Conventional DA Research Articles

A Novel Contactless SiC Wafer Planarization Processing after Mechanical Slicing by Dynamic Thermal Annealing Processes

In conventional machining of SiC wafers, material loss and sub-surface damage (SSD) of both the front and back surfaces are major issues. In this study, we focused on Dynamic AGE-ing® (DA), which is a sublimation-controlled process, and applied it to the total wafering process without any mechanical contact of both the front and back surfaces to explore the possibilities to reach the CMP-equivalent quality. DA process enables material lossless planarization of SiC wafers by applying a temperature gradient to achieve simultaneous etching and growth at the same rate on one and the other surfaces, respectively. To drive the planarization function for a multi-wire saw finished as-sliced wafer, as an example, a high-temperature regime above 2000 °C under an Ar background pressure higher than 1 kPa to suppress etching and growth rates was employed as the first step in the DA treatment. In this step, an effective annealing function arises where sublimation and recrystallization occur simultaneously through a sub-surface region on both sides of the wafer. Due to the active interchange of the surface and subsurface layer, a self-organizing planarization effect occurs on a macroscopic scale on both surfaces with the removal of SSD. The conventional DA processes were employed for the following microscopic flatness control. As a result, the roughness of the 6-inch as-sliced wafer was reduced to 0.7 nm on the Si-face and 2.0 nm on the C-face while maintaining the wafer thickness. This is the first promising result exhibiting the potential of thermal contactless treatment for next-generation wafer manufacturing by improving quality and cost.

Learning a target-dependent classifier for cross-domain semantic segmentation: Fine-tuning versus meta-learning

Recently proposed domain adaptation arts have dominated the field of cross-domain semantic segmentation by operating domain manifolds alignment and learning an optimal joint hypothesis (joint-domain classifier) for both source and target domains. However, a joint-domain classifier can still violate the cluster assumption in the target domain in case domain manifolds are not fully aligned after domain adaptation. In this work, we raise the intractability of perfect domain alignment and turn to exploit a novel hypothesis: a target-dependent classifier, to efficiently adapt to the target domain clusters even given a certain degree of domain misalignment. Specifically, we first propose an unsupervised fine-tuning strategy, which optimizes the joint hypothesis of vanilla domain adaptation into a target-dependent hypothesis to better fit with the target domain clusters. Second, we connect the “learning to learn” concept of meta-learning with pixel-wise domain adaptation, which serves as a reliable hypothesis initialization, providing an alternative solution to learning a more generalized target-dependent classifier. The proposed learning method is general to conventional domain adaptation models. In experiments, we recycle the pre-trained conventional DA models and learn target-dependent classifiers with the proposed method. Experimental results on synthetic-to-real adaptation and cross-city adaptation benchmarks demonstrate that the target-dependent classifier leads over state-of-the-art performance.

