bluuebunny/crossref_metadata_2025 huggingface dataset:
Verification region selection and data assimilation for adaptive sampling
Authors: Bishop Craig H. , Etherton Brian J. , Majumdar Sharanya J.
Published: June 2006

Adaptive or targeted observations supplement routine observations at a pre‐specified targeting time. Adaptive observation locations are selected to supplement routine observations in an attempt to minimize the forecast error variance of a future target forecast within some predefined verification region (VR) at some predefined verification time. Ideally, the VR is placed in a location where unusually large forecast errors are likely. Here, we compare three methods of selecting VRs: a climatological method based on seasonal averages of forecast errors; an unconditioned method based on verification time ensemble spread; and a conditioned method based on an ensemble transform Kalman filter (ETKF) estimate of forecast error variance given the routine observations to be taken at the targeting time. To test the effectiveness of the three approaches, observation‐system simulation experiments on a chaotic barotropic flow were performed using an imperfect model. To test the sensitivity of our results to the type of forecast error covariance model used in the data assimilation (DA) scheme, two types of DA schemes were tested: an isotropic and a hybrid scheme. For isotropic DA, correlations between vorticity forecast errors at any two points were solely a function of the distance between the points; for hybrid DA, the forecast error covariance matrix was a linear combination of the covariance matrix used in isotropic DA and the sample covariance matrix of an ETKF ensemble. For each of the three VRs, the ETKF was used to select two adaptive observations. To assess targeted‐observation‐induced error reductions, forecast errors with and without targeted observations were computed for the VR, the total domain and also for an empirical VR which was defined to be the VR with the largest forecast error without targeted observations. The sensitivity, to the type of DA scheme employed, of the ETKF's ability to distinguish high‐impact targeted observations from low‐impact observations, was also examined. Amongst other things, it was found that: conditioned VRs were more prone to large errors than the other VRs; and the targeted‐observation‐induced reduction in forecast error variance was largest when hybrid DA and conditioned VRs were used, as was the range of forecast impacts distinguished by ETKF predictions. Copyright © 2006 Royal Meteorological Society.
Dynamics of the MAP IOP 15 severe Mistral event: Observations and high‐resolution numerical simulations
Authors: Guéenard V. , Drobinski P. , Caccia J. L. , Tedeschi G. , Currier P.
Published: June 2006

This paper investigates the fundamental processes involved in a severe Mistral event that occurred during the Mesoscale Alpine Program (from 6 to 9 November 1999). The Mistral refers to a violent north/north‐westerly wind blowing in south‐eastern France from the Rhône valley to the French Riviera. The study is based on measurements from radiosoundings launched from Lyon and Nîmes and from two UHF wind profilers located near Marseille and Toulon allowing a good description of the flow in the complex terrain formed by the southwestern Alps. Observational results are compared with RAMS non‐hydrostatic numerical simulations performed with 27 km, 9 km and 3 km nested grids. The numerical simulations capture the flow complexity both upstream of the Alps and in the coastal area affected by the Mistral. They correctly reproduce horizontal wind speeds and directions, vertical velocities, virtual potential temperature and relative humidity documented by the observational network. The simulations are used to point out the main dynamical processes generating the Mistral. It is found that flow splitting around the Alps and around the isolated peaks bordering the south‐eastern part of the Rhône valley (Mont Ventoux 1909 m, Massif du Lubéron 1425 m) induces the low‐level jet observed near Marseille that lasts for 36 hours. The high‐resolution simulation indicates that the transient low‐level jet lasting for only 9 hours observed at Toulon is due to a gravity wave breaking over local topography (the Sainte Baume 1147 m) where hydraulic jumps are involved. A mountain wake with two opposite‐sign potential‐vorticity banners is generated. The mesoscale wake explains the westward progression of the large‐scale Alpine wake. Copyright © 2006 Royal Meteorological Society.
Low potential for stratospheric dynamical change to be implicated in the large winter warming in the central Antarctic Peninsula
Authors: Roscoe H. K. , Marshall G. J. , King J. C.
Published: June 2006

Stratospheric change associated with the Antarctic ozone hole is clearly implicated in changing surface climate near 65°S in late summer, in both measurements and models, via downward propagation of height anomalies following the final warming. But one of the largest changes in surface temperature in Antarctica has occurred in the Antarctic Peninsula at 60 to 65°S in winter, and most of the change at 65°S occurred before the ozone hole. Stratospheric change can cause tropospheric change in Antarctic winter by modifying the reflection and refraction of planetary waves, whereby a stronger stratospheric vortex moves the tropospheric jets polewards, which can modify the Southern Annular Mode (SAM) in surface pressure that forces the tropospheric circumpolar winds. We examine stratospheric influence on the SAM in winter by inter‐annual correlation of the SAM with the solar‐cycle and volcanic aerosols, which act to change forcing of the stratospheric vortex in winter. Correlations are a maximum in June (midwinter) and are significant then, but are poor averaged over winter months. Hence the potential of change in the stratosphere to change Antarctic tropospheric climate in winter by dynamical means is low. This negative result is important given the proven high potential for change in summer by dynamical means. Copyright © 2006 Royal Meteorological Society.
Radar scattering by aggregate snowflakes
Authors: Westbrook C. D. , Ball R. C. , Field P. R.
Published: June 2006

