bluuebunny/crossref_metadata_2025 huggingface dataset:
Some factors affecting the creep behaviour of metallic materials processed by equal-channel angular pressing
Authors: Sklenička Václav , Dvořák Jiří , Král Petr , Svoboda Milan , Saxl Ivan
Published: June 2009

Very few reports describing the creep behaviour of materials processed by equal-channel angular pressing (ECAP) have shown that there are both similarities and differences between the creep behaviour of coarse-grained metals and alloys and their ultrafine-grained counterparts. This paper examines these differences and evaluates some factors affecting the creep behaviour of pure aluminium, pure copper, and the binary Al-0.2 wt.% Sc alloy processed by ECAP. It was found that the creep behaviour of pressed material depends strongly on the number of ECAP passes and successive passes result in a gradual decrease in the creep resistance which may be attributed to microstructural changes, homogenization of the microstructure and the microtexture, nanoporosity induced by the ECAP procedure and thermal instability of the pressed material during creep exposure.
Nanostructuring of metallic materials by spd processing for advanced properties
Authors: Valiev Ruslan
Published: June 2009

During the past decade, fabrication of bulk nanostructured metals and alloys using severe plastic deformation (SPD) has been evolving as a rapidly advancing direction of nanomaterials science and technology aimed at developing materials with new mechanical and functional properties for advanced applications. The principle of these developments is based on grain refinement down to the nanoscale level via various SPD techniques. This paper is focused on recent studies of SPD processing regimes and routes enabling fabrication of ultrafine-grained metals and alloys. The paper also considers nanostructural features of SPD-processed materials that are responsible for enhancement of their properties.
Synchrotron X-ray line-profile analysis experiments for the in-situ microstructural characterisation of SPD nanometals during tensile deformation
Authors: Kerber Michael B. , Schafler Erhard , Wieczorek Arkadiusz K. , Ribarik Gabor , Bernstorff Sigrid , Ungar Tamas , Zehetbauer Michael J.
Published: June 2009

There is a great interest in the understanding of mechanical properties of nanocrystalline materials, especially of those processed by severe plastic deformation, since those exhibit both high strength and considerable ductility. A special setup for X-ray line profile analysis was developed for monitoring the microstructural evolution of in-situ tensile tests of high pressure torsion deformed samples. A comprehensive evaluation procedure is presented which allows the determination of several physical microstructural parameters. This includes a careful estimation of the error of the evaluation procedure. As an example, nickel shows a slight decrease of the size of the coherently scattering domains while the dislocation density tends to increase. The dislocation arrangement exhibits strain-field-screening of neighboring dislocations and an equal amount of screw and edge dislocations.
Tensile and fatigue properties of sub-microcrystalline ultra-low carbon steel produced by hpt-straining
Authors: Todaka Yoshikazu , Nagai Hironori , Takubo Yosuke , Yoshii Miki , Kumagai Masaaki , Umemoto Minoru
Published: June 2009

The tensile and fatigue properties of ultra-low carbon steel after HPT-straining at a rotation-speed of 0.2 rpm under a compression pressure of 5 GPa were investigated. Elongated grains with 300 nm thickness and 600 nm length with high dislocation density were formed by the HPT-straining. The obtained Vickers microhardness was around 3.6 GPa. The engineering tensile strength of the HPT-processed ultra-low carbon steel for 5 and 10 turns was 1.9 GPa, which is similar to the value of maraging high-alloy steels. The elongation increased with strain (at 5 to 10 turns). The increase in elongation is caused by the reduction of the stress concentration due to the existence of continuously recrystallized grains. The fatigue strengths of HPT-processed specimens were twice as high as those of the 90 % cold-rolled specimen in the low-cycle fatigue region, whereas in the high-cycle fatigue region the fatigue strengths were not so different due to the high notch sensitivity of the HPT-processed specimens.
The characteristics of superplastic flow in a magnesium alloy processed by ECAP
Authors: Figueiredo Roberto B. , Langdon Terence G.
Published: June 2009

It is well known that Equal-Channel Angular Pressing (ECAP) introduces an ultrafine grain size and leads to exceptional superplastic properties in a ZK60 (Mg-5.5 % Zn-0.5 % Zr) alloy. This paper presents an analysis of the flow behavior during superplastic deformation in the ZK60 alloy. It is shown that an increase in the ECAP processing temperature enhances the thermal stability of the grain structure. In addition, the optimum superplastic properties occur at higher strain rates when testing at higher temperatures thereby introducing the potential for achieving high strain-rate superplasticity.
Precipitation Effects in Ultra-Fine-Grained Mg–RE Alloys
Authors: Čížek Jakub , Procházka Ivan , Smola Bohumil , Stulíková Ivana , Vlach Martin , Očenášek Vladivoj , Kulyasova Olya B. , Islamgaliev Rinat K.
Published: June 2009

Mg-based alloys with rare-earth alloying elements are promising hardenable lightweight materials with good mechanical properties even at elevated temperatures. Ductility and strength of these alloys can be improved by grain refinement. Ultra fine grained Mg alloys with grain size around 100 nm were successfully prepared by high-pressure torsion. Ultra-fine-grained structure can enhance diffusivity of alloying elements due to the significant volume fraction of grain boundaries. As a consequence, precipitation effects in ultra-fine-grained alloys may occur faster than in corresponding coarse-grained materials. This phenomenon was examined in this work by comparison of the precipitation sequence in Mg – Tb – Nd and Mg – Gd alloys with ultra-fine-grained structure and corresponding coarse-grained alloys.
The optimization of ECAP conditions to achieve high strain-rate superplasticity in a Zr- and Sc-modified aa 7075 aluminum alloy
Authors: Turba Kryštof , Málek Přemysl , Rauch Edgar F. , Robaut Florence , Cieslar Miroslav
Published: June 2009

