WorldWideScience

Sample records for vf area variability

  1. Variable-Volume Flushing (V-VF) device for water conservation in toilets

    Science.gov (United States)

    Jasper, Louis J., Jr.

    1993-01-01

    Thirty five percent of residential indoor water used is flushed down the toilet. Five out of six flushes are for liquid waste only, which requires only a fraction of the water needed for solid waste. Designers of current low-flush toilets (3.5-gal. flush) and ultra-low-flush toilets (1.5-gal. flush) did not consider the vastly reduced amount of water needed to flush liquid waste versus solid waste. Consequently, these toilets are less practical than desired and can be improved upon for water conservation. This paper describes a variable-volume flushing (V-VF) device that is more reliable than the currently used flushing devices (it will not leak), is simple, more economical, and more water conserving (allowing one to choose the amount of water to use for flushing solid and liquid waste).

  2. Remote monitoring of solar PV system for rural areas using GSM, V-F & F-V converters

    Science.gov (United States)

    Tejwani, R.; Kumar, G.; Solanki, C. S.

    2016-05-01

    The Small capacity photovoltaic (PV) systems like solar lantern and home lighting systems installed in remote rural area often fail without any prior warning due to lack of monitoring and maintenance. This paper describes implementation of remote monitoring for small capacity solar PV system that uses GSM voice channel for communication. Through GSM analog signal of sine wave with frequency range 300-3500 Hz and amplitude range 2.5-4 V is transmitted. Receiver is designed to work in the same frequency range. The voltage from solar PV system in range of 2 to 7.5 V can be converted to frequency directly at the transmitting end. The frequency range from 300-6000 Hz can be sensed and directly converted to voltage signal at receiving end. Testing of transmission and reception of analog signal through GSM voice channel is done for voltage to frequency (V-F) and frequency to voltage (F-V) conversions.

  3. Is VF an Ablatable Rhythm?

    Science.gov (United States)

    Cheniti, Ghassen; Hocini, Meleze; Martin, Ruairidh; Sacher, Frederic; Dubois, Remi; Haissaguerre, Michel; Jais, Pierre

    2017-02-01

    Ventricular fibrillation (VF) has traditionally been considered to be a disorganized arrhythmia not amenable to catheter ablation. However, a better understanding of the VF pathophysiology has allowed identification of targets for ablation. Ablation targeting the premature ventricular complexes which trigger VF was proven to be associated with high success rates and long-term freedom from VF recurrence. Recent mapping data has identified rotors, focal breakthroughs, and figure of eight re-entries as main drivers maintaining human VF. Most interestingly, the type and the spatiotemporal behavior of these drivers are reproducible between different VF episodes. In addition, drivers are usually clustered at the scar borders. This has ushered in a new era of ablation targeting the VF substrate and the drivers maintaining VF with promising results.

  4. Kinematic Structures Description of Bionic Hand Based on VF Set

    Science.gov (United States)

    Liu, Xiancan; Bai, Pengying; Luo, Min; Gao, Meng; Zhan, Qiang

    2017-03-01

    This paper presents a method for describing kinematic structure of bionic hand based on VF (virtual finger) set. At first, a 20 DOFs (degrees of freedom) human hand kinematic model is built, which is expressed by five fingers’ kinematic chains consisting of kinematic pairs and symbols that represent geometric relationships of kinematic pairs’ axes. Based on the concept of VF, the hand fingers are divided into two types: VFAA having adduction/abduction motion and VFFE having flexion/extension motion. The concept of VF set comprising VFAAs and VFFEs is defined, human hand and six basic grasp postures are described by VF set. Then, the structures corresponding VFAA and VFFE are given according to active and passive forms of finger joints, and VFFE Structure-Base comprising 20 conventional structures is built. Based on VF set and the structures of VFAA and VFFE, VF sets and kinematic structures of several classic bionic hands are given.

  5. Prototype Variable-Area Exhaust Nozzle Designed

    Science.gov (United States)

    Lee, Ho-Jun; Song, Gangbring

    2005-01-01

    Ongoing research in NASA Glenn Research Center s Structural Mechanics and Dynamics Branch to develop smart materials technologies for adaptive aeropropulsion components has resulted in the design of a prototype variable-area exhaust nozzle (see the preceding photograph). The novel design exploits the potential of smart materials to improve the performance of existing fixed-area exhaust nozzles by introducing new capabilities for adaptive shape control, vibration damping, and flow manipulation. The design utilizes two different smart materials: shape memory alloy wires as actuators and magnetorheological fluids as damper locks.

  6. EFFICIENT RESTORATION OF VARIABLE AREA SOUNDTRACKS

    Directory of Open Access Journals (Sweden)

    Abdelâali Hassaïne

    2011-05-01

    Full Text Available The restoration of motion picture films using digital image processing has been an active research field for many years. The restoration of the soundtrack however, has mainly been performed in the sound domain, using signal processing methods, in spite of the fact that it is recorded as a continuous image between the images of the film and the perforations. In this paper a restoration method for variable area soundtrack restoration at the image level is presented. First, a novel method is proposed for the detection of the symmetry axis of the scanned soundtrack. Then, a comparison between the watershed and the region growing segmentation of the soundtrack is developed. Another algorithm aiming to enforce the symmetry and to correct the edges of the segmented image is presented. A last step aiming to smooth the edges of the obtained image is performed. Finally, experimental results are reported and possible future improvements are discussed.

  7. V.F. Gening and issues on the archaeology of Volga Bulgaria

    Directory of Open Access Journals (Sweden)

    Rudenko Konstantin A.

    2014-03-01

    Full Text Available V.F. Gening’s contribution to the study of the Volga Bulgaria and his views concerning the history and archaeology of this state formation are considered in the article. His sphere of interest first of all included the links between the Volga Bulgaria population and the tribes belonging to preceding cultures, such as Pyanoborye and Imenkovo ones. V.F. Gening investigated the Bolshie Tarkhany, Turaevo and Rozdestveno burial grounds dated by the 8-9th, 5th and 6-7th centuries A.D., and the materials collected modified the notion of the time and character of the Bulgars arrival in the Volga area. He reconsidered the chronology and interpretation of the archaeological monuments, which referred to the epoch preceding the Bulgars appearance on the Volga, and proposed a hypothesis of the Volga Bulgars as a Turkic-Ugrian ethnos. V.F. Gening created a periodization of the Bolgars history in Eastern Europe within the time span between 1st-3rd centuries AD and the early 13th century AD

  8. THE EFFECTS OF CLIMATIC VARIABLES AND CROP AREA ON MAIZE YIELD AND VARIABILITY IN GHANA

    Directory of Open Access Journals (Sweden)

    Henry De-Graft Acquah

    2012-10-01

    Full Text Available Climate change tends to have negative effects on crop yield through its influence on crop production. Understanding the relationship between climatic variables and crop area on the mean and variance of crop yield will facilitate development of appropriate policies to cope with climate change. This paper examines the effects of climatic variables and crop area on the mean and variance of maize yield in Ghana. The Just and Pope stochastic production function using the Cobb-Douglas functional form was employed. The results show that average maize yield is positively related to crop area and negatively related to rainfall and temperature. Furthermore, increase in crop area and temperature will enlarge maize yield variability while rainfall increase will decrease the variability in maize yield.

  9. Analysis, design and implementation of sensorless V/f control in a ...

    Indian Academy of Sciences (India)

    SOURABH PAITANDI

    Abstract. This paper presents a novel, reliable and efficient V/f control implementation on a 8-pole, 750 rpm,. 5 kW surface-mounted permanent magnet synchronous motor (PMSM) without damper winding. In the absence of a damper winding, open loop V/f control of SM is inherently unstable, particularly at high speeds.

  10. Analysis, design and implementation of sensorless V/f control in a ...

    Indian Academy of Sciences (India)

    These results establish the accuracy of the design of the proposed V/f control strategy and the precision of hardware implementation. A comparative study between the proposed V/f control method and standard vector control method, as implemented on this PMSM, has also been presented here to establish the advantages ...

  11. Sound propagation through a variable area duct - Experiment and theory

    Science.gov (United States)

    Silcox, R. J.; Lester, H. C.

    1981-01-01

    A comparison of experiment and theory has been made for the propagation of sound through a variable area axisymmetric duct with zero mean flow. Measurement of the acoustic pressure field on both sides of the constricted test section was resolved on a modal basis for various spinning mode sources. Transmitted and reflected modal amplitudes and phase angles were compared with finite element computations. Good agreement between experiment and computation was obtained over a wide range of frequencies and modal transmission variations. The study suggests that modal transmission through a variable area duct is governed by the throat modal cut-off ratio.

  12. Identification of image areas based on characteristics of statistical variables

    Directory of Open Access Journals (Sweden)

    Karol Onoszko

    2014-12-01

    Full Text Available [b]Abstract[/b]. In recent years increasing interest in the methods based on image processing has been observed. With today’s technology, these methods are becoming faster, more accurate, and the results of the tests are easier to interpret. The article describes an original method for identifying areas of an image, using the characteristics of statistical variables resulting from the observation of these areas.[b]Keywords[/b]: image recognition, auto-correlation, signal analysis

  13. Variable area radial turbine fabrication and test program

    Science.gov (United States)

    Rogo, C.

    1986-01-01

    A variable area radial turbine with a moveable nozzle sidewall was experimentally evaluated. The turbine was designed for an advanced variable capacity gas turbine rotorcraft engine. The turbine has a mass flow rate of 2.27 kg/sec (5.0 lbs/sec), and a rotor inlet temperature of 1477K (2200 F). Testing was conducted at a reduced inlet temperature, but the aerodynamic parameters and Reynolds numbers were duplicated. Overall performance was obtained for a range of nozzle areas from 50% to 100% of the maximum area. The test program determined the effect on performance of: (1) Moving the hub or shroud sidewall; (2) Sidewall-vane clearance leakage; (3) Vaneless space geometry change; and (4) Nozzle cooling flows. Data were obtained for a range of pressure ratios and speeds and are presented in a number of performance maps.

  14. A V/f= cte Control Drive for Permanent Capacitor Single-Phase Induction Motor

    Directory of Open Access Journals (Sweden)

    Pedram Shahriari Nasab

    2013-01-01

    Full Text Available Poor performance of the convectional household induction motors which used in home appliances such as refrigerator, cooler, laundry, washing machines, fans, hand-held power tools, and automotive window lift is generally caused by two main reasons. Firstly, they have high starting current which causes significant voltage drop, and secondly, they operate in a single speed mode and not in variable speed. In many home appliances, traditionally a discrete speed control method is used by changing the number of the poles. A proper solution for these problems can be achieved by using control drive systems. In this paper, a simple scalar control method is applied to control the speed of a permanent capacitor single phase induction motor (PCSPIM. The philosophy of this method is on the basis of simultaneous system’s frequency and voltage control on the machines terminals subject to V/f=cte. Simulation and practical implementation results clearly show the effectiveness of the simple V/f =cte speed control method for home appliances.

  15. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors

  16. Measurement of visual function among patients undergoing corneal transplantation using the VF-14 index in Morocco.

    Science.gov (United States)

    Belghmaidi, S; Adarmouch, L; Baali, M; Sebbani, M; Hajji, I; Amine, M; Moutaouakil, A

    2016-12-01

    To validate the Moroccan version of the VF-14 in candidates for keratoplasty and to assess their quality of life using this tool before and after transplantation. This is a longitudinal prospective study that assessed 57 patients who underwent penetrating keratoplasty, recruited in the ophthalmology service in Marrakech over 5 years. The original VF-14 questionnaire was adapted into Moroccan dialect. The questionnaire was administered before and 2 years after transplantation. The VF-12 questionnaire was also used, deleting the last two items. Data analysis was performed using SPSS 16.0 software. Comparisons of VF-14 scores before and after transplantation used the Wilcoxon test for paired samples. In total, 57 patients participated in the study. The most frequent indication for surgery was keratoconus (44%). All patients underwent penetrating keratoplasty. Chronbach's alpha value was 0.989 for VF-14 and 0.990 for VF-12. The two scores were negatively correlated with logMAR visual acuity. The strongest correlation was found with VA in the fellow eye. The average best-corrected visual acuity of the eye scheduled for keratoplasty was 1.1±0.16 logMAR. The average of VF-14 was 53±3. After keratoplasty, the average best-corrected visual acuity of operated eye was 0.34±0.31. The average postoperative astigmatism was 3 D. After keratoplasty, an increase in VF-14 score was observed from 53.5 to 81.92 (Pastigmatism, and good visual acuity have long been indicators of a successful corneal transplant. However, this does not provide information on visual quality and its impact on everyday life. It is in this sense that the VF-14 was adapted into several languages, as reliable, valid and sensitive as the original Anglo-American version, to assess objectively and subjectively the quality of life of patients after keratoplasty. With advances in techniques and availability of better materials, surgical success in performing keratoplasty is increasing. At the same time, vision

  17. Air suspension characterisation and effectiveness of a variable area orifice

    Science.gov (United States)

    Alonso, A.; Giménez, J. G.; Nieto, J.; Vinolas, J.

    2010-12-01

    The air spring is one of the components that most affects vehicle comfort. This element usually makes up the main part of the secondary suspension, which introduces both stiffness and damping between the bogie and the car body. Therefore, a deep understanding of this element is necessary in order to study the comfort of a vehicle, the influence of different parameters and the ways to improve it. In this work, the effect of the air spring system on comfort is studied. To accomplish this, a typical pneumatic suspension composition is briefly studied as a first step. Then, the test bench developed to characterise air springs is described, presenting experimental results. Correlation of the results with some theoretical models is also addressed. Afterwards, the effect of the air spring system on comfort is analysed, and finally, improvements from introducing a variable area orifice in the pipe that joints the air spring and the surge reservoir are discussed.

  18. The VASIMR[registered trademark] VF-200-1 ISS Experiment as a Laboratory for Astrophysics

    Science.gov (United States)

    Glover Tim W.; Squire, Jared P.; Longmier, Benjamin; Cassady, Leonard; Ilin, Andrew; Carter, Mark; Olsen, Chris S.; McCaskill, Greg; Diaz, Franklin Chang; Girimaji, Sharath; hide

    2010-01-01

    The VASIMR[R] Flight Experiment (VF-200-1) will be tested in space aboard the International Space Station (ISS) in about four years. It will consist of two 100 kW parallel plasma engines with opposite magnetic dipoles, resulting in a near zero-torque magnetic system. Electrical energy will come from ISS at low power level, be stored in batteries and used to fire the engine at 200 kW. The VF-200-1 project will provide a unique opportunity on the ISS National Laboratory for astrophysicists and space physicists to study the dynamic evolution of an expanding and reconnecting plasma loop. Here, we review the status of the project and discuss our current plans for computational modeling and in situ observation of a dynamic plasma loop on an experimental platform in low-Earth orbit. The VF-200-1 project is still in the early stages of development and we welcome new collaborators.

  19. 76 FR 12022 - Foreign-Trade Zone 230-Greensboro, NC; Application for Subzone; VF Jeanswear (Apparel...

    Science.gov (United States)

    2011-03-04

    ... status for the warehousing and distribution facility of VF Jeanswear, located in Mocksville, North... warehousing and distribution of foreign-origin apparel (duty rates 16.6%-28.6%) for the U.S. market and export... realize logistical benefits through the use of certain customs procedures. The request indicates that the...

  20. Effects of Load and Speed Variations in a Modified Closed Loop V/F ...

    African Journals Online (AJOL)

    This paper investigates the eects of load and reference speed variations in a modied closed loopv=f induction motor drive. A modied approach, involving the addition of a low frequency boostvoltage, is developed and adopted as an enhancement to the conventional closed loop v=f speedcontrol of a three phase squirrel ...

  1. New sensorless, efficient optimized and stabilized v/f control for pmsm machines

    Science.gov (United States)

    Jafari, Seyed Hesam

    With the rapid advances in power electronics and motor drive technologies in recent decades, permanent magnet synchronous machines (PMSM) have found extensive applications in a variety of industrial systems due to its many desirable features such as high power density, high efficiency, and high torque to current ratio, low noise, and robustness. In low dynamic applications like pumps, fans and compressors where the motor speed is nearly constant, usage of a simple control algorithm that can be implemented with least number of the costly external hardware can be highly desirable for industry. In recent published works, for low power PMSMs, a new sensorless volts-per-hertz (V/f) controlling method has been proposed which can be used for PMSM drive applications where the motor speed is constant. Moreover, to minimize the cost of motor implementation, the expensive rotor damper winding was eliminated. By removing the damper winding, however, instability problems normally occur inside of the motor which in some cases can be harmful for a PMSM drive. As a result, to address the instability issue, a stabilizing loop was developed and added to the conventional V/f. By further studying the proposed sensorless stabilized V/f, and calculating power loss, it became known that overall motor efficiency still is needed to be improved and optimized. This thesis suggests a new V/f control method for PMSMs, where both efficiency and stability problems are addressed. Also, although in nearly all recent related research, methods have been applied to low power PMSM, for the first time, in this thesis, the suggested method is implemented for a medium power 15 kW PMSM. A C2000 F2833x Digital Signal Processor (DSP) is used as controller part for the student custom built PMSM drive, but instead of programming the DSP in Assembly or C, the main control algorithm was developed in a rapid prototype software environment which here Matlab Simulink embedded code library is used.

  2. Modeling and control of V/f controlled induction motor using genetic-ANFIS algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Ustun, Seydi Vakkas (Vocational High School, Adiyaman University, Adiyaman/Turkey); Demirtas, Metin (Electrical and Electronics Engineering Department, Balikesir University, Balikesir/Turkey)

    2009-03-15

    This paper deals with modeling and performance analysis of the voltage/frequency (V/f) control of induction motor drives. The V/f control, which realizes a low cost and simple design, is advantageous in the middle to high-speed range. Its torque response depends on the electrical time constant of the motor and adjustments of the control parameters are not need. Therefore, V/f control of induction motor is carried out. Space vector pulse width modulation is used for controlling the motor because of including minimum harmonics according to the other PWM techniques. Proportional Integral (PI) controller is used to control speed of induction motor. In this work, optimization of PI coefficients is carried out by Ziegler-Nichols model and Genetic-Adaptive Neuro-Fuzzy Inference System (ANFIS) model. These controllers are applied to drive system with 0.55 kW induction motor. A digital signal processor controller (dsPIC30F6010) is used to carry out control applications. The proposed method is compared Ziegler-Nichols model. Experimental results show the effectiveness of the proposed control method. (author)

  3. Systematic benchmark of substructure search in molecular graphs - From Ullmann to VF2

    Directory of Open Access Journals (Sweden)

    Ehrlich Hans-Christian

    2012-07-01

    Full Text Available Abstract Background Searching for substructures in molecules belongs to the most elementary tasks in cheminformatics and is nowadays part of virtually every cheminformatics software. The underlying algorithms, used over several decades, are designed for the application to general graphs. Applied on molecular graphs, little effort has been spend on characterizing their performance. Therefore, it is not clear how current substructure search algorithms behave on such special graphs. One of the main reasons why such an evaluation was not performed in the past was the absence of appropriate data sets. Results In this paper, we present a systematic evaluation of Ullmann’s and the VF2 subgraph isomorphism algorithms on molecular data. The benchmark set consists of a collection of 1235 SMARTS substructure expressions and selected molecules from the ZINC database. The benchmark evaluates substructures search times for complete database scans as well as individual substructure-molecule pairs. In detail, we focus on the influence of substructure formulation and size, the impact of molecule size, and the ability of both algorithms to be used on multiple cores. Conclusions The results show a clear superiority of the VF2 algorithm in all test scenarios. In general, both algorithms solve most instances in less than one millisecond, which we consider to be acceptable. Still, in direct comparison, the VF2 is most often several folds faster than Ullmann’s algorithm. Additionally, Ullmann’s algorithm shows a surprising number of run time outliers.

  4. Rainfall trends and variability in selected areas of Ethiopian Somali ...

    African Journals Online (AJOL)

    The adverse effect of such variability and change is accelerating the already existing pastoral livelihood insecurity. ... Moreover, proper spatial distribution of meteorological stations together with early warning system are required to further support local adaptive and coping strategies that the community designed towards ...

  5. FPGA Based V/f Control of Three Phase Induction Motor Drives Integrating Super-Lift Luo Converter

    National Research Council Canada - National Science Library

    Elangovan P; Nalin Kant Mohanty

    2015-01-01

    .... The Voltage Source Inverter (VSI) of the suggested system renders both open loop and closed loop V/f control scheme for IM by feedback regulated Sinusoidal Pulse Width Modulation (SPWM) technique...

  6. Spatial variability of fine particle concentrations in three European areas

    Science.gov (United States)

    Hoek, Gerard; Meliefste, Kees; Cyrys, Josef; Lewné, Marie; Bellander, Tom; Brauer, Mike; Fischer, Paul; Gehring, Ulrike; Heinrich, Joachim; van Vliet, Patricia; Brunekreef, Bert

    Epidemiological studies of long-term air pollution effects have been hampered by difficulties in characterizing the spatial variation in air pollution. We conducted a study to assess the risk of long-term exposure to traffic-related air pollution for the development of inhalant allergy and asthma in children in Stockholm county, Munich and the Netherlands. Exposure to traffic-related air pollution was assessed through a 1-year monitoring program and regression modeling using exposure indicators. This paper documents the performance of the exposure monitoring strategy and the spatial variation of ambient particle concentrations. We measured the ambient concentration of PM2.5 and the reflectance of PM2.5 filters ('soot') at 40-42 sites representative of different exposure conditions of the three study populations. Each site was measured during four 14-day average sampling periods spread over one year (spring 1999 to summer 2000). In each study area, a continuous measurement site was operated to remove potential bias due to temporal variation. The selected approach was an efficient method to characterize spatial differences in annual average concentration between a large number of sites in each study area. Adjustment with data from the continuous measurement site improved the precision of the calculated annual averages, especially for PM2.5. Annual average PM2.5 concentrations ranged from 11 to 20 μg/m 3 in Munich, from 8 to 16 μg/m 3 in Stockholm and from 14 to 26 μg/m 3 in the Netherlands. Larger spatial contrasts were found for the absorption coefficient of PM2.5. PM2.5 concentrations were on average 17-18% higher at traffic sites than at urban background sites, but PM2.5 absorption coefficients at traffic sites were between 31% and 55% increased above background. This suggests that spatial variation of traffic-related air pollution may be underestimated if PM2.5 only is measured.

  7. Plasma nitriding and simultaneous tempering of VF 800AT tool steel; Nitretacao por plasma com revenimento simultaneo do aco ferramenta VF 800AT

    Energy Technology Data Exchange (ETDEWEB)

    Prass, Andre Ricardo; Fontana, Luis Cesar; Recco, Abel Andre Candido, E-mail: prass.andrericardo@gmail.com, E-mail: luis.fontana@udesc.br, E-mail: abel.recco@udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil)

    2017-04-15

    Plasma nitriding of tool steels improves the surface hardness due to formation of diffusion zone and/or compound layer. The process parameters such as temperature, gas composition and dwell time, allow to control the layer thickness, the microstructure, the crystalline phases and the type of layer (for example white layer or diffusion zone). This paper discusses an alternative procedure for the heat treatment of tempering and surface treatment, both in plasma or combining conventional heat treatment with subsequent plasma nitriding. Carrying out both treatments in plasma could enable reduction in manufacturing costs, lower energy consumption and less time for tools manufacturing. Samples of VF800AT steel were treated and characterized (at surface and core of samples) through the following technique: X-ray diffraction, optical microscopy, scanning electron microscopy, micro-hardness profile and Rockwell C measurement. Temperature measurements during the plasma treatment, show that arise thermal gradient between the surface and the core of the samples. In this work, it was observed that the surface was up to 7% hotter than the core of sample, during the plasma treatment with temperature of magnitude about 5 x 10{sup 2} °C. This thermal gradient seems inherent to the plasma process, so that it can produce different microstructure, hardness and crystalline phases between core and edge of samples. However, when two tempering operations are prior carried out in a muffle furnace and the third tempering treatment is subsequently carried out simultaneously with the plasma nitriding, it is observed that the microstructure, the crystalline phases, hardness and micro hardness (in both, edge and core) are similar to treatments done in conventional mode cycle (in muffle furnace) with subsequent plasma nitriding. (author)

  8. Using small area estimation and Lidar-derived variables for multivariate prediction of forest attributes

    Science.gov (United States)

    F. Mauro; Vicente Monleon; H. Temesgen

    2015-01-01

    Small area estimation (SAE) techniques have been successfully applied in forest inventories to provide reliable estimates for domains where the sample size is small (i.e. small areas). Previous studies have explored the use of either Area Level or Unit Level Empirical Best Linear Unbiased Predictors (EBLUPs) in a univariate framework, modeling each variable of interest...

  9. Nonlinear Dynamics of Permanent-magnet Synchronous Motor with v/f Control

    Science.gov (United States)

    Wei, Du-Qu; Zhang, Bo; Luo, Xiao-Shu; Qiu, Dong-Yuan

    2013-03-01

    The nonlinear dynamics of permanent-magnet synchronous motor (PMSM) with v/f control signals is investigated intensively. First, the equilibria and steady-state characteristics of the system are formulated by analytical analysis. Then, some of its basic dynamical properties, such as characteristic eigenvalues, Lyapunov exponents and phase trajectories are studied by varying the values of system parameters. It is found that when the values of the system parameters are smaller, the PMSM operates in stable domains, no matter what the values of control gains are. With the values of parameters increasing, the unstability appears and PMSM falls into chaotic operation. Furthermore, the complex dynamic behaviors are verified by means of simulation.

  10. Flexible Strategies for Coping with Rainfall Variability: Seasonal Adjustments in Cropped Area in the Ganges Basin.

    Directory of Open Access Journals (Sweden)

    Christian Siderius

    Full Text Available One of the main manifestations of climate change will be increased rainfall variability. How to deal with this in agriculture will be a major societal challenge. In this paper we explore flexibility in land use, through deliberate seasonal adjustments in cropped area, as a specific strategy for coping with rainfall variability. Such adjustments are not incorporated in hydro-meteorological crop models commonly used for food security analyses. Our paper contributes to the literature by making a comprehensive model assessment of inter-annual variability in crop production, including both variations in crop yield and cropped area. The Ganges basin is used as a case study. First, we assessed the contribution of cropped area variability to overall variability in rice and wheat production by applying hierarchical partitioning on time-series of agricultural statistics. We then introduced cropped area as an endogenous decision variable in a hydro-economic optimization model (WaterWise, coupled to a hydrology-vegetation model (LPJmL, and analyzed to what extent its performance in the estimation of inter-annual variability in crop production improved. From the statistics, we found that in the period 1999-2009 seasonal adjustment in cropped area can explain almost 50% of variability in wheat production and 40% of variability in rice production in the Indian part of the Ganges basin. Our improved model was well capable of mimicking existing variability at different spatial aggregation levels, especially for wheat. The value of flexibility, i.e. the foregone costs of choosing not to crop in years when water is scarce, was quantified at 4% of gross margin of wheat in the Indian part of the Ganges basin and as high as 34% of gross margin of wheat in the drought-prone state of Rajasthan. We argue that flexibility in land use is an important coping strategy to rainfall variability in water stressed regions.

  11. Potential Reductions in Variability with Alternative Approaches to Balancing Area Cooperation with High Penetrations of Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, M.; Kirby, B.; Beuning, S.

    2010-08-01

    The work described in this report was performed by the National Renewable Energy Laboratory (NREL) and funded by the Office of the Energy Efficiency and Renewable Energy, U.S. Department of Energy (EERE DOE). This project is a joint project with the Pacific Northwest National Laboratory. This report evaluates the physical characteristics that improve the ability of the power system to absorb variable generation. It then uses evidence from electricity markets in the Eastern Interconnection of the United States to show how large, fast energy markets can help with integration. The concept of Virtual Balancing Area is introduced, a concept that covers a broad range of cooperative measures that can be undertaken by balancing areas to help manage variability.

  12. Inter- and intrapatient variability of facial nerve response areas in the floor of the fourth ventricle.

    Science.gov (United States)

    Bertalanffy, Helmut; Tissira, Nadir; Krayenbühl, Niklaus; Bozinov, Oliver; Sarnthein, Johannes

    2011-03-01

    Surgical exposure of intrinsic brainstem lesions through the floor of the 4th ventricle requires precise identification of facial nerve (CN VII) fibers to avoid damage. To assess the shape, size, and variability of the area where the facial nerve can be stimulated electrophysiologically on the surface of the rhomboid fossa. Over a period of 18 months, 20 patients were operated on for various brainstem and/or cerebellar lesions. Facial nerve fibers were stimulated to yield compound muscle action potentials (CMAP) in the target muscles. Using the sites of CMAP yield, a detailed functional map of the rhomboid fossa was constructed for each patient. Lesions resected included 14 gliomas, 5 cavernomas, and 1 epidermoid cyst. Of 40 response areas mapped, 19 reached the median sulcus. The distance from the obex to the caudal border of the response area ranged from 8 to 27 mm (median, 17 mm). The rostrocaudal length of the response area ranged from 2 to 15 mm (median, 5 mm). Facial nerve response areas showed large variability in size and position, even in patients with significant distance between the facial colliculus and underlying pathological lesion. Lesions located close to the facial colliculus markedly distorted the response area. This is the first documentation of variability in the CN VII response area in the rhomboid fossa. Knowledge of this remarkable variability may facilitate the assessment of safe entry zones to the brainstem and may contribute to improved outcome following neurosurgical interventions within this sensitive area of the brain.

  13. EFFECTS OF MOUNTAINTOP MINING/VALLEY FILL (MTM/VF) ON FUNCTIONAL INDICATORS IN APPALACHIAN HEADWATER STREAMS

    Science.gov (United States)

    The objectives of this poster were 1)to evaluate the impact of MTM/VF on the functional attributes SOD, soil/sediment respiration rate, soil/sediment DEA and dissolved trace gas concentrations across gradients of mining disturbance and hydrolgy and 2)compare these functional attr...

  14. Effects of FCGRIIIa-158V/F polymorphism on antibody-dependent cellular cytotoxicity activity of adalimumab.

    Science.gov (United States)

    Kimura, Koji; Kobayashi, Daigo; Hatoyama, Saori; Yamamoto, Mizuki; Takayanagi, Risa; Yamada, Yasuhiko

    2017-09-15

    The associations between the efficacy of IgG reagents and the FCGRIIIa-158V/F polymorphism (rs396991) have been investigated. Although the genotype frequencies in healthy Japanese have been reported, those have varied, as one study reported that the proportions of V/V, V/F, and F/F were 59.1%, 38.6%, and 2.3%, respectively, while another study found that they were 4%, 44%, and 52%, respectively. However, there are no known investigations of the association between the antibody-dependent cellular cytotoxicity (ADCC) activity of adalimumab (ADA), an IgG reagent, in combination with FcγRIIIa and the polymorphism. In this study, we analyzed healthy Japanese to clarify genotype frequency using a direct sequence method. In addition, we examined the association between the ADA-mediated ADCC activity and the polymorphism. Our results showed that the frequencies of the V/V, V/F, and F/F genotypes in healthy Japanese were 9.2%, 39.8%, and 51.0%, respectively. The average activity of ADA-mediated ADCC was 25.0%, 19.0%, and 13.3% in the V/V, V/F, and F/F genotypes, respectively. Then, the ADCC activity of V/V was significantly higher than that of F/F (p F polymorphism. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  15. GENERATION ET DETECTION D'ONDES DE LAMB A L'AIDE DE P(VF rVFJ) :APPLICATION A LA MESURE DE DENSITES DE LIQUIDES

    OpenAIRE

    Scandelari, Luciano

    1999-01-01

    In this work, we accomplished a theoretical and experimental study of a Lamb wave device based on P(VF2-VF3). It is intended to measure liquids densities for industrial applications. Ibis device is composed of two identical piezo-polymer P(VF2-VF3) plates of 110~m thickness, coated on both sides with aluminum, and coupled to an aluminum media 90~m thick. The electrodes (a pair of single-phase transducers) were etched on the upper aluminum face of the piezo-polymer. The presence ofa liquid on ...

  16. Variability of morphometric leaf characteristics of black poplar from the area of Vojvodina

    Directory of Open Access Journals (Sweden)

    Čortan Dijana

    2014-01-01

    Full Text Available A morphological study of intra and interpopulation variability of black poplar leaves was conducted in two populations in the area of Vojvodina. Nine morphometric parameters of leaves have been analyzed. The results indicate that there is considerable variability within and between the populations. Morphological differentiation is clearly represented with the average values of analyzed parameters and a statistically significant difference between the mean values. On the basis of the obtained data, it has been concluded that the variability within the two populations is much more expressed than the variability between them. The uniformity of environmental conditions of the studied locations indicates that this variability is a consequence of the specific gene pool of the studied populations.

  17. Academician V.F. Utkin, General Designer of Space Launch Systems

    Science.gov (United States)

    Konyukhov, S.; Novykov, O.

    2002-01-01

    Academician Vladimir Fedorovich Utkin was an outstanding scientist and designer of rocket and space machinery, Doctor of Technical Science, Professor, Twice Hero of Socialist Labor, Lenin Prize and USSR State Prize winner, bearer of six Orders of Lenin and many other government awards. For 19 years, 1971 - 1990, V. F. Utkin held a position of General Designer in Yuzhnoye SDO having inherited this post from Academician Mikhail Kuzmich Yangel - Yuhnoye's founder. From 1990 till 2000 V. F. Utkin headed Central Scientific Research Institute of Machinery of Russia (TsNIIMash) as its General Designer. Under leadership of V. F. Utkin Yuzhnoye SDO designed several generations of unique strategic missile systems that laid the foundation for Rocket Strategic Forces of the Soviet Union and Russia, subsequently, developed one of the largest high-performance liquid- propellant ICBM SS-18 (Satan), solid-propellant ICBM SS-24 designed for both silo and rail- road deployment, environment friendly Zenit launch vehicle, delivered more than three hundred military, scientific and environmental satellites with tasks. A series of complicated scientific and technical problems has been resolved, a number of unique designing and technological solutions has been implemented in course of development, e.g. separating and orbital warheads, pop-up launch of heavy missiles from a container, continuous and persistent combat duty of liquid-propellant missiles, missile tolerance to nuclear explosion damage, liberation of vessels from ice captivity in the Arctic Ocean using Cosmos-1500 satellite - ancestor of the Ocean satellite constellation designed for accomplishment of seafaring tasks. The existing Russian Program for Rocket and Space Machinery development was designed under leadership of V.F. Utkin.

  18. Flexible strategies for coping with rainfall variability : seasonal adjustments in cropped area in the Ganges basin

    NARCIS (Netherlands)

    Siderius, C.; Biemans, H.J.A.; Walsum, van P.E.V.; Ierland, van E.C.; Hellegers, P.J.G.J.

    2016-01-01

    One of the main manifestations of climate change is expected to be increased rainfall variability. How to deal with this in agriculture will be a major societal challenge. In this paper we explore flexibility in land use, through deliberate seasonal adjustments in cropped area, as a specific

  19. Influence of weather and climate variables on the basal area growth of individual shortleaf pine trees

    Science.gov (United States)

    Pradip Saud; Thomas B. Lynch; Duncan S. Wilson; John Stewart; James M. Guldin; Bob Heinemann; Randy Holeman; Dennis Wilson; Keith Anderson

    2015-01-01

    An individual-tree basal area growth model previously developed for even-aged naturally occurring shortleaf pine trees (Pinus echinata Mill.) in western Arkansas and southeastern Oklahoma did not include weather variables. Individual-tree growth and yield modeling of shortleaf pine has been carried out using the remeasurements of over 200 plots...

  20. Trend Analysis of Hydro-meteorological variables in the coastal area ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT; This paper presents the application of Mann-Kendall trend test and Standard. Anomaly index onhydro-meteorological variables in the coastal area of Lagos state in order to determine the nature of trend and level of significance. The hydro-meteorological data such as air temperature, relative humidity, wind ...

  1. Do habitat variables correlate anuran abundance in arid terrain of Rawalpindi–Islamabad Areas, Pakistan?

    Directory of Open Access Journals (Sweden)

    Ayesha Akram

    2015-07-01

    Full Text Available The quantification of anuran abundance and habitat provides valuable baseline data for future monitoring in areas of planned or anticipated human activities. We carried out the present study to see if anuran abundance is associated with habitat variables (water quality, gravel size and vegetation in Rawalpindi–Islamabad Area, Pakistan. We used area-constrained searches and quadrat method to gather data on anuran abundance and vegetation diversity, respectively, from September, 2012 to July, 2013. We recorded 28 ± 4.83 (mean number ± SE individuals of six anuran species from the study area. We recorded Euphlyctis cyanophlyctis (10 ± 2.39 as the most abundant anuran species while Microhyla ornata (<1 ± 0.09 as the least abundant species. The Kernel regression revealed strong and statistically significant association between habitat variables and abundance of Hoplobatrachus tigerinus (R2 = 0.678 and Bufo stomaticus (R2 = 0.624 but weak and statistically significant association between habitat variables and abundance of E. cyanophlyctis (R2 = 0.482; Duttaphrynus melanostictus (R2 = 0. 451; M. ornata (R2 = 0.223 and Limnonectes limnocharis (R2 = 0. 006. We concluded that the common frogs and toads in our area belong to families Dicroglossidae and Bufonidae while uncommon frogs are of family Microhylidae. We suggest inclusion of monitoring of water quality (dissolved oxygen and pH and maintenance of native wild vegetation particularly herbs, shrubs and hydrophytes of the area in the on-going and proposed development schemes of Rawalpindi–Islamabad Areas.

  2. Variability of rainfall over Lake Kariba catchment area in the Zambezi river basin, Zimbabwe

    Science.gov (United States)

    Muchuru, Shepherd; Botai, Joel O.; Botai, Christina M.; Landman, Willem A.; Adeola, Abiodun M.

    2016-04-01

    In this study, average monthly and annual rainfall totals recorded for the period 1970 to 2010 from a network of 13 stations across the Lake Kariba catchment area of the Zambezi river basin were analyzed in order to characterize the spatial-temporal variability of rainfall across the catchment area. In the analysis, the data were subjected to intervention and homogeneity analysis using the Cumulative Summation (CUSUM) technique and step change analysis using rank-sum test. Furthermore, rainfall variability was characterized by trend analysis using the non-parametric Mann-Kendall statistic. Additionally, the rainfall series were decomposed and the spectral characteristics derived using Cross Wavelet Transform (CWT) and Wavelet Coherence (WC) analysis. The advantage of using the wavelet-based parameters is that they vary in time and can therefore be used to quantitatively detect time-scale-dependent correlations and phase shifts between rainfall time series at various localized time-frequency scales. The annual and seasonal rainfall series were homogeneous and demonstrated no apparent significant shifts. According to the inhomogeneity classification, the rainfall series recorded across the Lake Kariba catchment area belonged to category A (useful) and B (doubtful), i.e., there were zero to one and two absolute tests rejecting the null hypothesis (at 5 % significance level), respectively. Lastly, the long-term variability of the rainfall series across the Lake Kariba catchment area exhibited non-significant positive and negative trends with coherent oscillatory modes that are constantly locked in phase in the Morlet wavelet space.

  3. Spatial Variability of Ground-Water Recharge Estimates in the Glassboro Area, New Jersey

    Science.gov (United States)

    Nolan, B. T.; Baehr, A. L.

    2001-12-01

    The spatial variability of ground-water recharge estimates in the Glassboro area, NJ, was evaluated using geostatistical methods as a preliminarily assessment of aquifer vulnerability. Recharge was estimated using Darcy's law, based on parameters obtained from pedotransfer functions applied to measured soil texture values. The recharge estimates correspond to sediments overlying the Kirkwood-Cohansey aquifer, which comprises highly permeable unconsolidated sands and gravels. Knowing which areas receive greater recharge would indicate areas of greater vulnerability, depending on overlying land use. Recharge varied from -7.3 to 722 in/yr in the study area and the median was 12.1 in/yr. Experimental variograms of untransformed recharge data were erratic and related kriged maps were dominated by extreme values (250-722 in/yr) in the data set. An indicator transform stabilized the variograms. Indicator kriging (IK) reduced the influence of extreme values in the data set and yielded maps showing the probability of exceeding threshold values of recharge in the study area. The probability of exceeding the median recharge rate of 12.1 in/yr was 0.9 in the southern portion of the study area and might represent an area of focused recharge. As a check of model fit, probabilities predicted with IK were compared with the original recharge estimates and found to be strongly related. IK predictions corresponding to quintiles of recharge were used to estimate cumulative distribution functions (cdfs) for specific locations in the study area. The cdfs indicate the probability of exceeding any recharge rate at a particular location, and are shaped differently depending on location in the study area. The IK technique estimates cdfs with a single sampling realization (i.e., without a mean and variance at a given location). Additional variables were analyzed with regression to add a deterministic aspect to the analysis and to improve predictions. These variables included land slope

  4. Spatial variability of soil potassium in sugarcane areas subjected to the application of vinasse.

    Science.gov (United States)

    De Carvalho, Laércio A; Meurer, Ismael; Da Silva Junior, Carlos A; Santos, Cristiane F B; Libardi, Paulo L

    2014-12-01

    When deposited on land the vinasse can promote improvement in fertility, however, often fertilizer application occurs in areas considered homogeneous, without taking into account the variability of the soil. The objective of this study was to evaluate the effect of vinasse application on potassium content in two classes of soils cultivated with sugarcane, and characterize the spatial variability of soil using geostatistical techniques. In the 2010 and 2011 crop year, soil samples were collected from an experimental grid at 0-0.2 and 0.2-0.4 m depth in three soils cultivated with sugarcane, totaling 90 samplings in each grid, for the determination of pH, calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P), aluminum (Al) and potential acidity (H + Al). The data have been submitted to analysis of descriptive statistics and the K attribute was subjected to geostatistical analysis. The coefficient of variation indicated medium and high variability of K for the three soils. The results showed that the spatial dependence of K increased in depth to FRce and decreased to PHlv, indicating that the attribute could have followed the pattern of distribution of clay in depth. The investigation of the spatial variability of K on the surface and subsurface soils provided the definition of management zones with different levels of fertility, which can be organized into sub-areas for a more efficient management of the resources and the environment.

  5. Spatial variability of soil potassium in sugarcane areas subjected to the application of vinasse

    Directory of Open Access Journals (Sweden)

    LAÉRCIO A. DE CARVALHO

    2014-12-01

    Full Text Available When deposited on land the vinasse can promote improvement in fertility, however, often fertilizer application occurs in areas considered homogeneous, without taking into account the variability of the soil. The objective of this study was to evaluate the effect of vinasse application on potassium content in two classes of soils cultivated with sugarcane, and characterize the spatial variability of soil using geostatistical techniques. In the 2010 and 2011 crop year, soil samples were collected from an experimental grid at 0-0.2 and 0.2-0.4 m depth in three soils cultivated with sugarcane, totaling 90 samplings in each grid, for the determination of pH, calcium (Ca, magnesium (Mg, potassium (K, phosphorus (P, aluminum (Al and potential acidity (H + Al. The data have been submitted to analysis of descriptive statistics and the K attribute was subjected to geostatistical analysis. The coefficient of variation indicated medium and high variability of K for the three soils. The results showed that the spatial dependence of K increased in depth to FRce and decreased to PHlv, indicating that the attribute could have followed the pattern of distribution of clay in depth. The investigation of the spatial variability of K on the surface and subsurface soils provided the definition of management zones with different levels of fertility, which can be organized into sub-areas for a more efficient management of the resources and the environment.

  6. Influence of meteorological variables on rainfall partitioning for deciduous and coniferous tree species in urban area

    Science.gov (United States)

    Zabret, Katarina; Rakovec, Jože; Šraj, Mojca

    2018-03-01

    Rainfall partitioning is an important part of the ecohydrological cycle, influenced by numerous variables. Rainfall partitioning for pine (Pinus nigra Arnold) and birch (Betula pendula Roth.) trees was measured from January 2014 to June 2017 in an urban area of Ljubljana, Slovenia. 180 events from more than three years of observations were analyzed, focusing on 13 meteorological variables, including the number of raindrops, their diameter, and velocity. Regression tree and boosted regression tree analyses were performed to evaluate the influence of the variables on rainfall interception loss, throughfall, and stemflow in different phenoseasons. The amount of rainfall was recognized as the most influential variable, followed by rainfall intensity and the number of raindrops. Higher rainfall amount, intensity, and the number of drops decreased percentage of rainfall interception loss. Rainfall amount and intensity were the most influential on interception loss by birch and pine trees during the leafed and leafless periods, respectively. Lower wind speed was found to increase throughfall, whereas wind direction had no significant influence. Consideration of drop size spectrum properties proved to be important, since the number of drops, drop diameter, and median volume diameter were often recognized as important influential variables.

  7. Patterns and variability of projected bioclimatic habitat for Pinus albicaulis in the Greater Yellowstone Area.

    Directory of Open Access Journals (Sweden)

    Tony Chang

    Full Text Available Projected climate change at a regional level is expected to shift vegetation habitat distributions over the next century. For the sub-alpine species whitebark pine (Pinus albicaulis, warming temperatures may indirectly result in loss of suitable bioclimatic habitat, reducing its distribution within its historic range. This research focuses on understanding the patterns of spatiotemporal variability for future projected P.albicaulis suitable habitat in the Greater Yellowstone Area (GYA through a bioclimatic envelope approach. Since intermodel variability from General Circulation Models (GCMs lead to differing predictions regarding the magnitude and direction of modeled suitable habitat area, nine bias-corrected statistically down-scaled GCMs were utilized to understand the uncertainty associated with modeled projections. P.albicaulis was modeled using a Random Forests algorithm for the 1980-2010 climate period and showed strong presence/absence separations by summer maximum temperatures and springtime snowpack. Patterns of projected habitat change by the end of the century suggested a constant decrease in suitable climate area from the 2010 baseline for both Representative Concentration Pathways (RCPs 8.5 and 4.5 climate forcing scenarios. Percent suitable climate area estimates ranged from 2-29% and 0.04-10% by 2099 for RCP 8.5 and 4.5 respectively. Habitat projections between GCMs displayed a decrease of variability over the 2010-2099 time period related to consistent warming above the 1910-2010 temperature normal after 2070 for all GCMs. A decreasing pattern of projected P.albicaulis suitable habitat area change was consistent across GCMs, despite strong differences in magnitude. Future ecological research in species distribution modeling should consider a full suite of GCM projections in the analysis to reduce extreme range contractions/expansions predictions. The results suggest that restoration strageties such as planting of seedlings and

  8. Patterns and variability of projected bioclimatic habitat for Pinus albicaulis in the Greater Yellowstone Area.

    Science.gov (United States)

    Chang, Tony; Hansen, Andrew J; Piekielek, Nathan

    2014-01-01

    Projected climate change at a regional level is expected to shift vegetation habitat distributions over the next century. For the sub-alpine species whitebark pine (Pinus albicaulis), warming temperatures may indirectly result in loss of suitable bioclimatic habitat, reducing its distribution within its historic range. This research focuses on understanding the patterns of spatiotemporal variability for future projected P.albicaulis suitable habitat in the Greater Yellowstone Area (GYA) through a bioclimatic envelope approach. Since intermodel variability from General Circulation Models (GCMs) lead to differing predictions regarding the magnitude and direction of modeled suitable habitat area, nine bias-corrected statistically down-scaled GCMs were utilized to understand the uncertainty associated with modeled projections. P.albicaulis was modeled using a Random Forests algorithm for the 1980-2010 climate period and showed strong presence/absence separations by summer maximum temperatures and springtime snowpack. Patterns of projected habitat change by the end of the century suggested a constant decrease in suitable climate area from the 2010 baseline for both Representative Concentration Pathways (RCPs) 8.5 and 4.5 climate forcing scenarios. Percent suitable climate area estimates ranged from 2-29% and 0.04-10% by 2099 for RCP 8.5 and 4.5 respectively. Habitat projections between GCMs displayed a decrease of variability over the 2010-2099 time period related to consistent warming above the 1910-2010 temperature normal after 2070 for all GCMs. A decreasing pattern of projected P.albicaulis suitable habitat area change was consistent across GCMs, despite strong differences in magnitude. Future ecological research in species distribution modeling should consider a full suite of GCM projections in the analysis to reduce extreme range contractions/expansions predictions. The results suggest that restoration strageties such as planting of seedlings and controlling

  9. Interpolating a consumption variable for scaling and generalizing potential population pressure on urbanizing natural areas

    Science.gov (United States)

    Varanka, Dalia; Jiang, Bin; Yao, Xiaobai

    2010-01-01

    Measures of population pressure, referring in general to the stress upon the environment by human consumption of resources, are imperative for environmental sustainability studies and management. Development based on resource consumption is the predominant factor of population pressure. This paper presents a spatial model of population pressure by linking consumption associated with regional urbanism and ecosystem services. Maps representing relative geographic degree and extent of natural resource consumption and degree and extent of impacts on surrounding areas are new, and this research represents the theoretical research toward this goal. With development, such maps offer a visualization tool for planners of various services, amenities for people, and conservation planning for ecologist. Urbanization is commonly generalized by census numbers or impervious surface area. The potential geographical extent of urbanism encompasses the environmental resources of the surrounding region that sustain cities. This extent is interpolated using kriging of a variable based on population wealth data from the U.S. Census Bureau. When overlayed with land-use/land-cover data, the results indicate that the greatest estimates of population pressure fall within mixed forest areas. Mixed forest areas result from the spread of cedar woods in previously disturbed areas where further disturbance is then suppressed. Low density areas, such as suburbanization and abandoned farmland are characteristic of mixed forest areas.

  10. Assessing variability and long-term trends in burned area by merging multiple satellite fire products

    Directory of Open Access Journals (Sweden)

    L. Giglio

    2010-03-01

    Full Text Available Long term, high quality estimates of burned area are needed for improving both prognostic and diagnostic fire emissions models and for assessing feedbacks between fire and the climate system. We developed global, monthly burned area estimates aggregated to 0.5° spatial resolution for the time period July 1996 through mid-2009 using four satellite data sets. From 2001–2009, our primary data source was 500-m burned area maps produced using Moderate Resolution Imaging Spectroradiometer (MODIS surface reflectance imagery; more than 90% of the global area burned during this time period was mapped in this fashion. During times when the 500-m MODIS data were not available, we used a combination of local regression and regional regression trees developed over periods when burned area and Terra MODIS active fire data were available to indirectly estimate burned area. Cross-calibration with fire observations from the Tropical Rainfall Measuring Mission (TRMM Visible and Infrared Scanner (VIRS and the Along-Track Scanning Radiometer (ATSR allowed the data set to be extended prior to the MODIS era. With our data set we estimated that the global annual area burned for the years 1997–2008 varied between 330 and 431 Mha, with the maximum occurring in 1998. We compared our data set to the recent GFED2, L3JRC, GLOBCARBON, and MODIS MCD45A1 global burned area products and found substantial differences in many regions. Lastly, we assessed the interannual variability and long-term trends in global burned area over the past 13 years. This burned area time series serves as the basis for the third version of the Global Fire Emissions Database (GFED3 estimates of trace gas and aerosol emissions.

  11. Spatial Variability of Soil Characteristics along a Landscape Gradient in Bellanwila-Attidiya Area

    Directory of Open Access Journals (Sweden)

    S. Cooray

    2012-05-01

    Full Text Available Wetlands are comprised of unique components of soil, water and biodiversity which are interconnected. Although water and biodiversity components of wetlands are being somewhat investigated, a very few research have been carried out to investigate soil properties.This study focused on spatial variability of soil chemical and physical parameters in a land use gradient around the Bellanwila-Attidiya Sanctuary, This study was carried out for a period of 3 months and several random soil samples were obtained from all land use areas. Selected physical and chemical properties of soil were analyzed according to the Standard Methods and the GIS maps were developed using ArcView GIS 3.2. The results indicated that all chemical and physical parameters of soil varied across the land use gradient, except for temperature. According to the GIS maps there are apparent variations in distribution of soil properties. On the surface, the highest level of each parameter was found as follows: - NO3- – industrial area, PO4 3- - functioning paddy fields, SO4 2- - residential area, Cl- - residential area, Fe3+ - functioning paddy fields, moisture content - wetland, pH – industrial area, salinity- residential area, electrical conductivity – residential area. At a 1 m depth the pattern was different: NO3- – abandoned paddy fields, PO4 3- – functioning paddy fields, SO4 2- - wetland, Cl- - wetland, Fe3+ - residential area, moisture content - wetland, pH – industrial area, salinity - wetland, electrical conductivity - wetland. The findings clearly exhibit the increases in anthropogenic pressure have resulted in wide-scale alternation of soil properties, at least in the surface soil, across a land use gradient. Managing land use in the watershed of the wetland thus needs adequate attention to conserve this natural ecosystem.

  12. Variability of soil fertility properties in areas planted to sugarcane in the State of Goias, Brazil

    Directory of Open Access Journals (Sweden)

    José Avelino Cardoso

    2014-04-01

    Full Text Available Soil sampling should provide an accurate representation of a given area so that recommendations for amendments of soil acidity, fertilization and soil conservation may be drafted to increase yield and improve the use of inputs. The aim of this study was to evaluate the variability of soil fertility properties of Oxisols in areas planted to sugarcane in the State of Goias, Brazil. Two areas of approximately 8,100 m² each were selected, representing two fields of the Goiasa sugarcane mill in Goiatuba. The sugarcane crop had a row spacing of 1.5 m and subsamples were taken from 49 points in the row and 49 between the row with a Dutch auger at depths of 0.0-0.2 and 0.2-0.4 m, for a total of 196 subsamples for each area. The samples were individually subjected to chemical analyses of soil fertility (pH in CaCl2, potential acidity, organic matter, P, K, Ca and Mg and particle size analysis. The number of subsamples required to compose a sample within the acceptable ranges of error of 5, 10, 20 and 40 % of each property were computed from the coefficients of variation and the Student t-value for 95 % confidence. The soil properties under analysis exhibited different variabilities: high (P and K, medium (potential acidity, Ca and Mg and low (pH, organic matter and clay content. Most of the properties analyzed showed an error of less than 20 % for a group of 20 subsamples, except for P and K, which were capable of showing an error greater than 40 % around the mean. The extreme variability in phosphorus, particularly at the depth of 0.2-0.4 m, attributed to banded application of high rates of P fertilizers at planting, places limitations on assessment of its availability due to the high number of subsamples required for a composite sample.

  13. The Impact of Climatological Variables on Kelp Canopy Area in the Santa Barbara Channel

    Science.gov (United States)

    Zigner, K.; Bausell, J.; Kudela, R. M.

    2015-12-01

    Kelp canopy area (KCA), a proxy for kelp forest health, has important implications for small and large-scale processes pertaining to fisheries, near shore currents, and marine ecosystems. As part of the NASA Airborne Science Research Program (SARP), this study examines the impact of ocean chemistry and climatological variables on KCA in the Santa Barbara Channel through time series analysis. El Niño Southern Oscillation (ENSO), North Pacific Gyre Oscillation (NPGO), North Pacific Oscillation (NPO), and upwelling indices as well as sea surface temperature (SST), salinity, nitrate, and chlorophyll-a concentrations taken within the Santa Barbara channel (1990-2014) were acquired from the Climate Prediction Center (CPC), California Cooperative Oceanic Fisheries Investigation (CalCOFI), and Di Lorenzo's NPGO websites. These data were then averaged for winter (November-January) and summer (May-August) seasons and compared to KCA measurements derived from Landsat images via unsupervised classification. Regression, cumulative sum tests, and cross-correlation coefficients revealed a two year lag between KCA and the NPGO, indicating the presence of an additional factor driving both variables. Further analyses suggests that the NPO may be this driving factor, as indicated by the correlation (lag 0) with KCA. Comparing relationships between kelp and other variables over various time periods supports the acceleration of the NPGO and other variables in more recent years. Exploring relationships between KCA, NPGO, and NPO may provide insight into potential impacts of climate change on coastal marine ecosystems.

  14. Density of states, optical and thermoelectric properties of perovskite vanadium fluorides Na{sub 3}VF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Reshak, A.H. [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 30614 Pilsen (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Azam, Sikander, E-mail: sikander.physicst@gmail.com [New Technologies—Research Center, University of West Bohemia, Univerzitni 8, 30614 Pilsen (Czech Republic)

    2014-05-01

    The electronic structure, charge density and Fermi surface of Na{sub 3}VF{sub 6} compound have been examined with the support of density functional theory (DFT). Using the full potential linear augmented plane wave method, we employed the local density approximation (LDA), generalized gradient approximation (GGA) and Engel–Vosko GGA (EVGGA) to treat the exchange correlation potential to solve Kohn–Sham equations. The calculation show that Na{sub 3}VF{sub 6} compound has metallic nature and the Fermi energy (E{sub F}) is assessed by overlapping of V-d state. The calculated density of states at the E{sub F} are about 18.655, 51.932 and 13.235 states/eV, and the bare linear low-temperature electronic specific heat coefficient (γ) is found to be 3.236 mJ/mol-K{sup 2}, 9.008 mJ/mol-K{sup 2} and 2.295 mJ/mol-K{sup 2} for LDA, GGA and EVGGA, respectively. The Fermi surface is composed of two sheets. The chemical bonding of Na{sub 3}VF{sub 6} compound is analyzed through the electronic charge density in the (1 1 0) crystallographic plane. The optical constants and thermal properties were also calculated and discussed. - Highlights: • DFT-FPLAPW method used for calculating the properties of investigated compounds. • For predicting the chemical bonding the charge density behavior is studied in 2D. • The optical properties were also calculated and analyzed. • The Fermi surface is composed of two bands crossing along the EF level. • The thermoelectric properties have also calculated.

