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1

Recession slope curve analysis under human interferences  

NASA Astrophysics Data System (ADS)

To study the base flow recession at the watershed scale, the log-scale plot of - dQ/ dt ˜ Q proposed by Brutsaert and Nieber [10] has been used to estimate the recession parameters, i.e., the slope and interception of the theoretical recession slope curve. The lower envelope or the best fit in some studies is usually used to determine the recession slope curve for natural watersheds. However, human interferences exist in most watersheds around the world. This paper discusses the impact of human interferences, which include groundwater pumping, water diversion and return flow, on the determination of the recession slope curve and the cloud shape of the data points of - dQ/ dt ˜ Q. First, values of - dQ/ dt generated for hypothetical watersheds are analyzed. Then real data for three watersheds in Illinois is analyzed to verify the hypothetical analysis. The placement of the recession slope curve depends on the coexistence and relative amount of the evapotranspiration, groundwater pumping or even water diversion if it exists, and the return flow. When the water consumption rate is small, the recession slope curve can even be located at the upper envelope of the cloud of points representing historical data. These results suggest that the use of the lower envelope as a guideline for estimating recession parameters for watersheds subject to human interferences can result in biased estimates.

Wang, Dingbao; Cai, Ximing

2010-09-01

2

Recession slope curve analysis under human interferences  

Microsoft Academic Search

To study the base flow recession at the watershed scale, the log-scale plot of ?dQ\\/dt?Q proposed by Brutsaert and Nieber [10] has been used to estimate the recession parameters, i.e., the slope and interception of the theoretical recession slope curve. The lower envelope or the best fit in some studies is usually used to determine the recession slope curve for

Dingbao Wang; Ximing Cai

2010-01-01

3

Nonlinear analysis of flow recession curves  

Microsoft Academic Search

Flow recession curves of rivers are commonly simulated by the equation of a single linear reservoir which is determined by one param­ eter, the retention constant. In reality, however, retention-discharge characteristics are hardly linear and recession curves can be approxi­ mated only sectionwise by linear reservoirs with retention \\

H. WITTENBERG

4

A visual basic spreadsheet macro for recession curve analysis.  

PubMed

A Visual Basic program for an Excel spreadsheet was written to construct a master recession curve (MRC), using the adapted matching strip method, for recession analysis of ground water level time series. The program uses five different linear/nonlinear regression models to adjust individual recession segments to their proper positions in the MRC. The program can also be used to analyze the recession segments of other time series, such as daily stream discharge or stage. Some examples of field data from Croatia are used to illustrate the usefulness of its application. PMID:16961500

Posavec, Kristijan; Bacani, Andrea; Naki?, Zoran

2006-01-01

5

Recession Curve Analysis to Constrain Rainfall-Discharge Model Parameterisation  

Microsoft Academic Search

\\u000a This paper explores the conceptual reservoir model applied to karst aquifers. A methodology is proponed to facilitate model\\u000a parameter optimisation by improving overall parameter identifiability. This approach uses recession curve analysis to determine\\u000a a parameter often included in the optimisation process: the baseflow coefficient. The proposed methodology was applied to\\u000a six French karst systems representing a relatively large spectrum of

F. Moussu; V. Plagnes; L. Oudin; H. Bendjoudi

6

Using interactive recession curve analysis to specify a general catchment storage model  

Microsoft Academic Search

An analysis of hydrograph recessions can be used to identify the parameters of a conceptual catchment storage irnodel and, with the advent of large-scale digital data storage and automated logging systems, it has become desirable to automate recession curve analysis. Various studies have thus reported algorithms used to infer 'baseflow' storage models automatically from recession data. Such algorithms commonly operate

R. Lamb; K. Beven

1997-01-01

7

Interpretation of spring recession curves.  

PubMed

Recession curves contain information on storage properties and different types of media such as porous, fractured, cracked lithologies and karst. Recession curve analysis provides a function that quantitatively describes the temporal discharge decay and expresses the drained volume between specific time limits (Hall 1968). This analysis also allows estimating the hydrological significance of the discharge function parameters and the hydrological properties of the aquifer. In this study, we analyze data from perennial springs in the Judean Mountains and from others in the Galilee Mountains, northern Israel. All the springs drain perched carbonate aquifers. Eight of the studied springs discharge from a karst dolomite sequence, whereas one flows out from a fractured, slumped block of chalk. We show that all the recession curves can be well fitted by a function that consists of two exponential terms with exponential coefficients alpha1 and alpha2. These coefficients are approximately constant for each spring, reflecting the hydraulic conductivity of different media through which the ground water flows to the spring. The highest coefficient represents the fast flow, probably through cracks, or quickflow, whereas the lower one reflects the slow flow through the porous medium, or baseflow. The comparison of recession curves from different springs and different years leads to the conclusion that the main factors that affect the recession curve exponential coefficients are the aquifer lithology and the geometry of the water conduits therein. In normal years of rainy winter and dry summer, alpha1 is constant in time. However, when the dry period is longer than usual because of a dry winter, alpha1 slightly decreases with time. PMID:12236268

Amit, H; Lyakhovsk, V; Katz, A; Starinsky, A; Burg, A

2002-01-01

8

Probabilistic approach to modelling of recession curves  

Microsoft Academic Search

Recession curves of daily streamflow hydrographs are analysed by a probabilistic approach. Flow of a day on a recession curve is calculated by multiplying the previous day's flow with a value of K smaller than one; K, defined as the ratio of the flows of successive days on the recession curve, was determined from observed daily flow time series. The

HAFZULLAH AKSOY; MEHMETCIK BAYAZIT; HARTMUT WITTENBERG

9

A review of baseflow recession analysis  

Microsoft Academic Search

Recession analysis is a well-known tool in hydrological analysis. Its application, however, poses many methodical questions, and throughout the literature numerous solutions have been sought. The quantification of the recession curve involves the selection of an analytical expression, derivation of a characteristic recession and optimization of the recession parameters. A major problem is the high variability encountered in the recession

L. M. Tallaksen

1995-01-01

10

Prediction of Master Recession Curves and Baseflow Recessions in the Luquillo Mountains of Puerto Rico  

Microsoft Academic Search

An analysis of hydrograph recessions and rainfall data was performed to estimate the recession constants for two watersheds in the Luquillo mountains of Puerto Rico. To account for seasonal rainfall patterns, the data were grouped into dry and wet seasons. Sets of three Master Recession Curves (MRC) per season for each watershed were developed: one using the Matching Strip Method

Héctor D. Rivera-Ramírez; Glenn S. Warner; Frederick N. Scatena

2002-01-01

11

An improved method for delineating source protection zones for karst springs based on analysis of recession curve data  

Microsoft Academic Search

A standard method for delineating source protection zones, particularly for karst and carbonate springs, has been improved.\\u000a The method, based on recession curve analysis, defines four vulnerability scenarios with an evaluation of the appropriate\\u000a dimensions of the protection areas, accommodating situations where field-test data are not available. The new approach makes\\u000a it easier to separate the components of the spring

Massimo V. Civita

2008-01-01

12

An improved method for delineating source protection zones for karst springs based on analysis of recession curve data  

NASA Astrophysics Data System (ADS)

A standard method for delineating source protection zones, particularly for karst and carbonate springs, has been improved. The method, based on recession curve analysis, defines four vulnerability scenarios with an evaluation of the appropriate dimensions of the protection areas, accommodating situations where field-test data are not available. The new approach makes it easier to separate the components of the spring discharge hydrograph. The objective is to achieve simplification, and an effective, more rigorous, procedure in the determination of the parameters used by Mangin’s model—Mangin A (1975) Contribution a l’étude hydrodynamique des aquifères karstiques-Troisieme partie: Constitution et fonctionnement des aquifères karstiques (Contribution to the hydrodynamic study of karst aquifers, part 3: formation and work of karst aquifers). Ann Speleol 30(1):21 124. The original procedure, plus the lack of sufficient data, was open to subjective interpretation. With the aid of modern technology, a very large quantity of data is now available and it is necessary to process it using denoise type computer-based filters before passing to interpretation. Working with discharge data series, a statistical approach is proposed to give an analytical solution for determining the values of fundamental parameters of the recession curve model. The new procedure is defined and compared with the original methodology. The new approach has been tested and applied to a number of karst springs in Italy. A case history for a spring located in the Piedmont region of the Maritime Alps, is presented. The proposed new procedure can be utilised to mark the limits of the protection zones of tapped groundwater supplied for potable use, as required by European and local legislation.

Civita, Massimo V.

2008-08-01

13

Derivation of low flow distribution functions using recession curves  

Microsoft Academic Search

Recession analysis and low flow frequency analysis have been treated by tradition as separate problems, although both are related to low flow conditions. The shape and analytical expression of the streamflow decay during rainless periods might give an insight into the behaviour of the tails of low flow distribution functions. Furthermore, models for streamflow recession have, as a rule, a

Lars Gottschalk; Lena M. Tallaksen; Grzegorz Perzyna

1997-01-01

14

Interpretation of karst spring recession curves by the series reservoir model  

NASA Astrophysics Data System (ADS)

The analysis of karst spring recession is a commonly used approach for understanding the aquifer structure or acquiring hydrodynamic parameters. An approach frequently applied for recession analysis is based on the several parallel, typically two or three, linear reservoirs each of which represents different part with different hydraulic conductivities, such as the conduit system and the fissure system. However, this parallel reservoir structure cannot accord with the relationship between the conduit system and fissure system, which is actually in series rather than parallel. We, therefore, examine the recession curve of two linear reservoirs in series (the conduit reservoir and fissure reservoir), representing the conduit and fissure system respectively, and make comparisons with two corresponding parallel linear reservoirs. Some interesting results are presented. If the storages of two series systems are close and the recession coefficient of the conduit reservoir is larger than the fissure reservoir, two overlapping exponential recession processes still exist. And yet, the recession coefficient of each exponential process is different from that of each single reservoir. One of recession coefficient is larger than the conduit reservoir owing to extra water participation from the fissure reservoir except the drainage of conduit reservoir, while the other recession coefficient is smaller than the fissure reservoir because the water flowing out from the fissure reservoir is regulated by the conduit reservoir again. When the recession coefficient of conduit reservoir is close or smaller than the fissure system, the recession curve is expressed only by an exponential function and the recession coefficient is between the conduit and fissure system. Commonly, the storage of the conduit system is much smaller than the fissure system and the conduit flow is turbulent. When ignoring the storage of the conduit system, the conduit reservoir can be substituted by a pipe, in which the turbulent pipe flow obeys Darcy-Weisbach formula, in two series reservoir model. In this new conceptual model, the initial recession process deviates from the exponential behavior. This non-exponential recession curve might disappear unless the pipe diameter is large or initial discharge is small. In late recession stage, the recession process is exponential which mainly controlled by the fissure reservoir. Acknowledgments This research was supported by National Natural Science Foundation of China (Grant No. 41030746, 41172207 and 41102147).

chang, Y.; Wu, J.

2013-12-01

15

Stream recession curves and storage variability in small watersheds  

NASA Astrophysics Data System (ADS)

The pattern of streamflow recession after rain events offers clues about the relationship between watershed runoff (observable as river discharge) and water storage (not directly observable) and can help in water resource assessment and prediction. However, there have been few systematic assessments of how streamflow recession varies across flow rates and how it relates to independent assessments of terrestrial water storage. We characterized the streamflow recession pattern in 61 relatively undisturbed small watersheds (1-100 km2) across the coterminous United States with multiyear records of hourly streamflow from automated gauges. We used the North American Regional Reanalysis to help identify periods where precipitation, snowmelt, and evaporation were small compared to streamflow. The order of magnitude of the recession timescale increases from 1 day at high flow rates (~1 mm h-1) to 10 days at low flow rates (~0.01 mm h-1), leveling off at low flow rates. There is significant variability in the recession timescale at a given flow rate between basins, which correlates with climate and geomorphic variables such as the ratio of mean streamflow to precipitation and soil water infiltration capacity. Stepwise multiple regression was used to construct a six-variable predictive model that explained some 80 % of the variance in recession timescale at high flow rates and 30-50 % at low flow rates. Seasonal and interannual variability in inferred storage shows similar time evolution to regional-scale water storage variability estimated from GRACE satellite gravity data and from land surface modeling forced by observed meteorology, but is up to a factor of 10 smaller. Study of this discrepancy in the inferred storage amplitude may provide clues to the range of validity of the recession curve approach to relating runoff and storage.

Krakauer, N. Y.; Temimi, M.

2011-07-01

16

Geomorphic Signatures on Brutsaert Base Flow Recession Analysis  

NASA Astrophysics Data System (ADS)

This paper addresses the signatures of catchment geomorphology on base flow recession curves. Its relevance relates to the implied predictability of base flow features, which are central to catchment-scale transport phenomena and to ecohydrological function. Moving from the classical recession curve analysis method, originally applied to the Finger Lakes Region, a large set of recession curves has been analyzed from Swiss streamflow data relatively unaffected by snowmelt. For these catchments, digital terrain models have been accurately analyzed. Recent results aimed at the geomorphic origins of recession curves have been then applied to the Swiss dataset. The method links river network morphology, epitomized by time-varying geometry of saturated channel sites, with the classic parametrization of recession events, in particular by assimilating two scaling exponents, ? and bG (i.e. |dQ/dt|?Q?where Q is at-a-station gauged flow rate; N(l) ?G(l)bG where l is the downstream distance from the channel heads receding in time, N(l) is the number of draining channel reaches located at distance l from their heads, and G(l) is the total drainage network length at a distance greater or equal to l, the active drainage network). Here, we confirm that the method provides good results, yet only in catchments where drainage density can be regarded as spatially constant. A correction to the method is proposed, which accounts for arbitrary local drainage densities affecting the local drainage inflow per unit channel length. Such corrections properly vanish should drainage density become spatially constant. A comparative analysis on the Swiss streamflow and Digital Elevation Model data shows that the proposed correction proves indeed statistically significant. Overall, definite geomorphic signatures are recognized for recession curves, with notable theoretical and practical implications.

Rinaldo, Andrea; Mutzner, Raphael; Bertuzzo, Enrico; Tarolli, Paolo; Weijs, Steven; Ceola, Serena; Tomasic, Nevena; Rodríguez-Iturbe, Ignacio; Parlange, Marc

2013-04-01

17

Geomorphic signatures on Brutsaert base flow recession analysis  

NASA Astrophysics Data System (ADS)

This paper addresses the signatures of catchment geomorphology on base flow recession curves. Its relevance relates to the implied predictability of base flow features, which are central to catchment-scale transport processes and to ecohydrological function. Moving from the classical recession curve analysis method, originally applied in the Finger Lakes Region of New York, a large set of recession curves has been analyzed from Swiss streamflow data. For these catchments, digital elevation models have been precisely analyzed and a method aimed at the geomorphic origins of recession curves has been applied to the Swiss data set. The method links river network morphology, epitomized by time-varying distribution of contributing channel sites, with the classic parameterization of recession events. This is done by assimilating two scaling exponents, ? and bG, with |dQ/dt| ? Q? where Q is at-a-station gauged flow rate and N(l) ? N>(l>)?G>(l>)bG where l is the downstream distance from the channel heads receding in time, N(l) is the number of draining channel reaches located at distance l from their heads, and G(l) is the total drainage network length at a distance greater or equal to l, the active drainage network. We find that the method provides good results in catchments where drainage density can be regarded as spatially constant. A correction to the method is proposed which accounts for arbitrary local drainage densities affecting the local drainage inflow per unit channel length. Such corrections properly vanish when the drainage density become spatially constant. Overall, definite geomorphic signatures are recognizable for recession curves, with notable theoretical and practical implications.

Mutzner, Raphaël.; Bertuzzo, Enrico; Tarolli, Paolo; Weijs, Steven V.; Nicotina, Ludovico; Ceola, Serena; Tomasic, Nevena; Rodriguez-Iturbe, Ignacio; Parlange, Marc B.; Rinaldo, Andrea

2013-09-01

18

Estimation of recession curve of karst spring hydrograph: example of the spring Gradole  

NASA Astrophysics Data System (ADS)

The spring Gradole represents a typical karst spring of the rising type, which is situated in central part of Istria (Croatia). The drainage area is composed mostly of carbonate rocks (limestone) and partly of flysch components (marls and sandstones). The average altitude of the catchment area is approximately 330 m a.s.l. Strong tectonic deformations have made carbonate deposits very permeable, enabling the infiltration of water. The average rainfall is between 1046 and 1120 mm. The catchment area of the spring is estimated to approximately 114 km2. Several studies have shown that the recession curves of karst spring hydrographs characterize the storage properties of karst aquifers. The change in slope can be explained with the drainage of different types of media typical for karst, such as conduits, fractures, pores and fissures. The main factors that affect the recession curve are aquifer lithology and geometry of conduits. Consequently, the recession curve analyzes can provide information about the aquifer and the main features of karst rock massif. Usually, the recession curves can be fitted well by the function that consists of two or more exponential terms with exponential coefficients ?1,?2,…, where the lower coefficient ?1 represents the slow flow through porous medium or base flow. The recession curve that represents base flow is usually named as the master recession curve and its exponential coefficient ?1 is named as the master recession coefficient. In this study, classical methods for estimation of recession curve are applied to the hydrograph of the spring Gradole. The results are compared with those obtained by applying Composite Transfer Functions (CTF). Differently from classical parametric and nonparametric transfer functions that represent the quick flow and base flow component of spring response by a single function, CTF represents the spring response by two functions adapted for the quick flow and the slow flow component. The quick flow component is represented by a nonparametric transfer function, whereas the slow flow component is represented by a parametric transfer function which is an Instantaneous Unit Hydrograph (IUH) formulated and defined mathematically from a conceptual model. By using CTF for Rainfall-Runoff (RR) modeling, the simulations of long recession periods as well as the simulations of complete hydrograph become more successful. If IUH defined from the conceptual model of linear reservoir is applied, the parametric transfer function representing slow flow component has exponential form. It means that the recession coefficient of IUH represents the master recession coefficient of the spring hydrograph, i.e. the recession coefficient of IUH can be determined by using classical methods for the estimation of master recession coefficient, and vice versa, the problem of determination of master recession coefficient can be transformed to the problem of determination of the recession coefficient of IUH. The recession coefficient of IUH is determined simultaneously with the values of nonparametric transfer function in the optimization procedure for estimation of parameters of RR model based on CTF. The recession coefficients of IUH are obtained separately in the optimization procedures for each hydrological year during the period 1987-2002. The results show that the recession curve of the spring Gradole has not a unique form. Depending on hydrological year, the obtained nonparametric transfer functions representing quick flow component can be fitted by one or two exponential terms. The values of master recession coefficient vary between 100 and 260 days. The average value for the entire period of 15 years is 140 days. These results are similar to the results obtained by applying classical methods for estimation of master recession curve. It confirms practically that the recession coefficient of IUH can be estimated from the spring hydrograph, which can be useful for RR modeling based on CTF because the number of unknown parameters is reduced.

Deni?-Juki?, V.; Kuštera, K.; Juki?, D.

2009-04-01

19

Stream recession curves and storage variability in small watersheds  

NASA Astrophysics Data System (ADS)

The pattern of streamflow recession after rain events offers clues about the relationship between watershed runoff (observable as river discharge) and water storage (not directly observable) and can help in water resource assessment and prediction. However, it has not been systematically analyzed across flow rates or related to independent assessments of terrestrial water storage. We characterized the streamflow recession pattern in 61 relatively undisturbed small watersheds (1-100 km2) across the coterminous United States with multiyear records of hourly streamflow from automated gauges. We used the North American Regional Reanalysis (NARR) to help identify periods where precipitation, snowmelt, and evaporation were small compared to streamflow. The order of magnitude of the recession timescale increases from 1 day at high flow rates (~1 mm/h) to 10 days at low flow rates (~0.01 mm/h), leveling off at low flow rates. There is significant variability in the recession timescale at a given flow rate between basins, correlated with climate and geomorphic variables such as the ratio of mean streamflow to precipitation and soil water infiltration capacity. Stepwise multiple regression was used to construct a six-variable predictive model that explained some 80% of the variance in recession timescale at high flow rates and 30-50% at low flow rates. Seasonal and interannual variability in storage shows similar time evolution to but is up to a factor of 10 smaller than regional-scale water storage variability estimated from GRACE satellite gravity data and from land surface modeling forced by observed meteorology. The discrepancy may point to a "disconnection" between the conceptual pool that supplies streamflow during dry periods and other dynamic pools such as soil moisture and deep groundwater.

Krakauer, N. Y.; Temimi, M.

2011-02-01

20

Estimation of Groundwater Storage Variations based on Baseflow Recession Analysis  

NASA Astrophysics Data System (ADS)

One of the intrinsic assumptions of the widely used Brutsaert and Nieber (B-N) method for groundwater recession slope analysis is the existence of a general non-linear proportional relationship between (unconfined) aquifer storage and baseflow recession. The parameters in the B-N method estimated from baseflow recession slope curve analysis in principle can be linked to the parameters characterizing aquifer storage-discharge relations. However, this has seldom been tested due to the lack of observed data on groundwater storage. In this study, we test the hypothesis that baseflow recession behaviors depend on the adjacent shallow unconfined aquifer storage by using the daily measurements of water table depth from nine shallow wells in Illinois and the concurrent streamflow data at the nearest gauges. The purpose is to test how much information of groundwater storage variations can be obtained from baseflow recession analysis. The results indicate that baseflow fluctuations in general faithfully reflect the variations in nearby unconfined aquifer storage and a consistent estimation of specific yield can be derived from the data, whereby substantiate the linkage between aquifer storage-discharge relationship and the GW recession parameters. In addition, the following issues are identified for further studies: (1) The interference of recharge to (evaporation from) the underlying aquifers need to be clarified and removed when analyzing winter (summer) recession data; (2) for all the wells analyzed, a threshold depth exists below which baseflow cannot reflect aquifer storage decline usually caused by high evaporation in summer. Finally, the implications of this study to various critical issues in land surface hydrologic modeling are discussed.

Yeh, P. J.; He, X.; Oki, T.

2012-12-01

21

Recession Cloud as Indicator of Karstic Spring Hydrograph Characteristics  

Microsoft Academic Search

Extensive theory about groundwater depletion in karst aquifer reflected through spring recession curves has been developed. To skip theoretical presumptions about the analysis of karst spring recession, the concept of recession cloud has been introduced. The recession cloud is defined as set of all Nrec recession curves in the spring hydrogram. Inside of the apperent chaotic set of all recession

Mihael Brencic

2010-01-01

22

Streamflow Recession Analysis Incorporating Human Water Use  

NASA Astrophysics Data System (ADS)

Hydrologic studies of streamflow recessions are common in hydrology, yet nearly all previous studies have ignored the impact of human water withdrawals on the recession behavior of streamflow. The baseflow recession constant (Kb), commonly used in hydrologic models, can be estimated from a hydrologic recession. Resulting estimates of Kb are used widely in rainfall runoff models, low flow forecasting, and estimation of low flow characteristics. The accurate estimation of the baseflow recession constant is critical due to its common use in low flow characterization for water management strategies and Clean Water Act permitting requirements. This study documents the impact of water withdrawals on estimates of streamflow recession constants. We combine existing information on both groundwater and surface water resources and readily available information on human water use. We document that estimates of the baseflow recession constant depend critically upon the ratio of groundwater withdrawals to the average magnitude of baseflows. We document that without careful attention to the impact of groundwater withdrawals, estimates of streamflow recession constants will exhibit significant bias. Observed streamflow response is best approximated by a streamflow recession constant that incorporates human water use.

Thomas, B. F.; Vogel, R. M.

2011-12-01

23

Fully automated objective-based method for master recession curve separation.  

PubMed

The fully automated objective-based method for master recession curve (MRC) separation was developed by using Microsoft Excel spreadsheet and Visual Basic for Applications (VBA) code. The core of the program code is used to construct an MRC by using the adapted matching strip method (Posavec et al. 2006). Criteria for separating the MRC into two or three segments are determined from the flow-duration curve and are represented as the probable range of percent of flow rate duration. Successive separations are performed automatically on two and three MRCs using sets of percent of flow rate duration from selected ranges and an optimal separation model scenario, having the highest average coefficient of determination R(2), is selected as the most appropriate one. The resulting separated master recession curves are presented graphically, whereas the statistics are presented numerically, all in separate sheets. Examples of field data obtained from two springs in Istria, Croatia, are used to illustrate its application. The freely available Excel spreadsheet and VBA program ensures the ease of use and applicability for larger data sets. PMID:20100291

Posavec, Kristijan; Parlov, Jelena; Naki?, Zoran

2010-01-01

24

Recession analysis of the Hupselse Beek catchment, The Netherlands  

Microsoft Academic Search

Many parametric hydrological models use one or more linear reservoirs as model components. However, linear reservoirs may not be ideal to represent the real, nonlinear hydrologic behavior of a catchment. The reservoir coefficients of catchments can be obtained from discharge data with a method suggested by Brutsaert and Nieber (1977). From dry weather recession curves in hydrographs, the negative of

C. C. Brauer; J. N. M. Stricker; P. M. M. Warmerdam; R. Uijlenhoet

2009-01-01

25

Latent Curve Analysis.  

ERIC Educational Resources Information Center

A model based on latent trait theory, with maximum likelihood parameter estimates and associated asymptotic tests, is presented. Latent curve analysis is a method for representing development and is an alternative to repeated measures analysis of variance and first-order auto-regressive models. (SLD)

Meredith, William; Tisak, John

1990-01-01

26

A computer program for predicting recharge with a master recession curve  

USGS Publications Warehouse

Water-table fluctuations occur in unconfined aquifers owing to ground-water recharge following precipitation and infiltration, and ground-water discharge to streams between storm events. Ground-water recharge can be estimated from well hydrograph data using the water-table fluctuation (WTF) principle, which states that recharge is equal to the product of the water-table rise and the specific yield of the subsurface porous medium. The water-table rise, however, must be expressed relative to the water level that would have occurred in the absence of recharge. This requires a means for estimating the recession pattern of the water-table at the site. For a given site there is often a characteristic relation between the water-table elevation and the water-table decline rate following a recharge event. A computer program was written which extracts the relation between decline rate and water-table elevation from well hydrograph data and uses it to construct a master recession curve (MRC). The MRC is a characteristic water-table recession hydrograph, representing the average behavior for a declining water-table at that site. The program then calculates recharge using the WTF method by comparing the measured well hydrograph with the hydrograph predicted by the MRC and multiplying the difference at each time step by the specific yield. This approach can be used to estimate recharge in a continuous fashion from long-term well records. Presented here is a description of the code including the WTF theory and instructions for running it to estimate recharge with continuous well hydrograph data.

Heppner, Christopher S.; Nimmo, John R.

2005-01-01

27

Geomorphic Signatures on Brutsaert Base Flow Recession Analysis: case study of 27 Swiss Catchments  

NASA Astrophysics Data System (ADS)

Recession flow analysis are crucial in many areas of water resource management and useful to forecast base flow in gauged rivers. Moving from a classical recession curve analysis method, a large set of recession curves has been analyzed from Swiss streamflow data of 27 watersheds. For these catchments, digital elevation models have been precisely analyzed and a method aimed at the geomorphic origins of recession curves has been applied to the Swiss dataset. The method links river network morphology, epitomized by time-varying distribution of contributing channel sites, with the classic parametrization of recession events. This is done by assimilating two scaling exponents, ? and bG, with |dQ/dt|?Q? where Q is at-a-station gauged flow rate and N(l)?G(l)bG where l is the downstream distance from the channel heads receding in time at constant speed c, N(l) is the number of draining channel reaches located at distance l from their heads, and G(l) is the total drainage network length at a distance greater or equal to l. We find that the method provides good results in catchments where drainage density can be regarded as spatially constant. We propose several corrections to the method accounting for arbitrary local drainage densities affecting the local drainage inflow per unit channel length. In particular, we relax the assumption of uniform constant speed c. Such corrections properly vanish when the local drainage density become spatially constant. Overall, definite geomorphic signatures are recognizable for recession curves. In general, we suggest that this conceptual model might be useful to estimate the low flow regime of natural ungauged basins by predicting its features solely from information remotely acquired and objectively manipulated through DEM data.

Mutzner, R.; Bertuzzo, E.; Tarolli, P.; Weijs, S. V.; Nicotina, L.; Ceola, S.; Tomasic, N.; Rodriguez-Iturbe, I.; Parlange, M. B.; Rinaldo, A.

2013-12-01

28

Regional patterns of recession curves and their relationships with climate, soil, vegetation and topography across the continental United States  

NASA Astrophysics Data System (ADS)

Subsurface runoff is an important component of water balance especially in steep forested areas. It has been shown that the subsurface runoff parameterization significantly affects the partitioning of water budget, and subsequently the simulations of energy budget, carbon cycle and atmospheric cycle in land surface models such as the Community Land Model (CLM). A robust parameterization of subsurface runoff within land surface models, however, remains a grand challenge. This work is a first major step towards developing empirical relationships between the parameters of a generalized power-law form of TOPMODEL and measurable data such as climate, soil, vegetation and topographic conditions. We analyzed the flow data from over 300 MOPEX catchments across the continental United States and extracted the values of the recession curve coefficient and exponent in the form of the slope-recession curve, i.e., - dQ/dt vs Q for each catchment. By improving the estimation of soil properties within MOPEX database such as the mean and variance of saturated hydraulic conductivity and porosity based on the SSURGO dataset for 30 selected catchments across the continent covering a range of climate conditions, we examined the regional patterns of recession curve coefficient and exponent. Our results suggest that the recession curve exponent is higher in the eastern humid Appalachian forested catchments but relatively smaller in the central flat catchments. We further explored the possible linkages between the exponent and coefficient and climate and landscape properties through data analyses and numerical experiments. Results of this study will serve as the basis for improving subsurface representations in CLM.

Ye, S.; Li, H.; Ali, M.; Huang, M.; Leung, L.; Sivapalan, M.

2012-12-01

29

Recession Cloud as Indicator of Karstic Spring Hydrograph Characteristics  

NASA Astrophysics Data System (ADS)

Extensive theory about groundwater depletion in karst aquifer reflected through spring recession curves has been developed. To skip theoretical presumptions about the analysis of karst spring recession, the concept of recession cloud has been introduced. The recession cloud is defined as set of all Nrec recession curves in the spring hydrogram. Inside of the apperent chaotic set of all recession discharges some statistical structures can be observed. The cloud could be described with the set of parameter curves (e.g average curve, median curve…). It has been shown that these curves can be modeled with simple exponential or power models. The model curves converge in one point at concentration time tc and concentration discharge Qc. On the basis of extreme value theory has been also shown that it is possible to model return period of the convergence. This convergence point is indicator of karstic aquifer development.

Brencic, Mihael

2010-05-01

30

Multiscale transfer printing into recessed microwells and on curved surfaces via hierarchical perfluoropolyether stamps.  

PubMed

A simple method for the formation of multiscale metal patterns is presented using hierarchical polymeric stamps with perfluoropolyether (PFPE). A dual-scale PFPE structure is made via two-step moulding process under partial photocrosslinking conditions. The hierarchical PFPE stamp enables multiscale transfer printing (MTP) of metal pattern in one step within microwells as well as on curved surfaces. PMID:23606663

Park, Hyunchul; Cho, Hyesung; Kim, Junsoo; Bang, Jung Won; Seo, Soonmin; Rahmawan, Yudi; Lee, Deuk Yeon; Suh, Kahp-Yang

2014-01-15

31

Recession flow analysis of the Blue Nile River  

Microsoft Academic Search

Estimates of the amount of recession flow can be derived from streamflow records. Such estimates are critical in the assessment of low flow characteristics for the Blue Nile River, from which about two-thirds of the irrigation requirements in Sudan are satisfied. The recession flow hydrograph can be estimated by fitting the conceptual non-linear storage outflow model using an iterative algorithm.

Anil Mishra; Takeshi Hata; A. W. Abdelhadi; Akio Tada; Haruya Tanakamaru

2003-01-01

32

Peak flow rate and recession-curve characteristics of a karst spring in the Inner Bluegrass, central Kentucky  

NASA Astrophysics Data System (ADS)

The flow rate at the terminal spring of a 1929 ha karst ground-water catchment has been continuously monitored for 2 years, and 108 identifiable events were analyzed. The peak flow rates followed a beta frequency distribution with parameters ? = 0.365 and ? = 1.135. Events were separated into high-flow and low-flow. High-flow events had characteristics attributable to pipe flow. Correlation and stepwise regression were used to develop peak flow rate prediction equations for the combined 108 events and for the 81 low-flow events. The portion of the recession curve identified as pipe flow was a watershed constant and time invariant. The base flow was seasonal, increasing in the winter to approximately 0.071 m 3s -1 and decreasing in the summer to approximately 0.014 m 3s -1.

Felton, Gary K.; Currens, James C.

1994-10-01

33

Peak flow rate and recession-curve characteristics of a karst spring in the Inner Bluegrass, central Kentucky  

USGS Publications Warehouse

The flow rate at the terminal spring of a 1929 ha karst ground-water catchment has been continuously monitored for 2 years, and 108 identifiable events were analyzed. The peak flow rates followed a beta frequency distribution with parameters ?? = 0.365 and ?? = 1.135. Events were separated into high-flow and low-flow. High-flow events had characteristics attributable to pipe flow. Correlation and stepwise regression were used to develop peak flow rate prediction equations for the combined 108 events and for the 81 low-flow events. The portion of the recession curve identified as pipe flow was a watershed constant and time invariant. The base flow was seasonal, increasing in the winter to approximately 0.071 m3s-1 and decreasing in the summer to approximately 0.014 m3s-1. ?? 1994.

Felton, G. K.; Currens, J. C.

1994-01-01

34

Shakedown Analysis of Curved Beams  

Microsoft Academic Search

Shakedown analysis of fixed-ended elastoplastic curved beams is presented. Both nonlinear and piecewise linearized yield conditions are considered. It is shown that the former assumption requires the solution of a nonlinear programming problem, while the latter assumption leads to a linear programming problem. Although these formulations cover both cases when either incremental collapse or alternating plasticity governs the shakedown limit

F. Tin Lol

1984-01-01

35

Aerodynamic Analysis of Simulated Heat Shield Recession for the Orion Command Module  

NASA Technical Reports Server (NTRS)

The aerodynamic effects of the recession of the ablative thermal protection system for the Orion Command Module of the Crew Exploration Vehicle are important for the vehicle guidance. At the present time, the aerodynamic effects of recession being handled within the Orion aerodynamic database indirectly with an additional safety factor placed on the uncertainty bounds. This study is an initial attempt to quantify the effects for a particular set of recessed geometry shapes, in order to provide more rigorous analysis for managing recession effects within the aerodynamic database. The aerodynamic forces and moments for the baseline and recessed geometries were computed at several trajectory points using multiple CFD codes, both viscous and inviscid. The resulting aerodynamics for the baseline and recessed geometries were compared. The forces (lift, drag) show negligible differences between baseline and recessed geometries. Generally, the moments show a difference between baseline and recessed geometries that correlates with the maximum amount of recession of the geometry. The difference between the pitching moments for the baseline and recessed geometries increases as Mach number decreases (and the recession is greater), and reach a value of -0.0026 for the lowest Mach number. The change in trim angle of attack increases from approx. 0.5deg at M = 28.7 to approx. 1.3deg at M = 6, and is consistent with a previous analysis with a lower fidelity engineering tool. This correlation of the present results with the engineering tool results supports the continued use of the engineering tool for future work. The present analysis suggests there does not need to be an uncertainty due to recession in the Orion aerodynamic database for the force quantities. The magnitude of the change in pitching moment due to recession is large enough to warrant inclusion in the aerodynamic database. An increment in the uncertainty for pitching moment could be calculated from these results and included in the development of the aerodynamic database uncertainty for pitching moment.

Bibb, Karen L.; Alter, Stephen J.; Mcdaniel, Ryan D.

2008-01-01

36

Using Hydrograph Recession Analysis for Linking Hydrology to Chemistry: A Flow Regime Approach  

Microsoft Academic Search

Hydrograph recession analysis is of great utility for the interpretation of water quality data, particularly when examining the hydrological processes responsible for runoff generation and impacts of changing land use on water quality. The theoretical basis for hydrograph recession analysis is well known, however the technique has traditionally been under-utilized for studies in which water quality is linked to runoff.

D. H

2003-01-01

37

Timing of the uv mutagenesis in yeast: a pedigree analysis of induced recessive mutation  

Microsoft Academic Search

The mechanism of uv-induced mutation in eukaryotes was studied in individual yeast cells by a procedure that combined pedigree analysis and tetrad analysis. The technique involved the induction of recessive lethals and semilethals in G1 diploid cells. Induced frequencies were 25 and 61% at survival levels of 90 and 77%, respectively. No evidence of gross chromosome aberrations was detected. Recessive

A. P. James; B. J. Kilbey

1977-01-01

38

Recession analysis of the Hupselse Beek catchment, The Netherlands  

NASA Astrophysics Data System (ADS)

Many parametric hydrological models use one or more linear reservoirs as model components. However, linear reservoirs may not be ideal to represent the real, nonlinear hydrologic behavior of a catchment. The reservoir coefficients of catchments can be obtained from discharge data with a method suggested by Brutsaert and Nieber (1977). From dry weather recession curves in hydrographs, the negative of the discharge changes over time were extracted and plotted against the discharge in a double logarithmic graph. The slope of the lower envelope around the separate points corresponds with the exponent of the reservoir (one for linear reservoirs). Kirchner (in press) adapted this method and fitted a regression line through the means of the points to determine reservoir coefficients for the Plynlimon catchment. The obtained reservoir coefficients were implemented in a simple model based on an integration of the nonlinear storage - discharge relation to reconstruct the streamflow hydrograph In this research project Kirchner's method is used to determine the reservoir coefficients and run the model for the Hupselse Beek catchment in the Netherlands. Hourly discharge, precipitation and evapotranspiration data for the period May 1979 - March 1987 have been used for this purpose. Compared to the Plynlimon catchment, our study catchment is much less humid and soil physical processes such as capillary rise play a more important role. The results show that the reservoir exponent is larger than one, which implies that the behavior of the catchment is nonlinear. The reservoir coefficients obtained for summer periods differ from those obtained for winter periods. Another result is that streamflow in the Hupselse Beek catchment cannot be reconstructed completely with the simple model described above. Winter discharges can often be modeled quite well, but the model fails in simulating summer periods or dry spells. When evapotranspiration rates exceed modeled storage volume plus precipitation, negative discharges are produced and the model collapses. A quick fix could be to introduce a fixed lower limit to avoid negative discharges. However, it does not yield satisfactory results either. This suggests that additional hydrological processes (eg. a soil moisture reservoir and capillary rise) should be included in the parameterization in order to obtain plausible model results for the study catchment. Brutsaert, W. and J. L. Nieber, Regionalized drought flow hydrographs from a mature glaciated plateau, Water Resources Research, 13, 637-643, 1977 Kirchner, J.W., Catchments as simple dynamical systems: catchment characterization, rainfall-runoff modeling, and doing hydrology backwards, Water Resources Research, in press

Brauer, C. C.; Stricker, J. N. M.; Warmerdam, P. M. M.; Uijlenhoet, R.

2009-04-01

39

Hydromorphologic Recession Analysis: Accounting for Human Influences in Watershed Behaviors  

NASA Astrophysics Data System (ADS)

Integrated management of ground and surface waters has generally relied on baseflow characterization to understand the temporal variability in the contribution of watershed storage to streamflow. Recent research, however, indicates that small disturbances attributed to humans can impact our ability to characterize baseflow behaviors. In this study, we present an approach to account for human impacts on the estimation of baseflow recession parameters in California's Central Valley. The framework assesses how baseflow characterization is impacted by the combination of groundwater abstractions and surface water management strategies used to meet both residential and agricultural water demands. The results highlight the importance of accounting for human influences to characterize watershed properties by evaluating traditional (i.e. natural) and human-corrected recession parameters. Such results can influence studies ranging from water resources management to stream restoration projects that rely on accurate accounting of baseflow, especially during low flows.

Thomas, B. F.; Famiglietti, J. S.

2013-12-01

40

Are streamflow recession characteristics really characteristic?  

NASA Astrophysics Data System (ADS)

Streamflow recession has been investigated by a variety of methods, often involving the fit of a model to empirical recession plots to parameterize a non-linear storage-outflow relationship based on the dQ/dt-Q method. Such recession analysis methods (RAMs) are used to estimate hydraulic conductivity, storage capacity, or aquifer thickness and to model streamflow recession curves for regionalization and prediction at the catchment scale. Numerous RAMs have been published, but little is known about how comparably the resulting recession models distinguish characteristic catchment behavior. In this study we combined three established recession extraction methods with three different parameter-fitting methods to the power-law storage-outflow model to compare the range of recession characteristics that result from the application of these different RAMs. Resulting recession characteristics including recession time and corresponding storage depletion were evaluated for 20 meso-scale catchments in Germany. We found plausible ranges for model parameterization; however, calculated recession characteristics varied over two orders of magnitude. While recession characteristics of the 20 catchments derived with the different methods correlate strongly, particularly for the RAMs that use the same extraction method, not all rank the catchments consistently, and the differences among some of the methods are larger than among the catchments. To elucidate this variability we discuss the ambiguous roles of recession extraction procedures and the parameterization of the storage-outflow model and the limitations of the presented recession plots. The results suggest strong limitations to the comparability of recession characteristics derived with different methods, not only in the model parameters but also in the relative characterization of different catchments. A multiple-methods approach to investigating streamflow recession characteristics should be considered for applications whenever possible.

Stoelzle, M.; Stahl, K.; Weiler, M.

2013-02-01

41

Are streamflow recession characteristics really characteristic?  

NASA Astrophysics Data System (ADS)

Streamflow recession has been investigated by a variety of methods, often involving the fit of a model to empirical recession plots to parameterize a non-linear storage-outflow relationship. Such recession analysis methods (RAMs) are used to estimate hydraulic conductivity, storage capacity, or aquifer thickness and to model streamflow recession curves for regionalization and prediction at the catchment scale. Numerous RAMs have been published, but little is known about how characteristic the resulting recession models are to distinguish characteristic catchment behavior. In this study we combined three established recession extraction methods with three different parameter-fitting methods to the power-law storage-outflow model to compare the range of recession characteristics that result from the application of these different RAMs. Resulting recession characteristics including recession time and corresponding storage depletion were evaluated for 20 meso-scale catchments in Germany. We found plausible ranges for model parameterization, however, calculated recession characteristics varied over two orders of magnitude. While recession characteristics of the 20 catchments derived with the different methods correlate strongly, particularly for the RAMs that use the same extraction method and while they rank the catchments relatively consistent, there are still considerable differences among the methods. To elucidate this variability we discuss the ambiguous roles of recession extraction procedures and the parameterization of storage-outflow model and the limitations of the presented recession plots. The results suggest strong limitations to the comparability of recession characteristics derived with different methods, not only in the model parameters but also in the relative characterization of different catchments. A multiple methods approach to investigate streamflow recession characteristics should be considered for applications whenever possible.

Stoelzle, M.; Stahl, K.; Weiler, M.

2012-09-01

42

Evaluating the effect of partial contributing storage on the storage-discharge function from recession analysis  

NASA Astrophysics Data System (ADS)

Hydrograph recession during dry periods has been used to construct water storage-discharge relationships and to quantify storage dynamics and evaporation when streamflow data is available. However, variable hydrologic connectivity among hillslope-riparian-stream zones may affect the lumped storage-discharge relationship, and as a result, affect the estimation of evaporation and storage change. Given observations of rainfall and runoff, and remote-sensing-based observations of evaporation, the ratio (?) between estimated daily evaporation from recession analysis and observed evaporation, and the ratio (?) between estimated contributing storage and total watershed storage are computed for 9 watersheds located in different climate regions. Both evaporation and storage change estimation from recession analysis are underestimated due to the effect of partial contributing storage, particularly when the discharge is low. It was found that the values of ? decrease significantly during individual recession events, while the values of ? are relatively stable during a recession event. The values of ? are negatively correlated with the water table depth and vary significantly among recession events. The partial contributing storage effect is one possible cause for the multi-valued storage-discharge relationship.

Chen, X.; Wang, D.

2013-10-01

43

Analysis of recessive CD2AP and ACTN4 mutations in steroid-resistant nephrotic syndrome.  

PubMed

Mutations in podocyte genes have been identified in patients with steroid-resistant nephrotic syndrome (SRNS). Point mutations in the ACTN4 gene cause an autosomal dominant form of human focal segmental glomerular sclerosis (FSGS); however, reports of CD2AP mutations remain scarce. Based on the phenotype of Actn4 and Cd2ap null mice, we aimed to define the role of recessive CD2AP and ACTN4 mutations in a cohort of children with SRNS for which NPHS1, NPHS2, and PLCE1 mutations had been previously excluded. CD2AP and ACTN4 mutational analysis was performed in 42 children from 35 unrelated families. The median age of disease onset was 20 (range 0-102) months. Sixteen patients reached end-stage kidney disease at a median age of 84 (range 4-161) months. Renal histology showed FSGS lesions and minimal glomerular changes in 49% and 20% of patients, respectively. Microsatellite marker analysis excluded linkage to the CD2AP locus in 26 families and to the ACTN4 locus in 31 families. No disease-causing mutations were identified in the remaining families. Recessive CD2AP and ACTN4 mutations are rare in children with SRNS. The absence of mutations in this study suggests that there are other genetic causes of SRNS that still need to be identified. PMID:19956976

Benoit, Geneviève; Machuca, Eduardo; Nevo, Fabien; Gribouval, Olivier; Lepage, David; Antignac, Corinne

2010-03-01

44

Recession Flow Analysis for Selection of a Basin Drainage Model and Estimation of Basin-Wide Hydraulic Parameters  

Microsoft Academic Search

To guide us toward a correct description of the drainage processes in the coastal range of central Chile, we evaluated several analytical models for post-rainfall aquifer drainage: the Boussinesq model, various TOPMODEL expressions, and non-linear reservoirs. Based on discharge recession curves from one large basin and three sub-basins with areas on the order of 0.1, 1, 10 and 1000 km2,

D. E. Rupp; H. Uribe; O. Lagos; J. S. Selker

2004-01-01

45

Rapid multipoint linkage analysis of recessive traits in nuclear families, including homozygosity mapping  

SciTech Connect

Homozygosity mapping is a powerful strategy for mapping rare recessive traits in children of consanguineous marriages. Practical applications of this strategy are currently limited by the inability of conventional linkage analysis software to compute, in reasonable time, multipoint LOD scores for pedigrees with inbreeding loops. We have developed a new algorithm for rapid multipoint likelihood calculations in small pedigrees, including those with inbreeding loops. The running time of the algorithm grows, at most, linearly with the number of loci considered simultaneously. The running time is not sensitive to the presence of inbreeding loops, missing genotype information, and highly polymorphic loci. We have incorporated this algorithm into a software package, MAPMAKER/HOMOZ, that allows very rapid multipoint mapping of disease genes in nuclear families, including homozygosity mapping. Multipoint analysis with dozens of markers can be carried out in minutes on a personal workstation. 23 refs., 4 figs., 1 tab.

Kruglyak, L.; Daly, M.J. [Whitehead Institute for Biomedical Research, Cambridge, MA (United States); Lander, E.S. [Whitehead Institute for Biomedical Research, Cambridge, MA (United States)]|[Massachusetts Institute of Technology, Cambridge, MA (United States)

1995-02-01

46

Rapid multipoint linkage analysis of recessive traits in nuclear families, including homozygosity mapping.  

PubMed

Homozygosity mapping is a powerful strategy for mapping rare recessive traits in children of consanguineous marriages. Practical applications of this strategy are currently limited by the inability of conventional linkage analysis software to compute, in reasonable time, multipoint LOD scores for pedigrees with inbreeding loops. We have developed a new algorithm for rapid multipoint likelihood calculations in small pedigrees, including those with inbreeding loops. The running time of the algorithm grows, at most, linearly with the number of loci considered simultaneously. The running time is not sensitive to the presence of inbreeding loops, missing genotype information, and highly polymorphic loci. We have incorporated this algorithm into a software package, MAPMAKER/HOMOZ, that allows very rapid multipoint mapping of disease genes in nuclear families, including homozygosity mapping. Multipoint analysis with dozens of markers can be carried out in minutes on a personal workstation. PMID:7847388

Kruglyak, L; Daly, M J; Lander, E S

1995-02-01

47

Analysis of Light Curve of OJ287  

NASA Astrophysics Data System (ADS)

A Fourier series fitting of order 10 to the historical light curve of OJ287 (3648 data points) is presented with correlation coefficient ˜ 0.73. It is found that the Weierstrass function may be used to imitate the short time scale variability of OJ287. A fractal curve constructed by the function possesses the similar correlation coefficient to the light curve as the regression curve. We also calculate the capacity-dimension, information-dimension and correlation-dimension of the light curve. The calculations indicate that their values > 1.

He, Jin; Xie, G. Z.

1997-12-01

48

Analysis of light curve of OJ287.  

NASA Astrophysics Data System (ADS)

A Fourier series fitting of order 10 to the historical light curve of OJ287 (3648 data points) is presented with correlation coefficient ?0.73. It is found that the Weierstrass function may be used to imitate the short time scale variability of OJ287. A fractal curve constructed by the function possesses the similar correlation coefficient to the light curve as the regression curve. The authors also calculate the capacity-dimension, information-dimension and correlation-dimension of the light curve. The calculations indicate that their values >1.

Jin, He; Xie, G. Z.

1997-12-01

49

Functional Analysis of HSF4 Mutations Found in Patients With Autosomal Recessive Congenital Cataracts  

PubMed Central

Purpose. The goal of this study was to functionally evaluate three previously uncharacterized heat shock factor protein 4 (HSF4) mutations (c.595_599delGGGCC, c.1213C>T, c.1327+4A>G) encoding mutant HSF4 proteins (G199EfsX15, R405X, and M419GfsX29) with missing C-terminal ends. These HSF4 mutations were previously identified in families with congenital autosomal recessive cataracts. Methods. FLAG-tagged recombinant wild type (WT) and mutant HSF4 proteins were analyzed using the protein stability assay, cellular immunofluorescence, Western blotting, electrophoretic mobility shift assay (EMSA), and reporter activation. Results. HSF4 mutant proteins did not differ in the protein turnover rate when compared with WT HSF4. Immunofluorescence revealed that WT and mutant HSF4 proteins were properly trafficked to the nucleus. EMSA analysis revealed that the G199EfsX15 and M419GfsX29 proteins exhibited decreased heat shock element (HSE)-mediated DNA binding, whereas the R405X mutant exhibited increased HSE-mediated DNA binding when compared with WT HSF4. All three HSF4 mutant proteins exhibited abolished HSE-mediated luciferase reporter activation. Detailed evaluation of the C-terminal region identified three novel domains: two activation domains and one repression domain. Conclusions. The three HSF4 autosomal recessive mutations evaluated here result in a loss of HSF4 function due to a loss of regulatory domains present at the C-terminal end. These findings collectively indicate that the transcriptional activation of HSF4 is mediated by interactions between activator and repressor domains within the C-terminal end.

