiadochokinesia, and sensorimotor polyneuropathy in the 31 year-old half-brother of the index-patient, and as sensorimotor polyneuropathy and foot deformityin the father of the two. The half-brother additionally presented with hypertelorism, not previously reported in PMP22tandem-duplication carriers. The presented cases show that the tandem-duplication 17p11.2 may present with marked intra-familialphenotype variability and that mild facial dysmorphism with stuck-out ears and hypertelorism may be a rare phenotypic feature of this mutation. The causal relation between facial dysmorphism and the PMP22 tandem-duplication, however, remains speculative.

  13. Silver(I) triflate-catalyzed direct synthesis of N-PMP protected alpha-aminopropargylphosphonates from terminal alkynes.

    Dodda, Rajasekhar; Zhao, Cong-Gui


    [reaction: see text] N-PMP protected alpha-aminopropargylphosphonates have been synthesized by using a silver(I) triflate-catalyzed one-pot three-component reaction of terminal alkynes, p-anisidine, and diethyl formylphosphonate hydrate. Good to excellent yields of the desired products may be obtained with a very simple procedure.

  14. Assessing the forecasting performance of a generic Bio-Economic farm model calibrated with two different PMP variants

    Kanellopoulos, A.; Berentsen, Paul; Heckelei, T.; Ittersum, van M.K.; Oude Lansink, A.G.J.M.


    Using linear programming in bio-economic farm modelling often results in overspecialised model solutions. The positive mathematical programming (PMP) approach guarantees exact calibration to base year data but the forecasting capacity of the model is affected by necessary but arbitrary assumptions i

  15. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    Zhang, C.P., E-mail: [SMRC, Northwest Institute for Non-ferrous Metal Research, Xi’an (China); Physics Department, Université Joseph Fourier, Grenoble (France); State Key Lab of Solidification Processing, Northwest Polytechnical University, Xi’an (China); Chaud, X. [CRETA/CNRS, 25 avenue des martyrs, 38042 Grenoble Cedex 9 (France); Beaugnon, E. [Physics Department, Université Joseph Fourier, Grenoble (France); CRETA/CNRS, 25 avenue des martyrs, 38042 Grenoble Cedex 9 (France); Zhou, L. [SMRC, Northwest Institute for Non-ferrous Metal Research, Xi’an (China); State Key Lab of Solidification Processing, Northwest Polytechnical University, Xi’an (China)


    Highlights: • It was the first time we measured the susceptibility of bulk YBCO in powder-melting-process at high temperature up to 1060 °C. • It revealed that the crystalline phase transition of bulk PMP-YBCO growth in process. • A new discovery of Y123 phase pre-formed then melted in heating stage has been found. • It discovered that Y123 crystal solidification started at 1004 °C in cooling stage in PMP route. - Abstract: The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu{sub 2}O reciprocally as well as the copper ion valence changed between divalent Cu{sup 2+} and trivalent Cu{sup 1+} each other. It was essential to keep quantities of CuO phase instead of the Cu{sub 2}O for Y123 crystal solidification.

  16. Physical and chemical characteristics of mucin secreted by pseudomyxoma peritonei (PMP)

    Pillai, Krishna; Akhter, Javed; Mekkawy, Ahmed; Chua, Terence C; Morris, David L


    Background: Pseudomyxoma peritonei (PMP) is a rare disease with excess intraperitoneal mucin secretion. Treatment involves laparotomy, cytoreduction and chemotherapy that is very invasive with patients often acquiring numerous compromises. Hence a mucolytic comprising of bromelain and N-acetyl cystein has been developed to solubilise mucin in situ for removal by catherization. Owing to differences in mucin appearance and hardness, dissolution varies. Therefore the current study investigates the inter-mucin physical and chemical characteristics, in order to reformulate an effective mucolytic for all mucin. Method: PMP mucin, from the three categories (soft, semi hard and hard mucin) was solubilised and then various physical characteristics such as turbidity, density, kinematic viscosity were measured. The water content and the density of solid mucin were also determined. This was followed by the determination of sialic acid, glucose, lipid, Thiol (S-S and S-H) content of the samples. Lastly, the distribution of MUC2, MUC5B and MUC5AC was determined using western blot technique. Results: Both turbidity and kinematic viscosity and sialic acid content increased linearly as the hardness of mucin increased. However, density, hydration, protein, glucose, lipid and sulfhydryl and disulphide content decreased linearly as hardness of mucin increased. The distribution ratio of mucins (MUC2:MUC5B:MUC5AC) in soft mucin is 2.25:1.5:1.0, semi hard mucin is 1:1:1 and hard mucin is 3:2:1. Conclusion: The difference in texture and hardness of mucin may be due to cellular content, hydration, glucose, protein, lipids, thiol and MUC distribution. Soft mucin is solely made of glycoprotein whilst the others contained cellular materials. PMID:28138305

  17. Cloning and prokaryotic expression of N-domain of PmpD gene of Chlamydophila psittaci%禽鹦鹉热嗜性衣原体PmpD基因N端区的克隆与表达

    袁吉磊; 何诚; 蒋毅; 凌勇; 杨君敬; 张发明; 李应超; 陈曦


    为探讨禽鹦鹉热嗜性衣原体PmpD基因的生物学功能,本实验根据禽类鹦鹉热嗜性衣原体Cal-10株全基因序列设计引物,用PCR法扩增禽嗜性衣原体PmpD基因N端区,将特异性目的基因片段克隆入PBS-TⅡ栽体,经测序后确认为目的基因,并提交GenBank.试验扩增的禽鹦鹉热嗜性衣原体Cal株PmpD基因与禽鹦鹉热衣原体6BC株的PmpD基因和氨基酸序列的相似性均达99%,与流产衣原体成员嗜流产衣原体S26/3株、嗜豚鼠衣原体(GPIC)、嗜猫衣原体(Fe/C-56)核苷酸相似性分别为89%、82%和77%.PmpD基因N端区基因亚克隆到pET-32a(+)载体上,重组表达栽体转化BL21(DE3)表达宿主菌,以IPTG诱导该重组菌,结果表达了约63 ku大小的融合蛋白;分别用禽鹦鹉热嗜性衣原体多克隆抗体、猪、羊流产嗜性衣原体多克隆抗体与表达出的重组蛋白进行Western blotting检测,结果表明该蛋白与禽源衣原体多克隆抗体呈阳性反应,与猪、羊源衣原体多克隆抗体呈阴性反应,显示该重组蛋白具有种属特异性.本研究首次表达了禽类鹦鹉热嗜性衣原体PmpD基因的N端区的重组蛋白,为进一步研究其生物学功能提供依据.

  18. 灵芝孢子粉多糖的PMP-HPLC指纹分析%Analysis of PMP-HPLC Fingerprints of Polysaccharides From Ganoderma lucidum Spores

    王浩豪; 戴军; 陈尚卫; 朱松


    Partial acidic hydrolysis coupled PMP-HPLC analysis was applied to indentify and characterize polysaccharides from Ganoderma lucidum spores from different zones in China.Chromatographic fingerprint of the polysaccharide was built using 15 different sources of Ganoderma lucidum spore powder samples and 19 common peaks were found.The similarity between products from the same zone was much higher than 0.97,while it was lower but still greater than 0.80 when the products originated in different zones.There are quite a lot of differences among Ganoderma lucidum spore and other species spore and between spore and fruit body of Ganoderma lucidum.The similarities and differences may be used as main basis for quality control,identification from different origins and parts of Ganoderma and their adulteration detection.%采用部分酸水解耦合PMP柱前衍生反相高效液相色谱法对15个不同灵芝(赤芝)孢子粉样品中多糖进行检测和指纹表征,研究建立灵芝孢子粉多糖的HPLC指纹图谱。标定了19个共有特征指纹峰,同一产地不同批次产品间的相似度均大于0.97,不同产地产品间的相似度大于0.8;赤芝孢子粉与其他不同部位及不同品种的灵芝类产品的多糖指纹图谱显示出较大的差异。这些相似性和差异可作为灵芝孢子粉产品质量监控、与其他不同部位和不同品种的灵芝类产品的区别鉴定以及灵芝孢子粉的真伪与掺假检测的主要依据之一。

  19. Computational Analysis Reveals the Association of Threonine 118 Methionine Mutation in PMP22 Resulting in CMT-1A

    Chundi Vinay Kumar


    Full Text Available The T118M mutation in PMP22 gene is associated with Charcot Marie Tooth, type 1A (CMT1A. CMT1A is a form of Charcot-Marie-Tooth disease, the most common inherited disorder of the peripheral nervous system. Mutations in CMT related disorder are seen to increase the stability of the protein resulting in the diseased state. We performed SNP analysis for all the nsSNPs of PMP22 protein and carried out molecular dynamics simulation for T118M mutation to compare the stability difference between the wild type protein structure and the mutant protein structure. The mutation T118M resulted in the overall increase in the stability of the mutant protein. The superimposed structure shows marked structural variation between the wild type and the mutant protein structures.

  20. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    Zhang, C. P.; Chaud, X.; Beaugnon, E.; Zhou, L.


    The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu2O reciprocally as well as the copper ion valence changed between divalent Cu2+ and trivalent Cu1+ each other. It was essential to keep quantities of CuO phase instead of the Cu2O for Y123 crystal solidification.

  1. Molecular dynamics simulations on pars intercerebralis major peptide-C (PMP-C) reveal the role of glycosylation and disulfide bonds in its enhanced structural stability and function.

    Kaushik, Sandeep; Mohanty, Debasisa; Surolia, Avadhesha


    Fucosylation of Thr 9 in pars intercerebralis major peptide-C (PMP-C) enhances its structural stability and functional ability as a serine protease inhibitor. In order to understand the role of disulfide bonds and glycosylation on the structure and function of PMP-C, we have carried out multiple explicit solvent molecular dynamics (MD) simulations on fucosylated and non-fucosylated forms of PMP-C, both in the presence and absence of the disulfide bonds. Our simulations revealed that there were no significant structural changes in the native disulfide bonded forms of PMP-C due to fucosylation. On the other hand, the non-fucosylated form of PMP-C without disulfide bonds showed larger deviations from the starting structure than the fucosylated form. However, the structural deviations were restricted to the terminal regions while core β-sheet retained its hydrogen bonded structure even in absence of disulfide bonds as well as fucosylation. Interestingly, fucosylation of disulfide bonded native PMP-C led to a decreased thermal flexibility in the residue stretch 29-32 which is known to interact with the active site of the target proteases. Our analysis revealed that disulfide bonds covalently connect the residue stretch 29-32 to the central β-sheet of PMP-C and using a novel network of side chain interactions and disulfide bonds fucosylation at Thr 9 is altering the flexibility of the stretch 29-32 located at a distal site. Thus, our simulations explain for the first time, how presence of disulfide bonds between conserved cysteines and fucosylation enhance the function of PMP-C as a protease inhibitor.

  2. Vanadium-catalyzed oxidative Strecker reaction: α-C-H cyanation of para-methoxyphenyl (PMP)-protected primary amines.

    Zhu, Chen; Xia, Ji-Bao; Chen, Chuo


    We describe an oxidative Strecker reaction that allows for direct cyanation of para-methoxyphenyl (PMP)-protected primary amines. A vanadium(V) complex was used as the catalyst and TBHP as the oxidant. The cyanation occurs at the α-C position bearing either an alkyl or an aromatic group. This method provides a direct access to α-aminonitrile from amines with one-carbon extension.

  3. Identification of structurally closely related monosaccharide and disaccharide isomers by PMP labeling in conjunction with IM-MS/MS.

    Yang, Hongmei; Shi, Lei; Zhuang, Xiaoyu; Su, Rui; Wan, Debin; Song, Fengrui; Li, Jinying; Liu, Shuying


    It remains particularly difficult for gaining unambiguous information on anomer, linkage, and position isomers of oligosaccharides using conventional mass spectrometry (MS) methods. In our laboratory, an ion mobility (IM) shift strategy was employed to improve confidence in the identification of structurally closely related disaccharide and monosaccharide isomers using IMMS. Higher separation between structural isomers was achieved using 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization in comparison with phenylhydrazine (PHN) derivatization. Furthermore, the combination of pre-IM fragmentation of PMP derivatives provided sufficient resolution to separate the isomers not resolved in the IMMS. To chart the structural variation observed in IMMS, the collision cross sections (CCSs) for the corresponding ions were measured. We analyzed nine disaccharide and three monosaccharide isomers that differ in composition, linkages, or configuration. Our data show that coexisting carbohydrate isomers can be identified by the PMP labeling technique in conjunction with ion-mobility separation and tandem mass spectrometry. The practical application of this rapid and effective method that requires only small amounts of sample is demonstrated by the successful analysis of water-soluble ginseng extract. This demonstrated the potential of this method to measure a variety of heterogeneous sample mixtures, which may have an important impact on the field of glycomics.

  4. Claudins reign: The claudin/EMP/PMP22/γ channel protein family in C. elegans.

    Simske, Jeffrey S


    The claudin family of integral membrane proteins was identified as the major protein component of the tight junctions in all vertebrates. Since their identification, claudins, and their associated pfam00822 superfamily of proteins have been implicated in a wide variety of cellular processes. Claudin homologs have been identified in invertebrates as well, including Drosophila and C. elegans. Recent studies demonstrate that the C. elegans claudins, clc-1-clc- 5, and similar proteins in the greater PMP22/EMP/claudin/voltage-gated calcium channel γ subunit family, including nsy-4, and vab-9, while highly divergent at a sequence level from each other and from the vertebrate claudins, in many cases play roles similar to those traditionally assigned to their vertebrate homologs. These include regulating cell adhesion and passage of small molecules through the paracellular space, channel activity, protein aggregation, sensitivity to pore-forming toxins, intercellular signaling, cell fate specification and dynamic changes in cell morphology. Study of claudin superfamily proteins in C. elegans should continue to provide clues as to how claudin family protein function has been adapted to perform diverse functions at specialized cell-cell contacts in metazoans.

  5. A pmp genes-based PCR as a valuable tool for the diagnosis of avian chlamydiosis.

    Laroucau, Karine; Trichereau, Alain; Vorimore, Fabien; Mahé, Anne-Marie


    In a previous study we described the use of a new set of PCR primers (CpsiA/CpsiB) specific of the conserved pmp-family genes of Chlamydophila abortus as an efficient tool for the detection of these bacteria in ruminants including also preliminary results on avian strains. In this work, the use of this set of primers was extended to representative strains of the six major avian serovars (serovars A-F) and to field isolates of C. psittaci. For all the studied representative strains, using purified genomic DNA as a template, CpsiA/CpsiB primers allowed, as observed for C. abortus, a minimal 10-fold PCR signal increase compared to the one observed with ompA specific primers. In comparison to primers targeting the 16S-23S rRNA intergenic spacer, similar or increased sensitivity was observed depending on the strain. All the field isolates were amplified with CpsiA/CpsiB primers. On clinical samples, our primers are the best among those tested for detection of C. psittaci by simple conventional PCR. RFLP experiments performed using PCR fragments amplified with the CpsiA/CpsiB primers gave promising results demonstrating that these primers may provide an interesting tool for molecular typing when the bacterium cannot be grown from pathological samples.

  6. A cross-layer design approach on spectrum allocation and resource scheduling in cognitive PMP networks

    Jie CHEN; Min-jian ZHAO; Qiao ZHOU; Shi-ju LI


    We propose the spectrum allocation and resource scheduling algorithms in cognitive point to multipoint (PMP)networks with rapid changes of spectrum opportunities and present a media access control (MAC) protocol based on these algorithms. The objective of spectrum allocation is to make efficient use of the spectrum while maintaining the transceiver synchronization on frequency and time in the network. The objective of resource scheduling is to guarantee the quality of service (QoS)requirements of different kinds of connections and to minimize the total energy consumption in the network as well. By sensing only a small set of possible channels in each slot based on the state transition probability of each channel, our spectrum allocation algorithm achieves high spectrum efficiency in the network. The resource scheduling problem is divided into three sub problems and we derive optimal solutions to these problems by greedy algorithm and convex optimization. The simulation results show that our algorithm can make efficient use of the spectrum and the network resources at a cost of low computational complexity.

  7. Pmp-like proteins Pls1 and Pls2 are secreted into the lumen of the Chlamydia trachomatis inclusion.

    Jorgensen, Ine; Valdivia, Raphael H


    The obligate intracellular pathogen Chlamydia trachomatis secretes effector proteins across the membrane of the pathogen-containing vacuole (inclusion) to modulate host cellular functions. In an immunological screen for secreted chlamydial proteins, we identified CT049 and CT050 as potential inclusion membrane-associated proteins. These acidic, nonglobular proteins are paralogously related to the passenger domain of the polymorphic membrane protein PmpC and, like other Pmp proteins, are highly polymorphic among C. trachomatis ocular and urogenital strains. We generated antibodies to these Pmp-like secreted (Pls) proteins and determined by immunofluorescence microscopy that Pls1 (CT049) and Pls2 (CT050) localized to globular structures within the inclusion lumen and at the inclusion membrane. Fractionation of membranes and cytoplasmic components from infected cells by differential and density gradient centrifugation further indicated that Pls1 and Pls2 associated with membranes distinct from the bulk of bacterial and inclusion membranes. The accumulation of Pls1 and, to a lesser extent, Pls2 in the inclusion lumen was insensitive to the type III secretion inhibitor C1, suggesting that this translocation system is not essential for Pls protein secretion. In contrast, Pls secretion and stability were sensitive to low levels of beta-lactam antibiotics, suggesting that a functional cell wall is required for Pls secretion from the bacterial cell. Finally, we tested the requirement for these proteins in Chlamydia infection by microinjecting anti-Pls1 and anti-Pls2 antibodies into infected cells. Coinjection of anti-Pls1 and -Pls2 antibodies partially inhibited expansion of the inclusion. Because Pls proteins lack classical sec-dependent secretion signals, we propose that Pls proteins are secreted into the inclusion lumen by a novel mechanism to regulate events important for chlamydial replication and inclusion expansion.

  8. Analyses of the differentiation potential of satellite cells from myoD-/-, mdx, and PMP22 C22 mice

    Huxley Clare


    Full Text Available Abstract Background Sporadic and sometimes contradictory studies have indicated changes in satellite cell behaviour associated with the progressive nature of human Duchenne muscular dystrophy (DMD. Satellite cell proliferation and number are reportedly altered in DMD and the mdx mouse model. We recently found that satellite cells in MSVski transgenic mice, a muscle hypertrophy model showing progressive muscle degeneration, display a severe ageing-related differentiation defect in vitro. We tested the hypothesis that similar changes contribute to the gradual loss of muscle function with age in mdx and PMP22 mice, a model of human motor and sensory neuropathy type 1A (HMSN1A. Methods Single extensor digitorum longus muscle fibres were cultured from mdx and PMP22 mice and age- and genetic background-matched controls. Mice at several ages were compared with regard to the differentiation of satellite cells, assayed as the proportion of desmin-expressing cells that accumulated sarcomeric myosin heavy chain. Results Satellite cells of 2 month, 6 month, and 12 month old mdx mice were capable of differentiating to a similar extent to age-matched wild type control animals in an in vitro proliferation/differentiation model. Strikingly, differentiation efficiency in individual 6 month and 12 month old mdx animals varies to a much higher extent than in age-matched controls, younger mdx animals, or PMP22 mice. In contrast, differentiation of myoblasts from all myoD null mice assayed was severely impaired in this assay system. The defect in satellite cell differentiation that occurs in some mdx animals arises from a delay in differentiation that is not overcome by IGF-1 treatment at any phase of cultivation. Conclusion Overall, a defect in satellite cell differentiation above that arising through normal ageing does not occur in mdx or PMP22 mouse models of human disease. Nonetheless, the impaired differentiation of satellite cells from some mdx animals

  9. Trends in Precipitation Extremes over Southeast Asia

    Endo, N.; Matsumoto, J.


    Trends in precipitation extremes were examined using daily precipitation data from Southeast Asian countries during 1950's to 2000's. Number of wet day, defined by a day with daily precipitation exceeding 1 mm, tends to decrease over these countries, while average precipitation intensity of wet day shows an increasing trend. Heavy precipitation indices, which are defined by precipitation amount and percentile, demonstrate that the number of stations with significant upward trend is larger than that with significant downward trend. Heavy precipitation increases in southern Vietnam, northern part of Myanmar, and the Visayas and Luzon Islands in the Philippines, while heavy precipitation decreases in northern Vietnam. Annual maximum number of consecutive dry days decreases in the region where winter monsoon precipitation dominates. Prolongation of the dry season is suggested in Myanmar.

  10. Research of Spectrometric and Exploitation Characteristics of BGO-PMP-165 Scintiblock in Temperature Interval from +25 to -140$^{o}$C

    Ainbund, M R; Gundorin, N A; Matveev, D V; Serov, D G


    Photomultipliers based on microchannel plates are used for fast systems which form time marks of physical setups as well as in special technical areas. It is not uncommon when they substitute traditional dynode system photomultipliers. The possibility of compatible work of the PMP-165 photomultiplier with BGO crystal which were cooled down to temperature necessary for appropriate functioning of a semiconductor Ge detector with taking into account of temperature dependencies of own PMP characteristics is investigated during experiment. Cooling down of the system from room temperature down to v140^{o}C during 8 hours is done. Lower limit of temperature which allows PMP to function properly is registered. Changes of spectrometric characteristics caused by temperature are studied.

  11. All subtypes of the Pmp adhesin family are implicated in chlamydial virulence and show species-specific function.

    Becker, Elisabeth; Hegemann, Johannes H


    The bacterial pathogens Chlamydia trachomatis and C. pneumoniae are obligate intracellular parasites, cause a number of serious diseases, and can infect various cell types in humans. Chlamydial infections are probably initiated by binding of the bacterial outer membrane protein OmcB to host cell glycosaminoglycans (GAGs). Here, we show that all nine members of the polymorphic membrane protein (Pmp) family of C. trachomatis mediate adhesion to human epithelial and endothelial cells. Importantly, exposure of infectious particles to soluble recombinant Pmps blocks subsequent infection, thus implicating an important function of the entire protein family in the infection process. Analogous experiments with pairs of recombinant Pmps or a combination of Pmp and OmcB revealed that all Pmps probably act in an adhesion pathway that is distinct from the OmcB-GAG pathway. Finally, we provide evidence that the Pmps of C. trachomatis and C. pneumoniae exhibit species and tissue specificity. These findings argue for the involvement of C. trachomatis Pmps in the initial phase of infection and suggest that they may interact with a receptor other than the epidermal growth factor receptor recently identified for their counterparts in C. pneumoniae.

  12. An integrated PMP model to assess the development of agro-energy crops and the effect on water requirements

    Michele Donati


    Full Text Available This paper presents an integrated model for the economic and environmental assessment of the use of natural resources when new activities (i.e. biomass crops for energy production are introduced into the farm production plan. The methodology is based on the integration of positive mathematical programming (PMP with the AquaCrop model developed by FAO. PMP represents farmer decision processes and evaluates how farms react to the biomass-sorghum activity option at different price levels. AquaCrop evaluates the relationship between water needs and biomass production and assesses the effect of the land allocation on water requirements at regional level. The integration of these two models assists global policy evaluation at regional level as it makes it possible to identify the economic threshold for biomass crops, the change in land allocation and total water requirement. The model can help policy makers to evaluate the impacts of variations in crop profitability and market innovations on farm profitability, land use and water consumption and the sustainability of the market scenario.

  13. Afferent Visual Pathway Affection in Patients with PMP22 Deletion-Related Hereditary Neuropathy with Liability to Pressure Palsies

    Rinnenthal, Jan Leo; Zimmermann, Hanna; Mikolajczak, Janine; Oberwahrenbrock, Timm; Papazoglou, Sebastian; Pfüller, Caspar F.; Schinzel, Johann; Tackenberg, Björn; Paul, Friedemann; Hahn, Katrin; Bellmann-Strobl, Judith


    Background The PMP22 gene encodes a protein integral to peripheral myelin. Its deletion leads to hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is not expressed in the adult central nervous system, but previous studies suggest a role in CNS myelin development. The objective of this study was to identify potential structural and functional alterations in the afferent visual system in HNPP patients. Methods Twenty HNPP patients and 18 matched healthy controls (HC) were recruited in a cross-sectional study. Participants underwent neurological examination including visual acuity, visual evoked potential (VEP) examination, optical coherence tomography (OCT), and magnetic resonance imaging with calculation of brain atrophy, regarding grey and white matter, and voxel based morphometry (VBM), in addition answered the National Eye Institute’s 39-item Visual Functioning Questionnaire (NEI-VFQ). Thirteen patients and 6 HC were additionally examined with magnetic resonance spectroscopy (MRS). Results All patients had normal visual acuity, but reported reduced peripheral vision in comparison to HC in the NEI-VFQ (p = 0.036). VEP latency was prolonged in patients (P100 = 103.7±5.7 ms) in comparison to healthy subjects (P100 = 99.7±4.2 ms, p = 0.007). In OCT, peripapillary retinal nerve fiber layer thickness RNFL was decreased in the nasal sector (90.0±15.5 vs. 101.8±16.5, p = 0.013), and lower nasal sector RNFL correlated with prolonged VEP latency (Rho = -0.405, p = 0.012). MRS revealed reduced tNAA (731.4±45.4 vs. 814.9±62.1, p = 0.017) and tCr (373.8±22.2 vs. 418.7±31.1, p = 0.002) in the visual cortex in patients vs. HC. Whole brain volume, grey and white matter volume, VBM and metabolites in a MRS sensory cortex control voxel did not differ significantly between patients and HC. Conclusion PMP22 deletion leads to functional, metabolic and macro-structural alterations in the afferent visual system of HNPP patients. Our data suggest a

  14. Comparative study of SOS2 and a novel PMP3-1 gene expression in two sunflower (Helianthus annuus L.) lines differing in salt tolerance.

    Saadia, Mubshara; Jamil, Amer; Ashraf, Muhammad; Akram, Nudrat Aisha


    Gene expression pattern of two important regulatory proteins, salt overly sensitive 2 (SOS2) and plasma membrane protein 3-1 (PMP3-1), involved in ion homeostasis, was analyzed in two salinity-contrasting sunflower (Helianthus annuus L.) lines, Hysun-38 (salt tolerant) and S-278 (moderately salt tolerant). The pattern was studied at selected time intervals (24 h) under 150 mM NaCl treatment. Using reverse transcription PCR, SOS2 gene fragment was obtained from young leaf and root tissues of opposing lines while that for PMP3-1 was obtained only from young root tissues. Both tolerant and moderately tolerant lines showed a gradual increase in SOS2 expression in sunflower root tissues. Leaf tissues showed the gradually increasing pattern of SOS2 expression in tolerant plants as compared to that for moderately tolerant ones that showed a relatively lower level of expression for this gene. We found the highest level of PMP 3-1 expression in the roots of tolerant sunflower line at 6 and 12 h postsalinity treatment. The moderately tolerant line showed higher expression of PMP3-1 at 12 and 24 h after salt treatment. Overall, the expression of genes for both the regulator proteins varied significantly in the two sunflower lines differing in salinity tolerance.

  15. Perceived Parenting Self-Efficacy (PMP S-E) of mothers who are breastfeeding hospitalised preterm neonates.

    Barnes, Christopher R; Adamson-Macedo, Elvidina N


    Breastfeeding is a complex task for many mothers but may be particularly difficult when coping with the birth of a preterm. In the following article the task of breastfeeding a preterm neonate is identified as one facet of the parenting process and the many problems encountered when breastfeeding are highlighted. Research is presented which investigates whether breastfeeding a preterm neonate mediates mothers' Perceived Parenting Self-Efficacy (PMP S-E) whilst in hospital. The findings from this study suggest that not only do mothers who are breastfeeding their preterm neonate have a lower self-efficacy than non-breastfeeding mothers, but they also require further support in all aspects of parenting. The authors discuss these results in terms of self-efficacy theory and suggest that they may have implications for Neonatal Health Psychologists practice particularly with regard to the facilitation of breastfeeding within the neonatal unit.

  16. A dual-frequency online PMP method with phase-shifting parallel to moving direction of measured object

    Peng, Kuang; Cao, Yiping; Wu, Yingchun; Chen, Cheng; Wan, Yingying


    A dual-frequency online phase measurement profilometry (PMP) method with phase-shifting parallel to moving direction of measured object is proposed in this paper. The high-frequency fringe is used for the better modulation patterns in pixel matching and it is not modified by the measured object's surface. Based on the relative positive between the moving measured object and digital light processing (DLP), the high-frequency fringe in each dual-frequency deformed pattern after pixel matching is the same. As a result, the phase can be calculated directly by the improved Stoilov algorithm without filtering out the low-frequency component containing the measured object's height information. As there is no filtering process in phase calculation, the valid information loss can be avoided so that the accuracy of the proposed method can be guaranteed. Simulations and experiments prove the method's feasibility and precision.

  17. Mutation analysis of PMP22 in Slovak patients with Charcot-Marie-Tooth disease and hereditary neuropathy with liability to pressure palsies.

    Resko, Peter; Radvansky, Jan; Odnogova, Zuzana; Baldovic, Marian; Minarik, Gabriel; Polakova, Helena; Palffy, Roland; Kadasi, Ludevit


    Charcot-Marie-Tooth disease (CMT) and related peripheral neuropathies are the most commonly inherited neurological disorders in humans, characterized by clinical and genetic heterogeneity. The most prevalent clinical entities belonging to this group of disorders are CMT type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP). CMT1A and HNPP are predominantly caused by a 1.5 Mb duplication and deletion in the chromosomal region 17p11.2, respectively, and less frequently by other mutations in the peripheral myelin protein 22 (PMP22) gene. Despite being relatively common diseases, they haven't been previously studied in the Slovak population. Therefore, the aim of this study was to identify the spectrum and frequency of PMP22 mutations in the Slovak population by screening 119 families with CMT and 2 families with HNPP for causative mutations in this gene. The copy number determination of PMP22 resulted in the detection of CMT1A duplication in 40 families and the detection of HNPP deletion in 7 families, 6 of which were originally diagnosed as CMT. Consequent mutation screening of families without duplication or deletion using dHPLC and sequencing identified 6 single base changes (3 unpublished to date), from which only c.327C>A (Cys109X) present in one family was provably causative. These results confirm the leading role of PMP22 mutation analysis in the differential diagnosis of CMT and show that the spectrum and frequency of PMP22 mutations in the Slovak population is comparable to that seen in the global population.

  18. Nonrecurrent PMP22-RAI1 contiguous gene deletions arise from replication-based mechanisms and result in Smith-Magenis syndrome with evident peripheral neuropathy.

    Yuan, Bo; Neira, Juanita; Gu, Shen; Harel, Tamar; Liu, Pengfei; Briceño, Ignacio; Elsea, Sarah H; Gómez, Alberto; Potocki, Lorraine; Lupski, James R


    Hereditary neuropathy with liability to pressure palsies (HNPP) and Smith-Magenis syndrome (SMS) are genomic disorders associated with deletion copy number variants involving chromosome 17p12 and 17p11.2, respectively. Nonallelic homologous recombination (NAHR)-mediated recurrent deletions are responsible for the majority of HNPP and SMS cases; the rearrangement products encompass the key dosage-sensitive genes PMP22 and RAI1, respectively, and result in haploinsufficiency for these genes. Less frequently, nonrecurrent genomic rearrangements occur at this locus. Contiguous gene duplications encompassing both PMP22 and RAI1, i.e., PMP22-RAI1 duplications, have been investigated, and replication-based mechanisms rather than NAHR have been proposed for these rearrangements. In the current study, we report molecular and clinical characterizations of six subjects with the reciprocal phenomenon of deletions spanning both genes, i.e., PMP22-RAI1 deletions. Molecular studies utilizing high-resolution array comparative genomic hybridization and breakpoint junction sequencing identified mutational signatures that were suggestive of replication-based mechanisms. Systematic clinical studies revealed features consistent with SMS, including features of intellectual disability, speech and gross motor delays, behavioral problems and ocular abnormalities. Five out of six subjects presented clinical signs and/or objective electrophysiologic studies of peripheral neuropathy. Clinical profiling may improve the clinical management of this unique group of subjects, as the peripheral neuropathy can be more severe or of earlier onset as compared to SMS patients having the common recurrent deletion. Moreover, the current study, in combination with the previous report of PMP22-RAI1 duplications, contributes to the understanding of rare complex phenotypes involving multiple dosage-sensitive genes from a genetic mechanistic standpoint.

  19. Improved Electronic Control for Electrostatic Precipitators

    Johnston, D. F.


    Electrostatic precipitators remove particulate matter from smoke created by burning refuse. Smoke exposed to electrostatic field, and particles become electrically charged and migrate to electrically charged collecting surfaces. New microprocessor-based electronic control maintains precipitator power at maximum particulate-collection level. Control automatically senses changes in smoke composition due to variations in fuel or combustion and adjusts precipitator voltage and current accordingly. Also, sensitive yet stable fault detection provided.

  20. Maximum Autocorrelation Factorial Kriging

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.


    This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from...

  1. Difference between Expressions of PMP22 and MBP in Sural Nerve Biopsy and Its Significance%髓鞘特异蛋白PMP22和MBP在腓肠神经活检标本中表达差异及其意义

    唐璐; 张俊; 孙阿萍; 张燕; 王盛兰; 樊东升; 钟延丰


    目的 探讨周围髓鞘蛋白22(peripheral myelin protein 22,PMP22)、髓鞘碱性蛋白(myelin basic protein,MBP)在周围神经活检标本中的表达差异及其诊断意义.方法 收集35例成人腓肠神经活检标本,进行抗PMP22、MBP免疫组织化学染色,对其灰度值做定量分析,并与相应的光镜和电镜下组织学形态进行比较分析.结果 PMP22和MBP的表达部位并不完全相同;PMP22表达水平与有髓纤维髓鞘的残存数目、完整程度及无髓纤维-Schwann细胞单位的数量、功能状态等多个因素相关;MBP表达水平主要与残存的有髓纤维的数量和髓鞘脱失的程度相关;两者的表达具有一定的相关性,但PMP22更多反映Schwann细胞状态,而MBP反映有髓纤维髓鞘的状态.结论 周围神经活检中PMP22和MBP的检测有助于判断受损髓鞘的神经纤维分布以及Schwann细胞的功能状态,可考虑作为周围神经活检诊断的常规检测.

  2. A formal [3,3]-sigmatropic rearrangement route to quaternary alpha-vinyl amino acids: use of allylic N-PMP trifluoroacetimidates.

    Berkowitz, David B; Wu, Bin; Li, Huijie


    Pd(II)-mediated rearrangement of allylic N-PMP (p-methoxyphenyl) trifluoroacetimidates provides the first formal sigmatropic route to quaternary, alpha-vinylic amino acids, potential suicide substrates for PLP enzymes. The amino acid side chains enter via transition-metal-mediated C-C bond constructions, including (i) Cu(I)-mediated conjugate addition (Ala); (ii) Pd(0)/AsPh3-mediated Stille coupling (allyl-Gly, Phe, DOPA, m-Tyr); and (iii) Pd(0)/Pt-Bu3-mediated Negishi coupling (Leu). In the synthesis of the DOPA decarboxylase inactivator, alpha-vinyl-m-tyrosine, the new N-PMP trifluoroacetimidate rearranges much more efficiently than the corresponding trichloroacetimidate.

  3. Function of the PEX19-binding site of human adrenoleukodystrophy protein as targeting motif in man and yeast. PMP targeting is evolutionarily conserved.

    Halbach, André; Lorenzen, Stephan; Landgraf, Christiane; Volkmer-Engert, Rudolf; Erdmann, Ralf; Rottensteiner, Hanspeter


    We predicted in human peroxisomal membrane proteins (PMPs) the binding sites for PEX19, a key player in the topogenesis of PMPs, by virtue of an algorithm developed for yeast PMPs. The best scoring PEX19-binding site was found in the adrenoleukodystrophy protein (ALDP). The identified site was indeed bound by human PEX19 and was also recognized by the orthologous yeast PEX19 protein. Likewise, both human and yeast PEX19 bound with comparable affinities to the PEX19-binding site of the yeast PMP Pex13p. Interestingly, the identified PEX19-binding site of ALDP coincided with its previously determined targeting motif. We corroborated the requirement of the ALDP PEX19-binding site for peroxisomal targeting in human fibroblasts and showed that the minimal ALDP fragment targets correctly also in yeast, again in a PEX19-binding site-dependent manner. Furthermore, the human PEX19-binding site of ALDP proved interchangeable with that of yeast Pex13p in an in vivo targeting assay. Finally, we showed in vitro that most of the predicted binding sequences of human PMPs represent true binding sites for human PEX19, indicating that human PMPs harbor common PEX19-binding sites that do resemble those of yeast. Our data clearly revealed a role for PEX19-binding sites as PMP-targeting motifs across species, thereby demonstrating the evolutionary conservation of PMP signal sequences from yeast to man.

  4. Darcy permeability of hollow fiber membrane bundles made from Membrana® Polymethylpentene (PMP) fibers used in respiratory assist devices

    Madhani, Shalv. P.; D’Aloiso, Brandon. D.; Frankowski, Brian.; Federspiel, William. J.


    Hollow fiber membranes (HFMs) are used in blood oxygenators for cardiopulmonary bypass or in next generation artificial lungs. Flow analyses of these devices is typically done using computational fluid dynamics (CFD) modeling HFM bundles as porous media, using a Darcy permeability coefficient estimated from the Blake – Kozeny (BK) equation to account for viscous drag from fibers. We recently published how well this approach can predict Darcy permeability for fiber bundles made from polypropylene HFMs, showing the prediction can be significantly improved using an experimentally derived correlation between the BK constant (A) and bundle porosity (ε). In this study, we assessed how well our correlation for A worked for predicting the Darcy permeability of fiber bundles made from Membrana® polymethylpentene (PMP) HFMs, which are increasingly being used clinically. Swatches in the porosity range of 0.4 to 0.8 were assessed in which sheets of fiber were stacked in parallel, perpendicular and angled configurations. Our previously published correlation predicted Darcy within ±8%. A new correlation based on current and past measured permeability was determined: A=497ε-103; using this correlation measured Darcy permeability was within ±6%. This correlation varied from 8% to −3.5% of our prior correlation over the tested porosity range. PMID:26809086

  5. [Comparison on polysaccharide content and PMP-HPLC fingerprints of polysaccharide in stems and leaves of Dendrobium officinale].

    Zhou, Gui-Fen; Pang, Min-Xia; Chen, Su-Hong; Lv, Gui-Yuan; Yan, Mei-Qiu


    In order to provide scientific basics for exploitation and sufficient application of Dendrobium officinale leaves resources, the phenol-sulfuric acid method was applied to determine the polysaccharide content. The monosaccharides were derivated by PMP and the derivatives were identified by HPLC-DAD-ESI-MS(n) and the contents of mannose and glucose were determined simultaneously. Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004A) was employed to generate the mean chromatogram and similarity analysis of the samples was carried out. The results demonstrated that polysaccharide content, monosaccharide compositions and composition ratio had an obvious difference between stems and leaves. The polysaccharide content of stems was higher than that of leaves. Monosaccharide composition in leaf was significantly different from that in stem. The polysaccharide from stems was composed of mannose and glucose, however the polysaccharide of leaves was acid heteropolysaccharide and was mainly composed of five monosaccharides, including mannose, galacturonic acid, glucose, galactose and arabinose. The similarity value of the 14 batches was above 0.9, indicating that similarity of fingerprints among different samples was high. The study can provide evidence for expanding the medicinal parts of D. officinale.

  6. How often precipitation records break?

    Papalexiou, Simon Michael; Oikonomou, Maria; Floutsakou, Athina; Bessas, Nikolaos; Mamassis, Nikos


    How often precipitation records break? Are there any factors that determine the average time needed for the next maximum to occur? In order to investigate these simple questions we use several hundreds of daily precipitation records (more than 100 years long each) and we study the time intervals between each successive maximum precipitation value. We investigate if the record breaking time interval is related (a) to the autocorrelation structure, (b) to probability dry, and (c) to the tail of the marginal distribution. For the last, we first, evaluate which type of tail is better fitted by choosing among three general types of tails corresponding to the distributions Pareto, Lognormal and Weibull; and second, we assess the heaviness of the tail based on the estimated shape parameter. The performance of each tail is evaluated in terms of return period values, i.e., we compare the empirical return periods of precipitation values above a threshold with the predicted ones by each of the three types of fitted tails.

  7. Risk assessment of precipitation extremes in northern Xinjiang, China

    Yang, Jun; Pei, Ying; Zhang, Yanwei; Ge, Quansheng


    This study was conducted using daily precipitation records gathered at 37 meteorological stations in northern Xinjiang, China, from 1961 to 2010. We used the extreme value theory model, generalized extreme value (GEV) and generalized Pareto distribution (GPD), statistical distribution function to fit outputs of precipitation extremes with different return periods to estimate risks of precipitation extremes and diagnose aridity-humidity environmental variation and corresponding spatial patterns in northern Xinjiang. Spatiotemporal patterns of daily maximum precipitation showed that aridity-humidity conditions of northern Xinjiang could be well represented by the return periods of the precipitation data. Indices of daily maximum precipitation were effective in the prediction of floods in the study area. By analyzing future projections of daily maximum precipitation (2, 5, 10, 30, 50, and 100 years), we conclude that the flood risk will gradually increase in northern Xinjiang. GEV extreme value modeling yielded the best results, proving to be extremely valuable. Through example analysis for extreme precipitation models, the GEV statistical model was superior in terms of favorable analog extreme precipitation. The GPD model calculation results reflect annual precipitation. For most of the estimated sites' 2 and 5-year T for precipitation levels, GPD results were slightly greater than GEV results. The study found that extreme precipitation reaching a certain limit value level will cause a flood disaster. Therefore, predicting future extreme precipitation may aid warnings of flood disaster. A suitable policy concerning effective water resource management is thus urgently required.