  15. Spatial representation and cognitive modulation of response variability in the lateral intraparietal area priority map.

    Science.gov (United States)

    Falkner, Annegret L; Goldberg, Michael E; Krishna, B Suresh

    2013-10-09

    The lateral intraparietal area (LIP) in the macaque contains a priority-based representation of the visual scene. We previously showed that the mean spike rate of LIP neurons is strongly influenced by spatially wide-ranging surround suppression in a manner that effectively sharpens the priority map. Reducing response variability can also improve the precision of LIP's priority map. We show that when a monkey plans a visually guided delayed saccade with an intervening distractor, variability (measured by the Fano factor) decreases both for neurons representing the saccade goal and for neurons representing the broad spatial surround. The reduction in Fano factor is maximal for neurons representing the saccade goal and steadily decreases for neurons representing more distant locations. LIP Fano factor changes are behaviorally significant: increasing expected reward leads to lower variability for the LIP representation of both the target and distractor locations, and trials with shorter latency saccades are associated with lower Fano factors in neurons representing the surround. Thus, the LIP Fano factor reflects both stimulus and behavioral engagement. Quantitative modeling shows that the interaction between mean spike count and target-receptive field (RF) distance in the surround during the predistractor epoch is multiplicative: the Fano factor increases more steeply with mean spike count further away from the RF. A negative-binomial model for LIP spike counts captures these findings quantitatively, suggests underlying mechanisms based on trial-by-trial variations in mean spike rate or burst-firing patterns, and potentially provides a principled framework to account simultaneously for the previously observed unsystematic relationships between spike rate and variability in different brain areas.

  16. Future Interannual Variability of Arctic Sea Ice Area and its Implications for Marine Navigation

    Science.gov (United States)

    Vavrus, S. J.; Mioduszewski, J.; Holland, M. M.; Wang, M.; Landrum, L.

    2016-12-01

    As both a symbol and driver of ongoing climate change, the diminishing Arctic sea ice pack has been widely studied in a variety of contexts. Most research, however, has focused on time-mean changes in sea ice, rather than on short-term variations that also have important physical and societal consequences. In this study we test the hypothesis that interannual Arctic sea ice variability will increase in the future by utilizing a set of 40 independent simulations from the Community Earth System Model's Large Ensemble for the 1920-2100 period. The model projects that ice variability will indeed grow substantially in all months but with a strong seasonal dependence in magnitude and timing. The variability increases most during late autumn (November-December) and least during spring. This increase proceeds in a time-transgressive manner over the course of the year, peaking soonest (2020s) in late-summer months and latest (2090s) during late spring. The variability in every month is inversely correlated with the average melt rate, resulting in an eventual decline in both terms as the ice pack becomes seasonal by late century. These projected changes in sea ice variations will likely have significant consequences for marine navigation, which we assess with the empirical Ice Numeral (IN) metric. A function of ice concentration and thickness, the IN quantifies the difficulty in traversing a transect of sea ice-covered ocean as a function of vessel strength. Our results show that although increasingly open Arctic seas will mean generally more favorable conditions for navigation, the concurrent rise in the variability of ice cover poses a competing risk. In particular, future intervals featuring the most rapid declines in ice area that coincide with the highest interannual ice variations will offer more inviting shipping opportunities tempered by less predictable navigational conditions.

  17. A comparison of experiment and theory for sound propagation in variable area ducts

    Science.gov (United States)

    Nayfeh, A. H.; Kaiser, J. E.; Marshall, R. L.; Hurst, C. J.

    1980-01-01

    An experimental and analytical program has been carried out to evaluate sound suppression techniques in ducts that produce refraction effects due to axial velocity gradients. The analytical program employs a computer code based on the method of multiple scales to calculate the influence of axial variations due to slow changes in the cross-sectional area as well as transverse gradients due to the wall boundary layers. Detailed comparisons between the analytical predictions and the experimental measurements have been made. The circumferential variations of pressure amplitudes and phases at several axial positions have been examined in straight and variable area ducts, with hard walls and lined sections, and with and without a mean flow. Reasonable agreement between the theoretical and experimental results has been found.

  18. Surface Area Variability of a North-Central Tanzanian Crater Lake

    Directory of Open Access Journals (Sweden)

    Lindsey Higgins

    2016-06-01

    Full Text Available A history of modern (1973–2015 surface area variability for Lake Basotu in north-central Tanzania has been reconstructed using archived Landsat images from the dry season between June and October. This record was compared to local weather data as well as larger scale weather patterns. The lake has been in a state of decline interrupted by major flood events since the beginning of the satellite record. From 1973 to 1997, the lake area was between 0.97 km2 and 4.28 km2. Lake extent abruptly increased to 13.86 km2 in 1998, when a co-occurrence of El Niño and a positive Indian Ocean Dipole led to extensive flooding. It is hypothesized that local agricultural practices leading to soil erosion and subsequent basin sedimentation have most likely increased the sensitivity of Lake Basotu to climatic fluctuations.

  19. Climate Variability and Industrial-Suburban Heat Environment in a Mediterranean Area

    Directory of Open Access Journals (Sweden)

    Giuseppina A. Giorgio

    2017-05-01

    Full Text Available The Urban Heat Island (UHI phenomenon prevalently concerns industrialized countries. It consists of a significant increase in temperatures, especially in industrialized and urbanized areas, in particular, during extreme warm periods like summer. This paper explores the climate variability of temperatures in two stations located in Matera city (Southern Italy, evaluating the increase in temperatures from 1988 to 2015. Moreover, the Corine Land Covers (1990–2000–2006–2012 were used in order to investigate the effect of land use on temperatures. The results obtained confirm the prevalence of UHI phenomena for industrialized areas, highlighting the proposal that the spreading of settlements may further drive these effects on the microclimate. In particular, the presence of industrial structures, even in rural areas, shows a clear increase in summer maximum temperatures. This does not occur in the period before 2000, probably due to the absence of the industrial settlement. On the contrary, from 2000 to 2015, changes are not relevant, but the maximum temperatures have always been higher than in the suburban area (station localized in green zone during daylight hours.

  20. Urban mobility, socioeconomic and urban transport variables in metropolitan areas in three continents

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho da Costa, F.B. de; Nassi, C.D.

    2016-07-01

    Transportation is the soul of urban cities. Find sustainable ways to keep people moving in our cities is more important than ever. Historically, cities have developed in different ways. Each has its own personality and complexity. But in all cases, transport and mobility have played a key role in city life. Due to the relevance of mobility this article tries to establish the relationship between some variables. The method was developed by collecting, analyzing and comparing data on metropolitan regions in North America, South America, Europe and Oceania through a mathematical model. From each selected location the following data were gathered: population, area (km²), demographic density (inhab/km²), socio-economic aspects (annual GDP per capita), transport system (subway extension), number of trips per person per day and modal split (% non-motorized, % public transport and % private transport). In this study we analyze some variables that influence the number of trips per person per day. Understanding the associations between all the variables that influence the number of trips per person per day contributes the planners to determine whether changes are needed to improve in the transport system in the metropolitan region. (Author)

  1. Short-term variability of fish condition and growth in estuarine and shallow coastal areas.

    Science.gov (United States)

    Duarte, Irina A; Vasconcelos, Rita P; França, Susana; Batista, Marisa I; Tanner, Susanne; Cabral, Henrique N; Fonseca, Vanessa F

    2018-03-01

    Short-term variability in condition factor: relative condition factor Kn; biochemical condition: RNA:DNA and protein content; and instantaneous growth rates were determined in estuarine and coastal fish. Dicentrarchus labrax, Solea senegalensis and Pomatoschistus microps were sampled in the Tejo estuary, while Trachurus trachurus was sampled in an adjacent shallow coastal area. Variation of condition indices was more frequent at the week scale (sampling periods with fortnight intervals) than at the daily scale (consecutive days in each sampling period) in all species. Water temperature was correlated with biochemical indices, while salinity showed no effect, evidencing the influence of environmental short-term variation (temperature) on biochemical condition in natural populations. Yet, decreasing individual variability in fish condition was observed along the sampled weeks, resulting in a more homogeneous condition of populations, particularly for T. trachurus likely due to a more stable coastal environment. Biochemical indices proved to be sensitive to short-term environmental variability, despite species-specific responses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Urban green land cover changes and their relation to climatic variables in an anthropogenically impacted area

    Science.gov (United States)

    Zoran, Maria A.; Dida, Adrian I.

    2017-10-01

    Urban green areas are experiencing rapid land cover change caused by human-induced land degradation and extreme climatic events. Vegetation index time series provide a useful way to monitor urban vegetation phenological variations. This study quantitatively describes Normalized Difference Vegetation Index NDVI) /Enhanced Vegetation Index (EVI) and Leaf Area Index (LAI) temporal changes for Bucharest metropolitan region land cover in Romania from the perspective of vegetation phenology and its relation with climate changes and extreme climate events. The time series from 2000 to 2016 of the NOAA AVHRR and MODIS Terra/Aqua satellite data were analyzed to extract anomalies. Time series of climatic variables were also analyzed through anomaly detection techniques and the Fourier Transform. Correlations between NDVI/EVI time series and climatic variables were computed. Temperature, rainfall and radiation were significantly correlated with almost all land-cover classes for the harmonic analysis amplitude term. However, vegetation phenology was not correlated with climatic variables for the harmonic analysis phase term suggesting a delay between climatic variations and vegetation response. Training and validation were based on a reference dataset collected from IKONOS high resolution remote sensing data. The mean detection accuracy for period 2000- 2016 was assessed to be of 87%, with a reasonable balance between change commission errors (19.3%), change omission errors (24.7%), and Kappa coefficient of 0.73. This paper demonstrates the potential of moderate - and high resolution, multispectral imagery to map and monitor the evolution of the physical urban green land cover under climate and anthropogenic pressure.

  3. Characterizing spatial variability of air pollution from vehicle traffic around the Houston Ship Channel area

    Science.gov (United States)

    Zhang, Xueying; Craft, Elena; Zhang, Kai

    2017-07-01

    Mobile emissions are a major source of urban air pollution and have been associated with a variety of adverse health outcomes. The Houston Ship Channel area is the home of a large number of diesel-powered vehicles emitting fine particulate matter (PM2.5; ≤2.5 μm in aerodynamic diameter) and nitrogen oxides (NOx). However, the spatial variability of traffic-related air pollutants in the Houston Ship Channel area has rarely been investigated. The objective of this study is to characterize spatial variability of PM2.5 and NOx concentrations attributable to on-road traffic in the Houston Ship Channel area in the year of 2011. We extracted the road network from the Texas Department of Transportation Road Inventory, and calculated emission rates using the Motor Vehicle Emission Simulator version 2014a (MOVES2014a). These parameters and preprocessed meteorological parameters were entered into a Research LINE-source Dispersion Model (RLINE) to conduct a simulation. Receptors were placed at 50 m resolution within 300 m to major roads and at 150 m resolution in the rest of the area. Our findings include that traffic-related PM2.5 were mainly emitted from trucks, while traffic-related NOx were emitted from both trucks and cars. The traffic contributed 0.90 μg/m3 PM2.5 and 29.23 μg/m3 NOx to the annual average mass concentrations of on-road air pollution, and the concentrations of the two pollutants decreased by nearly 40% within 500 m distance to major roads. The pollution level of traffic-related PM2.5 and NOx was higher in winter than those in the other three seasons. The Houston Ship Channel has earlier morning peak hours and relative late afternoon hours, which indicates the influence of goods movement from port activity. The varied near-road gradients illustrate that proximities to major roads are not an accurate surrogate of traffic-related air pollution.

  4. Variable Scheduling to Mitigate Channel Losses in Energy-Efficient Body Area Networks

    Directory of Open Access Journals (Sweden)

    Lavy Libman

    2012-11-01

    Full Text Available We consider a typical body area network (BAN setting in which sensor nodes send data to a common hub regularly on a TDMA basis, as defined by the emerging IEEE 802.15.6 BAN standard. To reduce transmission losses caused by the highly dynamic nature of the wireless channel around the human body, we explore variable TDMA scheduling techniques that allow the order of transmissions within each TDMA round to be decided on the fly, rather than being fixed in advance. Using a simple Markov model of the wireless links, we devise a number of scheduling algorithms that can be performed by the hub, which aim to maximize the expected number of successful transmissions in a TDMA round, and thereby significantly reduce transmission losses as compared with a static TDMA schedule. Importantly, these algorithms do not require a priori knowledge of the statistical properties of the wireless channels, and the reliability improvement is achieved entirely via shuffling the order of transmissions among devices, and does not involve any additional energy consumption (e.g., retransmissions. We evaluate these algorithms directly on an experimental set of traces obtained from devices strapped to human subjects performing regular daily activities, and confirm that the benefits of the proposed variable scheduling algorithms extend to this practical setup as well.

  5. Variable scheduling to mitigate channel losses in energy-efficient body area networks.

    Science.gov (United States)

    Tselishchev, Yuriy; Boulis, Athanassios; Libman, Lavy

    2012-11-02

    We consider a typical body area network (BAN) setting in which sensor nodes send data to a common hub regularly on a TDMA basis, as defined by the emerging IEEE 802.15.6 BAN standard. To reduce transmission losses caused by the highly dynamic nature of the wireless channel around the human body, we explore variable TDMA scheduling techniques that allow the order of transmissions within each TDMA round to be decided on the fly, rather than being fixed in advance. Using a simple Markov model of the wireless links, we devise a number of scheduling algorithms that can be performed by the hub, which aim to maximize the expected number of successful transmissions in a TDMA round, and thereby significantly reduce transmission losses as compared with a static TDMA schedule. Importantly, these algorithms do not require a priori knowledge of the statistical properties of the wireless channels, and the reliability improvement is achieved entirely via shuffling the order of transmissions among devices, and does not involve any additional energy consumption (e.g., retransmissions). We evaluate these algorithms directly on an experimental set of traces obtained from devices strapped to human subjects performing regular daily activities, and confirm that the benefits of the proposed variable scheduling algorithms extend to this practical setup as well.

  6. [French translation and validation of a short version of the Suicide Intervention Response Inventory-2 (SIRI-2-VF)].

    Science.gov (United States)

    Kopp-Bigault, C; Audouard-Marzin, Y; Scouarnec, P; Beauchamp, G; Séguin, M; Walter, M

    2017-10-30

    Training health professionals about suicidal crisis is one major line of suicide prevention worldwide. France has one of the highest suicide rates in Europe, and although crisis intervention training has been set up since 2001, there presently is no training assessment tool in the French language for health professionals trained in suicide prevention. In the four levels of Kirpatrick's education pyramid, training that takes place in France today solely assesses level one status, that is to say relative to the level of satisfaction of participants (self-report). This study proposes a validated short French version of the Suicide Intervention Response Inventory-2 (SIRI-2) of Neimeyer & Mc Innes. The SIRI-2 questionnaire assesses the ability of first line intervention in dealing with suicidal individuals. The translation methodology was inspired from Vallerand's model of cross-cultural back translation. This method is regularly used for translating from the English language to a French version. In order to translate the English version, we used an extensive 7-step methodology implicating several bilingual translators, expert reviewers (psychologists and psychiatrists) and a scientific committee. Participants were 107 students from different French universities and study programs: psychology, medicine and nursing (17 were men; average age was 26.6). Fifteen of these participants answered the SIRI-2-VF on two occasions (separated by a 15-day interval) in order to estimate the temporal stability of the instrument. The scores of the students were compared to six French experts in suicide prevention and with the original expert group who worked on the development of SIRI-2 (n=7). We used Student t Test for construct validity, Cronbach's Alpha for internal consistency and Pearson's correlation coefficient for temporal stability. Following a fidelity comparison of the results of the French experts with those of the American experts, ten items presenting the least good

  7. Dynamic Analysis for a Geared Turbofan Engine with Variable Area Fan Nozzle

    Science.gov (United States)

    Csank, Jeffrey T.; Thomas, George L.

    2017-01-01

    Aggressive design goals have been set for future aero-propulsion systems with regards to fuel economy, noise, and emissions. To meet these challenging goals, advanced propulsion concepts are being explored and current operating margins are being re-evaluated to find additional concessions that can be made. One advanced propulsion concept being evaluated is a geared turbofan with a variable area fan nozzle (VAFN), developed by NASA. This engine features a small core, a fan driven by the low pressure turbine through a reduction gearbox, and a shape memory alloy (SMA)-actuated VAFN. The VAFN is designed to allow both a small exit area for efficient operation at cruise, while being able to open wider at high power conditions to reduce backpressure on the fan and ensure a safe level of stall margin is maintained. The VAFN is actuated via a SMA-based system instead of a conventional system to decrease overall weight of the system, however, SMA-based actuators respond relatively slowly, which introduces dynamic issues that are investigated in this work. This paper describes both a control system designed specifically for issues associated with SMAs, and dynamic analysis of the geared turbofan VAFN with the SMA actuators. Also, some future recommendations are provided for this type of propulsion system.

  8. Spatial and temporal variability of rainfall and their effects on hydrological response in urban areas - A review

    NARCIS (Netherlands)

    Cristiano, E.; ten Veldhuis, J.A.E.; van de Giesen, N.C.

    2017-01-01

    In urban areas, hydrological processes are characterized by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques, and methods have been developed to capture rainfall and hydrological

  9. The Effect of Type and Volume Fraction (Vf) of Steel Fiber on the Mechanical Properties of Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Ghanbarpour, S.; Mazaheripour, H.; Mirmoradi, S. H.

    2010-01-01

    is to investigate the effects of type and volume fraction of steel fiber on the compressive strength, split tensile strength, flexural strength and modulus of elasticity of steel fiber reinforced self-compacting concrete (SFRSCC). Design/methodology/approach – For this purpose, Micro wire and Wave type steel fibers...... with l/d ratios of 50 were used. Three different fiber volumes were added to concrete mixes at 0.5, 0.75 and 1 per cent by volume of SCC. Six different SFRSCC mixes were prepared. After 28 days of curing, compressive, split and flexural strength and modulus of elasticity were determined. Findings...... – It was found that, inclusion of steel fibers significantly affect the split tensile and flexural strength of SCC accordance with type and vf. Besides, mathematical expressions were developed to estimate the flexural, modulus of elasticity and split tensile strength of SFRSCCs regarding of compressive strength...

  10. Increased dipicolinic acid production with an enhanced spoVF operon in Bacillus subtilis and medium optimization.

    Science.gov (United States)

    Takahashi, Fumikazu; Sumitomo, Nobuyuki; Hagihara, Hiroshi; Ozaki, Katsuya

    2015-01-01

    Dipicolinic acid (DPA) is a multi-functional agent for cosmetics, antimicrobial products, detergents, and functional polymers. The aim of this study was to design a new method for producing DPA from renewable material. The Bacillus subtilis spoVF operon encodes enzymes for DPA synthase and the part of lysine biosynthetic pathway. However, DPA is only synthesized in the sporulation phase, so the productivity of DPA is low level. Here, we report that DPA synthase was expressed in vegetative cells, and DPA was produced in the culture medium by replacement of the spoVFA promoter with other highly expressed promoter in B. subtilis vegetative cells, such as spoVG promoter. DPA levels were increased in the culture medium of genetically modified strains. DPA productivity was significantly improved up to 29.14 g/L in 72 h culture by improving the medium composition using a two-step optimization technique with the Taguchi methodology.

  11. Occurrence and genetic variability of Phlebotomus papatasi in an urban area of southern Italy

    Directory of Open Access Journals (Sweden)

    Dantas-Torres Filipe

    2010-08-01

    Full Text Available Abstract Background A phlebotomine sand fly was noticed in the second floor of an old building in a highly urbanized area of southern Italy. A short-term entomological survey was carried out in the subsequent weeks to this event, allowing the collection of additional phlebotomine sand flies that were later identified as Phlebotomus papatasi. We assessed the genetic variability among P. papatasi sequences obtained in this study and those available from Italy using a mitochondrial DNA (mtDNA fragment (from cytochrome b gene to NADH1 and the internal transcribed spacer 2 (ITS2 as genetic markers. Results From 9 June to 19 July, eight males and seven females (two blood-fed of P. papatasi were collected in the old town of Bari (southern Italy. The insects were found near the bed and in the bathroom and potential blood sources (e.g., pigeons and dogs for them were common in the neighbourhood. Again, five females of P. papatasi collected in Valenzano, another urban area in the province of Bari, were also identified and included in the genetic study. The mtDNA sequences (945 bp obtained from Bari and Valenzano were identical except for a single transition (T ↔ C at the 793 nucleotide residue. Pairwise comparison of the last 440 bp of the mtDNA fragment analyzed herein with other sequences of P. papatasi from Italy revealed a nucleotide variation ranging from 0.2 to 1.3%. Three ITS2 sequence types were detected within specimens collected in Valenzano, one of them identical to that from Bari. Pairwise comparison of ITS2 sequences of P. papatasi from Italy revealed a nucleotide variation up to 1.8%. Conclusions This study reports the occurrence of P. papatasi in an urban area of southern Italy and shows a low nucleotide difference among ITS2 and mtDNA sequences of this species available from Italy. The presence of P. papatasi in urban areas might represent a risk for human health, particularly for the potential transmission of sandfly fever viruses.

  12. Satellite Observed Variability in Antarctic and Arctic Surface Temperatures and Their Correlation to Open Water Areas

    Science.gov (United States)

    Comiso, Josefino C.; Zukor, Dorothy (Technical Monitor)

    2000-01-01

    Recent studies using meterological station data have indicated that global surface air temperature has been increasing at a rate of 0.05 K/decade. Using the same set of data but for stations in the Antarctic and Arctic regions (>50 N) only, the increases in temperature were 0.08, and 0.22 K/decade, when record lengths of 100 and 50 years, respectively, were used. To gain insights into the increasing rate of warming, satellite infrared and passive microwave observations over the Arctic region during the last 20 years were processed and analyzed. The results show that during this period, the ice extent in the Antarctic has been increasing at the rate of 1.2% per decade while the surface temperature has been decreasing at about 0.08 K per decade. Conversely, in the Northern Hemisphere, the ice extent has been decreasing at a rate of 2.8% per decade, while the surface temperatures have been increasing at the rate of 0.38 K per decade. In the Antarctic, it is surprising that there is a short term trend of cooling during a global period of warming. Very large anomalies in open water areas in the Arctic were observed especially in the western region, that includes the Beaufort Sea, where the observed open water area was about 1x10(exp 6) sq km, about twice the average for the region, during the summer of 1998. In the eastern region, that includes the Laptev Sea, the area of open water was also abnormally large in the summer of 1995. Note that globally, the warmest and second warmest years in this century, were 1998 and 1995, respectively. The data, however, show large spatial variability with the open water area distribution showing a cyclic periodicity of about ten years, which is akin to the North Atlantic and Arctic Oscillations. This was observed in both western and eastern regions but with the phase of one lagging the other by about two years. This makes it difficult to interpret what the trends really mean. But although the record length of satellite data is still

  13. Periodontal inflamed surface area as a novel numerical variable describing periodontal conditions

    Science.gov (United States)

    2017-01-01

    Purpose A novel index, the periodontal inflamed surface area (PISA), represents the sum of the periodontal pocket depth of bleeding on probing (BOP)-positive sites. In the present study, we evaluated correlations between PISA and periodontal classifications, and examined PISA as an index integrating the discrete conventional periodontal indexes. Methods This study was a cross-sectional subgroup analysis of data from a prospective cohort study investigating the association between chronic periodontitis and the clinical features of ankylosing spondylitis. Data from 84 patients without systemic diseases (the control group in the previous study) were analyzed in the present study. Results PISA values were positively correlated with conventional periodontal classifications (Spearman correlation coefficient=0.52; Pperiodontal indexes, such as BOP and the plaque index (PI) (r=0.94; Pperiodontal classification, PI, bleeding index, and smoking, but not in the multivariate analysis. In the multivariate linear regression analysis, PISA values were positively correlated with the quantity of current smoking, PI, and severity of periodontal disease. Conclusions PISA integrates multiple periodontal indexes, such as probing pocket depth, BOP, and PI into a numerical variable. PISA is advantageous for quantifying periodontal inflammation and plaque accumulation. PMID:29093989

  14. Periodontal inflamed surface area as a novel numerical variable describing periodontal conditions.

    Science.gov (United States)

    Park, Shin-Young; Ahn, Soyeon; Lee, Jung-Tae; Yun, Pil-Young; Lee, Yun Jong; Lee, Joo Youn; Song, Yeong Wook; Chang, Yoon-Seok; Lee, Hyo-Jung

    2017-10-01

    A novel index, the periodontal inflamed surface area (PISA), represents the sum of the periodontal pocket depth of bleeding on probing (BOP)-positive sites. In the present study, we evaluated correlations between PISA and periodontal classifications, and examined PISA as an index integrating the discrete conventional periodontal indexes. This study was a cross-sectional subgroup analysis of data from a prospective cohort study investigating the association between chronic periodontitis and the clinical features of ankylosing spondylitis. Data from 84 patients without systemic diseases (the control group in the previous study) were analyzed in the present study. PISA values were positively correlated with conventional periodontal classifications (Spearman correlation coefficient=0.52; Pperiodontal indexes, such as BOP and the plaque index (PI) (r=0.94; Pperiodontal classification, PI, bleeding index, and smoking, but not in the multivariate analysis. In the multivariate linear regression analysis, PISA values were positively correlated with the quantity of current smoking, PI, and severity of periodontal disease. PISA integrates multiple periodontal indexes, such as probing pocket depth, BOP, and PI into a numerical variable. PISA is advantageous for quantifying periodontal inflammation and plaque accumulation.

  15. Factor analysis of soil spatial variability in gully erosion area of ...

    African Journals Online (AJOL)

    The effect of soil characteristics on gully development and distribution has made it desirable to determine the spatial variability of its physical and chemical properties. This paper examines the spatial variability of soil properties and factors contributing to the general pattern of variability in Agulu- Nanka- Oko gully complex, ...

  16. GGOS Focus Area 3: Understanding and Forecasting Sea-Level Rise and Variability

    Science.gov (United States)

    Schöne, Tilo; Shum, Ck; Tamisiea, Mark; Woodworth, Philip

    2017-04-01

    Sea level and its change have been measured for more than a century. Especially for coastal nations, deltaic regions, and coastal-oriented industries, observations of tides, tidal extremes, storm surges, and sea level rise at the interannual or longer scales have substantial impacts on coastal vulnerability towards resilience and sustainability of world's coastal regions. To date, the observed global sea level rise is largely associated with climate related changes. To find the patterns and fingerprints of those changes, and to e.g., separate the land motion from sea level signals, different monitoring techniques have been developed. Some of them are local, e.g., tide gauges, while others are global, e.g., satellite altimetry. It is well known that sea level change and land vertical motion varies regionally, and both signals need to be measured in order to quantify relative sea level at the local scale. The Global Geodetic Observing System (GGOS) and its services contribute in many ways to the monitoring of the sea level. These includes tide gauge observations, estimation of gravity changes, satellite altimetry, InSAR/Lidar, GNSS-control of tide gauges, providing ground truth sites for satellite altimetry, and importantly the maintenance of the International Reference Frame. Focus Area 3 (Understanding and Forecasting Sea-Level Rise and Variability) of GGOS establishes a platform and a forum for researchers and authorities dealing with estimating global and local sea level changes in a 10- to 30-year time span, and its project to the next century or beyond. It presents an excellent opportunity to emphasize the global, through to regional and local, importance of GGOS to a wide range of sea-level related science and practical applications. Focus Area 3 works trough demonstration projects to highlight the value of geodetic techniques to sea level science and applications. Contributions under a call for participation (http://www.ggos.org/Applications/theme3_SL

  17. Validation of the USGS Landsat Burned Area Essential Climate Variable (BAECV) across the conterminous United States

    Science.gov (United States)

    Vanderhoof, Melanie; Fairaux, Nicole; Beal, Yen-Ju G.; Hawbaker, Todd J.

    2017-01-01

    The Landsat Burned Area Essential Climate Variable (BAECV), developed by the U.S. Geological Survey (USGS), capitalizes on the long temporal availability of Landsat imagery to identify burned areas across the conterminous United States (CONUS) (1984–2015). Adequate validation of such products is critical for their proper usage and interpretation. Validation of coarse-resolution products often relies on independent data derived from moderate-resolution sensors (e.g., Landsat). Validation of Landsat products, in turn, is challenging because there is no corresponding source of high-resolution, multispectral imagery that has been systematically collected in space and time over the entire temporal extent of the Landsat archive. Because of this, comparison between high-resolution images and Landsat science products can help increase user's confidence in the Landsat science products, but may not, alone, be adequate. In this paper, we demonstrate an approach to systematically validate the Landsat-derived BAECV product. Burned area extent was mapped for Landsat image pairs using a manually trained semi-automated algorithm that was manually edited across 28 path/rows and five different years (1988, 1993, 1998, 2003, 2008). Three datasets were independently developed by three analysts and the datasets were integrated on a pixel by pixel basis in which at least one to all three analysts were required to agree a pixel was burned. We found that errors within our Landsat reference dataset could be minimized by using the rendition of the dataset in which pixels were mapped as burned if at least two of the three analysts agreed. BAECV errors of omission and commission for the detection of burned pixels averaged 42% and 33%, respectively for CONUS across all five validation years. Errors of omission and commission were lowest across the western CONUS, for example in the shrub and scrublands of the Arid West (31% and 24%, respectively), and highest in the grasslands and

  18. Modeling and mapping of cadmium in soils based on qualitative and quantitative auxiliary variables in a cadmium contaminated area.

    Science.gov (United States)

    Cao, Shanshan; Lu, Anxiang; Wang, Jihua; Huo, Lili

    2017-02-15

    The aim of this study was to measure the improvement in mapping accuracy of spatial distribution of Cd in soils by using geostatistical methods combined with auxiliary factors, especially qualitative variables. Significant correlations between Cd content and correlation environment variables that are easy to obtain (such as topographic factors, distance to residential area, land use types and soil types) were analyzed systematically and quantitatively. Based on 398 samples collected from a Cd contaminated area (Hunan Province, China), we estimated the spatial distribution of Cd in soils by using spatial interpolation models, including ordinary kriging (OK), and regression kriging (RK) with each auxiliary variable, all quantitative variables (RKWQ) and all auxiliary variables (RKWA). Results showed that mapping with RK was more consistent with the sampling data of the spatial distribution of Cd in the study area than mapping with OK. The performance indicators (smaller mean error, mean absolute error, root mean squared error values and higher relative improvement of RK than OK) indicated that the introduction of auxiliary variables can improve the prediction accuracy of Cd in soils for which the spatial structure could not be well captured by point-based observation (nugget to sill ratio=0.76) and strong relationships existed between variables to be predicted and auxiliary variables. The comparison of RKWA with RKWQ further indicated that the introduction of qualitative variables improved the prediction accuracy, and even weakened the effects of quantitative factors. Furthermore, the significantly different relative improvement with similar R2 and varying spatial dependence showed that a reasonable choice of auxiliary variables and analysis of spatial structure of regression residuals are equally important to ensure accurate predictions. Copyright © 2016. Published by Elsevier B.V.

  19. The Effect of Climate Variability on Gray Whales (Eschrichtius robustus) within Their Wintering Areas.

    Science.gov (United States)

    Salvadeo, Christian J; Gómez-Gallardo U, Alejandro; Nájera-Caballero, Mauricio; Urbán-Ramirez, Jorge; Lluch-Belda, Daniel

    2015-01-01

    The environmental conditions of the breeding and feeding grounds of the gray whale (Eschrichtius robustus) fluctuates at inter-annual scales in response to regional and basin climate patterns. Thus, the goals of this study were to assess if there are any relationships between summer sea ice on their feeding ground and counts of gray whale mother-calf (MC) pairs at Ojo de Liebre Lagoon (OLL); and if El Niño Southern Oscillation (ENSO) influences the winter distribution of gray whales MC pairs in the three primary breeding lagoons of OLL, San Ignacio Lagoon (SIL) and Santo Domingo Channel north of Bahia Magdalena (SDCh). Maximum February counts of MC pairs were compared with the length of the open-water season at the Bering Sea during the previous year. Then, an ENSO index and sea surface temperature anomalies outside the primary lagoons was compared with the maximum February counts of MC pairs at these lagoons. Results showed that maximum counts of MC pairs in OLL correlates with sea ice conditions in their feeding grounds from the previous feeding season, and this relationship can be attributed to changes in nutritive condition of females. ENSO-related variability influences distribution of MC pairs in the southern area of SDCh during the warm 1998 El Niño and cold 1999 La Niña. This supports the hypothesis that changes in the whales' distribution related to sea temperature occurs to reduce thermal-stress and optimize energy utilization for newborn whales. Although this last conclusion should be considered in view of the limited data available from all the whales' wintering locations in all the years considered.

  20. Implications of Wide-Area Geographic Diversity for Short- Term Variability of Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Andrew; Wiser, Ryan

    2010-08-23

    Worldwide interest in the deployment of photovoltaic generation (PV) is rapidly increasing. Operating experience with large PV plants, however, demonstrates that large, rapid changes in the output of PV plants are possible. Early studies of PV grid impacts suggested that short-term variability could be a potential limiting factor in deploying PV. Many of these early studies, however, lacked high-quality data from multiple sites to assess the costs and impacts of increasing PV penetration. As is well known for wind, accounting for the potential for geographic diversity can significantly reduce the magnitude of extreme changes in aggregated PV output, the resources required to accommodate that variability, and the potential costs of managing variability. We use measured 1-min solar insolation for 23 time-synchronized sites in the Southern Great Plains network of the Atmospheric Radiation Measurement program and wind speed data from 10 sites in the same network to characterize the variability of PV with different degrees of geographic diversity and to compare the variability of PV to the variability of similarly sited wind. The relative aggregate variability of PV plants sited in a dense 10 x 10 array with 20 km spacing is six times less than the variability of a single site for variability on time scales less than 15-min. We find in our analysis of wind and PV plants similarly sited in a 5 x 5 grid with 50 km spacing that the variability of PV is only slightly more than the variability of wind on time scales of 5-15 min. Over shorter and longer time scales the level of variability is nearly identical. Finally, we use a simple approximation method to estimate the cost of carrying additional reserves to manage sub-hourly variability. We conclude that the costs of managing the short-term variability of PV are dramatically reduced by geographic diversity and are not substantially different from the costs for managing the short-term variability of similarly sited wind in

  1. The Use of Woodland Products to Cope with Climate Variability in Communal Areas in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Lotte S. Woittiez

    2013-12-01

    Full Text Available Common lands provide smallholder farmers in Africa with firewood, timber, and feed for livestock, and they are used to complement human diets through the collection of edible nontimber forest products (NTFPs. Farmers have developed coping mechanisms, which they deploy at times of climatic shocks. We aimed to analyze the importance of NTFPs in times of drought and to identify options that could increase the capacity to adapt to climate change. We used participatory techniques, livelihood analysis, observations, and measurements to quantify the use of NTFPs. Communities recognized NTFPs as a mechanism to cope with crop failure. We estimated that indigenous fruits contributed to approximately 20% of the energy intake of wealthier farmers and to approximately 40% of the energy intake of poor farmers in years of inadequate rainfall. Farmers needed to invest a considerable share of their time to collect wild fruits from deforested areas. They recognized that the effectiveness of NTFPs as an adaptation option had become threatened by severe deforestation and by illegal harvesting of fruits by urban traders. Farmers indicated the need to plan future land use to (1 intensify crop production, (2 cultivate trees for firewood, (3 keep orchards of indigenous fruit trees, and (4 improve the quality of grazing lands. Farmers were willing to cultivate trees and to organize communal conservation of indigenous fruits trees. Through participatory exercises, farmers elaborated maps, which were used during land use discussions. The process led to prioritization of pressing land use problems and identification of the support needed: fast-growing trees for firewood, inputs for crop production, knowledge on the cultivation of indigenous fruit trees, and clear regulations and compliance with rules for extraction of NTFPs. Important issues that remain to be addressed are best practices for regeneration and conservation, access rules and implementation, and the

  2. Variable stars around selected open clusters in the VVV area: Young Stellar Objects

    Science.gov (United States)

    Medina, Nicolas; Borissova, Jura; Bayo, Amelia; Kurtev, Radostin; Lucas, Philip

    2017-09-01

    Time-varying phenomena are one of the most substantial sources of astrophysical information, and led to many fundamental discoveries in modern astronomy. We have developed an automated tool to search and analyze variable sources in the near infrared Ks band, using the data from the Vista Variables in the Vía Láctea (VVV) ESO Public Survey ([5, 8]). One of our main goals is to investigate the Young Stellar Objects (YSOs) in the Galactic star forming regions, looking for: •Variability. •New pre-main sequence star clusters. Here we present the newly discovered YSOs within some selected stellar clusters in our Galaxy.

  3. Geostatistical modeling of the spatial variability and risk areas of southern root-knot nematodes in relation to soil properties

    OpenAIRE

    Ortiz, B.V.; Perry, C; Goovaerts, P.; Vellidis, G.; Sullivan, D.

    2010-01-01

    Identifying the spatial variability and risk areas for southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) is key for site-specific management (SSM) of cotton (Gossypium hirsutum L.) fields. The objectives of this study were to: (i) determine the soil properties that influence RKN occurrence at different scales; and (ii) delineate risk areas of RKN by indicator kriging. The study site was a cotton field located in the southeastern coastal plain region of the US...

  4. Verification of an acoustic transmission matrix analysis of sound propagation in a variable area duct without flow

    Science.gov (United States)

    Miles, J. H.

    1981-01-01

    A predicted standing wave pressure and phase angle profile for a hard wall rectangular duct with a region of converging-diverging area variation is compared to published experimental measurements in a study of sound propagation without flow. The factor of 1/2 area variation used is sufficient magnitude to produce large reflections. The prediction is based on a transmission matrix approach developed for the analysis of sound propagation in a variable area duct with and without flow. The agreement between the measured and predicted results is shown to be excellent.

  5. Climate Variability in the Subarctic Area for the Last Two Millennia: Influence of North Atlantic Sector and Millennial Trend.

    Science.gov (United States)

    Nicolle, M.; Debret, M.; Massei, N.; Hormes, A.; Swingedouw, D.; Christophe, C.; de Vernal, A.; Arctic 2k Working Group

    2016-12-01

    Understanding climate variability for the last two millennia is an key issue to propose new constraints on climate modeling. This study is based on the Arctic2k database compiled by the PAGES Arctic2k working group. All records meet several quality criteria concerning location, time period span, resolution and age-dating control. All the proxy used are sensitivity to temperature changes. The database high quality allows to investigate climate variability from millennial trend to high frequencies. There is spatially heterogeneous record distribution throughout the Arctic-subarctic area, most of the archives being located in the North Atlantic sector. We divided the study region into 3 sectors (Siberia, Alaska and North Atlantic areas) and compared them to the global Arctic2k temperature reconstruction using statistics and signal analysis method (wavelet coherence). Wavelet coherence allows investigation of the relationships in time-frequency space between two time series and identification of common variability. The results highlight better significant correlations between North Atlantic and global Arctic signals. The results is confirmed by wavelet coherence, showing common variability at centennial to multi-centennial scales. Millennial trends showed significant cooling trends before 1900 A.D., except for two records. Cooling trends are consistent with reconstructed temperatures for north hemisphere and warming trends seemed to be the results of regional particularity. Studying millennial variability also highlights the inconsistency between some marine proxies which reflect summer temperatures. The characterization of centennial to multidecadal variability will be an important issue to link the high frequency variability of paleoclimate series to low frequency variability recorded by instrumental data.

  6. Spatial and temporal variability of rainfall and their effects on hydrological response in urban areas – a review

    Directory of Open Access Journals (Sweden)

    E. Cristiano

    2017-07-01

    Full Text Available In urban areas, hydrological processes are characterized by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques, and methods have been developed to capture rainfall and hydrological processes at high resolution. Weather radars have been introduced to estimate high spatial and temporal rainfall variability. At the same time, new models have been proposed to reproduce hydrological response, based on small-scale representation of urban catchment spatial variability. Despite these efforts, interactions between rainfall variability, catchment heterogeneity, and hydrological response remain poorly understood. This paper presents a review of our current understanding of hydrological processes in urban environments as reported in the literature, focusing on their spatial and temporal variability aspects. We review recent findings on the effects of rainfall variability on hydrological response and identify gaps where knowledge needs to be further developed to improve our understanding of and capability to predict urban hydrological response.

  7. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits.

    Science.gov (United States)

    Klonner, Günther; Fischer, Stefan; Essl, Franz; Dullinger, Stefan

    2016-01-01

    The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value), habitat use (agricultural and ruderal habitats, occurrence under the montane belt), and propagule pressure (frequency) were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties.

  8. A Source Area Approach Demonstrates Moderate Predictive Ability but Pronounced Variability of Invasive Species Traits.

    Directory of Open Access Journals (Sweden)

    Günther Klonner

    Full Text Available The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value, habitat use (agricultural and ruderal habitats, occurrence under the montane belt, and propagule pressure (frequency were most closely associated with invasiveness. However, even the best multiple model, including interactions, only explained a moderate fraction of the differences in invasive success. In addition, multidimensional variability in trait space was even larger among invasive than among non-invasive species. This pronounced variability suggests that invasive success has a considerable idiosyncratic component and is probably highly context specific. We conclude that basing risk assessment protocols on species trait profiles will probably face hardly reducible uncertainties.

  9. Variability of morphometric characteristics of the leaves of European white elm from the area of Great War Island

    Directory of Open Access Journals (Sweden)

    Devetaković Jovana

    2013-01-01

    Full Text Available The European White Elm (Ulmus effusa Willd. is indicated as a rare and endangered species in the growing stock of the Republic of Serbia. In the area of Great War Island, its natural populations were reduced to 56 registered trees, which occur in three spatially isolated subpopulations. On the basis of the research conducted on the level of variability of adaptible morphometric characteristics of leaves from 14 selected test trees of European White Elm, it can be concluded that the degree of interpopulation variability is satisfactory, which is a good basis for the conservation of the available gene pool.

  10. Increased variability of watershed areas in patients with high-grade carotid stenosis

    DEFF Research Database (Denmark)

    Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine

    2018-01-01

    . Despite of high relevance for both clinical diagnostics and research, individual in vivo WSA definition is fairly limited to date. Thus, this study proposes a standardized segmentation approach to delineate individual WSAs by use of time-to-peak (TTP) maps and investigates spatial variability...... time atlas and individual super-selective arterial spin labeling. We compared spatial variability of WSA probability maps between groups and assessed TTP differences between hemispheres in individual and group-average watershed locations. Results: Patients showed significantly higher spatial...... of individual WSAs. Methods: We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit...

  11. Climate variability in the subarctic area for the last 2 millennia

    Science.gov (United States)

    Nicolle, Marie; Debret, Maxime; Massei, Nicolas; Colin, Christophe; deVernal, Anne; Divine, Dmitry; Werner, Johannes P.; Hormes, Anne; Korhola, Atte; Linderholm, Hans W.

    2018-01-01

    To put recent climate change in perspective, it is necessary to extend the instrumental climate records with proxy data from paleoclimate archives. Arctic climate variability for the last 2 millennia has been investigated using statistical and signal analyses from three regionally averaged records from the North Atlantic, Siberia and Alaska based on many types of proxy data archived in the Arctic 2k database v1.1.1. In the North Atlantic and Alaska, the major climatic trend is characterized by long-term cooling interrupted by recent warming that started at the beginning of the 19th century. This cooling is visible in the Siberian region at two sites, warming at the others. The cooling of the Little Ice Age (LIA) was identified from the individual series, but it is characterized by wide-range spatial and temporal expression of climate variability, in contrary to the Medieval Climate Anomaly. The LIA started at the earliest by around AD 1200 and ended at the latest in the middle of the 20th century. The widespread temporal coverage of the LIA did not show regional consistency or particular spatial distribution and did not show a relationship with archive or proxy type either. A focus on the last 2 centuries shows a recent warming characterized by a well-marked warming trend parallel with increasing greenhouse gas emissions. It also shows a multidecadal variability likely due to natural processes acting on the internal climate system on a regional scale. A ˜ 16-30-year cycle is found in Alaska and seems to be linked to the Pacific Decadal Oscillation, whereas ˜ 20-30- and ˜ 50-90-year periodicities characterize the North Atlantic climate variability, likely in relation with the Atlantic Multidecadal Oscillation. These regional features are probably linked to the sea ice cover fluctuations through ice-temperature positive feedback.

  12. Applying theories and interventions from behavioral medicine to understand and reduce visual field variability in patients with vision loss.

    Science.gov (United States)

    Rozanski, Collin; Haythornthwaite, Jennifer A; Dagnelie, Gislin; Bittner, Ava K

    2014-08-01

    Visual field (VF) test results are often unreliable in visually impaired patients, but continue to be a cornerstone of clinical trials and play a vital role in clinical decision making since they are the primary method to determine patients' functional vision loss or progression. Currently, patients are typically asked to perform VF tasks with minimal instruction or consideration of their psychological experience during the test. The gradual loss of vision due to retinal diseases, such as retinitis pigmentosa (RP), age-related macular degeneration (AMD), or glaucoma can contribute to the experience of negative psychosocial states, such as anxiety, stress, and depression, as well as diminished quality of life. We hypothesize that VF testing elicits test performance anxiety and perception of functional losses of vision, which induces distracting negative thoughts that result in increased VF test variability. Resources for processing and responding to vision-related information may be diverted from task-relevant VF stimuli to task-irrelevant ones, such as internal worry and test anxiety, thereby resulting in VF test performance decrements. We present a theoretical model to support the hypothesis that VF variability is linked to patients' negative thoughts during VF testing. This conceptual framework provides a basis for the development of coping strategies and mindfulness-based interventions to be evaluated in future research aimed at improving psychosocial states and VF reliability in visually-impaired patients. It would be highly significant to intervene by modifying negative thoughts during VF testing to reduce test variability in glaucoma patients who are progressively losing vision to a blinding eye disease, but whose vision loss has not been accurately identified and treated early enough due to variable VF results. In clinical trials of potential interventions for RP and non-neovascular AMD, reducing VF variability would effectively increase the precision for

  13. Repetitive ERTS-1 observations of surface water variability along rivers and low-lying areas

    Science.gov (United States)

    Rango, A.; Salomonson, V. V.

    1973-01-01

    The Earth Resources Technology Satellite, ERTS-1, provides an 18 day repetitive coverage capability and observations in the 0.8-1.1 micron spectral region where the contrast between water and adjacent surfaces is relatively large. Using these capabilities, observations in Virginia, Iowa, Missouri, and California have been acquired showing distinct patterns of flooding. Repetitive views of these areas before and after flooding have been examined, and flood mapping was performed. Sloughs in California can be seen to expand in terms of the area covered by standing water as time extends from summer to autumn. The results indicate that ERTS-1 imagery can be a valuable adjunct to conventional and aircraft survey methods for ascertaining the amount of area covered by water or affected by flooding.

  14. Pore-scale modeling of vapor transport in partially saturated capillary tube with variable area using chemical potential

    DEFF Research Database (Denmark)

    Addassi, Mouadh; Schreyer, Lynn; Johannesson, Björn

    2016-01-01

    Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross-sectional area using a single equation. There are no fitting parameters and the nu......Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross-sectional area using a single equation. There are no fitting parameters...... and the numerical solutions to the equation are compared with experimental results with excellent agreement. We demonstrate that isothermal vapor transport can be accurately modeled without modeling the details of the contact angle, microscale temperature fluctuations, or pressure fluctuations using a modification...

  15. Biological variability in human body composition : implication in the rules and methodology research areas

    OpenAIRE

    Silva, Analiza Mónica Lopes de Almeida

    2005-01-01

    Doutoramento em Motricidade Humana na especialidade de Saúde e Condição Física This thesis presents five investigations related to the body composition rules and methodology research areas. In the rules, newly developed methods such as in vivo neutron activation analysis are used as the reference to evaluate the assumption of the stable mineral-to-protein density in Siri's three-compartment model for estimating total-body-fat mass. In the methodology area, the assessment of extracellular w...

  16. Assessing genetic variability in two ancient chicken breeds of Padova area

    Directory of Open Access Journals (Sweden)

    Martino Cassandro

    2010-01-01

    Full Text Available Genetic diversity in two ancient indigenous chicken breeds of the Veneto region was assessed using Amplified Fragment Length Polymorphism (AFLP markers. A total of 63 individuals were analysed using three selected AFLP primer combinations that produced 66 clear polymorphisms. The breeds analyzed were the Padovana and the Polverara (two ancient breeds and a reference broiler line. The expected heterozygosity (Het did not differ significantly among breeds. The variability at AFLP loci was largely maintained across breeds, as indicated by the coefficient of genetic differentiation (Gst value. The lowest genetic distance is found between the Padovana and Polverara breeds suggesting that they could be genetically close.

  17. Seasonal variability of leaf area index and foliar nitrogen in contrasting dry-mesic tundras

    DEFF Research Database (Denmark)

    Campioli, Matteo; Michelsen, Anders; Lemeur, Raoul

    2009-01-01

    Assimilation and exchange of carbon for arctic ecosystems depend strongly on leaf area index (LAI) and total foliar nitrogen (TFN). For dry-mesic tundras, the seasonality of these characteristics is unexplored. We addressed this knowledge gap by measuring variations of LAI and TFN at five contras...

  18. Influence of Siberian High on temperature variability over northern areas of South Asia

    Science.gov (United States)

    Riaz, Syed Muhammad Fahad; Iqbal, Muhammad Jawed; Baig, Mirza Jawwad

    2017-05-01

    Siberian High pressure plays a significant role in wintertime climate variability over South Asia. It brings coldest air masses in the region. The available literature has linked Siberian High with climate of East Asia, central Asia, and Eurasia. This paper examines the linkage between Siberian High pressure and inter-annual variations in temperature over the region of South Asia during winters. The methods employed in this study are that of centers of action approach, maximum covariance, and canonical correlation analyses. The wintertime temperature is not only significantly influenced by the intensity of Siberian High pressure, but it is also significantly correlated with zonal movement of Indian Ocean High. The intensity of Siberian High pressure explains more variance of the temperature during winters over the South Asian region than that of large-scale circulation phenomena, namely, Arctic Oscillation, North Atlantic Oscillation, and El-Nino-Southern Oscillation. A linear model of wintertime temperature has also been constructed using the Siberian High pressure index and the Indian Ocean High longitudinal index, which explains 28% variability of wintertime temperature for the Northern part of South Asia. We have also presented the justification that this statistical evidence is supported by the circulations and changes in the atmosphere. The modes having maximum possible covariance between the regional wintertime temperature and sea-level pressure of Siberian High have been isolated using the method of maximum covariance analysis and the modes having maximum possible correlations between the two fields have been isolated using canonical correlation analysis.

  19. Variability in Estimated Glomerular Filtration Rate by Area under the Curve Predicts Renal Outcomes in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Szu-Chia Chen

    2014-01-01

    Full Text Available Greater variability in renal function is associated with mortality in patients with chronic kidney disease (CKD. However, few studies have demonstrated the predictive value of renal function variability in relation to renal outcomes. This study investigates the predictive ability of different methods of determining estimated glomerular filtration rate (eGFR variability for progression to renal replacement therapy (RRT in CKD patients. This was a prospective observational study, which enrolled 1,862 CKD patients. The renal end point was defined as commencement of RRT. The variability in eGFR was measured by the area under the eGFR curve (AUC%. A significant improvement in model prediction was based on the −2 log likelihood ratio statistic. During a median 28.7-month follow-up, there were 564 (30.3% patients receiving RRT. In an adjusted Cox model, a smaller initial eGFR AUC%_12M (P<0.001, a smaller peak eGFR AUC%_12M (P<0.001, and a larger negative eGFR slope_12M (P<0.001 were associated with a higher risk of renal end point. Two calculated formulas: initial eGFR AUC%_12M and eGFR slope_12M were the best predictors. Our results demonstrate that the greater eGFR variability by AUC% is associated with the higher risk of progression to RRT.

  20. Variability in estimated runoff in a forested area based on different cartographic data sources

    Energy Technology Data Exchange (ETDEWEB)

    Fragoso, L.; Quirós, E.; Durán-Barroso, P.

    2017-11-01

    Aim of study: The goal of this study is to analyse variations in curve number (CN) values produced by different cartographic data sources in a forested watershed, and determine which of them best fit with measured runoff volumes. Area of study: A forested watershed located in western Spain. Material and methods: Four digital cartographic data sources were used to determine the runoff CN in the watershed. Main results: None of the cartographic sources provided all the information necessary to determine properly the CN values. Our proposed methodology, focused on the tree canopy cover, improves the achieved results. Research highlights: The estimation of the CN value in forested areas should be attained as a function of tree canopy cover and new calibrated tables should be implemented in a local scale.

  1. Resource communication: Variability in estimated runoff in a forested area based on different cartographic data sources

    Directory of Open Access Journals (Sweden)

    Laura Fragoso

    2017-10-01

    Full Text Available Aim of study: The goal of this study is to analyse variations in curve number (CN values produced by different cartographic data sources in a forested watershed, and determine which of them best fit with measured runoff volumes. Area of study: A forested watershed located in western Spain. Material and methods: Four digital cartographic data sources were used to determine the runoff CN in the watershed. Main results: None of the cartographic sources provided all the information necessary to determine properly the CN values. Our proposed methodology, focused on the tree canopy cover, improves the achieved results. Research highlights: The estimation of the CN value in forested areas should be attained as a function of tree canopy cover and new calibrated tables should be implemented in a local scale.

  2. On a random area variable arising in discrete-time queues and compact directed percolation

    Science.gov (United States)

    Kearney, Michael J.

    2004-09-01

    A well-known discrete-time, single-server queueing system with mean arrival rate lgr and mean departure rate mgr is considered from the perspective of the area, A, swept out by the queue occupation process during a busy period. We determine the exact form of the tail of the distribution, Pr(A > x); in particular, we show that Pr(A > x) ~ Cx-1/4 exp(-Dx1/2) for all rgr \

  3. Snow season variability in a boreal-Arctic transition area monitored by MODIS data

    Science.gov (United States)

    Malnes, Eirik; Rune Karlsen, Stein; Johansen, Bernt; Bjerke, Jarle W.; Tømmervik, Hans

    2016-12-01

    The duration and extent of snow cover is expected to change rapidly with climate change. Therefore, there is a need for improved monitoring of snow for the benefit of forecasting, impact assessments and the population at large. Remotely sensed techniques prove useful for remote areas where there are few field-based monitoring stations. This paper reports on a study of snow season using snow cover area fraction data from the two northernmost counties in Norway, Troms and Finnmark. The data are derived from the daily 500 m standard snow product (MOD10A1) from the NASA Terra MODerate Resolution Imaging Spectroradiometer (MODIS) sensor for the 2000-2010 period. This dataset has been processed with multi-temporal interpolation to eliminate clouds. The resulting cloud-free daily time series of snow cover fraction maps, have subsequently been used to derive the first and last snow-free day for the entire study area. In spring, the correlation between the first snow-free day mapped by MODIS data and snow data from 40 meteorological stations was highly significant (p climate change studies and ecology. Therefore refinement and further testing of this method should be encouraged.

  4. Identifying potential sources of variability between vegetation carbon storage estimates for urban areas.

    Science.gov (United States)

    Davies, Zoe G; Dallimer, Martin; Edmondson, Jill L; Leake, Jonathan R; Gaston, Kevin J

    2013-12-01

    Although urbanisation is a major cause of land-use change worldwide, towns and cities remain relatively understudied ecosystems. Research into urban ecosystem service provision is still an emerging field, yet evidence is accumulating rapidly to suggest that the biological carbon stores in cities are more substantial than previously assumed. However, as more vegetation carbon densities are derived, substantial variability between these estimates is becoming apparent. Here, we review procedural differences evident in the literature, which may be drivers of variation in carbon storage assessments. Additionally, we quantify the impact that some of these different approaches may have when extrapolating carbon figures derived from surveys up to a city-wide scale. To understand how/why carbon stocks vary within and between cities, researchers need to use more uniform methods to estimate stores and relate this quantitatively to standardised 'urbanisation' metrics, in order to facilitate comparisons. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Photoepilation with variable pulsed light in non-facial body areas: evaluation of efficacy and safety.

    Science.gov (United States)

    Holzer, G; Nahavandi, H; Neumann, R; Knobler, R

    2010-05-01

    Variable Pulsed Light (VPL) is a new intensity pulse light (IPL) system. We evaluated VPL for safety and long-term efficacy in non-facial hair removal. The Variable Pulsed Light [VPL System (Energist Limited, UK), 610-950 nm] system was used for the removal of unwanted non-facial dark pigmented body hair in 42 volunteers (40 females, two males, age: 18-43 years, mean: 30.4 +/- 7.4 years) with Fitzpatrick skin phototype (SPT) II (33.3%), III (38.1%) and IV (28.6%), and brown (43.8%) or black (56.2%) fine (19.0%), medium (47.6%) or coarse (9.4%) body hair. Minimum follow-up period was 12 months (mean: 13.14 +/- 2.38). Treatment parameters were as follows: number x duration of micropulses: 15 x 5-15 x 7 ms, pulse delay: 1-8 ms, fluence: 30-45 J/cm(2). Very good (> or =76% hair reduction) and good treatment efficacies (hair reduction: 51-75%) were observed in the majority of treated patients (n = 18; 42.9%; n = 14; 33.3% respectively), four patients (9.5%) had only moderate (hair reduction: 26-50%) and six (14.3%) patients had no (hair reduction hair and younger patients. The VPL System is a relatively efficient and safe treatment for long-term hair removal. Higher SPT (III and IV) with black and medium to coarse hair, and younger age of the patients appear to be factors of significant importance predicting long-term efficacy.