The radar scattering properties of realistic aggregate snowflakes have been calculated using the Rayleigh–Gans theory. We find that the effect of the snowflake geometry on the scattering may be described in terms of a single universal function, which depends only on the overall shape of the aggregate and not the geometry or size of the pristine ice crystals which compose the flake. This function is well approximated by a simple analytic expression at small sizes; for larger snowflakes we fit a curve to our numerical data. We then demonstrate how this allows a characteristic snowflake radius to be derived from dual wavelength radar measurements without knowledge of the pristine crystal size or habit, while at the same time showing that this detail is crucial to using such data to estimate ice water content. We also show that the ‘effective radius’, characterizing the ratio of particle volume to projected area, cannot be inferred from dual wavelength radar data for aggregates. Finally, we consider the errors involved in approximating snowflakes by ‘air–ice spheres', and show that for small enough aggregates the predicted dual wavelength ratio typically agrees to within a few percent, provided some care is taken in choosing the radius of the sphere and the dielectric constant of the air–ice mixture; at larger sizes the radar becomes more sensitive to particle shape, and the errors associated with the sphere model are found to increase accordingly. Copyright © 2006 Royal Meteorological Society.
Fraudulent Trading: The Intent to Defraud Element
Authors: Keay Andrew
Published: June 2006

The Insolvency Act 1986, s. 213 permits liquidators of companies in winding up to bring proceedings to obtain orders against those who have committed fraudulent trading. The most contentious element that has to be proved in a claim for fraudulent trading is that the business of the company was carried on with intent to defraud creditors or for any other fraudulent purpose. The phrase ‘intent to defraud’ has never been defined statutorily and there has been inconsistency concerning the test which should be applied and how the phrase should be interpreted. The article traces the manner in which the courts have interpreted the expression ‘intent to defraud,’ and in doing so it ascertains what the present test is for establishing intent to defraud.
Restrictions on Assignment of Commercial Leases: A Comparative Perspective
Authors: Crabb Letitia
Published: June 2006

The operation of restrictions on the assignment of commercial leases is examined in a number of common law jurisdictions to ascertain whether lessons can be learned to inform the future development of the law. It is concluded that while absolute restrictions have a useful role to play, there is a case for banning them in sectors of the market where tenants lack adequate legal advice. Drawing on the US experience, it is considered that qualified restrictions have little to commend them. In relation to fully qualified restrictions, it is submitted that the ‘reasonableness' standard needs to be rebalanced in favour of tenants. Even if that were to be achieved however, vulnerable tenants would still need protection from sophisticated drafting mechanisms adverse to their interests. A special statutory regime for small commercial tenants is recommended.
Ablation of Proliferating Marrow with 5-Fluorouracil Allows Partial Purification of Mesenchymal Stem Cells
Authors: Wang Zhuo , Song Junhui , Taichman Russell S. , Krebsbach Paul H.
Published: June 2006

The ability to identify and maintain mesenchymal stem cells in vitro is a prerequisite for the ex vivo expansion of cells capable of effecting mesenchymal tissue regeneration. The aim of this investigation was to develop an assay to enrich and ultimately purify mesenchymal stem cells. To enrich the population of mesenchymal stem cell-like cells, rats or mice were administered 5-fluorouracil (5-FU) in vivo. Limiting dilution analysis demonstrated that 5-FU-treated bone marrow had the potential to form colony-forming units-fibroblastic (CFU-F) at a 10-fold or sixfold enrichment compared to normal bone marrow in rats or mice, respectively. In vivo and in vitro differentiation assays supported the enrichment and purification effects. In vitro, bone marrow cultures from 5-FU-treated bone marrow demonstrated lineage-specific gene expression in lineage-specific medium conditions in contrast to the multilineage gene expression of control bone marrow cultures. In vivo implantation of 5-FU-treated cells that were not expanded in culture generated ossicles containing an intact bone cortex and mature hematopoietic components, whereas non-5-FU-treated bone marrow only formed fibrous tissues. Our results demonstrate that enrichment of a quiescent cell population in the bone marrow by in vivo treatment of 5-FU spares those undifferentiated mesenchymal stem cells and influences the differentiation of bone marrow stromal cells in vitro and in vivo. This prospective identification of a population of mesenchymal cells from the marrow that maintain their multilineage potential should lead to more focused studies on the characterization of a true mesenchymal stem cell.
Splenic Endothelial Cell Lines Support Development of Dendritic Cells from Bone Marrow
Authors: Despars Geneviève , O'Neill Helen C.
Published: June 2006

