bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect on down syndrome screening performance of adjusting for marker levels in a previous pregnancy
Authors: Wald Nicholas J. , Barnes Isobel M. , Birger Ruthie , Huttly Wayne 
Published: April 2006

AbstractObjectivesIn prenatal screening for Down syndrome, serum marker values can be adjusted using values from a previous pregnancy to avoid the problem of women having a high chance of recurrent false‐positive results. We investigate the effect of such adjustment on overall screening performance.MethodsMonte Carlo simulation was used to investigate the effect of this adjustment on five widely used screening tests for Down syndrome (Triple, Quadruple, Combined, serum Integrated, Integrated tests).ResultsAdjustment for screening marker values (expressed in multiples of the median, (MoM)) in a previous pregnancy improved screening performance. The detection rate for a 1% false‐positive rate (FPR) increased from 54 to 59% with the Triple test, from 63 to 68% with the Quadruple test, from 71 to 75% for the Combined test, from 71 to 76% for the serum Integrated test, and from 85 to 88% for the Integrated test. The FPR for an 85% detection rate decreased from 10 to 7.9%, 7.1 to 4.9%, 4.9 to 3.7%, 4.7 to 2.9% and 1.1 to 0.7% respectively for the five tests. Among women who have had a false‐positive result in a previous pregnancy, adjustment substantially lowers the false‐positive rate, for example, from 19 to 7.3% with the Combined test using a 1 in 250 risk cut‐off.ConclusionMoM adjustment for values in a previous pregnancy improves overall screening performance and substantially reduces the high recurrent false‐positive rate. This adjustment can be routinely applied in screening programmes through the screening software used to interpret a woman's screening results. Copyright © 2006 John Wiley & Sons, Ltd.
Less‐ordered lamellar structure of intercalated poly(L‐lactide)/organo‐modified montmorillonite hybrids
Authors: Nam Pham Hoai , Ninomiya Naoya , Fujimori Atsuhiro , Masuko Toru 
Published: April 2006

AbstractHybrids of poly(L‐lactide)/organophilic clay (PLACHs) have been prepared via a melt‐compounding process using poly(L‐lactide) (PLLA) and different contents of surface‐treated montmorillonite modified with dimethyl dioctadecyl ammonium‐salt. The crystalline structures of PLLA and dispersion states of clay particles in those PLACHs were investigated by use of wide‐angle X‐ray diffraction, small‐angle X‐ray scattering, transmission electron microscopy (both cross section and replication modes), and polarized optical microscopy. Those structures are viewed from the conformational changes of PLLA chains in the space of a few nanometer widths between silicate galleries to crystalline lamellae of several nanometer thicknesses, and spherulitic textures more than micrometer sizes. After annealing treatments at 115°C for 1 hr, the PLACHs formed coarse‐grained spherulitic textures with 40 μm diameter composed of less‐ordered and fragmented lamellae, caused by the reduced mobility of the PLLA chain due to the dispersed clay particles in the PLLA matrix and the intercalation of the PLLA chains in the silicate galleries. The formation of the interfibril structure accompanied by the fragmented lamellae among the dispersed clay particles was examined. POLYM. ENG. SCI., 46:703–711, 2006. © 2006 Society of Plastics Engineers
Group hydrotherapy versus group land‐based treatment for chronic low back pain
Authors: Sjogren Tracey , Long Nerida , Story Ian , Smith Jenni 
Published: April 2006

AbstractSixty subjects with chronic low back pain (LBP) were sequentially allocated to either hydrotherapy treatment or land treatment groups in order of presentation. Subjects acted as their own controls for a period of three weeks, after which they attended their respective group sessions twice weekly for six weeks. Twenty‐eight subjects from each group attended all treatment and assessment sessions. Results indicated that both groups improved significantly in functional ability and in decreasing pain levels. Thoracolumbar mobility did not improve significantly in either group. Overall there was no significant difference found between the two types of treatment, although results should be viewed as encouraging for the advocates of both hydrotherapy and land‐based exercise as a treatment for chronic LBP. Copyright © 1997 Whurr Publishers Ltd.
Preparation of arrays of metallic nanoparticles exhibiting coulomb blockade at room temperature: an approach based on the self‐organization of metal‐loaded diblock‐copolymers
Authors: Dietrich Christof , Koslowski Berndt , Weigl Frank , Ziemann Paul 
Published: April 2006