An AA 7075 aluminum alloy with Zr and Sc additions was subjected to 6 – 8 passes of equal-channel angular pressing at 120, 170, and 220 °C in order to study the effect of the pressing conditions on the microstructural characteristics and the consequences for high-temperature mechanical properties. Using the method of electron backscatter diffraction, a decrease in pressing temperature was found to lead to a more pronounced refinement of the microstructure and a higher fraction of high-angle grain boundaries, but at the same time compromised the ability of the Al3 (Zr, Sc) phase to stabilize the ultra-fine-grained microstructure at elevated temperatures. Optimum superplastic properties were therefore achieved after pressing at the intermediate temperature of 170 °C. The material exhibited high strain-rate superplasticity with a ductility of 650 % at an initial strain rate of 1 × 10 – 1 s – 1.
Multilayer composite al99.99/almg3 sheets prepared by accumulative roll bonding
Authors: Slámová† Margarita , Sláma Peter , Homola Petr , Uhlíř Jaromír , Cieslar Miroslav
Published: June 2009

Accumulative roll bonding (ARB) allows producing ultrafine-grained sheets of high strength and has been successfully used to prepare such materials from aluminium alloys. However, due to intensive work hardening of bond-rolled AlMg3 sheets, significant edge cracking occurred. Cracking was reduced by cladding AlMg3 with aluminium. Lamellar composites were thus prepared. Their structure was studied by electron backscatter diffraction and transmission electron microscopy; hardening was evaluated by microhardness measurements and tensile tests. Composite grain sizes are coarser than in the mono-material sheets. Accordingly, the evolution of strength with ARB-cycling in both materials differs. AlMg3 composite layers exhibit less work hardening than the mono-material; the composite strength is between that of the two mono-material ARB-sheets while the ductility does not differ substantially.
Low sliding-wear resistance of ultrafine-grained Al alloys and steel having undergone severe plastic deformation
Authors: Kim Yong-Suk , Seok Yu Hyun , Hyuk Shin Dong
Published: June 2009

Dry sliding wear characteristics of ultrafine-grained Al alloys 1100, 5052, and low carbon ferrite-martensite dual phase steel (Fe-0.15C-0.25Si-1.11Mn-0.06V) were investigated. The Al alloys and the steel were processed by the accumulative roll bonding and the equal channel angular pressing, respectively, to produce the ultrafine-grained microstructure. Pin-on-disk wear tests were performed on the alloys at various applied loads at room temperature. Hardness and strength of the ultrafine-grained alloys increased with the increase in the accumulated total plastic strain. However, wear resistance of the ultrafine-grained alloys was not improved after the severe deformation. The low wear-resistance of the ultrafine-grained alloys was attributed to the lack of strain hardening due to unstable and non-equilibrium grain boundaries of the alloys and the cracking at the interface of the ferrite and martensite phases.
Acoustic emission study of the deformation behaviour of magnesium sheets
Authors: Bohlen Jan , Dobroň Patrik , Hantzsche Kerstin , Letzig Dietmar , Chmelík Frantisek , Ulrich Kainer Karl
Published: June 2009

In this study, acoustic emission (AE) measurements were performed during tensile testing of sheets of four magnesium alloys in different orientations with respect to the tensile axis in order to investigate the influence of microstructure and texture on the deformation behaviour. AE measurements could especially be used for analysing the activity of twinning. It was shown that the grain size has an important impact on the AE count rates which was directly related to the activity of deformation mechanisms. Small changes in the texture can significantly affect the activity of twins. It was further shown that a weak texture promotes ductility.
Acoustic emission study of the mechanical anisotropy of the extruded AZ31 alloy
Authors: Dobroň Patrik , Chmelík František , Bohlen Jan , Hantzsche Kerstin , Letzig Dietmar , Ulrich Kainer Karl
Published: June 2009

The mechanical anisotropy behaviour of the extruded AZ31 magnesium alloy was investigated by in-situ measurements of acoustic emission.

Specimens taken in the extrusion direction were uniaxially loaded in tension and compression at room temperature. The acoustic emission count rates were correlated with stress – strain curves and their values show local maxima at the yield point, which is linked with cooperative dislocation processes and/or with the occurrence of deformation twins, especially in compression tests. During compression tests, another acoustic emission maximum occurs after the yield point which indicates the activation of further deformation mechanisms. In this paper the acoustic emission results are presented and discussed in terms of texture evolution during plastic deformation.
Mechanical properties of pure titanium and Ti-6Al-4V alloys with a new tailored nano/meso hybrid microstructure
Authors: Fujiwara Hiroshi , Sekiguchi Tatsuya , Ameyama Kei
Published: June 2009

Pure titanium and Ti-6Al-4V alloy powders are treated by a mechanical milling process, which is one of the severe plastic deformation processes. The mechanical milling enables to produce a nano-grain microstructure very easily and has been applied to many powder materials. The bimodal microstructure in those mechanically milled powders is composed of a nano-grain structure with a grain size of about 50 nm in the surface-near region and of a work-hardened microstructure in the core region of the powder. We applied the hot roll sintering process to pure titanium and to Ti-6Al-4V mechanically milled powders. These compacts have a hybrid microstructure that consists of nano-grain structure with grain sizes of 200 to 500 nm and a micron size meso-grain structure. The hybrid microstructure materials demonstrate enhanced mechanical properties compared to conventional materials.
In-situ SEM/EBSD observation of abnormal grain growth in electrodeposited nanocrystalline nickel
Authors: Tsurekawa Sadahiro , Fukino Tatsuya , Matsuzaki Takashi
Published: June 2009