  6. Spatial Patterns and Temporal Variability of Drought in Beijing-Tianjin-Hebei Metropolitan Areas in China

    Directory of Open Access Journals (Sweden)

    Wanyuan Cai

    2015-01-01

    Full Text Available Drought identification and assessment are essential for regional water resources management. In this paper, the spatiotemporal characteristics of drought were evaluated based on monthly precipitation data from 33 synoptic stations during the period of 1960–2010. The percent of normal precipitation was applied to illustrate the driest years in Beijing-Tianjin-Hebei metropolitan areas (BTHMA (1965, 1997, and 2002. The modified Reconnaissance Drought Index (RDI was applied to capture the drought patterns and to estimate the drought severity at 33 meteorological stations. Agglomerative hierarchical cluster analysis (AHCA and principal component analysis (PCA were used to identify three different drought subregions R1, R2, and R3 based on the monthly precipitation values in BTHMA, which is located in southeast, north, and south of BTHMA, respectively. The year 1965 was the driest and 1964 was the wettest during the observed period. The characteristics of drought were analyzed in terms of the temporal evolution of the RDI-12 values and the frequency of drought for the three identified regions. The percentage of years characterized by drought was 13.73% for R1, 16.50% for R2, and 15.53% for R3. 66.91% of drought belongs to the near normal drought category. The obtained results can aid to improve water resources management in the area.

  7. Variability and scaling of hydraulic properties for 200 Area soils, Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, R.; Freeman, E.J.

    1995-10-01

    Over the years, data have been obtained on soil hydraulic properties at the Hanford Site. Much of these data have been obtained as part of recent site characterization activities for the Environmental Restoration Program. The existing data on vadose zone soil properties are, however, fragmented and documented in reports that have not been formally reviewed and released. This study helps to identify, compile, and interpret all available data for the principal soil types in the 200 Areas plateau. Information on particle-size distribution, moisture retention, and saturated hydraulic conductivity (K{sub s}) is available for 183 samples from 12 sites in the 200 Areas. Data on moisture retention and K{sub s} are corrected for gravel content. After the data are corrected and cataloged, hydraulic parameters are determined by fitting the van Genuchten soil-moisture retention model to the data. A nonlinear parameter estimation code, RETC, is used. The unsaturated hydraulic conductivity relationship can subsequently be predicted using the van Genuchten parameters, Mualem`s model, and laboratory-measured saturated hydraulic conductivity estimates. Alternatively, provided unsaturated conductivity measurements are available, the moisture retention curve-fitting parameters, Mualem`s model, and a single unsaturated conductivity measurement can be used to predict unsaturated conductivities for the desired range of field moisture regime.

  8. Larval fish variability in response to oceanographic features in a nearshore nursery area.

    Science.gov (United States)

    Pattrick, P; Strydom, N A

    2014-09-01

    The influence of oceanographic features on ichthyoplankton assemblages in the warm temperate nearshore region of Algoa Bay, South Africa, was assessed. The nearshore ichthyoplankton comprised 88 taxa from 34 families. Samples were collected at six stations between August 2010 and July 2012 using a plankton ring net of 750 mm diameter and 500 µm mesh aperture. The majority of larvae collected were in a preflexion stage, indicating the potential importance of the nearshore for newly hatched larvae. Engraulidae dominated the catch (38·4%), followed by Cynoglossidae (28·1%) and Sparidae (8·4%). Larval fish abundance was highest during austral spring and summer (September to February). Unique patterns in responses of each dominant fish species to oceanographic features in the nearshore indicate the sensitivity of the early developmental stage to environmental variables. Using generalized linear models, ichthyoplankton abundance responded positively to upwelling and when warm water plumes originating from an Agulhas Current meander entered Algoa Bay. Highest abundances of Engraulis encrasicolus and Sardinops sagax were observed during Agulhas Plume intrusions into Algoa Bay. When a mixed and stratified water column persisted in the nearshore region of Algoa Bay, larval fish abundance decreased. The nearshore region of Algoa Bay appears to serve as a favourable environment for the accumulation of ichthyoplankton. © 2014 The Fisheries Society of the British Isles.

  9. Spatial variability of some soil properties varies in oil palm (Elaeis guineensis Jacq.) plantations of west coastal area of India

    Science.gov (United States)

    Behera, Sanjib Kumar; Suresh, Kancherla; Narsimha Rao, Bezawada; Mathur, Ravi Kumar; Shukla, Arvind Kumar; Manorama, Kamireddy; Ramachandrudu, Kummari; Harinarayana, Parasa; Prakash, Chandra

    2016-06-01

    Mapping spatial variability of soil properties is the key to efficient soil resource management for sustainable crop yield. Therefore, the present study was conducted to assess the spatial variability of soil properties such as acidity (pH), salinity (electrical conductivity (EC)), organic carbon, available K, available P, exchangeable Ca2+, exchangeable Mg2+, available S and hot water soluble B in surface (0-20 cm) and subsurface (20-40 cm) soil layers of oil palm plantations in south Goa district of Goa located in west coastal area of India. A total of 128 soil samples were collected from 64 oil palm plantations of Goa located at an approximate interval of 1-2 km and analyzed. Soil was acidic to neutral in reaction. Other soil properties varied widely in both the soil layers. Correlations between soil pH and exchangeable Ca2+, between soil EC and available K, between available P and available S and between exchangeable Ca2+ and exchangeable Mg2+ in both the soil layers were found to be positive and significant (P < 0.01). Geostatistical analysis revealed a varied spatial distribution pattern for the measured soil properties. Best-fit models for measured soil properties were exponential, Gaussian, stable, K-Bessel and spherical with moderate to strong spatial dependency. The results revealed that site-specific fertilizer management options needed to be adopted in the oil palm plantations of the study area owing to variability in soil properties.

  10. Variable exchange between a stream and an aquifer in the Rio Grande Project Area

    Science.gov (United States)

    Sheng, Z.; Abudu, S.; Michelsen, A.; King, P.

    2016-12-01

    Both surface water and groundwater in the Rio Grande Project area in southern New Mexico and Far West Texas have been stressed by natural conditions such as droughts and human activities, including urban development and agricultural irrigation. In some area pumping stress in the aquifer becomes so great that it depletes the river flow especially during the irrigation season, typically from March through October. Therefore understanding such relationship between surface water and groundwater becomes more important in regional water resources planning and management. In this area, stream flows are highly regulated by the upstream reservoirs during the irrigation season and greatly influenced by return flows during non-irrigation season. During a drought additional groundwater pumping to supplement surface water shortage further complicates the surface water and groundwater interaction. In this paper the authors will use observation data and results of numerical models (MODFLOW) to characterize and quantify hydrological exchange fluxes between groundwater in the aquifers and surface water as well as impacts of groundwater pumping. The interaction shows a very interesting seasonal variation (irrigation vs. non-irrigation) as well as impact of a drought. Groundwater has been pumped for both municipal supplies and agricultural irrigation, which has imposed stresses toward both stream flows and aquifer storage. The results clearly show that historic groundwater pumping has caused some reaches of the river change from gaining stream to losing stream. Beyond the exchange between surface water and groundwater in the shallow aquifer, groundwater pumping in a deep aquifer could also enhance the exchanges between different aquifers through leaky confining layers. In the earlier history of pumping, pumping from the shallow aquifer is compensated by simple depletion of surface water, while deep aquifer tends to use the aquifer storage. With continued pumping, the cumulative

  11. Variability of Ozone, OX and NOx in Rural and Urban Areas in Marmara Region of Turkey

    Science.gov (United States)

    Kasparoǧlu, Sabin; İncecik, Selahattin; Topçu, H. Sema

    2017-04-01

    Marmara region is located in northwest of Turkey and it is bordered by Greece and the Aegean Sea to the west, and Bulgaria, the Black Sea to the north covers about 11,000 km2. Sea of Marmara is located at the center of the region. The region has the largest population in Turkey with about 23 million inhabitants. It is Turkey's main industrial region and It is the territory which is provided by a quarter of the Turkish economy. Moreover, the region is economically the most developed area of Turkey. Its agricultural potential is very rich. For example, about 73% of the sunflower production and 30 % of corn production of Turkey is done in this region. The aim of the study is to assess the spatial and temporal variations in O3, NO, and NO2 in Marmara region of Turkey based on the analysis of hourly concentrations collected at 22 monitoring stations (7 rural and 15 urban) over three years (2013-2016). This is the first study in the region. In this way possible reasons of the results will be useful in the design of control strategies for photochemical pollution in this region. For this purpose, diurnal variations of NOx, O3 and OX were examined for rural and urban sites. The total levels of oxidant (OX) which are considered to be sum of O3 and NO2 were determined. In rural sites, NOx concentrations are generally lower than at urban and polluted sites of Marmara region. We found that usually O3 peak time in rural areas are occurred at around 15:00 LST while mean peak values vary between 70-85 µg/m3. The highest mean concentrations of NO were also observed at 09:00 LST around 35-50 µg/m3 in rural areas while varies at the highest at around 75-85 µg/m3 in polluted sites. Due to the NOx -dependent contribution corresponds to local production of ozone and the NOx -independent contribution corresponds to regional concentrations, we examined OX versus NOx for daytime (10:00-18:00LST) and nighttime (19:00-09:00LST)periods to understand the contaminants of NOx from local

  12. Summer variability of Saharan dust transport events in mountain areas north and south of Po basin

    Science.gov (United States)

    Landi, Tony C.; Marinoni, Angela; Cristofanelli, Paolo; Putero, Davide; Duchi, Rocco; Alborghetti, Marcello; Bonafè, Ubaldo; Calzolari, Francescopiero; Pietro Verza, Gian; Bonasoni, Paolo

    2013-04-01

    Mineral dust intrusions from northern African desert regions have a strong impact on the Mediterranean areas and Italian peninsula as they can cause an anomalous increase of aerosol concentrations in the tropospheric column and often an increase of particulate matter at ground level. The estimate of Saharan dust contribution to aerosols concentrations is therefore a key issue in air quality assessment and policy formulation, since can cause air quality exceedances of the PM10 daily limits (50 μg m-3) set by the European Union (EU/2008/50). This study presents a first identification and characterization of Saharan dust outbreaks observed during summer season at two high mountain stations located both South (Mt. Cimone, 2165 m asl) and North (Rifugio Guasti, Stelvio National Park, 3285 m asl) of Po valley. An estimation of their impact on PM10 concentrations in both sites, and in urban and rural areas of the Po basin is provided. Joining specific measurements (ground and satellite based) and numerical modeling, an investigation into the vertical structure of dust load will be presented. Actually, methodologies conceived for distinguishing dust outbreaks transported above the boundary layer without any impact at the ground level from those causing deposition are currently still lacking. Basically, the approach proposed in this work includes a deep analysis of in-situ measurements starting from long-term observation of Saharan dust carried out at the Mt. Cimone and more recent measurements performed in the framework of SHARE Stelvio Project, as well as the usage of ad hoc model chain (meteorological processor, chemical transport model, and aerosols optical properties calculation) to describe emission, transport and deposition dynamics of mineral dust that - in summertime - often affect the North Italy.

  13. Variability of airborne bacteria in an urban Mediterranean area (Thessaloniki, Greece)

    Science.gov (United States)

    Genitsaris, Savvas; Stefanidou, Natassa; Katsiapi, Matina; Kormas, Konstantinos A.; Sommer, Ulrich; Moustaka-Gouni, Maria

    2017-05-01

    The abundance, biomass and the taxonomic composition of the total airborne bacterial communities in a coastal urban area of Northeastern Mediterranean Sea were examined. In total, 27 air samples were collected across three seasons from a sampling point of approximately 30 m altitude in the center of the city. The abundance and biomass were determined with the use of epifluorescent microscopy, while the taxonomic composition was characterized by next-generation sequencing methods. Overall, the highest values of bacterial abundance were recorded during summer, with values exceeding abundances recorded in other urban sites across Europe, reaching 41 × 104 cells m-3. Out of 6 core meteorological parameters, only air temperature was found to significantly affect the abundance and biomass of airborne bacteria. Concerning the taxonomic composition of the airborne bacterial community, the group of Proteobacteria was the most diverse, with 47% of the total number of OTUs belonging to them, followed by Firmicutes, Actinobacteria and Bacteroidetes. The most dominant OTU belonged to γ-Proteobacteria, and was closely affiliated to Pseudomonas sp., a taxon commonly found to actively participate in the formation of ice-nuclei in the atmosphere. Finally, 19 OTUs were shared between all seasons and were found to be among the most dominant overall. The majority of these OTUs were affiliated to genera from soil and wastewater origin, while several were affiliated to genera that include known or opportunistic pathogens. Yet, only rare OTUs were affiliated to taxa with possible marine origin (e.g. Synechococcus sp.). The results showed that the atmosphere of the study area harbors a diverse and abundant bacterial community.

  14. Data mining for cataclysmic variables in the Large Sky Area Multi-Object Fibre Spectroscopic Telescope archive

    Science.gov (United States)

    Jiang, Bin; Luo, Ali; Zhao, Yongheng; Wei, Peng

    2013-04-01

    With the commissioning year of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST), the data archive of one-dimensional spectra is being released gradually. Searching for special objects like cataclysmic variables (CVs) in the data is one of LAMOST's objectives. This paper presents a novel method to identify CVs from optical spectra by using the support-vector machine (SVM) technique combined with principal-component analysis (PCA). After dimension reduction and feature extraction by PCA, spectral data are classified by SVM and most non-CVs are excluded. The final reduced list can be identified manually or by a template-matching algorithm. Experiments show that this data-mining method can find CVs from the LAMOST data base in an effective and efficient manner. We report the identification of 10 cataclysmic variables, of which two are new discoveries. In addition, this method is also applicable to mining other special celestial objects in sky-survey telescope data.

  15. Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area

    Science.gov (United States)

    Xu, L.; Williams, L. R.; Young, D. E.; Allan, J. D.; Coe, H.; Massoli, P.; Fortner, E.; Chhabra, P.; Herndon, S.; Brooks, W. A.; Jayne, J. T.; Worsnop, D. R.; Aiken, A. C.; Liu, S.; Gorkowski, K.; Dubey, M. K.; Fleming, Z. L.; Visser, S.; Prévôt, A. S. H.; Ng, N. L.

    2016-02-01

    The composition of PM1 (particulate matter with diameter less than 1 µm) in the greater London area was characterized during the Clean Air for London (ClearfLo) project in winter 2012. Two high-resolution time-of-flight aerosol mass spectrometers (HR-ToF-AMS) were deployed at a rural site (Detling, Kent) and an urban site (North Kensington, London). The simultaneous and high-temporal resolution measurements at the two sites provide a unique opportunity to investigate the spatial distribution of PM1. We find that the organic aerosol (OA) concentration is comparable between the rural and urban sites, but the contribution from different sources is distinctly different between the two sites. The concentration of solid fuel OA at the urban site is about twice as high as at the rural site, due to elevated domestic heating in the urban area. While the concentrations of oxygenated OA (OOA) are well-correlated between the two sites, the OOA concentration at the rural site is almost twice that of the urban site. At the rural site, more than 70 % of the carbon in OOA is estimated to be non-fossil, which suggests that OOA is likely related to aged biomass burning considering the small amount of biogenic SOA in winter. Thus, it is possible that the biomass burning OA contributes a larger fraction of ambient OA in wintertime than what previous field studies have suggested. A suite of instruments was deployed downstream of a thermal denuder (TD) to investigate the volatility of PM1 species at the rural Detling site. After heating at 250 °C in the TD, 40 % of the residual mass is OA, indicating the presence of non-volatile organics in the aerosol. Although the OA associated with refractory black carbon (rBC; measured by a soot-particle aerosol mass spectrometer) only accounts for organics have similar sources or have undergone similar chemical processing as rBC in the atmosphere. Although the atomic O : C ratio of OOA is substantially larger than that of solid fuel OA and

  16. The genetic variability of the Podolica cattle breed from the Gargano area. Preliminary results

    Directory of Open Access Journals (Sweden)

    Dario Cianci

    2010-01-01

    Full Text Available The Podolica cattle breed is autochthonous of Southern Italy and denoted by its particular rusticity. This study presents the preliminary results of the genetic characterization of the Podolica breed using DNA STR markers. A total of 20 microsatellite loci were analysed in 79 individuals reared in the Gargano area. Number of polymorphisms, allele fre- quencies, deviations from Hardy-Weinberg proportions, linkage disequilibrium between loci and genetic similarities between animals were calculated. The results showed a high deficiency of heterozygotes, the observed mean of het- erozygosis being 0.449, whereas the expected mean was 0.766. Many markers showed also deviations from the Hardy- Weinberg proportions and significant linkage disequilibrium between loci. However the genetic similarity within the pop- ulation was low (0.281 and the average number of alleles per locus was high (10, representing a high genetic vari- ability. In order to explain these results, a stratification of the breed in sub-populations with a high interior genetic homo- geneity but markedly differentiated one from each other could be hypothesized; this situation probably derived from non- random mating within each herd (consanguinity and from the lack of exchange of genetic material between the herds. A further study is needed on a wider sample and extending the analysis to FAO-ISAG microsatellite panel in order to con- firm this hypothesis. This could eventually provide the information necessary for the correct management of the repro- ductive schemes and for genomic traceability of meat production.

  17. EFFECT OF BORDERLINE TREES IN POPULATION PARAMETERS ESTIMATED BY VARIABLE SAMPLING AREA METHODS

    Directory of Open Access Journals (Sweden)

    Rodrigo Geroni Mendes Nascimento

    2015-03-01

    Full Text Available The objective of this research was to evaluate the effect of the borderline tree in the population parameters estimated by Bitterlich (1948, Prodan (1968 and Strand (1958 sampling methods. The database came from a census carried out in a fragment of Mixed Ombrophylous Montana Forest located in the Campus III, of Federal University of Parana, Curitiba-PR, Brazil. All trees with DBH ≥ 10 cm were measured, identified, georeferenced, and considered as possible plot center of the sampling units in each method. The sampling simulation was conducted with 185 randomly selected points for the estimation of N.ha-1, G.ha-1 and V.ha-1 to three different treatments: without the influence of borderline tree, count half borderline tree and count of partial borderline tree corrected by the P factor introduced by Péllico Netto (1994. Regardless of the method and the treatment used there was always an overestimation of N.ha-1. To estimate the basal area and volume per hectare, the Bitterlich method achieved the best results, followed by Strand and Prodan, respectively. Application of P factor in borderline trees did not cause a significant improvement in the population estimators compared with the estimates generated by borderline trees counted as half a tree or without its influence.

  18. Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area

    Directory of Open Access Journals (Sweden)

    L. Xu

    2016-02-01

    Full Text Available The composition of PM1 (particulate matter with diameter less than 1 µm in the greater London area was characterized during the Clean Air for London (ClearfLo project in winter 2012. Two high-resolution time-of-flight aerosol mass spectrometers (HR-ToF-AMS were deployed at a rural site (Detling, Kent and an urban site (North Kensington, London. The simultaneous and high-temporal resolution measurements at the two sites provide a unique opportunity to investigate the spatial distribution of PM1. We find that the organic aerosol (OA concentration is comparable between the rural and urban sites, but the contribution from different sources is distinctly different between the two sites. The concentration of solid fuel OA at the urban site is about twice as high as at the rural site, due to elevated domestic heating in the urban area. While the concentrations of oxygenated OA (OOA are well-correlated between the two sites, the OOA concentration at the rural site is almost twice that of the urban site. At the rural site, more than 70 % of the carbon in OOA is estimated to be non-fossil, which suggests that OOA is likely related to aged biomass burning considering the small amount of biogenic SOA in winter. Thus, it is possible that the biomass burning OA contributes a larger fraction of ambient OA in wintertime than what previous field studies have suggested. A suite of instruments was deployed downstream of a thermal denuder (TD to investigate the volatility of PM1 species at the rural Detling site. After heating at 250 °C in the TD, 40 % of the residual mass is OA, indicating the presence of non-volatile organics in the aerosol. Although the OA associated with refractory black carbon (rBC; measured by a soot-particle aerosol mass spectrometer only accounts for < 10 % of the total OA (measured by a HR-ToF-AMS at 250 °C, the two measurements are well-correlated, suggesting that the non-volatile organics have similar sources or have

  19. Variability of extreme climate events in the territory and water area of Russia

    Science.gov (United States)

    Serykh, Ilya; Kostianoy, Andrey

    2016-04-01

    (depending on the parameters) in the territory and water area of Russia for determining and mapping of the observed characteristics and trends in the extreme climate events and statistical forecast of these events for the next decades. Determination of a frequency, intensity and duration of extreme climate events in the territory and water area of Russia was done for the first time. It was found that the interannual-scale dynamics of ENSO is actually reflected in the climate features of different regions of the Earth, including the Russian Arctic. In particular, when the boreal winter season coincides with an El Niño event it is indicative by a negative anomaly of near-surface temperature (about -1°C) and a positive anomaly of sea level pressure over the Russian Western Arctic Basin. In contrary, significant (about +1°C) positive anomaly of near-surface temperature along with reduced sea level pressure over the regions of the Barents, White and Kara Seas is typical for any La Niña event (up to 95% significance of Student's t-test). The study was carried out with a support of the Russian Science Foundation Grant (Project N 14-50-00095).

  20. Seasonal variability of carbonaceous aerosols in an urban background area in Southern Italy

    Science.gov (United States)

    Cesari, D.; Merico, E.; Dinoi, A.; Marinoni, A.; Bonasoni, P.; Contini, D.

    2018-02-01

    Organic (OC) and Elemental Carbon (EC) are important components of atmospheric aerosol particles, playing a key role in climate system and potentially affecting human health. There is a lack of data reported for Southern Italy and this work aims to fill this gap, focusing the attention on the long-term trends of OC and EC concentrations in PM2.5 and PM10, and on atmospheric processes and sources influencing seasonal variability. Measurements were taken at the Environmental-Climate Observatory of Lecce (SE Italy, 40°20‧8″N-18°07‧28″E, 37 m a.s.l.), regional station of the Global Atmosphere Watch program (GAW-WMO). Daily PM10 and PM2.5 samples were collected between July 2013 and July 2016. In addition, starting in December 2014, simultaneous equivalent Black Carbon (eBC) concentrations in PM10 were measured using a Multi Angle Absorption Photometer. A subset of 722 PM samples (361 for each size fraction) was analysed by using a thermo-optical method with a Sunset Laboratory OC/EC analyser, to determine elemental and organic carbon concentrations. The average PM10 and PM2.5 concentrations were 28.8 μg/m3 and 17.5 μg/m3. The average OC and EC concentrations in PM10 were 5.4 μg/m3 and 0.8 μg/m3, in PM2.5 these were 4.7 μg/m3 and 0.6 μg/m3. Carbonaceous content was larger during cold season with respect to warm season as well as secondary organic carbon (SOC) that was evaluated using the OC/EC minimum ratio method. SOC was mainly segregated in PM2.5 and represented 53% - 75% of the total OC. A subset of EC data was compared with eBC measurements, showing a good correlation (R2 = 0.80), however, eBC concentrations were higher than EC concentrations of an average factor of 1.95 (+/- 0.55 standard deviation). This could be explained by the presence of a contribution of Brown Carbon (BrC), for example from biomass burning, in eBC measurements. Weekly patterns showed a slight decrease of carbon content during weekends with respect to weekdays especially

  1. Spring hydrograph simulation of karstic aquifers: Impacts of variable recharge area, intermediate storage and memory effects

    Science.gov (United States)

    Hosseini, Seiyed Mossa; Ataie-Ashtiani, Behzad; Simmons, Craig T.

    2017-09-01

    A simple conceptual rainfall-runoff model is proposed for the estimation of groundwater balance components in complex karst aquifers. In the proposed model the effects of memory length of different karst flow systems of base-flow, intermediate-flow, and quick-flow and also time variation of recharge area (RA) during a hydrological year were investigated. The model consists of three sub-models: soil moisture balance (SMB), epikarst balance (EPB), and groundwater balance (GWB) to simulate the daily spring discharge. The SMB and EPB sub-models utilize the mass conservation equation to compute the variation of moisture storages in the soil cover and epikarst, respectively. The GWB sub-model computes the spring discharge hydrograph through three parallel linear reservoirs for base-flow, intermediate-flow, and quick-flow. Three antecedent recharge indices are defined and embedded in the model structure to deal with the memory effect of three karst flow systems to antecedent recharge flow. The Sasan Karst aquifer located in the semi-arid region of south-west Iran with a continuous long-term (21-years) daily meteorological and discharge data are considered to describe model calibration and validation procedures. The effects of temporal variations of RA of karst formations during the hydrological year namely invariant RA, two RA (winter and summer), four RA (seasonal), and twelve RA (monthly) are assessed to determine their impact on the model efficiency. Results indicated that the proposed model with monthly-variant RA is able to reproduce acceptable simulation results based on modified Kling-Gupta efficiency (KGE = -0.83). The results of density-based global sensitivity analysis for dry (June to September) and a wet (October to May) period reveal the dominant influence of RA (with sensitivity indices equal to 0.89 and 0.93, respectively) in spring discharge simulation. The sensitivity of simulated spring discharge to memory effect of different karst formations during the

  2. Geostatistical modeling of the spatial variability and risk areas of southern root-knot nematodes in relation to soil properties.

    Science.gov (United States)

    Ortiz, B V; Perry, C; Goovaerts, P; Vellidis, G; Sullivan, D

    2010-05-01

    Identifying the spatial variability and risk areas for southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) is key for site-specific management (SSM) of cotton (Gossypium hirsutum L.) fields. The objectives of this study were to: (i) determine the soil properties that influence RKN occurrence at different scales; and (ii) delineate risk areas of RKN by indicator kriging. The study site was a cotton field located in the southeastern coastal plain region of the USA. Nested semivariograms indicated that RKN samples, collected from a 50×50 m grid, exhibited a local and regional scale of variation describing small and large clusters of RKN population density. Factorial kriging decomposed RKN and soil properties variability into different spatial components. Scale dependent correlations between RKN data showed that the areas with high RKN population remained stable though the growing season. RKN data were strongly correlated with slope (SL) at local scale and with apparent soil electrical conductivity deep (EC(a-d)) at both local and regional scales, which illustrate the potential of these soil physical properties as surrogate data for RKN population. The correlation between RKN data and soil chemical properties was soil texture mediated. Indicator kriging (IK) maps developed using either RKN, the relation between RKN and soil electrical conductivity or a combination of both, depicted the probability for RKN population to exceed the threshold of 100 second stage juveniles/100 cm(3) of soil. Incorporating EC(a-d) as soft data improved predictions favoring the reduction of the number of RKN observations required to map areas at risk for high RKN population.

  3. Normalization of flow-mediated dilation to shear stress area under the curve eliminates the impact of variable hyperemic stimulus

    Directory of Open Access Journals (Sweden)

    Mickleborough Timothy D

    2008-09-01

    Full Text Available Abstract Background Normalization of brachial artery flow-mediated dilation (FMD to individual shear stress area under the curve (peak FMD:SSAUC ratio has recently been proposed as an approach to control for the large inter-subject variability in reactive hyperemia-induced shear stress; however, the adoption of this approach among researchers has been slow. The present study was designed to further examine the efficacy of FMD normalization to shear stress in reducing measurement variability. Methods Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 healthy, physically active young adults (25.3 ± 0. 6 yrs; 10 men, 10 women by manipulating forearm cuff occlusion duration: 1, 2, 3, 4, and 5 min, in a randomized order. A venous blood draw was performed for determination of baseline whole blood viscosity and hematocrit. The magnitude of occlusion-induced forearm ischemia was quantified by dual-wavelength near-infrared spectrometry (NIRS. Brachial artery diameters and velocities were obtained via high-resolution ultrasound. The SSAUC was individually calculated for the duration of time-to-peak dilation. Results One-way repeated measures ANOVA demonstrated distinct magnitudes of occlusion-induced ischemia (volume and peak, hyperemic shear stress, and peak FMD responses (all p AUC (p = 0.785. Conclusion Our data confirm that normalization of FMD to SSAUC eliminates the influences of variable shear stress and solidifies the utility of FMD:SSAUC ratio as an index of endothelial function.

  4. [The analysis of the causes of variability of the relationship between leaf dry mass and area in plants].

    Science.gov (United States)

    Vasfilov, S P

    2011-01-01

    The lamina dry mass: area ratio (LMA - Leaf Mass per Area) is a quite variable trait. Leaf dry mass consists of symplast mass (a set of all leaf protoplasts) and apoplast mass (a set of all cell walls in a leaf). The ratio between symplast and apoplast masses is positively related to any functional trait of leaf calculated per unit of dry mass. The value of this ratio is defined by cells size and their number per unit of leaf area, number of mesophyll cells layers and their differentiation between palisade and spongy ones, and also by density of cells packing. The LMA value is defined by leaf thickness and density. The extent and direction of variability in both leaf traits define the extent and direction of variability in LMA. Negative correlation between leaf thickness and density reduces the level of LMA variability. As a consequence of this correlation the following pattern emerges: the thinner a leaf, the denser it is. Changes in the traits that define the LMA value take place both within a species under the influence of environmental factors and between species that differ in leaf structure and functions. Light is the most powerful environmental factor that influences the LMA, increase in illumination leading to increase in LMA. This effect occurs during leaf growth at the expense of structural changes associated with the reduction of symplast/apoplast mass ratio. Under conditions of intense illumination, LMA may increase due to accumulation of starch. With regard to the majority of leaf functions, the mass of starch may be ascribed to apoplast. Starch accumulation in leaves is observed also under conditions of elevated CO2 concentration in the air. Under high illumination, however, LMA increases also due to increased apoplast contribution to leaf dry mass. Scarce mineral nutrition leads to LMA increase due to lowering of growth zones demands for phothosyntates and, therefore, to increase in starch content of leaves. High level of mineral nutrition during

  5. Mapping trees in high resolution imagery across large areas using locally variable thresholds guided by medium resolution tree maps

    Science.gov (United States)

    Fisher, Adrian; Danaher, Tim; Gill, Tony

    2017-06-01

    Large area tree maps, important for environmental monitoring and natural resource management, are often based on medium resolution satellite imagery. These data have difficulty in detecting trees in fragmented woodlands, and have significant omission errors in modified agricultural areas. High resolution imagery can better detect these trees, however, as most high resolution imagery is not normalised it is difficult to automate a tree classification method over large areas. The method developed here used an existing medium resolution map derived from either Landsat or SPOT5 satellite imagery to guide the classification of the high resolution imagery. It selected a spatially-variable threshold on the green band, calculated based on the spatially-variable percentage of trees in the existing map of tree cover. The green band proved more consistent at classifying trees across different images than several common band combinations. The method was tested on 0.5 m resolution imagery from airborne digital sensor (ADS) imagery across New South Wales (NSW), Australia using both Landsat and SPOT5 derived tree maps to guide the threshold selection. Accuracy was assessed across 6 large image mosaics revealing a more accurate result when the more accurate tree map from SPOT5 imagery was used. The resulting maps achieved an overall accuracy with 95% confidence intervals of 93% (90-95%), while the overall accuracy of the previous SPOT5 tree map was 87% (86-89%). The method reduced omission errors by mapping more scattered trees, although it did increase commission errors caused by dark pixels from water, building shadows, topographic shadows, and some soils and crops. The method allows trees to be automatically mapped at 5 m resolution from high resolution imagery, provided a medium resolution tree map already exists.

  6. Laser Welding Process Parameters Optimization Using Variable-Fidelity Metamodel and NSGA-II

    Directory of Open Access Journals (Sweden)

    Wang Chaochao

    2017-01-01

    Full Text Available An optimization methodology based on variable-fidelity (VF metamodels and nondominated sorting genetic algorithm II (NSGA-II for laser bead-on-plate welding of stainless steel 316L is presented. The relationships between input process parameters (laser power, welding speed and laser focal position and output responses (weld width and weld depth are constructed by VF metamodels. In VF metamodels, the information from two levels fidelity models are integrated, in which the low-fidelity model (LF is finite element simulation model that is used to capture the general trend of the metamodels, and high-fidelity (HF model which from physical experiments is used to ensure the accuracy of metamodels. The accuracy of the VF metamodel is verified by actual experiments. To slove the optimization problem, NSGA-II is used to search for multi-objective Pareto optimal solutions. The results of verification experiments show that the obtained optimal parameters are effective and reliable.

  7. Digital Cover Photography for Estimating Leaf Area Index (LAI in Apple Trees Using a Variable Light Extinction Coefficient

    Directory of Open Access Journals (Sweden)

    Carlos Poblete-Echeverría

    2015-01-01

    Full Text Available Leaf area index (LAI is one of the key biophysical variables required for crop modeling. Direct LAI measurements are time consuming and difficult to obtain for experimental and commercial fruit orchards. Devices used to estimate LAI have shown considerable errors when compared to ground-truth or destructive measurements, requiring tedious site-specific calibrations. The objective of this study was to test the performance of a modified digital cover photography method to estimate LAI in apple trees using conventional digital photography and instantaneous measurements of incident radiation (Io and transmitted radiation (I through the canopy. Leaf area of 40 single apple trees were measured destructively to obtain real leaf area index (LAID, which was compared with LAI estimated by the proposed digital photography method (LAIM. Results showed that the LAIM was able to estimate LAID with an error of 25% using a constant light extinction coefficient (k = 0.68. However, when k was estimated using an exponential function based on the fraction of foliage cover (ff derived from images, the error was reduced to 18%. Furthermore, when measurements of light intercepted by the canopy (Ic were used as a proxy value for k, the method presented an error of only 9%. These results have shown that by using a proxy k value, estimated by Ic, helped to increase accuracy of LAI estimates using digital cover images for apple trees with different canopy sizes and under field conditions.

  8. Digital Cover Photography for Estimating Leaf Area Index (LAI) in Apple Trees Using a Variable Light Extinction Coefficient

    Science.gov (United States)

    Poblete-Echeverría, Carlos; Fuentes, Sigfredo; Ortega-Farias, Samuel; Gonzalez-Talice, Jaime; Yuri, Jose Antonio

    2015-01-01

    Leaf area index (LAI) is one of the key biophysical variables required for crop modeling. Direct LAI measurements are time consuming and difficult to obtain for experimental and commercial fruit orchards. Devices used to estimate LAI have shown considerable errors when compared to ground-truth or destructive measurements, requiring tedious site-specific calibrations. The objective of this study was to test the performance of a modified digital cover photography method to estimate LAI in apple trees using conventional digital photography and instantaneous measurements of incident radiation (Io) and transmitted radiation (I) through the canopy. Leaf area of 40 single apple trees were measured destructively to obtain real leaf area index (LAID), which was compared with LAI estimated by the proposed digital photography method (LAIM). Results showed that the LAIM was able to estimate LAID with an error of 25% using a constant light extinction coefficient (k = 0.68). However, when k was estimated using an exponential function based on the fraction of foliage cover (ff) derived from images, the error was reduced to 18%. Furthermore, when measurements of light intercepted by the canopy (Ic) were used as a proxy value for k, the method presented an error of only 9%. These results have shown that by using a proxy k value, estimated by Ic, helped to increase accuracy of LAI estimates using digital cover images for apple trees with different canopy sizes and under field conditions. PMID:25635411

  9. Digital cover photography for estimating leaf area index (LAI) in apple trees using a variable light extinction coefficient.

    Science.gov (United States)

    Poblete-Echeverría, Carlos; Fuentes, Sigfredo; Ortega-Farias, Samuel; Gonzalez-Talice, Jaime; Yuri, Jose Antonio

    2015-01-28

    Leaf area index (LAI) is one of the key biophysical variables required for crop modeling. Direct LAI measurements are time consuming and difficult to obtain for experimental and commercial fruit orchards. Devices used to estimate LAI have shown considerable errors when compared to ground-truth or destructive measurements, requiring tedious site-specific calibrations. The objective of this study was to test the performance of a modified digital cover photography method to estimate LAI in apple trees using conventional digital photography and instantaneous measurements of incident radiation (Io) and transmitted radiation (I) through the canopy. Leaf area of 40 single apple trees were measured destructively to obtain real leaf area index (LAI(D)), which was compared with LAI estimated by the proposed digital photography method (LAI(M)). Results showed that the LAI(M) was able to estimate LAI(D) with an error of 25% using a constant light extinction coefficient (k = 0.68). However, when k was estimated using an exponential function based on the fraction of foliage cover (f(f)) derived from images, the error was reduced to 18%. Furthermore, when measurements of light intercepted by the canopy (Ic) were used as a proxy value for k, the method presented an error of only 9%. These results have shown that by using a proxy k value, estimated by Ic, helped to increase accuracy of LAI estimates using digital cover images for apple trees with different canopy sizes and under field conditions.

  10. Long and Short Term Variability of the Main Physical Parameters in the Coastal Area of the SE Baltic Proper

    Science.gov (United States)

    Mingelaite, Toma; Rukseniene, Viktorija; Dailidiene, Inga

    2015-04-01

    Keywords: SE Baltic Sea, coastal upwelling, IR Remote Sensing The memory of the ocean and seas of atmospheric forcing events contributes to the long-term climate change. Intensifying climate change processes in the North Atlantic region including Baltic Sea has drawn widespread interest, as a changing water temperature has ecological, economic and social impact in coastal areas of the Europe seas. In this work we analyse long and short term variability of the main physical parameters in the coastal area of the South Eastern Baltic Sea Proper. The analysis of long term variability is based on monitoring data measured in the South Eastern Baltic Sea for the last 50 years. The main focus of the long term variability is changes of hydro meteorological parameters relevant to the observed changes in the climate.The water salinity variations in the Baltic Sea near the Lithuanian coast and in the Curonian Lagoon, a shallow and enclosed sub-basin of the Baltic Sea, were analysed along with the time series of some related hydroclimatic factors. The short term water temperature and salinity variations were analysed with a strong focus on coastal upwelling events. Combining both remote sensing and in situ monitoring data physical parameters such as vertical salinity variations during upwelling events was analysed. The coastal upwelling in the SE Baltic Sea coast, depending on its scale and intensity, may lead to an intrusion of colder and saltier marine waters to the Curonian Lagoon resulting in hydrodynamic changes and pronounced temperature drop extending for 30-40 km further down the Lagoon. The study results show that increasing trends of water level, air and water temperature, and decreasing ice cover duration are related to the changes in meso-scale atmospheric circulation, and more specifically, to the changes in regional and local wind regime climate. That is in a good agreement with the increasing trends in local higher intensity of westerly winds, and with the winter

  11. A Zinc-Finger-Family Transcription Factor, AbVf19, Is Required for the Induction of a Gene Subset Important for Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Akhil [Univ. of Hawaii, Manoa, HI (United States); Ohm, Robin A. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Oxiles, Lindsay [Univ. of Hawaii, Manoa, HI (United States); Brooks, Fred [Univ. of Hawaii, Manoa, HI (United States); Lawrence, Christopher B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Cho, Yangrae [Univ. of Hawaii, Manoa, HI (United States)

    2011-10-26

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen with a broad host range within the family Brassicaceae. It produces secondary metabolites that marginally affect virulence. Cell wall degrading enzymes (CDWE) have been considered important for pathogenesis but none of them individually have been identified as significant virulence factors in A. brassicicola. In this study, knockout mutants of a gene, AbVf19, were created and produced considerably smaller lesions than the wild type on inoculated host plants. The presence of tandem zinc-finger domains in the predicted amino acid sequence and nuclear localization of AbVf19- reporter protein suggested that it was a transcription factor. Gene expression comparisons using RNA-seq identified 74 genes being downregulated in the mutant during a late stage of infection. Among the 74 downregulated genes, 28 were putative CWDE genes. These were hydrolytic enzyme genes that composed a small fraction of genes within each family of cellulases, pectinases, cutinases, and proteinases. The mutants grew slower than the wild type on an axenic medium with pectin as a major carbon source. This study demonstrated the existence and the importance of a transcription factor that regulates a suite of genes that are important for decomposing and utilizing plant material during the late stage of plant infection.

  12. Chromium removal from wastewater using HSF and VF pilot-scale constructed wetlands: Overall performance, and fate and distribution of this element within the wetland environment.

    Science.gov (United States)

    Papaevangelou, Vassiliki A; Gikas, Georgios D; Tsihrintzis, Vassilios A

    2017-02-01

    The current experimental work aimed at the investigation of the overall chromium removal capacity of constructed wetlands (CWs) and the chromium fate-distribution within a wetland environment. For this purpose, the experimental setup included the parallel operation and monitoring of two horizontal subsurface flow (HSF) pilot-scale CWs and two vertical flow (VF) pilot-scale CWs treating Cr-bearing wastewater. Samples were collected from the influent, the effluent, the substrate and the plants. Apart from the continuous experiment, batch experiments (kinetics and isotherm) were conducted in order to investigate the chromium adsorption capacity of the substrate material. According to the findings, HSF-CWs demonstrated higher removal capacities in comparison to VF-CWs, while in both types the planted units indicated better performance compared to the unplanted ones. Analysis in various wetland compartments and annual mass balance calculation highlighted the exceptional contribution of substrate to chromium retention, while Cr accumulation in plant was not so high. Finally, experimental data fitted better to the pseudo-second-order and Langmuir models regarding kinetics and isotherm simulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Variability of the Leaf Area Index in natural fields and transition forest in Southern Amazonas State, Brazil

    Directory of Open Access Journals (Sweden)

    Walleson Higor Corrêa Jordão

    2015-04-01

    Full Text Available The Leaf Area Index (LAI has strong influence on ecosystems’ energy and mass exchange and is fundamental to the understanding of regional climate changes and ecosystem dynamics. The main goal of this work was to establish, based on geostatistical analyses, the variability and spatial dependence of LAI in the natural fields and transitional forest in southern Amazonas State, in Brazil. The LAI was measured in a regular grid with 33 points at each studied area. Field measurements were done using the canopy analyser LAI-2000, which calculates the structure of the vegetation based on the radiation beneath the tree canopy. The average values of LAI varied according to the studied sites: the highest values were found in the transitional forest (4.42 m²m -2 , followed by the high (2.03 m²m -2 and low (1.72 m²m -2 natural fields. All studied sites showed spatial dependence according to the kriging methods, but with different degrees of dependence: spatial dependence was moderate at the transition forest and weak at the natural fields. In the more arboreal open field, the maximum limit at which the points are correlated reached a distance of 35.3 m. The kriging maps proved to be very important tools for describing the spatial distribution of LAI in the Amazon.

  14. Characterization of soils in terms of pedological variability under different physiography of Damodar command area (part, West Bengal, India

    Directory of Open Access Journals (Sweden)

    Ranjan Bera

    2015-12-01

    Full Text Available Five representative soil profiles occurring on four different physiography under subtropical environment of Damodar command area, India, were studied for soil pedological variability. Two way approaches were taken to evaluate the extent of profile development. Firstly different extractants were used to determine various forms of Fe and Al and their different ratios. Average contents of Fe and Al, extracted by different extracting reagents were found to be in descending order, as follows: Aldith > Aloxa > Alpyr and Fedith > Feoxa > Fepyr. Analysis of pyrophosphate (pyr, oxalate (oxa, and dithionate (dith extractable Fe and Al fractions indicated that with increasing soil age, the content of crystalline Fe and Al oxides increased at the expense of the poorly crystalline forms. The mean content of amorphous Fe and Al, crystalline Fe and Al, and their ratios estimated the degree of soil development. In the second part, elemental analysis was done, silica to sesquioxide ratio as well as ratio of alkali cations was measured and weathering index of each horizon was determined. The ratios and weathering indices indicated that except Madhpur soil series, all other soils were young and pedological development was still in progress in Damodar command area.

  15. The Level of Psychological Burnout at the Teachers of Students with Autism Disorders in Light of a Number of Variables in Al-Riyadh Area

    Science.gov (United States)

    Atiyat, Omar Khalil

    2017-01-01

    This study aimed at measuring the level of the psychological burnout in the teachers of students that have autism symptoms in Al-Riyadh area--kingdom of Saudi Arabia. In light of variables. These variables are the gender, the teaching place, the academic qualification of the teachers, the experience of the teachers, the age of the teachers, and…

  16. Effect of Dietary Omega-3 Polyunsaturated Fatty Acids on Heart Rate and Heart Rate Variability in Animals Susceptible or Resistant to Ventricular Fibrillation

    Directory of Open Access Journals (Sweden)

    George E Billman

    2012-03-01

    Full Text Available The consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs has been reported to reduce cardiac mortality following myocardial infarction as well as to decrease resting heart rate (HR and increase heart rate variability (HRV. However, it has not been established whether n-3 PUFAs exhibit the same actions on HR and HRV in individuals known to be either susceptible or resistant to ventricular fibrillation (VF. Therefore, HR and HRV (high frequency and total R-R interval variability were evaluated before and 3 months after n-3 PUFA treatment in dogs with healed myocardial infarction that were either susceptible (VF+, n = 31 or resistant (VF-, n = 31 to ventricular tachyarrhythmias induced by a 2 min coronary artery occlusion during the last minute of a submaximal exercise test. HR and HRV were evaluated at rest, during submaximal exercise and in response to acute myocardial ischemia at rest before and after either placebo (1 g/day, corn oil, VF+, n = 9; VF- n = 8 or n-3 PUFA (docosahexaenoic acid + eicosapentaenoic acid ethyl esters, 1-4g/day, VF+, n = 22; VF-, n = 23 treatment for 3 months. The n-3 PUFA treatment elicited similar increases in red blood cell membrane, right atrial, and left ventricular n-3 PUFA levels in both the VF+ and VF- dogs. The n-3 PUFA treatment also provoked similar reductions in baseline HR and increases in baseline HRV in both groups that resulted in parallel shifts in the response to either exercise or acute myocardial ischemia (that is, the change in these variables induced by physiological challenges was not altered after n-3 PUFA treatment. These data demonstrate that dietary n-3 PUFA decreased HR and increased HRV to a similar extent in animals known to be prone to or resistant to malignant cardiac tachyarrhythmias.

  17. Variability and dilemmas in harm reduction for anabolic steroid users in the UK: a multi-area interview study

    Science.gov (United States)

    2014-01-01

    Background The UK continues to experience a rise in the number of anabolic steroid-using clients attending harm reduction services such as needle and syringe programmes. Methods The present study uses interviews conducted with harm reduction service providers as well as illicit users of anabolic steroids from different areas of England and Wales to explore harm reduction for this group of drug users, focussing on needle distribution policies and harm reduction interventions developed specifically for this population of drug users. Results The article addresses the complexity of harm reduction service delivery, highlighting different models of needle distribution, such as peer-led distribution networks, as well as interventions available in steroid clinics, including liver function testing of anabolic steroid users. Aside from providing insights into the function of interventions available to steroid users, along with principles adopted by service providers, the study found significant tensions and dilemmas in policy implementation due to differing perspectives between service providers and service users relating to practices, risks and effective interventions. Conclusion The overarching finding of the study was the tremendous variability across harm reduction delivery sites in terms of available measures and mode of operation. Further research into the effectiveness of different policies directed towards people who use anabolic steroids is critical to the development of harm reduction. PMID:24986546

  18. Inverse modeling of variable-density groundwater flow in a semi-arid area in Iran using a genetic algorithm

    Science.gov (United States)

    Bastani, Mehrdad; Kholghi, Majid; Rakhshandehroo, Gholam Reza

    2010-08-01

    Flow and mass transport parameter estimation was done by creating an inverse model of a seawater intrusion system using a genetic algorithm (GA) method as the optimization procedure. Firstly, the SEAWAT code was used for the forward solution part and then a program was written in MATLAB for coupling the forward and inverse processes. The auto-calibration objective function was defined with the root mean square errors (RMSE) between the observed and the simulated values. A simple GA was used to minimize the RMSE criterion. The methodology was applied to a coastal aquifer with heterogeneous formations in a semi-arid area near salty Tashk Lake (electrical conductivity 61,420 µS/cm), Fars province, Iran. In the last two decades, the overexploitation of groundwater has caused a major water level drawdown and, consequently, salt-water intrusion. Firstly, flow and transport parameters (hydraulic conductivity, porosity, specific storage coefficient and longitudinal dispersivity) were estimated simultaneously in steady-state and, secondly, in the developed code, these results were used as initial values of the parameters in transient-state. Results show a good match for observed and simulated data. It can be concluded that GA is a helpful tool for automatic calibration of variable density fluid systems such as seawater intrusion cases.

  19. Advanced Engine Cycles Analyzed for Turbofans With Variable-Area Fan Nozzles Actuated by a Shape Memory Alloy

    Science.gov (United States)

    Berton, Jeffrey J.

    2002-01-01

    Advanced, large commercial turbofan engines using low-fan-pressure-ratio, very high bypass ratio thermodynamic cycles can offer significant fuel savings over engines currently in operation. Several technological challenges must be addressed, however, before these engines can be designed. To name a few, the high-diameter fans associated with these engines pose a significant packaging and aircraft installation challenge, and a large, heavy gearbox is often necessary to address the differences in ideal operating speeds between the fan and the low-pressure turbine. Also, the large nacelles contribute aerodynamic drag penalties and require long, heavy landing gear when mounted on conventional, low wing aircraft. Nevertheless, the reduced fuel consumption rates of these engines are a compelling economic incentive, and fans designed with low pressure ratios and low tip speeds offer attractive noise-reduction benefits. Another complication associated with low-pressure-ratio fans is their need for variable flow-path geometry. As the design fan pressure ratio is reduced below about 1.4, an operational disparity is set up in the fan between high and low flight speeds. In other words, between takeoff and cruise there is too large a swing in several key fan parameters-- such as speed, flow, and pressure--for a fan to accommodate. One solution to this problem is to make use of a variable-area fan nozzle (VAFN). However, conventional, hydraulically actuated variable nozzles have weight, cost, maintenance, and reliability issues that discourage their use with low-fan-pressure-ratio engine cycles. United Technologies Research, in cooperation with NASA, is developing a revolutionary, lightweight, and reliable shape memory alloy actuator system that can change the on-demand nozzle exit area by up to 20 percent. This "smart material" actuation technology, being studied under NASA's Ultra-Efficient Engine Technology (UEET) Program and Revolutionary Concepts in Aeronautics (Rev

  20. Spatial variability of the physical and mineralogical properties of the soil from the areas with variation in landscape shapes

    Directory of Open Access Journals (Sweden)

    Zigomar Menezes de Souza

    2009-04-01

    Full Text Available The objective of this work it was to use the geostatistics methods to investigate the spatial relationships between the physical and mineralogical properties of an oxisol planted with the sugarcane in an area of slight variations in the landform. The soil was sampled at 10 m regular intervals in the crossing points of a 100 x 100 m grid. At each point, the soil was collected at 0.0-0.2 m, 0.2-0.4 m and 0.4-0.6 m depths for the analyzes of physical properties and at 0.6-0.8 m for the mineralogical analyses. Both the Kt/Kt+Gb ratio and Kt relative crystallization level were higher in the compartment I than in the compartment II. As a consequence, the soil penetration resistance and bulk density were higher in the compartment I, while the macroporosity and Ksat were lower. Therefore, it was concluded that both the identification and mapping of a landform were efficient for understanding the spatial variability of the soil properties. Moreover, variations in the landscape shape promoted the differentiated variability of the physical and mineralogical soil properties: the more variable the landscape, the more variable was the soil properties.Este trabalho teve como objetivo avaliar a influência das formas do relevo na variabilidade espacial de atributos físicos e suas relações com a mineralogia da argila de um Latossolo Vermelho eutroférrico, utilizando a técnica da geoestatística. Os solos foram amostrados nos pontos de cruzamento de uma malha, com intervalos regulares de 10 m, nas profundidades de 0,0-0,2 m, 0,2-0,4 m e 0,4-0,6 m para os atributos físicos e 0,6-0,8 m para os atributos mineralógicos. Os valores médios para a densidade do solo e resistência do solo à penetração são maiores no compartimento I onde a relação Ct/Ct+Gb é relativamente maior, indicando a presença de maior teor de caulinita. No compartimento II a condutividade hidráulica e a macroporsidade são maiores, influenciados provavelmente pelo predomínio da

  1. Comparing bias correction methods in downscaling meteorological variables for hydrologic impact study in an arid area in China

    Science.gov (United States)

    Fang, G. H.; Yang, J.; Chen, Y. N.; Zammit, C.

    2014-11-01

    Water resources are essential to the ecosystem and social economy in the desert and oasis of the arid Tarim River Basin, Northwest China, and expected to be vulnerable to climate change. Regional Climate Models (RCM) have been proved to provide more reliable results for regional impact study of climate change (e.g. on water resources) than GCM models. However, it is still necessary to apply bias correction before they are used for water resources research due to often considerable biases. In this paper, after a sensitivity analysis on input meteorological variables based on Sobol' method, we compared five precipitation correction methods and three temperature correction methods to the output of a RCM model with its application to the Kaidu River Basin, one of the headwaters of the Tarim River Basin. Precipitation correction methods include Linear Scaling (LS), LOCal Intensity scaling (LOCI), Power Transformation (PT), Distribution Mapping (DM) and Quantile Mapping (QM); and temperature correction methods include LS, VARIance scaling (VARI) and DM. These corrected precipitation and temperature were compared to the observed meteorological data, and then their impacts on streamflow were also compared by driving a distributed hydrologic model. The results show: (1) precipitation, temperature, solar radiation are sensitivity to streamflow while relative humidity and wind speed are not, (2) raw RCM simulations are heavily biased from observed meteorological data, which results in biases in the simulated streamflows, and all bias correction methods effectively improved theses simulations, (3) for precipitation, PT and QM methods performed equally best in correcting the frequency-based indices (e.g. SD, percentile values) while LOCI method performed best in terms of the time series based indices (e.g. Nash-Sutcliffe coefficient, R2), (4) for temperature, all bias correction methods performed equally well in correcting raw temperature. (5) For simulated streamflow

  2. Comparing bias correction methods in downscaling meteorological variables for a hydrologic impact study in an arid area in China

    Science.gov (United States)

    Fang, G. H.; Yang, J.; Chen, Y. N.; Zammit, C.

    2015-06-01

    Water resources are essential to the ecosystem and social economy in the desert and oasis of the arid Tarim River basin, northwestern China, and expected to be vulnerable to climate change. It has been demonstrated that regional climate models (RCMs) provide more reliable results for a regional impact study of climate change (e.g., on water resources) than general circulation models (GCMs). However, due to their considerable bias it is still necessary to apply bias correction before they are used for water resources research. In this paper, after a sensitivity analysis on input meteorological variables based on the Sobol' method, we compared five precipitation correction methods and three temperature correction methods in downscaling RCM simulations applied over the Kaidu River basin, one of the headwaters of the Tarim River basin. Precipitation correction methods applied include linear scaling (LS), local intensity scaling (LOCI), power transformation (PT), distribution mapping (DM) and quantile mapping (QM), while temperature correction methods are LS, variance scaling (VARI) and DM. The corrected precipitation and temperature were compared to the observed meteorological data, prior to being used as meteorological inputs of a distributed hydrologic model to study their impacts on streamflow. The results show (1) streamflows are sensitive to precipitation, temperature and solar radiation but not to relative humidity and wind speed; (2) raw RCM simulations are heavily biased from observed meteorological data, and its use for streamflow simulations results in large biases from observed streamflow, and all bias correction methods effectively improved these simulations; (3) for precipitation, PT and QM methods performed equally best in correcting the frequency-based indices (e.g., standard deviation, percentile values) while the LOCI method performed best in terms of the time-series-based indices (e.g., Nash-Sutcliffe coefficient, R2); (4) for temperature, all

  3. Evaluation of winter food quality and its variability for red deer in forest environment: overwintering enclosures vs. free-ranging areas

    Directory of Open Access Journals (Sweden)

    Holá Michaela

    2016-09-01

    Full Text Available Populations of European ungulates have grown substantially over recent decades, resulting in considerable environmental and socio-economic impacts. Availability and quality of natural and supplemental food sources are among the main factors driving their population dynamics. Detailed knowledge of food quality of management-targeted species is therefore of primary importance for their successful management. The main aim of this study was to evaluate winter food quality and its variability for an important ungulate species in the Czech Republic - i.e. red deer, using faecal indices (faecal nitrogen, faecal acid detergent fibre, faecal neutral detergent fibre and near infrared reflectance spectroscopy. We compared food quality for red deer and its possible differences between overwintering enclosures (i.e. fenced areas where red deer spend harsh winter conditions and neighbouring unfenced free-ranging areas within two study areas. The results obtained showed that winter food quality and its variability for red deer are of different quality and variability in the overwintering enclosure and neighbouring free-ranging area. The observed differences in concentrations and amounts of variation of faecal indices are most probably related to animal densities at individual study areas. Wildlife managers should therefore keep animals in overwintering enclosures at moderate densities and to provide high quality forage to all individuals in order to balance nutrition of both the individuals inside and outside the enclosures. Nevertheless, further studies are needed in order to provide deeper knowledge on red deer food quality and its variability in space and time.

  4. A comparison of small-area estimation techniques to estimate selected stand attributes using LiDAR-derived auxiliary variables

    Science.gov (United States)

    Michael E. Goerndt; Vicente J. Monleon; Hailemariam. Temesgen

    2011-01-01

    One of the challenges often faced in forestry is the estimation of forest attributes for smaller areas of interest within a larger population. Small-area estimation (SAE) is a set of techniques well suited to estimation of forest attributes for small areas in which the existing sample size is small and auxiliary information is available. Selected SAE methods were...