Although growth factors are commonly used to generate dendritic cells (DCs) in vitro, the role of the microenvironment necessary for DC development is still poorly understood. The mixed splenic stromal cell population STX3 defines an in vitro microenvironment supportive of DC development. Dissection of cellular components of the STX3 stroma should provide information about a niche for DC development. STX3 was therefore cloned by single-cell sorting, and a panel of 102 splenic stromal cell lines was established. Four representative splenic stromal cell lines that support hematopoiesis from bone marrow are described here in terms of stromal cell type and DC production. All four stromal lines express the endothelial genes Acvrl1, Cd34, Col18a1, Eng, Flt1, Mcam, and Vcam1 but not Cd31 or Vwf. Three of the four lines form tube-like structures when cultured on Matrigel. Their endothelial maturity correlates with the ability to support myeloid DC development from bone marrow. A fourth cell line, unable to form tube-like structures in Matrigel, produced large granulocytic cells expressing CD11b and CD86 but not CD11c and CD80. Conditioned media from splenic stromal cell lines also support DC production, indicating that soluble growth factors and cytokines produced by stromal lines drive DC development. This article reports characterization of immature endothelial cell lines derived from spleen that are supportive of DC development and predicts the existence of such a cell type in vivo which regulates DC development within spleen.
Determination of the efficiency coefficient of slag under various mixing and curing conditions
Authors: Ezziane K. , Bougara A. , Kassoul A. , Kadri A.
Published: June 2006

Currently the prediction of the strength of blended cement constitutes a major preoccupation leading the promoters of such constructions to be more and more interested in predicting the timing of removal of the framework or the prestressing at suitable ages. The prediction of the strength of the slag concrete, using simple models of prediction such as Feret's model, with the introduction of the concept of the equivalent binder, was studied and this led to the definition of an efficiency coefficient of the slag which defines the latter according to the cement. This efficiency coefficient, once deduced, characterised the slag from the El-Hadjar steel factory (Algeria) well and made it possible to predict the strength of a slag concrete of a given age and replacement level from the data of a reference concrete made without slag. This coefficient is defined on the basis of the age, the replacement level, the specific surface area of the slag and the curing temperature.
Linear Filtering and Recursive Credibility Estimation
Authors: Zehnwirth Ben
Published: June 2006

Recursive credibility estimation is discussed from the viewpoint of linear filtering theory. A conjunction of geometric interpretation and the innovation approach leads to general algorithms not developed before. Moreover, covariance characterizations considered by other researchers drop our elegantly as a result of geometric considerations. Examples are presented of Kalman type filters valid for non-Gaussian measurements.
Unbayesed Credibility Revisited
Authors: Norberg Ragnar
Published: June 2006

The unbayesed credibility procedure proposed by Gerber is revisited. Its performance is discussed, connections are drawn to earlier literature, and some possible ideas of generalizations are investigated (and found fruitless).
Asymptotic Behaviour of Compound Distributions
Authors: Embrechts Paul , Maejima Makoto , Teugels Jozef L.
Published: June 2006

We improve on some results of Sundt (1982) on the asymptotic behaviour of compound negative binomial distributions.
On Combining Quota-Share and Excess of Loss
Authors: Centeno Lourdes
Published: June 2006

This paper considers reinsurance retention limits in cases where the cedent has a choice between a pure quota-share treaty, a pure excess of loss treaty or a combination of the two. Our primary aim is to find the combination of retention limits which minimizes the skewness coefficient of the insurer's retained risk subject to constraints on the variance and the expected value of his retained risk. The results are given without specifying precisely how the excess of loss reinsurance premium is calculated. It is also shown that, depending to some extent on the constraint on the variance, the solution to the problem is a pure excess of loss treaty if the excess of loss premium is calculated using the expected value or standard deviation principle but that this need not be true if the variance principle is used.
A Heuristic Review of some Ruin Theory Results
Authors: Taylor G. C.
Published: June 2006

The paper deals with the renewal equation governing the infinite-time ruin probability. It is emphasized as intended to be no more than a pleasant ramble through a few scattered results. An interesting connection between ruin probability and a recursion formula for computation of the aggregate claims distribution is noted and discussed. The relation between danger of the claim size distribution and ruin probability is reexamined in the light of some recent results on stochastic dominance. Finally, suggestions are made as to the way in which the formula for ruin probability leads easily to conclusions about the effect on that probability of the long-tailedness of the claim size distribution. Stable distributions, in particular, are examined.
The Reinsurer's Monopoly and the Bowley Solution
Authors: Chan Fung-Yee , Gerber Hans U.
Published: June 2006

The reinsurer has a monopoly in the following sense: He will select a random variable P that determines the reinsurance premiums. The first insurer can purchase a payment of R (a random variable) for a premium of π = E[PR]. For known P, the first insurer chooses R to maximize his expected utility. Knowing this, i.e., the demand for reinsurance as a function of P, the reinsurer chooses P to maximize his utility. The resulting pair (P, R) is called the Bowley solution. Assuming exponential, quadratic and/or linear utility functions, some explicit results are obtained.
A Statistical Approach to IBNR-Reserves in Marine Reinsurance
Authors: Hertig Joakim
Published: June 2006