An in-situ SEM/EBSD technique has been applied to observe initial-stage and late-stage abnormal grain growth in electrodeposited nanocrystalline nickel with the aim of obtaining a comprehensive understanding of the dynamics of abnormal grain growth. We found that the late-stage abnormal grain growth occurred in an anisotropic manner such that the area of faceted {001} planes increased, and the faceted interface migrated by step motion. During abnormal grain growth, low-angle boundary and low- CSL boundaries such as 3 and 9 were found to migrate more slowly than random boundaries. As a result, small grains that possessed a CSL relation with the abnormally growing grain were often embedded into the abnormal grain. Initial-stage and late-stage abnormal grain growth both obeyed a parabolic growth law.
Strain release from pre-deformed Ni53.6Mn27.1Ga19.3 shape memory alloy during thermal cycling
Authors: Frost Miroslav , Rudajevová Alexandra
Published: June 2009

A polycrystalline Ni53.6Mn27.1Ga19.3 shape memory alloy was deformed in compression in four steps up to a final deformation of 3.0 % at room temperature. After each deformation step the relative elongation was measured in two thermal cycles in the temperature range 300 K to 640 K, where a thermoelastic martensitic phase transformation occurs.

A one-way shape memory effect and a two-way shape memory effect were observed after deformation of the alloy and their relation to other mechanical characteristics of the alloy are discussed.
Simulation of the growth kinetics of FeB and Fe2B phases on the AISI M2 borided steel: Effect of the paste thickness
Authors: Keddam M.
Published: June 2009

The influence of boron paste thickness on the simulated growth kinetics of Fe borides grown on the AISI M2 steel's substrate was investigated. The boron potential was varied using two boron paste thicknesses (3 and 4 mm) with time durations of 2 and 6 h, and treatment temperatures of 1223, 1253, and 1273 K. Assuming that the growth of the boride layers follows a parabolic law, a kinetic model was applied to evaluate the parabolic growth constant at each growing phase interface, the layer thicknesses of Fe borides, as well as the associated mass gain depending on the treatment parameters (process time, temperature, and boron paste thickness). The simulation results were in good agreement with experimental data taken from the literature.
Beyond fick's equations, an overview
Authors: Philibert Jean
Published: June 2009

Fick's equations do not allow modelling of a large number of diffusion phenomena. Several extensions are described and some applications outside the field of physical metallurgy are briefly described. Departure from Brownian motion appears to be very common, so that anomalous diffusion would actually appear as normal.
Ethnography Versus Case Study ‐ Positioning Research and Researchers
Authors: White Julie , Drew Sarah , Hay Trevor
Published: June 2009

In this paper we narrate a story of working on a large project funded by an Australian Research Council Linkage grant the ‘Keeping Connected: Young People, Identity and Schooling’ project. The purpose of the study is to consider the social connection and schooling of young people who have experienced long‐term chronic illness. While the research involves both quantitative and qualitative elements, the qualitative component is the largest and involves the most researcher time and diversity. At an early stage of the project, three of the researchers working on the qualitative team consider why the study was framed as a series of case studies rather than as ethnography. The second issue considered in this paper is the different approaches to data collection, data analysis and truth claims we might take.
What Do We Mean by ‘Collaboration’ and When is a ‘Team’ Not a ‘Team’? ‐ A Qualitative Unbundling of Terms and Meanings
Authors: Croker Anne , Higgs Joy , Trede Fanziska
Published: June 2009

‘Collaboration’ and ‘team’ are terms commonly used in literature related to the provision of health care, including rehabilitation. However, the complexity of the phenomena represented by these terms is often overlooked. ‘Collaboration’ is rarely defined, and ‘teams’ are often presented as easily identifiable and stable entities. Simplistic use of these terms often results in different aspects of interprofessional practice being researched and discussed without reference to the ‘messiness’ (the ambiguities and complexities) surrounding professional practice. As a consequence, health professionals may have difficulties in understanding the relevance of such research to their particular situations. This paper explores the complexities of the phenomenon of collaboration and the concept of team, with the aim of highlighting the benefits of researchers embracing rather than simplifying these phenomena. The paper reports on emerging models in action, which is one part of a wider research project exploring collaboration within rehabilitation teams. The research approach was informed by hermeneutic phenomenology. Insights gained through this project led to the development of two models: the first conceptualising collaboration in relation to domains of process, product and players; the other model proposing the notion of collaborative arenas. The model of collaborative arenas recognises the blurred boundaries and interrelated team memberships that occur in rehabilitation teams. Both models informed ongoing data collection and analysis for this research project and have potential to inform conceptualisation of teams and collaboration for other researchers.
A Service-Oriented Healthcare Message Alerting Architecture in an Asia Medical Center: A Case Study
Authors: Cheng Po-Hsun , Lai Feipei , Lai Jin-Shin
Published: June 2009

