50 research outputs found
An 8-DOF dual-arm system for advanced teleoperation performance experiments
This paper describes the electro-mechanical and control features of an 8-DOF manipulator manufactured by AAI Corporation and installed at the Jet Propulsion Lab. (JPL) in a dual-arm setting. The 8-DOF arm incorporates a variety of features not found in other lab or industrial manipulators. Some of the unique features are: 8-DOF revolute configuration with no lateral offsets at joint axes; 1 to 5 payload to weight ratio with 20 kg (44 lb) payload at a 1.75 m (68.5 in.) reach; joint position measurement with dual relative encoders and potentiometer; infinite roll of joint 8 with electrical and fiber optic slip rings; internal fiber optic link of 'smart' end effectors; four-axis wrist; graphite epoxy links; high link and joint stiffness; use of an upgraded JPL Universal Motor Controller (UMC) capable of driving up to 16 joints. The 8-DOF arm is equipped with a 'smart' end effector which incorporates a 6-DOF forcemoment sensor at the end effector base and grasp force sensors at the base of the parallel jaws. The 8-DOF arm is interfaced to a 6 DOF force reflecting hand controller. The same system is duplicated for and installed at NASA-Langley
Guiding-fields for phase-separation: Controlling Liesegang patterns
Liesegang patterns emerge from precipitation processes and may be used to
build bulk structures at submicron lengthscales. Thus they have significant
potential for technological applications provided adequate methods of control
can be devised. Here we describe a simple, physically realizable
pattern-control based on the notion of driven precipitation, meaning that the
phase-separation is governed by a guiding field such as, for example, a
temperature or a pH field. The phase-separation is modeled through a
non-autonomous Cahn-Hilliard equation whose spinodal is determined by the
evolving guiding field. Control over the dynamics of the spinodal gives control
over the velocity of the instability front which separates the stable and
unstable regions of the system. Since the wavelength of the pattern is largely
determined by this velocity, the distance between successive precipitation
bands becomes controllable. We demonstrate the above ideas by numerical studies
of a 1D system with diffusive guiding field. We find that the results can be
accurately described by employing a linear stability analysis (pulled-front
theory) for determining the velocity -- local-wavelength relationship. From the
perspective of the Liesegang theory, our results indicate that the so-called
revert patterns may be naturally generated by diffusive guiding fields.Comment: Minor changes, to be published in Phys. Rev. E. 10 pages, 8 figure
Die ungarische Landwirtschaft nach der Einführung der Marktwirtschaft: das Komitat Szabolcs-Szatmár-Bereg
The free-market economy introduction into the Hungarian agriculture also passes through a noticeable transition phase with a great number of structural and socio-economic adaptation and transition phenomena. In Hungary, the orientation towards the national and international market is accompanied by internal and external economic and social radical change phenomena which in return resulted in a production decline and market loss for the agriculture at home and abroad. The sales loss due to the breakdown of the COMECON market is the most important phenomenon. Production declines and sales losses concern both the crops and animal production. The relationship with the decline of the manufacturing industry is clearly demontrated. With the transition to the free-market economy the significance assessment of the previous production locations change. The increasing removal of subsidy and the uncertain sales situation bring about completely changed advantage and disadvantage evaluations of agricultural production locations in connection with their natural and social locational conditions. Market requirements and natural production factors determine more distinctly than before the production profile and the efficiency of the Hungarian farms. Regional disadvantages are not longer notably compensated by subsidies. Another leg bearing the main weight of the Hungarian agriculture, namely the, since more than 20 years existing production of agricultural raw materials for the industry, has almost complety disappeared in the wake of the nation-wide recession process. The, with the social drastic change in the country associated, reprivatisation process in agriculture results in the installation of many small farms poor in soil and deprived of financial means. Their long-term competitiveness is low and depends on the speed of Hungary's economy opening itself to the EC. The relatively unfavourable natural provisions of the Scabolcs-Szatmár-Bereg territory complicate the transition to the free-market economy for agriculture in this komitat. The existing specialisation in production is very cost-intensive and now especially crisis-prone on the mostly low-yield soils