The run off-pattern of long-term reinsurance treaties is described by means and standard deviations of logarithmic increments of premiums and loss ratios in a normal distribution. From this description forecasts of ultimate claims and current IBNR-reserves are derived, with associated distributions and confidence limits. Aggregation from individual treaties to portfolio level is proposed by normal approximation. Security loading of IBNR-reserves is proposed by a contingency reserve at portfolio level.
Experience Rating of ARIMA Processes by the Kalman Filter
Authors: Rantala Jukka
Published: June 2006

This paper deals with experience rating of claims processes of ARIMA structures. By experience rating we mean that future premiums should be only a function of past values of the claims process. The main emphasis is on demonstrating the usefulness of the control-theoretical approach in the search for optimal rating rules. Optimality is here defined to mean as smooth a flow of premiums as possible when the variation in the accumulated profit is restricted to a certain amount. First it is shown how the underlying model in its simplest form can be transformed into the state-space form. Then the Kalman filter technique is used to find the optimal rules. Also a time delay in information is taken into account. The optimal rules are illustrated by examples.
Finite Time Ruin Problems for Perturbed Experience Rating and Connection with Discounting Risk Models
Authors: Abikhalil F.
Published: June 2006

We consider a generalisation of a risk process under experience rating when the aggregation of claims up to time t is a Brownian motion (B.M.) with a drift. We prove that the distribution of ruin before time t is equivalent to the distribution of the first passage time of B.M. for parabolic boundary.

Using Wald identity for continuous time we give an explicit formula for this distribution. A connection is made with discounting risk model when the income process is a diffusion.

When the aggregation of claims is a mixture of B.M. and compound Poisson process, we give (using Gerber's result 1973) an upper bound for the distribution of finite time ruin probability.
A Model to Evaluate the Rebuilding Costs of Dwellings
Authors: Corlier Freddy , Ingenbleek Jean-François , Lemaire Jean
Published: June 2006

Under-insurance is one of the scourges of homeowner insurance: when it is established after a claim that the rebuilding cost of a dwelling has been underestimated by the policyholder, the proportional rule applies in the sense that the indemnity is reduced in proportion of the under-insurance. To avoid this dramatic problem, prejudicial to all parties concerned, a Belgian company has in 1983 marketed a model to evaluate rebuilding costs: if the policyholder fills in correctly a two-page form, the company forgoes the application of the proportional rule.

The construction of this model is explained; then, it is shown how a statistical study sponsored by the Professional Union of Insurance Companies allowed the model to improve.
Recursive Calculation of the Net Premium for Largest Claims Reinsurance Covers
Authors: Kremer E.
Published: June 2006

In the present paper the author investigates the problem of calculating the net premium for some versions of the largest claims reinsurance cover. A very handy recursive rating method is derived by applying some recursion formulas for the expectations of order statistics.
Run-Off Risk as a Part of Claims Fluctuation
Authors: Pentikäinen T. , Rantala J.
Published: June 2006

A conventional practice in standard risk theory considerations has been to assume that claims are paid immediately as they have incurred (see BPP, item 3.1c, BPP is used as an abbreviation for the book “Risk Theory”, 1984 edition, by Beard, Pentikäinen, Pesonen). The delay of the claims settlement has been, of course, a central aspect in reserve calculation theory and practices, and numerous valuable works have been published on this topic in recent years. However, its regard in general model building and in risk theory considerations has gained little attention until recent years. The purpose of this paper is to contribute to this research work by discussing how the “run-off” risk, i.e., the variability due to the delay of the claims payment, could be incorporated into the standard risk theory models as a separate entry (see BPP, item 10.2e) and to find some evaluation of the order of magnitude of the “extra” (if any) fluctuation so rendered. We expect that the proposed technique can also be utilized in testing different reserve calculation methods and in comparing their effectiveness. The main ideas follow very much along the lines given by Rantala in his doctoral thesis (1984).

One should appreciate the fact that any risk theory model can never be more than an idealization of real-life processes. An intricate problem for practitioners is to evaluate the uncertainties ensuing from the fact that the model, more or less, ignores or only approximates the factors affecting the real events, and that the practical applications are often based on and their necessary parameters estimated from observed data that are subject to random fluctuations and to many other kinds of uncertainties. The problem complex of the run-off risk, when understood in a broad sense, is so wide that it requires a series of studies, and this paper should be regarded as a first step only. The posing of the problem follows the conventional risk theory approach by using the mixed compound Poisson process further allowing for long-term variations of risk exposure (“cycles”), and now extending the model to cope with the delayed settlement of the claims. At this stage of the on-going researchwork the impact of the parameter estimation is excluded from consideration. Therefore, our results and the numerical examples, as given in what follows, do not describe the total uncertainty of the claims or the reserves.
Tarification de l'Incendie des Risques Industriels Français par la Méthode de la Crédibilité
Authors: Cohen Albert , Dupin Gilles , Levi Charles
Published: June 2006

The industrial risks insurance market has shown a deficit for a few years, in France as well as in other European countries. In order to change that situation, insurers, with the help of their professional organizations, have begun to re-build their tariffs. Further, the progressive opening of the services European market has led these countries towards a standardization of their actuarial methods to estimate premiums. Among these methods, the credibility approach has already been adopted by Germany, Switzerland and partly by Belgium.

