Exploring the link between the corporate governance and efficiency of Italian water utilities

The present paper analyzes the linkage between the corporate governance of Italian water utilities (ownership, board size and board composition) and their ef fi ciency measured through data envelopment analysis (DEA). Using a general panel data regression model, we found that board size negatively affects the ef fi ciency of water utilities. Moreover, the presence of directors with political af fi liations or who are/were members of local or national go- vernment negatively affects ef fi ciency, and the presence of directors with a degree on the board has a slight negative effect on productivity. Conversely, other variables (ownership, gender diversity and average age of board members) were found not to affect the ef fi ciency of Italian water utilities. The existence of economies of scale was also confirmed .Este artículo analiza la relación entre el gobierno corporativo de los servicios del agua italianos (propiedad, tamaño y composición del consejo) y su e fi ciencia medida a través del análisis envolvente de datos (AED). Usando un modelo general de regresión de datos de panel averiguamos que el tamaño del consejo afecta negativamente la e fi ciencia de los servicios del agua. Además, la presencia de directores con a fi liaciones políticas o que son o fueron miembros del gobierno local o nacional afecta negativamente a la e fi ciencia, y la presencia de directores con una carrera universitaria en el consejo tiene un efecto ligeramente negativo sobre la productividad. Inversamente, otras variables (propiedad, diversidad de género y edad media de los miembros del consejo) no afectan a la e fi ciencia de los servicios del agua italianos. La existencia de economías de escala también fue con fi rmada

New spatial mechanisms for the kinematic analysis of the tibiotalar joint

In virtually unloaded conditions, the tibiotalar (ankle) joint behaves as a single degree-of-freedom system, and two fibres within the calcaneal-fibular and tibio-calcaneal ligaments remain nearly isometric throughout the flexion arc. A relevant theoretical model also showed that three articular surfaces and two ligaments act together as a mechanism to control the passive kinematics. Two equivalent spatial parallel mechanisms were formulated, with ligament fibres assumed isometric and articulating surfaces assumed rigid, either as three sphere-plane contacts, or as a single spherical pair. Predicted and measured motion in three specimens compared fairly well. Important enhancement of this previous work is here presented, with more accurate experimental data, more anatomical model surfaces, and a more robust mathematical model

A new ligament-compatible patient-specific 3D-printed implant and instrumentation for total ankle arthroplasty: from biomechanical studies to clinical cases

Background: Computer navigation and patient-specific instrumentation for total ankle arthroplasty have still to demonstrate their theoretical ability to improve implant positioning and functional outcomes. The purpose of this paper is to present a new and complete total ankle arthroplasty customization process for severe posttraumatic ankle joint arthritis, consisting of patient-specific 3D-printed implant and instrumentation, starting from a ligament-compatible design. Case presentation: The new customization process was proposed in a 57-year-old male patient and involved image analysis, joint modeling, prosthesis design, patient-specific implant and instrumentation development, relevant prototyping, manufacturing, and implantation. Images obtained from a CT scan were processed for a 3D model of the ankle, and the BOX ankle prosthesis (MatOrtho, UK) geometries were customized to best fit the model. Virtual in silico, i.e., at the computer, implantation was performed to optimize positioning of these components. Corresponding patient-specific cutting guides for bone preparation were designed. The obtained models were printed in ABS by additive manufacturing for a final check. Once the planning procedure was approved, the models were sent to final state-of-the-art additive manufacturing (the metal components using cobalt-chromium-molybdenum powders, and the guides using polyamide). The custom-made prosthesis was then implanted using the cutting guides. The design, manufacturing, and implantation procedures were completed successfully and consistently, and final dimensions and location for the implant corresponded with the preoperative plan. Immediate post-op X-rays showed good implant positioning and alignment. After 4 months, clinical scores and functional abilities were excellent. Gait analysis showed satisfactory joint moment at the ankle complex and muscle activation timing within normality. Conclusions: The complete customization process for total ankle arthroplasty provided accurate and reliable implant positioning, with satisfactory short-term clinical outcomes. However, further studies are needed to confirm the potential benefits of this complete customization process. Level of evidence: 5. Case report

A methodology for the development of a Hinged Ankle-Foot Orthosis compatible with natural joint kinematics

This work presents a new concept to design Hinged Ankle-Foot Orthoses (HAFOs), based on the definition of a special mechanical articulation able to mimic the physiological behavior of the human ankle joint. Current commercial braces typically do not take into account the natural variability of the ankle joint axis. As the hinge location as well as the rotation axis variability are both relevant for the overall function of the device, and strongly depend on the subject-specific characteristics, a methodology for the development of a HAFO with a floating axis of rotation, based on the in-vivo kinematic analysis of the ankle joint, is here proposed. The kinematic analysis was performed by calculation of the instantaneous and mean helical axes over the collected stereo-photogrammetric data of joint motion. This procedure was tested on a healthy subject, leading to the design and fabrication of a first customized prototype of the orthosis. The performance of this HAFO was experimentally verified by motion analysis. All relevant results are presented, and further possible future improvements of the procedure are discussed

Synthesis of Ternary Borocarbonitrides by High Temperature Pyrolysis of Ethane 1,2-Diamineborane