PMON169 D2R Expression in Dopamine-Agonist Resistant Prolactinomas

Abstract Introduction Dopamine-agonist (DA) resistant prolactinomas are characterized by failure to achieve normal prolactin levels or reduce tumor size by at least 50% on maximal conventional DA dosages. This occurs in about 10% of patients on cabergoline and is more common in larger macroadenomas, and in men compared with women. The underlying cause of resistance may be a lack of D2 receptor (D2R) tumor expression. As high dose DA therapy may have serious cardiac side effects, it is important to determine the D2R expression. Further, the sexual dimorphism observed in resistant prolactinomas may be due to estrogen receptor alpha (ERα) expression in female tumors, as ERα signaling has been shown to enhance sensitivity to DAs. We investigated the possibility that androgen receptor (AR) signaling in males promotes resistance via induction of transmembrane serine protease 2 (TMPRSS2), a cell surface serine protease, a known promoter of tumor progression in prostate and lung cancer. Methods This is a retrospective, single-center study conducted at an academic quaternary-care center. Immunohistochemical (IHC) analysis was performed on 16 specimens from surgically removed lactotroph cell type tumors, including D2R, growth hormone (GH), prolactin (PRL), TMPRSS2, ERα, AR, and the stem cell marker, CD133. We simultaneously conducted a chart review of the Electronic Medical Record to determine age at diagnosis, tumor size, initial PRL level, medical treatment, and reason for surgical resection. Results A total of 14 patients were included in our study. Two patients had multiple surgeries for resistant prolactinomas such that the sample size included 16 specimens- 7 resistant prolactinomas and 9 controls (resected for another reason other than treatment resistance). There were 2 men and 3 women in the resistant group, and 5 women and 4 men in the control group. Baseline prolactin level was higher in the resistant group (2413ng/mL) than the control group (676.4ng/mL) and tumor size was larger—2.05cm vs. 1.57cm in the largest diameter in the resistant vs. control groups, respectively. D2R expression was positive in 8 out of 9 controls vs. 1 out of 7 in resistant tumors. ERα positivity did not correlate with DA resistance. AR expression was negative in all specimens although the majority of tumors in both groups did express TMPRSS2. CD133 was negative in all but one of the resistant tumors. Conclusion We found that 80% of specimens from patients with DA-resistant prolactinomas had negative D2R expression. The one resistant tumor that had positive D2R and negative TMPRSS2 expression was from an 11 year old girl who also had negative ERα expression that may explain the lack of response to dopamine agonist therapy. D2R IHC can identify lack of D2R expression in DA-resistant tumors and provide a rationale for discontinuation of high dose DA therapy to avoid toxicity. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Radio Resource Management Approaches for Reliable Device-to-Device (D2D) Communication in Wireless Industrial Applications

The manufacturing industry is regarded as one of the most demanding verticals with respect to URLLC requirements. A Device-to-Device (D2D) communication system is a key enabler that has been introduced to support URLLC. To enhance spectrum utilisation, D2D links can share access of radio spectrum resources occupied by cellular users. Spectrum reuse may result in performance degradation due to mutual co-channel interference of co-existing cellular and D2D users. Resource sharing in a D2D-based cellular network for wireless industrial applications is investigated in this article. The presented schemes aim to maximise the overall system throughput while maintaining the Quality of Service/Experience (QoS/QoE) requirements. Interference is managed by jointly considering admission and power control based on the relative distance between devices. A priced-Deferred Acceptance (p-DA) scheme with an incentive-based stability is developed to match D2D users to cellular resources. Numerical simulations show that the p-DA scheme is able to achieve better performance than the conventional DA algorithm and is close in performance to the presented centralised optimisation approach.

Reverse flotation separation of quartz from phosphorite ore at low temperatures by using an emerging Gemini surfactant as the collector

Quartz, the gangue of phosphorite ore, is challenging to be separated at low temperatures. In this work, an amine-typed Gemini surfactant, N,N’-bis(dodecyldimethyl)-1,4-butane dibromide (BBD) was recommended as an emerging collector for reverse flotation separation quartz from phosphorite ore. Its collecting ability for quartz and selectivity for phosphorite were also compared with the corresponding unimolecular surfactant 1-dodecylamine (DA) under various experimental conditions. The flotation test results indicated that the BBD, which exhibited a forceful collecting function to quartz and preeminent selectivity for phosphorite at room temperature (25 °C), was a better collector than the conventional DA collector. With 2 × 10-5 mol/L dosage, the quartz recoveries with BBD and DA were 99.0% and 64.5%, respectively. Meanwhile, the phosphorite recoveries of two were not more than 16.0%. When the environment temperature descended, the separating power of the BBD collector for quartz exhibited a more definite stable trend. The recovery of quartz with BBD as a collector raised notably from 61.5% to 93.0% with temperature ranging from 0 °C to 15 °C. However, in the same conditions, the recovery with DA as a collector only raised from 19.5% to 49.5%. At 0 °C, DA lost the vast majority of its collector performance, while BBD still showed high performance. Therefore, BBD presented a better flotation ability for separation of quartz than DA at low temperatures.

