Significance of the compliance of the joints on the dynamic slip resistance of a bioinspired hoof

Robust mechanisms for slip resistance are an open challenge in legged locomotion. Animals such as goats show impressive ability to resist slippage on cliffs. It is not fully known what attributes in their body determine this ability. Studying the slip resistance dynamics of the goat may offer insight toward the biologically inspired design of robotic hooves. This article tests how the embodiment of the hoof contributes to solving the problem of slip resistance. We ran numerical simulations and experiments using a passive robotic goat hoof for different compliance levels of its three joints. We established that compliant yaw and pitch and stiff roll can increase the energy required to slide the hoof by ≈ 20% compared to the baseline (stiff hoof). Compliant roll and pitch allow the robotic hoof to adapt to the irregularities of the terrain. This produces an antilock braking system-like behavior of the robotic hoof for slip resistance. Therefore, the pastern and coffin joints have a substantial effect on the slip resistance of the robotic hoof, while the fetlock joint has the lowest contribution. These shed insights into how robotic hooves can be used to autonomously improve slip resistance

Online Optimal Neuro-Fuzzy Flux Controller for DTC Based Induction Motor Drives

In this paper a fast flux search controller based on the Neuro-fuzzy systems is proposed to achieve the best efficiency of a direct torque controlled induction motor at light load. In this method the reference flux value is determined through a minimization algorithm with stator current as objective function. This paper discusses and demonstrates the application of Neurofuzzy filtering to stator current estimation. Simulation and experimental results are presented to show the fast response of proposed controller

A stiffness controllable multimodal whisker sensor follicle for texture comparison

Mammals like rats, who live in dark burrows, heav-ily depend on tactile perception obtained through the vibrissalsystem to move through gaps and to discriminate textures. Theorganization of a mammalian whisker follicle contains multiplesensory receptors and glands strategically organized to capturetactile sensory stimuli of different frequencies. In this paper, weused a controllable stiffness soft robotic follicle to test the hy-pothesis that the multimodal sensory receptors together with thecontrollable stiffness tissues in the whisker follicle form a physicalstructure to maximize tactile information. In our design, the ringsinus and ringwulst of a biological follicle are represented by alinear actuator connected to a stiffness controllable mechanismin-between two different frequency-dependent data capturingmodules. In this paper, we show for the first time the effectof the interplay between the stiffness and the speed of whiskingon maximizing a difference metric for texture classification

Primary culture of ovarian follicular cells of Sterlet, Acipenser ruthenus to develop an in vitro system

The aim of the present study was to develop an in vitro system for functional investigation of ovarian follicular cells in Sterlet, Acipenser ruthenus. Oocytes for the primary culture were obtained from the ovaries of a 6 years old Sterlet 729 g in weight and 47 cm in total length. The oocytes were in advanced vitellogenesis stage (PI >10). A part of the ovary (containing about 300 follicles) was removed, ovarian follicles isolated by manually removing those from the interstitial tissue and washed with sterile phosphate buffered saline (PBS) containing antibiotics and Amphotericin B. Follicular cells were separated by treating oocytes with 0.25% trypsin-EDTA in Ca2+ and Mg2+ free PBS and cultured in medium L-15 supplemented with 20% FBS, streptomycin sulphate (Gibco, 100 mg.ml-1), penicillin G potassium (Gibco, 100 IU.ml-1) and Amphotericin B (Gibco, 2.5 mg.ml-1) at 22 °C. The concentrations of Testosterone (T), Estradiol-17β (E2), Progesterone (P4) and 17α-hydroxyprogestron (17αOHP) in the medium were measured at days 3, 5 & 7 by the Enzyme-Linked Immunosorbent Assay. According to the results, the ovarian follicular cells of Sterlet proliferated in L-15 medium were steroidogenically active as expressed by the secretion of T, E2, P4 & 17αOHP. Testosterone was the dominant hormone secreted by cultivated follicular cells, which was correlated closely with the end of vitellogenesis in the isolated oocytes. Decrease in production of these hormones was greater at days 3 & 4 in comparison with those at days 5 & 6. By successfully culturing ovarian follicular cells of Sterlet in L-15 culture medium, an in vitro system was developed which enables functional studies to be carried out similar to the in vivo situation in the ovarian follicles

Stiffness Imaging With a Continuum Appendage: Real-Time Shape and Tip Force Estimation From Base Load Readings

In this paper, we propose benefiting from load readings at the base of a continuum appendage for real-time forward integration of Cosserat rod model with application in configuration and tip load estimation. The application of this method is successfully tested for stiffness imaging of a soft tissue, using a 3-DOF hydraulically actuated braided continuum appendage. Multiple probing runs with different actuation pressures are used for mapping the tissue surface shape and directional linear stiffness, as well as detecting non-homogeneous regions, e.g. a hard nodule embedded in a soft silicon tissue phantom. Readings from a 6-axis force sensor at the tip is used for comparison and verification. As a result, the tip force is estimated with 0.016-0.037 N (7-20%) mean error in the probing and 0.02-0.1 N (6-12%) in the indentation direction, 0.17 mm (14%) mean error is achieved in estimating the surface profile, and 3.4-15 [N/m] (10-16%) mean error is observed in evaluating tissue directional stiffness, depending on the appendage actuation. We observed that if the appendage bends against the slider motion (toward the probing direction), it provides better horizontal stiffness estimation and better estimation in the perpendicular direction is achieved when it bends toward the slider motion (against the probing direction). In comparison with a rigid probe, ≈ 10 times smaller stiffness and ≈ 7 times larger mean standard deviation values were observed, suggesting the importance of a probe stiffness in estimation the tissue stiffness