We have applied this method to statistical data from the French market. The estimation of the pure premium is based on the Bühlmann-Straub model with a measure of volume for every category (sums insured in our case). Loadings for fluctuation have been evaluated by the N.P. approximation of the distribution function of the loss ratio.

Beyond the simple use of the mathematical formulas, we have tried to measure the reaction of the model under different scenarii: risks typology with one, two or three levels, rough disturbance of the loss ratio of a category of risk, stability of the tariff over a long period of time, comparison of this tariff with the tariff built with the help of the existing French method based on a correction for large claims.
Increasing Social Interaction among Adolescents with Intellectual Disabilities and Their General Education Peers: Effective Interventions
Authors: Carter Erik W. , Hughes Carolyn
Published: June 2006

Research indicates that peer interaction can have a substantial impact on the lives of adolescents with disabilities. However, social interaction among adolescents with intellectual disabilities and their general education peers typically occurs infrequently in secondary schools. This paper provides a critical analysis of twenty-six empirical interventions aimed at promoting social interaction among adolescents with intellectual disabilities and their general education peers in middle and high school settings. Findings are analyzed with regard to intervention components; student characteristics; interaction settings; measures of interaction; observation procedures; experimental designs; intervention components; and measures of generalization, social validity, and treatment integrity. Based upon findings from this literature, we present recommendations to guide future research and the development of effective social interaction interventions for adolescents with intellectual disabilities in middle and high schools.
The Impact of Siblings with Disabilities on Their Brothers and Sisters Pursuing a Career in Special Education
Authors: Marks Susan Unok , Matson Amy , Barraza Lori
Published: June 2006

It is well known that growing up with a sibling who has a disability has both positive and negative impacts on the non-disabled sibling (Beckman, 2002; Fisman, Wolf, Ellison, & Freeman, 2000; Gans, 1997; McHugh, 2003). In fact, the concern for ameliorating the potential negative impacts on nondisabled siblings has been a major impetus for the development of sibling support groups and agencies serving families of children with disabilities for a number of years (Gallagher et al., 2000; Powell & Gallagher, 1993). This article reports on a project in which we explored this sibling experience from the perspective of those who chose to enter the field of special education. The current study involved interviews with 7 individuals who have chosen special education as a career in order to understand what may have contributed to this decision as well as how their experiences growing up with a brother or sister who has a disability influenced their work and their views of special education.
Anchoring Schoolwide Positive Behavior Support in Structural School Reform
Authors: Sailor Wayne , Zuna Nina , Choi Jeong-Hoon , Thomas Jamie , McCart Amy , Roger Blair
Published: June 2006

Schoolwide positive behavior support (SWPBS) exemplifies a longitudinal research program originating in the fields of special education and school psychology that has produced an extensive national database encompassing an evidence-based set of practices applicable to general education as well as special education students including those with severe disabilities. Schoolwide applications of evidence-based practices, however, are at some risk of falling victim to the ongoing bifurcation of education into the general and special education parallel and often noninteractive, professional systems of instruction. One potential solution to bifurcated practice is to embed (or contextualize) SWPBS in a broader, universal school reform agenda that coordinates and evaluates all educational intervention services and supports for the benefit of all students. A structural school reform process called the Schoolwide Applications Model (SAM) is described, which includes SWPBS as 1 of 15 critical features. Results from a 3-year, ongoing research project in a low-income, multicultural, urban school district in Northern California suggests that SWPBS, with its three levels of student support, guided by teams of general as well as special educators, can be an important contributor to academic as well as social achievement among students with and without disabilities and, as grounded within systematic school reform, can help to mitigate against the bifurcation of general and special education practices.
Individualized Behavioral Supports at 15 Years: It's Still Lonely at the Top
Authors: Crimmins Daniel , Farrell Anne F.
Published: June 2006

Positive behavior support (PBS) has evolved over the past 15 years from an individualized approach to behavior management to one with an increased focus on universal applications. Although there are clear areas of convergence between individualized and universal supports, it is also clear that the provision of individualized supports is an independent activity and an area where there is still much left to be accomplished. We assert that the research agenda is unfinished, crucial research-to-practice questions remain unresolved, and knowledge about the extent to which individualized PBSs are available is incomplete at best. We argue that individualized supports need to be a primary consideration in research and training, particularly as aspects of individualized supports are mandated considerations under the Individuals with Disabilities Education Act (IDEA). Emphasis on individualized supports is important not only because they demonstrate promise but also because of their potential to protect the interests of individuals with severe disabilities.
Building Inclusive School Cultures Using School-Wide Positive Behavior Support: Designing Effective Individual Support Systems for Students with Significant Disabilities
Authors: Freeman Rachel , Eber Lucille , Anderson Cynthia , Irvin Larry , Horner Rob , Bounds Monica , Dunlap Glen
Published: June 2006