Merath, Kate; Ronchetti, Adam; Sidjanin, Duska J.

2013-01-01

50

Estimating basin-wide hydraulic parameters of a semi-arid mountainous watershed by recession-flow analysis  

Microsoft Academic Search

Insufficient sub-surface hydraulic data from watersheds often hinders design of water resources structures. This is particularly true in developing countries and in watersheds with low population densities because well-drilling to obtain the hydraulic data is expensive. The objective of this study was to evaluate the applicability of ‘Brutsaert’ recession flow analysis to steeper and more arid watersheds than those that

Guillermo F. Mendoza; Tammo S. Steenhuis; M. Todd Walter; J.-Yves Parlange

2003-01-01

51

The Informative Analysis of Individual Trend Curves  

ERIC Educational Resources Information Center

Additive and non-additive models for an individual trend curve are examined, and five methods for fitting these to a set of individuals are described. It is suggested that classical fitting methods are more informative than latent curve methods, and commonly preferable. A limited study of the effect of time-structure is reported, and results on…

McDonald, Roderick P.

2004-01-01

52

Curving Performance Analysis of Freight Car Trucks.  

National Technical Information Service (NTIS)

A mathematical model of steady-state curve negotiation was used to simulate experimental curving tests of one conventional and six new concept railway freight car trucks. The report describes the model parameters used to characterize the trucks and test c...

R. Young P. P. Marcotte

1981-01-01

53

Molecular and phenotypic analysis of 25 recessive, homozygous-viable alleles at the mouse agouti locus.  

PubMed Central

Agouti is a paracrine-acting, transient antagonist of melanocortin 1 receptors that specifies the subapical band of yellow on otherwise black hairs of the wild-type coat. To better understand both agouti structure/function and the germline damage caused by chemicals and radiation, an allelic series of 25 recessive, homozygous-viable agouti mutations generated in specific-locus tests were characterized. Visual inspection of fur, augmented by quantifiable chemical analysis of hair melanins, suggested four phenotypic categories (mild, moderate, umbrous-like, severe) for the 18 hypomorphs and a single category for the 7 amorphs (null). Molecular analysis indicated protein-coding alterations in 8 hypomorphs and 6 amorphs, with mild-moderate phenotypes correlating with signal peptide or basic domain mutations, and more devastating phenotypes resulting from C-terminal lesions. Ten hypomorphs and one null demonstrated wild-type coding potential, suggesting that they contain mutations elsewhere in the > or = 125-kb agouti locus that either reduce the level or alter the temporal/spatial distribution of agouti transcripts. Beyond the notable contributions to the field of mouse germ cell mutagenesis, analysis of this allelic series illustrates that complete abrogation of agouti function in vivo occurs most often through protein-coding lesions, whereas partial loss of function occurs slightly more frequently at the level of gene expression control.

Miltenberger, Rosalynn J; Wakamatsu, Kazumasa; Ito, Shosuke; Woychik, Richard P; Russell, Liane B; Michaud, Edward J

2002-01-01

54

Physiological response curve analysis using nonlinear mixed models  

Microsoft Academic Search

Nonlinear response curves are often used to model the physiological responses of plants. These models are preferable to polynomials because the coefficients fit to the curves have biological meaning. The response curves are often generated by repeated measurements on one subject, over a range of values for the environmental variable of interest. However, the typical analysis of differences in coefficients

Michael S. Peek; Estelle Russek-Cohen; Alexander D. Wait; Irwin N. Forseth

2002-01-01

55

Contrasting models for lactation curve analysis.  

PubMed

Several statistical models have been proposed for the genetic evaluation of production traits in dairy cattle based on test-day records. Three main approaches have been put forward in the literature: random regression, orthogonal polynomials, and, more recently, character process models. The aim of this paper is to show how these different approaches are related, to compare their performance for the genetic analysis of lactation curves, and to assess equivalence between sire and animal models for repeated measures analyses. It was found that, with an animal model, a character process model with 11 parameters performed better, regarding the likelihood criterion, than a quartic random regression model (with 31 parameters). However, although the likelihood was higher, the genetic variance was very different with the character process model from the unstructured model, which raises important issues concerning model selection criteria. There are advantages in combining methodologies. A quadratic random regression model for the environmental part, combined with a character process model for the residual, performed better than the quartic random regression model and had fewer parameters. A character process structure allowing for a correlation pattern modeled the residual better than a simple quadratic variance, and had only one extra parameter. PMID:12018443

Jaffrezic, F; White, I M S; Thompson, R; Visscher, P M

2002-04-01

56

Differential thermal analysis. III. Melting curves of oils and fats  

Microsoft Academic Search

Summary  The application of the differential thermal-analysis method for studying the melting behavior of oils and fats has proved\\u000a very useful. The shapes of the curves depend largely on the pretreatment of the fats. From these curves, indications regarding\\u000a the tempering of the fats can be obtained. DTA curves show the frequent occurrence of mixed crystals in fats. The curves are

J. Hannewijk; A. J. Haighton

1958-01-01

57

Evaluation of karstic aquifers contribution to streams by the statistical analysis of recession curves  

Microsoft Academic Search

Karstic aquifers significantly contribute to streams in most of Turkey’s river basins, so studies on karst water resources\\u000a have great importance for Turkey. Karstic aquifer contributions are generally emerging at several locations near the river\\u000a bed and are not readily measured by direct hydrometric methods. In this study, the extent of karstic aquifer contributions\\u000a to a stream will be investigated

A. Cem Koc

2008-01-01

58

Evaluation of karstic aquifers contribution to streams by the statistical analysis of recession curves  

Microsoft Academic Search

Karstic aquifers significantly contribute to streams in most of Turkey's river basins, so studies on karst water resources have great importance for Turkey. Karstic aquifer contributions are generally emerging at several locations near the river bed and are not readily measured by direct hydrometric methods. In this study, the extent of karstic aquifer contributions to a stream will be investigated

A. Cem Koc

2008-01-01

59

INFERRING CHANGES IN DYNAMIC GROUNDWATER STORAGE FROM RECESSION CURVE ANALYSIS OF DISCHARGE DATA  

Microsoft Academic Search

Groundwater storage is an important element of terrestrial water storage. It in- fluences the baseflow component of the river discharge which constitutes the majority of the outflow of Polish rivers. An evaluation of changes in the dynamic groundwater storage from point measurements of groundwater levels is usually a difficult task as groundwater data are scarce in time and space. Alternative

Urszula Somorowska

60

Dominant Controls on Early and Late Stages of Base Flow Recession at the Watershed Scale  

NASA Astrophysics Data System (ADS)

Base flow at the watershed scale is an integrated response of groundwater discharges along the active stream network. It is a challenge to interpret the observed exponents of the power relationship between recession slope and base flow due to the temporal and spatial variability of landscape and shallow aquifer. Spatial heterogeneity, which causes the contraction of active streams, and groundwater hydraulics may contribute to the observed recession slopes. In this paper, it is hypothesized that both groundwater hydraulics and contraction of ephemeral streams are important controlling factors on early recessions; however, at the late recession when perennial stream is the main contribution to the base flow, groundwater hydraulics dominates the recession slopes. This hypothesis is tested at the Panola Mountain Research Watershed by comparing the base flows at the moment when ephemeral streams dry out and at the transition from early to late recession which is characterized by distinct exponents in the recession slope curve analysis. Exponents at the early recession and base flow values at the transition vary with different recession events. The base flow at the transition indeed matches the observed base flow at the outlet when streamflow at the perennial stream head becomes zero. It is also found that no single factor dominates the base flow recession during early recession at the watershed scale.

Wu, L.; Wang, D.

2012-12-01

61

Evaluation of aquifer thickness by analysing recession hydrographs. Application to the Oman ophiolite hard-rock aquifer  

Microsoft Academic Search

For more than a century, hydrologists and hydrogeologists have been investigating the processes of stream and spring baseflow recession, for obtaining data on aquifer characteristics. The Maillet Formula [Librairie Sci., A. Hermann, Paris (1905) 218], an exponential equation widely used for recession curve analysis, is an approximate analytical solution for the diffusion equation in porous media whereas the equation proposed

B. Dewandel; P Lachassagne; M Bakalowicz; Ph Weng; A Al-Malki

2003-01-01

62

Recession Rebound  

ERIC Educational Resources Information Center

A return to normal after a crisis is a good thing. Who doesn't want back what once seemed lost? The problem is it usually isn't a simple task figuring out how to patch together a scaled-back training program. When the recession hit in fall 2008, trainers were asked to scale down programming and make do with fewer resources. With a recovery in full…

Weinstein, Margery

2011-01-01

63

Mutation analysis of 272 Spanish families affected by autosomal recessive retinitis pigmentosa using a genotyping microarray  

Microsoft Academic Search

PURPOSE: Retinitis pigmentosa (RP) is a genetically heterogeneous disorder characterized by progressive loss of vision. The aim of this study was to identify the causative mutations in 272 Spanish families using a genotyping microarray. METHODS: 272 unrelated Spanish families, 107 with autosomal recessive RP (arRP) and 165 with sporadic RP (sRP), were studied using the APEX genotyping microarray. The families

A. Avila-Fernandez; D. Cantalapiedra; E. Aller; E. Vallespin; J. Aguirre-Lamban; F. Blanco-Kelly; M. Corton; R. Riveiro-Alvarez; R. Allikmets; M. J. Trujillo-Tiebas; J. M. Millan; F. P. M. Cremers; C. Ayuso

2010-01-01

64

Histomorphological analysis of the osteophytic appositions in patients with lumbar lateral recess syndrome.  

PubMed

Patients with lumbar lateral recess syndrome (LRS) can be successfully cured by removing osseous excrescences that grow on the peripheral edge of articular surface of the facet joint. They cause narrowing of the lateral recess and compress a root of the spinal nerve. Their appearance is related to the instability of respective dynamic vertebral segment. The aim of this study was to analyze the osteophytic composition morphohistochemically and elucidate cellular processes that lead to this new formation appearance. It is necessary to find a possible causative-consequential relation between the osteophyte and instability. The ideal object to explore was the osteophyte in the lateral recess because it had to be removed during operative treatment. The group of 30 patients with clinical feature of LRS was chosen. Each patient had clinically verified LRS with consequential radiculopathy. Bony outgrowths were removed surgically and analyzed by histological and immunohistochemical methods: toluidine blue, Goldner trichrome, TRAP, indirect peroxidase with antibodies against BMP 3 and BMP 7. The outgrowths that caused lateral recess stenosis were composed of fibrous and hyaline cartilage and cancellous bone. The changes in cartilage and bone, and occurrence of intramembranous bone formation in sense of enlargement of trabeculae, leads to the conclusion that marginal osteophytic formations could be an adaptation to changed conditions in the dynamic vertebral segment and an attempt to stabilize this segment by enlargement of articular surface. PMID:21302706

Bajek, Goran; Bajek, Snjezana; Cvek, Sanja Zorici?; Bobinac, Dragica; Splavski, Bruno; Grahovac, Dubravka Sepi?

2010-04-01

65

Computational Analysis of TRAPPC9: Candidate Gene for Autosomal Recessive Non-Syndromic Mental Retardation.  

PubMed

Mental retardation (MR)/ intellectual disability (ID) is a neuro-developmental disorder characterized by a low intellectual quotient (IQ) and deficits in adaptive behavior related to everyday life tasks such as delayed language acquisition, social skills or self-help skills with onset before age 18. To date, a few genes (PRSS12, CRBN, CC2D1A, GRIK2, TUSC3, TRAPPC9, TECR, ST3GAL3, MED23, MAN1B1, NSUN1) for autosomal-recessive forms of non syndromic MR (NS-ARMR) have been identified and established in various families with ID. The recently reported candidate gene TRAPPC9 was selected for computational analysis to explore its potentially important role in pathology as it is the only gene for ID reported in more than five different familial cases worldwide. YASARA (12.4.1) was utilized to generate three dimensional structures of the candidate gene TRAPPC9. Hybrid structure prediction was employed. Crystal Structure of a Conserved Metalloprotein From Bacillus Cereus (3D19-C) was selected as best suitable template using position-specific iteration-BLAST. Template (3D19-C) parameters were based on E-value, Z-score and resolution and quality score of 0.32, -1.152, 2.30°A and 0.684 respectively. Model reliability showed 93.1% residues placed in the most favored region with 96.684 quality factor, and overall 0.20 G-factor (dihedrals 0.06 and covalent 0.39 respectively). Protein-Protein docking analysis demonstrated that TRAPPC9 showed strong interactions of the amino acid residues S(253), S(251), Y(256), G(243), D(131) with R(105), Q(425), W(226), N(255), S(233), its functional partner 1KBKB. Protein-protein interacting residues could facilitate the exploration of structural and functional outcomes of wild type and mutated TRAPCC9 protein. Actively involved residues can be used to elucidate the binding properties of the protein, and to develop drug therapy for NS-ARMR patients. PMID:24040793

Khattak, Naureen Aslam; Mir, Asif

2014-01-01

66

Information, artifacts, and noise in dQ\\/dtQ recession analysis  

Microsoft Academic Search

The plotting of the time rate of change in discharge dQ\\/dt versus discharge Q has become a widely used tool for analyzing reces- sion data since Brutseart and Nieber (Water Resour Res 13 (1977) 637-643) proposed the method. Typically the time increment Dt over which the recession slope dQ\\/dt is approximated is held constant. It is shown here this that

David E. Rupp; John S. Selker

2005-01-01

67

Genetic analysis of autosomal recessive osteopetrosis in Chuvashiya: the unique splice site mutation in TCIRG1 gene spread by the founder effect.  

PubMed

The rare malignant disorder autosomal recessive osteopetrosis (OPTB) is one of the most prevalent autosomal recessive diseases in the Chuvash Republic of Russia. The purpose of this study was to determine the underlying molecular cause of osteopetrosis in Chuvashiya and to reveal the factors causing the unusual high frequency of the disease in this region. Having assumed a founder effect, we performed linkage disequilibrium (LD) mapping of the OPTB locus at the TCIRG1 region and found a unique splice site mutation c.807+5G>A in all Chuvashian OPTB patients studied. We then analyzed the mutational change in mRNA and detected an intron insertion within the mutant transcript, resulting in a frameshift and premature stop-codon formation (p.Leu271AspfsX231). A decreased expression of the mutant transcript was also detected, which may have been the result of nonsense-mediated decay. Real-time qPCR and MLPA melting curve analysis-based systems were designed and used for c.807+5G>A mutation screening. In addition to analyzing the gene frequency in Chuvashiya, we also estimated three other populations in the Volga-Ural region (Mari, Udmurt and Bashkir). We found a 1.68% prevalence in Chuvashiya (calculated disease frequency, 1/3500 newborns) and a 0.84% in the Mari population (1/14 000 newborns). The haplotype analysis revealed that all OPTB cases in Chuvashians and Marians originated from a single mutational event and the age of the mutation in Chuvashians was estimated to be approximately 890 years. PMID:19172990

Bliznetz, Elena A; Tverskaya, Svetlana M; Zinchenko, Rena A; Abrukova, Anna V; Savaskina, Ekaterina N; Nikulin, Maxim V; Kirillov, Alexander G; Ginter, Evgeny K; Polyakov, Alexander V

2009-05-01

68

Base-Flow Recession in Illinois.  

National Technical Information Service (NTIS)

Base-flow recession curves of nineteen Illinois streams were analyzed to determine the most significant factors which affected the base-flow recession rate. The eight most significant factors were (in order): number of days since the last major storm, ave...

R. N. Farvolden

1971-01-01

69

Protections against Differential Analysis for Elliptic Curve Cryptography  

Microsoft Academic Search

We propose several new methods to protect the scalar multi- plication on an elliptic curve against Dieren tial Analysis. The basic idea consists in transforming the curve through various random morphisms to provide a non-deterministic execution of the algorithm. The solutions we suggest complement and improve the state-of-the-art, but also provide a practical toolbox of ecien t countermeasures. These should

Marc Joye; Christophe Tymen

2001-01-01

70

Light curve analysis of 44 Tauri  

NASA Astrophysics Data System (ADS)

Two separate sets of data obtained at Merate (Poretti et al. 1992) and Ege University Observatories were combined and analyzed by means of the program PERIOD (Breger, 1990) in order to monitor the star's pulsational behaviour. The present data have been obtained on 12 nights (three nights on December 1 989, two nights on November 1990, six nights on January 1991 and one night on February 1991), being mostly crowded around January 1991 which is separated by roughly one year from the Poretti et al. data. The analysis led to a seven-frequency solution (Table 1) and gave a clue that 44 Tau might have experienced some variations in its pulsational behaviour within a one-year period.

Akan, M. C.

1993-05-01

71

Bifurcation analysis of an automobile model negotiating a curve  

Microsoft Academic Search

The paper deals with the bifurcation analysis of a rather simple model describing an automobile negotiating a curve. The mechanical model has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. Bifurcation analysis is adopted as the proper procedure for analysing steady-state cornering. Two independent parameters referring to running conditions, namely steering angle and

Fabio Della Rossa; Giampiero Mastinu; Carlo Piccardi

2012-01-01

72

Investigating storage-discharge relations in a lowland catchment using hydrograph fitting, recession analysis, and soil moisture data  

NASA Astrophysics Data System (ADS)

The relation between storage and discharge is an essential characteristic of many rainfall-runoff models. The simple dynamical systems approach, in which a rainfall-runoff model is constructed from a single storage-discharge relation, has been successfully applied to humid catchments. Here we investigate (1) if and when the less humid lowland Hupsel Brook catchment also behaves like a simple dynamical system by hydrograph fitting, and (2) if system parameters can be inferred from streamflow recession rates or more directly from soil moisture storage observations. Only 39% of the fitted monthly hydrographs yielded Nash-Sutcliffe efficiencies above 0.5, from which we can conclude that the Hupsel Brook catchment does not always behave like a simple dynamical system. Model results were especially poor in summer, when evapotranspiration is high and the thick unsaturated zone attenuates the rainfall input. Using soil moisture data to obtain system parameters is not trivial, mainly because there is a discrepancy between local and catchment storage. Parameters obtained with direct storage-discharge fitting led to a strong underestimation of the response of runoff to rainfall, while recession analysis leads to an overestimation.

Brauer, C. C.; Teuling, A. J.; Torfs, P. J. J. F.; Uijlenhoet, R.

2013-07-01

73

Molecular Analysis of DMP1 Mutants Causing Autosomal Recessive Hypophosphatemic Rickets  

PubMed Central

We previously demonstrated that the mutations Met1Val (M1V) and the deletion of nucleotides 1484-1490 (1484-1490del) in Dentin matrix protein-1 (DMP1) cause the novel disorder autosomal recessive hypophosphatemic rickets (ARHR), which is associated with elevated Fibroblast growth factor-23 (FGF23). To further understand the role of DMP1 in ARHR, we undertook molecular genetic and in vitro expression studies. First, we examined a kindred with a severe hypophosphatemic rickets phenotype and recessive inheritance. Analyses of this family demonstrated that the affected members had elevated serum FGF23 and carried a large, biallelic deletion that removed the majority of DMP1. At a minimum, this deletion encompassed 49 kb between DMP1 exon 3 and an intergenic region 5? to the next telomeric gene, integrin-binding sialoprotein (IBSP). We next performed immunofluorescent studies in cells to understand the effects of the known ARHR mutations on DMP1 cellular processing. These analyses showed that the M1V DMP1 mutant was not sorted to the trans-Golgi network (TGN) and secretory pathway, but filled the entire cytoplasm. In contrast, the 1484-1490del mutant localized to the TGN and was secreted, similar to wild type DMP1. The 1484-1490del mutation replaces the DMP1 18 C-terminal amino acids with 33 non-native residues. Truncation of wild type DMP1 by these native 18 residues followed by Western blot and confocal microscopic analyses demonstrated a wild type expression pattern when compared with the 1484-1490del mutant, indicating that the last 18 residues are not critical for cellular trafficking, but that the 33 additional residues arising from the 1484-1490del mutation likely compromise DMP1 processing. The relationship between DMP1 and FGF23 is unclear. To test endogenous DMP1 response to serum metabolites that also regulate FGF23, UMR-106 cells were treated with 1,25(OH)2 vitamin D (1×10?7M) and showed a 12-fold increase in DMP1 mRNA and protein at 24 hr. In summary, we have identified a novel DMP1 deletion as the cause of ARHR, as well as demonstrated that the ARHR mutations alter DMP1 cellular processing, and that DMP1 can be regulated by vitamin D. Taken together, this work expands our understanding of the genetic and molecular mechanisms associated with DMP1 alterations causing ARHR.

Farrow, Emily G.; Davis, Siobhan I.; Ward, Leanne M.; Summers, Lelia J.; Bubbear, Judith S.; Keen, Richard; Stamp, Trevor C.B.; Baker, Laurence R. I.; Bonewald, Lynda F.; White, Kenneth E.

2009-01-01

74

COMPREHENSIVE CLINICAL AND MOLECULAR ANALYSIS OF 12 FAMILIES WITH TYPE 1 RECESSIVE CUTIS LAXA  

PubMed Central

Autosomal recessive cutis laxa type I (ARCL type I) is characterized by generalized cutis laxa with pulmonary emphysema and/or vascular complications. Rarely, mutations can be identified in FBLN4 or FBLN5. Recently, LTBP4 mutations have been implicated in a similar phenotype. Studying FBLN4, FBLN5 and LTBP4 in 12 families with ARCL type I, we found bi-allelic FBLN5 mutations in 2 probands, whereas 9 probands harbored biallelic mutations in LTBP4. FBLN5 and LTBP4 mutations cause a very similar phenotype associated with severe pulmonary emphysema, in the absence of vascular tortuosity or aneurysms. Gastro-intestinal and genitourinary tract involvement seems to be more severe in patients with LTBP4 mutations. Functional studies showed that most premature termination mutations in LTBP4 result in severely reduced mRNA and protein levels. This correlated with increased transforming growth factor beta (TGF?) signaling. However, one mutation, c.4127dupC, escaped nonsense-mediated decay. The corresponding mutant protein (p.Arg1377Alafs*27) showed reduced colocalization with fibronectin, leading to an abnormal morphology of microfibrils in fibroblast cultures, while retaining normal TGF? signaling. We conclude that LTBP4 mutations cause disease through both loss of function and gain of function mechanisms.

Callewaert, Bert; Su, Chi-Ting; Van Damme, Tim; Vlummens, Philip; Malfait, Fransiska; Vanakker, Olivier; Schulz, Bianca; Neal, Meghan Mac; Davis, Elaine C.; Lee, Joseph G.H.; Salhi, Aicha; Unger, Sheila; Heimdal, Ketil; De Almeida, Salome; Kornak, Uwe; Gaspar, Harald; Bresson, Jean-Luc; Prescott, Katrina; Gosendi, Maria E.; Mansour, Sahar; Pierard, Gerald E.; Madan-Khetarpal, Suneeta; Sciurba, Frank C.; Symoens, Sofie; Coucke, Paul J; Van Maldergem, Lionel; Urban, Zsolt; De Paepe, Anne

2014-01-01

75

Regional estimation of catchment-scale soil properties by means of streamflow recession analysis for use in distributed hydrological models  

NASA Astrophysics Data System (ADS)

The estimation of catchment-scale soil properties, such as water storage capacity and hydraulic conductivity, is of primary interest for the implementation of distributed hydrological models at the regional scale. This estimation is generally done on the basis of information provided by soil databases. However, such databases are often established for agronomic uses and generally do not document deep weathered rock horizons (i.e. pedologic horizons of type C and deeper), which can play a major role in water transfer and storages. Here we define the Drainable Storage Capacity Index (DSCI), an indicator that relies on the comparison of cumulated streamflow and precipitation to assess catchment-scale storage capacities. The DSCI is found to be reliable to detect underestimation of soil storage capacities in soil databases. We also use the streamflow recession analysis methodology defined by Brutsaert and Nieber (Water Resources Research 13(3), 1977) to estimate water storage capacities and lateral saturated hydraulic conductivities of the non-documented deep horizons. The analysis is applied to a sample of twenty-three catchments (0.2 km² - 291 km²) located in the Cévennes-Vivarais region (south of France). In a regionalisation purpose, the obtained results are compared to the dominant catchments geology. This highlights a clear hierarchy between the different geologies present in the area. Hard crystalline rocks are found to be associated to the thickest and less conductive deep soil horizons. Schist rocks present intermediate values of thickness and of saturated hydraulic conductivity, whereas sedimentary rocks and alluvium are found to be the less thick and the most conductive. Consequently, deep soil layers with thicknesses and hydraulic conductivities differing with the geology were added to a distributed hydrological model implemented over the Cévennes-Vivarais region. Preliminary simulations show a major improvement in terms of simulated discharge when compared to simulations done without deep soil layers. KEY WORDS: hydraulic soil properties, streamflow recession, deep soil horizons, soil databases, Boussinesq equation, storage capacity, regionalisation

Vannier, Olivier; Braud, Isabelle; Anquetin, Sandrine

2013-04-01

76

Are streamflow recession characteristics characteristic?  

NASA Astrophysics Data System (ADS)

Streamflow recession analysis methods reveal relationships between catchment storage and discharge when precipitation, evapotranspiration, surface storage and groundwater withdrawals are negligible. The falling limb of a hydrograph typically declines over several orders of magnitude and discharge (Q) versus rate of change (-dQ/dt) relationships illustrate a characteristic non-linearity in this storage-outflow dynamic. In the past many different recession analysis methods have been applied in order to quantify the characteristics of this dynamic. Hence there is a need to investigate the influence of the choice of method on recession characteristics. This study assesses a variety of different recession analysis methods to provide information about the reliability and uncertainty of the derived recession characteristics. The different methods can be distinguished by a two-step procedure: first, three different extraction methods select suitable recession segments either with stepwise algorithms from declining hydrographs or supported by precipitation data. The extraction methods lead to a variety of -dQ/dt-Q-plots. Second, the parameters of a commonly used non-linear storage-outflow relationship were estimated from fitting the equation to binned means or to lower envelopes. Finally, the influence of hourly versus daily time step for recession extraction is analyzed. Since each combination of methods may result in different parameters of the non-linear storage-outflow relationships these parameters as well as other characteristic of the derived streamflow recessions like half-life, 30day-low flow or relative storage volume are compared. For 25 meso-scale catchments with different topography and geology in southwest Germany, the observed variability within each catchment was relative large compared to the overall variability among the catchments. In addition, the derived streamflow recession characteristics were not only different due to the methodological approach, but the approaches produced systematically different results with relative low correlation among them for several of the methods. We conclude that different methods to characterize streamflow recessions provide non-unique descriptions of the storage-discharge dynamics and hence make a characterization and also regionalization of these recession characteristics problematic.

Stoelzle, M.; Weiler, M.; Stahl, K.

2012-04-01

77

Early recession behaviour of spring hydrographs  

NASA Astrophysics Data System (ADS)

SummaryThe long-term flow recession of many springs can be approximated by an exponential function. However, the early recession often exhibits a different behaviour. The exponential recession function represents a long-term approximation of analytical solutions of the flow equation of fissured matrix blocks draining toward a fixed-head boundary. Thus, early deviations from the exponential behaviour potentially originate from the inappropriateness of this approximation at short times. We therefore examine the properties of the exact analytical solutions and make comparisons with field data. If hydraulic heads are initially constant within the matrix blocks the flow recession exhibits a power-law decrease at short times. Both from steady-state initial conditions and after finite recharge pulses the early flow recession follows a power law, too, if discharge is appropriately shifted and rescaled. If the catchment is composed of multiple blocks drained by highly conductive conduits the recession behaviour of the spring is identical to that of the individual blocks if the blocks are of the same size. The recession curves of the published hydrograph of Cheddar spring (Great Britain) are found to be in good agreement with this model if reasonable initial conditions are assumed. A brief look at recession curves from other springs suggests that the model might be applicable to most of them, too. The model also provides satisfactory fits to the flow recession of the Gallusquelle (Germany). However, the observed power-law exponent differs from that predicted by the analytical model. A consistent interpretation of the shape of several recession curves from this spring is provided by a more general fractal approach, which assumes that the catchment is composed of blocks of strongly different sizes.

Birk, Steffen; Hergarten, Stefan

2010-06-01

78

Kinetic analysis of derivative curves in thermal analysis  

Microsoft Academic Search

Two methods of obtaining kinetic parameters from derivative thermoanalytical curves are proposed. The methods are based on the general form of kinetic formulae and are applicable to general types of reactions governed by a single activation energy. One method utilizes the linear relation between peak temperature and heating rate in order to estimate the activation energy, and only the information

T. Ozawa

1970-01-01

79

Exclusion of the locus for autosomal recessive pseudohypoaldosteronism type 1 from the mineralocorticoid receptor gene region on human chromosome 4q by linkage analysis  

SciTech Connect

Pseudohypoaldosteronism type 1 (PHA1) is an uncommon inherited disorder characterized by salt-wasting in infancy arising from target organ unresponsiveness to mineralocorticoids. Clinical expression of the disease varies from severely affected infants who may die to apparently asymptomatic individuals. Inheritance is Mendelian and may be either autosomal dominant or autosomal recessive. A defect in the mineralocortiocoid receptor has been implicated as a likely cause of PHA1. The gene for human mineralocorticoid receptor (MLR) has been cloned and physically mapped to human chromosome 4q31.1-31.2. The etiological role of MLR in autosomal recessive PHA1 was investigated by performing linkage analysis between PHA1 and three simple sequence length polymorphisms (D4S192, D4S1548, and D4S413) on chromosome 4q in 10 consanguineous families. Linkage analysis was carried out assuming autosomal recessive inheritance with full penetrance and zero phenocopy rate using the MLINK program for two-point analysis and the HOMOZ program for multipoint analysis. Lod scores of less than -2 were obtained over the whole region from D4S192 to D4S413 encompassing MLR. This provides evidence against MLR as the site of mutations causing PHA1 in the majority of autosomal recessive families. 34 refs., 3 figs., 2 tabs.

Chung, E.; Hanukoglu, A.; Rees, M.; Thompson, R.; Gardiner, R.M. [Univ. College London Medical School, London (United Kingdom)] [and others] [Univ. College London Medical School, London (United Kingdom); and others

1995-10-01

80

An analysis of the shapes of ultraviolet extinction curves. III - An atlas of ultraviolet extinction curves  

NASA Technical Reports Server (NTRS)

The basic data needed to produce UV extinction curves for a sample of 78 stars, including spectral types, visual photometry, parameters used to produce fits to the UV extinction curves, distances to the program stars, and line-of-sight H I column densities, are presented. The observational and numerical techniques used to obtain the results are discussed in detail. The UV extinction curves and their analytic fits are shown graphically.

Fitzpatrick, Edward L.; Massa, Derck

1990-01-01

81

Straight thinking about groundwater recession  

NASA Astrophysics Data System (ADS)

in catchment and hillslope hydrology a more nuanced approach is now taken to streamflow recession analysis, in the context of major aquifers it is commonly still assumed that the groundwater head recession rate will take exponential form, an idea originally proposed in the 19th Century. However it is shown here that, in early times, the groundwater head recession in a major aquifer should take an almost straight line form with a rate approximately equal to the long-term recharge rate divided by the aquifer storage coefficient. The length of this phase can be estimated from an analytical expression derived in the paper which depends on the aquifer diffusivity, length scale, and the position of the monitoring point. A transitional phase then leads to an exponential phase after some critical time which is independent of the position of the monitoring point. Major aquifers in a state of periodic quasi-steady state are expected to have rates of groundwater flux recession which deviate little from the average rate of groundwater recharge. Where quasi-exponential groundwater declines are observed in nature, their form may be diagnostic of particular types of aquifer properties and/or boundary effects, such as proximity to drainage boundaries, variations in transmissivity with hydraulic head, storage changes due to pumping, nonequilibrium flow at a range of spatial and temporal scales, and variations in specific yield with depth. Recession analysis has applicability to a range of groundwater problems and is powerful way of gaining insight into the hydrologic functioning of an aquifer.

Cuthbert, M. O.

2014-03-01

82

Genetic Linkage Analysis of 15 DFNB Loci in a Group of Iranian Families with Autosomal Recessive Hearing Loss  

PubMed Central

Background: Hearing loss (HL) is the most frequent sensory birth defect in humans. Autosomal recessive non-syndromic HL (ARNSHL) is the most common type of hereditary HL. It is extremely heterogeneous and over 70 loci (known as DFNB) have been identified. This study was launched to determine the relative contribution of more frequent loci in a cohort of ARNSHL families. Methods: Thirty-seven Iranian families including 36 ARNSHL families and 1 family with Pendred syndrome each with ? 4 affected individuals, from seven provinces of Iran, were ascertained. DFNB1 contribution was initially studied by DNA sequencing of GJB2 and linkage analysis using the relative STR markers. The excluded families were then subjected to homozygosity mapping for fifteen ARNSHL loci. Results: Sixteen families were found to be linked to seven different known loci, including DFNB1 (6 families), DFNB4 (3 families +1 family with Pendred syndrome), DFNB63 (2 families), DFNB2 (1 family), DFNB7/11 (1 family), DFNB9 (1 family) and DFNB21 (1 family). DNA sequencing of the corresponding genes is in progress to identify the pathogenic mutations. Conclusion: The genetic causes were clarified in 43.2% of the studied families, giving an overview of the causes of ARNSHL in Iran. DFNB4 is ranked second after DFNB1 in the studied cohort. More genetic and epigenetic investigations will have to be done to reveal the causes in the remaining families.

Tabatabaiefar, MA; Alasti, F; Zohour, M Montazer; Shariati, L; Farrokhi, E; Farhud, DD; Camp, GV; Noori-Daloii, MR; Chaleshtori, M Hashemzadeh

2011-01-01

83

X linked recessive thrombocytopenia.  

PubMed Central

A Saudi Arab boy presented in early childhood with thrombocytopenia, morphologically large and normal sized platelets, increased mean platelet volume, and a hypermegakaryocytic bone marrow. There was no clinical and laboratory evidence of any significant immunological abnormalities. Similar findings in two other brothers suggested strongly that they were all suffering from an X linked recessive thrombocytopenic disorder. Results of DNA analysis with the probe M27 beta are consistent with X linkage and indicate also that the locus of the relevant gene lies close to or is identical to the locus of the gene for the Wiskott-Aldrich syndrome (WAS). Because of various features which include the presence of large and normal sized platelets (rather than small platelets) and freedom from significant immune deficiencies, it is likely that the X linked recessive thrombocytopenia in this family is an isolated entity quite distinct from the classical WAS phenotype. However, a modified expression of the WAS gene producing a mild phenotypic variant cannot be excluded entirely.

Knox-Macaulay, H H; Bashawri, L; Davies, K E

1993-01-01

84

An Analysis of Progress Curve Conceptual Advances and Progress Curve Uses, Since 1956.  

National Technical Information Service (NTIS)

The progress curve concept is traced in historical developments through 1956. The paper then concentrates on extensions of concepts through review and evaluation of articles and reports. Non-linearity is discussed, as is capital-intensive production and n...

V. Colasuonno

1967-01-01

85

Estimated hydrologic characteristics of shallow aquifer systems in the Valley and Ridge, the Blue Ridge, and the Piedmont physiographic provinces based on analysis of streamflow recession and base flow  

USGS Publications Warehouse

Inferences are drawn about properties of aquifer systems from the interpretation of streamflow records in the Appalachian Valley and Ridge, Piedmont, and Blue Ridge physiographic provinces. The analysis is divided into two parts--analysis of streamflow recession and base-flow analysis. Analysis of recession yields information about aquifer diffusivity and variation in specific yield. Base-flow analysis is used to develop water balances for representative basins in the study area.

Rutledge, A. T.; Mesko, T. O.

1996-01-01

86

Quantification of magnetic coercivity components by the analysis of acquisition curves of isothermal remanent magnetisation  

Microsoft Academic Search

A new method of analysing isothermal remanent magnetisation (IRM) acquisition curves based on cumulative log Gaussian analysis [Robertson and France, Phys. Earth Planet. Inter. 82 (1994) 223–234] is proposed. It is based on the curve fitting of the IRM acquisition curve versus the logarithm of the applied field with: (i) the acquisition curve on a linear scale, (ii) the acquisition

Pauline P. Kruiver; Mark J. Dekkers; David Heslop

2001-01-01

87

Examining individual recession events instead of a data cloud: Using a modified interpretation of dQ/dt-Q streamflow recession in glaciated watersheds to better inform models of low flow  

NASA Astrophysics Data System (ADS)

SummaryTo examine stream recession rates, hydrologists have plotted the rate of change in discharge (dQ/dt) versus the mean discharge (Q). Such plots typically result in a large cloud of data points where the slope of the lower bound of the cloud is often used to infer aquifer hydraulic properties as informed by certain interpretations of the Boussinesq Equation. For seven watersheds in New York State, USA ranging from 100 km2 to 6415 km2, we distinguish data points in the dQ/dt-Q plot belonging to individual recession events instead of looking at the entire data cloud. The recession curve of individual events consistently shifts upward during the summer and late fall (relative to spring and late fall curves) and much of the scatter in the data cloud appears to be due to seasonal variations in recession. We speculate that these seasonal variations in recession rate may be due to variations in watershed evapotranspiration (ET). Additionally, most individual recession events have slopes of approximately two when plotted as log dQ/dt versus log Q. Application of the Boussinesq Equation to watershed-scale recession date predicts slopes shifting from 3 to 3/2 as recession progresses, thus the observed slope of two casts doubt on whether it is appropriate to apply hydraulic aquifer theory to these types of watersheds to infer aquifer properties or predict low flows. As a further validation of the hydrologic information content of individual recession curves, the individual recession curves from time periods with minimal ET (early spring and late fall) were used to establish storage-discharge functions for two of the smaller watersheds. With these storage-discharge functions, a simple hydrologic model could reasonably simulate time series with minimal calibration (Nash-Sutcliffe R2 of 0.71 and 0.67 on log transformed discharge). Overall, this paper suggests that the analysis of individual event recession curves (particularly when compared among watersheds and seasons) can be a valuable tool for gaining insights into hydrological processes at the scale of large watersheds and can justify alternatives to current low flow models.

Shaw, Stephen B.; Riha, Susan J.

2012-04-01

88

COMPLEMENTATION ANALYSIS OF METHYL METHANE SULFONATE-INDUCED RECESSIVE LETHAL MUTATIONS IN THE ZESTE-WHITE REGION OF THE X CHROMOSOME OF DROSOPHILA MELANOGASTERI  

Microsoft Academic Search

Recessive lethal mutations in the 3A1 to 3C2 region of the X chromosome of Drosophila melanogaster were detected in 113 of 33,544 sperm treated by feeding 5 mM methyl metllanesulfonate in 1% sucrose for 22 hours. Seven of the 113 lethals were sterile, leaving 106 for analysis by complementation tests. With only one exception, these mutants were found to have

J. K. LIM

89

Tradeoff analysis of FPGA based elliptic curve cryptography  

Microsoft Academic Search

FPGAs are an attractive platform for elliptic curve cryptography hardware. Since field multiplication is the most critical operation in elliptic curve cryptography, we have studied how efficient sev- eral field multipliers can be mapped to lookup table based FPGAs. Furthermore we have compared different curve coordinate repre- sentations with respect to the number of required field operations, and show how

Marcus Bednara; M. Daldrup; Jürgen Teich; Joachim Von Zur Gathen; Jamshid Shokrollahi

2002-01-01

90

Suspension characteristics analysis running on curve for maglev train  

Microsoft Academic Search

The suspension characteristics of maglev train are studied in this paper when it is running on different curves. The suspension gap variation when maglev train is running on three different curves are presented. And the limitation to the vertical semi-diameter of the curve at the point where the grade of the longitudinal section of the track changes is also calculated.

Xiaolong Li; Zhizhou Zhang; Zhiqiang Long

2008-01-01

91

Analysis of infant growth curves using multivariate adaptive splines.  

PubMed

In this paper, we study the effect of cocaine use by a pregnant woman on the growth of her infant after birth. Using a data set from a retrospective study, we found that cocaine use was a marginally significant contributor to the infant growth as measured by bodyweight. From a statistical point of view, the data represent a common, though complex, structure that has received little attention in the statistical literature. To analyze these data, we adopt and further enhance an approach developed recently called MASAL (multivariate adaptive splines for the analysis of longitudinal data). In addition to the fitting of growth curves, we demonstrate particularly how to explore and estimate the underlying covariance structures for the longitudinal data that were collected from a rather irregular schedule. PMID:11318199

Zhang, H

1999-06-01

92

Analysis of missense variants in the PKHD1 -gene in patients with autosomal recessive polycystic kidney disease (ARPKD)  

Microsoft Academic Search

Autosomal recessive polycystic kidney disease (ARPKD) is a severe form of polycystic kidney disease characterized by enlarged kidneys and congenital hepatic fibrosis. Given the poor prognosis for the majority of children with the severe perinatal ARPKD phenotype, there is a regular request for prenatal testing. ARPKD is caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene,

Monique Losekoot; Cathleen Haarloo; Claudia Ruivenkamp; Stefan J. White; Martijn H. Breuning; Dorien J. M. Peters

2005-01-01

93

The effect of the recess shape on performance analysis of the gas-lubricated bearing in optical lithography  

Microsoft Academic Search

Gas-lubricated bearings are widely used in the optical lithographic manufacturing of wafers to realize nearly zero friction for the motion of the stage. As the extreme precise positioning accuracy of these equipments has reached nanometer level, and almost approaches the physical limit, the effect of the recess shape of the gas bearings cannot be neglected any longer. This paper studies

Xue-Dong Chen; Xue-Ming He

2006-01-01

94

Recess Makes Kids Smarter  

ERIC Educational Resources Information Center

Recess has been scaled back or cut altogether in a number of schools around the country. The trend can be traced back to the late eighties and was accelerated under No Child Left Behind. Districts under pressure to show academic progress began to squeeze as much instruction into the day as possible. Others eliminated recess because of concerns…

Adams, Caralee

2011-01-01

95

Recess--It's Indispensable!  

ERIC Educational Resources Information Center

The demise of recess in many elementary schools--and of outdoor play in general--is an issue of great concern to many members of the Play, Policy, and Practice Interest Forum. Most people remember recess as an important part of the school day. It was a time to be outdoors; to organize games; to play on the swings, slides, and other playground…

Jarrett, Olga; Waite-Stupiansky, Sandra

2009-01-01

96

Autosomal Recessive Cerebellar Hypoplasia  

Microsoft Academic Search

Cerebellar hypoplasia is found in association with a variety of neurologic and systemic disorders. It is the primary finding in the uncommonly reported condition of autosomal recessive cerebellar hypoplasia. We describe two siblings with cerebellar hypoplasia documented in both by magnetic resonance imaging (MRI) and review the clinical features of previously reported cases of autosomal recessive cerebellar hypoplasia. The most

Katherine D. Mathews; Adel K. Afifi; James W. Hanson

1989-01-01

97

Starving for Recess  

ERIC Educational Resources Information Center

Every weekday, millions of American schoolchildren throw away their half-eaten cafeteria lunches so that they can run outside to play. The traditional placement of lunch before recess, coupled with the recent decline in overall recess time to meet academic time constraints, forces children to choose between two essential needs: (1) food; and (2)…

Patt, Mary Johnson

2011-01-01

98

Comparisons of Two Statistical Approaches to Study Growth Curves: The Multilevel Model and the Latent Curve Analysis.  

ERIC Educational Resources Information Center

Compares two statistical approaches to modeling growth across time: the multilevel model and latent curve analysis. A longitudinal data set from a school-based substance-use-prevention model for adolescents (2,779 students) illustrates differences and similarities between the approaches and shows very compatible results for both. (SLD)

Chou, Chih-Ping; Bentler, Peter M.; Pentz, Mary Ann

1998-01-01

99

GRB Swift X-ray light curves analysis (Margutti+, 2013)  

NASA Astrophysics Data System (ADS)

We present a comprehensive statistical analysis of Swift X-ray light curves of gamma-ray bursts (GRBs) collecting data from more than 650 GRBs discovered by Swift and other facilities. The unprecedented sample size allows us to constrain the rest-frame X-ray properties of GRBs from a statistical perspective, with particular reference to intrinsic time-scales and the energetics of the different light-curve phases in a common rest-frame 0.3-30keV energy band. Temporal variability episodes are also studied and their properties constrained. Two fundamental questions drive this effort: (i) Does the X-ray emission retain any kind of 'memory' of the prompt ?-ray phase? (ii) Where is the dividing line between long and short GRB X-ray properties? We show that short GRBs decay faster, are less luminous and less energetic than long GRBs in the X-rays, but are interestingly characterized by similar intrinsic absorption. We furthermore reveal the existence of a number of statistically significant relations that link the X-ray to prompt ?-ray parameters in long GRBs; short GRBs are outliers of the majority of these two-parameter relations. However and more importantly, we report on the existence of a universal three-parameter scaling that links the X-ray and the ?-ray energy to the prompt spectral peak energy of both long and short GRBs: EX,iso{prop.to}E1.00+/-0.06?,iso/E0.60+/-0.10pk. (3 data files).

Margutti, R.; Zaninoni, E.; Bernardini, M. G.; Chincarini, G.; Pasotti, F.; Guidorzi, C.; Angelini, L.; Burrows, D. N.; Capalbi, M.; Evans, P. A.; Gehrels, N.; Kennea, J.; Mangano, V.; Moretti, A.; Nousek, J.; Osborne, J. P.; Page, K. L.; Perri, M.; Racusin, J.; Romano, P.; Sbarufatti, B.; Stafford, S.; Stamatikos, M.

2013-11-01

100

Analysis of selected Kepler Mission planetary light curves  

NASA Astrophysics Data System (ADS)

We have modified the graphical user interfaced close binary system analysis program CurveFit to the form WinKepler and applied it to 16 representative planetary candidate light curves found in the NASA Exoplanet Archive (NEA) at the Caltech website http://exoplanetarchive.ipac.caltech.edu, with an aim to compare different analytical approaches. WinKepler has parameter options for a realistic physical model, including gravity-brightening and structural parameters derived from the relevant Radau equation. We tested our best-fitting parameter-sets for formal determinacy and adequacy. A primary aim is to compare our parameters with those listed in the NEA. Although there are trends of agreement, small differences in the main parameter values are found in some cases, and there may be some relative bias towards a 90? value for the NEA inclinations. These are assessed against realistic error estimates. Photometric variability from causes other than planetary transits affects at least 6 of the data-sets studied; with small pulsational behaviour found in 3 of those. For the false positive KOI 4.01, we found that the eclipses could be modelled by a faint background classical Algol as effectively as by a transiting exoplanet. Our empirical checks of limb-darkening, in the cases of KOI 1.01 and 12.01, revealed that the assigned stellar temperatures are probably incorrect. For KOI 13.01, our empirical mass-ratio differs by about 7 % from that of Mislis and Hodgkin (Mon. Not. R. Astron. Soc. 422:1512, 2012), who neglected structural effects and higher order terms in the tidal distortion. Such detailed parameter evaluation, additional to the usual main geometric ones, provides an additional objective for this work.

Rhodes, M. D.; Budding, E.

2014-06-01

101

On the base flow recession at the Panola Mountain Research Watershed, Georgia, United States  

NASA Astrophysics Data System (ADS)

There are two types of nonlinearity for recession slope curves: (1) the data cloud of observed ln(-dQ/dt) versus ln(Q) along a straight line where the slope is not equal to 1, and (2) the data cloud of observed ln(-dQ/dt) versus ln(Q) is concave or convex. From the 0.1 ha hillslope, the 10 ha headwater subwatershed, and the 41 ha watershed at the Panola Mountain Research Watershed (PMRW), the observed ln(-dQ/dt) versus ln(Q) changes from convex to concave. This has been explained by the spatial heterogeneity of recession properties and nonlinearity of hillslope hydraulics. Hillslope bedrock leakage and return flow to the perennial riparian zone aquifer are important factors affecting the ln(-dQ/dt) versus ln(Q) relations, and an assessment of this mechanism for explaining the observed base flow recessions at the PMRW is the sole focus of this research. As a result, the lower envelope and the upper envelope should be used to estimate the recession parameters for the 0.1 ha hillslope and the 41 ha watershed, respectively, and the recession at the 10 ha watershed is a mixture of them. Based on the recession analysis, the leakage to the bedrock on the hillslope and return flow to the perennial stream riparian groundwater can be estimated, and the estimation can be verified by other studies.

Wang, Dingbao

2011-03-01

102

Descriptive and Predictive Growth Curves in Energy System Analysis  

Microsoft Academic Search

This study reviews a variety of growth curve models and the theoretical frameworks that lay behind them. In many systems,\\u000a growth patterns are, or must, ultimately be subjected to some form of limitation. A number of curve models have been developed\\u000a to describe and predict such behaviours. Symmetric growth curves have frequently been used for forecasting fossil fuel production,\\u000a but

Mikael Höök; Junchen Li; Noriaki Oba; Simon Snowden

2011-01-01

103

Moving boundary approximation for curved streamer ionization fronts: solvability analysis.  