    Barrick, J.G.; Manion, J.P.


    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  9. Maximum Autocorrelation Factorial Kriging

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Pedersen, John L.; Steenfelt, Agnete


    This paper describes maximum autocorrelation factor (MAF) analysis, maximum autocorrelation factorial kriging, and its application to irregularly sampled stream sediment geochemical data from South Greenland. Kriged MAF images are compared with kriged images of varimax rotated factors from an ordinary non-spatial factor analysis, and they are interpreted in a geological context. It is demonstrated that MAF analysis contrary to ordinary non-spatial factor analysis gives an objective discrimina...

  10. Inhibition of acetylcholinesterase in CSF versus brain assessed by 11C-PMP PET in AD patients treated with galantamine.

    Darreh-Shori, T; Kadir, A; Almkvist, O; Grut, M; Wall, A; Blomquist, G; Eriksson, B; Långström, B; Nordberg, A


    The relationship between acetylcholinesterase (AChE) activity in the CSF and brain of patients with Alzheimer's disease (AD) was investigated in 18 mild AD patients following galantamine treatment. The first 3 months of the study had a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24 mg/day) and six patients placebo. This was followed by 9 months galantamine treatment in all patients. Activities and protein levels of both the "read-through" AChE (AChE-R) and the synaptic (AChE-S) variants in CSF were assessed in parallel together with the regional brain AChE activity by (11)C-PMP and PET. The AChE-S inhibition was 30-36% in CSF, which correlated well with the in vivo AChE inhibition in the brain. No significant AChE inhibition was observed in the placebo group. The increased level of the AChE-R protein was 16% higher than that of AChE-S. Both the AChE inhibition and the increased level of AChE-R protein positively correlated with the patient's performance in cognitive tests associated with visuospatial ability and attention. In conclusion, AChE levels in CSF closely mirror in vivo brain AChE levels prior to and after treatment with the cholinesterase inhibitors. A positive cognitive response seems to dependent on the AChE inhibition level, which is balanced by an increased protein level of the AChE-R variant in the patients.

  11. Maximum likely scale estimation

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo


    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  12. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert


    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  13. Modelled Precipitation Over Greenland

    National Aeronautics and Space Administration — This data set includes the annual total precipitation from 1985 to 1999 and monthly total precipitation from January 1985 to December 1999. The data is derived from...

  14. Nucleotide sequences of two fimbrial major subunit genes, pmpA and ucaA, from canine-uropathogenic Proteus mirabilis strains.

    Bijlsma, I G; van Dijk, L; Kusters, J G; Gaastra, W


    Proteus mirabilis strains were isolated from dogs with urinary tract infection (UTI) and fimbriae were prepared from two strains. The N-terminal amino acid sequences of the major fimbrial subunits were determined and both sequences appeared identical to the N-terminal amino acid sequence of a urinary cell adhesin (UCA) (Wray, S. K., Hull, S. I., Cook, R. G., Barrish, J. & Hull, R. A., 1986, Infect Immun 54, 43-49). The genes of two different major fimbrial subunits were cloned using oligonucleotide probes that were designed on the basis of the N-terminal UCA sequence. Nucleotide sequencing revealed the complete ucaA gene of 540 bp (from strain IVB247) encoding a polypeptide of 180 amino acids, including a 22 amino acid signal sequence peptide, and the pmpA (P. mirabilis P-like pili) gene of 549 bp (from strain IVB219) encoding a polypeptide of 183 amino acids, including a 23 amino acid signal sequence. Hybridization experiments gave clear indications of the presence of both kinds of fimbriae in many UTI-related canine P. mirabilis isolates. However, the presence of these fimbriae could not be demonstrated in P. vulgaris or other Proteus-related species. Database analysis of amino acid sequences of major subunit proteins revealed that the UcaA protein shares about 56% amino acid identity with the F17A and F111A major fimbrial subunits from bovine enterotoxigenic Escherichia coli. In turn, the PmpA protein more closely resembled the pyelonephritis-associated pili (Pap)-like major subunit protein from UTI-related E. coli. The evolutionary relationship of UcaA, PmpA and various other fimbrial subunit proteins is presented in a phylogenetic tree.

  15. Crystal structures of the PLP- and PMP-bound forms of BtrR, a dual functional aminotransferase involved in butirosin biosynthesis.

    Popovic, Bojana; Tang, Xiao; Chirgadze, Dimitri Y; Huang, Fanglu; Blundell, Tom L; Spencer, Jonathan B


    The aminotransferase (BtrR), which is involved in the biosynthesis of butirosin, a 2-deoxystreptamine (2-DOS)-containing aminoglycoside antibiotic produced by Bacillus circulans, catalyses the pyridoxal phosphate (PLP)-dependent transamination reaction both of 2-deoxy-scyllo-inosose to 2-deoxy-scyllo-inosamine and of amino-dideoxy-scyllo-inosose to 2-DOS. The high-resolution crystal structures of the PLP- and PMP-bound forms of BtrR aminotransferase from B. circulans were solved at resolutions of 2.1 A and 1.7 A with R(factor)/R(free) values of 17.4/20.6 and 19.9/21.9, respectively. BtrR has a fold characteristic of the aspartate aminotransferase family, and sequence and structure analysis categorises it as a member of SMAT (secondary metabolite aminotransferases) subfamily. It exists as a homodimer with two active sites per dimer. The active site of the BtrR protomer is located in a cleft between an alpha helical N-terminus, a central alphabetaalpha sandwich domain and an alphabeta C-terminal domain. The structures of the PLP- and PMP-bound enzymes are very similar; however BtrR-PMP lacks the covalent bond to Lys192. Furthermore, the two forms differ in the side-chain conformations of Trp92, Asp163, and Tyr342 that are likely to be important in substrate selectivity and substrate binding. This is the first three-dimensional structure of an enzyme from the butirosin biosynthesis gene cluster.

  16. Evaluation of extreme precipitation estimates from TRMM in Angola

    Pombo, Sandra; de Oliveira, Rodrigo Proença


    In situ ground observation measurement of precipitation is difficult in vast and sparsely populated areas, with poor road networks. This paper examines the use of remote sensors installed in satellites and evaluates the accuracy of TRMM 3B42 annual maximum daily precipitation estimates in Angola, in West Africa, a region where ground monitoring networks are generally. TRMM 3B42 estimates of annual maximum daily precipitation are compared to ground observation data from 159 locations. As a direct comparison between the two datasets for a common specific period and sites is not possible, a statistical approach was adopted to test the hypothesis that the TRMM 3B42 estimates and the ground monitoring records exhibit similar statistical characteristics. The study shows that the annual maximum daily precipitation estimates obtained from TRMM 3B42 slightly underestimate the quantiles obtained from the in situ observations. The use of remote sensing products to estimate extreme precipitation values for engineering design purposes is however promising. A maximum daily precipitation map for a return period of 20 years was computed and in the future, as the length of the remote sensing data series increases, it may be possible to estimate annual maximum daily precipitation estimates exclusively from these datasets for larger return periods. The paper also presents maps of the PdT/PDT ratios, where PdT is the annual maximum precipitation for a duration d and a return period of T years, and PDT is the annual maximum daily precipitation for a return period of T years. In conjunction with these maps it is possible to estimate the maximum precipitation for durations between 3 h and 5 days.

  17. Maximum information photoelectron metrology

    Hockett, P; Wollenhaupt, M; Baumert, T


    Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are a high-information, coherent observable. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, 3D, photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyse the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et. al., Phys. Rev. Lett. 112, 223001 (2014)] over the main spectral features, but also indicate unexpected symmetry-breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum information measurements of th...

  18. Maximum Likelihood Associative Memories

    Gripon, Vincent; Rabbat, Michael


    Associative memories are structures that store data in such a way that it can later be retrieved given only a part of its content -- a sort-of error/erasure-resilience property. They are used in applications ranging from caches and memory management in CPUs to database engines. In this work we study associative memories built on the maximum likelihood principle. We derive minimum residual error rates when the data stored comes from a uniform binary source. Second, we determine the minimum amo...

  19. Maximum likely scale estimation

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo


    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and....../or having different derivative orders. Although the principle is applicable to a wide variety of image models, the main focus here is on the Brownian model and its use for scale selection in natural images. Furthermore, in the examples provided, the simplifying assumption is made that the behavior...... of the measurements is completely characterized by all moments up to second order....

  20. Study of orotidine 5'-monophosphate decarboxylase in complex with the top three OMP, BMP, and PMP ligands by molecular dynamics simulation.

    Jamshidi, Shirin; Jalili, Seifollah; Rafii-Tabar, Hashem


    Catalytic mechanism of orotidine 5'-monophosphate decarboxylase (OMPDC), one of the nature most proficient enzymes which provides large rate enhancement, has not been fully understood yet. A series of 30 ns molecular dynamics (MD) simulations were run on X-ray structure of the OMPDC from Saccharomyces cerevisiae in its free form as well as in complex with different ligands, namely 1-(5'-phospho-D-ribofuranosyl) barbituric acid (BMP), orotidine 5'-monophosphate (OMP), and 6-phosphonouridine 5'-monophosphate (PMP). The importance of this biological system is justified both by its high rate enhancement and its potential use as a target in chemotherapy. This work focuses on comparing two physicochemical states of the enzyme (protonated and deprotonated Asp91) and three ligands (substrate OMP, inhibitor, and transition state analog BMP and substrate analog PMP). Detailed analysis of the active site geometry and its interactions is properly put in context by extensive comparison with relevant experimental works. Our overall results show that in terms of hydrogen bond occupancy, electrostatic interactions, dihedral angles, active site configuration, and movement of loops, notable differences among different complexes are observed. Comparison of the results obtained from these simulations provides some detailed structural data for the complexes, the enzyme, and the ligands, as well as useful insights into the inhibition mechanism of the OMPDC enzyme. Furthermore, these simulations are applied to clarify the ambiguous mechanism of the OMPDC enzyme, and imply that the substrate destabilization and transition state stabilization contribute to the mechanism of action of the most proficient enzyme, OMPDC.

  1. Historical changes and future projection of extreme precipitation in China

    Yuan, Zhe; Yang, Zhiyong; Yan, Denghua; Yin, Jun


    Investigating changes in extreme precipitation, i.e., maximum precipitation for multiday events, is critical for flood management and risk assessment. Based on the observed daily precipitation from China's Ground Precipitation 0.5° × 0.5° Gridded Dataset (V2.0) and simulated daily precipitation from five general circulation models (GCMs) provided by The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), extreme precipitation indices corresponding to annual maximum 1-, 3-, 15-, and 30-day precipitation across China from 1961 to 2011 and 2011 to 2050 were calculated. Relative changes in the 10-, 20-, and 50-year return period estimates, using 1-, 3-, 15-, and 30-day precipitation, are discussed to represent changes in extreme precipitation in the future. Results show that (1) the spatial distribution of annual maximum precipitation for 1, 3, 15, and 30 days is similar with that of annual precipitation. An increasing trend from the northwest to the southeast was found, with the highest values shown to be in the plain region adjacent to the mountains and coastal area; (2) Comparing the observed and simulated data, it could be seen that climate models have good simulation of 10-, 20-, and 50-year return period events. Absolute relative error is less than 30 % in 80 % in the study area; (3) Extreme precipitation in the future has an increasing trend in China. In the south, extreme precipitation associated with short duration as well as the 50-year return period will likely increase to a comparatively large degree in the future. In the north, extreme precipitation associated with long duration and the 10-year return period will likely see a large increase in the future.

  2. Maximum Entropy Fundamentals

    F. Topsøe


    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  3. Regularized maximum correntropy machine

    Wang, Jim Jing-Yan


    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  4. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    Gherardi, Laureano A; Sala, Osvaldo E


    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.

  5. Precipitates in electrical steels

    Jenkins, Keith [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)], E-mail:; Lindenmo, Magnus [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)


    Precipitates heavily influence the magnetic properties of electrical steels, either as a key controlled requirement as part of the manufacturing process or as an unwanted harmful residual in the final product. In this current work copper-manganese sulphides precipitates are the primary inhibitor species in the conventional grain-oriented (CGO) steels examined and grain boundary pinning is effective at a mean precipitate size of 30-70 nm. The growth of CuMnS has been studied and the results show that a precipitate size above {approx}100 nm allows the onset of secondary recrystallisation in the heating conditions applied. The effect of precipitates on the magnetic properties of both grain-oriented and non-oriented steels in their final product form is then examined. Examples of grain-oriented material still containing large numbers of precipitates clearly show the detrimental effects with increases in total power loss of 40% or more. Loss deterioration by about 20% is also seen in samples of high silicon non-oriented material in which titanium carbo-nitride precipitates have been observed. In this case the precipitates are believed to have formed during cooling after final annealing. Finally a grain-oriented steel with a large number of very small precipitates, which do not seem to have any harmful effect on the magnetic properties, is demonstrated.

  6. Impact of Precipitation Fluctuation on Desert-Grassland ANPP

    Liangxu Liu


    Full Text Available Precipitation change has significantly influenced annual net primary productivity (ANPP at either annual or seasonal scales in desert steppes in arid and semi-arid regions. In order to reveal the process of precipitation driving ANPP at different time scales, responses of different ANPP levels to the inter-annual and intra-annual precipitation fluctuations were analyzed. ANPP was reversed by building a ground reflectance spectrum model, from 2000 to 2015, using the normalized differential vegetation index of the Moderate-Resolution Imaging Spectroradiometer (MODIS-NDVI data at 250 m × 250 m spatial resolution. Since the description of the differently expressing forms of precipitation are not sufficient in former studies in order to overcome the deficiency of former studies, in this study, intra-annual precipitation fluctuations were analyzed not only with precipitation of May–August, June–August, July–August, and August, respectively, which have direct influence on vegetation productivity within the year, but quantitative description, vector precipitation (R, concentration ratio (Cd, and concentration period (D, were also used to describe the overall characteristics of intra-annual precipitation fluctuations. The concentration ratio and the maximum precipitation period of the intra-annual precipitation were represented by using monthly precipitation. The results showed that: (1 in the period from 1971 to 2015, the maximum annual precipitation is 3.76 times that of the minimum in the Urat desert steppe; (2 vector precipitation is more significantly related to ANPP (r = 0.7724, p = 0.000 compared to meteorological annual precipitation and real annual precipitation influence; and (3 annual precipitation is almost concentrated in 5–8 months and monthly precipitation accumulation has significantly effected ANPP, especially in the period of June–August, since the vegetation composition in the study area was mainly sub-shrubs and perennial

  7. Equalized near maximum likelihood detector


    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  8. Generalized Maximum Entropy

    Cheeseman, Peter; Stutz, John


    A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].

  9. Changes in the annual range of precipitation under global warming

    Chou, C.; Lan, C.


    The annual range of precipitation, which is the difference between maximum and minimum precipitation within a year, is examined in climate model simulations under global warming. For global averages, the annual range of precipitation tends to increase as the globe warms. On a regional basis, this enhancement is found over most areas of the world, except for the bands along 30°S and 30N°, respectively. The enhancement in the annual range of precipitation is mainly associated with larger upward trends of maximum precipitation and smaller upward trends or downward trends of minimum precipitation. Based on the moisture budget analysis, the dominant mechanism is vertical moisture advection, both on a global average and on a regional scale. The vertical moisture advection, moisture convergence induced by vertical motion, includes the thermodynamic component, which is associated with increased water vapor, and the dynamic component, which is associated with changes in circulation. Generally, the thermodynamic component enhances the annual range of precipitation, while the dynamic component tends to reduce it. Evaporation has a positive contribution to both maximum and minimum precipitation, but very little to the annual range of precipitation. Even though evaporation and horizontal moisture advection are small for a global average, they could be important on a regional basis.

  10. Global Precipitation Measurement Poster

    Azarbarzin, Art


    This poster presents an overview of the Global Precipitation Measurement (GPM) constellation of satellites which are designed to measure the Earth's precipitation. It includes the schedule of launches for the various satellites in the constellation, and the coverage of the constellation, It also reviews the mission capabilities, and the mission science objectives.

  11. Physical and genetic mapping of the CMT4A locus and exclusion of PMP-2 as the defect in CMT4A

    Othmane, K.B.; Loeb, D.; Roses, A.D.; Pericak-Vance, M.A.; Vance, J.M. [Duke Univ. Medical Center, Durham, NC (United States)] [and others


    We have previously localized one form of the autosomal recessive Charcot-Marie-Tooth disease type 4 (CMT4A) to a 5-cM region of chromosome 8q13-q21. We now report the formation of a 7-Bp YAC contig spanning the region. This contig was used to map nine additional microsatellites and six STSs to this region, and subsequent haplotype analysis has narrowed the CMT4A flanking interval to less than 1 cM. In addition, using SSCP and our physical map, we have demonstrated that the myelin protein PMP-2, mapped by FISH to this region, is not the defect in CMT4A. 27 refs., 3 figs., 1 tab.

  12. Comparison of polysaccharides of Haliotis discus hannai and Volutharpa ampullacea perryi by PMP-HPLC-MS(n) analysis upon acid hydrolysis.

    Wang, Hongxu; Zhao, Jun; Li, Dongmei; Wen, Chengrong; Liu, Haiman; Song, Shuang; Zhu, Beiwei


    Haliotis discus hannai Ino (Haliotis) is a highly valued marine shellfish, and it is sometimes replaced by another cheaper Gastropoda mollusk, Volutharpa ampullacea perryi (Volutharpa). Polysaccharides from pleopods, viscera and gonads of these two gastropods were compared by analyzing the mono- and di-saccharides in their acid hydrolysates using high performance liquid chromatography-mass spectrometry (HPLC-MS(n)) after 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization. Disaccharide analysis revealed the distribution of uronic acid-containing polysaccharides (UACPs) in the biological samples. GlcA-(1 → 2)-Man, GlcA-(1 → 3)-GalN, and another disaccharide consisting of a hexuronic acid linked to a hexose were found in the hydrolysates, which indicated the existence of AGSP (abalone gonad sulfated polysaccharide) with the backbone composed of → 2)-α-Man(1 → 4)-β-GlcA(1 → repeating unit, AAP (abalone glycosaminoglycan-like polysaccharide) with the backbone of → 3)-GalNAc-(1 → 2)-GlcA-(1 → 3)-GalNAc-(1 → 4)-GlcA-(1 → repeating unit, and unidentified DS1P containing a hexuronic acid linked to a hexose unit, respectively. As shown by extracted ion chromatograms (XICs), AAP was the only UACP found in pleopods of the two gastropods; gonads and viscera of Haliotis contained DS1P and AGSP, while those of Volutharpa contained DS1P, AGSP as well as AAP. Monosaccharides in the acid hydrolysates were demonstrated in XICs by extracting their corresponding PMP derivative quasi-molecular ions one by one, and the results indicated the similar conclusion to the disaccharide analysis. Therefore, it could be concluded that polysaccharides from pleopods of the two gastropods are very similar, while those from their viscera and gonads differ greatly.

  13. Polymorphic membrane protein I of Chlamydia trachomatis:prokaryotic expression, purification, antibody preparation and identification%沙眼衣原体多形外膜蛋白PmpI的原核表达、纯化、抗体制备及鉴定

    郭睿; 刘原君; 郑蕾; 王生; 魏世娟; 刘全忠


    Objective To clone and express the polymorphic membrane protein I(PmpI)gene of Chlamydia trachomatis(Ct), and to assess the immunogenicity and biological characteristics of PmpI. Methods A bioinformatic software was used to analyze the sequence of the PmpI gene of Ct, and to predict B cell epitopes in PmpI. With Ct serovar D DNA as the template, PCR was performed to amplify the N⁃terminal region(from position 90 to 1464)of the PmpI gene, which was cloned into a prokaryotic expression vector pET28a to express the recombinant protein PmpI. A Ni⁃ion affinity chromatography column was used to purify the recombinant protein, which was used to immunize New Zealand rabbits for preparation of polyclonal antibodies. Western blot analysis was conducted to evaluate the immunogenicity of this protein. Results A comprehensive analysis was carried out on the secondary structure, flexible regions, hydrophilicity plot, antigenic index and surface probability plot of the protein, which suggested that PmpI had 8 dominant B⁃cell epitopes. The product of PCR targeting the PmpI gene of Ct serovar D showed a total length of 1 375 bp. The recombinant prokaryotic expression vector pET28a⁃PmpI was successfully constructed. A recombi⁃nant protein with a relative molecular mass of approximately 50 000 was successfully expressed after isopropylβ⁃d⁃1⁃thiogalactopyranoside (IPTG) induction, and purified by affinity chromatography. Polyclonal antibodies against the recombinant protein were successfully prepared. Conclusion The N⁃PmpI protein of Ct serovar D is cloned and expressed successfully, laying a foundation for further studies on its biological functions.%目的:克隆、表达沙眼衣原体多形外膜蛋白I(PmpI)基因,并进行免疫原性鉴定,分析其生物学特征。方法用生物信息软件分析沙眼衣原体多形外膜蛋白PmpI的基因序列并预测PmpI蛋白的B细胞抗原表位。以D型沙眼衣原体DNA为模板,PCR扩增Pmp

  14. Storage Gage Precipitation Observations

    National Oceanic and Atmospheric Administration, Department of Commerce — A storage gage is a precipitation gage that requires reading and maintenance only monthly or seasonal intervals. This library includes reports from such gages,...

  15. WPA Precipitation Tabulations

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly precipitation data tabulated under the Work Projects Administration (WPA), a New Deal program created to reduce unemployment during the Great Depression....

  16. Chemisorption And Precipitation Reactions

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  17. [A new precipitation distribution hydrological model and its application].

    Zhang, Shengtang; Kang, Shaozhong; Liu, Yin


    In distribution hydrological models, precipitation is the key input data for analyzing and computing hydrological processes. Finding a way to produce distribution precipitation data is a hotspot in hydrological research. This paper presented the hypothesis that the distribution of precipitation on the earth surface is the result of the effects of atmosphere system and terrain. Moreover, the spatial distribution of natural precipitation is a group of concentric ovals on the flat earth surface, and has a definite centre with maximum precipitation not affected by terrain. Supporting by the hypothesis, this paper established a new precipitation distribution hydrological model which could simulate the spatial distribution of precipitation, and modified the terrain effect on precipitation through Newton interpolation. The position of the precipitation centre and its precipitation amount were simulated in first time, and thus, the model could have a practical value in basin storm analysis and real-time runoff forecasting. The model was tested by the precipitation data of the Xichuan river basin in the Loess Plateau, which indicated that the model had a high precision.

  18. Recent and future extreme precipitation over Ukraine

    Vyshkvarkova, Olena; Voskresenskaya, Elena


    The aim of study is to analyze the parameters of precipitation extremes and inequality over Ukraine in recent climate epoch and their possible changes in the future. Data of observations from 28 hydrometeorological stations over Ukraine and output of GFDL-CM3 model (CMIP5) for XXI century were used in the study. The methods of concentration index (J. Martin-Vide, 2004) for the study of precipitation inequality while the extreme precipitation indices recommended by the ETCCDI - for the frequency of events. Results. Precipitation inequality on the annual and seasonal scales was studied using estimated CI series for 1951-2005. It was found that annual CI ranges vary from 0.58 to 0.64. They increase southward from the north-west (forest zone) and the north-east (forest steppe zone) of Ukraine. CI maxima are located in the coastal regions of the Black Sea and the Sea of Azov. Annual CI spatial distribution indicates that the contribution of extreme precipitation into annual totals is most significant at the boundary zone between steppe and marine regions. At the same time precipitation pattern at the foothill of Carpathian Mountains is more homogenous. The CI minima (0.54) are typical for the winter season in foothill of Ukrainian Carpathians. The CI maxima reach 0.71 in spring at the steppe zone closed to the Black Sea coast. It should be noted that the greatest ranges of CI maximum and CI minimum deviation are typical for spring. It is associated with patterns of cyclone trajectories in that season. The most territory is characterized by tendency to decrease the contribution of extreme precipitation into the total amount (CI linear trends are predominantly negative in all seasons). Decadal and interdecadal variability of precipitation inequality associated with global processes in ocean-atmosphere system are also studied. It was shown that precipitation inequality over Ukraine on 10 - 15 % stronger in negative phase of Pacific Decadal Oscillation and in positive phase

  19. as the Strengthening Precipitates

    Lu, Qi; Xu, Wei; van der Zwaag, Sybrand


    Generally, Laves phase and M23C6 are regarded as undesirable phases in creep-resistant steels due to their very high-coarsening rates and the resulting depletion of beneficial alloying elements from the matrix. In this study, a computational alloy design approach is presented to develop martensitic steels strengthened by Laves phase and/or M23C6, for which the coarsening rates are tailored such that they are at least one order of magnitude lower than those in existing alloys. Their volume fractions are optimized by tuning the chemical composition in parallel. The composition domain covering 10 alloying elements at realistic levels is searched by a genetic algorithm to explore the full potential of simultaneous maximization of the volume fraction and minimization of the precipitates coarsening rate. The calculations show that Co and W can drastically reduce the coarsening rate of Laves and M23C6 and yield high-volume fractions of precipitates. Mo on the other hand was shown to have a minimal effect on coarsening. The strengthening effects of Laves phase and M23C6 in the newly designed alloys are compared to existing counterparts, showing substantially higher precipitation-strengthening contributions especially after a long service time. New alloys were designed in which both Laves phase and M23C6 precipitates act as strengthening precipitates. Successfully combining MX and M23C6 was found to be impossible.

  20. Precipitating factors of asthma.

    Lee, T H


    Asthma is characterised by bronchial hyperresponsiveness. This feature of the asthmatic diathesis predisposes patients to wheezing in response to a number of different factors. These precipitating factors include specific allergen acting via sensitised mediator cells through an IgE-dependent mechanism. There are irritants which may work through a non-specific manner, or stimuli such as exercise and hyperventilation, which probably also act through mediator release via a non-IgE-dependent manner. The mechanism whereby physical stimuli such as exercise induce bronchoconstriction is of interest, because it increases the context in which the mast cell may participate in acute asthmatic bronchoconstriction. Respiratory infections also commonly provoke asthma, especially in infants and may, indeed, precipitate the asthmatic state itself. Finally, drugs can often trigger asthma attacks and the mechanisms of asthma precipitated by non-steroidal anti-inflammatory drugs such as aspirin have been the subject of recent research.

  1. Precipitation-Regulated Feedback

    Voit, Mark


    Star formation in the central galaxies of galaxy clusters appears to be fueled by precipitation of cold clouds out of hot circumgalactic gas via thermal instability. I will present both observational and theoretical support for the precipitation mode in large galaxies and discuss how it can be implemented in cosmological simulations of galaxy evolution. Galaxy cluster cores are unique laboratories for studying the astrophysics of thermal instability and may be teaching us valuable lessons about how feedback works in galaxies spanning the entire mass spectrum.

  2. Reproducibility of summertime diurnal precipitation over northern Eurasia simulated by CMIP5 climate models

    Hirota, N.; Takayabu, Y. N.


    Reproducibility of diurnal precipitation over northern Eurasia simulated by CMIP5 climate models in their historical runs were evaluated, in comparison with station data (NCDC-9813) and satellite data (GSMaP-V5). We first calculated diurnal cycles by averaging precipitation at each local solar time (LST) in June-July-August during 1981-2000 over the continent of northern Eurasia (0-180E, 45-90N). Then we examined occurrence time of maximum precipitation and a contribution of diurnally varying precipitation to the total precipitation.The contribution of diurnal precipitation was about 21% in both NCDC-9813 and GSMaP-V5. The maximum precipitation occurred at 18LST in NCDC-9813 but 16LST in GSMaP-V5, indicating some uncertainties even in the observational datasets. The diurnal contribution of the CMIP5 models varied largely from 11% to 62%, and their timing of the precipitation maximum ranged from 11LST to 20LST. Interestingly, the contribution and the timing had strong negative correlation of -0.65. The models with larger diurnal precipitation showed precipitation maximum earlier around noon. Next, we compared sensitivity of precipitation to surface temperature and tropospheric humidity between 5 models with large diurnal precipitation (LDMs) and 5 models with small diurnal precipitation (SDMs). Precipitation in LDMs showed high sensitivity to surface temperature, indicating its close relationship with local instability. On the other hand, synoptic disturbances were more active in SDMs with a dominant role of the large scale condensation, and precipitation in SDMs was more related with tropospheric moisture. Therefore, the relative importance of the local instability and the synoptic disturbances was suggested to be an important factor in determining the contribution and timing of the diurnal precipitation. Acknowledgment: This study is supported by Green Network of Excellence (GRENE) Program by the Ministry of Education, Culture, Sports, Science and Technology

  3. Precipitation Reconstruction (PREC)

    National Oceanic and Atmospheric Administration, Department of Commerce — The PREC data set is an analysis of monthly precipitation constructed on a 2.5(o)lat/lon grid over the global for the period from 1948 to the present. The land...

  4. Reaction systems with precipitation

    Marek Rogalski


    Full Text Available This article proposes expanding Reaction Systems of Ehrenfeucht and Rozenberg by incorporating precipitation reactions into it. This improves the computing power of Reaction Systems by allowing us to implement a stack. This addition enables us to implement a Deterministic Pushdown Automaton.

  5. 基于PMP模式的IEEE 802.16 系统中Ranging问题%Ranging problem in IEEE 802.16 system based on PMP mode

    关艳峰; 胡爱群; 王兴建


    研究了IEEE 802.16在PMP(点到多点)模式下的Ranging过程中竞争冲突问题.运用生灭过程分析了在确定SS数目的情况下需要Ranging的SS数量模型,并计算出了需要Ranging的SS数量的稳态解.根据随机过程理论提出了SS在Ranging过程中单步竞争转移模型,在此基础上以单位Ranging带宽下SS的 Ranging竞争成功率最大为原则推导出了最优的Ranging带宽.最后,分别在非最优带宽、Sungmin给出的带宽和最优带宽下对Ranging过程进行仿真,结果表明,最优Ranging带宽下比其他2种带宽下的Ranging成功率提高20%,而Ranging的竞争次数和总的Ranging时延分别降低25%和20%.

  6. Structural investigation of a uronic acid-containing polysaccharide from abalone by graded acid hydrolysis followed by PMP-HPLC-MSn and NMR analysis.

    Wang, Hong-xu; Zhao, Jun; Li, Dong-mei; Song, Shuang; Song, Liang; Fu, Ying-huan; Zhang, Li-peng


    A new strategy was applied to elucidate the structure of a polysaccharide from abalone gonad (AGSP). It was hydrolyzed by 0.05 M, 0.2 M, 0.5 M, and 2.0 M TFA at 100 °C for 1 h, sequentially. Every hydrolysate was ultrafiltrated (3000 Da) to collect oligo- and monosaccharides, and the final retentate was further hydrolyzed with 2.0 M TFA at 110 °C and 121 °C for 2 h, respectively. 1-Phenyl-3-methyl-5-pyrazolone (PMP) derivatization followed by HPLC-MSn analysis was applied to detect the sugar residues in these hydrolysates, which allowed proposing their location in the polysaccharide structure. The retentate after 0.5 M TFA hydrolysis was confirmed as the polysaccharide backbone, and it was further analyzed by 1D and 2D NMR spectroscopy. Thus, the structural elucidation of AGSP was accomplished, and it has a backbone of →4)-β-GlcA(1→2)-α-Man(1→ repeating unit with Fuc, Xyl and Gal in the branch. The analytical strategy demonstrated was useful to characterize the structure of polysaccharides.

  7. Clinical, electrophysiological and magnetic resonance findings in a family with hereditary neuropathy with liability to pressure palsies caused by a novel PMP22 mutation.

    Yurrebaso, Izaskun; Casado, Oscar L; Barcena, Joseba; Perez de Nanclares, Guiomar; Aguirre, Urko


    Hereditary neuropathy with liability to pressure palsies (HNPP) is a disorder mainly caused by a 1.5-Mb deletion at 17p11.2-12 (and in some rare cases by point mutations) and clinically associated with recurrent painless palsies. Here, we performed electrophysiological (motor, sensory and terminal latency index), MRI and genetic studies in a family referred for ulnar neuropathy with pain. Surprisingly, we found typical neurophysiological features of HNPP (prolongation of distal motor latencies and diffuse SNCV slowing with significant slowing of motor nerve conduction velocities). Besides, the proband presented conduction block in left ulnar, left median and both peroneal nerves. MRI findings were consistent with an underlying neuropathy. Molecular studies identified a novel frameshift mutation in PMP22 confirming the diagnosis of HNPP. Our data suggest that neurophysiological studies are essential to characterize underdiagnosed HNPP patients referred for peripheral neuropathy. Our experience shows that MRI could be a complementary tool for the diagnosis of these patients. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Probability Distribution and Projected Trends of Daily Precipitation in China

    CAO; Li-Ge; ZHONG; Jun; SU; Bu-Da; ZHAI; Jian-Qing; Macro; GEMMER


    Based on observed daily precipitation data of 540 stations and 3,839 gridded data from the high-resolution regional climate model COSMO-Climate Limited-area Modeling(CCLM)for 1961–2000,the simulation ability of CCLM on daily precipitation in China is examined,and the variation of daily precipitation distribution pattern is revealed.By applying the probability distribution and extreme value theory to the projected daily precipitation(2011–2050)under SRES A1B scenario with CCLM,trends of daily precipitation series and daily precipitation extremes are analyzed.Results show that except for the western Qinghai-Tibetan Plateau and South China,distribution patterns of the kurtosis and skewness calculated from the simulated and observed series are consistent with each other;their spatial correlation coefcients are above 0.75.The CCLM can well capture the distribution characteristics of daily precipitation over China.It is projected that in some parts of the Jianghuai region,central-eastern Northeast China and Inner Mongolia,the kurtosis and skewness will increase significantly,and precipitation extremes will increase during 2011–2050.The projected increase of maximum daily rainfall and longest non-precipitation period during flood season in the aforementioned regions,also show increasing trends of droughts and floods in the next 40 years.

  9. OECD Maximum Residue Limit Calculator

    With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.

  10. Radiative and precipitation controls on root zone soil moisture spectra

    Nakai, Taro; Katul, Gabriel G.; Kotani, Ayumi; Igarashi, Yasunori; Ohta, Takeshi; Suzuki, Masakazu; Kumagai, Tomo'omi


    Temporal variability in root zone soil moisture content (w) exhibits a Lorentzian spectrum with memory dictated by a damping term when forced with white-noise precipitation. In the context of regional dimming, radiation and precipitation variability are needed to reproduce w trends prompting interest in how the w memory is altered by radiative forcing. A hierarchy of models that sequentially introduce the spectrum of precipitation, net radiation, and the effect of w on evaporative and drainage losses was used to analyze the spectrum of w at subtropical and temperate forested sites. Reproducing the w spectra at long time scales necessitated simultaneous precipitation and net radiation measurements depending on site conditions. The w memory inferred from observed w spectra was 25-38 days, larger than that determined from maximum wet evapotranspiration and field capacity. The w memory can be reasonably inferred from the Lorentzian spectrum when precipitation and evapotranspiration are in phase.

  11. Does extreme precipitation intensity depend on the emissions scenario?

    Pendergrass, Angeline; Lehner, Flavio; Sanderson, Benjamin; Xu, Yangyang


    The rate of increase of global-mean precipitation per degree surface temperature increase differs for greenhouse gas and aerosol forcings, and therefore depends on the change in composition of the emissions scenario used to drive climate model simulations for the remainder of the century. We investigate whether or not this is also the case for extreme precipitation simulated by a multi-model ensemble driven by four realistic emissions scenarios. In most models, the rate of increase of maximum annual daily rainfall per degree global warming in the multi-model ensemble is statistically indistinguishable across the four scenarios, whether this extreme precipitation is calculated globally, over all land, or over extra-tropical land. These results indicate that, in most models, extreme precipitation depends on the total amount of warming and does not depend on emissions scenario, in contrast to mean precipitation.

  12. Uncertainties in Arctic Precipitation

    Majhi, I.; Alexeev, V. A.; Cherry, J. E.; Cohen, J. L.; Groisman, P. Y.


    Arctic precipitation is riddled with measurement biases; to address the problem is imperative. Our study focuses on comparison of various datasets and analyzing their biases for the region of Siberia and caution that is needed when using them. Five sources of data were used ranging from NOAA's product (RAW, Bogdanova's correction), Yang's correction technique and two reanalysis products (ERA-Interim and NCEP). The reanalysis dataset performed better for some months in comparison to Yang's product, which tends to overestimate precipitation, and the raw dataset, which tends to underestimate. The sources of bias vary from topography, to wind, to missing data .The final three products chosen show higher biases during the winter and spring season. Emphasis on equations which incorporate blizzards, blowing snow and higher wind speed is necessary for regions which are influenced by any or all of these factors; Bogdanova's correction technique is the most robust of all the datasets analyzed and gives the most reasonable results. One of our future goals is to analyze the impact of precipitation uncertainties on water budget analysis for the Siberian Rivers.

  13. Hourly Precipitation Data (HPD) Publication

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly Precipitation Data (HPD) Publication is archived and available from the National Climatic Data Center (NCDC). This publication contains hourly precipitation...

  14. Maximum margin Bayesian network classifiers.

    Pernkopf, Franz; Wohlmayr, Michael; Tschiatschek, Sebastian


    We present a maximum margin parameter learning algorithm for Bayesian network classifiers using a conjugate gradient (CG) method for optimization. In contrast to previous approaches, we maintain the normalization constraints on the parameters of the Bayesian network during optimization, i.e., the probabilistic interpretation of the model is not lost. This enables us to handle missing features in discriminatively optimized Bayesian networks. In experiments, we compare the classification performance of maximum margin parameter learning to conditional likelihood and maximum likelihood learning approaches. Discriminative parameter learning significantly outperforms generative maximum likelihood estimation for naive Bayes and tree augmented naive Bayes structures on all considered data sets. Furthermore, maximizing the margin dominates the conditional likelihood approach in terms of classification performance in most cases. We provide results for a recently proposed maximum margin optimization approach based on convex relaxation. While the classification results are highly similar, our CG-based optimization is computationally up to orders of magnitude faster. Margin-optimized Bayesian network classifiers achieve classification performance comparable to support vector machines (SVMs) using fewer parameters. Moreover, we show that unanticipated missing feature values during classification can be easily processed by discriminatively optimized Bayesian network classifiers, a case where discriminative classifiers usually require mechanisms to complete unknown feature values in the data first.

  15. Maximum Entropy in Drug Discovery

    Chih-Yuan Tseng


    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  16. Modeling solid-state precipitation

    Nebylov, AlexanderKozeschnik, Ernst


    Over recent decades, modeling and simulation of solid-state precipitation has attracted increased attention in academia and industry due to their important contributions in designing properties of advanced structural materials and in increasing productivity and decreasing costs for expensive alloying. In particular, precipitation of second phases is an important means for controlling the mechanical-technological properties of structural materials. However, profound physical modeling of precipitation is not a trivial task. This book introduces you to the classical methods of precipitation model

  17. Climate changes in temperature and precipitation extremes in an alpine grassland of Central Asia

    Hu, Zengyun; Li, Qingxiang; Chen, Xi; Teng, Zhidong; Chen, Changchun; Yin, Gang; Zhang, Yuqing


    The natural ecosystem in Central Asia is sensitive and vulnerable to the arid and semiarid climate variations, especially the climate extreme events. However, the climate extreme events in this area are still unclear. Therefore, this study analyzed the climate variability in the temperature and precipitation extreme events in an alpine grassland (Bayanbuluk) of Central Asia based on the daily minimum temperature, daily maximum temperature, and daily precipitation from 1958 to 2012. Statistically significant ( p < 0.01) increasing trends were found in the minimum temperature, maximum temperature at annual, and seasonal time scales except the winter maximum temperature. In the seasonal changes, the winter temperature had the largest contribution to the annual warming. Further, there appeared increasing trends for the warm nights and the warm days and decreasing trends for the cool nights and the cool days at a 99 % confidence level. These trends directly resulted in an increasing trend for the growing season length (GSL) which could have positively influence on the vegetation productivity. For the precipitation, it displayed an increasing trend for the annual precipitation although it was not significant. And the summer precipitation had the same variations as the annual precipitation which indicated that the precipitation in summer made the biggest contribution to the annual precipitation than the other three seasons. The winter precipitation had a significant increasing trend (1.49 mm/10a) and a decreasing trend was found in spring. We also found that the precipitation of the very wet days mainly contributes to the annual precipitation with the trend of 4.5 mm/10a. The maximum 1-day precipitation and the heavy precipitation days only had slight increasing trend. A sharp decreasing trend was found before the early 1980s, and then becoming increase for the above three precipitation indexes. The climate experienced a warm-wet abrupt climate change in the 1980s

  18. The Maximum Density of Water.

    Greenslade, Thomas B., Jr.


    Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)

  19. Abolishing the maximum tension principle

    Dabrowski, Mariusz P


    We find the series of example theories for which the relativistic limit of maximum tension $F_{max} = c^2/4G$ represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  20. Abolishing the maximum tension principle

    Mariusz P. Da̧browski


    Full Text Available We find the series of example theories for which the relativistic limit of maximum tension Fmax=c4/4G represented by the entropic force can be abolished. Among them the varying constants theories, some generalized entropy models applied both for cosmological and black hole horizons as well as some generalized uncertainty principle models.

  1. Expression of TM4SF10, a Claudin/EMP/PMP22 family cell junction protein, during mouse kidney development and podocyte differentiation.

    Bruggeman, Leslie A; Martinka, Scott; Simske, Jeffrey S


    Cell junctions in the nephron are highly specialized to perform specific and distinct filtration and reabsorption functions. The mature kidney forms complex cell junctions including slit diaphragms that prevent the passage of serum proteins into the filtrate, and tubule cell junctions that regulate specific paracellular ion reuptake. We have investigated the expression of TM4SF10 (Trans-Membrane tetra(4)-Span Family 10) in mouse kidneys. TM4SF10 is the vertebrate orthologue of Caenorhabditis elegans VAB-9, a tetraspan adherens junction protein in the PMP22/EMP/Claudin family of proteins. We found that TM4SF10 localizes at the basal-most region of podocyte precursors before the capillary loop stage, at some tubule precursors, and at the ureteric bud junction with S-shaped bodies. Overall expression of TM4SF10 peaked at postnatal day 4 and was virtually absent in adult kidneys. The very limited expression of TM4SF10 protein that persisted into adulthood was restricted to a few tubule segments but remained localized to the basal region of lateral membranes. In undifferentiated cultured podocytes, TM4SF10 localized to the perinuclear region and translocated to the cell membrane after Cadherin appearance at cell-cell contacts. TM4SF10 colocalized with ZO1 and p120ctn in undifferentiated confluent podocytes and also colocalized with the tips of actin filaments at cell contacts. Upon differentiation of cultured podocytes, TM4SF10 protein disappeared from cell contacts and expression ceased. These results suggest that TM4SF10 functions during differentiation of podocytes and may participate in the maturation of cell junctions from simple adherens junctions to elaborate slit diaphragms. TM4SF10 may define a new class of Claudin-like proteins that function during junctional development.

  2. Determination of the degree of acetylation and the distribution of acetyl groups in chitosan by HPLC analysis of nitrous acid degraded and PMP labeled products.

    Han, Zhangrun; Zeng, Yangyang; Lu, Hong; Zhang, Lijuan


    Chitin is one of the most abundant polysaccharides on earth. It consists of repeating β-1,4 linked N-acetylated glucosamine (A) units. Chitosan is an N-deacetylated product of chitin. Chitosan and its derivatives have broad medical applications as drugs, nutraceuticals, or drug delivery agents. However, a reliable analytical method for quality control of medically used chitosans is still lacking. In current study, nitrous acid was used to cleave all glucosamine residues in chitosan into 2,5-anhydromannose (M) or M at the reducing end of di-, tri-, and oligosaccharides. PMP, i.e. 1-phenyl-3-methyl-5-pyrazolone, was used to label all the Ms. Online UV detection allowed quantification of all M-containing UV peaks whereas online MS analysis directly identified 11 different kinds of mono-, di-, tri-, and oligosaccharides that correlated each oligosaccharide with specific UV peak after HPLC separation. The DA (degree of acetylation) for chitosans was calculated based on the A/(A+M) value derived from the UV data. This newly developed method had several advantages for quality control of chitosan: 1. the experimental procedures were extensively optimized; 2. the reliability of the method was confirmed by online LC-MS analysis; 3. the DA value was obtainable based on the UV data after HPLC analysis, which was comparableto that of (1)H NMR and conductometric titration analyses; 4. finally and most importantly, this method could be used to obtain the DA as well as chemical acetylation/deacetylation mechanisms for chitosan by any laboratory equipped with a HPLC and an online UV detector.

  3. Trends in monthly precipitation over the northwest of Iran (NWI)

    Asakereh, Hossein


    Increasing global temperatures during the last century have had their own effects on other climatic conditions, particularly on precipitation characteristics. This study was meant to investigate the spatial and temporal monthly trends of precipitation using the least square error (LSE) approach for the northwest of Iran (NWI). To this end, a database was obtained from 250 measuring stations uniformly scattered all over NWI from 1961 to 2010. The spatial average of annual precipitation in NWI during the period of study was approximately 220.9-726.7 mm. The annual precipitation decreased from southwest to northeast, while the large amount of precipitation was concentrated in the south-west and in the mountainous areas. All over NWI, the maximum and minimum precipitation records occurred from March to May and July to September, respectively. The coefficient of variation (CV) is greater than 44 % in all of NWI and may reach over 76 % in many places. The greatest range of CV, for instance, occurred during July. The spatial variability of precipitation was consistent with a tempo-spatial pattern of precipitation trends. There was a considerable difference between the amounts of change during the months, and the negative trends were mainly attributed to areas concentrated in eastern and southern parts of NWI far from the western mountain ranges. Moreover, limited areas with positive precipitation trends can be found in very small and isolated regions. This is observable particularly in the eastern half of NWI, which is mostly located far from Westerlies. On the other hand, seasonal precipitation trends indicated a slight decrease during winter and spring and a slight increase during summer and autumn. Consequently, there were major changes in average precipitation that occurred negatively in the area under study during the observation period. This finding is in agreement with those findings by recent studies which revealed a decreasing trend of around 2 mm/year over NWI

  4. Maximum Genus of Strong Embeddings

    Er-ling Wei; Yan-pei Liu; Han Ren


    The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.

  5. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo


    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  6. D(Maximum)=P(Argmaximum)

    Remizov, Ivan D


    In this note, we represent a subdifferential of a maximum functional defined on the space of all real-valued continuous functions on a given metric compact set. For a given argument, $f$ it coincides with the set of all probability measures on the set of points maximizing $f$ on the initial compact set. This complete characterization lies in the heart of several important identities in microeconomics, such as Roy's identity, Sheppard's lemma, as well as duality theory in production and linear programming.

  7. The Testability of Maximum Magnitude

    Clements, R.; Schorlemmer, D.; Gonzalez, A.; Zoeller, G.; Schneider, M.


    Recent disasters caused by earthquakes of unexpectedly large magnitude (such as Tohoku) illustrate the need for reliable assessments of the seismic hazard. Estimates of the maximum possible magnitude M at a given fault or in a particular zone are essential parameters in probabilistic seismic hazard assessment (PSHA), but their accuracy remains untested. In this study, we discuss the testability of long-term and short-term M estimates and the limitations that arise from testing such rare events. Of considerable importance is whether or not those limitations imply a lack of testability of a useful maximum magnitude estimate, and whether this should have any influence on current PSHA methodology. We use a simple extreme value theory approach to derive a probability distribution for the expected maximum magnitude in a future time interval, and we perform a sensitivity analysis on this distribution to determine if there is a reasonable avenue available for testing M estimates as they are commonly reported today: devoid of an appropriate probability distribution of their own and estimated only for infinite time (or relatively large untestable periods). Our results imply that any attempt at testing such estimates is futile, and that the distribution is highly sensitive to M estimates only under certain optimal conditions that are rarely observed in practice. In the future we suggest that PSHA modelers be brutally honest about the uncertainty of M estimates, or must find a way to decrease its influence on the estimated hazard.

  8. Alternative Multiview Maximum Entropy Discrimination.

    Chao, Guoqing; Sun, Shiliang


    Maximum entropy discrimination (MED) is a general framework for discriminative estimation based on maximum entropy and maximum margin principles, and can produce hard-margin support vector machines under some assumptions. Recently, the multiview version of MED multiview MED (MVMED) was proposed. In this paper, we try to explore a more natural MVMED framework by assuming two separate distributions p1( Θ1) over the first-view classifier parameter Θ1 and p2( Θ2) over the second-view classifier parameter Θ2 . We name the new MVMED framework as alternative MVMED (AMVMED), which enforces the posteriors of two view margins to be equal. The proposed AMVMED is more flexible than the existing MVMED, because compared with MVMED, which optimizes one relative entropy, AMVMED assigns one relative entropy term to each of the two views, thus incorporating a tradeoff between the two views. We give the detailed solving procedure, which can be divided into two steps. The first step is solving our optimization problem without considering the equal margin posteriors from two views, and then, in the second step, we consider the equal posteriors. Experimental results on multiple real-world data sets verify the effectiveness of the AMVMED, and comparisons with MVMED are also reported.

  9. Analysis of changes in the magnitude, frequency, and seasonality of heavy precipitation over the contiguous USA

    Mallakpour, Iman; Villarini, Gabriele


    Auc(bstract) Gridded daily precipitation observations over the contiguous USA are used to investigate the past observed changes in the frequency and magnitude of heavy precipitation, and to examine its seasonality. Analyses are based on the Climate Prediction Center (CPC) daily precipitation data from 1948 to 2012. We use a block maxima approach to identify changes in the magnitude of heavy precipitation and a peak-over-threshold (POT) approach for the changes in the frequency. The results of this study show that there is a stronger signal of change in the frequency rather than in the magnitude of heavy precipitation events. Also, results show an increasing trend in the frequency of heavy precipitation over large areas of the contiguous USA with the most notable exception of the US Northwest. These results indicate that over the last 65 years, the stronger storms are not getting stronger, but a larger number of heavy precipitation events have been observed. The annual maximum precipitation and annual frequency of heavy precipitation reveal a marked seasonality over the contiguous USA. However, we could not find any evidence suggesting shifting in the seasonality of annual maximum precipitation by investigating whether the day of the year at which the maximum precipitation occurs has changed over time. Furthermore, we examine whether the year-to-year variations in the frequency and magnitude of heavy precipitation can be explained in terms of climate variability driven by the influence of the Atlantic and Pacific Oceans. Our findings indicate that the climate variability of both the Atlantic and Pacific Oceans can exert a large control on the precipitation frequency and magnitude over the contiguous USA. Also, the results indicate that part of the spatial and temporal features of the relationship between climate variability and heavy precipitation magnitude and frequency can be described by one or more of the climate indices considered here.

  10. Regional frequency analysis of extremes precipitations in Northern of Mozambique

    M. Álvarez


    Full Text Available Extreme precipitation events that occur over internal basins of Cabo Delgado (Northern Mozambique often result in the occurrence of flood events with associated loss of life and infrastructure. This paper presents a study of regional frequency analysis of maximum daily precipitations based on the index flood procedure with estimated parameters by L-moments approach. Observed annual maximum daily precipitation series of 12 stations with records of more than 20 years were analyzed. The discordancy and heterogeneity measures based on the L-moments suggest that the region can be considered as homogeneous. Among the candidate distributions analyzed Monte Carlo simulations identified the Generalized Logistic distribution function as the best regional fit for the region. The achieved results will be useful in hydrologic and hydraulic studies related to floods and floodplain delineation in the region.

  11. Extreme precipitation events in the Czech Republic in the context of climate change

    V. Květoň


    Full Text Available As an introduction, short survey of two analyses of long-term fluctuations of annual precipitation totals in the Czech Republic is presented. The main focus of this paper is to contribute to investigation of precipitation trends in the Czech Republic by another point of view. For every pixel of 1 km2 size, annual maxima of daily precipitation were obtained for time period of 112 years (1895–2006. Based on these time series, we were trying to answer question if there are some changes of area size/distribution of annual maximum of daily precipitation totals. Courses and trends are analyzed for some parameters of area distribution of annual maximum of daily precipitation totals in the area of the Czech Republic. No significant climate changes of tested precipitation characteristics were found.

  12. Liesegang patterns: Complex formation of precipitate in an electric field

    István Lagzi


    Formation of 1D Liesegang patterns was studied numerically in precipitation and reversible complex formation of precipitate scenarios in an electric field. The Ostwald’s supersaturation model reported by Büki, Kárpáti-Smidróczki and Zrínyi (BKZ model) was extended further. In the presence of an electric field the position of the first and the last bands () measured from the junction point of the outer and the inner electrolytes can be described by the function = 1 $_{}^{1/2}$ + 2 + 3 , where is the time elapsed until the nth band formation, 1, 2 and 3 are constants. The variation of the total number of bands with different electric field strengths () has a maximum. For higher one can observe a moving precipitation zone that becomes wider due to precipitation and reversible complex formation.

  13. Precipitation extremes under climate change

    O'Gorman, Paul A


    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to...

  14. Spatial and temporal variability of precipitation and drought in Portugal

    D. S. Martins


    Full Text Available The spatial variability of precipitation and drought are investigated for Portugal using monthly precipitation from 74 stations and minimum and maximum temperature from 27 stations, covering the common period of 1941–2006. Seasonal precipitation and the corresponding percentages in the year, as well as the precipitation concentration index (PCI, was computed for all 74 stations and then used as an input matrix for an R-mode principal component analysis to identify the precipitation patterns. The standardized precipitation index at 3 and 12 month time scales were computed for all stations, whereas the Palmer Drought Severity Index (PDSI and the modified PDSI for Mediterranean conditions (MedPDSI were computed for the stations with temperature data. The spatial patterns of drought over Portugal were identified by applying the S-mode principal component analysis coupled with varimax rotation to the drought indices matrices. The result revealed two distinct sub-regions in the country relative to both precipitation regimes and drought variability. The analysis of time variability of the PC scores of all drought indices allowed verifying that there is no linear trend indicating drought aggravation or decrease. In addition, the analysis shows that results for SPI-3, SPI-12, PDSI and MedPDSI are coherent among them.

  15. Diurnal variation of precipitation over the Carolina Sandhills region

    A Wootten; S Raman; A Sims


    The Carolina Sandhills are known to have an area of maximum precipitation on its western boundary during the summer mainly due to differences in soil types.Statistical analysis was performed on summer precipitation data from automated weather stations in the Carolinas,along the Sandhills for the years 2001 to 2006.Statistically significant difference was observed between the day and night precipitation amounts.A case study also revealed the diurnal pattern of convective precipitation. North American Mesoscale (NAM)model forecasts for the summers of 2004 to 2006 were evaluated using observations.The model underpredicted precipitation significantly during nights. A numerical simulation using Weather Research and Forecast (WRF)model was performed for August 9 –11,2001 and the forecasts were compared with observed precipitation data.The model precipitation forecasts were better for daytime as compared to the night.This feature is attributed to model physics not capturing cloud –radiation interaction processes dominant during nights. Although this study is for a specific region in the US,results are applicable for other regions for similar conditions.

  16. Cacti with maximum Kirchhoff index

    Wang, Wen-Rui; Pan, Xiang-Feng


    The concept of resistance distance was first proposed by Klein and Randi\\'c. The Kirchhoff index $Kf(G)$ of a graph $G$ is the sum of resistance distance between all pairs of vertices in $G$. A connected graph $G$ is called a cactus if each block of $G$ is either an edge or a cycle. Let $Cat(n;t)$ be the set of connected cacti possessing $n$ vertices and $t$ cycles, where $0\\leq t \\leq \\lfloor\\frac{n-1}{2}\\rfloor$. In this paper, the maximum kirchhoff index of cacti are characterized, as well...

  17. Generic maximum likely scale selection

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo


    The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...... on second order moments of multiple measurements outputs at a fixed location. These measurements, which reflect local image structure, consist in the cases considered here of Gaussian derivatives taken at several scales and/or having different derivative orders....

  18. Climate Prediction Center (CPC)Weekly U.S. Precipitation and Temperature Summary

    National Oceanic and Atmospheric Administration, Department of Commerce — Weekly U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

  19. Climate Prediction Center(CPC)Daily U.S. Precipitation and Temperature Summary

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily U.S. minimum and maximum temperatures in whole degrees Fahrenheit and reported and estimated precipitation amounts in hundredths of inches(ex 100 is 1.00...

  20. Gridded 5km GHCN-Daily Temperature and Precipitation Dataset, Version 1

    National Oceanic and Atmospheric Administration, Department of Commerce — The Gridded 5km GHCN-Daily Temperature and Precipitation Dataset (nClimGrid) consists of four climate variables derived from the GHCN-D dataset: maximum temperature,...

  1. Analysis of future precipitation in the Koshi river basin, Nepal

    Agarwal, Anshul; Babel, Mukand S.; Maskey, Shreedhar


    We analyzed precipitation projections for the Koshi river basin in Nepal using outputs from 10 General Circulation Models (GCMs) under three emission scenarios (B1, A1B and A2). The low resolution future precipitation data obtained from the GCMs was downscaled using the statistical downscaling model LARS-WG. The data was downscaled for 48 stations located in the six physiographic regions in the Koshi basin. The precipitation projections for three future periods, i.e. 2020s, 2055s and 2090s, are presented using empirical Probability Density Functions (PDFs) for each physiographic region. The differences between the mean values of individual GCM projections and the mean value of the multi-model for the three scenarios allow for the estimation of uncertainty in the projections. We also analyzed the precipitation of the baseline and future periods using six indices that are recommended by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI). Results indicate that not all GCMs agree on weather changes in precipitation will be positive or negative. A majority of the GCMs and the average values of all the GCMs for each scenario, indicate a positive change in summer, autumn and annual precipitation but a negative change in spring precipitation. Differences in the GCM projections exist for all the three future periods and the differences increase with time. The estimated uncertainty is higher for scenario A1B compared to B1 and A2. Differences among scenarios are small during the 2020s, which become significant during the 2055s and 2090s. The length of the wet spell is expected to increase, whereas the length of the dry spell is expected to decrease in all three future periods. There is a large scatter in the values of the indices: number of days with precipitation above 20 mm, 1-day maximum precipitation, 5-day maximum precipitation, and amount of precipitation on the days with precipitation above 95th percentile, both in direction and magnitude of

  2. Effective Assimilation of Global Precipitation

    Lien, G.; Kalnay, E.; Miyoshi, T.; Huffman, G. J.


    Assimilating precipitation observations by modifying the moisture and sometimes temperature profiles has been shown successful in forcing the model precipitation to be close to the observed precipitation, but only while the assimilation is taking place. After the forecast start, the model tends to "forget" the assimilation changes and lose their extra skill after few forecast hours. This suggests that this approach is not an efficient way to modify the potential vorticity field, since this is the variable that the model would remember. In this study, the ensemble Kalman filter (EnKF) method is used to effectively change the potential vorticity field by allowing ensemble members with better precipitation to receive higher weights. In addition to using an EnKF, two other changes in the precipitation assimilation process are proposed to solve the problems related to the highly non-Gaussian nature of the precipitation variable: a) transform precipitation into a Gaussian distribution based on its climatological distribution, and b) only assimilate precipitation at the location where some ensemble members have positive precipitation. The idea is first tested by the observing system simulation experiments (OSSEs) using SPEEDY, a simplified but realistic general circulation model. When the global precipitation is assimilated in addition to conventional rawinsonde observations, both the analyses and the medium range forecasts are significantly improved as compared to only having rawinsonde observations. The improvement is much reduced when only modifying the moisture field with the same approach, which shows the importance of the error covariance between precipitation and all other model variables. The effect of precipitation assimilation is larger in the Southern Hemisphere than that in the Northern Hemisphere because the Northern Hemisphere analyses are already accurate as a result of denser rawinsonde stations. Assimilation of precipitation using a more comprehensive

  3. Electrical operation of electrostatic precipitators

    Parker, Ken


    The electrostatic precipitator remains on of the most cost effective means of controlling the emission of particulates from most industrial processes. This book will be of interest to both users and suppliers of electrostatic precipitators as well as advanced students on environmental based courses. The author identifies the physical and engineering basis for the development of electrical equipment for electrostatic precipitators and thoroughly explores the technological factors which optimize the efficiency of the precipitator and hence minimize emissions, as well as future developments in th

  4. 腓骨肌萎缩症1型患者肌电图及PMP22基因特点分析%Electromyography and PMP22 gene analysis in patients with type 1 Charcot-Marie-Tooth disease

    潘晓丽; 潘志宏; 张楠楠; 高红


    目的:探讨和研究腓骨肌萎缩症1型(Charcot‐Marie‐Tooth disease 1,CMT1)患者肌电图和 PMP22基因改变特点。方法对43例CM T1患者进行常规神经传导速度和肌电图检查,应用PCR双酶切方法对其中33例CM T1患者及15名健康志愿者(对照组)检测17p11.2‐12 PM P22基因重复序列(即1760 bp片段)。33例CM T1患者依有无17p11.2‐12 PM P22基因特异性片段分为 PM P22基因特异性片段阳性组与阴性组,比较两组患者神经传导改变有无差异。结果43例患者均行肌电图检测,均表现为运动或感觉神经传导速度存在明显减慢(100%),感觉神经病变重于运动神经,下肢受累程度重于上肢;所检129块肌肉中,88块(68.2%)呈神经源性损害。经 PM P22基因学检测的33例中20例(60.6%)检测出1760 bp片断,对照组均未检测到此片段。PM P22基因特异性片段阳性组感觉神经传导速度、运动神经传导速度及远端潜伏期与阴性组比较差异均无统计学意义(P>0.05)。结论 CMT1患者肌电图改变具有其特异性,结合PCR‐双酶切法检测 PMP22特异性基因重复序列可提高诊断CM T1的准确性及敏感性。%Objective To study the electromyography and PM P22 gene features in patients with type 1 Charcot‐Marie‐Tooth (CMT ) disease . Methods Routine electromyography and nerve conduction were performed in 43 patients with CMT 1 .Polymerase chain reaction (PCR) combined with restriction enzyme digestion was used to detect PMP22 gene duplication on chromosome 17p11.2‐12 (1760 bp) in 33 CMT 1 patients and 15 healthy volunteers (the control group) .According to the presence or absence of 17 p11.2‐12 PMP22 gene segments ,33 CMT 1 patients were divided into the positive group and the negative group . Parameters of nerve conduction were compared between two groups .Results All of the patients had the nerve conduction velocities slower or disappeared

  5. Projection of Korean Probable Maximum Precipitation under Future Climate Change Scenarios

    Okjeong Lee


    Full Text Available According to the IPCC Fifth Assessment Report, air temperature and humidity of the future are expected to gradually increase over the current. In this study, future PMPs are estimated by using future dew point temperature projection data which are obtained from RCM data provided by the Korea Meteorological Administration. First, bias included in future dew point temperature projection data which is provided on a daily basis is corrected through a quantile-mapping method. Next, using a scale-invariance technique, 12-hour duration 100-year return period dew point temperatures which are essential input data for PMPs estimation are estimated from bias-corrected future dew point temperature data. After estimating future PMPs, it can be shown that PMPs in all future climate change scenarios (AR5 RCP2.6, RCP 4.5, RCP 6.0, and RCP 8.5 are very likely to increase.

  6. Economics and Maximum Entropy Production

    Lorenz, R. D.


    Price differentials, sales volume and profit can be seen as analogues of temperature difference, heat flow and work or entropy production in the climate system. One aspect in which economic systems exhibit more clarity than the climate is that the empirical and/or statistical mechanical tendency for systems to seek a maximum in production is very evident in economics, in that the profit motive is very clear. Noting the common link between 1/f noise, power laws and Self-Organized Criticality with Maximum Entropy Production, the power law fluctuations in security and commodity prices is not inconsistent with the analogy. There is an additional thermodynamic analogy, in that scarcity is valued. A commodity concentrated among a few traders is valued highly by the many who do not have it. The market therefore encourages via prices the spreading of those goods among a wider group, just as heat tends to diffuse, increasing entropy. I explore some empirical price-volume relationships of metals and meteorites in this context.

  7. Rising Precipitation Extremes across Nepal

    Ramchandra Karki


    Full Text Available As a mountainous country, Nepal is most susceptible to precipitation extremes and related hazards, including severe floods, landslides and droughts that cause huge losses of life and property, impact the Himalayan environment, and hinder the socioeconomic development of the country. Given that the countrywide assessment of such extremes is still lacking, we present a comprehensive picture of prevailing precipitation extremes observed across Nepal. First, we present the spatial distribution of daily extreme precipitation indices as defined by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI from 210 stations over the period of 1981–2010. Then, we analyze the temporal changes in the computed extremes from 76 stations, featuring long-term continuous records for the period of 1970–2012, by applying a non-parametric Mann−Kendall test to identify the existence of a trend and Sen’s slope method to calculate the true magnitude of this trend. Further, the local trends in precipitation extremes have been tested for their field significance over the distinct physio-geographical regions of Nepal, such as the lowlands, middle mountains and hills and high mountains in the west (WL, WM and WH, respectively, and likewise, in central (CL, CM and CH and eastern (EL, EM and EH Nepal. Our results suggest that the spatial patterns of high-intensity precipitation extremes are quite different to that of annual or monsoonal precipitation. Lowlands (Terai and Siwaliks that feature relatively low precipitation and less wet days (rainy days are exposed to high-intensity precipitation extremes. Our trend analysis suggests that the pre-monsoonal precipitation is significantly increasing over the lowlands and CH, while monsoonal precipitation is increasing in WM and CH and decreasing in CM, CL and EL. On the other hand, post-monsoonal precipitation is significantly decreasing across all of Nepal while winter precipitation is decreasing

  8. PMP-2: Equatorial wave dynamics

    Hirota, I.


    After the discovery of the quasi-biennial oscillation (QBO) in the stratospheric zonal wind, there were, in the last two decades, a large number of observational and theoretical studies on the structure and behavior of the mean zonal wind and waves in the tropical stratosphere. Planetary-scale, vertically propagating equatorial waves play an important role in producing the QBO through the mechanism of wave-mean flow interaction. Concerning the dynamics of the equatorial upper stratosphere and mesosphere, however, little was known about the possible wave motions, except for tides, mainly because of the lack of adequate observations in this region. The main purpose is to provide the nature of various types of equatorial wave modes, with the aid of improved sounding techniques and sophisticated numerical modelings.


    MARSHALL, PA; KRIMKEVICH, YI; LARK, RH; DYER, JM; VEENHUIS, M; GOODMAN, JM; Krimkevich, Yelena I.; Lark, Richard H.; Dyer, John M.; Goodman, Joel M.


    Peroxisomes perform many essential functions in eukaryotic cells. The weight of evidence indicates that these organelles divide by budding from preexisting peroxisomes. This process is not understood at the molecular level. Peroxisomal proliferation can be induced in Saccharomyces cerevisiae by olea

  10. Precipitation in the Solar System

    McIntosh, Gordon


    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  11. Precipitation in the Solar System

    McIntosh, Gordon


    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  12. Objects of maximum electromagnetic chirality

    Fernandez-Corbaton, Ivan


    We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.

  13. Maximum mutual information regularized classification

    Wang, Jim Jing-Yan


    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  14. The strong maximum principle revisited

    Pucci, Patrizia; Serrin, James

    In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.

  15. Modeling solid-state precipitation

    Nebylov, AlexanderKozeschnik, Ernst


    Over recent decades, modeling and simulation of solid-state precipitation has attracted increased attention in academia and industry due to their important contributions in designing properties of advanced structural materials and in increasing productivity and decreasing costs for expensive alloying. In particular, precipitation of second phases is an important means for controlling the mechanical-technological properties of structural materials. However, profound physical modeling of precipitation is not a trivial task. This book introduces you to the classical methods of precipitation modeling and to recently-developed advanced, computationally-efficient techniques. If you're a research professional, academic, or student, you'll learn: nucleation theory, precipitate growth, calculation of interfacial energies. advanced techniques for technologically relevant multicomponent systems and complex thermo-mechanical treatments. numerical approaches using evolution equations and discrete particle size distribu...

  16. Encoding information into precipitation structures

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan


    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A+ + B- → C reaction-diffusion processes. Our main result, based on simulating the reaction-diffusion-precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm.

  17. Structural characteristics of annual precipitation in Lake Urmia basin

    Vaheddoost, Babak; Aksoy, Hafzullah


    Precipitation as the main process that brings evaporated water from the oceans to the land's surface is a critical role player in Lake Urmia basin (Iran). As a hyper-saline lake declared as UNESCO's biosphere reserve in Ramsar Convention, it is dealing with gradual atrophy. In this study, characteristics of annual precipitation in the Lake Urmia basin are investigated by means of several statistical measures and tests. Data in 53 meteorological stations widespread across the basin for a period of 31 years from 1981 to 2011 are considered for analysis. Fundamental statistical characteristics of the data like mean, maximum, minimum, standard deviation, coefficient of variation, coefficient of skewness, coefficient of kurtosis, auto-correlation and cross-correlation coefficients of the annual precipitation are calculated. Entropy in each station is also calculated with respect to the long-run mean precipitation of the basin. Results of the analysis are plotted in contour maps. Several tests for consistency, randomness, trend and best-fit probability distribution function are applied to investigate characteristics of the annual precipitation. Heterogeneity and dependence on local conditions are the main results revealed by this study while consistency and dependency of precipitation on North West and West of the basin are considered as the most effective among other regions. Due to the North-South oriented mountains, a relatively sharp decline in the precipitation from West to East can be compared to the gradual decline in precipitation from North to South due to smooth change in the terrain. It is also seen that such characteristics as probability distribution, consistency, randomness, trend, and uncertainty of annual precipitation in the Lake Urmia basin become more complex as crossing from West to East than crossing from North to South on the basin.

  18. Temperature and precipitation changes in Extensive Hexi Region, China, 1960-2011

    Wei Liu; ZongXing Li; Meng Zhu; XiaoYan Guo; LiJuan Chen


    Global climate change has been evident in many places worldwide. This study provides a better understanding of the variability and changes in frequency, intensity, and duration of temperature, precipitation, and climate extremes in the Extensive Hexi Region, based on meteorological data from 26 stations. The analysis of average, maximum, and minimum temperatures revealed that statistically significant warming occurred from 1960 to 2011. All temperature extremes dis-played trends consistent with warming, with the exception of coldest-night temperature (TNn) and coldest-day tempera-ture (TXn), which were particularly evident in high-altitude areas and at night. Amount of precipitation and number of rainy days slowly increased with no significant regional trends, mainly occurring in the Qilian Mountains and Hexi Cor-ridor. The significance of changes in precipitation extremes during 1960–2011 was high, but the regional trends of max-imum 5-day precipitation (RX5day), the average precipitation on wet days (SDII), and consecutive wet days (CWD) were not significant. The variations in the studied parameters indicate an increase in both the extremity and strength of precip-itation events, particularly in higher-altitude regions. Furthermore, the contribution from very wet precipitation (R95) and extremely wet precipitation (R99) to total precipitation also increased between 1960 and 2011. The assessment of these changes in temperature and precipitation may help in developing better management practices for water resources. Future studies in the region should focus on the impact of these changes on runoffs and glaciers.

  19. Analyses of the cell-wall peptidoglycan structures in three genera Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae by derivatization with FDLA and PMP using LC/MS.

    Také, Akira; Nakashima, Takuji; Inahashi, Yuki; Shiomi, Kazuro; Takahashi, Yōko; Ōmura, Satoshi; Matsumoto, Atsuko


    It is the major characteristic of the cell-wall peptidoglycan structure in members of the family Micromonosporaceae that N-acetylmuramic acid (MurNAc) of glycan strand is replaced with N-glycolylmuramic acid (MurNGlyc). Consequently, it is difficult to use enzymatic methods for their peptidoglycan analyses. We therefore developed analysis method of peptidoglycan without using cell wall lytic enzymes as example to take the 3 genera, Micromonospora, Catenuloplanes, and Couchioplanes belonging to the family Micromonosporaceae, and their peptidoglycans were partially hydrolyzed with 4 M HCl at 60°C for 16 h followed by derivatization with N(α)-(5-fluoro-2,4-dinitrophenyl)-D-leucinamide (FDLA) or 1-phenyl-3-methyl-5-pyrazolone (PMP) and LC/MS analysis. Peptidoglycan of the genus Micromonospora consisted of a MurNGlyc-Gly-D-Glu-meso-diaminopimelyl (DAP)-D-Ala peptide stem and direct linkage between D-Ala and meso-DAP. In contrast, peptidoglycans of the genera Catenuloplanes and Couchioplanes consisted of a MurNGlyc-Gly-D-Glu-L-Lys-D-Ala peptide stem, and cross-linkage between D-Ala and L-Lys was mediated by an L-Ser residue. This method can be used to analyze the cell-wall peptidoglycan structure of other bacteria as well. By derivatization with FDLA or PMP followed by LC/MS analysis, the structure can be determined using only 0.2 mg of purified peptidoglycan.

  20. Maximum entropy production in daisyworld

    Maunu, Haley A.; Knuth, Kevin H.


    Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.

  1. Maximum stellar iron core mass

    F W Giacobbe


    An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.

  2. Maximum Matchings via Glauber Dynamics

    Jindal, Anant; Pal, Manjish


    In this paper we study the classic problem of computing a maximum cardinality matching in general graphs $G = (V, E)$. The best known algorithm for this problem till date runs in $O(m \\sqrt{n})$ time due to Micali and Vazirani \\cite{MV80}. Even for general bipartite graphs this is the best known running time (the algorithm of Karp and Hopcroft \\cite{HK73} also achieves this bound). For regular bipartite graphs one can achieve an $O(m)$ time algorithm which, following a series of papers, has been recently improved to $O(n \\log n)$ by Goel, Kapralov and Khanna (STOC 2010) \\cite{GKK10}. In this paper we present a randomized algorithm based on the Markov Chain Monte Carlo paradigm which runs in $O(m \\log^2 n)$ time, thereby obtaining a significant improvement over \\cite{MV80}. We use a Markov chain similar to the \\emph{hard-core model} for Glauber Dynamics with \\emph{fugacity} parameter $\\lambda$, which is used to sample independent sets in a graph from the Gibbs Distribution \\cite{V99}, to design a faster algori...

  3. The removal of sulphate from mine water by precipitation as ettringite and the utilisation of the precipitate as a sorbent for arsenate removal.

    Tolonen, Emma-Tuulia; Hu, Tao; Rämö, Jaakko; Lassi, Ulla


    The aim of this research was to investigate sulphate removal from mine water by precipitation as ettringite (Ca6Al2(SO4)3(OH)12·26H2O) and the utilisation of the precipitate as a sorbent for arsenate removal. The mine water sulphate concentration was reduced by 85-90% from the initial 1400 mg/L during ettringite precipitation depending on the treatment method. The precipitation conditions were also simulated with MINEQL + software, and the computational results were compared with the experimental results. The precipitated solids were characterised with X-ray diffraction and a scanning electron microscope. The precipitated solids were tested as sorbents for arsenate removal from the model solution. The arsenic(V) model solution concentration reduced 86-96% from the initial 1.5 mg/L with a 1 g/L sorbent dosage. The effect of initial arsenate concentration on the sorption of arsenate on the precipitate was studied and Langmuir, Freundlich, and Langmuir-Freundlich sorption isotherm models were fitted to the experimental data. The maximum arsenate sorption capacity (qm = 11.2 ± 4.7 mg/g) of the precipitate was obtained from the Langmuir-Freundlich isotherm. The results indicate that the precipitate produced during sulphate removal from mine water by precipitation as ettringite could be further used as a sorbent for arsenate removal.

  4. 76 FR 1504 - Pipeline Safety: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure...


    ...: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and... facilities of their responsibilities, under Federal integrity management (IM) regulations, to perform... system, especially when calculating Maximum Allowable Operating Pressure (MAOP) or Maximum Operating...

  5. Recent precipitation trends, flash floods and landslides in southern Brazil

    Ávila, Alvaro; Justino, Flavio; Wilson, Aaron; Bromwich, David; Amorim, Marcelo


    In order to understand the rising number of flash floods and landslides in the densely populated region of southeastern Brazil, this study analyzes the spatial and temporal changes in precipitation from 1978 to 2014. We focus on the sensitivity of mountainous regions, specifically the Rio de Janeiro (RJMR) and Santa Catarina (SCMR) regions. Daily rainfall observations are aggregated into annual and seasonal indexes, and RClimdex is used to evaluate a suite of precipitation and extreme event indexes. Results show positive annual and seasonal precipitation trends during all seasons except for the winter season in the RJMR. Diverse change points in their time series, spatial differences in the trends at individual stations, and trends associated with elevation suggest that despite the close proximity of these two regions, climate impacts are not uniform across all of southeastern Brazil. The majority of precipitation-related indexes present positive trends, especially in the extreme precipitation indexes (PRCPTOT, RX1day, Rx5day and R30 mm). Statistically significant positive correlations are discovered between landslides/flash floods events and annual maximum 1-day and 5-day consecutive precipitation, and these indexes may be useful indicators of natural hazard events for this region.

  6. Extreme Precipitation and Runoff under Changing Climate in Southern Maine

    Yan, Eugene [Argonne National Lab. (ANL), Argonne, IL (United States); Jared, Alissa [Argonne National Lab. (ANL), Argonne, IL (United States); Mahat, Vinod [Argonne National Lab. (ANL), Argonne, IL (United States); Picel, Mark [Argonne National Lab. (ANL), Argonne, IL (United States); Verner, Duane [Argonne National Lab. (ANL), Argonne, IL (United States); Wall, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Moges, Edom M. [Washington State Univ., Pullman, WA (United States); Demissie, Yonas K. [Washington State Univ., Pullman, WA (United States); Pierce, Julia [Argonne National Lab. (ANL), Argonne, IL (United States)


    The quantification of extreme precipitation events is vitally important for designing and engineering water and flood sensitive infrastructure. Since this kind of infrastructure is usually built to last much longer than 10, 50, or even 100 years, there is great need for statistically sound estimates of the intensity of 10-, 50-, 100-, and 500-year rainstorms and associated floods. The recent assessment indicated that the intensity of the most extreme precipitation events (or the heaviest 1% of all daily events) have increased in every region of the contiguous states since the 1950s (Melillo et al. 2014). The maximum change in precipitation intensity of extreme events occurred in the northeast region reaching 71%. The precipitation extremes can be characterized using intensity-duration-frequency analysis (IDF). However, the current IDFs in this region were developed around the assumption that climate condition remains stationary over the next 50 or 100 years. To better characterize the potential flood risk, this project will (1) develop precipitation IDFs on the basis of both historical observations and future climate projections from dynamic downscaling with Argonne National Laboratory’s (Argonne’s) regional climate model and (2) develop runoff IDFs using precipitation IDFs for the Casco Bay Watershed. IDF development also considers non-stationary distribution models and snowmelt effects that are not incorporated in the current IDFs.

  7. Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

    Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.


    A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

  8. Spatiotemporal variation of precipitation based on three indicators in the flood season in Beijing

    Chen, Y.; Wang, J. H.; Xiao, W. H.; Zhou, Y. Y.; Wang, L. T.; Song, X. Y.


    This paper attempts to analyze the spatiotemporal variation of precipitation in Beijing in terms of three indicators, i.e., the total precipitation, the maximum daily precipitation, and the maximum 5h precipitation in the flood season, with data collected from 20 meteorological stations from 1975 to 2012 (June to September). The Mann-Kendall nonparametric test, the linear regression, and five-year moving average were used. The results showed that: (i) the three indicators showed a decreasing trend; however, from 1975 to 1995 and from 1995 to 2012, the precipitation in the flood season showed an increasing trend with an increasing rate of 3.36 and 2.90mm/a, respectively. (ii) The indicators demonstrated a similar spatial variation. The high value precipitation areas were mainly in the northern and central parts of the city. The central districts had increasing centers with maximum increasing rates of 0.35, 0.65, and 0.49mm/a, respectively. However, the northern part exhibited different degrees of decreasing trends. (iii) The increase in the precipitation in the city center was mainly due to the urban heat island effect and the change in the underlying surface. The temperature gradient was intensified due to the topography in the city center and the northern suburb, causing a decreasing trend of precipitation.

  9. The Sherpa Maximum Likelihood Estimator

    Nguyen, D.; Doe, S.; Evans, I.; Hain, R.; Primini, F.


    A primary goal for the second release of the Chandra Source Catalog (CSC) is to include X-ray sources with as few as 5 photon counts detected in stacked observations of the same field, while maintaining acceptable detection efficiency and false source rates. Aggressive source detection methods will result in detection of many false positive source candidates. Candidate detections will then be sent to a new tool, the Maximum Likelihood Estimator (MLE), to evaluate the likelihood that a detection is a real source. MLE uses the Sherpa modeling and fitting engine to fit a model of a background and source to multiple overlapping candidate source regions. A background model is calculated by simultaneously fitting the observed photon flux in multiple background regions. This model is used to determine the quality of the fit statistic for a background-only hypothesis in the potential source region. The statistic for a background-plus-source hypothesis is calculated by adding a Gaussian source model convolved with the appropriate Chandra point spread function (PSF) and simultaneously fitting the observed photon flux in each observation in the stack. Since a candidate source may be located anywhere in the field of view of each stacked observation, a different PSF must be used for each observation because of the strong spatial dependence of the Chandra PSF. The likelihood of a valid source being detected is a function of the two statistics (for background alone, and for background-plus-source). The MLE tool is an extensible Python module with potential for use by the general Chandra user.

