Model Risk Management. Le prassi e il modello a tendere.

I modelli hanno assunto un ruolo pervasivo nell’operatività bancaria configurandosi come driver essenziali nel decision making sia in ambito regolamentare che gestionale, e questa considerazione, seppur con caratterizzazioni diverse, risulta valida sia per banche “significant” che “less significant”. Si evidenzia che il numero e la complessità dei modelli hanno raggiunto un livello di ampiezza tale da richiederne una gestione dedicata e strumenti specifici per evitare che la base decisionale si poggi su algoritmi, dati o elaborazioni non adeguati. Oltre alla complessità intrinseca dei modelli, si aggiunge una crescente interconnessione tra gli stessi per cui le criticità di un modello possono riverberarsi sui modelli collegati con effetti poco prevedibili. Le mutevoli condizioni di contesto (accentuate dall’emergenza Covid), hanno ulteriormente amplificato l’esigenza di ridurre la distanza tra l’identificazione delle criticità sui modelli, la presa in carico delle azioni correttive, il relativo monitoraggio e il rilascio degli interventi. Una catena di trasmissione non adeguata comporta inevitabilmente tempi di risposta più lunghi, con modelli che non sono in grado di rappresentare adeguatamente il contesto operativo

Orally available Mn porphyrins with superoxide dismutase and catalase activities

Superoxide dismutase/catalase mimetics, such as salen Mn complexes and certain metalloporphyrins, catalytically neutralize reactive oxygen and nitrogen species, which have been implicated in the pathogenesis of many serious diseases. Both classes of mimetic are protective in animal models of oxidative stress. However, only AEOL11207 and EUK-418, two uncharged Mn porphyrins, have been shown to be orally bioavailable. In this study, EUK-418 and several new analogs (the EUK-400 series) were synthesized and shown to exhibit superoxide dismutase, catalase, and peroxidase activities in vitro. Some also protected PC12 cells against staurosporine-induced cell death. All EUK-400 compounds were stable in simulated gastric fluid, and most were substantially more lipophilic than the salen Mn complexes EUK-189 and EUK-207, which lack oral activity. Pharmacokinetics studies demonstrate the presence of all EUK-400 series compounds in the plasma of rats after oral administration. These EUK-400 series compounds are potential oral therapeutic agents for cellular damage caused by oxidative stress

Interior potential of a toroidal shell from pole values

International audienceWe have investigated the toroidal analog of ellipsoidal shells of matter, which are of great significance in Astrophysics. The exact formula for the gravitational potential $\Psi(R,Z)$ of a shell with a circular section at the pole of toroidal coordinates is first established. It depends on the mass of the shell, its main radius and axis-ratio $e$ (i.e. core-to-main radius ratio), and involves the product of the complete elliptic integrals of the first and second kinds. Next, we show that successive partial derivatives $\partial^{n +m} \Psi/\partial_{R^n} \partial_{Z^m}$ are also accessible by analytical means at that singular point, thereby enabling the expansion of the interior potential as a bivariate series. Then, we have generated approximations at orders $0$, $1$, $2$ and $3$, corresponding to increasing accuracy. Numerical experiments confirm the great reliability of the approach, in particular for small-to-moderate axis ratios ($e^2 \lesssim 0.1$ typically). In contrast with the ellipsoidal case (Newton's theorem), the potential is not uniform inside the shell cavity as a consequence of the curvature. We explain how to construct the interior potential of toroidal shells with a thick edge (i.e. tubes), and how a core stratification can be accounted for. This is a new step towards the full description of the gravitating potential and forces of tori and rings. Applications also concern electrically-charged systems, and thus go beyond the context of gravitation

Microscopic scale conductivity as explanation of MT results from the Alps of western Switzerland

Recent MT soundings carried out in the Penninic Alps of Valais have shown the presence of a very good, outcropping conductor. Extremely high conductivity was attributed to the presence of graphite. To verify this assumption, the electrical properties of borehole black shales were measured under simulated physical conditions (electrical frequency, hydrostatic confining pressure, internal fluid pressure, temperature). These measurements showed that under all physical conditions (electrical frequency, in the 0.005-200 Hz interval; hydrostatic confining pressure up to 39 MPa; internal fluid pressure up to 23 MPa; temperature up to 180 degreesC) one of the samples studied was very conductive (resistivity less than 2 Omegam under all physical conditions). Interestingly, despite similar macroscopic aspect, other samples from a nearby borehole were found to be only slightly conductive. Chemical, mineralogical and petrographic investigations revealed that the enhanced electrical conductivity is mostly due to textural characteristics (such as grain size and carbon film distribution at the grain boundaries) rather than to chemical differences

Defective AMH signaling disrupts GnRH neuron development and function and contributes to hypogonadotropic hypogonadism.

Congenital hypogonadotropic hypogonadism (CHH) is a condition characterized by absent puberty and infertility due to gonadotropin releasing hormone (GnRH) deficiency, which is often associated with anosmia (Kallmann syndrome, KS). We identified loss-of-function heterozygous mutations in anti-Müllerian hormone (AMH) and its receptor, AMHR2, in 3% of CHH probands using whole-exome sequencing. We showed that during embryonic development, AMH is expressed in migratory GnRH neurons in both mouse and human fetuses and unconvered a novel function of AMH as a pro-motility factor for GnRH neurons. Pathohistological analysis of Amhr2-deficient mice showed abnormal development of the peripheral olfactory system and defective embryonic migration of the neuroendocrine GnRH cells to the basal forebrain, which results in reduced fertility in adults. Our findings highlight a novel role for AMH in the development and function of GnRH neurons and indicate that AMH signaling insufficiency contributes to the pathogenesis of CHH in humans

The scheme of cloning pGA-BGL and pGA-EGIV plasmids.

<p>The scheme of cloning pGA-BGL and pGA-EGIV plasmids.</p

Defective AMH signaling disrupts GnRH neuron development and function and contributes to hypogonadotropic hypogonadism

Congenital hypogonadotropic hypogonadism (CHH) is a condition characterized by absent puberty and infertility due to gonadotropin releasing hormone (GnRH) deficiency, which is often associated with anosmia (Kallmann syndrome, KS). We identified loss-of-function heterozygous mutations in anti-Müllerian hormone (AMH) and its receptor, AMHR2, in 3% of CHH probands using whole-exome sequencing. We showed that during embryonic development, AMH is expressed in migratory GnRH neurons in both mouse and human fetuses and unconvered a novel function of AMH as a pro-motility factor for GnRH neurons. Pathohistological analysis of Amhr2-deficient mice showed abnormal development of the peripheral olfactory system and defective embryonic migration of the neuroendocrine GnRH cells to the basal forebrain, which results in reduced fertility in adults. Our findings highlight a novel role for AMH in the development and function of GnRH neurons and indicate that AMH signaling insufficiency contributes to the pathogenesis of CHH in humans.</jats:p