Gender Differences in Cardiovascular Risks of Obese Adolescents in the Bronx
Objective: The associations between the degree of obesity and cardiovascular disease (CVD) risks and the impact of gender differences with regard to these risk factors are not well understood. The aim of our study was to examine the gender−specific differences in CVD risk factors in inner−city minority youths
N_f=2+1 flavour equation of state
We conclude our investigation on the QCD equation of state (EoS) with 2+1
staggered flavors and one-link stout improvement. We extend our previous study
[JHEP 0601:089 (2006)] by choosing even finer lattices. These new results [for
details see arXiv:1007.2580] support our earlier findings. Lattices with
N_t=6,8 and 10 are used, and the continuum limit is approached by checking the
results at N_t=12. A Symanzik improved gauge and a stout-link improved
staggered fermion action is taken; the light and strange quark masses are set
to their physical values. Various observables are calculated in the temperature
(T) interval of 100 to 1000~MeV. We compare our data to the equation of state
obtained by the "hotQCD" collaboration.Comment: presented at the XXVIII. International Symposium on Lattice Field
Theory, June 14-19,2010, Villasimius, Sardinia Ital
Catches of Euxoa tritici in pheromone traps for Anarsia lineatella are due to the presence of (Z)-5-decenyl acetate as an impurity
Traps baited with the synthetic pheromone of Anarsia lineatella Zeller (Lepidoptera: Gelechiidae) frequently captured also Euxoa tritici L. males (Lepidoptera: Noctuidae) in field tests in Hungary. As (E)-monounsaturated compounds are uncommon among sex attractants or pheromone components of Noctuidae, it was hypothesized that the Euxoa catches may have been due to impurities of the (Z) isomer in synthetic (E)-5-decenyl acetate, which is the major component in the pheromone lure of A. lineatella. Traps baited with synthetic (Z)-5-decenyl acetate captured large numbers of E. tritici, and the compound showed a clear dose-response effect. Reanalysis of the synthetic batch of (E)-5-decenyl acetate used in preparation of the A. lineatella lure showed the presence of 10% of the (Z) isomer. Traps baited with synthetic (Z)-5-decenyl acetate can be used in the future for detection and monitoring purposes of E. tritici, a widely distributed pest of cereals and other field crops. The compound also showed attraction of Euxoa seliginis Duponchel
Potential Barriers of Patient Involvement in Health Technology Assessment in Central and Eastern European Countries
Patients' perspectives are important to identify preferences, estimate values and appreciate unmet medical needs in the process of research and development and subsequent assessment of new health technologies. Patient and public involvement in health technology assessment (HTA) is essential in understanding and assessing wider implications of coverage and reimbursement decisions for patients, their relatives, caregivers, and the general population. There are two approaches to incorporating the patients' voice in HTA, preferably used in a mix. In the first one, patients, caregivers and/or their representatives directly participate at discussions in different stages of the HTA process, often at the same table with other stakeholders. Secondly, patient involvement activities can be supported by evidence on patient value and experience collected directly from patients, caregivers and/or their representatives often by patient groups Patient involvement practices, however, are limited in Central and Eastern European (CEE) countries without clear methodology or regulatory mechanisms to guide patient involvement in the HTA process. This poses the question of transferability of practices used in other countries, and might call for the development of new CEE-specific guidelines and methods. In this study we aim to map potential barriers of patient involvement in HTA in countries of the CEE region
Prevalence, significance and predictive value of antiphospholipid antibodies in Crohn's disease
AIM
To assess the prevalence and stability of different antiphospholipid antibodies (APLAs) and their association with disease phenotype and progression in inflammatory bowel diseases (IBD) patients.