  5. Wind forcing of sea level variability in a tropical coral reef area in the western Gulf of Mexico

    National Research Council Canada - National Science Library

    Román Rodolfo Vera-Mendoza; David Alberto Salas-de-León; David Salas-Monreal; Modesto Ortiz-Figueroa

    2017-01-01

    Sea level, water temperature, and wind stress data were obtained from the Western Gulf of Mexico to elucidate the relationship between sea level changes and meteorological variables in a tropical coral reef system...

  6. Recognizing Prosody across Modalities, Face Areas and Speakers: Examining Perceivers' Sensitivity to Variable Realizations of Visual Prosody

    Science.gov (United States)

    Cvejic, Erin; Kim, Jeesun; Davis, Chris

    2012-01-01

    Prosody can be expressed not only by modification to the timing, stress and intonation of auditory speech but also by modifying visual speech. Studies have shown that the production of visual cues to prosody is highly variable (both within and across speakers), however behavioural studies have shown that perceivers can effectively use such visual…

  7. Analysis of wind events in a coastal area: a tool for assessing turbulence variability for studies on plankton

    Directory of Open Access Journals (Sweden)

    Òscar Guadayol

    2006-03-01

    Full Text Available Turbulence at different scales, from generation to dissipation, influences planktonic communities. Many experimental studies have recently been done to determine the effects of small-scale turbulence on plankton, but it is difficult to state the relevance of the findings since there is little unbiased information on turbulence variability in the sea. In this study, we use wind velocity data series from several meteorological stations located along the Catalan coast to estimate the spatial and temporal variability of small-scale turbulence in the upper ocean. Using a peaks-over-threshold approach, we develop a statistical model to assess the frequency of wind events as a function of their persistence and intensity. Finally, the wind speed data series are converted into turbulent energy dissipation rate estimates at 1 m depth to determine the general distribution of turbulence on the Catalan coast. Geographical variability is larger than seasonal variability in frequency and persistence of wind events, owing to differences in local relief. These statistical models developed for wind events combined with empirical relationships between wind and turbulence, are tools for estimating the occurrence and persistence of turbulent events at a given location and season. They serve to put into context the past, present and future studies of the effects of turbulence on coastal planktonic organisms and processes.

  8. Spatial and Temporal Variability of Carbon Dioxide Using Structure Functions in Urban Areas: Insights for Future Active Remote CO2 Sensors

    Science.gov (United States)

    Choi, Yonghoon; Yang, Melissa; Kooi, Susan A.; Browell, Edward V.; DiGangi, Joshua P.

    2015-01-01

    High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaigns during July 2011 over Washington DC/Baltimore, MD; January-February 2013 over the San Joaquin Valley, CA; September 2013 over Houston, TX; and July-August 2014 over Denver, CO. Each of these campaigns have approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 kilometers) at 6-8 different sites in each of the urban areas. In this study, we used structure function analysis, which is a useful way to quantify spatial and temporal variability, by displaying differences with average observations, to evaluate the variability of CO2 in the 0-2 kilometers range (representative of the planetary boundary layer). These results can then be used to provide guidance in the development of science requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission to measure near-surface CO2 variability in different urban areas. We also compare the observed in-situ CO2 variability with the variability of the CO2 column-averaged optical depths in the 0-1 kilometer and 0-3.5 kilometers altitude ranges in the four geographically different urban areas, using vertical weighting functions for potential future ASCENDS lidar CO2 sensors operating in the 1.57 and 2.05 millimeter measurement regions. In addition to determining the natural variability of CO2 near the surface and in the column, radiocarbon method using continuous CO2 and CO measurements are used to examine the variation of emission quantification between anthropogenic and biogenic sources in the DC/Maryland urban site.

  9. Variability modes of precipitation along a Central Mediterranean area and their relations with ENSO, NAO, and other climatic patterns

    Science.gov (United States)

    Kalimeris, Anastasios; Ranieri, Ezio; Founda, Dimitra; Norrant, Caroline

    2017-12-01

    This study analyses a century-long set of precipitation time series in the Central Mediterranean (encompassing the Greek Ionian and the Italian Puglia regions) and investigates the statistically significant modes of the interannual precipitation variability using efficient methods of spectral decomposition. The statistical relations and the possible physical couplings between the detected modes and the global or hemispheric patterns of climatic variability (the El Niño Southern Oscillation or ENSO, the North Atlantic Oscillation or NAO, the East Atlantic or EA, the Scandinavian or SCAND, and others) were examined in the time-frequency domain and low-order synchronization events were sought. Significant modes of precipitation variability were detected in the Taranto Gulf and the southern part of the Greek Ionian region at the sub-decadal scales (mostly driven by the SCAND pattern) and particularly at the decadal and quasi-decadal scales, where strong relations found with the ENSO activity (under complex implications of EA and NAO) prior to the 1930s or after the early-1970s. The precipitation variations in the Adriatic stations of Puglia are dominated by significant bi-decadal modes which found to be coherent with the ENSO activity and also weakly related with the Atlantic Ocean sea surface temperature intrinsic variability. Additionally, important discontinuities characterize the evolution of precipitation in certain stations of the Taranto Gulf and the Greek Ionian region during the early-1960s and particularly during the early-1970s, followed by significant reductions in the mean annual precipitation. These discontinuities seem to be associated with regional effects of NAO and SCAND, probably combined with the impact of the 1970s climatic shift in the Pacific and the ENSO variability.

  10. Quantifying spatial and temporal variability of methane emissions from a complex area source: case study of a central Indiana landfill

    Science.gov (United States)

    strengths, limitations, and uncertainties of these two approaches. Because US landfills are highly-engineered and composed of daily, intermediate, and final cover areas with differing thicknesses, composition, and implementation of gas recovery, we also expected different emissi...

  11. Area- and Depth-Weighted Averages of Selected SSURGO Variables for the Conterminous United States and District of Columbia

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data release consists of seven national data files of area- and depth-weighted averages of select soil attributes for every available county in the...

  12. Instability of a quasi-magnetic structure in a layer compound, Cs{sub 0.5}Rb{sub 0.5}VF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, M.; Yoshimura, M. [Department of Physics, Faculty of Sciences, Kyushu University, Fukuoka 812-8581 (Japan); Akiyama, H. [Department of Physics, Faculty of Education, Miyazaki University, Miyazaki 889-21 (Japan); Watanabe, S.; Yoshizawa, H. [Neutron scattering Laboratory, ISSP, University of Tokyo, Tokai, Ibaraki 319-1106 (Japan); Wanklyn, B.M. [Claredon Laboratory, Oxford University, Oxford OX1 3PU (United Kingdom)

    2002-07-01

    Magnetic properties of Cs{sub 0.5}Rb{sub 0.5}VF{sub 4} are studied by neutron diffraction. The layer compound shows an antiferromagnetic phase transition at about 34 K (T{sub N}). Its normal antiferromagnetic unit cell is 2a{sub p} x 2b{sub p} x 2c{sub p}, where a{sub p} x a{sub p} x c{sub p} is an ideal unit cell of TlAlF{sub 4}-type. It is found that a quasi-antiferromagnetic phase having a unit cell of 2a{sub p} x 2a{sub p} x c{sub p} is easily induced under a suitable applied field after doing a field cooling of 3 T from 50 K to 2.5 K. The quasi-magnetic structure shows a relaxation dependent on the field strength and the temperature. In the relaxation process, it is found that there is a coexistence of the normal and quasi-antiferromagnetic phases and that the two magnetic phases show a good compensation for a population ratio between two phases made in a used crystal. A metastable magnetic phase transition between the normal and quasi-magnetic phases occurs at about 13 K (T{sub M}). It is also found that only the quasi-magnetic phase shows a critical behavior in the vicinity of the antiferromagnetic phase transition (T{sub N}). It is interpreted that the residual normal antiferromagnetic phases below T{sub M} are made by local structural modulations, which mainly result from an inhomogeneous substitution of Cs with Rb ions in the crystal. (orig.)

  13. Seasonal variability of the drought phenomena in the Danube River catchment area and its relationship with large-scale anomaly patterns in spring

    Science.gov (United States)

    Chelcea, Silvia; Ionita, Monica; Scholz, Patrick; Rimbu, Norel

    2013-04-01

    Seasonal variability of the drought phenomena in the Danube River catchment area and its relationship with the large-scale climate anomaly patterns for the spring season (March-May) is investigated trough a statistical analysis of the self calibrated Palmer drought severity index (scPDSI) and the Standardized Precipitation Evapotranspiration Index (SPEI) and global climate anomaly fields. Empirical orthogonal functions analysis (EOFs) was employed to study the spatio-temporal variability of the drought phenomena over the Danube River catchment area. The first EOF mode (EOF1) for both scPDSI and SPEI shows a monopolar structure with negative loadings all over the catchment area, while the second EOF (EOF2) shows a dipole structure between the western part and the eastern part of the catchment area. A composite analysis reveals that the drought conditions, in spring, over the whole catchment area (corresponding to EOF1) are related to a sea surface temperature pattern characterized by positive SST anomalies over the eastern part of the U.S. coast and the western part of the European coast and negative SST anomalies over the central and the northern part of the Atlantic Ocean. The corresponding atmospheric circulation pattern is characterized by negative Geopotential Height at 500 mb (Z500) over Greenland and positive Z500 anomalies over the central Atlantic Ocean extending up to the whole European continent. Dry (wet) conditions over the western (eastern) part of the Danube River catchment area, related to the second mode of variability (EOF2), are related with a more regional SST pattern characterized by negative SST anomalies over the eastern coast of U.S and the Mediterranean Sea and positive SST anomalies over the western coast of Europe. The corresponding Z500 pattern is characterized by a center of positive Z500 anomalies over the British Isles and the north-western part of Europe and negative Z500 anomalies over the southern part of Europe. A wavelet analysis

  14. [Spatio-temporal variability of habitat quality in Beijing-Tianjin-Hebei Area based on land use change].

    Science.gov (United States)

    Wu, Jian-sheng; Cao, Qi-wen; Shi, Shu-qin; Huang, Xiu-lan; Lu, Zhi-qiang

    2015-11-01

    Land use change is the core content of global change. To achieve sustainable land use planning, it is necessary to evaluate the habitat quality pattern and its spatio-temporal variation resulted from land use change, which can provide basis for the formulation of land management policy. Based on the analysis of land use change from 2000 to 2010, this study investigated the spatio-temporal variation of habitat quality pattern of Beijing-Tianjin-Hebei Area. We used the watershed profile sampling points and spatial autocorrelation analysis based on watershed subdivision. The results showed that the main land use change types from 2000 to 2010 in this area included the transition from cultivated land to construction land, the transition between forest and grassland, and the transition from water bodies to cultivated land. This land use/cover change process led to the decrease of heterogeneity of landscape structure and increase of fragmentation. The overall spatial pattern of habitat quality was that southeast and south areas were relatively lower, while north and west areas were relatively higher. The analysis based on watershed profile showed that the habitat quality of each watershed presented significant difference in each part. Habitat quality of most sampling points degraded in a way, while some improved compared with 2000. In general, the habitat quality of the bottom part of Luanhe River basin, the medium part of Bai-Chaobai-Chaobaixin River basin, the medium and the bottom part of Yongding River basin and medium part of Laozhang-Fudongpai- Beipai River basin were poor and volatile, while other parts were relatively good. There was a decreasing agglomeration characteristic of distribution of habitat quality in Beijing-Tianjin-Hebei Area under the disturbance of human activities. Areas of high habitat quality in 2000 were mainly located in Luanhe River basin and top part of Baihe basin. Areas of low habitat quality were mainly located in medium and bottom part

  15. The effects of landscape variables on the species-area relationship during late-stage habitat fragmentation.

    Science.gov (United States)

    Hu, Guang; Wu, Jianguo; Feeley, Kenneth J; Xu, Gaofu; Yu, Mingjian

    2012-01-01

    Few studies have focused explicitly on the later stages of the fragmentation process, or "late-stage fragmentation", during which habitat area and patch number decrease simultaneously. This lack of attention is despite the fact that many of the anthropogenically fragmented habitats around the world are, or soon will be, in late-stage fragmentation. Understanding the ecological processes and patterns that occur in late-stage fragmentation is critical to protect the species richness in these fragments. We investigated plant species composition on 152 islands in the Thousand Island Lake, China. A random sampling method was used to create simulated fragmented landscapes with different total habitat areas and numbers of patches mimicking the process of late-stage fragmentation. The response of the landscape-scale species-area relationship (LSAR) to fragmentation per se was investigated, and the contribution of inter-specific differences in the responses to late-stage fragmentation was tested. We found that the loss of species at small areas was compensated for by the effects of fragmentation per se, i.e., there were weak area effects on species richness in landscapes due to many patches with irregular shapes and high variation in size. The study also illustrated the importance of inter-specific differences for responses to fragmentation in that the LSARs of rare and common species were differently influenced by the effects of fragmentation per se. In conclusion, our analyses at the landscape scale demonstrate the significant influences of fragmentation per se on area effects and the importance of inter-specific differences for responses to fragmentation in late-stage fragmentation. These findings add to our understanding of the effects of habitat fragmentation on species diversity.

  16. The effects of landscape variables on the species-area relationship during late-stage habitat fragmentation.

    Directory of Open Access Journals (Sweden)

    Guang Hu

    Full Text Available Few studies have focused explicitly on the later stages of the fragmentation process, or "late-stage fragmentation", during which habitat area and patch number decrease simultaneously. This lack of attention is despite the fact that many of the anthropogenically fragmented habitats around the world are, or soon will be, in late-stage fragmentation. Understanding the ecological processes and patterns that occur in late-stage fragmentation is critical to protect the species richness in these fragments. We investigated plant species composition on 152 islands in the Thousand Island Lake, China. A random sampling method was used to create simulated fragmented landscapes with different total habitat areas and numbers of patches mimicking the process of late-stage fragmentation. The response of the landscape-scale species-area relationship (LSAR to fragmentation per se was investigated, and the contribution of inter-specific differences in the responses to late-stage fragmentation was tested. We found that the loss of species at small areas was compensated for by the effects of fragmentation per se, i.e., there were weak area effects on species richness in landscapes due to many patches with irregular shapes and high variation in size. The study also illustrated the importance of inter-specific differences for responses to fragmentation in that the LSARs of rare and common species were differently influenced by the effects of fragmentation per se. In conclusion, our analyses at the landscape scale demonstrate the significant influences of fragmentation per se on area effects and the importance of inter-specific differences for responses to fragmentation in late-stage fragmentation. These findings add to our understanding of the effects of habitat fragmentation on species diversity.

  17. Mapping Fish Community Variables by Integrating Field and Satellite Data, Object-Based Image Analysis and Modeling in a Traditional Fijian Fisheries Management Area

    Directory of Open Access Journals (Sweden)

    Stacy Jupiter

    2011-03-01

    Full Text Available The use of marine spatial planning for zoning multi-use areas is growing in both developed and developing countries. Comprehensive maps of marine resources, including those important for local fisheries management and biodiversity conservation, provide a crucial foundation of information for the planning process. Using a combination of field and high spatial resolution satellite data, we use an empirical procedure to create a bathymetric map (RMSE 1.76 m and object-based image analysis to produce accurate maps of geomorphic and benthic coral reef classes (Kappa values of 0.80 and 0.63; 9 and 33 classes, respectively covering a large (>260 km2 traditional fisheries management area in Fiji. From these maps, we derive per-pixel information on habitat richness, structural complexity, coral cover and the distance from land, and use these variables as input in models to predict fish species richness, diversity and biomass. We show that random forest models outperform five other model types, and that all three fish community variables can be satisfactorily predicted from the high spatial resolution satellite data. We also show geomorphic zone to be the most important predictor on average, with secondary contributions from a range of other variables including benthic class, depth, distance from land, and live coral cover mapped at coarse spatial scales, suggesting that data with lower spatial resolution and lower cost may be sufficient for spatial predictions of the three fish community variables.

  18. Rainfall variability and its impact on large mammal populations in a complex of semi-arid African savanna protected areas

    NARCIS (Netherlands)

    Gandiwa, Edson; Heitkönig, I.M.A.; Eilers, Paul H.C.; Prins, Herbert H.T.

    2016-01-01

    We investigated the rainfall patterns and associated fluctuations of wild large herbivore species in the Great Limpopo Transfrontier Conservation Area (GLTFCA), southern Africa. The study objectives were to: (i) establish the synchrony in rainfall and drought occurrence patterns in Gonarezhou

  19. Effects of canopy structural variables on retrieval of leaf dry matter content and specific leaf area from remotely sensed data

    NARCIS (Netherlands)

    Ali, A.M.; Darvishzadeh, R.; Skidmore, A.K.; van Duren, I.C.

    2016-01-01

    Leaf dry matter content (LDMC) and specific leaf area (SLA) are two important traits in measuring biodiversity. To use remote sensing for the estimation of these traits, it is essential to understand the underlying factors that influence their relationships with canopy reflectance. The effect of

  20. Can benthic foraminifera be used as bio-indicators of pollution in areas with a wide range of physicochemical variability?

    Science.gov (United States)

    Martins, Maria Virgínia Alves; Pinto, Anita Fernandes Souza; Frontalini, Fabrizio; da Fonseca, Maria Clara Machado; Terroso, Denise Lara; Laut, Lazaro Luiz Mattos; Zaaboub, Noureddine; da Conceição Rodrigues, Maria Antonieta; Rocha, Fernando

    2016-12-01

    The Ria de Aveiro, a lagoon located in the NW coast of Portugal, presents a wide range of changes to the natural hydrodynamical and physicochemical conditions induced for instance by works of port engineering and pollution. In order to evaluate the response of living benthic foraminifera to the fluctuations in physicochemical parameters and pollution (metals and TOC), eight sediment samples were collected from canals and salt pans within the Aveiro City, in four different sampling events. During the sampling events, salinity showed the most significant fluctuations among the physicochemical parameters with the maximum range of variation at Troncalhada and Santiago salt pans. Species such as Haynesina germanica, Trochammina inflata and Entzia macrescens were found inhabiting these hypersaline environments with the widest fluctuations of physicochemical parameters. In contrast, Ammonia tepida dominated zones with high concentrations of metals and organic matter and in lower salinity waters. Parameters related to benthic foraminiferal assemblages (i.e., diversity and evenness) were found to significantly decline in stations polluted by metals and characterized by higher TOC content. Foraminiferal density reduced significantly in locations with a wide range of physicochemical temporal variability. This work shows that, even under extreme conditions caused by highly variable physicochemical parameters, benthic foraminiferal assemblages might be used as valuable bioindicators of environmental stress.

  1. [Prevalence of impaired fasting glucose in a working population of Spanish Mediterranean area: influence of sociodemographic variables and healthy habits].

    Science.gov (United States)

    López-González, Ángel Arturo; Manzanero, Zoe; Vicente-Herrero, Ma Teófila; García-Agudo, Sheila; Gil-Llinás, María; Moreno-Morcillo, Francisco

    The impaired fasting glucose (IFG) is an intermediate clinical situation between normal glucose and type 2 diabetes, it is known that 25% of people with IFG progress to type 2 diabetes. Descriptive study in 60,798 Spanish workers. The IFG was determined using the American Diabetes Association (ADA) criteria: 100-125 mg/dl and the World Health Organization (WHO) criteria: 110-125 mg/dl. The influence of sociodemographic variables (age, sex, social class, studies class) and healthy habits (tobacco, alcohol consumption, physical activity, feeding) were evaluated in the IFG prevalence. The IFG prevalence was 3.3% (1.8% in women and 4.5% in men) using the WHO criteria and 11.8% (7% in women and 15.4% in men) using the ADA criteria. The IFG is more common in men and increases with age. People with low socioeconomic status (social classes IV and V, blue collar and primary studies) and poor health habits (smokers, heavy alcohol consumption and low physical activity) have a higher prevalence. The sociodemographic variables and the healthy habits, except consumption of fruits and vegetables, influence the prevalence of IFG.

  2. Spatial and temporal variability of ultrafine particles, NO2, PM2.5, PM2.5 absorbance, PM10 and PMcoarse in Swiss study areas

    Science.gov (United States)

    Eeftens, Marloes; Phuleria, Harish C.; Meier, Reto; Aguilera, Inmaculada; Corradi, Elisabetta; Davey, Mark; Ducret-Stich, Regina; Fierz, Martin; Gehrig, Robert; Ineichen, Alex; Keidel, Dirk; Probst-Hensch, Nicole; Ragettli, Martina S.; Schindler, Christian; Künzli, Nino; Tsai, Ming-Yi

    2015-06-01

    Exposure to outdoor air pollutants remains an important concern in Europe, as limit values for NO2 and PM10 continue to be exceeded. Few studies have addressed the long-term spatial contrasts in PM2.5, PM absorbance, PMcoarse and especially ultrafine particles. This scarcity of data hampers the possibility to conduct epidemiological studies, assessing the health relevance of these markers of potentially harmful pollutants. Air pollution measurements were performed in eight geographically distinct areas of the Swiss Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) in Switzerland. NO2 was measured in all eight areas at 40 sites per area, and PM2.5, PM2.5 absorbance, PM10 and ultrafine particles (particle number concentration (PNC) and lung deposited surface area (LDSA)) were measured in 4 of these areas, at a subset of 20 out of 40 sites. Each site was sampled three times during different seasons of the year, using the same equipment, sampling protocols and the same central facilities for analysis of samples. We assessed the spatial variability between areas and between individual sites, as well as pollution contrasts between the seasons and correlations between different pollutants. Within-area spatial contrasts (defined as the ratio between the 90th and 10th percentile) were highest for NO2 (3.14), moderate for PMcoarse (2.19), PNC (2.00) and PM2.5 absorbance (1.94), and lowest for LDSA (1.63), PM2.5 (1.50) and PM10 (1.46). Concentrations in the larger cities were generally higher than in smaller towns and rural and alpine areas, and were higher in the winter than in the summer and intermediate seasons, for all pollutants. Between-area differences accounted for more variation than within-area differences for all pollutants except NO2 and PMcoarse. Despite substantial within-area contrasts for PNC and LDSA, 74.7% and 83.3% of the spatial variance was attributed to between-area variability, respectively. Coefficients of determination between

  3. Combining land use regression models and fixed site monitoring to reconstruct spatiotemporal variability of NO2 concentrations over a wide geographical area.

    Science.gov (United States)

    Cordioli, M; Pironi, C; De Munari, E; Marmiroli, N; Lauriola, P; Ranzi, A

    2017-01-01

    The epidemiological research benefits from an accurate characterization of both spatial and temporal variability of exposure to air pollution. This work aims at proposing a method to combine the high spatial resolution of Land Use Regression (LUR) models with the high temporal resolution of fixed site monitoring data, to model spatiotemporal variability of NO2 over a wide geographical area in Northern Italy. We developed seasonal LUR models to reconstruct the spatial distribution of a scaling factor that relates local concentrations to those measured at two reference central sites, one for the northern flat area and one for the southern mountain area. We calculated the daily average concentrations at 19 locations spread over the study areas as the product of the local scaling factor and the reference central site concentrations. We evaluated model performance comparing modeled and measured NO2 data. LUR model's R2 ranges from 0.76 to 0.92. The main predictors refers substantially to traffic, industrial land use, buildings volume and altitude a.s.l. The model's performance in reproducing measured concentrations was satisfactory. The temporal variability of concentrations was well captured: Spearman correlation between model and measures was >0.7 for almost all sites. Model's average absolute errors were in the order of 10μgm-3. The model for the southern area tends to overestimate measured concentrations. Our modeling framework was able to reproduce spatiotemporal differences in NO2 concentrations. This kind of model is less data-intensive than usual regional atmospheric models and it may be very helpful to assess population exposure within studies in which individual relevant exposure occurs along periods of days or months. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Application of satellite images analysis to assess the variability of the surface thermal heat island distribution in urban areas

    Science.gov (United States)

    Fudała, Janina; Nádudvari, Ádám; Bronder, Joachim; Fudała, Marta

    2018-01-01

    One of the elements of the urban plans for adapting to climate change is to identify the range the urban heat island (UHI). To a relatively rare ground station network air temperature, one of the possible methods to identify this phenomenon in cities is the analysis of satellite images, and in particular the thermal images surface cities in conjunction with the land-use structure. In the publication is presented the application of indirect methods of determining surface characteristics of heat island in the cities of Upper Silesia Agglomeration on the basis of the analysis of the thermal images from the satellite Landsat for the period 1986-2016. It presents ways to interpret these images depending on the needs of determination the areas sensitive to the impact of the (UHI) and define the areas where adaptation actions to the climate change should be undertaken.

  5. Application of satellite images analysis to assess the variability of the surface thermal heat island distribution in urban areas

    Directory of Open Access Journals (Sweden)

    Fudała Janina

    2018-01-01

    Full Text Available One of the elements of the urban plans for adapting to climate change is to identify the range the urban heat island (UHI. To a relatively rare ground station network air temperature, one of the possible methods to identify this phenomenon in cities is the analysis of satellite images, and in particular the thermal images surface cities in conjunction with the land-use structure. In the publication is presented the application of indirect methods of determining surface characteristics of heat island in the cities of Upper Silesia Agglomeration on the basis of the analysis of the thermal images from the satellite Landsat for the period 1986-2016. It presents ways to interpret these images depending on the needs of determination the areas sensitive to the impact of the (UHI and define the areas where adaptation actions to the climate change should be undertaken.

  6. Temporal dynamics and spatial variability in the enhancement of canopy leaf area under elevated atmospheric CO2

    Science.gov (United States)

    Heather R. McCarthy; Ram Oren; Adrien C. Finzi; David S. Ellsworth; Hyun-Seok Kim; Kurt H. Johnsen; Bonnie Millar

    2007-01-01

    Increased canopy leaf area (L) may lead to higher forest productivity and alter processes such as species dynamics and ecosystem mass and energy fluxes. Few CO2enrichment studies have been conducted in closed canopy forests and none have shown a sustained enhancement of L. We reconstructed 8 years (1996–2003) of L at Duke’s Free Air CO...

  7. The Effects of Landscape Variables on the Species-Area Relationship during Late-Stage Habitat Fragmentation

    OpenAIRE

    Guang Hu; Jianguo Wu; Feeley, Kenneth J.; Gaofu Xu; Mingjian Yu

    2012-01-01

    Few studies have focused explicitly on the later stages of the fragmentation process, or "late-stage fragmentation", during which habitat area and patch number decrease simultaneously. This lack of attention is despite the fact that many of the anthropogenically fragmented habitats around the world are, or soon will be, in late-stage fragmentation. Understanding the ecological processes and patterns that occur in late-stage fragmentation is critical to protect the species richness in these fr...

  8. On the Glyadenovo culture dwellings and certain aspects of the ancient permians adaptation to natural conditions and economic activity peculiarities (BACK TO THE MID-20TH-CENTURY STUDIES BY V.F. GENING

    Directory of Open Access Journals (Sweden)

    Chernykh Elizaveta M.

    2014-03-01

    Full Text Available Typical features of Upper-Kama dwellings characteristic of the final stage of the Early Iron Age, which have become a “calling card” of the Glyadenovo cultural community (the so-called Fedotovo type, are analyzed in the article. In the past half-century, the data on dwellings investigated by V.F. Gening at the Fedotovo fortified settlement have been substantially completed by materials from the newly-excavated settlements. It is suggested that the differences in dwelling construction technology on different Glyadenovo culture sites cannot be invariably regarded as cultural and chronological features but often bear an adaptive character, i.e. depend on the natural environment. The version of the Fedotovo dwellings reconstruction proposed in the early works by V.F. Gening also needs some correction, which is offered by the author in accordance with a number of features.

  9. Recovery trajectories of kelp forest animals are rapid yet spatially variable across a network of temperate marine protected areas

    Science.gov (United States)

    Caselle, Jennifer E.; Rassweiler, Andrew; Hamilton, Scott L.; Warner, Robert R.

    2015-09-01

    Oceans currently face a variety of threats, requiring ecosystem-based approaches to management such as networks of marine protected areas (MPAs). We evaluated changes in fish biomass on temperate rocky reefs over the decade following implementation of a network of MPAs in the northern Channel Islands, California. We found that the biomass of targeted (i.e. fished) species has increased consistently inside all MPAs in the network, with an effect of geography on the strength of the response. More interesting, biomass of targeted fish species also increased outside MPAs, although only 27% as rapidly as in the protected areas, indicating that redistribution of fishing effort has not severely affected unprotected populations. Whether the increase outside of MPAs is due to changes in fishing pressure, fisheries management actions, adult spillover, favorable environmental conditions, or a combination of all four remains unknown. We evaluated methods of controlling for biogeographic or environmental variation across networks of protected areas and found similar performance of models incorporating empirical sea surface temperature versus a simple geographic blocking term based on assemblage structure. The patterns observed are promising indicators of the success of this network, but more work is needed to understand how ecological and physical contexts affect MPA performance.

  10. Recovery trajectories of kelp forest animals are rapid yet spatially variable across a network of temperate marine protected areas.

    Science.gov (United States)

    Caselle, Jennifer E; Rassweiler, Andrew; Hamilton, Scott L; Warner, Robert R

    2015-09-16

    Oceans currently face a variety of threats, requiring ecosystem-based approaches to management such as networks of marine protected areas (MPAs). We evaluated changes in fish biomass on temperate rocky reefs over the decade following implementation of a network of MPAs in the northern Channel Islands, California. We found that the biomass of targeted (i.e. fished) species has increased consistently inside all MPAs in the network, with an effect of geography on the strength of the response. More interesting, biomass of targeted fish species also increased outside MPAs, although only 27% as rapidly as in the protected areas, indicating that redistribution of fishing effort has not severely affected unprotected populations. Whether the increase outside of MPAs is due to changes in fishing pressure, fisheries management actions, adult spillover, favorable environmental conditions, or a combination of all four remains unknown. We evaluated methods of controlling for biogeographic or environmental variation across networks of protected areas and found similar performance of models incorporating empirical sea surface temperature versus a simple geographic blocking term based on assemblage structure. The patterns observed are promising indicators of the success of this network, but more work is needed to understand how ecological and physical contexts affect MPA performance.

  11. Optimization of operating variables for production of ultra-fine talc in a stirred mill. Specific surface area investigations

    Directory of Open Access Journals (Sweden)

    Toraman Oner Yusuf

    2016-01-01

    Full Text Available Due to its properties such as chemical inertness, softness, whiteness, high thermal conductivity, low electrical conductivity and adsorption properties talc has wide industrial applications in paper, cosmetics, paints, polymer, ceramics, refractory materials and pharmaceutical. The demand for ultra-fine talc is emerging which drives the mineral industry to produce value added products. In this study, it was investigated how certain grinding parameters such as mill speed, ball filling ratio, powder filling ratio and grinding time of dry stirred mill affect grindability of talc ore (d97=127 μm. A series of laboratory experiments using a 24 full factorial design was conducted to determine the optimal operational parameters of a stirred mill in order to minimize the specific surface area. The main and interaction effects on the volume specific surface area (SV, m2.cm−3 of the ground product were evaluated using the Yates analysis. Under the optimal conditions at the stirrer speed of 600 rpm, grinding time of 20 min, sample mass of 5% and ball ratio of 70%, the resulting talc powder had larger volume specific surface area (i.e., 3.48 m2.cm−3 than the starting material (i.e., 1.84 m2.cm−3.

  12. Diel variability of feeding activity in haddock ( Melanogrammus aeglefinus ) larvae in the East Shetland area, North Sea

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Ueberschar, B.; Basford, D.

    1999-01-01

    aeglifinus) larvae four times per day during a 10-d cruise in the northern North Sea. Feeding activity was evaluated using indices of gut fullness, prey digestive state and biochemical measurements (tryptic enzyme activity). The gut fullness and the enzyme activity indices indicated moderate to high rates...... of food consumption throughout the cruise. Time series analysis of the three indices showed significant diel variability in all indices and enabled identification of significant lags between food uptake and peak digestive enzyme activity. The typical pattern of food consumption and digestion...... was characterized by maximal ingestion of prey early in the evening (19:00 hrs) and peak digestive enzyme activity at 01:00 hrs. The time scale over which enzyme activities reacted to prey ingestion was ca. 6 h, and is consistent with expectations from controlled laboratory experiments with other larval fish...

  13. Environmental variables associated with anopheline larvae distribution and abundance in Yanomami villages within unaltered areas of the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Jordi Sánchez-Ribas

    2017-11-01

    Full Text Available Abstract Background Many indigenous villages in the Amazon basin still suffer from a high malaria burden. Despite this health situation, there are few studies on the bionomics of anopheline larvae in such areas. This publication aims to identify the main larval habitats of the most abundant anopheline species and to assess their associations with some environmental factors. Methods We conducted a 19-month longitudinal study from January 2013 to July 2014, sampling anopheline larvae in two indigenous Yanomami communities, comprised of four villages each. All natural larval habitats were surveyed every two months with a 350 ml manual dipper, following a standardized larval sampling methodology. In a third study area, we conducted two field expeditions in 2013 followed by four systematic collections during the long dry season of 2014–2015. Results We identified 177 larval habitats in the three study areas, from which 9122 larvae belonging to 13 species were collected. Although species abundance differed between villages, An. oswaldoi (s.l. was overall the most abundant species. Anopheles darlingi, An. oswaldoi (s.l., An. triannulatus (s.s. and An. mattogrossensis were primarily found in larval habitats that were partially or mostly sun-exposed. In contrast, An. costai-like and An. guarao-like mosquitoes were found in more shaded aquatic habitats. Anopheles darlingi was significantly associated with proximity to human habitations and larval habitats associated with river flood pulses and clear water. Conclusions This study of anopheline larvae in the Brazilian Yanomami area detected high heterogeneities at micro-scale levels regarding species occurrence and densities. Sun exposure was a major modulator of anopheline occurrence, particularly for An. darlingi. Lakes associated with the rivers, and particularly oxbow lakes, were the main larval habitats for An. darlingi and other secondary malaria vectors. The results of this study will serve as a

  14. Area-Selective ZnO Thin Film Deposition on Variable Microgap Electrodes and Their Impact on UV Sensing

    Directory of Open Access Journals (Sweden)

    Q. Humayun

    2013-01-01

    Full Text Available ZnO thin films were deposited on patterned gold electrodes using the sol-gel spin coating technique. Conventional photolithography process was used to obtain the variable microgaps of 30 and 43 μm in butterfly topology by using zero-gap chrome mask. The structural, morphological, and electrical properties of the deposited thin films were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, and Keithley SourceMeter, respectively. The current-voltage (I-V characterization was performed to investigate the effect of UV light on the fabricated devices. The ZnO fabricated sensors showed a photo to dark current (Iph/Id ratios of 6.26 for 30 μm and 5.28 for 43 μm gap electrodes spacing, respectively. Dynamic responses of both fabricated sensors were observed till 1V with good reproducibility. At the applied voltage of 1 V, the response time was observed to be 4.817 s and 3.704 s while the recovery time was observed to be 0.3738 s and 0.2891 s for 30 and 43 μm gaps, respectively. The signal detection at low operating voltages suggested that the fabricated sensors could be used for miniaturized devices with low power consumption.

  15. Geophysical variables and behavior: LIII. Epidemiological considerations for incidence of cancer and depression in areas of frequent UFO reports.

    Science.gov (United States)

    Persinger, M A

    1988-12-01

    Luminous phenomena and anomalous physical forces have been hypothesized to be generated by focal tectonic strain fields that precede earthquakes. If these geophysical processes exist, then their spatial and temporal density should be greatest during periods of protracted, localized UFO reports; they might be used as dosimetric indicators. Contemporary epidemiological data concerning the health risks of power frequency electromagnetic fields and radon gas levels (expected correlates of certain tectonic strain fields), suggest that increased incidence (odds ratios greater 1:3) of brain tumors and leukemia should be evident within "flap" areas. In addition the frequency of variants of temporal lobe lability, psychological depression and posttraumatic stress should be significantly elevated. UFO field investigators, because they have repeated, intermittent close proximity to these fields, are considered to be a particularly high risk population for these disorders.

  16. [Tuberculosis in a primary care center in a socioeconomically depressed area: variables associated with giving up treatment].

    Science.gov (United States)

    Solá, M; Gardella, A; Llauger, M A; Muñoz, J; Birulés, M; Foz, G

    1990-06-01

    We report the features of 72 patients with tuberculosis of a low socioeconomical level, seen at the primary care center of Perecamps (Barcelona). We identify the factors associated with giving up therapy. We found a predominance of males and of the 40-59 years age group. In 1988 we found an increased rate of young patients (20-39 years) and PDA/HIV+. Twenty-five patients (35%) had had previous episodes of tuberculosis. 19 had had inadequate chemotherapy because of abandonment. The rate of follow-up losses was high (36%). A history of previous PDA/HIV+ were associated with giving up therapy. We indicate the several measures to be applied in our area to improve compliance with chemotherapy in patients with tuberculosis.

  17. Representation of fine scale atmospheric variability in a nudged limited area quasi-geostrophic model: application to regional climate modelling

    Science.gov (United States)

    Omrani, H.; Drobinski, P.; Dubos, T.

    2009-09-01

    In this work, we consider the effect of indiscriminate nudging time on the large and small scales of an idealized limited area model simulation. The limited area model is a two layer quasi-geostrophic model on the beta-plane driven at its boundaries by its « global » version with periodic boundary condition. This setup mimics the configuration used for regional climate modelling. Compared to a previous study by Salameh et al. (2009) who investigated the existence of an optimal nudging time minimizing the error on both large and small scale in a linear model, we here use a fully non-linear model which allows us to represent the chaotic nature of the atmosphere: given the perfect quasi-geostrophic model, errors in the initial conditions, concentrated mainly in the smaller scales of motion, amplify and cascade into the larger scales, eventually resulting in a prediction with low skill. To quantify the predictability of our quasi-geostrophic model, we measure the rate of divergence of the system trajectories in phase space (Lyapunov exponent) from a set of simulations initiated with a perturbation of a reference initial state. Predictability of the "global", periodic model is mostly controlled by the beta effect. In the LAM, predictability decreases as the domain size increases. Then, the effect of large-scale nudging is studied by using the "perfect model” approach. Two sets of experiments were performed: (1) the effect of nudging is investigated with a « global » high resolution two layer quasi-geostrophic model driven by a low resolution two layer quasi-geostrophic model. (2) similar simulations are conducted with the two layer quasi-geostrophic LAM where the size of the LAM domain comes into play in addition to the first set of simulations. In the two sets of experiments, the best spatial correlation between the nudge simulation and the reference is observed with a nudging time close to the predictability time.

  18. Deglacial-Holocene variability in sea ice, primary productivity, and sea-level change in the Pacific-Arctic gateway area

    Science.gov (United States)

    Stein, R. H.; Méheust, M.; Manurung, A.; Schade, I.; Fahl, K.; Niessen, F.; Nam, S.

    2013-12-01

    Sea-ice is an essential component of the global climate system and, especially, the Polar Oceans. An alarming decrease in term of sea-ice concentration, thickness and duration, has been observed in the Arctic Ocean and its marginal seas over the last 30 years. Thus, understanding the processes controlling modern sea-ice variability and reconstructing paleo-sea-ice extent and variability in polar regions have become of great interest for the international scientific community during the last years. Here, we present new high-resolution proxy records from the Chukchi-Bering Sea area - including organic geochemical bulk parameters, specific biomarkers (IP25, sterols, alkenones), biogenic opal, etc. - that give new insight into the sea-ice variability and related changes in sea-surface temperatures, primary productivity, sea-level change, and terrigenous input during deglacial-Holocene times. Such proxy records representing natural climate variability in the past on time scales going back in time beyond the period of direct measurements and observations, might be used to test the reliability of climate models for forecasting future climate change. Map of core locations

  19. Effect of site level environmental variables, spatial autocorrelation and sampling intensity on arthropod communities in an ancient temperate lowland woodland area.

    Science.gov (United States)

    Horak, Jakub

    2013-01-01

    The interaction of arthropods with the environment and the management of their populations is a focus of the ecological agenda. Spatial autocorrelation and under-sampling may generate bias and, when they are ignored, it is hard to determine if results can in any way be trusted. Arthropod communities were studied during two seasons and using two methods: window and panel traps, in an area of ancient temperate lowland woodland of Zebracka (Czech Republic). The composition of arthropod communities was studied focusing on four site level variables (canopy openness, diameter in the breast height and height of tree, and water distance) and finally analysed using two approaches: with and without effects of spatial autocorrelation. I found that the proportion of variance explained by space cannot be ignored (≈20% in both years). Potential bias in analyses of the response of arthropods to site level variables without including spatial co-variables is well illustrated by redundancy analyses. Inclusion of space led to more accurate results, as water distance and tree diameter were significant, showing approximately the same ratio of explained variance and direction in both seasons. Results without spatial co-variables were much more disordered and were difficult to explain. This study showed that neglecting the effects of spatial autocorrelation could lead to wrong conclusions in site level studies and, furthermore, that inclusion of space may lead to more accurate and unambiguous outcomes. Rarefactions showed that lower sampling intensity, when appropriately designed, can produce sufficient results without exploitation of the environment.

  20. Variability of 550 nm MODIS-retrieved Aerosol Optical Depth over Urban and Rural Areas in the Philippines from 2005 to 2015

    Science.gov (United States)

    Vallar, E. A.; Castilla, R. M.; Santillices, J. S.; Eneria, R. B. A.; Galvez, M. C. D.

    2016-12-01

    This study determined the temporal variability and spatial variability of aerosol optical depth (AOD) in urban and rural areas in the Philippines. It was investigated using the Level 3 daily global gridded (1 deg by 1 deg) 550 nm wavelength aerosol data retrieved by the MODerate Resolution Imaging Spectroradiometer (MODIS) on-board NASA's Terra satellite. Monthly, inter-annual and seasonal variations of AOD values were examined. The results revealed that the distribution of aerosols was largely affected by topography and local economic activities. The average AOD value for the eleven-year study is 0.19. Generally, high AODs are distributed in urban areas which constitute high population density and heavy aerosol loading. Moreover, the highest value of AOD was observed in Regions XI and XII on October 2015. AOD in the wet season (June - November) is relatively higher compared to the dry season (December - May) in both rural and urban areas. On average, year 2005 has the highest AOD value recorded. Determining aerosol temporal and spatial patterns can improve the atmospheric correction of remotely sensed surface features, monitoring the sources and sinks of aerosols, observing air quality and detection of biomass burning, volcanic eruptions and forest fire.

  1. Association of Lutzomyia longipalpis (Diptera: Psychodidae population density with climate variables in Montes Claros, an area of American visceral leishmaniasis transmission in the state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Érika Monteiro Michalsky

    2009-12-01

    Full Text Available In the present paper, we evaluate the relationship between climate variables and population density of Lutzomyia longipalpis in Montes Claros, an area of active transmission of American visceral leishmaniasis (AVL in Brazil. Entomological captures were performed in 10 selected districts of the city, between September 2002-August 2003. A total of 773 specimens of L. longipalpiswere captured in the period and the population density could be associated with local climate variables (cumulative rainfall, average temperature and relative humidity through a mathematical linear model with a determination coefficient (Rsqr of 0.752. Although based on an oversimplified statistical analysis, as far as the vector is concerned, this approach showed to be potentially useful as a starting point to guide control measures for AVL in Montes Claros.

  2. Present and past Gulf Stream variability in a cold-water coral area off Cape Lookout, West Atlantic

    Science.gov (United States)

    Mienis, F.; Pedersen, A.; Duineveld, G.; Seidenkrantz, M.; Fischel, A.; Matos, L.; Bane, J. M.; Frank, N.; Hebbeln, D.; Ross, S.

    2012-12-01

    Cold-water coral mounds are common on the SE slope of the US from Florida to Cape Hatteras between depths of 400-600 m. All coral areas lie in the vicinity of the Gulf Stream, which is characterized by strong currents transporting relatively warm water northwards. Thus far little is known about the recent and past environmental conditions inside the cold-water coral habitats on the SE US slope and particularly the effect of changing patterns of the Gulf Stream. Near Cape Lookout, which is the northern most cold-water coral area on the SE US slope, cold-water corals have formed mounds up to 60 m high with a tear drop shape, which are oriented in a SSW-NNE direction. Past explorations of major reef sites of N Carolina using remote and manned submersibles have shown living Lophelia pertusa colonies on the current facing side of the mound structures and a high biodiversity of associated fauna, especially fish. Two autonomous benthic landers were deployed amidst Lophelia reefs off Cape Lookout (NC) for a period of 6 months to define oceanographic patterns that are relevant for the development and persistence of cold-water coral ecosystems. Furthermore, a 3.6 m long piston core was collected in 2010 during a cruise with the R.V. Pelagia. This pistoncore was used to determine the changes of current strength through time, using foraminiferal counts, stable oxygen and carbon isotopes on foraminifera, XRF and magnetic susceptibility measurements. Cold-water coral fragments were dated with U/Th and foraminifera from the same depth interval were dated with C14. Bottom landers have recorded a number of events that are characterized by of peaks in temperature and salinity, coinciding with increased flow and turbidity. The current during these events was directed to the NNE. During some of these events temperature rose up to 9 degrees in one day. The temporary replacement of the colder bottom water by warm (and saline) water in combination with the strong currents to the NNE

  3. Vulnerability Assessment of Mangrove Habitat to the Variables of the Oceanography Using CVI Method (Coastal Vulnerability Index) in Trimulyo Mangrove Area, Genuk District, Semarang

    Science.gov (United States)

    Ahmad, Rifandi Raditya; Fuad, Muhammad

    2018-02-01

    Some functions of mangrove areas in coastal ecosystems as a green belt, because mangrove serves as a protector of the beach from the sea waves, as a good habitat for coastal biota and for nutrition supply. Decreased condition or degradation of mangrove habitat caused by several oceanographic factors. Mangrove habitats have some specific characteristics such as salinity, tides, and muddy substrates. Considering the role of mangrove area is very important, it is necessary to study about the potential of mangrove habitat so that the habitat level of mangrove habitat in the east coast of Semarang city is known. The purpose of this research is to obtain an index and condition of habitat of mangrove habitat at location of research based on tidal, salinity, substrate type, coastline change. Observation by using purposive method and calculation of habitat index value of mangrove habitat using CVI (Coastal Vulnerability Index) method with scores divided into 3 groups namely low, medium and high. The results showed that there is a zone of research belonging to the medium vulnerability category with the most influential variables is because there is abrasion that sweeps the mangrove substrate. Trimulyo mangrove habitat has high vulnerable variable of tidal frequency, then based on value variable Salinity is categorized as low vulnerability, whereas for mangrove habitat vulnerability based on variable type of substrate belong to low and medium vulnerability category. The CVI values of mangrove habitats divided into zones 1; 2; and 3 were found to varying values of 1.54; 3.79; 1.09, it indicates that there is a zone with the vulnerability of mangrove habitat at the study site belonging to low and medium vulnerability category.

  4. Assessment of morphological variability and chemical composition of some local pepper (Capsicum annuum L. populations on the area of Kosovo

    Directory of Open Access Journals (Sweden)

    Sali A Aliu

    2017-09-01

    Full Text Available Seven local pepper populations (Capsicum annuum L. from different geographical regions of Kosovo, were evaluated for morphological traits, chemical composition, and antioxidant contents using standard analytical techniques. All local peppers populations were characterized for different morphological traits from seedling emergence to crop maturity. The total genetic variation for plant height (PH was 11.72 cm or expressed in relative values was 27.94 %. Average of leaf area (LA per plant was 2308.38 cm2, while the lowest value for LA was 1136 cm2. Yield per plant ranged from 265 to 691 g plant-1. The   acidity level was ranging from 1.44 to 1.61 %, carbohydrates varied greatly from 4.21 to 6.07 %. Vitamin C (as ascorbic acid content in fresh fruit ranged from 65.544 to 520.51 mg 100g-1 of fresh mass. Minerals were of reasonable levels with Fe (15.31 mg kg-1, Ca (216.71 mg kg-1, Na (406.01 mg kg-1, K (1851 mg kg-1, and Zn (5.74 mg kg-1.

  5. Variability of the groundwater sulfate concentration in fractured rock slopes: a tool to identify active unstable areas

    Directory of Open Access Journals (Sweden)

    S. Binet

    2009-12-01

    Full Text Available Water chemical analysis of 100 springs from the Orco and the Tinée valleys (Western Italy and Southern France and a 7 year groundwater chemistry monitoring of the 5 main springs were performed. All these springs drain from crystalline rock slopes. Some of these drain from currently active gravitational slope deformations.

    All groundwaters flowing through presently unstable slopes show anomalies in the sulfate concentrations compared to stable aquifers. Particularly, an increase of sulfate concentrations was observed repeatedly after each of five consecutive landslides on the La Clapière slope, thus attesting to the mechanical deformations are at the origin of this concentration change. Significant changes in the water chemistry are produced even from slow (mm/year and low magnitude deformations of the geological settings.

    Pyrite nuclei in open fractures were found to be coated by iron oxides. This suggests that the increase of dissolved sulfate relates to oxidative dissolution of Pyrite. Speciation calculations of Pyrite versus Gypsum confirmed that observed changes in the sulfate concentrations is predominantly provided from Pyrite. Calculated amounts of dissolved minerals in the springs water was obtained through inverse modelling of the major ion water analysis data. It is shown that the concentration ratio of calculated dissolved Pyrite versus calculated dissolved gneiss rock allows us to unambiguously distinguish water from stable and unstable areas. This result opens an interesting perspective for the follow-up of sliding or friction dynamic in landslides or in (a seismic faults.

  6. Phytoplankton variability and community structure in relation to hydrographic features in the NE Aegean frontal area (NE Mediterranean Sea)

    Science.gov (United States)

    Lagaria, A.; Mandalakis, M.; Mara, P.; Frangoulis, C.; Karatsolis, B.-Th.; Pitta, P.; Triantaphyllou, M.; Tsiola, A.; Psarra, S.

    2017-10-01

    The structure of phytoplankton community in the salinity-stratified Northeastern Aegean frontal area adjacent to the Dardanelles Straits was investigated on a seasonal basis (autumn, spring and summer) and in relation to circulating water masses: the modified Black Sea Water (BSW) and the Levantine Water (LW). By employing High Performance Liquid Chromatography (HPLC) for the analysis of phytoplankton pigments in conjunction with conventional cell counting methodologies (i.e. inverted light microscopy, flow cytometry) and primary production measurements, a comprehensive qualitative and quantitative characterization of phytoplankton community composition and its activity was conducted. Chlorophyll-a normalized production and estimated growth rates presented the highest values within the 'fresh' BSW mass during summer, though generally growth rates were low (<0.4 d-1) at all seasons. The spatiotemporal variation of BSW outflow was found to greatly affect the relative contribution of pico-, nano- and micro-phytoplankton to total phytoplankton biomass and production. Large cell organisms, and in particular diatoms, were closely associated with the surface BSW masses outflowing from the Straits. Our results showed that all phytoplankton size components were significant over time and space suggesting a rather multivorous food web functioning of the system.

  7. Atmospheric aerosol variability above the Paris Area during the 2015 heat wave - Comparison with the 2003 and 2006 heat waves

    Science.gov (United States)

    Chazette, Patrick; Totems, Julien; Shang, Xiaoxia

    2017-12-01

    The aerosol layers during the heat wave of July 2015 over Paris Area have been studied using a N2-Raman lidar with co- and cross-polarized channels. The lidar observations are examined to allow the identification of main aerosol types and their origins, in synergy with measurements of the AERONET sunphotometer network and back trajectory studies from the HYSPLIT model. The results are compatible with spaceborne observations of MODIS and CALIOP. As for previous heat waves of August 2003 and July 2006 occurring in France, the aerosol optical thickness is very large, up to 0.8 at the lidar wavelength of 355 nm (between 0.5 and 0.7 at 550 nm). However, air mass trajectories highlight that the observed aerosol layers may have multiple and diverse origins during the 2015 heat wave (North America, Northwest Africa, Southern and Northern Europe). Biomass burning, pollution and desert dust aerosols have been identified, using linear particle depolarization ratio, lidar ratio and analysis of back trajectories initiated at the altitudes and arrival times of the plumes. These layers are elevated and are shown to have little impact on surface aerosol concentrations (PM10 albedo distributions at 550 nm: 0.90 ± 0.03, 0.95 ± 0.02 and 0.93 ± 0.04 for 2003, 2006 and 2015, respectively.

  8. A study of the hourly variability of the urban heat island effect in the Greater Athens Area during summer.

    Science.gov (United States)

    Kourtidis, K; Georgoulias, A K; Rapsomanikis, S; Amiridis, V; Keramitsoglou, I; Hooyberghs, H; Maiheu, B; Melas, D

    2015-06-01

    Measurements of air temperature and humidity in the urban canopy layer during July 2009 in 26 sites in Athens, Greece, allowed for the mapping of the hourly spatiotemporal evolution of the urban heat island (UHI) effect. City districts neighboring to the mountains to the east were the hottest during the afternoon, while being among the coolest during the early morning hours. While during the early morning some coastal sites were the hottest, the warm air plume slowly moved to the densely urbanized center of the city until 14:00-15:00, moving then further west, to the Elefsis industrial area in the afternoon. Results from the UrbClim model agree fairly well with the observations. Satellite-derived land surface temperature (LST) data from AATSR, ASTER, AVHRR and MODIS, for pixels corresponding to ground stations measuring Tair, showed that LST can be up to 5K lower than the respective Tair during nighttime, while it can be up to 15K higher during the rest of the day. Generally, LST during late afternoon as acquired from AATSR is very near to Tair for all stations and all days, i.e., the AATSR LST afternoon retrieval can be used as a very good approximation of Tair. The hourly evolution of the spatial Tair distribution was almost the same during days with NE Etesian flow as in days with sea breeze circulation, indicating that the mean wind flow was not the main factor controlling the diurnal UHI evolution, although it influenced the temperatures attained. No unambiguous observation of the urban moisture excess (UME) phenomenon could be made. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The age of second language acquisition determines the variability in activation elicited by narration in three languages in Broca's and Wernicke's area.

    Science.gov (United States)

    Bloch, Constantine; Kaiser, Anelis; Kuenzli, Esther; Zappatore, Daniela; Haller, Sven; Franceschini, Rita; Luedi, Georges; Radue, Ernst-Wilhelm; Nitsch, Cordula

    2009-02-01

    It is generally accepted that the presence of a second language (L2) has an impact on the neuronal substrates build up and used for language processing; the influence of the age of L2 exposure, however, is not established. We tested the hypothesis that the age of L2 acquisition has an effect on the cortical representation of a multilingual repertoire in 44 multilinguals with different age of exposure to a L2 (simultaneous or covert simultaneous exposure to L1 and L2, sequential acquisition of L1 and L2 between 1 and 5 years, late learning of L2 after 9 years of age) and all fluent in a late learned L3. Regional activation in a language production task showed a high in-between-subject variability, which was higher than within-subject variability between L1, L2, and L3. We, therefore, performed a single subject analysis and calculated the within-subject variance in the numbers of activated voxels in Broca's and Wernicke's area. Subjects with early exposure to L2 showed low variability in brain activation in all three languages, in the two early as well as the late learned language. In contrast, late multilinguals exhibited higher variability. Thus, cerebral representation of languages is linked to the age of L2 acquisition: early exposure to more than one language gives rise to a language processing network that is activated homogeneously by early and late learned languages, while the inhomogeneous activation in late multilinguals indicates more independent access to the multilingual repertoire. Early passive exposure to L2 results in the same low variance as active bilingual upbringing. Variability in local brain activity increases progressively from the simultaneous to late L2 exposure, indicating a gradual transition from the mode of early bilingual language representation to that of late ones.

  10. Variable wind, pack ice, and prey dispersion affect the long-term adequacy of protected areas for an Arctic sea duck.

    Science.gov (United States)

    Lovvorn, James R; Anderson, Eric M; Rocha, Aariel R; Larned, William W; Grebmeier, Jacqueline M; Cooper, Lee W; Kolts, Jason M; North, Christopher A

    2014-03-01

    With changing climate, delineation of protected areas for sensitive species must account for long-term variability and geographic shifts of key habitat elements. Projecting the future adequacy of protected areas requires knowing major factors that drive such changes, and how readily the animals adjust to altered resources. In the Arctic, the viability of habitats for marine birds and mammals often depends on sea ice to dissipate storm waves and provide platforms for resting. However, some wind conditions (including weak winds during extreme cold) can consolidate pack ice into cover so dense that air-breathing divers are excluded from the better feeding areas. Spectacled Eiders (Somateria fischeri) winter among leads (openings) in pack ice in areas where densities of their bivalve prey are quite high. During winter 2009, however, prevailing winds created a large region of continuous ice with inadequate leads to allow access to areas of dense preferred prey. Stable isotope and fatty acid biomarkers indicated that, under these conditions, the eiders did not diversify their diet to include abundant non-bivalve taxa but did add a smaller, less preferred, bivalve species. Consistent with a computer model of eider energy balance, the body fat of adult eiders in 2009 was 33-35% lower than on the same date (19 March) in 2001 when ice conditions allowed access to higher bivalve densities. Ice cover data suggest that the eiders were mostly excluded from areas of high bivalve density from January to March in about 30% of 14 winters from 1998 to 2011. Thus, even without change in total extent of ice, shifts in prevailing winds can alter the areal density of ice to reduce access to important habitats. Because changes in wind-driven currents can also rearrange the dispersion of prey, the potential for altered wind patterns should be an important concern in projecting effects of climate change on the adequacy of marine protected areas for diving endotherms in the Arctic.