  10. Vestige: Maximum likelihood phylogenetic footprinting

    Maxwell Peter


    Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational

  11. Atrial Ectopics Precipitating Atrial Fibrillation

    Johnson Francis


    Holter monitor tracing showing blocked atrial ectopics and atrial ectopic precipitating atrial fibrillation is being demonstrated. Initially it was coarse atrial fibrillation, which rapidly degenerated into fine atrial fibrillation.

  12. CPC Merged Analysis of Precipitation

    National Oceanic and Atmospheric Administration, Department of Commerce — The monthly data set consists of two files containing global monthly averaged precipitation rate values at a 2.5x2.5 resolution starting in 1979. Values are obtained...

  13. Hourly and Daily Precipitation Data

    National Oceanic and Atmospheric Administration, Department of Commerce — Precipitation reports submitted on many form types, including tabular and autographic charts. Reports are almost exclusively from the US Cooperative Observer Network.

  14. Characteristic features of winter precipitation and its variability over northwest India

    R K Yadav; K Rupa Kumar; M Rajeevan


    Northwestern parts of India receive considerable amount of precipitation during the winter months of December–March. Although, it is only about 15% of the annual precipitation, the precipitation is very important for rabi crops and to maintain the glaciers extend in the Himalaya, which melt and supply water to the rivers during other seasons. The precipitation is mainly associated with the sequence of synoptic systems known as ‘western disturbances’. The precipitation has considerable spatial and temporal variability, with maximum precipitation occurring particularly over northern hilly regions, with decreasing influence southwards. The spatially coherent winter precipitation series has been prepared for the largest possible area comprising nine meteorological subdivisions of northwest India, which constitute about 32% of the total area of the country, having similar precipitation characteristics. The precipitation series has been statistically analysed to understand its characteristics and variability. The seasonal precipitation series is found to be homogeneous, Gaussian (normal) distributed and free from persistence. The precipitation variability has increased during the most recent three decades with more excess and deficient years.

  15. Spatio-temporal observations of tertiary ozone maximum

    V. F. Sofieva


    Full Text Available We present spatio-temporal distributions of tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at altitude ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time obtaining spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  16. Changes in precipitation extremes projected by a 20-km mesh global atmospheric model

    Akio Kitoh


    Full Text Available High-resolution modeling is necessary to project weather and climate extremes and their future changes under global warming. A global high-resolution atmospheric general circulation model with grid size about 20 km is able to reproduce climate fields as well as regional-scale phenomena such as monsoonal rainfall, tropical and extratropical cyclones, and heavy precipitation. This 20-km mesh model is applied to project future changes in weather and climate extremes at the end of the 21st century with four different spatial patterns in sea surface temperature (SST changes: one with the mean SST changes by the 28 models of the Coupled Model Intercomparison Project Phase 5 (CMIP5 under the Representative Concentration Pathways (RCP-8.5 scenario, and the other three obtained from a cluster analysis, in which tropical SST anomalies derived from the 28 CMIP5 models were grouped. Here we focus on future changes in regional precipitation and its extremes. Various precipitation indices averaged over the Twenty-two regional land domains are calculated. Heavy precipitation indices (maximum 5-day precipitation total and maximum 1-day precipitation total increase in all regional domains, even where mean precipitation decrease (Southern Africa, South Europe/Mediterranean, Central America. South Asia is the domain of the largest extreme precipitation increase. In some domains, different SST patterns result in large precipitation changes, possibly related to changes in large-scale circulations in the tropical Pacific.

  17. Verification of precipitation forecasts by the DWD limited area model LME over Cyprus

    K. Savvidou


    Full Text Available A comparison is made between the precipitation forecasts by the non-hydrostatic limited area model LME of the German Weather Service (DWD and observations from a network of rain gauges in Cyprus. This is a first attempt to carry out a preliminary verification and evaluation of the LME precipitation forecasts over the area of Cyprus. For the verification, model forecasts and observations were used covering an eleven month period, from 1/2/2005 till 31/12/2005. The observations were made by three Automatic Weather Observing Systems (AWOS located at Larnaka and Paphos airports and at Athalassa synoptic station, as well as at 6, 6 and 8 rain gauges within a radius of about 30 km around these stations, respectively. The observations were compared with the model outputs, separately for each of the three forecast days. The "probability of detection" (POD of a precipitation event and the "false alarm rate" (FAR were calculated. From the selected cases of the forecast precipitation events, the average forecast precipitation amounts in the area around the three stations were compared with the measured ones. An attempt was also made to evaluate the model's skill in predicting the spatial distribution of precipitation and, in this respect, the geographical position of the maximum forecast precipitation amount was contrasted to the position of the corresponding observed maximum. Maps with monthly precipitation totals observed by a local network of 150 rain gauges were compared with the corresponding forecast precipitation maps.


    Heriansyah ePutra


    Full Text Available The optimization of enzyme-mediated calcite precipitation (EMCP was evaluated as a soil improvement technique. In our previous works, purified urease was utilized to bio-catalyze the hydrolysis of urea, which causes the supplied Ca2+ to precipitate with CO32- as calcium carbonate. In the present work, magnesium chloride was newly added to the injecting solutions to delay the reaction rate and to enhance the amount of carbonate precipitation. Soil specimens were prepared in PVC cylinders and treated with concentration-controlled solutions composed of urea, urease, calcium, and magnesium chloride. The mechanical properties of the treated soil specimens were examined through unconfined compressive strength (UCS tests. A precipitation ratio of the carbonate up to 90% of the maximum theoretical precipitation was achieved by adding a small amount of magnesium chloride. Adding magnesium chloride as a delaying agent was indeed found to reduce the reaction rate of the precipitation, which may increase the volume of the treated soil if used in real fields because of the slower precipitation rate and the resulting higher injectivity. A mineralogical analysis revealed that magnesium chloride decreases the crystal size of the precipitated materials and that another carbonate of aragonite is newly formed. Mechanical test results indicated that carbonate precipitates within the soils and brings about a significant improvement in strength. A maximum UCS of 0.6 MPa was obtained from the treated samples.

  19. Induced calcium carbonate precipitation using Bacillus species.

    Seifan, Mostafa; Samani, Ali Khajeh; Berenjian, Aydin


    Microbially induced calcium carbonate precipitation is an emerging process for the production of self-healing concrete. This study was aimed to investigate the effects and optimum conditions on calcium carbonate biosynthesis. Bacillus licheniformis, Bacillus sphaericus, yeast extract, urea, calcium chloride and aeration were found to be the most significant factors affecting the biomineralization of calcium carbonate. It was noticed that the morphology of microbial calcium carbonate was mainly affected by the genera of bacteria (cell surface properties), the viscosity of the media and the type of electron acceptors (Ca(2+)). The maximum calcium carbonate concentration of 33.78 g/L was achieved at the optimum conditions This value is the highest concentration reported in the literature.

  20. Immunization of a wild koala population with a recombinant Chlamydia pecorum Major Outer Membrane Protein (MOMP) or Polymorphic Membrane Protein (PMP) based vaccine: New insights into immune response, protection and clearance

    Robbins, Amy; Jelocnik, Martina; Khan, Shahneaz Ali; Hanger, Jon; Gerdts, Volker; Potter, Andrew; Polkinghorne, Adam; Timms, Peter


    We assessed the effects of two different single-dose anti-Chlamydia pecorum (C. pecorum) vaccines (containing either Major Outer Membrane Protein (3MOMP) or Polymorphic Membrane Protein (Pmp) as antigens) on the immune response of a group of wild koalas. Both vaccines elicited a systemic humoral response as seen by the production of anti-chlamydial IgG antibodies in more than 90% of vaccinated koalas. A mucosal immune response was also observed, with an increase in Chlamydia-specific mucosal IgG and/or IgA antibodies in some koalas post-vaccination. Both vaccines elicited a cell-mediated immune response as measured by the production of the cytokines IFN-γ and IL-17 post-vaccination. To determine the level of protection provided by the vaccines under natural conditions we assessed C. pecorum infection loads and chlamydial disease status of all vaccinated koalas pre- and post-vaccination, compared to a non-vaccinated cohort from the same habitat. The MOMP vaccinated koalas that were infected on the day of vaccination showed significant clearance of their infection at 6 months post-vaccination. In contrast, the number of new infections in the PMP vaccine was similar to the control group, with some koalas progressing to disease. Genotyping of the ompA gene from the C. pecorum strains infecting the vaccinated animals, identified genetic variants of ompA-F genotype and a new genotype ompA-O. We found that those animals that were the least well protected became infected with strains of C. pecorum not covered by the vaccine. In conclusion, a single dose vaccine formulated with either recombinant PmpG or MOMP can elicit both cell-mediated and humoral (systemic and mucosal) immune responses, with the MOMP vaccine showing clearance of infection in all infected koalas. Although the capability of our vaccines to stimulate an adaptive response and be protective needs to be fully evaluated, this work illustrates the necessity to combine epitopes most relevant to a large panel of

  1. Localized precipitation and runoff on Mars

    Kite, Edwin S; Rafkin, Scot; Manga, Michael; Dietrich, William E


    We use the Mars Regional Atmospheric Modeling System (MRAMS) to simulate lake storms on Mars, finding that intense localized precipitation will occur for lake size >=10^3 km^2. Mars has a low-density atmosphere, so deep convection can be triggered by small amounts of latent heat release. In our reference simulation, the buoyant plume lifts vapor above condensation level, forming a 20km-high optically-thick cloud. Ice grains grow to 200 microns radius and fall near (or in) the lake at mean rates up to 1.5 mm/hr water equivalent (maximum rates up to 6 mm/hr water equivalent). Because atmospheric temperatures outside the surface layer are always well below 273K, supersaturation and condensation begin at low altitudes above lakes on Mars. In contrast to Earth lake-effect storms, lake storms on Mars involve continuous precipitation, and their vertical velocities and plume heights exceed those of tropical thunderstorms on Earth. Convection does not reach above the planetary boundary layer for lakes O(10^2) mbar. In...

  2. Stochastic precipitation generator with hidden state covariates

    Kim, Yongku; Lee, GyuWon


    Time series of daily weather such as precipitation, minimum temperature and maximum temperature are commonly required for various fields. Stochastic weather generators constitute one of the techniques to produce synthetic daily weather. The recently introduced approach for stochastic weather generators is based on generalized linear modeling (GLM) with covariates to account for seasonality and teleconnections (e.g., with the El Niño). In general, stochastic weather generators tend to underestimate the observed interannual variance of seasonally aggregated variables. To reduce this overdispersion, we incorporated time series of seasonal dry/wet indicators in the GLM weather generator as covariates. These seasonal time series were local (or global) decodings obtained by a hidden Markov model of seasonal total precipitation and implemented in the weather generator. The proposed method is applied to time series of daily weather from Seoul, Korea and Pergamino, Argentina. This method provides a straightforward translation of the uncertainty of the seasonal forecast to the corresponding conditional daily weather statistics.

  3. Precipitable water vapor and its relationship with the Standardized Precipitation Index: ground-based GPS measurements and reanalysis data

    Bordi, Isabella; Zhu, Xiuhua; Fraedrich, Klaus


    Monthly means of ground-based GPS measurements of precipitable water vapor (PWV) from six stations in the USA covering the period January 2007-December 2012 are analyzed to investigate their usefulness for monitoring meteorological wet/dry spells. For this purpose, the relationship between PWV and the Standardized Precipitation Index (SPI) on 1-month timescale is investigated. The SPI time series at grid points close to the stations are computed using gridded precipitation records from the NOAA Climate Prediction Center (CPC) unified precipitation dataset (January 1948-April 2012). GPS measurements are first verified against PWV data taken from the latest ECMWF reanalysis ERA-Interim; these PWV reanalysis data, which extend back to 1979, are then used jointly with CPC precipitation to compute precipitation efficiency (PE), defined as the percentage of total water vapor content that falls onto the surface as measurable precipitation in a given time period. The overall results suggest that (i) PWV time series are dominated by the seasonal cycle with maximum values during summer months, (ii) the comparison between GPS and ERA-Interim PWV monthly data shows good agreement with differences less than 4 mm, (iii) at all stations and for almost all months, PWV is only poorly correlated with recorded precipitation and the SPI, while PE correlates highly with the SPI, providing an estimate of the water availability at a given location and useful information on wet/dry spell occurrence, and (iv) long data records would allow, for each month of the year, the identification of PE thresholds associated with different SPI classes that, in turn, have potential for forecasting meteorological wet/dry spells. Thus, it is through PE that ground-based GPS measurements appear of relevance for assessing wet/dry spells, although there is not a direct relationship between PWV and SPI.

  4. Evaluation of probable maximum snow accumulation: Development of a methodology for climate change studies

    Klein, Iris M.; Rousseau, Alain N.; Frigon, Anne; Freudiger, Daphné; Gagnon, Patrick


    Probable maximum snow accumulation (PMSA) is one of the key variables used to estimate the spring probable maximum flood (PMF). A robust methodology for evaluating the PMSA is imperative so the ensuing spring PMF is a reasonable estimation. This is of particular importance in times of climate change (CC) since it is known that solid precipitation in Nordic landscapes will in all likelihood change over the next century. In this paper, a PMSA methodology based on simulated data from regional climate models is developed. Moisture maximization represents the core concept of the proposed methodology; precipitable water being the key variable. Results of stationarity tests indicate that CC will affect the monthly maximum precipitable water and, thus, the ensuing ratio to maximize important snowfall events. Therefore, a non-stationary approach is used to describe the monthly maximum precipitable water. Outputs from three simulations produced by the Canadian Regional Climate Model were used to give first estimates of potential PMSA changes for southern Quebec, Canada. A sensitivity analysis of the computed PMSA was performed with respect to the number of time-steps used (so-called snowstorm duration) and the threshold for a snowstorm to be maximized or not. The developed methodology is robust and a powerful tool to estimate the relative change of the PMSA. Absolute results are in the same order of magnitude as those obtained with the traditional method and observed data; but are also found to depend strongly on the climate projection used and show spatial variability.

  5. Temperature and Precipitation Changes in China During the Holocene


    We review here proxy records of temperatare and precipitation in China during the Holocene,especially the last two millennia.The quality of proxy data,methodology of reconstruction,and uncertainties in reconstruction were emphasized in comparing different temperatare and precipitation reconstruction and clarilying temporal and spatial patterns of temperature and precipitation during the Holocene.The Holocene climate was generally warm and wet.The warmest period occurred in 9.6-6.2 cal ka BP,whereas a period of maximum monsoon precipitation started at about 11.0 cal ka BP and lasted until about 8.O-5.0 cal ka BP.There were a series of millennial-scale cold or dry events superimposed on the general trend of climate changes.During past two millennia,a warming trend in the 20th century was clearly detected,but the warming magnitude was smaller than the maximum level of the Medieval Warm Period and the Middle Holocene.Cold conditions occurred over the whole of China during the Little Ice Age (AD 1400-AD 1900),but the warming of the Medieval Warm Period(AD 900-AD 1300)was not distinct in China,especially west China.The spatial pattern of precipitation showed significant regional differences in China,especially east China.The modern warm period has lasted 20、years from 1987 to 2006.Bi-decadal oscillation in precipitation variability was apparent over China during the 20th century. Solar activity and volcanic eruptions both were major forcings governing the climate variability during the last millennium.

  6. Precipitation regime and stable isotopes at Dome Fuji, East Antarctica

    Dittmann, Anna; Schlosser, Elisabeth; Masson-Delmotte, Valérie; Powers, Jordan G.; Manning, Kevin W.; Werner, Martin; Fujita, Koji


    A unique set of 1-year precipitation and stable water isotope measurements from the Japanese Antarctic station, Dome Fuji, has been used to study the impact of the synoptic situation and the precipitation origin on the isotopic composition of precipitation on the Antarctic Plateau. The Antarctic Mesoscale Prediction System (AMPS) archive data are used to analyse the synoptic situations that cause precipitation. These situations are investigated and divided into five categories. The most common weather situation during a precipitation event is an upper-level ridge that extends onto the Antarctic Plateau and causes strong northerly advection from the ocean. Most precipitation events are associated with an increase in temperature and wind speed, and a local maximum of δ18O. During the measurement period, 21 synoptically caused precipitation events caused 60 % of the total annual precipitation, whereas the remaining 40 % were predominantly attributed to diamond dust. By combining the synoptic analyses with 5-day back-trajectories, the moisture source regions for precipitation events were estimated. An average source region around a latitude of 55° S was found. The atmospheric conditions in the source region were used as initial conditions for running a Rayleigh-type isotopic model in order to reproduce the measured isotopic composition of fresh snow and to investigate the influence of the precipitation source region on the isotope ratios. The model represents the measured annual cycle of δ18O and the second-order isotopic parameter deuterium excess reasonably well, but yields on average too little fractionation along the transport/cooling path. While simulations with an isotopic general circulation model (GCM) (ECHAM5-wiso) for Dome Fuji are on average closer to the observations, this model cannot reproduce the annual cycle of deuterium excess. In the event-based analysis, no evidence of a correlation of the measured deuterium excess with the latitude of the

  7. Chemical Data for Precipitate Samples

    Foster, Andrea L.; Koski, Randolph A.


    During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

  8. Metal particle's precipitation behavior in direct reading ferrography precipitator tube

    尹凤福; 李谋渭


    A new metal particle monitoring instrument was developed by improving the traditional direct reading ferrography. The precipitation behaviors of sub-magnetic particles, magnetic particles, and the mixture of these particles were examined with the instrument. The results show that the precipitation behavior of sub-magnetic metal particles of copper and aluminum is not random as it was believed previously. The sub-magnetic particles show a distribution in the precipitator tube, almost the same as the deposition curves as the magnetic particles have. The deposition amount of particles is increased in the oil which consists of several different kinds of particles. On the base of these experiments, a new index used for the total quantity of wear was redefined.

  9. 周围髓鞘蛋白22基因重复突变致夏科-马里-图斯病1A亚型的临床变异性%Clinical variability of Charcot-Marie-Tooth disease type 1A patients with PMP22 duplication mutation

    段晓慧; 顾卫红; 王国相; 郝莹; 王康; 汪仁斌; 孙少杰; 杨斯柳


    目的 探讨夏科-马里-图斯病(CMT)患者周围髓鞘蛋白22(PMP22)基因重复突变特征及临床变异性.方法 联合应用改良的等位基因特异性PCR-双酶切和基于荧光标记毛细管电泳短串联重复序列(STR)分析对45例临床拟诊CMT患者进行PMP22基因重复突变的检测,详细分析其中阳性病例的临床特征.结果 在45例拟诊CMT患者中共检测出PMP22基因重复病例21例,包括10例临床特征符合四肢远端萎缩无力的典型CMT1型患者和11例不典型的CMT患者,后者具有特殊表型:1例仅以轻度头晕就诊;1例合并听力障碍;2例以反复发作性肢体无力起病;2例伴有上肢姿势性震颤;4例伴有小脑性共济失调;1例伴有癫(癎)发作.结论 PMP22基因重复突变为CMT病最常见的病因,改良的等位基因特异性PCR-双酶切提供了一种准确、可靠并易于操作的检测方法,有助于该病的诊断和鉴别.同时,通过综合分析PMP22重复突变阳性的CMT1A患者临床表现、电生理及病理特征,提示该组疾病具有高度的临床变异性.%Objective To investigate the characteristics of PMP22 duplication mutation and the clinical variability of Charcot-Marie-Tooth disease type 1A (CMT1A) patients. Methods PMP22 duplication mutation analysis were performed in 45 cases diagnosed probably CMT by combination of improved allele-specific PCR-restriction enzyme digestion and short tandem repeat (STR) analysis based on laser-induced fluorescence detection in capillary electrophoresis. The clinical features of the positive cases were precisely analyzed. Results With the combined use of two methods, PMP22 duplication was detected in 21 cases, i.e. 10 CMT1 cases with typical presentations including weakness and atrophy in the distal limbs, and 11 atypical cases with special phenotypes including 1 case with mild dizziness, 1 case with hearing loss, 2 cases with recurrent limbs weakness, 2 cases with postural tremor in the upper limbs, 4

  10. Divergent, stereoselective access to heterocyclic α,α-quaternary- and β(2,3,3)-amino acid derivatives from a N-Pmp-protected Orn-derived β-lactam.

    Núñez-Villanueva, Diego; García-López, M Teresa; Martín-Martínez, Mercedes; González-Muñiz, Rosario


    A suitably protected Orn-derived (3S,4S)-β-lactam was used as common intermediate in the synthesis of conformationally constrained (3S,4S)-2-oxoazepane α,α- and (2S,3S)-2-oxopiperidine-β(2,3,3)-amino acid derivatives. Compared to alternative procedures using an N-p-methoxybenzyl group at the 2-azetidinone, the incorporation of a p-methoxyphenyl moiety is crucial for the excellent stereochemical outcomes in the preparation of these heterocyclic amino acids. Chemoselective 7- or 6-exo-trig cyclization was achieved through alternative sequences of Pmp-deprotection/Boc-activation, followed by inter- and intramolecular β-lactam ring opening, respectively.

  11. The L2b real-time PCR targeting the pmpH gene of Chlamydia trachomatis used for the diagnosis of lymphogranuloma venereum is not specific to L2b strains.

    Touati, A; Peuchant, O; Hénin, N; Bébéar, C; de Barbeyrac, B


    The French Reference Centre for chlamydiae uses two real-time PCRs targeting the pmpH gene of Chlamydia trachomatis to differentiate between L strains and variant L2b, responsible for a lymphogranuloma venereum outbreak in Europe. We compared the results obtained for 122 L2b C. trachomatis-positive specimens, using the two real-time PCRs, with the sequencing of the ompA gene. Only 91 specimens were confirmed as L2b. Our results demonstrate that the lymphogranuloma venereum outbreak is no longer dominated by the variant L2b, and that many L-positive specimens were misidentified as L2b with the method used, which raises the question of its specificity. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  12. The Global Precipitation Measurement Mission

    Jackson, Gail


    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  13. Characterization of flood and precipitation events in Southwestern Germany and stochastic simulation of extreme precipitation (Project FLORIS-SV)

    Florian, Ehmele; Michael, Kunz


    Several major flood events occurred in Germany in the past 15-20 years especially in the eastern parts along the rivers Elbe and Danube. Examples include the major floods of 2002 and 2013 with an estimated loss of about 2 billion Euros each. The last major flood events in the State of Baden-Württemberg in southwest Germany occurred in the years 1978 and 1993/1994 along the rivers Rhine and Neckar with an estimated total loss of about 150 million Euros (converted) each. Flood hazard originates from a combination of different meteorological, hydrological and hydraulic processes. Currently there is no defined methodology available for evaluating and quantifying the flood hazard and related risk for larger areas or whole river catchments instead of single gauges. In order to estimate the probable maximum loss for higher return periods (e.g. 200 years, PML200), a stochastic model approach is designed since observational data are limited in time and space. In our approach, precipitation is linearly composed of three elements: background precipitation, orographically-induces precipitation, and a convectively-driven part. We use linear theory of orographic precipitation formation for the stochastic precipitation model (SPM), which is based on fundamental statistics of relevant atmospheric variables. For an adequate number of historic flood events, the corresponding atmospheric conditions and parameters are determined in order to calculate a probability density function (pdf) for each variable. This method involves all theoretically possible scenarios which may not have happened, yet. This work is part of the FLORIS-SV (FLOod RISk Sparkassen Versicherung) project and establishes the first step of a complete modelling chain of the flood risk. On the basis of the generated stochastic precipitation event set, hydrological and hydraulic simulations will be performed to estimate discharge and water level. The resulting stochastic flood event set will be used to quantify the

  14. Towards Quantitative Ocean Precipitation Validation

    Klepp, C.; Bakan, S.; Andersson, A.


    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding and successful modelling of the global climate system as it is an important component of the water cycle. However, reliable detection of quantitative precipitation over the global oceans, especially at high latitudes during the cold season remains a challenging task for remote sensing and model based estimates. Quantitative ship validation data using reliable instruments for measuring rain and snowfall hardly exist but are highly demanded for ground validation of such products. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from Especially for North Atlantic mid-latitude mix-phase precipitation, the HOAPS precipitation retrieval has been investigated in some depth. This analysis revealed that the HOAPS retrieval qualitatively well represents cyclonic and intense mesoscale precipitation in agreement with ship observations and Cloudsat data, while GPCP, ECMWF forecast, ERA-40 and regional model data miss mesoscale precipitation substantially. As the differences between the investigated data sets are already large under mix-phase precipitation conditions, further work is carried out on snowfall validation during the cold season at high-latitudes. A Norwegian Sea field campaign in winter 2005 was carried out using an optical disdrometer capable of measuring quantitative amounts of snowfall over the ocean

  15. Receiver function estimated by maximum entropy deconvolution

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生


    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  16. Precipitation in the Central Mediterranean during the last century

    Maheras, P.; Balafoutis, Ch.; Vafiadis, M.


    Monthly precipitation data from 10 stations (Patras, Corfu, Hvar, Trieste, Venice, Florence, Rome, Naples, Catania and Malta) in the Central Mediterranean area are used for a period of 95 years (1894 1988). The homogeneity of these precipitation time series is tested and their statistical characteristics are analysed. An abrupt climatic change is found at Naples and Rome. The application of Principal Component Analysis (PCA) has yielded three groups of stations where the precipitation data indicate similar fluctuations. Group A includes the stations situated along the coasts of the Ionian and Adriatic seas and the station Naples, while Group B includes the Northern Italian stations and Group C includes the stations at Catania and Malta. In all three groups maximum precipitation was observed during the 1930s. The periodicities of the scores of the significant components have been studied by spectral analysis and significant periodicities of 13.6, 3.5 and 2.2 years were found. Finally, a discussion of the relationships between these precipitation fluctuations and circulation types over the Mediterranean is presented.

  17. Spatial interpolation schemes of daily precipitation for hydrologic modeling

    Hwang, Y.; Clark, M.; Rajagopalan, B.; Leavesley, G.


    Distributed hydrologic models typically require spatial estimates of precipitation interpolated from sparsely located observational points to the specific grid points. We compare and contrast the performance of regression-based statistical methods for the spatial estimation of precipitation in two hydrologically different basins and confirmed that widely used regression-based estimation schemes fail to describe the realistic spatial variability of daily precipitation field. The methods assessed are: (1) inverse distance weighted average; (2) multiple linear regression (MLR); (3) climatological MLR; and (4) locally weighted polynomial regression (LWP). In order to improve the performance of the interpolations, the authors propose a two-step regression technique for effective daily precipitation estimation. In this simple two-step estimation process, precipitation occurrence is first generated via a logistic regression model before estimate the amount of precipitation separately on wet days. This process generated the precipitation occurrence, amount, and spatial correlation effectively. A distributed hydrologic model (PRMS) was used for the impact analysis in daily time step simulation. Multiple simulations suggested noticeable differences between the input alternatives generated by three different interpolation schemes. Differences are shown in overall simulation error against the observations, degree of explained variability, and seasonal volumes. Simulated streamflows also showed different characteristics in mean, maximum, minimum, and peak flows. Given the same parameter optimization technique, LWP input showed least streamflow error in Alapaha basin and CMLR input showed least error (still very close to LWP) in Animas basin. All of the two-step interpolation inputs resulted in lower streamflow error compared to the directly interpolated inputs. ?? 2011 Springer-Verlag.

  18. Measurement of precipitation using lysimeters

    Fank, Johann; Klammler, Gernot


    Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between

  19. Maximum Power from a Solar Panel

    Michael Miller


    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  20. Kinetics of asphaltene precipitation from crude oils

    Maqbool, T.; Hussein, I.A.; Fogler, H.S. [Michigan Univ., Ann Arbor (United States). Dept. of Chemical Engineering


    The kinetics of asphaltene precipitation from crude oils was investigated using n-alkane precipitants. Recent studies have shown that there is a kinetic phenomenon associated with asphaltene precipitation. This study showed that the time needed to precipitate the asphaltenes can vary from a few minutes to several months, depending on the amount of n-alkane precipitant added. As such, the onset of asphaltene precipitation is a function of the concentration of precipitant and time. A technique to quantify the amount of asphaltenes precipitated as a function of time and precipitant concentration was presented. This study also investigated the kinetic effects caused by various precipitants. Optical microscopy was used to monitor the growth of asphaltene aggregates with time. Refractive index measurements provided further insight into the kinetics of asphaltene precipitation. Polarity based fractionation and dielectric constant measurements were used to compare the nature of asphaltenes precipitated early in the precipitation process with the asphaltenes precipitated at later times. It was concluded that asphaltenes precipitating at different times from the same crude oil-precipitant mixture are different from one another. 3 refs.

  1. Radar-Derived Quantitative Precipitation Estimation Based on Precipitation Classification

    Lili Yang


    Full Text Available A method for improving radar-derived quantitative precipitation estimation is proposed. Tropical vertical profiles of reflectivity (VPRs are first determined from multiple VPRs. Upon identifying a tropical VPR, the event can be further classified as either tropical-stratiform or tropical-convective rainfall by a fuzzy logic (FL algorithm. Based on the precipitation-type fields, the reflectivity values are converted into rainfall rate using a Z-R relationship. In order to evaluate the performance of this rainfall classification scheme, three experiments were conducted using three months of data and two study cases. In Experiment I, the Weather Surveillance Radar-1988 Doppler (WSR-88D default Z-R relationship was applied. In Experiment II, the precipitation regime was separated into convective and stratiform rainfall using the FL algorithm, and corresponding Z-R relationships were used. In Experiment III, the precipitation regime was separated into convective, stratiform, and tropical rainfall, and the corresponding Z-R relationships were applied. The results show that the rainfall rates obtained from all three experiments match closely with the gauge observations, although Experiment II could solve the underestimation, when compared to Experiment I. Experiment III significantly reduced this underestimation and generated the most accurate radar estimates of rain rate among the three experiments.

  2. A hybrid framework for verification of satellite precipitation products

    Li, J.; Hsu, K.; AghaKouchak, A.; Sorooshian, S.


    Advances in satellite technology have led to the development of many remote-sensing algorithms to estimate precipitation at quasi-global scales. A number of satellite precipitation products are provided at high spatial and temporal resolutions that are suitable for short-term hydrologic applications. Several coordinated validation activities have been established to evaluate the accuracy of satellite precipitation. Traditional verification measures summarize pixel-to-pixel differences between observation and estimates. Object-based verification methods, however, extend pixel based validation to address errors related to spatial patterns and storm structure, such as the shape, volume, and distribution of precipitation rain-objects. In this investigation, a 2D watershed segmentation technique is used to identify rain storm objects and is further adopted in a hybrid verification framework to diagnose the storm-scale rainfall objects from both satellite-based precipitation estimates and ground observations (radar estimates). Five key scores are identified in the objective-based verification framework, including false alarm ratio, missing ratio, maximum of total interest, equal weight and weighted summation of total interest. These scores indicate the performance of satellite estimates with features extracted from the segmented storm objects. The proposed object-based verification framework was used to evaluate PERSIANN, PERSIANN-CCS, CMORPH, 3B42RT against NOAA stage IV MPE multi-sensor composite rain analysis. All estimates are evaluated at 0.25°x0.25° daily-scale in summer 2008 over the continental United States (CONUS). The five final scores for each precipitation product are compared with the median of maximum interest (MMI) of the Method for Object-Based Diagnostic Evaluation (MODE). The results show PERSIANN and CMORPH outperform 3B42RT and PERSIANN-CCS. Different satellite products presented distinct features of precipitation. For example, the sizes of

  3. Analysis of satellite precipitation over East Africa during last decades

    Cattani, Elsa; Wenhaji Ndomeni, Claudine; Merino, Andrés; Levizzani, Vincenzo


    Daily accumulated precipitation time series from satellite retrieval algorithms (e.g., ARC2 and TAMSAT) are exploited to extract the spatial and temporal variability of East Africa (EA - 5°S-20°N, 28°E-52°E) precipitation during last decades (1983-2013). The Empirical Orthogonal Function (EOF) analysis is applied to precipitation time series to investigate the spatial and temporal variability in particular for October-November-December referred to as the short rain season. Moreover, the connection among EA's precipitation, sea surface temperature, and soil moisture is analyzed through the correlation with the dominant EOF modes of variability. Preliminary results concern the first two EOF's modes for the ARC2 data set. EOF1 is characterized by an inter-annual variability and a positive correlation between precipitation and El Niño, positive Indian Ocean Dipole mode, and soil moisture, while EOF2 shows a dipole structure of spatial variability associated with a longer scale temporal variability. This second dominant mode is mostly linked to sea surface temperature variations in the North Atlantic Ocean. Further analyses are carried out by computing the time series of the joint CCI/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI,, i.e. RX1day, RX5day, CDD, CDD, CWD, SDII, PRCPTOT, R10, R20. The purpose is to identify the occurrenes of extreme events (droughts and floods) and extract precipitation temporal variation by trend analysis (Mann-Kendall technique). Results for the ARC2 data set demonstrate the existence of a dipole spatial pattern in the linear trend of the time series of PRCPTOT (annual precipitation considering days with a rain rate > 1 mm) and SDII (average precipitation on wet days over a year). A negative trend is mainly present over West Ethiopia and Sudan, whereas a positive trend is exhibited over East Ethiopia and Somalia. CDD (maximum number of consecutive dry days) and

  4. Utilization of Precipitation and Moisture Products Derived from Satellites to Support NOAA Operational Precipitation Forecasts

    Ferraro, R.; Zhao, L.; Kuligowski, R. J.; Kusselson, S.; Ma, L.; Kidder, S. Q.; Forsythe, J. M.; Jones, A. S.; Ebert, E. E.; Valenti, E.


    of lives. To provide observations-based forecast guidance for TC heavy rain, the Tropical Rainfall Potential (TRaP), an extrapolation forecast generated by accumulating rainfall estimates from satellites with microwave sensors as the storm is translated along the forecast track, was originally developed to predict the maximum rainfall at landfall, as well as the spatial pattern of precipitation. More recently, an enhancement has been made to combine the TRaP forecasts from multiple sensors and various start times into an ensemble (eTRaP). The ensemble approach provides not only more accurate quantitative precipitation forecasts, including more skillful maximum rainfall amount and location, it also produces probabilistic forecasts of rainfall exceeding various thresholds that decision makers can use to make critical risk assessments. Examples of the utilization and performance of eTRaP will be given in the presentation.

  5. Experimental study of brushite precipitation

    Arifuzzaman, S. M.; Rohani, S.


    A systematic approach was developed for the synthesis of orthophosphates in the laboratory. A set of experiments was designed to investigate the influence of initial calcium and phosphorus concentration on the precipitated phase, nucleation pH and product size distribution at 25°C. Another goal was to characterize the precipitated phase. The investigation was conducted in a batch reactor. The initial molar concentration of calcium chloride and hydrated sodium phosphate solutions was varied from 0.005 to 0.08-mole dm -3 and the solution pH was kept under 7.1. Analysis by powder XRD, FTIR and elemental P/Ca revealed that the crystals precipitated were pure brushite (dicalcium phosphate dihydrate), as expected, except in one experiment in which amorphous calcium phosphate precipitated. The brushite crystals produced had plate-like morphology as investigated by scanning electron microscopy (SEM). The nucleation pH showed a decreasing trend as the concentration of the calcium and phosphorus increased in the reactor, but the volume mean diameter of the crystals and the span of the crystal size distribution did not show any sensitivity to the changes in the initial calcium and phosphorus concentration.

  6. Electrostatic Precipitator (ESP) TRAINING MANUAL

    The manual assists engineers in using a computer program, the ESPVI 4.0W, that models all elements of an electrostatic precipitator (ESP). The program is a product of the Electric Power Research Institute and runs in the Windows environment. Once an ESP is accurately modeled, the...

  7. Grassland responses to precipitation extremes

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  8. The inverse maximum dynamic flow problem

    BAGHERIAN; Mehri


    We consider the inverse maximum dynamic flow (IMDF) problem.IMDF problem can be described as: how to change the capacity vector of a dynamic network as little as possible so that a given feasible dynamic flow becomes a maximum dynamic flow.After discussing some characteristics of this problem,it is converted to a constrained minimum dynamic cut problem.Then an efficient algorithm which uses two maximum dynamic flow algorithms is proposed to solve the problem.

  9. Is the intensification of precipitation extremes with global warming better detected at hourly than daily resolutions?

    Barbero, R.; Fowler, H. J.; Lenderink, G.; Blenkinsop, S.


    Although it has been documented that daily precipitation extremes are increasing worldwide, faster increases may be expected for subdaily extremes. Here after a careful quality control procedure, we compared trends in hourly and daily precipitation extremes using a large network of stations across the United States (U.S.) within the 1950-2011 period. A greater number of significant increasing trends in annual and seasonal maximum precipitation were detected from daily extremes, with the primary exception of wintertime. Our results also show that the mean percentage change in annual maximum daily precipitation across the U.S. per global warming degree is 6.9% °C-1 (in agreement with the Clausius-Clapeyron rate) while lower sensitivities were observed for hourly extremes, suggesting that changes in the magnitude of subdaily extremes in response to global warming emerge more slowly than those for daily extremes in the climate record.

  10. A comparison of total precipitation values estimated from measurements and a 1D cloud model

    Z. Aslan

    Full Text Available The purpose of this study is to establish a relation between observed total precipitation values and estimations from a one-dimensional diagnostic cloud model. Total precipitation values estimated from maximum liquid water content, maximum vertical velocity, cloud top height, and temperature excess are also used to provide an equation for the total precipitation prediction. Data for this study were collected in Istanbul during the autumns of 1987 and 1988. The statistical models are developed with multiple regression technique and then comparatively verified with independent data for 1990. The multiple regression coefficients are in the range of 75% to 80% in the statistical models. Results of the test showed that total precipitation values estimated from the above techniques are in good agreement, with correlation coefficient between 40% and 46% based on test data for 1990.

  11. Maximum permissible voltage of YBCO coated conductors

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)


    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  12. Variability and Trends in Precipitation, Temperature and Drought Indices in the State of California

    Minxue He; Mahesh Gautam


    This study presents a comprehensive assessment of the variability and trends of the precipitation and temperature along with the trends in drought indices over the State of California. The non-parametric Mann–Kendall trend test is applied with a trend-free pre-whitening procedure in trend identification. A dataset containing 120-year (water years 1896–2015) monthly precipitation, average temperature, maximum temperature, minimum temperature and the Palmer Index for seven climatic regions of t...

  13. Features of cross-Pacific climate shown in the variability of China and US precipitation

    Li, Q.; Yang, S.; Kousky, V. E.; Higgins, R. W.; Lau, K.-M.; Xie, P.


    In this study, we have analyzed the climate features of China and the United States with a focus on the differences, similarities, connectivity, and predictability of precipitation and the relationships between precipitation and large-scale patterns of natural variability. China precipitation is characterized by large seasonality, with a maximum in summer and a minimum in winter. The seasonality of precipitation shows an increasing linear tendency in northwest China, with a change of about 20% from 1901 to 1998. A relatively weaker increasing tendency also appears in the Big Bend of Yellow River (BBYR) and the Tibetan Plateau, while southwest China experiences a decreasing tendency. Furthermore, the seasonality in the BBYR shows particularly significant interdecadal variability, while that of southern and eastern China has decreased slightly in the recent decades.Compared to China, the United States as a whole has less precipitation in summer but more precipitation in other seasons. Here, the seasonality of precipitation is only about 24% of that in China. The annual mean precipitation is 64.1 mm per month in the United States, compared to 54.6 mm per month in China. The seasonality of precipitation exhibits a decreasing tendency in the southeast, Pacific Northwest, and Gulf Coast and an increasing tendency in the Great Lakes. The seasonality in the Great Plains exhibits large interdecadal variability.The long-term variations of precipitation are highly seasonally dependent. In summer, a decreasing trend is observed in north China and an increasing trend is found in eastern-central China. However, these trends are almost opposite in spring. In addition, the fall precipitation decreases with time nearly everywhere in China except for the middle and lower reaches of the Yangtze River Valley.Results also indicate that the El Niño/Southern Oscillation (ENSO), the Arctic Oscillation (AO), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), and

  14. Nonstationary modeling of extreme precipitation in China

    Gao, Meng; Mo, Dingyuan; Wu, Xiaoqing


    The statistical methods based on extreme value theory have been traditionally used in meteorology and hydrology for a long time. Due to climate change and variability, the hypothesis of stationarity in meteorological or hydrological time series was usually not satisfied. In this paper, a nonstationary extreme value analysis was conducted for annual maximum daily precipitation (AMP) at 631 meteorological stations over China for the period 1951-2013. Stationarity of all 631 AMP time series was firstly tested using KPSS test method, and only 48 AMP time series showed non-stationarity at 5% significance level. The trends of these 48 nonstationary AMP time series were further tested using M-K test method. There were 25 nonstationary AMP time series mainly distributed in southern and western China showing significant positive trend at 5% level. Another 5 nonstationary AMP time series with significant negative trends were near northern urban agglomeration, Sichuan Basin, and central China. For these nonstationary AMP time series with significant positive or negative trends, the location parameter in generalized extreme value (GEV) distribution was assumed to be time-varying, and the trends were successfully characterized by the nonstationary GEV models. For the remaining 18 nonstationary AMP time series mainly in the eastern portion of China, no significant trend was detected. The correlation analysis showed that only 5 nonstationary AMP time series were significantly correlated with one or two of the four climate indices EASMI, WPI, SOI, and PDO. Then, the location and scale parameters in the GEV distribution were modeled as functions of the significantly correlated climate indices. The modeling results in this study showed that the nonstationary GEV distributions performed better than their stationary equivalents. Finally, 20-year and 50-year return levels of precipitation extremes at all 631 stations were estimated using the best fitting distribution for the year 1961

  15. Correlation between total precipitable water and precipitation over East Asia

    Keum, Wangho; Lim, Gyu-Ho


    The precipitation rate(PR) and the total precipitable water(TPW) interact with various physical mechanisms. The correlation of two variables changes with difference of domain resolution and characteristics of the region. This poster analyzes the correlation between PR and TPW over East Asia using Cyclostationary Empirical Orthogonal Function(CSEOF) which is one of the PCA analysis. The CSEOF is useful to search a periodic pattern of the data. The anomalies which is subtracted climatological mean from the original data are used to represent annual cycles. Two variances of ERA-Interim Monthly Total Column Water vapor and GPCP monthly precipitation amounts with 372 time since January, 1984 to December, 2014 are decomposed into several modes separately. The first mode which explain largest variance are used in analysis. PC of both PR and TPW increase recently on mean value and amplitude, and they show considerable correlation on phase. The correlation coefficient of PR and TPW is 0.61 and maintains the same values by month. The result of harmonic analysis shows 2 to 6 year oscillations. As result of decomposed modes of two variables, there is the relationship between TPW PC series and horizontal moisture gradient. The Horizontal moist gradient can change affect moisture flux convergence which is one of important variable of rainfall events.