Low Power High Throughput Memory Less Adaptive Filter using Distributed Arithmetic

This paper briefs an area efficient, low power and high throughput LMS adaptive filter using Distributed Arithmetic architecture. The throughput is increased because of parallel updating of filter coefficient and computing the inner product simultaneously. Here we have proposed memory-less design of distributed arithmetic (MLDA) unit. The proposed design uses 2:1 multiplexer’s architecture to replace LUT of the conventional DA to reduce the overall area of the filter. Enhanced compressor adder is used for accumulation of the partial products, which further helps to reduce the area. Parallel updating of the generation and accumulation enhance the throughput of the design. The proposed architecture requires more than half area that required for the existing LUT based inner product block. The proposed design is implemented in synopsis design compiler and the result shows that the area decreased by 52.7% and also the MUX based DA for the Adaptive filter causes 69.25% less power consumption for filter tap N=16, 32 and 64. Proposed design provides 36.50% less Area Delay Product (ADP).

Adding tetrahydrofuran to dilute acid pretreatment provides new insights into substrate changes that greatly enhance biomass deconstruction by Clostridium thermocellum and fungal enzymes

BackgroundConsolidated bioprocessing (CBP) by anaerobes, such as Clostridium thermocellum, which combine enzyme production, hydrolysis, and fermentation are promising alternatives to historical economic challenges of using fungal enzymes for biological conversion of lignocellulosic biomass. However, limited research has integrated CBP with real pretreated biomass, and understanding how pretreatment impacts subsequent deconstruction by CBP vs. fungal enzymes can provide valuable insights into CBP and suggest other novel biomass deconstruction strategies. This study focused on determining the effect of pretreatment by dilute sulfuric acid alone (DA) and with tetrahydrofuran (THF) addition via co-solvent-enhanced lignocellulosic fractionation (CELF) on deconstruction of corn stover and Populus with much different recalcitrance by C. thermocellum vs. fungal enzymes and changes in pretreated biomass related to these differences.ResultsCoupling CELF fractionation of corn stover and Populus with subsequent CBP by the anaerobe C. thermocellum completely solubilized polysaccharides left in the pretreated solids within only 48 h without adding enzymes. These results were better than those from the conventional DA followed by either CBP or fungal enzymes or CELF followed by fungal enzyme hydrolysis, especially at viable enzyme loadings. Enzyme adsorption on CELF-pretreated corn stover and CELF-pretreated Populus solids were virtually equal, while DA improved the enzyme accessibility for corn stover more than Populus. Confocal scanning light microscopy (CSLM), transmission electron microscopy (TEM), and NMR characterization of solids from both pretreatments revealed differences in cell wall structure and lignin composition, location, coalescence, and migration-enhanced digestibility of CELF-pretreated solids.ConclusionsAdding THF to DA pretreatment (CELF) greatly enhanced deconstruction of corn stover and Populus by fungal enzymes and C. thermocellum CBP, and the CELF–CBP tandem was agnostic to feedstock recalcitrance. Composition measurements, material balances, cellulase adsorption, and CSLM and TEM imaging revealed adding THF enhanced the enzyme accessibility, cell wall fractures, and cellular dislocation and cell wall delamination. Overall, enhanced deconstruction of CELF solids by enzymes and particularly by C. thermocellum could be related to lignin removal and alteration, thereby pointing to these factors being key contributors to biomass recalcitrance as a barrier to low-cost biological conversion to sustainable fuels.

An Efficient Low Power and High Speed Distributed Arithmetic Design for FIR Filter

Background/Objectives: FIR filters play a vital role in signal processing applications. This research work presents a low power and high speed efficient buffer based Distributed Algorithms and it is analyzed with Electro Cardio Gram (ECG) signal Finite Impulse Response (FIR) filter design. Methods/Statistical Analysis: The proposed FIR filter is designed using buffer based DA and it is simulated and synthesized using Cadence digital labs. This is compared with different architectures such as conventional DA, separated look up table DA and LUT less DA. Findings: Synthesis report shows that the proposed design has 52% less power dissipation compared with the conventional DA, 21% reduction in delay with separated Look Up Table (LUT) DA and 8% reduction in area with LUT less DA. Conclusion/Improvements: Presently this method is applied for ECG signal input with 16-tap FIR filter. This can be extended for higher order filters to achieve better performance.

