Curvature Oscillations in Modified Gravity and High Energy Cosmic Rays

It is shown that F(R)-modified gravitational theories lead to curvature oscillations in astrophysical systems with rising energy density. The frequency and the amplitude of such oscillations could be very high and would lead to noticeable production of energetic cosmic ray particles.Comment: 7 pages, 2 figures, author's affiliation is correcte

Jeans Instability in Classical and Modified Gravity

Gravitational instability in classical Jeans theory, General Relativity, and modified gravity is considered. The background density increase leads to a faster growth of perturbations in comparison with the standard theory. The transition to the Newtonian gauge in the case of coordinate dependent background metric functions is studied. For modified gravity a new high frequency stable solution is found

Cosmic ray production in modified gravity

This paper is a reply to the criticism of our work on particle production in modified gravity by D. Gorbunov and A. Tokareva. We show that their arguments against efficient particle production are invalid. $F(R)$ theories can lead to an efficient generation of high energy cosmic rays in contracting systems.Comment: In response to criticism by referees several clarifying comments are added. The results of the paper remain largely unchanged. Version to appear on EPJ

Some Observable Effects of Modified Gravity in Cosmology and Astrophysics

In Chapter 1 I present the current picture of the universe and briefly review the cosmological constant problem and some of the theories proposed to solve it. The following Chapters essentially contain the published papers with some modifications and additions: in Chapter 2 I study the radiation-dominated epoch in $R^2$ gravity, gravitational particle production and its implications for the early and contemporary universe; in Chapter 3 I investigate the formation of curvature singularities in contracting astronomical systems; in Chapter 4, I discuss some mechanisms to prevent such singularities and calculate the related cosmic-ray production; finally, in Chapter 5, I deal with spherically symmetric solutions and explore the possibility of gravitational repulsion.Comment: Doctoral thesis successfully defended in March 2014, grade: Excellent. Advisor: Prof. A.D. Dolgov. Part of the work done in collaboration with E.V. Arbuzova

Seasonal variation of platelets in a cohort of Italian blood donors: a preliminary report

Massimo Gallerani1*, Roberto Reverberi2, Raffaella Salmi1, Michael H Smolensky3 and Roberto Manfredini4 Author Affiliations 1 Internal Medicine, Azienda Ospedaliera-Universitaria, Ferrara, Italy 2 Immunohematological and Transfusional Service, Azienda Ospedaliera-Universitaria, Ferrara, Italy 3 Department of Biomedical Engineering, The University of Texas at Austin, Austin, USA 4 Clinica Medica, Azienda Ospedaliera-Universitaria, Ferrara, ItalyBackground: Since available data are not univocal, the aim of this study was to explore the existence of a seasonal variation in platelet count. Methods: The study was based on the database of the Italian Association of Blood Volunteers (AVIS), section of Ferrara, Italy, 2001–2010. Hematological data (170,238 exams referring to 16,422 donors) were categorized into seasonal and monthly intervals, and conventional and chronobiological analyses were applied. Results: Platelets and plateletcrit were significantly higher in winter-autumn, with a main peak in December-February (average +3.4% and +4.6%, respectively, P <0.001 for both). Conclusions: Although seasonal variations have been reported for several acute cardiovascular diseases, it is extremely unlikely that such a slight increase in platelet count in winter alone may be considered as a risk factor.Biomedical [email protected]

I contributi alle imprese colpite dal sisma del 2012 in Emilia-Romagna: una base informativa per l'analisi e il monitoraggio della ricostruzione

In the project Energie Sisma Emilia (www.energie.unimore.it), the data on contributions paid for the reconstruction of economic activities damaged by the earthquake that hit Emilia in 2012 are an essential information for monitoring the reconstruction. This paper aims to describe the criteria to assign contributions for the restoration and reconstruction of the buildings (for industrial, agricultural and commercial) damaged by an earthquake. The data collected during the submission of applications for assistance, then processed by the head of the procedure for its payment, may allow to draw a clear picture of the reconstruction process by highlighting the specific sector and size of businesses affected, in the municipalities of the crater of the earthquake as well as of construction companies and professionals involved in the process of submitting applications for assistance and the implementation of the intervention. In the Emilia Romagna region, businesses companies affected by the earthquake were given access to four sources of contributions: (a) for the reconstruction of buildings, temporary relocation, restoration of machinery and equipment and compensation for damage to the inventory of raw materials, semi-finished and finished products; (b) funds made available by Inail (National Institute for insurance against accidents at work) for seismic retrofitting; (c) funds intended for productive investment for innovation and (d) to support the location in case of unavailability of local unit in which it was performed, the activity before the earthquake, (ERDF - POR Regione-Emilia Romagna). By systematizing data and information available to date, we share some preliminary information gathered by the research group Energy Sisma Emilia for the analysis of data on the reconstruction of business companies, which will start once the data will be made available in an appropriate manner by the Emilia-Romagna

Lipid profile of Xylella fastidiosa Subsp. pauca associated with the olive quick decline syndrome

Lipids, components of the plasma and intracellular membranes as well as of droplets, provide different biological functions related to energy, carbon storage, and stress responses. Bacterial species display diverse membrane composition that changes in response to the different environmental conditions. During plant-pathogen interactions, lipids might have roles in several aspects such as recognition, signal transduction, and downstream responses. Among lipid entities, free fatty acids (FFAs) and their oxidized form, the oxylipins, represent an important class of signaling molecules in host-pathogen perception, especially related to virulence and defense. In bacteria, FFAs (e.g., diffusible signaling factors) and oxylipins have a crucial role in modulating motility, biofilm formation, and virulence. In this study, we explore by LC-TOF and LC-MS/MS the lipid composition of Xylella fastidiosa subsp. pauca strain De Donno in pure culture; some specific lipids (e.g., ornithine lipids and the oxylipin 7,10-diHOME), characteristic of other pathogenic bacteria, were revealed. Nicotiana tabacum was used for testing the ability of this pathogen in producing such lipids in the host. Different lipid compounds present a clear distribution pattern within the infected plant tissues compared to the uninfected ones