PubMed

The minimal density model for negative streamer ionization fronts is investigated. An earlier moving boundary approximation for this model consisted of a "kinetic undercooling" type boundary condition in a Laplacian growth problem of Hele-Shaw type. Here we derive a curvature correction to the moving boundary approximation that resembles surface tension. The calculation is based on solvability analysis with unconventional features, namely, there are three relevant zero modes of the adjoint operator, one of them diverging; furthermore, the inner-outer matching ahead of the front must be performed on a line rather than on an extended region; and the whole calculation can be performed analytically. The analysis reveals a relation between the fields ahead and behind a slowly evolving curved front, the curvature and the generated conductivity. This relation forces us to give up the ideal conductivity approximation, and we suggest to replace it by a charge neutrality approximation. This implies that the electric potential in the streamer interior is no longer constant but solves a Laplace equation; this leads to a Muskat-type problem. PMID:19113205

Brau, Fabian; Davidovitch, Benny; Ebert, Ute

2008-11-01

104

The Use of the Recession Index as an Indicator for Streamflow Recovery After a Multi-Year Drought  

Microsoft Academic Search

A procedure is proposed that enables the estimation of natural baseflow in a gauged watershed through analyses of recession curves and stream hydrographs. The analysis results in a surrogate for the recovery level of a watershed after a prolonged drought and allows the medium term prediction of runoff behaviour for water resources management.The method has been applied for the Upper

Stefan W. Kienzle

2006-01-01

105

Trends in population mental health before and after the 2008 recession: a repeat cross-sectional analysis of the 1991-2010 Health Surveys of England  

PubMed Central

Objective To assess short-term differences in population mental health before and after the 2008 recession and explore how and why these changes differ by gender, age and socio-economic position. Design Repeat cross-sectional analysis of survey data. Setting England. Participants Representative samples of the working age (25–64?years) general population participating in the Health Survey for England between 1991 and 2010 inclusive. Main outcome measures Prevalence of poor mental health (caseness) as measured by the general health questionnaire-12 (GHQ). Results Age–sex standardised prevalence of GHQ caseness increased from 13.7% (95% CI 12.9% to 14.5%) in 2008 to 16.4% (95% CI 14.9% to 17.9%) in 2009 and 15.5% (95% CI 14.4% to 16.7%) in 2010. Women had a consistently greater prevalence since 1991 until the current recession. However, compared to 2008, men experienced an increase in age-adjusted caseness of 5.1% (95% CI 2.6% to 7.6%, p<0.001) in 2009 and 3% (95% CI 1.2% to 4.9%, p=0.001) in 2010, while no statistically significant changes were seen in women. Adjustment for differences in employment status and education level did not account for the observed increase in men nor did they explain the differential gender patterning. Over the last decade, socio-economic inequalities showed a tendency to increase but no clear evidence for an increase in inequalities associated with the recession was found. Similarly, no evidence was found for a differential effect between age groups. Conclusions Population mental health in men has deteriorated within 2?years of the onset of the current recession. These changes, and their patterning by gender, could not be accounted for by differences in employment status. Further work is needed to monitor recessionary impacts on health inequalities in response to ongoing labour market and social policy changes.

Katikireddi, Srinivasa Vittal; Niedzwiedz, Claire L; Popham, Frank

2012-01-01

106

Seismic Analysis/Design of Curved Steel Box Girder Bridges.  

National Technical Information Service (NTIS)

Results are presented of a study of the seismic response of curved steel box girder bridges. One, two, three, four, and five-span bridges are examined and a model is developed in which special elements are introduced to account for the curved geometry and...

C. P. Heins M. N. Abdel-Salam

1983-01-01

107

A method for analysis of DMFC performance curves  

Microsoft Academic Search

Our recent analytical model of direct methanol fuel cell is used to fit experimental performance curves. Based on evolutionary genetic algorithm, a new fitting procedure is developed. The idea is to fit simultaneously a set of performance curves, which have several common fitting parameters. On the first stage of evolution all parameters are determined independently. Starting from certain step a

A. A. Kulikovsky

2003-01-01

108

FEM analysis for different configurations of non-recessed hole-entry hybrid journal bearings for non-Newtonian lubricants  

Microsoft Academic Search

Purpose – The present work aims to predict accurately the bearing design data for non-recessed hybrid journal bearings, considering the effect of non-Newtonian behavior of lubricant for different symmetric and non-symmetric bearing geometric configurations. Design\\/methodology\\/approach – The simultaneous solution of generalized Reynold's equation governing the laminar flow of incompressible lubricant and the equation of flow of lubricant through the capillary

R. K. Duvedi; Manpreet Singh; V. K. Jadon

2007-01-01

109

Three-Dimensional Postbuckling Analysis of Curved Beams  

NASA Technical Reports Server (NTRS)

Presented here is a method of solving highly flexible curved beam undergoing huge static or quasi-static deformations. A geometrically exact beam theory based on the use of Jaumann stresses and strains and exact coordinate transformation is presented in terms of 17 first-order ordinary differential equations, and a multiple shooting method is used to solve the corresponding nonlinear two-point boundary value problems. The geometrically exact beam theory accounts far large rotations, large displacements, initial curvatures, extensionality, and transverse shear strains. Four examples are used to demonstrate this method, including a rotating clamped-free beam under the influence of gravity and centrifugal forces, an L-frame subjected to an in-plane tip load, a circular arch subjected to a concentrated load, and a clamped-hinged helical spring subjected to an axial displacement. Results show that the combination of the multiple shooting method and the geometrically exact beam theory works very well. Moreover, the obtained numerically exact solutions can be used to verify the accuracy of nonlinear finite element codes for nonlinear analysis of complex structures.

Pai, P. Frank; Lee, Seung-Yoon

2002-01-01

110

Empirical Bayes Analysis of Families of Survival Curves: Applications to the Analysis of Degree Attainment.  

ERIC Educational Resources Information Center

An approach to empirical Bayes analysis of aggregated survival data from different groups of subjects is presented based on a contingency table representation of data using transformations to permit the use of normal priors. Analysis of families of survival curves leads to improvements over classical estimates. (SLD)

Braun, Henry I.; Zwick, Rebecca

1993-01-01

111

Analysis of Lorenz and Concentration Curves: A Flexible Approach.  

National Technical Information Service (NTIS)

Lorenz and concentration curves are used to estimate expenditure elasticities and an expenditure inequality measure for nine major food groups. A generalized functional form which incorporates a flexible heteroskedastic error term is proposed and estimate...

J. Blaylock D. Smallwood

1980-01-01

112

FDTD analysis of dielectric resonators with curved surfaces  

Microsoft Academic Search

In this paper, the finite-difference time-domain (FDTD) method is applied to calculate the resonant frequency of dielectric resonators (DRs) with curved surface. The contour-path integral FDTD (CFDTD) is modified to deal with the curved surface of the dielectric body while the traditional rectangular cells are maintained. Results are compared with theoretical values and staircase approximation, and show that the present

Noriaki Kaneda; Bijan Houshmand; Tatsuo Itoh

1997-01-01

113

Numerical analysis as applied to x-ray scattering curves  

SciTech Connect

Various numerical methods involving polynomials were employed for both interpolation and linear least-square curve fitting of the atomic scattering factors of x-ray diffraction. This included use of Lagrangian and orthogonal Legendre polynomials, as well as cubic spline and Stineman interpolation. Interpolation is a method that uniquely matches known data points within small segments of an unknown curve to approximate points in between. Special emphasis was placed on establishing both the minimum grid spacing and polynomial degree that are needed to perform accurate interpolations. The grid spacing in a region of the x-argument near 1.0 A/sup -1/ that is commonly employed in standard tabulations of x-ray scattering factors was found to be too coarse for wholly accurate interpolation by polynomials of low degree. Least-squares curve fitting is a procedure that approximates the entire unknown curve with an analytical function that matches the known data points as closely as possible by minimizing the sum of their squared deviations from the fitted curve. Analytical representations of x-ray scattering curves are advantageous, since otherwise the complete scattering table must be sorted and the values of individual scattering factors derived by interpolation.

Jeffries, T.V.

1987-01-01

114

Empirical Analysis of Titanium Stress-Strain Curves.  

National Technical Information Service (NTIS)

Stress-strain curves of titanium of two purity levels were analyzed by a Crussard and Jaoul method that assumes the Ludwik equation sigma = sigma sub o + k((epsilon sub p) to the n power) in the form where sigma is the true stress and epsilon sub p the tr...

R. E. Reed-Hill S. N. Monteiro

1972-01-01

115

QV and PV curves as a planning tool of analysis  

Microsoft Academic Search

This paper deals with the problem of system voltage security. In this sense, load margin, QV curve and system loss reduction are focused. The idea is to use these tools in the planning scenario to determine the best locations for installation of distributed generation . For this purpose, from a base case, the system load margin and its losses are

Pablo Guimaraes; Ubaldo Fernandez; Tito Ocariz; Fritz W. Mohn; A. C. Zambroni de Souza

2011-01-01

116

Computational analysis of stress-based forming limit curves  

Microsoft Academic Search

This article, through computational analyses, examines the validity of using the stress-based and extended stress-based forming limit curves to predict the onset of necking during proportional loading of sheet metal. To this end, a model material consisting of a homogeneous zone and a zone that has voids (material inhomogeneity) is proposed and used to simulate necking under plane strain and

C. Hari Manoj Simha; Rassin Grantab; Michael J. Worswick

2007-01-01

117

Performance analysis of elliptic curve cryptography for SSL  

Microsoft Academic Search

Elliptic Curve Cryptography (ECC) is emerging as an attractive public-key cryptosystem for mobile\\/wireless environments. Compared to traditional cryptosystems like RSA, ECC offers equivalent security with smaller key sizes, which results in faster computations, lower power consumption, as well as memory and bandwidth savings. This is especially useful for mobile devices which are typically limited in terms of their CPU, power

Vipul Gupta; Sumit Gupta; Sheueling Chang; Douglas Stebila

2002-01-01

118

Critical load analysis of undamped nonconservative systems using bieigenvalue curves  

NASA Astrophysics Data System (ADS)

To study the instability of an undamped nonconservative system using the finite element method, an asymmetric load matrix has to be included to account for the path-dependent nature of the applied loads, in addition to the mass matrix, elastic stiffness matrix, and geometric stiffness matrix. Before the critical loads can be determined for a structure, one basic problem in research of this sort has been the construction of load-frequency relationships from the eigenvalue equations. Traditionally, this requires solution of complex eigenvalues from the characteristic equations at many load levels, which in practice is very time consuming. In this paper, an efficient approach based on a fourth-order hyperbolic curve will be proposed for predicting the critical loads. This curve, also known as the bieigenvalue curve, can be uniquely determined, once the first and second derivatives of the frequency with respect to the load parameter have been calculated for the structure under a preset load level, based on the eigensolutions for the first few or all modes of vibration. Effectiveness and accuracy of the procedure based on the bieigenvalue curve is demonstrated in the numerical study.

Kuo, Shyh-Rong; Yang, Yeong-Bin

1994-12-01

119

Critical load analysis of undamped nonconservative systems using bieigenvalue curves  

NASA Astrophysics Data System (ADS)

To study the instability of an undamped nonconservative system using the finite element method, an axisymmetric load matrix has to be included to account for the path-dependent nature of the applied loads, in addition to the mass matrix, elastic stiffness matrix, and geometric stiffness matrix. Before the critical loads can be determined for a structure, one basic problem in research of this sort has been the construction of load-frequency relationships from the eigenvalue equations. Traditionally, this requires solution of complex eigenvalues from the charateristic equations at many load levels, which in practice is very time consuming. In this paper, an efficient approach based on a fourth-order hyperbolic curve will be proposed for predicting the critical loads. This curve, also known as the bieigenvalue curve, can be uniquely determined, once the first and second derivatives of the frequency with respect to the load parameter have been calculated for the structure under a preset load level, based on the eigensolutions for the first few or all modes of vibration. Effectiveness and accuracy of the procedure based on the bieigenvalue curve is demonstrated in the numerical study.

Kuo, Shyh-Rong; Yang, Yeong-Bin

1994-12-01

120

A Biological Approach to Lactation Curve Analysis for Milk Yield  

Microsoft Academic Search

Lactation records of milk yield are commonly ana- lyzed with empirical mathematical models. A family of new models is described based on the known biology of the mammary gland during pregnancy and lacta- tion. The new models fit two logistic curves represent- ing secretory cell differentiation and cell death (apoptosis) throughout lactation. A further function describes secretion rate changes. Both

G. E. Pollott

2000-01-01

121

Nonlinear Thermoelastic Stress Analysis of Spherically Curved Solar Panels.  

National Technical Information Service (NTIS)

Spherically curved glass panels are used to concentrate solar energy onto a line focus in fixed mirror distributed focus type solar collectors. These solar panels consists of thin flat glass plates bent to form a spherical surface, glued onto a paper hone...

C. V. G. Vallabhan K. Vungutur R. P. Selvam

1984-01-01

122

SMC RR Lyrae stars light curve analysis (Deb+, 2010)  

NASA Astrophysics Data System (ADS)

The RRL stars analysed in the present work were selected from the high-quality photometric catalogue of RRL stars in the SMC from OGLE-II data base (Soszynski et al., 2002AcA....52..369S). The catalogue contains B, V and I light curves of 58 RRc stars and 478 RRab stars located in the 11 areas close to the bar of the SMC in the Johnson-Cousins photometric system. (4 data files).

Deb, S.; Singh, H. P.

2013-05-01

123

New method for calculating a mathematical expression for streamflow recession  

USGS Publications Warehouse

An empirical method has been devised to calculate the master recession curve, which is a mathematical expression for streamflow recession during times of negligible direct runoff. The method is based on the assumption that the storage-delay factor, which is the time per log cycle of streamflow recession, varies linearly with the logarithm of streamflow. The resulting master recession curve can be nonlinear. The method can be executed by a computer program that reads a data file of daily mean streamflow, then allows the user to select several near-linear segments of streamflow recession. The storage-delay factor for each segment is one of the coefficients of the equation that results from linear least-squares regression. Using results for each recession segment, a mathematical expression of the storage-delay factor as a function of the log of streamflow is determined by linear least-squares regression. The master recession curve, which is a second-order polynomial expression for time as a function of log of streamflow, is then derived using the coefficients of this function.

Rutledge, Albert, T.

1991-01-01

124

Evolutionary-algorithm-based analysis of gravitational microlensing light curves  

NASA Astrophysics Data System (ADS)

A new algorithm developed to perform autonomous fitting of gravitational microlensing light curves is presented. The new algorithm is conceptually simple, versatile and robust, and parallelizes trivially; it combines features of extant evolutionary algorithms with some novel ones, and fares well on the problem of fitting binary-lens microlensing light curves, as well as on a number of other difficult optimization problems. Success rates in excess of 90 per cent are achieved when fitting synthetic though noisy binary-lens light curves, allowing no more than 20 min per fit on a desktop computer; this success rate is shown to compare very favourably with that of both a conventional (iterated simplex) algorithm, and a more state-of-the-art, artificial neural network based approach. As such, this work provides proof of concept for the use of an evolutionary algorithm as the basis for real-time, autonomous modelling of microlensing events. Further work is required to investigate how the algorithm will fare when faced with more complex and realistic microlensing modelling problems; it is, however, argued here that the use of parallel computing platforms, such as inexpensive graphics processing units, should allow fitting times to be constrained to under an hour, even when dealing with complicated microlensing models. In any event, it is hoped that this work might stimulate some interest in evolutionary algorithms, and that the algorithm described here might prove useful for solving microlensing and/or more general model-fitting problems.

Rajpaul, V.

2012-12-01

125

The learning curve: Implications of a quantitative analysis  

PubMed Central

The negatively accelerated, gradually increasing learning curve is an artifact of group averaging in several commonly used basic learning paradigms (pigeon autoshaping, delay- and trace-eye-blink conditioning in the rabbit and rat, autoshaped hopper entry in the rat, plus maze performance in the rat, and water maze performance in the mouse). The learning curves for individual subjects show an abrupt, often step-like increase from the untrained level of responding to the level seen in the well trained subject. The rise is at least as abrupt as that commonly seen in psychometric functions in stimulus detection experiments. It may indicate that the appearance of conditioned behavior is mediated by an evidence-based decision process, as in stimulus detection experiments. If the appearance of conditioned behavior is taken instead to reflect the increase in an underlying associative strength, then a negligible portion of the function relating associative strength to amount of experience is behaviorally visible. Consequently, rate of learning cannot be estimated from the group-average curve; the best measure is latency to the onset of responding, determined for each subject individually.

Gallistel, Charles R.; Fairhurst, Stephen; Balsam, Peter

2004-01-01

126

Eigenvalue Analysis of Curved Waveguides Employing an Orthogonal Curvilinear Frequency-Domain Finite-Difference Method  

Microsoft Academic Search

An eigenvalue analysis numerical technique for curved closed waveguiding structures loaded with inhomogeneous and\\/or anisotropic materials is presented. For this purpose, a frequency-domain finite-difference method is developed for a general orthogonal curvilinear coordinate system. The main strength of the technique is the accurate modeling of curved transverse boundaries, as well as curved geometries along the propagation direction, under certain limitations

Christos S. Lavranos; George A. Kyriacou

2009-01-01

127

mtDNA analysis shows common ancestry in two kindreds with X-linked recessive hypoparathyroidism and reveals a heteroplasmic silent mutation.  

PubMed Central

Two kindreds residing in eastern Missouri and exhibiting X-linked recessive idiopathic hypoparathyroidism have been described. Genealogical records extending back five generations revealed no common ancestor. To investigate the possibility of relatedness, the DNA sequence of the mitochondrial D-loop was compared among several individuals in both kindreds. The mtDNA D-loop was amplified from the total DNA of individuals by use of nested PCR reactions, and the resulting 430-bp fragment was sequenced. The mtDNA sequence was identical among affected males and their maternal lineage for individuals in both kindreds. Conversely, the mtDNA sequence of the fathers of the affected males differed from that of the maternal lineage at three to six positions. These results demonstrate that the two kindreds exhibiting X-linked recessive hypoparathyroidism are indeed related and that an identical gene defect is responsible for the disease. A further feature of the inheritance pattern was examined when a unique point mutation was identified in the mtDNA of one branch of one of the kindreds. This mutation appears to be de novo and segregates in subsequent generations without obscuring relatedness. In addition, the results of our study of mtDNA analysis indicate that this approach may be of importance in investigating common ancestry in other X-linked disorders. Images Figure 3 Figure 4 Figure 5

Mumm, S; Whyte, M P; Thakker, R V; Buetow, K H; Schlessinger, D

1997-01-01

128

Evaluating the influence of watershed moisture storage on variations in base flow recession rates during prolonged rain-free periods in medium-sized catchments in New York and Illinois, USA  

NASA Astrophysics Data System (ADS)

When dQ/dt-Q plots of stream recession are constructed for individual recession events, the slopes of the dQ/dt-Q curves are near constant in log space, but the intercepts vary seasonally. Because the intercepts increase during the summer (indicating an increase in the recession rate at a given discharge), it has often been assumed that increased evapotranspiration (ET) leads to increased recession rates. To test this assumption, we related the intercepts of dQ/dt-Q curves from 72 recession events to the concurrent ET and watershed moisture storage as determined from the National Center for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) data set. The analysis suggests that at least for the nine watersheds from Illinois and New York we studied, shifts in recession rate during prolonged rain-free periods had little linkage to concurrent ET. Instead, we observe that the shifting has a moderately strong linkage to watershed moisture storage during the recession event. While this seeming lack of dependence on ET during these prolonged rain-free periods is not necessarily reflective of more normal conditions, we suggest it provides some insight into underlying subsurface controls at the watershed scale. In particular, we hypothesize that the shift in intercept in dQ/dt-Q curves results from spatial heterogeneities in watershed surficial geology; under dryer conditions near-stream subsurface zones with high hydraulic conductivities contribute most streamflow but under wetter conditions subsurface zones in upland areas with lower hydraulic conductivities also contribute.

Shaw, Stephen B.; McHardy, Theodore M.; Riha, Susan J.

2013-09-01

129

Numerical analysis of heat transfer during jet impingement on curved surfaces  

Microsoft Academic Search

The flow structure and convective heat transfer behavior of a free liquid jet ejecting from a round nozzle impinging vertically on a hemispherical solid plate and a slot nozzle impinging vertically on a cylindrical curved plate have been studied using a numerical analysis approach. The simulation model incorporated the entire fluid region and the solid hemisphere or curved plate. Solution

Cesar F Hernandez-Ontiveros

2007-01-01

130

Simulation of Bileaf Curved Surface Mechanical Heart Valve: A Steady Flow Analysis  

Microsoft Academic Search

Approximately two-thirds of heart valves are bileaf plane mechanical heart valves, however the plane valveleaf is not the best shape for the hydrodynamic characteristics. The main purpose of this study is to compare the hydrodynamic characteristics of plane valve with curved valve under the steady flow analysis. In this work, two styles of curved valves were designed and nine different

J. Xu; Jie Yang; C. Tong; Ji Yang; N. Huang; Y. L. Liu

2010-01-01

131

Latent growth curve modeling as an integrative approach to the analysis of change  

Microsoft Academic Search

Latent Growth Curve Models (LGCM) are discussed as a general data-analytic approach to the analysis of change. Conventional, but popular, methods of analyzing change over time, such as the paired t-test, repeated measures ANOVA, or MANOVA, have a tradition, which is quite different from the more recently developed latent growth curve models. While the former originated from the idea of

MANUEL C. VOELKLE

2007-01-01

132

Model-based analysis of dispersion curves using chirplets.  

PubMed

Time-frequency representations, like the spectrogram or the scalogram, are widely used to characterize dispersive waves. The resulting energy distributions, however, suffer from the uncertainty principle, which complicates the allocation of energy to individual propagation modes (especially when the dispersion curves of these modes are close to each other in the time-frequency domain). This research applies the chirplet as a tool to analyze dispersive wave signals based on a dispersion model. The chirplet transform, a generalization of both the wavelet and the short-time Fourier transform, enables the extraction of components of a signal with a particular instantaneous frequency and group delay. An adaptive algorithm identifies frequency regions for which quantitative statements can be made about an individual mode's energy, and employs chirplets (locally adapted to a dispersion curve model) to extract the (proportional) energy distribution of that single mode from a multimode dispersive wave signal. The effectiveness of this algorithm is demonstrated on a multimode synthetic Lamb wave signal for which the ground-truth energy distribution is known for each mode. Finally, the robustness of this algorithm is demonstrated on real, experimentally measured Lamb wave signals by an adaption of a correlation technique developed in previous research. PMID:16642827

Kuttig, Helge; Niethammer, Marc; Hurlebaus, Stefan; Jacobs, Laurence J

2006-04-01

133

Combination of Linkage Mapping and Microarray-Expression Analysis Identifies NF-?B Signaling Defect as a Cause of Autosomal-Recessive Mental Retardation  

PubMed Central

Autosomal-recessive inheritance accounts for nearly 25% of nonsyndromic mental retardation (MR), but the extreme heterogeneity of such conditions markedly hampers gene identification. Combining autozygosity mapping and RNA expression profiling in a consanguineous Tunisian family of three MR children with mild microcephaly and white-matter abnormalities identified the TRAPPC9 gene, which encodes a NF-?B-inducing kinase (NIK) and I?B kinase complex ? (IKK-?) binding protein, as a likely candidate. Sequencing analysis revealed a nonsense variant (c.1708C>T [p.R570X]) within exon 9 of this gene that is responsible for an undetectable level of TRAPPC9 protein in patient skin fibroblasts. Moreover, TNF-? stimulation assays showed a defect in IkB? degradation, suggesting impaired NF-?B signaling in patient cells. This study provides evidence of an NF-?B signaling defect in isolated MR.

Philippe, Orianne; Rio, Marlene; Carioux, Astrid; Plaza, Jean-Marc; Guigue, Philippe; Molinari, Florence; Boddaert, Nathalie; Bole-Feysot, Christine; Nitschke, Patrick; Smahi, Asma; Munnich, Arnold; Colleaux, Laurence

2009-01-01

134

Application of Growth Curve Analysis to the Ammunition Stockpile Deterioration Model.  

National Technical Information Service (NTIS)

Ammunition deterioration during storage has considerable economic consequences. A reliable prediction model for the ammunition deterioration rate is necessary for long-term procurement and maintenance planning. A random effect growth curve analysis is emp...

S. Y. So

1992-01-01

135

Re-Analysis of the Solar Phase Curves of the Icy Galilean Satellites.  

National Technical Information Service (NTIS)

Re-analysis of the solar phase curves of the icy Galilean satellites demonstrates that the quantitative results are dependent on the single particle scattering function incorporated into the photometric model; however, the qualitative properties are indep...

D. Domingue A. Verbiscer

1997-01-01

136

Are we thinking straight about groundwater recession?  

NASA Astrophysics Data System (ADS)

By exploring what governs the form of groundwater head recession in idealised and real aquifers, it will be shown that the analysis of groundwater recessions is a powerful but underused way of gaining insight into the hydrologic functioning of an aquifer from local to regional scales. It is commonly assumed that groundwater head recession in aquifers will take exponential form. However, here it is demonstrated that ideal regional aquifers should, given enough time between recharge events, actually develop through three distinct phases of recession: (1) in early times the groundwater recession should take an almost straight line form with a rate approximately equal to the long term recharge rate divided by the specific yield. The length of this phase can be estimated from a new analytical expression, which depends on the aquifer diffusivity, length scale and the position of the monitoring point, (2) a transitional phase then leads to, (3) an exponential phase after some critical time which is described by an existing analytical expression which is independent of the position of the monitoring point. Further analysis reveals that major aquifers in a state of periodic quasi-steady state are expected to have rates of net groundwater drainage which deviate little from the average rate of groundwater recharge. To back up these theoretical considerations, a range of real groundwater hydrographs will be presented which demonstrate the characteristic behaviour and interactions of groundwater flow systems interacting at local to regional scales. Where groundwater declines are observed in nature to have a quasi-exponential form, this may be diagnostic of particular types of aquifer properties and/or boundary effects such as: storage changes due to pumping, proximity to drainage boundaries, variations in transmissivity with hydraulic head, and variations in specific yield with depth. Furthermore, 'non-equilibrium' flow at a range of spatial and temporal scales helps explain the recession behaviour of nested flow systems where local scale and regional scale recessions become superposed.

Cuthbert, M. O.

2013-12-01

137

A Brief Review: The Z-curve Theory and its Application in Genome Analysis.  

PubMed

In theoretical physics, there exist two basic mathematical approaches, algebraic and geometrical methods, which, in most cases, are complementary. In the area of genome sequence analysis, however, algebraic approaches have been widely used, while geometrical approaches have been less explored for a long time. The Z-curve theory is a geometrical approach to genome analysis. The Z-curve is a three-dimensional curve that represents a given DNA sequence in the sense that each can be uniquely reconstructed given the other. The Z-curve, therefore, contains all the information that the corresponding DNA sequence carries. The analysis of a DNA sequence can then be performed through studying the corresponding Z-curve. The Z-curve method has found applications in a wide range of areas in the past two decades, including the identifications of protein-coding genes, replication origins, horizontally-transferred genomic islands, promoters, translational start sides and isochores, as well as studies on phylogenetics, genome visualization and comparative genomics. Here, we review the progress of Z-curve studies from aspects of both theory and applications in genome analysis. PMID:24822026

Zhang, Ren; Zhang, Chun-Ting

2014-04-01

138

Determination of the optimum working range from a calibration curve for colorimetric analysis with an "autoanalyzer".  

PubMed

A study has been made of the types and distribution of errors in determining the optimum working range from a calibration curve for automated analysis. Three error equations are derived for the fitting of a linear, quadratic or cubic curve, involving a thorough statistical analysis of the data. The errors from a set of silica and alumina standards, requiring a quadratic and cubic fit respectively, compare favourably with replicate analyses of standard rocks done on a previous occasion. PMID:18961254

Whitehead, D

1973-02-01

139

Parent involvement and science achievement: A latent growth curve analysis  

NASA Astrophysics Data System (ADS)

This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study - Kindergarten Class of 1998--1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day kindergarten class in 1998--1999. The present study's sample (N = 8,070) was based on students that had a sampling weight available from the public-use data file. Students were assessed in science achievement at third, fifth, and eighth grades and parents of the students were surveyed at the same time points. Analyses using latent growth curve modeling with time invariant and varying covariates in an SEM framework revealed a positive relationship between science achievement and parent involvement at eighth grade. Furthermore, there were gender and racial/ethnic differences in parents' school involvement as a predictor of science achievement. Findings indicated that students with lower initial science achievement scores had a faster rate of growth across time. The achievement gap between low and high achievers in earth, space and life sciences lessened from elementary to middle school. Parents' involvement with school usually tapers off after elementary school, but due to parent school involvement being a significant predictor of eighth grade science achievement, later school involvement may need to be supported and better implemented in secondary schooling.

Johnson, Ursula Yvette

140

Genetic analysis of autosomal recessive osteopetrosis in Chuvashiya: the unique splice site mutation in TCIRG1 gene spread by the founder effect  

Microsoft Academic Search

The rare malignant disorder autosomal recessive osteopetrosis (OPTB) is one of the most prevalent autosomal recessive diseases in the Chuvash Republic of Russia. The purpose of this study was to determine the underlying molecular cause of osteopetrosis in Chuvashiya and to reveal the factors causing the unusual high frequency of the disease in this region. Having assumed a founder effect,

Elena A Bliznetz; Svetlana M Tverskaya; Rena A Zinchenko; Anna V Abrukova; Ekaterina N Savaskina; Maxim V Nikulin; Alexander G Kirillov; Evgeny K Ginter; Alexander V Polyakov

2009-01-01

141

Drainage-system development in consecutive melt seasons at a polythermal, Arctic glacier, evaluated by flow-recession analysis and linear-reservoir simulation  

NASA Astrophysics Data System (ADS)

The drainage systems of polythermal glaciers play an important role in high-latitude hydrology, and are determinants of ice flow rate. Flow-recession analysis and linear-reservoir simulation of runoff time series are here used to evaluate seasonal and inter-annual variability in the drainage system of the polythermal Finsterwalderbreen, Svalbard, in 1999 and 2000. Linear-flow recessions are pervasive, with mean coefficients of a fast reservoir varying from 16 (1999) to 41 h (2000), and mean coefficients of an intermittent, slow reservoir varying from 54 (1999) to 114 h (2000). Drainage-system efficiency is greater overall in the first of the two seasons, the simplest explanation of which is more rapid depletion of the snow cover. Reservoir coefficients generally decline during each season (at 0.22 h d-1 in 1999 and 0.52 h d-1 in 2000), denoting an increase in drainage efficiency. However, coefficients do not exhibit a consistent relationship with discharge. Finsterwalderbreen therefore appears to behave as an intermediate case between temperate glaciers and other polythermal glaciers with smaller proportions of temperate ice. Linear-reservoir runoff simulations exhibit limited sensitivity to a relatively wide range of reservoir coefficients, although the use of fixed coefficients in a spatially lumped model can generate significant subseasonal error. At Finsterwalderbreen, an ice-marginal channel with the characteristics of a fast reservoir, and a subglacial upwelling with the characteristics of a slow reservoir, both route meltwater to the terminus. This suggests that drainage-system components of significantly contrasting efficiencies can coexist spatially and temporally at polythermal glaciers.

Hodgkins, Richard; Cooper, Richard; Tranter, Martyn; Wadham, Jemma

2013-07-01

142

Receiver Operating Characteristic (ROC) Curve Analysis for Medical Diagnostic Test Evaluation  

PubMed Central

This review provides the basic principle and rational for ROC analysis of rating and continuous diagnostic test results versus a gold standard. Derived indexes of accuracy, in particular area under the curve (AUC) has a meaningful interpretation for disease classification from healthy subjects. The methods of estimate of AUC and its testing in single diagnostic test and also comparative studies, the advantage of ROC curve to determine the optimal cut off values and the issues of bias and confounding have been discussed.

Hajian-Tilaki, Karimollah

2013-01-01

143

Iceland Glacier Recession 1997 to 2000  

NSDL National Science Digital Library

This animation is a close up zoom into largest area of glacier recesion at the Breidamerkurjokull glacier in Iceland. The data from 1997 is taken from Landsat 5 and the 2000 data is from Landsat 7. The Breidamerkurjokull glacier in Iceland has been measured by Landsat to be receding since 1973. In 1997, Landsat 5 took several other images of the glacier. It was thought by some glacierologists that this particular glacier was receding quicker in the late 1990s than it did in the late 1980s or 1970s. After careful analysis Goddards Glacierologist, Dorothy Hall, concluded that the recession from 1997 to 2000 occurs at a similar rate to the recession between 1973 and 2000. It is extremely controversial whether or not this recession is caused by global warming.

Perkins, Lori; Hall, Dorothy

2001-04-09

144

An Analysis of 900 Rotation Curves of Southern Sky Spiral Galaxies: Do Rotation Curves Fall into Discrete Classes?  

Microsoft Academic Search

One of the largest rotation curve data bases of spiral galaxies currently available is that provided by Persic & Salucci (1995; hereafter, PS) which has been derived by them from unreduced rotation curve data of 965 southern sky spirals obtained by Mathewson, Ford & Buchhorn (1992; hereafter, MFB). Of the original sample of 965 galaxies, the observations on 900 were

D. F. Roscoe

1997-01-01

145

Analysis and Design of Stimulus Response Curves of E. coli  

PubMed Central

Metabolism and signalling are tightly coupled in bacteria. Combining several theoretical approaches, a core model is presented that describes transcriptional and allosteric control of glycolysis in Escherichia coli. Experimental data based on microarrays, signaling components and extracellular metabolites are used to estimate kinetic parameters. A newly designed strain was used that adjusts the incoming glucose flux into the system and allows a kinetic analysis. Based on the results, prediction for intracelluar metabolite concentrations over a broad range of the growth rate could be performed and compared with data from literature.

Kremling, Andreas; Goehler, Anna; Jahreis, Knut; Nees, Markus; Auerbach, Benedikt; Schmidt-Heck, Wolfgang; Kokpinar, Oznur; Geffers, Robert; Rinas, Ursula; Bettenbrock, Katja

2012-01-01

146

Analysis and Simulation of Long-Range Correlations in Curved Space  

NASA Astrophysics Data System (ADS)

Numerical simulation and analysis of long-range correlations in curved space are studied. The study is motivated by the problem of constructing accurate models of large-scale porous media which usually contain long-range correlations in their various properties (such as their permeability, porosity, and elastic moduli) within and between their strata that are typically curved layers. The problem is, however, relevant to many other important models and phenomena in which extended correlations in curved space play a prominent role. Examples include the nonlinear ?-model in a curved space, models for describing the long-range structural correlations of amorphous semiconductors that consist of polytopes (tilings of positively-curved three-dimensional space), long-range correlations in the extrapolar total zone, and models in which the Universe is created by bubble nucleations and contain long-range correlations in the fluctuations in the curved spacetime. The study is also relevant to the important industrial problem of designing highly curved objects, such as cars and ships, which use composite materials that contain extended correlations in their property values. We study such correlations along two- and three-dimensional curves, as well as curved surfaces. We show that such correlations are well-defined only on developable surfaces, i.e. those that can be flattened to form planar surfaces without any stretching or distortion, and preserve the distance between two points on such surfaces after the stretching. If a given curved surface is not developable, but can be approximated as piecewise developable, one may still define and analyze extended correlations on it. Representative examples are presented and analyzed.

Mehrabi, Ali Reza; Sahimi, Muhammad

147

A Fourier method for the analysis of exponential decay curves.  

PubMed Central

A method based on the Fourier convolution theorem is developed for the analysis of data composed of random noise, plus an unknown constant "base line," plus a sum of (or an integral over a continuous spectrum of) exponential decay functions. The Fourier method's usual serious practical limitation of needing high accuracy data over a very wide range is eliminated by the introduction of convergence parameters and a Gaussian taper window. A computer program is described for the analysis of discrete spectra, where the data involves only a sum of exponentials. The program is completely automatic in that the only necessary inputs are the raw data (not necessarily in equal intervals of time); no potentially biased initial guesses concerning either the number or the values of the components are needed. The outputs include the number of components, the amplitudes and time constants together with their estimated errors, and a spectral plot of the solution. The limiting resolving power of the method is studied by analyzing a wide range of simulated two-, three-, and four-component data. The results seem to indicate that the method is applicable over a considerably wider range of conditions than nonlinear least squares or the method of moments.

Provencher, S W

1976-01-01

148

Who Suffers during Recessions? NBER Working Paper No. 17951  

ERIC Educational Resources Information Center

In this paper we examine how business cycles affect labor market outcomes in the United States. We conduct a detailed analysis of how cycles affect outcomes differentially across persons of differing age, education, race, and gender, and we compare the cyclical sensitivity during the Great Recession to that in the early 1980s recession. We present…

Hoynes, Hilary W.; Miller, Douglas L.; Schaller, Jessamyn

2012-01-01

149

Genome-wide analysis of defense-responsive genes in bacterial blight resistance of rice mediated by the recessive R gene xa13  

Microsoft Academic Search

Defense responses triggered by dominant and recessive disease resistance ( R) genes are presumed to be regulated by different molecular mechanisms. In order to characterize the genes activated in defense responses against bacterial blight mediated by the recessive R gene xa13, two pathogen-induced subtraction cDNA libraries were constructed using the resistant rice line IRBB13—which carries xa13 —and its susceptible, near-isogenic,

Z. Chu; Y. Ouyang; J. Zhang; H. Yang; S. Wang

2004-01-01

150

An analysis of 900 rotation curves of southern sky spiral galaxies: Do rotation curves fall into discrete classes?  

Microsoft Academic Search

One of the largest rotation curve data bases of spiral galaxies currently available is that provided by Persic& Salucci (1995;\\u000a hereafter, PS) which has been derived by them from unreduced rotation curve data of 965 southern sky spirals obtained by Mathewson,\\u000a Ford& Buchhorn (1992; hereafter, MFB). Of the original sample of 965 galaxies, the observations on 900 were considered by

D. F. Roscoe

1997-01-01

151

AtomicJ: An open source software for analysis of force curves.  

PubMed

We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh. PMID:24985823

Hermanowicz, Pawe?; Sarna, Micha?; Burda, Kvetoslava; Gabry?, Halina

2014-06-01

152

AtomicJ: An open source software for analysis of force curves  

NASA Astrophysics Data System (ADS)

We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh.

Hermanowicz, Pawe?; Sarna, Micha?; Burda, Kvetoslava; Gabry?, Halina

2014-06-01

153

Fort Play Children Recreate Recess  

ERIC Educational Resources Information Center

Recess beckons well before it actually arrives. Its allure can be heard in children's lunchtime conversations as they discuss imaginary roles, plans, alliances and teams, with an obvious appetite for play and its unbounded possibility. For some children, recess provides the most important reasons to come to school. In team sports, games of chase…

Powell, Mark

2007-01-01

154

Gingival Recession: Review and Strategies in Treatment of Recession  

PubMed Central

One of the most common esthetic concerns associated with the periodontal tissues is gingival recession. Gingival recession is the exposure of root surfaces due to apical migration of the gingival tissue margins; gingival margin migrates apical to the cementoenamel junction. Although it rarely results in tooth loss, marginal tissue recession is associated with thermal and tactile sensitivity, esthetic complaints, and a tendency toward root caries. This paper reviews etiology, consequences, and the available surgical procedures for the coverage of exposed root surfaces, including three case reports.

Pradeep, Koppolu; Rajababu, Palaparthy; Satyanarayana, Durvasula; Sagar, Vidya

2012-01-01

155

Identification of Four Tuna Species by Means of Real-Time PCR and Melting Curve Analysis  

Microsoft Academic Search

Dalmasso, A., Fontanella, E., Piatti, P., Civera, T., Secchi, C. and Bottero, M.T., 2007. Identification of four tuna species\\u000a by means of Real-Time PCR and melting curve analysis. Veterinary Research Communications, 31(Suppl. 1), 355–357

A. Dalmasso; E. Fontanella; P. Piatti; T. Civera; C. Secchi; M. T. Bottero

2007-01-01

156

Computational Tools for Probing Interactions in Multiple Linear Regression, Multilevel Modeling, and Latent Curve Analysis  

Microsoft Academic Search

Simple slopes, regions of significance, and confidence bands are commonly used to evaluate interactions in multiple linear regression (MLR) models, and the use of these techniques has recently been extended to multilevel or hierarchical linear modeling (HLM) and latent curve analysis (LCA). However, conducting these tests and plotting the conditional relations is often a tedious and error-prone task. This article

Kristopher J. Preacher; Patrick J. Curran; Daniel J. Bauer

2006-01-01

157

Analysis of the Effects of Fixed Costs on Learning Curve Calculations.  

National Technical Information Service (NTIS)

The goal of this research was to analyze the effect of fixed costs on learning curve calculations. The research focused on two general research areas. The first area addressed the identification of current cost analysis practice for handling fixed costs i...

C. B. Shea K. P. Thomson

1994-01-01

158

Identification of Chlamydial species in crocodiles and chickens by PCR-HRM curve analysis.  

PubMed

Recently, a PCR protocol (16SG), targeting 16S rRNA gene coupled with high resolution melt (HRM) curve analysis was developed in our laboratory and shown to reliably detect and identify the seven different Chlamydiaceae spp. In this study, the potential of this method was assessed for detection and differentiation of Chlamydiosis in clinical specimens. Of the total number of 733 specimens from a range of animal species, 219 (30%) were found positive by 16SG PCR. When a sufficient amount of DNA was available (64 submissions), amplicons generated by the 16SG PCR were subjected to HRM curve analysis and results were compared to that of nucleotide sequencing. In all instances, the infecting Chlamydiaceae spp. was genotyped according to the identity of its nucleotide sequence to a reference species. Analysis of the HRM curves and nucleotide sequences from 16SG PCR amplicons also revealed the occurrence of a Chlamydophila-like, a Parachlamydia-like and a variant of Chlamydophila psittaci in chickens. These results reveal the potential of 16SG PCR-HRM curve analysis for rapid and simultaneous detection and identification of Chlamydiaceae spp. in animals and demonstrate the capacity of this system for rapid identification of new Chlamydiaceae spp. in animals during routine diagnostic testings. PMID:20570064

Robertson, T; Bibby, S; O'Rourke, D; Belfiore, T; Agnew-Crumpton, R; Noormohammadi, A H

2010-10-26

159

A new explanation for recessive myotonia congenita  

PubMed Central

Objective: To assess whether exon deletions or duplications in CLCN1 are associated with recessive myotonia congenita (MC). Methods: We performed detailed clinical and electrophysiologic characterization in 60 patients with phenotypes consistent with MC. DNA sequencing of CLCN1 followed by multiplex ligation-dependent probe amplification to screen for exon copy number variation was undertaken in all patients. Results: Exon deletions or duplications in CLCN1 were identified in 6% of patients with MC. Half had heterozygous exonic rearrangements. The other 2 patients (50%), with severe disabling infantile onset myotonia, were identified with both a homozygous mutation, Pro744Thr, which functional electrophysiology studies suggested was nonpathogenic, and a triplication/homozygous duplication involving exons 8–14, suggesting an explanation for the severe phenotype. Conclusions: These data indicate that copy number variation in CLCN1 may be an important cause of recessive MC. Our observations suggest that it is important to check for exon deletions and duplications as part of the genetic analysis of patients with recessive MC, especially in patients in whom sequencing identifies no mutations or only a single recessive mutation. These results also indicate that additional, as yet unidentified, genetic mechanisms account for cases not currently explained by either CLCN1 point mutations or exonic deletions or duplications.

Raja Rayan, D.L.; Haworth, A.; Sud, R.; Matthews, E.; Fialho, D.; Burge, J.; Portaro, S.; Schorge, S.; Tuin, K.; Lunt, P.; McEntagart, M.; Toscano, A.; Davis, M.B.

2012-01-01

160

Protections against Differential Analysis for Elliptic Curve Cryptography — An Algebraic Approach —  

Microsoft Academic Search

\\u000a We propose several new methods to protect the scalar multiplication on an elliptic curve against Differential Analysis. The\\u000a basic idea consists in transforming the curve through various random morphisms to provide a non-deterministic execution of\\u000a the algorithm.\\u000a \\u000a \\u000a The solutions we suggest complement and improve the state-of-the-art, but also provide a practical toolbox of efficient countermeasures.\\u000a These should suit most of

Marc Joye; Christophe Tymen

161

Computer programs for describing the recession of ground-water discharge and for estimating mean ground-water recharge and discharge from streamflow records-update  

USGS Publications Warehouse

The computer programs included in this report can be used to develop a mathematical expression for recession of ground-water discharge and estimate mean ground-water recharge and discharge. The programs are intended for analysis of the daily streamflow record of a basin where one can reasonably assume that all, or nearly all, ground water discharges to the stream except for that which is lost to riparian evapotranspiration, and where regulation and diversion of flow can be considered to be negligible. The program RECESS determines the master reces-sion curve of streamflow recession during times when all flow can be considered to be ground-water discharge and when the profile of the ground-water-head distribution is nearly stable. The method uses a repetitive interactive procedure for selecting several periods of continuous recession, and it allows for nonlinearity in the relation between time and the logarithm of flow. The program RORA uses the recession-curve displacement method to estimate the recharge for each peak in the streamflow record. The method is based on the change in the total potential ground-water discharge that is caused by an event. Program RORA is applied to a long period of record to obtain an estimate of the mean rate of ground-water recharge. The program PART uses streamflow partitioning to estimate a daily record of base flow under the streamflow record. The method designates base flow to be equal to streamflow on days that fit a requirement of antecedent recession, linearly interpolates base flow for other days, and is applied to a long period of record to obtain an estimate of the mean rate of ground-water discharge. The results of programs RORA and PART correlate well with each other and compare reasonably with results of the corresponding manual method.

Rutledge, A. T.

1998-01-01

162

High-Resolution Melting Curve Analysis for Rapid Detection of Rifampin Resistance in Mycobacterium tuberculosis: a Meta-Analysis  

PubMed Central

A rapid, simple, accurate, and affordable method for the detection of drug-resistant tuberculosis is very critical for the selection of antimicrobial therapy and management of patient treatment. High-resolution melting curve analysis has been used for the detection of rifampin resistance in Mycobacterium tuberculosis and has shown promise. We did a systematic review and meta-analysis of published studies to evaluate the accuracy of high-resolution melting curve analysis for the detection of rifampin resistance in clinical M. tuberculosis isolates. We searched the PubMed, BIOSIS Previews, and Web of Science databases to identify studies and included them according to predetermined criteria. We used the DerSimonian-Laird random-effects model to calculate pooled measures and applied Moses' constant for linear models to fit the summary receiver operating characteristic curve. According to the selection criteria, most of the identified studies were excluded, and only seven studies were included in the final analysis. The overall sensitivity of the high-resolution melting curve analysis was 94% (95% confidence interval [CI], 92% to 96%), and the overall specificity was very high at 99% (95% CI, 98% to 100%). The values for the pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 63.39 (95% CI, 30.21 to 133.00), 0.06 (95% CI, 0.04 to 0.09), and 892.70 (95% CI, 385.50 to 2,067.24), respectively. There was no significant heterogeneity across all included studies for the measurements we evaluated. The summary receiver operating characteristic curve for the same data shows an area of 0.99 and a Q* value of 0.97. High-resolution melting curve analysis has high sensitivity and specificity for the detection of rifampin resistance in clinical M. tuberculosis isolates. This method might be a good alternative to conventional drug susceptibility tests in clinical practice.

Yin, Xiaomao; Zheng, Lei; Liu, Qinlan; Lin, Li; Hu, Xiumei; Hu, Yanwei

2013-01-01

163

Evidence of genetic heterogeneity in the autosomal recessive adult forms of limb-girdle muscular dystrophy following linkage analysis with 15q probes in Brazilian families  

Microsoft Academic Search

The autosomal recessive limb-girdle muscular dystrophies (LGMD) represent a heterogeneous group of diseases which may be characterised by one or more autosomal loci. A gene at 15q has recently been found to be responsible for a mild form of LGMD in a group of families from the isolated island of Réunion, now classified as LGMD2. Based on results of eight

M R Passos-Bueno; I Richard; M Vainzof; F Fougerousse; J Weissenbach; O Broux; D Cohen; J Akiyama; S K Marie; A A Carvalho

1993-01-01

164

What's Getting in the Way of Play? An Analysis of the Contextual Factors that Hinder Recess in Elementary Schools  

ERIC Educational Resources Information Center

This article describes the first two years of an ongoing, collaborative action research project focused on the troubled recess environment in 4 elementary schools in southern Ontario. The project involves an iterative, dynamic process of inquiry, planning, action, and reflection among students, teachers, university researchers, university student…

McNamara, Lauren

2013-01-01

165

Eprobe Mediated Real-Time PCR Monitoring and Melting Curve Analysis  

PubMed Central

Real-time monitoring of PCR is one of the most important methods for DNA and RNA detection widely used in research and medical diagnostics. Here we describe a new approach for combined real-time PCR monitoring and melting curve analysis using a 3? end-blocked Exciton-Controlled Hybridization-sensitive fluorescent Oligonucleotide (ECHO) called Eprobe. Eprobes contain two dye moieties attached to the same nucleotide and their fluorescent signal is strongly suppressed as single-stranded oligonucleotides by an excitonic interaction between the dyes. Upon hybridization to a complementary DNA strand, the dyes are separated and intercalate into the double-strand leading to strong fluorescence signals. Intercalation of dyes can further stabilize the DNA/DNA hybrid and increase the melting temperature compared to standard DNA oligonucleotides. Eprobes allow for specific real-time monitoring of amplification reactions by hybridizing to the amplicon in a sequence-dependent manner. Similarly, Eprobes allow for analysis of reaction products by melting curve analysis. The function of different Eprobes was studied using the L858R mutation in the human epidermal growth factor receptor (EGFR) gene, and multiplex detection was demonstrated for the human EGFR and KRAS genes using Eprobes with two different dyes. Combining amplification and melting curve analysis in a single-tube reaction provides powerful means for new mutation detection assays. Functioning as “sequence-specific dyes”, Eprobes hold great promises for future applications not only in PCR but also as hybridization probes in other applications.

Kanamori, Hajime; Tanaka, Yuki; Kimura, Yasumasa; Nakasone, Ayako; Soma, Takahiro; Hayashizaki, Yoshihide; Usui, Kengo; Harbers, Matthias

2013-01-01

166

Nonlinear time series analysis of the light curves from the black hole system GRS1915+105  

Microsoft Academic Search

GRS 1915+105 is a prominent black hole system exhibiting variability over a wide range of time scales and its observed light curves have been classified into 12 temporal states. Here we undertake a complete analysis of these light curves from all the states using various quantifiers from nonlinear time series analysis, such as the correlation dimension (D2), the correlation entropy

K. P. Harikrishnan; Ranjeev Misra; G. Ambika

2011-01-01

167

Analysis of water intake and dry matter intake using different lactation curve models.  

