A graphical environment to express the semantics of control systems

We present the concept of a unified graphical environment for expressing the semantics of control systems. The graphical control system design environment in Simulink already allows engineers to insert a variety of assertions aimed the verification and validation of the control software. We propose extensions to a Simulink-like environment's annotation capabilities to include formal control system stability, performance properties and their proofs. We provide a conceptual description of a tool, that takes in a Simulink-like diagram of the control system as the input, and generates a graphically annotated control system diagram as the output. The annotations can either be inserted by the user or generated automatically by a third party control analysis software such as IQC$\beta$ or $\mu$-tool. We finally describe how the graphical representation of the system and its properties can be translated to annotated programs in a programming language used in verification and validation such as Lustre or C

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

Generation of 3D bone mimetic culture system for drug screening: the Vitamin K2 model.

Menaquinones, also known as the vitamin K2 family, regulate calcium homeostasis in a "bonevascular cross-talk" and have recently received particular attention for their positive effect on bone formation. Since the correlation between menaquinones and bone metabolism is not yet clear, we verified the effect of the MK-4 molecule, a type of menaquinone, in the modulation of osteogenesis. For this reason, we compared two-dimensional (2D) and three-dimensional (3D; RCCS-4™ bioreactor) in vitro culture models. In particular, to recreate the "bone remodeling unit" in vitro, human amniotic fluid mesenchymal stem cells (hAFMSC) were co-cultured in the 3D system with human monocytes (hMCs) cells as osteoclast precursors. The results showed that in a conventional 2D culture system, hAFMSCs responded to MK-4, which improved the osteogenic process through the γ-glutamyl carboxylase-dependent pathway. The same results were identified in the 3D dynamic system in which the MK-4 treatment supported osteoblast-like formation by promoting extracellular deposition of the bone matrix and the expression of osteogenic-related proteins (alkaline phosphatase, osteopontin, type 1 collagen and osteocalcin). In particular, when hAFMSCs were cultivated in co-culture in a 3D dynamic system with hMCs, the presence of MK-4 supported the formation of cellular aggregates and the osteogenic function of hAFMSC, but negatively influenced the process of osteoclastogenesis. Our results demonstrated that 3D hAFMSC/ hMC construct can be a useful cellular model for the in vitro screening of bioactive molecules in bone tissue. As we previously demonstrated(a) by using the same experimental culture model, 3D osteoblasts/osteoclasts co-culture can be generated employing limited amounts of human primary cells from the same patient, mimicking the bone microenvironment both in healthy or pathological condition. This will allow the establishment of a smart system providing information on the efficacy of pharmacological treatment aimed at considering the characteristics of each patient. Reference a. Penolazzi, L, Lolli, A, Sardelli, L, Angelozzi, M, et al.. Establishment of a 3D-dynamic osteoblasts-osteoclasts co-culture model to simulate the jawbone microenvironment in vitro. Life Sci. 2016 May 1;152:82-93

Mesenchymal stromal cells from amniotic fluid are less prone to senescence compared to those obtained from bone marrow: An in vitro study.

Mesenchymal stromal cells (MSCs) are considered to be an excellent source in regenerative medicine. They contain several cell subtypes, including multipotent stem cells. MSCs are of particular interest as they are currently being tested using cell and gene therapies for a number of human diseases. They represent a rare population in tissues; for this reason, they require, before being transplanted, an in vitro amplification. This process may induce replicative senescence, thus affecting differentiation and proliferative capacities. Increasing evidence suggests that MSCs from fetal tissues are significantly more plastic and grow faster than MSCs from bone marrow. Here, we compare amniotic fluid mesenchymal stromal cells (AF-MSCs) and bone marrow mesenchymal stromal cells (BM-MSCs) in terms of cell proliferation, surface markers, multidifferentiation potential, senescence, and DNA repair capacity. Our study shows that AF-MSCs are less prone to senescence with respect to BM-MSCs. Moreover, both cell models activate the same repair system after DNA damage, but AF-MSCs are able to return to the basal condition more efficiently with respect to BM-MSCs. Indeed, AF-MSCs are better able to cope with genotoxic stress that may occur either during in vitro cultivation or following transplantation in patients. Our findings suggest that AF-MSCs may represent a valid alternative to BM-MSCs in regenerative medicine, and, of great relevance, the investigation of the mechanisms involved in DNA repair capacity of both AF-MSCs and BM-MSCs may pave the way to their rational use in the medical field

Vitamin K2 and Bone: Focus on Osteogenesis

Vitamin K2 (VitK2) is a lipid-soluble vitamin that regulates calcium homeostasis in “bone vascular cross talk” acting as cofactor for the enzyme γ-glutamyl carboxylase (GGCX). Recently, it has been shown that it plays a main role in this crosstalk by reducing the calcium deposit in the arteries and increasing it in the bone tissue (“calcium paradox”) through carboxylation and then activation of specific Gla proteins, Matrix Gla protein and osteocalcin (OC) respectively. This evidence made VitK2 a potential osteoinductive factor for bone tissue regeneration. Since little is known about the potential effect of VitK2 in the osteogenesis of mesenchymal stem cells, aim of our study was to investigate the possible role of VitK2 in the modulation of osteogenesis in a model of human amniotic fluid mesenchymal stem cells (hAFMSCs) both in two-dimensional (2D) and three-dimensional (3D) in vitro culture systems. In 2D culture system, using Alizarin Red S staining, we observed that VitK2 significantly enhanced hAFMSCs osteogenic differentiation compared to cells treated with osteogenic medium alone. These data were confirmed by VitK2 increased expression of specific osteogenic markers such as alkaline phosphatase (ALP), Runt-related transcription factor 2 (RUNX2), OC, alpha-1type I collagen (COL1A1) and osteopontin (OPN) (real time PCR and immunocytochemistry). Notably, the GGCX downregulation (by RNA interference) reverted the osteoinductive effects of VitK2, confirming the relevant role of this vitamin as cofactor for the enzymatic activity of GGCX. hAFMSCs were also cultured in 3D dynamic model represented by RCCS™ (Rotary Cell Culture System), generating sizeable aggregates that exhibited the same improvement in osteogenic markers following VitK2 treatment. Finally, to reproduce in vitro the “bone remodeling unit” we co-cultured hAFMSCs and human monocyte (hMCs) osteoclast precursors in RCCS™. Our preliminary data suggest that: 1. the cells are able to form viable aggregates with a well organized architecture characterized by the ability of hAFMSCs to sustain osteoclastogenic differentiation; 2. the presence of VitK2 significantly supports osteogenic process (monitored by immunohistochemical analysis of typical osteogenic markers and by Alizarin Red staining of mineralized matrix); 3. osteoclastogenic process, the number and the functionality of mature osteoclasts are negatively affected by Vitk2, as demonstrated by TRAP and Cathepsin K assays. The development of this 3D coculture system i. validates the positive role of Vitk2 in the anabolic process sustained by the osteoblastic cellular component, and ii. offers the possibility to improve the knowledge on the molecular mechanisms supporting the response of osteoblasts and osteoclasts to VitK2. These evidences suggest a possible employment of VitK2 in cell – based therapy for bone regenerative medicine. Moreover, our study support the use of VitK2 as food supplement in order to prevent bone related diseases

Menaquinone-4 enhances osteogenic potential of human Amniotic Fluid Mesenchymal Stem Cells cultured in 2D and 3D dynamic culture system

enaquinones, also known as Vitamin K2 family, regulate calcium homeostasis in a 'bone-vascular cross-talk' and recently received particular attention for their positive effect on bone formation. Given that the correlation between menaquinones and bone metabolism to date is still unclear, the objective of our study was to investigate the possible role of menaquinone-4 (MK-4), an isoform of the menaquinones family, in the modulation of osteogenesis. For this reason, we used a model of human amniotic fluid mesenchymal stem cells (hAFMSCs) cultured both in two-dimensional (2D) and three-dimensional (3D; RCCS™bioreactor) in vitro culture systems. Furthermore, to mimic the 'bone remodelling unit' in vitro, hAFMSCs were co-cultured in the 3D system with human monocyte cells (hMCs) as osteoclast precursors. The results showed that in a conventional 2D culture system, hAFMSCs were responsive to the MK-4, which significantly improved the osteogenic process through γ-glutamyl carboxylase-dependent pathway. The same results were obtained in the 3D dynamic system where MK-4 treatment supported the osteoblast-like formation promoting the extracellular bone matrix deposition and the expression of the osteogenic-related proteins (alkaline phosphatase, osteopontin, collagen type-1 and osteocalcin). Notably, when the hAFMSCs were co-cultured in a 3D dynamic system with the hMCs, the presence of MK-4 supported the cellular aggregate formation as well as the osteogenic function of hAFMSCs, but negatively affected the osteoclastogenic process. Taken together, our results demonstrate that MK-4 supported the aggregate formation of hAFMSCs and increased the osteogenic functions. Specifically, our data could help to optimize bone regenerative medicine combining cell-based approaches with MK-4 treatment