School-wide positive behavior support (SWPBS) is a systematic and effective approach for broadly improving student behavior across school environments. SWPBS includes data-based strategies for supporting all students along a continuum of need and intensity based on a three-tiered model of prevention. Students with the most significant behavioral challenges are provided with assessment-based, individualized supports. To date, considerable evaluation research has demonstrated the benefits of SWPBS, documenting behavioral improvements using the whole school as the unit of analysis. Notably, less evaluation research has focused on the effects of SWPBS on the behavior of individual students with the most significant disabilities. In this paper, we describe SWPBS with an emphasis on the conceptual and procedural elements that are intended to benefit the full range of students within a school, with a particular focus on those students with the most intense needs. We discuss the SWPBS process, provide case illustrations, and call for additional research on the inclusion of students with significant disabilities with all applications of SWPBS.
Including Students with Severe Disabilities in All Levels of School-Wide Positive Behavior Support
Authors: Hawken Leanne S. , O'Neill Robert E.
Published: June 2006

Throughout its evolution, school-wide positive behavior support (SWPBS) has explicitly promoted the perspective that it should involve all students in a given school setting. However, the literature on SWPBS has not always fully and clearly addressed the involvement of students with severe disabilities. This article will (a) briefly review the literature of SWPBS as it addresses the involvement of students with severe disabilities, particularly those exhibiting severe problem behaviors; (b) discuss the involvement of students with severe disabilities in all three typical levels of SWPBS; and (c) provide recommendations for increasing the involvement of students with severe disabilities at all three levels of SWPBS.
Principals' Perspectives on Inclusive Elementary Schools
Authors: Salisbury Christine L.
Published: June 2006

A growing number of schools are engaged in efforts to become more inclusive in their service delivery and educational practices. To date, accounts of principals involved in reform efforts have largely been absent from the research literature. To address this need, this study examined the perspectives and experiences of eight principals who were involved in developing inclusive elementary schools in urban, suburban, and metropolitan communities. Quantitative indices of inclusiveness were combined with principal interview data to develop a deeper understanding of how inclusive education was viewed by these principals, their perspectives on implementation, and the challenges they encountered. Results revealed that despite being considered inclusive, schools varied markedly from one another in their level of implementation, and that level of implementation was unrelated to an index of inclusiveness or to a measure of program quality. Schools with stronger administrative support and commitment reported serving more students with disabilities, including those with significant support needs, in general education for a greater percentage of time. Patterns among proponents were contrasted with viewpoints of administrators voicing conditional support for inclusive education.
Presalvage prostate‐specific antigen (PSA) and PSA doubling time as predictors of biochemical failure of salvage cryotherapy in patients with locally recurrent prostate cancer after radiotherapy
Authors: Spiess Philippe E. , Lee Andrew K. , Leibovici Dan , Wang Xuemei , Do Kim‐Anh , Pisters Louis L.
Published: June 2006

BACKGROUND.

The value of presalvage cryotherapy serum PSA level in predicting biochemical failure in patients with local recurrence of prostate cancer (PCa) after radiotherapy was documented; however, little is known about the predictive value of prostate‐specific antigen (PSA) doubling time (DT) in this patient group. The purpose of the current study was to evaluate serum PSA level and PSA DT as predictors of salvage cryotherapy outcomes in patients being treated for postradiotherapy locally recurrent PCa.

METHODS.

The charts of patients treated with salvage cryotherapy were retrospectively reviewed for locally recurrent PCa at the M. D. Anderson Cancer Center from January 1980 to July 2004. Patients who received neoadjuvant or adjuvant hormone therapy were excluded. We assessed pre‐ and postradiotherapy clinical data, pre‐ and postsalvage cryotherapy clinical data, and other variables. Kaplan–Meier and log rank tests were performed to assess unadjusted survival probabilities and 2‐group survival comparisons, respectively. Cox proportional hazards regression models were used to assess the effect of patient characteristics in predicting overall, disease‐specific, and biochemical failure‐free survival.

RESULTS.

Forty‐nine patients met the eligibility criteria. The median age of patients at diagnosis was 66 years (58–81 years) with the initial clinical stage before radiotherapy most commonly T2 (n= 25) or T3 (n= 21). The median presalvage cryotherapy serum PSA level was 5.9 ng/mL (0.4–23.1 ng/mL) and the presalvage prostatic biopsies were frequently high grade (Gleason grade ≥8 in 51% of patients). The median postsalvage cryotherapy serum PSA level was 0.1 ng/mL (0.1‐9.5 ng/mL), and biochemical failure (defined as a serum PSA level ≥2 ng/mL above the postsalvage cryotherapy PSA nadir) occurred in 26 patients. In these 26 patients, there was a statistically significant difference between pre‐ and postsalvage cryotherapy PSA DTs (12.3 months to 5.6 months, respectively;P= .02). A presalvage cryotherapy serum PSA level >10 ng/mL (P= .002) and PSA DT ≤16 months (P= .06) were found to predict the subsequent risk of biochemical failure.

CONCLUSIONS.