METHODS
About 458 consecutive patients [Crohn's disease (CD): 271 and ulcerative colitis (UC): 187] were enrolled into a follow-up cohort study in a tertiary IBD referral center in Hungary. Detailed clinical phenotypes were determined at enrollment by reviewing the patients' medical charts. Disease activity, medical treatment and data about evolvement of complications or surgical interventions were determined prospectively during the follow-up. Disease course (development f complicated disease phenotype and need for surgery), occurrence of thrombotic events, actual state of disease activity according to clinical, laboratory and endoscopic scores and accurate treatment regime were recorded during the follow-up, (median, 57.4 and 61.6 mo for CD and UC). Sera of IBD patients and 103 healthy controls (HC) were tested on individual anti-β2-Glycoprotein-I (anti-β2-GPI IgA/M/G), anti-cardiolipin (ACA IgA/M/G) and anti-phosphatidylserine/prothrombin (anti-PS/PT IgA/M/G) antibodies and also anti-Saccharomyces cerevisiae antibodies (ASCA IgA/G) by enzyme-linked immunosorbent assay (ELISA). In a subgroup of CD (n = 198) and UC patients (n = 103), obtaining consecutive samples over various arbitrary time-points during the disease course, we evaluated the intraindividual stability of the APLA status. Additionally, we provide an overview of studies, performed so far, in which significance of APLAs in IBD were assessed.
RESULTS
Patients with CD had significantly higher prevalence of both ACA (23.4%) and anti-PS/PT (20.4%) antibodies than UC (4.8%, P < 0.0001 and 10.2%, P = 0.004) and HC (2.9%, P < 0.0001 and 15.5%, P = NS). No difference was found for the prevalence of anti-β2-GPI between different groups (7.2%-9.7%). In CD, no association was found between APLA and ASCA status of the patients. Occurrence of anti-β2-GPI, ACA and anti-PS/PT was not different between the group of patients with active vs inactive disease state according to appropriate clinical, laboratory and endoscopic scores in CD as well as in UC patients. All subtypes of anti-β2-GPI and ACA IgM status were found to be very stable over time, in contrast ACA IgG and even more ACA IgA status showed significant intraindividual changes. Changes in antibody status were more remarkable in CD than UC (ACA IgA: 49.9% vs 23.3% and ACA IgG: 21.2% vs 5.8%). Interestingly, 59.1% and 30.1% of CD patients who received anti-TNF therapy showed significant negative to positive changes in ACA IgA and IgG antibody status respectively. APLA status was not associated with the clinical phenotype at diagnosis or during follow-up, medical therapy, or thrombotic events and it was not associated with the probability of developing complicated disease phenotype or surgery in a Kaplan-Meier analysis.
CONCLUSION
The present study demonstrated enhanced formation of APLAs in CD patients. However, presence of different APLAs were not associated with the clinical phenotype or disease course
Implementation of coverage with evidence development schemes for medical devices : a decision tool for late technology adopter countries
Experiences with coverage with evidence development (CED) schemes are fairly limited in Central and Eastern European (CEE) countries, which are usually late adopters of new health technologies. Our aim was to put forward recommendations on how CEE health technology assessment bodies and payer organizations can apply CED to reduce decision uncertainty on reimbursement of medical devices, with a particular focus on transferring the structure and data from CED schemes in early technology adopter countries in Western Europe. Structured interviews on the practices and feasibility of transferring CED schemes were conducted and subsequently, a draft tool for the systematic classification of decision alternatives and recommendations was developed. The decision tool was reviewed in a focus group discussion and validated within a wider group of CEE experts in a virtual workshop. Transferability assessment is needed in case of (1) joint implementation of a CED scheme; (2) transferring the structure of an existing CED scheme to a CEE country; (3) reimbursement decisions that are linked to outcomes of an ongoing CED scheme in another country and (4) real-world evidence transferred from completed CED schemes. Efficient use of available resources may be improved by adequately transferring evidence and policy tools from early technology adopter countries