PubMed

The objective was to evaluate 6 different lactation curve models for daily water and dry matter intake. Data originated from the Futterkamp dairy research farm of the Chamber of Agriculture of Schleswig-Holstein in Germany. A data set of about 23,000 observations from 193 Holstein cows was used. Average daily water and dry matter intake were 82.3 and 19.8 kg, respectively. The basic linear mixed model included the fixed effects of parity and test-day within feeding group. Additionally, 6 different functions were tested for the fixed effect of lactation curve and the individual (random) effect of cow-lactation curve. Furthermore, the autocorrelation between repeated measures was modeled with the spatial (power) covariance structure. Model fit was evaluated by the likelihood ratio test, Akaike's and Bayesian information criteria, and the analysis of mean residual at different days in milk. The Ali and Schaeffer function was best suited for modeling the fixed lactation curve for both traits. A Legendre polynomial of order 4 delivered the best model fit for the random effect of cow-lactation. Applying the error covariance structure led to a significantly better model fit and indicated that repeated measures were autocorrelated. Generally, the best information criteria values were yielded by the most complex model using the Ali and Schaeffer function and Legendre polynomial of order 4 to model the average lactation and cow-specific lactation curves, respectively, with inclusion of the spatial (power) error covariance structure. This model is recommended for the analysis of water and dry matter intake including missing observations to obtain estimation of correct statistical inference and valid variance components. PMID:19620691

Kramer, E; Stamer, E; Spilke, J; Thaller, G; Krieter, J

2009-08-01

168

Bio-sensing using recessed gold-filled capillary amperometric electrodes.  

PubMed

A novel recessed electrode is reported for amperometric detection of hydrogen peroxide and via glucose oxidase for the detection of glucose. The electrode utilised electrodeposited platinum over a gold wire surface, which proved to be an effective peroxide-detecting surface. Compared with a traditional exposed electrode surface, the recessed tip facilitated an extended linear range for glucose from 4 to over 14 mM. Bio-fouling, as assessed by exposure to bovine serum albumin, was also significantly reduced. Though response time at the recess was increased, it was within an acceptable range for physiological monitoring. Moreover, the recess enabled precise measurement of the hydrogen peroxide diffusion coefficient; this was based on a bipartite expression for the transient amperometric current at the recessed structure following a step change in ambient hydrogen peroxide concentration. An important aspect of the diffusion measurement was the curve fitting routine used to map on to the theoretical response curve. PMID:20661730

Kacanovska, A; Rong, Z; Schmidt, M; Russell, P St J; Vadgama, P

2010-10-01

169

Consistent higher-order analysis on shock response of cross-ply curved panels  

Microsoft Academic Search

A consistent higher-order analysis is presented for the shock response of doubly-curved cross-ply laminated thick panels simply supported on four edges. Emphasis is laid on consistency with the three-dimensional boundary conditions and interlaminar stress continuity, respectively. In each layer, a three-dimensional dynamic displacement field is assumed in terms of in-plane double Fourier series and cubic polynomials in the thickness direction.

C. C. Chao; T. P. Tung

1995-01-01

170

Thermo-XRD-analysis of montmorillonite treated with protonated Congo-red. Curve fitting  

Microsoft Academic Search

The adsorption of protonated Congo red (CR) by montmorillonite was investigated by thermo-XRD-analysis. Montmorillonite was loaded at pH 1 with increasing amounts of CR up to 75 mmol per 100 g clay. Diffractograms of samples treated at 420 °C showed broad peaks and were curve-fitted to determine the different basal spacings, which composed the XRD peaks. The broad peak of

Z. Yermiyahu; I. Lapides; S. Yariv

2005-01-01

171

A finite thin circular beam element for out-of-plane vibration analysis of curved beams  

Microsoft Academic Search

A finite thin circular beam element for the out-of-plane vibration analysis of curved beams is presented in this paper. Its\\u000a stiffness matrix and mass matrix are derived, respectively, from the strain energy and the kinetic energy by using the natural\\u000a shape functions derived from an integration of the differential equations in static equilibrium. The matrices are formulated\\u000a with respect to

Bo Yeon Kim; Chang-Boo Kim; Seung Gwan Song; Hyeon Gyu Beom; Chongdu Cho

2009-01-01

172

Finite difference stress analysis of anisotropic three-dimensional curved bodies with free boundaries  

Microsoft Academic Search

This paper investigates normal and shear stress distributions of anisotropic three-dimensional (3D) curved bodies using the\\u000a Refined Finite Difference method (FDM). In the numerical analysis of various mechanical problems involving complex partial\\u000a differential equations, the FDM has an advantage over the Finite Element Method in its ability to avoid mesh generation and\\u000a numerical integration. One of the important points in

Han Sol Paik; Sang Youl Lee; Suk Yoon Chang

2004-01-01

173

A new 3-dimensional receiver operating characteristic curve for detection performance analysis  

NASA Astrophysics Data System (ADS)

Target detection for remotely sensed imagery has been invasively researched for decades. Many detection algorithms are designed and claimed to be outperform others. In order to make an objective comparison, two issues need to be solved. The first one is to have standardized data sets with accurate ground truth, and the second one is to use objective performance analysis techniques. The Receiver Operating Characteristic (ROC) curve is one of the most recognized tools for detection performance analysis. It is based on binary hypothesis test approach. First it constructs two hypothesis distributions (null and alternative hypotheses) and then draws the ROC curve by calculating all the possible detection probability and false-alarm probability pairs. The larger area under the curve means the better detection performance of the algorithm. But one issue is rarely discussed. In ROC analysis, the alternative hypothesis means target exists, but we seldom discuss how much target is presented. In this paper, we include target abundance as the third dimension to form 3-Dimension ROC. The proposed technique can be used to analyze the performance of detection algorithms or the sensor instruments from the different point of views. It can perform the detection probability versus false-alarm probability test as the original ROC, and it can also be use to estimate the minimum target abundance the algorithm can detect.

Ren, Hsuan

2006-06-01

174

Evidence of genetic heterogeneity in the autosomal recessive adult forms of limb-girdle muscular dystrophy following linkage analysis with 15q probes in Brazilian families.  

PubMed

The autosomal recessive limb-girdle muscular dystrophies (LGMD) represent a heterogeneous group of diseases which may be characterised by one or more autosomal loci. A gene at 15q has recently been found to be responsible for a mild form of LGMD in a group of families from the isolated island of Réunion, now classified as LGMD2. Based on results of eight out of 11 large Brazilian LGMD families of different racial background (which were informative for the closest available probe to the LGMD2 gene), we confirmed linkage to the LGMD2 gene at 15q in two of these families and exclusion in six others. These data provide the first evidence of genetic heterogeneity for the autosomal recessive limb-girdle muscular dystrophies. PMID:8320700

Passos-Bueno, M R; Richard, I; Vainzof, M; Fougerousse, F; Weissenbach, J; Broux, O; Cohen, D; Akiyama, J; Marie, S K; Carvalho, A A

1993-05-01

175

Light curve solution and orbital period analysis of the contact binary V842 Herculis  

NASA Astrophysics Data System (ADS)

New photoelectric BV light curves were obtained for the neglected eclipsing binary V842 Her at the TÜB{?TAK National Observatory (TUG) and studied for the first time in detail to determine the orbital parameters and geometry of the system. The solutions obtained simultaneously for the new light curves and the radial velocity curves in the literature by using the Wilson-Devinney code reveal a typical W-type contact system. The light curves exhibit the so-called O'Connell effect which the level of the primary maxima being higher than that of the secondary ones in both pass-bands. The O'Connell effect in the light curves is explained in terms of a dark-spot located on the more massive component which makes the more massive larger component slightly cooler than the less massive smaller one. The O-C diagram constructed for all available times of minima of V842 Her exhibits a cyclic character superimposed on a quadratic variation. The quadratic character yields a orbital period increase with a rate of dP/dt=7.76×10-7 days yr-1 which can be attributed to the mass exchange/loss mechanism in the system. By assuming the presence of a gravitationally bound third body in the system, the analysis of the cyclic nature in the O-C diagram revealed a third body with mass of 0.4M\\sun orbiting around the eclipsing pair. The possibility of magnetic activity cycle effect as a cause for the observed cyclic variation in the O-C diagram was also discussed.

Selam, S. O.; Albayrak, B.; ?enavci, H. V.; Aksu, O.

2005-10-01

176

Recession Raises Poverty in West Virginia, Especially Among Children  

Microsoft Academic Search

Based on an analysis of previous recessions, one in four West Virginians is expected to fall into poverty during the current recession. The number of state children living in poverty is estimated to increase by more than a third to 130,585, or 34.4 percent. Each one-percent increase in the unemployment rate is projected to raise the number of West Virginia

Paul E. Miller

2009-01-01

177

Test of the accuracy of the computerized glow curve deconvolution algorithm for the analysis of thermoluminescence glow curves  

NASA Astrophysics Data System (ADS)

The accuracy of the thermoluminescence (TL) kinetics parameters obtained using the computerized glow curve deconvolution (CGCD) algorithm was tested. The differential equation governing the electron traffic in the one trap-one recombination (OTOR) level model was solved with almost no approximation using the Fehlberg-Runge-Kutta method. A set of simulated glow peaks was generated for a wide range of kinetics parameter values. These glow peaks were then fitted using the general-order kinetics equation. Comparisons between the kinetics parameter values of the simulated glow peaks and those obtained by the CGCD method were made. The results show that the accuracy of the different kinetics parameters obtained by the CGCD method is not the same and that it varies according to the value of the kinetics order (b). The overlapping of two glow peaks with very close maximum peak positions (Tms) results in a glow peak with unexpected values for the kinetics parameters. A set of different cases of overlapping glow peaks is also discussed.

Sadek, A. M.

2013-06-01

178

Analysis of pendulum-structure influencing on guidance systm for high-speed Maglev train running on curve  

Microsoft Academic Search

For Analysis of curve-running performances and influencing factors of maglev guidance system. This paper is based on double bogies system and investigates influences of pendulum-structure when system running on the curve. Firstly, system structure and simplification conditions are described. Secondly, dynamics model of carriage and kinematics model of bogies have been set up. Thirdly, formulas of movement and pulling forces

Chunxia Zhao; Longhua She; Wensen Chang

2011-01-01

179

An analysis of the light curves of short-period RS Canum Venaticorum stars - Starspots and fundamental properties  

Microsoft Academic Search

An analysis is performed of selected light curves for the short-period RS CVn group: UV Psc, XY UMa, RT And, SV Cam, BH Vir, ER Vul, WY Cnc, and Cg Cyg. The photometric fitting parameters are optimized for the 'distorted' light curves in order to derive the maculation wave for each system. A dark circular spot model is fitted to

E. Budding; M. Zeilik

1987-01-01

180

3D combinational curves for accuracy and performance analysis of positive biometrics identification  

NASA Astrophysics Data System (ADS)

The receiver operating characteristic (ROC) curve has been widely used as an evaluation criterion to measure the accuracy of biometrics system. Unfortunately, such an ROC curve provides no indication of the optimum threshold and cost function. In this paper, two kinds of 3D combinational curves are proposed: the 3D combinational accuracy curve and the 3D combinational performance curve. The 3D combinational accuracy curve gives a balanced view of the relationships among FAR (false alarm rate), FRR (false rejection rate), threshold t, and Cost. Six 2D curves can be derived from the 3D combinational accuracy curve: the conventional 2D ROC curve, 2D curve of (FRR, t), 2D curve of (FAR, t), 2D curve of (FRR, Cost), 2D curve of (FAR, Cost), and 2D curve of ( t, Cost). The 3D combinational performance curve can be derived from the 3D combinational accuracy curve which can give a balanced view among Security, Convenience, threshold t, and Cost. The advantages of using the proposed 3D combinational curves are demonstrated by iris recognition systems where the experimental results show that the proposed 3D combinational curves can provide more comprehensive information of the system accuracy and performance.

Du, Yingzi; Chang, Chein-I.

2008-06-01

181

Modeling and regression analysis of semiochemical dose-response curves of insect antennal reception and behavior.  

PubMed

Dose-response curves of the effects of semiochemicals on neurophysiology and behavior are reported in many articles in insect chemical ecology. Most curves are shown in figures representing points connected by straight lines, in which the x-axis has order of magnitude increases in dosage vs. responses on the y-axis. The lack of regression curves indicates that the nature of the dose-response relationship is not well understood. Thus, a computer model was developed to simulate a flux of various numbers of pheromone molecules (10(3) to 5 × 10(6)) passing by 10(4) receptors distributed among 10(6) positions along an insect antenna. Each receptor was depolarized by at least one strike by a molecule, and subsequent strikes had no additional effect. The simulations showed that with an increase in pheromone release rate, the antennal response would increase in a convex fashion and not in a logarithmic relation as suggested previously. Non-linear regression showed that a family of kinetic formation functions fit the simulated data nearly perfectly (R(2) >0.999). This is reasonable because olfactory receptors have proteins that bind to the pheromone molecule and are expected to exhibit enzyme kinetics. Over 90 dose-response relationships reported in the literature of electroantennographic and behavioral bioassays in the laboratory and field were analyzed by the logarithmic and kinetic formation functions. This analysis showed that in 95% of the cases, the kinetic functions explained the relationships better than the logarithmic (mean of about 20% better). The kinetic curves become sigmoid when graphed on a log scale on the x-axis. Dose-catch relationships in the field are similar to dose-EAR (effective attraction radius, in which a spherical radius indicates the trapping effect of a lure) and the circular EARc in two dimensions used in mass trapping models. The use of kinetic formation functions for dose-response curves of attractants, and kinetic decay curves for inhibitors, will allow more accurate predictions of insect catch in monitoring and control programs. PMID:23897111

Byers, John A

2013-08-01

182

In-plane vibration analysis of curved carbon nanotubes conveying fluid embedded in viscoelastic medium  

NASA Astrophysics Data System (ADS)

The effect of the induced vibrations in the carbon nanotubes (CNTs) arising from the internal fluid flow is a critical issue in the design of CNT-based fluidic devices. In this study, in-plane vibration analysis of curved CNTs conveying fluid embedded in viscoelastic medium is investigated. The CNT is modeled as a linear elastic cylindrical tube where the internal moving fluid is characterized by steady flow velocity and mass density of fluid. A modified-inextensible theory is used in formulation and the steady-state initial forces due to the centrifugal and pressure forces of the internal fluid are also taken into account. The finite element method is used to discretize the equation of motion and the frequencies are obtained by solving a quadratic eigenvalue problem. The effects of CNT opening angle, the elastic modulus and the damping factor of the viscoelastic surrounded medium and fluid velocity on the resonance frequencies are elucidated. It is shown that curved CNTs are unconditionally stable even for a system with sufficiently high flow velocity. The most results presented in this investigation have been absent from the literature for fluid-induced vibration of curved CNTs embedded in viscoelastic foundations.

Ghavanloo, Esmaeal; Rafiei, Masoud; Daneshmand, Farhang

2011-05-01

183

Receiver Operating Characteristic Curve Analysis of Beach Water Quality Indicator Variables  

PubMed Central

Receiver operating characteristic (ROC) curve analysis is a simple and effective means to compare the accuracies of indicator variables of bacterial beach water quality. The indicator variables examined in this study were previous day's Enterococcus density and antecedent rainfall at 24, 48, and 96 h. Daily Enterococcus densities and 15-min rainfall values were collected during a 5-year (1996 to 2000) study of four Boston Harbor beaches. The indicator variables were assessed for their ability to correctly classify water as suitable or unsuitable for swimming at a maximum threshold Enterococcus density of 104 CFU/100 ml. Sensitivity and specificity values were determined for each unique previous day's Enterococcus density and antecedent rainfall volume and used to construct ROC curves. The area under the ROC curve was used to compare the accuracies of the indicator variables. Twenty-four-hour antecedent rainfall classified elevated Enterococcus densities more accurately than previous day's Enterococcus density (P = 0.079). An empirically derived threshold for 48-h antecedent rainfall, corresponding to a sensitivity of 0.75, was determined from the 1996 to 2000 data and evaluated to ascertain if the threshold would produce a 0.75 sensitivity with independent water quality data collected in 2001 from the same beaches.

Morrison, Ann Michelle; Coughlin, Kelly; Shine, James P.; Coull, Brent A.; Rex, Andrea C.

2003-01-01

184

Determining the nucleation rate curve for lithium disilicate glass by differential thermal analysis  

NASA Technical Reports Server (NTRS)

The crystallization of lithium disilicate (Li2O+2SiO2) glass nucleated at various temperatures was studied by differential thermal analysis (DTA). A plot of the DTA crystallization peak height versus nucleation temperature closely resembles the classical nucleation rate curve for lithium disilicate glass whose maximum is at 453 C. The glass becomes saturated with internal nuclei when heated at 453 C for 10 h. The activation energy for crystallization and the heat of crystallization are independent of the concentration of nuclei and are 249 + or - 10 and 67 + or - 3 kJ/mol, respectively. The Avrami exponent, n, depends strongly on the concentration of nuclei in the glass.

Ray, Chandra S.; Day, Delbert E.

1990-01-01

185

High-resolution melt curve analysis: initial screening for mutations in BCR-ABL kinase domain.  

PubMed

Mutations in BCR-ABL kinase domain are associated with resistance to tyrosine kinase inhibitors in some patients with chronic myeloid leukemia. Therefore, mutation detection becomes essential in such patients. We aimed to apply high-resolution melt curve analysis (HRM) for a rapid screening prior to sequencing to select only mutation positive samples. One hundred and one samples with different mutations and mutational ratios were used for HRM testing. HRM results of 100/101 samples were concordant with sequencing data. We found HRM as a suitable and sensitive method for initial rapid screening of BCR-ABL KD mutations to sequence only positive samples. PMID:18308387

Poláková, Katerina Machová; Lopotová, Tereza; Klamová, Hana; Moravcová, Jana

2008-08-01

186

Is the exponent 3/2 justified in analysis of loading curve of pyramidal nanoindentations?  

PubMed

Kaupp and Naimi-Jamal (2010) claimed that the analysis of published loading curves reveals the exponent 3/2 to the depth for nanoindentations with sharp pyramidal or conical tips. To demonstrate this, they plotted the load vs. the penetration depth to the power 3/2. We show, through examples, the authors' assertion is not credible because the methodology used is misleading and it cannot be asserted that the exponent 3/2 has a universal validity that applies to all kinds of materials. PMID:22589011

Troyon, M; Abbès, F; Garcia Guzman, J A

2012-01-01

187

Mathematical properties of ?-curve in the frame work of the homotopy analysis method  

NASA Astrophysics Data System (ADS)

As it is described in the frame work of the homotopy analysis method (HAM), the convergence-control parameter is the main auxiliary tool which distinguishes this method form the other analytical methods. Moreover the convergence is usually obtained by the so-called ?-curve which possesses horizontal line property. The purpose of this paper is to answer this fundamental question: That is, why the horizontal line occurs in the plot of HAM series solution at some points corresponding to the convergence-control parameter. Also, the mathematical proof and the properties of this main issue are presented. Furthermore, some illustrative examples are presented and the salient features are discussed.

Abbasbandy, S.; Shivanian, E.; Vajravelu, K.

2011-11-01

188

Autosomal recessive polycystic kidney disease  

Microsoft Academic Search

The clinical features of 55 cases of autosomal recessive polycystic kidney disease (ARPCKD) have been reviewed. Each had evidence of ARPCKD. The outcomes of 87% were known; 24 had died. Twenty-four of 31 were seen between 1980 and 1986; 7 could not be traced. Forty-five percent presented under 1 month; 38% between 1 month and 1 year; and 9 cases

Bernard S. Kaplan; J. Fay; Vanita Shah; Michael J. Dillon; T. Martin Barratt

1989-01-01

189

Algebra, Home Mortgages, and Recessions  

ERIC Educational Resources Information Center

The current financial crisis and recession in the United States present an opportunity to discuss relevant applications of some topics in typical first-and second-year algebra and precalculus courses. Real-world applications of percent change, exponential functions, and sums of finite geometric sequences can help students understand the problems…

Mariner, Jean A. Miller; Miller, Richard A.

2009-01-01

190

Detection and differentiation of coccidian oocysts by real-time PCR and melting curve analysis.  

PubMed

Rapid and reliable detection and identification of coccidian oocysts are essential for animal health and foodborne disease outbreak investigations. Traditional microscopy and morphological techniques can identify large and unique oocysts, but they are often subjective and require parasitological expertise. The objective of this study was to develop a real-time quantitative PCR (qPCR) assay using melting curve analysis (MCA) to detect, differentiate, and identify DNA from coccidian species of animal health, zoonotic, and food safety concern. A universal coccidia primer cocktail was designed and employed to amplify DNA from Cryptosporidium parvum, Toxoplasma gondii, Cyclospora cayetanensis, and several species of Eimeria, Sarcocystis, and Isospora using qPCR with SYBR Green detection. MCA was performed following amplification, and melting temperatures (T(m)) were determined for each species based on multiple replicates. A standard curve was constructed from DNA of serial dilutions of T. gondii oocysts to estimate assay sensitivity. The qPCR assay consistently detected DNA from as few as 10 T. gondii oocysts. T(m) data analysis showed that C. cayetanensis, C. parvum, Cryptosporidium muris, T. gondii, Eimeria bovis, Eimeria acervulina, Isospora suis, and Sarcocystis cruzi could each be identified by unique melting curves and could be differentiated based on T(m). DNA of coccidian oocysts in fecal, food, or clinical diagnostic samples could be sensitively detected, reliably differentiated, and identified using qPCR with MCA. This assay may also be used to detect other life-cycle stages of coccidia in tissues, fluids, and other matrices. MCA studies on multiple isolates of each species will further validate the assay and support its application as a routine parasitology screening tool. PMID:21506835

Lalonde, Laura F; Gajadhar, Alvin A

2011-08-01

191

Microarray analysis shows that recessive resistance to Watermelon mosaic virus in melon is associated with the induction of defense response genes.  

PubMed

Resistance to Watermelon mosaic virus (WMV) in melon (Cucumis melo L.) accession TGR-1551 is characterized by a significant reduction in virus titer, and is inherited as a recessive, loss-of-susceptibility allele. We measured virus RNA accumulation in TGR-1551 plants and a susceptible control ('Tendral') by real-time quantitative polymerase chain reaction, and also profiled the expression of 17,443 unigenes represented on a melon microarray over a 15-day time course. The virus accumulated to higher levels in cotyledons of the resistant variety up to 9 days postinoculation (dpi) but, thereafter, levels increased in the susceptible variety while those in the resistant variety declined. Microarray experiments looking at the early response to infection (1 and 3 dpi), as well as responses after 7 and 15 dpi, revealed more profound transcriptomic changes in resistant plants than susceptible ones. The gene expression profiles revealed deep and extensive transcriptome remodeling in TGR-1551 plants, often involving genes with pathogen response functions. Overall, our data suggested that resistance to WMV in TGR-1551 melon plants is associated with a defense response, which contrasts with the recessive nature of the resistance trait. PMID:21970693

Gonzalez-Ibeas, Daniel; Cañizares, Joaquin; Aranda, Miguel A

2012-01-01

192

Origin of the Uinta recess, Sevier fold–thrust belt, Utah: influence of basin architecture on fold–thrust belt geometry  

Microsoft Academic Search

Structural trends in the Sevier fold–thrust belt define a pronounced concave-to-the-foreland map-view curve, the Uinta recess, in north-central Utah. This recess separates two convex-to-the-foreland curves, the Provo salient on the south and the Wyoming salient on the north. The two limbs of the recess comprise transverse zones (fault zones at a high-angle to the regional trend of the orogen) that

Timothy Paulsen; Stephen Marshak

1999-01-01

193

Nonlinear Analysis and Post-Test Correlation for a Curved PRSEUS Panel  

NASA Technical Reports Server (NTRS)

The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept, developed by The Boeing Company, has been extensively studied as part of the National Aeronautics and Space Administration's (NASA s) Environmentally Responsible Aviation (ERA) Program. The PRSEUS concept provides a light-weight alternative to aluminum or traditional composite design concepts and is applicable to traditional-shaped fuselage barrels and wings, as well as advanced configurations such as a hybrid wing body or truss braced wings. Therefore, NASA, the Federal Aviation Administration (FAA) and The Boeing Company partnered in an effort to assess the performance and damage arrestments capabilities of a PRSEUS concept panel using a full-scale curved panel in the FAA Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility. Testing was conducted in the FASTER facility by subjecting the panel to axial tension loads applied to the ends of the panel, internal pressure, and combined axial tension and internal pressure loadings. Additionally, reactive hoop loads were applied to the skin and frames of the panel along its edges. The panel successfully supported the required design loads in the pristine condition and with a severed stiffener. The panel also demonstrated that the PRSEUS concept could arrest the progression of damage including crack arrestment and crack turning. This paper presents the nonlinear post-test analysis and correlation with test results for the curved PRSEUS panel. It is shown that nonlinear analysis can accurately calculate the behavior of a PRSEUS panel under tension, pressure and combined loading conditions.

Gould, Kevin; Lovejoy, Andrew E.; Jegley, Dawn; Neal, Albert L.; Linton, Kim, A.; Bergan, Andrew C.; Bakuckas, John G., Jr.

2013-01-01

194

School-based extracurricular activity involvement and adolescent self-esteem: a growth-curve analysis.  

PubMed

Research on adolescent self-esteem indicates that adolescence is a time in which individuals experience important changes in their physical, cognitive, and social identities. Prior research suggests that there is a positive relationship between an adolescent's participation in structured extracurricular activities and well-being in a variety of domains, and some research indicates that these relationships may be dependent on the type of activities in which adolescents participate. Building on previous research, a growth-curve analysis was utilized to examine self-esteem trajectories from adolescence (age 14) to young adulthood (age 26). Using 3 waves of data from National Longitudinal Study of Adolescent Health (n = 5,399; 47.8% male), the analysis estimated a hierarchical growth-curve model emphasizing the effects of age and type of school-based extracurricular activity portfolio, including sports and school clubs, on self-esteem. The results indicated that age had a linear relationship with self-esteem over time. Changes in both the initial level of self-esteem and the growth of self-esteem over time were significantly influenced by the type of extracurricular activity portfolio. The findings were consistent across race and sex. The results support the utility of examining the longitudinal impact of portfolio type on well-being outcomes. PMID:20495855

Kort-Butler, Lisa A; Hagewen, Kellie J

2011-05-01

195

Genetics Home Reference: Autosomal recessive primary microcephaly  

MedlinePLUS

... literature OMIM Genetic disorder catalog Conditions > Autosomal recessive primary microcephaly (often shortened to MCPH ) On this page: ... Reviewed April 2011 What is MCPH? Autosomal recessive primary microcephaly (often shortened to MCPH, which stands for " ...

196

Permanent Lane Marking (Recessed Lane Edge Stripe).  

National Technical Information Service (NTIS)

The project goal was to evaluate different methods of cutting recessed skip stripe grooves, and to evaluate various pavement marking materials placed into the recesses. The project objective was to find a marking system for our mountain pass highways that...

K. W. Anderson

1981-01-01

197

Efficient broken line fitting procedure for analysis of force spectroscopy curves in chemical force microscopy  

NASA Astrophysics Data System (ADS)

The procedure for the analysis of force-distance curves in chemical force microscopy is presented. This procedure is based upon the Broken Line Fitting algorithm with an adaptation of knots positions. The strength of this method relies on the fact that it has O(N) complexity, which means that it is as efficient as standard peak detection techniques utilized by commercially available software. It is shown by means of computer simulations that the algorithm is able to detect snap-out points of a height comparable to a noise level, which is a significant improvement in comparison to previously reported techniques. The proposed method is also resistant to base line distortions. Using this procedure for an analysis of CH3-CH3 interactions enabled measurements of interactions between only two molecules, which has been confirmed experimentally. The obtained results strongly support validity of the Johnson-Kendall-Roberts model at the sub-nanometer scale.

Jó?wiak, G.; Masalska, A.; Gotszalk, T.; Schroeder, G.

2013-08-01

198

The composition-explicit distillation curve technique: Relating chemical analysis and physical properties of complex fluids.  

PubMed

The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. The analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. By far, the most widely used analytical technique we have used with the ADC is gas chromatography. This has enabled us to study finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this special issue of the Journal of Chromatography, specifically dedicated to extraction technologies, we describe the essential features of the advanced distillation curve metrology as an analytical strategy for complex fluids. PMID:20004402

Bruno, Thomas J; Ott, Lisa S; Lovestead, Tara M; Huber, Marcia L

2010-04-16

199

A Cognitive Approach to Elementary School Recess  

ERIC Educational Resources Information Center

This article talks about the Cognitive Recess Curriculum as a cognitive approach to elementary school recess. The concept of a cognitive recess curriculum is based on three research studies conducted by the author. The largest study involved over 1,564 educators (superintendents, principals, teachers K 12). It sought to determine the subjects'…

Jones, Rose B.

2005-01-01

200

Differences in Physical Activity during School Recess  

ERIC Educational Resources Information Center

Background: School recess provides a daily opportunity for physical activity engagement. The purpose of this study was to examine physical activity levels during recess by gender, ethnicity, and grade, and establish the contribution of recess to daily school physical activity levels. Methods: Two hundred and ten children (45% boys) from grades 3…

Ridgers, Nicola D.; Saint-Maurice, Pedro F.; Welk, Gregory J.; Siahpush, Mohammad; Huberty, Jennifer

2011-01-01

201

Analysis of X-ray rocking curves from strain relieved heterostructures  

NASA Astrophysics Data System (ADS)

X-ray diffraction is widely used to analyse the lattice mismatch and the elastic strain in heteroepitaxial semiconductor structures. In this paper we present two sets of practical relations for a routine analysis of Bragg peak spacing in X-ray rocking curves recorded from partly relaxed heteroepitaxial layers on (001) substrates. One procedure is applicable to the case of two asymmetric reflections taken from the same net planes in different diffraction geometries. The second, more general method enables rocking curve data from any net planes to be combined. As an example, a strain relieved SiGe alloy layer on Si(001) is analysed by this method. In both cases the mismatch and the residual layer strain are directly obtained. However, the results obtained from various reflection combinations show a differing strong dependence on any error in the peak separation measurement. This effect is discussed in detail by means of a Si 0.5Ge 0.5/Si model structure. The degree of sensitivity is assessed for a few reflections which are frequently used.

Herzog, H.-J.; Kasper, E.

1994-12-01

202

Analysis of variation in L-365,260 competition curves in radioligand binding assays.  

PubMed

1. For several years, we have used the cholecystokinin (CCK)B/gastrin receptor selective antagonist, L-365,260, as a reference compound in a variety of studies in CCKB/gastrin receptor radioligand binding assays. Here, we have analysed the competition curve data sets obtained between L-365,260 and [125I]-BH-CCK8S in guinea-pig gastric gland and mouse and rat cerebral cortex preparations. 2. Competition curves obtained for L-365,260 in the mouse cortex assay were not different from rectangular hyperbolae (slope = 1.01 +/- 0.02) implying the presence of a single population of binding sites (pKI = 8.41 +/- 0.01; data from 47 experiments, slope constrained to unity). However, in the rat cortex and guinea-pig gastric gland assays, the mean slope of the competition curves was significantly less than one and the mean apparent pKI significantly lower than that obtained in the mouse cortex (slope = 0.85 +/- 0.03, 0.90 +/- 0.03; apparent pKI = 7.98 +/- 0.05, 8.07 +/- 0.05; 48 and 45 experiments, in rat and guinea-pig, respectively). The distribution of the individual pKI and slope estimates of the competition curves in these two assays was consistent with expectations for the variable expression (in terms of absolute number and proportion) of two binding sites. The two sites were characterized by pKI values for L-365,260 of 8.50 +/- 0.04 and 8.48 +/- 0.04 for the high affinity site and 7.32 +/- 0.04 and 7.22 +/- 0.06 for the low affinity site in guinea-pig and rat, respectively. 3. The affinity estimates for L-365,260, although obtained on different tissues, are consistent with data obtained from the analysis of L-365,260 antagonism of pentagastrin-stimulated responses in mouse and rat stomach (acid secretion) and guinea-pig gastric muscle (isotonic contraction) assays. To this extent, these data suggest the existence of two CCKB/gastrin receptor subtypes. PMID:8842437

Harper, E A; Roberts, S P; Shankley, N P; Black, J W

1996-08-01

203

Analysis and computation of three-dimensional flow in strongly curved ducts  

NASA Technical Reports Server (NTRS)

Numerical solutions are presented for three-dimensional laminar and turbulent flow in curved ducts of rectangular cross section and significant curvature. The analysis is based on a primary-secondary velocity decomposition in a given coordinate system, and leads to approximate governing equations which correct an a priori inviscid solution for viscous effects, secondary flows, total pressure distortion, heat transfer, and internal flow blockage and losses. Solution of the correction equations is accomplished as an initial-value problem in space using an implicit forward-marching technique. The overall solution procedure requires significantly less computational effort than Navier-Stokes algorithms. The present solution procedure is effective even with the extreme local mesh resolution which is necessary to resolve near-wall sublayer regions in turbulent flow calculations. Computed solutions for both laminar and turbulent flow compare very favorably with available analytical and experimental results.

Kreskovsky, J. P.; Briley, W. R.; Mcdonald, H.

1981-01-01

204

Recurrence plot analysis of nonstationary data: the understanding of curved patterns.  

PubMed

Recurrence plots of the calls of the Nomascus concolor (Western black crested gibbon) and Hylobates lar (White-handed gibbon) show characteristic circular, curved, and hyperbolic patterns superimposed to the main temporal scale of the signal. It is shown that these patterns are related to particular nonstationarities in the signal. Some of them can be reproduced by artificial signals like frequency modulated sinusoids and sinusoids with time divergent frequency. These modulations are too faint to be resolved by conventional time-frequency analysis with similar precision. Therefore, recurrence plots act as a magnifying glass for the detection of multiple temporal scales in slightly modulated signals. The detected phenomena in these acoustic signals can be explained in the biomechanical context by taking in account the role of the muscles controlling the vocal folds. PMID:16196612

Facchini, A; Kantz, H; Tiezzi, E

2005-08-01

205

“Blind” mapping of genic DNA sequence polymorphisms in Lolium perenne L. by high resolution melting curve analysis  

Microsoft Academic Search

High resolution melting curve analysis (HRM) measures dissociation of double stranded DNA of a PCR product amplified in the\\u000a presence of a saturating fluorescence dye. Recently, HRM proved successful to genotype DNA sequence polymorphisms such as\\u000a SSRs and SNPs based on the shape of the melting curves. In this study, HRM was used for simultaneous screening and genotyping\\u000a of genic

Bruno Studer; Louise Bach Jensen; Alice Fiil; Torben Asp

2009-01-01

206

Two aspects of the Simplex Model: goodness of Fit to Linear Growth Curve Structures and the Analysis of Mean Trends  

Microsoft Academic Search

Considers the analysis of longitudinal data by means of the autogressive or simplex model. The finding by D. Rogosa and J. B. Willett that the quasi-Markov simplex model fits a linear growth curve covariance structure is investigated. Under various circumstances the quasi-Markov simplex model is rejected. The procedure is reversed by fitting the linear growth curve to quasi-Markov simplex covariance

P. C. M. Molenaar; Conor V. Dolan; F. Mandys

1994-01-01

207

Complicated recessive dystonia parkinsonism syndromes.  

PubMed

In addition to pure PD and pure dystonic syndromes, there are a group of disorders with overlapping features. The differential diagnosis of these dystonia parkinsonism syndromes can be complex. In view of the growing list of recognized disorders and recent advances in genetics, we review the autosomal recessive forms of dystonia parkinsonism, summarizing clinical presentations, results of investigations, and response to treatment of gene-proven cases. We concentrate on PANK2-, PLA2G6-, ATP13A2-, FBX07, TAF1-, and PRKRA-associated neurodegeneration. Parkin, PINK1, and DJ-1 are also briefly reviewed. PMID:19185014

Schneider, Susanne A; Bhatia, Kailash P; Hardy, John

2009-03-15

208

6.RP Games at Recess  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The students in Mr. Hillâs class played games at recess. $\\hskip30pt$6 boys played soccer $\\hskip30pt$4 girls played soccer $\\hskip30pt$2 boys jumped r...

209

What does the early recession of spring hydrographs tell about aquifer properties? (Invited)  

NASA Astrophysics Data System (ADS)

The recession of spring hydrographs is frequently analyzed using Maillet’s equation, which predicts an exponential decay of discharge with time. However, the early stage of the hydrograph recession often deviates from the exponential function. The analytical solution for the flow recession of a homogeneous aquifer reveals that the non-exponential early recession is dependent on the initial condition. A look at hydrograph data from several springs suggests that the observed deviations from the exponential function are often within a range that is consistent with the analytical solution if reasonable initial conditions are assumed. Thus, earlier interpretations that attribute the non-exponential early recession to additional flow components, such as the conduit system or the vadose zone, need to be revisited. The dependence of the early recession on the initial condition suggests that it provides information about the recharge event rather than about the aquifer properties. If the discharge is appropriately rescaled, however, the analytical recession curves initially exhibit a power law both after steady-state initial conditions and after finite recharge pulses. A closer look at early recession curves of the karst spring Gallusquelle (Germany) indeed reveals a characteristic power-law behavior. However, the power-law exponent is found to be different from that predicted by the analytical solution for a homogeneous aquifer. One approach that may account for this observation is the fractal model provided by Hergarten and Birk (Geophys. Res. Lett., 34, L11401, 2007). This model assumes that the spring catchment is composed of fissured porous blocks of strongly different sizes. If the block sizes can be described by a fractal distribution, the power-law exponent of the rescaled recession curve is found to be related to the fractal dimension of the size distribution. More generally, this suggests that the early recession is governed by the superposition of multiple storages with different recession properties. Thus, the early recession provides information about the scaling behavior of the aquifer storages rather than about the properties of the individual storages.

Birk, S.; Hergarten, S.

2009-12-01

210

reMelting curve analysis as a tool for enrichment monitoring in the SELEX process.  

PubMed

Current aptamer selection procedures enable limited control and transparency on how the DNA selection pool is evolving. Affinity tests and binding analyses are not always informative. Here we show that real-time PCR provides a valuable tool for the follow-up of aptamer selection. Limited time, work and amount of amplified ssDNA make this an interesting instrument to set-up a SELEX design and monitor the enrichment of oligonucleotides. reMelting Curve Analysis (rMCA) after reannealing under stringent conditions provides information about enrichment, compared to a random library. Monitoring the SELEX process and optimising conditions by means of the proposed methods can increase the selection efficiency in a controlled way. rMCA is applied in enrichment simulations and three different selection procedures. Our results imply that rMCA can be used for different SELEX designs and different targets. SELEX pool diversity analysis by rMCA has been proven to be a useful, reproducible tool to detect and evaluate enrichment of specific binding aptamers while the selection procedure is being performed. PMID:24325000

Vanbrabant, Jeroen; Leirs, Karen; Vanschoenbeek, Katrijn; Lammertyn, Jeroen; Michiels, Luc

2014-02-01

211

Ogive Curves  

NSDL National Science Digital Library

This page contains a discussion of ogive curves, logistic regression curves, and architecture. Nice photographs of architectural applications are included. The classic Birthday Problems is included as an example of an ogive curve.

2008-01-01

212

Experimental and simulation analysis of concave-down resistance curve during electromigration in solder joints  

NASA Astrophysics Data System (ADS)

Resistance curves play a crucial role in detecting damage of solder joints during electromigration. In general, resistance increases slowly in the beginning, and then rises abruptly in the very late stage; i.e., the resistance curve behaves concave-up. However, several recent studies have reported concave-down resistance curves in solder joints with no satisfactory explanation for the discrepancy. In this study, electromigration failure mode in Sn2.5Ag solder joints was experimentally investigated. The bump resistance curve exhibited concave-down behavior due to formation of intermetallic compounds (IMCs). In contrast, the curve was concave-up when void formation dominated the failure mechanism. Finite element simulation was carried out to simulate resistance curves due to formation of IMCs and voids, respectively. The simulation results indicate that the main reason causing the concave-down curve is rapid formation of resistive Cu6Sn5 IMCs in the current-crowding region, which are 9 times larger than Cu IMCs. Therefore, when Cu reacted with Sn to form Cu6Sn5 IMCs, resistance increased abruptly, resulting in the concave-down resistance curve.

Lin, C. K.; Chang, Yuan Wei; Chen, Chih

2014-02-01

213

Duration of Load Effect on Curved Glulam Beams. Part 2. Long Term Load Tests and Analysis.  

National Technical Information Service (NTIS)

This research related to the duration of load effect on curved glulam is part of an EC-AIR project carried out a VTT in co-operation with four other EU member countries. The project includes the long term loading of 32 curved beams, as well as equivalent ...

S. Gowda, M. Kortesmaa, A. Ranta-Maunus

1998-01-01

214

International Planetary Patrol observations of Saturn's rings. II. Four color phase curves and their analysis  

Microsoft Academic Search

New phase curves for Saturn's rings at an intermediate tilt angle B approx.17 ° are presented. Quantitative results for each of the A and B rings are reported in terms of the opposition effect, phase coefficient, and best logarithmic fit to the phase curve. In each of the four colors, there is no significant difference between the shape of the

L. W. Esposito; K. Lumme; W. D. Benton; L. J. Martin; H. M. Ferguson; D. T. Thompson; S. E. Jones

1979-01-01

215

Improved modeling of the nonlinear BH curve and its application in power cable analysis  

Microsoft Academic Search

An improved model of the nonlinear B-H curve of ferromagnetic material is introduced. The B-H curve is represented by a Fourier series, based on a set of measurement data. With the Fourier series expression, the magnetic energy density can be calculated and then used in an iterative procedure for determining the permeability everywhere within the ferromagnetic material. To validate the

Guanghao Liu; Xiao-Bang Xu

2002-01-01

216

Inverted papilloma in the sphenoethmoidal recess.  

PubMed

Inverted papilloma is a nasal benign tumor that usually arises from the lateral nasal wall, especially from the middle meatus. It has high local invasive likelihood, high recurrence rates and malignancy potential. Sphenoethmoidal recess involvement is rare and is usually due to sphenoid sinus primary disease. In the literature, no case of isolated sphenoethmoidal recess inverted papilloma has been reported yet. The present report describes an exceptional location of inverted papilloma, arising from the sphenoethmoid recess, without involving the sphenoid sinus. PMID:18392518

Kosugi, Eduardo Macoto; Santos, Rodrigo de Paula; Ganança, Fernando Freitas; Tangerina, Rodrigo de Paiva; Suguri, Vinícius Magalhães; Yamaoka, Wellington Yugo; Gregório, Luis Carlos

2008-01-01

217

On the use of the Boussinesq equation for interpreting recession hydrographs from sloping aquifers  

Microsoft Academic Search

(1) The method of recession analysis proposed by Brutsaert and Nieber (1977) remains one of the few analytical tools for estimating aquifer hydraulic parameters at the field scale and beyond. In the method, the recession hydrograph is examined asdQ\\/dt = f(Q), where Q is aquifer discharge and f is an arbitrary function. The observed function f is parameterized through analytical

David E. Rupp; John S. Selker

2006-01-01

218

Recession, Retrenchment, and Recovery: State Higher Education Funding & Student Financial Aid. Volume II: State Profiles  

ERIC Educational Resources Information Center

This report is a companion to "Recession, Retrenchment and Recovery: Higher Education Funding and Student Financial Aid" (ED502180). It provides profiles of individual states and their performance on a variety of measures used in the economic and fiscal analysis of the Recession, Retrenchment and Recovery project. The profiles describe the results…

Ambrose, Allison S.; Hines, Edward R.; Hodel, Ross A.; Kelly, Kathleen F.; Mushrush, Christopher E., Pruden, Sheila J.; Vogt, W. Paul

2006-01-01

219

The gene mutated in autosomal recessive polycystic kidney disease encodes a large, receptor-like protein  

Microsoft Academic Search

Autosomal recessive polycystic kidney disease (ARPKD) is characterized by dilation of collecting ducts and by biliary dysgenesis and is an important cause of renal- and liver-related morbidity and mortality. Genetic analysis of a rat with recessive polycystic kidney disease revealed an orthologous relationship between the rat locus and the ARPKD region in humans; a candidate gene was identified. A mutation

Christopher J. Ward; Marie C. Hogan; Sandro Rossetti; Denise Walker; Tam Sneddon; Xiaofang Wang; Vicky Kubly; Julie M. Cunningham; Robert Bacallao; Masahiko Ishibashi; Dawn S. Milliner; Vicente E. Torres; Peter C. Harris

2002-01-01

220

On the use of the Boussinesq equation for interpreting recession hydrographs from sloping aquifers  

Microsoft Academic Search

The method of recession analysis proposed by Brutsaert and Nieber (1977) remains one of the few analytical tools for estimating aquifer hydraulic parameters at the field scale and beyond. In the method, the recession hydrograph is examined as ?dQ\\/dt = f(Q), where Q is aquifer discharge and f is an arbitrary function. The observed function f is parameterized through analytical

David E. Rupp; John S. Selker

2006-01-01

221

Reliability analysis of laser ultrasonics for train axle diagnostics based on model assisted POD curves  

NASA Astrophysics Data System (ADS)

High speed train axles are integrated for a lifetime and it is time and resource consuming to conduct in service inspection with high accuracy. Laser ultrasonics is a proposed solution as a subset of non-contact measuring methods effective also for hard to reach areas and even recently proved to be effective using Laser Doppler Vibrometer (LDV) or air-coupled probes in reception. A reliability analysis of laser ultrasonics for this specific application is here performed. The research is mainly based on numerical study of the effect of high energy laser pulses on the surface of a steel axle and of the behavior of the ultrasonic waves in detecting possible defects. Probability of Detection (POD) concept is used as an estimated reliability of the inspection method. In particular Model Assisted Probability of Detection (MAPOD), a modified form of POD where models are used to infer results for making a decisive statistical approach of POD curve, is here adopted. This paper implements this approach by taking the inputs from limited experiments conducted on a high speed train axle using laser ultrasonics (source pulsed Nd:Yag, reception by high-frequency LDV) to calibrate a multiphysics FE model and by using the calibrated model to generate data samples statistically representative of damaged train axles. The simulated flaws are in accordance with the real defects present on the axle. A set of flaws of different depth has been modeled in order to assess the laser ultrasonics POD for this specific application.

Malik, M. S.; Cavuto, A.; Martarelli, M.; Pandarese, G.; Revel, G. M.

2014-05-01

222

Cognitive Vulnerabilities and Depression in Young Adults: An ROC Curves Analysis.  

PubMed

Objectives and Methods. The aim of the present study was to evaluate, by means of receiver operating characteristic (ROC) curves, whether cognitive vulnerabilities (CV), as measured by three well-known instruments (the Beck Hopelessness Scale, BHS; the Life Orientation Test-Revised, LOT-R; and the Attitudes Toward Self-Revised, ATS-R), independently discriminate between subjects with different severities of depression. Participants were 467 young adults (336 females and 131 males), recruited from the general population. The subjects were also administered the Beck Depression Inventory-II (BDI-II). Results. Four first-order (BHS Optimism/Low Standard; BHS Pessimism; Generalized Self-Criticism; and LOT Optimism) and two higher-order factors (Pessimism/Negative Attitudes Toward Self, Optimism) were extracted using Principal Axis Factoring analysis. Although all first-order and second-order factors were able to discriminate individuals with different depression severities, the Pessimism factor had the best performance in discriminating individuals with moderate to severe depression from those with lower depression severity. Conclusion. In the screening of young adults at risk of depression, clinicians have to pay particular attention to the expression of pessimism about the future. PMID:24058734

Balsamo, Michela; Imperatori, Claudio; Sergi, Maria Rita; Belvederi Murri, Martino; Continisio, Massimo; Tamburello, Antonino; Innamorati, Marco; Saggino, Aristide

2013-01-01

223

Analysis of stellar variability based on polynomial fittings of its light curve  

NASA Astrophysics Data System (ADS)

A method for analysis of stellar light curves (LCs), and in principle, time series, is presented here. It is based on polynomial fitting of the LC with increasing polynomial degree M. Two basic parameters from each polynomial fit of are regarded: residual mean square deviation (SD) of the data in respect to the polynomial fit, SM, and the half of the absolute average deviation of the polynomial (PD) in respect to the average of the data, PM. In each cases the maximal regarded polynomial degree L corresponds to the minimal SD, SL. (In practice the polynomial with degree L + 1 produces larger standard deviation because the number of data is not large and the calculation errors accumulate.) We found well pronounced anti-correlations between SM and PM when M changes from 1 to L. The respective slope PD/SD turns out to be a useful quantify parameter of the LC, characterizing the presence of significant coarse details and giving possibilities for classification of LCs.

Georgiev, Ts. B.

2013-09-01

224

Sintering Behavior of Nanocrystalline Silicon Carbide Using a Plasma Pressure Compaction System: Master Sintering Curve Analysis  

NASA Astrophysics Data System (ADS)

Nanostructured ceramics offer significant improvements in properties over corresponding materials with larger grain sizes on the order of tens to hundreds of micrometers. Silicon carbide (SiC) samples with grain sizes on the order of 100 nm can result in improved strength, chemical resistance, thermal stability, and tailored electrical resistivity. In this study, nanocrystalline SiC was processed in a plasma pressure compaction (P2C) system at a temperature of 1973 K (1700 °C) that was much lower than the temperatures reported for other sintering techniques. Microstructure of the resulting samples was studied and the hardness and the fracture toughness were measured. The grain sizes were on the order of 700 nm, the hardness between 22 and 24 GPa, and the toughness between 5 and 6.5 MPa·m1/2. The master sintering curve (MSC) analysis was used to model the densification behavior of SiC powder sintered by the P2C method. The apparent activation energies for three different pressures of 10, 30, and 50 MPa were obtained to be 1666, 1034, and 1162 kJ/mol, respectively. Although densification occurs via diffusion, the activation energies were higher than those associated with self-diffusion in SiC (between 570 and 920 kJ/mol). A validation study of the MSC was also conducted and the variation in observed density from the density predicted by the MSC was found to range from 1 to 10 pct.

Bothara, Manish G.; Atre, Sundar V.; Park, Seong-Jin; German, Randall M.; Sudarshan, T. S.; Radhakrishnan, R.