Critical Path Reduction of Distributed Arithmetic Based FIR Filter

Operating speed, which is reciprocal of critical path computation time, is one of the prominent design matrices of finite impulse response (FIR) filters. It is largely affected by both, system architecture as well as technique used to design arithmetic modules. A large computation time of multipliers in conventionally designed multipliers, limits the speed of system architecture. Distributed arithmetic is one of the techniques, used to provide multiplier-free multiplication in the implementation of FIR filter. However suffers from a sever limitation of exponential growth of look up table (LUT) with order of filter. An improved distributed arithmetic technique is addressed here to design for system architecture of FIR filter. In proposed technique, a single large LUT of conventional DA is replaced by number of smaller indexed LUT pages to restrict exponential growth and to reduce system access time. It also eliminates the use of adders. Selection module selects the desired value from desired page, which leads to reduce computational time of critical path. Trade off between access times of LUT pages and selection module helps to achieve minimum critical path so as to maximize the operating speed. Implementations are targeted to Xilinx ISE, Virtex IV devices. FIR filter with 8 bit data width of input sample results are presented here. It is observed that, proposed design perform significantly faster as compared to the conventional DA and existing DA based designs.

An Efficient Hardware Realization of Distributed Arithmetic Based Discrete Cosine Transform

Objective: This paper presents an efficient design for the implementation of Discrete Cosine Transform (DCT) which is widely used in still and motion picture compression. In this work cyclic convolution and Grouped Distributed Arithmetic (GDA) technique are used. Method: In GDA, Read Only Memory (ROM) size could be reduced compared to conventional DA. For example, 1-D DCT of transform length N=13, the proposed design requires 31 Look-Up Tables (LUTs) while conventional DA requires 384 LUTs. Findings: From the synthesis results, it is found that proposed design has less area requirement and low power consumption compared to the conventional DA of same length. Conclusion: This paper proposes an efficient design for implementation of cyclic convolution based on modified GDA technique.

Changes to DA-CPR instructions: Can we reduce time to first compression and improve quality of bystander CPR?

IntroductionDispatcher-assisted CPR (DA-CPR) can increase rates of bystander CPR, survival, and quality of life following cardiac arrest. Dispatcher protocols designed to improve rapid recognition of arrest and coach CPR may increase survival by (1) reducing preventable time delays to start of chest compressions and (2) improving the quality of bystander CPR. MethodsWe conducted a randomized controlled trial comparing a simplified DA CPR script to a conventional DA CPR script in a manikin cardiac arrest simulation with lay participants. The primary outcomes measured were the time interval from call receipt to the first chest compression and the core metrics of chest compression (depth, rate, release, and compression fraction). CPR was measured using a recording manikin for the first 3min of participant CPR. ResultsOf the 75 participants, 39 were randomized to the simplified instructions and 36 were randomized to the conventional instructions. The interval from call receipt to first compression was 99s using the simplified script and 124s using the conventional script for a difference of 24s (p<0.01). Although hand position was judged to be correct more often in the conventional instruction group (88% versus 63%, p<0.01), compression depth was an average 7mm deeper among those receiving the simplified CPR script (32mm versus 25mm, p<0.05). No statistically significant differences were detected between the two instruction groups for compression rate, complete release, number of hands-off periods, or compression fraction. DiscussionSimplified DA-CPR instructions to lay callers in simulated cardiac arrest settings resulted in significant reductions in time to first compression and improvements in compression depth. These results suggest an important opportunity to improve DA CPR instructions to reduce delays and improve CPR quality.

Is Standard Treatment (DA 3+7) Is Still Recommended As Front Line Therapy for Adult Patients with De Novo AML? the Role of Etoposide