  11. Seasonal and spatial variability of appendicularian density and taxonomic composition in the Caravelas Estuary (Northeastern Brazil and adjacent coastal area

    Directory of Open Access Journals (Sweden)

    Pedro Freitas de Carvalho

    2010-02-01

    Full Text Available This study aimed to identify and assess the seasonal and spatial variations of the appendicularians in the Caravelas River estuary and the adjacent coastal area. Samples were taken during 12 campaigns over five years (2001 and 2003-2006. Ten species were identified; the most abundant were Oikopleura dioica, Oikopleura rufescens, and Oikopleura longicauda. These species represented more than 95% of the total numbers of appendicularians. The remaining species were less frequent and occurred in low densities. The mean density of appendicularians found at the coastal stations (804 ind.m-3. was higher than in the estuary (66 ind.m-3. However, the differences observed between the estuary and coastal stations were not significant (p=0.54. The samples taken during the dry season showed a higher mean density (587 ind.m-3 than in the rainy season (376 ind.m-3, and the differences between the seasons were statistically significant (p=0.004.Esse trabalho teve como objetivo identificar e avaliar as variações espaciais e sazonais das apendiculárias no estuário do rio Caravelas e área costeira adjacente (17º35' - 18º22' S e 39º8' - 39º55'W. As coletas foram realizadas em 12 campanhas durante cinco anos (2001 e 2003 - 2006. Foram identificadas dez espécies, sendo que Oikopleura dioica, O. rufescens e O. longicauda foram as mais abundantes. Estas três espécies representaram mais de 95% do total de apendiculárias coletadas. As outras espécies foram menos freqüentes e ocorreram em baixas densidades. A densidade média de apendiculárias encontrada nas estações e costeiras (804 ind.m-3 foi maior que na de estuário (158 ind.m-3. As diferenças encontradas entre as estações de estuário e costeiras não foram significativas (p=0,73. As campanhas realizadas durante o período seco apresentaram densidade média (587 ind.m-3 maior que do período chuvoso (376 ind.m-3. As diferenças entre os períodos chuvoso e seco foram estatisticamente

  12. Beyond imperviousness: A statistical approach to identifying functional differences between development morphologies on variable source area-type response in urbanized watersheds

    Science.gov (United States)

    Lim, T. C.

    2016-12-01

    Empirical evidence has shown linkages between urbanization, hydrological regime change, and degradation of water quality and aquatic habitat. Percent imperviousness, has long been suggested as the dominant source of these negative changes. However, recent research identifying alternative pathways of runoff production at the watershed scale have called into question percent impervious surface area's primacy in urban runoff production compared to other aspects of urbanization including change in vegetative cover, imported water and water leakages, and the presence of drainage infrastructure. In this research I show how a robust statistical methodology can detect evidence of variable source area (VSA)-type hydrologic response associated with incremental hydraulic connectivity in watersheds. I then use logistic regression to explore how evidence of VSA-type response relates to the physical and meterological characteristics of the watershed. I find that impervious surface area is highly correlated with development, but does not add significant explanatory power beyond percent developed in predicting VSA-type response. Other aspects of development morphology, including percent developed open space and type of drainage infrastructure also do not add to the explanatory power of undeveloped land in predicting VSA-type response. Within only developed areas, the effect of developed open space was found to be more similar to that of total impervious area than to undeveloped land. These findings were consistent when tested across a national cross-section of urbanized watersheds, a higher resolution dataset of Baltimore Metropolitan Area watersheds, and a subsample of watersheds confirmed not to be served by combined sewer systems. These findings suggest that land development policies that focus on lot coverage should be revisited, and more focus should be placed on preserving native vegetation and soil conditions alongside development.

  13. Evaluation of the U.S. Geological Survey Landsat burned area essential climate variable across the conterminous U.S. using commercial high-resolution imagery

    Science.gov (United States)

    Vanderhoof, Melanie; Brunner, Nicole M.; Beal, Yen-Ju G.; Hawbaker, Todd J.

    2017-01-01

    The U.S. Geological Survey has produced the Landsat Burned Area Essential Climate Variable (BAECV) product for the conterminous United States (CONUS), which provides wall-to-wall annual maps of burned area at 30 m resolution (1984–2015). Validation is a critical component in the generation of such remotely sensed products. Previous efforts to validate the BAECV relied on a reference dataset derived from Landsat, which was effective in evaluating the product across its timespan but did not allow for consideration of inaccuracies imposed by the Landsat sensor itself. In this effort, the BAECV was validated using 286 high-resolution images, collected from GeoEye-1, QuickBird-2, Worldview-2 and RapidEye satellites. A disproportionate sampling strategy was utilized to ensure enough burned area pixels were collected. Errors of omission and commission for burned area averaged 22 ± 4% and 48 ± 3%, respectively, across CONUS. Errors were lowest across the western U.S. The elevated error of commission relative to omission was largely driven by patterns in the Great Plains which saw low errors of omission (13 ± 13%) but high errors of commission (70 ± 5%) and potentially a region-growing function included in the BAECV algorithm. While the BAECV reliably detected agricultural fires in the Great Plains, it frequently mapped tilled areas or areas with low vegetation as burned. Landscape metrics were calculated for individual fire events to assess the influence of image resolution (2 m, 30 m and 500 m) on mapping fire heterogeneity. As the spatial detail of imagery increased, fire events were mapped in a patchier manner with greater patch and edge densities, and shape complexity, which can influence estimates of total greenhouse gas emissions and rates of vegetation recovery. The increasing number of satellites collecting high-resolution imagery and rapid improvements in the frequency with which imagery is being collected means greater opportunities to utilize these sources

  14. Estimation of Land Surface Temperature for the Quantitative Analysis of Land Cover of Lower Areas of Sindh to Assess the Impacts of Climate Variability

    Science.gov (United States)

    Qaisar, Maha

    2016-07-01

    Due to the present land use practices and climate variability, drastic shifts in regional climate and land covers are easily seen and their future reduction and gain are too well predicted. Therefore, there is an increasing need for data on land-cover changes at narrow and broad spatial scales. In this study, a remote sensing-based technique for land-cover-change analysis is applied to the lower Sindh areas for the last decade. Landsat satellite products were analyzed on an alternate yearly basis, from 1990 to 2016. Then Land-cover-change magnitudes were measured and mapped for alternate years. Land Surface Temperature (LST) is one of the critical elements in the natural phenomena of surface energy and water balance at local and global extent. However, LST was computed by using Landsat thermal bands via brightness temperature and a vegetation index. Normalized difference vegetation index (NDVI) was interpreted and maps were achieved. LST reflected NDVI patterns with complexity of vegetation patterns. Along with this, Object Based Image Analysis (OBIA) was done for classifying 5 major classes of water, vegetation, urban, marshy lands and barren lands with significant map layouts. Pakistan Meteorological Department provided the climate data in which rainfall, temperature and air temperature are included. Once the LST and OBIA are performed, overlay analysis was done to correlate the results of LST with OBIA and LST with meteorological data to ascertain the changes in land covers due to increasing centigrade of LST. However, satellite derived LST was also correlated with climate data for environmental analysis and to estimate Land Surface Temperature for assessing the inverse impacts of climate variability. This study's results demonstrate the land-cover changes in Lower Areas of Sindh including the Indus Delta mostly involve variations in land-cover conditions due to inter-annual climatic variability and temporary shifts in seasonality. However it is too concluded

  15. [Variability in antibiotic consumption within a regional health service, according to health area and model of healthcare coverage: national health system vs. civil servants' mutual insurance society].

    Science.gov (United States)

    Sánchez-Martínez, Diego Pablo; Guillén-Pérez, José Jesús; Sánchez-Martínez, Fernando Ignacio; Torres-Cantero, Alberto Manuel

    2015-08-01

    The aim of this study is to describe antibiotic consumption in the Region of Murcia in 2011, within the Spanish and European context, as well as to analyze the differences within the Region, both between health areas, and between users of the regional health service and those protected by the civil servants' mutual insurance society (MUFACE). Retrospective observational study of prescriptions dispensed by the pharmacies in the Region of Murcia during 2011. Consumption rates were expressed as defined daily doses (DDD) per 1,000 inhabitants/day and standardized consumption ratios (SCR). Overall antibiotics consumption rate in the Region of Murcia in 2011 was 30.05 DDD/1000/ day (DID), which is much above the average rate for Spain (20.9 DID) and for the European Union (21.57 DID). Health areas within the Region with the highest and lowest consumption rate are, respectively, Vega Alta (SCR: 124.44; CI95% 124.26 to 124.61) and Cartagena (SCR:84.16; CI95% 84.10 to 84.22). Civil servants covered by the mutual society have higher consumption rates than users of the regional health service (SCR: 105.01; CI95% 104.86 to 105.17). There is a high level of antibiotic prescription in the Region of Murcia Region in relative terms. A great variability in antibiotics consumption was observed between the different health areas, which might be related to the higher rate of the frequency of visits. The highest amount of variability in antibiotics prescription was found in cephalosporins and macrolides.

  16. Improving estimates of regional vegetation: Using pre-settlement vegetation data and variable wind speed to quantify pollen dispersal and source area

    Science.gov (United States)

    Burke, K. D.; Goring, S. J.; Williams, J. W.; Holloway, T.

    2014-12-01

    Pollen-based vegetation reconstructions are the primary source of information about spatio-temporal trends in vegetation dynamics at timescales of centuries to millennia. Pollen samples from individual lakes, bogs, and small hollows provide information about the vegetation within their respective source areas, which when mapped together generate vegetation reconstructions across spatial and temporal scales. Climate histories also can be reconstructed using empirical taxa-climate relationships. A fundamental need in these reconstructions is to estimate the pollen source area and account for the effects of intertaxonomic differences in pollen production and dispersal. Mechanistic pollen-vegetation models have continuously evolved for nearly a century, with recent advances culminating in the Landscape Reconstruction Algorithm. However, most applications of the LRA do not account for anisotropies in pollen source area introduced by atmospheric variations. Given that wind direction is often anisotropic and variable we investigate the effects of wind speed, wind direction, and a simple treatment of wet versus dry deposition on vegetation reconstruction from pollen. We obtained long term estimates of dominant wind patterns using North American Regional Reanalysis (NARR) weather data for 1979-2012. However, because contemporary vegetation and pollen distributions have been heavily affected by Euro-American land use, we use pre-settlement (ca. 1810-1904) forest composition across the prairie-forest ecotone in the upper Midwestern United States and a dataset of settlement-era pollen samples compiled by the PalEON project to model pollen-vegetation relationships. Comparisons of our modelled results with those of a unidirectional, homogenous model shows a substantial effect of regionally varying winds on vegetation reconstructions. In addition to variable wind speed and direction, other atmospheric effects including precipitation and instability play an important role in

  17. Interannual variability of a precipitation gradient along the semi-arid catchment areas for the metropolitan region of Lima- Peru in relation to atmospheric circulation at the mesoscale

    Science.gov (United States)

    Otto, Marco; Seidel, Jochen; Trachte, Katja

    2013-04-01

    The main moisture source for precipitation on the western slopes of the Central Andes is located east of the mountain range known as the Amazon basin. However, the Andean mountains, which reach up to 6000 m a.s.l., strongly influence climatic conditions along the Pacific coastline of South America as a climatic barrier for the low-level tropospheric flow and associated moisture transport from the Amazon basin. Additional, large scale subsidence caused by the South Pacific High inhabits convective rainfall at the Pacific coast where large metropolitan areas such as the Peruvian capital Lima are located. Two contrasts in precipitation can be found while crossing the Andean mountains from West to East. On the Pacific coast, at the location of the metropolitan area of Lima, no more than 10 mm mean annual rainfall occurs. In contrast, up to 1000 mm mean annual rainfall occur only 100 km east of Lima within the upper region (4000 m .a.s.l.) of the Western Cordillera. The transition takes place along the western slopes of the Western Cordillera and is characterised by a strong precipitation gradient. Here, catchment areas are located that provide most of the water resources needed to sustain an urban area of approximately 10 million people. This study investigates the interannual variability of the precipitation gradient between 1998 and 2012. The analysis is based on daily precipitation data of 22 rain gauge station, daily rainfall data of the Tropical Rainfall Mission (TRMM 3B42) at 0.25 degrees and reanalysis data at 36 km spatial resolution at the mesoscale. The reanalysis data was produced using the Weather Research and Forecasting Model. Station data was provided by the Peruvian weather service during the project "Sustainable Water and Wastewater Management in Urban Growth Centres Coping with Climate Change - Concepts for Lima Metropolitana (Peru) (LiWa)", which is financed by the German Federal Ministry of Education and Research (BMBF). We are interested in the

  18. Climate variability reflected by tree-ring width and δ18O in a heavily glaciated area of the Patagonian Andes since the Little Ice Age

    Science.gov (United States)

    Meier, W. J. H.; Wernicke, J., Jr.; Braun, M.; Aravena, J. C.; Jaña, R.; Griessinger, J.

    2016-12-01

    Since the end of the Little Ice Age, the area of the Northern and Southern Patagonian ice sheet decreased by more than 14% and 11%, respectively. The melting increased since the last decade by 2.3%. The glaciers of Cordillera Darwin recorded a surface decrease of approximately 14% for the last 140 years. The reason for the excessive glacial change is often explained through the rise in temperature combined with a decrease in precipitation or a change in seasonality. Since a spatially coherent coverage of climatological measurement is lacking it is not possible to verify this assumption in a differentiated manner. Hence, the German- Chilean joint project "Responses of GlAciers, Biosphere and hYdrology to climate Variability and climate chAnge across the Southern Andes (GABY-VASA)" aims to determine the influence of long and short term climate variabilities (El Niño-Southern Oscillation (ENSO), Southern Hemisphere Annular Mode (SAM)) on the cryo- and biosphere. Trees growing at the glacier margins and at the natural treeline were sampled at four different locations ranging from the humid western part of the southern Andes (annual precipitation > 10.000mma-1) to the distinct dryer eastern part (annual precipitation meteorological back trajectories and the derivation of air masses since the Little Ice Age. It thus interlinks past and present climate and allows to draw conclusions about the driving forces of glacial change.

  19. Preliminary analysis of variability in concentration of fine particulate matter - PM1.0, PM2.5 and PM10 in area of Poznań city

    Science.gov (United States)

    Sówka, Izabela; Chlebowska-Styś, Anna; Mathews, Barbara

    2018-01-01

    It is commonly known, that suspended particulate matter pose a threat to human life and health, negatively influence the flora, climate and also materials. Especially dangerous is the presence of high concentration of particulate matter in the area of cities, where density of population is high. The research aimed at determining the variability of suspended particulate matter concentration (PM1.0, PM2.5 and PM10) in two different thermal seasons, in the area of Poznań city. As a part of carried out work we analyzed the variability of concentrations and also performed a preliminary analysis of their correlation. Measured concentrations of particulate matter were contained within following ranges: PM10 - 8.7-69.6 μg/m3, PM2.5 - 2.2-88.5 μg/m3, PM1.0 - 2.5-22.9 μg/m3 in the winter season and 1.0-42.8 μg/m3 (PM10), 1.2-40.3 μg/m3 (PM2.5) and 2.7-10.4 (PM1.0) in the summer season. Preliminary correlative analysis indicated interdependence between the temperature of air, the speed of wind and concentration of particulate matter in selected measurement points. The values of correlation coefficients between the air temperature, speed of wind and concentrations of particulate matter were respectively equal to: for PM10: -0.59 and -0.55 (Jana Pawła II Street), -0.53 and -0.53 (Szymanowskiego Street), for PM2.5: -0.60 and -0.53 (Jana Pawła II Street) and for PM1.0 -0.40 and -0.59 (Jana Pawła II Street).

  20. The Spatial and Temporal Variability of Ozone in the Houston Metropolitan Area during DISCOVER-AQ and its' Relation to Meteorological Conditions

    Science.gov (United States)

    Lefer, B. L.; Flynn, J. H., III; Judd, L.; Ren, X.; Estes, M. J.; Griffin, R. J.

    2014-12-01

    During the 2013 NASA DISCOVER-AQ in Texas, the atmospheric abundance of ozone and its precursor species (NOx and VOCs) were sampled throughout the Houston metropolitan area from a variety of observing platforms, including in situ sampling from the NASA P-3B aircraft, ozonesonde balloons, several mobile ground laboratories, and some 40 different ground-based monitoring sites. This unprecedented array of air quality measurement tools provides both high-temporal and high-spatial resolution sampling of both ozone and ozone production throughout a relatively small (100 km x 100 km) area during a 4-week period in the Fall of 2013. This study will examine the representativeness of this detailed "snapshot" of Houston air quality and how September 2013 fits into both the long-term trends in the local air quality and the current Houston conceptual model. The impact of meteorology as well as the year-to-year variability in meteorological conditions on ozone and ozone production determined from 0-D photochemical box modeling will also be examined.

  1. Phenotypic variability and population structure of peridomestic Triatoma infestans in rural areas of the arid Chaco (Western Argentina): spatial influence of macro- and microhabitats.

    Science.gov (United States)

    Hernández, María Laura; Abrahan, Luciana Beatriz; Dujardin, Jean Pierre; Gorla, David E; Catalá, Silvia S

    2011-05-01

    Triatoma infestans, one of the main vectors of Trypanosoma cruzi, is strongly associated with rural human ecotopes. Infested peridomestic places could act as a source of house infestation as a result of the movement of vectors among habitats. The quantitative study of phenotypic traits and nutritional variables could be informative about the population structure and the relative mobility of vectors. This is the first approach toward analyzing the phenetic characteristics of T. infestans and the relationship with their potential role to invade and colonize other habitats in the arid Chaco region. This article compares the phenotypic structure of T. infestans populations living in chicken coops and goat corrals, analyzing the geometric morphometry of wings and heads, antennal phenotypes, and the nutritional status of 257 adults and nymphs. The study area remained untreated with insecticides during the 15 years before the present study. The insects collected in peridomestic structures located in two zones 80 km apart exhibited significant differences in their morphotypes, suggesting an environmental effect and/or the absence of individual exchange between zones. The population structure was clear in T. infestans from goat corrals and chicken coops in one zone and less pronounced in the other. These results suggest the existence of a different rate of individual exchange among ecotopes within each zone. Morphometric variables of heads and wings were significantly correlated in insects collected in goat corrals but not in chicken coops, suggesting a habitat effect and supporting the hypothesis of different canalization forces that affect the two organs. The nutritional status of adults indicated a low dispersal probability with zonal differences. This article provides the first combined morphometric analysis of the head of adults and fifth instar nymphs in triatomines and the first combined analysis of head and wing in T. infestans.

  2. Limited Spatial and Temporal Variability in Meiofauna and Nematode Communities at Distant but Environmentally Similar Sites in an Area of Interest for Deep-Sea Mining

    Directory of Open Access Journals (Sweden)

    Ellen Pape

    2017-06-01

    Full Text Available To be able to adequately assess potential environmental impacts of deep-sea polymetallic nodule mining, the establishment of a proper environmental baseline, incorporating both spatial and temporal variability, is essential. The aim of the present study was to evaluate both spatial and intra-annual variability in meiofauna (higher taxa and nematode communities (families and genera, and Halalaimus species within the license area of Global Sea mineral Resources (GSR in the northeastern Clarion Clipperton Fracture Zone (CCFZ, and to determine the efficiency of the current sampling of meiofauna and nematode diversity. In October 2015, three polymetallic nodule-bearing sites, about 60–270 km apart, located at similar depths (ca. 4,500 m were sampled, of which one site was sampled in April in that same year. Despite the relatively large geographical distances and the statistically significant, but small, differences in sedimentary characteristics between sites, meiofauna and nematode communities were largely similar in terms of abundance, composition and diversity. Between-site differences in community composition were mainly driven by a set of rare and less abundant taxa. Moreover, although surface primary productivity in April exceeded that in October, no significant changes were observed in sedimentary characteristics or in meiofauna and nematode communities. At all sites and in both periods, Nematoda were the prevailing meiofaunal phylum, which was in turn dominated by Monhysterid genera and Acantholaimus. Our findings support the earlier purported notion of a low degree of endemism for nematode genera and meiofauna taxa in the deep sea, and hint at the possibility of large distribution ranges for at least some Halalaimus species. Taxon richness estimators revealed that the current sampling design was able to characterize the majority of the meiofauna and nematode taxa present. To conclude, implications of the present findings for environmental

  3. Small-scale variability of particulate matter and perception of air quality in an inner-city recreational area in Aachen, Germany

    Directory of Open Access Journals (Sweden)

    Bastian Paas

    2016-06-01

    Full Text Available Spatial micro-scale variability of particle mass concentrations is an important criterion for urban air quality assessment. In this study we present results from detailed spatio-temporal measurements in the urban roughness layer along with a survey to determine perceptions of citizens regarding air quality in an inner city park in Aachen, Germany. Particles were sampled with two different approaches in February, May, July and September 2014 using an optical particle counter at six fixed measurement locations, representing different degrees of outdoor particle exposure that can be experienced by a pedestrian walking in an intra-urban recreational area. A simulation of aerosol emissions induced by road traffic was conducted using the German reference dispersion model Austal2000. The mobile measurements revealed unexpected details in the distribution of urban particles with highest mean concentrations of PM(1;10$\\text{PM}_{(1;10}$ inside the green area 100 m away from bus routes (arithmetic mean: 22.5 μg m−3 and 18.9 μg m−3; geometric mean: 9.3 μg m−3 and 6.5 μg m−3, whereas measurement sites in close proximity to traffic lines showed far lower mean values (arithmetic mean: 7.5 μg m−3 and 8.7 μg m−3; geometric mean: 5.8 μg m−3 and 6.5 μg m−3. Concerning simulation results, motor traffic is still proved to be an important aerosol source in the area, although the corresponding concentrations declined rapidly as the distances to the line sources increased. Further analysis leads to the assumption that particularly coarse particles were emitted through diffuse sources e.g. on the ability of surfaces to release particles by resuspension which were dominantly apparent in measured PM(1;10$\\text{PM}_{(1;10}$ and PM(0.25;10$\\text{PM}_{(0.25;10}$ data. The contribution of diffuse particle sources and urban background transport to local PM(0.25;10$\\text{PM}_{(0.25;10}$ concentrations inside the

  4. Spatio-temporal variability of fluorescent dissolved organic matter in the Rhône River delta and the Fos-Marseille marine area (NW Mediterranean Sea, France).

    Science.gov (United States)

    Ferretto, Nicolas; Tedetti, Marc; Guigue, Catherine; Mounier, Stéphane; Raimbault, Patrick; Goutx, Madeleine

    2017-02-01

    The spatio-temporal variability of fluorescent dissolved organic matter (FDOM) and its relationships with physical (temperature, salinity) and chemical (nutrients, chlorophyll a, dissolved and particulate organic carbon, nitrogen and phosphorus) parameters were investigated in inland waters of the Rhône River delta and the Fos-Marseille marine area (northwestern Mediterranean, France). Samples were taken approximately twice per month in two inland sites and three marine sites from February 2011 to January 2012. FDOM was analysed using fluorescence excitation-emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC). In inland waters, humic-like components C1 (λEx/λEm: 250 (330)/394 nm) and C3 (λEx/λEm: 250 (350)/454 nm) dominated over one tryptophan-like component C2 (λEx/λEm: 230 (280)/340 nm), reflecting a background contribution of terrigenous material (~67% of total fluorescence intensity, in quinine sulphate unit (QSU)) throughout the year. In marine waters, protein-like material, with tyrosine-like C4 (λEx/λEm: sediment resuspension. In marine sites, intrusions of the Berre Lagoon and Rhône River waters had a significant impact on the local biogeochemistry, leading to higher fluorescence intensities of humic- and protein-like components in spring-summer. On average, the fluorescence intensities of FDOM components C4, C5 and C6 increased by 33-81% under lower salinity. This work highlights the complex dynamics of FDOM in coastal waters and confirms the link between marine FDOM and the Rhône River freshwater intrusions on larger spatial and temporal scales in the Fos-Marseille marine area.

  5. Task-specific noise exposure during manual concrete surface grinding in enclosed areas-influence of operation variables and dust control methods.

    Science.gov (United States)

    Akbar-Khanzadeh, Farhang; Ames, April L; Milz, Sheryl A; Akbar-Khanzadeh, Mahboubeh

    2013-01-01

    Noise exposure is a distinct hazard during hand-held concrete grinding activities, and its assessment is challenging because of the many variables involved. Noise dosimeters were used to examine the extent of personal noise exposure while concrete grinding was performed with a variety of grinder sizes, types, accessories, and available dust control methods. Noise monitoring was conducted in an enclosed area covering 52 task-specific grinding sessions lasting from 6 to 72 minutes. Noise levels, either in minute average noise level (Lavg, dBA) or in minute peak (dBC), during concrete grinding were significantly (P noise levels (98.7 ± 2.8) than 5-inch (96.3 ± 3.2) or 4-inch (95.3 ± 3.5) cup wheels. The minute peak noise levels (dBC) during grinding was 113 ± 5.2 ranging from 104 to 153. The minute peak noise levels during uncontrolled grinding (119 ± 10.2) were significantly higher than those during wet-grinding (115 ± 4.5) and LEV-grinding (112 ± 3.4). A 6-inch grinding cup wheel generated significantly higher minute peak noise levels (115 ± 5.3) than 5-inch (112 ± 4.5) or 4-inch (111 ± 5.4) cup wheels. Assuming an 8-hour work shift, the results indicated that noise exposure levels during concrete grinding in enclosed areas exceeded the recommended permissible exposure limits and workers should be protected by engineering control methods, safe work practices, and/or personal protective devices.

  6. An example of aerosol pattern variability over bright surface using high resolution MODIS MAIAC: The eastern and western areas of the Dead Sea and environs

    Science.gov (United States)

    Sever, Lee; Alpert, Pinhas; Lyapustin, Alexei; Wang, Yujie; Chudnovsky, Alexandra

    2017-09-01

    The extreme rate of evaporation of the Dead Sea (DS) has serious implications for the surrounding area, including atmospheric conditions. This study analyzes the aerosol properties over the western and eastern parts of the DS during the year 2013, using MAIAC (Multi-Angle Implementation of Atmospheric Correction) for MODIS, which retrieves aerosol optical depth (AOD) data at a resolution of 1 km. The main goal of the study is to evaluate MAIAC over the study area and determine, for the first time, the prevailing aerosol spatial patterns. First, the MAIAC-derived AOD data was compared with data from three nearby AERONET sites (Nes Ziona - an urban site, and Sede Boker and Masada - two arid sites), and with the conventional Dark Target (DT) and Deep Blue (DB) retrievals for the same days and locations, on a monthly basis throughout 2013. For the urban site, the correlation coefficient (r) for DT/DB products showed better performance than MAIAC (r = 0.80, 0.75, and 0.64 respectively) year-round. However, in the arid zones, MAIAC showed better correspondence to AERONET sites than the conventional retrievals (r = 0.58-0.60 and 0.48-0.50 respectively). We investigated the difference in AOD levels, and its variability, between the Dead Sea coasts on a seasonal basis and calculated monthly/seasonal AOD averages for presenting AOD patterns over arid zones. Thus, we demonstrated that aerosol concentrations show a strong preference for the western coast, particularly during the summer season. This preference, is most likely a result of local anthropogenic emissions combined with the typical seasonal synoptic conditions, the Mediterranean Sea breeze, and the region complex topography. Our results also indicate that a large industrial zone showed higher AOD levels compared to an adjacent reference-site, i.e., 13% during the winter season.

  7. Seasonal variations of phytoplankton assemblages and its relation to environmental variables in a scallop culture sea area of Bohai Bay, China.

    Science.gov (United States)

    Chen, Yang-Hang; Gao, Ya-Hui; Chen, Chang-Ping; Liang, Jun-Rong; Sun, Lin; Zhen, Yu; Qiao, Ling

    2016-12-15

    Seasonal variations of phytoplankton assemblages were examined in a scallop culture sea area of Bohai Bay (China) with regard to some major physical and chemical variables. Samples were collected at three stations from July 2011 to September 2013. A total of 134 species belong to 4 phyla were identified, of which 104 were diatoms, 27 were dinoflagellates, 1 was euglenophyte and 2 were chrysophytes. The cells abundance in autumn (55.44×103cells/L) was higher than that in summer (6.99×103cells/L), spring (3.46×103cells/L) and winter (2.69×103cells/L). The Shannon-Wiener diversity index was higher in summer (3.06), followed by spring (3.02) and winter (2.91), and low in autumn (1.40). Results of canonical correspondence analysis showed that phosphate, salinity, temperature, silicate and DIN/SiO2 ratio were the most important environmental factors influencing the variation of phytoplankton community structure. It is suggested that eutrophication resulted from scallop culture would cause a potential red tide risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. [Autism spectrum disorder and evaluation of perceived stress parents and professionals: Study of the psychometric properties of a French adaptation of the Appraisal of Life Event Scale (ALES-vf)].

    Science.gov (United States)

    Cappe, É; Poirier, N; Boujut, É; Nader-Grosbois, N; Dionne, C; Boulard, A

    2017-08-01

    Autism and related disorders are grouped into the category of « Autism Spectrum Disorder » (ASD) in the DSM-5. This appellation reflects the idea of a dimensional representation of autism that combines symptoms and characteristics that vary in severity and intensity. Despite common characteristics, there are varying degrees in intensity and in the onset of symptoms, ranging from a disability that can be very heavy with a total lack of communication and major disorders associated with the existence of a relative autonomy associated, sometimes, with extraordinary intellectual abilities. Parents are faced with several difficult situations, such as sleep disturbances, agitation, shouting, hetero violence, self-harm, learning difficulties, stereotyping, lack of social and emotional reciprocity, inappropriate behavior, etc. They can feel helpless and may experience stress related to these developmental and behavioral difficulties. The heterogeneity of symptoms, the presence of behavioral problems, the lack of reciprocity and autonomy also represent a challenge for practitioners in institutions and teachers at school. The objective of this research is to present the validation of a French translation of the Appraisal of Life Events Scale (ALES-vf) from Ferguson, Matthex and Cox, specifically adapted to the context of ASD. ALES was originally developed to operationalize the three dimensions of perceived stress (threat, loss and challenge) described by Lazarus and Folkman. ALES-vf was initially translated into French and adapted to the situation of parents of children with ASD. It was subsequently administered to 343 parents, 150 paramedical professionals involved with people with ASD, and 155 teachers from an ordinary school environment and from specialized schools, welcoming in their classroom at least one child with ASD. An exploratory factor analysis performed on data from 170 parents highlighted two exploratory models with four and three factors, slightly different

  9. Mid-Late Holocene climate variability and fire events in a High Atlantic mountain area in NW Iberia (Picos de Europa)

    Science.gov (United States)

    Ruiz-Fernández, Jesus; Nieuwendam, Alexandre; Oliva, Marc; Lopes, Vera; Cruces, Anabela; Conceição Freitas, Maria; Janeiro, Ana; López-Sáez, José Antonio; Gallinar, David; García-Hernández, Cristina

    2016-04-01

    In this contribution we present data from a 182 cm-long sedimentary sequence collected in the mid-altitude area of Belbín, a depression dammed by a moraine during the Last Glaciation in the Western Massif of the Picos de Europa (Cantabrian Mountains, NW Spain), in order to reconstruct the environmental changes and the conditioning factors of these changes occurred during the Mid-Late Holocene in this mountain area. The uppermost 60 cm of the sediments have been studied using a multi-proxy analysis including the texture, the organic matter content, the micromorphology of the quartz grains, and the concentration of charcoal particles. The geochronological framework of the environmental and climatic events for the Mid-late Holocene was established with three AMS 14C dates. During the last 6.7 ky cal BP a sequence of environmental changes took place in Belbin area driven by both warmer (between 6.7-5, 3.7-3, 2.6-1.1, 0.87-0.51 and since 0.01 ky cal BP) and colder stages (between 5-3.7, 3-2.6, 1.1-0.87 and 0.51 to 0.01 ky cal BP). The warmer stages were defined by the prevalence of chemical weathering of the quartz grains and relative increases of the C/N ratio. Conversely, during colder stages physical weathering of the quartz grains particles prevailed and the C/N values were lower. During the Late Holocene the sequence shows a progressive increase in the organic matter content, which may be associated with higher temperatures. Higher or lower concentration of charcoal particles according to warmer or colder climatic conditions is not detected, so the fires that have occurred in the area were likely to be related to human-induced fire management for grazing purposes. The period with the most frequent fire events occurred between 3.5 and 3 ky cal BP during the Bronze Age. Other significant peaks of charcoal particles occurred at ca. 2.6, 0.71 and 0.36 ky cal BP. This study shows evidence that the environmental changes occurred during the Mid-Late Holocene in this area

  10. Leaf area index estimation in a pine plantation with LAI-2000 under direct sunlight conditions: relationship with inventory and hydrologic variables; Estimacion del indice de area foliar en pinares de repolacion con LAI-2000 bajo radiacion solar directa: relacion con variables de inventario e hidrologicas

    Energy Technology Data Exchange (ETDEWEB)

    Molina, A.; Campo, A. D. del

    2011-07-01

    LAI is a key factor in light and rainfall interception processes in forest stands and, for this reason, is called to play an important role in global change adaptive silviculture. Therefore, it is necessary to develop practical and operative methodologies to measure this parameter as well as simple relationships with other silviculture variables. This work has studied 1) the feasibility of LAI-2000 sensor in estimating LAI-stand when readings are taken under direct sunlight conditions; and 2) the ability of LAI in studying rainfall partitioned into throughfall (T) in an Aleppo pine stand after different thinning intensities, as well as its relationships to basal area, (G), cover (FCC), and tree density (D). Results showed that the angular correction scheme applied to LAI-2000 direct-sunlight readings stabilized them for different solar angles, allowing a better operational use of LAI-2000 in Mediterranean areas, where uniform overcast conditions are difficult to meet and predict. Forest cover showed the highest predictive ability of LAI (R{sup 2} = 0.98; S = 0.28), then G (R{sup 2} = 0.96; S = 0.43) and D (R{sup 2} = 0.50; S = 0.28). In the hydrological plane, T increased with thinning intensity, being G the most explanatory variable (R{sup 2} = 0.81; S = 3.07) and LAI the one that showed the poorest relation with it (R{sup 2} = 0.69; S = 3.95). These results open a way for forest hydrologic modeling taking LAI as an input variable either estimated form LAI-2000 or deducted from inventory data. (Author) 36 refs.

  11. Estudo comparativo da deglutição com nasofibrolaringoscopia e videodeglutograma em pacientes com acidente vascular cerebral Comparison of functional endoscopic swallow study (FESS vs. videofluoroscopy (VF in patients with stroke

    Directory of Open Access Journals (Sweden)

    Sandra Doria

    2003-10-01

    proposed as a quick and highly sensitive way to evaluate patients with dysphagia. AIM: Comparative analysis between NFL and VD in relation to some parameters studied by both of them. STUDY DESIGN: Control study. MATERIAL AND METHODS: Twelve patients with sequelae of ischemic brain strokes were studied prospectively from January to May, 2002. All patients were submitted to VF and FESS with final statistical analysis of the results. RESULTS: VF is essential to evaluate the oral phase and micro aspirations, as well as the triggering of the swallow reflex in the pharyngeal phase. FESS may not visualize the triggering of the pharyngeal phase but is capable of testing the motility and sensibility of the larynx and it also allows direct vision of the food in the pharynx and/or larynx. No statistically significant difference was found for any of the parameters studied when comparing FESS and VF (McNemar test. CONCLUSION: The comparative analysis between the results of NFL and VD in patients with disphagia showed no significant differences between them.

  12. Accumulation variability over a small area in east Dronning Maud Land, Antarctica, as determined from shallow firn cores and snow pits : some implications for ice-core records

    NARCIS (Netherlands)

    Karlof, Lars; Isaksson, Elisabeth; Winther, Jan-Gunnar; Gundestrup, Niels; Meijer, Harro A. J.; Mulvaney, Robert; Pourchet, Michel; Hofstede, Coen; Lappegard, Gaute; Pettersson, Rickard; Van den Broeke, Michiel; Van De Wal, Roderik S. W.

    2005-01-01

    We investigate and quantify the variability of snow accumulation rate around a medium-depth firn core (1160 m) drilled in east Dronning Maud Land, Antarctica (75 degrees 00'S, 15 degrees 00'E; 3470 m h.a.e. (ellipsoidal height)). We present accumulation data from five snow pits and five shallow (20

  13. Application of steady state finite element and transient finite difference theory to sound propagation in a variable area duct: A comparison with experiment

    Science.gov (United States)

    Baumeister, K. J.; Eversman, W.; Astley, R. J.; White, J. W.

    1981-01-01

    Sound propagation without flow in a rectangular duct with a converging-diverging area variation was studied experimentally and theoretically. The area variation was of sufficient magnitude to produce large reflections and induce modal scattering. The rms (root-mean-squared) pressure and phase angle on both the flat and curved surface were measured and tabulated. The steady state finite element theory and the transient finite difference theory are in good agreement with the data. It is concluded that numerical finite difference and finite element theories appear ideally suited for handling duct propagation problems which encounter large area variations.

  14. Identifying the spatial and temporal variability of economic opportunity costs to promote the adoption of alternative land uses in grain growing agricultural areas: an Australian example.

    Science.gov (United States)

    Lyle, G; Bryan, B A; Ostendorf, B

    2015-05-15

    Grain growers face many future challenges requiring them to adapt their land uses to changing economic, social and environmental conditions. To understand where to make on ground changes without significant negative financial repercussions, high resolution information on income generation over time is required. We propose a methodology which utilises high resolution yield data collected with precision agriculture (PA) technology, gross margin financial analysis and a temporal standardisation technique to highlight the spatial and temporal consistency of farm income. On three neighbouring farms in Western Australia, we found non-linear relationships between income and area. Spatio-temporal analysis on one farm over varying seasons found that between 37 and 49% (1082-1433ha) of cropping area consistently produced above the selected income thresholds and 43-32% (936-1257ha) regularly produced below selected thresholds. Around 20% of area showed inconsistent temporal variation in income generation. Income estimated from these areas represents the income forgone if a land use change is undertaken (the economic opportunity cost) and the average costs varied spatially from $190±114/ha to $560±108/ha depending on what scenario was chosen. The interaction over space and time showed the clustering of areas with similar values at a resolution where growers make input decisions. This new evidence suggests that farm area could be managed with two strategies: (a) one that maximises grain output using PA management in temporally stable areas which generate moderate to high income returns and (b) one that proposes land use change in low and inconsistent income returning areas where the financial returns from an alternative land use may be comparable. The adoption of these strategies can help growers meet the demand for agricultural output and offer income diversity and adaptive capacity to deal with the future challenges to agricultural production. Copyright © 2015 Elsevier Ltd

  15. Accumulation variability over a small area in east Dronning Maud Land, Antarctica, as determined from shallow firn cores and snow pits: some implications for ice-core records

    Science.gov (United States)

    Karlöf, Lars; Isaksson, Elisabeth; Winther, Jan-Gunnar; Gundestrup, Niels; Meijer, Harro A. J.; Mulvaney, Robert; Pourchet, Michel; Hofstede, Coen; Lappegard, Gaute; Pettersson, Rickard; van den Broeke, Michiel; van de Wal, Roderik S. W.

    We investigate and quantify the variability of snow accumulation rate around a medium-depth firn core (160 m) drilled in east Dronning Maud Land, Antarctica (75°00‧S, 15°00‧E; 3470 m h.a.e. (ellipsoidal height)). We present accumulation data from five snow pits and five shallow (20 m) firn cores distributed within a 3.5 7 km distance, retrieved during the 2000/01 Nordic EPICA (European Project for Ice Coring in Antarctica) traverse. Snow accumulation rates estimated for shorter periods show higher spatial variance than for longer periods. Accumulation variability as recorded from the firn cores and snow pits cannot explain all the variation in the ion and isotope time series; other depositional and post-depositional processes need to be accounted for. Through simple statistical analysis we show that there are differences in sensitivity to these processes between the analyzed species. Oxygen isotopes and sulphate are more conservative in their post-depositional behaviour than the more volatile acids, such as nitrate and to some degree chloride and methanesulphonic acid. We discuss the possible causes for the accumulation variability and the implications for the interpretation of ice-core records.

  16. Cold-air performance of a 15.41-cm-tip-diameter axial-flow power turbine with variable-area stator designed for a 75-kW automotive gas turbine engine

    Science.gov (United States)

    Mclallin, K. L.; Kofskey, M. G.; Wong, R. Y.

    1982-01-01

    An experimental evaluation of the aerodynamic performance of the axial flow, variable area stator power turbine stage for the Department of Energy upgraded automotive gas turbine engine was conducted in cold air. The interstage transition duct, the variable area stator, the rotor, and the exit diffuser were included in the evaluation of the turbine stage. The measured total blading efficiency was 0.096 less than the design value of 0.85. Large radial gradients in flow conditions were found at the exit of the interstage duct that adversely affected power turbine performance. Although power turbine efficiency was less than design, the turbine operating line corresponding to the steady state road load power curve was within 0.02 of the maximum available stage efficiency at any given speed.

  17. Variability in stream chemistry in relation to urban development and biological condition in seven metropolitan areas of the United States, 1999-2004

    Science.gov (United States)

    Beaulieu, Karen M.; Bell, Amanda H.; Coles, James F.

    2012-01-01

    Beginning in 1999, the U.S. Geological Survey National Water Quality Assessment Program investigated the effects of urban development on stream ecosystems in nine metropolitan study areas across the United States. In seven of these study areas, stream-chemistry samples were collected every other month for 1 year at 6 to 10 sites. Within a study area, the sites collectively represented a gradient of urban development from minimally to highly developed watersheds, based on the percentage of urban land cover; depending on study area, the land cover before urban development was either forested or agricultural. The stream-chemistry factors measured in the samples were total nitrogen, total phosphorus, chloride, and pesticide toxicity. These data were used to characterize the stream-chemistry factors in four ways (hereafter referred to as characterizations)—seasonal high-flow value, seasonal low-flow value, the median value (representing a single integrated value of the factor over the year), and the standard deviation of values (representing the variation of the factor over the year). Aquatic macroinvertebrate communities were sampled at each site to infer the biological condition of the stream based on the relative sensitivity of the community to environmental stressors. A Spearman correlation analysis was used to evaluate relations between (1) urban development and each characterization of the stream-chemistry factors and (2) the biological condition of a stream and the different characterizations of chloride and pesticide toxicity. Overall, the study areas where the land cover before urban development was primarily forested had a greater number of moderate and strong relations compared with the study areas where the land cover before urban development was primarily agriculture; this was true when urban development was correlated with the stream-chemistry factors (except chloride) and when chloride and pesticide toxicity was correlated with the biological condition

  18. Climate and the inter-annual variability of fire in southern Africa: a meta-analysis using long-term field data and satellite-derived burnt area data

    CSIR Research Space (South Africa)

    Archibald, S

    2010-11-01

    Full Text Available of the landscape from year to year (Balfour & Howison, 2001; Van Wilgen et al., 2004; Mendelsohn, 2002), and this is generally attributed to variation in the amount of grass fuel available, driven by variable rainfall patterns. Recently, continental... percent of the variance in burnt area between years (Norton-Gri ths, 1979; Balfour & Howison, 2001; Mendelsohn, 2002; Van Wilgen et al., 2004; Mulqueeny, 2005). Similarly, preliminary studies using remotely sensed data have found relationships with re...

  19. THE ECONOMIC FACTORS AND OTHER VARIABLES THAT AFFECT THE EMPOWERMENT OF THE MICRO-BUSINESSES RUN BY FARMING COMMUNITIES IN VILLAGES AROUND THE FOREST AREAS

    Directory of Open Access Journals (Sweden)

    Yoyo Sunaryo Nitiwijaya

    2016-09-01

    Full Text Available This research is conducted in Kuningan regency, West Java, Indonesia and aims to analyze the economic, social, institutional, and cosmopolitan factors which affect the empowerment of the communities of micro-business entrepreneurs. It attempts to investigate the problems that persist for this community, in that the people living near the forest are heavily dependent on it, and on their agricultural activities. They have to face institutional regulations and competition from immigrants. Due to the nature of the data, the complexity of the structured relationship, the multiple endogenous variables; SEM or Structural Equation Modeling is used to analyze and confirm the extant association between the studied variables in a covariance based approach assisted by AMOS. The results suggest that the micro-business community is strongly influenced by the dynamics of the institutional businesses in the village, their social interactions, economic capabilities and cosmopolitan drives with the immigrant communities. It shows the efficiency and importance of the institutional community while dealing with micro-businesses’ agrarian economic empowerment. Improvement in the regulations is necessary and is expected to improve the partnership between the government and private and public entities, to cope with the economic development of society in such communities, and others which may share the same characteristics.

  20. Unusual geologic evidence of coeval seismic shaking and tsunamis shows variability in earthquake size and recurrence in the area of the giant 1960 Chile earthquake

    Science.gov (United States)

    Cisternas, M.; Garrett, E; Wesson, Robert L.; Dura, T.; Ely, L. L

    2017-01-01

    An uncommon coastal sedimentary record combines evidence for seismic shaking and coincident tsunami inundation since AD 1000 in the region of the largest earthquake recorded instrumentally: the giant 1960 southern Chile earthquake (Mw 9.5). The record reveals significant variability in the size and recurrence of megathrust earthquakes and ensuing tsunamis along this part of the Nazca-South American plate boundary. A 500-m long coastal outcrop on Isla Chiloé, midway along the 1960 rupture, provides continuous exposure of soil horizons buried locally by debris-flow diamicts and extensively by tsunami sand sheets. The diamicts flattened plants that yield geologically precise ages to correlate with well-dated evidence elsewhere. The 1960 event was preceded by three earthquakes that probably resembled it in their effects, in AD 898 - 1128, 1300 - 1398 and 1575, and by five relatively smaller intervening earthquakes. Earthquakes and tsunamis recurred exceptionally often between AD 1300 and 1575. Their average recurrence interval of 85 years only slightly exceeds the time already elapsed since 1960. This inference is of serious concern because no earthquake has been anticipated in the region so soon after the 1960 event, and current plate locking suggests that some segments of the boundary are already capable of producing large earthquakes. This long-term earthquake and tsunami history of one of the world's most seismically active subduction zones provides an example of variable rupture mode, in which earthquake size and recurrence interval vary from one earthquake to the next.

  1. Dissolved-solids loads discharged from irrigated areas near Manila, Utah, May 2007-October 2012, and relation of loads to selected variables

    Science.gov (United States)

    Thiros, Susan A.; Gerner, Steven J.

    2015-01-01

    The Manila/Washam Salinity Project (MWSP) is a cooperative effort by the Natural Resources Conservation Service (NRCS) and local farmers and ranchers to reduce the transport of dissolved solids to Flaming Gorge Reservoir from irrigated agricultural lands near Manila, Utah. To estimate dissolved-solids loads from the MWSP area, discharge and water quality from Birch Spring Draw and other selected outflows and inflows were monitored from May 2007 to October 2012. An average annual May–April streamflow of 5,960 acre-feet discharged from Birch Spring Draw at site BSD-2 to Flaming Gorge Reservoir during 2007–12, containing an average dissolved-solids load of 14,660 tons. An average May–April net dissolved-solids load of 24,300 tons per year discharged from the MWSP area, estimated from the relation between streamflow and dissolved-solids concentration at site BSD-2 and other measured inflows and outflows.

  2. [Survey on sports practice and physical activity of primary school children living in the area of Bologna Local Health Unit in relation with some individual and environmental variables].

    Science.gov (United States)

    Leoni, E; Beltrami, P; Poletti, G; Baldi, E; Sacchetti, R; Garulli, A; Masotti, A; Bianco, L; Ventura, F A M; Pandolfi, P; Guberti, E

    2008-01-01

    A randomized stratified sample of 522 children attending the third class of primary schools within the area of Bologna Local Health Unit was analysed for physical activity and sports practice. Information about the children's habits and availability of facilities for physical and sports activities were collected by means of structured questionnaires completed by children (507 respondents), parents (491), reference teachers for physical education (26) and class teachers (46) during the school year 2006-07. At the same time, the children's heights and weights were measured in order to calculate BMI values. Regular sports activity is practised by 80.1% of children (males: 82.4%, females: 77.6%), with significant diferences between genders only in children with at least one non-Italian parent (M>F, p sports is influenced by the area of residence (metropolitan > plain and hills, p non-Italians, p sports practising parent are involved more frequently in sports activities (p sports-practising children and not. However children not involved in regular sports activities tend to practise outdoor physical activities with a frequency significantly higher than children involved in sports (17.3% vs 10.4% of respondents). The percentage of completely sedentary children, who stated that they practise neither sports nor physical activity in their free time, is 7.3% (metropolitan area: 4.5%, hills: 8.7%, plain: 10.6%). The prevalence of overweight is 24.4%, of obesity 9.7%, with a better distribution of BMI values in the metropolitan area where there is the highest occurrence of positive conditions and behaviours: availability of sports facilities, the highest prevalence of sports practice, and the lowest prevalence of completely sedentary children.

  3. Decadal to millennial-scale variability in sea ice, primary productivity, and Pacific-Water inflow in the Chukchi/East Siberian Sea area (Arctic Ocean)

    Science.gov (United States)

    Stein, Ruediger; Fahl, Kirsten; Matthiessen, Jens; Méheust, Marie; Nam, Seung-il; Niessen, Frank; Schade, Inka; Schreck, Michael; Wassmuth, Saskia; Xiao, Xiaotong

    2014-05-01

    Sea-ice is an essential component of the global climate system and, especially, the Polar Oceans. An alarming decrease in term of sea-ice concentration, thickness and duration, has been observed in the Arctic Ocean and its marginal seas over the last 30 years. Thus, understanding the processes controlling modern sea-ice variability and reconstructing paleo-sea-ice extent and variability in polar regions have become of great interest for the international scientific community during the last years. Here, we present new proxy records determined in sediment cores from the East Siberian Sea (RV Polarstern Expedition ARK-XXIII/3 in 2008; Core PS72/350) and from the Chukchi Sea (RV Araon Expedition ARA2B in 2011; Core ARA2B-1A, -1B). These records, including organic-geochemical bulk parameters, specific biomarkers (IP25 and sterols; PIP25; for recent reviews see Stein et al., 2012; Belt and Müller, 2013), biogenic opal, mineralogical data as well as high-resolution XRF scanning data, give new insight into the short-term (decadal-, centennial- to millennial-scale) variability in sea-ice, primary productivity and Pacific-Water inflow during Holocene times. Maximum concentrations of phytoplankton biomarkers and biogenic opal were determined between 8.5 and 4 kyrs. BP, suggesting enhanced primary productivity triggered by increased inflow of nutrient-rich Pacific Water (and/or an increased nutrient input due to an ice-edge position). Short-lived peak values in productivity might be related to strong pulses of Pacific-Water input during this time period (cf., Ortiz et al., 2009). A seasonal sea-ice cover was present in the Chukchi Sea throughout the last 10 kyrs. During the last 3-4 kyrs. BP, the sea-ice cover significantly extended. References Belt, S.T. and Müller, J., 2013. The Arctic sea ice biomarker IP25: a review of current understanding, recommendations for future research and applications in palaeo sea ice reconstructions. Quaternary Science Review 73, 9-25. Ortiz

  4. Variability of Blowing Dust Weather Frequency over Semi-Arid Areas of China (Baicheng, Jilin Province and Relationships with Climatic Factors During 1951 - 2006

    Directory of Open Access Journals (Sweden)

    Yun-Fei Wu

    2011-01-01

    Full Text Available We analyzed the variability of blowing dust weather frequency (BDWF and patterns in climatic factors over Baicheng for the period 1951 - 2006 in this study. The data showed that blowing dust over Baicheng occurs intensively during the spring and shows significant inter-decadal variability. One of the main findings is that the occurrence of blowing dust has significantly decreased after the mid-1980s. The mean wind speed (WS, diurnal temperature range (DTR, relative humidity (RH and precipitation at Baicheng during the spring show decreasing trends. The decreasing trends of the mean WS and DTR are significant at 99% confidence levels according to the t-test; the dataset also indicated a sharp decrease in WS occurred after the mid-1980s. The mean surface air temperature (SAT escalated in a fluctuating manner during 1951 - 2006. BDWF at Baicheng was significantly related to local WS, SAT and DTR during the spring [correlation coefficients (CCs are 0.41, -0.47 and 0.36, respectively]. The correlation between BDWF at Baicheng and selected climatic factors over the sand-dust source regions and transmission paths were also calculated. We found that BDWF is well correlated to the mean WS and SAT during the spring, with CCs of 0.45 and -0.48, respectively. The most likely causes for the dramatic decrease observed in BDWF after the mid-1980s were related to the adjustment of large-scale circulation patterns in response to a decrease of meridional temperature differences, the weakening of steering westerlies and the strengthening of downward motions that has occurred at the middle latitudes of eastern Eurasia in recent decades.

  5. Seven year satellite observations of the mean structures and variabilities in the regional aerosol distribution over the oceanic areas around the Indian subcontinent

    Directory of Open Access Journals (Sweden)

    S. K. Nair

    2005-09-01

    Full Text Available Aerosol distribution over the oceanic regions around the Indian subcontinent and its seasonal and interannual variabilities are studied using the aerosol optical depth (AOD derived from NOAA-14 and NOAA-16 AVHRR data for the period of November 1995–December 2003. The air-mass types over this region during the Asian summer monsoon season (June–September are significantly different from those during the Asian dry season (November–April. Hence, the aerosol loading and its properties over these oceanic regions are also distinctly different in these two periods. During the Asian dry season, the Arabian Sea and Bay of Bengal are dominated by the transport of aerosols from Northern Hemispheric landmasses, mainly the Indian subcontinent, Southeast Asia and Arabia. This aerosol transport is rather weak in the early part of the dry season (November–January compared to that in the later period (February–April. Large-scale transport of mineral dust from Arabia and the production of sea-salt aerosols, due to high surface wind speeds, contribute to the high aerosol loading over the Arabian Sea region during the summer monsoon season. As a result, the monthly mean AOD over the Arabian Sea shows a clear annual cycle with the highest values occurring in July. The AOD over the Bay of Bengal and the Southern Hemisphere Indian Ocean also displays an annual cycle with maxima during March and October, respectively. The amplitude of the annual variation is the largest in coastal Arabia and the least in the Southern Hemisphere Indian Ocean. The interannual variability in AOD is the largest over the Southeast Arabian Sea (seasonal mean AOD varies from 0.19 to 0.42 and the northern Bay of Bengal (seasonal mean AOD varies from 0.24 to 0.39 during the February–April period and is the least over the Southern Hemisphere Indian Ocean. This study also investigates the altitude regions and pathways of dominant aerosol transport by combining the AOD distribution with

  6. Chronic kidney disease in the type 2 diabetic patients: prevalence and associated variables in a random sample of 2642 patients of a Mediterranean area

    Directory of Open Access Journals (Sweden)

    Coll-de-Tuero Gabriel

    2012-08-01

    Full Text Available Abstract Background Kidney disease is associated with an increased total mortality and cardiovascular morbimortality in the general population and in patients with Type 2 diabetes. The aim of this study is to determine the prevalence of kidney disease and different types of renal disease in patients with type 2 diabetes (T2DM. Methods Cross-sectional study in a random sample of 2,642 T2DM patients cared for in primary care during 2007. Studied variables: demographic and clinical characteristics, pharmacological treatments and T2DM complications (diabetic foot, retinopathy, coronary heart disease and stroke. Variables of renal function were defined as follows: 1 Microalbuminuria: albumin excretion rate & 30 mg/g or 3.5 mg/mmol, 2 Macroalbuminuria: albumin excretion rate & 300 mg/g or 35 mg/mmol, 3 Kidney disease (KD: glomerular filtration rate according to Modification of Diet in Renal Disease 2 and/or the presence of albuminuria, 4 Renal impairment (RI: glomerular filtration rate 2, 5 Nonalbuminuric RI: glomerular filtration rate 2 without albuminuria and, 5 Diabetic nephropathy (DN: macroalbuminuria or microalbuminuria plus diabetic retinopathy. Results The prevalence of different types of renal disease in patients was: 34.1% KD, 22.9% RI, 19.5% albuminuria and 16.4% diabetic nephropathy (DN. The prevalence of albuminuria without RI (13.5% and nonalbuminuric RI (14.7% was similar. After adjusting per age, BMI, cholesterol, blood pressure and macrovascular disease, RI was significantly associated with the female gender (OR 2.20; CI 95% 1.86–2.59, microvascular disease (OR 2.14; CI 95% 1.8–2.54 and insulin treatment (OR 1.82; CI 95% 1.39–2.38, and inversely associated with HbA1c (OR 0.85 for every 1% increase; CI 95% 0.80–0.91. Albuminuria without RI was inversely associated with the female gender (OR 0.27; CI 95% 0.21–0.35, duration of diabetes (OR 0.94 per year; CI 95% 0.91–0.97 and directly associated with HbA1c (OR 1.19 for every

  7. Seasonal abundance of soil-surface arthropods in relation to some meteorological and edaphic variables of the grassland and tree-planted areas in a tropical semi-arid savanna

    Science.gov (United States)

    Vikram Reddy, M.; Venkataiah, B.

