Redundancy analysis of cooperative dual-arm manipulators

This paper presents the redundancy analysis of two cooperative manipulators, showing how they can be considered as a single redundant manipulator through the use of the relative Jacobian matrix. In this way, the kinematic redundancy can be resolved by applying the principal local optimization techniques used in the single manipulator case. We resolve the redundancy by using the Jacobian null space technique, which permits us to perform several tasks with different execution priority levels at the same time; this is a useful feature, especially when the manipulators are to be mounted on and cooperate with a mobile platform. As an illustrative example, we present a case study consisting of two planar manipulators mounted on a smart wheelchair, whose degrees of redundancy are employed to move an object along a pre-defined path, while avoiding an obstacle in the manipulator's workspace at the same time

Comparison of methodologies and geostatistical approaches for diagenesis quantification

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Metabolites from the Euryhaline Ciliate Pseudokeronopsis erythrina

TThree new secondary metabolites (named erythrolactones A2, B2 and C2), that are characterized by a central 4‐hydroxy‐unsaturated δ lactone ring bearing an alkyl saturated chain at C(2) and a butyl‐benzenoid group at C(5), together with their respective sulfate esters (erythrolactones A1, B1 and C1), have been isolated from cell cultures of Pseudokeronopsis erythrina, clone TL‐1. The structures are assigned on the basis of extensive spectroscopic measurements (1D and 2D NMR, UV, IR and HR‐MALDI‐TOF). A plausible biogenetic route for their formation is also suggested. Cold‐shock treatment was performed in order to induce the discharge of the metabolites contained in pigment granules lying on the ciliary organelles of this microorganism. HPLC‐ESI‐MS analysis of this granule discharge reveals that erythrolactones A2–C2 are actually therein contained, strongly suggesting a possible role for these metabolites in the chemical defence strategy of P. erythrina

Nationwide analysis of laparoscopic groin hernia repair in Italy from 2015 to 2020

Since its introduction, the minimally invasive treatment of groin hernias has become widely accepted as a viable alternative to open surgery. Still, the rates and reasons for its adoption vary highly among countries and the regions within a country. After almost thirty years since its introduction, its spread is still limited. The present study, conducted under the auspices of AGENAS (Italian National Agency for Regional Services), aims at giving a snapshot of the spreading of minimally invasive and robotic techniques for the treatment of groin hernia in Italy. This study is retrospective, with data covering the period from 1st January 2015 to 31st December 2020. AGENAS provided data using the operation and diagnosis codes used at discharge and reported in the International Classification of Diseases 9th revision (ICD9 2002 version). Admissions performed on an outpatient basis, i.e., without an overnight stay of at least one night in hospital, were excluded. A total of 33,925 laparoscopic hernia repairs were performed during the considered period. Overall, a slight increase in the number of procedures performed was observed from 2015 to 2019, with a mean annual change of 8.60% (CI: 6.46-10.74; p < 0.0001). The number of laparoscopic procedures dropped in 2020, and when considering the whole period, the mean annual change was - 0.98% (CI: - 7.41-5.45; p < 0.0001). Urgent procedures ranged from 335 in 2015 to 508 in 2020 referring to absolute frequencies, and from 0.87% to 9.8% in relative frequencies of overall procedures in 2017 and 2020, respectively (mean = 4.51%; CI = 3.02%-6%; p < 0.001). The most relevant observation that could be made according to our analysis was that the adoption of the laparoscopic approach knew a slow but steady increase from 2015 onward

