Environmental assessment of light weighting solutions for automotive components: results, trade‐off and challenges from real case studies

In the last few decades, the automotive industry is facing the most deal with sustainability programs due to the increase of legislate limits on CO2 emissions and vehicle recyclability rate. Consequently, decisions on products design and development go together with environmental considerations, by starting to look for the employment of lighter materials, thus reducing vehicle mass weight and therefore fuel consumption and CO2 emissions during the dominant operation stage of a vehicle’s life cycle. To tackle this problem many of today automotive components are made of alternative materials like plastics, polymer composites, lighter metals which should lead to weight reduction with the same mechanical performances. Magneti Marelli® designs and produces hi-tech systems and components for the automotive sector representing a significant contribution on vehicle mass weight with a roughly 15% portion of incidence. So, in accordance to the environmental regulations, the Company has started to get involved into sustainability programs by focusing attention on the environmental impact of its products. In particular since 2012 Magneti Marelli has included in its mission the “improvement of environmental and energy performances of products and relatives processes during their whole life cycle, through innovative methodologies that assess the potential impacts in a quantitative way”, in this way highlighting the importance of meeting the increasing stakeholders’ expectations and their requests for transparency in results’ communication. This work addresses the main outcomes stemmed from the several LCA studies carried out over different components in terms of materials and technologies production allowing a wider environmental conscious related to the usage of different materials and manufacturing processes. Results showed that the materials employed offer the major contribution on the total impact especially for raw materials extraction and production and for the vehicle use phase, with a further substantial difference connected to the use of virgin instead of recycled materials. The main discussed points will be: i) the trade-off between production phase and use phase impacts; ii) End-of-Life analysis at component level beside the ISO 22628:2002 for the whole vehicle; iii) critical analysis and selection of environmental indicators significant for the automotive sector. Keywords Automotive sector, Life Cycle Assessment, vehicle component, Sustainable Manufacturing, Design for Environment, composites, light weightin

Overactivation of Notch1 Signaling Induces Ectopic Hair Cells in the Mouse Inner Ear in an Age-Dependent Manner

Background: During mouse inner ear development, Notch1 signaling first specifies sensory progenitors, and subsequently controls progenitors to further differentiate into either hair cells (HCs) or supporting cells (SCs). Overactivation of NICD (Notch1 intracellular domain) at early embryonic stages leads to ectopic HC formation. However, it remains unclear whether such an effect can be elicited at later embryonic or postnatal stages, which has important implications in mouse HC regeneration by reactivation of Notch1 signaling. Methodology/Principal Findings: We performed comprehensive in vivo inducible overactivation of NICD at various developmental stages. In CAG CreER+; Rosa26-NICD loxp/+ mice, tamoxifen treatment at embryonic day 10.5 (E10.5) generated ectopic HCs in the non-sensory regions in both utricle and cochlea, whereas ectopic HCs only appeared in the utricle when tamoxifen was given at E13. When tamoxifen was injected at postnatal day 0 (P0) and P1, no ectopic HCs were observed in either utricle or cochlea. Interestingly, Notch1 signaling induced new HCs in a non-cell-autonomous manner, because the new HCs did not express NICD. Adjacent to the new HCs were cells expressing the SC marker Sox10 (either NICD+ or NICDnegative). Conclusions/Significance: Our data demonstrate that the developmental stage determines responsiveness of embryonic otic precursors and neonatal non-sensory epithelial cells to NICD overactivation, and that Notch 1 signaling in the wild type, postnatal inner ear is not sufficient for generating new HCs. Thus, our genetic mouse model is suitable to test additiona

Generating inner ear organoids containing putative cochlear hair cells from human pluripotent stem cells

In view of the prevalence of sensorineural hearing defects in an ageing population, the development of protocols to generate cochlear hair cells and their associated sensory neurons as tools to further our understanding of inner ear development are highly desirable. We report herein a robust protocol for the generation of both vestibular and cochlear hair cells from human pluripotent stem cells which represents an advance over currently available methods that have been reported to generate vestibular hair cells only. Generating otic organoids from human pluripotent stem cells using a three-dimensional culture system, we show formation of both types of sensory hair cells bearing stereociliary bundles with active mechano-sensory ion channels. These cells share many morphological characteristics with their in vivo counterparts during embryonic development of the cochlear and vestibular organs and moreover demonstrate electrophysiological activity detected through single-cell patch clamping. Collectively these data represent an advance in our ability to generate cells of an otic lineage and will be useful for building models of the sensory regions of the cochlea and vestibule

A Late Role for bmp2b in the Morphogenesis of Semicircular Canal Ducts in the Zebrafish Inner Ear

