Thermoelasticity of Fe2+-bearing bridgmanite

We present LDA+U calculations of high temperature elastic properties of bridgmanite with composition (Mg$_{(1-x)}$Fe$_{x}^{2+}$)SiO$_3$ for $0\le{x}\le0.125$. Results of elastic moduli and acoustic velocities for the Mg-end member (x=0) agree very well with the latest high pressure and high temperature experimental measurements. In the iron-bearing system, we focus particularly on the change in thermoelastic parameters across the state change that occurs in ferrous iron above $\sim$30 GPa, often attributed to a high-spin (HS) to intermediate spin (IS) crossover but explained by first principles calculations as a lateral displacement of substitutional iron in the perovskite cage. We show that the measured effect of this change on the equation of state of this system can be explained by the lateral displacement of substitutional iron, not by the HS to IS crossover. The calculated elastic properties of (Mg$_{0.875}$Fe$_{0.125}^{2+}$)SiO$_3$ along an adiabatic mantle geotherm, somewhat overestimate longitudinal velocities but produce densities and shear velocities quite consistent with Preliminary Reference Earth Model data throughout most of the lower mantle.Comment: Accepted for Geophysical Research Letters (DOI: 10.1002/2014GL062888

Design of a High-Speed Ferrite-based Brushless DC Machine for Electric Vehicles

In the present paper an analytic procedure for the preliminary design of a High-Speed ferrite-based Brushless DC Machine (HS-BLDC) has been proposed. In particular, mechanical and electromagnetic modeling have been developed in order to take into account their mutual influence in the definition of the geometry of the electrical machine. In addition, suitable design targets have been imposed in accordance with electric vehicle application requirements. Hence, several mechanical and electromagnetic constraints have been introduced in order to comply with high-speed operation, preventing demagnetization issues of ferrite magnets as well. Subsequently, an HS-BLDC characterized by an inner rotor configuration has been designed in accordance with the proposed methodology. The analytical procedure and the corresponding results have been reported and validated by means of Finite Element Analyses (FEAs), highlighting the effectiveness of the proposed configuration and design solutions

Star-related lipid transfer protein 10 (STARD10): a novel key player in alcohol-induced breast cancer progression

Ethanol abuse promotes breast cancer development, metastasis and recurrence stimulating mammary tumorigenesis by mechanisms that remain unclear. Normally, 35% of breast cancer is receptor tyrosine-protein kinase (ERBB2)-positive that predisposes to poor prognosis and relapse, while ethanol drinking leads to invasion of their positive cells triggering the phosphorylation status of mitogen-activated protein kinase. StAR-related lipid transfer protein 10 (STARD10) is a lipid transporter of phosphatidylcholine and phosphatidylethanolamine; their changes on membrane composition occur before the morphological tumorigenic events. Interestingly, STARD10 has been described to be highly expressed in 35-40% of ERBB2-positive breast cancers. In this study, we demonstrate that ethanol administration promotes STARD10 and ERBB2 expression that is significantly associated with increased cell malignancy and aggressiveness. Consistently, ERBB2 overexpression causes an increase in STARD10 expression, while overexpression of ERBB2’s downstream targets, p65, c-MYC, c-FOS or c-JUN induces STARD10 promoter activity, correlative of enhanced ERBB2 function STARD10-mediated cellular membrane fluidity and intracellular calcium concentration impacts ERBB2 signaling pathway as evaluated by enhancedp65 nuclear translocation and binding to both ERBB2 and STARD10 promoters. Basically, we proved that STARD10 and ERBB2 positively regulate each other’s expression and function. Taken together, our data demonstrate that ethanol can modulate ERBB2’s function in breast cancer via a novel interplay with STARD10

Long term effects of major events on urban transport systems

LAUREA SPECIALISTICANel periodo che precede un Grande Evento la comunità locale della città ospitante è euforica per via della necessità di investire a per le opportunità che possono derivare dall’evento. Vengono realizzati grandi investimenti e, con un intenso impegno degli attori coinvolti, la città riesce a gestire il trasporto in queste circostanze straordinarie. Poiché la preparazione per l’evento viene effettuata con una scadenza stringente e con dei requisiti che fissano la qualità, i costi esplodono. Dopo l’evento è difficile valutare l’eredità: ci sono cambiamenti nelle infrastrutture, nella domanda e nell’offerta di servizi di trasporto; ma gli effetti non sono misurati rigorosamente. Attraverso un frame work comune questo studio analizza tre grandi eventi e mostra che, nonostante la mancanza di competenze per gestire strategicamente questi processi, le città riescono a ottenere degli effetti positivi sui loro sistemi di trasporto. I diversi casi mostrano alcuni tratti comuni nelle misure attuate e, conseguentemente, negli effetti. L’intervento sulla governance, su aspetti infrastrutturali, operativi, funzionali e gestionali rende possibile il miglioramento dell’offerta nella sua infrastruttura e organizzazione, nelle caratteristiche di qualità e costo. Tuttavia i casi presentano dei problemi e falliscono nel migliorare la composizione della domanda. È necessario prendere in considerazione degli aspetti aggiuntivi nel pianificare l’eredità di un grande evento per i sistemi di trasporto.Prior to a Major event the local community of the host city is euphoric about the need to invest and the opportunities that may come from the event. Large investments are realized and, with an intense work of the actors involved, the city manages its transport system in these extraordinary circumstances. Being the preparation done with a tight due date and fixed quality of the service, the costs explode. After the event the legacy is hard to evaluate, there have been changes in the infrastructure, in demand and in supply of services; but the effects of the event are not rigorously measured. Through a common framework the study analyses three major events and shows that, even if there is a lack of competencies to manage strategically these processes, the cities manage to gain positive effects on their transport systems. The different cases show some common patterns in the measures followed and thus, to a certain extent, in the effects. The intervention on the governance, structural, operational, functional and managerial aspects makes it possible to improve the characteristics of supply in its organization, infrastructure and cost or quality. However the cases present some problems and fail in improving the composition of the demand. There are some additional aspects that need to be taken in consideration when planning the transport legacy of a Major event