This paper illustrates how our development team has used some information technologies to let physicians obtain an instant abnormal laboratory result report for critical patient care services. We have implementeda healthcare message alerting system (HMAS) on a healthcare short message service (HSMS) engine and the distributed healthcare-oriented service environment (DiHOSE) in the National Taiwan University Hospital (NTUH). The HSMS engine has a general interface for all applications which could easily send any kind of alerting messages. Fundamentally, the DiHOSE uses HL7 standard formats to process the information exchange behaviors and can be flexibly extended for reasonable user requirements. The disease surveillance subsystem is an integral part of NTUH new hospital information system which is based on DiHOSE and the disease surveillance subsystem would send alerting messages through the HSMS engine. The latest cell phone message alerting subsystem, a case study, in NTUH proved that the DiHOSE could integrate the user required functions without much work. We concluded that both HSMS and DiHOSE can generalize and extend application demands efficiently.
Optimization of the Adhesion Strength of Arc Ion Plating TiAlN Films by the Taguchi Method
Authors: Joo Yun-Kon , Zhang Shi-Hong , Yoon Jae-Hong , Cho Tong-Yul
Published: June 2009

A three-level six-factor (arc power, substrate temperature, pre-treatment bias voltage, working pressure, deposition bias voltage and pretreatment time) orthogonal experimental array (L18) to optimize the adhesion strength of arc ion plating (AIP) TiAlN films was designed using the Taguchi method. An optimized film process, namely substrate temperature 220 °C, arc power 60 A, negative bias voltage -800 V, nitrogen pressure 10-2 Torr, pretreated voltage -450 V and pretreated time 15 minutes was obtained by the Taguchi program for the purpose of obtaining a larger critical load. The critical load of the optimized TiAlN film (53 N) was increased by 43% compared to the film with the highest critical load before optimization. The improvement in the adhesion strength of the films was attributed to the enhancement of hardness and the competitive growth of the (111), (200) and (220) orientations in the film.
Synthesis of Two New Hemisynthetic Diterpenylhydroquinones from Natural Ent-Labdanes
Authors: Catalán Luis Espinoza , Marín Karen Catalán , Villegas Alejandro Madrid , Altamirano Héctor Carrasco , García Joan Villena , Fritis Mauricio Cuellar
Published: June 2009

The synthesis and structural determination of two new diterpenylhydroquinones: 2β-acetoxy-15-phenyl-(22,25-dihydroxy)-ent-labda-8(17),13(E)-diene(1) and 2β-hydroxy-15-phenyl-(22,25-dihydroxy)-ent-labda-8(17),13(E)-dieneis reported (2). These compounds were obtained by coupling via Electrophilic Aromatic Substitution (EAS) of 1,4-hydroquinone with primary or tertiary allyl alcohol derivatives of the natural ent-labdanes 3 and 4. With this new method, the best results were observed when mixtures of the primary alcohol derivatives 5-6 (26% yield of compound 1) and diol derivatives 9-10 (28% yield of compound 2) were used.
Optimization-Based Channel Constrained Data Aggregation Routing Algorithms in Multi-Radio Wireless Sensor Networks
Authors: Yen Hong-Hsu
Published: June 2009

In wireless sensor networks, data aggregation routing could reduce the number of data transmissions so as to achieve energy efficient transmission. However, data aggregation introduces data retransmission that is caused by co-channel interference from neighboring sensor nodes. This kind of co-channel interference could result in extra energy consumption and significant latency from retransmission. This will jeopardize the benefits of data aggregation. One possible solution to circumvent data retransmission caused by co-channel interference is to assign different channels to every sensor node that is within each other’s interference range on the data aggregation tree. By associating each radio with a different channel, a sensor node could receive data from all the children nodes on the data aggregation tree simultaneously. This could reduce the latency from the data source nodes back to the sink so as to meet the user’s delay QoS. Since the number of radios on each sensor node and the number of non-overlapping channels are all limited resources in wireless sensor networks, a challenging question here is to minimize the total transmission cost under limited number of non-overlapping channels in multi-radio wireless sensor networks. This channel constrained data aggregation routing problem in multi-radio wireless sensor networks is an NP-hard problem. I first model this problem as a mixed integer and linear programming problem where the objective is to minimize the total transmission subject to the data aggregation routing, channel and radio resources constraints. The solution approach is based on the Lagrangean relaxation technique to relax some constraints into the objective function and then to derive a set of independent subproblems. By optimally solving these subproblems, it can not only calculate the lower bound of the original primal problem but also provide useful information to get the primal feasible solutions. By incorporating these Lagrangean multipliers as the link arc weight, the optimization-based heuristics are proposed to get energy-efficient data aggregation tree with better resource (channel and radio) utilization. From the computational experiments, the proposed optimization-based approach is superior to existing heuristics under all tested cases.
DEVELOPMENT AND SIMULATIONS OF AIRCRAFT GUIDANCE SYSTEM USING A 3–DEGREE‐OF‐FREEDOM POINT MASS MODEL
Authors: Sudars Martins
Published: June 2009

Numerical simulations play an essential role in the development and testing of navigation and guidance algorithms, especially when developer must keep the development costs as low as possible. Low budget development focuses mainly on utilization of numerical flight mechanics simulators including optimization and hardware in loop tests. Reliable, high fidelity results can be easily obtained by numerical simulations of flight dynamics utilizing computing power provided by a normal off‐the‐shelf home PC. However, it still requires a simple, but good and valid model of the aircraft and environment. This paper describes an approach to a numerical simulation of aircraft motion that respects the requirement for a full environment high fidelity model and keeps a good interface for further development of attitude control. The goal is achieved by directly specifying the aerodynamic angles of the vehicle in the simulation environment by the guidance system, which can later be used as input for attitude control algorithms. It is proved how an appropriate selection of reference frames and formulation of laws of motion gives very quick and reliable results by employing large integration time steps that would be difficult to achieve in 6–degree‐of‐freedom simulations. This paper also investigates the range of applicability, advantages, and drawbacks of this method. An example of an aerodynamic angle‐based guidance law for a UAV is explained and demonstrated by figures.