2010-12-01

225

Multiplex Fluorescence Melting Curve Analysis for Mutation Detection with Dual-Labeled, Self-Quenched Probes  

PubMed Central

Probe-based fluorescence melting curve analysis (FMCA) is a powerful tool for mutation detection based on melting temperature generated by thermal denaturation of the probe-target hybrid. Nevertheless, the color multiplexing, probe design, and cross-platform compatibility remain to be limited by using existing probe chemistries. We hereby explored two dual-labeled, self-quenched probes, TaqMan and shared-stem molecular beacons, in their ability to conduct FMCA. Both probes could be directly used for FMCA and readily integrated with closed-tube amplicon hybridization under asymmetric PCR conditions. Improved flexibility of FMCA by using these probes was illustrated in three representative applications of FMCA: mutation scanning, mutation identification and mutation genotyping, all of which achieved improved color-multiplexing with easy probe design and versatile probe combination and all were validated with a large number of real clinical samples. The universal cross-platform compatibility of these probes-based FMCA was also demonstrated by a 4-color mutation genotyping assay performed on five different real-time PCR instruments. The dual-labeled, self-quenched probes offered unprecedented combined advantage of enhanced multiplexing, improved flexibility in probe design, and expanded cross-platform compatibility, which would substantially improve FMCA in mutation detection of various applications.

Huang, Qiuying; Liu, Zanzan; Liao, Yiqun; Chen, Xiaoyun; Zhang, Yi; Li, Qingge

2011-01-01

226

Development of synthetic velocity - depth damage curves using a Weighted Monte Carlo method and Logistic Regression analysis  

NASA Astrophysics Data System (ADS)

Damage curves are the most significant component of the flood loss estimation models. Their development is quite complex. Two types of damage curves exist, historical and synthetic curves. Historical curves are developed from historical loss data from actual flood events. However, due to the scarcity of historical data, synthetic damage curves can be alternatively developed. Synthetic curves rely on the analysis of expected damage under certain hypothetical flooding conditions. A synthetic approach was developed and presented in this work for the development of damage curves, which are subsequently used as the basic input to a flood loss estimation model. A questionnaire-based survey took place among practicing and research agronomists, in order to generate rural loss data based on the responders' loss estimates, for several flood condition scenarios. In addition, a similar questionnaire-based survey took place among building experts, i.e. civil engineers and architects, in order to generate loss data for the urban sector. By answering the questionnaire, the experts were in essence expressing their opinion on how damage to various crop types or building types is related to a range of values of flood inundation parameters, such as floodwater depth and velocity. However, the loss data compiled from the completed questionnaires were not sufficient for the construction of workable damage curves; to overcome this problem, a Weighted Monte Carlo method was implemented, in order to generate extra synthetic datasets with statistical properties identical to those of the questionnaire-based data. The data generated by the Weighted Monte Carlo method were processed via Logistic Regression techniques in order to develop accurate logistic damage curves for the rural and the urban sectors. A Python-based code was developed, which combines the Weighted Monte Carlo method and the Logistic Regression analysis into a single code (WMCLR Python code). Each WMCLR code execution provided a flow velocity-depth damage curve for a specific land use. More specifically, each WMCLR code execution for the agricultural sector generated a damage curve for a specific crop and for every month of the year, thus relating the damage to any crop with floodwater depth, flow velocity and the growth phase of the crop at the time of flooding. Respectively, each WMCLR code execution for the urban sector developed a damage curve for a specific building type, relating structural damage with floodwater depth and velocity. Furthermore, two techno-economic models were developed in Python programming language, in order to estimate monetary values of flood damages to the rural and the urban sector, respectively. A new Monte Carlo simulation was performed, consisting of multiple executions of the techno-economic code, which generated multiple damage cost estimates. Each execution used the proper WMCLR simulated damage curve. The uncertainty analysis of the damage estimates established the accuracy and reliability of the proposed methodology for the synthetic damage curves' development.

Vozinaki, Anthi Eirini K.; Karatzas, George P.; Sibetheros, Ioannis A.; Varouchakis, Emmanouil A.

2014-05-01

227

Re-Analysis of the Solar Phase Curves of the Icy Galilean Satellites  

NASA Technical Reports Server (NTRS)

Re-analysis of the solar phase curves of the icy Galilean satellites demonstrates that the quantitative results are dependent on the single particle scattering function incorporated into the photometric model; however, the qualitative properties are independent. The results presented here show that the general physical characteristics predicted by a Hapke model (B. Hapke, 1986, Icarus 67, 264-280) incorporating a two parameter double Henyey-Greenstein scattering function are similar to the predictions given by the same model incorporating a three parameter double Henyey-Greenstein scattering function as long as the data set being modeled has adequate coverage in phase angle. Conflicting results occur when the large phase angle coverage is inadequate. Analysis of the role of isotropic versus anisotropic multiple scattering shows that for surfaces as bright as Europa the two models predict very similar results over phase angles covered by the data. Differences arise only at those phase angles for which there are no data. The single particle scattering behavior between the leading and trailing hemispheres of Europa and Ganymede is commensurate with magnetospheric alterations of their surfaces. Ion bombardment will produce more forward scattering single scattering functions due to annealing of potential scattering centers within regolith particles (N. J. Sack et al., 1992, Icarus 100, 534-540). Both leading and trailing hemispheres of Europa are consistent with a high porosity model and commensurate with a frost surface. There are no strong differences in predicted porosity between the two hemispheres of Callisto, both are consistent with model porosities midway between that deduced for Europa and the Moon. Surface roughness model estimates predict that surface roughness increases with satellite distance from Jupiter, with lunar surface roughness values falling midway between those measured for Ganymede and Callisto. There is no obvious variation in predicted surface roughness with hemisphere for any of the Galilean satellites.

Domingue, Deborah; Verbiscer, Anne

1997-01-01

228

Analysis of light curves and apsidal motion of neglected southern eclipsing binary V399 Pup  

NASA Astrophysics Data System (ADS)

In this study, the Hipparcos and ASAS light curves of the eclipsing binary V399 Pup have been analyzed using the Wilson-Devinney program. The light curve analyses have found that V399 Pup is a detached binary system with eccentric orbit. The apsidal motion parameters of the system have been obtained from the O-C curve analyses. The system has been revealed to have an orbital eccentricity of e = 0.145 ± 0.006, the apsidal motion rate has been obtained ?? = 0.0385 ± 0.0069 deg cycle-1, and it corresponds to an apsidal motion period of U = 100.2 ± 18.0 years.

Bulut, ?.; Bulut, A.; Çiçek, C.

2014-10-01

229

Influence of plasma conditions on the intensity ratio calibration curve during laser induced breakdown spectroscopy analysis.  

PubMed

Quantitative prediction of elemental concentration or concentration ratio of solid samples can be achieved by laser induced breakdown spectroscopy if a calibration curve that is little influenced by plasma conditions could be obtained. This work demonstrates that such a calibration curve is available for copper indium gallium diselenide (CuIn1-xGaxSe2) thin film solar cells for properly selected spectral lines. The possible changes of calibration curves based on the selected spectral lines are discussed in consideration of self-absorption in optically thick plasma and the dependency of spectral line properties on plasma temperature. PMID:24978745

Kim, Chan-Kyu; In, Jung-Hwan; Lee, Seok-Hee; Jeong, Sungho

2014-07-01

230

Analysis of the Diagnostic Value of Plasma Endothelin for Diabetic Retinopathy Using the Receiver Operating Characteristic Curve  

Microsoft Academic Search

Aim: To investigate the diagnostic efficacy and clinical application value of plasma endothelin-1 for diabetic retinopathy using receiver operating characteristic (ROC) curve analysis. Methods: This was a prospective investigational study. Funduscopy and fundus fluorescein angiography were used as gold standards for the diagnosis of diabetic retinopathy. Plasma endothelin-1 was measured in 96 diabetic patients with retinopathy (the case group) and

Hong Zhu; Cai-Hong Shi

2007-01-01

231

Analysis of pressure and pressure derivative without type-curve matching, 5. Horizontal well tests in naturally fractured reservoirs  

Microsoft Academic Search

Pressure transient analysis of horizontal wells penetrating naturally fractured reservoirs is a complicated and arduous task. That is, results from type-curve matching frequently suffer from nonuniqueness. Specialized plots (semilog or square root) are accurate but require individual plots for each identifiable flow regime. Subsequently, a new approach, known as direct synthesis, is proposed to overcome these problems.This method couples the

T. Engler; D. Tiab

1996-01-01

232

Case studies in the use of ROC curve analysis for sensor-based estimates in human computer interaction  

Microsoft Academic Search

Applications that use sensor-based estimates face a fundamental tradeoff between true positives and false positives when examining the reliability of these estimates, one that is inadequately described by the straightforward notion of accuracy. To address this tradeoff, this paper examines the use of Receiver Operating Characteristic (ROC) curve analysis, a method that has a long history but is under-appreciated in

James Fogarty; Ryan S. Baker; Scott E. Hudson

2005-01-01

233

Enhancing the Psychological Well-Being of Elderly Individuals through Tai Chi Exercise: A Latent Growth Curve Analysis.  

ERIC Educational Resources Information Center

Examined whether a Tai Chi exercise program enhanced the psychological well-being of 98 elderly individuals. Analyzed repeated measures data about participants using latent growth curve analysis. Results indicate the beneficial effects of participation in the Tai Chi program. Discusses implications related to the exercise-psychological health…

Li, Fuzhong; Duncan, Terry E.; Duncan, Susan C.; McAuley, Edward; Chaumeton, Nigel R.; Harmer, Peter

2001-01-01

234

Multivariable and Multigroup Receiver Operating Characteristics Curve Analyses for Qualitative and Quantitative Analysis.  

National Technical Information Service (NTIS)

An algorithm was developed using univariate statistics to reduce and analyze multivariate and multiple group data sets. The algorithm features the quantitative and selectivity figures of merit of receiver operating characteristics (ROC) curve methodology....

A. P. Snyder W. M. Maswadeh

2012-01-01

235

Seasonal recession of Mars' south polar CAP in 1986  

NASA Astrophysics Data System (ADS)

Photographs of Mars obtained during the 1986 opposition of the planet have been used to derive the regression curve for the south polar cap between Ls = 190 deg and Ls = 255 deg. The 1986 regression appears to have been unexceptional until after Ls = 230 deg, when it becomes retarded relative to the normal established by the 1971 and 1977 regressions. A study of the data as a function of the filter used suggests that circumpolar clouds were present in early spring, unlike the case in the 1977 recession.

James, P. B.; Martin, L. J.; Henson, J. R.; Birch, P. V.

1990-02-01

236

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin  

Microsoft Academic Search

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin

Naoki Noguchi; Keiji Shinoda; Kaori Masuda

2009-01-01

237

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin  

NASA Astrophysics Data System (ADS)

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin

Noguchi, Naoki; Shinoda, Keiji; Masuda, Kaori

238

Ultraviolet Surface Properties of the Icy Galilean Satellites from Phase Curve Analysis  

NASA Technical Reports Server (NTRS)

In this study, we use ultraviolet observations from the International Ultraviolet Explorer (IUE) and the Galileo Ultraviolet Spectrometer (UVS) to compose the ultraviolet solar phase curves of the icy Galilean satellites. Broadband rotation phase curves from 0.26 to 0.32 microns are constructed in order to examine the rotational behavior of the icy Galilean satellites in the ultraviolet. After normalizing the rotational variations, modeling of the solar phase variations are compared to comparable studies in the visible.

Hendrix, A. R.; Dominique, D. L.

2002-01-01

239

Analysis of Fractional Window Recoding Methods and Their Application to Elliptic Curve Cryptosystems  

Microsoft Academic Search

Elliptic curve cryptosystems (ECC) are suitable for memory-constraint devices like smart cards due to their small key-size. A standard way of computing elliptic curve scalar multiplication, the most frequent operation in ECC, is window methods, which enhance the efficiency of the binary method at the expense of some precomputation. The most established window methods are sliding window on NAF (NAF+SW),

Katja Schmidt-samoa; Olivier Semay; Tsuyoshi Takagi

2006-01-01

240

Analysis of creep curves of a nickel base superalloy in a wide stress\\/temperature range  

Microsoft Academic Search

The creep behaviour of the nickel base superalloy Nimonic 263 has been studied at constant load and temperature in the 750–30MPa\\/600–950°C range. The experimental results have shown a very strong dependence of the creep curve shape with the applied stress\\/temperature. At high stresses, when an instantaneous plastic strain occurs during the initial loading, the creep curves are characterised by an

M. Maldini; G. Angella; V. Lupinc

2007-01-01

241

An Analysis of 900 Optical Rotation Curves: The Universal Rotation Curve As A Power-Law And The Development Of A Theory-Independent  

Microsoft Academic Search

One of the largest Hrotation curve data bases of spiral galaxies currently available is that provided by Persic & Salucci, (astro-ph\\/9502091) hereafter PS 1995, which has been derived by them from unre- duced rotation curve data of 965 southern sky spirals obtained by Mathewson, Ford & Buchhorn, hereafter MFB 1992. Of the original sample of 965 galaxies, the observations on

Dark-Matter Modeller

242

An analysis of 900 optical rotation curves: the universal rotation curve as a power-law and the development of a theory-independent dark-matter modeller  

Microsoft Academic Search

One of the largest H_alpha rotation curve data bases of spiral galaxies currently available is that provided by Persic & Salucci, hereafter PS 1995, which has been derived by them from unreduced rotation curve data of 965 southern sky spirals obtained by Mathewson, Ford & Buchhorn, hereafter MFB 1992. Of the original sample of 965 galaxies, the observations on 900

D. F. Roscoe

1999-01-01

243

Exponential Decay Nonlinear Regression Analysis of Patient Survival Curves: Preliminary Assessment in Non-Small Cell Lung Cancer  

PubMed Central

Background For processes that follow first order kinetics, exponential decay nonlinear regression analysis (EDNRA) may delineate curve characteristics and suggest processes affecting curve shape. We conducted a preliminary feasibility assessment of EDNRA of patient survival curves. Methods EDNRA was performed on Kaplan-Meier overall survival (OS) and time-to-relapse (TTR) curves for 323 patients with resected NSCLC and on OS and progression-free survival (PFS) curves from selected publications. Results and Conclusions In our resected patients, TTR curves were triphasic with a “cured” fraction of 60.7% (half-life [t1/2] >100,000 months), a rapidly-relapsing group (7.4%, t1/2=5.9 months) and a slowly-relapsing group (31.9%, t1/2=23.6 months). OS was uniphasic (t1/2=74.3 months), suggesting an impact of co-morbidities; hence, tumor molecular characteristics would more likely predict TTR than OS. Of 172 published curves analyzed, 72 (42%) were uniphasic, 92 (53%) were biphasic, 8 (5%) were triphasic. With first-line chemotherapy in advanced NSCLC, 87.5% of curves from 2-3 drug regimens were uniphasic vs only 20% of those with best supportive care or 1 drug (p<0.001). 54% of curves from 2-3 drug regimens had convex rapid-decay phases vs 0% with fewer agents (p<0.001). Curve convexities suggest that discontinuing chemotherapy after 3-6 cycles “synchronizes” patient progression and death. With postoperative adjuvant chemotherapy, the PFS rapid-decay phase accounted for a smaller proportion of the population than in controls (p=0.02) with no significant difference in rapid-decay t1/2, suggesting adjuvant chemotherapy may move a subpopulation of patients with sensitive tumors from the relapsing group to the cured group, with minimal impact on time to relapse for a larger group of patients with resistant tumors. In untreated patients, the proportion of patients in the rapid-decay phase increased (p=0.04) while rapid-decay t1/2 decreased (p=0.0004) with increasing stage, suggesting that higher stage may be associated with tumor cells that both grow more rapidly and have a higher probability of surviving metastatic processes than in early stage tumors. This preliminary assessment of EDNRA suggests that it may be worth exploring this approach further using more sophisticated, statistically rigorous nonlinear modelling approaches. Using such approaches to supplement standard survival analyses could suggest or support specific testable hypotheses.

Stewart, David J.; Behrens, Carmen; Roth, Jack; Wistuba, Ignacio I.

2010-01-01

244

Light Curves and Analysis of the Overcontact Binaries GN Boo, V608 Cas and V789 Cyg  

NASA Astrophysics Data System (ADS)

New precision V & Rc light curves of the eclipsing overcontact binaries GN Boo, V608 Cas and V789 Cyg have been obtained using the 41-cm telescope at the Eastern University Observatory equipped with an SBIG ST-10XME CCD. GN Boo (P = 0.3016 days, m = 10.8) has only one published light curve (Blattler & Diethelm 2001a) which is noisy and had no subsequent analysis. The system was observed on 5 nights from 3 - 14 Mar 2005, accumulating approximately 750 observations in both V and Rc. Because the previously published light curve had rather large excursions in light, it was hoped that GN Boo would display total eclipses, which in fact it does. Preliminary analysis indicates that it has a mass ratio of q = 0.33, a temperature difference of 360 K between the two components, and a fillout f = 0.21. The maxima are markedly asymmetric which was modeled with a cool spot region. V608 Cas (P = 0.3804 days, m = 12.0) was observed by Blattler & Diethelm (2001b) who published a complete but noisy light curve. Although chosen for study because its published light curve suggested possible totality in the eclipses, this did not turn out to be the case. V608 Cas was observed on 3 nights from 18 Oct - 7 Nov 2004, accumulating approximately 560 observations in both V and Rc. Preliminary light curve models indicate an overcontact system with a small temperature difference between the two stars of approximately 200 K and a fillout f = 0.25. V789 Cyg (P = 0.4483, m = 13.3) is classified in the GCVS as an RR Lyrae variable, and the system was presented as such by Ponce & Sharp (2000). However their light curve looked to us very much like a W UMa light curve folded upon itself with half the true period, and so this system was observed in V and Rc on 8 nights from 27 Jun - 21 Jul 2004. The resulting light curves confirmed the overcontact nature of the system, and the modeling is still in progress. The final results of the analyses of these systems will be presented.

Sanders, S. J.; Bradstreet, D. H.; Hargis, J. R.

2005-12-01

245

Use of a mathematical model in the analysis of survival curves of Daphnia magna exposed to toxicants.  

PubMed

Chronic toxicity tests carried out on species of the genus Daphnia (Crustacea: Cladocera) are bioassays commonly used in ecotoxicology. Mortality in the cohorts exposed to toxicants can be examined by the analysis of survival curves. The shape of these curves may be very different because of inter-individual heterogeneity: the less rectangular is the shape the more different is the probability of dying of daphnids in the cohort. Aim of this paper is to analyze the characteristics-in particular the shape-of survival curves of cohorts of Daphnia magna exposed to heavy metals in chronic toxicity tests. Experimental curves were fitted by a mathematical model recently proposed, which puts emphasis just on this heterogeneity, described by the parameter of the model S(0). The information contained in S(0) is very useful for the present purposes: the higher the value of S(0) the less rectangular the shape of the curve and, as a consequence, the higher the age-at-death heterogeneity of the cohort is thought to be. The model contains a second parameter, omega, representing the maximum potential ability of the individuals to survive in a specific environment and is related with the maximal life span. The model fitted well the survival curves in most cases and both S(0) and omega showed statistically different values between treatments, useful for comparisons. It was concluded that S(0) provides a quantitative estimation of curve "rectangularization", useful to check different sensitivities to a specific toxicant concentration among daphnids belonging to the same cohort, while omega provides an estimate of maximal life span. PMID:12727245

Santojanni, Alberto; Rossolini, Giuliana; Gorbi, Gessica; Piantanelli, Lucio; Sartore, Franco

2003-05-01

246

A Case-Acquisition and Decision-Support System for the Analysis of Group-Average Lactation Curves  

Microsoft Academic Search

A case-acquisition and decision-support system was developed to support the analysis of group-average lac- tation curves and to acquire example cases from domain specialists. This software was developed through several iterations of a three-step approach involving 1) problem analysis and formulation in consultation with two dairy nutrition specialists; 2) development of a case-acquisi- tion and decision-support prototype by the system

D. Pietersma; R. Lacroix; D. Lefebvre; E. Block; K. M. Wade

2001-01-01

247

Measuring recession severity and its impact on healthcare expenditure.  

PubMed

The financial crisis that manifested itself in late 2007 resulted in a Europe-wide economic crisis by 2009. As the economic climate worsened, Governments and households were put under increased strain and more focus was placed on prioritising expenditures. Across European countries and their heterogeneous health care systems, this paper examines the initial responsiveness of health expenditures to the crisis and whether recession severity can be considered a predictor of health expenditure growth. In measuring severity we move away from solely gross domestic product (GDP) as a metric and construct a recession severity index predicated on a number of key macroeconomic indicators. We then regress this index on measures of total, public and private health expenditure to identify potential relationships. Analysis suggests that for 2009, the Baltic States, along with Ireland, Italy and Greece, experienced comparatively severe recessions. We find, overall, an initial counter-cyclical response in health spending (both public and private) across countries. However, our analysis finds evidence of a negative relationship between recession severity and changes in certain health expenditures. As a predictor of health expenditure growth in 2009, the derived index is an improvement over GDP change alone. PMID:23417124

Keegan, Conor; Thomas, Steve; Normand, Charles; Portela, Conceição

2013-06-01

248

The Crucial Role of Recess in Schools  

ERIC Educational Resources Information Center

Background: Recess is at the heart of a vigorous debate over the role of schools in promoting optimal child development and well-being. Reallocating time to accentuate academic concerns is a growing trend and has put recess at risk. Conversely, pressure to increase activity in school has come from efforts to combat childhood obesity. The purpose…

Ramstetter, Catherine L.; Murray, Robert; Garner, Andrew S.

2010-01-01

249

Recess for Elementary School Students. Position Statement  

ERIC Educational Resources Information Center

It is the position of the National Association for Sport and Physical Education (NASPE) that all elementary school children should be provided with at least one daily period of recess of at least 20 minutes in length. Recess is an essential component of a comprehensive school physical activity program and of the total education experience for…

National Association for Sport and Physical Education, 2006

2006-01-01

250

Combined statistical analysis of vasodilation and flow curves in brachial ultrasonography: technique and its connection to cardiovascular risk factors  

NASA Astrophysics Data System (ADS)

Clinical studies report that impaired endothelial function is associated with Cardio-Vascular Diseases (CVD) and their risk factors. One commonly used mean for assessing endothelial function is Flow-Mediated Dilation (FMD). Classically, FMD is quantified using local indexes e.g. maximum peak dilation. Although such parameters have been successfully linked to CVD risk factors and other clinical variables, this description does not consider all the information contained in the complete vasodilation curve. Moreover, the relation between flow impulse and the vessel vasodilation response to this stimulus, although not clearly known, seems to be important and is not taken into account in the majority of studies. In this paper we propose a novel global parameterization for the vasodilation and the flow curves of a FMD test. This parameterization uses Principal Component Analysis (PCA) to describe independently and jointly the variability of flow and FMD curves. These curves are obtained using computerized techniques (based on edge detection and image registration, respectively) to analyze the ultrasound image sequences. The global description obtained through PCA yields a detailed characterization of the morphology of such curves allowing the extraction of intuitive quantitative information of the vasodilation process and its interplay with flow changes. This parameterization is consistent with traditional measurements and, in a database of 177 subjects, seems to correlate more strongly (and with more clinical parameters) than classical measures to CVD risk factors and clinical parameters such as LDL- and HDL-Cholesterol.

Boisrobert, Loic; Laclaustra, Martin; Bossa, Matias; Frangi, Andres G.; Frangi, Alejandro F.

2005-04-01

251

An analysis of the shapes of ultraviolet extinction curves. II - The far-UV extinction  

NASA Technical Reports Server (NTRS)

In this paper the properties of interstellar extinction in the far-ultraviolet region are examined utilizing IUE extinction curves for a primary data sample of 45 reddened Milky Way OB stars. These results are combined with those derived for the 2175 A bump in a previous study. It is found that IUE extinction curves can be represented by linear combinations of a Lorentzian-like 2175 A bump profile, a well-determined FUV curvature term, and an underlying linear component. The parameters of the linear component are strongly correlated and therefore only five free parameters are required to fit all of the curves in our sample. Three parameters describe the 2175 A bump, one parameter describes the linear background, and one parameter describes the strength of the FUV curvature term. The shape of the FUV curvature is found to be identical, to within the observational errors, for all the curves in the sample - which spans virtually the entire range of extinction curve morphologies observed in the Milky Way.

Fitzpatrick, Edward L.; Massa, Derck

1988-01-01

252

Nonlinear time series analysis of the light curves from the black hole system GRS1915+105  

NASA Astrophysics Data System (ADS)

GRS 1915+105 is a prominent black hole system exhibiting variability over a wide range of time scales and its observed light curves have been classified into 12 temporal states. Here we undertake a complete analysis of these light curves from all the states using various quantifiers from nonlinear time series analysis, such as the correlation dimension (D2), the correlation entropy (K2), singular value decomposition (SVD) and the multifractal spectrum (f(?) spectrum). An important aspect of our analysis is that, for estimating these quantifiers, we use algorithmic schemes which we have recently proposed and successfully tested on synthetic as well as practical time series from various fields. Though the schemes are based on the conventional delay embedding technique, they are automated so that the above quantitative measures can be computed using conditions prescribed by the algorithm and without any intermediate subjective analysis. We show that nearly half of the 12 temporal states exhibit deviation from randomness and their complex temporal behavior could be approximated by a few (three or four) coupled ordinary nonlinear differential equations. These results could be important for a better understanding of the processes that generate the light curves and hence for modeling the temporal behavior of such complex systems. To our knowledge, this is the first complete analysis of an astrophysical object (let alone a black hole system) using various techniques from nonlinear dynamics.

Harikrishnan, K. P.; Misra, Ranjeev; Ambika, G.

2011-01-01

253

The mathematical analysis for peristaltic flow of nano fluid in a curved channel with compliant walls  

NASA Astrophysics Data System (ADS)

In the present paper, we have investigated the peristaltic flow of nano fluid in a curved channel with compliant walls. The governing equations of nano fluid model for curved channel are derived including the effects of curvature. The highly nonlinear partial differential equations are simplified using the long wave length and low Reynolds number assumptions. The reduced nonlinear partial differential equation is solved analytically with the help of homotopy perturbation method. The physical features of pertinent parameters have been discussed by plotting the graphs of pressure rise, velocity, temperature, nano particle volume fraction and stream functions.

Nadeem, S.; Maraj, E. N.

2014-01-01

254

The Mathematical Analysis for Peristaltic Flow of Hyperbolic Tangent Fluid in a Curved Channel  

NASA Astrophysics Data System (ADS)

In the present paper, we have investigated the peristaltic flow of hyperbolic tangent fluid in a curved channel. The governing equations of hyperbolic tangent fluid model for curved channel are derived including the effects of curvature. The highly nonlinear partial differential equations are simplified by using the wave frame transformation, long wave length and low Reynolds number assumptions. The reduced nonlinear partial differential equation is solved analytically with the help of homotopy perturbation method (HPM). The physical features of pertinent parameters have been discussed by plotting the graphs of pressure rise and stream functions.

Nadeem, S.; E. N., Maraj

2013-06-01

255

Genotype-phenotype correlations in recessive RYR1-related myopathies  

PubMed Central

Background RYR1 mutations are typically associated with core myopathies and are the most common overall cause of congenital myopathy. Dominant mutations are most often associated with central core disease and malignant hyperthermia, and genotype-phenotype patterns have emerged from the study of these mutations that have contributed to the understanding of disease pathogenesis. The recent availability of genetic testing for the entire RYR1 coding sequence has led to a dramatic expansion in the identification of recessive mutations in core myopathies and other congenital myopathies. To date, no clear patterns have been identified in these recessive mutations, though no systematic examination has yet been performed. Methods In this study, we investigated genotype-phenotype correlations in a large combined cohort of unpublished (n?=?14) and previously reported (n?=?92) recessive RYR1 cases. Results Overall examination of this cohort revealed nearly 50% of cases to be non-core myopathy related. Our most significant finding was that hypomorphic mutations (mutations expected to diminish RyR1 expression) were enriched in patients with severe clinical phenotypes. We also determined that hypomorphic mutations were more likely to be encountered in non-central core myopathies. With analysis of the location of non-hypomorphic mutations, we found that missense mutations were generally enriched in the MH/CCD hotspots and specifically enriched in the selectivity filter of the channel pore. Conclusions These results support a hypothesis that loss of protein function is a key predictive disease parameter. In addition, they suggest that decreased RyR1 expression may dictate non-core related pathology though, data on protein expression was limited and should be confirmed in a larger cohort. Lastly, the results implicate abnormal ion conductance through the channel pore in the pathogenesis in recessive core myopathies. Overall, our findings represent a comprehensive analysis of genotype-phenotype associations in recessive RYR1-myopathies.

2013-01-01

256

Recess Physical Activity and Perceived School Environment among Elementary School Children  

PubMed Central

Differences in recess physical activity (PA) according to perceived school environment among elementary school children were examined. Participants were 103 children from two schools in Japan. PA was measured using accelerometry for seven consecutive days. Time spent in sedentary or PA (light, moderate, or vigorous) during their morning recess (25 min) and lunch recess (15 min) was determined. The School Physical Activity Environment Scale (three factors: equipment, facility, and safety) was used to investigate perceived school environment. Environmental factor scores were assigned to low or high groups for each factor by median. An analysis of covariance, with grade as the covariate, was conducted separately by gender to examine differences in PA between two groups. During lunch recess, boys in the high-equipment group spent significantly more time in moderate PA (high: 1.5; low: 0.8 min) whereas girls in this group spent less time in light PA (9.3, 11.0). Boys in the high-facility group spent significantly less time in sedentary (2.3, 3.9) and more time in vigorous PA (2.4, 1.4) during lunch recess, and girls spent more time in moderate (2.1, 1.2) and vigorous PA (1.9, 1.3) during morning recess. Differences were observed in recess PA according to school environment perceptions. The present study may be useful for further intervention studies for the promotion of PA during recess.

Ishii, Kaori; Shibata, Ai; Sato, Mai; Oka, Koichiro

2014-01-01

257

Recess Physical Activity and Perceived School Environment among Elementary School Children.  

PubMed

Differences in recess physical activity (PA) according to perceived school environment among elementary school children were examined. Participants were 103 children from two schools in Japan. PA was measured using accelerometry for seven consecutive days. Time spent in sedentary or PA (light, moderate, or vigorous) during their morning recess (25 min) and lunch recess (15 min) was determined. The School Physical Activity Environment Scale (three factors: equipment, facility, and safety) was used to investigate perceived school environment. Environmental factor scores were assigned to low or high groups for each factor by median. An analysis of covariance, with grade as the covariate, was conducted separately by gender to examine differences in PA between two groups. During lunch recess, boys in the high-equipment group spent significantly more time in moderate PA (high: 1.5; low: 0.8 min) whereas girls in this group spent less time in light PA (9.3, 11.0). Boys in the high-facility group spent significantly less time in sedentary (2.3, 3.9) and more time in vigorous PA (2.4, 1.4) during lunch recess, and girls spent more time in moderate (2.1, 1.2) and vigorous PA (1.9, 1.3) during morning recess. Differences were observed in recess PA according to school environment perceptions. The present study may be useful for further intervention studies for the promotion of PA during recess. PMID:25029495

Ishii, Kaori; Shibata, Ai; Sato, Mai; Oka, Koichiro

2014-01-01

258

Renormalization-group analysis of grand unified theories in curved spacetime  

Microsoft Academic Search

We consider a class of grand unified theories (GUT's) based on the Georgi-Glashow model in curved spacetime. We are particularly concerned with the coupling constants involving the curvature. These include the cosmological and gravitational constants, as well as coupling constants appearing in terms quadratic in the curvature and in terms which link the Higgs bosons to the scalar curvature. For

Leonard Parker; David J. Toms

1984-01-01

259

Renormalization-group analysis of grand unified theories in curved space-time  

Microsoft Academic Search

We consider a class of grand unified theories (GUT's) based on the Georgi-Glashow model in curved space-time. We are particularly concerned with the coupling constants involving the curvature. These include the cosmological and gravitational constants, as well as coupling constants appearing in terms quadratic in the curvature and in terms which link the Higgs bosons to the scalar curvature. For

L. Parker; D. J. Toms

1984-01-01

260

Analysis of Network-Wide Impacts of Behavioral Response Curves for Evacuation Conditions  

Microsoft Academic Search

Demand generation and network loading models under evacuation conditions are crucial yet challenging components of evacuation studies. This study aims to assess network-wide impacts of behavioral response curves, which are the most popular evacuation demand generation models in the literature. System optimal dynamic traffic assignment (SO-DTA) formulation originally proposed by Ziliaskopoulos (2000) is used to model a simplified version of

Kaan Ozbay; M. Anil Yazici

2006-01-01

261

Free and forced vibration analysis of thin, laminated, cylindrically curved panels  

Microsoft Academic Search

A comprehensive vibration study of thin, laminated, cylindrically curved shell panels (based on the shell theory of Love with a modification by Arnold and Warburton) is conducted by using the h-p version of the finite-element method (FEM). Polynomially enriched stiffness and mass matrices are derived from classical shell theory using Symbolic Computing, and then stored in algebraic form for a

N. S. Bardell; J. M. Dunsdon; R. S. Langley

1997-01-01

262

Development of Oral Reading Fluency in Children with Speech or Language Impairments: A Growth Curve Analysis  

ERIC Educational Resources Information Center

This longitudinal study used piece-wise growth curve analyses to examine growth patterns in oral reading fluency for 1,991 students with speech impairments (SI) or language impairments (LI) from first through third grade. The main finding of this study was that a diagnosis of SI or LI can have a detrimental and persistent effect on early reading…

Puranik, Cynthia S.; Petscher, Yaacov; Al Otaiba, Stephanie; Catts, Hugh W.; Lonigan, Christopher J.

2008-01-01

263

Analysis of Some Efficient Window Methods and their Application to Elliptic Curve Cryptosystems  

Microsoft Academic Search

Abstract: Elliptic curve cryptosystems (ECC) are suitable for smart cards due to their small key-size. We have to make an effort to reduce both computation time and memory usage on such memory-constraint devices. A standard way to achieve this goal are window methods, which can enhance the speed of the scalar multiplication with a reasonable memory usage. The most famous

Katja Schmidt-samoa; Olivier Semay; Tsuyoshi Takagi

2004-01-01

264

Analysis of buck-boost converter inductor loss using a simple online BH curve tracer  

Microsoft Academic Search

A simple method to plot online B-H curves and calculate the core loss of the inductor in a conventional buck-boost power converter is developed. In order to obtain a reliable loss data, measurement error and phase shift error are analyzed and then quantified. A new method to minimize measurement error is given. A new core loss model in terms of

H. Y. Chung; F. N. K. Poon; C. P. Liu; M. H. Pong

2000-01-01

265

Texture analysis by space-filling curves and one-dimensional Haar wavelets  

Microsoft Academic Search

A 1-D scan that follows the Peano curve to a desired resolution is demonstrated to preserve a 2-D proximity relationship and is shown to be efficient for wavelet transform (WT) processing and artificial neural network pattern recognition. This deterministic fractal sampling method can be implemented in real time using optoelectronic scanning. For example, 2-D texture patterns are analyzed by using

Sonlinh Phuvan; Tae Kwan Oh; Nicholas P. Caviris; Yao Li; Harold H. Szu

1992-01-01

266

Analysis of hyperspherical adiabatic curves of helium: A classical dynamics study  

NASA Astrophysics Data System (ADS)

The hyperspherical adiabatic curves (adiabatic eigenenergies as functions of the hyperradius R) of helium for zero total angular momentum are analyzed by studying the underlying classical dynamics which in the adiabatic treatment reduces to constrained two-electron motion on a hypersphere. This dynamics supports five characteristic classical configurations which can be represented by five types of short periodic orbits: the frozen planet (FP), the inverted frozen planet (IFP), the asymmetric stretch (AS), the asynchronous (ASC), and the Langmuir periodic orbit (PO). These POs are considered as fundamental modes of the two-electron motion on a hypersphere which, after quantization, give five families of so-called adiabatic lines (adiabatic energies related to these POs as functions of R). It is found that multiplets, each of them consisting of adiabatic curves which converge to the same ionization threshold, are at large values of R delimited from the bottom and from the top by the adiabatic lines which are related to the IFP and stable AS POs and to the FP PO, respectively. At smaller values of R, where the AS PO becomes unstable, the curves move to the area between the ASC (bottom) and AS (top) lines by crossing the latter. Therefore, at different values of R the lower limiting line of the multiplet is related to the three types of PO (IFP, AS, and ASC), which are all stable in the negative-energy part of this line. As a consequence, the quantum states of helium in principle are not related individually to a single classical configuration on the hypersphere. In addition, it is demonstrated that “unstable parts” of adiabatic lines (the so-called diabatic curves) determine the positions and type of avoided and hidden crossings between hyperspherical adiabatic curves. Two clearly visible classes of avoided crossings are related to the AS and ASC POs. In addition, a number of avoided crossings of the adiabatic curves is observed at the positions where the adiabatic lines that are related to different types of PO cross mutually. Finally, a class of hidden crossings which is located near the saddle point of the potential is related to the Langmuir orbit. The large spacing between adiabatic curves at the positions of these hidden crossings is explained by high instability of the Langmuir PO compared to the AS and ASC POs.

Simonovi?, N. S.; Solov'ev, E. A.

2013-05-01

267

Use of high-resolution melting curve analysis to identify Mycoplasma species commonly isolated from ruminant, avian, and canine samples.  

PubMed

A real-time polymerase chain reaction assay coupled with high resolution melting curve analysis (PCR-HRM) was developed for identifying and distinguishing Mycoplasma species commonly isolated from ruminant, avian, and canine samples. The real-time PCR used 1 set of universal primers specific for the spacer region between the 16S ribosomal RNA and the 23S ribosomal RNA genes; the melting curve analysis of the PCR product used a high-resolution melt fluorescent dye. The real-time PCR-HRM assay was able to distinguish M. arginini, M. bovigenitalium, M. bovis, M. bovirhinis, M. canadense, M. cynos, M. spumans, M. iowae, M. meleagridis, and M. agalactiae reference strains. The real-time PCR-HRM assay developed was evaluated by testing field isolates of M. bovis, M. arginini, M. bovirhinis, M. bovigenitalium, M. iowae, and M. spumans with results consistent with those of the fluorescent antibody test. PMID:21908349

Rebelo, Ana Rita; Parker, Lois; Cai, Hugh Y

2011-09-01

268

Light Iceland Glacier Recession 1973 to 2000  

NSDL National Science Digital Library

This animation shows glacier recesion at the Breidamerkurjokull glacier in Iceland. The data from 1973 is taken from Landsat 1 and the 2000 data is from Landsat 7. The Breidamerkurjokull glacier in Iceland has been measured by Landsat to be receding since 1973. The glacierologists in Iceland and here at NASAs Goddard Space Flight Center have measured the recession throughout the entire glacier and found different rates of recession in different areas. In genral, the glacier seems to be receding at about 2% annually. It is extremely controversial whether or not this recession is caused by global warming.

Perkins, Lori; Hall, Dorothy

2001-04-09

269

NEW REACTOR DESIGN AND ANALYSIS OF NON LINEAR VIBRATIONS OF DOUBLY CURVED SHALLOW SHELL UNDER A THERMAL GRADIENT  

SciTech Connect

The present study concerns with the effects of material orthotropy,curvature, shear ratio and circumferential modulus under the influence of a temperature distribution throughout the shell structure. Here analysis is restricted to the study of nonlinear vibration of a doubly curved shell structure considering the periodic response of a simple bending mode due to curtailment of pages. Solutions of the problems with suitable illustrations are also presented.

Chanda, S.

2004-10-06

270

Hydroreactivity of stomata in kale leaves of different insertion level as determined by analysis of transpiration curves  

Microsoft Academic Search

Values of the water saturation deficit (WSD) for hydroactive stomatal movements of kale leaves were estimated using the method\\u000a of transpiration curve analysis.\\u000a \\u000a Stomata of young leaves started closing at WSD values of 5 to 6 per cent and were completely closed at 18 to 20 per cent WSD.\\u000a During maturation and ageing of leaves these WSD values increased to

Jarmila Solárová

1970-01-01

271

Analysis of thermoluminescence glow curves obtained from diethylpyrocarbonate-treated spinach thylakoid preparations using the general order kinetics model  

Microsoft Academic Search

The general order kinetics model was applied for the fitting and analysis of thermoluminescence (TL) glow curves obtained from diethylpyrocarbonate (DEPC)-treated chloroplast samples in order to understand the mechanism of TL dynamics.Incubation of thylakoids for 15 min in the presence of DEPC resulted in a reduction in the intensity of the B band at around 30°C, with a concomitant enhancement

Sarah Thomas; M. Banerjee; P. B. Vidyasagar; U. Hegde; A. D. Shaligram

1996-01-01

272

Analysis of a New Variational Model to Restore Point-Like and Curve-Like Singularities in Imaging  

SciTech Connect

The paper is concerned with the analysis of a new variational model to restore point-like and curve-like singularities in biological images. To this aim we investigate the variational properties of a suitable energy which governs these pathologies. Finally in order to realize numerical experiments we minimize, in the discrete setting, a regularized version of this functional by fast descent gradient scheme.

Aubert, Gilles, E-mail: gaubert@unice.fr [Universite de Nice Sophia Antipolis, Laboratoire J.A. Dieudonne (France)] [Universite de Nice Sophia Antipolis, Laboratoire J.A. Dieudonne (France); Blanc-Feraud, Laure, E-mail: Laure.Blanc-Feraud@inria.fr; Graziani, Daniele, E-mail: Daniele.Graziani@inria.fr [Inria, Morpheme CNRS/INRIA/UNSA Sophia Antipolis (France)] [Inria, Morpheme CNRS/INRIA/UNSA Sophia Antipolis (France)

2013-02-15

273

Automatic fragility curve evaluation of masonry churches accounting for partial collapses by means of 3D FE homogenized limit analysis  

Microsoft Academic Search

A novel 3D homogenized FE limit analysis software is proposed for the fragility curve evaluation of entire existing masonry churches. The approach is a two-step one. In the first phase homogenized masonry strength domains are obtained using a simplified kinematic procedure applied on a three-leaf unitary cell. In the second phase, homogenized domains are implemented at a structural level on

Gabriele Milani; Gennj Venturini

2011-01-01

274

Open-Mode Debonding Analysis of Curved Sandwich Panels Subjected to Heating and Cryogenic Cooling on Opposite Faces  

NASA Technical Reports Server (NTRS)

Increasing use of curved sandwich panels as aerospace structure components makes it vital to fully understand their thermostructural behavior and identify key factors affecting the open-mode debonding failure. Open-mode debonding analysis is performed on a family of curved honeycomb-core sandwich panels with different radii of curvature. The curved sandwich panels are either simply supported or clamped, and are subjected to uniform heating on the convex side and uniform cryogenic cooling on the concave side. The finite-element method was used to study the effects of panel curvature and boundary condition on the open-mode stress (radial tensile stress) and displacement fields in the curved sandwich panels. The critical stress point, where potential debonding failure could initiate, was found to be at the midspan (or outer span) of the inner bonding interface between the sandwich core and face sheet on the concave side, depending on the boundary condition and panel curvature. Open-mode stress increases with increasing panel curvature, reaching a maximum value at certain high curvature, and then decreases slightly as the panel curvature continues to increase and approach that of quarter circle. Changing the boundary condition from simply supported to clamped reduces the magnitudes of open-mode stresses and the associated sandwich core depth stretching.

Ko, William L.

1999-01-01

275

Photometry, period variations and light curve analysis of eclipsing binary V1191 Cyg  

NASA Astrophysics Data System (ADS)

New observations of the eclipsing binary system V1191 Cyg were carried out by using CCD in BVR filters and new times of light minimum and new ephemeris were obtained. For the first time, the O-C curve of this binary was analyzed by using the Kalimeris method and the orbital period and its rate of change were calculated as functions of time. The BVR light curves were analyzed using both the Binary Maker 3.0 and PHOEBE 0.31a programs to determine some geometrical and physical parameters. By analyzing O-C diagram, the period variation was calculated to be dP/dt=3.13×10-6 d yr and the rate of mass transfer was M=5.23×10-7 M yr.

Ostadnezhad, S.; Delband, M.; Hasanzadeh, A.

2014-08-01

276

The Great Recession's impact on children.  

PubMed

Since that first day of the millennium the United States has experienced two recessions. The first recession began in 2001 and lasted for 10 months. The second, now referred to as the Great Recession, began in December of 2007, was approximately 18 months in duration and was followed by a weak and jobless recovery that has persisted into the second decade of this century. This commentary will examine how low-income children have fared in regard to economic security, food insecurity and housing instability as a result of the Great Recession and recent economic downturn. It concludes with a call to action for a renewed investment in our children through a Children's Recovery and Stimulus Initiative. PMID:21528399

Oberg, Charles N

2011-07-01

277

Genetic analysis of the growth curve of Rous sarcoma virus-induced tumors in chickens.  

PubMed

White Leghorn chicks homozygous for B19 MHC haplotype were selected for 18 generations on tumor regression after inoculation in the wing web with an SR-D strain of Rous sarcoma virus (RSV) at 4 wk of age. Each chick was assigned a tumor profile index (TPI) based on age at death and size of the tumor. During 18 generations, 2,010 birds were divergently selected on TPI for either progression or regression of the tumor (P and R lines). A Brody growth curve was fitted for each bird. Brody function parameters included the asymptotic tumor volume (A), the factor for increased growth in progression phase (K1), the factor for decreased growth in regression phase (K2), age at maximum volume (Tmax), and maximum volume of the tumor (Vmax). Tumor growth curves were found to be different according to line, sex, and restriction fragment pattern Y complex Rfp-Y MHC haplotype (Yw*15, Yw*16, and Yw*17). Within the P line, birds from the Yw*16 haplotype reached Vmax at an earlier age than Yw*15 and Yw*17, but with a lower Vmax value. Within the R line, tumor growth curves of birds from Yw*16 and Yw*17 haplotypes were similar. Rank correlations between the different parameters and TPI were low (between -0.26 and 0.36). Heritability estimated by the sire component was high for Vmax (0.73). Heritabilities of Tmax and K2 were moderate (0.20 to 0.23 for Tmax and 0.18 to 0.21 for K2) allowing these traits to be used as selection criteria. Heritabilities of A and K1 were lower than 0.12. Modeling the growth curve should contribute to better distinction between progressors and regressors. PMID:15384897

Praharaj, N; Beaumont, C; Dambrine, G; Soubieux, D; Mérat, L; Bouret, D; Luneau, G; Alletru, J-M; Pinard-Van der Laan, M-H; Thoraval, P; Mignon-Grasteau, S

2004-09-01

278

Genetic variation of lactation curves in dairy sheep: a Bayesian analysis of Wood’s function  

Microsoft Academic Search

Test-day milk yield records (1752) of 451 first-lactation ewes in four flocks from Nebraska and Wisconsin were analyzed. Breeds included crosses among Dorset, Romanov, Targhee, Rideau Arcott, Polypay, Booroola Merino, Suffolk, Rambouillet, Finnsheep and East Friesian. The objective was to investigate genetic variation of features of lactation curves using a three-stage Bayesian hierarchy. Wood’s model, E(y | a, b, c,

Yu-Mei Chang; Romdhane Rekaya; Daniel Gianola; David L. Thomas

2001-01-01

279

An analysis of the light curves of the overcontact binary system V2388 Ophiuchi  

Microsoft Academic Search

We present four seasons' (2000-2003) ground-based photometry of the short-period contact binary V2388 Oph. The system is the brighter component of visual binary HIP 87655. The magnitude difference between the visual companion and the eclipsing pair was estimated to be 1.19 m, 1.09 m and 1.09 m in B, V and R bandpasses, respectively. The light curves in BVR are

K. Yakut; B. Kalomeni; C. Ibanoglu

2004-01-01

280

Micro-foundations of the Environmental Kuznets Curve hypothesis: an empirical analysis  

Microsoft Academic Search

The Environmental Kuznets Curve (EKC) hypothesis argues for an inverted-U shaped relationship between economic development and environmental quality. Although this relation has been mainly enquired at the macro-economic level, it is actually resting on the assumption of a number of changes in the attitudes and behaviours of high-income country citizens. This paper looks for empirical evidence underneath this assumption using

Giangiacomo Bravol; Beatrice Marelli

2007-01-01

281

Micromagnetic and Preisach analysis of the First Order Reversal Curves (FORC) diagram  

Microsoft Academic Search

The First Order Reversal Curve (FORC) diagrams of interacting single-domain ferromagnetic particle systems have been found experimentally to contain negative regions. In this paper, we use micromagnetic and phenomenological (Preisach-type) models to help explain the occurrence of these negative regions. In Preisach-type modeling, the position of the negative region is correlated with the sign of the mean-field interactions. In micromagnetic

Alexandru Stancu; Christopher Pike; Laurentiu Stoleriu; Petronel Postolache; Dorin Cimpoesu

2003-01-01

282

Breakthrough curve analysis of pressure swing adsorption for hydrogen isotope separation  

SciTech Connect

For the purpose of developing an effective system for hydrogen isotope separation, we have been studying the adsorption-desorption dynamic behavior of hydrogen and deuterium in a packed-bed column with synthetic zeolites, aimed at applying the pressure swing adsorption process. The adsorption behavior of molecules in the packed-bed is reflected in the breakthrough curves. To understand the characteristic behaviors of hydrogen isotopes in the packed-bed, we carried out breakthrough experiments in a conventional adsorption process and in a practical process following sequential processes alternating between adsorption and desorption. From the former experiments, the results were obtained that the overall mass transfer was influenced by longitudinal dispersion relating to the superficial velocity and that the process governing the mass transfer within adsorbents was diffusion in the macro-pores of pellets. In the latter experiments, unique profile breakthrough curves were observed. These curves can be described with the numerical simulation assuming the initial distributions in a packed-bed. (authors)

Kotoh, K. [Faculty of Eng., Kyushu Univ., 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Tanaka, M. [National Inst. for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292 (Japan); Sakamoto, T.; Nakamura, Y. [Faculty of Eng., Kyushu Univ., 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Asakura, Y.; Uda, T. [National Inst. for Fusion Science, 322-6 Oroshi-cho, Toki-shi, Gifu 509-5292 (Japan); Sugiyama, T. [Faculty of Eng., Nagoya Univ., Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2008-07-15

283

CONFIRMATION OF HOT JUPITER KEPLER-41b VIA PHASE CURVE ANALYSIS  

SciTech Connect

We present high precision photometry of Kepler-41, a giant planet in a 1.86 day orbit around a G6V star that was recently confirmed through radial velocity measurements. We have developed a new method to confirm giant planets solely from the photometric light curve, and we apply this method herein to Kepler-41 to establish the validity of this technique. We generate a full phase photometric model by including the primary and secondary transits, ellipsoidal variations, Doppler beaming, and reflected/emitted light from the planet. Third light contamination scenarios that can mimic a planetary transit signal are simulated by injecting a full range of dilution values into the model, and we re-fit each diluted light curve model to the light curve. The resulting constraints on the maximum occultation depth and stellar density combined with stellar evolution models rules out stellar blends and provides a measurement of the planet's mass, size, and temperature. We expect about two dozen Kepler giant planets can be confirmed via this method.