Presalvage PSA and PSA DT can predict biochemical failure of salvage cryotherapy, although the predictive value of PSA DT only trended toward significance. The statistically significant difference in pre‐ and postsalvage cryotherapy PSA DTs was reflective of aggressive tumor biology. Cancer 2006. © 2006 American Cancer Society.
Thapsigargin resistance in human prostate cancer cells
Authors: O'Neill John P. , Velalar Chidambaram Natesa , Lee Dong Ik , Zhang Bin , Nakanishi Takeo , Tang Yao , Selaru Florin , Ross Douglas , Meltzer Stephen J. , Hussain Arif
Published: June 2006

BACKGROUND.

Thapsigargin (TG) is a potent inhibitor of sarcoplasmic/endoplasmic reticulum Ca2+ ATPases (SERCAs). TG‐based prodrugs are being developed for the treatment of prostate cancer (PC). To develop optimal TG‐based therapeutics it is important to understand the mechanisms of resistance to TG that may potentially occur in cancer cells.

METHODS.

DU145/TG and PC3/TG cells were derived from human PC DU145 and PC3 cells, respectively, by incremental exposure to TG. Growth assays, Western blot analyses, cDNA microarrays, semiquantitative and real‐time polymerase chain reaction (PCR), Northern blot analyses, and immunohistochemistry were used to study these cells.

RESULTS.

DU145/TG cells are 1100‐fold and PC3/TG cells are 1350‐fold resistant to TG. Although expression of both SERCA and p‐glycoprotein can mediate TG resistance in hamster cells, neither is modulated in DU145/TG cells. In contrast, in PC3/TG cells, SERCA, and not p‐glycoprotein, is significantly overexpressed but cannot by itself account for the 1350‐fold resistance to TG in these cells. Several genes not previously identified to be altered by TG selection are modulated in DU145/TG and PC3/TG cells. Furthermore, the spectrum of genes modulated in DU145/TG cells are distinct from that in PC3/TG cells, even though both cells are of prostate origin and share the same TG‐resistant phenotype.

CONCLUSIONS.

PC cells can adapt to SERCA inhibition by TG. However, they demonstrate cell type‐specific plasticity with respect to gene expression upon TG selection. Further, previously not described mechanisms of resistance appear to be recruited in the TG‐resistant PC cells, which provide a novel model to study mechanisms of resistance and adaptation in PC on TG‐mediated dysregulation of Ca2+ homeostasis. Cancer 2006. © 2006 American Cancer Society.
Mach Probe Measurements in Unmagnetized Plasmas with Subsonicand Supersonic Flow
Authors: Ando A. , Watanabe T. K. , Makita T. , Tobari H. , Hattori K. , Inutake M.
Published: June 2006

Characteristics of an up‐down type Mach probe are investigated by using a directional Langmuir probe (DLP) in unmagnetized plasmas with subsonic and supersonic flow produced by a magneto‐plasma‐dynamic arcjet (MPDA). The ion acoustic Mach number Mi is derived from plasma flow velocity Up and ion temperature Ti measured by spectroscopy and electron temperature Te by Langmuir probe. The obtained values of Mi are compared to the DLP data in various conditions of plasma flow and the coefficient of Mc in the Mach probe formula,Mi = Mc ln(Jup/Jdown ) , is evaluated. The obtained data are also compared with Hutchinson's PIC simulation results in an unmagnetized plasma and are in good agreement with each other. The dependence of ln(Jup/Jdown ) on cosϕ can be expressed as a quadratic function under subsonic (Mi < 1) and supersonic (Mi > 1) flow, so that the up‐down type Mach probe can detect the components of plasma flow vector even when the probe collection surface inclines to plasma flow direction. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric Probe Systems for Diversified Plasma Simulator (DiPS)
Authors: Chung K.‐S. , Woo H.‐J. , Choi G.‐S. , Do J.‐J. , Seo Y.‐J. , You H.‐J.
Published: June 2006

DiPS (Diversified Plasma Simulator), a new versatile linear machine (length=3400 mm, diameter=200‐600 mm), is developed for the simulations of divertor, space and processing plasmas with various electric probes: fast‐scanning systems with single, triple, and Mach Probes, slow‐scanning water‐cooled single probe, griddedenergy analyzer (GEA), and several fixed single probes. For the verification of current probe theories and the development of new theories with magnetic vector field, collisional effects, various particle sources, and wide range of plasma parameters, two different plasma sources are installed: (1) For a stable high density dc plasma, a LaB6 disk is used as the thermal electron emission source with 5 kW graphite heater. Initial plasma density of the LaB6 source is 5 × 1012 cm−:3, electron temperature is 8‐10 eV with magnetic field around 1 kG. The electron density would be decreased severely, i.e., to 106–108 cm−3 with grid, and expanded into space simulation region without magnetic field; (2) Helicon plasma source is also installed for a processing simulation in DiPS and for the space propulsion study with magnetic expansion, which generates the plasma with density of 2 × 1013 cm−3 and electron temperature 3‐4 eV for the rf power of 2.5 kW at optimum pressure of 7.5 mTorr. As a unique feature for the diversified uses of sources and divertor simulator experiments, space and processing simulation chambers can be detached from and attached to the divertor simulation chamber on the rail. Initial data of various electric probes (single, triple, emissive, mach probes, GEA, etc.) are introduced for the the following conditions of DiPS with B= 1 kG, P= 130 mTorr at source region, P= 2 mTorr at divertor simulation region, ne = 1×1012 – 1×1014 cm−3, Te = 2 ‐ 3 eV, Ti = 0.2 eV with laser induced fluorescence (LIF) (Ar gas), ne = 1 × 1012 – 1 × 1013 cm−3, Te =5 ‐ 6 eV (He gas) at divertor simulation region, Ti = 0.47 ‐ 0.74 eV with GEA at space simulation region and vd = 500 ‐ 600 m/s. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Observation of Wave‐Like Structures in Magnetized DC Dischargein Cylindrical Symmetry in Argon
Authors: Bilyk O. , Holík M. , Kudrna P. , Marek A. , Tichý M.
Published: June 2006