    1990-03-01

    Seasonality of relative population abundance in different groups of soil-surface arthropods was investigated monthly by pit-fall traps during a 2-year period in the grassland and tree-planted areas of a tropical semi-arid savanna at Warangal (south India). Densities of most groups were lowest during summer and highest during the rainy season. They were less abundant during winter. Arthropods were recorded in higher numbers in tree-planted compared to grassland areas. Certain arthropods that were found only during part of the year were recorded for a longer period in the tree-planted area. Formicidae, Monomorium indicum Forel, Crematogaster sp. and Pachycondyla? tesserinoda (Emery), and Coleoptera, Pachycera sp. reached maximum densities in the rainy season and minimum numbers during winter and summer in the grassland area. However, these species had lower densities during the rainy season and reached maximum densities during winter and summer in the tree-planted area. The seasonal abundance of arthropods showed significant linear correlations with different abiotic environmental variables such as rainfall, soil moisture, organic matter, soil and air temperatures, soil pH, relative humidity at the soil surface, and potassium and phosphorus of surface soil. Soil moisture and rainfall were generally the strongest correlates with densities, particularly in the grassland area.

  8. Method of particle trajectory recognition in particle flows of high particle concentration using a candidate trajectory tree process with variable search areas

    Science.gov (United States)

    Shaffer, Franklin D.

    2013-03-12

    The application relates to particle trajectory recognition from a Centroid Population comprised of Centroids having an (x, y, t) or (x, y, f) coordinate. The method is applicable to visualization and measurement of particle flow fields of high particle. In one embodiment, the centroids are generated from particle images recorded on camera frames. The application encompasses digital computer systems and distribution mediums implementing the method disclosed and is particularly applicable to recognizing trajectories of particles in particle flows of high particle concentration. The method accomplishes trajectory recognition by forming Candidate Trajectory Trees and repeated searches at varying Search Velocities, such that initial search areas are set to a minimum size in order to recognize only the slowest, least accelerating particles which produce higher local concentrations. When a trajectory is recognized, the centroids in that trajectory are removed from consideration in future searches.

  9. Influence of local and regional sources on the observed spatial and temporal variability of size resolved atmospheric aerosol mass concentrations and water-soluble species in the Athens metropolitan area

    Science.gov (United States)

    Eleftheriadis, Konstantinos; Ochsenkuhn, Klaus M.; Lymperopoulou, Theopisti; Karanasiou, Angeliki; Razos, Panayiotis; Ochsenkuhn-Petropoulou, Maria

    2014-11-01

    The variability of common aerosol species in large Metropolitan urban areas is a major air quality issue with strong health impacts of large populations. PM10 and PM2.5 particulate matter samples were obtained at three sites characteristic of industrial, urban traffic and sub-urban residential areas in the Athens basin. Samples were analysed for anions (Cl-, NO3-, SO42-) and cations (K+, Na+, Ca2+, Mg2+, NH4+) using ion chromatography. The spatial and temporal variability for the particulate matter (PM) concentration mass and water-soluble ionic species concentrations for the investigated sites were studied. Mean PM fine concentration levels were 20% higher at the industrial and the central urban areas compared to those in the suburban area (24.2 μg/m3). The mean values for the coarse fraction at those two sites were two to three times higher compared to those at the suburban site (12.4 μg/m3). Comparable concentration levels of most species were observed in all areas, while SO42- and NO3- differ at a significant level. Furthermore, the average size distributions of the mass and individual ions at the suburban site (NCSR Demokritos) showed a bimodal size distribution. SO42- and NH4+ have their main peak in the fine fraction while NO3- showed equal distribution on the fine and coarse mode.. Good correlation was found for SO42- and NO3- with Ca2+ and Na+ with Cl- for the coarse fraction in the industrial area. NH4+ was closely correlated with SO42- in the fine particles and in all areas. For the urban site the best correlations in coarse particulates were reported between Na+/Mg2+-Cl-, Ca2+/Mg2+-SO42-, explained by neutralization of acidic aerosol by soil dust and sea salt in the coarse fraction. Moreover, time weighted concentrations roses at the industrial and urban sites, showed no significant directional dependence, indicating either uniform generation of mainly the coarse species within the metropolitan area or major influence of the regional background for

  10. Variable Surface Area Thermal Radiator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Due to increased complexity of spacecraft and longer expected life, more sophisticated and complex thermal management schemes are needed that will be capable of...

  11. Ashtekar variables

    Science.gov (United States)

    Ashtekar, Abhay

    2015-05-01

    In the spirit of Scholarpedia, this invited article is addressed to students and younger researchers. It provides the motivation and background material, a summary of the main physical ideas, mathematical structures and results, and an outline of applications of the connection variables for general relativity. These variables underlie both the canonical/Hamiltonian and the spinfoam/path integral approaches in loop quantum gravity.

  12. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    2017-01-01

    be exploited. Variability bugs are not confined to any particular type of bug, error-prone feature, or location. In addition to introducing an exponential number of program variants, variability increases the complexity of bugs due to unintended feature interactions, hidden features, combinations of layers...... and bug finding, but not terribly so. This is positive and consistent with the existence of highly-configurable software systems with hundreds, even thousands, of features, testifying that developers in the trenches are able to deal with variability.......Many modern software systems are highly configurable. They embrace variability to increase adaptability and to lower cost. To implement configurable software, developers often use the C preprocessor (CPP), which is a well-known technique, mainly in industry, to deal with variability in code...

  13. Variability of pesticide residues in eggplant units collected from a field trial and marketplaces in Greece.

    Science.gov (United States)

    Prodhan, Mohammad Dalower Hossain; Papadakis, Emmanouil-Nikolaos; Papadopoulou-Mourkidou, Euphemia

    2017-10-06

    Variability of pesticide residues among food items is very important when assessing the risks and food safety for the consumers. Therefore, the present study was undertaken to estimate the unit-to-unit residue variability factors for eggplant. In total, 120 samples from a trial field and 142 samples from different marketplaces in Thessaloniki, Greece, were collected to estimate the variability of pesticide residues in eggplant units. They were extracted by the QuEChERS method and the residues were determined by LC-MS/MS. For the field samples, the unit-to-unit variability factors (VFs) obtained for cypermethrin and deltamethrin residues were 2.54 and 2.51, respectively. The mean residue levels of both pesticides were higher in the composite samples than in the individual samples. The average VFs for the marketplace samples was 3.89. The eggplant units exposed to pesticides were higher in residues than the non-exposed units. The variability factors obtained in the marketplace samples were higher than those in the samples collected from the field trial. A default VF value of 3 for field trials is appropriate for use when assessing the acute dietary intake but a VF for the marketplace samples should be reconsidered with a larger data. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Analysis of urban residential environments using color infrared aerial photography: An examination of socioeconomic variables and physical characteristics of selected areas in the Los Angeles basin, with addendum: An application of the concepts of the Los Angeles residential environment study to the Ontario-Upland region of California

    Science.gov (United States)

    Mullens, R. H., Jr.; Senger, L. W.

    1969-01-01

    Aerial photographs taken with color infrared film were used to differentiate various types of residential areas in the Los Angeles basin, using characteristics of the physical environment which vary from one type of residential area to another. Residential areas of varying quality were classified based on these characteristics. Features of the physical environment, identifiable on CIR aerial photography were examined to determine which of these are the best indicators of quality of residential areas or social areas, as determined by the socioeconomic characteristics of the inhabitants of the selected areas. Association between several physical features and the socioeconomic variables was found to exist.

  15. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  16. Spatial Variability of Rainfall

    DEFF Research Database (Denmark)

    Jensen, N.E.; Pedersen, Lisbeth

    2005-01-01

    As a part of a Local Area Weather Radar (LAWR) calibration exercise 15 km south of Århus, Denmark, the variability in accumulated rainfall within a single radar pixel (500 by 500 m) was measured using nine high-resolution rain gauges. The measured values indicate up to a 100% variation between ne...

  17. Chatter Prediction for Variable Pitch and Variable Helix Milling

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2015-01-01

    Full Text Available Regenerative chatter is a self-excited vibration that can occur during milling, which shortens the lifetime of the tool and results in unacceptable surface quality. In this paper, an improved semidiscretization method for modeling and simulation with variable pitch and variable helix milling is proposed. Because the delay between each flute varies along the axial depth of the tool in milling, the cutting tool is discrete into some axial layers to simplify calculation. A comparison of the predicted and observed performance of variable pitch and variable helix against uniform pitch and uniform helix milling is presented. It is shown that variable pitch and variable helix milling can obtain larger stable cutting area than uniform pitch and uniform helix milling. Thus, it is concluded that variable pitch and variable helix milling are an effective way for suppressing chatter.

  18. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  19. Complex variables

    CERN Document Server

    Taylor, Joseph L

    2011-01-01

    The text covers a broad spectrum between basic and advanced complex variables on the one hand and between theoretical and applied or computational material on the other hand. With careful selection of the emphasis put on the various sections, examples, and exercises, the book can be used in a one- or two-semester course for undergraduate mathematics majors, a one-semester course for engineering or physics majors, or a one-semester course for first-year mathematics graduate students. It has been tested in all three settings at the University of Utah. The exposition is clear, concise, and lively

  20. Phonological Variability in Canadian English.

    Science.gov (United States)

    de Wolf, Gaelan Dodds

    A study compared salient variables of Canadian English from two concurrent sociodialectal surveys, one for Ottawa, Ontario and one for Vancouver, British Columbia. Using the Labovian model of phonological variation in association with sociological parameters and other linguistic variables within each specific area, the analysis investigated four…

  1. Speed control variable rate irrigation

    Science.gov (United States)

    Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

  2. Combining Amplitude Spectrum Area with Previous Shock Information Using Neural Networks Improves Prediction Performance of Defibrillation Outcome for Subsequent Shocks in Out-Of-Hospital Cardiac Arrest Patients.

    Science.gov (United States)

    He, Mi; Lu, Yubao; Zhang, Lei; Zhang, Hehua; Gong, Yushun; Li, Yongqin

    2016-01-01

    Quantitative ventricular fibrillation (VF) waveform analysis is a potentially powerful tool to optimize defibrillation. However, whether combining VF features with additional attributes that related to the previous shock could enhance the prediction performance for subsequent shocks is still uncertain. A total of 528 defibrillation shocks from 199 patients experienced out-of-hospital cardiac arrest were analyzed in this study. VF waveform was quantified using amplitude spectrum area (AMSA) from defibrillator's ECG recordings prior to each shock. Combinations of AMSA with previous shock index (PSI) or/and change of AMSA (ΔAMSA) between successive shocks were exercised through a training dataset including 255shocks from 99patientswith neural networks. Performance of the combination methods were compared with AMSA based single feature prediction by area under receiver operating characteristic curve(AUC), sensitivity, positive predictive value (PPV), negative predictive value (NPV) and prediction accuracy (PA) through a validation dataset that was consisted of 273 shocks from 100patients. A total of61 (61.0%) patients required subsequent shocks (N = 173) in the validation dataset. Combining AMSA with PSI and ΔAMSA obtained highest AUC (0.904 vs. 0.819, pdefibrillation outcome for subsequent shocks.

  3. An evaluation of FIA's stand age variable

    Science.gov (United States)

    John D. Shaw

    2015-01-01

    The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume,...

  4. Using stable isotopes and multi-spatial variable parameters in characterising the karstic aquifer of the Ajloun area, NW-Jordan - A case study of the Tanour and Rasoun springs

    Science.gov (United States)

    Hamdan, Ibraheem; Wiegand, Bettina; Ptak, Thomas; Licha, Tobias; Toll, Mathias; Margane, Armin; Sauter, Martin

    2015-04-01

    . Application of a travel time-based groundwater vulnerability method, and other different groundwater vulnerability methods for karst systems. The resulting data will be processed and used as spatially variable parameters for determining the karst aquifer characteristics within the study area. The springs show a rapid response to rainfall events which reflects a fast travel time and short residence time in the karst aquifer. References - Al Kharadsheh E, Akroush S and Mazahreh S (2012) Land Degradation in Jordan - Review of Knowledge Resources, International Center for Agricultural Research in the Dry Areas (ICARDA), OASIS Country Report 1. - MWI - Ministry of Water and Irrigation (2013) Discharge Data for Tanour and Rasoun Springs, Water Information System, National Master Plan Directorate, Amman, Jordan. - UNDP (United Nations Development Programme) (2014, September) About Jordan, http://www.jo.undp.org/content/jordan/en/home/countryinfo/

  5. Control Areas

    Data.gov (United States)

    Department of Homeland Security — This feature class represents electric power Control Areas. Control Areas, also known as Balancing Authority Areas, are controlled by Balancing Authorities, who are...

  6. Multivariate analysis of water quality and environmental variables in the Great Barrier Reef catchments

    Science.gov (United States)

    Ryu, D.; Liu, S.; Western, A. W.; Webb, J. A.; Lintern, A.; Leahy, P.; Wilson, P.; Watson, M.; Waters, D.; Bende-Michl, U.

    2016-12-01

    The Great Barrier Reef (GBR) lagoon has been experiencing significant water quality deterioration due in part to agricultural intensification and urban settlement in adjacent catchments. The degradation of water quality in rivers is caused by land-derived pollutants (i.e. sediment, nutrient and pesticide). A better understanding of dynamics of water quality is essential for land management to improve the GBR ecosystem. However, water quality is also greatly influenced by natural hydrological processes. To assess influencing factors and predict the water quality accurately, selection of the most important predictors of water quality is necessary. In this work, multivariate statistical techniques - cluster analysis (CA), principal component analysis (PCA) and factor analysis (FA) - are used to reduce the complexity derived from the multidimensional water quality monitoring data. Seventeen stations are selected across the GBR catchments, and the event-based measurements of 12 variables monitored during 9 years (2006 - 2014) were analysed by means of CA and PCA/FA. The key findings are: (1) 17 stations can be grouped into two clusters according to the hierarchical CA, and the spatial dissimilarity between these sites is characterised by the different climatic and land use in the GBR catchments. (2) PCA results indicate that the first 3 PCs explain 85% of the total variance, and FA on the entire data set shows that the varifactor (VF) loadings can be used to interpret the sources of spatial variation in water quality on the GBR catchments level. The impact of soil erosion and non-point source of pollutants from agriculture contribution to VF1 and the variability in hydrological conditions and biogeochemical processes can explain the loadings in VF2. (3) FA is also performed on two groups of sites identified in CA individually, to evaluate the underlying sources that are responsible for spatial variability in water quality in the two groups. For the Cluster 1 sites

  7. Accounting for Pharmacokinetic Variability of Certolizumab Pegol in Patients with Crohn's Disease.

    Science.gov (United States)

    Vande Casteele, Niels; Mould, Diane R; Coarse, Jason; Hasan, Iram; Gils, Ann; Feagan, Brian; Sandborn, William J

    2017-12-01

    Certolizumab pegol is an effective biologic for patients with Crohn's disease (CD). Individual differences in certolizumab pegol apparent clearance (CL/F) affect exposure and possibly efficacy. A previously developed population pharmacokinetic (PK) model did not account for dynamic changes in clinical parameters during therapy. The aim of this study was to refine the existing PK model to capture the time-varying influence of covariates. Data collected from 2157 Crohn's disease patients in nine studies were analyzed using nonlinear mixed-effects modeling software (NONMEM). Certolizumab pegol concentration-time data were described by a one-compartment PK model with first-order absorption, and one-compartment disposition with linear, time-dependent elimination using antidrug antibody (ADAb) concentration as a continuous variable. The final dataset consisted of 12,926 analyzable records. Parameter estimates were absorption rate constant 1.83/day, CL/F 0.527 L/day, and apparent volume of distribution (V/F) 8.33 L. ADAb concentration (2.5-214 units/mL) increased the median CL/F by 142-174%. For a typical patient, body weight (46.8-100.5 kg) increased the median CL/F and V/F from 82 to 120%. Albumin (32-48 g/L) decreased and C-reactive protein (0.5-54.0 mg/L) increased the median CL/F from 123 to 85% and from 83 to 113%, respectively. Between-patient variability of CL/F was 19.6%. By incorporating time-varying covariates, this population PK model reduces between-patient variability on CL/F estimates, and the relative influence of ADAb can now be assessed. As Crohn's disease patient covariates are often time-dependent, this model is more reflective of patient drug exposure with sustained treatment.

  8. Relationship between abdominal fat area measured by screening abdominal fat CT and metabolic syndrome in asymptomatic Korean individuals

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dae Woong; Park, Noh Hyuck; Park, Ji Yeon; Kim, Seon Jeong [Dept. of Radiology, MyoungJi Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of)

    2017-07-15

    The purpose of this study was to investigate the relationship between abdominal fat as assessed by abdominal fat CT and metabolic syndrome (MS), especially in asymptomatic Korean individuals. Retrospectively, a medical record analysis was performed in a total of 111 patients with screening abdominal fat CT. The data such as visceral fat (VF), subcutaneous fat (SF) and VF/SF were elicited by abdominal fat CT, and we analyzed the relationship of VF, SF, and VF/SF with MS and cardiovascular risk factors. In males, VF and SF had a positive correlation with many cardiovascular risk factors and MS, but VF was superior to SF. In females, VF, but not SF, had a positive correlation with some cardiovascular risk factors and MS. The cut-off values of VF and SF to predict MS, which were calculated by drawing receiver operating characteristic curves, were as follows: the cut-off value of VF in men: 136.50 cm{sup 2}, the cut-off value of SF in men: 159.50 cm{sup 2}, and the cut-off value of VF in women: 134.50 cm{sup 2}. In conclusion, VF accumulation was the best predictor of MS and it had a positive correlation with cardiovascular risk factors in both sexes. SF also had a significant association with MS, especially in men, although it was not superior to VF.

  9. Heart rate turbulence and variability in patients with ventricular arrhythmias

    Directory of Open Access Journals (Sweden)

    Diego Tarricone

    2009-08-01

    Full Text Available Background: To evaluate the changes in autonomic neural control mechanisms before malignant ventricular arrhythmias, we measured heart rate variability (HRV and heart rate turbulence (HRT in patients with ventricular tachycardia or fibrillation (Group I; n=6, non sustained ventricular tachycardia (Group II; n=32, frequent premature ventricular beats (Group III; n=26 and with ICD implantation (Group IV; n=11. Methods: Time domain parameters of HRV and turbulence onset (TO and slope (TS were calculated on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0% and TS >2.5 msec/RR-I for HRT. Results: Whereas SDNN was within normal range and similar in all study groups, HRT parameters were significantly different in patients who experienced VT/VF during Holter recording. Abnormal TO and/or TS were present in 100% of Group I patients and only in about 50% of Group II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV patients and none of Group I. Conclusions: These data suggest that HRT analysis is more suitable than HRV to detect those transient alterations in autonomic control mechanisms that are likely to play a major trigger role in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7

  10. Solar Variability and Planetary Climates

    CERN Document Server

    Calisesi, Y; Gray, L; Langen, J; Lockwood, M

    2007-01-01

    Variations in solar activity, as revealed by variations in the number of sunspots, have been observed since ancient times. To what extent changes in the solar output may affect planetary climates, though, remains today more than ever a subject of controversy. In 2000, the SSSI volume on Solar Variability and Climate reviewed the to-date understanding of the physics of solar variability and of the associated climate response. The present volume on Solar Variability and Planetary Climates provides an overview of recent advances in this field, with particular focus at the Earth's middle and lower atmosphere. The book structure mirrors that of the ISSI workshop held in Bern in June 2005, the collection of invited workshop contributions and of complementary introductory papers synthesizing the current understanding in key research areas such as middle atmospheric processes, stratosphere-troposphere dynamical coupling, tropospheric aerosols chemistry, solar storm influences, solar variability physics, and terrestri...

  11. External bulb variable volume maser

    Science.gov (United States)

    Reinhardt, V. S.; Cervenka, P. O. (Inventor)

    1978-01-01

    A maser functioning as a frequency standard stable to one part in 10 to the 14th power includes a variable volume, constant surface area storage bulb having a fixed volume portion located in a resonant cavity from which the frequency standard is derived. A variable volume portion of the bulb, exterior to the resonant cavity, has a maximum volume on the same order of magnitude as the fixed volume bulb portion. The cavity has a length to radius ratio of at least 3:1 so that the operation is attained without the need for a feedback loop. A baffle plate, between the fixed and variable volume bulb portions, includes apertures for enabling hydrogen atoms to pass between the two bulb portions and is an electromagnetic shield that prevents coupling of the electromagnetic field of the cavity into the variable volume bulb portion.

  12. Validation of 'variable number of tandem repeat'-based approach for examination of 'Candidatus Liberibacter asiaticus' diversity and its applications for the analysis of the pathogen populations in the areas of recent introduction.

    Directory of Open Access Journals (Sweden)

    Luis A Matos

    Full Text Available Citrus greening (Huanglongbing, HLB is one of the most destructive diseases of citrus worldwide. In South Asia HLB has been known for more than a century, while in Americas the disease was found relatively recently. HLB is associated with three species of 'Candidatus Liberibacter' among which 'Ca. Liberibacter asiaticus' (CLas has most wide distribution. Recently, a number of studies identified different regions in the CLas genome with variable number of tandem repeats (VNTRs that could be used for examination of CLas diversity. One of the objectives of the work presented here was to further validate the VNTR analysis-based approach by assessing the stability of these repeats upon multiplication of the pathogen in a host over an extended period of time and upon its passaging from a host to a host using CLas populations from Florida. Our results showed that the numbers of tandem repeats in the four loci tested display very distinguishable "signature profiles" for the two Florida-type CLas haplotype groups. Remarkably, the profiles do not change upon passage of the pathogen in citrus and psyllid hosts as well as after its presence within a host over a period of five years, suggesting that VNTR analysis-based approach represents a valid methodology for examination of the pathogen populations in various geographical regions. Interestingly, an extended analysis of CLas populations in different locations throughout Florida and in several countries in the Caribbean and Central America regions and in Mexico where the pathogen has been introduced recently demonstrated the dispersion of the same haplotypes of CLas. On the other hand, these CLas populations appeared to differ significantly from those obtained from locations where the disease has been present for a much longer time.

  13. Satisfacción laboral: Análisis de las variables predictoras en una muestra de profesionales de la salud, en Atención Especializada, de un área sanitaria de la Comunidad de Madrid Job satisfaction: Analysis of predictor variables in a sample of healthcare proffessionals, in Specialty Care, of a sanitary area of the Comunidad de Madrid

    Directory of Open Access Journals (Sweden)

    Antonia Bernat Jiménez

    2009-12-01

    Full Text Available Este trabajo presenta los resultados del estudio de satisfacción laboral realizado a una muestra de 873 trabajadores de la sanidad pública, mediante aplicación de un cuestionario ad hoc, cuya estructura se presenta. A partir de estos resultados, se analizan las variables con capacidad predictiva sobre la satisfacción laboral general en la muestra. El objetivo es la búsqueda de un modelo válido que permita el planteamiento de estrategias preventivas y de intervención en el contexto laboral analizado, como vía para aumentar los niveles de satisfacción y salud laboral.This work presents the result of a study in job satisfaction performed to a sample of 873 workers of public healthcare by applying an ad hoc questionnaire whose structure will be presented here too. With the support of these results, the variables with predictor potential over the general sample job satisfaction will be analyzed. The main aim of this work is the finding of a valid model that allows the development of prevention and intervention strategies in the job context analyzed, as a way to increase job satisfaction and public health.

  14. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  15. Classifying variability modeling techniques

    NARCIS (Netherlands)

    Sinnema, Marco; Deelstra, Sybren

    Variability modeling is important for managing variability in software product families, especially during product derivation. In the past few years, several variability modeling techniques have been developed, each using its own concepts to model the variability provided by a product family. The

  16. Revitalization Areas

    Data.gov (United States)

    Department of Housing and Urban Development — Revitalization areas are HUD-designated neighborhoods in need of economic and community development and where there is already a strong commitment by the local...

  17. 700 Area

    Data.gov (United States)

    Federal Laboratory Consortium — The 700 Area of the Hanford Site is located in downtown Richland.Called the Federal Office Building, the Richland Operations Site Manager and the Richland Operations...

  18. Decomposing global crop yield variability

    Science.gov (United States)

    Ben-Ari, Tamara; Makowski, David

    2014-11-01

    Recent food crises have highlighted the need to better understand the between-year variability of agricultural production. Although increasing future production seems necessary, the globalization of commodity markets suggests that the food system would also benefit from enhanced supplies stability through a reduction in the year-to-year variability. Here, we develop an analytical expression decomposing global crop yield interannual variability into three informative components that quantify how evenly are croplands distributed in the world, the proportion of cultivated areas allocated to regions of above or below average variability and the covariation between yields in distinct world regions. This decomposition is used to identify drivers of interannual yield variations for four major crops (i.e., maize, rice, soybean and wheat) over the period 1961-2012. We show that maize production is fairly spread but marked by one prominent region with high levels of crop yield interannual variability (which encompasses the North American corn belt in the USA, and Canada). In contrast, global rice yields have a small variability because, although spatially concentrated, much of the production is located in regions of below-average variability (i.e., South, Eastern and South Eastern Asia). Because of these contrasted land use allocations, an even cultivated land distribution across regions would reduce global maize yield variance, but increase the variance of global yield rice. Intermediate results are obtained for soybean and wheat for which croplands are mainly located in regions with close-to-average variability. At the scale of large world regions, we find that covariances of regional yields have a negligible contribution to global yield variance. The proposed decomposition could be applied at any spatial and time scales, including the yearly time step. By addressing global crop production stability (or lack thereof) our results contribute to the understanding of a key

  19. All varieties of encoding variability are not created equal: Separating variable processing from variable tasks

    Science.gov (United States)

    Huff, Mark J.; Bodner, Glen E.

    2014-01-01

    Whether encoding variability facilitates memory is shown to depend on whether item-specific and relational processing are both performed across study blocks, and whether study items are weakly versus strongly related. Variable-processing groups studied a word list once using an item-specific task and once using a relational task. Variable-task groups’ two different study tasks recruited the same type of processing each block. Repeated-task groups performed the same study task each block. Recall and recognition were greatest in the variable-processing group, but only with weakly related lists. A variable-processing benefit was also found when task-based processing and list-type processing were complementary (e.g., item-specific processing of a related list) rather than redundant (e.g., relational processing of a related list). That performing both item-specific and relational processing across trials, or within a trial, yields encoding-variability benefits may help reconcile decades of contradictory findings in this area. PMID:25018583

  20. Photospheric Variability and the Solar Atmosphere

    Science.gov (United States)

    Rosner, R.

    Variations in the bolometric luminosity of the Sun (due to photospheric variability) have for some time been related to solar magnetic activity. Such variations are observed on both the solar rotational period and on much longer time scales; I will review the current work in this area, and discuss related work in observations of stellar photospheric variability tied to stellar magnetic activity.

  1. Combining Amplitude Spectrum Area with Previous Shock Information Using Neural Networks Improves Prediction Performance of Defibrillation Outcome for Subsequent Shocks in Out-Of-Hospital Cardiac Arrest Patients.

    Directory of Open Access Journals (Sweden)

    Mi He

    Full Text Available Quantitative ventricular fibrillation (VF waveform analysis is a potentially powerful tool to optimize defibrillation. However, whether combining VF features with additional attributes that related to the previous shock could enhance the prediction performance for subsequent shocks is still uncertain.A total of 528 defibrillation shocks from 199 patients experienced out-of-hospital cardiac arrest were analyzed in this study. VF waveform was quantified using amplitude spectrum area (AMSA from defibrillator's ECG recordings prior to each shock. Combinations of AMSA with previous shock index (PSI or/and change of AMSA (ΔAMSA between successive shocks were exercised through a training dataset including 255shocks from 99patientswith neural networks. Performance of the combination methods were compared with AMSA based single feature prediction by area under receiver operating characteristic curve(AUC, sensitivity, positive predictive value (PPV, negative predictive value (NPV and prediction accuracy (PA through a validation dataset that was consisted of 273 shocks from 100patients.A total of61 (61.0% patients required subsequent shocks (N = 173 in the validation dataset. Combining AMSA with PSI and ΔAMSA obtained highest AUC (0.904 vs. 0.819, p<0.001 among different combination approaches for subsequent shocks. Sensitivity (76.5% vs. 35.3%, p<0.001, NPV (90.2% vs. 76.9%, p = 0.007 and PA (86.1% vs. 74.0%, p = 0.005were greatly improved compared with AMSA based single feature prediction with a threshold of 90% specificity.In this retrospective study, combining AMSA with previous shock information using neural networks greatly improves prediction performance of defibrillation outcome for subsequent shocks.

  2. Variable Valve Actuation

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of

  3. In vivo porcine model of reperfused myocardial infarction: in situ double staining to measure precise infarct area/area at risk.

    Science.gov (United States)

    Suzuki, Yoriyasu; Lyons, Jennifer K; Yeung, Alan C; Ikeno, Fumiaki

    2008-01-01

    The aim of this study is to evaluate a catheter-based porcine model for reperfused myocardial infarction and investigate the appropriate location and duration of the occlusion. A balloon catheter was placed in the left descending coronary artery (LAD) in 78 swine, and used to occlude the LAD. To evaluate this model, left ventricular ejection fraction (LVEF), infarct size, incidence of ventricular fibrillation (VF), and mortality was compared among three groups: 60-min proximal LAD occlusion (60P), 60-min mid LAD occlusion (60M), and 30-min proximal LAD occlusion (30P). In 72 of the 78 pigs, the procedures were successfully completed. Both mortality and incidence of VF were highest in the 60P group (66.7% and 91.7%, respectively). Myocardial infarction was successfully induced in all 72 animals and in situ double-staining with Evans blue dye and 2,3,5-triphenyltetrazolium chloride was performed to delineate area at risk for ischemia and infarcted myocardium. There was no difference in infarct size, expressed as a percentage of the area at risk, between the 60P and 60M groups (49.5% +/- 3.9% vs. 45.4% +/- 13.3%, respectively). Serial changes in LVEF of the 60M group demonstrated that until 14 days after reperfusion, LVEF improved naturally over time (36.4% +/- 6.6% at 24 hr, and 47.3% +/- 10.1% at 14 days). This model and methodology could provide a reproducible and consistent infarct size. The current study demonstrated that 60-min mid LAD occlusion can be the most feasible to serve as a porcine reperfused myocardial infarction model. Copyright 2008 Wiley-Liss, Inc.

  4. Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2011-07-15

    A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT. To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation. A total of 137 patients (mean age, 7.6 years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient ({gamma}{sup 2} = 0.86, P < 0.001). For the next study, 177 patients (mean age, 7.9 years; the CTDIvol group) underwent contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the best fit equation. CTDIvol values on the dose report after CT scanning, noise differences from the target noise, areas, and mean densities were compared between these two groups. The CTDIvol values (mean{+-}standard deviation, 1.6 {+-} 0.7 mGy) and the noise differences from the target noise (1.1 {+-} 0.9 HU) of the CTDIvol group were significantly lower than those of the weight-based group (2.0 {+-} 1.0 mGy, 1.8 {+-} 1.4 HU) (P < 0.001). In contrast, no statistically significant difference was found in area (317.0 {+-} 136.8 cm{sup 2} vs. 326.3 {+-} 124.8 cm{sup 2}), mean density (-212.9 {+-} 53.1 HU vs. -221.1 {+-} 56.3 HU), and image noise (13.8 {+-} 2.3 vs. 13.6 {+-} 1.7 HU) between the weight-based and the CTDIvol groups (P > 0.05). Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation. (orig.)

  5. Mapping the variation of soil organic carbon (SOC) stock in time and space in Sicily, an extremely variable semi-arid Mediterranean region, highlighted that C was lost in area rich in organic C and gained in poor-C areas

    Science.gov (United States)

    Schillaci, Calogero; Acutis, Marco; Lombardo, Luigi; Lipani, Aldo; Fantappiè, Maria; Märker, Michael; Saia, Sergio

    2017-04-01

    The stock of organic carbon in the soil (SOC) is an indicator of soil ability to support agro-ecosystems productivity and resilience to environmental changes (Schillaci et al. 2016; 2017). In addition, SOC stock change through space and especially time is a valuable indicator of the soil ability to sequester CO2 from the atmosphere and thus its potential to reduce the greenhouse gas effect. In the present work, we mapped (1-km resolution) the space-time variation of the SOC stock after 15 years (1993 to 2008) in a semi-arid Mediterranean area (25,286 km2) after modelling SOC concentration (0-0.4 m depth) with boosted regression trees (BRT) and computing the SOC stock after the application of the bulk density maps of ISRIC (soilgrid.com, Hengl et al., 2014). The area under study (Sicily, south of Italy) has a plenty of contrasting environments, with changing ecosystems, soils, and microclimatic regions. The BRT procedure was run with a set of 25 predictors per year, including land use, soil traits, morphometric indicators and remote sensing covariates (derived from Landsat5 data). The BRT output consisted of a high pseudo-R2(=0.71 for 1993 and 0.63 for 2008) of the SOC concentration, low uncertainty (standard deviation mountainous environments with high initial SOC stock and extensively used for forestry. This decrease was likely due to both high erosion rates and a short-term change in the climate, especially temperature. A high and positive percentage variation of the SOC stock (+39.1 % to +180.0%, corresponding to the data higher than the mean+s.d.) was found in 14.3% of the area under study. These environments are dominated by non-irrigated arable lands and characterized by low SOC, low rainfall and high temperature. In these conditions, the increase of the SOC stock found in 15 years likely occurred to the compulsory application of some Good Agricultural and Environmental Conditions, some of which were compulsory during the study period. Despite the mean SOC

  6. Types of biological variables.

    Science.gov (United States)

    Mayya, Shreemathi S; Monteiro, Ashma D; Ganapathy, Sachit

    2017-06-01

    Identification and description of variables used in any study is a necessary component in biomedical research. Statistical analyses rely on the type of variables that are involved in the study. In this short article, we introduce the different types of biological variables. A researcher has to be familiar with the type of variable he/she is dealing with in his/her research to decide about appropriate graphs/diagrams, summary measures and statistical analysis.

  7. Variable mechanical ventilation

    OpenAIRE

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini Jr.,Luiz Alberto; Friedman, Gilberto

    2017-01-01

    Objective To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Methods Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE?, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". Results A total of 36 studies were selected. ...

  8. Latent variable theory

    NARCIS (Netherlands)

    Borsboom, D.

    2008-01-01

    This paper formulates a metatheoretical framework for latent variable modeling. It does so by spelling out the difference between observed and latent variables. This difference is argued to be purely epistemic in nature: We treat a variable as observed when the inference from data structure to

  9. Amplification variable factor amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  10. Amplification variable factor amplifier

    NARCIS (Netherlands)

    Akitsugu, O.; Nauta, Bram

    2006-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  11. Variable-density thinning in coast redwood: a comparison of marking strategies to attain stand variability

    Science.gov (United States)

    Kevin L. O' Hara; Lathrop P. Leonard; Christopher R. Keyes

    2012-01-01

    Variable-density thinning (VDT) is an emerging thinning method that attempts to enhance stand structural heterogeneity by deliberately thinning at different intensities throughout a stand. VDT may create stands with dense areas, open areas, and other areas that may be intermediate in density. Subsequent stand development forms a more varied structure than is...

  12. Quiet areas

    DEFF Research Database (Denmark)

    Petersen, Rikke Munck

    2016-01-01

    This paper argues that drone filming can substantiate our understanding of multisensorial experiences of quiet areas and urban landscapes. Contrary to the distanced gaze often associated with the drone, this paper discusses drone filming as an intimate performativity apparatus that can affect...... perception as a result of its interrelationships between motion, gaze, and sound. This paper uses four films, one of which is a drone flyover, to launch a discussion concerning a smooth and alluring gaze, a sliding gaze that penetrates landscapes, and site appearance. Films hold the capacity to project both...... and transcendence can facilitate a deeper understanding of intimate sensations, substantiating their role in the future design and planning of urban landscapes. Hence, it addresses the ethics of an intimacy perspective (of drone filming) in the qualification of quiet areas....

  13. Variable mechanical ventilation

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini Jr., Luiz Alberto; Friedman, Gilberto

    2017-01-01

    Objective To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Methods Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". Results A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Conclusion Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation. PMID:28444076

  14. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  15. Climate variation explains a third of global crop yield variability.

    Science.gov (United States)

    Ray, Deepak K; Gerber, James S; MacDonald, Graham K; West, Paul C

    2015-01-22

    Many studies have examined the role of mean climate change in agriculture, but an understanding of the influence of inter-annual climate variations on crop yields in different regions remains elusive. We use detailed crop statistics time series for ~13,500 political units to examine how recent climate variability led to variations in maize, rice, wheat and soybean crop yields worldwide. While some areas show no significant influence of climate variability, in substantial areas of the global breadbaskets, >60% of the yield variability can be explained by climate variability. Globally, climate variability accounts for roughly a third (~32-39%) of the observed yield variability. Our study uniquely illustrates spatial patterns in the relationship between climate variability and crop yield variability, highlighting where variations in temperature, precipitation or their interaction explain yield variability. We discuss key drivers for the observed variations to target further research and policy interventions geared towards buffering future crop production from climate variability.

  16. Area-normalized thematic views

    Energy Technology Data Exchange (ETDEWEB)

    Keahey, T.A.

    1998-10-01

    This paper presents a novel technique for dealing with a classic problem that frequently arises in visualization. Very expressive nonlinear transformations can be automatically generated to correct thematic maps so that the areas of map regions are proportional to the thematic variables assigned to them. This helps to eliminate one of the most commonly occurring visual lies that occurs in information visualization. Thematic variables are commonly used in cartography to encode additional information within the spatial layout of a map. Common examples of thematic variables are population density, pollution level and birth rate. The method is illustrated with two examples, mapping interstate speed limits and presidential election results.

  17. Lectures on several complex variables

    CERN Document Server

    Gauthier, Paul M

    2014-01-01

    This monograph provides a concise, accessible snapshot of key topics in several complex variables, including the Cauchy Integral Formula, sequences of holomorphic functions, plurisubharmonic functions, the Dirichlet problem, and meromorphic functions.  Based on a course given at Université de Montréal, this brief introduction covers areas of contemporary importance that are not mentioned in most treatments of the subject, such as modular forms, which are essential for Wiles' theorem and the unification of quantum theory and general relativity.   Also covered is the Riemann manifold of a function, which generalizes the Riemann surface of a function of a single complex variable and is a topic that is well-known in one complex variable, but rarely treated in several variables.  Many details, which are intentionally left out, as well as many theorems are stated as problems, providing students with carefully structured instructive exercises.   Prerequisites for use of this book are functions of one complex ...

  18. The nebular variables

    CERN Document Server

    Glasby, John S

    1974-01-01

    The Nebular Variables focuses on the nebular variables and their characteristics. Discussions are organized by type of nebular variable, namely, RW Aurigae stars, T Orionis stars, T Tauri stars, and peculiar nebular objects. Topics range from light variations of the stars to their spectroscopic and physical characteristics, spatial distribution, interaction with nebulosity, and evolutionary features. This volume is divided into four sections and consists of 25 chapters, the first of which provides general information on nebular variables, including their stellar associations and their classifi

  19. INTER-EXAMINER VARIABILITY

    African Journals Online (AJOL)

    Background: The traditional clinical examination has fallen into disfavour on account of considerable inter-examiner variability. The OSCE is gaining popularity as it is perceived to be less prone to this. Objective: To establish whether inter-examiner variability is still a significant factor for the undergraduate orthopaedic ...

  20. Software variability management

    NARCIS (Netherlands)

    Bosch, J; Nord, RL

    2004-01-01

    During recent years, the amount of variability that has to be supported by a software artefact is growing considerably and its management is evolving into a major challenge during development, usage, and evolution of software artefacts. Successful management of variability in software leads to

  1. Microinertia and internal variables

    CERN Document Server

    Berezovski, A

    2015-01-01

    The origin of microinertia of micromorphic theories is investigated from the point of view of non-equilibrium thermodynamics. In the framework of dual internal variables microinertia stems from a thermodynamic equation of state related to the internal variable with the properties of mechanical momentum.

  2. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  3. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  4. Real variables with basic metric space topology

    CERN Document Server

    Ash, Robert B

    2009-01-01

    Designed for a first course in real variables, this text presents the fundamentals for more advanced mathematical work, particularly in the areas of complex variables, measure theory, differential equations, functional analysis, and probability. Geared toward advanced undergraduate and graduate students of mathematics, it is also appropriate for students of engineering, physics, and economics who seek an understanding of real analysis.The author encourages an intuitive approach to problem solving and offers concrete examples, diagrams, and geometric or physical interpretations of results. Deta

  5. Eficiência do modelo ceres-maize na predição da produtividade de milho em áreas com presença de variabilidade espacial Ceres-Maize model efficiency in corn yield prediction within spatial variable areas

    Directory of Open Access Journals (Sweden)

    Sandro Manuel Carmelino Hurtado

    2005-12-01

    Full Text Available Modelos são utilizados para a simulação do crescimento de plantas como ferramentas na otimização das práticas de manejo, bem como para estimar produtividades. Com este estudo objetivou-se testar a eficiência do modelo CERES-maize na estimação da produtividade de milho, em função da variabilidade espacial presente na área. Foram instaladas no Campus da UFLA parcelas experimentais em áreas variáveis segundo o teor de saturação por bases (V%, ao ter-se mostrado decisivo nas observações realizadas. Também foram obtidos dados de temperaturas máxima e mínima, precipitação e radiação solar; dados de solo nas camadas de 0-27, 27-45, 45-68 68-80 e 80-100 cm; dados de manejo da cultura do milho, e estimados os parâmetros genéticos do híbrido utilizado. Os resultados da simulação mostraram que as produtividades foram maiores em áreas com elevada saturação por bases, coincidindo com as produtividades observadas. Melhores aproximações nas respostas estimadas ficaram evidentes quando foram utilizados os valores dos parâmetros genéticos próprios a cada parcela. Concluiu-se que o modelo CERES-maize foi capaz de estimar a tendência das diferentes produtividades observadas, em função da variabilidade espacial da saturação por bases (V%, obtendo-se simulações mais precisas ao utilizar os valores dos parâmetros genéticos próprios a cada parcela.Simulation models are tools utilized for optimization of managements practices as well as to estimate crop yield. The present study aimed to test the efficiency of the CERES-maize model to simulate corn yield related to the field spatial variability. The experimental area was located at Federal University of Lavras, where experimental plots were established according to the variable areas of base saturation (V%, a parameter regarded as decisive in the observed yields. Data of maximum and minimum temperatures, rainfall and solar radiation; soil data in the 0-27, 27-45, 45-68, 68

  6. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  7. Cognitive Variables Implicated In Chronic Pain

    Directory of Open Access Journals (Sweden)

    Moretti, Luciana Sofía

    2010-12-01

    Full Text Available Since the creation of gate control theory, the importance of psychological variables in chronic pain has emerged. Thus, the cognitive variables are emphasized in between behaviors, emotions and social factors for the explanation of chronic pain. Considering the gate control theory, cognitive variables modulate the other two dimensions of the chronic pain experience: the motivational-afective dimension and the sensory-discriminative dimension (Camacho Martel & Anarte Ortiz, 2001; Gatchel, Peng, Peters, Fuchs & Turk, 2007. The aim of this work is to review the main cognitive variables implicated in the chronic pain experience. Moreover, empirical evidence that support the importance of these variables is presented. Furthermore, it is discussed the clinical implications and the importance of this area in the local context.

  8. Quantum engineering of continuous variable quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Sabuncu, Metin

    2009-10-29

    Quantum information with continuous variables is a field attracting increasing attention recently. In continuous variable quantum information one makes use of the continuous information encoded into the quadrature of a quantized light field instead of binary quantities such as the polarization state of a single photon. This brand new research area is witnessing exciting theoretical and experimental achievements such as teleportation, quantum computation and quantum error correction. The rapid development of the field is mainly due higher optical data rates and the availability of simple and efficient manipulation tools in continuous-variable quantum information processing. We in this thesis extend the work in continuous variable quantum information processing and report on novel experiments on amplification, cloning, minimal disturbance and noise erasure protocols. The promising results we obtain in these pioneering experiments indicate that the future of continuous variable quantum information is bright and many advances can be foreseen. (orig.)

  9. Eternity Variables to Simulate Specifications

    NARCIS (Netherlands)

    Hesselink, WH; Boiten, EA; Moller, B

    2002-01-01

    Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward

  10. Variable-Rate Premiums

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — These interest rates are used to value vested benefits for variable rate premium purposes as described in PBGC's regulation on Premium Rates (29 CFR Part 4006) and...

  11. Software Testing Requires Variability

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2003-01-01

    Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic i...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability.......Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...

  12. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  13. Calculus of one variable

    CERN Document Server

    Grossman, Stanley I

    1986-01-01

    Calculus of One Variable, Second Edition presents the essential topics in the study of the techniques and theorems of calculus.The book provides a comprehensive introduction to calculus. It contains examples, exercises, the history and development of calculus, and various applications. Some of the topics discussed in the text include the concept of limits, one-variable theory, the derivatives of all six trigonometric functions, exponential and logarithmic functions, and infinite series.This textbook is intended for use by college students.

  14. Neuroanatomical variability of religiosity.

    Science.gov (United States)

    Kapogiannis, Dimitrios; Barbey, Aron K; Su, Michael; Krueger, Frank; Grafman, Jordan

    2009-09-28

    We hypothesized that religiosity, a set of traits variably expressed in the population, is modulated by neuroanatomical variability. We tested this idea by determining whether aspects of religiosity were predicted by variability in regional cortical volume. We performed structural magnetic resonance imaging of the brain in 40 healthy adult participants who reported different degrees and patterns of religiosity on a survey. We identified four Principal Components of religiosity by Factor Analysis of the survey items and associated them with regional cortical volumes measured by voxel-based morphometry. Experiencing an intimate relationship with God and engaging in religious behavior was associated with increased volume of R middle temporal cortex, BA 21. Experiencing fear of God was associated with decreased volume of L precuneus and L orbitofrontal cortex BA 11. A cluster of traits related with pragmatism and doubting God's existence was associated with increased volume of the R precuneus. Variability in religiosity of upbringing was not associated with variability in cortical volume of any region. Therefore, key aspects of religiosity are associated with cortical volume differences. This conclusion complements our prior functional neuroimaging findings in elucidating the proximate causes of religion in the brain.

  15. Classifying TDSS Stellar Variables

    Science.gov (United States)

    Amaro, Rachael Christina; Green, Paul J.; TDSS Collaboration

    2017-01-01

    The Time Domain Spectroscopic Survey (TDSS), a subprogram of SDSS-IV eBOSS, obtains classification/discovery spectra of point-source photometric variables selected from PanSTARRS and SDSS multi-color light curves regardless of object color or lightcurve shape. Tens of thousands of TDSS spectra are already available and have been spectroscopically classified both via pipeline and by visual inspection. About half of these spectra are quasars, half are stars. Our goal is to classify the stars with their correct variability types. We do this by acquiring public multi-epoch light curves for brighter stars (rclassifications and parameters in the Catalina Surveys Periodic Variable Star Catalog. Variable star classifications include RR Lyr, close eclipsing binaries, CVs, pulsating white dwarfs, and other exotic systems. The key difference between our catalog and others is that along with the light curves, we will be using TDSS spectra to help in the classification of variable type, as spectra are rich with information allowing estimation of physical parameters like temperature, metallicity, gravity, etc. This work was supported by the SDSS Research Experience for Undergraduates program, which is funded by a grant from Sloan Foundation to the Astrophysical Research Consortium.

  16. Cancer Related-Knowledge - Small Area Estimates

    Science.gov (United States)

    These model-based estimates are produced using statistical models that combine data from the Health Information National Trends Survey, and auxiliary variables obtained from relevant sources and borrow strength from other areas with similar characteristics.

  17. ALMOST IDEAL AREA YIELD CROP INSURANCE CONTRACTS

    OpenAIRE

    Smith, Vincent H.; Chouinard, Hayley H.; Baquet, Alan E.

    1994-01-01

    Using yield data for a sample of 123 dryland wheat producers in Montana, the effects of three area yield contracts, including the contract currently offered by the United States Federal Crop Insurance Corporation and two individual yield contracts on individual farm yield variability, are examined. The results indicate that while the Federal Crop Insurance Corporation area yield contract provides all farmers in the sample with some protection against yield variability, a simpler, actuarially ...

  18. Resiliencia y variables sociodemograficas

    OpenAIRE

    Calero Martinez, Edgar David

    2015-01-01

    En el presente trabajo se aborda la definición de una de las variables dentro de lo que se denomina Capital psicológico positivo, la Resiliencia, sus principales características y algunas de las variables socio demográficas que en el estudio pretenden ver el nivel de relación existente entre cada una de ellas (indirecta o directamente) en el proceso resiliente de una persona para posteriores discusiones y su implicación dentro de la gestión empresarial y sus direcciones futuras.

  19. Validation and Variability

    DEFF Research Database (Denmark)

    Carusi, Annamaria

    2014-01-01

    as inter-subject variability. This need is simultaneously social and epistemic: social as systems biologists attempt to engage with the interests and concerns of clinicians and others in applied medical research; epistemic as they attempt to develop new strategies to cope with variability in the validation...... of the computational models typical of systems biology. This paper describes one attempt to develop such a strategy: a trial with a population of models approach in the context of cardiac electrophysiology. I discuss the development of this approach against the background of ongoing tensions between mathematically...

  20. Applied complex variables

    CERN Document Server

    Dettman, John W

    1965-01-01

    Analytic function theory is a traditional subject going back to Cauchy and Riemann in the 19th century. Once the exclusive province of advanced mathematics students, its applications have proven vital to today's physicists and engineers. In this highly regarded work, Professor John W. Dettman offers a clear, well-organized overview of the subject and various applications - making the often-perplexing study of analytic functions of complex variables more accessible to a wider audience. The first half of Applied Complex Variables, designed for sequential study, is a step-by-step treatment of fun

  1. Internal variables in thermoelasticity

    CERN Document Server

    Berezovski, Arkadi

    2017-01-01

    This book describes an effective method for modeling advanced materials like polymers, composite materials and biomaterials, which are, as a rule, inhomogeneous. The thermoelastic theory with internal variables presented here provides a general framework for predicting a material’s reaction to external loading. The basic physical principles provide the primary theoretical information, including the evolution equations of the internal variables. The cornerstones of this framework are the material representation of continuum mechanics, a weak nonlocality, a non-zero extra entropy flux, and a consecutive employment of the dissipation inequality. Examples of thermoelastic phenomena are provided, accompanied by detailed procedures demonstrating how to simulate them.

  2. Terrestrial Carbon Cycle Variability.

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2 , temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1 ) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1 ), and

  3. Complex variables I essentials

    CERN Document Server

    Solomon, Alan D

    2013-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Complex Variables I includes functions of a complex variable, elementary complex functions, integrals of complex functions in the complex plane, sequences and series, and poles and r

  4. A pocket of variability in Pinus rigida

    Science.gov (United States)

    F. Thomas Ledig; John H. Fryer

    1971-01-01

    Steady state gene frequencies around a pocket of differential fitness have been formulated by Hanson (1966) in a generalization of the work of Haldane (1948). A pocket of differential fitness would result in a pocket-of-variability, assuming that the radius of the area of contrasting fitness was large in relation to the vagility of the organism. Conversely, the absence...

  5. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  6. Proper elimination of latent variables

    NARCIS (Netherlands)

    Polderman, Jan W.

    1997-01-01

    We consider behaviors in which we distinguish two types of variables, manifest variables, the variables that are of interest to the user and latent variables, the variables that are introduced to obtain a first representation. The problem is to find a representation of the manifest behavior, that

  7. DATA COLLECTION METHOD FOR PEDESTRIAN MOVEMENT VARIABLES

    Directory of Open Access Journals (Sweden)

    Hajime Inamura

    2000-01-01

    Full Text Available The need of tools for design and evaluation of pedestrian areas, subways stations, entrance hall, shopping mall, escape routes, stadium etc lead to the necessity of a pedestrian model. One approach pedestrian model is Microscopic Pedestrian Simulation Model. To be able to develop and calibrate a microscopic pedestrian simulation model, a number of variables need to be considered. As the first step of model development, some data was collected using video and the coordinate of the head path through image processing were also taken. Several numbers of variables can be gathered to describe the behavior of pedestrian from a different point of view. This paper describes how to obtain variables from video taking and simple image processing that can represent the movement of pedestrians and its variables

  8. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  9. Classes of Instructional Variables.

    Science.gov (United States)

    Reigeluth, Charles M.; Merrill, M. David

    1979-01-01

    Describes three classes of variables which should be considered when one is designing instructional materials, doing research on instruction, or developing better methods of instruction, and proposes a classification scheme which is summarized in the last of the 13 figures that illustrate the article. A blbliography is included. (Author/RAO)

  10. Variable rate irrigation

    Science.gov (United States)

    Systems are available to producers to make variable-rate applications of defoliants, fertilizer, lime, pesticides, plant growth regulators, and seed. These systems could potentially offer cost savings to a producer; however, the full potential of the benefits and savings cannot be realized if water ...

  11. Variable gravity research facility

    Science.gov (United States)

    Allan, Sean; Ancheta, Stan; Beine, Donna; Cink, Brian; Eagon, Mark; Eckstein, Brett; Luhman, Dan; Mccowan, Daniel; Nations, James; Nordtvedt, Todd

    1988-01-01

    Spin and despin requirements; sequence of activities required to assemble the Variable Gravity Research Facility (VGRF); power systems technology; life support; thermal control systems; emergencies; communication systems; space station applications; experimental activities; computer modeling and simulation of tether vibration; cost analysis; configuration of the crew compartments; and tether lengths and rotation speeds are discussed.

  12. Typhoon Structural Variability,

    Science.gov (United States)

    1985-10-01

    1980: An analytical model of the wind and pressure profiles in hurricanes. Mort . KUa. Rev., 108, 8, 1212-1218. Holland, G. J., and R. T. Merrill, 1984...Recipient’s Acce..sion No. SHEET ATS-391 4. Title and Subit le 5. Report Date Typhoon Structural Variability October, 1985 6. 7. Author(s) S. Performing

  13. Variable thrust cartridge

    Science.gov (United States)

    Taleyarkhan, Rusi P.

    2000-11-07

    The present invention is a variable thrust cartridge comprising a water-molten aluminum reaction chamber from which a slug is propelled. The cartridge comprises a firing system that initiates a controlled explosion from the reaction chamber. The explosive force provides a thrust to a slug, preferably contained within the cartridge.

  14. Variability and component composition

    NARCIS (Netherlands)

    T. van der Storm (Tijs)

    2004-01-01

    textabstractIn component-based product populations, feature models have to be described at the component level to be able to benefit from a product family approach. As a consequence, composition of components becomes very complex. We describe how component-level variability can be managed in the

  15. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  16. All Those Independent Variables.

    Science.gov (United States)

    Meacham, Merle L.

    This paper presents a case study of a sixth grade remedial math class which illustrates the thesis that only the "experimental attitude," not the "experimental method," is appropriate in the classroom. The thesis is based on the fact that too many independent variables exist in a classroom situation to allow precise measurement. The case study…

  17. Technological Capability's Predictor Variables

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2011-03-01

    Full Text Available The aim of this study was to identify the factors that influence in configuration of the technological capability of companies in sectors with medium-low technological intensity. To achieve the goal proposed in this article a survey was carried out. Based on the framework developed by Lall (1992 which classifies firms in basic, intermediate and advanced level of technological capability; it was found that the predominant technological capability is intermediate, with 83.7% of respondent companies (plastics companies in Brazil. It is believed that the main contribution of this study is the finding that the dependent variable named “Technological Capability” can be explained at a rate of 65% by six variables: development of new processes; selection of the best equipment supplier; sales of internally developed new technology to third parties; design and manufacture of equipment; study of the work methods and perform inventory control; and improvement of product quality.

  18. Complex variable HVPT

    Energy Technology Data Exchange (ETDEWEB)

    Killingbeck, John P [Mathematics Department, University of Hull, Hull HU6 7RX (United Kingdom); Grosjean, Alain [Laboratoire d' Astrophysique de l' Observatoire de Besancon (CNRS, UPRES-A 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France); Jolicard, Georges [Laboratoire d' Astrophysique de l' Observatoire de Besancon (CNRS, UPRES-A 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France)

    2004-08-13

    Complex variable hypervirial perturbation theory is applied to the case of oscillator and Coulomb potentials perturbed by a single term potential of the form Vx{sup n} or Vr{sup n}, respectively. The trial calculations reported show that this approach can produce accurate complex energies for resonant states via a simple and speedy calculation and can also be useful in studies of PT symmetry and tunnelling resonance effects. (addendum)

  19. Spreading with variable viscosity

    OpenAIRE

    Foit, J.J.

    1997-01-01

    Ausbreitung mit variabler Viskosität Die isotherme Ausbreitung eines Volumenstromes, , in Form von dünnen Schichten kann mit Hilfe selbstähnlicher Lösungen beschrieben werden (Huppert). Für die axialsymmetrische Ausbreitung eines konstanten Volumens mit einer variablen Viskosität von der Form existieren ebenfalls selbstähnliche Lösungen (Sakimoto, Zuber). Dieses Ergebnis wird auf den Fall einer eindimensionalen und einer axialsymmetrischen Ausbreitung für alle , erweitert.

  20. Historical Variable Star Catalogs

    OpenAIRE

    Pagnotta, Ashley; Graur, Or; Murray, Zachary; Kruk, Julia; Christie-Dervaux, Lucien; Chen, Dong Yi

    2015-01-01

    Slides from my talk during one of the Historical Astronomy Division sessions at AAS 225 in Seattle, WA (January 2015). A brief history of the variable star catalogs Henrietta Swan Leavitt and Cecilia Payne-Gaposchkin assembled at Harvard, and the update to them that some of our students at AMNH have done.(Figshare only previews the first few slides. Download the PDF to see all of them!)

