Evolution of hepatitis B virus surface gene and protein among Iranian chronic carriers from different provinces

Background and Objectives: Iranian chronic HBV carrier�s population has shown a unique pattern of genotype D distribution all around the country. The aim of this study was to explore more details of evolutionary history of carriers based on structural surface proteins from different provinces. Materials and Methods: Sera obtained from 360 isolates from 12 Different regions of country were used for amplification and sequencing of surface proteins. A detailed mutational analysis was undertaken. Results: The total ratio for Missense/Silent nucleotide substitutions was 0.96. Sistan and Kermanshah showed the lowest rate of evolution between provinces (P = 0.055). On the other hand, Khorasan Razavi and Khoozestan contained the highest ratio (P = 0.055). The rest of regions were laid between these two extremes. Azarbayjan and Guilan showed the highest proportion of immune epitope distribution (91.3 and 96, respectively). Conversely, Sistan and Tehran harbored the least percentage (66.6 and 68.8, respectively). Kermanshah province contained only 5.2, whereas Isfahan had 54.5 of B cell epitope distribution. In terms of T helper epitopes, all provinces showed a somehow homogeneity: 22.58 (Fars) to 46.6 (Khuzestan). On the other hand, distribution of substitutions within the CTL epitopes showed a wide range of variation between 6.6 (Khuzestan) and 63 (Kermanshah). Conclusion: Further to low selection pressure found in Iranian population, the variations between different regions designate random genetic drift within the surface proteins. These finding would have some applications in terms of specific antiviral regimen, design of more efficient vaccine and public health issues. © 2015, Tehran University of Medical Science. All rights reserved

Human sit-to-stand transfer modeling towards intuitive and biologically-inspired robot assistance

© 2016, Springer Science+Business Media New York. Sit-to-stand (STS) transfers are a common human task which involves complex sensorimotor processes to control the highly nonlinear musculoskeletal system. In this paper, typical unassisted and assisted human STS transfers are formulated as optimal feedback control problem that finds a compromise between task end-point accuracy, human balance, energy consumption, smoothness of motion and control and takes further human biomechanical control constraints into account. Differential dynamic programming is employed, which allows taking the full, nonlinear human dynamics into consideration. The biomechanical dynamics of the human is modeled by a six link rigid body including leg, trunk and arm segments. Accuracy of the proposed modelling approach is evaluated for different human healthy and patient/elderly subjects by comparing simulations and experimentally collected data. Acceptable model accuracy is achieved with a generic set of constant weights that prioritize the different criteria. Finally, the proposed STS model is used to determine optimal assistive strategies suitable for either a person with specific body segment weakness or a more general weakness. These strategies are implemented on a robotic mobility assistant and are intensively evaluated by 33 elderlies, mostly not able to perform unassisted STS transfers. The validation results show a promising STS transfer success rate and overall user satisfaction

An Integrated Decision Making Approach for Adaptive Shared Control of Mobility Assistance Robots

© 2016, Springer Science+Business Media Dordrecht. Mobility assistance robots provide support to elderly or patients during walking. The design of a safe and intuitive assistance behavior is one of the major challenges in this context. We present an integrated approach for the context-specific, on-line adaptation of the assistance level of a rollator-type mobility assistance robot by gain-scheduling of low-level robot control parameters. A human-inspired decision-making model, the drift-diffusion Model, is introduced as the key principle to gain-schedule parameters and with this to adapt the provided robot assistance in order to achieve a human-like assistive behavior. The mobility assistance robot is designed to provide (a) cognitive assistance to help the user following a desired path towards a predefined destination as well as (b) sensorial assistance to avoid collisions with obstacles while allowing for an intentional approach of them. Further, the robot observes the user long-term performance and fatigue to adapt the overall level of (c) physical assistance provided. For each type of assistance a decision-making problem is formulated that affects different low-level control parameters. The effectiveness of the proposed approach is demonstrated in technical validation experiments. Moreover, the proposed approach is evaluated in a user study with 35 elderly persons. Obtained results indicate that the proposed gain-scheduling technique incorporating ideas of human decision-making models shows a general high potential for the application in adaptive shared control of mobility assistance robots

Hepatitis B virus genotype D is the only genotype circulating in Iranian chronic carriers, the unique pattern of genotypic homogeneity