AbstractThe self‐organization of HAuCl4 loaded poly (styrene)‐block‐poly (2‐vinylpyridine) (PS‐b‐P2VP) diblock‐copolymers resulting in hexagonally ordered arrays of Au nanoparticles is exploited to prepare a system exhibiting single electron charging effects at room temperature. For this purpose, the metallic nanoparticles are deposited on top of an Al2O3 tunnel barrier separating them from a Niobium thin film backelectrode grown on a c‐cut Sapphire substrate. The single electron system is completed by the metal tip of a scanning tunneling microscope (STM), which is positioned right above the nanoparticle and serves as the second electrode. The STM additionally allowed taking current‐voltage I (V) characteristics revealing a large gap around zero bias typical of a Coulomb blockade. This interpretation is supported by the good agreement between experimental I (V) curves and their theoretical description. Copyright © 2006 John Wiley & Sons, Ltd.
Haplotype associations of 90 rare alleles from the National Marrow Donor Program®®
Authors: Kempenich J. H. , Setterholm M. , Maiers M. 
Published: April 2006

AbstractThe National Marrow Donor Program maintains an HLA database of over 4.1 million US adult volunteers, 43,000 cord blood units, and 111,000 patients from which we identified 1,999,424 samples having allele‐level HLA‐A, HLA‐B, or HLA‐DRB1 results. We analyzed 811 rare alleles reported at a frequency of less than 1 in 50,000 in this study pool and found strong predicted haplotype associations for 90 of them. The data set includes the number of times the allele was seen, the predicted haplotypes, and the racial or ethnic groups in which it was identified. This information can be helpful in designing search strategies for patients with rare alleles requiring hematopoietic stem cell therapy.
THE MOBILIZATION OF HUMAN RESOURCES AS AN EFFECT OF THE DEPLETION OF ENVIRONMENTAL AND SOCIAL ASSETS
Authors: Bartolini Stefano , Bonatti Luigi 
Published: April 2006

ABSTRACTIn this paper, the growth process is not fed by the accumulation of productive assets (physical and/or human capital, knowledge etc.), but by the depletion of environmental or social resources, which induces individuals to increase their labor supply in order to consume more of the market goods that substitute for the depleted resources. Hence, production is expanded, thus eroding the resources’ ability to regenerate, which decreases with aggregate production. Within this context, the ‘green’ net national product is derived and it is shown how a regulatory authority should manage the resources for achieving Pareto‐optimality.
RELIABILITY ANALYSIS OF COMPLEX SYSTEMS BASED ON THE LOSSES FROM FAILURES
Authors: TODINOV M. T. 
Published: April 2006

The conventional reliability analysis is based on the premise that increasing the reliability of a system will decrease the losses from failures. In this paper it is demonstrated that increasing the reliability of the system does not always mean decreasing the losses from failures. An inappropriate increase of the reliability of the system may lead to a simultaneous increase of the losses from failure. In other words, a system reliability improvement, which is disconnected from the losses from failure does not necessarily reduce the losses from failures. An efficient discrete-event simulation model and algorithm have been proposed for reliability analysis based on the losses from failure for production systems with complex topology. The model links reliability with losses from failures. A new algorithm has also been developed for system reliability analysis related to productions systems based on multiple production units where the absence of critical failure means that at least m out n production units are working. The parametric study conducted on the basis of the developed models revealed that a dual-control production system is characterized by enhanced production availability, which increases with increasing the number of production units in the system. A production unit from a dual-control production system including multiple production units is characterized by a larger availability compared to a production unit from a dual-control production system including a single production unit. The proposed approach has been demonstrated by comparing the losses from failures and the net present values of two competing design topologies: one based on a single-channel control and the other based on a dual-channel control. The proposed models have been successfully applied and tested for reliability value analysis of productions systems in deepwater oil and gas production. It is also argued that the reliability allocation in a production system should be done to maximize the net profit/value obtained from the system. Consequently, a method for setting reliability requirements and reliability allocation maximizing the net profit by minimizing the sum of the capital costs and the expected losses from failures has been proposed. Reliability allocation which maximizes the net profit in case of a system consisting of blocks arranged in series is achieved by determining for each block individually, the reliabilities of the components which minimize the sum of the capital costs and the expected losses from failures.
Stochastic Forcing of the North Atlantic Wind-Driven Ocean Circulation. Part II: An Analysis of the Dynamical Ocean Response Using Generalized Stability Theory
Authors: Chhak Kettyah C. , Moore Andrew M. , Milliff Ralph F. , Branstator Grant , Holland William R. , Fisher Michael 
Published: April 2006