Santrauka

Straipsnyje pateiktas lektuvo slenkamojo judesio dinamikos modeliavimo efektyvus ir patikimas metodas. Ivedus konkrečias koordinačiu sistemas, šiuo metodu galima nustatyti aerodinaminius duomenis ir greičio atskaitos sistema. Tai ypač naudinga modeliuojant skrydžio valdymo ir navigacijos algoritmus, nes čia nebūtini visi aerodinaminiai duomenys. Šis metodas ir jo pritaikymas iliustruojamas BSA valdymo pavyzdžiu.
Observations on Cryoglobulin Testing: I. The Association of Cryoglobulins Containing Rheumatoid Factors with Manifestation of Cryoglobulinemic Vasculitis
Authors: DE ROSA FRANCESCO G. , AGNELLO VINCENT
Published: June 2009

Objective.

To investigate the results of mixed cryoglobulin tests performed on patients with and without hepatitis C virus (HCV) infection, to determine whether type II cryoglobulins containing rheumatoid factor (Type II-RF) were associated with cryoglobulinemic vasculitis.

Methods.

The cryoglobulin test protocol differed from the routine protocol. In addition to determination of both cryoglobulin concentration and immunoglobulin composition, the presence or absence of RF concentrated in the cryoglobulins was determined.

Results.

A qualitative and quantitative association of Type II-RF cryoglobulins with cryoglobulinemic vasculitis was present among HCV-infected patients.

Conclusion.

Detection and quantification of Type II-RF may enhance clinical monitoring of cryoglobulinemic vasculitis in HCV-infected patients.
Severe Disease Activity and Complications of Immunosuppressive Therapy: A Challenge for Acute Hospital-based Rehabilitation in Rheumatology
Authors: KUJATH KERSTIN , HERMANN KAY-GEERT A. , MATHISKE-SCHMIDT KIRSTEN , SCHWEDTKE CHRISTINE , HIEPE FALK , BURMESTER GERD-RÜDIGER , REISSHAUER ANETT
Published: June 2009

Acute rehabilitation refers to the multidisciplinary rehabilitative treatment of patients in continuing need of integrated acute and rehabilitative longterm care. As a result of the advances in acute rheumatology and improved emergency services, an increasing number of patients survive episodes of severe disease and complications of immunosuppressive therapy. These patients require not only treatment of their acute medical problems but also specialized multidisciplinary acute rehabilitation starting as early as possible during their hospital stay. We describe 4 typical cases from the major fields of rheumatology. (1) Acute rehabilitation of a 63-year-old woman with rheumatoid arthritis after replacement of both preexisting knee endoprostheses in one session and removal of the left hip endoprosthesis due to infection and sepsis. (2) Rehabilitation of a 29-year-old man with a 7-year history of ankylosing spondylitis who lived in an adjustable easy chair for 2 years due to severe pain prior to admission. (3) A 61-year-old woman with active refractory Wegener’s granulomatosis who developed respiratory insufficiency due to aspergillus and pseudomonas pneumonia. (4) The acute rehabilitation of a 21-year-old woman with systemic lupus erythematosus and a history of 14 laparotomies due to severe acute pancreatitis and multiple gut perforations. Acute rehabilitation was complicated by a large defect of the abdominal wall and significant critical illness polyneuropathy. Our report points out differences between acute, postacute, and longterm rehabilitation, describes the mobilization of patients in acute rheumatology units, and defines specific problems encountered in acute hospital-based rehabilitation of rheumatological patients.
Which Measure of Inflammation to Use? A Comparison of Erythrocyte Sedimentation Rate and C-Reactive Protein Measurements from Randomized Clinical Trials of Golimumab in Rheumatoid Arthritis
Authors: CROWSON CYNTHIA S. , RAHMAN MAHBOOB U. , MATTESON ERIC L.
Published: June 2009

Objective.

To assess clinical utility of measurements of C-reactive protein (CRP) versus Westergren erythrocyte sedimentation rate (ESR) in evaluating patients with rheumatoid arthritis (RA).

Methods.

Data from 3 randomized clinical trials of golimumab involving 1247 patients with RA in which ESR and CRP were obtained at baseline and Week 24, along with standard measures of clinical disease activity [swollen and tender joint counts, global disease activity assessment, composite Disease Activity Scores (DAS) and Clinical Disease Activity Index (CDAI)], were utilized.

Result.

Both ESR and CRP were significant predictors of swollen joint count (p < 0.001 for each). Only 4.5% of patients with no swollen joints had elevated CRP and normal ESR, but 15.2% had elevated ESR and normal CRP. ESR and CRP correlated significantly (Pearson r = 0.59, p < 0.001) with each other. DAS-ESR and DAS-CRP were highly correlated (r = 0.96, p < 0.001) with each other, although DAS-ESR values were slightly lower than the DAS-CRP values at the upper end of the range (DAS > 8). Both ESR and CRP were significantly associated with CDAI (p < 0.001 for each).

Conclusion.

It is not necessary to obtain both ESR and CRP measures for clinical disease activity assessment in clinical trials of RA. Neither test adds significantly to clinical measures of disease activity including joint counts and global assessments. Where available, the CRP alone may be preferred for disease activity assessment as a simple, validated, reproducible, non age-dependent test.
Declines in Erythrocyte Sedimentation Rates in Patients with Rheumatoid Arthritis Over the Second Half of the 20th Century
Authors: ABELSON BENJAMIN , SOKKA TUULIKKI , PINCUS THEODORE
Published: June 2009

Objective.

To analyze baseline erythrocyte sedimentation rates (ESR) in cohorts of patients with rheumatoid arthritis (RA), which had been included in a review concerning longterm mortality, in reports published between 1973 and 2008, with baseline observations between 1954 and 2000.