Wave‐like structures in the dc discharge in cylindrical magnetron in conventional arrangement were investigated. Two Langmuir probes measured simultaneously fluctuations of floating potential. Power spectra were evaluated according to the method developed in [1] to obtain frequency – wave number histogram. The measurements were carried out at the different external discharge parameters – pressure, discharge current and magnetic field. Comparison with different theoretical description of fluctuations was performed to find out origin of the instabilities in the cylindrical magnetron dc discharge. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Concept of Negative Ion Flow Velocity Measurement Using a Laser Photodetachment Velocimetry (LPDV)
Authors: Kado S. , Kajita S. , Shikama T. , Iida Y. , Yamasaki D. , Okamoto A. , Tanaka S.
Published: June 2006

A concept of the thermal and flow velocities measurement for negative ions by means of a laser photodetachment technique, laser photodetachment velocimetry (LPDV), is presented. The difference in the temporal evolution of the photodetached excess electron current between the upstream and the downstream regions corresponds to the flow velocity, while the average of the recovery times corresponds to the thermal velocity, namely the negative ion temperature. Initial results in a divertor/edge plasma simulator MAP(material and plasma)‐II suggest that the parallel flow velocity is small in the periphery of the linear plasma column where the negative ions exist. The negative ion temperature is similar to that of helium ion obtained for helium discharges. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetized Features of Sheath and Collection Region of Photodetached Electrons in Negative Ion Measurement
Authors: Kajita S. , Kado S. , Tanaka S.
Published: June 2006

The magnetized features of the sheath and collection region of photodetached electrons (PDE's) are experimentally studied in the linear divertor simulator MAP‐II. The thickness of the electron sheath formed around a cylindrical electrostatic probe is measured by analyzing the variation in the temporal evolution of the laser photodetachment (LPD) signal. The effect of the magnetic field on the electron sheath thickness along the field is revealed by comparing the experimental result to the theoretical thickness derived using the Child‐Langmuir (CL) law. The length of the collection region of PDE's is measured in several magnetized regimes by using the recently developed eclipse‐LPD method. The physical meaning of this collection region is discussed based on the measured electron sheath thickness and the length of the collection region. Finally, the necessary conditions for applying the LPD technique in magnetized plasmas are discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Baffled‐Probe Cluster for Simultaneous, Single‐Point Monitoring of Magnetized Plasma Fluctuations
Authors: Koepke M. E. , Demidov V. I. , Finnegan S. M. , Reynolds E. W.
Published: June 2006

An array of baffled probes for the real‐time monitoring of oscillating values of space potential, electric field and electron/ion temperature in magnetized plasma is assembled and tested. The multi‐probe array samples a region with dimensions on the order or less than an ion gyroradius, essentially a single point, and does not require voltage sweeps. We refer to an array of probes contained within such a single point as a probe cluster. Here, we describe two versions of the baffled‐probe cluster. In the first cluster, four independent coils of collection wire are mounted at 90‐degree intervals around the circumference of a short, thin, cylindrical, four‐bore ceramic tube. This tube slides into a larger‐diameter, single bore, ceramic tube having four azimuthally separated masks (baffles), each lining up with a coil‐coil gap on the 4‐bore tube, and four baffle‐to‐baffle gaps, each lining up with a coil on the 4‐bore tube. The second cluster uses a single four‐bore ceramic tube, with four longitudinal slots to allow side access to each bore, and probes made from a single strand of collection wire. With the tubes oriented perpendicular to the magnetic field, the baffled‐probe cluster is rotated around its axis in order to regulate the ratio between electron and ion currents to the baffled probes and, thereby, change the probes' relative sensitivity to space potential and temperature oscillations. This probe‐cluster design has the advantages of realtime monitoring of magnetized‐plasma fluctuations, post‐acquisition determination of electron‐temperature or ion‐temperature time series, post‐acquisition determination of cross‐phase and coherence between fluctuations of individual plasma parameters, compact size, minimal plasma perturbation (probes are non‐emissive), and relative insensitivity to alignment uncertainty. The clusters have been used for distinguishing temperature fluctuations from potential fluctuations in plasma of the WVU Q‐machine. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)