Abstract
As discussed in Part I of this study, the magnitude of the stochastic component of wind stress forcing is comparable to that of the seasonal cycle and thus will likely have a significant influence on the ocean circulation. By forcing a quasigeostrophic model of the North Atlantic Ocean circulation with stochastic wind stress curl data from the NCAR CCM3, it was found in Part I that much of the stochastically induced variability in the ocean circulation is confined to the western boundary region and some major topographic features even though the stochastic forcing is basinwide. This can be attributed to effects of bathymetry and vorticity gradients in the basic state on the system eigenmodes. Using generalized stability theory (GST), it was found in Part I that transient growth due to the linear interference of nonnormal eigenmodes enhances the stochastically induced variance. In the present study, the GST analysis of Part I is extended and it is found that the patterns of wind stress curl that are most effective for inducing variability in the model have their largest projection on the most nonnormal eigenmodes of the system. These eigenmodes are confined primarily to the western boundary region and are composed of long Rossby wave packets that are Doppler shifted by the Gulf Stream to have eastward group velocity. Linear interference of these eigenmodes yields transient growth of stochastically induced perturbations, and it is this process that maintains the variance of the stochastically induced circulations. Analysis of the large-scale circulation also reveals that the system possesses a large number of degrees of freedom, which has significant implications for ocean prediction. Sensitivity studies show that the results and conclusions of this study are insensitive and robust to variations in model parameters and model configuration.
The Relative Importance of Wind Strength and Along-Shelf Bathymetric Variations on the Separation of a Coastal Upwelling Jet
Authors: Castelao Renato M. , Barth John A. 
Published: April 2006

Abstract
A high-resolution numerical model with idealized topography is used to investigate the degree to which a coastal upwelling jet separates from the shelf as it flows around a submarine bank depending on the wind strength and the horizontal scale of the bank. Experiments were run using several wind forcing magnitudes and submarine banks with different geometries, so as to explore a wide range of the flow strength as measured by the Rossby number (Ro) and the ratio of the squares of the internal Rossby radius of deformation and curvature of the topography as denoted by the Burger number (Bu). The intensity of the jet separation is strongly dependent on both parameters, with maximum separation with increasing Ro and Bu close to 1, when large amounts of upwelled water are exported toward deeper waters. For small Bu, separation is minimal and independent of Ro. For high Ro, the degree of separation decreases at large Bu since the bank acts only as a small perturbation to the flow. Term balances in the along-shelf momentum equation reveal that the primary balance over the bank is between the nonlinear and the ageostrophic terms. In an asymmetric bank, the radius of curvature in the upstream half of the bank dominates in terms of determining the offshore deflection of a water particle at the surface. The asymmetry increases the cross-isobath transport but not the offshore deflection of the jet.
On a stochastic integral equation of the Volterra type in telephone traffic theory
Authors: Padgett W. J. , Tsokos C. P. 
Published: April 2006

In mathematical models of phenomena occurring in the general areas of the engineering, biological, and physical sciences, random or stochastic equations appear frequently. In this paper we shall formulate a problem in telephone traffic theory which leads to a stochastic integral equation which is a special case of the Volterra type of the form

where:
(i)ω∊Ω, where Ω is the supporting set of the probability measure space (Ω,B,P);(ii)x(t; ω) is the unknown random variable for t ∊ R+, where R+ = [0, ∞);(iii)y(t; ω) is the stochastic free term or free random variable for t ∊ R+;(iv)k(t, τ; ω) is the stochastic kernel, defined for 0 ≦ τ ≦ t < ∞; and(v)f(t, x) is a scalar function defined for t ∊ R+ and x ∊ R, where R is the real line.
Embedding submartingales in wiener processes with drift, with applications to sequential analysis
Authors: Hall W. J. 
Published: April 2006

