The Planck-LFI flight model composite waveguides

The Low Frequency Instrument on board the PLANCK satellite is designed to give the most accurate map ever of the CMB anisotropy of the whole sky over a broad frequency band spanning 27 to 77 GHz. It is made of an array of 22 pseudo-correlation radiometers, composed of 11 actively cooled (20 K) Front End Modules (FEMs), and 11 Back End Modules (BEMs) at 300K. The connection between the two parts is made with rectangular Wave Guides. Considerations of different nature (thermal, electromagnetic and mechanical), imposed stringent requirements on the WGs characteristics and drove their design. From the thermal point of view, the WG should guarantee good insulation between the FEM and the BEM sections to avoid overloading the cryocooler. On the other hand it is essential that the signals do not undergo excessive attenuation through the WG. Finally, given the different positions of the FEM modules behind the focal surface and the mechanical constraints given by the surrounding structures, different mechanical designs were necessary. A composite configuration of Stainless Steel and Copper was selected to satisfy all the requirements. Given the complex shape and the considerable length (about 1.5-2 m), manufacturing and testing the WGs was a challenge. This work deals with the development of the LFI WGs, including the choice of the final configuration and of the fabrication process. It also describes the testing procedure adopted to fully characterize these components from the electromagnetic point of view and the space qualification process they underwent. Results obtained during the test campaign are reported and compared with the stringent requirements. The performance of the LFI WGs is in line with requirements, and the WGs were successfully space qualified.Comment: this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jins

Off-line radiometric analysis of Planck/LFI data

The Planck Low Frequency Instrument (LFI) is an array of 22 pseudo-correlation radiometers on-board the Planck satellite to measure temperature and polarization anisotropies in the Cosmic Microwave Background (CMB) in three frequency bands (30, 44 and 70 GHz). To calibrate and verify the performances of the LFI, a software suite named LIFE has been developed. Its aims are to provide a common platform to use for analyzing the results of the tests performed on the single components of the instrument (RCAs, Radiometric Chain Assemblies) and on the integrated Radiometric Array Assembly (RAA). Moreover, its analysis tools are designed to be used during the flight as well to produce periodic reports on the status of the instrument. The LIFE suite has been developed using a multi-layered, cross-platform approach. It implements a number of analysis modules written in RSI IDL, each accessing the data through a portable and heavily optimized library of functions written in C and C++. One of the most important features of LIFE is its ability to run the same data analysis codes both using ground test data and real flight data as input. The LIFE software suite has been successfully used during the RCA/RAA tests and the Planck Integrated System Tests. Moreover, the software has also passed the verification for its in-flight use during the System Operations Verification Tests, held in October 2008.Comment: Planck LFI technical papers published by JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/1748-022

Stroke care in Central Eastern Europe: current problems and call for action.

Stroke is a major medical problem and one of the leading causes of mortality and disability all over in Europe. However, there are significant East-West differences in stroke care as well as in stroke mortality and morbidity rates. Central and Eastern European countries that formerly had centralized and socialist health care systems have serious and similar problems in organizing health and stroke care 20 years after the political transition. In Central and Eastern Europe, stroke is more frequent, the mortality rate is higher, and the victims are younger than in Western Europe. High-risk patients live in worse environmental conditions, and the socioeconomic consequences of stroke further weaken the economic development of these countries. To address these issues, a round table conference was organized. The main aim of this conference was to discuss problems to be solved related to acute and chronic stroke care in Central and Eastern European countries, and also, to exchange ideas on possible solutions. In this article, the discussed problems and possible solutions will be summarized, and introduce 'The Budapest Statement of Stroke Experts of Central and Eastern European countries'

PREAMI: Perindopril and remodelling in elderly with acute myocardial infarction: Study rationale and design

Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, the development of remodeling, left ventricular (LV) dysfunction, and ischemic events, both when administered alone as long-term treatment in patients with impaired LV function and/or heart failure (HF) and as short-term treatment, early after acute myocardial infarction (AMI) and/or HF. The few data available on the use of ACE inhibitors in the elderly after AMI are conflicting. Nothing is known about the effects of ACE inhibitors in elderly postinfarction patients with preserved LV function: these patients have a remarkable medium- to long-term mortality and HF incidence after infarction. The aim of this study is to evaluate, in patients with AMI aged ≥65 years, the effects of Perindopril on the combined outcome of death, hospitalization for HF, and heart remodeling, considered to be a ≥8% increase in LV end-diastolic volume (LVEDV). Secondary objectives include the same factors listed in the primary end points hut considered separately. In addition, safety of the drug, ventricular remodeling, and adaptation are being evaluated. A total of 1100 patients with AMI (first episode or reinfarction), aged ≥65 years, and preserved or only moderately depressed LV (LV ejection fraction ≥40%), are to he enrolled and randomly assigned to treatment (8 mg for 12 months of Perindopril or placebo, in double-blind conditions). Clinical assessment is performed at fixed times, and periodic evaluations of (1) ventricular shape, dimensions, and function by quantitative 2-D echocardiography, and (2) heart rate variability and arrhythmias by ambulatory electrocardiographic monitoring are anticipated. The results and conclusions will be available by 2002 year