Methods.

A computer search and complementary review of the literature had identified 84 unique cohorts with RA for which mortality over 5–40 years was reported. Baseline ESR data were available for 23 of the 84 cohorts. Mean and median ESR, age, disease duration, and rheumatoid factor (RF) status were compiled and analyzed in tertiles according to first year of patient recruitment.

Results.

Among 7 cohorts recruited initially between 1954 and 1980, median ESR at baseline was 47 mm/h (mean 50 mm/h, range 43–66), compared to median 38 mm/h (mean 41 mm/h, range 34–64) among 8 cohorts recruited between 1981 and 1984, and median 36 mm/h (mean 35 mm/h, range 28–42) among 8 cohorts recruited between 1985 and 1996. The lowest mean ESR among 7 cohorts with baseline in 1980 or earlier was 43 mm/h, and the highest reported mean ESR among 8 cohorts recruited after 1985 was 42 mm/h. In 3 cohorts recruited after 1985 from Sweden, Finland, and Spain, mean baseline ESR was < 30 mm/h.

Conclusion.

Mean ESR fell by 30% in cohorts of patients with RA recruited before 1981 compared to cohorts recruited after 1984. This decline may reflect changes in both the natural history and approaches to therapy of RA.
Association Between Toll-like Receptor 4 Gene Polymorphism and Biopsy-proven Giant Cell Arteritis
Authors: PALOMINO-MORALES ROGELIO , TORRES ORLANDO , VAZQUEZ-RODRIGUEZ TOMAS R. , MORADO INMACULADA C. , CASTAÑEDA SANTOS , CALLEJAS-RUBIO JOSE L. , MIRANDA-FILLOY JOSE A. , FERNANDEZ-GUTIERREZ BENJAMIN , MARTIN JAVIER , GONZALEZ-GAY MIGUEL A.
Published: June 2009

Objective.

Dendritic cells localized at the adventitia-media border of the normal medium-sized arteries play a pivotal role in the initiation of giant cell arteritis (GCA). These cells express a singular surface receptor profile, including a series of Toll-like receptors (TLR). Ligands of TLR-4 promote activation and differentiation of adventitial dendritic cells and are directly implicated in the pathogenesis of GCA. We aimed to assess the potential implication of theTLR4-(+896 A/G)gene polymorphism in the susceptibility to GCA.

Methods.

A total of 210 patients diagnosed with biopsy-proven GCA and 678 matched controls were included in our study. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for theTLR4-(+896 A/G)(rs4986790) gene polymorphism by polymerase chain reaction, using a predesigned TaqMan allele discrimination assay.

Results.

TheTLR4 +896G allele was significantly increased in biopsy-proven GCA patients compared to controls [p = 0.01; odds ratio (OR) 1.65; 95% confidence interval (CI) 1.08–2.52]. The increase was due to a significantly increased frequency of heterozygosity for theTLR4−896 A/G genotype in the group of patients with biopsy-proven GCA compared to controls (TLR4−896 A/G heterozygous in patients with GCA 18.1% compared to 11.4% in controls: p = 0.01; OR 1.72; 95% CI 1.10–2.69). However, no significant differences were observed when patients with GCA were stratified according to the presence of specific clinical features of the disease.

Conclusion.

Our results show for the first time an association ofTLR4-(+896 A/G)gene polymorphism with susceptibility to biopsy-proven GCA.
Elevated Circulating TWEAK Levels in Systemic Sclerosis: Association with Lower Frequency of Pulmonary Fibrosis
Authors: YANABA KOICHI , YOSHIZAKI AYUMI , MUROI EIJI , HARA TOSHIHIDE , OGAWA FUMIHIDE , USUI AYA , HASEGAWA MINORU , FUJIMOTO MANABU , TAKEHARA KAZUHIKO , SATO SHINICHI
Published: June 2009

Objective.

To determine serum levels of tumor necrosis factor-related weak inducer of apoptosis (TWEAK) and its clinical associations in patients with systemic sclerosis (SSc).

Methods.

Serum TWEAK levels from 70 patients with SSc were examined by ELISA. In a retrospective longitudinal study, sera from 23 patients with SSc were analyzed (followup 0.8–7.2 yrs).

Results.

Serum TWEAK levels were elevated in patients with SSc (n = 70) compared with healthy controls (n = 31) and patients with systemic lupus erythematosus (n = 22). Among patients with SSc, there were no differences in serum TWEAK levels between limited cutaneous SSc and diffuse cutaneous SSc. Patients with SSc who had elevated TWEAK levels less often had pulmonary fibrosis and decreased vital capacity than those with normal TWEAK levels. In the longitudinal study, SSc patients with inactive pulmonary fibrosis or without pulmonary fibrosis consistently exhibited increased TWEAK levels, while those with active pulmonary fibrosis showed decreased TWEAK levels during the followup period.

Conclusion.

TWEAK levels were increased in patients with SSc, and associated with a lower frequency of pulmonary fibrosis in patients with SSc. TWEAK could be a protective factor against the development of pulmonary fibrosis in this disease and as such would be a possible therapeutic target.
Observations on Cryoglobulin Testing: II. The Association of Oligoclonal Mixed Cryoglobulinemia with Cirrhosis in Patients Infected with Hepatitis C Virus: Table 1.
Authors: DE ROSA FRANCESCO G. , ÁBEL GYÖRGY , AGNELLO VINCENT
Published: June 2009

Objective.

To determine whether a mixed cryoglobulin type correlated with cirrhosis in patients infected with hepatitis C virus (HCV).