The non-proteic extrusive secondary metabolites in ciliated protists

The non-proteic extrusive secondary metabolites in ciliated protists F. Buonanno1, A. Anesi2, G. Guella2, E. Marcantoni3, S. Giorgi3, C. Ortenzi1 1Laboratory of Protistology and Biology Education, University of Macerata, 62100 Macerata, Italy 2Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38050 Povo, Trento, Italy 3School of Sciences and Technologies, Section of Chemistry, University of Camerino, 62032 Camerino, Macerata, Italy Extrusomes are membrane-bound ejectable organelles widely distributed in protists. They are usually localized in the cell cortex and attached to the cell membrane, and they are able to discharge their contents to the outside of the cell in response to mechanical or chemical stimuli. Notably, cells that discharge their extrusomes remains intact and functional. The chemical nature of protists\u2019 extrusive compounds characterized to date is extremely variable, including proteins, carbohydrates, lipids, and dozens of additional classes of secondary metabolites. However an increasing set of data are now available for particular group of protists, the ciliated protozoa. Many of non-proteic extrusive secondary metabolites in ciliates function for chemical offense or defense in prey-predator interactions against unicellular or/and multicellular organisms. It is worthy of note that at least some of these secondary metabolites have been demonstrated to show antibiotic, anti-cancer and pro-apoptotic properties in addition to their physiological functions. Among these compounds, euplotin C produced by the ciliate Euplotes crassus, and climacostol produced by Climacostomum virens, have been shown to activate programmed cell death by impairing mitochondrial membrane potential and inducing ROS generation in mammalian tumor cell lines. Interestingly, an antimicrobial activity against Gram-positive bacteria and fungal pathogens was also demonstrated for climacostol. Overall, in addition to the understanding of their physiological and ecological functions, the study of non-proteic secondary metabolites of ciliated protozoa may set the basis for the development of a novel series of antitumor and antimicrobial agents

Nationwide analysis of inpatient laparoscopic ventral hernia repair in Italy from 2015 to 2020

Since 2010, several guidelines and consensus papers have been proposed to support surgeons in the decision-making process (Cuccurullo et al. in Hernia 17(5):557-566, 2013; Silecchia et al. in Surg Endosc 29:2463-2484, 2015; Bittner et al. in Surg Endosc 33(11):3511-3549, 2015) with the conclusion that laparoscopic repair (LR) has gained popularity in the treatment of IH.To date, however, it is not yet clear as to the uptake of LR for IH on national basis. Only dated studies encompassing of all types of incisional hernia repairs are available in literature (Bisgaard et al. in Br J Surg 96:1452-1457, 2009). The aim of our study is to present a snapshot of Italian data for LR of ventral hernias, over a 6 years period, including volume of LR, procedural features and major postoperative outcomes. Data were extracted from the Italian Hospital Information System (HIS) that collects clinical and administrative information regarding each hospital admission of every patient discharged from any hospital in Italy. Using Hospital Discharge records regional Databases (HDD), all laparoscopic ventral hernia procedures carried out in public and private hospitals between 2015 and 2020, in patients over 18 years and resident in Italy, were collected based on diagnosis and procedure codes. The National Agency for Regional Health Services (AgeNaS) oversees the management and analysis of data. All hospital admissions that occurred between 2015 and 2020 were analyzed.A total of 154,546 incisional hernia repairs were performed in Italy from 2015 to 2020. Of these, 20,789 (13.45%) were minimally invasive repairs. The number of procedures performed increased significantly over time, constituting 11.96 and 15.24% of all procedures performed in 2015 and 2020 respectively. However, considering the whole period, the mean annual change was-5.58% (CI - 28.6% to 17.44%; p < 0.0001).Urgent minimally invasive repairs were performed in 1968 cases (1.27%). The absolute rate of laparoscopically treated patients needing an urgent surgical procedure increased overtime (from 7.36% in 2015 to 13.418% in 2020). The mean annual change registered over the whole period was 7.42%. 92% (CI - 0.03 to 14.09%; p < 0.0001). However, when considering the period from 2015 to 2019, the mean annual change was 10.42% (CI 6.35 to 14.49%; p < 0.0001). To our knowledge this is the first nationwide Italian report presenting the national workload of surgical units and the main perioperative features of minimally invasive surgery for ventral hernia repairs

modelling clay diagenesis using a combined crystalchemistry and thermochemistry approach a case study on smectite illitization

Abstract A general procedure that integrates laboratory mineral analysis and numerical tools is proposed to investigate the main diagenetic processes occurring in clayey and arenaceous sediments. The methodology relies on the use of experimental data from natural samples as input, on the use of numerical algorithms to estimate the thermodynamic parameters of site-specific dehydrated phyllosilicates, and produce an internally consistent thermodynamic database in a ready-to-use format for the Geochemist's Workbench, PHREEQC, and TOUGHREACT simulators. A set of non-isothermal 0D and 1D numerical models is set-up to explore the efficiency of smectite-illite transformation under variable geochemical conditions

