Bio-inspired swing leg control for spring-mass robots running on ground with unexpected height disturbance

We proposed three swing leg control policies for spring-mass running robots, inspired by experimental data from our recent collaborative work on ground running birds. Previous investigations suggest that animals may prioritize injury avoidance and/or efficiency as their objective function during running rather than maintaining limit-cycle stability. Therefore, in this study we targeted structural capacity (maximum leg force to avoid damage) and efficiency as the main goals for our control policies, since these objective functions are crucial to reduce motor size and structure weight. Each proposed policy controls the leg angle as a function of time during flight phase such that its objective function during the subsequent stance phase is regulated. The three objective functions that are regulated in the control policies are (i) the leg peak force, (ii) the axial impulse, and (iii) the leg actuator work. It should be noted that each control policy regulates one single objective function. Surprisingly, all three swing leg control policies result in nearly identical subsequent stance phase dynamics. This implies that the implementation of any of the proposed control policies would satisfy both goals (damage avoidance and efficiency) at once. Furthermore, all three control policies require a surprisingly simple leg angle adjustment: leg retraction with constant angular acceleration

The Trend of Hydatidosis in Kermanshah Province, Western Iran (1986–2008)

Background: Hydatidosis is the larval stage of the Echinococcus granulosus. This disease is en­demic in Iran. There are many studies about hydatidosis in different regions of the country, but there is not any information about the disease in Kermanshah Province. This article will review all available data about hydatidosis in this province.Methods: Using web based search engines and a survey on medical student's theses, all the informa­tion about hydatid cysts in the province from 1986 -2008 was collected.Results: During these twenty years, at least 482 proven cases of hydatid cyst have been identified in the province. Accordingly, the trend of hydatid cyst operation in the province has been grow­ing and the average annual number of cases has reached 1.41/100,000. Frequency of disease in urban areas was slightly higher than rural areas and the rate of infection in housewives was more than others.Conclusion: Because of the growing trend of hydatid cyst operation in Kermanshah Province, which may be due to many different reasons, this province should be considered as one of the impor­tant endemic regions of hydatidosis in Iran

How can patient journey in surgical wards of a referral hospital be improved?

Background: We studied the patient journey in surgical wards in order to find an effective and efficient way of scheduling in surgical wards.Methods: We applied Root cause analysis (RCA) model within three months in a referral hospital. After understanding root causes of the events occurred through a focus discussion group, required interventions were proposed according to literatures, experiences, and preference of the stakeholders. Possible interventions were also analyzed based on its ability to reduce contributing factors in the events and the belief of process-owner that if interventions can be implemented.Results: The results were provided for five main steps: 1) the most important root cause was “not prioritizing patients and pre-scheduling the number of surgical procedures in the days before”. 2) Constraints indicated that workforce weren't allocated proportionally to the number of surgical operations in varying shift lengths, increased numbers of on-calls physicians increased related costs, the admission of patients in VIP wards have been getting a high priority, and surgeon compensation based on fee for service method was challenging. 3) The current situation of allocating three rooms on average for each physician can be changed depending on numbers of surgeries. 4) Proposed interventions are establishing a computer registration system, reforming payment methods, setting up an electronic waiting list, development of scheduling guidelines, and Applying MIP model.Conclusions: Implementing of scheduling reforms requires a comprehensive action plan system and predefined functional indicators. These should be achieved with considering comments of all clinical and technical groups to ensure the feasibility of an operating room schedule.Keywords: patient journey, surgery, scheduling, Root cause analysis (RCA), patient transfe

Diagnostic and Therapeutic Costs of Patients With a Diagnosis of Or Suspected of Coronavirus Disease in Iran