Aim: To characterize the hepatitis B virus surface protein genotypes and sequence variations among HBsAg positive chronic Iranian patients from different ethnic groups. Method: The surface genes from 312 patients were amplified and directly sequenced. Results: All strains (100) belonged to genotype D and subtypes ayw2. The average nucleotide mutation frequency was 0.91 (dN/dS < 1.0), indicated negative selection. There was no significant correlation between HBV DNA and ALT levels and the occurrence of amino acid substitutions. However, in terms of HBeAg/Anti-HBe status, the association between both groups for silent nucleotide mutation was strong, indicating selection bias on missense mutations. A higher number of amino acid mutations was found in anti-HBe positive versus HBeAg positive patients.Conclusion: The uniqueness pattern of HBV genetics hemogeniety together with the low mutational frequency indicated that HBV has introduced to Iran recently and isolation of people in the absence of intermixing with other genotypes led to a homologous pattern. © 2014 ACT

Evaluating the sit-to-stand transfer assistance from a smart walker in older adults with motor impairments

Aim: To evaluate the effectiveness and user satisfaction with the sit-to-stand (STS) assistance system of a smart walker (SW), and to identify factors associated with them in potential users. Methods: A total of 33 older adults (29 women, aged 6565 years) with motor impairments (habitual rollator use) and no severe cognitive impairment (Mini-Mental State Examination 6517 points) carried out a Five-Chair Stand Test without assistance and five STS transfers with the STS assistance system. Based on the number of successfully completed STS transfers, success rates were calculated for the Five-Chair Stand Test and the SW-assisted STS transfers, and compared using the Wilcoxon signed-rank test. User satisfaction was assessed using the Tele-healthcare Satisfaction Questionnaire-Wearable Technology (0\u201380 points, higher score = higher satisfaction). Bivariate correlations and multiple linear regression analyses were used to identify participant characteristics associated with the success rate and user satisfaction with the STS assistance system. Results: The success rate for the SW-assisted STS transfers was significantly higher than for the Five-Chair Stand Test (93.3 \ub1 12.9% vs 54.5 \ub1 50.6%, P < 0.001). User satisfaction was high (Tele-healthcare Satisfaction Questionnaire-Wearable Technology 62.5 \ub1 11.2 points). The success rate with the STS assistance system was not significantly associated with any participant characteristics. Higher body mass index was a significant independent predictor of higher user satisfaction. Conclusions: The SW-integrated STS assistance system can provide effective STS support with high user satisfaction for a wide range of potential users. Our findings suggest the high potential of the STS assistance system for promoting mobility, independence and quality of life for older adults with motor impairments. Geriatr Gerontol Int 2020; 20: 312\u2013316

Human sit-to-stand transfer modeling for optimal control of assistive robots

Sit-to-stand (STS) transfers are a common human task which involves very complex sensorimotor processes to control the highly nonlinear musculoskeletal system. In this paper, typical unassisted and assisted human STS transfers are formulated as optimal feedback control problem that finds a compromise between task end-point accuracy, human balance, jerk, effort, and torque change and takes further human biomechanical control constraints into account. Differential dynamic programming is employed, which allows taking the full, nonlinear human dynamics into consideration. The biomechanical dynamics of the human is modeled by a six link rigid body including leg, trunk and arm segments. Accuracy of the proposed modelling approach is evaluated for different human healthy subjects by comparing simulations and experimentally collected data. Acceptable model accuracy is achieved with a generic set of constant weights that prioritize the different criteria. The proposed STS model is finally used to determine optimal assistive strategies to be performed by a robotic mobility assistant suitable for either a person with specific body segment weakness or a more general weakness

Evaluation von robotergestützten Rollatoren aus der Perspektive der Nutzer. Ein Systematisches Revies

