CMB Polarization Systematics, Cosmological Birefringence and the Gravitational Waves Background

Cosmic Microwave Background experiments must achieve very accurate calibration of their polarization reference frame to avoid biasing the cosmological parameters. In particular, a wrong or inaccurate calibration might mimic the presence of a gravitational wave background, or a signal from cosmological birefringence, a phenomenon characteristic of several non-standard, symmetry breaking theories of electrodynamics that allow for \textit{in vacuo} rotation if the polarization direction of the photon. Noteworthly, several authors have claimed that the BOOMERanG 2003 (B2K) published polarized power spectra of the CMB may hint at cosmological birefringence. Such analyses, however, do not take into account the reported calibration uncertainties of the BOOMERanG focal plane. We develop a formalism to include this effect and apply it to the BOOMERanG dataset, finding a cosmological rotation angle $\alpha=-4.3^\circ\pm4.1^\circ$. We also investigate the expected performances of future space borne experiment, finding that an overall miscalibration larger then $1^\circ$ for Planck and $0.2\circ$ for EPIC, if not properly taken into account, will produce a bias on the constraints on the cosmological parameters and could misleadingly suggest the presence of a GW background.Comment: 10 pages, 3 figure

Hybrid Treatment of Acute Abdominal Aortic Thrombosis Presenting with Paraplegia

Acute thrombotic or embolic occlusion of the abdominal aorta is a rare vascular emergency associated with high morbidity and mortality rates. Classically, the clinical presentation is a severe peripheral ischemia with bilateral leg pain as the predominant feature. Aortic occlusion presenting as an isolated acute onset of paraplegia due to spinal cord ischemia is very rare and requires improved awareness to prevent adverse outcomes associated with delayed diagnosis. We report the case of a 54-year-old man who presented with sudden paraplegia due to the thrombotic occlusion of the infrarenal aorta involving the first segment of the common iliac arteries on both sides; emergent transperitoneal aorto iliac thrombectomy combined with the endovascular iliac kissing-stent technique were performed achieving perioperative complete regression of the symptoms

Images of the Early Universe from the BOOMERanG experiment

The CMB is the fundamental tool to study the properties of the early universe and of the universe at large scales. In the framework of the Hot Big Bang model, when we look to the CMB we look back in time to the end of the plasma era, at a redshift ~ 1000, when the universe was ~ 50000 times younger, ~ 1000 times hotter and ~ 10^9 times denser than today. The image of the CMB can be used to study the physical processes there, to infer what happened before, and also to study the background geometry of our Universe

ℓ-space spectroscopy of the Cosmic Microwave Background with the BOOMERanG experiment

The BOOMERanG experiment has recently produced detailed maps of the Cosmic Microwave Background, where sub-horizon structures are resolved with good signal to noise ratio. A power spectrum (spherical harmonics) analysis of the maps detects three peaks, at multipoles ℓ = (213_(-13)^(+10)),(541_(-32)^(+20))(845_(-25)^(+12)). In this paper we discuss the data analysis and the implications of these results for cosmology

Current drive at plasma densities required for thermonuclear reactors

Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors

Corrigendum: Current drive at plasma densities required for thermonuclear reactors

Nature Communications 1: Article number: 55 (2010); Published: 10 August 2010; Updated:19 September 2013. In Fig. 3 of this Article, the colours of the blue and green curves were accidentally interchanged while the manuscript was being revised. In addition, the x axis labels on Fig. 4 should have read 'Frequency (MHz)'

The SIFIPAC/WSES/SICG/SIMEU guidelines for diagnosis and treatment of acute appendicitis in the elderly (2019 edition).

The epidemiology and the outcomes of acute appendicitis in elderly patients are very different from the younger population. Elderly patients with acute appendicitis showed higher mortality, higher perforation rate, lower diagnostic accuracy, longer delay from symptoms onset and admission, higher postoperative complication rate and higher risk of colonic and appendiceal cancer. The aim of the present work was to investigate age-related factors that could influence a different approach, compared to the 2016 WSES Jerusalem guidelines on general population, in terms of diagnosis and management of elderly patient with acute appendicitis. During the XXIX National Congress of the Italian Society of Surgical Pathophysiology (SIFIPAC) held in Cesena (Italy) in May 2019, in collaboration with the Italian Society of Geriatric Surgery (SICG), the World Society of Emergency Surgery (WSES) and the Italian Society of Emergency Medicine (SIMEU), a panel of experts participated to a Consensus Conference where eight panelists presented a number of statements, which were developed for each of the four topics about diagnosis and management of acute appendicitis in elderly patients, formulated according to the GRADE system. The statements were then voted, eventually modified and finally approved by the participants to the Consensus Conference. The current paper is reporting the definitive guidelines statements on each of the following topics: diagnosis, non-operative management, operative management and antibiotic therapy

The SIFIPAC/WSES/SICG/SIMEU guidelines for diagnosis and treatment of acute appendicitis in the elderly (2019 edition).

The epidemiology and the outcomes of acute appendicitis in elderly patients are very different from the younger population. Elderly patients with acute appendicitis showed higher mortality, higher perforation rate, lower diagnostic accuracy, longer delay from symptoms onset and admission, higher postoperative complication rate and higher risk of colonic and appendiceal cancer. The aim of the present work was to investigate age-related factors that could influence a different approach, compared to the 2016 WSES Jerusalem guidelines on general population, in terms of diagnosis and management of elderly patient with acute appendicitis. During the XXIX National Congress of the Italian Society of Surgical Pathophysiology (SIFIPAC) held in Cesena (Italy) in May 2019, in collaboration with the Italian Society of Geriatric Surgery (SICG), the World Society of Emergency Surgery (WSES) and the Italian Society of Emergency Medicine (SIMEU), a panel of experts participated to a Consensus Conference where eight panelists presented a number of statements, which were developed for each of the four topics about diagnosis and management of acute appendicitis in elderly patients, formulated according to the GRADE system. The statements were then voted, eventually modified and finally approved by the participants to the Consensus Conference. The current paper is reporting the definitive guidelines statements on each of the following topics: diagnosis, non-operative management, operative management and antibiotic therapy