Stereoselectivity and electrostatics in charge-transfer Mn- and Cs-TCNQ4 networks on Ag(100)

Controlling supramolecular self-assembly is a fundamental step towards molecular nanofabrication, which involves a formidable reverse engineering problem. It is known that a variety of structures are efficiently obtained by assembling appropriate organic molecules and transition metal atoms on well-defined substrates. Here we show that alkali atoms bring in new functionalities compared with transition metal atoms because of the interplay of local chemical bonding and long-range forces. Using atomic-resolution microscopy and theoretical modelling, we investigate the assembly of alkali (Cs) and transition metals (Mn) co-adsorbed with 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules, forming chiral superstructures on Ag(100). Whereas Mn-TCNQ4 domains are achiral, Cs-TCNQ4 forms chiral islands. The specific behaviour is traced back to the different nature of the Cs- and Mn-TCNQ bonding, opening a novel route for the chiral design of supramolecular architectures. Moreover, alkali atoms provide a means to modify the adlayer electrostatic properties, which is important for the design of metal–organic interfaces

Single-shot readout of an electron spin in silicon

The size of silicon transistors used in microelectronic devices is shrinking to the level where quantum effects become important. While this presents a significant challenge for the further scaling of microprocessors, it provides the potential for radical innovations in the form of spin-based quantum computers and spintronic devices. An electron spin in Si can represent a well-isolated quantum bit with long coherence times because of the weak spin-orbit coupling and the possibility to eliminate nuclear spins from the bulk crystal. However, the control of single electrons in Si has proved challenging, and has so far hindered the observation and manipulation of a single spin. Here we report the first demonstration of single-shot, time-resolved readout of an electron spin in Si. This has been performed in a device consisting of implanted phosphorus donors coupled to a metal-oxide-semiconductor single-electron transistor - compatible with current microelectronic technology. We observed a spin lifetime approaching 1 second at magnetic fields below 2 T, and achieved spin readout fidelity better than 90%. High-fidelity single-shot spin readout in Si opens the path to the development of a new generation of quantum computing and spintronic devices, built using the most important material in the semiconductor industry.Comment: 5 pages, 4 figure

Maximal subgroups in the Cremona group

We show that for any $n\geq5$ there exist connected algebraic subgroups in the Cremona group $\mathrm{Bir}(\mathbb{P}^n)$ that are not contained in any maximal connected algebraic subgroup. Our approach exploits the existence of stably rational, non-rational threefolds.Comment: Mistake in proof of Proposition 2.1 is fixed, added Appendi

Localized Polycentric Orbital Basis Set for Quantum Monte Carlo Calculations Derived from the Decomposition of Kohn-Sham Optimized Orbitals

In this work, we present a simple decomposition scheme of the Kohn-Sham optimized orbitals which is able to provide a reduced basis set, made of localized polycentric orbitals, specifically designed for Quantum Monte Carlo. The decomposition follows a standard Density functional theory (DFT) calculation and is based on atomic connectivity and shell structure. The new orbitals are used to construct a compact correlated wave function of the Slater–Jastrow form which is optimized at the Variational Monte Carlo level and then used as the trial wave function for a final Diffusion Monte Carlo accurate energy calculation. We are able, in this way, to capture the basic information on the real system brought by the Kohn-Sham orbitals and use it for the calculation of the ground state energy within a strictly variational method. Here, we show test calculations performed on some small selected systems to assess the validity of the proposed approach in a molecular fragmentation, in the calculation of a barrier height of a chemical reaction and in the determination of intermolecular potentials. The final Diffusion Monte Carlo energies are in very good agreement with the best literature data within chemical accuracy

The cGAS Paradox:Contrasting Roles for cGAS-STING Pathway in Chromosomal Instability

Chromosomal instability (CIN) is an intricate phenomenon that is often found in human cancer, characterized by persisting errors in chromosome segregation. This ongoing chromosome mis-segregation results in structural and numerical chromosomal abnormalities that have been widely described to promote tumor evolution. In addition to being a driver of tumor evolution, recent evidence demonstrates CIN to be the central node of the crosstalk between a tumor and its surrounding microenvironment, as mediated by the cGAS-STING pathway. The role that cGAS-STING signaling exerts on CIN tumors is both complex and paradoxical. On one hand, the cGAS-STING axis promotes the clearance of CIN tumors through recruitment of immune cells, thus suppressing tumor progression. On the other hand, the cGAS-STING pathway has been described to be the major regulator in the promotion of metastasis of CIN tumors. Here, we review this dual role of the cGAS-STING pathway in the context of chromosomal instability and discuss the potential therapeutic implications of cGAS-STING signaling for targeting CIN tumors