Control of Time-Varying Epidemic-Like Stochastic Processes and Their Mean-Field Limits

The optimal control of epidemic-like stochastic processes is important both historically and for emerging applications today, where it can be especially important to include time-varying parameters that impact viral epidemic-like propagation. We connect the control of such stochastic processes with time-varying behavior to the stochastic shortest path problem and obtain solutions for various cost functions. Then, under a mean-field scaling, this general class of stochastic processes is shown to converge to a corresponding dynamical system. We analogously establish that the optimal control of this class of processes converges to the optimal control of the limiting dynamical system. Consequently, we study the optimal control of the dynamical system where the comparison of both controlled systems renders various important mathematical properties of interest.Comment: arXiv admin note: substantial text overlap with arXiv:1709.0798

An Experimental Model of Prostatic Inflammation for Drug Discovery

There is increasing evidence to support a significant role for chronic non-bacterial, prostatic inflammation in the development of human voiding dysfunction and prostate cancer. Their increased prevalence with age suggests that the decrease of testosterone concentration and/or the ratio of testosterone-to-estradiol in serum may have a role in their development. The main objective of this study was to explore prostatic inflammation and its relationship with voiding dysfunction and prostate carcinogenesis by developing an experimental model. A novel selective estrogen receptor modulator (SERM), fispemifene, was tested for the prevention and treatment of prostatic inflammation in this model. Combined treatment of adult Noble rats with testosterone and estradiol for 3 to 6 weeks induced gradually developing prostatic inflammation in the dorsolateral prostatic lobes. Inflammatory cells, mainly T-lymphocytes, were first seen around capillaries. Thereafter, the lymphocytes migrated into the stroma and into periglandular space. When the treatment time was extended to 13 weeks, the number of inflamed acini increased. Urodynamical recordings indicated voiding dysfunction. When the animals had an above normal testosterone and estradiol concentrations but still had a decreased testosterone-to-estradiol ratio in serum, they developed obstructive voiding. Furthermore, they developed precancerous lesions and prostate cancers in the ducts of the dorsolateral prostatic lobes. Interestingly, inflammatory infiltrates were observed adjacent to precancerous lesions but not in the adjacency of adenocarcinomas suggesting that inflammation has a role in the early stages of prostate carcinogenesis. Fispemifene, a novel SERM tested in this experimental model, showed anti-inflammatory action by attenuating the number of inflamed acini in the dorsolateral prostate. Fispemifene exhibited also antiestrogenic properties by decreasing expression of estrogen-induced biomarkers in the acinar epithelium. These findings suggest that SERMs could be considered as a new therapeutic possibility in the prevention and in the treatment of chronic prostatic inflammationSiirretty Doriast

Cretaceous ammonites from Fuerteventura, Canary Islands

Mesozoic deep-water sediments occurring on the island of Fuerteventura were deposited near the continent-ocean boundary adjacent to the African margin. During Tertiary times, they were uplifted and intruded by ultramafic, mafic and alkaline plutons and dykes and are now exposed as part of the ‘Basal Complex' of the island. These sediments reflect more or less continuous hemipelagic and turbiditic deposition during most of Jurassic and Cretaceous times. Two ammonites, described in this paper, document a Valanginian to Hauterivian age for part of the Lower Cretaceous siliciclastic turbidites, and a latest Albian to early Cenomanian age for part of the Upper Cretaceous hemipelagic limestone

Presentazione di una nuova teoria sulla valutazione del rischio e concetto di utilità, ovvero traduzione, con breve introduzione, del saggio (1738) Specimen Theoriae Novae de Mensura Sortis di Daniel Bernoulli

Come noto nella teoria delle decisioni il valore atteso di una particolare scelta non può essere sempre preso come criterio per determinare la decisione ottimale dal punto di vista razionale. Daniel Bernoulli in una fortunata memoria scritta nel 1731 e contenuta nel volume dei Commentarii Academiae Scientiarum Imperialis Petropolitanae pubblicato nel 1738, per primo suggerì di utilizzare in luogo del valore atteso un valore morale o utilità attesa che una persona è disposta a spendere e che dipende dal patrimonio che possiede. La proposta di Bernoulli ha avuto grandi influenza ed eco, fino ai nostri giorni, in davvero molte discipline e diversi settori di ricerca. In particolare la prospettiva aperta dal saggio è alla base del cosiddetto approccio utilitarista, sia in filosofia che in politica ed economia, per il quale ogni decisione individuale dovrebbe essere ispirata dalla necessità di massimizzare la propria utilità attesa e l’insieme delle decisioni individuali dovrebbe andare nella direzione della massimizzazione del benessere collettivo. Senza inoltrarci qui in una discussione di questi od altri importanti aspetti, riassumiamo prima brevemente l’idea di Bernoulli ed il contesto in cui fu concepita e presentiamo poi la traduzione integrale del suo articolo dall’originale latino