  16. Stable isotopes of fossil teeth corroborate key general circulation model predictions for the Last Glacial Maximum in North America

    Kohn, Matthew J.; McKay, Moriah


    Oxygen isotope data provide a key test of general circulation models (GCMs) for the Last Glacial Maximum (LGM) in North America, which have otherwise proved difficult to validate. High δ18O pedogenic carbonates in central Wyoming have been interpreted to indicate increased summer precipitation sourced from the Gulf of Mexico. Here we show that tooth enamel δ18O of large mammals, which is strongly correlated with local water and precipitation δ18O, is lower during the LGM in Wyoming, not higher. Similar data from Texas, California, Florida and Arizona indicate higher δ18O values than in the Holocene, which is also predicted by GCMs. Tooth enamel data closely validate some recent models of atmospheric circulation and precipitation δ18O, including an increase in the proportion of winter precipitation for central North America, and summer precipitation in the southern US, but suggest aridity can bias pedogenic carbonate δ18O values significantly.

  17. Increased Stream Temperature in Response to Extreme Precipitation Events

    Wilson, C. E.; Gooseff, M. N.


    Aquatic ecosystem temperature regulation is essential to the survival of riverine fish species restricted to limited water temperature ranges. Dissolved oxygen levels, similarly necessary to fish health, are decreased by rising temperatures, as warmer waters can hold less oxygen than colder waters. Climate change projections forecast increased precipitation intensities, a trend that has already been observed in the past decade. Though extreme events are becoming more common, the stream temperature response to high-intensity rainfall is not yet completely understood. Precipitation and stream temperature records from gages in the Upper Midwestern United States were analyzed to determine whether there exists a positive relationship between high-intensity rainfall and stream temperature response. This region was chosen for its already observed trends in increasing precipitation intensity, and rural gages were used in order to minimize the effect of impervious surfaces on runoff amounts and temperature. Days with recorded precipitation were divided by an intensity threshold and classified as either high-intensity or low-intensity days. While the effects of rain events on temperature are variable, increases in stream temperature in response to high-intensity rainfall were observed. For some basins, daily maximum rates of stream temperature increase were, on average, greater for higher intensity events. Similarly, the average daily stream temperature range was higher in streams on days of high-intensity precipitation, compared to days of low-intensity events. Understanding the effect of increasing precipitation intensity in conjunction with rising air temperatures will provide insight into the future of aquatic ecosystems and their adaptation to climate change.

  18. Decadal modulation of East China winter precipitation by ENSO

    Liu, Jia; Wang, Hui; Lu, Er; Kumar, Arun


    The decadal modulation of East China winter precipitation by the El Niño-Southern Oscillation (ENSO) is examined using both observational data and coupled global climate model simulations. The co-variability between 68-year (1948-2015) observed East China precipitation and tropical Pacific sea surface temperature (SST) is quantified by the singular value decomposition (SVD) method. The first SVD mode relates Southeast China winter pluvial (drought) to the tropical Pacific El Niño (La Niña) SST. A comparison between two 480-year model simulations with and without ENSO suggests that ENSO can modulate both the intensity and frequency of East China winter precipitation. In the presence of ENSO, maximum precipitation anomalies over Southeast China can be increased by 50% and largely on the interannual timescale (3-6 years). It is also demonstrated that there is an asymmetry in the precipitation and circulation responses to warm and cold phases of ENSO. The responses are sensitive to the intensity of SST anomalies during El Niño, but less sensitive to SSTs during La Niña. This sensitivity, together with the decadal variations of ENSO, helps understand the observed decadal changes in the strength of the association between wintertime tropical Pacific SST and East China precipitation. The association is relatively weak during 1948-1977 when La Niña occurred more frequently, but strong during 1978-1999 when El Niño occurred more frequently. In the last 16 years (2000-2015) the association is weakest, likely due to the weakened variability of tropical Pacific SST since 2000.

  19. Generalised maximum entropy and heterogeneous technologies

    Oude Lansink, A.G.J.M.


    Generalised maximum entropy methods are used to estimate a dual model of production on panel data of Dutch cash crop farms over the period 1970-1992. The generalised maximum entropy approach allows a coherent system of input demand and output supply equations to be estimated for each farm in the sam

  20. 20 CFR 229.48 - Family maximum.


    ... month on one person's earnings record is limited. This limited amount is called the family maximum. The family maximum used to adjust the social security overall minimum rate is based on the employee's Overall..., when any of the persons entitled to benefits on the insured individual's compensation would, except...

  1. The maximum rotation of a galactic disc

    Bottema, R


    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously

  2. Niobium carbide precipitation in microalloyed steel

    Klinkenberg, C.; Hulka, K. [Niobium Products Co. GmbH, Duesseldorf (Germany); Bleck, W. [Inst. for Ferrous Metallurgy, RWTH Aachen Univ., Aachen (Germany)


    The precipitation of niobium carbo-nitrides in the austenite phase, interphase and ferrite phase of microalloyed steel was assessed by a critical literature review and a round table discussion. This work analyses the contribution of niobium carbide precipitates formed in ferrite in the precipitation hardening of commercially hot rolled strip. Thermodynamics and kinetics of niobium carbo-nitride precipitation as well as the effect of deformation and temperature on the precipitation kinetics are discussed in various examples to determine the amount of niobium in solid solution that will be available for precipitation hardening after thermomechanical rolling in the austenite phase and successive phase transformation. (orig.)


    Narcis MAIER


    Full Text Available CLUJ-NAPOCA precipitation forecast using WSR-98D Doppler radar. Forecasting inundations requires accurate spatial and temporal estimation of rainfalls in an area. Depending on the Z-R relationship (reflectivity-precipitation rate, the thresholds, maximum reflectivity data processing, VIL, cloud height or speed, provided by the WSR-98D affects the estimated precipitation used in the prediction of inundations. How much precipitation receives a watershed during an extreme event and what response will result depends on the basin hydrographic characteristics. A study of summer weather events between the years 2004-2008 and a new method in establishing relations between the radar estimated and recorded precipitations led to the determination of new relations between them which will balance the connections between them.

  4. When do oxide precipitates form during consolidation of oxide dispersion strengthened steels?

    Deschamps, A.; De Geuser, F.; Malaplate, J.; Sornin, D.


    The processing of oxide dispersion strengthened (ODS) steels involves ball milling, where the oxide forming species are driven in solid solution. Precipitation of the nanometre-scale oxides occurs during subsequent annealing and consolidation. This paper reports in-situ Small-Angle X-ray Scattering measurements of the formation of these precipitates during heating of cold-compressed as-milled powders. Clusters are already initially present, and precipitation starts at 300 °C. The maximum precipitate density is achieved at 600 °C, followed by very slow coarsening at higher temperature. These results open the way to understand the coupled evolution of precipitation and crystalline defects during heating and consolidation of ODS steels.

  5. Can reanalysis datasets describe the persistent temperature and precipitation extremes over China?

    Zhu, Jian; Huang, Dan-Qing; Yan, Pei-Wen; Huang, Ying; Kuang, Xue-Yuan


    The persistent temperature and precipitation extremes may bring damage to the economy and human due to their intensity, duration and areal coverage. Understanding the quality of reanalysis datasets in descripting these extreme events is important for detection, attribution and model evaluation. In this study, the performances of two reanalysis datasets [the twentieth century reanalysis (20CR) and Interim ECMWF reanalysis (ERA-Interim)] in reproducing the persistent temperature and precipitation extremes in China are evaluated. For the persistent temperature extremes, the two datasets can better capture the intensity indices than the frequency indices. The increasing/decreasing trend of persistent warm/cold extremes has been reasonably detected by the two datasets, particularly in the northern part of China. The ERA-Interim better reproduces the climatology and tendency of persistent warm extremes, while the 20CR has better skill to depict the persistent cold extremes. For the persistent precipitation extremes, the two datasets have the ability to reproduce the maximum consecutive 5-day precipitation. The two datasets largely underestimate the maximum consecutive dry days over the northern part of China, while overestimate the maximum consecutive wet days over the southern part of China. For the response of the precipitation extremes against the temperature variations, the ERA-Interim has good ability to depict the relationship among persistent precipitation extremes, local persistent temperature extremes, and global temperature variations over specific regions.

  6. Duality of Maximum Entropy and Minimum Divergence

    Shinto Eguchi


    Full Text Available We discuss a special class of generalized divergence measures by the use of generator functions. Any divergence measure in the class is separated into the difference between cross and diagonal entropy. The diagonal entropy measure in the class associates with a model of maximum entropy distributions; the divergence measure leads to statistical estimation via minimization, for arbitrarily giving a statistical model. The dualistic relationship between the maximum entropy model and the minimum divergence estimation is explored in the framework of information geometry. The model of maximum entropy distributions is characterized to be totally geodesic with respect to the linear connection associated with the divergence. A natural extension for the classical theory for the maximum likelihood method under the maximum entropy model in terms of the Boltzmann-Gibbs-Shannon entropy is given. We discuss the duality in detail for Tsallis entropy as a typical example.

  7. Precipitation Thresholds for Triggering Floods in the Corgo Basin, Portugal

    Mónica Santos


    Full Text Available Thresholds based on critical combinations of amount/duration of precipitation and flood events were estimated for the Corgo hydrographic basin, in northern Portugal. Thirty-one flood events in the Corgo basin were identified between 1865 and 2011 from a database of hydrometeorological disasters in Portugal. The minimum, maximum, and pre-warning thresholds that define the boundaries for flood occurrence were determined. The results show that the ratio between the total number of floods and precipitation events exceeding the minimum threshold denotes a relatively low probability of successful forecasting. This result may be due to the reduced number of flooding events in the floods database, which only include floods that caused damage as reported by the media. The estimated maximum threshold is not adequate for use in floods, since the majority of true positives are below this limit. However, and more interestingly, the retrospective verification of the estimated thresholds suggests that the minimum and pre-warning thresholds are well adjusted. Therefore, the application of these precipitation thresholds may contribute to minimize possible situations of pre-crisis or immediate crisis by reducing the flood consequences and the resources involved in emergency response to flood events.

  8. Acid precipitation; an annotated bibliography

    Wiltshire, Denise A.; Evans, Margaret L.


    This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

  9. Precipitation patterns during channel flow

    Jamtveit, B.; Hawkins, C.; Benning, L. G.; Meier, D.; Hammer, O.; Angheluta, L.


    Mineral precipitation during channelized fluid flow is widespread in a wide variety of geological systems. It is also a common and costly phenomenon in many industrial processes that involve fluid flow in pipelines. It is often referred to as scale formation and encountered in a large number of industries, including paper production, chemical manufacturing, cement operations, food processing, as well as non-renewable (i.e. oil and gas) and renewable (i.e. geothermal) energy production. We have studied the incipient stages of growth of amorphous silica on steel plates emplaced into the central areas of the ca. 1 meter in diameter sized pipelines used at the hydrothermal power plant at Hellisheidi, Iceland (with a capacity of ca 300 MW electricity and 100 MW hot water). Silica precipitation takes place over a period of ca. 2 months at approximately 120°C and a flow rate around 1 m/s. The growth produces asymmetric ca. 1mm high dendritic structures ';leaning' towards the incoming fluid flow. A novel phase-field model combined with the lattice Boltzmann method is introduced to study how the growth morphologies vary under different hydrodynamic conditions, including non-laminar systems with turbulent mixing. The model accurately predicts the observed morphologies and is directly relevant for understanding the more general problem of precipitation influenced by turbulent mixing during flow in channels with rough walls and even for porous flow. Reference: Hawkins, C., Angheluta, L., Hammer, Ø., and Jamtveit, B., Precipitation dendrites in channel flow. Europhysics Letters, 102, 54001

  10. Orientation Relationships between Precipitates and Their Parent Phases in Steels at Low Transformation Temperatures

    Lee, Dong Nyung; Han, Heung Nam

    The directed growth of precipitates proceeds in their parent phases at low transformation temperatures. The growth needs the activation energy. The activation energy is usually supplied in the form of thermal energy. However, at low transformation temperatures, the thermal energy is not enough to surmount the activation barrier, and so the strain energy developed in the parent phase assists surmounting the barrier, resulting in the directed growth of precipitates. The strain energy can result from a difference in density between the nucleus and matrix and a lattice mismatch along the nucleus:matrix interface. The fundamental concept of the model is that the maximum growth rate of precipitate is along the direction that generates the maximum strain energy and minimizes the interface energy. In this paper, orientation relationships between ferrite precipitate and parent austenite, between orthorhombic cementite precipitate and parent austenite, between cementite precipitate and parent ferrite, and between hexagonal Mo2C precipitate and parent ferrite have been discussed based on the directed growth model.

  11. Global Precipitation Mission Visualization Tool

    Schwaller, Mathew


    The Global Precipitation Mission (GPM) software provides graphic visualization tools that enable easy comparison of ground- and space-based radar observations. It was initially designed to compare ground radar reflectivity from operational, ground-based, S- and C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This design is also applicable to other groundbased and space-based radars, and allows both ground- and space-based radar data to be compared for validation purposes. The tool creates an operational system that routinely performs several steps. It ingests satellite radar data (precipitation radar data from TRMM) and groundbased meteorological radar data from a number of sources. Principally, the ground radar data comes from national networks of weather radars (see figure). The data ingested by the visualization tool must conform to the data formats used in GPM Validation Network Geometry-matched data product generation. The software also performs match-ups of the radar volume data for the ground- and space-based data, as well as statistical and graphical analysis (including two-dimensional graphical displays) on the match-up data. The visualization tool software is written in IDL, and can be operated either in the IDL development environment or as a stand-alone executable function.

  12. Changes in extreme dry and wet precipitation spell

    Papalexiou, Simon Michael; Foufoula-Georgiou, Efi; Onof, Chris


    Global warming is expected to alter the behavior of hydroclimatic variables in various ways. Therefore, it is of great importance not only to identify which hydroclimatic variables are going through changes but also which of their specific characteristics change and in what way. For example the major focus regarding precipitation has been on changes or trends in extreme events or in annual totals, obviously, not without a reason. Yet one of the aspects of precipitation we believe is of equal importance and has not been extensively studied is extreme dry and wet spells. Changes in dry and wet spells can severely impact all aspects of human lives, ranging from infrastructure planning and water resources management to agriculture and infectious disease spread. In this study we perform an extensive analysis of extreme dry and wet precipitation spells using tenths of thousands of daily precipitation records in order to identify trends or variability changes in the maximum number of consecutive dry or wet days of each year. Our final goal is to evaluate the percentage of stations globally with positive/negative trends either in the mean value or in variability of extreme dry and wet spells and assess if this percentage is statistically justifiable.

  13. European climate change experiments on precipitation change

    Beier, Claus

    Presentation of European activities and networks related to experiments and databases within precipitation change......Presentation of European activities and networks related to experiments and databases within precipitation change...

  14. Seasonal precipitation forecast skill over Iran

    Shirvani, A


    Full Text Available of the Global Precipitation Climatology Centre (GPCC) Version 6 gridded precipitation data, using model output statistics (MOS) developed through the canonical correlation analysis (CCA) option of the Climate Predictability Tool (CPT). Retroactive validations...

  15. River Forecasting Center Quantitative Precipitation Estimate Archive

    U.S. Geological Survey, Department of the Interior — Radar indicated-rain gage verified and corrected hourly precipitation estimate on a corrected ~4km HRAP grid. This archive contains hourly estimates of precipitation...

  16. U.S. 15 Minute Precipitation Data

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. 15 Minute Precipitation Data is digital data set DSI-3260, archived at the National Climatic Data Center (NCDC). This is precipitation data. The primary source...

  17. Maximum Simplified Dynamic Model of Grass Field Ecosystem With Two Variables

    曾庆存; 卢佩生; 曾晓东


    Based on general consideration and analysis, a maximum simplified dynamic model of grass field ecosystem with a single species is developed. The model consists of two variables: grass biomass of grass field per unit area and soil wetness, and is suitable for describing their mutual interaction. Other factors such as physical-chemical characteristics of soil, precipitation, irrigation, sunlight, temperature and consumers, are taken into account as parameters in the dynamical system. Qualitative analysis of the model shows that grass biomass of a possible ecological regime is determined by the stable equilibrium state of the dynamical system. For the grass species interacting weakly with soil wetness the grass biomass continuously depends on the precipitation. While, for a species interacting strongly with soil wetness, grass biomass is abundant if precipitation is larger than some critical value; otherwise, it becomes a desertification regime with very little or even zero grass biomass. The model also sh

  18. Nickel hydroxide precipitation from aqueous sulfate media

    Sist, Cinziana; Demopoulos, George P.


    Hydrometallurgical processing of laterite ores constitutes a major industrial and R&D activity in extractive metallurgy. In some of the process flowsheets, nickel hydroxide precipitation is incorporated. For these operations, the optimization of nickel hydroxide precipitation is important to assure efficiency and product quality. The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulfate system using supersaturation controlled precipitation.

  19. Global Precipitation Measurement (GPM) Mission: NASA Precipitation Processing System (PPS)

    Stocker, Erich Franz


    NASA is contributing the precipitation measurement data system PPS to support the GPM mission. PPS will distribute all GPM data products including NASA s GMI data products freely and quickly. PPS is implementing no system mechanisms for restricting access to GPM data. PPS is implementing no system mechanisms for charging for GPM data products. PPS will provide a number of geographical and parameter subsetting features available to its users. The first implementation of PPS (called PPS--) will assume processing of TRMM data effective 1 June 2008. TRMM realtime data will be available via PPS- to all users requesting access

  20. Effects of pore-scale precipitation on permeability and flow

    Noiriel, Catherine; Steefel, Carl I.; Yang, Li; Bernard, Dominique


    rate boundary conditions, precipitation resulted in an increase in both the average and maximum velocities. Increases in pore roughness led to a more heterogeneous flow field, principally through the effects on the fastest and slowest velocities within the domain.

  1. A dual method for maximum entropy restoration

    Smith, C. B.


    A simple iterative dual algorithm for maximum entropy image restoration is presented. The dual algorithm involves fewer parameters than conventional minimization in the image space. Minicomputer test results for Fourier synthesis with inadequate phantom data are given.

  2. Maximum Throughput in Multiple-Antenna Systems

    Zamani, Mahdi


    The point-to-point multiple-antenna channel is investigated in uncorrelated block fading environment with Rayleigh distribution. The maximum throughput and maximum expected-rate of this channel are derived under the assumption that the transmitter is oblivious to the channel state information (CSI), however, the receiver has perfect CSI. First, we prove that in multiple-input single-output (MISO) channels, the optimum transmission strategy maximizing the throughput is to use all available antennas and perform equal power allocation with uncorrelated signals. Furthermore, to increase the expected-rate, multi-layer coding is applied. Analogously, we establish that sending uncorrelated signals and performing equal power allocation across all available antennas at each layer is optimum. A closed form expression for the maximum continuous-layer expected-rate of MISO channels is also obtained. Moreover, we investigate multiple-input multiple-output (MIMO) channels, and formulate the maximum throughput in the asympt...

  3. Photoemission spectromicroscopy with MAXIMUM at Wisconsin

    Ng, W.; Ray-Chaudhuri, A.K.; Cole, R.K.; Wallace, J.; Crossley, S.; Crossley, D.; Chen, G.; Green, M.; Guo, J.; Hansen, R.W.C.; Cerrina, F.; Margaritondo, G. (Dept. of Electrical Engineering, Dept. of Physics and Synchrotron Radiation Center, Univ. of Wisconsin, Madison (USA)); Underwood, J.H.; Korthright, J.; Perera, R.C.C. (Center for X-ray Optics, Accelerator and Fusion Research Div., Lawrence Berkeley Lab., CA (USA))


    We describe the development of the scanning photoemission spectromicroscope MAXIMUM at the Wisoncsin Synchrotron Radiation Center, which uses radiation from a 30-period undulator. The article includes a discussion of the first tests after the initial commissioning. (orig.).

  4. Maximum-likelihood method in quantum estimation

    Paris, M G A; Sacchi, M F


    The maximum-likelihood method for quantum estimation is reviewed and applied to the reconstruction of density matrix of spin and radiation as well as to the determination of several parameters of interest in quantum optics.

  5. The maximum entropy technique. System's statistical description

    Belashev, B Z


    The maximum entropy technique (MENT) is applied for searching the distribution functions of physical values. MENT takes into consideration the demand of maximum entropy, the characteristics of the system and the connection conditions, naturally. It is allowed to apply MENT for statistical description of closed and open systems. The examples in which MENT had been used for the description of the equilibrium and nonequilibrium states and the states far from the thermodynamical equilibrium are considered

  6. 19 CFR 114.23 - Maximum period.


    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Maximum period. 114.23 Section 114.23 Customs... CARNETS Processing of Carnets § 114.23 Maximum period. (a) A.T.A. carnet. No A.T.A. carnet with a period of validity exceeding 1 year from date of issue shall be accepted. This period of validity cannot be...

  7. Maximum-Likelihood Detection Of Noncoherent CPM

    Divsalar, Dariush; Simon, Marvin K.


    Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

  8. Trends in daily temperature and precipitation extremes over Georgia, 1971–2010

    I. Keggenhoff


    Full Text Available Annual changes to climate extreme indices in Georgia (Southern Caucasus from 1971 to 2010 are studied using homogenized daily minimum and maximum temperature and precipitation series. Fourteen extreme temperature and 11 extreme precipitation indices are selected from the list of core climate extreme indices recommended by the World Meteorological Organization – Commission for Climatology (WMO-CCL and the research project on Climate Variability and Predictability (CLIVAR of the World Climate Research Programme (WCRP. Trends in the extreme indices are studied for 10 minimum and 11 maximum temperature and 24 precipitation series for the period 1971–2010. Between 1971 and 2010 most of the temperature extremes show significant warming trends. In 2010 there are 13.3 fewer frost days than in 1971. Within the same time frame there are 13.6 more summer days and 7.0 more tropical nights. A large number of stations show significant warming trends for monthly minimum and maximum temperature as well as for cold and warm days and nights throughout the study area, whereas warm extremes and night-time based temperature indices show greater trends than cold extremes and daytime indices. Additionally, the warm spell duration indicator indicates a significant increase in the frequency of warm spells between 1971 and 2010. Cold spells show an insignificant increase with low spatial coherence. Maximum 1-day and 5-day precipitation, the number of very heavy precipitation days, very wet and extremely wet days as well as the simple daily intensity index all show an increase in Georgia, although all trends manifest a low spatial coherence. The contribution of very heavy and extremely heavy precipitation to total precipitation increased between 1971 and 2010, whereas the number of wet days decreases.

  9. North Pacific atmospheric rivers and their influence on western North America at the Last Glacial Maximum

    Lora, Juan M.; Mitchell, Jonathan L.; Risi, Camille; Tripati, Aradhna E.


    Southwestern North America was wetter than present during the Last Glacial Maximum. The causes of increased water availability have been recently debated, and quantitative precipitation reconstructions have been underutilized in model-data comparisons. We investigate the climatological response of North Pacific atmospheric rivers to the glacial climate using model simulations and paleoclimate reconstructions. Atmospheric moisture transport due to these features shifted toward the southeast relative to modern. Enhanced southwesterly moisture delivery between Hawaii and California increased precipitation in the southwest while decreasing it in the Pacific Northwest, in agreement with reconstructions. Coupled climate models that are best able to reproduce reconstructed precipitation changes simulate decreases in sea level pressure across the eastern North Pacific and show the strongest southeastward shifts of moisture transport relative to a modern climate. Precipitation increases of ˜1 mm d-1, due largely to atmospheric rivers, are of the right magnitude to account for reconstructed pluvial conditions in parts of southwestern North America during the Last Glacial Maximum.

  10. Using NORAPS for forecasting heavy precipitation with topographic forcing

    Kong, J.; Leach, M.J.


    Heavy precipitation events, associated with winter storm systems, frequently produce devastating flooding throughout the state of California. One of the most disastrous floods in recent years occurred in March of 1995. A storm moved through California from March 7 to 11, 1995 causing flooding in a total of 57 counties in California. the storm moved to the northwest coast of California on March 7 and started producing heavy rainfall on March 8 in northern California. Then the storm moved southward and continuously produced heavy rain as it moved through California. On March 9, a maximum of 177 mm precipitation fell in northern California and brought a maximum of 140 mm precipitation to that area on March 10. In addition to the heavy rain, heavy snow fell in the higher elevations, with snow depths exceeding 12 meters in some locations in the Sierra Nevada mountains, reported by late March. Although such storms have been a research subject for many years, some features of the California storms, such as slow movement, the mesoscale structure and orographic effects on the storm movement and structure are not well understood. Consequently, storms such as the March 1995 event, are often not well predicted. The purpose of this study is to try to improve our understanding of the underlying physical mechanisms that produce the mesoscale structure and storm movement throughout the state. A greater understanding of the physical interactions un these storms will ultimately lead to improved precipitation forecasts, including both the spatial and temporal distribution. Improved forecasts benefit society by reducing threat to life and property and to improved water resource management. We have chosen the Navy Operational Regional Atmospheric Prediction System (NORAPS) to simulate the storms and study the dynamics and physics of these storm systems.


    Pandya A M


    Full Text Available Sexual identification from the skeletal parts has medico legal and anthropological importance. Present study aims to obtain values of maximum femoral length and to evaluate its possible usefulness in determining correct sexual identification. Study sample consisted of 184 dry, normal, adult, human femora (136 male & 48 female from skeletal collections of Anatomy department, M. P. Shah Medical College, Jamnagar, Gujarat. Maximum length of femur was considered as maximum vertical distance between upper end of head of femur and the lowest point on femoral condyle, measured with the osteometric board. Mean Values obtained were, 451.81 and 417.48 for right male and female, and 453.35 and 420.44 for left male and female respectively. Higher value in male was statistically highly significant (P< 0.001 on both sides. Demarking point (D.P. analysis of the data showed that right femora with maximum length more than 476.70 were definitely male and less than 379.99 were definitely female; while for left bones, femora with maximum length more than 484.49 were definitely male and less than 385.73 were definitely female. Maximum length identified 13.43% of right male femora, 4.35% of right female femora, 7.25% of left male femora and 8% of left female femora. [National J of Med Res 2011; 1(2.000: 67-70

  12. Skill assessment of precipitation nowcasting in Mediterranean Heavy Precipitation Events

    Bech, Joan; Berenguer, Marc


    Very short-term precipitation forecasting (i.e nowcasting) systems may provide valuable support in the weather surveillance process as they allow to issue automated early warnings for heavy precipitation events (HPE) as reviewed recently by Pierce et al. (2012). The need for warnings is essential in densely populated regions of small catchments, such as those typically found in Mediterranean coastal areas, prone to flash-floods. Several HPEs that occurred in NE Spain are analyzed using a nowcasting system based on the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011). Radar-based nowcasts, with lead times up to 3 h, are verified here against quality-controlled weather radar quantitative precipitation estimates and also against a dense network of raingauges. The basic questions studied are the dependence of forecast quality with lead time and rainfall amounts in several high-impact HPEs such as the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) - both cases had intense rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and daily values above 100 mm. Verification scores indicated that forecasts of 30' precipitation amounts provided useful guidance for lead times up to 60' for moderate intensities (up to 1 mm in 30') and up to 2.5h for lower rates (above 0.1 mm). On the other hand correlations of radar estimates and forecasts exceeded Eulerian persistence of precipitation estimates for lead times of 1.5 h for moderate intensities (up to 0.8 mm/h). We complete the analysis with a discussion on the reliability of threshold to lead time dependence based on the event-to-event variability found. This work has been done in the framework of the ProFEWS project (CGL2010-15892). References Bech J, N Pineda, T Rigo, M Aran, J Amaro, M

  13. Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

    Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib


    The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970-1999 and 2000-2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000-2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970-1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes.

  14. Numerical Simulations of Urea Hydrolysis and Calcite Precipitation in Porous Media Using STOMP

    Luanjing Guo; Hai Huang; Bill X. Hu


    Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising in situ immobilization approach of these contaminants is engineered mineral (co)precipitation of calcite driven by urea hydrolysis that is catalyzed by enzyme urease. The tight nonlinear coupling among flow, transport, reaction and reaction-induced property changes of media of this approach was studied by reactive transport simulations with systematically increasing level of complexities of reaction network and physical/chemical heterogeneities using a numerical simulator named STOMP. Sensitivity studies on the reaction rates of both urea hydrolysis and calcite precipitation are performed via controlling urease enzyme concentration and precipitation rate constant according to the rate models employed. We have found that the rate of ureolysis is a dominating factor in the amount of precipitated mineral; however, the spatial distribution of the precipitates depends on both rates of ureolysis and calcite precipitation. A maximum 5% reduction in the porosity was observed within the simulation time period of 6 pore volumes in our 1-dimensional (1D) column simulations. When a low permeability inclusion is considered in the 2D simulations, the altered flow fields redistribute mineral forming constituents, leading to a distorted precipitation reaction front. The simulations also indicate that mineral precipitation occurs along the boundary of the low permeability zone, which implies that contaminants in the low permeability zone could be encapsulated and isolated from the flow paths.

  15. Limnological aspects of acid precipitation

    Hendrey, G.R. (ed.)


    Lakes and streams in parts of Norway, Sweden, Canada, and the United States are being severely impacted by acidic precipitation. Scientists meeting at Sagamore, New York, agreed that this is the most serious limnological problem today. The factor responsible for determining the sensitivity of surface waters to acidification is alkalinity derived by weathering of soils and bedrock in the watershed. Acidification, defined as a reduction in alkalinity, can be quantified if preacidification alkalinity data exist, but often they do not. Data on pH and Ca from surface waters in areas not affected by acid precipitation were compared to similar data from areas which receive precipitation with a weighted average hydrogen ion concentration of pH < 4.6. A semiquantitative estimation of surface water acidification can be made for lakes and streams, where earlier chemistry data are lacking, based on this analysis of pH and Ca data. Biological responses to acidification range from a reduction in numbers of species of algae and zooplankton to complete elimination of all fish life. Major biological processes such as primary production and decomposition may be altered leading to an accumulation of plant material and organic debris within lakes and streams. Increased concentrations of aluminum from the to mg/l range have been found at levels shown to be toxic to fish. These elevated levels apparently result from the exchange of H/sup +/ and Al in the watershed. There also appears to be a relationship between lake acidification and the accumulation of mercury in fish. Problems of aluminum analysis received detailed attention, and watershed mass balances, comparative watershed studies, whole lake manipulations, synoptic surveys, and the liming of acidified waters were discussed. A priority-rated list of recommendations for research was presented.

  16. Struvite Precipitation and Biological Dissolutions.

    Ezquerro, Ander


    Struvite is a salt that is formed out of  Mg2+,NH4+ and PO43- and it crystallizes in form of MgNH4PO4.6H2O. Struvite‟s (magnesium ammonium phosphate or MAP) precipitation has recently been regarded as an interesting technique to remove phosphate and ammonium from waste water. The high elimination rates and the possibility of recycling the struvite as a direct slow release fertilizer make this process feasible and appealing. However, the costs due to the raw chemicals needed are drawbacks that...

  17. Simulation of extreme precipitation over the Yangtze River Basin using Wakeby distribution

    Su, Buda; Kundzewicz, Zbigniew W.; Jiang, Tong


    Based on the daily observational precipitation data at 147 stations in the Yangtze River Basin during 1960-2005 and projected daily data of 79 grid cells from the ECHAM5/ MPI-OM model in the 20th and 21st century, time series of precipitation extremes which contain AM (Annual Maximum) and MI (Munger Index) are constructed. The distribution feature of precipitation extremes is analyzed based on the two index series. Three principal results were obtained, as stated in the sequel. (i) In the past half century, the intensity of extreme heavy precipitation and drought events was higher in the mid-lower Yangtze than in the upper Yangtze reaches. Although the ECHAM5 model still can’t capture the precipitation extremes over the Yangtze River Basin satisfactorily, spatial pattern of the observed and the simulated precipitation extremes are much similar to each other. (ii) For quantifying the characteristics of extremely high and extremely low precipitation over the Yangtze River Basin, four probability distributions are used, namely: General Extreme Value (GEV), General Pareto (GPA), General Logistic (GLO), and Wakeby (WAK). It was found that WAK can adequately describe the probability distribution of precipitation extremes calculated from both observational and projected data. (iii) Return period of precipitation extremes show spatially different changes under three greenhouse gas emission scenarios. The 50-year heavy precipitation and drought events from simulated data during 1951-2000 will become more frequent, with return period below 25 years, for the most mid-lower Yangtze region in 2001-2050. The changing character of return periods of precipitation extremes should be taken into account for the hydrological design and future water resources management.

  18. The Contribution of Extreme Precipitation to the Total Precipitation in China

    SUN Jian-Qi


    Using daily precipitation data from weather stations in China, the variations in the contribution of extreme precipitation to the total precipitation are analyzed. It is found that extreme precipitation accounts for approximately one third of the total precipitation based on the overall mean for China. Over the past half century, extreme precipitation has played a dominant role in the year-to-year variability of the total precipitation. On the decadal time scale, the extreme precipitation makes different contributions to the wetting and drying regions of China. The wetting trends of particular regions are mainly attributed to increases in extreme precipitation; in contrast, the drying trends of other regions are mainly due to decreases in non-extreme precipitation.

  19. Heavy precipitation episodes and cosmic rays variation

    A. Mavrakis


    Full Text Available In this paper an attempt is made to investigate the possible temporal correlation between heavy precipitation episodes and cosmic rays' activity, on various time scales. Cosmic rays measurements are sparse and cover less extended periods than those of precipitation. Precipitation is largely influenced by local climatic and even physiographic conditions, while cosmic rays' distribution is far more uniform over an area. Thus, in an effort to cover a larger range of climatic characteristics, each cosmic rays station was correlated with several nearby precipitation stations. Selected statistical methods were employed for the data processing. The analysis was preformed on annual, seasonal, monthly and daily basis whenever possible. Wet and dry regions and/or seasons seem to present a different response of precipitation to cosmic rays variations. Also Forbush decreases in most cases will not lead to heavy precipitation, yet this might be sensitive to precipitable water availability.

  20. Estimating Tropical Cyclone Precipitation from Station Observations

    REN Fumin; WANG Yongmei; WANG Xiaoling; LI Weijing


    In this paper, an objective technique for estimating the tropical cyclone (TC) precipitation from station observations is proposed. Based on a comparison between the Original Objective Method (OOM) and the Expert Subjective Method (ESM), the Objective Synoptic Analysis Technique (OSAT) for partitioning TC precipitation was developed by analyzing the western North Pacific (WNP) TC historical track and the daily precipitation datasets. Being an objective way of the ESM, OSAT overcomes the main problems in OOM,by changing two fixed parameters in OOM, the thresholds for the distance of the absolute TC precipitation (D0) and the TC size (D1), into variable parameters.Case verification for OSAT was also carried out by applying CMORPH (Climate Prediction Center MORPHing technique) daily precipitation measurements, which is NOAA's combined satellite precipitation measurement system. This indicates that OSAT is capable of distinguishing simultaneous TC precipitation rain-belts from those associated with different TCs or with middle-latitude weather systems.

  1. Tritium in Australian precipitation: A 50 year record

    Tadros, Carol V.; Hughes, Catherine E.; Crawford, Jagoda; Hollins, Suzanne E.; Chisari, Robert


    Tritium in precipitation has been measured in Australia over the past 50 years, as an essential research tool in hydro-climate studies, and to contribute to the Global Network for Isotopes in Precipitation (GNIP). Tritium, a component of the water molecule (HTO), is the only true age tracer for waters. The elevated level of tritium in the environment as a result of last century’s atmospheric thermonuclear testing delivers the benefit of tracing groundwater systems over a 100 year timeframe. The concentration of tritium in Australian precipitation reached a maximum of 160 Tritium Units (TU) in 1963, during one of the most intense periods of nuclear weapons testing. From 1963 to present we observe a rapid drop in the concentration of tritium, more than expected from natural decay, and this can be attributed to the wash out of tritium into the oceans and groundwater. Spikes in the tritium level are superimposed over this general trend; the first around 1969, with levels ranging from 39.4 to 84.4 TU was due to French atmospheric weapon testing, and again in 1990, levels peaked between 6.6 and 12.9 TU, which is attributed to tritium leaking from underground tests in the French Pacific. Since 1990 the levels of tritium have declined globally and regionally. Currently the levels of tritium in Australia are stabilising to around 2-3 TU increasing with latitude across the continent, suggesting that today the tritium in precipitation is predominantly natural. The spatial distribution of tritium is presented and found to be dominated by the annual stratosphere-troposphere exchange in combination with latitude and continental effects. A precipitation amount effect is also observed for inland sites.

  2. Phoenix-1 observations of equatorial zone particle precipitation

    Miah, M. A.; Guzik, T. G.; Mitchell, J. W.; Wefel, J. P.

    The precipitation of magnetospheric particles at low altitude (160 - 300 km) near the geomagnetic equator during moderate geomagnetic conditions was studied by the ONR-602 experiment on board the S81-1 pallet mission in 1982. Significant fluxes of low energy (≡1 MeV) protons were observed, with maximum intensity along the line of minimum magnetic field strength. These protons exhibit an altitude dependence that varies as the fifth power of the altitude, and a flux that is higher than that measured in previous missions (circa 1970). The source function, atmospheric loss processes and pitch angle distributions of these particles are investigated.

  3. Formation of nuclei during precipitation in metallic mixed crystals

    Becker, R.


    Assuming that the energy of a mixed crystal can be calculated by simple addition of neighboring bonds, the nuclear formation energy is calculated for precipation in a super-saturated binary mixed crystal. From this can be determined the frequency of the formation of nuclei. From the calculation of a numerical example we can obtain, for the degree of sub-cooling at which the frequency of the formation of nuclei reaches its maximum, satisfactory agreement with available measurements of the rate of precipitation.

  4. Precipitation chemistry in central Amazonia

    Andreae, M. O.; Talbot, R. W.; Berresheim, H.; Beecher, K. M.


    Rain samples from three sites in central Amazonia were collected over a period of 6 weeks during the 1987 wet season and analyzed for ionic species and dissolved organic carbon. A continuous record of precipitation chemistry and amount was obtained at two of these sites, which were free from local or regional pollution, for a time period of over 1 month. The volume-weighted mean concentrations of most species were found to be about a factor of 5 lower during the wet season compared with previous results from the dry season. Only sodium, potassium, and chloride showed similar concentrations in both seasons. When the seasonal difference in rainfall amount is taken into consideration, the deposition fluxes are only slightly lower for most species during the wet season than during the dry season, again with the exception of chloride, potassium, and sodium. Sodium and chloride are present in the same ratio as in sea salt; rapid advection of air masses of marine origin to the central Amazon Basin during the wet season may be responsible for the observed higher deposition flux of these species. Statistical analysis suggests that sulfate is, to a large extent, of marine (sea salt and biogenic) origin, but that long-range transport of combustion-derived aerosols also makes a significant contribution to sulfate and nitrate levels in Amazonian rain. Organic acid concentrations in rain were responsible for a large fraction of the observed precipitation acidity; their concentration was strongly influenced by gas/liquid interactions.

  5. The maximum rotation of a galactic disc

    Bottema, R


    The observed stellar velocity dispersions of galactic discs show that the maximum rotation of a disc is on average 63% of the observed maximum rotation. This criterion can, however, not be applied to small or low surface brightness (LSB) galaxies because such systems show, in general, a continuously rising rotation curve until the outermost measured radial position. That is why a general relation has been derived, giving the maximum rotation for a disc depending on the luminosity, surface brightness, and colour of the disc. As a physical basis of this relation serves an adopted fixed mass-to-light ratio as a function of colour. That functionality is consistent with results from population synthesis models and its absolute value is determined from the observed stellar velocity dispersions. The derived maximum disc rotation is compared with a number of observed maximum rotations, clearly demonstrating the need for appreciable amounts of dark matter in the disc region and even more so for LSB galaxies. Matters h...