BACKGROUND:The Bone Morphogenetic Protein (BMP) genes bmp2 and bmp4 are expressed in highly conserved patterns in the developing vertebrate inner ear. It has, however, proved difficult to elucidate the function of BMPs during ear development as mutations in these genes cause early embryonic lethality. Previous studies using conditional approaches in mouse and chicken have shown that Bmp4 has a role in semicircular canal and crista development, but there is currently no direct evidence for the role of Bmp2 in the developing inner ear. METHODOLOGY/PRINCIPAL FINDINGS:We have used an RNA rescue strategy to test the role of bmp2b in the zebrafish inner ear directly. Injection of bmp2b or smad5 mRNA into homozygous mutant swirl (bmp2b(-/-)) embryos rescues the early patterning defects in these mutants and the fish survive to adulthood. As injected RNA will only last, at most, for the first few days of embryogenesis, all later development occurs in the absence of bmp2b function. Although rescued swirl adult fish are viable, they have balance defects suggestive of vestibular dysfunction. Analysis of the inner ears of these fish reveals a total absence of semicircular canal ducts, structures involved in the detection of angular motion. All other regions of the ear, including the ampullae and cristae, are present and appear normal. Early stages of otic development in rescued swirl embryos are also normal. CONCLUSIONS/SIGNIFICANCE:Our findings demonstrate a critical late role for bmp2b in the morphogenesis of semicircular canals in the zebrafish inner ear. This is the first demonstration of a developmental role for any gene during post-embryonic stages of otic morphogenesis in the zebrafish. Despite differences in the early stages of semicircular canal formation between zebrafish and amniotes, the role of Bmp2 in semicircular canal duct outgrowth is likely to be conserved between different vertebrate species

Bmp4 Is Essential for the Formation of the Vestibular Apparatus that Detects Angular Head Movements

Angular head movements in vertebrates are detected by the three semicircular canals of the inner ear and their associated sensory tissues, the cristae. Bone morphogenetic protein 4 (Bmp4), a member of the Transforming growth factor family (TGF-β), is conservatively expressed in the developing cristae in several species, including zebrafish, frog, chicken, and mouse. Using mouse models in which Bmp4 is conditionally deleted within the inner ear, as well as chicken models in which Bmp signaling is knocked down specifically in the cristae, we show that Bmp4 is essential for the formation of all three cristae and their associated canals. Our results indicate that Bmp4 does not mediate the formation of sensory hair and supporting cells within the cristae by directly regulating genes required for prosensory development in the inner ear such as Serrate1 (Jagged1 in mouse), Fgf10, and Sox2. Instead, Bmp4 most likely mediates crista formation by regulating Lmo4 and Msx1 in the sensory region and Gata3, p75Ngfr, and Lmo4 in the non-sensory region of the crista, the septum cruciatum. In the canals, Bmp2 and Dlx5 are regulated by Bmp4, either directly or indirectly. Mechanisms involved in the formation of sensory organs of the vertebrate inner ear are thought to be analogous to those regulating sensory bristle formation in Drosophila. Our results suggest that, in comparison to sensory bristles, crista formation within the inner ear requires an additional step of sensory and non-sensory fate specification

Algebraic representation of Gaussian Markov combinations

Markov combinations for structural meta-analysis problems provide a way of constructing a statistical model that takes into account two or more marginal distributions by imposing conditional independence constraints between the variables that are not jointly observed. This paper considers Gaussian distributions and discusses how the covariance and concentration matrices of the different combinations can be found via matrix operations. In essence all these Markov combinations correspond to finding a positive definite completion of the covariance matrix over the set of random variables of interest and respecting the constraints imposed by each Markov combination. The paper further shows the potential of investigating the properties of the combinations via algebraic statistics tools. An illustrative application will motivate the importance of solving problems of this type

Isolated GHD: investigation and implication of JAK/STAT related genes before and after rhGH treatment.

Isolated GH deficiency (IGHD) is a rare disorder that occurs as an idiopathic form in most cases. The pathway JAK/STAT promotes cellular growth and it could be implicated in this condition. In order to characterize IGHD in the pediatric population and identify genes differently expressed before and after GH therapy, we performed a quantitative evaluation of 84 genes related to the JAK/STAT pathway which, by promoting cellular growth. RT(2) Profiler PCR Array and the other/subsequent evaluations were performed in three children with severe IGHD before and after 6 months of GH therapy and in three matched normal children. Gene profiling was modified by the IGHD status and the GH therapy, with a modulation of GHR and some inflammatory genes such as CRP. We found a heterozygous nonsense mutation R43X in the GHR gene in two out of three IGHD subjects, despite a good response to therapy. After therapy cardiovascular markers linked to genes as IL6, IL8 and TNF-\u3b1 displayed a trend toward reduction. Pre- and post therapy status differently affects gene expression. Mutational screening of GHR may be useful in investigating IGHD's etiology. Genes linked to inflammation suggest to evaluate cardiovascular risks also in pediatric IGHD subjects