Additive energy forward curves in a Heath-Jarrow-Morton framework

One of the peculiarities of power and gas markets is the delivery mechanism of forward contracts. The seller of a futures contract commits to deliver, say, power, over a certain period, while the classical forward is a financial agreement settled on a maturity date. Our purpose is to design a Heath-Jarrow-Morton framework for an additive, mean-reverting, multicommodity market consisting of forward contracts of any delivery period. The main assumption is that forward prices can be represented as affine functions of a universal source of randomness. This allows us to completely characterize the models which prevent arbitrage opportunities: this boils down to finding a density between a risk-neutral measure $\mathbb{Q}$, such that the prices of traded assets like forward contracts are true $\mathbb{Q}$-martingales, and the real world probability measure $\mathbb{P}$, under which forward prices are mean-reverting. The Girsanov kernel for such a transformation turns out to be stochastic and unbounded in the diffusion part, while in the jump part the Girsanov kernel must be deterministic and bounded: thus, in this respect, we prove two results on the martingale property of stochastic exponentials. The first allows to validate measure changes made of two components: an Esscher-type density and a Girsanov transform with stochastic and unbounded kernel. The second uses a different approach and works for the case of continuous density. We apply this framework to two models: a generalized Lucia-Schwartz model and a cross-commodity cointegrated market.Comment: 28 page

Coverage, efficacy or dosing interval: which factor predominantly influences the impact of routine childhood vaccination for the prevention of varicella? A model-based study for Italy

Background: Varicella is a highly infectious disease with a significant public health and economic burden, which can be prevented with childhood routine varicella vaccination. Vaccination strategies differ by country. Some factors are known to play an important role (number of doses, coverage, dosing interval, efficacy and catch-up programmes), however, their relative impact on the reduction of varicella in the population remains unclear. This paper aims to help policy makers prioritise the critical factors to achieve the most successful vaccination programme with the available budget. Methods: Scenarios assessed the impact of different vaccination strategies on reduction of varicella disease in the population. A dynamic transmission model was used and adapted to fit Italian demographics and population mixing patterns. Inputs included coverage, number of doses, dosing intervals, first-dose efficacy and availability of catch-up programmes, based on strategies currently used or likely to be used in different countries. The time horizon was 30 years. Results: Both one- and two-dose routine varicella vaccination strategies prevented a comparable number of varicella cases with complications, but two-doses provided broader protection due to prevention of a higher number of milder varicella cases. A catch-up programme in susceptible adolescents aged 10-14 years old reduced varicella cases by 27-43 % in older children, which are often more severe than in younger children. Coverage, for all strategies, sustained at high levels achieved the largest reduction in varicella. In general, a 20 % increase in coverage resulted in a further 27-31 % reduction in varicella cases. When high coverage is reached, the impact of dosing interval and first-dose vaccine efficacy had a relatively lower impact on disease prevention in the population. Compared to the long (11 years) dosing interval, the short (5 months) and medium (5 years) interval schedules reduced varicella cases by a further 5-13 % and 2-5 %, respectively. Similarly, a 10 % increase in first-dose efficacy (from 65 to 75 % efficacy) prevented 2-5 % more varicella cases, suggesting it is the least influential factor when considering routine varicella vaccination. Conclusions: Vaccination strategies can be implemented differently in each country depending on their needs, infrastructure and healthcare budget. However, ensuring high coverage remains the critical success factor for significant prevention of varicella when introducing varicella vaccination in the national immunisation programme

Economic burden of HPV9-related diseases : a real world cost analysis from Italy

The objectives of this study were to estimate the economic burden of HPV in Italy, accounting for total direct medical costs associated with nine major HPV-related diseases, and to provide a measure of the burden attributable to HPV 6, 11, 16, 18, 31, 33, 45, 52, 58 infections

High spatial resolution passive microwave sounding systems

Two extensive series of flights aboard the ER-2 aircraft were conducted with the MIT 118 GHz imaging spectrometer together with a 53.6 GHz nadir channel and a TV camera record of the mission. Other microwave sensors, including a 183 GHz imaging spectrometer were flown simultaneously by other research groups. Work also continued on evaluating the impact of high-resolution passive microwave soundings upon numerical weather prediction models

The unmet need for pertussis prevention in patients with chronic obstructive pulmonary disease in the Italian context

Despite high rates of vaccination, pertussis resurgence has been reported worldwide in recent years, including in Italy, especially in older adults. Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with progressive inflammation of the respiratory tract. Regional population studies have shown the prevalence of COPD in Italy to be approximately 15% with an age-dependent increase in proportion of COPD cases. Emerging data shows that individuals with COPD are at high risk of contracting pertussis. Furthermore, those who develop pertussis could experience exacerbation of their pre-existent COPD and further susceptibility to other infections. Immunization programs in Italy currently recommend a decennial reduced-antigen-content diphtheria-tetanus-acellular pertussis booster vaccine dose for adults. Active measures to encourage booster vaccination, especially for high-risk adults such as those with COPD, could positively impact pertussis morbidity and the associated healthcare burden

Fourteen years’ clinical experience and the first million babies protected with human live-attenuated vaccine against rotavirus disease in Italy

Rotavirus (RV) causes up to half of hospital and community acute gastroenteritis (AGE) cases in young children in Italy. Two RV vaccines, available since 2006, are human RV (HRV) and human bovine RV (HBRV). This report looks back at the implementation of RV vaccination with HRV in Italy, and at HRV current and future perspectives. Initial regional policies led to national implementation by 2018, after scientific societies’ disease awareness efforts. Following vaccination, RV hospitalizations declined significantly, and cost savings were observed. The two-dose HRV vaccine is easily administered during compulsory vaccine visits, helping increase coverage. Intussusception, a serious event in children <1 year, was reported in Italy with a rate of 33–40 per 100,000 infants. RV vaccination presents a low increased risk of intussusception after the first dose, estimated at 0.6 cases per 100,000 doses in Italy in 2019. Parents should be aware of the intussusception risk and symptoms to ensure prompt treatment. It is widely recognized that the vaccination benefits (large numbers of RV hospitalizations prevented) outweigh the risk. HRV introduction in Italy was supported by epidemiologic burden studies, healthcare provider opinions, and congress debates, which significantly contributed to implementation of RV universal routine infant vaccination in Italy

Observation of strong-coupling effects in a diluted magnetic semiconductor (Ga,Fe)N

A direct observation of the giant Zeeman splitting of the free excitons in (Ga,Fe)N is reported. The magnetooptical and magnetization data imply the ferromagnetic sign and a reduced magnitude of the effective p-d exchange energy governing the interaction between Fe^{3+} ions and holes in GaN, N_0 beta^(app) = +0.5 +/- 0.2 eV. This finding corroborates the recent suggestion that the strong p-d hybridization specific to nitrides and oxides leads to significant renormalization of the valence band exchange splitting.Comment: 4 pages, 2 figure