Quintana, Elisa V.; Rowe, Jason F.; Caldwell, Douglas A.; Christiansen, Jessie L.; Jenkins, Jon M.; Morris, Robert L.; Smith, Jeffrey C.; Thompson, Susan E. [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, CA 94043 (United States); Barclay, Thomas [Bay Area Environmental Research Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Howell, Steve B.; Borucki, William J.; Sanderfer, Dwight T.; Still, Martin [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, 770 South Wilson Ave., MC 100-2, Pasadena, CA 91125 (United States); Demory, Brice-Olivier [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Klaus, Todd C. [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fulton, Benjamin J.; Shporer, Avi, E-mail: elisa.quintana@nasa.gov [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States)

2013-04-20

284

Photometric analysis of the contact binary star V842 Hercules on the basis of seasonal light curves  

NASA Astrophysics Data System (ADS)

We present new BVR light curves and photometric analysis of the contact binary star V842 Her. The light curves were obtained at the ÇOMU Observatory in the consecutive years 2003, 2004, 2005, and also 2007. We studied the variation of the orbital period of the system. The O- C diagram shows a quasi-sinusoidal form superimposed on a parabola. The parabolic variation, which indicates the secular increase of the orbital period of the system, was interpreted in terms of the combined effect of mass transfer between the components of the system and mass loss by a stellar wind from the system. The sinusoidal form of the orbital period variation was considered as an apparent change and interpreted in term of the light-time effect due to an unseen component in the system. We have also studied the nature of asymmetries and the intrinsic variability in the light curves of the system. The differences between light levels of both maxima (i.e. O'Connell effect) and minima are changing with time. These peculiar asymmetries were explained by a dark spot on the surface of the large and more massive component star. The present BVR light curves and radial velocity curves obtained by [Rucinski, S.M., Lu, W., 1999. AJ 118, 2451] were analysed by means of the Wilson-Devinney method supplemented with a Monte Carlo type algorithm. Absolute parameters of the system were also derived. They are m1 = 0.38 m?, m2 = 1.45 m?, R1 = 0.81 R?, R2 = 1.47 R?, M = 5m.08 and M = 4m.06.

Erdem, A.; Özkarde?, B.

2009-04-01

285

Advances in the interpretation and analysis of lunar occultation light curves  

NASA Astrophysics Data System (ADS)

Context. The introduction of fast 2D detectors and the use of very large telescopes have significantly advanced the sensitivity and accuracy of the lunar occultation technique. Recent routine observations at the ESO Very Large Telescope have yielded hundreds of events with results, especially in the area of binary stars, which are often beyond the capabilities of any other techniques. Aims: With the increase in the quality and in the number of the events, subtle features in the light curve patterns have occasionally been detected which challenge the standard analytical definition of the lunar occultation phenomenon as diffraction from an infinite straight edge. We investigate the possible causes for the observed peculiarities. Methods: We have evaluated the available statistics of distortions in occultation light curves observed at the ESO VLT, and compared it to data from other facilities. We have developed an alternative approach to model and interpret lunar occultation light curves, based on 2D diffraction integrals describing the light curves in the presence of an arbitrary lunar limb profile. We distinguish between large limb irregularities requiring the Fresnel diffraction formalism, and small irregularities described by Fraunhofer diffraction. We have used this to generate light curves representative of several limb geometries, and attempted to relate them to some of the peculiar data observed. Results: We conclude that the majority of the observed peculiarities is due to limb irregularities, which can give origin both to anomalies in the amplitude of the diffraction fringes and to varying limb slopes. We investigate also other possible effects, such as detector response and atmospheric perturbations, finding them negligible. We have developed methods and procedures that for the first time allow us to analyze data affected by limb irregularities, with large ones bending the fringe pattern along the shape of the irregularity, and small ones creating fringe amplitude perturbations in comparison to the ideal fringe pattern. Conclusions: The effects of a variable limb slope can be satisfactorily corrected. More complex limb irregularities could be fitted in principle with a grid search based on the standard analytical model, however this method is time consuming and does not lead to unique solutions. The incidence of the limb perturbations is relatively small, but its significance is increased with the use of very large telescopes due both to the footprint at the lunar limb and to the increased sensitivity. In general, we recommend to observe occultations using sub-pupils. This will be a necessary requirement with the next generation of extremely large telescopes. Based on observations made with ESO telescopes at Paranal Observatory.

Richichi, A.; Glindemann, A.

2012-02-01

286

Unlocking the potential of survival data for model organisms through a new database and online analysis platform: SurvCurv.  

PubMed

Lifespan measurements, also called survival records, are a key phenotype in research on aging. If external hazards are excluded, aging alone determines the mortality in a population of model organisms. Understanding the biology of aging is highly desirable because of the benefits for the wide range of aging-related diseases. However, it is also extremely challenging because of the underlying complexity. Here, we describe SurvCurv, a new database and online resource focused on model organisms collating survival data for storage and analysis. All data in SurvCurv are manually curated and annotated. The database, available at www.ebi.ac.uk/thornton-srv/databases/SurvCurv/, offers various functions including plotting, Cox proportional hazards analysis, mathematical mortality models and statistical tests. It facilitates reanalysis and allows users to analyse their own data and compare it with the largest repository of model-organism data from published experiments, thus unlocking the potential of survival data and demographics in model organisms. PMID:23826631

Ziehm, Matthias; Thornton, Janet M

2013-10-01

287

The Vanderbilt EB Factory: Development of Light Curve Analysis Tools for Precision Stellar Astrophysics with Kepler Eclipsing Binaries  

NASA Astrophysics Data System (ADS)

The goal of the Vanderbilt EB Factory is to develop an end-to-end computational pipeline that allows automatic processing of massive amounts of light curve data -- from period finding, to object classification, to determination of the stellar physical properties -- in order to find the most scientifically interesting eclipsing binaries (EBs) and to permit accurate modeling of these EBs for detailed tests and benchmarking of theoretical stellar evolution models. We are integrating the most successful algorithms into a single, cohesive workflow environment, and are applying this 'EB Factory' to the full public Kepler dataset to find and characterize new "benchmark grade" EBs, and will disseminate both the enhanced data products from this pipeline and the pipeline itself to the broader NASA science community, especially other Kepler mission researchers. More generally, we are developing the EB Factory as a flexible, open source, modular framework in order to permit simple modifications by other users for a wide array of other types of variable stars of interest, such as RR Lyraes. Finally, we will present our developing suite of light-curve analysis tools available to the community from the Vanderbilt Initiative in Data-intensive Astrophysics (VIDA), including the Filtergraph instant data portal service, and the web-based LCchopper and LCanimator light-curve analysis services.

Stassun, Keivan; Paegert, M.; De Lee, N. M.; Cargile, P.

2013-01-01

288

Unlocking the potential of survival data for model organisms through a new database and online analysis platform: SurvCurv  

PubMed Central

Lifespan measurements, also called survival records, are a key phenotype in research on aging. If external hazards are excluded, aging alone determines the mortality in a population of model organisms. Understanding the biology of aging is highly desirable because of the benefits for the wide range of aging-related diseases. However, it is also extremely challenging because of the underlying complexity. Here, we describe SurvCurv, a new database and online resource focused on model organisms collating survival data for storage and analysis. All data in SurvCurv are manually curated and annotated. The database, available at http://www.ebi.ac.uk/thornton-srv/databases/SurvCurv/, offers various functions including plotting, Cox proportional hazards analysis, mathematical mortality models and statistical tests. It facilitates reanalysis and allows users to analyse their own data and compare it with the largest repository of model-organism data from published experiments, thus unlocking the potential of survival data and demographics in model organisms.

Ziehm, Matthias; Thornton, Janet M

2013-01-01

289

Origin of the Uinta recess, Sevier fold thrust belt, Utah: influence of basin architecture on fold thrust belt geometry  

NASA Astrophysics Data System (ADS)

Structural trends in the Sevier fold-thrust belt define a pronounced concave-to-the-foreland map-view curve, the Uinta recess, in north-central Utah. This recess separates two convex-to-the-foreland curves, the Provo salient on the south and the Wyoming salient on the north. The two limbs of the recess comprise transverse zones (fault zones at a high-angle to the regional trend of the orogen) that border the flanks of the east-west-trending Uinta/Cottonwood arch. Our structural analysis indicates that the transverse zones formed during the Sevier orogeny, and that they differ markedly from each other in structural style. The Charleston transverse zone (CTZ), on the south side of the arch, initiated as a complex sinistral strike-slip fault system that defines the abrupt northern boundary of the Provo salient. The Mount Raymond transverse zone (MRTZ), on the north side of the arch, represents the region in which the southeast-verging southern limb of the gently curving Wyoming salient was tilted northwards during the Laramide phase of uplift of the Uinta/Cottonwood arch. In effect, the MRTZ represents an oblique cross section through a thrust belt. The contrasting architecture of these transverse zones demonstrates how pre-deformation basin geometry influences the geometry of a fold-thrust belt. Analysis of isopach maps indicates that, at the time the Sevier fold-thrust belt formed, the area just north of the present site of the Uinta/Cottonwood arch was a basement high, with a gently dipping north flank, and a steeply dipping south flank. Thus, predeformational sediment thickened abruptly to the south of the high and thickened gradually to the north of the high. As illustrated by sandbox models, the distance that a fold-thrust belt propagates into the foreland depends on the thickness of the sedimentary layer being deformed, so the shape of the salient mimics the longitudinal cross-sectional shape of the sedimentary basin. Where basins taper gradually along strike, the thrust belt curves gently, but where basins taper abruptly along strike, the thrust belt curves so tightly that it disarticulates and becomes bounded laterally by a strike-slip accommodation zone. The geometry of the Uinta recess provides a field example of this concept. Differential movement of Sevier thrusts led to formation of gradually curving thrusts on the north side of the high, because of the gradual slope of the high's north flank, but led to the along-strike disarticulation of thrusts on the south side of the high, because of the steep slope of the high's south flank. In effect, therefore, thrust belt map-view geometry provides insight into predeformational basin geometry.

Paulsen, Timothy; Marshak, Stephen

1999-11-01

290

Maintaining health insurance during a recession: likely COBRA eligibility: an updated analysis using the Commonwealth Fund 2007 Biennial Health Insurance Survey.  

PubMed

As the U.S. economic downturn continues and job losses mount, more working Americans are likely to lose access to affordable health benefits subsidized by their employers. Analysis of the 2007 Commonwealth Fund Biennial Health Insurance Survey finds that two of three working adults would be eligible to extend job-based coverage, under the 1985 Consolidated Omnibus Budget Reconciliation Act (COBRA) if they became unemployed. Under COBRA, however, unemployed workers would have to pay four to six times their current contribution at a time of sharply reduced income. In fact, the latest national figures indicate that, because of high premiums, only 9 percent of unemployed workers have COBRA coverage. Substantial financial assistance of 75 percent to 85 percent of premiums could help laid-off workers maintain coverage. In addition, expansion of Medicaid and the State Children's Health Insurance Program would benefit low-income, laid-off workers and their families who are ineligible for COBRA. PMID:19288628

Doty, Michelle; Rustgi, Sheila D; Schoen, Cathy; Collins, Sara R

2009-01-01

291

Non-specific nasal provocation test with histamine. Analysis of the dose-response curve.  

PubMed

Non-Specific Nasal Hyper-reactivity (NSNH) is described as a clinical condition characterized by the presence of rhinitic symptoms that are a consequence of non-specific stimulations. Because of its effects on vascular, epithelial, and glandular receptors, NSNP Test (NSNPT) with histamine allows the study of NSNH. The aims of this study are 1. to analyze the behavior of NSNH both in non-allergic chronic vasomotory patients and in healthy control subjects 2. to correlate total nasal resistance(TNR) to each dosage of histamine to derive the dose/response curves and 3. to study these curves to analyze and possibly define different stages according to the intensities of response of NSNH. We have studied 26 subjects affected by non-allergic vasomotor rhinitis and 10 healthy control subjects. We sprayed a NSNPT with histamine-phosphate (0.2-0.3-0.4-0.5-0.6-0.8 mg) in different sessions to avoid accumulation phenomena. Five minutes before and five minutes after each challenge, TNR was determined by active anterior rhinomanometry. TNR was correlated to the doses of histamine by an empirical equation. The most important results of this study are as follows: a) the variation of TNR follows a model of exponential curve, b) it is possible to classify NSNH, as a function of the regression b coefficient belonging to the empirical equation used, in reactivity classes, c) from one reactivity class to another, post-stimulation TNRs double; 0.5 mg of histamine of the NSNPT is the optimal dose, d) there is an overlap between the responses of some normal subjects and rhinopathic patients that will be the subject of a further study. Finally, our data suggest that, in a future perspective, it is possible to use the NSNPT with histamine for diagnostic, prognostic and therapeutic control purposes. PMID:10670031

Zambetti, G; Moresi, M; Romeo, R; Luce, M; Filiaci, F

1999-12-01

292

Criticism of Lake's analysis of the rotation curves of dwarf spirals  

NASA Astrophysics Data System (ADS)

This paper disputes the presence of a disparity found by Lake (1989) between the predictions of MOND and the observed rotation curves of five (out of the total six observed) dwarf spirals. Lake reported that the observed rotation velocities of DDO 154, NGC 3109, VCC 381, IC 1613, and DDO 125 were smaller than the velocities predicted by MOND by factors of about 1.2, 1.3, 1.5, 2, and 1.8. It is shown that, in each case, errors in the adopted distances and/or inclinations can fully account for the observed disparities between the theory and measurements.

Milgrom, Mordehai

1991-02-01

293

Analysis and solution of the light and radial velocity curves of the contact binary TY Bootis  

SciTech Connect

Observations and analyses of the binary TY Bootis are presented. Radial velocity data are used for the first time to establish the mass ratio without ambiguity, and an advanced version of the Wilson-Devinney synthetic light curve program is used to analyze and solve the system. A reasonably robust set of parameters is obtained. TY Boo is found to be a W-type W UMa system with a mass ratio near two and a contact parameter of 0.12 + or - 0.903, indicating only shallow contact. 69 refs.

Milone, E.F.; Groisman, G.; Fry, D.J.I.; Bradstreet, D.H. (Rothney Astrophysical Observatory, Calgary (Canada) Eastern College, Saint Davids, PA (USA))

1991-04-01

294

Buckling Analysis of Anisotropic Curved Panels and Shells with Variable Curvature  

NASA Technical Reports Server (NTRS)

A buckling formulation for anisotropic curved panels with variable curvature is presented in this paper. The variable curvature panel is assumed to consists of two or more panels of constant but different curvatures. Bezier functions are used as Ritz functions Displacement (C(sup 0)), and slope (C(sup 1)) continuities between segments are imposed by manipulation of the Bezier control points. A first-order shear-deformation theory is used in the buckling formulation. Results obtained from the present formulation are compared with those from finite element simulations and are found to be in good agreement.

Jaunky, Navin; Knight, Norman F., Jr.; Ambur, Damodar R.

1998-01-01

295

Using growth curve analysis to examine challenges in instrumentation in longitudinal measurement in home visiting.  

PubMed

Home visitation programs aim to decrease child maltreatment, yet limited longitudinal data exists concerning their screening and assessment instruments. "At risk" families (N = 2,054) were screened using the Family Stress Checklist and referred to Healthy Families Indiana. The Home Observation Measurement of the Environment Scale (HOME) and Community Life Skills Scale (CLS) were administered at multiple intervals. Growth curve analyses indicate families with lower HOME and CLS scores received more home visits and visits between assessments. However, these instruments may have "ceiling effects" and may be unsuitable for longitudinal assessment and program evaluation. Programmatic changes were made based on evaluation results. PMID:24405137

Goltz, Heather Honoré; Mena, Kristin Cotter; Swank, Paul R

2014-01-01

296

Consequence analysis by means of characteristic curves to determine the damage to humans from the detonation of explosive substances as a function of TNT equivalence  

Microsoft Academic Search

In a previous paper, the characteristic overpressure–impulse–distance curves for the detonation of explosive substances were presented. They allow the overpressure and impulse to be determined at each distance from the detonation. When combined with damage criteria (such as those shown by the Probit equations), the characteristic curves allow consequence analysis for this kind of explosion to be carried out in

Fernando Díaz Alonso; Enrique González Ferradás; Juan Francisco Sánchez Pérez; Agustín Miñana Aznar; José Ruiz Gimeno; Jesús Martínez Alonso

2007-01-01

297

Models for recession flows in the upper Blue Nile River  

Microsoft Academic Search

Stream-flow recessions are commonly characterized by the exponential equation or in the alternative power form equation of a single linear reservoir. The most common measure of recession is the recession constant K, which relates to the power function form of the recession equation for a linear reservoir. However, in reality it can be seen that the groundwater dynamics of even

A. Mishra; T. Hata; A. W. Abdelhadi

2004-01-01

298

Classification of breast mass lesions using model-based analysis of the characteristic kinetic curve derived from fuzzy c-means clustering.  

PubMed

The purpose of this study is to evaluate the diagnostic efficacy of the representative characteristic kinetic curve of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) extracted by fuzzy c-means (FCM) clustering for the discrimination of benign and malignant breast tumors using a novel computer-aided diagnosis (CAD) system. About the research data set, DCE-MRIs of 132 solid breast masses with definite histopathologic diagnosis (63 benign and 69 malignant) were used in this study. At first, the tumor region was automatically segmented using the region growing method based on the integrated color map formed by the combination of kinetic and area under curve color map. Then, the FCM clustering was used to identify the time-signal curve with the larger initial enhancement inside the segmented region as the representative kinetic curve, and then the parameters of the Tofts pharmacokinetic model for the representative kinetic curve were compared with conventional curve analysis (maximal enhancement, time to peak, uptake rate and washout rate) for each mass. The results were analyzed with a receiver operating characteristic curve and Student's t test to evaluate the classification performance. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value of the combined model-based parameters of the extracted kinetic curve from FCM clustering were 86.36% (114/132), 85.51% (59/69), 87.30% (55/63), 88.06% (59/67) and 84.62% (55/65), better than those from a conventional curve analysis. The A(Z) value was 0.9154 for Tofts model-based parametric features, better than that for conventional curve analysis (0.8673), for discriminating malignant and benign lesions. In conclusion, model-based analysis of the characteristic kinetic curve of breast mass derived from FCM clustering provides effective lesion classification. This approach has potential in the development of a CAD system for DCE breast MRI. PMID:22245697

Chang, Yeun-Chung; Huang, Yan-Hao; Huang, Chiun-Sheng; Chang, Pei-Kang; Chen, Jeon-Hor; Chang, Ruey-Feng

2012-04-01

299

Evolution of the North Caucasus foredeep: constraints based on the analysis of subsidence curves  

NASA Astrophysics Data System (ADS)

Using a database of more than 130 wells the Alpine evolution of the North Caucasus foredeep can be described in three main periods. (1) The Early Jurassic to Middle-Late Cretaceous (including the Cenomanian) relates to the initial rifting phase and was characterised by succession of comparatively high rates of subsidence and uplift. During this stage, many events in the eastern and western parts were synchronous, whereas some of them appeared to be smoothed in the Stavropol high. The southern border of the area had a more complex behaviour often moving in the opposite direction relative to the rest of the area. The main peculiarities of evolution of the Great Caucasus region can be explained if we adopt the hypothesis of Stamply and Pillevuit (1993)and suppose that the Early Jurassic extension of the trough was accompanied by a strong left-lateral transform movement. As a result the central part of the Great Caucasus trough formed as a pull-apart basin. Analysis of the style of movements of the southern border of the Scythian plate as well as data on tectonics and volcanism in the Great and Lesser Caucasus showed that other regional compressional and extensional Mesozoic events could also have a transform component. Shear stresses within the lithosphere of the Great Caucasus can be due to oblique subduction or even transform movements at the plate boundary to the south of the Caucasus region ( Dercourt et al., 1993). (2) The period from the Late Cretaceous to the Middle Eocene (from the Turonian to the Bartonian) relates to the oceanic suture of the Lesser Caucasus and was characterised in the Great Caucasus area by alternating subsidence and uplift events of considerably lower amplitude (at least up to the Maastrichtian). Beginning in the Late Paleocene, subsidence curves for almost all the area reflect the same events, but in the western part and also in the north of the central part the rate of movements was considerably higher and since the Late Paleocene short term events in this area took place on the background of rather fast subsidence at nearly constant rate. We believe that this subsidence and formation of the East Black Sea depression have the same origin. We consider strong differences in evolution of the eastern, western and central parts during the second stage to be due to closure of the Lesser Caucasus oceanic basin and arrival of the Nakhichevan block. This led to changes of configuration of the plate boundary and resulted in reorganisation of stress and displacements within the Caucasus region. This reorganisation was a reason for the opening of the East Black Sea depression and rapid subsidence of the western and central parts of the area at the end of the second stage. (3) The period from the Middle Eocene to the present relates to the development of a foreland basin coeval with shortening and uplift in the adjacent Great Caucasus range. It was characterised by alternation of relatively short uplift and longer subsidence events. An important feature of this stage is that although the amplitude of movements varied from place to place, these events were synchronous in all parts of the foredeep (at the Stavropol region sediments preserved only for the beginning of this stage). Formation and evolution of the foredeep during the third stage can not be explained exclusively by elastic flexure. To do this we used the model of a small-scale convection within the asthenosphere ( Mikhailov et al. 1996, 1999). By the comparison of numerical results with the data on the evolution of the North Caucasus foredeep we concluded that there were four main stages of compression in the processes of formation of the Great Caucasus mountain belt. The first compression took place before the Maykopian (between 39.5 and 36.0 Ma). The other three were in the Tarkhanian (16.6-15.8 Ma), Konkian-Early Sarmatian (14.3-12.3 Ma) and Pontian (7.0-5.2 Ma). The different width of the Great Caucasus trough by the beginning of the compression, as well as variations in thickness of the lithosphere and a different thermal state can cause in

Mikhailov, Valentine O.; V. Panina, Ludmila; Polino, Riccardo; Koronovsky, Nikolay V.; Kiseleva, Elena A.; Klavdieva, Natalya V.; Smolyaninova, Ekaterina I.

1999-06-01

300

Light Curves  

NSDL National Science Digital Library

This is a game about light curves that will test your ability to figure out things about an asteroid from just a graph of its brightness. Astronomers use telescopes to collect light curves - measurements of the brightness of distant asteroids over time. It is part of the Killer Asteroids Web Site. The site also features a background overview of the differences between asteroids and comets, information on different types of asteroids (rubble piles vs monoliths), a discussion of how at risk Earth really is to an asteroid or comet impact, and background information on light curves.

301

Inferior rectus recession--an effective procedure?  

PubMed Central

AIMS—To examine the postoperative stability of inferior rectus recession, with particular reference to the incidence of progressive overcorrection.?METHODS—The results of consecutive patients undergoing inferior rectus recession over a 3 year period were reviewed.?RESULTS—21 patients underwent inferior rectus recession, using an adjustable suture technique in all but three cases. In 16 patients additional vertical muscle surgery was performed at the time of the inferior rectus recession. All patients were followed for a minimum of 3 months postoperatively, with a mean follow up of 9.3 months. At the final postoperative visit 11 patients were well aligned, eight were undercorrected, and two were overcorrected. In five of the eight undercorrected cases, the residual deviation was the result of postoperative drift in the direction of the preoperative deviation, following an initially good alignment. Review of the results failed to reveal any factor predictive for this postoperative drift.?CONCLUSION—The risk of postoperative overcorrection following inferior rectus recession should be considered, but in this study, undercorrection occurred more frequently than overcorrection. The possible reasons for overcorrection and undercorrection are discussed.??

Scotcher, S.; O'Flynn, E.; Morris, R.

1997-01-01

302

Estimation of aquifer parameters from the recession of spring hydrographs - Influence of flow geometry  

NASA Astrophysics Data System (ADS)

The recession of spring hydrographs can be used to infer information about hydraulic aquifer properties, such as hydraulic conductivity and storage coefficient, at the catchment scale . Frequently, the approach by Rorabaugh (IAHS Publ. 63, 432-441, 1964) is employed for this purpose. Since this approach was derived for parallel flow from the aquifer to a stream, Sahuquillo and Gomez-Hernandez (Water Resour. Res. 39(6), 2003) questioned its applicability to springs with radial flow geometry. The objective of this work is to assess the influence of the flow geometry on the parameter estimates resulting from the evaluation of recession hydrographs. To this end, the radial flow equation is solved using a finite-difference model and the resulting recession curves are compared to the analytical solution by Rorabaugh. We found that the hydrograph of a homogeneous spring catchment with radial flow approaches the long-term exponential recession much more rapidly than that with parallel flow. But even more important, the recession coefficient itself strongly depends on the flow geometry: In case of radial flow the recession is significantly slower and thus the recession coefficient is lower than that predicted by the parallel flow model. As a consequence, the application of the parallel flow model to observed recession curves results in an underestimation of the hydraulic conductivity (given a constant storage) by an order of magnitude if flow to the spring is actually radial. However, the assumption of a homogeneous radial flow domain may be inappropriate at least in the case of karst catchments where the spring is fed by highly conductive karst conduits: Results from karst evolution models (e.g. Liedl et al., Water Resour. Res. 39(3), 2003) suggest that the hydraulic conductivity of the conduit system increases towards the spring. An increase inversely proportional to the distance from the spring compensates the effect of the decrease in flow cross-section towards the spring. In this case, the recession coefficient is similar to that of a homogeneous model with parallel flow geometry. Thus, the parallel flow approach by Rorabaugh indeed might be suitable for obtaining rough estimates of the hydraulic conductivity of karst aquifers at catchment scale.

Birk, S.; Hergarten, S.

2012-04-01

303

Light Curve Analysis for W UMa-Type Eclipsing Binary Star Systems  

NASA Astrophysics Data System (ADS)

We report results from summer 2006 in an ongoing study of eclipsing binary stars. Our investigations have focused on the measurement and interpretation of light curves for W UMa-type systems 44i Boötis and VW Cephei. These contact binaries have component stars of spectral type G, and revolve with periods of 6.43 and 6.67 hours. Dome automation and scripting capabilities introduced this summer have significantly reduced experimental uncertainties in our data. In support of previous findings we continue to observe an increase in the orbital period of 44i Boo at a rate of 10.4 µs/epoch or 14.2 ms/yr. Residuals computed after incorporating the increasing period suggest an underlying sinusoidal oscillation with a 61.5 year period and amplitude of 648 seconds. AAPT Member Thomas Olsen is sponsoring the lead presenter, SPS Member Scott Henderson, and the co-presenter, SPS Member Nick Peach.

Henderson, Scott; Peach, N.; Olsen, T.

2006-12-01

304

Quantitative vibrational imaging by hyperspectral stimulated Raman scattering microscopy and multivariate curve resolution analysis.  

PubMed

Spectroscopic imaging has been an increasingly critical approach for unveiling specific molecules in biological environments. Toward this goal, we demonstrate hyperspectral stimulated Raman loss (SRL) imaging by intrapulse spectral scanning through a femtosecond pulse shaper. The hyperspectral stack of SRL images is further analyzed by a multivariate curve resolution (MCR) method to reconstruct quantitative concentration images for each individual component and retrieve the corresponding vibrational Raman spectra. Using these methods, we demonstrate quantitative mapping of dimethyl sulfoxide concentration in aqueous solutions and in fat tissue. Moreover, MCR is performed on SRL images of breast cancer cells to generate maps of principal chemical components along with their respective vibrational spectra. These results show the great capability and potential of hyperspectral SRL microscopy for quantitative imaging of complicated biomolecule mixtures through resolving overlapped Raman bands. PMID:23198914

Zhang, Delong; Wang, Ping; Slipchenko, Mikhail N; Ben-Amotz, Dor; Weiner, Andrew M; Cheng, Ji-Xin

2013-01-01

305

Type curve analysis of inertial effects in the response of a well to a slug test.  

USGS Publications Warehouse

The water level response to a slug or bailer test in a well completed in a confined aquifer, has been evaluated taking into account well-bore storage and inertial effects of the water column in the well. The response range, from overdamped with negligible inertial effects to damped oscillations, was covered employing numerical inversions of the Laplace-transform solution. By scaling the time with respect to the undamped natural period of the well-aquifer system and by using the damping parameter for a second-order damped, inertial-elastic system, a set of type curves was constructed that enables water level response data from a slug or bailer test to be analyzed under conditions where the inertial parameter is large.-from Author

Kipp, Jr, K. L.

1985-01-01

306

Quantitative Vibrational Imaging by Hyperspectral Stimulated Raman Scattering Microscopy and Multivariate Curve Resolution Analysis  

PubMed Central

Spectroscopic imaging has been an increasingly critical approach for unveiling specific molecules in biological environments. Towards this goal, we demonstrate hyperspectral stimulated Raman loss (SRL) imaging by intra-pulse spectral scanning through a femtosecond pulse shaper. The hyperspectral stack of SRL images is further analyzed by a multivariate curve resolution (MCR) method to reconstruct quantitative concentration images for each individual component and retrieve the corresponding vibrational Raman spectra. Using these methods, we demonstrate quantitative mapping of dimethyl sulfoxide concentration in aqueous solutions and in fat tissue. Moreover, MCR is performed on SRL images of breast cancer cells to generate maps of principal chemical components along with their respective vibrational spectra. These results show the great capability and potential of hyperspectral SRL microscopy for quantitative imaging of complicated biomolecule mixtures through resolving overlapped Raman bands.

Zhang, Delong; Wang, Ping; Slipchenko, Mikhail N.; Ben-Amotz, Dor; Weiner, Andrew M.; Cheng, Ji-Xin

2013-01-01

307

Simultaneous detection of Listeria monocytogenes and Salmonella spp. in dairy products using real time PCR-melt curve analysis  

Microsoft Academic Search

The present investigation reports development of post real time PCR (RTi-PCR) - melt curve analysis for simultaneous detection\\u000a of Listeria monocytogenes and Salmonella spp. The optimal Sybr Green I (SG-I) concentration of 1.6 ?M resulted in two specific peaks with melting temperature (Tm)\\u000a of 79.90?±?0.39 °C and 86.29?±?0.13 °C for L. monocytogenes and Salmonella spp respectively. The detection sensitivity of the assay in

Jitender Singh; Virender K. Batish; Sunita Grover

308

Estimation of kinetic parameters by progress curve analysis for the synthesis of (R)-mandelonitrile by Prunus amygdalus hydroxynitrile lyase.  

PubMed

Consistent sets of kinetic parameters were estimated for the synthesis of (R)-mandelonitrile, catalyzed by Prunus amygdalus hydroxynitrile lyase, at 5 and 25 degrees C and pH 5.5 by progress curve analysis. The rate constants and equilibrium constants of the nonenzymatic reaction were determined separately to reduce the number of parameters to be estimated simultaneously. At a lower temperature the equilibrium is much more favorable and the formation of rac-mandelonitrile by the nonenzymatic reaction is suppressed. The estimated kinetic parameters were used to identify that the rate determining step in the catalytic cycle is the release of (R)-mandelonitrile from the ternary complex. PMID:10938422

Willeman; Hanefeld; Straathof; Heijnen

2000-09-01

309

Non-regularized inversion method from light scattering applied to ferrofluid magnetization curves for magnetic size distribution analysis  

NASA Astrophysics Data System (ADS)

A numerical inversion method known from the analysis of light scattering by colloidal dispersions is now applied to magnetization curves of ferrofluids. The distribution of magnetic particle sizes or dipole moments is determined without assuming that the distribution is unimodal or of a particular shape. The inversion method enforces positive number densities via a non-negative least squares procedure. It is tested successfully on experimental and simulated data for ferrofluid samples with known multimodal size distributions. The created computer program MINORIM is made available on the web.

van Rijssel, Jos; Kuipers, Bonny W. M.; Erné, Ben H.

2014-03-01

310

Acoustic emission analysis of full-scale honeycomb sandwich composite curved fuselage panels  

NASA Astrophysics Data System (ADS)

Acoustic emission (AE) was monitored in notched full-scale honeycomb sandwich composite curved fuselage panels during loading. The purpose of the study was to evaluate the AE technique as a tool for detecting notch tip damage initiation and evaluating damage severity in such structures. This evaluation was a part of a more general study on the damage tolerance of six honeycomb sandwich composite curved panels, each containing a different damage scenario. The overall program objective was to investigate the effects of holes and notches on residual strength. The investigation was conducted using the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration William J. Hughes Technical Center, Atlantic City International Airport, NJ. This paper reports on the AE results recorded during the loading to failure of two selected panels. The results show that damage initiation at the tips of the notches, and its progression along the panel, could be detected and located. These AE results were correlated with the deformation and strain fields measured through strain photogrammetry, throughout loading, at the vicinity of these notches. This correlation aided in interpreting the AE results. While the fretting among the newly created fracture surfaces generated a large number of low-intensity AE signals, the high-intensity signals generated at high load levels provided a good measure for anticipating incipient fracture. Further, the AE results located internal disbonding caused during panel fabrication. The large number of low-intensity AE signals generated from the disbonded regions was associated with the fretting among the disbonded surfaces.

Leone, Frank A., Jr.; Ozevin, Didem; Godinez, Valery; Mosinyi, Bao; Bakuckas, John G., Jr.; Awerbuch, Jonathan; Lau, Alan; Tan, Tein-Min

2008-04-01

311

Simultaneous detection of Fusarium culmorum and F. graminearum in plant material by duplex PCR with melting curve analysis  

PubMed Central

Background Fusarium head blight (FHB) is a disease of cereal crops, which has a severe impact on wheat and barley production worldwide. Apart from reducing the yield and impairing grain quality, FHB leads to contamination of grain with toxic secondary metabolites (mycotoxins), which pose a health risk to humans and livestock. The Fusarium species primarily involved in FHB are F. graminearum and F. culmorum. A key prerequisite for a reduction in the incidence of FHB is an understanding of its epidemiology. Results We describe a duplex-PCR-based method for the simultaneous detection of F. culmorum and F. graminearum in plant material. Species-specific PCR products are identified by melting curve analysis performed in a real-time thermocycler in the presence of the fluorescent dye SYBR Green I. In contrast to multiplex real-time PCR assays, the method does not use doubly labeled hybridization probes. Conclusion PCR with product differentiation by melting curve analysis offers a cost-effective means of qualitative analysis for the presence of F. culmorum and F. graminearum in plant material. This method is particularly suitable for epidemiological studies involving a large number of samples.

Brandfass, Christoph; Karlovsky, Petr

2006-01-01

312

Surface recession characteristics of a cryogenic insulation subjected to arc-tunnel heating  

NASA Technical Reports Server (NTRS)

Specimens of a cryogenic insulation, proposed for use on the space shuttle external tank, were tested in an arc tunnel over a range of heating rates, pressures, and enthalpies corresponding to the shuttle ascent environment. A regression analysis was used to correlate the test data. Correlation equations involving surface recession rate as a function of heating rate, pressure, and enthalpy were developed. These equations can be used to make total surface recession predictions for shuttle ascent flight environments.

Pittman, C. M.; Brown, R. D.

1975-01-01

313

Perception of smile esthetics varies between patients and dental professionals when recession defects are present.  

PubMed

The aim of this study was to compare the smile esthetic perception of patients, dental students and dentists faced to different situations concerning gingival margin position. A total of 123 individuals (41 patients, 41 dental students and 41 dentists) completed a structured questionnaire and evaluated 6 pictures of the same smile modified in Adobe Photoshop® image-editing software representing: no gingival recession, 2 mm recession in one maxillary lateral incisor, 2 mm recession in both maxillary lateral incisors, 2 mm recession in one maxillary canine, 2 mm recession in both maxillary canines and generalized 2 mm recession. The visual analogue scale (VAS) was used to rate the esthetic perception. Mean VAS values were calculated and compared among gingival situations as well as group of respondents by one-way ANOVA, with an alpha level of 0.05. VAS analysis revealed that mean values ranged from 4.2 (±1.8) to 6.8 (±1.7). Images with no gingival recession received the highest score by all groups, with statistically significant differences among dentists and dental students. However, patients scored images with no recession with significantly lower ranks as compared with dentists and dental students. No significant differences were observed among patients for any of the situations. When dentists and dental students were compared, the worst situation was observed for generalized gingival recession, with scores 4.2 (±1.8) and 4.9 (±1.8), respectively. Patients and dental professionals had different perceptions about esthetics related to gingival margin position. PMID:24173262

Musskopf, Marta Liliana; Rocha, José Mariano da; Rösing, Cassiano Kuchenbecker

2013-01-01

314

Transforaminal arthroscopic decompression of lateral recess stenosis.  

PubMed

The purpose of this study was to evaluate the feasibility and efficacy of arthroscopic decompression of lateral recess stenosis, determine potential associated complications, and present an alternative method to access the lateral recess of the lumbar spine. Forty patients were selected in whom the authors found clinical and computerized tomography evidence of lateral recess stenosis and sequestered foraminal herniations. All 40 were treated with a posterolateral arthroscopic technique, and 38 were available for this follow-up evaluation. A satisfactory result was obtained in 31 patients (82%). No neurovascular complications were encountered; however, other complications included an infection of the disc space in one patient and a causalgic-type pain in the involved extremity in four patients. The associated postoperative morbidity in this group of patients was minimal and resulted in rapid rehabilitation and return of patients to preoperative functioning level. PMID:8609559

Kambin, P; Casey, K; O'Brien, E; Zhou, L

1996-03-01

315

Quantitative summaries of treatment effect estimates obtained with network meta-analysis of survival curves to inform decision-making  

PubMed Central

Background Increasingly, network meta-analysis (NMA) of published survival data are based on parametric survival curves as opposed to reported hazard ratios to avoid relying on the proportional hazards assumption. If a Bayesian framework is used for the NMA, rank probabilities associated with the alternative treatments can be obtained, which directly support decision-making. In the context of survival analysis multiple treatment effect measures are available to inform the rank probabilities. Methods A fractional polynomial NMA of overall survival in advanced melanoma was performed as an illustrative example. Rank probabilities were calculated and presented for the following effect measures: 1) median survival; 2) expected survival; 3) mean survival at the follow-up time point of the trial with the shortest follow-up; 4) hazard or hazard ratio over time; 5) cumulative hazard or survival proportions over time; and 6) mean survival at subsequent time points. The advantages and disadvantages of the alternative measures were discussed. Results Since hazard and survival estimates may vary over time for the compared interventions, calculations of rank probabilities for an NMA of survival curves may depend on the effect measure. With methods 1–3 rank probabilities do not vary over time, which are easier to understand and communicate than rank probabilities that vary over time as obtained with methods 4–6. However, rank probabilities based on methods 4–6 provide useful information regarding the relative treatment effects over time. Conclusions Different approaches to summarize results of a NMA of survival curves with rank probabilities have pros and cons. Rank probabilities of treatment effects over time provide a more transparent and informative approach to help guide decision-making than single rank probabilities based on collapsed measures, such as median survival or expected survival. Rank probabilities based on survival proportions are the most intuitive and straightforward to communicate, but alternatives based on the hazard function or mean survival over time may also be useful.

2013-01-01

316

3 Tesla Dynamic Contrast Enhanced Magnetic Resonance Imaging of the Breast: Pharmacokinetic Parameters versus Conventional Kinetic Curve Analysis  

PubMed Central

Purpose To evaluate the incremental value of pharmacokinetic analysis of dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) compared to conventional breast MRI (morphology plus kinetic curve type analysis) in characterizing breast lesions as malignant or benign. Patients and Methods The study was approved by our institutional review board. Patients underwent 3D high resolution T1 (3DT1) contrast enhanced MRI and dynamic contrast enhancement (DCE) MRI at 3T, and had pathology proven diagnosis (95%) or more than 2 years follow up confirming lesion stability (5%). Lesions were identified using the high-spatial resolution post-contrast MRI. Morphologic features (margin, enhancement pattern) and conventional DCE-MRI results (kinetic curve types I, II or III) or pharmacokinetic parameters (wash-in rate Ktrans, washout rate Kep, and leakage space volume Ve), were included in multivariate models for prediction of benign versus malignant diagnosis. Results 95 patients with 101 lesions were included: 52% of patients were pre-menopausal and 48% post-menopausal. Sixty eight lesions (67.3%) were malignant and 33 (32.7%) were benign. There was a significant association between Ktrans and Kep and the diagnosis of benign versus malignant (p<0.001). The AUC for morphologic features (lesion margin and enhancement pattern) was 0.85, while inclusion of Ktrans or Kep in the model showed similar modest improvement in performance (AUC, 0.88–0.89). Conclusion The use of kinetic curve type assessment or pharmacokinetic modeling in conjunction with high resolution 3D breast MRI appears to offer similar improvement in diagnostic performance..

El Khouli, Riham H.; Macura, Katarzyna J.; Kamel, Ihab R.; Jacobs, Michael A.; Bluemke, David A.

2012-01-01

317

A canine autosomal recessive model of collagen type III glomerulopathy.  

PubMed

Collagen type III glomerulopathy (Col3GP) is a rare renal disease characterized by massive glomerular accumulations of collagen type III. The disease occurs in both humans and animals, and has been presumed to be heritable with an autosomal recessive inheritance pattern. The pathogenesis is unknown. We describe herein a condition of canine autosomal recessive Col3GP. This spontaneously occurring canine disease was incidentally diagnosed in six mongrel dogs. We then established and studied a pedigree segregating the disease to confirm the genetic nature and inheritance of canine Col3GP. Twenty-nine percent of offspring (14/48) were affected, strongly supporting a simple autosomal recessive inheritance pattern. Kidney specimens were studied by light microscopy, electron microscopy (EM), immunohistochemistry and in situ hybridization. Characteristic findings of Col3GP previously reported in both humans and animals were demonstrated, including massive glomerular collagen type III deposition, and evidence of local mesangial collagen type III synthesis was found. We propose that canine Col3GP may serve as an animal model of human Col3GP. Our initial studies, using simple segregation analysis, showed that the Col3A1 gene was not involved in the disease. This is the first animal model of Col3GP, and further studies of this phenotype in dogs may have the potential to provide information on the pathogenesis and genetics of the disease in both animals and humans, and may thus contribute to the development of treatment regimes. PMID:22890554

Rørtveit, Runa; Lingaas, Frode; Bønsdorff, Tina; Eggertsdóttir, Anna V; Grøndahl, Ann M; Thomassen, Ragnar; Fogo, Agnes B; Jansen, Johan H

2012-10-01

318

Glacier recession in Iceland and Austria  

NASA Technical Reports Server (NTRS)

It has been possible to measure glacier recession on the basis of Landsat data, in conjunction with comparisons of the magnitude of recession of a glacier margin with in situ measurements at fixed points along the same margin. Attention is presently given to the cases of Vatnajokull ice cap, in Iceland, and the Pasterze Glacier, in Austria, on the basis of satellite data from 1973-1987 and 1984-1990, respectively. Indications of a trend toward negative mass balance are noted. Nevertheless, while most of the world's small glaciers have been receding, some are advancing either due to local climate or the tidewater glacier cycle.

Hall, Dorothy K.; Williams, Richard S., Jr.; Bayr, Klaus J.

1992-01-01

319

Glacier recession in Iceland and Austria  

NASA Astrophysics Data System (ADS)

It has been possible to measure glacier recession on the basis of Landsat data, in conjunction with comparisons of the magnitude of recession of a glacier margin with in situ measurements at fixed points along the same margin. Attention is presently given to the cases of Vatnajokull ice cap, in Iceland, and the Pasterze Glacier, in Austria, on the basis of satellite data from 1973-1987 and 1984-1990, respectively. Indications of a trend toward negative mass balance are noted. Nevertheless, while most of the world's small glaciers have been receding, some are advancing either due to local climate or the tidewater glacier cycle.

Hall, Dorothy K.; Williams, Richard S., Jr.; Bayr, Klaus J.

1992-03-01

320

From principal curves to granular principal curves.  

PubMed

Principal curves arising as an essential construct in dimensionality reduction and data analysis have recently attracted much attention from theoretical as well as practical perspective. In many real-world situations, however, the efficiency of existing principal curves algorithms is often arguable, in particular when dealing with massive data owing to the associated high computational complexity. A certain drawback of these constructs stems from the fact that in several applications principal curves cannot fully capture some essential problem-oriented facets of the data dealing with width, aspect ratio, width change, etc. Information granulation is a powerful tool supporting processing and interpreting massive data. In this paper, invoking the underlying ideas of information granulation, we propose a granular principal curves approach, regarded as an extension of principal curves algorithms, to improve efficiency and achieve a sound accuracy-efficiency tradeoff. First, large amounts of numerical data are granulated into C intervals-information granules developed with the use of fuzzy C-means clustering and the two criteria of information granulation, which significantly reduce the amount of data to be processed at the later phase of the overall design. Granular principal curves are then constructed by determining the upper and the lower bounds of the interval data. Finally, we develop an objective function using the criteria of information confidence and specificity to evaluate the granular output formed by the principal curves. We also optimize the granular principal curves by adjusting the level of information granularity (the number of clusters), which is realized with the aid of the particle swarm optimization. A number of numeric studies completed for synthetic and real-world datasets provide a useful quantifiable insight into the effectiveness of the proposed algorithm. PMID:23996588

Zhang, Hongyun; Pedrycz, Witold; Miao, Duoqian; Wei, Zhihua

2014-06-01

321

Evaluation of pollutant loads from stormwater BMPs to receiving water using load frequency curves with uncertainty analysis.  

PubMed

This study examined pollutant loads released to receiving water from a typical urban watershed in the Los Angeles (LA) Basin of California by applying a best management practice (BMP) performance model that includes uncertainty. This BMP performance model uses the k-C model and incorporates uncertainty analysis and the first-order second-moment (FOSM) method to assess the effectiveness of BMPs for removing stormwater pollutants. Uncertainties were considered for the influent event mean concentration (EMC) and the aerial removal rate constant of the k-C model. The storage treatment overflow and runoff model (STORM) was used to simulate the flow volume from watershed, the bypass flow volume and the flow volume that passes through the BMP. Detention basins and total suspended solids (TSS) were chosen as representatives of stormwater BMP and pollutant, respectively. This paper applies load frequency curves (LFCs), which replace the exceedance percentage with an exceedance frequency as an alternative to load duration curves (LDCs), to evaluate the effectiveness of BMPs. An evaluation method based on uncertainty analysis is suggested because it applies a water quality standard exceedance based on frequency and magnitude. As a result, the incorporation of uncertainty in the estimates of pollutant loads can assist stormwater managers in determining the degree of total daily maximum load (TMDL) compliance that could be expected from a given BMP in a watershed. PMID:22578429

Park, Daeryong; Roesner, Larry A

2012-12-15

322

Bayesian analysis for nonlinear regression model under skewed errors, with application in growth curves.  

PubMed

We have considered a Bayesian approach for the nonlinear regression model by replacing the normal distribution on the error term by some skewed distributions, which account for both skewness and heavy tails or skewness alone. The type of data considered in this paper concerns repeated measurements taken in time on a set of individuals. Such multiple observations on the same individual generally produce serially correlated outcomes. Thus, additionally, our model does allow for a correlation between observations made from the same individual. We have illustrated the procedure using a data set to study the growth curves of a clinic measurement of a group of pregnant women from an obstetrics clinic in Santiago, Chile. Parameter estimation and prediction were carried out using appropriate posterior simulation schemes based in Markov Chain Monte Carlo methods. Besides the deviance information criterion (DIC) and the conditional predictive ordinate (CPO), we suggest the use of proper scoring rules based on the posterior predictive distribution for comparing models. For our data set, all these criteria chose the skew-t model as the best model for the errors. These DIC and CPO criteria are also validated, for the model proposed here, through a simulation study. As a conclusion of this study, the DIC criterion is not trustful for this kind of complex model. PMID:19629998

De la Cruz, Rolando; Branco, Márcia D

2009-08-01

323

Stability and dynamic analysis of a slender column with curved longitudinal stiffeners  

NASA Technical Reports Server (NTRS)

The results of a stability design study are presented for a slender column with curved longitudinal stiffeners for large space structure applications. Linear stability analyses are performed using a link-plate representation of the stiffeners to determine stiffener local buckling stresses. Results from a set of parametric analyses are used to determine an approximate explicit expression for stiffener local buckling in terms of its geometric parameters. This expression along with other equations governing column stability and mass are assembled into a determinate system describing minimum mass stiffened column design. An iterative solution is determined to solve this system and a computer program incorporating this routine is presented. Example design problems are presented which verify the solution accuracy and illustrate the implementation of the solution routine. Also, observations are made which lead to a greatly simplified first iteration design equation relating the percent increase in column mass to the percent increase in column buckling load. From this, generalizations are drawn as to the mass savings offered by the stiffened column concept. Finally, the percent increase in fundamental column vibration frequency due to the addition of deployable stiffeners is studied.

Lake, Mark S.

1989-01-01

324

A semi-micromechanic interlaminar strain analysis on curved-beam specimens  

NASA Technical Reports Server (NTRS)

Experimental analyses were performed for determination of interlaminar strains in circumferentially unidirectional curved beam specimens. Semi-circular and semi-elliptic carbon-epoxy specimens were subjected to opening mode tensile loadings. Whole field measurements were recorded at load levels from about 5 to more than 90 pct of failure loads. Contour maps of displacement fields were obtained by using moire interferometry, using reference gratings of 2400 lines/mm or 60,690 lines/in. Whole field contour maps of circumferential and interlaminar strains were obtained by using moire interferometry in a semi-micromechanic scale. Various anomalous effects were observed in the displacement fields. The zig-zag fringe patterns indicated that the fiber orientation in each layer was not truly circumferential. This deviation from the unidirectionality caused free-edge effects, such as interlaminar shear strains even at the axis of symmetry and the altered normal strains in the thickness direction. In the resin rich zones between layers, the tensile interlaminar strain was excessively large due to the large compliance. As the result of the combined effect of these anomalous behaviors, the values of the interlaminar tensile strains were larger than those predicted analytically. The modulus E sub 3 was actually smaller than the assumed value E sub 2 by 20 pct.