SummarySkorokhod (1961) demonstrated how the study of martingale sequences (and zero-mean random walks) can be reduced to the study of the Wiener process (without drift) at a sequence of random stopping times. We show how the study of certain submartingale sequences, including certain random walks with drift and log likelihood ratio sequences, can be reduced to the study of the Wiener process with drift at a sequence of stopping times (Theorem 4.1). Applications to absorption problems are given. Specifically, we present new derivations of a number of the basic approximations and inequalities of classical sequential analysis, and some variations on them — including an improvement on Wald's lower bound for the expected sample size function (Corollary 7.5).
On random genetic drift in a subdivided population
Authors: Pollak Edward 
Published: April 2006

SummaryGenerations are assumed to be non-overlapping. We consider a haploid population divided intoKparts, each of which containNadults in any generation. These are obtained by a random sampling of the offspring of the previous generation. We assume that the probability of an adult offspring of an individual in one subpopulation being in some other subpopulation is the same small positive number, no matter what two subpopulations are considered.If the population initially has individuals of two types, A and a, it is of interest to study approximations, if n is large, to(1)the rate at which A or a is lost between generations n-1 and n,(2)the probability that A and a are still present in generation n,(3)the joint distribution of frequencies of A in the subpopulations.A solution is given for the first problem. It is found that if the mean number of migrants per generation from one subpopulation to another is at least as large as 1, the population behaves almost as if it were not subdivided. But if this number is considerably less that 1, then the rate at which one or the other gene is lost is slower than in an undivided population. The other two problems are discussed for K = 2.
Record values and inter-record times
Authors: Shorrock R. W. 
Published: April 2006

First, asymptotic results for inter-record times when the CDF of the underlying IID process is not necessarily continuous are obtained, by a stochastic order argument, from known results for the continuous case. Then the asymptotic behaviour of the bivariate process of upper-record values and inter-record times is studied. Finally, assuming continuity of the underlying CDF, we derive the law of the process of total times spent in sets of states, viewing upper record values as states and inter-record times as times spent in a state, the process so viewed being a discrete time continuous state Markov jump process.The possible relevance of this result to single lane road traffic flow is indicated.
A multitrap model for high-intensity reciprocity failure in the photographic grain
Authors: Anderson William J. 
Published: April 2006

The response of the photographic grain to light is a non-deterministic process which is as yet not completely understood. This response, as measured by the photographic density, is usually taken to be a function of the product of incident light intensity and exposure time interval duration, but at extreme values of either of these two quantities, this is no longer true. This latter effect is called reciprocity-law failure.This paper discusses a probabilistic model, similar to a multiserver queue, for high-intensity reciprocity failure.
Band-limited spectral estimation of autoregressive-moving-average processes
Authors: Thomson P. J. 
Published: April 2006

Consider an autoregressive-moving-average process of given order where it is known that a number of moving-average roots are of unit modulus. Such a situation might arise, for example, when a time series has been differenced to induce stationarity by removing a non-stationary polynomial or seasonal trend. A band-limited spectral estimation procedure is proposed for estimating the coefficients of such a process and the asymptotic properties of the estimators investigated. The asymptotic theory is illustrated with reference to simulated and real data. A preliminary investigation of the use of Akaike's AIC criterion and this procedure to determine the number of roots of unit modulus (in the case where this is unknown) is also carried out by means of simulation.The proposed band-limited spectral estimation procedure can also be used to take account of other possible effects met in practice. These include, for example, the band-limited response of a recording device or trend-contaminated low-frequency components.
A comparison theorem for conditioned Markov processes
Authors: Roberts G. O. 
Published: April 2006