Methods.

We investigated the results of mixed cryoglobulin tests performed in the clinical laboratory on patients with and without HCV infection.

Results.

A higher prevalence of oligoclonal cryoglobulins designated Type IIa was present in HCV-infected patients with cirrhosis than in those without cirrhosis.

Conclusion.

An association of Type IIa cryoglobulins with cirrhosis in HCV-infected patients has not previously been reported.
DESIGN AND FABRICATION OF HIGH-INTENSITY FOCUSED ULTRASOUND PHASED ARRAY FOR LIVER TUMOR THERAPY
Authors: Chen Gin-Shin , Cannata Jonathan , Liu Ruibin , Chang Hsu , Shung K. Kirk
Published: June 2009

Noninvasive surgery of the liver tumors has been carried out by using the high-intensity focused ultrasound (HIFU). However, the liver tumor can be moved by the human respirations and heartbeats, which may cause the ablation and damage of normal tissues during the sonications of HIFU. The purpose of this study was to design and fabricate a cylindrical HIFU phased array transducer for treating the moving liver tumor efficiently. The total number of the element was 512 but only 256 channels were required since the elements along the elevation direction were connected in pairs with respect to the central line of the array. Field II software was used to simulate the acoustic field, and a formula for predicting the spatial averaged intensity at focus was developed based on the practical factors. The results of the simulations showed that the cylindrical HIFU phased array in water had a dynamic focusing range from 145 to 175 mm in the depth direction and a steering range from -15 to 15 mm in azimuthal direction with respect to the center of the array. After the dissipation of cables and the attenuation of various media, the designed array could still generate the intensity at focus up to 1095 W/cm2when the input electrical power was approximately 410 W. The prototype of the array was fabricated and the preliminary test was completed. The testing results showed that each element of the array prototype can work well.
Ecology of Arboviruses in Sri Lanka: A Summary of Studies from 1984-1990
Authors: Peiris JSM , Arunagiri CK , Perera LP
Published: June 2009

Studies on arboviruses carried out between 1984 -1990 at the University of Peradeniya are summarized here. The isolation of Nairobi sheep disease virus, Getah, Batai and Arkonam and serological evidence of the circulation of California encephalitis serogroup and Chandipura viruses have been reported for the first time in Sri Lanka. The ecology of Japanese encephalitis (JE) in areas with epidemic disease and sylvatic infection has been compared. A synchronous pattern of seroconversion in pigs and seroprevalence in cattle are more predictive of epidemic JE risk than overall porcine seroprevalence which is a good indicator of the presence of sylvatic JE rather than of human epidemic risk. Relatively modest changes in vector abundance associated with rainfall or agricultural practices have dramatic changes on the emergence of epidemic JE. Chandipura virus which is known to cause major outbreaks of encephalitis in India is endemic in Sri Lanka as are viruses belonging to the California encephalitis serogroup. Both these viruses are potential causes of human encephalitis and should be sought in patients with undiagnosed encephalitis. Nairobi sheep disease virus is endemic in animals (especially goats) and infects humans working closely with such livestock. Arboviruses remain an under-recognised cause of human and animal disease and an inter-sectoral multidisciplinary approach is needed to confront such emerging infectious disease threat. Keywords: Japanese encephalitis, California serogroup, Alphavirus, mosquito, Chandipura virus   doi: 10.4038/cjsbs.v37i1.492 Cey. J. Sci. (Bio. Sci.) 37 (1): 7-14, 2008
Current Status of Malaria and Anti-Malarial Drug Resistance in Sri Lanka
Authors: Rajakaruna Rupika S , Amerasinghe Priyanie H , Galappaththy Gawrie NL , Konradsen Flemming , Briet Olivier JT
Published: June 2009

Even though malaria continues to cause high morbidity and mortality in most of the malaria endemic countries in the world, it is currently not a major health problem in Sri Lanka. Despite the low malaria incidence, the development and spread of anti-malarial drug resistance, combined with a recent increase in the armed conflict hindering provision of effective health services will make it difficult to control malaria in Sri Lanka. Since chloroquine (CQ) resistant Plasmodium falciparum was first reported from Dambulla area in 1984, the number has increased to more than 50% observed in vivo from various endemic areas. In concordance with this, single nucleotide polymorphisms (SNPs) in genes of P. falciparum responsible for CQ resistance are present. A limited number of trials have investigated the efficacy of the second line drug, sulfadoxine/ pyrimethamine (SP) against P. falciparum and a few cases of resistance have been reported. Moreover, SNPs in P. falciparum genes responsible for SP resistance are present and may constitute a sign of evolving SP resistance development. For P. vivax, drug resistance is not yet recorded as a problem in Sri Lanka, however the prevalence of SP resistant SNPs in P. vivax populations seems high and may pose a risk despite that SP is not used directly against P. vivax infections. Continuous monitoring of drug efficacy in vivo, as well by measuring the prevalence of SNPs related to drug resistance are major issues to be addressed. doi: 10.4038/cjsbs.v37i1.493 Cey. J. Sci. (Bio. Sci.) 37 (1): 15-22, 2008
Diversity of Bees at Different Altitudes in the Knuckles Forest Reserve
Authors: Karunaratne WAIP , Edirisinghe JP
Published: June 2009