Joh, Duksung

1990-01-01

325

Modeling and nonlinear hunting stability analysis of high-speed railway vehicle moving on curved tracks  

NASA Astrophysics Data System (ADS)

A heuristic nonlinear creep model is used to derive the nonlinear coupled differential equations of motion of a high-speed railway vehicle traveling on a curved track. The vehicle dynamics are modeled using a 21 degree-of-freedom (21-DOF) system which takes account of the lateral displacement and yaw angle of each wheelset, the lateral displacement, vertical displacement, roll angle and yaw angle of the truck frames, and the lateral displacement, vertical displacement, roll angle, pitch angle and yaw angle of the car body. To analyze the respective effects of the major system parameters on the vehicle dynamics, the 21-DOF system is reduced to 20-DOF, 14-DOF and 6-DOF models, respectively, by excluding designated subsets of the system parameters. The validity of the analytical models and the numerical solution procedure is confirmed by comparing the result obtained using the 6-DOF model for the critical velocity of a railway vehicle traveling on a tangent track with the solution presented in the literature. In general, the results obtained in this study show that the critical hunting speed derived using the 6-DOF or 14-DOF model is generally higher than that evaluated using the 20-DOF model. In addition, the critical hunting speed evaluated via the heuristic nonlinear creep model is lower than that derived using a linear creep model.

Cheng, Yung-Chang; Lee, Sen-Yung; Chen, Hsing-Hao

2009-07-01

326

Numerical analysis of thermal creep flow in curved channels for designing a prototype of Knudsen micropump  

NASA Astrophysics Data System (ADS)

The possibility to generate a gas flow inside a channel just by imposing a tangential temperature gradient along the walls without the existence of an initial pressure difference is well known. The gas must be under rarefied conditions, meaning that the system must operate between the slip and the free molecular flow regimes, either at low pressure or/and at micro/nano-scale dimensions. This phenomenon is at the basis of the operation principle of Knudsen pumps, which are actually compressors without any moving parts. Nowadays, gas flows in the slip flow regime through microchannels can be modeled using commercial Computational Fluid Dynamics softwares, because in this regime the compressible Navier-Stokes equations with appropriate boundary conditions are still valid. A simulation procedure has been developed for the modeling of thermal creep flow using ANSYS Fluent®. The implementation of the boundary conditions is achieved by developing User Defined Functions (UDFs) by means of C++ routines. The complete first order velocity slip boundary condition, including the thermal creep effects due to the axial temperature gradient and the effect of the wall curvature, and the temperature jump boundary condition are applied. The developed simulation tool is used for the preliminary design of Knudsen micropumps consisting of a sequence of curved and straight channels.

Leontidis, V.; Brandner, J. J.; Baldas, L.; Colin, S.

2012-05-01

327

Analysis of a two-dimensional radome of arbitrarily curved surface  

Microsoft Academic Search

The transmission effect of a dielectric shell on electromagnetic radiation is analyzed by a modal cylindrical-wave spectrum technique. This method takes into consideration the curvature effect, which is generally ignored in classical approaches such as the ray method and the plane-wave spectrum analysis. The technique is applied to the analysis of radomes of elliptic shape. Numerical results are presented

Jeng-Hwa Chang; Kuan-Kin Chan

1990-01-01

328

Algorithm for treatment of sedimentation curves in particle size analysis for powders  

Microsoft Academic Search

An algorithm is suggested for calculating the particle size distribution in powdered materials from the results of sedimentation analysis in gravitational and centrifugal fields. Comparison of the particle size analysis for a Stokes' suspension of a specific fractional composition shows that the suggested algorithm eliminates a bias of the differential characteristic of the distribution toward an increase in particle size.

Yu. N. Kryuchkov

1995-01-01

329

The economic recession and its effect on utilization of elective total joint arthroplasty.  

PubMed

The United States economy entered a recession in December 2007. This study aims to determine whether the utilization of elective orthopedic surgeries has been impacted by this recession. From January 2007 to December 2009 at a single private practice in New Jersey, 4820 total joint replacement procedures were scheduled, of which 649 of those were cancelled. The rate of cancellation for financial reasons was compared to multiple economic measures by linear regression analysis. The results show that the rate of financially motivated cancellations increased over time concurring with multiple financial markers reflecting the economic recession. The results suggest that the recession has created a financial barrier for a significant number of Americans, leading to decreased utilization of care. While there was a statistically significant increase in cancellations for financial reasons, the overall rate of cancellations in the total joint population is still low, representing only about 1% of all cases. PMID:24340319

Klein, Gregg R; Parcells, Bertrand W; Levine, Harlan B; Dabaghian, Laurie; Hartzband, Mark A

2013-11-01

330

A historical perspective of the effect of the great recession on hospitals.  

PubMed

At 18 months, the Great Recession of December 2007 to June 2009 is the longest recession since World War II. The recession led to soaring unemployment, resulting in loss of employment-based health insurance for millions of people. In addition to seeing increases in uninsured patients, hospitals experienced losses in their investment portfolios, which in turn increased bad debt, charity care, and uncompensated care nationwide. Hospital executives began to devise cost-cutting strategies to balance the rising debt, such as standardizing medical equipment, cutting staff positions, and delaying construction projects and capital expenditures as well as implementing value analysis strategies. The recession is officially over, and, although economic recovery has been slow and unemployment continues to be an issue, hospitals' net revenue started improving as of 2009 and hospital construction started increasing in 2010. Still, caution is warranted in the postrecession climate, because it is unknown what effects will be seen when the Baby Boomer generation begins using Medicare. PMID:25080418

Shortt, Janet

2014-08-01

331

The influence of grain-size analysis methods and sediment mixing on curve shapes and textural parameters: Implications for sediment trend analysis  

NASA Astrophysics Data System (ADS)

To this day, deterministic physical models capable of explaining the evolution of grain-size distributions in the course of transport are still lacking. For this reason, various attributes of particle frequency distributions, in particular curve shapes and textural parameters, have for many decades been investigated for potential information about transport behaviour and size-sorting processes of sediments in numerous environments. Such approaches are essentially conceptual and hence rely heavily on the validity of the assumptions on which they are based. A factor which has to date been largely ignored in this context, is the fact that different methods of grain-size analysis (e. g. sieving, laser absorption and diffraction, settling velocity measurements), when applied to the same sample material, produce variable curve shapes, and hence incongruous textural data. This is illustrated by selected examples showing the differences between sieving and settling results, conversion of settling velocities into equivalent settling diameters (psi-phi-transformations), and the influences of particle shape, particle density, and water temperature. It is demonstrated that particle-size distributions are not only method-dependent but also dependent on the adopted post-processing procedure. As a result, only frequency curves generated by the same method and subsequently processed by identical computational procedures can be meaningfully compared. Furthermore, the computation of textural parameters from bi- or multimodal size distributions produces spurious results which are unrelated to the processes leading to the mixing of different size populations frequently observed in nature. In such cases, only the decomposition of such distributions into individual populations and the spatial comparison of such populations makes any sense. Because a physical explanation for the generation of size distributions is lacking, a particular curve shape of a grain-size population has no meaning on its own. Only a systematic comparison of progressively changing curve shapes (and associated textural parameters) of sediments collected on a closely spaced grid can yield data suitable for sediment trend analysis.

Flemming, Burghard W.

2007-12-01

332

Peturbational Analysis of the Curved Anisotropic Optical Fiber for the Birefringence Due to the Geometry,  

National Technical Information Service (NTIS)

Birefringence, due to a uniform bending of an anisotropic optical fiber, is studied. The analysis is perturbational and valid only for large radii of curvature. First, the theory is given to a general inhomogeneous weakly-guiding anisotropic waveguide lea...

M. Oksanen

1987-01-01

333

Breast magnetic resonance imaging: A computer-based analysis of enhancement curves  

Microsoft Academic Search

The aim of this work is to report our experience in contrast-enhanced magnetic resonance (MR) automatic analysis. This technique\\u000a is usually used in our practice for the diagnosis of breast cancer. Study execution and semiautomatic data analysis require\\u000a at least 1 hour of the radiologist. So, we decided to develop a tool that aids the radiologist in locating the regions

E. Setti; G. Trecate; M. Ferrari; L. Mainardi; R. Musumeci

2001-01-01

334

Not proper ROC curves as new tool for the analysis of differentially expressed genes in microarray experiments  

PubMed Central

Background Most microarray experiments are carried out with the purpose of identifying genes whose expression varies in relation with specific conditions or in response to environmental stimuli. In such studies, genes showing similar mean expression values between two or more groups are considered as not differentially expressed, even if hidden subclasses with different expression values may exist. In this paper we propose a new method for identifying differentially expressed genes, based on the area between the ROC curve and the rising diagonal (ABCR). ABCR represents a more general approach than the standard area under the ROC curve (AUC), because it can identify both proper (i.e., concave) and not proper ROC curves (NPRC). In particular, NPRC may correspond to those genes that tend to escape standard selection methods. Results We assessed the performance of our method using data from a publicly available database of 4026 genes, including 14 normal B cell samples (NBC) and 20 heterogeneous lymphomas (namely: 9 follicular lymphomas and 11 chronic lymphocytic leukemias). Moreover, NBC also included two sub-classes, i.e., 6 heavily stimulated and 8 slightly or not stimulated samples. We identified 1607 differentially expressed genes with an estimated False Discovery Rate of 15%. Among them, 16 corresponded to NPRC and all escaped standard selection procedures based on AUC and t statistics. Moreover, a simple inspection to the shape of such plots allowed to identify the two subclasses in either one class in 13 cases (81%). Conclusion NPRC represent a new useful tool for the analysis of microarray data.

Parodi, Stefano; Pistoia, Vito; Muselli, Marco

2008-01-01

335

The Global Picture. Recession to Recovery  

ERIC Educational Resources Information Center

The objectives of this study were to: (1) document government and HE (higher education) sector responses to the recession within a select number of key countries which compete with the UK; and (2) compare these responses and analyse them by theme to draw out any common patterns. The focus of the work was to find, where possible, an evidence base…

Universities UK, 2010

2010-01-01

336

The Recession and Education: Seize New Opportunities!  

ERIC Educational Resources Information Center

The teaching profession has long been thought of as recession proof. Indeed, that may have been one of the reasons why teachers took far lower starting salaries right out of college. Perhaps the greatest common feature of teachers, besides their desire to serve society in a humanitarian way, may be the lack of risk-taking the occupation previously…

Haskvitz, Alan

2011-01-01

337

Five mandibular incisors: an autosomal recessive trait?  

Microsoft Academic Search

A fifth mandibular incisor is a eumorphic supernumerary tooth and has rarely been described in the medical literature. We report here a large Lebanese consanguineous family where four individuals displayed five incisors in the anterior mandible. Such familial observation has not been previously described. The possibility of an autosomal recessive inheritance for this nonsyndromic trait is discussed.

A Cassia; A Feki; A Megarbane; S El-Toum

2004-01-01

338

Measuring Fluctuating Pressures With Recessed Gauges  

NASA Technical Reports Server (NTRS)

Report discusses use of pressure gauges mounted in recesses in interior wall of model scramjet engine. Consists of brief memorandum plus excerpts from NASA Technical Paper 3189, "Unsteady Pressure Loads In A Generic High-Speed Engine Model." Focuses mainly on factors affecting accuracy of gauge readings.

Parrott, Tony L.; Jones, Michael G.

1993-01-01

339

Nevada, the Great Recession, and Education  

ERIC Educational Resources Information Center

The impact of the Great Recession and its aftermath has been devastating in Nevada, especially for public education. This article discusses the budget shortfalls and the impact of the economic crisis in Nevada using case study methodology. It provides a review of documents, including Governor Gibbon's proposals for the public K-12 education system…

Verstegen, Deborah A.

2013-01-01

340

Numerical analysis of anomalous tailing on breakthrough curves during a typical convergent-flow tracer tests  

NASA Astrophysics Data System (ADS)

Breakthrough curves (BTCs) observed during convergent-flow tracer tests (CFTT) usually show non-symmetric shapes. Experimental evidences indicate that the late-time behavior of these BTCs can follow a power-law distributions of the form c=t-m, where the parameter 'm' (the 'BTC slope') range between 1 and 4. While this behavior exist and can be predicted in certain reactive or purely diffusive systems, it also occur when the tracer is conservative and the tests are performed in heterogeneous coarse (e.g. sandy) aquifers. In the latter cases, a quantitative link between the parameters describing geological or hydrodynamic aquifer heterogeneities and the formation and development of power-law BTC tailing has not been found yet. We show here the results of a numerical investigation, by means of which we reproduced flow and conservative transport in unconditional 3D multigaussian fields of log-transformed hydraulic conductivity (Y). We found that, in typical CFTT, BTC tailing may occur due to the stratification of the plume as an effect of the injection mechanisms, which control the arrival times of contaminants to the controlling well. Heterogeneity plays a fundamental role, since it controls the transport connectivity between the injection and the extraction well at each horizon composing the aquifer. When some conditions are fulfilled (highly variability of layer properties, injection distances comparable with the characteristic scale of heterogeneity, and global high Y variance), the power-law slope approaches the unit (m=1), which is also very similar to the travel time scaling of a purely stratified media with log-normal distribution of hydraulic conductivity. For intermediate cases, m varies between 1 and 4. This study suggests that the nature of the memory functions, in coarse aquifers, is an intrinsic characteristic of three-dimensional solute transport, and cannot be reproducible with 2D multigaussian simulations of Y-fields and transport solutions based on the advection-dispersion equation, unless new phenomena are accounted for (such as mass transfer).

Pedretti, D.; Fernandez-Garcia, D.; Sanchez-Vila, X.; Bolster, D.

2012-12-01

341

Functional torque ratios and torque curve analysis of shoulder rotations in overhead athletes with and without impingement symptoms.  

PubMed

In this study, we evaluated the peak torque, functional torque ratios, and torque curve profile of the shoulder rotators in overhead athletes with impingement symptoms so as to examine possible alterations in response to sports training and shoulder pain. Twenty-one overhead athletes with impingement symptoms were compared with 25 overhead athletes and 21 non-athletes, none of whom were symptomatic for impingement. The participants performed five maximal isokinetic concentric and eccentric contractions of medial and lateral shoulder rotations at 1.57 rad · s(-1) and 3.14 rad · s(-1). Isokinetic peak torque was used to calculate the eccentric lateral rotation-to-concentric medial rotation and the eccentric medial rotation-to-concentric lateral rotation ratios. An analysis of the torque curve profiles was also carried out. The eccentric lateral rotation-to-concentric medial rotation torque ratio of asymptomatic athletes was lower than that of non-athletes at both test velocities. The concentric medial rotation isokinetic peak torque of the asymptomatic athletes, at 3.14 rad · s(-1), was greater than that of the non-athletes, and the peak appeared to occur earlier in the movement for athletes than non-athletes. These findings suggest that there may be adaptations to shoulder function in response to throwing practice. The eccentric medial rotation-to-concentric lateral rotation torque ratio was altered neither by the practice of university-level overhead sports nor impingement symptoms. PMID:22092229

Zanca, Gisele G; Oliveira, Ana B; Saccol, Michele F; Ejnisman, Benno; Mattiello-Rosa, Stela M

2011-12-01

342

Efficient electromagnetic analysis for curved open thin-wire structures using intervallic wavelets in the method of moments  

NASA Astrophysics Data System (ADS)

Efficient electromagnetic (EM) analysis for curved open thin-wire structures is developed by solving integral equations with intervallic wavelets in the method of moments (MoM). The electrical field integral equation for curved thin-wire structures is formulated based on the generalized Pocklington integral equation and the unknown current is expanded using the intervallic Coifman father wavelets as basis functions. In the current representation, an appropriate geometric map is established between thin-wire segments and bounded intervallic wavelets to match different domains. Since the Coifman wavelets (Coiflets) possess a unique feature, i.e. the vanishing moments which can yield a Dirac-?-like sampling property, they are used to construct the intervallic wavelets. Also, the corresponding edge basis functions are built to represent the unknown current in the edge intervals for open structures. By using the intervallic wavelets in the MoM and performing a fast wavelet transform, sparse impedance matrices can be obtained and the drawbacks of dense matrices are overcome. Numerical examples for analyzing the scattering or radiation properties in different thin-wire structures are presented to demonstrate the robustness of the intervallic wavelets.

Tong, Mei Song

2011-03-01

343

Rapid, Sensitive, and Discriminating Identification of Naegleria spp. by Real-Time PCR and Melting-Curve Analysis  

PubMed Central

The free-living amoeboflagellate genus Naegleria includes one pathogenic and two potentially pathogenic species (Naegleria fowleri, Naegleria italica, and Naegleria australiensis) plus numerous benign organisms. Monitoring of bathing water, water supplies, and cooling systems for these pathogens requires a timely and reliable method for identification, but current DNA sequence-based methods identify only N. fowleri or require full sequencing to identify other species in the genus. A novel closed-tube method for distinguishing thermophilic Naegleria species is presented, using a single primer set and the DNA intercalating dye SYTO9 for real-time PCR and melting-curve analysis of the 5.8S ribosomal DNA gene and flanking noncoding spacers (ITS1, ITS2). Collection of DNA melting data at close temperature intervals produces highly informative melting curves with one or more recognizable melting peaks, readily distinguished for seven Naegleria species and the related Willaertia magna. Advantages over other methods used to identify these organisms include its comprehensiveness (encompassing all species tested to date), simplicity (no electrophoresis required to verify the product), and sensitivity (unambiguous identification from DNA equivalent to one cell). This approach should be applicable to a wide range of microorganisms of medical importance.

Robinson, Bret S.; Monis, Paul T.; Dobson, Phillip J.

2006-01-01

344

New approaches to direct gradient analysis using environmental scalars and statistical curve-fitting procedures  

Microsoft Academic Search

The conceptual framework of direct gradient analysis (DGA) is discussed in relation to the functional, factorial approach to vegetation. Both approaches use abstract simplified environment gradients with which to correlate vegetation response. Environmental scalars based on physical process models of environment and\\/or known biological growth processes can be incorporated to make analyses less location specific. An example of an environmental

M. P. Austin; R. B. Cunningham; P. M. Fleming

1984-01-01

345

A Computer Program for Calculation of Calibration Curves for Quantitative X-Ray Diffraction Analysis.  

ERIC Educational Resources Information Center

Describes a FORTRAN IV program written to supplement a laboratory exercise dealing with quantitative x-ray diffraction analysis of mixtures of polycrystalline phases in an introductory course in x-ray diffraction. Gives an example of the use of the program and compares calculated and observed calibration data. (Author/GS)

Blanchard, Frank N.

1980-01-01

346

Uncertainty Analysis of Bivariate Drought Frequency Curve Using Copula-Based Random Generation  

NASA Astrophysics Data System (ADS)

Several works have been performed to capture the joint behaviors of drought based on hydro-meteorological observations and hydro-statistical models. However, in general, hydro-meteorological observations such as rainfalls are quite limited for reliable analyses due to their short length of records, especially bivariate drought analyses. To address this limitation, this study introduces copulas to generate random variables used in drought analyses. As applied in previous studies, Copulas are employed in this study to facilitate the identification and construction of dependence structure of droughts in South Korea. After copulas construct the joint distribution of drought-related variables, monthly rainfalls are generated to preserve randomness as well as the dependent structure of drought. The rainfall data generated by copula-based random generation provides a probability-based description of the overall drought status through bivariate drought frequency analysis. The bivariate frequency analysis is performed in this study to quantify the relationship between duration and severity of drought in statistical scheme. The estimates of drought severity and their uncertainties acquired from the bivariate drought frequency analysis are discussed in this study. The results indicate that the use of copulas allows the construction and generation of inter and/or intra-variable drought variables to enhance the bivariate drought frequency analysis.

Kim, T.; Yoo, J.; Kim, U.; Ahn, J.

2011-12-01

347

BLOT: A Mesh and Curve Plot Program for the Output of a Finite Element Analysis.  

National Technical Information Service (NTIS)

BLOT is a graphics program for post-processing of finite element analysis output that is presented in the EXODUS database format. It is command driven with free-format input and can drive any graphics device supported by the Sandia Virtual Device Interfac...

A. P. Gilkey J. H. Glick

1989-01-01

348

Gene Scanning of an Internalin B Gene Fragment Using High-Resolution Melting Curve Analysis as a Tool for Rapid Typing of Listeria monocytogenes  

PubMed Central

The ability to accurately track Listeria monocytogenes strains involved in outbreaks is essential for control and prevention of listeriosis. Because current typing techniques are time-consuming, cost-intensive, technically demanding, and difficult to standardize, we developed a rapid and cost-effective method for typing of L. monocytogenes. In all, 172 clinical L. monocytogenes isolates and 20 isolates from culture collections were typed by high-resolution melting (HRM) curve analysis of a specific locus of the internalin B gene (inlB). All obtained HRM curve profiles were verified by sequence analysis. The 192 tested L. monocytogenes isolates yielded 15 specific HRM curve profiles. Sequence analysis revealed that these 15 HRM curve profiles correspond to 18 distinct inlB sequence types. The HRM curve profiles obtained correlated with the five phylogenetic groups I.1, I.2, II.1, II.2, and III. Thus, HRM curve analysis constitutes an inexpensive assay and represents an improvement in typing relative to classical serotyping or multiplex PCR typing protocols. This method provides a rapid and powerful screening tool for simultaneous preliminary typing of up to 384 samples in approximately 2 hours.

Pietzka, Ariane T.; Stoger, Anna; Huhulescu, Steliana; Allerberger, Franz; Ruppitsch, Werner

2011-01-01

349

InTube DNA Methylation Profiling by Fluorescence Melting Curve Analysis  

Microsoft Academic Search

Background: Most PCR assays for detection of 5-meth- ylcytosine in genomic DNA entail a two-step procedure, comprising initial PCR amplification and subsequent product analysis in separate operations that usually require manual transfer. These methods generally pro- vide information about methylation of only a few CpG dinucleotides within the target sequence. Methods: An in-tube methylation assay is described that integrates amplification

Jesper Worm; Anni Aggerholm; Per Guldberg

2001-01-01

350

Molecular component distribution imaging of living cells by multivariate curve resolution analysis of space-resolved Raman spectra  

NASA Astrophysics Data System (ADS)

Label-free Raman microspectroscopy combined with a multivariate curve resolution (MCR) analysis can be a powerful tool for studying a wide range of biomedical molecular systems. The MCR with the alternating least squares (MCR-ALS) technique, which retrieves the pure component spectra from complicatedly overlapped spectra, has been successfully applied to in vivo and molecular-level analysis of living cells. The principles of the MCR-ALS analysis are reviewed with a model system of titanium oxide crystal polymorphs, followed by two examples of in vivo Raman imaging studies of living yeast cells, fission yeast, and budding yeast. Due to the non-negative matrix factorization algorithm used in the MCR-ALS analysis, the spectral information derived from this technique is just ready for physical and/or chemical interpretations. The corresponding concentration profiles provide the molecular component distribution images (MCDIs) that are vitally important for elucidating life at the molecular level, as stated by Schroedinger in his famous book, "What is life?" Without any a priori knowledge about spectral profiles, time- and space-resolved Raman measurements of a dividing fission yeast cell with the MCR-ALS elucidate the dynamic changes of major cellular components (lipids, proteins, and polysaccharides) during the cell cycle. The MCR-ALS technique also resolves broadly overlapped OH stretch Raman bands of water, clearly indicating the existence of organelle-specific water structures in a living budding yeast cell.

Ando, Masahiro; Hamaguchi, Hiro-o.

2014-01-01

351

Analysis of the width-w non-adjacent form in conjunction with hyperelliptic curve cryptography and with lattices?  

PubMed Central

In this work the number of occurrences of a fixed non-zero digit in the width-w non-adjacent forms of all elements of a lattice in some region (e.g. a ball) is analysed. As bases, expanding endomorphisms with eigenvalues of the same absolute value are allowed. Applications of the main result are on numeral systems with an algebraic integer as base. Those come from efficient scalar multiplication methods (Frobenius-and-add methods) in hyperelliptic curves cryptography, and the result is needed for analysing the running time of such algorithms. The counting result itself is an asymptotic formula, where its main term coincides with the full block length analysis. In its second order term a periodic fluctuation is exhibited. The proof follows Delange’s method.

Krenn, Daniel

2013-01-01

352

First-order-reversal-curve analysis of exchange-coupled SmCo/NdFeB nanocomposite alloys  

NASA Astrophysics Data System (ADS)

Exchange-coupled SmCo5/Nd2Fe14B nanocomposite magnets have been fabricated by ball milling of the micrometer sized SmCo5 and Nd2Fe14B powders. The influence of Nd2Fe14B content on the microstructure and magnetic properties of these hybrid alloys was investigated. The alloys that show strong intergrain exchange-coupling behavior with (BH)max=2.95 MGOe was obtained when the two hard phases are well coupled. A first-order-reversal-curve (FORC) analysis was performed for both SmCo5 single-phase magnet and SmCo5/Nd2Fe14B hybrid magnet; the FORC diagrams results show two major peaks for the hybrid magnets. In both cases, the magnetization reversal behaviors for these alloys were discussed in detail and are consistent with the results of ?M plots.

Pan, Mingxiang; Zhang, Pengyue; Ge, Hongliang; Yu, Nengjun; Wu, Qiong

2014-06-01

353

High-throughput real-time PCR and melt curve analysis for sexing Southern Ocean seabirds using fecal samples.  

PubMed

Sex identification of birds is of great interest in ecological studies, however this can be very difficult in many species because their external features are almost monomorphic between the sexes. Molecular methodology has simplified this process but limitations still occur with widely accepted methods using polymerase chain reaction and gel electrophoresis, especially when applied to degraded DNA. Real-time polymerase chain reaction assays are emerging as a more efficient, sensitive, and higher throughput means of identification, but there are very few techniques validated using fecal samples and small target sizes. We present a real-time melt curve analysis assay targeting a small region of the CHD-1 gene allowing for high-throughput, sensitive, specific, and easy-to-interpret sexing results for a variety of Southern Ocean seabirds using fecal and tissue samples. PMID:24507073

Faux, Cassandra E; McInnes, Julie C; Jarman, Simon N

2014-04-01

354

A Latent Growth Curve Analysis of Early and Increasing Peer Victimization as Predictors of Mental Health Across Elementary School  

PubMed Central

Peer victimization has been implicated as a traumatic stressor that compromises children’s long-term mental health, yet a dearth of prospective research specifically demonstrates lasting effects of early victimization. This research examined whether early (2nd grade) victimization and increasing (2nd – 5th grade) victimization independently predicted depressive symptoms and aggressive behavior (overt and relational) in 5th grade. Participants included 433 children (238 girls, 195 boys). Children reported on peer victimization and depressive symptoms; teachers reported on peer victimization and aggressive behavior. Latent growth curve analysis revealed that both early and increasing victimization made unique contributions to subsequent depressive symptoms and aggressive behavior. Relational aggression was particularly likely to follow victimization in girls.

Rudolph, Karen D.; Troop-Gordon, Wendy; Hessel, Elenda T.; Schmidt, Jennifer D.

2011-01-01

355

Analysis of stellar occultation data - Effects of photon noise and initial conditions. [planetary atmosphere temperature, pressure and density profiles from occultation light curve  

NASA Technical Reports Server (NTRS)

An occultation light curve can be analyzed to provide information about a planetary atmosphere. Temperature, pressure, and number density profiles for the atmosphere of Mars are derived from a series of boundary layer equations, which invert equal increments of altitude (as opposed to time) in order to predict the noise quality of the occultation. Numerical results are given for a noisy isothermal light curve, with special attention to error analysis.

French, R. G.; Elliot, J. L.; Gierasch, P. J.

1978-01-01

356

Job Loss and Infrastructure Job Creation Spending During the Recession.  

National Technical Information Service (NTIS)

After the long economic expansion that characterized much of the current decade, the nation entered its 11th postwar recession in December 2007. The subsequent decrease in jobs and comparison of the latest recession to the Great Depression intensified con...

L. Levine

2010-01-01

357

Automated AFM force curve analysis for determining elastic modulus of biomaterials and biological samples.  

PubMed

The analysis of atomic force microscopy (AFM) force data requires the selection of a contact point (CP) and is often time consuming and subjective due to influence from intermolecular forces and low signal-to-noise ratios (SNR). In this report, we present an automated algorithm for the selection of CPs in AFM force data and the evaluation of elastic moduli. We propose that CP may be algorithmically easier to detect by identifying a linear elastic indentation region of data (high SNR) rather than the contact point itself (low SNR). Utilizing Hertzian mechanics, the data are fitted for the CP. We first detail the algorithm and then evaluate it on sample polymeric and biological materials. As a demonstration of automation, 64 × 64 force maps were analyzed to yield spatially varying topographical and mechanical information of cells. Finally, we compared manually selected CPs to automatically identified CPs and demonstrated that our automated approach is both accurate (< 10nm difference between manual and automatic) and precise for non-interacting polymeric materials. Our data show that the algorithm is useful for analysis of both biomaterials and biological samples. PMID:24951927

Chang, Yow-Ren; Raghunathan, Vijay Krishna; Garland, Shaun P; Morgan, Joshua T; Russell, Paul; Murphy, Christopher J

2014-09-01

358

Curve-based multivariate distance matrix regression analysis: application to genetic association analyses involving repeated measures.  

PubMed

Most, if not all, human phenotypes exhibit a temporal, dosage-dependent, or age effect. Despite this fact, it is rare that data are collected over time or in sequence in relevant studies of the determinants of these phenotypes. The costs and organizational sophistication necessary to collect repeated measurements or longitudinal data for a given phenotype are clearly impediments to this, but greater efforts in this area are needed if insights into human phenotypic expression are to be obtained. Appropriate data analysis methods for genetic association studies involving repeated or longitudinal measures are also needed. We consider the use of longitudinal profiles obtained from fitted functions on repeated data collections from a set of individuals whose similarities are contrasted between sets of individuals with different genotypes to test hypotheses about genetic influences on time-dependent phenotype expression. The proposed approach can accommodate uncertainty of the fitted functions, as well as weighting factors across the time points, and is easily extended to a wide variety of complex analysis settings. We showcase the proposed approach with data from a clinical study investigating human blood vessel response to tyramine. We also compare the proposed approach with standard analytic procedures and investigate its robustness and power via simulation studies. The proposed approach is found to be quite flexible and performs either as well or better than traditional statistical methods. PMID:20423962

Salem, Rany M; O'Connor, Daniel T; Schork, Nicholas J

2010-07-01

359

What can we learn from the Fourier analysis of blazar light curves?  

NASA Astrophysics Data System (ADS)

Blazars display strong variability on multiple timescales and in multiple radiation bands. Their variability can be characterized by power spectral densities (PSDs) and time lags as a function of Fourier frequency. We develop a new theoretical model based on analysis of the electron continuity equation carried out in the Fourier domain. This model predicts features in the synchrotron, synchrotron self-Compton (SSC), and external Compton (EC) PSDs and time lags associated with electron cooling, escape, and light travel time effects across the electromagnetic spectrum, from sub-mm to gamma-rays. We also find that FSRQs should have steeper PSD power-law indices than BL Lac objects at low Fourier frequencies if FSRQs produce gamma-rays by EC and BL Lac objects by SSC emission, in qualitative agreement with reported observations by the Fermi Large Area Telescope.

Finke, Justin; Becker, Peter A.

2014-08-01

360

Simultaneous Genotyping of GSTT1 and GSTM1 Null Polymorphisms by Melting Curve Analysis in Presence of SYBR Green I  

PubMed Central

Due to their ability to metabolize xenobiotics, glutathione S-transferases (GSTs) play an important role in cellular protection. GST family members ? (GSTM1) and ? (GSTT1) exhibit a common polymorphism that results in the complete deletion of the gene (null allele). Homozygous deletions, which result in the absence of the enzyme, are considered a risk factor for several diseases, including cancer. We report a simple, low cost, and high throughput assay for the simultaneous analysis of the GSTM1 and GSTT1 null polymorphisms in a single step. The assay is based on multiplex real-time PCR in the presence of SYBR Green I and genotype discrimination by melting curve analysis in a LightCycler. We have genotyped 792 samples to compare this new approach with conventional PCR followed by gel electrophoresis. Comparison of the methods gave a good agreement, with ? values of 0.88 for GSTM1 and 0.64 for GSTT1. Reanalysis of discrepant samples indicated that absence of amplification of the larger GSTT1 fragment by conventional PCR accounted for most of the discrepancies. Moreover, the improved amplification efficiency of the real-time PCR results in a significant reduction of missing values. Due to its simplicity and low cost, this assay is well suited for the rapid analysis of GST-null genotypes in studies that involve large number of samples.

Marin, Fatima; Garcia, Nadia; Munoz, Xavier; Capella, Gabriel; Gonzalez, Carlos A.; Agudo, Antonio; Sala, Nuria

2010-01-01

361

Recessive mutations in CAKUT and VACTERL association.  

PubMed

Understanding the complex genetic makeup underlying congenital anomalies of the kidney and urinary tract (CAKUT) is of primary importance to improve diagnosis, stratify risk for later-onset complications, and develop therapeutic strategies. Saisawat et al. used homozygosity mapping coupled with next-generation sequencing to identify recessive mutations in TRAP1 in families with isolated CAKUT and with VACTERL association. This study points to a novel player in kidney development, possibly affecting apoptosis and endoplasmic reticulum stress signaling. PMID:24875543

Westland, Rik; Sanna-Cherchi, Simone

2014-06-01

362

Does orthodontic treatment lead to gingival recession?  

Microsoft Academic Search

Data sourcesMedline, Embase, The Cochrane Central Register of Controlled Trials (CENTRAL) and the reference lists of identified studies.Study selectionHuman controlled or randomised clinical trials and animal studies reporting occurrence of gingival recession and crown length changes were included. Case reports, descriptive studies, review articles, opinion articles and studies concerning impacted teeth or injured anterior teeth, pre-orthodontic treatment for dental restoration

Carlos Flores-Mir

2011-01-01

363

Cutting Symmetrical Recesses In Soft Ceramic Tiles  

NASA Technical Reports Server (NTRS)

Simple tool cuts hemispherical recesses in soft ceramic tiles. Designed to expose wires of thermocouples embedded in tiles without damaging leads. Creates neat, precise holes around wires. End mill includes axial hole to accommodate thermocouple wires embedded in material to be cut. Wires pass into hole without being bent or broken. Dimensions in inches. Used in place of such tools as dental picks, tweezers, spatulas, and putty knives.

Nesotas, Tony C.; Tyler, Brent

1989-01-01

364

Photogrammetric recession measurements of an ablating surface  

NASA Technical Reports Server (NTRS)

An instrument and method for measuring the time history of recession of an ablating surface of a test article during testing in a high enthalpy thermal test facility, such as an arcjet. The method advances prior art by providing time-history data over the full ablating surface without targets and without any modifications to the test article. The method is non-intrusive, simple to implement, requires no external light source, and does not interfere with normal operations of the arcjet facility.

Schairer, Edward T. (Inventor); Heineck, James T. (Inventor)

2012-01-01

365

Understanding High Recession Rates of Carbon Ablators Seen in Shear Tests in an Arc Jet  

NASA Technical Reports Server (NTRS)

High rates of recession in arc jet shear tests of Phenolic Impregnated Carbon Ablator (PICA) inspired a series of tests and analysis on FiberForm (a carbon preform used in the fabrication of PICA). Arc jet tests were performed on FiberForm in both air and pure nitrogen for stagnation and shear configurations. The nitrogen tests showed little or no recession, while the air tests of FiberForm showed recession rates similar to that of PICA (when adjusted for the difference in density). While mechanical erosion can not be ruled out, this is the first step in doing so. Analysis using a carbon oxidation boundary condition within DPLR was used to predict the recession rate of FiberForm. The analysis indicates that much of the anomalous recession behavior seen in shear tests may simply be an artifact of the non-flight like test configuration (copper upstream of the test article) a result of dissimilar enthalpy and oxygen concentration profiles on the copper. Shape change effects were also investigated and shown to be relatively small.

Driver, David M.; Olson, Michael W.; Barnhardt, Michael D.; MacLean, Matthew

2010-01-01

366

Embrasure morphology and central papilla recession  

PubMed Central

Background: The aim of this study was to ascertain the effects of vertical and horizontal distances between the maxillary central incisors on the presence of interproximal dental papilla and to assess the association between the embrasure morphology and central papilla recession. Materials and Methods: The central papilla was visually assessed in 50 subjects using the standardized periapical radiographs of maxillary central incisors. The following vertical distances were measured; distance from the contact point to papilla tip, CP to proximal cementoenamel (pCEJ) junction, bone crest to CP (BC-CP) and BC-PT. The horizontal distance measured was interdental width (IDW) at pCEJ level. The measurements were recorded using a digital electronic caliper. Results: Significant association between the embrasure morphology and central papilla recession was observed for all study groups. All the interdental variables were significantly related to the presence of interdental papillae, with BC-CP distance being the strongest determinant of central papilla presence. The percentage of interdental papilla presence was 100% when the BC-CP distance was ?6 mm and IDW ranged between 0.5 and 1.5 mm. Central papilla recession was observed most frequently with wide-long and narrow-long embrasure morphology. Conclusion: In relation to maxillary central incisors, all the interdental variables have significant influences on the presence of interdental papillae, with distance from BC to CP being the strongest determinant of central papilla presence.

Saxena, Divya; Kapoor, Anoop; Malhotra, Ranjan; Grover, Vishakha

2014-01-01

367

Periosteoplasty for covering gingival recessions: Clinical results  

PubMed Central

This is a case series in which a new technique for the surgical treatment of periodontal recessions is presented along with the results of the first clinical trial. A new technique of periodontal flap surgery was performed on 30 patients with severe periodontal recessions of the upper or lower front teeth. Root and soft tissue scaling was carried out with an open approach, then the periosteum was incised and mobilized at the apical part of the mucoperiosteum flap to cover the defect before the mucoperiosteum was reattached and fixed by sutures. Sulcus bleeding, periodontal probing depths, attachment loss and the length of the attached gingiva of the affected teeth were recorded preoperatively and at 3, 6, and 12 months postoperatively. Every clinical parameter was improved by surgery. No sulcus bleeding was observed at any time during the postoperative follow-up. A mean reattachment of 5.5 mm was noticed 12 months postoperatively at a mean probing depth of 0.3 mm. The mean height of the attached gingiva was 0 mm before surgery, 2.3 mm at three and six months postoperatively, and 2.2 mm at 12 months. The periosteum eversion technique is suitable for the treatment of gingival recessions resulting in good gingival function and a clear improvement in aesthetics.

Virnik, Sascha; Chiari, Friedrich Michael; Gaggl, Alexander

2009-01-01

368

Cone-beam computed tomography analysis of curved root canals after mechanical preparation with three nickel-titanium rotary instruments.  

PubMed

Cone beam computed tomography is a 3-dimensional high resolution imaging method. The purpose of this study was to compare the effects of 3 different NiTi rotary instruments used to prepare curved root canals on the final shape of the curved canals and total amount of root canal transportation by using cone-beam computed tomography. A total of 81 mesial root canals from 42 extracted human mandibular molars, with a curvature ranging from 15 to 45 degrees, were selected. Canals were randomly divided into 3 groups of 27 each. After preparation with Protaper, Revo-S and Hero Shaper, the amount of transportation and centering ability that occurred were assessed by using cone beam computed tomography. Utilizing pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Canals were metrically assessed for changes (surface area, changes in curvature and transportation) during canal preparation by using software SimPlant; instrument failures were also recorded. Mean total widths and outer and inner width measurements were determined on each central canal path and differences were statistically analyzed. The results showed that all instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.226). During preparation there was failure of only one file (the protaper group). In conclusion, under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. Areas of uninstrumented root canal wall were left in all regions using the various systems. PMID:23885273

Elsherief, Samia M; Zayet, Mohamed K; Hamouda, Ibrahim M

2013-07-01

369

A melting curve analysis--based PCR assay for one-step genotyping of ?-thalassemia mutations a multicenter validation.  

PubMed

The increasing number of disease-causing mutations demands a simple, direct, and cost-effective diagnostic genotyping technique capable of detecting multiple mutations. This study validated the efficacy of a novel melting curve analysis-based genotyping assay (MeltPro HBB assay) for 24 ?-thalassemia mutations in the Chinese population. The diagnostic potential of this assay was evaluated in 1022 pretyped genomic DNA samples, including 909 clinical cases of ?-thalassemia minor or major, using a double-blind analysis in a multicenter validation study. Reproducibility of the assay was 100%, and the limit of detection was 10 pg per reaction. All 24 ?-thalassemia mutations were accurately genotyped, and ?-thalassemia genotypes were correctly determined in all 1022 samples, yielding overall sensitivity and specificity of 100%. The concordance rate was 99.4% between this assay and the reference method. It was concluded that the MeltPro HBB assay is useful for reliable genotyping of multiple ?-thalassemia mutations in clinical settings and may have potential as a versatile method for rapid genotyping of known mutations because of its high throughput, accuracy, ease of use, and low cost. PMID:21704277

Xiong, Fu; Huang, Qiuying; Chen, Xiaoyun; Zhou, Yuqiu; Zhang, Xinhua; Cai, Ren; Chen, Yajun; Xie, Jiansheng; Feng, Shanwei; Wei, Xiaofeng; Xiao, Qizhi; Zhang, Tianlang; Luo, Shiqiang; Yang, Xuehuang; Hao, Ying; Qu, Yanxia; Li, Qingge; Xu, Xiangmin

2011-07-01

370

Cyclic Fatigue Testing of Three Different Rotary Nickel Titanium Endodontic Instruments in Simulated Curved Canals - An in Vitro Sem Analysis  

PubMed Central

Introduction: Instrument separation is a serious concern in endodontics. Stainless steel instruments usually deform before they separate whereas Nickel Titanium instruments do not show any sign of deformation. Aim: of the present study was to compare the cyclic rotations needed to fracture three different rotary nickel titanium endodontic instruments namely Profile, K3 Endo, RaCe in simulated curved canals having 2 different radii of curvature i.e., 5mm &10mm with a constant angle of curvature of 45°. The fractured surfaces were analysed using Scanning Electron Microscopy (SEM). Materials and Methods: Sixty rotary nickel titanium instruments were used for analysis in this study. The instruments were divided into three groups based on the different cross sections. Three groups were further divided into two sub groups based on radius of curvatures. Ten files were tested in each sub-group. Results: Group A (Profile) showed increased number of cycles to failure i.e., low incidence of fracture at both the radii of curvatures when compared to the other two groups. SEM analysis showed that in Group A the fractured surface of the files tested were characterized by the presence of smooth area on their edges associated with nucleation and slow fatigue crack propagation when compared to Group B and C. Therefore Group A (Profile) demonstrated least cyclic fatigue when compared to the other two groups.

Reddy Y., Pallavi; S., Kavita; Subbarao, C.V.

2014-01-01

371

High-throughput phenotypic profiling of gene-environment interactions by quantitative growth curve analysis in Saccharomyces cerevisiae.  

PubMed

Cell-based assays are widely used in high-throughput screening to determine the effects of toxicants and drugs on their biological targets. To enable a functional genomics modeling of gene-environment interactions, quantitative assays are required both for gene expression and for the phenotypic responses to environmental challenge. To address this need, we describe an automated high-throughput methodology that provides phenotypic profiling of the cellular responses to environmental stress in Saccharomyces cerevisiae. Standardized assay conditions enable the use of a single metric value to quantify yeast microculture growth curves. This assay format allows precise control of both genetic and environmental determinants of the cellular responses to oxidative stress, a common mechanism of environmental insult. These yeast-cell-based assays are validated with hydrogen peroxide, a simple direct-acting oxidant. Phenotypic profiling of the oxidative stress response of a yap1 mutant strain demonstrates the mechanistic analysis of genetic susceptibility to oxidative stress. As a proof of concept for analysis of more complex gene-environment interactions, we describe a combinatorial assay design for phenotypic profiling of the cellular responses to tert-butyl hydroperoxide, a complex oxidant that is actively metabolized by its target cells. Thus, the yeast microculture assay format supports comprehensive applications in toxicogenomics. PMID:15033507

Weiss, Andrew; Delproposto, James; Giroux, Craig N

2004-04-01

372

Analysis of protein film voltammograms as Michaelis-Menten saturation curves yield the electron cooperativity number for deconvolution.  

PubMed

Deconvolution of protein film voltammetric data by fitting multiple components (sigmoids, derivative peaks) often is ambiguous when features are partially overlapping, due to exchangeability between the width and the number of components. Here, a new method is presented to obtain the width of the components. This is based on the equivalence between the sigmoidal catalytic response as function of electrode potential, and the classical saturation curve obtained for the enzyme activity as function of the soluble substrate concentration, which is also sigmoidal when plotted versus log[S]. Thus, analysis of the catalytic voltammogram with Lineweaver-Burk, Eadie-Hofstee, and Hanes-Woolf plots is feasible. This provides a very sensitive measure of the cooperativity number (Hill coefficient), which for electrons equals the apparent (fractional) number of electrons that determine the width, and thereby the number of components (kinetic phases). This analysis is applied to the electrocatalytic oxygen reduction by Paracoccus denitrificans cytochrome aa(3) (cytochrome c oxidase). Four partially overlapping kinetic phases are observed that (stepwise) increase the catalytic efficiency with increasingly reductive potential. Translated to cell biology, the activity of the terminal oxidase stepwise adapts to metabolic demand for oxidative phosphorylation. PMID:22265100

Heering, Hendrik A

2012-10-01

373

Analysis of photometric light curves solution for massive contact OB binary stars. LY Aurigae, BH Centauri, SV Centauri  

Microsoft Academic Search

We searched for signs of the presence of circumstellar gaseous matter in photometric data for massive contact early-type binaries by analyzing residual curves (the dependence of the difference between the observed and theoretical brightness variations on the orbital-period phase) for three such stars. The residual curves make it possible to estimate the influence of gas in the common envelope on

E. A. Avvakumova

2010-01-01

374

Mutations of the tyrosinase gene produce autosomal recessive ocular albinism  

SciTech Connect

Albinism has historically been divided into ocular (OA) and oculocutaneous (OCA) types based on the presence or absence of clinically apparent skin and hair involvement in an individual with the ocular features of albinism. The major genes for OCA include the tyrosinase gene in OCA1 and the P gene in OCA2. X-linked and autosomal recessive OA have been described and the responsible genes have not been identified. We now present six Caucasian individuals who have the phenotype of autosomal recessive OA but who have OCA1 as shown by the presence of mutations of the tyrosinase. They had white or very light hair and white skin at birth, and cutaneous pigment developed in the first decade of life. At ages ranging from 1.5-23 years, hair color was dark blond to light brown. The skin had generalized pigment and well developed tan was present on the exposed arm and face skin of four. Iris pigment was present and iris translucency varied. Molecular analysis of the tyrosinase gene, using PCR amplification and direct di-deoxy sequencing showed the following mutations: E398Z/E398Q, P406S/g346a, R402E/T373K, ?/D383N, and H211N/T373K. The homozygous individual was not from a known consanguineous mating. T373K is the most common tyrosinase gene mutation in our laboratory. Three of these mutations are associated with a total loss of tyrosinase activity (g346a splice-site, T373K, and D383N), while four are associated with residual enzyme activity (H211N, R402E, E398Q, and P406S). These studies show that mutations of the tyrosinase gene can produce the phenotype of autosomal recessive OA in an individual who has normal amounts of cutaneous pigment and the ability to tan after birth. This extends the phenotypic range of OCA1 to normal cutaneous pigment after early childhood, and suggest that mutations of the tyrosinase gene account for a significant number of individuals with autosomal recessive OA.

King, R.A.; Summers, C.G.; Oetting, W.S. [Univ. of Minnesota, Minneapolis, MN (United States)] [and others

1994-09-01

375

Effects of Tip Clearance and Casing Recess on Heat Transfer and Stage Efficiency in Axial Turbines  

NASA Technical Reports Server (NTRS)

Calculations were performed to assess the effect of the tip leakage flow on the rate of heat transfer to blade, blade tip and casing. The effect on exit angle and efficiency was also examined. Passage geometries with and without casing recess were considered. The geometry and the flow conditions of the GE-E 3 first stage turbine, which represents a modem gas turbine blade were used for the analysis. Clearance heights of 0%, 1%, 1.5% and 3% of the passage height were considered. For the two largest clearance heights considered, different recess depths were studied. There was an increase in the thermal load on all the heat transfer surfaces considered due to enlargement of the clearance gap. Introduction of recessed casing resulted in a drop in the rate of heat transfer on the pressure side but the picture on the suction side was found to be more complex for the smaller tip clearance height considered. For the larger tip clearance height the effect of casing recess was an orderly reduction in the suction side heat transfer as the casing recess height was increased. There was a marked reduction of heat load and peak values on the blade tip upon introduction of casing recess, however only a small reduction was observed on the casing itself. It was reconfirmed that there is a linear relationship between the efficiency and the tip gap height. It was also observed that the recess casing has a small effect on the efficiency but can have a moderating effect on the flow underturning at smaller tip clearances.

Ameri, A. A.; Steinthorsson, E.; Rigby, David L.

1998-01-01

376

Effects of tip clearance and casing recess on heat transfer and stage efficiency in axial turbines  

SciTech Connect

Calculations were performed to assess the effect of the tip leakage flow on the rate of heat transfer to blade, blade tip, and casing. The effect on exit angle and efficiency was also examined. Passage geometries with and without casing recess were considered. The geometry and the flow conditions of the GE-E{sup 3} first-stage turbine, which represents a modern gas turbine blade, were used for the analysis. Clearance heights of 0, 1, 1.5, and 3 percent of the passage height were considered. For the two largest clearance heights considered, different recess depths were studied. There was an increase in the thermal load on all the heat transfer surfaces considered due to enlargement of the clearance gap. Introduction, of recessed casing resulted in a drop in the rate of heat transfer on the pressure side, but the picture on the suction side was found to be more complex for the smaller tip clearance height considered. For the larger tip clearance height, the effect of casing recess was an orderly reduction in the suction side heat transfer as the casing recess height was increased. There was a marked reduction of heat load and peak values on the blade tip upon introduction of casing recess; however, only a small reduction was observed on the casing itself. It was reconfirmed that there is a linear relationship between the efficiency and tip gap height. It was also observed that the recess casing has a small effect on the efficiency but can have a moderating effect on the flow underturning at smaller tip clearances.