Abstract 4272 Background:Early intensification of chemotherapy in the remission induction phase of patients with acute myeloid leukemia (AML) has been shown to improve the remission rate and long-term leukemia-free survival. Aim:This trail is designed to assess the role of etoposide in the induction remission schedules in younger patients with de novo AML. Methods:Newly diagnosed previously untreated younger patients (15–60 years) with AML were randomly assigned to 3 groups; group A received conventional treatment DA 3+7 [daunorubicin 60 mg/m2/day (days 1–3) and cytosine arabinoside (Ara-C) 200 mg/m2/day by continuous iv infusion (days 1–7)], group B received conventional treatment [ Ara-C 100 mg/m2/day by continuous iv infusion (days 1–10) + daunorubicin 50mg/m2/day (days 1,3,5)] + etoposide (50 mg/m2/day; days 1–5), and group C received high dose AraC (HD-AraC) 3g/m2/12 hrs. (days 1, 3, 5 and 7) + daunorubicin and etoposide in the same dose as above (as in group B). All patients were treated in the Department of Hematology, University Hospital, Bratislava. Informed consents were obtained. RT-PCR was done to determine the expression of topoizomerase I, II-alpha and II-beta genes in bone marrow samples at diagnosis. The data were analyzed using SPSS statistical software versions 16.0, 2008. Results:Between September 2000 and August 2011, 128 patients were recruited (group A = 27, group B = 57, and group C = 44). There was no statistically significant difference in age, sex, performance state, AML subtype (M4-5), WBC count and cytogenetic risk distribution in the 3 groups. Patients have been followed for a median of 92 months. After 1 course of induction the complete remission (CR) rate was 55.6%, 75.4% and 81.8% in group A, B and C respectively (P = 0.048). Group A vs. B (P = 0.025), group A vs. C (P = 0.027), group B vs. C (P = 0.81). Induction toxicity profile and grade was similar in all groups except for conjunctivitis grade 2 and 3 which was higher in group C. The 5 year's overall survival (OS) was 17%, 41% and 33% (P = 0.36) and disease free survival (DFS) was 25%, 44% and 35% (P = 0.21) in group A, B and C respectively. There was statistically significant improvement in OS but not DFS in patient receiving etoposide (P < 0.00001). Overexpression of topoisomerase I and II genes were detected in 12/19 (63%) and 14/19 (74%) patients at diagnosis; respectively. Topoisomerase II-alpha and II-beta genes were increased by a median of 4.1 (range 1.7–27.3) and 2.9 (range 2.4–5.1) than normal; respectively. Conclusion:the addition of etoposide to standard treatment of AML can improve the rate of complete remission and outcome in adult de novo AML patients. The incorporation of etoposide to HD-AraC regimens during induction may further improve the rate of CR without effect on outcome (DFS and OS). Measurement of topoisomerase II gene expression at diagnosis can help in selecting patients who will benefit from the addition of etoposide. Disclosures:No relevant conflicts of interest to declare.

Optics and nonlinear effects in repetitive systems

The weakly nonlinear dynamics in repetitive systems like synchrotrons, storage rings, linacs, and many new compact accelerators in the class of FFAGs is determined by criteria different from those in single pass optical systems. In the latter case, a clean description is obtained by the aberrations, i.e. nonlinear terms in the Taylor representation of the transfer map, and possible connections between them because of the symplectic symmetry of Hamiltonian systems or geometric symmetries of the system under consideration. For repetitive systems other criteria are relevant because conventional aberrations can be either enhanced or weakened by the repeated passage through the same system.We begin with methods that provide highly accurate representations of fields, a pre-requisite for a detailed analysis of nonlinear motion, and discuss surface-based methods that assure accurate field representation far from midplane or axis. We then discuss methods to enforce the symplectic symmetry of the motion by minimal deformations in a suitable metric of Hamiltonian spaces, which is important in the attempt of long-term tracking of the dynamics. We then develop an analytical mechanism most closely related to the conventional aberration correction in conventional systems, the method of normal forms. As a result, quantitative measures of those linearities that matter are obtained in the form of resonance strengths and tune shifts. Residual effects can be described quantitatively using normal form defect methods, which allow rigorous predictions of long-term stability.For practical calculations, the above methods can be expressed seamlessly in terms of differential algebraic structures on Taylor representations, either in a truncated representation in the conventional DA framework, or under consideration of remainder error terms in a fully rigorous setting.