Objectives: To understand the social and individual effects of the disease and make decisions on the allocation of health resources, it is necessary to understand the economic burden of coronavirus disease (COVID-19); however, there are limited data in this field. This study aimed to estimate diagnostic and therapeutic costs of patients with a diagnosis of or suspected of COVID-19 disease admitted to hospitals in northeast Iran. Methods: This descriptive and analytical research was conducted as a retrospective study using the data collected from 2980 patients admitted to 30 hospitals from February to April 2020 in Iran. For data collection, an appropriate data capture tool was designed to record detailed resource use. A multivariate regression analysis was performed to examine the association between the treatment costs and sociodemographic, disease severity, and underlying diseases. Data were analyzed using Excel 2017 (Microsoft, Redmond, WA) and SPSS version 21 software (SPSS Inc., Chicago, IL). Results: The inpatient costs per patient were Int$416, of which 74% were paid by social health insurance systems, 19% by the government, and 7% by the patients. The largest cost components were hoteling (37%) and medicine (36%). The 4 subscales of age, sex, underlying disease, and severity predicted 48.6% of the cost variance. Conclusion: Understanding the economic consequences of diseases can help policymakers to make plans to reduce out-of-pocket payments and make plans for funding. Since COVID-19 is a newly emerging disease and there is no definitive cure for the disease, the discovery of an effective medicine may alter medical costs and reduce the hospital length of stay, therefore significantly reducing treatment costs

Association between Randall's Plaque and Calcifying Nanoparticles

Randall's plaques, first described by Alexander Randall in the 1930s, are small subepithelial calcifications in the renal papillae (RP) that also extend deeply into the renal medulla. Despite the strong correlation between the presence of these plaques and the formation of renal stones, the precise origin and pathogenesis of Randall s plaque formation remain elusive. The discovery of calcifying nanoparticles (CNP) and their detection in many calcifying processes of human tissues has raised hypotheses about their possible involvement in renal stone formation. We collected RP and blood samples from 17 human patients who had undergone laparoscopic nephrectomy due to neoplasia. Homogenized RP tissues and serum samples were cultured for CNP. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis were performed on fixed RP samples. Immunohistochemical staining (IHS) was applied on the tissue samples using CNP-specific monoclonal antibody (mAb). Randall s plaques were visible on gross inspection in 11 out of 17 collected samples. Cultures of all serum samples and 13 tissue homogenates had CNP growth within 4 weeks. SEM revealed spherical apatite formations in 14 samples, with calcium and phosphate peaks detected by EDS analysis. IHS was positive in 9 out of 17 samples. A strong link was found between the presence of Randall s plaques and the detection of CNP, also referred to as nanobacteria. These results suggest new insights into the etiology of Randall's plaque formation, and will help us understand the pathogenesis of stone formation. Further studies on this topic may lead us to new approaches on early diagnosis and novel medical therapies of kidney stone formation

Swing-Leg Trajectory of Running Guinea Fowl Suggests Task-Level Priority of Force Regulation Rather than Disturbance Rejection

To achieve robust and stable legged locomotion in uneven terrain, animals must effectively coordinate limb swing and stance phases, which involve distinct yet coupled dynamics. Recent theoretical studies have highlighted the critical influence of swing-leg trajectory on stability, disturbance rejection, leg loading and economy of walking and running. Yet, simulations suggest that not all these factors can be simultaneously optimized. A potential trade-off arises between the optimal swing-leg trajectory for disturbance rejection (to maintain steady gait) versus regulation of leg loading (for injury avoidance and economy). Here we investigate how running guinea fowl manage this potential trade-off by comparing experimental data to predictions of hypothesis-based simulations of running over a terrain drop perturbation. We use a simple model to predict swing-leg trajectory and running dynamics. In simulations, we generate optimized swing-leg trajectories based upon specific hypotheses for task-level control priorities. We optimized swing trajectories to achieve i) constant peak force, ii) constant axial impulse, or iii) perfect disturbance rejection (steady gait) in the stance following a terrain drop. We compare simulation predictions to experimental data on guinea fowl running over a visible step down. Swing and stance dynamics of running guinea fowl closely match simulations optimized to regulate leg loading (priorities i and ii), and do not match the simulations optimized for disturbance rejection (priority iii). The simulations reinforce previous findings that swing-leg trajectory targeting disturbance rejection demands large increases in stance leg force following a terrain drop. Guinea fowl negotiate a downward step using unsteady dynamics with forward acceleration, and recover to steady gait in subsequent steps. Our results suggest that guinea fowl use swing-leg trajectory consistent with priority for load regulation, and not for steadiness of gait. Swing-leg trajectory optimized for load regulation may facilitate economy and injury avoidance in uneven terrain

Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented

Study of doubly strange systems using stored antiprotons

Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions