Majorana and the theoretical problem of photon-electron scattering

Relevant contributions by Majorana regarding Compton scattering off free or bound electrons are considered in detail, where a (full quantum) generalization of the Kramers-Heisenberg dispersion formula is derived. The role of intermediate electronic states is appropriately pointed out in recovering the standard Klein-Nishina formula (for free electron scattering) by making recourse to a limpid physical scheme alternative to the (then unknown) Feynman diagram approach. For bound electron scattering, a quantitative description of the broadening of the Compton line was obtained for the first time by introducing a finite mean life for the excited state of the electron system. Finally, a generalization aimed to describe Compton scattering assisted by a non-vanishing applied magnetic field is as well considered, revealing its relevance for present day research.Comment: latex, amsart, 10 pages, 1 figur

Surgical management of rhinosinusitis in onco-hematological patients

ObjectivesIn onco-hematological diseases, the incidence of paranasal sinuses infection dramatically increase and requires a combination of medical and surgical therapy. Balloon dilatation surgery (DS) is a minimally invasive, tissue preserving procedure. The study evaluates the results of DS for rhinosinusitis in immunocompromised patients.MethodsA retrospective chart review was conducted in 110 hematologic patients with rhinosinusitis. Twenty-five patients were treated with DS technique and 85 patients with endoscopic sinus surgery (ESS). We considered the type of anesthesia and the extent of intra- and postoperative bleeding. Patients underwent Sino-Nasal Outcome Test (SNOT-20) to evaluate changes in subjective symptoms and global patient assessment (GPA) questionnaire to value patient satisfaction.ResultsLocal anesthesia was employed in 8 cases of DS and in 15 of ESS. In 50 ESS patients, an anterior nasal packing was placed and in 12 cases a repacking was necessary. In the DS group, nasal packing was required in 8 cases and in 2 cases a repacking was placed (P=0.019 and P=0.422, respectively). The SNOT-20 change score showed significant improvement of health status in both groups. However the DS group showed a major improvement in 3 voices: need to blow nose, runny nose, and facial pain/pressure. The 3-month follow-up GPA questionnaire showed an higher satisfaction of DS group.ConclusionBalloon DS represents a potentially low aggressive treatment and appears to be relatively safe and effective in onco-hematologic patients. All these remarks may lead the surgeon to consider a larger number of candidates for surgical procedure

Update on monitoring of magnetic and electromagnetic tectonic signals in Central Italy

A network of three absolute magnetometer stations and the geomagnetic observatory of L’Aquila (42°23N, 13°19E) monitors possible seismo- or tectonomagnetic effects in Central Italy, using L’Aquila Observatory as a reference for differentiation. A system of two VLF search coil wide-band antennas, working in two different frequency bands, at the L’Aquila Observatory, monitors possible electromagnetic effects related to seismic events occurring in Central Italy. Absolute magnetic field observations and VLF signals have been collected for several years. In particular the tectono-magnetic network started its operations in 1989. In this paper we report on the time variation of above mentioned data for the most recent years 2002 and 2003, also in connection with older measurements time series; we also report on seismic activity recorded in this area by the national seismic network. In the above mentioned time interval, no strong earthquake activity was recorded, and at the same time no clear evidence for magnetic or electromagnetic signals related to seismic events was found

Industrial risk in the Lombardy Region (Italy): what people perceive and what are the gaps to improve the risk communication and the participatory processes

Risk communication is of vital importance in today\u2019s society, as audiences become ever more questioning about the causes and effects of risk. However, the communication of risk is a complex activity involving many different types of communicators and destinataries, from scientists, to the media, to government agencies, industry and consumer groups, each of which having its own agendas to fulfil. Such variation across the communication of the same risk can lead to confusion, misunderstandings, misreporting in the media and subsequent conflicts. The goal of risk communication is to produce an informed public. The personal nature of risk issues and the uncertainty associated with estimating risk can provoke considerable anxiety for the public and make adopted risk management strategies less acceptable. Lombardy is one of the most densely populated and industrialized regions in Europe and nearly 280 Seveso sites interest it. The Seveso Directive requires specific measures on risk communication to the population. Nevertheless, the Lombardy Region Authorities consider that the implementation of such provisions is too weak. Therefore an exploratory research has been concluded, in order to estimate the gaps in risk communication and to improve the participation of the population in the emergency preparedness activities. The paper reports the main results of the research and illustrates the potential strategies to improve the risk communication and the population participation and preparedness (\uc9upolis Lombardia 2011)

Efficiency of microsatellite markers in assisted selection for resistance to soybean cyst nematode (race 3).

Four microsatellite sequences were tested in soybean DNA from cultivars and segregating genotypes. Three of them were close to the resistance locus rhg 1 on molecular linkage group G (Satt 309, Sat_168, Sat_163) and one was close to Rhg4 locus on group A2 (Sat_162). Progenies previously classified as cyst nematode (SNC) resistant and others with unknown reaction were tested, using the resistant cultivars Liderança, and Renascença and the susceptibles 'Cristalina' and 'OCEPAR-4' as control. The best primer for resistance to SCN was Sat_162. Twenty segregant progenies tested with Sat_162 presented a 150 bp band for homozygous resistant genotypes and 200 bp for susceptible ones, and both for the heterozigous genotypes. Previous studies have shown that this microsatellite marker is efficient to select genotypes carrying Peking-derivative resistance. 'Peking' takes part in the in the genealogy of all segregant progenies evaluated in this study. Thus, the obtained results showed that Sat_162 distinguished resistant and susceptible soybean genotypes to SCN, race 3

Exploring the international linkages of the Euro area: a global VAR analysis

We presents a global model linking individual country vector error-correcting models in which domestic variables are related to country-specific variables as an approximate solution to a global common factor model. The model is estimated for 26 economies. It provides a theoretical framework where the GVAR is derived as an approximation to a global unobserved common factor model, and using average pair-wise cross-section error correlations, the approach is shown to be quite effective in dealing with common factor interdependencies and international co-movements of business cycles. In addition to generalised impulse response functions, we propose an identification scheme to derive structural impulse responses. We focus on identification of shocks to the US economy, particularly the monetary policy shocks, and consider the time profiles of their effects on the euro area. To this end we include the US model as the first country model and consider alternative orderings of the US variables