A year around survey of bees carried out in the Knuckles mountain range at different altitudes having specific habitat types highlighted the effect of altitude and habitat on the presence and abundance of bees. The study was based on hourly counts of bees made once every month in five selected habitats; natural forest, managed cardamom, Patana grassland, cultivated home gardens and mixture of habitats including home gardens, scrublands and rice fields, situated at different altitudes ranging from 150 - 1350 m. The study recorded a total of 62 bee species belonging to 26 genera in 4 families representing more than ¾ of the total bee fauna recorded for Sri Lanka. The distribution of bee species decreased with increasing elevation. Areas under cardamom cultivation harboured the lowest number of bee species. Shannon diversity index gave the highest score for the bee diversity in home gardens. The finding of this study highlights the fact that the highest diversity of bees is at lower elevations where the climate is comparatively warmer. Furthermore, at lower elevations due to human settlements, the vegetation comprises a mixture of cultivated crops, flowering herbs and patches of natural vegetation providing a ready source of pollen and nectar for bees throughout the year. Key Words: Knuckles Forest Reserve, bees, altitude, climate, vegetation doi: 10.4038/cjsbs.v37i1.496 Cey. J. Sci. (Bio. Sci.) 37 (1): 61-72, 2008
Application of Geospatial Tools to Monitor Change in a Micro-Tidal Estuary for the Purpose of Management Planning
Authors: Nagabhatla N , Finlayson CM , Sellamuttu S Seneratna , Gunawardena A
Published: June 2009

The sustainable management of wetlands requires up-to-date inventory and regular monitoring. Also, the understanding of change dynamics and response of these ecosystems to natural and social pressures provides information and impetus for conservation planning. Earth observation data and geospatial tools have immense potential for developing integrated geospatial models/methods for wetland mapping and change analysis. The present study in a coastal wetland system in Sri Lanka describes an approach to mapping and monitoring of change using a combination of multi-spectral and temporal remote sensing data and the IDRISI-Land Change Modeller (LCM). Socioeconomic data and ancillary details were integrated at different levels of analysis for refinement and validation. A multi-level analysis reflects the present status and highlights the trends of wetland use in the landscape. Along with the participation of the Sri Lanka Environmental Authority (CEA) the biophysical analysis and the socioeconomic components were inter-linked wherein the spatial and the social information are qualitatively and quantitatively integrated to understand the dynamics of change in the micro-tidal estuary. Keywords: Geospatial, socioeconomic, wetland, sustainable, IDRISI-Andes, micro-tidal estuary doi: 10.4038/cjsbs.v37i1.497 Cey. J. Sci. (Bio. Sci.) 37 (1): 73-86, 2008
Identification and Screening of New Generation Insecticides against Cardamom Thrips (Sciothrips cardamomi) in Cardamom Cultivations in Sri Lanka
Authors: Dharmadasa M , Nagalingam T , Seneviratne PHM
Published: June 2009

Two thrips species were identified from cardamom (Elettaria cardamomum) cultivations in Sri Lanka. They are the cardamom leaf thrips, Panchaetothrips indicus Bagnall (1912) and the cardamom thrips, Sciothrips cardamomi (Ramakrishna, 1935). Sciothrips cardamomi collected from Nuwara Eliya district is emerging as a devastating pest of cardamom (Elettaria cardamomum) in the district. Both adults and larvae damage panicles, flowers and capsules of cardamom. Injury to panicles leads to stunted growth, and damaged flowers fall prematurely. Affected tender capsules show scabby growth on the surface as they mature and hence have no market value. To manage this problem and as an immediate control measure, damage causing thrips were identified, damage estimated and seven new generation insecticides were screened at Kabragala Estate in Elamulla, Nuwara Eliya. The estimated direct pod damage was 91.7 ± 3.2%. Severely damaged pods showed significantly lower pod weight than undamaged pods. No significant difference in the pod weight was observed between undamaged pods and pods with less than 2/3 of scabby area. The insecticides Actara (thiamethoxam), Match (lufenuron), Regent (fipronil) and Calypso (thiacloprid) successfully reduced the pod damage while Matric (chromafenozide), Mimic (tebufenozide) and Mospilan (acetamiprid) did not reduce the damage percentage. But higher yields of 335.54 and 304.98 g/bush/harvest were obtained from the plots treated with Actara or Match respectively, in comparison to all other treatments. Therefore, either Actara or Match could be recommended for the management of S. cardamomi in cardamom plantations. Key words: Sciothrips cardamomi, Panchaetothrips indicus, Elettaria cardamomum doi: 10.4038/cjsbs.v37i2.501 Cey. J. Sci. (Bio. Sci.) 37 (2): 137-142, 2008
Rediscription of Ponyfishes ( Teleostei: Leiognathidae) of Sri Lanka and the Status of Aurigequula Fowler 1918
Authors: Chakrabarty Prosanta , Amarasinghe Thasun , Sparks John S
Published: June 2009

The ponyfishes of Sri Lanka are redescribed from recent collections. Comparisons are made among species in a Principal Components Analysis. Sri Lanka's proximity to the type localities of many inadequately described ponyfish species makes it ideal for the rediscovery and redescription of populations consistent in features with those from the original descriptions. Many ponyfish species were described over a hundred years ago (sometimes over 200 years ago) without designation of type material and using vague and non-apomorphic features. The descriptions made here will allow for comparison with those earlier descriptions and leiognathid specimens from localities throughout their range. These comparisons may lead to the discovery of new species and to a better understanding of the relationships within the group. In addition, Aurigequula Fowler, 1918 is resurrected from synonymy with Leiognathus Lacepède, 1802 to replace a previously established invalid name. Aurigequula comprises, A. fasciata and A. longispinis. Key words: Leiognathids, ponyfish, Sri Lanka, taxonomy  doi: 10.4038/cjsbs.v37i2.502 Cey. J. Sci. (Bio. Sci.) 37 (2): 143-161, 2008