New solar metallicity measurements

In the past years, a systematic downward revision of the metallicity of the Sun has led to the "solar modeling problem", namely the disagreement between predictions of standard solar models and inferences from helioseismology. Recent solar wind measurements of the metallicity of the Sun, however, provide once more an indication of a high-metallicity Sun. Because of the effects of possible residual fractionation, the derived value of the metallicity $Z_{\odot} = 0.0196 \pm 0.0014$ actually represents a lower limit to the true metallicity of the Sun. However, when compared with helioseismological measurements, solar models computed using these new abundances fail to restore agreement, owing to the implausibly high abundance of refractory (Mg, Si, S, Fe) elements, which correlates with a higher core temperature and hence an overproduction of solar neutrinos. Moreover, the robustness of these measurements is challenged by possible first ionization potential fractionation processes. I will discuss these solar wind measurements, which leave the "solar modeling problem" unsolved.Comment: 6 pages, extended version of contribution to proceedings of the 51st Rencontres de Moriond, Cosmology Session, published as communication in Atom

Diurnal modulation signal from dissipative hidden sector dark matter

We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken $U(1)'$ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength $\epsilon \sim 10^{-9}$. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large ($\gtrsim 10\%$) for a wide range of parameters.Comment: 12 pages, 4 figures, clarifying comments and references adde

Mimetic gravity: a review of recent developments and applications to cosmology and astrophysics

Mimetic gravity is a Weyl-symmetric extension of General Relativity, related to the latter by a singular disformal transformation, wherein the appearance of a dust-like perfect fluid can mimic cold dark matter at a cosmological level. Within this framework, it is possible to provide an unified geometrical explanation for dark matter, the late-time acceleration, and inflation, making it a very attractive theory. In this review, we summarize the main aspects of mimetic gravity, as well as extensions of the minimal formulation of the model. We devote particular focus to the reconstruction technique, which allows the realization of any desired expansionary history of the Universe by an accurate choice of potential, or other functions defined within the theory (as in the case of mimetic $f(R)$ gravity). We briefly discuss cosmological perturbation theory within mimetic gravity. As a case study within which we apply the concepts previously discussed, we study a mimetic Ho\v{r}ava-like theory, of which we explore solutions and cosmological perturbations in detail. Finally, we conclude the review by discussing static spherically symmetric solutions within mimetic gravity, and apply our findings to the problem of galactic rotation curves. Our review provides an introduction to mimetic gravity, as well as a concise but self-contained summary of recent findings, progresses, open questions, and outlooks on future research directions.Comment: 68 pages, invited review to appear in Advances in High Energy Physic

Sales online of Health Products: Economical and Administrative Perspective

The continuing decline in the pharmaceutical expenditure deduction, the increasing fees paid by pharmacies in favor of the NHS and the crisis that reduces the spending power of the citizen, triggered a huge drop in the profitability of the Italian pharmacies. However the crisis can also be positive because it forces the companies to deploy all the resources needed to invert the situation, changing certain vicious behaviors in favor of virtuous ones. But if on the one hand, it is the single pharmacist who should implement corrective measures, on the other hand some problems must be solved by the entire distribution system in order to prevent the marginalization of the pharmacy. A good solution might be represented by the emerging tendency of the online sale of OTC pharmaceuticals, already recognized by the market trends and regulated at the European Law level, and almost completely implemented by the Italian legislation . This opportunity might increase the health related products demand whereas an optimal marketing and administrative strategy is executed. Nevertheless, the strategy should be designed to create the prospective for the pharmacy to re-achieve the distribution that has been lost; with a direct distribution the pharmacy loses and the intermediate distribution channel as well, with an higher number of losers than winners, in the end. Hence, the technological solution proposition i.e. the web pharmacy, has to take into consideration this disintermediation problem that should be strengthened instead of weakened, at least to some degrees. It can be already anticipated that the Italian normative alignment with the European directive proposes to solve the problem of the disintermediation naturally related to the e-commerce adoption, with the possibility for the E-pharmacy to exist only if a physical shop already exists behind it

Architettura Orientata Ai Servizi (SOA) e Analisi dei Costi: Inteligent Agent e Predittivita’ del miglior Servizio

Nel seguente articolo viene proposta un’analisi SOA su tre livelli consecutivi e crescenti vale a dire: Stabilità, Condivisione e Predittività, ognuno dei quali supportato dallo studio di casi concreti e specifici per ogni singolo livello. Lo schema proposto ha lo scopo di scindere in tre fasi l’implementazione SOA per una più immediata comprensione e analisi dei costi associati a ogni specifico livello. L’obiettivo razionale su cui si fonda l’approccio proposto è quello della previsione in termini di costi e ricavi, di benefici quantificabili, nonché di nuove opportunità al fine di ridurre i costi stimati e offrire servizi personalizzati agli utenti. La suddetta prospettiva è stata finora poco esplorata dalle aziende considerata l’ingente quantità di dati che andrebbero raccolti sistematicamente; a tal proposito il metodo innovativo che si vuole suggerire si deve basare sull’implementazione di un Service Index (SI), ovvero di un indice di ranking di utilità del cliente che snellirà e agevolerà la SOA in un sistema più efficace di valutazione e risposta. I vantaggi del procedimento proposto possono considerarsi due: un’analisi dettagliata di costi associati alla SOA e supportata dallo studio di casi, al fine di derivarne una corretta comprensione dei benefici apportati; l’analisi ovviamente distribuita su tutti e tre i livelli permette una maggiore specificità senza lasciare scoperto nessun processo dal momento dell’Implementazione SOA alla previsione. Il secondo vantaggio è quello di combinare la Predittività ( si veda il video di Hal Varian ) e l’analisi dei costi all’interno di una cornice SOA come unico mezzo tramite il quale un’impresa potrebbe affrontare le nuove sfide per migliorare i servizi resi ai clienti, in quanto è il risultato di un uso più efficiente delle risorse così come di un risparmio sia di tempo che di costi