Model-free vision-based shaping of deformable plastic materials

We address the problem of shaping deformable plastic materials using non-prehensile actions. Shaping plastic objects is challenging, since they are difficult to model and to track visually. We study this problem, by using kinetic sand, a plastic toy material which mimics the physical properties of wet sand. Inspired by a pilot study where humans shape kinetic sand, we define two types of actions: \textit{pushing} the material from the sides and \textit{tapping} from above. The chosen actions are executed with a robotic arm using image-based visual servoing. From the current and desired view of the material, we define states based on visual features such as the outer contour shape and the pixel luminosity values. These are mapped to actions, which are repeated iteratively to reduce the image error until convergence is reached. For pushing, we propose three methods for mapping the visual state to an action. These include heuristic methods and a neural network, trained from human actions. We show that it is possible to obtain simple shapes with the kinetic sand, without explicitly modeling the material. Our approach is limited in the types of shapes it can achieve. A richer set of action types and multi-step reasoning is needed to achieve more sophisticated shapes.Comment: Accepted to The International Journal of Robotics Research (IJRR

Low-pressure versus standard-pressure pneumoperitoneum in laparoscopic cholecystectomy: a systematic review and meta-analysis of randomized controlled trials

Introduction: It has been previously demonstrated that the rise of intra-abdominal pressures and prolonged exposure to such pressures can produce changes in the cardiovascular and pulmonary dynamic which, though potentially well tolerated in the majority of healthy patients with adequate cardiopulmonary reserve, may be less well tolerated when cardiopulmonary reserve is poor. Nevertheless, theoretically lowering intra-abdominal pressure could reduce the impact of pneumoperitoneum on the blood circulation of intra-abdominal organs as well as cardiopulmonary function. However, the evidence remains weak, and as such, the debate remains unresolved. The aim of this systematic review and meta-analysis was to demonstrate the current knowledge around the effect of pneumoperitoneum at different pressures levels during laparoscopic cholecystectomy. Materials and methods: This systematic review and meta-analysis were reported according to the recommendations of the 2020 updated Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines, and the Cochrane handbook for systematic reviews of interventions. Results: This systematic review and meta-analysis included 44 randomized controlled trials that compared different pressures of pneumoperitoneum in the setting of elective laparoscopic cholecystectomy. Length of hospital, conversion rate, and complications rate were not significantly different, whereas statistically significant differences were observed in post-operative pain and analgesic consumption. According to the GRADE criteria, overall quality of evidence was high for intra-operative bile spillage (critical outcome), overall complications (critical outcome), shoulder pain (critical outcome), and overall post-operative pain (critical outcome). Overall quality of evidence was moderate for conversion to open surgery (critical outcome), post-operative pain at 1 day (critical outcome), post-operative pain at 3 days (important outcome), and bleeding (critical outcome). Overall quality of evidence was low for operative time (important outcome), length of hospital stay (important outcome), post-operative pain at 12 h (critical outcome), and was very low for post-operative pain at 1 h (critical outcome), post-operative pain at 4 h (critical outcome), post-operative pain at 8 h (critical outcome), and post-operative pain at 2 days (critical outcome). Conclusions: This review allowed us to draw conclusive results from the use of low-pressure pneumoperitoneum with an adequate quality of evidence

Digital twin reference model development to prevent operators' risk in process plants

In the literature, many applications of Digital Twin methodologies in the manufacturing, construction and oil and gas sectors have been proposed, but there is still no reference model specifically developed for risk control and prevention. In this context, this work develops a Digital Twin reference model in order to define conceptual guidelines to support the implementation of Digital Twin for risk prediction and prevention. The reference model proposed in this paper is made up of four main layers (Process industry physical space, Communication system, Digital Twin and User space), while the implementation steps of the reference model have been divided into five phases (Development of the risk assessment plan, Development of the communication and control system, Development of Digital Twin tools, Tools integration in a Digital Twin perspective and models and Platform validation). During the design and implementation phases of a Digital Twin, different criticalities must be taken into consideration concerning the need for deterministic transactions, a large number of pervasive devices, and standardization issues. Practical implications of the proposed reference model regard the possibility to detect, identify and develop corrective actions that can affect the safety of operators, the reduction of maintenance and operating costs, and more general improvements of the company business by intervening both in strictly technological and organizational terms