Maximal Sobolev regularity for solutions of elliptic equations in infinite dimensional Banach spaces endowed with a weighted Gaussian measure

Let $X$ be a separable Banach space endowed with a non-degenerate centered Gaussian measure $\mu$. The associated Cameron-Martin space is denoted by $H$. Let $\nu=e^{-U}\mu$, where $e^{-U}$ is a sufficiently regular weight and $U:X\rightarrow\mathbb{R}$ is a convex and continuous function. In this paper we are interested in the $W^{2,2}$ regularity of the weak solutions of elliptic equations of the type $$\lambda u-L_\nu u=f,$$ where $\lambda>0$, $f\in L^2(X,\nu)$ and $L_\nu$ is the self-adjoint operator associated with the quadratic form \[(\psi,\varphi)\mapsto \int_X\left\langle\nabla_H\psi,\nabla_H\varphi\right\rangle_Hd\nu\qquad\psi,\varphi\in W^{1,2}(X,\nu).\

Typing Context-Dependent Behavioural Variation

Context Oriented Programming (COP) concerns the ability of programs to adapt to changes in their running environment. A number of programming languages endowed with COP constructs and features have been developed. However, some foundational issues remain unclear. This paper proposes adopting static analysis techniques to reason on and predict how programs adapt their behaviour. We introduce a core functional language, ContextML, equipped with COP primitives for manipulating contexts and for programming behavioural variations. In particular, we specify the dispatching mechanism, used to select the program fragments to be executed in the current active context. Besides the dynamic semantics we present an annotated type system. It guarantees that the well-typed programs adapt to any context, i.e. the dispatching mechanism always succeeds at run-time.Comment: In Proceedings PLACES 2012, arXiv:1302.579

Very Large PoreMesoporous Bioactive Silicate Glasses: Comparison of Behavior toward Classical Mesoporous Bioactive Glasses in Terms of Drug Loading/Release and Bioactivity

Abstract: Considering the increase in patients who suffer from osteoporosis and the bone defects that occur in these patients, bone tissue regeneration is a promising option to solve this problem. To achieve a synergistic effect between the synthesis of a proper structure and bioactive/pharmaceutical activity, ions with a physiological effect can be added to silica structures, such as Ca2+, thanks to its bioactive behavior, and Ga3+ for its antibacterial and anticancer action. In this work, the synthesis of large pore mesoporous silica (LPMS), potential bioactive glasses containing Ca2+ and Ga3+, has been studied. Corresponding structures, in terms of composition, have been synthesized following the Sol-Gel EISA (Evaporation Induced Self-Assembly) process (obtaining Classical Mesoporous Silica, MS). Pore structure characterization of LPMSs and MSs has been performed using N2 adsorption/ desorption and Hg-porosimetry, showing the presence of pores for LPMSs in the range of 20–60 and 200–600 nm. Nisin, a polycyclic antibacterial peptide, has been used for load tests. The load and release tests performed highlight a higher loading and releasing, doubled for LPMSs if compared to MSs. To confirm the maintenance of the structure of LPMSs and their mechanical strength and resistance, scanning electron microscopy images were acquired before and after release tests. Ca and Ga release in SBF has been studied through inductively coupled plasma—optical emission spectroscopy (ICP-OES), showing a particularly high release of these ions performed with LPMSs. The bioactive behavior of Ca-containing structures has been confirmed using FT-IR (Fourier-transform infrared spectroscopy), SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy), and X-ray powder diffraction (XRDP). In conclusion, LPMSs showed better loading and releasing properties compared with classical MS and better release in terms of active ions. In addition, it has also been demonstrated that LPMSs have bioactive behavior (a well-known characteristic of MSs)

Very large pores mesoporous silica as new candidate for delivery of big therapeutics molecules, such as pharmaceutical peptides

The synthesis of a scaffold that can accommodate big molecules with a pharmaceutical role is important to shield them and maintain their biological activity. In this field, silica particles with large pores (LPMS) are innovative supports. Large pores allow for the loading of bioactive molecules inside the structure and contemporarily their stabilization and protection. These purposes cannot be achieved using classical mesoporous silica (MS, pore size 2–5 nm), because their pores are not big enough and pore blocking occurs. LPMSs with different porous structures are synthesized starting from an acidic water solution of tetraethyl orthosilicate reacting with pore agents (Pluronic® F127 and mesitylene), performing hydrothermal and microwave-assisted reactions. Time and surfactant optimization were performed. Loading tests were conducted using Nisin as a reference molecule (polycyclic antibacterial peptide, with dimensions of 4–6 nm); UV-Vis analyses on loading solutions were performed. For LPMSs, a significantly higher loading efficiency (LE%) was registered. Other analyses (Elemental Analysis, Thermogravimetric Analysis and UV-Vis) confirmed the presence of Nisin in all the structures and its stability when loaded on them. LPMSs showed a lower decrease in specific surface area if compared to MS; in terms of the difference in LE% between samples, it is explained considering the filling of pores for LPMSs, a phenomenon that is not allowed for MSs. Release studies in simulated body fluid highlight, only for LPMSs, a controlled release, considering the longer time scale of release. Scanning Electron Microscopy images acquired before and after release tests shows the LPMSs’ maintenance of the structure, demonstrating strength and mechanical resistance of structures. In conclusion, LPMSs were synthesized, performing time and surfactant optimization. LPMSs showed better loading and releasing properties with respect to classical MS. All collected data confirm a pore blocking for MS and an in-pore loading for LPMS

Neutrino current in a gravitational plane wave collision background

The behaviour of a massless Dirac field on a general spacetime background representing two colliding gravitational plane waves is discussed in the Newman-Penrose formalism. The geometrical properties of the neutrino current are analysed and explicit results are given for the special Ferrari-Ibanez solution.Comment: 17 pages, 6 Postscript figures, accepted by International Journal of Modern Physics

Test particle motion in a gravitational plane wave collision background

Test particle geodesic motion is analysed in detail for the background spacetimes of the degenerate Ferrari-Ibanez colliding gravitational wave solutions. Killing vectors have been used to reduce the equations of motion to a first order system of differential equations which have been integrated numerically. The associated constants of the motion have also been used to match the geodesics as they cross over the boundary between the single plane wave and interaction zones.Comment: 11 pages, 6 Postscript figure

Eliciting the Double-edged Impact of Digitalisation: a Case Study in Rural Areas

Designing systems that account for sustainability concerns demands for a better understanding of the \textit{impact} that digital technology interventions can have on a certain socio-technical context. However, limited studies are available about the elicitation of impact-related information from stakeholders, and strategies are particularly needed to elicit possible long-term effects, including \textit{negative} ones, that go beyond the planned system goals. This paper reports a case study about the impact of digitalisation in remote mountain areas, in the context of a system for ordinary land management and hydro-geological risk control. The elicitation process was based on interviews and workshops. In the initial phase, past and present impacts were identified. In a second phase, future impacts were forecasted through the discussion of two alternative scenarios: a dystopic, technology-intensive one, and a technology-balanced one. The approach was particularly effective in identifying negative impacts. Among them, we highlight the higher stress due to the excess of connectivity, the partial reduction of decision-making abilities, and the risk of marginalisation for certain types of stakeholders. The study posits that before the elicitation of system goals, requirements engineers need to identify the socio-economic impacts of ICT technologies included in the system, as negative effects need to be properly mitigated. Our study contributes to the literature with: a set of impacts specific to the case, which can apply to similar contexts; an effective approach for impact elicitation; and a list of lessons learned from the experience.Comment: Accepted to IEEE RE 2023, International Conference on Requirements Engineering, 10 pages plus 2 pages of reference