  6. Maximum permissible voltage of YBCO coated conductors

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.


    Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  7. Computing Rooted and Unrooted Maximum Consistent Supertrees

    van Iersel, Leo


    A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.

  8. Maximum magnitude earthquakes induced by fluid injection

    McGarr, Arthur F.


    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  9. Maximum magnitude earthquakes induced by fluid injection

    McGarr, A.


    Analysis of numerous case histories of earthquake sequences induced by fluid injection at depth reveals that the maximum magnitude appears to be limited according to the total volume of fluid injected. Similarly, the maximum seismic moment seems to have an upper bound proportional to the total volume of injected fluid. Activities involving fluid injection include (1) hydraulic fracturing of shale formations or coal seams to extract gas and oil, (2) disposal of wastewater from these gas and oil activities by injection into deep aquifers, and (3) the development of enhanced geothermal systems by injecting water into hot, low-permeability rock. Of these three operations, wastewater disposal is observed to be associated with the largest earthquakes, with maximum magnitudes sometimes exceeding 5. To estimate the maximum earthquake that could be induced by a given fluid injection project, the rock mass is assumed to be fully saturated, brittle, to respond to injection with a sequence of earthquakes localized to the region weakened by the pore pressure increase of the injection operation and to have a Gutenberg-Richter magnitude distribution with a b value of 1. If these assumptions correctly describe the circumstances of the largest earthquake, then the maximum seismic moment is limited to the volume of injected liquid times the modulus of rigidity. Observations from the available case histories of earthquakes induced by fluid injection are consistent with this bound on seismic moment. In view of the uncertainties in this analysis, however, this should not be regarded as an absolute physical limit.

  10. Impact of soil moisture on extreme maximum temperatures in Europe

    Kirien Whan


    Full Text Available Land-atmosphere interactions play an important role for hot temperature extremes in Europe. Dry soils may amplify such extremes through feedbacks with evapotranspiration. While previous observational studies generally focused on the relationship between precipitation deficits and the number of hot days, we investigate here the influence of soil moisture (SM on summer monthly maximum temperatures (TXx using water balance model-based SM estimates (driven with observations and temperature observations. Generalized extreme value distributions are fitted to TXx using SM as a covariate. We identify a negative relationship between SM and TXx, whereby a 100 mm decrease in model-based SM is associated with a 1.6 °C increase in TXx in Southern-Central and Southeastern Europe. Dry SM conditions result in a 2–4 °C increase in the 20-year return value of TXx compared to wet conditions in these two regions. In contrast with SM impacts on the number of hot days (NHD, where low and high surface-moisture conditions lead to different variability, we find a mostly linear dependency of the 20-year return value on surface-moisture conditions. We attribute this difference to the non-linear relationship between TXx and NHD that stems from the threshold-based calculation of NHD. Furthermore the employed SM data and the Standardized Precipitation Index (SPI are only weakly correlated in the investigated regions, highlighting the importance of evapotranspiration and runoff for resulting SM. Finally, in a case study for the hot 2003 summer we illustrate that if 2003 spring conditions in Southern-Central Europe had been as dry as in the more recent 2011 event, temperature extremes in summer would have been higher by about 1 °C, further enhancing the already extreme conditions which prevailed in that year.

  11. Spatiotemporal Variability and Trends of Extreme Precipitation in the Huaihe River Basin, a Climatic Transitional Zone in East China

    Zhengwe Ye


    Full Text Available Precipitation data from 30 stations in the Huaihe River basin (HRB, a climatic transitional zone in east China, were used to investigate the spatiotemporal variability and trends of extreme precipitation on multitimescales for the period 1961–2010. Results indicated that (1 the spatial pattern of the annual precipitation, rainy days, extreme precipitation, and maximum daily precipitations shows a clear transitional change from the south (high to the north (low in the HR; it confirmed the conclusion that the HRB is located in the transitional zone of the 800 mm precipitation contour in China, where the 800 mm precipitation contour is considered as the geographical boundary of the south and the north. (2 Higher value of the extreme precipitation intensity mainly occurs in the middle of the east and the central part of the basin; it reveals a relatively distinct west-east spatial disparity, and this is not in line with the spatial pattern of the extreme precipitation total, the sum of the precipitation in 95th precipitation days. (3 Annual precipitation of 22 stations exhibits increasing trend, and these 22 stations are located from the central to the northern part. There is no significant trend detected for the seasonal precipitation. The summer precipitation exhibits a larger change range; this might cause the variation of the flood and drought in the HBR. However, the increasing trend in winter precipitation may be beneficial to the relief of winter agricultural drought. Rainy days in 12 stations, mostly located in and around the central northeastern part, experienced significant decreasing trend. Extreme precipitation days and precipitation intensity have increasing trends, but no station with significant change trend is detected for the maximum precipitation of the basin. (4 The spatiotemporal variability in the HRB is mainly caused by the geographic differences and is largely influenced by the interdecadal variations of East Asian

  12. Effect of Nb on solution and precipitation of inhibitors in grain-oriented silicon steel

    Feng, Yunli; Guo, Jing; Li, Jie; Ning, Jiangli


    In this study, three grain-oriented silicon steels with different Nb contents were designed to investigate the effect of Nb on the behaviors of inhibitor solution and precipitation by Thermo-Calc software combined with TEM technology. The influence of Nb on precipitation rate of inhibitors in the silicon steels was also discussed. The results show that besides MnS and AlN, Nb(C,N) also exists in Nb-containing silicon steels, and with the increase of Nb content, the precipitation temperature and maximum mole fraction of Nb(C,N) increases significantly. Different Nb contents have no obvious effect on MnS. While the precipitation temperature of AlN decreases from 1190 °C to 1140 °C with Nb addition from 0.044wt% to 0.09 wt%, but the maximum mole fraction of AlN does not change. According to the PTT (Precipitation-Time-Temperature) curve, Nb addition accelerates the precipitation process of second phase particles and shortens the incubation period. Combining the theoretical calculations with TEM analyses, it is known that proper Nb addition in the silicon steel can reduce the slab reheating temperature. Whereas, with excessive Nb addition, the inhibitors can not dissolve into the matrix totally at 1250 °C, which will have a negative effect on the production of grain-oriented silicon steel.

  13. Maximum Multiflow in Wireless Network Coding

    Zhou, Jin-Yi; Jiang, Yong; Zheng, Hai-Tao


    In a multihop wireless network, wireless interference is crucial to the maximum multiflow (MMF) problem, which studies the maximum throughput between multiple pairs of sources and sinks. In this paper, we observe that network coding could help to decrease the impacts of wireless interference, and propose a framework to study the MMF problem for multihop wireless networks with network coding. Firstly, a network model is set up to describe the new conflict relations modified by network coding. Then, we formulate a linear programming problem to compute the maximum throughput and show its superiority over one in networks without coding. Finally, the MMF problem in wireless network coding is shown to be NP-hard and a polynomial approximation algorithm is proposed.

  14. Modeling the East Asian climate during the last glacial maximum

    ZHAO; Ping(赵平); CHEN; Longxun(陈隆勋); ZHOU; Xiuji(周秀骥); GONG; Yuanfa(巩远发); HAN; Yu(韩余)


    Using the CCM3 global climate model of National Center for AtmosphericResearch(NCAR), this paper comparatively analyzes the characteristics of East Asian monsoon and surface water condition and the expansion of glacier on the Qinghai-Xizang(Tibetan) Plateau(QXP) between the present and the last glacial maximum(LGM). It is found that the winter monsoon is remarkably stronger during the LGM than at present in the north part of China and the western Pacific but varies little in the south part of China. The summer monsoon remarkably weakens inSouth China Sea and the south part of China during the LGM and has no remarkable changes in the north part of China between the present and the LGM. Due to thealternations of the monsoons during the LGM, the annual mean precipitation significantly decreases in the northeast of China and the most part of north China and the Loess Plateau and the eastern QXP, which makes the earth surface lose more water and becomes dry, especially in the eastern QXP and the western Loess Plateau. In some areas of the middle QXP the decrease of evaporation at the earth surface causes soil to become wetter during the LGM than at present, which favorsthe water level of local lakes to rise during the LGM. Additionally, compared to the present, the depth of snow cover increases remarkably on the most part of the QXP during the LGM winter. The analysis of equilibrium line altitude(ELA) of glaciers on the QXP, calculated on the basis of the simulated temperature and precipitation, shows that although a less decrease of air temperature was simulated during the LGM in this paper, the balance between precipitation and air temperature associated with the atmospheric physical processes in the model makes the ELA be 300-900 m lower during the LGM than at present, namely going down fromthe present ELA above 5400 m to 4600-5200 m during the LGM, indicating a unified ice sheet on the QXP during the LGM.

  15. The Wiener maximum quadratic assignment problem

    Cela, Eranda; Woeginger, Gerhard J


    We investigate a special case of the maximum quadratic assignment problem where one matrix is a product matrix and the other matrix is the distance matrix of a one-dimensional point set. We show that this special case, which we call the Wiener maximum quadratic assignment problem, is NP-hard in the ordinary sense and solvable in pseudo-polynomial time. Our approach also yields a polynomial time solution for the following problem from chemical graph theory: Find a tree that maximizes the Wiener index among all trees with a prescribed degree sequence. This settles an open problem from the literature.

  16. Maximum confidence measurements via probabilistic quantum cloning

    Zhang Wen-Hai; Yu Long-Bao; Cao Zhuo-Liang; Ye Liu


    Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states.In this paper,we show that if incorrect copies are allowed to be produced,linearly dependent quantum states may also be cloned by the PQC.By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states,we derive the upper bound of the maximum confidence measure of a set.An explicit transformation of the maximum confidence measure is presented.

  17. Maximum floodflows in the conterminous United States

    Crippen, John R.; Bue, Conrad D.


    Peak floodflows from thousands of observation sites within the conterminous United States were studied to provide a guide for estimating potential maximum floodflows. Data were selected from 883 sites with drainage areas of less than 10,000 square miles (25,900 square kilometers) and were grouped into regional sets. Outstanding floods for each region were plotted on graphs, and envelope curves were computed that offer reasonable limits for estimates of maximum floods. The curves indicate that floods may occur that are two to three times greater than those known for most streams.

  18. Revealing the Maximum Strength in Nanotwinned Copper

    Lu, L.; Chen, X.; Huang, Xiaoxu


    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  19. The Maximum Resource Bin Packing Problem

    Boyar, J.; Epstein, L.; Favrholdt, L.M.


    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  20. Maximum entropy analysis of EGRET data

    Pohl, M.; Strong, A.W.


    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  1. Revealing the Maximum Strength in Nanotwinned Copper

    Lu, L.; Chen, X.; Huang, Xiaoxu


    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain...... boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  2. Maximum phytoplankton concentrations in the sea

    Jackson, G.A.; Kiørboe, Thomas


    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collected...... in the North Atlantic as part of the Bermuda Atlantic Time Series program as well as data collected off Southern California as part of the Southern California Bight Study program. The observed maximum particulate organic carbon and volumetric particle concentrations are consistent with the predictions...

  3. Bias Adjusted Precipitation Threat Scores

    F. Mesinger


    Full Text Available Among the wide variety of performance measures available for the assessment of skill of deterministic precipitation forecasts, the equitable threat score (ETS might well be the one used most frequently. It is typically used in conjunction with the bias score. However, apart from its mathematical definition the meaning of the ETS is not clear. It has been pointed out (Mason, 1989; Hamill, 1999 that forecasts with a larger bias tend to have a higher ETS. Even so, the present author has not seen this having been accounted for in any of numerous papers that in recent years have used the ETS along with bias "as a measure of forecast accuracy".

    A method to adjust the threat score (TS or the ETS so as to arrive at their values that correspond to unit bias in order to show the model's or forecaster's accuracy in extit{placing} precipitation has been proposed earlier by the present author (Mesinger and Brill, the so-called dH/dF method. A serious deficiency however has since been noted with the dH/dF method in that the hypothetical function that it arrives at to interpolate or extrapolate the observed value of hits to unit bias can have values of hits greater than forecast when the forecast area tends to zero. Another method is proposed here based on the assumption that the increase in hits per unit increase in false alarms is proportional to the yet unhit area. This new method removes the deficiency of the dH/dF method. Examples of its performance for 12 months of forecasts by three NCEP operational models are given.

  4. Analysis of Photovoltaic Maximum Power Point Trackers

    Veerachary, Mummadi

    The photovoltaic generator exhibits a non-linear i-v characteristic and its maximum power point (MPP) varies with solar insolation. An intermediate switch-mode dc-dc converter is required to extract maximum power from the photovoltaic array. In this paper buck, boost and buck-boost topologies are considered and a detailed mathematical analysis, both for continuous and discontinuous inductor current operation, is given for MPP operation. The conditions on the connected load values and duty ratio are derived for achieving the satisfactory maximum power point operation. Further, it is shown that certain load values, falling out of the optimal range, will drive the operating point away from the true maximum power point. Detailed comparison of various topologies for MPPT is given. Selection of the converter topology for a given loading is discussed. Detailed discussion on circuit-oriented model development is given and then MPPT effectiveness of various converter systems is verified through simulations. Proposed theory and analysis is validated through experimental investigations.

  5. On maximum cycle packings in polyhedral graphs

    Peter Recht


    Full Text Available This paper addresses upper and lower bounds for the cardinality of a maximum vertex-/edge-disjoint cycle packing in a polyhedral graph G. Bounds on the cardinality of such packings are provided, that depend on the size, the order or the number of faces of G, respectively. Polyhedral graphs are constructed, that attain these bounds.

  6. Hard graphs for the maximum clique problem

    Hoede, Cornelis


    The maximum clique problem is one of the NP-complete problems. There are graphs for which a reduction technique exists that transforms the problem for these graphs into one for graphs with specific properties in polynomial time. The resulting graphs do not grow exponentially in order and number. Gra

  7. Maximum Likelihood Estimation of Search Costs

    J.L. Moraga-Gonzalez (José Luis); M.R. Wildenbeest (Matthijs)


    textabstractIn a recent paper Hong and Shum (forthcoming) present a structural methodology to estimate search cost distributions. We extend their approach to the case of oligopoly and present a maximum likelihood estimate of the search cost distribution. We apply our method to a data set of online p

  8. Weak Scale From the Maximum Entropy Principle

    Hamada, Yuta; Kawana, Kiyoharu


    The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\

  9. Weak scale from the maximum entropy principle

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu


    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  10. Global characterization of the Holocene Thermal Maximum

    Renssen, H.; Seppä, H.; Crosta, X.; Goosse, H.; Roche, D.M.V.A.P.


    We analyze the global variations in the timing and magnitude of the Holocene Thermal Maximum (HTM) and their dependence on various forcings in transient simulations covering the last 9000 years (9 ka), performed with a global atmosphere-ocean-vegetation model. In these experiments, we consider the i

  11. Instance Optimality of the Adaptive Maximum Strategy

    L. Diening; C. Kreuzer; R. Stevenson


    In this paper, we prove that the standard adaptive finite element method with a (modified) maximum marking strategy is instance optimal for the total error, being the square root of the squared energy error plus the squared oscillation. This result will be derived in the model setting of Poisson’s e

  12. Maximum phonation time: variability and reliability.

    Speyer, Renée; Bogaardt, Hans C A; Passos, Valéria Lima; Roodenburg, Nel P H D; Zumach, Anne; Heijnen, Mariëlle A M; Baijens, Laura W J; Fleskens, Stijn J H M; Brunings, Jan W


    The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia versus a group of healthy control subjects matched by age and gender. Over a period of maximally 6 weeks, three video recordings were made of five subjects' maximum phonation time trials. A panel of five experts were responsible for all measurements, including a repeated measurement of the subjects' first recordings. Patients showed significantly shorter maximum phonation times compared with healthy controls (on average, 6.6 seconds shorter). The averaged interclass correlation coefficient (ICC) over all raters per trial for the first day was 0.998. The averaged reliability coefficient per rater and per trial for repeated measurements of the first day's data was 0.997, indicating high intrarater reliability. The mean reliability coefficient per day for one trial was 0.939. When using five trials, the reliability increased to 0.987. The reliability over five trials for a single day was 0.836; for 2 days, 0.911; and for 3 days, 0.935. To conclude, the maximum phonation time has proven to be a highly reliable measure in voice assessment. A single rater is sufficient to provide highly reliable measurements.

  13. Maximum Phonation Time: Variability and Reliability

    R. Speyer; H.C.A. Bogaardt; V.L. Passos; N.P.H.D. Roodenburg; A. Zumach; M.A.M. Heijnen; L.W.J. Baijens; S.J.H.M. Fleskens; J.W. Brunings


    The objective of the study was to determine maximum phonation time reliability as a function of the number of trials, days, and raters in dysphonic and control subjects. Two groups of adult subjects participated in this reliability study: a group of outpatients with functional or organic dysphonia v

  14. Maximum likelihood estimation of fractionally cointegrated systems

    Lasak, Katarzyna

    In this paper we consider a fractionally cointegrated error correction model and investigate asymptotic properties of the maximum likelihood (ML) estimators of the matrix of the cointe- gration relations, the degree of fractional cointegration, the matrix of the speed of adjustment...

  15. Maximum likelihood estimation for integrated diffusion processes

    Baltazar-Larios, Fernando; Sørensen, Michael

    EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...

  16. Maximum gain of Yagi-Uda arrays

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.


    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  17. Nonstationarity in timing of extreme precipitation across China and impact of tropical cyclones

    Gu, Xihui; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun


    This study examines the seasonality and nonstationarity in the timing of extreme precipitation obtained by annual maximum (AM) sampling and peak-over-threshold (POT) sampling techniques using circular statistics. Daily precipitation data from 728 stations with record length of at least 55 years across China were analyzed. In general, the average seasonality is subject mainly to summer season (June-July - August), which is potentially related to East Asian monsoon and Indian monsoon activities. The strength of precipitation seasonality varied across China with the highest strength being in northeast, north, and central-north China; whereas the weakest seasonality was found in southeast China. There are three seasonality types: circular uniform, reflective symmetric, and asymmetric. However, the circular uniform seasonality of extreme precipitation was not detected at stations across China. The asymmetric distribution was observed mainly in southeast China, and the reflective distribution of precipitation extremes was also identified the other regions besides the above-mentioned regions. Furthermore, a strong signal of nonstationarity in the seasonality was detected at half of the weather stations considered in the study, exhibiting a significant shift in the timing of extreme precipitation, and also significant trends in the average and strength of seasonality. Seasonal vapor flux and related delivery pathways and also tropical cyclones (TCs) are most probably the driving factors for the shifts or changes in the seasonality of extreme precipitation across China. Timing of precipitation extremes is closely related to seasonal shifts of floods and droughts and which means much for management of agricultural irrigation and water resources management. This study sheds new light on nonstationarity in timing of precipitation extremes which differs from existing ones which focused on precipitation extremes from perspective of magnitude and intensity.

  18. Late Quaternary glacier sensitivity to temperature and precipitation distribution in the Southern Alps of New Zealand

    Ann V. Rowan; Simon H. Brocklehurst; David M. Schultz; Mitchell A. Plummer; Leif S. Anderson; Neil F. Glasser


    Glaciers respond to climate variations and leave geomorphic evidence that represents an important terrestrial paleoclimate record. However, the accuracy of paleoclimate reconstructions from glacial geology is limited by the challenge of representing mountain meteorology in numerical models. Precipitation is usually treated in a simple manner and yet represents difficult-to-characterize variables such as amount, distribution, and phase. Furthermore, precipitation distributions during a glacial probably differed from present-day interglacial patterns. We applied two models to investigate glacier sensitivity to temperature and precipitation in the eastern Southern Alps of New Zealand. A 2-D model was used to quantify variations in the length of the reconstructed glaciers resulting from plausible precipitation distributions compared to variations in length resulting from change in mean annual air temperature and precipitation amount. A 1-D model was used to quantify variations in length resulting from interannual climate variability. Assuming that present-day interglacial values represent precipitation distributions during the last glacial, a range of plausible present-day precipitation distributions resulted in uncertainty in the Last Glacial Maximum length of the Pukaki Glacier of 17.1?km (24%) and the Rakaia Glacier of 9.3?km (25%), corresponding to a 0.5°C difference in temperature. Smaller changes in glacier length resulted from a 50% decrease in precipitation amount from present-day values (-14% and -18%) and from a 50% increase in precipitation amount (5% and 9%). Our results demonstrate that precipitation distribution can produce considerable variation in simulated glacier extents and that reconstructions of paleoglaciers should include this uncertainty.

  19. Prediction of winter precipitation over northwest India using ocean heat fluxes

    Nageswararao, M. M.; Mohanty, U. C.; Osuri, Krishna K.; Ramakrishna, S. S. V. S.


    The winter precipitation (December-February) over northwest India (NWI) is highly variable in terms of time and space. The maximum precipitation occurs over the Himalaya region and decreases towards south of NWI. The winter precipitation is important for water resources and agriculture sectors over the region and for the economy of the country. It is an exigent task to the scientific community to provide a seasonal outlook for the regional scale precipitation. The oceanic heat fluxes are known to have a strong linkage with the ocean and atmosphere. Henceforth, in this study, we obtained the relationship of NWI winter precipitation with total downward ocean heat fluxes at the global ocean surface, 15 regions with significant correlations are identified from August to November at 90 % confidence level. These strong relations encourage developing an empirical model for predicting winter precipitation over NWI. The multiple linear regression (MLR) and principal component regression (PCR) models are developed and evaluated using leave-one-out cross-validation. The developed regression models are able to predict the winter precipitation patterns over NWI with significant (99 % confidence level) index of agreement and correlations. Moreover, these models capture the signals of extremes, but could not reach the peaks (excess and deficit) of the observations. PCR performs better than MLR for predicting winter precipitation over NWI. Therefore, the total downward ocean heat fluxes at surface from August to November are having a significant impact on seasonal winter precipitation over the NWI. It concludes that these interrelationships are more useful for the development of empirical models and feasible to predict the winter precipitation over NWI with sufficient lead-time (in advance) for various risk management sectors.

  20. CPLFD-GDPT5: high-resolution gridded daily precipitation and temperature dataset for two largest Polish river basins

    Berezowski, T.; Szcześniak, M.; Kardel, I.; Michałowski, R.; Okruszko, T.; Mezghani, A.; Piniewski, M.


    The CHASE-PL Forcing Data-Gridded Daily Precipitation and Temperature Dataset-5 km (CPLFD-GDPT5) consists of 1951-2013 daily minimum and maximum air temperatures and precipitation totals interpolated onto a 5 km grid based on daily meteorological observations from Institute of Meteorology and Water Management (IMGW-PIB; Polish stations), Deutscher Wetterdienst (DWD, German and Czech stations), ECAD and NOAA-NCDC (Slovak, Ukrainian and Belarus stations). The main purpose for constructing this product was the need for long-term aerial precipitation and temperature data for earth-system modelling, especially hydrological modelling. The spatial coverage is the union of Vistula and Odra basin and Polish territory. The number of available meteorological stations for precipitation and temperature varies in time from about 100 for temperature and 300 for precipitation in 1950 up to about 180 for temperature and 700 for precipitation in 1990. The precipitation dataset was corrected for snowfall and rainfall under-catch with the Richter method. The interpolation methods were: kriging with elevation as external drift for temperatures and indicator kriging combined with universal kriging for precipitation. The kriging cross-validation revealed low root mean squared errors expressed as a fraction of standard deviation (SD): 0.54 and 0.47 for minimum and maximum temperature, respectively and 0.79 for precipitation. The correlation scores were 0.84 for minimum temperatures, 0.88 for maximum temperatures and 0.65 for precipitation. The CPLFD-GDPT5 product is consistent with 1971-2000 climatic data published by IMGW-PIB. We also confirm good skill of the product for hydrological modelling by performing an application using the Soil and Water Assessment Tool (SWAT) in the Vistula and Odra basins. Link to the dataset:

  1. Understanding Peripheral Bat Populations Using Maximum-Entropy Suitability Modeling

    Barnhart, Paul R.; Gillam, Erin H.


    Individuals along the periphery of a species distribution regularly encounter more challenging environmental and climatic conditions than conspecifics near the center of the distribution. Due to these potential constraints, individuals in peripheral margins are expected to change their habitat and behavioral characteristics. Managers typically rely on species distribution maps when developing adequate management practices. However, these range maps are often too simplistic and do not provide adequate information as to what fine-scale biotic and abiotic factors are driving a species occurrence. In the last decade, habitat suitability modelling has become widely used as a substitute for simplistic distribution mapping which allows regional managers the ability to fine-tune management resources. The objectives of this study were to use maximum-entropy modeling to produce habitat suitability models for seven species that have a peripheral margin intersecting the state of North Dakota, according to current IUCN distributions, and determine the vegetative and climatic characteristics driving these models. Mistnetting resulted in the documentation of five species outside the IUCN distribution in North Dakota, indicating that current range maps for North Dakota, and potentially the northern Great Plains, are in need of update. Maximum-entropy modeling showed that temperature and not precipitation were the variables most important for model production. This fine-scale result highlights the importance of habitat suitability modelling as this information cannot be extracted from distribution maps. Our results provide baseline information needed for future research about how and why individuals residing in the peripheral margins of a species’ distribution may show marked differences in habitat use as a result of urban expansion, habitat loss, and climate change compared to more centralized populations. PMID:27935936

  2. Trends and variability of daily temperature and precipitation extremes during 1960-2012 in the Yangtze River Basin, China

    Guan, Yinghui


    The variability of surface air temperature and precipitation extremes has been the focus of attention during the past several decades, and may exert a great influence on the global hydrologic cycle and energy balance through thermal forcing. Using daily minimum (TN), maximum temperature (TX) and precipitation from 143 meteorological stations in the Yangtze River Basin (YRB), a suite of extreme climate indices recommended by the Expert Team on Climate Change Detection and Indices, which has rarely been applied in this region, were computed and analyzed during 1960-2012. The results show widespread significant changes in all temperature indices associated with warming in the YRB during 1960-2012. On the whole, cold-related indices, i.e., cold nights, cold days, frost days, icing days and cold spell duration index significantly decreased by -3.45, -1.03, -3.04, -0.42 and -1.6 days/decade, respectively. In contrast, warm-related indices such as warm nights, warm days, summer days, tropical nights and warm spell duration index significantly increased by 2.95, 1.71, 2.16, 1.05 and 0.73 days/decade. Minimum TN, maximum TN, minimum TX and maximum TX increased significantly by 0.42, 0.18, 0.19 and 0.14 °C/decade. Because of a faster increase in minimum temperature than maximum temperature, the diurnal temperature range (DTR) exhibited a significant decreasing trend of -0.09 °C/decade for the whole YRB during 1960-2012. Geographically, stations in the eastern Tibet Plateau and northeastern YRB showed stronger trends in almost all temperature indices. Time series analysis indicated that the YRB was dominated by a general cooling trend before the mid-1980s, but a warming trend afterwards. For precipitation, simple daily intensity index, very wet day precipitation, extremely wet day precipitation, extremely heavy precipitation days, maximum 1-day precipitation, maximum 5-day precipitation and maximum consecutive dry days all increased significantly during 1960-2012. In

  3. Changes of the Temperature and Precipitation Extremes on Homogenized Data

    LAKATOS, Mónika


    Full Text Available Climate indices to detect changes have been defined in several international projects onclimate change. Climate index calculations require at least daily resolution of time series withoutinhomogeneities, such as transfer of stations, changes in observation practice. In many cases thecharacteristics of the estimated linear trends, calculated from the original and from the homogenizedtime series are significantly different. The ECA&D (European Climate Assessment & Dataset indicesand some other special temperature and precipitation indices of own development were applied to theClimate Database of the Hungarian Meteorological Service. Long term daily maximum, minimum anddaily mean temperature data series and daily precipitation sums were examined. The climate indexcalculation processes were tested on original observations and on homogenized daily data fortemperature; in the case of precipitation a complementation process was performed to fill in the gapsof missing data. Experiences of comparing the climate index calculation results, based on original andcomplemented-homogenized data, are reported in this paper. We present the preliminary result ofclimate index calculations also on gridded (interpolated daily data.

  4. Improving precipitation simulation from updated surface characteristics in South America

    Pereira, Gabriel; Silva, Maria Elisa Siqueira; Moraes, Elisabete Caria; Chiquetto, Júlio Barboza; da Silva Cardozo, Francielle


    Land use and land cover maps and their physical-chemical and biological properties are important variables in the numerical modeling of Earth systems. In this context, the main objective of this study is to analyze the improvements resulting from the land use and land cover map update in numerical simulations performed using the Regional Climate Model system version 4 (RegCM4), as well as the seasonal variations of physical parameters used by the Biosphere Atmosphere Transfer Scheme (BATS). In general, the update of the South America 2007 land use and land cover map, used by the BATS, improved the simulation of precipitation by 10 %, increasing the mean temporal correlation coefficient, compared to observed data, from 0.84 to 0.92 (significant at p < 0.05, Student's t test). Correspondingly, the simulations performed with adjustments in maximum fractional vegetation cover, in visible and shortwave infrared reflectance, and in the leaf area index, showed a good agreement for maximum and minimum temperature, with values closer to observed data. The changes in physical parameters and land use updating in BATS/RegCM4 reduced overestimation of simulated precipitation from 19 to 7 % (significant at p < 0.05, Student's t test). Regarding evapotranspiration and precipitation, the most significant differences due to land use updating were located (1) in the Amazon deforestation arc; (2) around the Brazil-Bolivia border (in the Brazilian Pantanal wetlands); (3) in the Northeast region of Brazil; (4) in northwestern Paraguay; and (5) in the River Plate Basin, in Argentina. Moreover, the main precipitation differences between sensitivity and control experiments occurred during the rainy months in central-north South America (October to March). These were associated with a displacement in the South Atlantic convergence zone (SACZ) positioning, presenting a spatial pattern of alternated areas with higher and lower precipitation rates. These important differences occur due to the

  5. Assessing the performance of satellite-based precipitation products over the Mediterranean region

    Xaver, Angelika; Dorigo, Wouter; Brocca, Luca; Ciabatta, Luca


    basin as well as for the individual catchments. While high correlation values are achieved for basins north of the Mediterranean Sea, the African Nile catchment is showing the lowest correlation values. When examining the climate indices, e.g. number of (very) heavy precipitation days, the maximum precipitation amount of five consecutive wet days, maximum number of consecutive wet days, it becomes clear that the satellite-based precipitation products are having difficulties in capturing consecutive rainfall events. More promising results are obtained when calculating the total annual amount of precipitation or the number of heavy precipitation days.

  6. Lightning activity and precipitation structure of hailstorms

    FENG GuiLi; QIE XiuShu; YUAN Tie; NIU ShuZhen


    By using the cloud-to-ground (CG) lightning location data from the lightning detection network of Henan Province, surface Doppler radar data and standard orbit data of PR, TMI and LIS on TRMM satellite, the apatjal and temporal characteristice of CG lightning flashes in 10 severe hailstorms are analyzed. The results show that the percentage of+CG lightning in these hailstorms is high with an average value of 45.5%.There is a distinct increase in CG flash rate during the rapid development stage of hailstorms. The hailstone falling corresponds to an active positive flash period, and the increase of+CG flash rate is generally accompanied with a decrease of-CG flash rate. The flash rate declines rapidly during the dissipating stage of hailstorms. The precipitation structure and lightning activity in two typical hailstorms are studied in detail. It is found that strong convective cells with reflectivity greater than 30dBZ mainly are situated in the front region of hailstorms, whereas the trailing stratiform region is in the rear part of the hailstorme. The maximum heights of echo top are higher than 14km.Convective rain contributes much more rainfall to the total than stratiform rain, and the convective rain takes about 85% and 97% of the total in the two cases, respectively. Total lightning in the hailstorms is very active with the flash rate up to 183 fl/min and 55 fl/min, respectively. The results also indicate that most lightning flashes occurred in the echo region greater than 30dBZ and its immediate periphery. The probability of lightning occurrence is 20 times higher in the convective region than in the stratiform region. The result suggests that the lightning information is helpful to the identification of convective rain region. The linear relationship between flash rate and ice water content is disclosed primarily.

  7. Lightning activity and precipitation structure of hailstorms


    By using the cloud-to-ground (CG) lightning location data from the lightning detection network of He- nan Province, surface Doppler radar data and standard orbit data of PR, TMI and LIS on TRMM satellite, the spatial and temporal characteristics of CG lightning flashes in 10 severe hailstorms are analyzed. The results show that the percentage of +CG lightning in these hailstorms is high with an average value of 45.5%. There is a distinct increase in CG flash rate during the rapid development stage of hailstorms. The hailstone falling corresponds to an active positive flash period, and the increase of +CG flash rate is generally accompanied with a decrease of –CG flash rate. The flash rate declines rapidly during the dissipating stage of hailstorms. The precipitation structure and lightning activity in two typical hail- storms are studied in detail. It is found that strong convective cells with reflectivity greater than 30dBZ mainly are situated in the front region of hailstorms, whereas the trailing stratiform region is in the rear part of the hailstorms. The maximum heights of echo top are higher than 14 km. Convective rain con- tributes much more rainfall to the total than stratiform rain, and the convective rain takes about 85% and 97% of the total in the two cases, respectively. Total lightning in the hailstorms is very active with the flash rate up to 183 fl/min and 55 fl/min, respectively. The results also indicate that most lightning flashes occurred in the echo region greater than 30 dBZ and its immediate periphery. The probability of lightning occurrence is 20 times higher in the convective region than in the stratiform region. The result suggests that the lightning information is helpful to the identification of convective rain region. The linear relationship between flash rate and ice water content is disclosed primarily.

  8. Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation

    McCabe, G.J.; Clark, M.P.


    Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.

  9. Radar-Derived Characteristics of Precipitation in South East Queensland

    Peter, Justin R; May, Peter T; Potts, Rodney J; Collis, Scott M.; Manton, Michael J; Wilson, Louise


    Statistics of radar-retrievals of precipitation are presented. A K-means clustering algorithm is applied to an historical record of radiosonde measurements which identified three major synoptic regimes; a dry, stable regime with mainly westerly winds prevalent during winter, a moist south easterly trade wind regime and a moist northerly regime both prevalent during summer. These are referred to as westerly, trade wind and northerly regimes, respectively. Cell statistics are calculated using an objective cell identification and tracking methodology on data obtained from a nearby S-band radar. Cell statistics are investigated for the entire radar observational period and also during sub-periods corresponding to the three major synoptic regimes. The statistics investigated are cell initiation location, area, rainrate, volume, height, height of the maximum reflectivity, volume greater than 40 dBZ and storm speed and direction. Cells are found predominantly along the elevated topography. The cell statistics reveal that storms which form in the dry, stable westerly regime are of comparable size to the deep cells which form in the northerly regime, larger than those in the trade regime and, furthermore, have the largest rainrate. However, they occur less frequently and have shorter lifetimes than cells in the other regimes. Diurnal statistics of precipitation area and rainrate exhibit early morning and mid afternoon peaks, although the areal coverage lags the rainrate by several hours indicative of a transition from convective to stratiform precipitation. The probability distributions of cell area, rainrate, volume, height and height of the maximum re ectivity are found to follow lognormal distributions.

  10. Model Selection Through Sparse Maximum Likelihood Estimation

    Banerjee, Onureena; D'Aspremont, Alexandre


    We consider the problem of estimating the parameters of a Gaussian or binary distribution in such a way that the resulting undirected graphical model is sparse. Our approach is to solve a maximum likelihood problem with an added l_1-norm penalty term. The problem as formulated is convex but the memory requirements and complexity of existing interior point methods are prohibitive for problems with more than tens of nodes. We present two new algorithms for solving problems with at least a thousand nodes in the Gaussian case. Our first algorithm uses block coordinate descent, and can be interpreted as recursive l_1-norm penalized regression. Our second algorithm, based on Nesterov's first order method, yields a complexity estimate with a better dependence on problem size than existing interior point methods. Using a log determinant relaxation of the log partition function (Wainwright & Jordan (2006)), we show that these same algorithms can be used to solve an approximate sparse maximum likelihood problem for...

  11. Maximum-entropy description of animal movement.

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M


    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  12. Pareto versus lognormal: a maximum entropy test.

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano


    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  13. Maximum Variance Hashing via Column Generation

    Lei Luo


    item search. Recently, a number of data-dependent methods have been developed, reflecting the great potential of learning for hashing. Inspired by the classic nonlinear dimensionality reduction algorithm—maximum variance unfolding, we propose a novel unsupervised hashing method, named maximum variance hashing, in this work. The idea is to maximize the total variance of the hash codes while preserving the local structure of the training data. To solve the derived optimization problem, we propose a column generation algorithm, which directly learns the binary-valued hash functions. We then extend it using anchor graphs to reduce the computational cost. Experiments on large-scale image datasets demonstrate that the proposed method outperforms state-of-the-art hashing methods in many cases.

  14. The Maximum Resource Bin Packing Problem

    Boyar, J.; Epstein, L.; Favrholdt, L.M.


    algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find......Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... the competitive ratio of various natural algorithms. We study the general versions of the problems as well as the parameterized versions where there is an upper bound of on the item sizes, for some integer k....

  15. Nonparametric Maximum Entropy Estimation on Information Diagrams

    Martin, Elliot A; Meinke, Alexander; Děchtěrenko, Filip; Davidsen, Jörn


    Maximum entropy estimation is of broad interest for inferring properties of systems across many different disciplines. In this work, we significantly extend a technique we previously introduced for estimating the maximum entropy of a set of random discrete variables when conditioning on bivariate mutual informations and univariate entropies. Specifically, we show how to apply the concept to continuous random variables and vastly expand the types of information-theoretic quantities one can condition on. This allows us to establish a number of significant advantages of our approach over existing ones. Not only does our method perform favorably in the undersampled regime, where existing methods fail, but it also can be dramatically less computationally expensive as the cardinality of the variables increases. In addition, we propose a nonparametric formulation of connected informations and give an illustrative example showing how this agrees with the existing parametric formulation in cases of interest. We furthe...

  16. Zipf's law, power laws and maximum entropy

    Visser, Matt


    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  17. Zipf's law, power laws, and maximum entropy

    Visser, Matt


    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines - from astronomy to demographics to economics to linguistics to zoology, and even warfare. A recent model of random group formation [RGF] attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present article I argue that the cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  18. Regions of constrained maximum likelihood parameter identifiability

    Lee, C.-H.; Herget, C. J.


    This paper considers the parameter identification problem of general discrete-time, nonlinear, multiple-input/multiple-output dynamic systems with Gaussian-white distributed measurement errors. Knowledge of the system parameterization is assumed to be known. Regions of constrained maximum likelihood (CML) parameter identifiability are established. A computation procedure employing interval arithmetic is proposed for finding explicit regions of parameter identifiability for the case of linear systems. It is shown that if the vector of true parameters is locally CML identifiable, then with probability one, the vector of true parameters is a unique maximal point of the maximum likelihood function in the region of parameter identifiability and the CML estimation sequence will converge to the true parameters.

  19. A Maximum Radius for Habitable Planets.

    Alibert, Yann


    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  20. Maximum Profit Configurations of Commercial Engines

    Yiran Chen


    An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m)] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by t...

  1. A stochastic maximum principle via Malliavin calculus

    Øksendal, Bernt; Zhou, Xun Yu; Meyer-Brandis, Thilo


    This paper considers a controlled It\\^o-L\\'evy process where the information available to the controller is possibly less than the overall information. All the system coefficients and the objective performance functional are allowed to be random, possibly non-Markovian. Malliavin calculus is employed to derive a maximum principle for the optimal control of such a system where the adjoint process is explicitly expressed.

  2. Tissue radiation response with maximum Tsallis entropy.

    Sotolongo-Grau, O; Rodríguez-Pérez, D; Antoranz, J C; Sotolongo-Costa, Oscar


    The expression of survival factors for radiation damaged cells is currently based on probabilistic assumptions and experimentally fitted for each tumor, radiation, and conditions. Here, we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. The obtained expression shows a remarkable agreement with the experimental data found in the literature.

  3. Maximum Estrada Index of Bicyclic Graphs

    Wang, Long; Wang, Yi


    Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.

  4. Maximum privacy without coherence, zero-error

    Leung, Debbie; Yu, Nengkun


    We study the possible difference between the quantum and the private capacities of a quantum channel in the zero-error setting. For a family of channels introduced by Leung et al. [Phys. Rev. Lett. 113, 030512 (2014)], we demonstrate an extreme difference: the zero-error quantum capacity is zero, whereas the zero-error private capacity is maximum given the quantum output dimension.