Comparison of conventional descriptive analysis and a citation frequency-based descriptive method for odor profiling: An application to Burgundy Pinot noir wines

The limitations of intensity scoring when describing the odor characteristics of a complex product have been documented in the literature. In the present work, the odor properties of 12 Burgundy Pinot noir wines were described by two independent panels performing, respectively, an intensity-based (conventional descriptive analysis) and a citation frequency-based method. Methods were compared according to three criteria: similarity of the sensory maps, control of panel performance and practical aspects. Intensity scoring and citation frequency data were analyzed, respectively, by Principal Components Analysis (PCA) and Correspondence Analysis (CA) followed by Hierarchical Cluster Analysis (HCA). Although both methods underlined the same main odor characteristics (fruity, vegetal and oak barrel), dimensionality of CA was higher (four axes) than that of PCA (three axes), probably as a consequence of the larger number of descriptors employed in the frequency-based method. The clustering of wines differed as well between methods. In conventional DA, one sample exhibiting intense barrel aged related notes was responsible for most of the variance of the PCA map. This induced a settling of the rest of the samples and, therefore, a less fine characterization of the emerging clusters than that obtained by CA. Considering both richness of product characterization and practical aspects, the frequency of citation method might represent a convenient alternative to conventional descriptive analysis when the odor assessment of a complex aroma product is required.

A Novel SNR Estimation Technique Associated with Hybrid ARQ

By using multiple repeated signal replicas to formulate the accumulative observed noisy signal sequence (AONSS) or the differential observed noisy signal sequence (DONSS) in the hybrid ARQ system, a novel data-aided maximum likelihood (DA ML) SNR estimation and a blind ML SNR estimation technique are proposed for the AWGN channel. It is revealed that the conventional DA ML estimate is a special case of the novel DA ML estimate, and both the proposed DA ML and the proposed blind ML SNR estimation techniques can offer satisfactory SNR estimation without introducing significant additional complexity to the existing hybrid ARQ scheme. Based on the AONSS, both the generalized deterministic and the random Cramer-Rao lower bounds (GCRLBs), which include the traditional Cramer-Rao lower bounds (CRLBs) as special cases, are also derived. Finally, the applicability of the proposed SNR estimation techniques based on the AONSS and the DONSS are validated through numerical analysis and simulation results.

Hierarchical Numerical Solution of Smoluchowski Equations with Rough Potentials.

We present an efficient and numerically robust algorithm to follow diffusive processes on rough potential energy surfaces. The hierarchical nature of the algorithm (hierarchical discrete approximation or HDA) fully explores the fine- and coarse-grained structure of the underlying interaction potential. The present approach does not impose any restriction on the topology of the potential. The hierarchical grid allows to capture the roughness of the potential and achieve significant reduction of computational time using fewer grid points compared to other DA methods. HDA is shown to be accurate and efficient by comparing with results from the conventional DA and from the "mean first passage time" (MFPT) method. Using potential-optimized grids HDA monotonically converges to results from an analytical treatment for a very rough interaction potential (107 minima). Contrary to MFPT the solution from HDA is numerically stable. Because of the hierarchical structure of the method HDA can be extended to multidimensional problems.

Effect of sodium hypochlorite on the bond strength of an adhesive system to superficial and deep dentin

The objective of this study was to evaluate the bond strength to superficial (SU) and deep (D) dentin, accessed via apical (DA) or occlusal (DO), using One-Step adhesive system applied according to the manufacturer's instructions (C) or following deproteinization with 10% sodium hypochlorite (H) for 60s, after acid etching. Three sound extracted human molars were prepared for each experimental condition. Restorations were performed using Z100 in 2mm increments, each one being light-cured for 40s. Teeth were longitudinally sectioned to obtain stick-shaped specimens with a cross-sectional area of 0.8mm², which were submitted to bond strength test (0.6mm/min). Results obtained after statistical analysis using a two-way ANOVA (substrate vs. surface treatment) and Tukey's test were: SU (35.4 ± 12.3), DO (26.5 ± 8.5), DA (26.1 ± 10.2) following conventional surface treatment, and SU (28.82 ± 12.7), DO (24.3 ± 8.3) and DA (23.5 ± 8.5), after surface treatment using sodium hypochlorite. The interaction of the factors was not significant (p>0.05). However, the main factors were significant (p<0.05). Mean bond strength values in superficial dentin were statistically superior to deep dentin (p<0.05), although no statistically significant difference was observed between the two via of access to deep dentin (SU>DO=DA). The conventional surface treatment resulted in higher bond strength values than the sodium hypochlorite treatment (p<0.05). It was concluded: 1) bond strength values were higher in superficial dentin, 2) no difference was found between the two deep substrate preparations, and 3) the application of sodium hypochlorite following dentin acid etching may reduce bond strengths.