Intuitively, the effect of conditioning a one-dimensional process to remain below a certain (possibly time-dependent) boundary is to ‘push' the process downwards. This paper investigates the effect of such conditioning, and finds the class of processes for which our intuition is accurate. It is found that ordinary stochastic inequalities are in general unsuitable for making statements about such conditioned processes, and that a stronger type of inequality is more appropriate.The investigation is motivated by applications in estimation of boundary hitting time distributions.
Fixation in bisexual models with variable population sizes
Authors: Möhle M. 
Published: April 2006

A general exchangeable bisexual model with variable population sizes is introduced. First the forward process, i.e. the number of certain descending pairs, is studied. For the bisexual Wright-Fisher model fixation of the descendants occurs, i.e. their proportion tends to 0 or 1 almost surely.The main part of this article deals with necessary and sufficient conditions for ultimate homozygosity, i.e. the proportion of an arbitrarily chosen allelic type tends to 0 or 1 almost surely. The results are applied to a bisexual Wright-Fisher model and to a bisexual Moran model.
Fraise mowing impacts soil physical properties of bermudagrass surfaces
Authors: McCauley Raymond K. , Miller Grady L. , Pinnix Garland D. , Heitman Joshua L. 
Published: February 2025

AbstractFraise mowing has traditionally been used as an aggressive cultural practice for bermudagrass thatch management in golf and sports turf settings. Despite expanded applications, its effect on edaphic characteristics has yet to be thoroughly explored. The objective of this research was to evaluate physical properties of two soil types beneath established Tifway hybrid bermudagrass (Cynodon dactylon × C. transvaalensis Burtt. Davy) following fraise mowing. A study was conducted during the summers of 2016–2019 on a Cecil sandy loam (loam) and a sand‐capped soccer field (sand) in Wake County, NC. Three fraise mowing depths of 0.6, 1.2, and 2.5 cm, and an untreated control were administered in mid‐June of each year. Thatch content decreased by 18%–50% after fraise mowing. Divot resistance measured within the sand rootzone decreased by ≤24% with increasing fraise mowing depth and the removal of roots, rhizomes, and stolons. Saturated hydraulic conductivity in the sand decreased by 0%–57% with increasing fraise mowing depth compared to the control. Surface hardness increased ≤53% with 1.2‐ and 2.5‐cm fraise mowing depths with differences more pronounced in the loam (≤28 gmax) compared to the sand (≤6 gmax). At saturation (0‐cm pressure) and field capacity (100‐cm pressure), water content decreased by 9%–18% and 5%–10%, respectively, with increasing fraise mowing depth in the sand. Results indicate fraise mowing did alter soil physical properties in both soils and increasing fraise mowing depths increased the effects.
Potato yield projections under climate change in Canada
Authors: Jégo Guillaume , Crépeau Marianne , Jing Qi , Grant Brian , Smith Ward , Mesbah Morteza , Qian Budong 
Published: February 2025

AbstractPotato (Solanum tuberosum L.) is an important staple crop in Canada. Past studies have forecasted future yield decreases under climate change, which could have major consequences for the economy of some regions. However, limitations in those studies suggest that further investigations are needed. In this study, we simulated the effect of 15 climate change scenarios (classified from low to moderate and high) on potato potential (no N and water stresses) and rainfed (no N stress) yields at 59 locations across Canada representing current and future potential production regions using three crop models (Decision Support System for Agrotechnology Transfer [DSSAT], DeNitrification and DeComposition [DNDC], and Simulateur mulTI‐disciplinaire pour les Cultures Standard [STICS]). Simulation trends were generally consistent across all three crop models and suggested (1) an increase in potential and rainfed yields in the future (up to 4.4 t ha−1 dry matter in 2051–2080 compared with 1991–2020) in the northern regions where production is currently limited, if not impossible, due to a too short growing season; (2) a slight‐to‐moderate increase in potential and rainfed yields in the near future (2021–2050) for the remaining regions with greater increases for drier regions (0.7–3.1 t ha−1) than in wetter regions (0.5–1.4 t ha−1); and (3) stable or lower yields (up to −2.7 t ha−1) in the distant future (2051–2080), for most regions except the northern ones, due to excessively high temperatures, especially in the moderate and high‐climate change scenarios. This study gave the first extensive projections of future potato yield in Canada, including northern locations where production may become possible.