Comparison of the Percentage of Regulatory T cells and their p-STAT5 Expression in Allergic and Non-Allergic Common Variable Immunodeficiency Patients

Background: Common Variable Immunodeficiency (CVID) is a primary immunodeficiency characterized by an immunologic deficiency in immunoglobulin production. Regulatory T cells (Tregs) play a key role in preventing the development allergic disorders. p-STAT5 is a known factor for the function and survival of Tregs. This study aimed to investigate the number of Tregs and their p-STAT5 expression in allergic and non-allergic CVID patients. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 10 healthy volunteers, 10 allergic patients, and 16 CVID patients (allergic and non-allergic) using Ficoll density centrifugation. The percentage of Tregs in PBMCs was analyzed by flow cytometry. Tregs were also isolated from participants using an immunomagnetic separation method and p-STAT5 expression was evaluated in Tregs using flow cytometry. Results: The results revealed that Treg percentage was significantly lower in the CVID patients than the control groups (healthy and allergic individuals) (p<0.001). There was a significant reduction in Treg percentage in allergic patients compared to healthy subjects (p<0.05). No significant difference in Treg percentage between allergic and non-allergic CVID patients was observed. The expression of p-STAT5 in Tregs was significantly lower in CVID patients than the control groups (p<0.001). In addition, the expression of p-STAT5 in Tregs of allergic patients was significantly decreased compared to healthy subjects (p<0.001). However, the deference of p-STAT5 level was not statistically significant between allergic and non-allergic CVID patients. Conclusion: These findings suggest that p-STAT5 signaling defect and decreased Treg number may not participate in the development of allergy in CVID patients. © 2018, © 2018 Taylor & Francis

A stiffness controllable multimodal whisker sensor follicle for texture comparison

Mammals like rats, who live in dark burrows, heavily depend on tactile perception obtained through the vibrissal system to move through gaps and to discriminate textures. The organization of a mammalian whisker follicle contains multiple sensory receptors and glands strategically organized to capture tactile sensory stimuli of different frequencies. In this paper, we used a controllable stiffness soft robotic follicle to test the hypothesis that the multimodal sensory receptors together with the controllable stiffness tissues in the whisker follicle form a physical structure to maximize tactile information. In our design, the ring sinus and ringwulst of a biological follicle are represented by a linear actuator connected to a stiffness controllable mechanism in-between two different frequency-dependent data capturing modules. In this paper, we show for the first time the effect of the interplay between the stiffness and the speed of whisking on maximizing a difference metric for texture classification

The effect of risk communication on preventive and protective Behaviours during the COVID-19 outbreak: mediating role of risk perception

Background: The COVID-19 outbreak is a global pandemic, during which the community preventive and protective behaviors play a crucial role in the containment and control of infection. This study was designed to contribute to the existing knowledge on how risk communication (RC) and risk perception (RP) affect protective and preventive behaviors (PPB) during the COVID-19 outbreak. Methods: The required data were extracted from a national online survey of Iranian adults aged 15 and older during March 15�19, 2020 (n=3213). Data analysis was performed using structural equation modeling. Results: The study findings reveal that RC has direct and indirect positive effects on PB. Furthermore, this study also provides new evidence indicating that RP mediates the relationship between RC and PB and there is a two-way relationship between RC and RP. These interactions may have impact on risk communication strategies which should be adopted during this pandemic. Conclusion: The study findings have remarkable implications for informing future communications as well as interventions during this ongoing outbreak and subsequent national risk events. © 2021, The Author(s)

Assessment of staff performance in cssd unit by 360 degree evaluation method

BACKGROUND: 360-degree evaluation is a method that an employee is evaluated by the others and given feedback to him/her. Considering the proper implementation of the sterilization process is important in the prevention of nosocomial infections and has a direct impact on the quality of performance of the surgical team in the operating room. This study was conducted to the Evaluation of CSSD Unit Personnel Performance in Sterilization Process using the 360 Degree technique. METHODS: This cross-sectional study was conducted in the educational hospitals of Gillan Province in IRAN, between 2018 and 2019. Assessment of staff performance in CSSD Unit was done by 360 Degree evaluation method in five different stages. The evaluators included the infection control nurses, Supervisors of the sterilization unit, the researcher and the staff of these units as self-assessors. Finally, the collected data were analyzed using SPSS version 20. RESULTS: The evaluation mean scores were as following: The researcher, 75.97 ± 18.9; infection control nurse, 87.62 ± 7.2; unit supervisor, 87.61 ± 7.8 and staff self-assessment, 88.01 ± 8.1; at different stages of the sterilization process. From all assessors view, the highest and lowest scores were related to the cleaning and Health dimensions. CONCLUSION: According to assessor's agreement in scoring of different stages of the sterilization process, the 360-degree evaluation method is a valuable tool in assessment of the staff performance in important tasks. By applying this method, it can be ethically prevented evaluators' individual judgments. © 2020 Australasian College of Health Service Management. All rights reserved