  5. Circulation factors affecting precipitation over Bulgaria

    Nojarov, Peter


    The objective of this paper is to determine the influence of circulation factors on precipitation in Bulgaria. The study succeeds investigation on the influence of circulation factors on air temperatures in Bulgaria, as the focus here is directed toward precipitation amounts. Circulation factors are represented through two circulation indices, showing west-east or south-north transport of air masses over Bulgaria and four teleconnection indices (patterns)—North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia, and Scandinavian. Omega values at 700-hPa level show vertical motions in the atmosphere. Annual precipitation trends are mixed and not statistically significant. A significant decrease of precipitation in Bulgaria is observed in November due to the strengthening of the eastward transport of air masses (strengthening of EA teleconnection pattern) and anticyclonal weather (increase of descending motions in the atmosphere). There is also a precipitation decrease in May and June due to the growing influence of the Azores High. An increase of precipitation happens in September. All this leads to a redistribution of annual precipitation course, but annual precipitation amounts remain the same. However, this redistribution has a negative impact on agriculture and winter ski tourism. Zonal circulation has a larger influence on precipitation in Bulgaria compared to meridional. Eastward transport throughout the year leads to lower than the normal precipitation, and vice versa. With regard to the four teleconnection patterns, winter precipitation in Bulgaria is determined mainly by EA/WR teleconnection pattern, spring and autumn by EA teleconnection pattern, and summer by SCAND teleconnection pattern.

  6. Precipitation Ground Validation over the Oceans

    Klepp, C.; Bakan, S.


    State-of-the-art satellite derived and reanalysis based precipitation climatologies show remarkably large differences in detection, amount, variability and temporal behavior of precipitation over the oceans. The uncertainties are largest for light precipitation within the ITCZ and for cold season high-latitude precipitation including snowfall. Our HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data, precipitation retrieval exhibits fairly high accuracy in such regions compared to our ground validation data. However, the statistical basis for a conclusive validation has to be significantly improved with comprehensive ground validation efforts. However, existing in-situ instruments are not designed for precipitation measurements under high wind speeds on moving ships. To largely improve the ground validation data basis of precipitation over the oceans, especially for snow, the systematic data collection effort of the Initiative Pro Klima funded project at the KlimaCampus Hamburg uses automated shipboard optical disdrometers, called ODM470 that are capable of measuring liquid and solid precipitation on moving ships with high accuracy. The main goal of this project is to constrain the precipitation retrievals for HOAPS and the new Global Precipitation Measurement (GPM) satellite constellation. Currently, three instruments are long-term mounted on the German research icebreaker R/V Polarstern (Alfred Wegner Institut) since June 2010, on R/V Akademik Ioffe (P.P.Shirshov Institute of Oceanology, RAS, Moscow, Russia) since September 2010 and on R/V Maria S. Merian (Brise Research, University of Hamburg) since December 2011. Three more instruments will follow shortly on further ships. The core regions for these long-term precipitation measurements comprise the Arctic Ocean, the Nordic Seas, the Labrador Sea, the subtropical Atlantic trade wind regions, the Caribbean, the ITCZ, and the Southern Oceans as far south to Antarctica. This

  7. Mean Annual Precipitation in West-Central Nevada using the Precipitation-Zone Method

    U.S. Geological Survey, Department of the Interior — This data set contains 1971-2000 mean annual precipitation estimates for west-central Nevada. This is a raster data set developed using the precipitation-zone...

  8. Automatic maximum entropy spectral reconstruction in NMR.

    Mobli, Mehdi; Maciejewski, Mark W; Gryk, Michael R; Hoch, Jeffrey C


    Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system.

  9. Maximum entropy analysis of cosmic ray composition

    Nosek, Dalibor; Vícha, Jakub; Trávníček, Petr; Nosková, Jana


    We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the sup...

  10. A Maximum Resonant Set of Polyomino Graphs

    Zhang Heping


    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  11. The maximum rate of mammal evolution

    Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

  12. Minimal Length, Friedmann Equations and Maximum Density

    Awad, Adel


    Inspired by Jacobson's thermodynamic approach[gr-qc/9504004], Cai et al [hep-th/0501055,hep-th/0609128] have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar--Cai derivation [hep-th/0609128] of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure $p(\\rho,a)$ leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature $k$. As an example w...

  13. Maximum saliency bias in binocular fusion

    Lu, Yuhao; Stafford, Tom; Fox, Charles


    Subjective experience at any instant consists of a single ("unitary"), coherent interpretation of sense data rather than a "Bayesian blur" of alternatives. However, computation of Bayes-optimal actions has no role for unitary perception, instead being required to integrate over every possible action-percept pair to maximise expected utility. So what is the role of unitary coherent percepts, and how are they computed? Recent work provided objective evidence for non-Bayes-optimal, unitary coherent, perception and action in humans; and further suggested that the percept selected is not the maximum a posteriori percept but is instead affected by utility. The present study uses a binocular fusion task first to reproduce the same effect in a new domain, and second, to test multiple hypotheses about exactly how utility may affect the percept. After accounting for high experimental noise, it finds that both Bayes optimality (maximise expected utility) and the previously proposed maximum-utility hypothesis are outperformed in fitting the data by a modified maximum-salience hypothesis, using unsigned utility magnitudes in place of signed utilities in the bias function.

  14. The maximum rate of mammal evolution

    Evans, Alistair R.; Jones, David; Boyer, Alison G.; Brown, James H.; Costa, Daniel P.; Ernest, S. K. Morgan; Fitzgerald, Erich M. G.; Fortelius, Mikael; Gittleman, John L.; Hamilton, Marcus J.; Harding, Larisa E.; Lintulaakso, Kari; Lyons, S. Kathleen; Okie, Jordan G.; Saarinen, Juha J.; Sibly, Richard M.; Smith, Felisa A.; Stephens, Patrick R.; Theodor, Jessica M.; Uhen, Mark D.


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous–Paleogene (K–Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes. PMID:22308461

  15. Maximum-biomass prediction of homofermentative Lactobacillus.

    Cui, Shumao; Zhao, Jianxin; Liu, Xiaoming; Chen, Yong Q; Zhang, Hao; Chen, Wei


    Fed-batch and pH-controlled cultures have been widely used for industrial production of probiotics. The aim of this study was to systematically investigate the relationship between the maximum biomass of different homofermentative Lactobacillus and lactate accumulation, and to develop a prediction equation for the maximum biomass concentration in such cultures. The accumulation of the end products and the depletion of nutrients by various strains were evaluated. In addition, the minimum inhibitory concentrations (MICs) of acid anions for various strains at pH 7.0 were examined. The lactate concentration at the point of complete inhibition was not significantly different from the MIC of lactate for all of the strains, although the inhibition mechanism of lactate and acetate on Lactobacillus rhamnosus was different from the other strains which were inhibited by the osmotic pressure caused by acid anions at pH 7.0. When the lactate concentration accumulated to the MIC, the strains stopped growing. The maximum biomass was closely related to the biomass yield per unit of lactate produced (YX/P) and the MIC (C) of lactate for different homofermentative Lactobacillus. Based on the experimental data obtained using different homofermentative Lactobacillus, a prediction equation was established as follows: Xmax - X0 = (0.59 ± 0.02)·YX/P·C.

  16. The maximum rate of mammal evolution.

    Evans, Alistair R; Jones, David; Boyer, Alison G; Brown, James H; Costa, Daniel P; Ernest, S K Morgan; Fitzgerald, Erich M G; Fortelius, Mikael; Gittleman, John L; Hamilton, Marcus J; Harding, Larisa E; Lintulaakso, Kari; Lyons, S Kathleen; Okie, Jordan G; Saarinen, Juha J; Sibly, Richard M; Smith, Felisa A; Stephens, Patrick R; Theodor, Jessica M; Uhen, Mark D


    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

  17. Impacts of extreme precipitation and seasonal changes in precipitation on plants

    M. J. B. Zeppel


    Full Text Available The hydrological cycle is predicted to become more intense in future climates, with both larger precipitation events and longer times between events. Redistribution of precipitation may occur both within and across seasons, and the resulting wide fluctuations in soil water content may dramatically affect plants. Though these responses remain poorly understood, recent research in this emerging field suggests the effects of redistributed precipitation may differ from predictions based on previous drought studies. We review available studies on both extreme precipitation (redistribution within seasons and seasonal changes in precipitation (redistribution across seasons on grasslands and forests. Extreme precipitation differentially affected Aboveground Net Primary Productivity (ANPP, depending on whether extreme precipitation led to increased or decreased soil water content (SWC, which differed based on the current precipitation at the site. Specifically, studies to date reported that extreme precipitation decreased ANPP in mesic sites, but, conversely, increased ANPP in xeric sites, suggesting that plant available water is a key factor driving responses to extreme precipitation. Similarly, the effects of seasonal changes in precipitation on ANPP, phenology, and leaf and fruit development varied with the effect on SWC. Reductions in spring or summer generally had negative effects on plants, associated with reduced SWC, while subsequent reductions in autumn or winter had little effect on SWC or plants. Similarly, increased summer precipitation had a more dramatic impact on plants than winter increases in precipitation. The patterns of response suggest xeric biomes may respond positively to extreme precipitation, while comparatively mesic biomes may be more likely to be negatively affected. And, seasonal changes in precipitation during warm or dry seasons may have larger effects than changes during cool or wet seasons. Accordingly, responses to

  18. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    Tao, P.; Tie-Yuan, S.; Zhi-Yuan, Y.; Jun-Chao, W.


    The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period....

  19. Nucleation pathway in coherent precipitation

    Philippe, T.; Blavette, D.


    The non-classical nucleation pathway of coherent precipitates has been computed through minimisation of the nucleation barrier in the composition (c)-size (R) space to predict the evolution of nucleus composition. The generalized Gibbs model, developed by Schmelzer et al. [J. Chem. Phys. 112 (2000) p.3820; J. Colloid Interface Sci. 272 (2004) p.109], has been extended to include misfit elastic energy. The composition of critical embryos c* was found to be independent of the interfacial constant. The composition of critical nuclei (c*) decreased with supersaturation. The elastic energy increased both c* and the nucleation barrier, as well as R*. The evolution of nucleus composition (c) as a function of size (R) along the minimum energy pathway was computed. Nucleation only starts when a size threshold is exceeded. Then, rapid enrichment to the expected composition (c β) precedes a constant composition regime. However, for small supersaturations, the change in cluster composition can occur sharply for a very small radius and then the composition slowly increased with a significant change in size. Coherency misfit energy was found to slow down the evolution of nuclei composition with R. The model was compared to experimental results.

  20. Precipitation of humic acid with divalent ions

    Andersen, Niels Peder Raj; Mikkelsen, Lene Haugaard; Keiding, Kristian


    and Ba2+. The phase diagram model can not account for the observed precipitation in region III and However, in region IV the HA appears to posses colloidal properties, which is supported by precipitation taking place at a constant zeta-potential -21mV with the same amount of added barium ion regardless...

  1. Dissolution of ordered precipitates under ion irradiation

    Camus, E.; Bourdeau, F.; Abromeit, C.; Wanderka, N.; Wollenberger, H. [Hahn-Meitner-Institut Berlin GmbH (Germany)


    The stability of the ordered {gamma}{prime} precipitates under 300-keV Ni{sup +} irradiation was investigated between room temperature and 623 K. The two competing mechanisms of destabilization by cascade producing irradiation, i.e. disordering and dissolution of the {gamma}{prime} precipitates in Nimonic PE16 alloy, has been studied separately by electron microscopy and field-ion microscopy with atom probe. At high temperatures, the precipitates are stable. At intermediate temperatures, the precipitates dissolve by ballistic mixing into the matrix, but the interface is restored by the radiation-enhanced atomic jumps. The order in the precipitates remains stable. At low temperatures, the precipitates are dissolved by atomic mixing. The dissolution proceeds in a diffusional manner with a diffusion coefficient normalized by the displacement rate D/K = 0.75 nm{sup 2}dpa{sup {minus}1}. The precipitates become disordered by a fluence of 0.1 dpa, whereas precipitate dissolution needs much higher fluences.

  2. MAXIS Balloon Observations of Electron Microburst Precipitation

    Millan, R. M.; Hunter, A. E.; McCarthy, M. P.; Lin, R. P.; Smith, D. M.


    Quantifying and understanding losses is an integral part of understanding relativistic electron variability in the radiation belts. SAMPEX observations indicate that electron microburst precipitation is a major loss mechanism during active periods; the loss of relativistic electrons during a six hour period due to microburst precipitation was recently estimated to be comparable to the total number of trapped electrons in the outer zone (Lorentzen et al., 2001). Microburst precipitation was first observed from a balloon (Anderson and Milton, 1964), but these early measurements were only sensitive to MAXIS 2000 long duration balloon campaign. MAXIS was launched from McMurdo Station in Antarctica carrying a germanium spectrometer, a BGO scintillator and two X-ray imagers designed to measure the bremsstrahlung produced by precipitating electrons. The balloon circumnavigated the south pole in 18 days covering magnetic latitudes ranging from 58o-90o South. During the week following a moderate geomagnetic storm (with Dst reaching -91 nT), MAXIS detected a total of over 16 hours of microburst precipitation. We present high resolution spectra obtained with the MAXIS germanium spectrometer which allow us to determine the precipitating electron energy distribution. The precipitating distribution will then be compared to the trapped distribution measured by the GPS and LANL satellites. We also examine the spatial distribution of the precipitation.

  3. Study of asphaltene precipitation by Calorimetry

    Verdier, Sylvain Charles Roland; Plantier, Frédéric; Bessières, David;


    of experiments showed that weak forces determine precipitation. Indeed, isothermal titration calorimetry could not detect any clear signal although this technique can detect low-energy transitions such as liquid-liquid equilibrium and rnicellization. The second series of tests proved that precipitation caused...

  4. Asphaltene precipitates in oil production wells

    Kleinitz, W,; Andersen, Simon Ivar


    At the beginning of production in a southern German oil field, flow blockage was observed during file initial stage of production from the oil wells. The hindrance was caused by the precipitation of asphaltenes in the proximity of the borehole and in the tubings. The precipitates were of solid...

  5. Investigation of Asphaltene Precipitation at Elevated Temperature

    Andersen, Simon Ivar; Lindeloff, Niels; Stenby, Erling Halfdan


    In order to obtain quantitative data on the asphaltene precipitation induced by the addition of n-alkane (heptane) at temperatures above the normal boiling point of the precipitant, a high temperature/high pressure filtration apparatus has been constructed. Oil and alkane are mixed at the appropr...

  6. Precipitation hardening in 350 grade maraging steel

    Viswanathan, U.K. (Bhabha Atomic Research Centre, Bombay, (India). Radiometallurgy Div.); Dey, G.K. (Bhabha Atomic Research Centre, Bombay, (India). Metallurgy Division); Asundi, M.K. (Government Colony, Bombay, (India))


    Evolution of microstructure in 350 grade commercial maraging steel has been examined. In the earlier stages of aging, the strengthening phases are formed by the heterogeneous precipitation, and these phases have been identified as intermetallic compounds of the Ni[sub 3] (Ti, Mo) and Fe[sub 2]Mo types. The kinetics of precipitation are studied in terms of the activation energy by carrying out isothermal hardness measurements of aged material. The mechanical properties in the peak-aged and overaged conditions were evaluated and the flow behavior examined. The overaging behavior of the steel has been studied and the formation of austenite of different morphologies identified. The crystallography of the austenite has been examined in detail. From the microstructural examination of peak-aged and deformed samples, it could be inferred that the dislocation-precipitate interaction is by precipitate shearing. Increased work hardening of the material in the overaged condition was suggestive of looping of precipitates by dislocations.

  7. Precipitation hardening in 350 grade maraging steel

    Viswanathan, U. K.; Dey, G. K.; Asundi, M. K.


    Evolution of microstructure in a 350 grade commercial maraging steel has been examined. In the earlier stages of aging, the strengthening phases are formed by the heterogeneous precipitation, and these phases have been identified as intermetallic compounds of the Ni3 (Ti, Mo) and Fe2Mo types. The kinetics of precipitation are studied in terms of the activation energy by carrying out isothermal hardness measurements of aged material. The mechanical properties in the peak-aged and overaged conditions were evaluated and the flow behavior examined. The overaging behavior of the steel has been studied and the formation of austenite of different morphologies identified. The crystallography of the austenite has been examined in detail. From the microstructural examination of peak-aged and deformed samples, it could be inferred that the dislocation-precipitate interaction is by precipitate shearing. Increased work hardening of the material in the overaged condition was suggestive of looping of precipitates by dislocations.

  8. Sensitivity of the simulated precipitation to changes in convective relaxation time scale

    S. K. Mishra


    Full Text Available The paper describes the sensitivity of the simulated precipitation to changes in convective relaxation time scale (TAU of Zhang and McFarlane (ZM cumulus parameterization, in NCAR-Community Atmosphere Model version 3 (CAM3. In the default configuration of the model, the prescribed value of TAU, a characteristic time scale with which convective available potential energy (CAPE is removed at an exponential rate by convection, is assumed to be 1 h. However, some recent observational findings suggest that, it is larger by around one order of magnitude. In order to explore the sensitivity of the model simulation to TAU, two model frameworks have been used, namely, aqua-planet and actual-planet configurations. Numerical integrations have been carried out by using different values of TAU, and its effect on simulated precipitation has been analyzed.

    The aqua-planet simulations reveal that when TAU increases, rate of deep convective precipitation (DCP decreases and this leads to an accumulation of convective instability in the atmosphere. Consequently, the moisture content in the lower- and mid- troposphere increases. On the other hand, the shallow convective precipitation (SCP and large-scale precipitation (LSP intensify, predominantly the SCP, and thus capping the accumulation of convective instability in the atmosphere. The total precipitation (TP remains approximately constant, but the proportion of the three components changes significantly, which in turn alters the vertical distribution of total precipitation production. The vertical structure of moist heating changes from a vertically extended profile to a bottom heavy profile, with the increase of TAU. Altitude of the maximum vertical velocity shifts from upper troposphere to lower troposphere. Similar response was seen in the actual-planet simulations. With an increase in TAU from 1 h to 8 h, there was a significant improvement in the simulation of the seasonal mean precipitation. The

  9. Metal chelate affinity precipitation: purification of BSA using poly(N-vinylcaprolactam-co-methacrylic acid) copolymers.

    Ling, Yuan-Qing; Nie, Hua-Li; Brandford-White, Christopher; Williams, Gareth R; Zhu, Li-Min


    This investigation involves the metal chelate affinity precipitation of bovine serum albumin (BSA) using a copper ion loaded thermo-sensitive copolymer. The copolymer of N-vinylcaprolactam with methacrylic acid PNVCL-co-MAA was synthesized by free radical polymerization in aqueous solution, and Cu(II) ions were attached to provide affinity properties for BSA. A maximum loading of 48.1mg Cu(2+) per gram of polymer was attained. The influence of pH, temperature, BSA and NaCl concentrations on BSA precipitation and of pH, ethylenediaminetetraacetic acid (EDTA) and NaCl concentrations on elution were systematically probed. The optimum conditions for BSA precipitation occurred when pH, temperature and BSA concentration were 6.0, 10°C and 1.0 mg/ml, respectively and the most favorable elution conditions were at pH 4.0, with 0.2M NaCl and 0.06 M EDTA. The maximum amounts of BSA precipitation and elution were 37.5 and 33.7 mg BSA/g polymer, respectively. It proved possible to perform multiple precipitation/elution cycles with a minimal loss of polymer efficacy. The results show that PNVCL-co-MAA is a suitable matrix for the purification of target proteins from unfractionated materials.

  10. Experimental Simulations of Extreme Precipitation Based on the Multi-Status Markov Chain Model

    DING Yuguo; ZHANG Jinling; JIANG Zhihong


    A multi-status Markov chain model is proposed to produce daily rainrall, and based on which extreme rainfall is simulated with the generalized Pareto distribution (GPD). The simulated daily rainfall shows high precision at most stations, especially in pluvial regions of East China. The analysis reveals that the multi-status Markov chain model excels the bi-status Markov chain model in simulating climatic features of extreme rainfall. Results from the selected six stations demonstrate excellent simulations in the following aspects: standard deviation of monthly precipitation, daily maximum precipitation, the monthly mean rainfall days, standard deviation of daily precipitation and mean daily precipitation, which are proved to be consistent with the observations. A comparative study involving 78 stations in East China also reveals good consistency in monthly mean rainfall days and mean daily maximum rainfall, except mean daily rainfall. Simulation results at the above 6 stations have shown satisfactory fitting capability of the extreme precipitation GPD method. Good analogy is also found between simulation and observation in threshold and return values. As the errors of the threshold decrease, so do the differences between the return and real values. All the above demonstrates the applicability of the Markov chain model to extreme rainfall simulations.

  11. Future increases in Arctic precipitation linked to local evaporation and sea-ice retreat.

    Bintanja, R; Selten, F M


    Precipitation changes projected for the end of the twenty-first century show an increase of more than 50 per cent in the Arctic regions. This marked increase, which is among the highest globally, has previously been attributed primarily to enhanced poleward moisture transport from lower latitudes. Here we use state-of-the-art global climate models to show that the projected increases in Arctic precipitation over the twenty-first century, which peak in late autumn and winter, are instead due mainly to strongly intensified local surface evaporation (maximum in winter), and only to a lesser degree due to enhanced moisture inflow from lower latitudes (maximum in late summer and autumn). Moreover, we show that the enhanced surface evaporation results mainly from retreating winter sea ice, signalling an amplified Arctic hydrological cycle. This demonstrates that increases in Arctic precipitation are firmly linked to Arctic warming and sea-ice decline. As a result, the Arctic mean precipitation sensitivity (4.5 per cent increase per degree of temperature warming) is much larger than the global value (1.6 to 1.9 per cent per kelvin). The associated seasonally varying increase in Arctic precipitation is likely to increase river discharge and snowfall over ice sheets (thereby affecting global sea level), and could even affect global climate through freshening of the Arctic Ocean and subsequent modulations of the Atlantic meridional overturning circulation.

  12. Reconstruction of precipitation in Morocco since 1100 A.D. Based on Cedrus atlantica tree-ring widths

    Till, Claudine; Guiot, Joël


    Annual (October through September) precipitation from 1100 A.D. to modern times is reconstructed for Morocco, using Cedrus atlantica (Endl.) Carrière tree-ring chronologies. Both multiple regression on principal components and the bootstrap method are use to calibrate tree-ring width with precipitation; precipitation variation is reconstructed for three climatically distinct areas: the humid, subhumid, and arid regions of Morocco. A series of successive wet and dry periods is identified for the past 1000 years; the maximum length of the 13 dry periods (during which precipitation was at least 1σ below normal) is 6 years. Twenty-one years are identified during which precipitation fell more than 2σ below normal. We are unable to identify significant correspondence in climatic variation in Morocco, Europe, and the Sahel during this time period.

  13. Observed variability of summer precipitation pattern and extreme events in East China associated with variations of the East Asian summer monsoon: VARIABILITY OF SUMMER PRECIPITATION AND EXTREME EVENT IN EAST CHINA

    Wang, Lei [School of Atmospheric Sciences, Nanjing University, China; Pacific Northwest National Laboratory, Richland WA USA; Qian, Yun [Pacific Northwest National Laboratory, Richland WA USA; Zhang, Yaocun [School of Atmospheric Sciences, Nanjing University, China; Zhao, Chun [Pacific Northwest National Laboratory, Richland WA USA; Leung, L. Ruby [Pacific Northwest National Laboratory, Richland WA USA; Huang, Anning [School of Atmospheric Sciences, Nanjing University, China; Xiao, Chuliang [Cooperative Institute for Limnology and Ecosystems Research, School of Natural Resources and Environment, University of Michigan, Ann Arbor MI USA


    This paper presents a comprehensive analysis of interannual and interdecadal variations of summer precipitation and precipitation-related extreme events in China associated with variations of the East Asian summer monsoon (EASM) from 1979-2012. A high-quality daily precipitation dataset covering 2287 weather stations in China is analyzed. Based on the precipitation pattern analysis using empirical orthogonal functions, three sub-periods of 1979-1992 (period I), 1993-1999 (period II) and 2000-2012 (period III) are identified to be representative of the precipitation variability. Similar significant variability of the extreme precipitation indices is found across four sub-regions in eastern China. The spatial patterns of summer mean precipitation, the number of days with daily rainfall exceeding 95th percentile precipitation (R95p) and the maximum number of consecutive wet days (CWD) anomalies are consistent, but opposite to that of maximum consecutive dry days (CDD) anomalies during the three sub-periods. However, the spatial patterns of hydroclimatic intensity (HY-INT) are notably different from that of the other three extreme indices, but highly correlated to the dry events. The changes of precipitation anomaly patterns are accompanied by the change of the EASM regime and the abrupt shift of the position of the west Pacific subtropical high around 1992/1993 and 1999/2000, respectively, which influence the moisture transport that contributes most to the precipitation anomalies. Lastly, the EASM intensity is linked to sea surface temperature anomaly over the tropical Indian and Pacific Ocean that influences deep convection over the oceans.

  14. Maximum power operation of interacting molecular motors

    Golubeva, Natalia; Imparato, Alberto


    We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors......, as compared to the non-interacting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics....

  15. Maximum a posteriori decoder for digital communications

    Altes, Richard A. (Inventor)


    A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.

  16. Kernel-based Maximum Entropy Clustering

    JIANG Wei; QU Jiao; LI Benxi


    With the development of Support Vector Machine (SVM),the "kernel method" has been studied in a general way.In this paper,we present a novel Kernel-based Maximum Entropy Clustering algorithm (KMEC).By using mercer kernel functions,the proposed algorithm is firstly map the data from their original space to high dimensional space where the data are expected to be more separable,then perform MEC clustering in the feature space.The experimental results show that the proposed method has better performance in the non-hyperspherical and complex data structure.

  17. The sun and heliosphere at solar maximum.

    Smith, E J; Marsden, R G; Balogh, A; Gloeckler, G; Geiss, J; McComas, D J; McKibben, R B; MacDowall, R J; Lanzerotti, L J; Krupp, N; Krueger, H; Landgraf, M


    Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind, and energetic charged particles from low-latitude sources reach all latitudes, including the polar caps. The very fast high-latitude wind and polar coronal holes disappear and reappear together. Solar wind speed continues to be inversely correlated with coronal temperature. The cosmic ray flux is reduced symmetrically at all latitudes.

  18. Conductivity maximum in a charged colloidal suspension

    Bastea, S


    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  19. Maximum entropy signal restoration with linear programming

    Mastin, G.A.; Hanson, R.J.


    Dantzig's bounded-variable method is used to express the maximum entropy restoration problem as a linear programming problem. This is done by approximating the nonlinear objective function with piecewise linear segments, then bounding the variables as a function of the number of segments used. The use of a linear programming approach allows equality constraints found in the traditional Lagrange multiplier method to be relaxed. A robust revised simplex algorithm is used to implement the restoration. Experimental results from 128- and 512-point signal restorations are presented.




    Full Text Available Ship squat is a combined effect of ship’s draft and trim increase due to ship motion in limited navigation conditions. Over time, researchers conducted tests on models and ships to find a mathematical formula that can define squat. Various forms of calculating squat can be found in the literature. Among those most commonly used are of Barrass, Millward, Eryuzlu or ICORELS. This paper presents a comparison between the squat formulas to see the differences between them and which one provides the most satisfactory results. In this respect a cargo ship at different speeds was considered as a model for maximum squat calculations in canal navigation conditions.

  1. Multi-Channel Maximum Likelihood Pitch Estimation

    Christensen, Mads Græsbøll


    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  2. Maximum entropy PDF projection: A review

    Baggenstoss, Paul M.


    We review maximum entropy (MaxEnt) PDF projection, a method with wide potential applications in statistical inference. The method constructs a sampling distribution for a high-dimensional vector x based on knowing the sampling distribution p(z) of a lower-dimensional feature z = T (x). Under mild conditions, the distribution p(x) having highest possible entropy among all distributions consistent with p(z) may be readily found. Furthermore, the MaxEnt p(x) may be sampled, making the approach useful in Monte Carlo methods. We review the theorem and present a case study in model order selection and classification for handwritten character recognition.

  3. CORA: Emission Line Fitting with Maximum Likelihood

    Ness, Jan-Uwe; Wichmann, Rainer


    CORA analyzes emission line spectra with low count numbers and fits them to a line using the maximum likelihood technique. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise, the software derives the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. CORA has been applied to an X-ray spectrum with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory.

  4. Dynamical maximum entropy approach to flocking

    Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco; Mora, Thierry; Piovani, Duccio; Tavarone, Raffaele; Walczak, Aleksandra M.


    We derive a new method to infer from data the out-of-equilibrium alignment dynamics of collectively moving animal groups, by considering the maximum entropy model distribution consistent with temporal and spatial correlations of flight direction. When bird neighborhoods evolve rapidly, this dynamical inference correctly learns the parameters of the model, while a static one relying only on the spatial correlations fails. When neighbors change slowly and the detailed balance is satisfied, we recover the static procedure. We demonstrate the validity of the method on simulated data. The approach is applicable to other systems of active matter.

  5. Maximum Temperature Detection System for Integrated Circuits

    Frankiewicz, Maciej; Kos, Andrzej


    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.

  6. Zipf's law and maximum sustainable growth

    Malevergne, Y; Sornette, D


    Zipf's law states that the number of firms with size greater than S is inversely proportional to S. Most explanations start with Gibrat's rule of proportional growth but require additional constraints. We show that Gibrat's rule, at all firm levels, yields Zipf's law under a balance condition between the effective growth rate of incumbent firms (which includes their possible demise) and the growth rate of investments in entrant firms. Remarkably, Zipf's law is the signature of the long-term optimal allocation of resources that ensures the maximum sustainable growth rate of an economy.

  7. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    P. Tao


    Full Text Available The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period. Hydrological forecast based on Ensemble Precipitation prediction gives better hydrological forecast information, better satisfying the need for risk information for flood prevention and disaster reduction, and has broad development opportunities.

  8. The Effect of the CO32- to Ca2+ Ion activity ratio on calcite precipitation kinetics and Sr2+ partitioning

    Gebrehiwet Tsigabu A


    Full Text Available Abstract Background A proposed strategy for immobilizing trace metals in the subsurface is to stimulate calcium carbonate precipitation and incorporate contaminants by co-precipitation. Such an approach will require injecting chemical amendments into the subsurface to generate supersaturated conditions that promote mineral precipitation. However, the formation of reactant mixing zones will create gradients in both the saturation state and ion activity ratios (i.e., aCO32-/aCa2+. To better understand the effect of ion activity ratios on CaCO3 precipitation kinetics and Sr2+ co-precipitation, experiments were conducted under constant composition conditions where the supersaturation state (Ω for calcite was held constant at 9.4, but the ion activity ratio (r=aCO32-/aCa2+ was varied between 0.0032 and 4.15. Results Calcite was the only phase observed, by XRD, at the end of the experiments. Precipitation rates increased from 41.3 ± 3.4 μmol m-2 min-1 at r = 0.0315 to a maximum rate of 74.5 ± 4.8 μmol m-2 min-1 at r = 0.306 followed by a decrease to 46.3 ± 9.6 μmol m-2 min-1 at r = 1.822. The trend was simulated using a simple mass transfer model for solute uptake at the calcite surface. However, precipitation rates at fixed saturation states also evolved with time. Precipitation rates accelerated for low r values but slowed for high r values. These trends may be related to changes in effective reactive surface area. The aCO32-/aCa2+ ratios did not affect the distribution coefficient for Sr in calcite (DPSr2+, apart from the indirect effect associated with the established positive correlation between DPSr2+ and calcite precipitation rate. Conclusion At a constant supersaturation state (Ω = 9.4, varying the ion activity ratio affects the calcite precipitation rate. This behavior is not predicted by affinity-based rate models. Furthermore, at the highest ion ratio tested, no precipitation was observed, while at the lowest ion ratio precipitation

  9. Precipitation behavior and effect of new precipitated β phase in AZ80 magnesium alloy

    TANG Wei; HAN En-hou; XU Yong-bo; LIU Lu


    Granular precipitate that was a new kind of β-Mg17Al12 phase found in aged AZ80 wrought Mg alloy at all aging temperature was studied. The structure and precipitation behavior of this granular β-Mg17Al12 precipitate were studied by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). The effect of the granular precipitate on mechanical properties of AZ80 alloy was also studied. The new precipitate that was granular and nucleated both on grain boundaries (GBs) and twin boundaries, has the same crystal structure and lattice parameter as those of the continuous or discontinuous precipitated β-Mg17Al12. And the nucleation and growth of the granular precipitate are faster than those of the other two precipitates at higher temperatures (above 583 K), but are suppressed at lower temperatures (below 423 K). At lower temperatures, the discontinuous β-Mg17Al12 precipitates firstly and the granular β-Mg17Al12 precipitates after aged more than 40 h. The crack is easily nucleated on the phase boundaries of granular phase and matrix because of the weak binding force. As a result, the strength and ductility of AZ80 Mg alloy are decreased by the granular β-Mg17Al12 precipitate.

  10. Accurate structural correlations from maximum likelihood superpositions.

    Douglas L Theobald


    Full Text Available The cores of globular proteins are densely packed, resulting in complicated networks of structural interactions. These interactions in turn give rise to dynamic structural correlations over a wide range of time scales. Accurate analysis of these complex correlations is crucial for understanding biomolecular mechanisms and for relating structure to function. Here we report a highly accurate technique for inferring the major modes of structural correlation in macromolecules using likelihood-based statistical analysis of sets of structures. This method is generally applicable to any ensemble of related molecules, including families of nuclear magnetic resonance (NMR models, different crystal forms of a protein, and structural alignments of homologous proteins, as well as molecular dynamics trajectories. Dominant modes of structural correlation are determined using principal components analysis (PCA of the maximum likelihood estimate of the correlation matrix. The correlations we identify are inherently independent of the statistical uncertainty and dynamic heterogeneity associated with the structural coordinates. We additionally present an easily interpretable method ("PCA plots" for displaying these positional correlations by color-coding them onto a macromolecular structure. Maximum likelihood PCA of structural superpositions, and the structural PCA plots that illustrate the results, will facilitate the accurate determination of dynamic structural correlations analyzed in diverse fields of structural biology.

  11. Maximum entropy production and the fluctuation theorem

    Dewar, R C [Unite EPHYSE, INRA Centre de Bordeaux-Aquitaine, BP 81, 33883 Villenave d' Ornon Cedex (France)


    Recently the author used an information theoretical formulation of non-equilibrium statistical mechanics (MaxEnt) to derive the fluctuation theorem (FT) concerning the probability of second law violating phase-space paths. A less rigorous argument leading to the variational principle of maximum entropy production (MEP) was also given. Here a more rigorous and general mathematical derivation of MEP from MaxEnt is presented, and the relationship between MEP and the FT is thereby clarified. Specifically, it is shown that the FT allows a general orthogonality property of maximum information entropy to be extended to entropy production itself, from which MEP then follows. The new derivation highlights MEP and the FT as generic properties of MaxEnt probability distributions involving anti-symmetric constraints, independently of any physical interpretation. Physically, MEP applies to the entropy production of those macroscopic fluxes that are free to vary under the imposed constraints, and corresponds to selection of the most probable macroscopic flux configuration. In special cases MaxEnt also leads to various upper bound transport principles. The relationship between MaxEnt and previous theories of irreversible processes due to Onsager, Prigogine and Ziegler is also clarified in the light of these results. (letter to the editor)

  12. Thermodynamic hardness and the maximum hardness principle

    Franco-Pérez, Marco; Gázquez, José L.; Ayers, Paul W.; Vela, Alberto


    An alternative definition of hardness (called the thermodynamic hardness) within the grand canonical ensemble formalism is proposed in terms of the partial derivative of the electronic chemical potential with respect to the thermodynamic chemical potential of the reservoir, keeping the temperature and the external potential constant. This temperature dependent definition may be interpreted as a measure of the propensity of a system to go through a charge transfer process when it interacts with other species, and thus it keeps the philosophy of the original definition. When the derivative is expressed in terms of the three-state ensemble model, in the regime of low temperatures and up to temperatures of chemical interest, one finds that for zero fractional charge, the thermodynamic hardness is proportional to T-1(I -A ) , where I is the first ionization potential, A is the electron affinity, and T is the temperature. However, the thermodynamic hardness is nearly zero when the fractional charge is different from zero. Thus, through the present definition, one avoids the presence of the Dirac delta function. We show that the chemical hardness defined in this way provides meaningful and discernible information about the hardness properties of a chemical species exhibiting integer or a fractional average number of electrons, and this analysis allowed us to establish a link between the maximum possible value of the hardness here defined, with the minimum softness principle, showing that both principles are related to minimum fractional charge and maximum stability conditions.

  13. Maximum Likelihood Analysis in the PEN Experiment

    Lehman, Martin


    The experimental determination of the π+ -->e+ ν (γ) decay branching ratio currently provides the most accurate test of lepton universality. The PEN experiment at PSI, Switzerland, aims to improve the present world average experimental precision of 3 . 3 ×10-3 to 5 ×10-4 using a stopped beam approach. During runs in 2008-10, PEN has acquired over 2 ×107 πe 2 events. The experiment includes active beam detectors (degrader, mini TPC, target), central MWPC tracking with plastic scintillator hodoscopes, and a spherical pure CsI electromagnetic shower calorimeter. The final branching ratio will be calculated using a maximum likelihood analysis. This analysis assigns each event a probability for 5 processes (π+ -->e+ ν , π+ -->μ+ ν , decay-in-flight, pile-up, and hadronic events) using Monte Carlo verified probability distribution functions of our observables (energies, times, etc). A progress report on the PEN maximum likelihood analysis will be presented. Work supported by NSF grant PHY-0970013.

  14. Regional Bias of Satellite Precipitation Estimates

    Modrick, T. M.; Georgakakos, K. P.; Spencer, C. R.


    Satellite-based estimates of precipitation have improved the spatial availability of precipitation data particularly for regions with limited gauge networks due to limited accessibility or infrastructure. Understanding the quality and reliability of satellite precipitation estimates is important, especially when the estimates are utilitized for real-time hydrologic forecasting and for fast-responding phenomena. In partnership with the World Meteorological Organization (WMO), the U.S. Agency of International Development (USAID) and the National Ocean and Atmospheric Administration (NOAA), the Hydrologic Research Center has begun implementation of real-time flash flood warning systems for diverse regions around the world. As part of this effort, bias characteristics of satellite precipitation have been examined in these various regions, such includes portions of Southeastern Asia, Southeastern Europe, the Middle East, Central America, and the southern half of the African continent. The work has focused on the Global Hydro-Estimator (GHE) precipitation product from NOAA/NESDIS. These real-time systems utilize the GHE given low latency times of this product. This presentation focuses on the characterization of precipitation bias as compared to in-situ gauge records, and the regional variations or similarities. Additional analysis is currently underway considering regional bias for other satellite precipitation products (e.g., CMORPH) for comparison with the GHE results.

  15. Effects of the Forecasting Methods, Precipitation Character, and Satellite Resolution on the Predictability of Short-Term Quantitative Precipitation Nowcasting (QPN from a Geostationary Satellite.

    Yu Liu

    Full Text Available The prediction of the short-term quantitative precipitation nowcasting (QPN from consecutive gestational satellite images has important implications for hydro-meteorological modeling and forecasting. However, the systematic analysis of the predictability of QPN is limited. The objective of this study is to evaluate effects of the forecasting model, precipitation character, and satellite resolution on the predictability of QPN using images of a Chinese geostationary meteorological satellite Fengyun-2F (FY-2F which covered all intensive observation since its launch despite of only a total of approximately 10 days. In the first step, three methods were compared to evaluate the performance of the QPN methods: a pixel-based QPN using the maximum correlation method (PMC; the Horn-Schunck optical-flow scheme (PHS; and the Pyramid Lucas-Kanade Optical Flow method (PPLK, which is newly proposed here. Subsequently, the effect of the precipitation systems was indicated by 2338 imageries of 8 precipitation periods. Then, the resolution dependence was demonstrated by analyzing the QPN with six spatial resolutions (0.1atial, 0.3a, 0.4atial rand 0.6. The results show that the PPLK improves the predictability of QPN with better performance than the other comparison methods. The predictability of the QPN is significantly determined by the precipitation system, and a coarse spatial resolution of the satellite reduces the predictability of QPN.

  16. Effects of the Forecasting Methods, Precipitation Character, and Satellite Resolution on the Predictability of Short-Term Quantitative Precipitation Nowcasting (QPN) from a Geostationary Satellite.

    Liu, Yu; Xi, Du-Gang; Li, Zhao-Liang; Ji, Wei


    The prediction of the short-term quantitative precipitation nowcasting (QPN) from consecutive gestational satellite images has important implications for hydro-meteorological modeling and forecasting. However, the systematic analysis of the predictability of QPN is limited. The objective of this study is to evaluate effects of the forecasting model, precipitation character, and satellite resolution on the predictability of QPN using images of a Chinese geostationary meteorological satellite Fengyun-2F (FY-2F) which covered all intensive observation since its launch despite of only a total of approximately 10 days. In the first step, three methods were compared to evaluate the performance of the QPN methods: a pixel-based QPN using the maximum correlation method (PMC); the Horn-Schunck optical-flow scheme (PHS); and the Pyramid Lucas-Kanade Optical Flow method (PPLK), which is newly proposed here. Subsequently, the effect of the precipitation systems was indicated by 2338 imageries of 8 precipitation periods. Then, the resolution dependence was demonstrated by analyzing the QPN with six spatial resolutions (0.1atial, 0.3a, 0.4atial rand 0.6). The results show that the PPLK improves the predictability of QPN with better performance than the other comparison methods. The predictability of the QPN is significantly determined by the precipitation system, and a coarse spatial resolution of the satellite reduces the predictability of QPN.

