Caveolin-1 Phosphorylation Is Essential for Axonal Growth of Human Neurons Derived From iPSCs.

Proper axonal growth and guidance is essential for neuron differentiation and development. Abnormal neuronal development due to genetic or epigenetic influences can contribute to neurological and mental disorders such as Down syndrome, Rett syndrome, and autism. Identification of the molecular targets that promote proper neuronal growth and differentiation may restore structural and functional neuroplasticity, thus improving functional performance in neurodevelopmental disorders. Using differentiated human neuronal progenitor cells (NPCs) derived from induced pluripotent stem cells (iPSCs), the present study demonstrates that during early stage differentiation of human NPCs, neuron-targeted overexpression constitutively active Rac1 (Rac1CA) and constitutively active Cdc42 (Cdc42CA) enhance expression of P-Cav-1, T-Cav-1, and P-cofilin and increases axonal growth. Similarly, neuron-targeted over-expression of Cav-1 (termed SynCav1) increases axonal development by increasing both axon length and volume. Moreover, inhibition of Cav-1(Y14A) phosphorylation blunts Rac1/Cdc42-mediated both axonal growth and differentiation of human NPCs and SynCav1(Y14A)-treated NPCs exhibited blunted axonal growth. These results suggest that: (1) SynCav1-mediated dendritic and axonal growth in human NPCs is dependent upon P-Cav-1, (2) P-Cav-1 is necessary for proper axonal growth during early stages of neuronal differentiation, and (3) Rac1/Cdc42CA-mediated neuronal growth is in part dependent upon P-Cav-1. In conclusion, Cav-1 phosphorylation is essential for human neuronal axonal growth during early stages of neuronal differentiation

On the zeroes and the critical points of a solution of a second order half-linear differential equation

This paper presents two methods to obtain upper bounds for the distance between a zero and an adjacent critical point of a solution of the second-order half-linear di¿erential equation p x ¿ y q x ¿ y 0, with p x and q x piecewise continuous and p x > 0, ¿ t |t| r¿2 t and r being real such that r > 1. It also compares between them in several examples. Lower bounds i.e., Lyapunov inequalities for such a distance are also provided and compared with other methods.This work has been supported by the Spanish Ministry of Science and Innovation Project DPI2010-C02-01.Almenar, P.; Jódar Sánchez, LA. (2012). On the zeroes and the critical points of a solution of a second order half-linear differential equation. Abstract and Applied Analysis. 2012(ID 78792):1-18. doi:10.1155/2012/787920S1182012ID 78792Almenar, P., & Jódar, L. (2012). An upper bound for the distance between a zero and a critical point of a solution of a second order linear differential equation. Computers & Mathematics with Applications, 63(1), 310-317. doi:10.1016/j.camwa.2011.11.023Li, H. J., & Yeh, C. C. (1995). Sturmian comparison theorem for half-linear second-order differential equations. Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 125(6), 1193-1204. doi:10.1017/s0308210500030468Yang, X. (2003). On inequalities of Lyapunov type. Applied Mathematics and Computation, 134(2-3), 293-300. doi:10.1016/s0096-3003(01)00283-1Lee, C.-F., Yeh, C.-C., Hong, C.-H., & Agarwal, R. P. (2004). Lyapunov and Wirtinger inequalities. Applied Mathematics Letters, 17(7), 847-853. doi:10.1016/j.aml.2004.06.016Pinasco, J. P. (2004). Lower bounds for eigenvalues of the one-dimensionalp-Laplacian. Abstract and Applied Analysis, 2004(2), 147-153. doi:10.1155/s108533750431002xPinasco, J. P. (2006). Comparison of eigenvalues for the p-Laplacian with integral inequalities. Applied Mathematics and Computation, 182(2), 1399-1404. doi:10.1016/j.amc.2006.05.027Almenar, P., & Jódar, L. (2009). Improving explicit bounds for the solutions of second order linear differential equations. Computers & Mathematics with Applications, 57(10), 1708-1721. doi:10.1016/j.camwa.2009.03.076Moore, R. (1955). The behavior of solutions of a linear differential equation of second order. Pacific Journal of Mathematics, 5(1), 125-145. doi:10.2140/pjm.1955.5.12

BiodiverCities: A roadmap to enhance the biodiversity and green infrastructure of European cities by 2030

BiodiverCities is a European Parliament Pilot Project, developed with the aim of enhancing the use of Urban Green Infrastructure (UGI) to enhance the condition of urban ecosystems, providing benefits for people and nature. In this report, an evaluation around the most appropriate reporting unit for an urban ecosystems assessment is carried out, comparing Functional Urban Areas (FUA) and Local Administrative Units (LAU). Furthermore, UGI are assessed from a multi-scale perspective. The status and scenarios of UGI in European urbanised areas is first analysed measuring the urban green areas and the tree canopy cover. Secondly, the contribution of UGI to the overall European Green Infrastructure (EU-GI) is quantified, evaluating the respective role of FUA and LAU. Finally, the effect of urban characteristics on biotic homogenization is analysed exploring how urbanised areas impact on avian population and communities in French cities. The results of this study will inform the development of a roadmap for greening cities in Europe in the 2020-2030 decade

Chromatin establishes an immature version of neuronal protocadherin selection during the naive-to-primed conversion of pluripotent stem cells.

In the mammalian genome, the clustered protocadherin (cPCDH) locus provides a paradigm for stochastic gene expression with the potential to generate a unique cPCDH combination in every neuron. Here we report a chromatin-based mechanism that emerges during the transition from the naive to the primed states of cell pluripotency and reduces, by orders of magnitude, the combinatorial potential in the human cPCDH locus. This mechanism selectively increases the frequency of stochastic selection of a small subset of cPCDH genes after neuronal differentiation in monolayers, 10-month-old cortical organoids and engrafted cells in the spinal cords of rats. Signs of these frequent selections can be observed in the brain throughout fetal development and disappear after birth, except in conditions of delayed maturation such as Down's syndrome. We therefore propose that a pattern of limited cPCDH-gene expression diversity is maintained while human neurons still retain fetal-like levels of maturation

Calculating the energy spectra of magnetic molecules: application of real- and spin-space symmetries

The determination of the energy spectra of small spin systems as for instance given by magnetic molecules is a demanding numerical problem. In this work we review numerical approaches to diagonalize the Heisenberg Hamiltonian that employ symmetries; in particular we focus on the spin-rotational symmetry SU(2) in combination with point-group symmetries. With these methods one is able to block-diagonalize the Hamiltonian and thus to treat spin systems of unprecedented size. In addition it provides a spectroscopic labeling by irreducible representations that is helpful when interpreting transitions induced by Electron Paramagnetic Resonance (EPR), Nuclear Magnetic Resonance (NMR) or Inelastic Neutron Scattering (INS). It is our aim to provide the reader with detailed knowledge on how to set up such a diagonalization scheme.Comment: 29 pages, many figure