Ameri, A.A.; Steinthorsson, E.; Rigby, D.L.

1999-10-01

377

Effects of Recession versus Tenotomy Surgery without Recession in Adult Rabbit Extraocular Muscle  

PubMed Central

Purpose. Surgical recession of an extraocular muscle (EOM) posterior to its original insertion is a common form of strabismus surgery, weakening the rotational force exerted by the muscle on the globe and improving eye alignment. The purpose of this study was to assess myosin heavy chain (MyHC) isoform expression and satellite cell activity as defined by Pax7 expression in recessed EOMs of adult rabbits compared with that in muscles tenotomized but not recessed and with that in normal control muscles. Methods. The scleral insertion of the superior rectus muscle was detached and sutured either 7 mm posterior to its original insertion site (recession surgery) or at the same site (tenotomy). One day before euthanatization, the rabbits received bromodeoxyuridine (BrdU) injections. After 7 and 14 days, selected EOMs from both orbits were examined for changes in fast, slow, neonatal, and developmental MyHC isoform expression, Pax7 expression, and BrdU incorporation. Results. Recession and tenotomy surgery resulted in similar changes in the surgical EOMs. These included a decreased proportion of fast MyHC myofibers, an increased proportion of slow MyHC myofibers, and increased BrdU-positive satellite cells. Similar changes were seen in the non-operated contralateral superior rectus muscles. The ipsilateral inferior rectus showed reciprocal changes to the surgical superior rectus muscles. Conclusions. The EOMs are extremely adaptive to changes induced by recession and tenotomy surgery, responding with modulations in fiber remodeling and myosin expression. These adaptive responses could be manipulated to improve surgical success rates.

Christiansen, Stephen P.; Antunes-Foschini, Rosalia S.

2010-01-01

378

Approximate Bézier curves by cubic LN curves  

Microsoft Academic Search

In order to derive the offset curves by using cubic Bézier curves with a linear field of normal vectors (the so-called LN Bézier curves) more efficiently, three methods for approximating degree n Bézier curves by cubic LN Bézier curves are considered, which includes two traditional methods and one new method based on Hausdorff distance. The approximation based on shifting control

Wei-Xian Huang; Cong-Jian Jin; Guo-Jin Wang

2011-01-01

379

Determination of sulphate in water and biodiesel samples by a sequential injection analysis--multivariate curve resolution method.  

PubMed

A spectrophotometric sequential injection analysis (SIA-DAD) method linked to multivariate curve resolution-alternating least squares (MCR-ALS) has been developed for sulphate determination. This method involves the reaction, inside the tubes of the SIA system, of sulphate with barium-dimethylsulphonazo (III) complex, Ba-DMSA (III), displacing Ba(2+) from the complex and forming DMSA (III). When the reaction products reach the detector a data matrix is obtained, which allows a second-order calibration to be developed. The experimental conditions (concentration and sample and reagent volumes) to obtain the highest sensitivity have been chosen applying a 2(4-1) fractional factorial design. The proposed sequential flow procedure permits up to 15 mg SO(4)(2-) L(-1) to be determined with a limit of detection of 1.42 mg L(-1) and it is able to monitor sulphate in samples at a frequency of 15 samples per hour. The method was applied to determine sulphate in natural and residual waters and in biodiesel. The reliability of the method was established for water samples by parallel determination using a standard turbidimetric method for sulphate in natural and residual water samples with results within statistical variation. For biodiesel samples, the method was validated comparing the concentration of some spiked samples with the expected concentration using a test-t. PMID:20800738

del Río, Vanessa; Larrechi, M Soledad; Callao, M Pilar

2010-08-31

380

Numerical ellipsometry: Analysis of thin metal layers using n-k-d twisted curve methods with multiple incidence angles  

SciTech Connect

A major challenge for those utilizing ellipsometry is numerical processing of the measured data. The transcendental, multivalued equations arising from the physics of simple reflection are problematic for the least-squares numerical methods in common use. These early numerical methods require fairly accurate initial estimates, bounding to avoid local minima, and only find solutions at the bottom of a relatively flat numerical topography. Previously the authors have applied complex analysis in the n-k plane to improve visualization of the mathematics, and this has led to a growing array of new numerical methods avoiding these difficulties. The work presented here extends these new numerical methods to three dimensions (n-k-d space) for use with absorbing films deposited on transparent and on absorbing substrates. The method finds intersections of three ''twisted curves'' resulting from three (or more) light incidence angle measurements per wavelength. The method is employed here to determine the thickness and optical properties of chromium films (between 10 and 25 nm nominal thickness) deposited onto two different substrates, silicon and silica oxide, employing measurements made at three different angles of incidence for light wavelengths between 280 and 2500 nm.

Urban, F. K. III; Barton, D.; Tiwald, T. [Florida International University, Miami, Florida 33199 (United States); J. A. Woollam, Co., Lincoln, Nebraska 68508 (United States)

2010-07-15

381

A Biometric Latent Curve Analysis of Memory Decline in Older Men of the NAS-NRC Twin Registry  

PubMed Central

Previous research has shown cognitive abilities to have different biometric patterns of age-changes. Here we examined the variation in episodic memory (Words Recalled) for over 6,000 twin pairs who were initially aged 59-75, and were subsequently re-assessed up to three more times over 12 years. In cross-sectional analyses, variation in Education was explained by strong additive genetic influences (~43%) together with shared family influences (~35%) that were independent of age. The longitudinal phenotypic analysis of the Word Recall task showed systematic linear declines over age, but with positive influences of Education and Retesting. The longitudinal biometric estimation yielded: (a) A separation of non-shared environmental influences and transient measurement error (~50%): (b) Strong additive genetic components of this latent curve (~70% at age 60) with increases over age that reach about 90% by age 90. (c) The minor influences of shared family environment (~17% at age 60) were effectively eliminated by age 75. (d) Non-shared environmental effects play an important role over most of the life-span (peak of 42% at age 70) but their relative role diminishes after age 75.

McArdle, John J.; Plassman, Brenda L.

2010-01-01

382

Fuel compositions for lessening valve seat recession  

SciTech Connect

A fuel composition is described for internal combustion engines comprising a major amount of a liquid hydrocarbon fuel and a minor, property improving amount sufficient to reduce valve seat recession when the fuel is used in an internal combustion engine of (A) at least one hydrocarbon-soluble alkali or alkaline earth metal containing composition containing at least 8 aliphatic carbon atoms and (B) at least one hydrocarbon-soluble ashless dispersant wherein (A) is the alkali metal or alkaline earth metal salt of a sulfur acid, a carboxylic acid or a phenol.

Johnston, T.E.; Dorer, C.J. Jr.

1987-04-21

383

Analysis of the terrestrial ion foreshock: 2D Full-Particle simulation of a curved supercritical shock  

NASA Astrophysics Data System (ADS)

Two distinct ion populations backstreaming into the solar wind have been clearly evidenced by various space missions within the quasi-perpendicular region of the ion foreshock located upstream of the Earth's Bow shock (i.e. for 45° ? Theta_Bn ? 90°, where Theta_Bn is the angle between the shock normal and the upstream magnetostatic field): (i) field-aligned ion beams (« FAB ») characterized by a gyrotropic distribution, and (ii) gyro-phase bunched ions («GPB »), characterized by a NON gyrotropic distribution. The origin of these backstreaming ions has not been clearly identified and is presently analyzed with the help of 2D PIC simulation of a curved shock, where full curvature effects, time of flight effects and both electrons and ions dynamics are fully described within a self consistent approach. Present simulations evidence that these two populations can be effectively created directly by the shock front without invoking microinstabilities. The analysis of both individual and statistical ion trajectories evidences that: (i) two new parameters, namely the interaction time DT_inter and distance of penetration L_depth into the shock wave, play a key role and allow to discriminate these two populations. "GPB" population is characterized by a very short interaction time (DT_inter = 1 to 2 Tci) in comparison to the "FAB" population (DT_inter = 2 Tci to 10 Tci) which moves back and forth between the upstream edge of the shock front and the overshoot, where tci is the upstream ion gyroperiod. (ii) the importance of the injection angle (i.e. the angle between the normal of the shock front and the gyration velocity when ions reach the shock) to understand how the reflection process takes place. (iii) "FAB" population drifts along the curved shock front scanning a large Theta_Bn range from 90°. (iv) "GPB" population is embedded within the "FAB" population near the shock front which explains the difficulty to identify such a population in the experimental data. The use of two additional parameters DT_inter and L_depth is necessary to separate clearly both populations.

Lembege, B.; Savoini, P.; Stienlet, J.

2013-05-01

384

Detecting differential allelic expression using high-resolution melting curve analysis: application to the breast cancer susceptibility gene CHEK2  

PubMed Central

Background The gene CHEK2 encodes a checkpoint kinase playing a key role in the DNA damage pathway. Though CHEK2 has been identified as an intermediate breast cancer susceptibility gene, only a small proportion of high-risk families have been explained by genetic variants located in its coding region. Alteration in gene expression regulation provides a potential mechanism for generating disease susceptibility. The detection of differential allelic expression (DAE) represents a sensitive assay to direct the search for a functional sequence variant within the transcriptional regulatory elements of a candidate gene. We aimed to assess whether CHEK2 was subject to DAE in lymphoblastoid cell lines (LCLs) from high-risk breast cancer patients for whom no mutation in BRCA1 or BRCA2 had been identified. Methods We implemented an assay based on high-resolution melting (HRM) curve analysis and developed an analysis tool for DAE assessment. Results We observed allelic expression imbalance in 4 of the 41 LCLs examined. All four were carriers of the truncating mutation 1100delC. We confirmed previous findings that this mutation induces non-sense mediated mRNA decay. In our series, we ruled out the possibility of a functional sequence variant located in the promoter region or in a regulatory element of CHEK2 that would lead to DAE in the transcriptional regulatory milieu of freely proliferating LCLs. Conclusions Our results support that HRM is a sensitive and accurate method for DAE assessment. This approach would be of great interest for high-throughput mutation screening projects aiming to identify genes carrying functional regulatory polymorphisms.

2011-01-01

385

A statistical model for the effect of casing treatment recesses on compressor rotor performance  

SciTech Connect

The tip clearance between a compressor's rotating blades and its casing has an unfavorable influence on performance. By applying an abradable coating (insert) to the casing over the rotating blades, this tip clearance can be reduced to practically zero. A rather frequent variant is for the rotor blade tips to carve an entire annular recess in this coating. Rectangular recesses of various configurations have been tested in several different researches. The results of these investigations are processed using the Group Method of Data Handling. A statistical model is developed that predicts the influence of rectangular recesses on a compressor stage's efficiency and stable operating (flow) range. The model takes into account the six principal geometric parameters of a rectangular recess, as well as the Lieblein rotor diffusion factor. Analysis of the derived model has also determined which of these parameters are the most influential. Rectangular entire annular recesses are one of the simplest and most progressive types of casing treatment, and this paper concludes with an overview of existing research that supports this claim. (author)

Nezym, Vitaliy [National Polytechnic Institute, Mexico DF, Av. Santa Ana, 1000, CP 04430 (Mexico)

2007-08-15

386

Autosomal recessive nonsyndromic deafness genes: a review.  

PubMed

More than 50 Percent of prelingual hearing loss is genetic in origin, and of these up to 93 Percent are monogenic autosomal recessive traits. Some forms of genetic deafness can be recognized by their associated syndromic features, but in most cases, hearing loss is the only finding and is referred to as nonsyndromic deafness. To date, more than 700 different mutations have been identified in one of 42 genes in individuals with autosomal recessive nonsyndromic hearing loss (ARNSHL). Reported mutations in GJB2, encoding connexin 26, makes this gene the most common cause of hearing loss in many populations. Other relatively common deafness genes include SLC26A4, MYO15A, OTOF, TMC1, CDH23, and TMPRSS3. In this report we summarize genes and mutations reported in families with ARNSHL. Founder effects were demonstrated for some recurrent mutations but the most significant findings are the extreme locus and allelic heterogeneity and different spectrum of genes and mutations in each population. PMID:22652773

Duman, Duygu; Tekin, Mustafa

2012-01-01

387

Analysis of photometric light curves solution for massive contact OB binary stars. LY Aurigae, BH Centauri, SV Centauri  

Microsoft Academic Search

We searched for signs of the presence of circumstellar gaseous matter in photometric data for massive contact early-type binaries\\u000a by analyzing residual curves (the dependence of the difference between the observed and theoretical brightness variations\\u000a on the orbital-period phase) for three such stars. The residual curves make it possible to estimate the influence of gas in\\u000a the common envelope on

E. A. Avvakumova

2010-01-01

388

Three-dimensional flow analysis and improvement of slip factor model for forward-curved blades centrifugal fan  

Microsoft Academic Search

This work developed improved slip factor model and correction method to predict flow through impeller in forward-curved centrifugal\\u000a fan. Both steady and unsteady three-dimensional CFD analyses were performed to validate the slip factor model and the correction\\u000a method. The results show that the improved slip factor model presented in this paper could provide more accurate predictions\\u000a for forward-curved centrifugal impeller

En-Min Guo; Kwang-Yong Kim

2004-01-01

389

Is the Elimination of Recess in School a Violation of a Child's Basic Human Rights?  

ERIC Educational Resources Information Center

The elimination of recess in schools across the country is becoming a normal occurrence in many communities, large and small. In each study presented in this content analysis, we find that free time and unstructured play is indeed essential to a child's healthy cognitive development. Article 31 of the United Nations Convention on the Rights of…

Dubroc, Alicia M.

2007-01-01

390

The Process of Integration of Newcomers at School: Students and Gender Networking during School Recess  

ERIC Educational Resources Information Center

This article examines the data obtained through a year-long ethnographic study of students from a Spanish primary school, and sheds light on their use of gender code networks during school recess. The results of this analysis confirm the conclusions on student interaction drawn by other studies (group segregation regarding age and gender and,…

Rodriguez-Navarro, Henar; García-Monge, Alfonso; Rubio-Campos, Maria del Carmen

2014-01-01

391

High-throughput avian molecular sexing by SYBR green-based real-time PCR combined with melting curve analysis  

PubMed Central

Background Combination of CHD (chromo-helicase-DNA binding protein)-specific polymerase chain reaction (PCR) with electrophoresis (PCR/electrophoresis) is the most common avian molecular sexing technique but it is lab-intensive and gel-required. Gender determination often fails when the difference in length between the PCR products of CHD-Z and CHD-W genes is too short to be resolved. Results Here, we are the first to introduce a PCR-melting curve analysis (PCR/MCA) to identify the gender of birds by genomic DNA, which is gel-free, quick, and inexpensive. Spilornis cheela hoya (S. c. hoya) and Pycnonotus sinensis (P. sinensis) were used to illustrate this novel molecular sexing technique. The difference in the length of CHD genes in S. c. hoya and P. sinensis is 13-, and 52-bp, respectively. Using Griffiths' P2/P8 primers, molecular sexing failed both in PCR/electrophoresis of S. c. hoya and in PCR/MCA of S. c. hoya and P. sinensis. In contrast, we redesigned sex-specific primers to yield 185- and 112-bp PCR products for the CHD-Z and CHD-W genes of S. c. hoya, respectively, using PCR/MCA. Using this specific primer set, at least 13 samples of S. c. hoya were examined simultaneously and the Tm peaks of CHD-Z and CHD-W PCR products were distinguished. Conclusion In this study, we introduced a high-throughput avian molecular sexing technique and successfully applied it to two species. This new method holds a great potential for use in high throughput sexing of other avian species, as well.

Chang, Hsueh-Wei; Cheng, Chun-An; Gu, De-Leung; Chang, Chia-Che; Su, San-Hua; Wen, Cheng-Hao; Chou, Yii-Cheng; Chou, Ta-Ching; Yao, Cheng-Te; Tsai, Chi-Li; Cheng, Chien-Chung

2008-01-01

392

Measuring the elastic properties of living cells through the analysis of current-displacement curves in scanning ion conductance microscopy.  

PubMed

Knowledge of mechanical properties of living cells is essential to understand their physiological and pathological conditions. To measure local cellular elasticity, scanning probe techniques have been increasingly employed. In particular, non-contact scanning ion conductance microscopy (SICM) has been used for this purpose; thanks to the application of a hydrostatic pressure via the SICM pipette. However, the measurement of sample deformations induced by weak pressures at a short distance has not yet been carried out. A direct quantification of the applied pressure has not been also achieved up to now. These two issues are highly relevant, especially when one addresses the investigation of thin cell regions. In this paper, we present an approach to solve these problems based on the use of a setup integrating SICM, atomic force microscopy, and optical microscopy. In particular, we describe how we can directly image the pipette aperture in situ. Additionally, we can measure the force induced by a constant hydrostatic pressure applied via the pipette over the entire probe-sample distance range from a remote point to contact. Then, we demonstrate that the sample deformation induced by an external pressure applied to the pipette can be indirectly and reliably evaluated from the analysis of the current-displacement curves. This method allows us to measure the linear relationship between indentation and applied pressure on uniformly deformable elastomers of known Young's modulus. Finally, we apply the method to murine fibroblasts and we show that it is sensitive to local and temporally induced variations of the cell surface elasticity. PMID:22744227

Pellegrino, Mario; Pellegrini, Monica; Orsini, Paolo; Tognoni, Elisabetta; Ascoli, Cesare; Baschieri, Paolo; Dinelli, Franco

2012-09-01

393

The role of the olfactory recess in olfactory airflow.  

PubMed

The olfactory recess - a blind pocket at the back of the nasal airway - is thought to play an important role in mammalian olfaction by sequestering air outside of the main airstream, thus giving odorants time to re-circulate. Several studies have shown that species with large olfactory recesses tend to have a well-developed sense of smell. However, no study has investigated how the size of the olfactory recess relates to air circulation near the olfactory epithelium. Here we used a computer model of the nasal cavity from a bat (Carollia perspicillata) to test the hypothesis that a larger olfactory recess improves olfactory airflow. We predicted that during inhalation, models with an enlarged olfactory recess would have slower rates of flow through the olfactory region (i.e. the olfactory recess plus airspace around the olfactory epithelium), while during exhalation these models would have little to no flow through the olfactory recess. To test these predictions, we experimentally modified the size of the olfactory recess while holding the rest of the morphology constant. During inhalation, we found that an enlarged olfactory recess resulted in lower rates of flow in the olfactory region. Upon exhalation, air flowed through the olfactory recess at a lower rate in the model with an enlarged olfactory recess. Taken together, these results indicate that an enlarged olfactory recess improves olfactory airflow during both inhalation and exhalation. These findings add to our growing understanding of how the morphology of the nasal cavity may relate to function in this understudied region of the skull. PMID:24577441

Eiting, Thomas P; Smith, Timothy D; Perot, J Blair; Dumont, Elizabeth R

2014-05-15

394

Inference and analysis of xenon outflow curves under multi-pulse injection in two-dimensional chromatography.  

PubMed

Multidimensional gas chromatography is widely applied to atmospheric xenon monitoring for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To improve the capability for xenon sampling from the atmosphere, sampling techniques have been investigated in detail. The sampling techniques are designed by xenon outflow curves which are influenced by many factors, and the injecting condition is one of the key factors that could influence the xenon outflow curves. In this paper, the xenon outflow curves of single-pulse injection in two-dimensional gas chromatography has been tested and fitted as a function of exponential modified Gaussian distribution. An inference formula of the xenon outflow curve for six-pulse injection is derived, and the inference formula is also tested to compare with its fitting formula of the xenon outflow curve. As a result, the curves of both the one-pulse and six-pulse injections obey the exponential modified Gaussian distribution when the temperature of the activated carbon column's temperature is 26°C and the flow rate of the carrier gas is 35.6mLmin(-1). The retention time of the xenon peak for one-pulse injection is 215min, and the peak width is 138min. For the six-pulse injection, however, the retention time is delayed to 255min, and the peak width broadens to 222min. According to the inferred formula of the xenon outflow curve for the six-pulse injection, the inferred retention time is 243min, the relative deviation of the retention time is 4.7%, and the inferred peak width is 225min, with a relative deviation of 1.3%. PMID:24007686

Shu-Jiang, Liu; Zhan-Ying, Chen; Yin-Zhong, Chang; Shi-Lian, Wang; Qi, Li; Yuan-Qing, Fan

2013-10-11

395

Drought Severity-Area-Duration curves Analysis Using Copulas-based Joint Drought Index in South Korea  

NASA Astrophysics Data System (ADS)

Drought Severity-effective Area-drought Duration (SAD) curves are constructed in order to examine spatio-temporal behavior of drought. A copulas-based joint drought index (JDI), also known as joint deficit index, is applied to measure the severity of drought. JDIs are calculated on a monthly basis using a total of 60 monthly precipitation records covering the period 1981-2010 was selected from the Korean network, and spatially expanded using empirical orthogonal function (EOF) and Kriging method. Locational JDIs are spatially extended into grid-based JDIs with spatial resolution of 10 km × 10 km. Grid JDIs are analyzed by drought duration and by effective area, and JDI-based SAD curves are created to represent historical drought events in South Korea. As a result from construction of SAD curves, drought events that occurred in the past in this country can be spatially and temporally characterized. In addition, JDI-based SAD curves are expected to contribute to determine the exact situation on the current drought condition. Fig 1. SAD curves for Drought Index (classified by duration) ;

Ryu, J.; Choi, D.; Park, M.; Kim, S.

2012-12-01

396

Autosomal recessive type of whistling face syndrome in twins.  

PubMed

A report of concordant monochorionic, diamnionic like-sex twins with whistling face syndrome is presented. The diagnosis was based on the characteristic facies with prominent supraorbital ridge, sunken eyes, telacanthus, short nose and colobomata of the nostrils, long philtrum, high narrow palate, and marked microstomia with puckered lips and an "H"-shaped cutaneous dimpling on the chin. The hands showed symmetrically clenched fingers with camptodactyly and ulnar deviation. The feet demonstrated mild bilateral talipes equinovarus. HLA studies to determine the zygosity of the twins showed discordance in HLA haplotypes, which indicated dizygosity. The pedigree analysis showed normal nonconsanguineos parents, and no other family members had the syndrome. The findings support the existence of an autosomal recessive type of whistling face syndrome. PMID:7199706

Kousseff, B G; McConnachie, P; Hadro, T A

1982-03-01

397

Analysis of tipping-curve measurements performed at the DSS-13 beam-waveguide antenna at 32.0 and 8.45 GigaHertz  

NASA Technical Reports Server (NTRS)

This article reports on the analysis of the Ka-band Antenna Performance Experiment tipping-curve data acquired at the DSS-13 research and development beam-waveguide (BWG) antenna. By measuring the operating system temperatures as the antenna is moved form zenith to low-elevation angles and fitting a model to the data, one can obtain information on how well the overall temperature model behaves at zenith and approximate the contribution due to the atmosphere. The atmospheric contribution estimated from the data can be expressed in the form of (1) atmospheric noise temperatures that can provide weather statistic information and be compared against those estimated from other methods and (2) the atmospheric loss factor used to refer efficiency measurements to zero atmosphere. This article reports on an analysis performed on a set of 68 8.4-GHz and 67 32-GHz tipping-curve data sets acquired between December 1993 and May 1995 and compares the results with those inferred from a surface model using input meteorological data and from water vapor radiometer (WVR) data. The general results are that, for a selected subset of tip curves, (1) the BWG tipping-curve atmospheric temperatures are in good agreement with those determined from WVR data (the average difference is 0.06 +/- 0.64 K at 32 GHz) and (2) the surface model average values are biased 3.6 K below those of the BWG and WVR at 32 GHz.

Morabito, D. D.; Skjerve, L.

1995-01-01

398

Multifocus lemniscates: Approximation of curves  

NASA Astrophysics Data System (ADS)

A focal method for the continuous approximation of smooth closed plane curves is proposed. Multifocus lemniscates are used as the approximating functions. The curve to be approximated is represented by a finite set of foci inside the curve; the number and the location of the foci provide the degrees of freedom for the focal approximation. An algorithmic solution of this problem in various modifications is constructed. Proximity criteria for curves are proposed. A comparative analysis of the approximative capabilities of the focal method with the capabilities of the classical harmonic approximation method is performed.

Rakcheeva, T. A.

2010-11-01

399

Multilayer theory for delamination analysis of a composite curved bar subjected to end forces and end moments  

NASA Technical Reports Server (NTRS)

A composite test specimen in the shape of a semicircular curved bar subjected to bending offers an excellent stress field for studying the open-mode delamination behavior of laminated composite materials. This is because the open-mode delamination nucleates at the midspan of the curved bar. The classical anisotropic elasticity theory was used to construct a multilayer theory for the calculations of the stress and deformation fields induced in the multilayered composite semicircular curved bar subjected to end forces and end moments. The radial location and intensity of the open-mode delamination stress were calculated and were compared with the results obtained from the anisotropic continuum theory and from the finite element method. The multilayer theory gave more accurate predictions of the location and the intensity of the open-mode delamination stress than those calculated from the anisotropic continuum theory.

Ko, William L.; Jackson, Raymond H.

1989-01-01

400

BVRcIc Light Curve Analysis of the Shallow Contact Extreme Mass Ratio W UMa Binary, HR Boo  

NASA Astrophysics Data System (ADS)

HR Boo [? (2000) = 14h 48m 33.015s, ? (2000) = +21° 44 ?01.09"] is an NSVS variable first observed in 1999 and listed in the 79th name list (Kazarovets, 2008). It was identified as a W UMa variable and first characterized by the period 0.27289 d. This was later corrected to 0.31587 d. Various observers have reported ~20 timings of minimum light over the past ~4000 orbital epochs. Our 2012 curve is of high precision, with probable errors averaging 5 mmag. The curves have shallow amplitudes, averaging 0.4 magnitudes, yet apparently exhibit total eclipses. J-K observations yield a G6V type for the system. A linear period determination of 0.31596785(7) d was computed with the available timings of minimum light. When the NSVS light curve is considered in the period study, it indicates that the period has been clearly decreasing over the past 15,000 orbits. The quadratic term from this period study is statistically significant at 5 ?. This indicates that the binary is evidently undergoing magnetic breaking due to enhanced magnetic solar activity.The light curve solution reveals that HR Boo is a shallow contact system with a Roche-lobe fill-out of ~4% and a mass ratio of q= 0.25. This is exceedingly rare, since extreme mass ratio binaries usually have high fill-outs. In addition, an unusually dark 13 degree radius cool spot with a T-factor of ~50% was computed near the L1 Point of the primary component. A 32 minute duration of constant light is seen in the secondary eclipse indicating the occurrence of a total eclipse. This was confirmed in the light curve solution. Although the secondary component has a slightly higher temperature than the primary component, some 30 K, the light curves have the appearance of an A-type W UMa system. The system may have come into contact recently.

Faulkner, Danny R.; Samec, Ronald G.; Shebs, Travis; Benkendorf, Barry

2014-06-01

401

[The decline in population growth, income distribution, and economic recession].  

PubMed

This work uses Keynesian principles and an analysis of the Colombian population in the 1970s to argue that the Colombian policy of slowing population growth, which was adopted with the aim of improving the general welfare of the population, has had shortterm negative effects on effective demand and thus on the level of employment and welfare. These negative effects were caused by the inflexibility of income distribution, which prevented expansion of the internal market, complicated by the stagnant condition of the external sector and the budget deficit. The results of the Colombian case study demonstrate how the deceleration of population growth beginning in the 1960s had a significant impact on the levels of consumption and savings and on the patterns of consumption, leading to low levels of investment and little dynamism. Although the current Colombian economic recession is aggravated by contextual factors such as the world economic recession, the high cost of capital, the industrial recession, and declining food production among others, at the core of the crisis are longer term structural determinants such as the decline in the rate of population growth and the highly unequal distribution of income and wealth, which have contributed to a shrinking of the internal market for some types of goods. Given the unlikelihood of renewed rapid population growth, the Keynesian model suggests that the only alternative for increasing aggregate demand is state intervention through public spending and investment and reorientation of the financial system to achieve a dynamic redistribution of income. Based on these findings and on proposals of other analysts, a stragegy for revitalization is proposed which would imply a gradual income redistribution to allow increased consumption of mass produced goods by the low income groups. Direct consumption subsidies would be avoided because of their inflationary and import-expanding tendencies; rather, incentives and support would be provided to 3 productive sectors: traditional agriculture, small factories producing mass consumption goods, and construction of low income housing. The strategy would promote economic growth and expansion without further deterioration of income distribution, employment, and price stability. A simulation study demonstrated the advantages of such a strategy in relation to alternative strategies. PMID:12266019

Banguero, H

1983-05-01

402

Analysis of pressure and pressure derivative without type-curve matching, 6. Horizontal well tests in anisotropic media  

Microsoft Academic Search

A new technique for interpreting pressure tests known as direct synthesis is proposed. This method couples the characteristic points and lines from a log-log plot of pressure and pressure derivative data with the exact analytical solution, consequently eliminating the need for multiple specialized plots or type curve matching.This paper concentrates on the interpretation of pressure tests in homogeneous and anisotropic

T. Engler; D. Tiab

1996-01-01

403

Analysis of the glow curve of SrB 4O 7:Dy compounds employing the GOT model  

NASA Astrophysics Data System (ADS)

The glow curve of SrB 4O 7:Dy phosphors has been analysed with the general one trap model (GOT). To solve the differential equation describing the GOT model a novel algorithm has been employed, which reduces significantly the deconvolution time with respect to the time required by usual integration algorithms, such as the Runge-Kutta method.

Ortega, F.; Molina, P.; Santiago, M.; Spano, F.; Lester, M.; Caselli, E.

2006-02-01

404

A Comprehensive Analysis of Swift XRT Data. III. Jet Break Candidates in X-Ray and Optical Afterglow Light Curves  

Microsoft Academic Search

The Swift XRT data for 179 GRBs (050124 to 070129) and the optical afterglow data for 57 pre- and post-Swift GRBs are analyzed to explore whether the observed breaks in the afterglow light curves can be interpreted as jet breaks, as well as their implications for jet energetics. We find that no burst is included in our ``Platinum'' sample, in

En-Wei Liang; Judith L. Racusin; Bing Zhang; Bin-Bin Zhang; David N. Burrows

2008-01-01

405

A Unified Latent Curve, Latent State-Trait Analysis of the Developmental Trajectories and Correlates of Positive Orientation  

ERIC Educational Resources Information Center

Literature documents that the judgments people hold about themselves, their life, and their future are important ingredients of their psychological functioning and well-being and are commonly related to each other. In this article, results from a longitudinal study (N = 298, 45% males) are presented. Using an integrative Latent Curve, Latent…

Alessandri, Guido; Caprara, Gian Vittorio; Tisak, John

2012-01-01

406

Mechanisms of Disease: autosomal dominant and recessive polycystic kidney diseases  

Microsoft Academic Search

Autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease are the best known of a large family of inherited diseases characterized by the development of renal cysts of tubular epithelial cell origin. Autosomal dominant and recessive polycystic kidney diseases have overlapping but distinct pathogeneses. Identification of the causative mutated genes and elucidation of the function of their encoded

Peter C Harris; Vicente E Torres

2006-01-01

407

Helping Primary Children with Recess Play: A Social Curriculum.  

ERIC Educational Resources Information Center

Advocates the use of recess meetings to help children succeed socially. Describes case studies of use of recess meetings in a first- and third-grade class, showing how teachers got to know each child better, and detailing how children were better able to express ideas, share experiences, voice concerns, solve problems, and laugh. (Author/SD)

Thompson, Susan; Knudson, Paula; Wilson, Darlene

1997-01-01

408

Children's Recess Physical Activity: Movement Patterns and Preferences  

ERIC Educational Resources Information Center

The benefits of recess can be reaped by all students regardless of socioeconomic status, race, or gender and at relatively little cost. The purpose of this study was to examine physical activity (PA) variables related to the recess PA patterns of third and fourth grade children and the social preferences and individuals influencing their PA…

Woods, Amelia Mays; Graber, Kim C.; Daum, David Newman

2012-01-01

409

Understanding the Economy: Working Mothers in the Great Recession.  

National Technical Information Service (NTIS)

The Great Recession has taken a huge toll on working families. The vast majority of jobs lost were lost by men, but a substantial number of jobs were lost by women during this recession. From December 2007 to April 2010, women lost 46 jobs for every 100 j...

C. B. Maloney

2010-01-01

410

Retail Economics 101: Lessons and Strategies of a Recession  

Microsoft Academic Search

Despite the fact that the economy has yet to hit the official benchmark of a recession, historically defined as two consecutive quarters of declining GDP, the majority of Americans feel the economy is in a recession. At the very least, we know there are sectors of the economy that are exhibiting strong recessionary indicators and the retail industry is at

Meghan OBrien

2008-01-01

411

Effects of gate recess etching on source resistance  

NASA Astrophysics Data System (ADS)

Recessed gate microwave MESFET's and MODFET's have a recessed but unmetallized length L(sub delta) of the channel adjacent to the gate, whose resistance R(sub delta) can significantly contribute to the source resistance R(sub s). The ratio R(sub delta)/R(sub s) can be determined using common test structures.

Cibuzar, Gregory T.

1995-06-01

412

Analysis of tipping-curve measurements performed at the DSS13 beam-waveguide antenna at 32.0 and 8.45 GigaHertz  

Microsoft Academic Search

This article reports on the analysis of the Ka-band Antenna Performance Experiment tipping-curve data acquired at the DSS-13 research and development beam-waveguide (BWG) antenna. By measuring the operating system temperatures as the antenna is moved form zenith to low-elevation angles and fitting a model to the data, one can obtain information on how well the overall temperature model behaves at

D. D. Morabito; L. Skjerve

1995-01-01

413

Application of dissociation curve analysis to radiation hybrid panel marker scoring: generation of a map of river buffalo (B. bubalis) chromosome 20  

Microsoft Academic Search

BACKGROUND: Fluorescence of dyes bound to double-stranded PCR products has been utilized extensively in various real-time quantitative PCR applications, including post-amplification dissociation curve analysis, or differentiation of amplicon length or sequence composition. Despite the current era of whole-genome sequencing, mapping tools such as radiation hybrid DNA panels remain useful aids for sequence assembly, focused resequencing efforts, and for building physical

Kelli J Kochan; M Elisabete J Amaral; Richa Agarwala; Alejandro A Schäffer; Penny K Riggs

2008-01-01

414

Experimental and micromagnetic first-order reversal curves analysis in NdFeB-based bulk “exchange spring”-type permanent magnets  

Microsoft Academic Search

In this paper we present the results of applying the first-order reversal curves (FORC) diagram experimental method to the analysis of the magnetization processes of NdFeB-based permanents magnets. The FORC diagrams for this kind of exchange spring magnets show the existence of two magnetic phases—a soft magnetic phase and a hard magnetic one. Micromagnetic modeling is used for validating the

Horia Chiriac; Nicoleta Lupu; Laurentiu Stoleriu; Petronel Postolache; Alexandru Stancu

2007-01-01

415

GNAT1 Associated with Autosomal Recessive Congenital Stationary Night Blindness  

PubMed Central

Purpose. Congenital stationary night blindness is a nonprogressive retinal disorder manifesting as impaired night vision and is generally associated with other ocular symptoms, such as nystagmus, myopia, and strabismus. This study was conducted to further investigate the genetic basis of CSNB in a consanguineous Pakistani family. Methods. A consanguineous family with multiple individuals manifesting cardinal symptoms of congenital stationary night blindness was ascertained. All family members underwent detailed ophthalmic examination, including fundus photographic examination and electroretinography. Blood samples were collected and genomic DNA was extracted. Exclusion and genome-wide linkage analyses were completed and two-point LOD scores were calculated. Bidirectional sequencing of GNAT1 was completed, and quantitative expression of Gnat1 transcript levels were investigated in ocular tissues at different postnatal intervals. Results. The results of ophthalmic examinations were suggestive of early-onset stationary night blindness with no extraocular anomalies. The genome-wide scan localized the critical interval to chromosome 3, region p22.1-p14.3, with maximum two-point LOD scores of 3.09 at ? = 0, flanked by markers D3S3522 and D3S1289. Subsequently, a missense mutation in GNAT1, p.D129G, was identified, which segregated within the family, consistent with an autosomal recessive mode of inheritance, and was not present in 192 ethnically matched control chromosomes. Expression analysis suggested that Gnat1 is expressed at approximately postnatal day (P)7 and is predominantly expressed in the retina. Conclusions. These data suggest that a homozygous missense mutation in GNAT1 is associated with autosomal recessive stationary night blindness.

Naeem, Muhammad Asif; Chavali, Venkata R. M.; Ali, Shahbaz; Iqbal, Muhammad; Riazuddin, Saima; Khan, Shaheen N.; Husnain, Tayyab; Sieving, Paul A.; Ayyagari, Radha; Riazuddin, Sheikh; Hejtmancik, J. Fielding

2012-01-01

416

Estimation of volume flow in curved tubes based on analytical and computational analysis of axial velocity profiles  

NASA Astrophysics Data System (ADS)

To monitor biomechanical parameters related to cardiovascular disease, it is necessary to perform correct volume flow estimations of blood flow in arteries based on local blood velocity measurements. In clinical practice, estimates of flow are currently made using a straight-tube assumption, which may lead to inaccuracies since most arteries are curved. Therefore, this study will focus on the effect of curvature on the axial velocity profile for flow in a curved tube in order to find a new volume flow estimation method. The study is restricted to steady flow, enabling the use of analytical methods. First, analytical approximation methods for steady flow in curved tubes at low Dean numbers (Dn) and low curvature ratios (?) are investigated. From the results a novel volume flow estimation method, the cos ?-method, is derived. Simulations for curved tube flow in the physiological range (1<=Dn<=1000 and 0.01<=?<=0.16) are performed with a computational fluid dynamics (CFD) model. The asymmetric axial velocity profiles of the analytical approximation methods are compared with the velocity profiles of the CFD model. Next, the cos ?-method is validated and compared with the currently used Poiseuille method by using the CFD results as input. Comparison of the axial velocity profiles of the CFD model with the approximations derived by Topakoglu [J. Math. Mech. 16, 1321 (1967)] and Siggers and Waters [Phys. Fluids 17, 077102 (2005)] shows that the derived velocity profiles agree very well for Dn<=50 and are fair for 50100), no analytical approximation method exists. In the position of the maximum axial velocity, a shift toward the inside of the curve is observed for low Dean numbers, while for high Dean numbers, the position of the maximum velocity is located at the outer curve. When the position of the maximum velocity of the axial velocity profile is given as a function of the Reynolds number, a ``zero-shift point'' is found at Re=21.3. At this point the shift in the maximum axial velocity to the outside of the curve, caused by the difference in axial pressure gradient, balances the shift to the inside of the curve, caused by the centrifugal forces (radial pressure gradient). Comparison of the volume flow estimation of the cos ?-method with the Poiseuille method shows that for Dn<=100 the Poiseuille method is sufficient, but for Dn>=100 the cos ?-method estimates the volume flow nearly three times better. For ?=0.01 the maximum deviation from the exact flow is 4% for the cos ?-method, while this is 12.7% for the Poiseuille method in the plane of symmetry. The axial velocity profile measured at a certain angle from the symmetry plane results in a maximum estimation error of 6.2% for Dn=1000 and ?=0.16. The results indicate that the estimation of the volume flow through a curved tube from a given asymmetrical axial velocity profile is more precise with the cos ?-method than the Poiseuille method, which is currently used in clinical practice.

Verkaik, A. C.; Beulen, B. W. A. M. M.; Bogaerds, A. C. B.; Rutten, M. C. M.; van de Vosse, F. N.

2009-02-01

417

Assessment of genetic mutations in the XRCC2 coding region by high resolution melting curve analysis and the risk of differentiated thyroid carcinoma in Iran  

PubMed Central

Homologous recombination (HR) is the major pathway for repairing double strand breaks (DSBs) in eukaryotes and XRCC2 is an essential component of the HR repair machinery. To evaluate the potential role of mutations in gene repair by HR in individuals susceptible to differentiated thyroid carcinoma (DTC) we used high resolution melting (HRM) analysis, a recently introduced method for detecting mutations, to examine the entire XRCC2 coding region in an Iranian population. HRM analysis was used to screen for mutations in three XRCC2 coding regions in 50 patients and 50 controls. There was no variation in the HRM curves obtained from the analysis of exons 1 and 2 in the case and control groups. In exon 3, an Arg188His polymorphism (rs3218536) was detected as a new melting curve group (OR: 1.46; 95%CI: 0.432–4.969; p = 0.38) compared with the normal melting curve. We also found a new Ser150Arg polymorphism in exon 3 of the control group. These findings suggest that genetic variations in the XRCC2 coding region have no potential effects on susceptibility to DTC. However, further studies with larger populations are required to confirm this conclusion.

Fayaz, Shima; Fard-Esfahani, Pezhman; Fard-Esfahani, Armaghan; Mostafavi, Ehsan; Meshkani, Reza; Mirmiranpour, Hossein; Khaghani, Shahnaz

2012-01-01

418

Assessment of genetic mutations in the XRCC2 coding region by high resolution melting curve analysis and the risk of differentiated thyroid carcinoma in Iran.  

PubMed

Homologous recombination (HR) is the major pathway for repairing double strand breaks (DSBs) in eukaryotes and XRCC2 is an essential component of the HR repair machinery. To evaluate the potential role of mutations in gene repair by HR in individuals susceptible to differentiated thyroid carcinoma (DTC) we used high resolution melting (HRM) analysis, a recently introduced method for detecting mutations, to examine the entire XRCC2 coding region in an Iranian population. HRM analysis was used to screen for mutations in three XRCC2 coding regions in 50 patients and 50 controls. There was no variation in the HRM curves obtained from the analysis of exons 1 and 2 in the case and control groups. In exon 3, an Arg(188)His polymorphism (rs3218536) was detected as a new melting curve group (OR: 1.46; 95%CI: 0.432-4.969; p = 0.38) compared with the normal melting curve. We also found a new Ser(150)Arg polymorphism in exon 3 of the control group. These findings suggest that genetic variations in the XRCC2 coding region have no potential effects on susceptibility to DTC. However, further studies with larger populations are required to confirm this conclusion. PMID:22481871

Fayaz, Shima; Fard-Esfahani, Pezhman; Fard-Esfahani, Armaghan; Mostafavi, Ehsan; Meshkani, Reza; Mirmiranpour, Hossein; Khaghani, Shahnaz

2012-01-01

419

Synthetic light-curve analysis of the very short period binaries TY Bootis, AD Cancri, and V523 Cassiopeiae  

Microsoft Academic Search

New photometric observations of TY Boo, AD Cnc, and V523 Cas are subjected to synthetic light-curve analyses using the Wilson-Devinney code. Solutions for each of the systems, and the several competing theories of contact binary structure are discussed in light of the results. Both AD Cnc and V523 Cas are modeled with subluminous regions, and the resulting starspot parameters are

Ronald G. Samec; Walter van Hamme; Beverly B. Bookmyer

1989-01-01

420

Human Capital, Social Support, and Economic Well-being among Rural, Low-income Mothers: A Latent Growth Curve Analysis  

Microsoft Academic Search

The purpose of this study was to better understand human capital and social support in the long-term economic well-being of\\u000a rural, low-income mothers in the US. Three waves of data from a multi-state, longitudinal investigation tracking the well-being\\u000a of rural families, known as “Rural Families Speak,” were used to test two latent growth curve models of economic well-being.\\u000a Results indicated

Leigh Ann Simmons; Bonnie Braun; David W. Wright; Scott R. Miller

2007-01-01

421

Efficacy of atomoxetine in adult attention-Deficit\\/Hyperactivity Disorder: a drug-placebo response curve analysis  

Microsoft Academic Search

BACKGROUND: The objective of this study was to evaluate the efficacy of atomoxetine, a new and highly selective inhibitor of the norepinephrine transporter, in reducing symptoms of attention-deficit\\/hyperactivity disorder (ADHD) among adults by using drug-placebo response curve methods. METHODS: We analyzed data from two double-blind, placebo-controlled, parallel design studies of adult patients (Study I, N = 280; Study II, N

Stephen V Faraone; Joseph Biederman; Thomas Spencer; David Michelson; Lenard Adler; Fred Reimherr; Stephen J Glatt

2005-01-01

422

Urbanization and the global malaria recession  

PubMed Central

Background The past century has seen a significant contraction in the global extent of malaria transmission, resulting in over 50 countries being declared malaria free, and many regions of currently endemic countries eliminating the disease. Moreover, substantial reductions in transmission have been seen since 1900 in those areas that remain endemic today. Recent work showed that this malaria recession was unlikely to have been driven by climatic factors, and that control measures likely played a significant role. It has long been considered, however, that economic development, and particularly urbanization, has also been a causal factor. The urbanization process results in profound socio-economic and landscape changes that reduce malaria transmission, but the magnitude and extent of these effects on global endemicity reductions are poorly understood. Methods Global data at subnational spatial resolution on changes in malaria transmission intensity and urbanization trends over the past century were combined to examine the relationships seen over a range of spatial and temporal scales. Results/Conclusions A consistent pattern of increased urbanization coincident with decreasing malaria transmission and elimination over the past century was found. Whilst it remains challenging to untangle whether this increased urbanization resulted in decreased transmission, or that malaria reductions promoted development, the results point to a close relationship between the two, irrespective of national wealth. The continuing rapid urbanization in malaria-endemic regions suggests that such malaria declines are likely to continue, particularly catalyzed by increasing levels of direct malaria control.

2013-01-01

423

Light-curve analysis of KIC 12557548b: an extrasolar planet with a comet-like tail  

NASA Astrophysics Data System (ADS)

We will demonstrate how amateur observations with small telescopes of ε Aur (a bright eclipsing binary with the longest known orbital period) help to understand the nature of this object and how the understanding of physical processes in this object helps to understand superb Kepler observations of KIC 12557548b (an extremely short-period transiting exoplanet with a comet-like tail). We modified the code SHELLSPEC, which is designed for modelling interacting binary stars to calculate the light curves of such planets. Mie absorption and scattering on spherical dust grains with realistic dust opacities, phase functions, and a finite radius of the source of the scattered light are taken into account. We prove that the peculiar light curve of this exoplanet agrees with the idea of a planet with a comet-like tail. The light curve has a prominent pre-transit brightening and a less prominent post-transit brightening. Both are caused by the forward scattering and are a strong function of the particle size. This feature enabled us to estimate a typical particle size (radius) in the dust tail of about 0.1-1 μm. However, there is an indication that the particle size changes (decreases) along the tail. The dust density in the tail is a steep decreasing function of the distance from the planet, which indicates a significant tail destruction caused by the star-planet interaction. Several possible combinations of other dust properties are tabulated. We reveal interesting periodic long-term evolution of the tail on a time scale of about 1.3 years and also argue that the 'planet' does not show a uniform behaviour, but may have at least two constituents. This exoplanet's tail evolution may find an analogy in the comet tail disconnection events caused by the magnetic/coronal activity of the Sun while the light curve with pre-transit brightening is analogous to the light curve of ε Aur and AZ Cas with mid-eclipse brightening and forward scattering playing a significant role in such eclipsing systems.

Budaj, J.

2014-03-01

424

Flow Curve Determination at Large Plastic Strain Levels: Limitations of the Membrane Theory in the Analysis of the Hydraulic Bulge Test  

NASA Astrophysics Data System (ADS)

Nowadays, an accurate determination of the true stress-strain curve is a key-element for all finite element (FE) forming predictions. Since the introduction of Advanced High Strength Steels (AHSS) for the automotive market, the standard uniaxial tension test suffers the drawback of relatively low uniform elongations. The extrapolation of the uniaxial stress-strain curve up to large strains is not without consequence in forming predictions--especially formability and springback. One of the means to solve this problem is to use experimental tests where large plastic strain levels can be reached. The hydraulic bulge test is one of these tests. The effective plastic strain levels reached in the bulge test are of about 0.7. From an experimental standpoint, the biaxial flow stress is estimated using measurement of fluid pressure, and calculation of thickness and curvature at the pole, via appropriate measurements and assumptions. The biaxial stress at the pole is determined using the membrane equilibrium equation. The analysis proposed in this paper consists of performing ``virtual experiments'' where the results obtained by means of FE calculations are used as input data for determining the biaxial stress-strain law in agreement with the experimental procedure. In this way, a critical discussion of the experimental procedure can be made, by comparing the ``experimental'' stress-strain curve (Membrane theory curve) with the ``reference'' one introduced in the simulations. In particular, the influences of the ``(die diameter)/thickness'' ratio and of the plastic anisotropy are studied, and limitations of the hydraulic bulge test analysis are discussed.

Lemoine, X.; Iancu, A.; Ferron, G.

2011-05-01

425

Autosomal Recessive Anhidrotic Ectodermal Dysplasia: A Rare Entity  

PubMed Central

We describe a case of anhidrotic ectodermal dysplasia (AED) with an autosomal recessive mode of inheritance, a very rare entity, in a 2-year-old female child of two asymptomatic, consanguineous parents. Their previous child also had a similar condition. Autosomal recessive AED (AR-AED) can have its full expression both in males and females and it is clinically indistinguishable from the x-linked recessive AED (XL-AED), which is the most common type of ectodermal dysplasia. Unlike the partially symptomatic carriers of XL-AED, the heterozygotes of AR-AED are phenotypically asymptomatic.

Ghosh, Sangita; Ghosh, Epsita; Dayal, Surabhi

2014-01-01

426

Surgical management of gingival recession: A clinical update  

PubMed Central

Gingival recession is defined as the apical migration of the junctional epithelium with exposure of root surfaces. It is a common condition seen in both dentally aware populations and those with limited access to dental care. The etiology of the condition is multifactorial but is commonly associated with underlying alveolar morphology, tooth brushing, mechanical trauma and periodontal disease. Given the high rate of gingival recession defects among the general population, it is imperative that dental practitioners have an understanding of the etiology, complications and the management of the condition. The following review describes the surgical techniques to treat gingival recession.

Alghamdi, Hamdan; Babay, Nadir; Sukumaran, Anil