  17. A substorm in midnight auroral precipitation

    V. G. Vorobjev

    Full Text Available DMSP F7 spacecraft observations for the whole of 1986 were used to construct the empirical model of the midnight auroral precipitation during a substorm. The model includes the dynamics of different auroral precipitation boundaries and simultaneous changes in average electron precipitation energy and energy flux in different precipitation regions during all substorm phases, as well as the IMF and solar wind plasma signatures during a substorm. The analysis of the model shows a few important features of precipitation. (1 During the magnetic quietness and just before the beginning of the substorm expansive phase the latitudinal width of the auroral precipitation in the nightside sector is about 5 – 6° CGL, while that of the auroral oval is about 2 – 3° CGL during such periods. (2 For about 5 min before the substorm onset a decrease in the average precipitating electron energy in the equatorward part of auroral zone was observed simultaneously, with an increase in both the average electron energy and energy flux of electron precipitation in the poleward part of the auroral zone. (3 The isotropy boundary position in the beginning of the substorm expansive phase coincides well with the inner edge of the central plasma sheet. The analysis of interplanetary medium parameters shows that, on average, during the substorm development, the solar wind dynamic pressure was about 1.5 times that of the magnetic quietness period. Substorms occurred predominantly during the southward IMF orientation, suggesting that substorm onset often was not associated with the northern turn or decrease in the southward interplanetary Bz . The Northern Hemisphere’s substorms occurred generally during the positive interplanetary By in winter, and they were observed when the interplanetary By was negative in summer.

    Key words. Ionosphere (auroral ionosphere; particle precipitation – Magnetospheric physics

  18. Thermodynamic Research on Precipitates in Low Carbon Nb-Microalloyed Steels Produced by Compact Strip Production

    Song XIANG; Guoquan LIU; Yang LI; Changrong LI; Andong WANG


    Microalloying element Nb in low carbon steels produced by compact strip production (CSP) process plays an important role in inhibiting recrystallization, decreasing the transformation temperature and grain refinement.With decreasing the rolling temperature, dislocations can be pinned by carbonitrides and the strength is increased. Based on the two sublattice model, with metal atom sublattice and interstitial atom sublattice,a thermodynamic model for carbonitride was established to calculate the equilibrium between matrix and carbonitride. In the steel produced by CSP, the calculation results showed that the starting temperature of precipitation of Ti and Nb are 1340℃ and 1040℃, respectively. In the range of 890-950℃, Nb rapidly precipitated. And the maximum of the atomic fraction of Nb in carbonitride was about 0.68. The morphologies and energy spectrum of the precipitates showed that (NbTi) (CN) precipitated near the dislocations. The experiment results show that Nb rapidly precipitated when the temperature was lower than 970℃, and the atomic fraction of Nb in carbonitride was about 60%-80%. The calculation results are in agreement with the experiment data. Therefore the thermodynamic model can be a useful assistant tool in the research on the precipitates in the low carbon steels produced by CSP.

  19. Identification of Precipitates in Cr-Mn-N Based Steel After Thermal Exposures

    Ondruška Michal


    Full Text Available The paper deals with the identification of precipitates in the Cr-Mn-N steels after thermal exposure. The purpose of the study is to clarify the M2N precipitation by isothermal annealing at the temperatures of 750 and 900 °C with a holding time of 5, 10, 30 min, 1 hr. and 10 hrs. Microstructure of austenitic steel was characterised by the typical presence of annealing twins. Stepwise etching was observed at the holding time of 5 and 10 minutes, but at the holding time of 30 minutes, secondary particles were precipitated at the grain boundaries. Corrosion tests revealed that holding time significantly affected steel structure. M2N is the dominant precipitate, but the occurrence of σ-phase was occasionally observed especially at the interface of discontinuous precipitation and austenitic matrix. Slight increase of hardness at the grain boundaries was caused due to the precipitation of secondary phases during isothermal holding. The maximum hardness of 294 HV was measured on the sample isothermally annealed at 750 °C and holding for 10 hrs. The research provides theoretical basis for the heat affecting of steels, such as, for example, in welding.

  20. An assessment of precipitation and surface air temperature over China by regional climate models

    Wang, Xueyuan; Tang, Jianping; Niu, Xiaorui; Wang, Shuyu


    An analysis of a 20-year summer time simulation of present-day climate (1989-2008) over China using four regional climate models coupled with different land surface models is carried out. The climatic means, interannual variability, linear trends, and extremes are examined, with focus on precipitation and near surface air temperature. The models are able to reproduce the basic features of the observed summer mean precipitation and temperature over China and the regional detail due to topographic forcing. Overall, the model performance is better for temperature than that of precipitation. The models reasonably grasp the major anomalies and standard deviations over China and the five subregions studied. The models generally reproduce the spatial pattern of high interannual variability over wet regions, and low variability over the dry regions. The models also capture well the variable temperature gradient increase to the north by latitude. Both the observed and simulated linear trend of precipitation shows a drying tendency over the Yangtze River Basin and wetting over South China. The models capture well the relatively small temperature trends in large areas of China. The models reasonably simulate the characteristics of extreme precipitation indices of heavy rain days and heavy precipitation fraction. Most of the models also performed well in capturing both the sign and magnitude of the daily maximum and minimum temperatures over China.

  1. Lake Basin Fetch and Maximum Length/Width

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  2. Scales of Topographic Dependence of Alpine Precipitation

    Hutchinson, M. F.


    Scales of topographic dependence of daily precipitation over the Swiss Alps are examined using a new multivariate precipitation interpolation technique. The method of additive regression splines has been designed to incorporate spatially varying dependences on several topographic variables. It avoids the "curse of dimension" by restricting the underlying spline structure to be two-dimensional. This is in keeping with the overall goal of delivering essentially two-dimensional maps. Moreover, it permits a separation between physical process, as represented by various topographic variables, and the empirically determined, continuous two-dimensional effects of these variables on precipitation across the landscape. The analysis determines horizontal and vertical scales of the interaction of precipitation with topography. A common limitation with existing precipitation interpolation methods lies in their difficulty in identifying effective topographic parameters other than elevation. Orographic effects associated with slope and aspect are often discussed but are not always statistically significant. The effects of two topographic parameters, the northern and eastern components of the unit normal to an appropriately vertically exaggerated digital elevation model, are investigated. These parameters have some basis in process modelling studies and, unlike topographic aspect, are continuous functions of horizontal position. They are used to identify significant topographic aspect effects on precipitation without prior knowledge of the prevailing wind field. Short range correlation structure has rarely been explicitly identified in precipitation interpolation studies but its impact is surprisingly strong. Evidence for its existence in these precipitation data was provided in an earlier study but effective methods for calibrating such correlation in spline analyses have only recently been developed. The spatial scale of correlation found here, around 5 km, is large enough to

  3. Importance of maximum snow accumulation for summer low flows in humid catchments

    Jenicek, M.; Seibert, J.; Zappa, M.; Staudinger, M.; Jonas, T.


    The expected increase of air temperature will increase the ratio of liquid to solid precipitation during winter and, thus decrease the amount of snow, especially in mid-elevation mountain ranges across Europe. The decrease of snow will affect groundwater recharge during spring and might cause low streamflow values in the subsequent summer period. To evaluate these potential climate change impacts, we investigated the effects of inter-annual variations in snow accumulation on summer low flow and addressed the following research questions: (1) how important is snow for summer low flows and how long is the "memory effect" in catchments with different elevations? (2) How sensitive are summer low flows to any change of winter snowpack? To find suitable predictors of summer low flow we used long time series from 14 alpine and pre-alpine catchments in Switzerland and computed different variables quantifying winter and spring snow conditions. We assessed the sensitivity of individual catchments to the change of maximum snow water equivalent (SWEmax) using the non-parametric Theil-Sen approach as well as an elasticity index. In general, the results indicated that maximum winter snow accumulation influenced summer low flow, but could only partly explain the observed inter-annual variations. One other important factor was the precipitation between maximum snow accumulation and summer low flow. When only the years with below average precipitation amounts during this period were considered, the importance of snow accumulation as a predictor of low flows increased. The slope of the regression between SWEmax and summer low flow and the elasticity index both increased with increasing mean catchment elevation. This indicated a higher sensitivity of summer low flow to snow accumulation in alpine catchments compared to lower elevation catchments.

  4. A New Method for Near Real Time Precipitation Estimates Using a Derived Statistical Relationship between Precipitable Water Vapor and Precipitation

    Roman, J.


    The IPCC 5th Assessment found that the predicted warming of 1oC would increase the risk of extreme events such as heat waves, droughts, and floods. Weather extremes, like floods, have shown the vulnerability and susceptibility society has to these extreme weather events, through impacts such as disruption of food production, water supply, health, and damage of infrastructure. This paper examines a new way of near-real time forecasting of precipitation. A 10-year statistical climatological relationship was derived between precipitable water vapor (PWV) and precipitation by using the NASA Atmospheric Infrared Sounder daily gridded PWV product and the NASA Tropical Rainfall Measuring Mission daily gridded precipitation total. Forecasting precipitation estimates in real time is dire for flood monitoring and disaster management. Near real time PWV observations from AIRS on Aqua are available through the Goddard Earth Sciences Data and Information Service Center. In addition, PWV observations are available through direct broadcast from the NASA Suomi-NPP ATMS/CrIS instrument, the operational follow on to AIRS. The derived climatological relationship can be applied to create precipitation estimates in near real time by utilizing the direct broadcasting capabilities currently available in the CONUS region. The application of this relationship will be characterized through case-studies by using near real-time NASA AIRS Science Team v6 PWV products and ground-based SuomiNet GPS to estimate the current precipitation potential; the max amount of precipitation that can occur based on the moisture availability. Furthermore, the potential contribution of using the direct broadcasting of the NUCAPS ATMS/CrIS PWV products will be demonstrated. The analysis will highlight the advantages of applying this relationship in near-real time for flash flood monitoring and risk management. Relevance to the NWS River Forecast Centers will be discussed.

  5. Maximum entropy production, carbon assimilation, and the spatial organization of vegetation in river basins.

    del Jesus, Manuel; Foti, Romano; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio


    The spatial organization of functional vegetation types in river basins is a major determinant of their runoff production, biodiversity, and ecosystem services. The optimization of different objective functions has been suggested to control the adaptive behavior of plants and ecosystems, often without a compelling justification. Maximum entropy production (MEP), rooted in thermodynamics principles, provides a tool to justify the choice of the objective function controlling vegetation organization. The application of MEP at the ecosystem scale results in maximum productivity (i.e., maximum canopy photosynthesis) as the thermodynamic limit toward which the organization of vegetation appears to evolve. Maximum productivity, which incorporates complex hydrologic feedbacks, allows us to reproduce the spatial macroscopic organization of functional types of vegetation in a thoroughly monitored river basin, without the need for a reductionist description of the underlying microscopic dynamics. The methodology incorporates the stochastic characteristics of precipitation and the associated soil moisture on a spatially disaggregated framework. Our results suggest that the spatial organization of functional vegetation types in river basins naturally evolves toward configurations corresponding to dynamically accessible local maxima of the maximum productivity of the ecosystem.

  6. SON68 glass dissolution driven by magnesium silicate precipitation

    Fleury, Benjamin; Godon, Nicole; Ayral, André; Gin, Stéphane


    possibilities. The first occurs when the composition of the magnesia glass results in a passivating gel composition containing mainly Na as a charge compensator (as in AVM6 glass). In this case, the addition of Mg in solution results in Mg incorporation in the gel, which increases the protective properties of the gel with respect to glass alteration and reduces the quantity of the precipitated phase. The second occurs when the composition of the magnesia glass results in a gel composition containing Mg, which makes the gel more passivating than a gel containing mainly sodium (AVM10 glass). In this case, the addition of Mg in solution increases the alteration of the glass and the dissolution of a part of the gel because of the precipitation of secondary magnesium phases. According to Thien, the affinity for the gel is the highest for Ca, followed by Mg and Na in that order. The affinity of Mg for the gel is thus stronger than for the secondary phase if the gel contains mainly Na. Conversely, if the gel already contains Mg or Ca, as is the case for SON68, R7T7, and M7 glass, Mg has a stronger affinity to precipitate in the secondary phase. Moreover, it is likely that the pH affects the affinity of Mg for the gel or the secondary phase since the gel solubility and the secondary phase precipitation kinetics are pH-dependent.Therefore, in the alteration of MW glass described by Curti et al. [28] it is possible that Mg had a greater affinity for the gel than for the secondary phase, considering that MW glass contains almost no Ca (0.03 wt% CaO) and that the MW glass gel contains Mg. The phenomenon limiting the precipitation of the secondary phase thus appears to be the dissolution of the gel, which supplies Mg at the maximum rate under the conditions of the experiment with MW glass. This is comparable to the situation with AVM10 glass [29] for which the addition of Mg in solution increases the precipitation rate: precipitation is thus limited by the availability of Mg. It is

  7. European summer climate modulated by NAO-related precipitation

    G. Wang


    Full Text Available Recent summer heat waves in Europe were preceded by precipitation deficits in winter. Numerical studies suggest that these phenomena are dynamically linked by land-atmosphere interactions. However, there is still no clear evidence that connects summer climate variability to winter precipitation and the relevant circulation pattern so far. Using a technique specially designed for detecting directional influences between climatic fields, we investigate the statistical responses of summer mean as well as maximum temperature variability (June–August, Tmean and Tmax to preceding winter precipitation (January–March, PJFM for the period 1901–2005. There appear distinctive Tmean and Tmax responses to PJFM over the Mediterranean, where it is most sensitive to land-atmosphere interactions. An analysis of soil moisture proxy (self-calibrating Palmer drought severity index, scPDSI shows that the PJFM seems to influence summer temperature via soil moisture, and therefore the Tmean and Tmax responses we present here are very likely to be physical hints of water cycle interactions with temperature. We estimate that roughly 10~20% of the interannual variability of Tmax and Tmean over the Mediterranean is forced by PJFM; for the scPDSI, these values amount to 20~25%. Further analysis shows that these responses are highly correlated to the North Atlantic Oscillation (NAO regime over the Mediterranean. Therefore we suggest that NAO modulates European summer temperature via controlling precipitation that initializes the moisture states of water cycle interactions with temperature. This clear picture of relations between European summer climate and NAO-related precipitation suggests potential for improved seasonal prediction of summer climate in

  8. The new record of daily precipitation in Lisbon since 1864: diagnosis and impacts of an exceptional precipitation episode

    Fragoso, M.; Trigo, R. M.; Zêzere, J. L.; Valente, M. A.


    On 18 February 2008 the city of Lisbon had its rainiest day on record, i.e. since the establishment of the D. Luís Observatory in 1853 (continuous observations of meteorological variables are only available since 1864). Fortunately a Portuguese funded project (SIGN) allowed to digitize all the data between 1864 and 1941, allowing a proper comparison with previous extreme events and also to compute more significant return periods. We can now state that a new absolute maximum of daily precipitation at this station occurred last 18 February, when 118.4 mm were registered, surpassing the previous maximum of 110.7 mm (observed on 5 December 1876). Interestingly, these record breaking characteristics were confined to the city of Lisbon, not being observed in rural and suburban neighborhoods, where the anterior maxima recorded in 26 November 1967 or 18 November 1983 were not achieved. In fact, this extreme event was relatively uncharacteristic when compared with typical extreme precipitation events in southern Portugal (Fragoso and Tildes Gomes, 2008). These extreme episodes tend to occur preferably in fall (late September until early December) and covering a wider area. In this work we present an extensive analysis of the large-scale and synoptic atmospheric circulation environment leading to this extreme rainstorm as well as the consequences, namely floods and landslides that produced relevant socio-economic impacts (including 4 casualties). This will be achieved through the characterization of the extreme precipitation episode, describing its temporal structure and the geographic incidence of the event and also assessing statistically the exceptionality of the daily rainfall. The study of the atmospheric context of the episode will be performed with Satellite and radar data, complemented by several large-scale fields obtained from the NCAR/NCEP Reanalyses dataset, including sea level pressure, 500 hPa Geopotential height, precipitation rate, CAPE index. FRAGOSO, M

  9. Hydrological and associated biogeochemical consequences of rapid global warming during the Paleocene-Eocene Thermal Maximum

    Carmichael, Matthew J.; Inglis, Gordon N.; Badger, Marcus P. S.; Naafs, B. David A.; Behrooz, Leila; Remmelzwaal, Serginio; Monteiro, Fanny M.; Rohrssen, Megan; Farnsworth, Alexander; Buss, Heather L.; Dickson, Alexander J.; Valdes, Paul J.; Lunt, Daniel J.; Pancost, Richard D.


    The Paleocene-Eocene Thermal Maximum (PETM) hyperthermal, 56 million years ago (Ma), is the most dramatic example of abrupt Cenozoic global warming. During the PETM surface temperatures increased between 5 and 9 °C and the onset likely took global warming on the Earth system, including both hydrological and associated biogeochemical feedbacks, and proxy data from the PETM can provide constraints on changes in warm climate hydrology simulated by general circulation models (GCMs). In this paper, we provide a critical review of biological and geochemical signatures interpreted as direct or indirect indicators of hydrological change at the PETM, explore the importance of adopting multi-proxy approaches, and present a preliminary model-data comparison. Hydrological records complement those of temperature and indicate that the climatic response at the PETM was complex, with significant regional and temporal variability. This is further illustrated by the biogeochemical consequences of inferred changes in hydrology and, in fact, changes in precipitation and the biogeochemical consequences are often conflated in geochemical signatures. There is also strong evidence in many regions for changes in the episodic and/or intra-annual distribution of precipitation that has not widely been considered when comparing proxy data to GCM output. Crucially, GCM simulations indicate that the response of the hydrological cycle to the PETM was heterogeneous - some regions are associated with increased precipitation - evaporation (P - E), whilst others are characterised by a decrease. Interestingly, the majority of proxy data come from the regions where GCMs predict an increase in PETM precipitation. We propose that comparison of hydrological proxies to GCM output can be an important test of model skill, but this will be enhanced by further data from regions of model-simulated aridity and simulation of extreme precipitation events.

  10. Productivity responses of desert vegetation to precipitation patterns across a rainfall gradient.

    Li, Fang; Zhao, Wenzhi; Liu, Hu


    The influences of previous-year precipitation and episodic rainfall events on dryland plants and communities are poorly quantified in the temperate desert region of Northwest China. To evaluate the thresholds and lags in the response of aboveground net primary productivity (ANPP) to variability in rainfall pulses and seasonal precipitation along the precipitation-productivity gradient in three desert ecosystems with different precipitation regimes, we collected precipitation data from 2000 to 2012 in Shandan (SD), Linze (LZ) and Jiuquan (JQ) in northwestern China. Further, we extracted the corresponding MODIS Normalized Difference Vegetation Index (NDVI, a proxy for ANPP) datasets at 250 m spatial resolution. We then evaluated different desert ecosystems responses using statistical analysis, and a threshold-delay model (TDM). TDM is an integrative framework for analysis of plant growth, precipitation thresholds, and plant functional type strategies that capture the nonlinear nature of plant responses to rainfall pulses. Our results showed that: (1) the growing season NDVIINT (INT stands for time-integrated) was largely correlated with the warm season (spring/summer) at our mildly-arid desert ecosystem (SD). The arid ecosystem (LZ) exhibited a different response, and the growing season NDVIINT depended highly on the previous year's fall/winter precipitation and ANPP. At the extremely arid site (JQ), the variability of growing season NDVIINT was equally correlated with the cool- and warm-season precipitation; (2) some parameters of threshold-delay differed among the three sites: while the response of NDVI to rainfall pulses began at about 5 mm for all the sites, the maximum thresholds in SD, LZ, and JQ were about 55, 35 and 30 mm respectively, increasing with an increase in mean annual precipitation. By and large, more previous year's fall/winter precipitation, and large rainfall events, significantly enhanced the growth of desert vegetation, and desert ecosystems

  11. Maximum entropy principle and texture formation

    Arminjon, M; Arminjon, Mayeul; Imbault, Didier


    The macro-to-micro transition in a heterogeneous material is envisaged as the selection of a probability distribution by the Principle of Maximum Entropy (MAXENT). The material is made of constituents, e.g. given crystal orientations. Each constituent is itself made of a large number of elementary constituents. The relevant probability is the volume fraction of the elementary constituents that belong to a given constituent and undergo a given stimulus. Assuming only obvious constraints in MAXENT means describing a maximally disordered material. This is proved to have the same average stimulus in each constituent. By adding a constraint in MAXENT, a new model, potentially interesting e.g. for texture prediction, is obtained.

  12. MLDS: Maximum Likelihood Difference Scaling in R

    Kenneth Knoblauch


    Full Text Available The MLDS package in the R programming language can be used to estimate perceptual scales based on the results of psychophysical experiments using the method of difference scaling. In a difference scaling experiment, observers compare two supra-threshold differences (a,b and (c,d on each trial. The approach is based on a stochastic model of how the observer decides which perceptual difference (or interval (a,b or (c,d is greater, and the parameters of the model are estimated using a maximum likelihood criterion. We also propose a method to test the model by evaluating the self-consistency of the estimated scale. The package includes an example in which an observer judges the differences in correlation between scatterplots. The example may be readily adapted to estimate perceptual scales for arbitrary physical continua.

  13. Maximum Profit Configurations of Commercial Engines

    Yiran Chen


    Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

  14. Maximum Segment Sum, Monadically (distilled tutorial

    Jeremy Gibbons


    Full Text Available The maximum segment sum problem is to compute, given a list of integers, the largest of the sums of the contiguous segments of that list. This problem specification maps directly onto a cubic-time algorithm; however, there is a very elegant linear-time solution too. The problem is a classic exercise in the mathematics of program construction, illustrating important principles such as calculational development, pointfree reasoning, algebraic structure, and datatype-genericity. Here, we take a sideways look at the datatype-generic version of the problem in terms of monadic functional programming, instead of the traditional relational approach; the presentation is tutorial in style, and leavened with exercises for the reader.

  15. Maximum Information and Quantum Prediction Algorithms

    McElwaine, J N


    This paper describes an algorithm for selecting a consistent set within the consistent histories approach to quantum mechanics and investigates its properties. The algorithm uses a maximum information principle to select from among the consistent sets formed by projections defined by the Schmidt decomposition. The algorithm unconditionally predicts the possible events in closed quantum systems and ascribes probabilities to these events. A simple spin model is described and a complete classification of all exactly consistent sets of histories formed from Schmidt projections in the model is proved. This result is used to show that for this example the algorithm selects a physically realistic set. Other tentative suggestions in the literature for set selection algorithms using ideas from information theory are discussed.

  16. Maximum process problems in optimal control theory

    Goran Peskir


    Full Text Available Given a standard Brownian motion (Btt≥0 and the equation of motion dXt=vtdt+2dBt, we set St=max0≤s≤tXs and consider the optimal control problem supvE(Sτ−Cτ, where c>0 and the supremum is taken over all admissible controls v satisfying vt∈[μ0,μ1] for all t up to τ=inf{t>0|Xt∉(ℓ0,ℓ1} with μ0g∗(St, where s↦g∗(s is a switching curve that is determined explicitly (as the unique solution to a nonlinear differential equation. The solution found demonstrates that the problem formulations based on a maximum functional can be successfully included in optimal control theory (calculus of variations in addition to the classic problem formulations due to Lagrange, Mayer, and Bolza.

  17. Maximum Spectral Luminous Efficacy of White Light

    Murphy, T W


    As lighting efficiency improves, it is useful to understand the theoretical limits to luminous efficacy for light that we perceive as white. Independent of the efficiency with which photons are generated, there exists a spectrally-imposed limit to the luminous efficacy of any source of photons. We find that, depending on the acceptable bandpass and---to a lesser extent---the color temperature of the light, the ideal white light source achieves a spectral luminous efficacy of 250--370 lm/W. This is consistent with previous calculations, but here we explore the maximum luminous efficacy as a function of photopic sensitivity threshold, color temperature, and color rendering index; deriving peak performance as a function of all three parameters. We also present example experimental spectra from a variety of light sources, quantifying the intrinsic efficacy of their spectral distributions.

  18. Maximum entropy model for business cycle synchronization

    Xi, Ning; Muneepeerakul, Rachata; Azaele, Sandro; Wang, Yougui


    The global economy is a complex dynamical system, whose cyclical fluctuations can mainly be characterized by simultaneous recessions or expansions of major economies. Thus, the researches on the synchronization phenomenon are key to understanding and controlling the dynamics of the global economy. Based on a pairwise maximum entropy model, we analyze the business cycle synchronization of the G7 economic system. We obtain a pairwise-interaction network, which exhibits certain clustering structure and accounts for 45% of the entire structure of the interactions within the G7 system. We also find that the pairwise interactions become increasingly inadequate in capturing the synchronization as the size of economic system grows. Thus, higher-order interactions must be taken into account when investigating behaviors of large economic systems.

  19. Quantum gravity momentum representation and maximum energy

    Moffat, J. W.


    We use the idea of the symmetry between the spacetime coordinates xμ and the energy-momentum pμ in quantum theory to construct a momentum space quantum gravity geometry with a metric sμν and a curvature tensor Pλ μνρ. For a closed maximally symmetric momentum space with a constant 3-curvature, the volume of the p-space admits a cutoff with an invariant maximum momentum a. A Wheeler-DeWitt-type wave equation is obtained in the momentum space representation. The vacuum energy density and the self-energy of a charged particle are shown to be finite, and modifications of the electromagnetic radiation density and the entropy density of a system of particles occur for high frequencies.

  20. Video segmentation using Maximum Entropy Model

    QIN Li-juan; ZHUANG Yue-ting; PAN Yun-he; WU Fei


    Detecting objects of interest from a video sequence is a fundamental and critical task in automated visual surveillance.Most current approaches only focus on discriminating moving objects by background subtraction whether or not the objects of interest can be moving or stationary. In this paper, we propose layers segmentation to detect both moving and stationary target objects from surveillance video. We extend the Maximum Entropy (ME) statistical model to segment layers with features, which are collected by constructing a codebook with a set of codewords for each pixel. We also indicate how the training models are used for the discrimination of target objects in surveillance video. Our experimental results are presented in terms of the success rate and the segmenting precision.

  1. Precipitation Recycling and the Vertical Distribution of Local and Remote Sources of Water for Precipitation

    Bosilovich, Michael G.; Atlas, Robert (Technical Monitor)


    Precipitation recycling is defined as the amount of water that evaporates from a region that precipitates within the same region. This is also interpreted as the local source of water for precipitation. In this study, the local and remote sources of water for precipitation have been diagnosed through the use of passive constituent tracers that represent regional evaporative sources along with their transport and precipitation. We will discuss the differences between this method and the simpler bulk diagnostic approach to precipitation recycling. A summer seasonal simulation has been analyzed for the regional sources of the United States Great Plains precipitation. While the tropical Atlantic Ocean (including the Gulf of Mexico) and the local continental sources of precipitation are most dominant, the vertically integrated column of water contains substantial water content originating from the Northern Pacific Ocean, which is not precipitated. The vertical profiles of regional water sources indicate that local Great Plains source of water dominates the lower troposphere, predominantly in the PBL. However, the Pacific Ocean source is dominant over a large portion of the middle to upper troposphere. The influence of the tropical Atlantic Ocean is reasonably uniform throughout the column. While the results are not unexpected given the formulation of the model's convective parameterization, the analysis provides a quantitative assessment of the impact of local evaporation on the occurrence of convective precipitation in the GCM. Further, these results suggest that local source of water is not well mixed throughout the vertical column.

  2. Fundamental features of copper ion precipitation using sulfide as a precipitant in a wastewater system.

    Choi, Jung-Yoon; Kim, Dong-Su; Lim, Joong-Yeon


    We have investigated the precipitation features of copper ion using sulfide as a precipitant by varying the mole ratio of sulfide to copper ion, pH, temperature and the kind and concentration of complexing agent. In the precipitation of copper ion by sulfide, sludge is produced as cupric sulfide; thus, there is a possibility for its recycled use in photochemical and ceramic processes. When the ratio of the concentration of copper ion to sulfide was increased to more than 1.0, the extent of precipitation was very high. As the ratio was increased, nucleation time was decreased and crystal growth rate was raised. The higher the pH, the greater the amount of precipitated copper ion due to lowered solubility of cupric sulfide. When temperature changed from 25 degrees C to 55 degrees C, the precipitation of copper ion was increased a little. On the basis of estimated thermodynamic parameters such as Gibbs free energy and enthalpy, the precipitation reaction was spontaneous and endothermic. The precipitation of copper ion was lowered in the presence of complexing agent and it was affected by the stability of the copper complex. The feasibility test for the application of precipitation treatment to actual wastewater containing copper ion showed, although there was a little decrease in the removal of copper, the precipitation extent of copper was higher than 90% compared with that for artificial wastewater.

  3. Evaluation of pliers' grip spans in the maximum gripping task and sub-maximum cutting task.

    Kim, Dae-Min; Kong, Yong-Ku


    A total of 25 males participated to investigate the effects of the grip spans of pliers on the total grip force, individual finger forces and muscle activities in the maximum gripping task and wire-cutting tasks. In the maximum gripping task, results showed that the 50-mm grip span had significantly higher total grip strength than the other grip spans. In the cutting task, the 50-mm grip span also showed significantly higher grip strength than the 65-mm and 80-mm grip spans, whereas the muscle activities showed a higher value at 80-mm grip span. The ratios of cutting force to maximum grip strength were also investigated. Ratios of 30.3%, 31.3% and 41.3% were obtained by grip spans of 50-mm, 65-mm, and 80-mm, respectively. Thus, the 50-mm grip span for pliers might be recommended to provide maximum exertion in gripping tasks, as well as lower maximum-cutting force ratios in the cutting tasks.

  4. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Hall, Alex


    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with very promising results. We find that the introduction of an intrinsic shape prior mitigates noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely sub-dominant. We show how biases propagate to shear estima...

  5. NESDIS Blended Total Precipitable Water (TPW) Products

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Total Precipitable Water (TPW) product is derived from multiple sensors/satellites. The Percentage of TPW normal (PCT), or TPW anomaly, shows the...

  6. U.S. Hourly Precipitation Data Publication

    National Oceanic and Atmospheric Administration, Department of Commerce — This publication contains hourly precipitation amounts obtained from recording rain gages located at National Weather Service, Federal Aviation Administration, and...

  7. U.S. Hourly Precipitation Data

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly Precipitation Data (HPD) is digital data set DSI-3240, archived at the National Climatic Data Center (NCDC). The primary source of data for this file is...

  8. Processing NPP Bottoms by Ferrocyanide Precipitation

    Savkin, A. E.; Slastennikov Y. T.; Sinyakin O. G.


    The purpose of work is a laboratory test of a technological scheme for cleaning bottoms from radionuclides by use of ozonization, ferrocyanide precipitation, filtration and selective sorption. At carrying out the ferrocyanide precipitation after ozonization, the specific activity of bottoms by Cs{sup 137} is reduced in 100-500 times. It has been demonstrated that the efficiency of ferrocyanide precipitation depends on the quality of consequent filtration. Pore sizes of a filter has been determined to be less than 0.2 {micro}m for complete separation of ferrocyanide residue. The comparison of two technological schemes for cleaning bottoms from radionuclides, characterized by presence of the ferrocyanide precipitation stage has been performed. Application of the proposed schemes allows reducing volumes of radioactive waste in many times.

  9. Acid precipitation - Effects on forest and fish

    Overrein, L.N.; Seip, H.M.; Tollan, A.


    The Norwegian Interdisciplinary Research Programme 'Acid Precipitation - Effects on Forest and Fish' (The SNSF-project) was initiated in 1972. The main objectives of the SNSF-project have been to: (1) establish as precisely as possible the effects of acid precipitation on forest and freshwater fish, (2) investigate the effects of air pollutants on soil, vegetation and water, required to satisfy point 1. The final report summarizes the results of the entire program on the basis of some 300 SNSF reports and data presented in various international journals in the period 1972-80. Attention is given to emissions and transport, atmospheric deposits in Norway, water acidification - status and trends, chemical modifications of precipitation in contact with soil and vegetation, snow and snowmelt, land-use changes and acidification, conceptual models for water acidification, effects of acid precipitation on soil productivity and plant growth, and effects of acid water on aquatic life.

  10. Identifying external influences on global precipitation

    Marvel, K.; Bonfils, C.


    Changes in global (ocean and land) precipitation are among the most important and least well-understood consequences of climate change. Increasing greenhouse gas concentrations are thought to affect the zonal-mean distribution of precipitation through two basic mechanisms. First, increasing temperatures will lead to an intensification of the hydrological cycle (“thermodynamic” changes). Second, changes in atmospheric circulation patterns will lead to poleward displacement of the storm tracks and subtropical dry zones and to a widening of the tropical belt (“dynamic” changes). We demonstrate that both these changes are occurring simultaneously in global precipitation, that this behavior cannot be explained by internal variability alone, and that external influences are responsible for the observed precipitation changes. Whereas existing model experiments are not of sufficient length to differentiate between natural and anthropogenic forcing terms at the 95% confidence level, we present evidence that the observed trends result from human activities.

  11. Precipitation Reconstruction over Land (PREC/L)

    National Oceanic and Atmospheric Administration, Department of Commerce — The monthly data set consists files of 3 resolutions of monthly averaged precipitation totals. The global analyses are defined by interpolation of gauge observations...

  12. BOREAS HYD-8 Gross Precipitation Data

    Fernandes, Richard; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Smith, David E. (Technical Monitor)


    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-08 team made measurements of surface hydrological processes at the Southern Study Area-Old Black Spruce (SSA-OBS) Tower Flux site to support its research into point hydrological processes and the spatial variation of these processes. Data collected may be useful in characterizing canopy interception, drip, throughfall, moss interception, drainage, evaporation, and capacity during the growing season at daily temporal resolution. This particular data set contains the gross precipitation measurements for July to August 1996. Gross precipitation is the precipitation that falls that is not intercepted by tree canopies. These data are stored in ASCII text files. The HYD-08 gross precipitation data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  13. Application of probabilistic precipitation forecasts from a ...

    Application of probabilistic precipitation forecasts from a deterministic model towards increasing the lead-time of flash flood forecasts in South Africa. ... An ensemble set of 30 adjacent basins is then identified as ensemble members for each ...

  14. Average Annual Precipitation (PRISM model) 1961 - 1990

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1961-1990. Parameter-elevation...

  15. VT Mean Annual Precipitation - 1971-2000

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPA7100 includes mean annual precipitation data (in inches) for Vermont (1971-2000). It's a raster dataset derived from...

  16. VT Mean Winter Precipitation - 1971-2000

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPW7100 includes mean winter precipitation data (October through March) for Vermont (1971-2000). It's a raster dataset derived...

  17. A comparative verification of high resolution precipitation forecasts using model output statistics

    van der Plas, Emiel; Schmeits, Maurice; Hooijman, Nicolien; Kok, Kees


    Verification of localized events such as precipitation has become even more challenging with the advent of high-resolution meso-scale numerical weather prediction (NWP). The realism of a forecast suggests that it should compare well against precipitation radar imagery with similar resolution, both spatially and temporally. Spatial verification methods solve some of the representativity issues that point verification gives rise to. In this study a verification strategy based on model output statistics is applied that aims to address both double penalty and resolution effects that are inherent to comparisons of NWP models with different resolutions. Using predictors based on spatial precipitation patterns around a set of stations, an extended logistic regression (ELR) equation is deduced, leading to a probability forecast distribution of precipitation for each NWP model, analysis and lead time. The ELR equations are derived for predictands based on areal calibrated radar precipitation and SYNOP observations. The aim is to extract maximum information from a series of precipitation forecasts, like a trained forecaster would. The method is applied to the non-hydrostatic model Harmonie (2.5 km resolution), Hirlam (11 km resolution) and the ECMWF model (16 km resolution), overall yielding similar Brier skill scores for the 3 post-processed models, but larger differences for individual lead times. Besides, the Fractions Skill Score is computed using the 3 deterministic forecasts, showing somewhat better skill for the Harmonie model. In other words, despite the realism of Harmonie precipitation forecasts, they only perform similarly or somewhat better than precipitation forecasts from the 2 lower resolution models, at least in the Netherlands.

  18. Updated analytical solutions of continuity equation for electron beams precipitation - II. Mixed energy losses

    Zharkova, V. V.; Dobranskis, R. R.


    In this paper we consider simultaneous analytical solutions of continuity equations for electron beam precipitation (a) in collisional losses and (b) in ohmic losses, or mixed energy losses (MEL) by applying the iterative method to calculate the resulting differential densities at given precipitation depth. The differential densities of precipitating electrons derived from the analytical solutions for MELs reveal increased flattening at energies below 10-30 keV compared to a pure collisional case. This flattening becomes stronger with an increasing precipitation depth turning into a positive slope at greater precipitation depths in the chromosphere resulting in a differential density distribution with maximum that shifts towards higher energies with increase in column depth, while the differential densities combining precipitating and returning electrons are higher at lower energies than those for a pure collisional case. The resulting hard X-ray (HXR) emission produced by the beams with different initial energy fluxes and spectral indices is calculated using the MEL approach for different ratios between the differential densities of precipitating and returning electrons. The number of returning electrons can be even further enhanced by a magnetic mirroring, not considered in the present model, while dominating at lower atmospheric depths where the magnetic convergence and magnitude are the highest. The proposed MEL approach provides an opportunity to account simultaneously for both collisional and ohmic losses in flaring events, which can be used for a quick spectral fitting of HXR spectra and evaluation of a fraction of returning electrons versus precipitating ones. The semi-analytical MEL approach is used for spectral fitting to Reuven High Energy Solar Spectroscopic Imager observations of nine C, M and X class flares revealing a close fit to the observations and good resemblance to numerical FP solutions.

  19. Ethanol causes protein precipitation--new safety issues for catheter locking techniques.

    Gernot Schilcher

    Full Text Available OBJECTIVE: The ethanol lock technique has shown great potential to eradicate organisms in biofilms and to treat or prevent central venous catheter related infections. Following instillation of ethanol lock solution, however, the inherent density gradient between blood and ethanol causes gravity induced seepage of ethanol out of the catheter and blood influx into the catheter. Plasma proteins so are exposed to highly concentrated ethanol, which is a classic agent for protein precipitation. We aimed to investigate the precipitating effect of ethanol locks on plasma proteins as a possible cause for reported catheter occlusions. METHODS: Plasma samples were exposed in-vitro to ethanol (concentrations ranging from 7 to 70 v/v% and heparin lock solutions. In catheter studies designed to mimic different in-vivo situations, the catheter tip was placed in a plasma reservoir and the material contained within the catheter was analyzed after ethanol lock instillation. The samples underwent standardized investigation for protein precipitation. RESULTS: Protein precipitation was observed in plasma samples containing ethanol solutions above a concentration of 28%, as well as in material retrieved from vertically positioned femoral catheters and jugular (subclavian catheters simulating recumbent or head down tilt body positions. Precipitates could not be re-dissolved by dilution with plasma, urokinase or alteplase. Plasma samples containing heparin lock solutions showed no signs of precipitation. CONCLUSIONS: Our in-vitro results demonstrate that ethanol locks may be associated with plasma protein precipitation in central venous catheters. This phenomenon could be related to occlusion of vascular access devices locked with ethanol, as has been reported. Concerns should be raised regarding possible complications upon injection or spontaneous gravity induced leakage of such irreversibly precipitated protein particles into the systemic circulation. We suggest

  20. Precipitation Aggregation and the Local Environment

    Smalley, Mark

    The details of large-scale spatial structures of precipitation have only recently become apparent with the advent of high-resolution near-global observations from space-borne radars. As such, the relationships between these structures and the local environment and global climate are just beginning to emerge in the scientific community. Precipitation aggregates on a wide variety of scales, from individual boundary layer instabilities to extra-tropical cyclones. Separate aggregation states have been associated with widely varying precipitation rates and atmospheric states, motivating the inclusion of spatial information in hydrologic and climate models. This work adds to the body of knowledge surrounding large-scale precipitation aggregation and its driving factors by describing and demonstrating a new method of defining the spatial characteristics of precipitation events. The analysis relies on the high sensitivity and high resolution of the CloudSat Cloud Profiling Radar for the identification of precipitation with near-global coverage. The method is based on the dependence of the probability of precipitation on search area, or spatial resolution. Variations in this relationship are caused by variations in the principal characteristics of event spatial patterns: the relative spacing between events, the number density of events, and the overall fraction of precipitating scenes at high resolution. Here, this relationship is modeled by a stretched exponential containing two coefficients, that are shown to depict seasonal general circulation patterns as well as local weather. NASA's Modern-Era Retrospective analysis for Research and Applications is then used to place those spatial characteristics in the context of the local and large-scale environment. At regional scale, precipitation event density during the Amazon wet season is shown to be dependent on zonal wind speed. On a global scale, the relative spacing of shallow oceanic precipitation depends on the