Ethane 1,2-diamineborane (EDAB) is an alkyl-containing amine-borane adduct with improved hydrogen desorption properties as compared to ammonia borane. In this work, it is reported the high temperature thermolytic decomposition of EDAB. Thermolysis of EDAB has been investigated by concomitant thermogravimetry-differential thermal analysis-mass spectrometry experiments. EDAB shows up to four H2 desorption events below 1000 °C. Small fractions of CH4, C2H4 and CO/CO2 are also observed at moderate-high temperatures. The solid-state thermolysis product has been characterized by means of different structural and chemical methods, such as X-ray diffraction, Raman spectroscopy, Scanning electron microscopy, Elemental analysis, and X-ray photoelectron spectroscopy (XPS). The obtained results indicate the formation of a ternary borocarbonitride compound with a poorly-crystalline graphitic-like structure. By contrast, XPS measurements show that the surface is rich in carbon and nitrogen oxides, which is quite different to the bulk of the materialSome authors (Fabrice Leardini, Lorenzo Massimi, Maria Grazia Betti and Carlo Mariani) also thank Sapienza Università di Roma for financial support under “Progetti di Ateneo”, and the Italian Ministry of Education and Research (MIUR) for the PRIN grant “GRAF” n. 20105ZZTS

Analysis of clinical profiles, deformities, and plantar pressure patterns in diabetic foot syndrome

Diabetic foot syndrome refers to heterogeneous clinical and biomechanical profiles, which render predictive models unsatisfactory. A valuable contribution may derive from identification and descriptive analysis of well-defined subgroups of patients. Clinics, biology, function, gait analysis, and plantar pressure variables were assessed in 78 patients with diabetes. In 15 of them, the 3D architecture of the foot bones was characterized by using weight-bearing CT. Patients were grouped by diabetes type (T1, T2), presence (DN) or absence (DNN) of neuropathy, and obesity. Glycated hemoglobin (HbA1c) and plantar lesions were monitored during a 48-month follow-up. Statistical analysis showed significant differences between the groups for at least one clinical (combined neuropathy score, disease duration, HbA1c), biological (age, BMI), functional (joint mobility, foot alignment), or biomechanical (regional peak pressure, pressure-time integral, cadence, velocity) variable. Twelve patients ulcerated during follow-up (22 lesions in total), distributed in all groups but not in the DNN T2 non-obese group. These showed biomechanical alterations, not always occurring at the site of lesion, and HbA1c and neuropathy scores higher than the expected range. Three of them, who also had weight-bearing CT analysis, showed >40% of architecture parameters outside the 95%CI. Appropriate grouping and profiling of patients based on multi-instrumental clinical and biomechanical analysis may help improve prediction modelling and management of diabetic foot syndrome

Comparison of Bone Segmentation Software over Different Anatomical Parts

Three-dimensional bone shape reconstruction is a fundamental step for any subject-specific musculo-skeletal model. Typically, medical images are processed to reconstruct bone surfaces via slice-by-slice contour identification. Freeware software packages are available, but commercial ones must be used for the necessary certification in clinics. The commercial software packages also imply expensive hardware and demanding training, but offer valuable tools. The aim of the present work is to report the performance of five commercial software packages (Mimics®, Amira™, D2P™, Simpleware™, and Segment 3D Print™), particularly the time to import and to create the model, the number of triangles of the mesh, and the STL file size. DICOM files of three different computed tomography scans from five different human anatomical areas were utilized for bone shape reconstruction by using each of these packages. The same operator and the same hosting hardware were used for these analyses. The computational time was found to be different between the packages analyzed, probably because of the pre-processing implied in this operation. The longer “time-to-import” observed in one software is likely due to the volume rendering during uploading. A similar number of triangles per megabyte (approximately 20 thousand) was observed for the five commercial packages. The present work showed the good performance of these software packages, with the main features being better than those analyzed previously in freeware packages

Optimizing the dialysate calcium concentration in bicarbonate haemodialysis

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Repeatability of skin-markers based kinematic measures from a multi-segment foot model in walking and running.

Skin-markers based multi-segment models are growing in popularity to assess foot joint kinematics in different motor tasks. However, scarce is the current knowledge of the effect of high-energy motor tasks, such as running, on the repeatability of these measurements. This study aimed at assessing and comparing the inter-trial, inter-session, and inter-examiner repeatability of skin-markers based foot kinematic measures in walking and running in healthy adults. The repeatability of 24 kinematic measures from an established multi-segment foot model were assessed in two volunteers during multiple barefoot walking and running trials by four examiners in three sessions. Statistical Parametric Mapping (1D-SPM) analysis was performed to assess the degree of shape-similarity between patterns of kinematic measurements. The average inter-trial variability across measurements (deg) was 1.0 ± 0.3 and 0.8 ± 0.3, the inter-session was 3.9 ± 1.4 and 4.4 ± 1.5, and the inter-examiner was 5.4 ± 2.3 and 5.7 ± 2.2, respectively in walking and running. Inter-session variability was generally similar between the two motor tasks, but significantly larger in running for two kinematic measures (p 0.01). Inter-examiner variability was generally larger than inter-trial and inter-session variability. While no significant differences in frame-by-frame offset variability was detected in foot kinematics between walking and running, 1D-SPM revealed that the shape of kinematic measurements was significantly affected by the motor task, with running being less repeatable than walking. Although confirmation on a larger population and with different kinematic protocols should be sought, attention should be paid in the interpretation of skin-markers based kinematics in running across sessions or involving multiple examiners