  1. Score test variable screening

    OpenAIRE

    Zhao, Sihai Dave; Li, Yi

    2014-01-01

    Variable screening has emerged as a crucial first step in the analysis of high-throughput data, but existing procedures can be computationally cumbersome, difficult to justify theoretically, or inapplicable to certain types of analyses. Motivated by a high-dimensional censored quantile regression problem in multiple myeloma genomics, this paper makes three contributions. First, we establish a score test-based screening framework, which is widely applicable, extremely computationally efficient...

  2. Short Timescale Variability In The Faint Sky Variability Survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V band variability analysis of the point sources in the Faint Sky Variability Survey on time scales from 24 minutes to tens of days. We find that about one percent of the point sources down to V = 24 are variables. We discuss the variability detection probabilities for each field

  3. Short timescale variability in the faint sky variability survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V-band variability analysis of the Faint Sky Variability Survey (FSVS). The FSVS combines colour and time variability information, from timescales of 24 minutes to tens of days, down to V = 24. We find that �1% of all point sources are variable along the main sequence reaching �3.5%

  4. Population effects and variability.

    Science.gov (United States)

    Dorne, Jean Lou; Amzal, Billy; Bois, Frédéric; Crépet, Amélie; Tressou, Jessica; Verger, Philippe

    2012-01-01

    Chemical risk assessment for human health requires a multidisciplinary approach through four steps: hazard identification and characterization, exposure assessment, and risk characterization. Hazard identification and characterization aim to identify the metabolism and elimination of the chemical (toxicokinetics) and the toxicological dose-response (toxicodynamics) and to derive a health-based guidance value for safe levels of exposure. Exposure assessment estimates human exposure as the product of the amount of the chemical in the matrix consumed and the consumption itself. Finally, risk characterization evaluates the risk of the exposure to human health by comparing the latter to with the health-based guidance value. Recently, many research efforts in computational toxicology have been put together to characterize population variability and uncertainty in each of the steps of risk assessment to move towards more quantitative and transparent risk assessment. This chapter focuses specifically on modeling population variability and effects for each step of risk assessment in order to provide an overview of the statistical and computational tools available to toxicologists and risk assessors. Three examples are given to illustrate the applicability of those tools: derivation of pathway-related uncertainty factors based on population variability, exposure to dioxins, dose-response modeling of cadmium.

  5. Interpolation of climate variables and temperature modeling

    Science.gov (United States)

    Samanta, Sailesh; Pal, Dilip Kumar; Lohar, Debasish; Pal, Babita

    2012-01-01

    Geographic Information Systems (GIS) and modeling are becoming powerful tools in agricultural research and natural resource management. This study proposes an empirical methodology for modeling and mapping of the monthly and annual air temperature using remote sensing and GIS techniques. The study area is Gangetic West Bengal and its neighborhood in the eastern India, where a number of weather systems occur throughout the year. Gangetic West Bengal is a region of strong heterogeneous surface with several weather disturbances. This paper also examines statistical approaches for interpolating climatic data over large regions, providing different interpolation techniques for climate variables' use in agricultural research. Three interpolation approaches, like inverse distance weighted averaging, thin-plate smoothing splines, and co-kriging are evaluated for 4° × 4° area, covering the eastern part of India. The land use/land cover, soil texture, and digital elevation model are used as the independent variables for temperature modeling. Multiple regression analysis with standard method is used to add dependent variables into regression equation. Prediction of mean temperature for monsoon season is better than winter season. Finally standard deviation errors are evaluated after comparing the predicted temperature and observed temperature of the area. For better improvement, distance from the coastline and seasonal wind pattern are stressed to be included as independent variables.

  6. FHFA Underserved Areas

    Data.gov (United States)

    Department of Housing and Urban Development — Federal Housing Finance Agency's (FHFA) Underserved Areas establishes underserved area designations for census tracts in Metropolitan Areas (MSAs), nonmetropolitan...

  7. Robust cluster analysis and variable selection

    CERN Document Server

    Ritter, Gunter

    2014-01-01

    Clustering remains a vibrant area of research in statistics. Although there are many books on this topic, there are relatively few that are well founded in the theoretical aspects. In Robust Cluster Analysis and Variable Selection, Gunter Ritter presents an overview of the theory and applications of probabilistic clustering and variable selection, synthesizing the key research results of the last 50 years. The author focuses on the robust clustering methods he found to be the most useful on simulated data and real-time applications. The book provides clear guidance for the varying needs of bot

  8. Correlation of end tidal carbon dioxide, amplitude spectrum area, and coronary perfusion pressure in a porcine model of cardiac arrest.

    Science.gov (United States)

    Segal, Nicolas; Metzger, Anja K; Moore, Johanna C; India, Laura; Lick, Michael C; Berger, Paul S; Tang, Wanchun; Benditt, David G; Lurie, Keith G

    2017-09-01

    Amplitude Spectrum Area (AMSA) values during ventricular fibrillation (VF) correlate with myocardial energy stores and predict defibrillation success. By contrast, end tidal CO2 (ETCO2) values provide a noninvasive assessment of coronary perfusion pressure and myocardial perfusion during cardiopulmonary resuscitation (CPR). Given the importance of the timing of defibrillation shock delivery on clinical outcome, we tested the hypothesis that AMSA and ETCO2 correlate with each other and can be used interchangably to correlate with myocardial perfusion in an animal laboratory preclinical, randomized, prospective investigation. After 6 min of untreated VF, 12 female pigs (32 ± 1 Kg), isoflurane anesthetized pigs received sequentially 3 min periods of standard (S) CPR, S-CPR+ an impedance threshold device (ITD), and then active compression decompression (ACD) + ITD CPR Hemodynamic, AMSA, and ETCO2 measurements were made with each method of CPR The Spearman correlation and Friedman tests were used to compare hemodynamic parameters. ETCO2, AMSA, coronary perfusion pressure, cerebral perfusion pressure were lowest with STD CPR, increased with STD CPR + ITD and highest with ACD CPR + ITD Further analysis demonstrated a positive correlation between AMSA and ETCO2 (r = 0.37, P = 0.025) and between AMSA and key hemodynamic parameters (P < 0.05). This study established a moderate positive correlation between ETCO2 and AMSA These findings provide the physiological basis for developing and testing a novel noninvasive method that utilizes either ETCO2 alone or the combination of ETCO2 and AMSA to predict when defibrillation might be successful. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  9. Section 7 of the Atomic Energy Law; Sect. 4 of AtVfV; Sect. 46 of VwVfG NW

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The preclusion provided in Section 7b of the Atomic Energy Law precludes the advancing of concrete situations but not the advancing of a theoretical course of events, independent of the prompting incident (only guiding principle). Any substantial modification of a nuclear power plant is subject to authorization under the Atomic Energy Law. It makes no difference whether the modification has a positive or negative effect on the safety level. The involvement of the public in licensing procedures as laid down in the Atomic Energy Law is the result of an effective protection of basic rights provided in Article 2 (2) of the Basic Law. A party affected has the right to claim the annulment of a licence that was granted with an offence being committed against these rights to be involved. The issue of material licensing capacity does not matter in this respect (following the decision on Muelheim-Kaerlich taken by the Federal Constitutional Court on December 20, 1979). A party affected may only reprove successfully the omitted involvement of the public if the essential modification might affect its rights negatively. Arnsberg Administrative Court, Decision of Jan. 27, 1981 - 7 K 74/79 - (not final).

  10. Rainfall variability and seasonality in northern Bangladesh

    Science.gov (United States)

    Bari, Sheikh Hefzul; Hussain, Md. Manjurul; Husna, Noor-E.-Ashmaul

    2017-08-01

    This paper aimed at the analysis of rainfall seasonality and variability for the northern part of South-Asian country, Bangladesh. The coefficient of variability was used to determine the variability of rainfall. While rainfall seasonality index ( SI ) and mean individual seasonality index ( \\overline{SI_i} ) were used to identify seasonal contrast. We also applied Mann-Kendall trend test and sequential Mann-Kendall test to determine the trend in seasonality. The lowest variability was found for monsoon among the four seasons whereas winter has the highest variability. Observed variability has a decreasing tendency from the northwest region towards the northeast region. The mean individual seasonality index (0.815378 to 0.977228) indicates that rainfall in Bangladesh is "markedly seasonal with a long dry season." It was found that the length of the dry period is lower at the northeastern part of northern Bangladesh. Trend analysis results show no significant change in the seasonality of rainfall in this region. Regression analysis of \\overline{SI_i} and SI, and longitude and mean individual seasonality index show a significant linear correlation for this area.

  11. Class 1 Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — A "Class 1" area is a geographic area recognized by the EPA as being of the highest environmental quality and requiring maximum protection. Class I areas are areas...

  12. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.

    2016-01-01

    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula...... of regularization, by external variables that shadow either the state or the switch of the original system. The shadow systems are derived from and inspired by various applications in electronic control, predator-prey preference, time delay, and genetic regulation....

  13. Atmospheric Infrared Radiance Variability.

    Science.gov (United States)

    1981-05-27

    ATMOSPHERIC VARIABILITY ON INFRARED RADIANCE PREDICTIONS - T. C. Degges 53 5. ATMOSPHERIC STRUCTURE - C.H. HLmphrey, C.R. Philbrick, S.M. Silverman , T.F. Tuan...variations similar to those shown in Figure 2. In arctic and subarctic regions, sudden warmings and coolings of the winter stratosphere and mesosphere... Silverman \\Jr I",rre. (;.L~~sIalmratorN Hanscom Air Force Base, Manss. T.F. Tuan Universitv of Cincinnati Cincinnati, (tio M. Anapol S.S.G.. Inc. Waltham

  14. Variable camshaft timing system

    Energy Technology Data Exchange (ETDEWEB)

    Butterfield, R.P.; Smith, F.R.

    1989-09-05

    This patent describes an improvement in a variable camshaft timing system for an internal combustion engine having intake and exhaust valves and a camshaft for each of the intake and exhaust valves, an intake sprocket and an exhaust sprocket keyed to their respective camshaft, only one of the camshafts being directly driven by an engine crankshaft, and a timing chain engaging both sprockets. The improvement comprising a single bracket carrying at least one idler sprocket engaging the timing chain, the bracket being mounted for movement to alter the timing relationship between the intake and exhaust sprockets.

  15. Complex variables II essentials

    CERN Document Server

    Solomon, Alan D

    2013-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Complex Variables II includes elementary mappings and Mobius transformation, mappings by general functions, conformal mappings and harmonic functions, applying complex functions to a

  16. The influence of selected socio-economic variables on poultry ...

    African Journals Online (AJOL)

    The influence of selected socio-economic variables on poultry farmers' choice of commercial and self-compounded feeds in Lagos area of Nigeria. ... cost consideration was the major factor determining the choice of feed types by the farmers.

  17. Glycemic variability: Clinical implications

    Directory of Open Access Journals (Sweden)

    Surabhi Venkata Satya Krishna

    2013-01-01

    Full Text Available Glycemic control and its benefits in preventing microvascular diabetic complications are convincingly proved by various prospective trials. Diabetes control and complications trial (DCCT had reported variable glycated hemoglobin (HbA1C as a cause of increased microvascular complications in conventional glycemic control group versus intensive one. However, in spite of several indirect evidences, its link with cardiovascular events or macrovascular complications is still not proved. Glycemic variability (GV is one more tool to explain relation between hyperglycemia and increased cardiovascular risk in diabetic patients. In fact GV along with fasting blood sugar, postprandial blood sugar, HbA1C, and quality of life has been proposed to form glycemic pentad, which needs to be considered in diabetes management. Postprandial spikes in blood glucose as well as hypoglycemic events, both are blamed for increased cardiovascular events in Type 2 diabetics. GV includes both these events and hence minimizing GV can prevent future cardiovascular events. Modern diabetes management modalities including improved sulfonylureas, glucagon like peptide-1 (GLP-1-based therapy, newer basal insulins, and modern insulin pumps address the issue of GV effectively. This article highlights mechanism, clinical implications, and measures to control GV in clinical practice.

  18. Score test variable screening.

    Science.gov (United States)

    Zhao, Sihai Dave; Li, Yi

    2014-12-01

    Variable screening has emerged as a crucial first step in the analysis of high-throughput data, but existing procedures can be computationally cumbersome, difficult to justify theoretically, or inapplicable to certain types of analyses. Motivated by a high-dimensional censored quantile regression problem in multiple myeloma genomics, this article makes three contributions. First, we establish a score test-based screening framework, which is widely applicable, extremely computationally efficient, and relatively simple to justify. Secondly, we propose a resampling-based procedure for selecting the number of variables to retain after screening according to the principle of reproducibility. Finally, we propose a new iterative score test screening method which is closely related to sparse regression. In simulations we apply our methods to four different regression models and show that they can outperform existing procedures. We also apply score test screening to an analysis of gene expression data from multiple myeloma patients using a censored quantile regression model to identify high-risk genes. © 2014, The International Biometric Society.

  19. Perception of Climate Variability on Agriculture and Food Security by ...

    African Journals Online (AJOL)

    Dr Osondu

    This paper focuses on how men and women farmers perceive climatic variability in Idanre Local. Government Area of Ondo ... Keywords: Climatic Variability, Agricultural Production, Food Security, Rainfall and Farmers. Department of Geography .... The consequences of global warming include sea level rise and flooding of ...

  20. On the product and ratio of Bessel random variables

    Directory of Open Access Journals (Sweden)

    Saralees Nadarajah

    2005-01-01

    Full Text Available The distributions of products and ratios of random variables are of interest in many areas of the sciences. In this paper, the exact distributions of the product |XY| and the ratio |X/Y| are derived when X and Y are independent Bessel function random variables. An application of the results is provided by tabulating the associated percentage points.

  1. 630 understanding farmers' response to climate variability in nigeria

    African Journals Online (AJOL)

    Osondu

    Abstract. In Nigeria, farming still depends largely on nature and therefore, vulnerable to climate variability. Climate variability affects production in a number of ways such as uncertainties with the onset of the farming season, flooding and drought in some areas .Farmers have responded by using adaptation strategies.

  2. Variable cycle engine

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.P.; Sprunger, E.V.

    1980-09-16

    A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relatively small high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

  3. Variable Amplitude Fatigue

    Science.gov (United States)

    Ranganathan, Narayanaswami; Joly, Damien; Leroy, René

    Fatigue crack growth behavior of selected aluminum alloys under variable amplitude loading is discussed in this study, based principally on experimental observations. The tests include single overloads tests in different environments, block load tests and tests using an aircraft wing loading spectrum. It is shown that conditions favoring a planar slip behavior lead to very high delays as opposed to conditions leading to multiple slip behavior. The Aluminium Liithium alloy studied here, has the best fatigue crack growth resistance in almost all test conditions studied here as compared to other conventional alloys. Under the spectrum loading studied here, the same alloy exhibits a change in micromechanism leading to a four fould acceleration of growth rates. Acceptable life predictions can be made, by taking into account this crack acceleration effect.

  4. Exam stressors, modulating variables and academic failure

    OpenAIRE

    Arturo Barraza Macías; Oscar Rodríguez

    2010-01-01

    This research was raised four objectives: a) to establish the profile of stress descriptive review of the higher education students, b) identify areas that cause more stress on the students of higher education when presenting a review c ) distinguish socio-demographic variables and situational which provide significant differences in stress examination of students in higher education d) determining the relationship between stress examination and the number of subjects disapproved of the stude...

  5. Applying Theories and Interventions from Behavioral Medicine to Understand and Reduce Visual Field Variability in Patients with Vision Loss

    OpenAIRE

    Rozanski, Collin; Haythornthwaite, Jennifer A.; Dagnelie, Gislin; Bittner, Ava K.

    2014-01-01

    Visual field (VF) test results are often unreliable in visually impaired patients, but continue to be a cornerstone of clinical trials and play a vital role in clinical decision making since they are the primary method to determine patients’ functional vision loss or progression. Currently, patients are typically asked to perform VF tasks with minimal instruction or consideration of their psychological experience during the test. The gradual loss of vision due to retinal diseases, such as ret...

  6. Difference in the Clinical Characteristics of Ventricular Fibrillation Occurrence in the Early Phase of an Acute Myocardial Infarction Between Patients With and Without J Waves.

    Science.gov (United States)

    Naruse, Yoshihisa; Nogami, Akihiko; Harimura, Yoshie; Ishibashi, Mayu; Noguchi, Yuichi; Sekiguchi, Yukio; Sato, Akira; Aonuma, Kazutaka

    2015-08-01

    We recently showed that the presence of J waves increases the risk of ventricular fibrillation (VF) occurrence in the early phase of an acute myocardial infarction (AMI). This study aimed to evaluate the clinical characteristics of VF occurrences in the early phase of an AMI between patients with and without J waves. This retrospective, observational study included 281 consecutive patients with an AMI (69 ± 12 years; 207 men) in whom 12-lead ECGs before AMI onset could be evaluated. The patients were classified based on a VF occurrence waves. J waves were electrocardiographically defined as an elevation of the terminal portion of the QRS complex of >0.1 mV from baseline in at least 2 contiguous inferior or lateral leads. VF occurred in 24 patients, and J waves were present in 37. VF occurrence was more prevalent in the patients with than without J waves (27% vs. 6%; P waves, peak creatine kinase level (P waves, there was no significant difference in these variables. There was no association between the location of J waves and the infarct area. In patients with AMI, those with J waves were more likely to develop VF and less likely to have high-risk clinical characteristics than those without J waves. © 2015 Wiley Periodicals, Inc.

  7. Topology optimization with flexible void area

    DEFF Research Database (Denmark)

    Clausen, Anders; Aage, Niels; Sigmund, Ole

    2014-01-01

    This paper presents a methodology for including fixed-area flexible void domains into the minimum compliance topology optimization problem. As opposed to the standard passive elements approach of rigidly specifying void areas within the design domain, the suggested approach allows these areas...... to be flexibly reshaped and repositioned subject to penalization on their moments of inertia, the positions of their centers of mass, and their shapes. The flexible void areas are introduced through a second, discrete design variable field, using the same discretization as the standard field of continuous...... density variables. The formulation is based on a combined approach: The primary sub-problem is to minimize compliance, subject to a volume constraint, with a secondary sub-problem of minimizing the disturbance from the flexible void areas. The design update is performed iteratively between the two...

  8. Gait Variability and Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Michael J. Socie

    2013-01-01

    Full Text Available Gait variability, that is, fluctuations in movement during walking, is an indicator of walking function and has been associated with various adverse outcomes such as falls. In this paper, current research concerning gait variability in persons with multiple sclerosis (MS is discussed. It is well established that persons with MS have greater gait variability compared to age and gender matched controls without MS. The reasons for the increase in gait variability are not completely understood. Evidence indicates that disability level, assistive device use, attentional requirement, and fatigue are related to gait variability in persons with MS. Future research should address the time-evolving structure (i.e., temporal characteristics of gait variability, the clinical importance of gait variability, and underlying mechanisms that drive gait variability in individuals with MS.

  9. Interindividual epigenetic variability: Sound or noise?

    Science.gov (United States)

    Tejedor, J Ramón; Fraga, Mario F

    2017-07-01

    Interindividual variability is an inherent characteristic of biological systems. Whereas the underlying molecular sources of interindividual variability remain poorly understood, recent work by Ecker et al. (Ecker S, Chen L, Pancaldi V, Bagger FO, et al. 2017. Genome Biol 18: 18.) sheds light on the characterization of this phenomenon in a complex biological scenario. By combining data from the BLUEPRINT Epigenome Project with a novel analytical approach, these authors were able to measure the degree of transcriptional and epigenetic variability across a wide panel of samples and types of immune cell. Interestingly, neutrophils displayed increased variability compared to monocytes and T cells, which may be related to the crucial role of the former as an initial mediator of immune responses. Here we review recent literature in this area, and discuss some important issues raised by these innovative analyses. Furthermore, we summarize other potential sources of epigenetic variability, such as epigenetic drift and the epigenetic clock, as well as the current ongoing direction of the field. © 2017 WILEY Periodicals, Inc.

  10. Localized spectral analysis of global satellite gravity fields for recovering time-variable mass redistributions

    NARCIS (Netherlands)

    Han, S.C.; Ditmar, P.

    2007-01-01

    A spatiospectral localization method is discussed for processing the global geopotential coefficients from satellite mission data to investigate time-variable gravity. The time-variable mass variation signal usually appears associated with a particular geographical area yielding inherently regional

  11. Modeling Shared Variables in VHDL

    DEFF Research Database (Denmark)

    Madsen, Jan; Brage, Jens P.

    1994-01-01

    A set of concurrent processes communicating through shared variables is an often used model for hardware systems. This paper presents three modeling techniques for representing such shared variables in VHDL, depending on the acceptable constraints on accesses to the variables. Also a set...... of guidelines for handling atomic updates of multiple shared variables is given. 1 Introduction It is often desirable to partition a computational system into discrete functional units which cooperates to....

  12. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.

    2007-01-01

    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...... of a discrete random variable....

  13. THE VARIABILITY OF INTERLANGUAGE USE

    African Journals Online (AJOL)

    www

    This pattern of linguistic behaviour is called "non-systematic variability". In this article, the phenomenon of this variability in L2 knowledge is investigated. The existing body of knowledge about L2 acquisition provides ample proof that L2 learners are characteristically variable in their interlanguage use. The question arises ...

  14. Preservice Teachers' Understanding of Variable

    Science.gov (United States)

    Brown, Sue; Bergman, Judy

    2013-01-01

    This study examines the research on middle school students' understanding of variables and explores preservice elementary and middle school teachers' knowledge of variables. According to research studies, middle school students have limited understanding of variables. Many studies have examined the performance of middle school students and offered…

  15. Integration i flere variable

    DEFF Research Database (Denmark)

    Markvorsen, Steen

    2010-01-01

    Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum-integraler. Udgangspu......Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum......-integralerne. Undervejs introduceres \\texttt{Integrator8}. Det er en pakke med Maple procedurer, som er udviklet specielt med henblik på eksempelbaseret visuel læring af de indledende integrationsbegreber og deres mangfoldige anvendelser. Vi giver eksempler på, hvordan integration i flere variable anvendes til beregning...... og forståelse af rumfang, vægt, massemidtpunkter, inertimomenter, kraftmomenter, etc. Flowkurverne for et givet vektorfelt i rummet kan findes og visualiseres med \\texttt{Integrator8}. De vigtige begreber divergens og rotation for et vektorfelt fremtræder derved som naturlige størrelser til...

  16. Variables moderadoras del estres

    Directory of Open Access Journals (Sweden)

    María Cristina Richaud de Minzi

    1999-01-01

    Full Text Available El objetivo del presente trabajo es analizar la influenciadel estilo atribucional, la confianza interpersonal y el soporte social sobre la percepción de la amenaza. Se administraron la Escala de Estilo Atribucional; la Manheim Interview 01 Social Support, la Escala de Confianza Interpersonal; y el Inventario de Situaciones y Respuestas de Ansiedad, a 260 sujetos de ambos sexos, de 30 años de edad promedio, de nivel socioeconómico medio, residentes en la ciudad de Buenos Aires. El soporte social no demostró influencia significativa sobre la percepción de la amenaza. Con respecto a la influencia del estilo atribucional se puede decir que las personas indefensas perciben más amenaza, especialmente expresada como ansiedad cognitiva y, en menor grado, como ansiedad motora o conductual. La confianza interpersonal demostró ser una variable importante en la percepción de la amenaza. Los sujetos que presentaron alta desconfianza hacia las personas de su entorno perciben un mundo amenazante, que se manifiesta como ansiedad cognitiva, fisiológica y motora o conductual.

  17. Hydrostatic continuously variable transmission

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, T.; Saito, M.; Matsuto, T.; Nakajima, Y.; Sakakibara, K.; Yakigaya, N.; Nakamura, K.

    1989-05-09

    A hydrostatic continuously variable transmission is described, comprising: a swashplate type hydraulic pump having a pump swashplate and annularly arranged pump plungers whose suction and discharge strokes are provided by the pump swashplate; a swashplate type hydraulic motor having a motor swashplate and annularly arranged motor plungers whose expansion and shrinkage strokes are provided by the motor swashplate; and a hydraulic closed circuit formed between the hydraulic pump and the hydraulic motor. The transmission has at least one of a relationship that a middle point of a discharge region of the hydraulic pump is angularly delayed at a given angle in a direction of rotation of the hydraulic pump relative to a tilting axis of the pump swashplate and a relationship that a middle point of an expansion region of the hydraulic motor is angularly advanced at a given angle in a direction of rotation of the hydraulic motor relative to a tilting axis of the motor swashplate, wherein the transmission has at least one of a relationship that a suction region of the hydraulic pump is set at an angle larger than that of the discharge region thereof and a relationship that a shrinkage region of the hydraulic motor is set at an angle larger than that of the expansion region of the motor.

  18. Variable subsistence indemnity

    CERN Document Server

    1999-01-01

    At its meeting on 9 December 1998, the Finance Committee approved, with effect from 1st January 1999, adjustments to the Variable Subsistence Indemnity according to the rates published by the United Nations Organization given in document CERN/FC/4113. This decision maintained the reference method in force since 1983. The Management now proposes to adjust the CERN rates of indemnities, with effect from 1st January 2000, on the basis of the United Nations 1999 rates, as shown for typical destinations in the table contained in this document. Although a precise estimate of the cost effect for duty travel is difficult to achieve due to currency exchange values, it is probable that this will remain unchanged if calculated in Swiss francs. The Management also proposes to formalise the practice of paying a lower subsistence indemnity than the approved basic amount, wherever feasible for events such as group duty travel to conferences or similar events, as discussed at the Finance Committee in December 1998. An amendm...

  19. Variable angle correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Kyo [Univ. of California, Berkeley, CA (United States)

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

  20. Research Areas: Liver Disease

    Science.gov (United States)

    ... Advisors, and committees that coordinate research activities Research Areas Overview of NIDDK activities in each major research area, including research advances, research coordination, and health information ...

  1. Seasonal and interannual variability in phytoplankton biomass on ...

    African Journals Online (AJOL)

    Surface ocean phytoplankton biomass variability on the southern African continental shelf area is investigated using coastal zone colour scanner data for the period 1979–1986. Coherent interannual trends in surface ocean chlorophyll for both the west coast Benguela and the south coast Agulhas Bank areas correspond ...

  2. GIS and correlation analysis of geo-environmental variables ...

    African Journals Online (AJOL)

    Analysing the significance of geo-environmental variables influencing malaria incidence will help decision makers design area-specific interventions for tackling the menace, particularly in high-risk areas. This study applied geocoding and raster extraction functionalities in GIS (ArcMap) and Pearson correlation in SPSS to ...

  3. Geomorphic Analysis in Determining Tectonic Activity Affected by Sumatra Fault in Liwa Region and Its Surrounding Area, Lampung, Indonesia

    Directory of Open Access Journals (Sweden)

    Yudhicara Yudhicara

    2017-08-01

    Full Text Available DOI: 10.17014/ijog.4.3.193-208The study discusses about characteristics of Sumatra Fault and its tectonic activity in Liwa and the adjacent area. The research uses quantitative methods of verification hypothetical deduction, which starts from the general approach, then it pursues into more specialized and focused ones. While the research work includes field measurements, remote sensing with GIS, and geomorphologic analysis using morphometry, such as: sinousity of mountain front (Smf, percentage of facets, ratio of the width and height of the valley (Vf, bifurcation ratios of the river (Rb, drainage density (Dd, shape of the watershed basin area (Bs, hypsometric curves (HI, and gradient index of stream length (SL. Basically, two blocks separated by the Sumatra Fault do not have a significant difference in tectonic activity, but the tectonic activity change can be seen when the studied area is divided into three blocks (northwest, middle, and southeast, then the change in each part can clearly be seen. Apparently, the tectonic activity in the studied area starts from the southeast continues toward the northwest. It is proved by this research, that geomorphological parameters which are associated with mountain fronts and watershed systems demonstrate the value of the activity increases towards the northwest. Hypsometric curves and a river analysis show that the tectonic activity in the northwest is relatively in a young stage, while towards the southeast it is getting in a mature stage.

  4. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  5. Forested riparian areas

    Science.gov (United States)

    Carolyn T. Hunsaker; Jonathan W. Long

    2014-01-01

    Riparian areas are typically highly productive areas that sustain important socioecological benefits, including the capacity to modulate effects of watershed disturbances on aquatic systems. Recent studies have shown that fire behavior in riparian areas varies with landscape attributes. Smaller, headwater riparian areas often burn similarly to adjacent uplands, whereas...

  6. Spatial variability of groundwater recharge - I. Is it really variable?

    OpenAIRE

    De Silva, RP

    2004-01-01

    The spatial variability of recharge is an important consideration in estimating recharge especially as all methods of estimating it are 'point' estimates and in most places recharge varies in space. This paper along with the accompanying paper attempts to find a suitable answer to the question of taking this variability into account in estimating groundwater recharge. This paper attempts to determine if recharge is actually varying in space and that this is 'true' variability and that it is n...

  7. Panel regressions to estimate low‐flow response to rainfall variability in ungaged basins

    National Research Council Canada - National Science Library

    Bassiouni, Maoya; Vogel, Richard M; Archfield, Stacey A

    2016-01-01

    Multicollinearity and omitted‐variable bias are major limitations to developing multiple linear regression models to estimate streamflow characteristics in ungaged areas and varying rainfall conditions...

  8. Variable Sampling Mapping

    Science.gov (United States)

    Smith, Jeffrey, S.; Aronstein, David L.; Dean, Bruce H.; Lyon, Richard G.

    2012-01-01

    The performance of an optical system (for example, a telescope) is limited by the misalignments and manufacturing imperfections of the optical elements in the system. The impact of these misalignments and imperfections can be quantified by the phase variations imparted on light traveling through the system. Phase retrieval is a methodology for determining these variations. Phase retrieval uses images taken with the optical system and using a light source of known shape and characteristics. Unlike interferometric methods, which require an optical reference for comparison, and unlike Shack-Hartmann wavefront sensors that require special optical hardware at the optical system's exit pupil, phase retrieval is an in situ, image-based method for determining the phase variations of light at the system s exit pupil. Phase retrieval can be used both as an optical metrology tool (during fabrication of optical surfaces and assembly of optical systems) and as a sensor used in active, closed-loop control of an optical system, to optimize performance. One class of phase-retrieval algorithms is the iterative transform algorithm (ITA). ITAs estimate the phase variations by iteratively enforcing known constraints in the exit pupil and at the detector, determined from modeled or measured data. The Variable Sampling Mapping (VSM) technique is a new method for enforcing these constraints in ITAs. VSM is an open framework for addressing a wide range of issues that have previously been considered detrimental to high-accuracy phase retrieval, including undersampled images, broadband illumination, images taken at or near best focus, chromatic aberrations, jitter or vibration of the optical system or detector, and dead or noisy detector pixels. The VSM is a model-to-data mapping procedure. In VSM, fully sampled electric fields at multiple wavelengths are modeled inside the phase-retrieval algorithm, and then these fields are mapped to intensities on the light detector, using the properties

  9. Sociolinguistic variables and cognition.

    Science.gov (United States)

    Thomas, Erik R

    2011-11-01

    Sociolinguistics has examined mental organization of language only sporadically. Meanwhile, areas of linguistics that deal with cognitive organization seldom delve deeply into language variation. Variation is essential for understanding how language is structured cognitively, however. Three kinds of evidence are discussed to illustrate this point. First, style shifting demonstrates that language users develop detailed associations of when to produce specific linguistic forms, depending on the pragmatic context. Second, variation in fine-grained phonetic cues shows that cognitive organization applies to linguistic forms not otherwise known to be under speakers' control. Finally, experiments on dialect comprehension and identification demonstrate that listeners have detailed cognitive associations of language variants with groups of people, whether or not they can produce the same variants themselves. A model is presented for how sociolinguistic knowledge can be viewed in relation to other parts of language with regard to cognitive and neural representations. WIREs Cogni Sci 2011 2 701-716 DOI: 10.1002/wcs.152 For further resources related to this article, please visit the WIREs website. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Sewerage Service Areas - MDC_DSWMServiceArea

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — The SWM Service Area polygon feature class was created and is mantained by the Miami-Dade Information Technology Department (ITD) with data provided by the Public...

  11. Intrasubject variability in power reflectance.

    Science.gov (United States)

    Abur, Defne; Horton, Nicholas J; Voss, Susan E

    2014-05-01

    Power reflectance measurements are an active area of research related to the development of noninvasive middle-ear assessment methods. There are limited data related to test-retest measures of power reflectance. This study investigates test-retest features of power reflectance, including comparisons of intrasubject versus intersubject variability and how ear-canal measurement location affects measurements. Repeated measurements of power reflectance were made at about weekly intervals. The subjects returned for four to eight sessions. Measurements were made at three ear-canal locations: a deep insertion depth (with a foam plug flush at the entrance to the ear canal) and both 3 and 6 mm more lateral to this deep insertion. Repeated measurements on seven subjects are reported. All subjects were female, between 19 and 22 yr old, and enrolled at an undergraduate women's college. Measurements on both the right and left ears were made at three ear-canal locations during each of four to eight measurement sessions. Random-effects regression models were used for the analysis to account for repeated measures within subjects. The mean power reflectance for each position over all sessions was calculated for each subject. The comparison of power reflectance from the left and right ears of an individual subject varied greatly over the seven subjects; the difference between the power reflectance measured on the left and that measured on the right was compared at 248 frequencies, and depending on the subject, the percentage of tested frequencies for which the left and right ears differed significantly ranged from 10% to 93% (some with left values greater than right values and others with the opposite pattern). Although the individual subjects showed left-right differences, the overall population generally did not show significant differences between the left and right ears. The mean power reflectance for each measurement position over all sessions depended on the location of the

  12. Climate Change and Variability in Ghana: Stocktaking

    Directory of Open Access Journals (Sweden)

    Felix A. Asante

    2014-12-01

    Full Text Available This paper provides a holistic literature review of climate change and variability in Ghana by examining the impact and projections of climate change and variability in various sectors (agricultural, health and energy and its implication on ecology, land use, poverty and welfare. The findings suggest that there is a projected high temperature and low rainfall in the years 2020, 2050 and 2080, and desertification is estimated to be proceeding at a rate of 20,000 hectares per annum. Sea-surface temperatures will increase in Ghana’s waters and this will have drastic effects on fishery. There will be a reduction in the suitability of weather within the current cocoa-growing areas in Ghana by 2050 and an increase evapotranspiration of the cocoa trees. Furthermore, rice and rooted crops (especially cassava production are expected to be low. Hydropower generation is also at risk and there will be an increase in the incidence rate of measles, diarrheal cases, guinea worm infestation, malaria, cholera, cerebro-spinal meningitis and other water related diseases due to the current climate projections and variability. These negative impacts of climate change and variability worsens the plight of the poor, who are mostly women and children.

  13. Main challenges of residential areas

    Directory of Open Access Journals (Sweden)

    Oana Luca

    2017-06-01

    Full Text Available The present article is a position paper aiming to initiate a professional debate related to the aspects related to the urban dysfunctions leading to the wear of the residential areas. The paper proposes a definition of the wear process, identify the main causes leading to its occurrence and propose a number of solutions to neutralise the dysfunctions. The three wearing phases of residential areas components are emphasized, exploring their lifecycle. In order to perform the study of urban wear, the status of the residential areas components can be established and monitored, and also the variables of the function that can mathematically model the specific wear process may be considered. The paper is considered a first step for the model adjustment, to be tested and validated in the following steps. Based on the mathematical method and model, there can be created, in a potential future research, the possibility of determining the precarity degree for residential areas/neighbourhoods and cities, by minimising the subjective component of the analyses preceding the decision for renovation or regeneration.

  14. HOW NORMAL IS VARIABLE, OR HOW VARIABLE IS NORMAL

    NARCIS (Netherlands)

    TOUWEN, BCL

    Variability is an important property of the central nervous system, and it shows characteristic changes during infancy and childhood. The large amount of variations in the performance of sensomotor functions in infancy is called indiscriminate or primary variability. During toddling age the child

  15. Variable Speed Rotor System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Variable speed rotors will give helicopters several advantages: higher top speed, greater fuel efficiency, momentary emergency over-power, resonance detuning...

  16. The Hubble Catalog of Variables

    Directory of Open Access Journals (Sweden)

    Sokolovsky K.

    2017-01-01

    Full Text Available We aim to construct an exceptionally deep (V ≲ 27 catalog of variable objects in selected Galactic and extragalactic fields visited multiple times by the Hubble Space Telescope (HST. While HST observations of some of these fields were searched for specific types of variables before (most notably, the extragalactic Cepheids, we attempt a systematic study of the population of variable objects of all types at the magnitude range not easily accessible with ground-based telescopes. The variability timescales that can be probed range from hours to years depending on how often a particular field has been visited. For source extraction and cross-matching of sources between visits we rely on the Hubble Source Catalog which includes 107 objects detected with WFPC2, ACS, and WFC3 HST instruments. The lightcurves extracted from the HSC are corrected for systematic effects by applying local zero-point corrections and are screened for bad measurements. For each lightcurve we compute variability indices sensitive to a broad range of variability types. The indices characterize the overall lightcurve scatter and smoothness. Candidate variables are selected as having variability index values significantly higher than expected for objects of similar brightness in the given set of observations. The Hubble Catalog of Variables will be released in 2018.

  17. Korean Conference on Several Complex Variables

    CERN Document Server

    Byun, Jisoo; Gaussier, Hervé; Hirachi, Kengo; Kim, Kang-Tae; Shcherbina, Nikolay

    2015-01-01

    This volume includes 28 chapters by authors who are leading researchers of the world describing many of the up-to-date aspects in the field of several complex variables (SCV). These contributions are based upon their presentations at the 10th Korean Conference on Several Complex Variables (KSCV10), held as a satellite conference to the International Congress of Mathematicians (ICM) 2014 in Seoul, Korea. SCV has been the term for multidimensional complex analysis, one of the central research areas in mathematics. Studies over time have revealed a variety of rich, intriguing, new knowledge in complex analysis and geometry of analytic spaces and holomorphic functions which were "hidden" in the case of complex dimension one. These new theories have significant intersections with algebraic geometry, differential geometry, partial differential equations, dynamics, functional analysis and operator theory, and sheaves and cohomology, as well as the traditional analysis of holomorphic functions in all dimensions. This...

  18. Groundwater level responses to precipitation variability in Mediterranean insular aquifers

    Science.gov (United States)

    Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique

    2017-09-01

    Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

  19. BOEM Wind Planning Areas

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set represents the most recent changes for the Wind Development Planning Areas in the Atlantic. Wind Planning Areas in this dataset represent up to six...

  20. Vermont Designated Natural Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Under Natural Areas Law (10 Vermont Statutes Annotated, Chapter 83 � 2607) the FPR commissioner, with the approval of the governor, may designate and set aside areas...

  1. VT ZIP Code Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) A ZIP Code Tabulation Area (ZCTA) is a statistical geographic entity that approximates the delivery area for a U.S. Postal Service five-digit...

  2. Sunk Lake Natural Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Sunk Lake Natural Area Management Plan guides the long-range development of the Natural Area by identifying and integrating appropriate habitats, management...

  3. Hydrologic Areas of Concern

    Data.gov (United States)

    University of New Hampshire — A Hydrologic Area of Concern (HAC) is a land area surrounding a water source, which is intended to include the portion of the watershed in which land uses are likely...

  4. Infrastructure Area Simplification Plan

    CERN Document Server

    Field, L.

    2011-01-01

    The infrastructure area simplification plan was presented at the 3rd EMI All Hands Meeting in Padova. This plan only affects the information and accounting systems as the other areas are new in EMI and hence do not require simplification.

  5. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  6. Students' Misconceptions about Random Variables

    Science.gov (United States)

    Kachapova, Farida; Kachapov, Ilias

    2012-01-01

    This article describes some misconceptions about random variables and related counter-examples, and makes suggestions about teaching initial topics on random variables in general form instead of doing it separately for discrete and continuous cases. The focus is on post-calculus probability courses. (Contains 2 figures.)

  7. A process variability control chart

    NARCIS (Netherlands)

    Riaz, M.; Does, R.J.M.M.

    2009-01-01

    In this study a Shewhart type control chart namely the Vt chart, is proposed for improvedmonitoring of the process variability of a quality characteristic of interest Y . The proposed control chart is based on the ratio type estimator of the variance using a single auxiliary variable X. It is

  8. Selected areas in cryptography

    CERN Document Server

    Oorschot, Paul

    1997-01-01

    Selected Areas in Cryptography brings together in one place important contributions and up-to-date research results in this fast moving area. Selected Areas in Cryptography serves as an excellent reference, providing insight into some of the most challenging research issues in the field.

  9. SPATIAL VARIABILITY OF PEDOZEMS MECHANICAL IMPEDANCE

    Directory of Open Access Journals (Sweden)

    Zhukov A.V.

    2013-04-01

    Full Text Available We studied the spatial variability of pedozem mechanical impedance in ResearchRemediation Center of the Dnipropetrovsk State Agrarian University in Ordzhonikidze. Thestatistical distribution of the soil mechanical impedance within the studied area is characterized by deviation from the normal law in 0–10 and 30–50 cm layers from the surface. 2D and 3D modeling shows the structural design of the soil as locations of high mechanical impedance which found in the soils with less hardness.

  10. vfødte børn og deres livsbetingelser

    DEFF Research Database (Denmark)

    Bengtsson, Steen; Larsen, Lena Bech; Lindsay Sommer, Mette

    døve. De får således lært at læse meget bedre end gruppen tidligere gjorde. CI løser dog langtfra alle problemer. Rapporten viser, at selv om børnene nu har mulighed for at kommunikere ved at lytte og tale, er de slet ikke kommet på linje med gruppen af børn, som er født uden hørehandicap. Baggrunden...

  11. effects of load and speed variations in a modified closed loop v/f

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Rotor Referred Resistance. 0.2Ω. Stator Reactance. 1.5Ω. Rotor Referred Reactance. 1.5Ω. Magnetizing Reactance. 30Ω. Moment of Inertia. 2.1kgm2. Figure 6: Speed reversal due to change in reference speed. 6.1. Effect of a step change in reference speed. The speed reference is changed from 25Hz to ...

  12. Seasonal and diurnal variability of Mars water-ice clouds

    Science.gov (United States)

    Christensen, Philip R.; Zurek, Richard W.; Jaramillo, L. L.

    1988-01-01

    The diurnal and seasonal behavior of cloud opacity and frequency of occurrence was studied using an atlas of cloud occurrences compiled from the Viking IRTM (Infrared Thermal Mapper) data set. It was found that in some areas the behavior of water appeared to repeat in the zonal mean. However, this interpretation is complicated by both poor coverage and the variability of dust and clouds. As a result, the extent and nature of interannual variability remains unclear.

  13. Numerical implementation of a state variable model for friction

    Energy Technology Data Exchange (ETDEWEB)

    Korzekwa, D.A. [Los Alamos National Lab., NM (United States); Boyce, D.E. [Cornell Univ., Ithaca, NY (United States)

    1995-03-01

    A general state variable model for friction has been incorporated into a finite element code for viscoplasticity. A contact area evolution model is used in a finite element model of a sheet forming friction test. The results show that a state variable model can be used to capture complex friction behavior in metal forming simulations. It is proposed that simulations can play an important role in the analysis of friction experiments and the development of friction models.

  14. Association between oral variables and heart rate variability.

    Science.gov (United States)

    Santana, Milana Drumond Ramos; de Souza, Ana Cecilia Amorim; de Abreu, Luiz Carlos; Valenti, Vitor E

    2013-12-27

    The heart rate variability is a useful method to assess cardiac autonomic modulation in patients undergoing dental procedures, because knowledge of physiological conditions provides greater security to the professional as well as the possibility of a better plan treatment to patient benefit. The aim of our study was to describe the association between cardiac autonomic control and dental variables. We consulted the databases Medline, SciELO, Lilacs and Cochrane, using the terms "autonomic", "dentistry", "heart rate variability", "cardiovascular physiology." The selected studies indicated a strong relationship between dental variables and HRV. There was an association between malocclusion, TMD, dental procedures cirugia and low HRV. Thus, they become more studies that relate to HRV in dental science, especially in clinical practice.

  15. Ecosystem stability in space: α, β and γ variability.

    Science.gov (United States)

    Wang, Shaopeng; Loreau, Michel

    2014-08-01

    The past two decades have seen great progress in understanding the mechanisms of ecosystem stability in local ecological systems. There is, however, an urgent need to extend existing knowledge to larger spatial scales to match the scale of management and conservation. Here, we develop a general theoretical framework to study the stability and variability of ecosystems at multiple scales. Analogously to the partitioning of biodiversity, we propose the concepts of alpha, beta and gamma variability. Gamma variability at regional (metacommunity) scale can be partitioned into local alpha variability and spatial beta variability, either multiplicatively or additively. On average, variability decreases from local to regional scales, which creates a negative variability-area relationship. Our partitioning framework suggests that mechanisms of regional ecosystem stability can be understood by investigating the influence of ecological factors on alpha and beta variability. Diversity can provide insurance effects at the various levels of variability, thus generating alpha, beta and gamma diversity-stability relationships. As a consequence, the loss of biodiversity and habitat impairs ecosystem stability at the regional scale. Overall, our framework enables a synthetic understanding of ecosystem stability at multiple scales and has practical implications for landscape management. © 2014 John Wiley & Sons Ltd/CNRS.

  16. Variable pixel size ionospheric tomography

    Science.gov (United States)

    Zheng, Dunyong; Zheng, Hongwei; Wang, Yanjun; Nie, Wenfeng; Li, Chaokui; Ao, Minsi; Hu, Wusheng; Zhou, Wei

    2017-06-01

    A novel ionospheric tomography technique based on variable pixel size was developed for the tomographic reconstruction of the ionospheric electron density (IED) distribution. In variable pixel size computerized ionospheric tomography (VPSCIT) model, the IED distribution is parameterized by a decomposition of the lower and upper ionosphere with different pixel sizes. Thus, the lower and upper IED distribution may be very differently determined by the available data. The variable pixel size ionospheric tomography and constant pixel size tomography are similar in most other aspects. There are some differences between two kinds of models with constant and variable pixel size respectively, one is that the segments of GPS signal pay should be assigned to the different kinds of pixel in inversion; the other is smoothness constraint factor need to make the appropriate modified where the pixel change in size. For a real dataset, the variable pixel size method distinguishes different electron density distribution zones better than the constant pixel size method. Furthermore, it can be non-chided that when the effort is spent to identify the regions in a model with best data coverage. The variable pixel size method can not only greatly improve the efficiency of inversion, but also produce IED images with high fidelity which are the same as a used uniform pixel size method. In addition, variable pixel size tomography can reduce the underdetermined problem in an ill-posed inverse problem when the data coverage is irregular or less by adjusting quantitative proportion of pixels with different sizes. In comparison with constant pixel size tomography models, the variable pixel size ionospheric tomography technique achieved relatively good results in a numerical simulation. A careful validation of the reliability and superiority of variable pixel size ionospheric tomography was performed. Finally, according to the results of the statistical analysis and quantitative comparison, the

  17. Symmetrization of binary random variables

    OpenAIRE

    Kagan, Abram; Mallows, Colin L.; Shepp, Larry A.; Vanderbei, Robert J.; Vardi, Yehuda

    1999-01-01

    A random variable [math] is called an independent symmetrizer of a given random variable [math] if (a) it is independent of [math] and (b) the distribution of [math] is symmetric about [math] . In cases where the distribution of [math] is symmetric about its mean, it is easy to see that the constant random variable [math] is a minimum-variance independent symmetrizer. Taking [math] to have the same distribution as [math] clearly produces a symmetric sum, but it may not be of minimum variance....

  18. Present and Future Modes of Low Frequency Climate Variability

    Energy Technology Data Exchange (ETDEWEB)

    Cane, Mark A.

    2014-02-20

    This project addressed area (1) of the FOA, “Interaction of Climate Change and Low Frequency Modes of Natural Climate Variability”. Our overarching objective is to detect, describe and understand the changes in low frequency variability between model simulations of the preindustrial climate and simulations of a doubled CO2 climate. The deliverables are a set of papers providing a dynamical characterization of interannual, decadal, and multidecadal variability in coupled models with attention to the changes in this low frequency variability between pre-industrial concentrations of greenhouse gases and a doubling of atmospheric concentrations of CO2. The principle mode of analysis, singular vector decomposition, is designed to advance our physical, mechanistic understanding. This study will include external natural variability due to solar and volcanic aerosol variations as well as variability internal to the climate system. An important byproduct is a set of analysis tools for estimating global singular vector structures from the archived output of model simulations.

  19. Sampling designs dependent on sample parameters of auxiliary variables

    CERN Document Server

    Wywiał, Janusz L

    2015-01-01

    The book offers a valuable resource for students and statisticians whose work involves survey sampling. An estimation of the population parameters in finite and fixed populations assisted by auxiliary variables is considered. New sampling designs dependent on moments or quantiles of auxiliary variables are presented on the background of the classical methods. Accuracies of the estimators based on original sampling design are compared with classical estimation procedures. Specific conditional sampling designs are applied to problems of small area estimation as well as to estimation of quantiles of variables under study. .

  20. Spatial ascariasis risk estimation using socioeconomic variables.

    Science.gov (United States)

    Valencia, Luis Iván Ortiz; Fortes, Bruno de Paula Menezes Drumond; Medronho, Roberto de Andrade

    2005-12-01

    Frequently, disease incidence is mapped as area data, for example, census tracts, districts or states. Spatial disease incidence can be highly heterogeneous inside these areas. Ascariasis is a highly prevalent disease, which is associated with poor sanitation and hygiene. Geostatistics was applied to model spatial distribution of Ascariasis risk and socioeconomic risk events in a poor community in Rio de Janeiro, Brazil. Data were gathered from a coproparasitologic and a domiciliary survey in 1550 children aged 1-9. Ascariasis risk and socioeconomic risk events were spatially estimated using Indicator Kriging. Cokriging models with a Linear Model of Coregionalization incorporating one socioeconomic variable were implemented. If a housewife attended school for less than four years, the non-use of a home water filter, a household density greater than one, and a household income lower than one Brazilian minimum wage increased the risk of Ascariasis. Cokriging improved spatial estimation of Ascariasis risk areas when compared to Indicator Kriging and detected more Ascariasis very-high risk areas than the GIS Overlay method.

  1. Effects of interannual climate variability on tropical tree cover

    Science.gov (United States)

    Holmgren, Milena; Hirota, Marina; van Nes, Egbert H.; Scheffer, Marten

    2013-08-01

    Climatic warming is substantially intensifying the global water cycle and is projected to increase rainfall variability. Using satellite data, we show that higher climatic variability is associated with reduced tree cover in the wet tropics globally. In contrast, interannual variability in rainfall can have neutral or even positive effects on tree cover in the dry tropics. In South America, tree cover in dry lands is higher in areas with high year-to-year variability in rainfall. This is consistent with evidence from case studies suggesting that in these areas rare wet episodes are essential for opening windows of opportunity where massive tree recruitment can overwhelm disturbance effects, allowing the establishment of extensive woodlands. In Australia, wet extremes have similar effects, but the net effect of rainfall variability is overwhelmed by negative effects of extreme dry years. In Africa, effects of rainfall variability are neutral for dry lands. It is most likely that differences in herbivore communities and fire regimes contribute to regulating tree expansion during wet extremes. Our results illustrate that increasing climatic variability may affect ecosystem services in contrasting, and sometimes surprising, ways. Expansion of dry tropical tree cover during extreme wet events may decrease grassland productivity but enhance carbon sequestration, soil nutrient retention and biodiversity.

  2. Quantification of variability in trichome patterns

    Directory of Open Access Journals (Sweden)

    Bettina eGreese

    2014-11-01

    Full Text Available While pattern formation is studied in various areas of biology, little is known about the intrinsic noise leading to variations between individual realizations of the pattern. One prominent example for de novo pattern formation in plants is the patterning of trichomes on Arabidopsis leaves, which involves genetic regulation and cell-to-cell communication. These processes are potentially variable due to , e.g., the abundance of cell components or environmental conditions. To elevate the understanding of the regulatory processes underlying the pattern formation it is crucial to quantitatively analyze the variability in naturally occurring patterns. Here, we review recent approaches towards characterization of noise on trichome initiation. We present methods for the quantification of spatial patterns, which are the basis for data-driven mathematical modeling and enable the analysis of noise from different sources. Besides the insight gained on trichome formation, the examination of observed trichome patterns also shows that highly regulated biological processes can be substantially affected by variability.

  3. Mirador - Climate Variability and Change

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. NASA's role in climate variability study is centered around providing the global scale observational data sets on oceans and...

  4. SUGARLOAF ROADLESS AREA, CALIFORNIA.

    Science.gov (United States)

    Powell, Robert E.; Campbell, Harry W.

    1984-01-01

    On the basis of geologic, geochemical, and geophysical investigations and a survey of mines, quarries, and prospects the Sugarloaf Roadless Area, California, has little promise for the occurrence of metallic mineral or energy resources. Units of carbonate rock and graphitic schist have demonstrated resources of magnesian marble and graphite. Sand, gravel, and construction stone other than carbonate rock are present in the roadless area, but similar or better quality materials are abundant and more accessible outside the area.

  5. Long-Term Variability of Surface Albedo and Its Correlation with Climatic Variables over Antarctica

    Directory of Open Access Journals (Sweden)

    Minji Seo

    2016-11-01

    Full Text Available The cryosphere is an essential part of the earth system for understanding climate change. Components of the cryosphere, such as ice sheets and sea ice, are generally decreasing over time. However, previous studies have indicated differing trends between the Antarctic and the Arctic. The South Pole also shows internal differences in trends. These phenomena indicate the importance of continuous observation of the Polar Regions. Albedo is a main indicator for analyzing Antarctic climate change and is an important variable with regard to the radiation budget because it can provide positive feedback on polar warming and is related to net radiation and atmospheric heating in the mainly snow- and ice-covered Antarctic. Therefore, in this study, we analyzed long-term temporal and spatial variability of albedo and investigated the interrelationships between albedo and climatic variables over Antarctica. We used broadband surface albedo data from the Satellite Application Facility on Climate Monitoring and data for several climatic variables such as temperature and Antarctic oscillation index (AAO during the period of 1983 to 2009. Time series analysis and correlation analysis were performed through linear regression using albedo and climatic variables. The results of this research indicated that albedo shows two trends, west trend and an east trend, over Antarctica. Most of the western side of Antarctica showed a negative trend of albedo (about −0.0007 to −0.0015 year−1, but the other side showed a positive trend (about 0.0006 year−1. In addition, albedo and surface temperature had a negative correlation, but this relationship was weaker in west Antarctica than in east Antarctica. The correlation between albedo and AAO revealed different relationships in the two regions; west Antarctica had a negative correlation and east Antarctica showed a positive correlation. In addition, the correlation between albedo and AAO was weaker in the west. This

  6. The winds of cataclysmic variables

    Energy Technology Data Exchange (ETDEWEB)

    Mauche, C.W. [Lawrence Livermore National Lab., CA (United States). Lab. for Experimental Astrophysics; Raymond, J.C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

    1994-02-16

    The authors present an observational and theoretical review of the winds of cataclysmic variables (CVs). Specifically, they consider the related problems of the geometry and mass-loss rate of the winds of CVs, their ionization state and variability, and the results from studies of eclipsing CVs. Finally, they consider the properties of accretion disk wind models. Some of these models predict substantial angular momentum loss, which could affect both disk structure and binary evolution.

  7. Ordering variable for parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Zoltán [DESY,Notkestrasse 85, 22607 Hamburg (Germany); Soper, Davison E. [Institute of Theoretical Science, University of Oregon,Eugene, OR 97403-5203 (United States)

    2014-06-30

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  8. Ordering variable for parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Zoltan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Soper, Davison E. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science

    2014-01-15

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  9. Investigation of load reduction for a variable speed, variable pitch, and variable coning wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, K. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A two bladed, variable speed and variable pitch wind turbine was modeled using ADAMS{reg_sign} to evaluate load reduction abilities of a variable coning configuration as compared to a teetered rotor, and also to evaluate control methods. The basic dynamic behavior of the variable coning turbine was investigated and compared to the teetered rotor under constant wind conditions as well as turbulent wind conditions. Results indicate the variable coning rotor has larger flap oscillation amplitudes and much lower root flap bending moments than the teetered rotor. Three methods of control were evaluated for turbulent wind simulations. These were a standard IPD control method, a generalized predictive control method, and a bias estimate control method. Each control method was evaluated for both the variable coning configuration and the teetered configuration. The ability of the different control methods to maintain the rotor speed near the desired set point is evaluated from the RMS error of rotor speed. The activity of the control system is evaluated from cycles per second of the blade pitch angle. All three of the methods were found to produce similar results for the variable coning rotor and the teetered rotor, as well as similar results to each other.

  10. Fishing Access Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — The Vermont Fish & Wildlife Department maintains developed fishing access areas. These sites provide public access to waters in Vermont for shore fishing...

  11. STANSBURY ROADLESS AREAS, UTAH.

    Science.gov (United States)

    Sorensen, Martin L.; Kness, Richard F.

    1984-01-01

    A mineral-resource survey of the Stansbury Roadless Areas, Utah was conducted and showed that there is little likelihood for the occurrence of metallic mineral resources in the areas. Limestone and dolomite underlie approximately 50 acres in the roadless areas and constitute a nonmetallic mineral resource of undetermined value. The oil and gas potential is not known and cannot be assessed without exploratory geophysical and drilling programs. There are no known geothermal resources. An extensive program of geophysical exploration and exploratory drilling would be necessary to determine the potential for oil and gas in the Stansbury Roadless Areas.