Hintergrund: Robotergestützte Rollatoren sind mit technisch fortgeschrittenen Systemen zur physischen, kognitiven und sensorischen Unterstützung des Nutzers ausgestattet. Bei der Evaluation von „Altersgerechten Assistenzsystemen für ein selbstbestimmtes Leben“ ist nicht nur die Überprüfung der technischen Funktionsfähigkeit wichtig, sondern auch die der Benutzertauglichkeit, der Effektivität und der Sicherheit des Systems aus der Perspektive des Nutzers. Zielstellung: Ziel des systematischen Reviews war es, das methodische Vorgehen von Studien zur Evaluierung robotergestützter Rollatoren aus der Nutzerperspektive zusammenzufassen und Empfehlungen für zukünftige Evaluationsstudien zu geben. Methodik: Eine systematische Literaturrecherche wurde nach Cochrane-Standards in den elektronischen Datenbanken Pubmed und IEEE Xplore durchgeführt (bis 12/2014). Folgende Einschlusskriterien wurden definiert: Evaluationsstudien zur Interaktion zwischen einem robotergestützten Rollator und dem Nutzer, keine Einzelfallstudien, publiziert in Englisch. Ergebnisse: Insgesamt konnten 28 Studien identifiziert werden. Diese zeigten hinsichtlich der Zielgruppe, der Studienteilnehmer sowie der verwendeten Studiendesigns und Assessmentverfahren eine große Heterogenität. Eine generische Methodik zur Evaluierung von robotergestützten Rollatoren konnte nicht identifiziert werden. Methodische Mängel zeigten sich in der unzureichenden Stichprobenbeschreibung und -größe sowie im Fehlen von geeigneten, standardisierten und validierten Assessmentverfahren. Die langfristige Nutzung in der habituellen Umgebung der Nutzer wurde nicht evaluiert. Schlussfolgerung: Für zukünftige Evaluationsstudien können folgende Empfehlungen gegeben werden: klare Definition der Zielgruppe; adäquate Studienteilnehmer; Einschluss anderer Mobilitätshilfen als Vergleich; Evaluation habitueller Anwendung von fortgeschrittenen Prototypen; angemessene Assessmentstrategien mit standardisierten und validierten Methoden; statistische Überprüfung der Studienergebnisse. Die Assessmentstrategien sollten außerdem auf spezifische Funktionalitäten des robotergestützten Rollators ausgerichtet sein, um eine individuell zugeschnittene Bewertung der innovativen Funktionen zu ermöglichen und um deren Mehrwert dokumentieren zu können

Supplementary Material for: Evaluation Studies of Robotic Rollators by the User Perspective: A Systematic Review

<b><i>Background:</i></b> Robotic rollators enhance the basic functions of established devices by technically advanced physical, cognitive, or sensory support to increase autonomy in persons with severe impairment. In the evaluation of such ambient assisted living solutions, both the technical and user perspectives are important to prove usability, effectiveness and safety, and to ensure adequate device application. <b><i>Objective:</i></b> The aim of this systematic review is to summarize the methodology of studies evaluating robotic rollators with focus on the user perspective and to give recommendations for future evaluation studies. <b><i>Methods:</i></b> A systematic literature search up to December 31, 2014, was conducted based on the Cochrane Review methodology using the electronic databases PubMed and IEEE Xplore. Articles were selected according to the following inclusion criteria: evaluation studies of robotic rollators documenting human-robot interaction, no case reports, published in English language. <b><i>Results:</i></b> Twenty-eight studies were identified that met the predefined inclusion criteria. Large heterogeneity in the definitions of the target user group, study populations, study designs and assessment methods was found across the included studies. No generic methodology to evaluate robotic rollators could be identified. We found major methodological shortcomings related to insufficient sample descriptions and sample sizes, and lack of appropriate, standardized and validated assessment methods. Long-term use in habitual environment was also not evaluated. <b><i>Conclusions:</i></b> Apart from the heterogeneity, methodological deficits in most of the identified studies became apparent. Recommendations for future evaluation studies include: clear definition of target user group, adequate selection of subjects, inclusion of other assistive mobility devices for comparison, evaluation of the habitual use of advanced prototypes, adequate assessment strategy with established, standardized and validated methods, and statistical analysis of study results. Assessment strategies may additionally focus on specific functionalities of the robotic rollators allowing an individually tailored assessment of innovative features to document their added value

Interferon-γ assay, a high-sensitivity, specific and appropriate method for detection of bovine tuberculosis in cattle

Bovine tuberculosis (TB) is an important zoonotic disease that is caused by Mycobacterium bovis. Eradication efforts in developed countries have reduced the prevalence of this disease significantly. TB can be difficult to diagnose based only on the clinical signs; therefore, it is usually diagnosed in the field with the tuberculin skin test and diagnostic blood tests, including the lymphocyte proliferation assay, the interferon (IFN)-γ assay, and enzyme-linked immunosorbent assay. The aim of this study was to compare the tuberculin and IFN-γ tests. A total of 110 animals were evaluated by tuberculin skin test (TST) and IFN-γ assay; the culture was selected as a gold standard. The animals were selected randomly from 700 cattle on dairy farms, aged 3–5 years and suspected of having TB. Ten cattle were positive using the TST and nine were positive by IFN-γ assay. All nine positive samples in the IFN-γ assay were positive in culture too. The observed errors in IFN-γ assay were less due to laboratorial tools. It is suggested that all positive samples in TST are also positive by IFN-γ too