Anomalous impurity transport: charge-state diffusion due to atomic processes in tokamak plasmas

A new interpretation of anomalous impurity transport in tokamak plasmas is presented. An alternative (compared with conventional) approach reveals the relative importance of the transport of impurity particles and the diffusion of impurity charge states due to ionization and recombination processes. The set of coupled transport equations is reduced to a novel kinetic equation which is analysed in terms of charge-state transport including both the transport of particles and charge-state diffusion due to atomic processes. From the analysis of this equation and from available spectroscopic data the relationship between diffusion coefficients of these types of transport is found. It is concluded that charge-state diffusion exceeds the radial diffusion of particles significantly. Hence, the conventional empirical coefficients of anomalous diffusion DA and convective velocity VA mainly model charge-state diffusion rather than radial transport of impurity particles. A simple model is developed to describe the diffusion of impurity charge states with ionization rates enhanced by non-thermal effects of electron energy distribution and with recombination rates dominated by charge exchange of impurities on hydrogen atoms. The model is tested by comparing the simulated and measured radial profiles of line emission from oxygen, scandium and iron impurities taken from the TFR and PLT tokamaks. The radial profiles of neutrals and of superthermal electrons are obtained by modelling of spectroscopic data instead of the conventional empirical coefficients DA and VA.

Modern map methods for charged particle optics

The differential algebraic methods, a natural tool for the description and determination of the solution of differential equations, have proven useful for the computation of aberrations of any desired order in any particle optical system. Besides conventional symplectic systems based on strongly or weakly focusing elements including fringe fields, they also readily allow the treatment of spin dynamics as well as classical synchrotron radiation. In recent years, a variety of codes have been written based on these techniques, including COSY INFINITY, which is currently used by approximately 150 registered users. Several examples of recent applications employing high order methods will be given. While the method makes the problem of computation of Taylor maps straightforward and their manipulation and analysis convenient, for many applications it is important to have exact bounds of the truncation error. Recently it was shown how such information can be determined conveniently and with rather limited effort. Furthermore, it is often important to know the domain and the speed of convergence of the Taylor expansion. We will show that similar to the conventional DA approach, such information can be obtained by carrying the three elementary operations of addition, multiplication, and differentiation on the space of infinitely often differentiable functions to a suitable smaller space that can be described on a computer.

Role of the bowel flora for development of immunity to hsp 65 and arthritis in three experimental models.

An infectious aetiology in rheumatoid arthritis (RA) has for long been suggested, although no conclusive evidence for this is at present available. Lately a large interest has been devoted to the involvement of heat shock proteins (hsps) in autoimmune disorders due to their conserved structure and immunogenic properties. Immunity to hsps has been observed both in human autoimmune conditions and in experimental models of autoimmune disease. We have studied the role of the bacterial flora and hsp immunity in the arthritic response in three experimental models of arthritis; type II collagen arthritis (CIA), adjuvant arthritis (AA) and oil induced arthritis (OIA); by using germ free and conventional DA rats. A high incidence of severe arthritis developed in all the models evaluated irrespectively of whether the animals were in the conventional or germ free state. This confirms earlier results which show a minor effect of the bacterial flora in CIA and AA in high responder strains. These results also show that a severe OIA can develop in germ free animals. Despite the severe arthritic response induced, no serum antibody levels to hsp 65 could be detected in the germ free animals, which was in contrast to the conventional animals where a positive anti-hsp 65 serum response was seen in 35-80% of the animals with CIA, AA or OIA. These results show that development of a humoral response to hsp 65 in these models of arthritis is dependent on the presence of a bacterial flora. Further, the lack of humoral immunity in germ free animals despite a severe arthritic response indicates that humoral immunity to hsp 65 is not involved in development of disease in these three models of experimental arthritis.