  12. Aperture area measurement facility

    Data.gov (United States)

    Federal Laboratory Consortium — NIST has established an absolute aperture area measurement facility for circular and near-circular apertures use in radiometric instruments. The facility consists of...

  13. Northwest Area Science

    Science.gov (United States)

    Fuentes, Tracy L.; van Heeswijk, Marijke; Grossman, Eric E.

    2010-01-01

    Northwest Area Facts * Population about 12 million * 43 federally recognized Tribes * Hydropower provides about two-thirds of electricity supply * 78 federally listed threatened and endangered species * 12 active or potentially active volcanoes * Columbia River system drains more than 260,000 square miles, an area about the size of Texas * More than 175 square miles covered by glaciers * More than 900 miles of Pacific Ocean coastline * More than 2,300 miles of greater Puget Sound coastline * Some forests store more carbon per unit area than any other area in the world, including the tropics * 51 percent federal lands * Significant lead, zinc, silver, and phosphate deposits

  14. CVP Service Area

    Data.gov (United States)

    California Department of Resources — Federal Water Contract Service Area boundaries are incorporated boundaries of districts having contracts with the U.S. Bureau of Reclamation (Reclamation), within...

  15. Variable Selection via Partial Correlation.

    Science.gov (United States)

    Li, Runze; Liu, Jingyuan; Lou, Lejia

    2017-07-01

    Partial correlation based variable selection method was proposed for normal linear regression models by Bühlmann, Kalisch and Maathuis (2010) as a comparable alternative method to regularization methods for variable selection. This paper addresses two important issues related to partial correlation based variable selection method: (a) whether this method is sensitive to normality assumption, and (b) whether this method is valid when the dimension of predictor increases in an exponential rate of the sample size. To address issue (a), we systematically study this method for elliptical linear regression models. Our finding indicates that the original proposal may lead to inferior performance when the marginal kurtosis of predictor is not close to that of normal distribution. Our simulation results further confirm this finding. To ensure the superior performance of partial correlation based variable selection procedure, we propose a thresholded partial correlation (TPC) approach to select significant variables in linear regression models. We establish the selection consistency of the TPC in the presence of ultrahigh dimensional predictors. Since the TPC procedure includes the original proposal as a special case, our theoretical results address the issue (b) directly. As a by-product, the sure screening property of the first step of TPC was obtained. The numerical examples also illustrate that the TPC is competitively comparable to the commonly-used regularization methods for variable selection.

  16. Climate variability and the European agricultural production

    Science.gov (United States)

    Guimarães Nobre, Gabriela; Hunink, Johannes E.; Baruth, Bettina; Aerts, Jeroen C. J. H.; Ward, Philip J.

    2017-04-01

    By 2050, the global demand for maize, wheat and other major crops is expected to grow sharply. To meet this challenge, agricultural systems have to increase substantially their production. However, the expanding world population, coupled with a decline of arable land per person, and the variability in global climate, are obstacles to achieving the increasing demand. Creating a resilient agriculture system requires the incorporation of preparedness measures against weather-related events, which can trigger disruptive risks such as droughts. This study examines the influence of large-scale climate variability on agriculture production applying a robust decision-making tool named fast-and-frugal trees (FFT). We created FFTs using a dataset of crop production and indices of climate variability: the El Niño Southern Oscillation (SOI) and the North Atlantic Oscillation (NAO). Our main goal is to predict the occurrence of below-average crop production, using these two indices at different lead times. Initial results indicated that SOI and NAO have strong links with European low sugar beet production. For some areas, the FFTs were able to detect below-average productivity events six months before harvesting with hit rate and predictive positive value higher than 70%. We found that shorter lead times, such as three months before harvesting, have the highest predictive skill. Additionally, we observed that the responses of low production events to the phases of the NAO and SOI vary spatially and seasonally. Through the comprehension of the relationship between large scale climate variability and European drought related agricultural impact, this study reflects on how this information could potentially improve the management of the agricultural sector by coupling the findings with seasonal forecasting system of crop production.

  17. Species richness, area and climate correlates

    DEFF Research Database (Denmark)

    Nogues, David Bravo; Bastos Araujo, Miguel

    2006-01-01

    . The assumption is that variation in grid cell size accrued from working in a three-dimensional world is negligible. Here we provide a first test of this idea. We measure the surface area of c. 50 × 50 km and c. 220 × 220 km grid cells across western Europe. We then ask how variation in the area of grid cells...... affects: (1) the selection of climate variables entering a species richness model; and (2) the accuracy of models in predicting species richness in unsampled grid cells. Location Western Europe. Methods Models are developed for European plant, breeding bird, mammal and herptile species richness using...... seven climate variables. Generalized additive models are used to relate species richness, climate and area. Results We found that variation in the grid cell area was large (50 × 50 km: 8-3311 km2; 220 × 220: 193-55,100 km2), but this did not affect the selection of variables in the models. Similarly...

  18. Operational Area Environmental Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Bailey-White, Brenda Eileen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagy, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wagner, Katrina Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Goodman, Thomas Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herring, Allen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Catechis, Christopher S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kinghorn, Aubrianna Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Ellie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barthel, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Casaus, Benito [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    The Operational Area Environmental Evaluation update provides a description of activities that have the potential to adversely affect natural and cultural resources, including soil, air, water, biological, ecological, and historical resources. The environmental sensitivity of an area is evaluated and summarized, which may facilitate informed management decisions as to where development may be prohibited, restricted, or subject to additional requirements.

  19. Available area isotherm

    NARCIS (Netherlands)

    Bosma, JC; Wesselingh, JA

    A new isotherm is presented for adsorption of proteins, the available area isotherm. This isotherm has a steric basis, unlike the (steric) mass action model. The shape of the available area isotherm is determined only by geometric exclusion. With the new isotherm, experimental results can be fitted

  20. Broca's area - thalamic connectivity.

    Science.gov (United States)

    Bohsali, Anastasia A; Triplett, William; Sudhyadhom, Atchar; Gullett, Joseph M; McGregor, Keith; FitzGerald, David B; Mareci, Thomas; White, Keith; Crosson, Bruce

    2015-02-01

    Broca's area is crucially involved in language processing. The sub-regions of Broca's area (pars triangularis, pars opercularis) presumably are connected via corticocortical pathways. However, growing evidence suggests that the thalamus may also be involved in language and share some of the linguistic functions supported by Broca's area. Functional connectivity is thought to be achieved via corticothalamic/thalamocortical white matter pathways. Our study investigates structural connectivity between Broca's area and the thalamus, specifically ventral anterior nucleus and pulvinar. We demonstrate that Broca's area shares direct connections with these thalamic nuclei and suggest a local Broca's area-thalamus network potentially involved in linguistic processing. Thalamic connectivity with Broca's area may serve to selectively recruit cortical regions storing multimodal features of lexical items and to bind them together during lexical-semantic processing. In addition, Broca's area-thalamic circuitry may enable cortico-thalamo-cortical information transfer and modulation between BA 44 and 45 during language comprehension and production. Published by Elsevier Inc.

  1. Atmospheric variables as driving variables of agricultural and forest ecosystems

    Directory of Open Access Journals (Sweden)

    Luigi Mariani

    Full Text Available Atmospheric variables, which represent meteorology if seen in their instantaneous behavior or climatology if seen in their long time behavior, can be considered among the main driving variables of agricultural and forest ecosystems. In other words meteo-climatic variables determine productivity and quality and territorial specificity of agroforestry productions. On the base of this premise some significant examples are shown in order to describe how different modeling approaches (empirical and mechanistic can improve our degree of description of phenomena and the rationality of our approach to management of agro-ecosystem. The need of strict linkage among agrometeorology and other physical and biological sciences referred to agro-forestry ecosystems is also discussed.

  2. OLALLIE ROADLESS AREA, OREGON.

    Science.gov (United States)

    Walker, George W.; Neumann, Terry R.

    1984-01-01

    The Olallie Roadless Area, Oregon, is devoid of mines and mineral prospects, and a mineral-resource evaluation of the area did not identify any mineral-resource potential. There is no evidence that fossil fuels are present in the roadless area. Nearby areas in Clackamas, Marion, Jefferson, and Wasco Counties are characterized by higher-than-normal heat flow and by numerous thermal springs, some of which have been partly developed. this may indicate that the region has some, as yet undefined, potential for the development of geothermal energy. Lack of thermal springs or other evidence of localized geothermal anomalies within the roadless area may be the result of masking by young, nonconductive rock units and by the flooding out and dilution of rising thermal waters by cool meteoric water.

  3. Crank drive for variable compression ratio; Kurbeltrieb fuer variable Verdichtung

    Energy Technology Data Exchange (ETDEWEB)

    Bollig, C. [FEV Motorentechnik GmbH und Co. KG, Aachen (Germany); Habermann, K.; Marckwardt, H.; Yapici, K.I. [Technische Hochschule Aachen (Germany). Lehrstuhl fuer Angewandte Thermodynamik (LAT)

    1997-11-01

    In a research project at the Institute of Applied Thermodynamics (LAT) of the University of Aachen (RWTH) between April 1995 and October 1996, a variable compression ratio was realised on a specially prepared FEV Single Cylinder Research Engine and investigated in terms of combustion and tribological behaviour. On the basis of an invention by the FEV Motorentechnik, the variable compression ratio was realised with a variable crankdrive. This technology allows a variable compression ratio across a wide range. In combination with High Pressure Supercharging, F.E. concept for S.I. engines results in a fuel saving potential of up to 30%. Equipped with well-known Three-Way-Catalyst (TWC) technology, it is capable of meeting future low emission standards. To achieve a weight-optimised design of the conrod, FEM analyses have been conducted. The primary goal of the test bench investigation was to obtain information about the influence of the unconventional piston movement during combustion as well as about the tribological behaviour of the variable crankdrive. (orig.) [Deutsch] Innerhalb eines Forschungsprojektes am Lehrstuhl fuer Angewandte Thermodynamik der RWTH-Aachen (LAT) wurde im Zeitraum April 1995 bis Oktober 1996 ein variables Verdichtungsverhaeltnis an einem speziell praeparierten FEV-Einzylinder-Ottomotor umgesetzt und brennverfahrenstechnisch wie auch tribologisch im Pruefstandsbetrieb untersucht. Basierend auf einer Erfindung der FEV Motorentechnik wurde das veraenderliche Verdichtungsverhaeltnis mit einem variablen Kurbeltrieb realisiert. Diese Technik ermoeglicht eine Variabilitaet der Verdichtung in einem grossen Bereich. In Verbindung mit Hochaufladung kann so ein ottomotorisches Verbrauchskonzept mit einem Einsparpotential von bis zu 30% dargestellt werden, das unter Beibehaltung der {lambda}=1-Technik zukuenftige Abgasnormen erfuellen kann. Die Eignung des variablen Kurbeltriebs zur Realisierung einer veraenderlichen Verdichtung konnte in der

  4. The cataclysmic variable AE Aquarii: orbital variability in V band

    Science.gov (United States)

    Zamanov, R.; Latev, G.

    2017-07-01

    We present 62.7 hours observations of the cataclysmic variable AE Aqr in Johnson V band. These are non-published archive electro-photometric data obtained during the time period 1993 to 1999. We construct the orbital variability in V band and obtain a Fourier fit to the double-wave quiescent light curve. The strongest flares in our data set are in phase interval 0.6 - 0.8. The data can be downloaded from http://www.astro.bas.bg/~rz/DATA/AEAqr.elphot.dat.

  5. Variable order variable stepsize algorithm for solving nonlinear Duffing oscillator

    Science.gov (United States)

    Fadly Nurullah Rasedee, Ahmad; Ishak, Norizarina; Raihana Hamzah, Siti; Ijam, Hazizah Mohd; Suleiman, Mohamed; Bibi Ibrahim, Zarina; Sathar, Mohammad Hasan Abdul; Ainna Ramli, Nur; Shuhada Kamaruddin, Nur

    2017-09-01

    Nonlinear phenomena in science and engineering such as a periodically forced oscillator with nonlinear elasticity are often modeled by the Duffing oscillator (Duffing equation). The Duffling oscillator is a type of nonlinear higher order differential equation. In this research, a numerical approximation for solving the Duffing oscillator directly is introduced using a variable order stepsize (VOS) algorithm coupled with a backward difference formulation. By selecting the appropriate restrictions, the VOS algorithm provides a cost efficient computational code without affecting its accuracy. Numerical results have demonstrated the advantages of a variable order stepsize algorithm over conventional methods in terms of total steps and accuracy.

  6. Testing of hypothesis of two-dimensional random variables independence on the basis of algorithm of pattern recognition

    Science.gov (United States)

    Lapko, A. V.; Lapko, V. A.; Yuronen, E. A.

    2016-11-01

    The new technique of testing of hypothesis of random variables independence is offered. Its basis is made by nonparametric algorithm of pattern recognition. The considered technique doesn't demand sampling of area of values of random variables.

  7. Sparse estimation for structural variability

    Directory of Open Access Journals (Sweden)

    Singh Rohit

    2011-04-01

    Full Text Available Abstract Background Proteins are dynamic molecules that exhibit a wide range of motions; often these conformational changes are important for protein function. Determining biologically relevant conformational changes, or true variability, efficiently is challenging due to the noise present in structure data. Results In this paper we present a novel approach to elucidate conformational variability in structures solved using X-ray crystallography. We first infer an ensemble to represent the experimental data and then formulate the identification of truly variable members of the ensemble (as opposed to those that vary only due to noise as a sparse estimation problem. Our results indicate that the algorithm is able to accurately distinguish genuine conformational changes from variability due to noise. We validate our predictions for structures in the Protein Data Bank by comparing with NMR experiments, as well as on synthetic data. In addition to improved performance over existing methods, the algorithm is robust to the levels of noise present in real data. In the case of Human Ubiquitin-conjugating enzyme Ubc9, variability identified by the algorithm corresponds to functionally important residues implicated by mutagenesis experiments. Our algorithm is also general enough to be integrated into state-of-the-art software tools for structure-inference.

  8. Continuous-variable supraquantum nonlocality

    Science.gov (United States)

    Ketterer, Andreas; Laversanne-Finot, Adrien; Aolita, Leandro

    2018-01-01

    Supraquantum nonlocality refers to correlations that are more nonlocal than allowed by quantum theory but still physically conceivable in postquantum theories, in the sense of respecting the basic no-faster-than-light communication principle. While supraquantum correlations are relatively well understood for finite-dimensional systems, little is known in the infinite-dimensional case. Here, we study supraquantum nonlocality for bipartite systems with two measurement settings and infinitely many outcomes per subsystem. We develop a formalism for generic no-signaling black-box measurement devices with continuous outputs in terms of probability measures, instead of probability distributions, which involves a few technical subtleties. We show the existence of a class of supraquantum Gaussian correlations, which violate the Tsirelson bound of an adequate continuous-variable Bell inequality. We then introduce the continuous-variable version of the celebrated Popescu-Rohrlich (PR) boxes, as a limiting case of the above-mentioned Gaussian ones. Finally, we characterize the geometry of the set of continuous-variable no-signaling correlations. Namely, we show that that the convex hull of the continuous-variable PR boxes is dense in the no-signaling set. We also show that these boxes are extreme in the set of no-signaling behaviors and provide evidence suggesting that they are indeed the only extreme points of the no-signaling set. Our results lay the grounds for studying generalized-probability theories in continuous-variable systems.

  9. Entropy as a collective variable

    Science.gov (United States)

    Parrinello, Michele

    Sampling complex free energy surfaces that exhibit long lived metastable states separated by kinetic bottlenecks is one of the most pressing issues in the atomistic simulations of matter. Not surprisingly many solutions to this problem have been suggested. Many of them are based on the identification of appropriate collective variables that span the manifold of the slow varying modes of the system. While much effort has been put in devising and even constructing on the fly appropriate collective variables there is still a cogent need of introducing simple, generic, physically transparent, and yet effective collective variables. Motivated by the physical observation that in many case transitions between one metastable state and another result from a trade off between enthalpy and entropy we introduce appropriate collective variables that are able to represent in a simple way these two physical properties. We use these variables in the context of the recently introduced variationally enhanced sampling and apply it them with success to the simulation of crystallization from the liquid and to conformational transitions in protein. Department of Chemistry and Applied Biosciences, ETH Zurich, and Facolta' di Informatica, Istituto di Scienze Computazionali, Universita' della Svizzera Italiana, Via G. Buffi 13, 6900 Lugano, Switzerland.

  10. Statistical variability of hydro-meteorological variables as indicators ...

    African Journals Online (AJOL)

    The aim of this study is to examine the variability patterns of rainfall and actual evapotranspiration during two climatic scenarios as an insight in climatic response to global warming. The comparison between evapotranspiration during the periods (1943-1977) and (1978-2012) at the five studied weather stations revealed a ...

  11. Cardinality-dependent Variability in Orthogonal Variability Models

    DEFF Research Database (Denmark)

    Mærsk-Møller, Hans Martin; Jørgensen, Bo Nørregaard

    2012-01-01

    During our work on developing and running a software product line for eco-sustainable greenhouse-production software tools, which currently have three products members we have identified a need for extending the notation of the Orthogonal Variability Model (OVM) to support what we refer...

  12. Time as a dynamical variable

    Science.gov (United States)

    Thron, Christopher

    2017-01-01

    Since the time of Galileo, the equations of physics have expressed dynamical variables such as particle position or electromagnetic field strength as functions of time. In this paper, we argue that this assumption reflects observational bias, and that there are many good reasons for viewing time also as a dynamical variable. We hypothesize that the spacetime universe is an outcome of a process, rather than a process unfolding in time. This new viewpoint gives rise to a physical interpretation of the wavefunction as a complex vibrational amplitude in a non-spacetime independent variable. It resolves quantum mechanical paradoxes involving wavefunction entanglement, and gives a much simpler solution to the problem of wavefunction collapse than the many-worlds interpretation. The Born rule is also shown to be a natural consequence. We also show that small deviations from conventional quantum probabilities are predicted.

  13. Variable geometry Darrieus wind machine

    Science.gov (United States)

    Pytlinski, J. T.; Serrano, D.

    1983-08-01

    A variable geometry Darrieus wind machine is proposed. The lower attachment of the blades to the rotor can move freely up and down the axle allowing the blades of change shape during rotation. Experimental data for a 17 m. diameter Darrieus rotor and a theoretical model for multiple streamtube performance prediction were used to develop a computer simulation program for studying parameters that affect the machine's performance. This new variable geometry concept is described and interrelated with multiple streamtube theory through aerodynamic parameters. The computer simulation study shows that governor behavior of a Darrieus turbine can not be attained by a standard turbine operating within normally occurring rotational velocity limits. A second generation variable geometry Darrieus wind turbine which uses a telescopic blade is proposed as a potential improvement on the studied concept.

  14. Complex variable methods in elasticity

    CERN Document Server

    England, A H

    2003-01-01

    The plane strain and generalized plane stress boundary value problems of linear elasticity are the focus of this graduate-level text, which formulates and solves these problems by employing complex variable theory. The text presents detailed descriptions of the three basic methods that rely on series representation, Cauchy integral representation, and the solution via continuation. Its five-part treatment covers functions of a complex variable, the basic equations of two-dimensional elasticity, plane and half-plane problems, regions with circular boundaries, and regions with curvilinear bounda

  15. A process variability control chart

    OpenAIRE

    Riaz, M.; Does, R.J.M.M.

    2009-01-01

    In this study a Shewhart type control chart namely the Vt chart, is proposed for improvedmonitoring of the process variability of a quality characteristic of interest Y . The proposed control chart is based on the ratio type estimator of the variance using a single auxiliary variable X. It is assumed that (Y, X) follows a bivariate normal distribution. The design structure of the Vt chart is developed for Phase-I quality control and its comparison is made with those of the S2 chart (a well-kn...

  16. Genetic Variability for Drought Adaptive Traits in A-511 Maize ...

    African Journals Online (AJOL)

    Drought causes considerable yield reduction in maize (Zea mays L.) grown in the moisture stressed areas of Ethiopia. Increased crop production through improvement is expected if the adapted local genotypes possess variability for drought adaptive traits. Randomly taken 196 S1 lines generated from Population A-511 ...

  17. Impacts of climate change, variability and adaptation strategies on ...

    African Journals Online (AJOL)

    hope&shola

    deal with impacts of climate change and variability. Further, development initiatives at community level in semi arid areas should put more emphasis on water harvesting to ensure water storage for crops and livestock. Key words: Agriculture production, climate change, Kamenyanga village, Manyoni District, rainfall, Singida.

  18. Parental views on some variables as determinants of sexuality ...

    African Journals Online (AJOL)

    This study investigated parental views on some variables as determinants of sexuality education. The sample consisted of 120 parents from four towns in Aniocha-North Local Government Area of Delta State, Nigeria. Descriptive survey method was used for the study, four research questions were generated to guide the ...

  19. Measuring spatial variability of land use associated with ...

    African Journals Online (AJOL)

    2011-06-07

    use system is linked to orderly .... i.e., the probability of an urban area occurring around a city centre (Chen et al., 2010). ..... represents around 53% of the maximum degree of land-use spa- tial variability. This means that ...

  20. Sociological Variables Influencing the Nigeria Premier League | Ogu ...

    African Journals Online (AJOL)

    The study investigated sociological variable influencing the Nigeria premier League. Three research questions and three hypotheses were raised. The area of the study was Nigeria. The population for the study was 1,118 which comprised of sports administrators, coaches and players in the Nigeria Premier League.

  1. Spatial variability in the density, distribution and vectorial capacity of ...

    African Journals Online (AJOL)

    Malaria transmission varies from one area to another and there are also local difference in time and space. The objective of the study was to determine the local variability of entomological parameters namely, mosquito abundance, human biting rate (HBR), sporozoite rate for Plasmodium falciparum and entomological ...

  2. Derivation and application of hydraulic equation for variable-rate ...

    African Journals Online (AJOL)

    The variable-rate contour-controlled sprinkler (VRCS) for precision irrigation can throw water on a given shaped area and the flow rate is also varied with the throw distance of the sprinkler for the purpose of high uniformity irrigation. Much of past research work were concentrated on the mechanical availability of ...

  3. Ethnicity and gender variability in the diversity, recognition and ...

    African Journals Online (AJOL)

    SARAH

    2014-02-12

    Feb 12, 2014 ... (K) were used to assess the diversity, the level of knowledge, use of wild mushrooms and variability among all three ethnic groups. A total ... Volaviella volvacea as the commonly exploited mushrooms in the study area (TUV between 2,14 and 2,40). All recorded ...... basidiomycetes mushrooms. International.

  4. Some aspects of climate variability in the north east Ethiopian ...

    African Journals Online (AJOL)

    To date little work has been done on climate reconstruction in Tigray and Wollo, however, a number of ongoing studies in the area using palaeosoil analysis, archaeological techniques and lake level reconstruction will help reveal the magnitude of past climate variability in the region. On recent time scales, rainfall over ...

  5. Influence of job frustration, narcissism and demographic variables ...

    African Journals Online (AJOL)

    The study examines the hypothesised relationship among job frustration, narcissism, demographic variables and professional ethical behaviour among Nigerian Police officers. One hundred policemen drawn from four police divisions of Benin Area Command of Edo State participated in the study. There were 18 females ...

  6. Variability in stratification and flushing times of the Gautami ...

    Indian Academy of Sciences (India)

    stretch of 36 km, at 500×50 m grid spacing using. Differential Global Positioning System (DGPS;. Ceeducer, Australia). The DGPS is a satellite-based. Figure 2. Variability of (a) along channel depth and (b) cross-sectional area at transect locations in the Gautami–. Godavari estuary. The numbers on the top indicate station.

  7. Fluid/Vapor Separator for Variable Flow Rates

    Science.gov (United States)

    Lee, J. M.; Chuang, C.; Frederking, T. H.; Brown, G. S.; Kamioka, Y.; Vorreiter, J.

    1984-01-01

    Shutter varies gas throughput of porous plug. Variable area exposed on porous plug allows to pass varying rates of vapor flow while blocking flow of liquid helium II from cryogenic bath. Applications in refining operations, industrial chemistry, and steam-powered equipment.

  8. Macroeconomic Variables and Money Supply: Evidence from Nigeria

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    This paper reviews the effect and implication of selected Macroeconomic variables ... the economy, due to its stupendous importance as a change in its amount can have a ... student who intent to do more research in this area and thus serve as .... period of money expansion and high inflation in the decade of the 1990's was.

  9. Effective Analysis of C Programs by Rewriting Variability

    DEFF Research Database (Denmark)

    Iosif-Lazar, Alexandru Florin; Melo, Jean; Dimovski, Aleksandar

    2017-01-01

    Context. Variability-intensive programs (program families) appear in many application areas and for many reasons today. Different family members, called variants, are derived by switching statically configurable options (features) on and off, while reuse of the common code is maximized. Inquiry...

  10. Climate variability and impacts on east African livestock herders: the ...

    African Journals Online (AJOL)

    East African pastoral adaptation and vulnerability to climate variability and climate change is assessed, using data from decision-making processes and ecological data of the Maasai of Ngorongoro Conservation Area as an example. The paper uses integrated modeling, linking PHEWS, a household model, to Savanna, ...

  11. Upper-Division Student Difficulties with Separation of Variables

    Science.gov (United States)

    Wilcox, Bethany R.; Pollock, Steven J.

    2015-01-01

    Separation of variables can be a powerful technique for solving many of the partial differential equations that arise in physics contexts. Upper-division physics students encounter this technique in multiple topical areas including electrostatics and quantum mechanics. To better understand the difficulties students encounter when utilizing the…

  12. Variable structure unit vector control of electric power generation ...

    African Journals Online (AJOL)

    A variable structure Automatic Generation Control (VSAGC) scheme is proposed in this paper for the control of a single area power system model dominated by steam powered electric generating plants. Unlike existing, VSAGC scheme where the selection of the control function is based on a trial and error procedure, the ...

  13. Ethnicity and gender variability in the diversity, recognition and ...

    African Journals Online (AJOL)

    SARAH

    2014-02-12

    Feb 12, 2014 ... recorded species are used in the study area either as food, drugs or source of cash incomes. The study revealed a great variability of knowledge, ..... Many edible mushrooms have also pharmaceutical property. Like in China, the ... selected mushrooms with psychoactive and hallucinogenic effects for idol ...

  14. modelling relationship between rainfall variability and yields in the ...

    African Journals Online (AJOL)

    yield models should be used for planning and forecasting the yield of millet and sorghum in the study area. Key words: modelling, rainfall, yields, millet, sorghum. INTRODUCTION. Meteorological variables, such as rainfall parameters, temperature, sunshine hours, relative humidity, and wind velocity and soil moisture are.

  15. Perceptions and adaptation to climate change and variability by ...

    African Journals Online (AJOL)

    Kenya comprises of 83% arid and semi-arid land mainly suited to extensive livestock production. Communities living in the semi-arid areas have been affected by serious effects of climate change and variability. A study was carried out to evaluate farmer perceptions and adaptation to climate change in Naro Moru and ...

  16. Climate Change and Variability: Implications for Household Food ...

    African Journals Online (AJOL)

    Daniel

    Ethiopia is one of the most vulnerable countries of the world to the impacts of climate change and variability. The impact is even stronger in pastoral areas of the country. However, studies on the actual climate change dynamics and its effect on food security at local and household levels are limited. The present study took ...

  17. Specific discharge variability in a boreal landscape

    Science.gov (United States)

    Lyon, Steve W.; Nathanson, Marcus; Spans, André; Grabs, Thomas; Laudon, Hjalmar; Temnerud, Johan; Bishop, Kevin H.; Seibert, Jan

    2012-08-01

    Specific discharge variations within a mesoscale catchment were studied on the basis of three synoptic sampling campaigns. These were conducted during stable flow conditions within the Krycklan catchment study area in northern Sweden. During each campaign, about 80 individual locations were measured for discharge draining from catchment areas ranging between 0.12 and 67 km2. These discharge samplings allowed for the comparison between years within a given season (September 2005 versus September 2008) and between seasons within a given year (May 2008 versus September 2008) of specific discharge across this boreal landscape. There was considerable variability in specific discharge across this landscape. The ratio of the interquartile range (IQR) defined as the difference between the 75th and 25th percentiles of the specific discharges to the median of the specific discharges ranged from 37% to 43%. Factor analysis was used to explore potential relations between landscape characteristics and the specific discharge observed for 55 of the individual locations that were measured in all three synoptic sampling campaigns. Percentage wet area (i.e., wetlands, mires, and lakes) and elevation were found to be directly related to the specific discharge during the drier September 2008 sampling while potential annual evaporation was found to be inversely related. There was less of a relationship determined during the wetter post spring flood May 2008 sampling and the late summer rewetted September 2005 sampling. These results indicate the ability of forests to "dry out" parts of the catchment over the summer months while wetlands "keep wet" other parts. To demonstrate the biogeochemical implications of such spatiotemporal variations in specific discharge, we estimate dissolved organic carbon (DOC) exports with available data for the May 2008 and September 2008 samplings using both the spatially variable observed specific discharges and the spatially constant catchment average

  18. SO2 Nonattainment Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for Sulfur dioxide and have...

  19. PM 10 Nonattainment Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for PM 10 and have been...

  20. Ice Engineering Research Area

    Data.gov (United States)

    Federal Laboratory Consortium — Refrigerated Physical Modeling of Waterways in a Controlled EnvironmentThe Research Area in the Ice Engineering Facility at the Cold Regions Research and Engineering...

  1. Pilot Boarding Areas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pilot boarding areas are locations at sea where pilots familiar with local waters board incoming vessels to navigate their passage to a destination port. Pilotage is...

  2. Carbon Monoxide Nonattainment Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for Carbon Monoxide and have...

  3. Driftless Area NWR ROCSTAR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Resources of Concern Selection Tool for Americas Refuges (ROCSTAR) was developed to assist national wildlife refuges, waterfowl production areas, wetland...

  4. Decontamination & decommissioning focus area

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    In January 1994, the US Department of Energy Office of Environmental Management (DOE EM) formally introduced its new approach to managing DOE`s environmental research and technology development activities. The goal of the new approach is to conduct research and development in critical areas of interest to DOE, utilizing the best talent in the Department and in the national science community. To facilitate this solutions-oriented approach, the Office of Science and Technology (EM-50, formerly the Office of Technology Development) formed five Focus AReas to stimulate the required basic research, development, and demonstration efforts to seek new, innovative cleanup methods. In February 1995, EM-50 selected the DOE Morgantown Energy Technology Center (METC) to lead implementation of one of these Focus Areas: the Decontamination and Decommissioning (D & D) Focus Area.

  5. RAINWATER MANAGEMENT IN PROTECTED AREAS

    Directory of Open Access Journals (Sweden)

    Wioletta Żarnowiec

    2017-03-01

    Full Text Available The aim of the study was to find out whether the climate of the southern Poland allows for removing rainwater from industrial areas by evaporation from roof surfaces. The study covered the premises of a Logistics Centre with an approximate area of 34 hectares, located in the catchment of the Wedonka stream and in the region of water intake for Kraków at the Rudawa river. In the future, the Centre will comprise nine large warehouses. Road traffic associated with the project will cause potential risks for groundwater and surface water of this protected area. Therefore, the Centre’s investor decided to evaporate rainwater from the premises. To establish advisability of this plan, the study team designed and built a unique experimental station consisting of experimental roof, tank for collecting water for the sprinkler system, system for delivering, distributing and discharging water from the roof, measuring tilt tray, automatic meteorological station, and electronic devices for recording measurement data. The research on the experimental station was carried out from April to October in 2011 and 2012 and included continuous measurements of the volume of water supplied to and discharged from the roof. Moreover, the temperature of the roof and water in the tank and a number of important meteorological parameters were measured. The difference between supplied and discharged water, divided by the wetted surface of the roof, helped to determine thickness of the evaporation layer in millimeters. The study confirmed the possibility of removing potentially contaminated rainwater by evaporating it from roof surfaces of the Logistics Centre located near Kraków at an average rate of 5.9 dm3·m–2.d–1. However, due to high seasonal variability of rainfall and air temperature, it is necessary to temporarily collect water in an expansion tank of suitable capacity.

  6. Offshore wind mapping Mediterranean area using SAR

    DEFF Research Database (Denmark)

    Calaudi, Rosamaria; Arena, Felice; Badger, Merete

    2013-01-01

    Satellite observations of the ocean surface, for example from Synthetic Aperture Radars (SAR), provide information about the spatial wind variability over large areas. This is of special interest in the Mediterranean Sea, where spatial wind information is only provided by sparse buoys, often...... with long periods of missing data. Here, we focus on evaluating the use of SAR for offshore wind mapping. Preliminary results from the analysis of SAR-based ocean winds in Mediterranean areas show interesting large scale wind flow features consistent with results from previous studies using numerical models...

  7. Inferring Cortical Variability from Local Field Potentials.

    Science.gov (United States)

    Cui, Yuwei; Liu, Liu D; McFarland, James M; Pack, Christopher C; Butts, Daniel A

    2016-04-06

    The responses of sensory neurons can be quite different to repeated presentations of the same stimulus. Here, we demonstrate a direct link between the trial-to-trial variability of cortical neuron responses and network activity that is reflected in local field potentials (LFPs). Spikes and LFPs were recorded with a multielectrode array from the middle temporal (MT) area of the visual cortex of macaques during the presentation of continuous optic flow stimuli. A maximum likelihood-based modeling framework was used to predict single-neuron spiking responses using the stimulus, the LFPs, and the activity of other recorded neurons. MT neuron responses were strongly linked to gamma oscillations (maximum at 40 Hz) as well as to lower-frequency delta oscillations (1-4 Hz), with consistent phase preferences across neurons. The predicted modulation associated with the LFP was largely complementary to that driven by visual stimulation, as well as the activity of other neurons, and accounted for nearly half of the trial-to-trial variability in the spiking responses. Moreover, the LFP model predictions accurately captured the temporal structure of noise correlations between pairs of simultaneously recorded neurons, and explained the variation in correlation magnitudes observed across the population. These results therefore identify signatures of network activity related to the variability of cortical neuron responses, and suggest their central role in sensory cortical function. The function of sensory neurons is nearly always cast in terms of representing sensory stimuli. However, recordings from visual cortex in awake animals show that a large fraction of neural activity is not predictable from the stimulus. We show that this variability is predictable given the simultaneously recorded measures of network activity, local field potentials. A model that combines elements of these signals with the stimulus processing of the neuron can predict neural responses dramatically better

  8. 300 Area Disturbance Report

    Energy Technology Data Exchange (ETDEWEB)

    LL Hale; MK Wright; NA Cadoret

    1999-01-07

    The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic

  9. Cooled variable nozzle radial turbine for rotor craft applications

    Science.gov (United States)

    Rogo, C.

    1981-01-01

    An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

  10. Variable selection and estimation for longitudinal survey data

    KAUST Repository

    Wang, Li

    2014-09-01

    There is wide interest in studying longitudinal surveys where sample subjects are observed successively over time. Longitudinal surveys have been used in many areas today, for example, in the health and social sciences, to explore relationships or to identify significant variables in regression settings. This paper develops a general strategy for the model selection problem in longitudinal sample surveys. A survey weighted penalized estimating equation approach is proposed to select significant variables and estimate the coefficients simultaneously. The proposed estimators are design consistent and perform as well as the oracle procedure when the correct submodel was known. The estimating function bootstrap is applied to obtain the standard errors of the estimated parameters with good accuracy. A fast and efficient variable selection algorithm is developed to identify significant variables for complex longitudinal survey data. Simulated examples are illustrated to show the usefulness of the proposed methodology under various model settings and sampling designs. © 2014 Elsevier Inc.

  11. Complex Variables throughout the Curriculum

    Science.gov (United States)

    D'Angelo, John P.

    2017-01-01

    We offer many specific detailed examples, several of which are new, that instructors can use (in lecture or as student projects) to revitalize the role of complex variables throughout the curriculum. We conclude with three primary recommendations: revise the syllabus of Calculus II to allow early introductions of complex numbers and linear…

  12. On colorings of variable words

    OpenAIRE

    Tyros, Konstantinos

    2014-01-01

    In this note, we prove that the base case of the Graham--Rothschild Theorem, i.e., the one that considers colorings of the ($1$-dimensional) variable words, admits bounds in the class $\\mathcal{E}^5$ of Grzegorczyk's hierarchy.

  13. UXOR Hunting among Algol Variables

    Science.gov (United States)

    Poxon, M.

    2015-06-01

    The class of variable typified by UX Orionis (UXORs or UXors) are young stars characterised by aperiodic or semiperiodic fades from maximum. This has led to several of the class being formerly catalogued as Algol-type eclipsing binaries (EAs), which can show superficially similar light variations. With this in view, I propose a campaign to search for more UX Ori type stars.

  14. Cataclysmic Variables in the Backyard

    Science.gov (United States)

    Patterson, J.

    2012-06-01

    (Abstract only) The last decade has seen plummeting prices and significant advances in CCD-camera and smart-telescope technology, reaching all the way to the humblest of telescopes. There are now thousands of well-equipped amateur astronomers interested in using their telescopes for research, and many hundreds already doing so in coordinated campaigns. Variable star science has benefited tremendously. Since it's always dark and always clear somewhere, coordinated photometry can accumulate nearly 24-hour coverage - and since the observers own their telescopes, very long campaigns are feasible, with little worry about weather. I'll describe one network of observers, the Center for Backyard Astrophysics (CBA). The telescope apertures are 20-50 cm, enabling good signal-to-noise and time resolution down to V=18. We organize campaigns of time-series photometry of cataclysmic variables (novae, dwarf novae, magnetic variables, some X-ray binaries) - and routinely achieve thousand-hour campaigns with no significant aliasing, since the telescopes are distributed around the world. This enables sensitive searches for periodic signals, extending even to long time scales (months). We now produce most of the world's supply of accretion-disk precession periods, and keep close watch on all the other clocks in cataclysmic variables (orbit, white-dwarf rotation and pulsation, and quasiperiodic oscillations).

  15. Operating Reserves and Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ela, E.; Milligan, M.; Kirby, B.

    2011-08-01

    This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

  16. Marginality and Variability in Esperanto.

    Science.gov (United States)

    Brent, Edmund

    This paper discusses Esperanto as a planned language and refutes three myths connected to it, namely, that Esperanto is achronical, atopical, and apragmatic. The focus here is on a synchronic analysis. Synchronic variability is studied with reference to the structuralist determination of "marginality" and the dynamic linguistic…

  17. Several topics in complex variables

    NARCIS (Netherlands)

    Smit, I.M.

    2015-01-01

    This thesis is based on three articles in the field of Several Complex Variables. The first article, which is joint work with M. El Kadiri, defines and studies the concept of maximality for plurifinely plurisubharmonic functions. Its main result is that a finite plurifinely plurisubharmonic function

  18. Variable rules meet Impoverishment theory

    DEFF Research Database (Denmark)

    Parrott, Jeffrey K.; Nevins, Andrew

    2010-01-01

    This paper revives the sociolinguistic notion of ‘variable rules’ (Labov 1969, Cedergren and Sankoff 1974, Guy 1991) as a specific and restricted mechanism within the theoretical framework of Distributed Morphology (Halle and Marantz 1993, Embick and Noyer 2007). We propose that intra-individual ...

  19. Compact plasmonic variable optical attenuator

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Rosenzveig, Tiberiu; Hermannsson, Pétur Gordon

    2008-01-01

    We demonstrate plasmonic nanowire-based thermo-optic variable optical attenuators operating in the 1525-1625 nm wavelength range. The devices have a footprint as low as 1 mm, extinction ratio exceeding 40 dB, driving voltage below 3 V, and full modulation bandwidth of 1 kHz. The polarization...

  20. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition

  1. MODIS/Terra+Aqua Leaf Area Index/FPAR 4-Day L4 Global 1km SIN Grid V005

    Data.gov (United States)

    National Aeronautics and Space Administration — Leaf Area Index (LAI) is a dimensionless variable defined as the total one-sided area of green leaves in a vegetation canopy relative to a unit ground area. LAI...

  2. Performance of variable selection methods using stability-based selection.

    Science.gov (United States)

    Lu, Danny; Weljie, Aalim; de Leon, Alexander R; McConnell, Yarrow; Bathe, Oliver F; Kopciuk, Karen

    2017-04-04

    Variable selection is frequently carried out during the analysis of many types of high-dimensional data, including those in metabolomics. This study compared the predictive performance of four variable selection methods using stability-based selection, a new secondary selection method that is implemented in the R package BioMark. Two of these methods were evaluated using the more well-known false discovery rate (FDR) as well. Simulation studies varied factors relevant to biological data studies, with results based on the median values of 200 partial area under the receiver operating characteristic curve. There was no single top performing method across all factor settings, but the student t test based on stability selection or with FDR adjustment and the variable importance in projection (VIP) scores from partial least squares regression models obtained using a stability-based approach tended to perform well in most settings. Similar results were found with a real spiked-in metabolomics dataset. Group sample size, group effect size, number of significant variables and correlation structure were the most important factors whereas the percentage of significant variables was the least important. Researchers can improve prediction scores for their study data by choosing VIP scores based on stability variable selection over the other approaches when the number of variables is small to modest and by increasing the number of samples even moderately. When the number of variables is high and there is block correlation amongst the significant variables (i.e., true biomarkers), the FDR-adjusted student t test performed best. The R package BioMark is an easy-to-use open-source program for variable selection that had excellent performance characteristics for the purposes of this study.

  3. Infrastructure features outperform environmental variables explaining rabbit abundance around motorways.

    Science.gov (United States)

    Planillo, Aimara; Malo, Juan E

    2018-01-01

    Human disturbance is widespread across landscapes in the form of roads that alter wildlife populations. Knowing which road features are responsible for the species response and their relevance in comparison with environmental variables will provide useful information for effective conservation measures. We sampled relative abundance of European rabbits, a very widespread species, in motorway verges at regional scale, in an area with large variability in environmental and infrastructure conditions. Environmental variables included vegetation structure, plant productivity, distance to water sources, and altitude. Infrastructure characteristics were the type of vegetation in verges, verge width, traffic volume, and the presence of embankments. We performed a variance partitioning analysis to determine the relative importance of two sets of variables on rabbit abundance. Additionally, we identified the most important variables and their effects model averaging after model selection by AICc on hypothesis-based models. As a group, infrastructure features explained four times more variability in rabbit abundance than environmental variables, being the effects of the former critical in motorway stretches located in altered landscapes with no available habitat for rabbits, such as agricultural fields. Model selection and Akaike weights showed that verge width and traffic volume are the most important variables explaining rabbit abundance index, with positive and negative effects, respectively. In the light of these results, the response of species to the infrastructure can be modulated through the modification of motorway features, being some of them manageable in the design phase. The identification of such features leads to suggestions for improvement through low-cost corrective measures and conservation plans. As a general indication, keeping motorway verges less than 10 m wide will prevent high densities of rabbits and avoid the unwanted effects that rabbit populations

  4. Cataclysmic variables: gladiators in the arena

    Science.gov (United States)

    Mennickent, R. E.; Tappert, C.; Diaz, M.

    2002-09-01

    Here we present some results of our recent research in the area of dwarf novae, a subclass of cataclysmic variables showing semi-regular outbursts in time scales of days to years with typical amplitudes of 2-6 mags. The origin of these dwarf-nova outbursts is not a thermonuclear runaway as in the case of a nova outburst, but a sudden jump in disc viscosity and mass transfer rate as a result of the hydrogen ionization. In this article we do not go into deep details. Instead, we will illustrate the application of some standard techniques in the field of CVs aimed to explore disc dynamics and also to reveal the nature of the donor star. The latter point is especially important to constrain theories of CV evolution.

  5. WECC Variable Generation Planning Reference Book: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.; Ma, Jian; Vyakaranam, Bharat

    2013-05-13

    The document titled “WECC Variable Generation Planning Reference Book”. This book is divided into two volumes; one is the main document (volume 1)and the other is appendices (volume 2). The main document is a collection of the best practices and the information regarding the application and impact of variables generation on power system planning. This volume (appendices) has additional information on the following topics: Probabilistic load flow problems. 2. Additional useful indices. 3. high-impact low-frequency (HILF) events. 4. Examples of wide-area nomograms. 5. Transmission line ratings, types of dynamic rating methods. 6. Relative costs per MW-km of different electric power transmission technologies. 7. Ultra-high voltage (UHV) transmission. 8.High voltage direct current (VSC-HVDC). 9. HVDC. 10. Rewiring of existing transmission lines. 11. High-temperature low sag (HTLS) conductors. 12. The direct method and energy functions for transient stability analysis in power systems. 13.Blackouts caused by voltage instability. 14. Algorithm for parameter continuation predictor-corrector methods. 15. Approximation techniques available for security regions. 16. Impacts of wind power on power system small signals stability. 17. FIDVR. 18. FACTS. 19. European planning standard and practices. 20. International experience in wind and solar energy sources. 21. Western Renewable Energy Zones (WREZ). 22. various energy storage technologies. 23. demand response. 24. BA consolidation and cooperation options. 25. generator power management requirements and 26. European planning guidelines.

  6. Exam stressors, modulating variables and academic failure

    Directory of Open Access Journals (Sweden)

    Arturo Barraza Macías

    2010-07-01

    Full Text Available This research was raised four objectives: a to establish the profile of stress descriptive review of the higher education students, b identify areas that cause more stress on the students of higher education when presenting a review c distinguish socio-demographic variables and situational which provide significant differences in stress examination of students in higher education d determining the relationship between stress examination and the number of subjects disapproved of the students in higher education. It is based on the model theoretically systemic cognoscitivism academic stress which is derived from the slope of transaccionalista Research Program Person-environment. To achieve these goals, a study was conducted transectional not experimental and correlational through the implementation of the Inventory Stress Test to 343 students, of the Preparatory Lomas of the city of Durango, in the state of Durango, Mexico. Its main results allow establishing a descriptive profile of stress examination of students in higher education, as well as confirm the modulatory effect of the variables and gender semester and the positive correlation between stress and the number of examination subject disapproved.

  7. Ecosystem Responses to Pacific Storm Track Variability

    Science.gov (United States)

    Dannenberg, M. P.; Wise, E.

    2016-12-01

    Much of the precipitation delivered to western North America arrives during winter via the midlatitude Pacific storm track. The strength and position and of the storm track varies from year to year, and this variation is a major driver of western hydroclimate. We examine the responses of both hydrological and ecological indicators to the position of the storm track using a regional reanalysis, historical climate data, and remotely sensed land surface phenology and burn area estimates. We find that the standardized precipitation-evapotranspiration index (SPEI) exhibits a dipole-type response to variation in the position of the storm track. In the northwestern United States, more northerly storm tracks are associated with dry winters while more southerly storm tracks are associated with wet winters. Northwestern Canada shows the opposite response. Likewise, there is a negative relationship between snow water equivalent and storm track latitude throughout the Cascades, Sierras, and parts of the Rockies, but a positive relationship in northwestern Canada and eastern Alaska. Variability of the Pacific storm track and associated precipitation and snow pack anomalies have significant consequences for ecological and biogeochemical processes in the water-sensitive ecosystems of western North America. In the northwestern United States, the area burned by moderate and severe fire is positively correlated with storm track latitude, likely a result of drier conditions when the storm track is displaced north. While there is a relatively small response of vegetation phenology to storm track variability, the peak greenness of the land surface exhibits a dipole response similar to the SPEI. A long-term northerly shift in the position of the midlatitude Pacific storm track, as expected under a warming climate, could therefore alter both the prevailing hydroclimatic regimes and ecosystem processes of western North America.

  8. 5 CFR 591.205 - Which areas are nonforeign areas?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Which areas are nonforeign areas? 591.205... ALLOWANCES AND DIFFERENTIALS Cost-of-Living Allowance and Post Differential-Nonforeign Areas Cost-Of-Living Allowances and Post Differentials § 591.205 Which areas are nonforeign areas? (a) The nonforeign areas are...

  9. 5 CFR 591.207 - Which areas are COLA areas?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Which areas are COLA areas? 591.207... ALLOWANCES AND DIFFERENTIALS Cost-of-Living Allowance and Post Differential-Nonforeign Areas Cost-Of-Living Allowances § 591.207 Which areas are COLA areas? OPM has established the following COLA areas: (a) City of...

  10. Assessment of Offshore Wind Energy Leasing Areas for the BOEM New Jersey Wind Energy Area

    Energy Technology Data Exchange (ETDEWEB)

    Musial, W.; Elliott, D.; Fields, J.; Parker, Z.; Scott, G.; Draxl, C.

    2013-10-01

    The National Renewable Energy Laboratory (NREL), under an interagency agreement with the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM), is providing technical assistance to identify and delineate leasing areas for offshore wind energy development within the Atlantic Coast Wind Energy Areas (WEAs) established by BOEM. This report focuses on NREL's development and evaluation of the delineations for the New Jersey (NJ) WEA. The overarching objective of this study is to develop a logical process by which the New Jersey WEA can be subdivided into non-overlapping leasing areas for BOEM's use in developing an auction process in a renewable energy lease sale. NREL identified a selection of leasing areas and proposed delineation boundaries within the established NJ WEA. The primary output of the interagency agreement is this report, which documents the methodology, including key variables and assumptions, by which the leasing areas were identified and delineated.

  11. Large area LED package

    Science.gov (United States)

    Goullon, L.; Jordan, R.; Braun, T.; Bauer, J.; Becker, F.; Hutter, M.; Schneider-Ramelow, M.; Lang, K.-D.

    2015-03-01

    Solid state lighting using LED-dies is a rapidly growing market. LED-dies with the needed increasing luminous flux per chip area produce a lot of heat. Therefore an appropriate thermal management is required for general lighting with LEDdies. One way to avoid overheating and shorter lifetime is the use of many small LED-dies on a large area heat sink (down to 70 μm edge length), so that heat can spread into a large area while at the same time light also appears on a larger area. The handling with such small LED-dies is very difficult because they are too small to be picked with common equipment. Therefore a new concept called collective transfer bonding using a temporary carrier chip was developed. A further benefit of this new technology is the high precision assembly as well as the plane parallel assembly of the LED-dies which is necessary for wire bonding. It has been shown that hundred functional LED-dies were transferred and soldered at the same time. After the assembly a cost effective established PCB-technology was applied to produce a large-area light source consisting of many small LED-dies and electrically connected on a PCB-substrate. The top contacts of the LED-dies were realized by laminating an adhesive copper sheet followed by LDI structuring as known from PCB-via-technology. This assembly can be completed by adding converting and light forming optical elements. In summary two technologies based on standard SMD and PCB technology have been developed for panel level LED packaging up to 610x 457 mm2 area size.

  12. SELKIRK ROADLESS AREA, IDAHO.

    Science.gov (United States)

    Miller, Fred K.; Benham, John R.

    1984-01-01

    On the basis of mineral-resource surveys the Selkirk Roadless Area, Idaho has little promise for the occurrence of mineral or energy resources. Molybdenum, lead, uranium, thorium, chromium, tungsten, zirconium, and several rare-earth elements have been detected in panned concentrates from samples of stream sediment, but no minerals containing the first five elements were found in place, nor were any conditions conducive to their concentration found. Zirconium, thorium, and the rare earths occur in sparsely disseminated accessory minerals in granitic rocks and no resource potential is identified. There is no history of mining in the roadless area and there are no oil, gas, mineral, or geothermal leases or current claims.

  13. Body Area Networks

    Directory of Open Access Journals (Sweden)

    G. Prabhakara Reddy

    2013-01-01

    Full Text Available Recent technological advances in integrated circuits, wireless networks, and physiological sensing have enabled miniature, lightweight, low power, intelligent monitoring devices to be integrated into a Body Area Network (BAN. This new type of technology hold much promise for future patient health monitoring. BANs promise inexpensive, unobtrusive, and unsupervised ambulatory monitoring during normal daily activities for long periods of time. However, in order for BANs to become ubiquitous and affordable, a number of challenging issues must be resolved, such as integration, standardisation, system design, customisation, security and privacy, and social issues. This paper presents an overview of many of these issues and indeed the background and rationale of body area networks.

  14. Soil variability in engineering applications

    Science.gov (United States)

    Vessia, Giovanna

    2014-05-01

    Natural geomaterials, as soils and rocks, show spatial variability and heterogeneity of physical and mechanical properties. They can be measured by in field and laboratory testing. The heterogeneity concerns different values of litho-technical parameters pertaining similar lithological units placed close to each other. On the contrary, the variability is inherent to the formation and evolution processes experienced by each geological units (homogeneous geomaterials on average) and captured as a spatial structure of fluctuation of physical property values about their mean trend, e.g. the unit weight, the hydraulic permeability, the friction angle, the cohesion, among others. The preceding spatial variations shall be managed by engineering models to accomplish reliable designing of structures and infrastructures. Materon (1962) introduced the Geostatistics as the most comprehensive tool to manage spatial correlation of parameter measures used in a wide range of earth science applications. In the field of the engineering geology, Vanmarcke (1977) developed the first pioneering attempts to describe and manage the inherent variability in geomaterials although Terzaghi (1943) already highlighted that spatial fluctuations of physical and mechanical parameters used in geotechnical designing cannot be neglected. A few years later, Mandelbrot (1983) and Turcotte (1986) interpreted the internal arrangement of geomaterial according to Fractal Theory. In the same years, Vanmarcke (1983) proposed the Random Field Theory providing mathematical tools to deal with inherent variability of each geological units or stratigraphic succession that can be resembled as one material. In this approach, measurement fluctuations of physical parameters are interpreted through the spatial variability structure consisting in the correlation function and the scale of fluctuation. Fenton and Griffiths (1992) combined random field simulation with the finite element method to produce the Random

  15. NASA's atmospheric variability experiments /AVE/

    Science.gov (United States)

    Hill, K.; Turner, R. E.

    1977-01-01

    A series of seven mesoscale experiments were conducted under the NASA program, Atmospheric Variability Experiments (AVE). Rawinsonde, satellite, aircraft, and ground observations were recorded during specially selected meteorological periods lasting from 1 to 3 days. Details are presented for each AVE relative to observation times, experiment size and location, and significant weather. Some research results based on the use of these AVE data are referenced. These include contributions to regional numerical prediction; relations between wind shears, instability, and thunderstorm motion and development; relations between moisture and temperature and the probability of convection; retrieval of tropospheric temperature profiles from cloud-contaminated satellite data; variation of convection intensity as a result of atmospheric variability; and effects of cloud rotation on their trajectories.

  16. Continuous-Variable Entanglement Swapping

    Directory of Open Access Journals (Sweden)

    Kevin Marshall

    2015-05-01

    Full Text Available We present a very brief overview of entanglement swapping as it relates to continuous-variable quantum information. The technical background required is discussed and the natural link to quantum teleportation is established before discussing the nature of Gaussian entanglement swapping. The limitations of Gaussian swapping are introduced, along with the general applications of swapping in the context of to quantum communication and entanglement distribution. In light of this, we briefly summarize a collection of entanglement swapping schemes which incorporate a non-Gaussian ingredient and the benefits of such schemes are noted. Finally, we motivate the need to further study and develop such schemes by highlighting requirements of a continuous-variable repeater.

  17. Variable immune molecules in invertebrates.

    Science.gov (United States)

    Cerenius, Lage; Söderhäll, Kenneth

    2013-12-01

    Recently it has become evident that invertebrates may mount a highly variable immune response that is dependent on which pathogen is involved. The molecular mechanisms behind this diversity are beginning to be unravelled and in several invertebrate taxa immune proteins exhibiting a broad range of diversity have been found. In some cases, evidence has been gathered suggesting that this molecular diversity translates into the ability of an affected invertebrate to mount a defence that is specifically aimed at a particular pathogen.

  18. Reproducing Kernels and Variable Bandwidth

    Directory of Open Access Journals (Sweden)

    R. Aceska

    2012-01-01

    Full Text Available We show that a modulation space of type ( is a reproducing kernel Hilbert space (RKHS. In particular, we explore the special cases of variable bandwidth spaces Aceska and Feichtinger (2011 with a suitably chosen weight to provide strong enough decay in the frequency direction. The reproducing kernel property is valid even if ( does not coincide with any of the classical Sobolev spaces because unbounded bandwidth (globally is allowed. The reproducing kernel will be described explicitly.

  19. AEROSOL VARIABILITY OBSERVED WITH RPAS

    Directory of Open Access Journals (Sweden)

    B. Altstädter

    2013-08-01

    Full Text Available To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter. Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  20. Simulating solar power plant variability :

    Energy Technology Data Exchange (ETDEWEB)

    Lave, Matthew Samuel; Ellis, Abraham; Stein, Joshua.

    2013-06-01

    It is important to be able to accurately simulate the variability of solar PV power plants for grid integration studies. We aim to inform integration studies of the ease of implementation and application-specific accuracy of current PV power plant output simulation methods. This report reviews methods for producing simulated high-resolution (sub-hour or even sub-minute) PV power plant output profiles for variability studies and describes their implementation. Two steps are involved in the simulations: estimation of average irradiance over the footprint of a PV plant and conversion of average irradiance to plant power output. Six models are described for simulating plant-average irradiance based on inputs of ground-measured irradiance, satellite-derived irradiance, or proxy plant measurements. The steps for converting plant-average irradiance to plant power output are detailed to understand the contributions to plant variability. A forthcoming report will quantify the accuracy of each method using application-specific validation metrics.