7 research outputs found
The State Socialist Mortality Syndrome
Death rates for working-age men in European state socialist countries deviated from general improvements in survival observed in the rest of Europe during the 20th century. The magnitude of structural labor force changes across countries correlates with lagged increases in death rates for men in the working ages. This pattern is consistent with a hypothesis that hyper-development of heavy industry and stagnation (even contraction) of the service sector created anomic conditions leading to unhealthy lifestyles and self-destructive behavior among men moving from primary-sector to secondary-sector occupations. Occupational contrasts within countries similarly show concentration of rising male death rates among blue collar workers. Collapse of state socialist systems produced rapid corrections in labor force structure after 1990, again correlated with a fading of the state socialist mortality syndrome in following decades
NEMA NU4-2008 performance evaluation of Albira: a two-ring small-animal PET system using continuous LYSO crystals
Goals: This paper presents the performance review based on a dual-ring Positron Emission Tomography (PET) scanner being a part
of Bruker Albira: a multi-modal small-animal imaging platform. Each ring of Albira PET contains eight detectors arranged as
octagon, and each detector is built using a single continuous lutetium-yttrium oxyorthosilicate crystal and multi-anode photo
multiplier tube. In two-ring configuration, the scanner covers 94.4 mm in axial- and 80´80 mm in trans-axial direction, which is
sufficient to acquire images of small animals (e.g. mice) without the need of moving the animal bed during the scan.
Methods: All measurements and majority of data processing were performed according to the NEMA NU4-2008 standard with one
exception. Due to the scanner geometry, the spatial resolution test was reconstructed using iterative algorithm instead of the
analytical one. The main performance characteristics were compared with those of the other PET sub-systems of tri-modal smallanimal
scanners.
Results: The measured spatial resolution at the centre of the axial field of view in radial, tangential and axial directions was 1.72,
1.70 and 2.45 mm, respectively. The scatter fraction for the mouse-like phantom was 9.8% and for the rat-like phantom, 21.8%. The
maximum absolute sensitivity was 5.30%. Finally, the recovery co-efficients for 5, 4, 3, 2, 1 mm diameter rods in image quality
phantom were: 0.90, 0.77, 0.66, 0.30 and 0.05, respectively.
Conclusion: The Bruker Albira is a versatile small-animal multi-modal device that can be used for variety of studies. Overall the
PET sub-system provides a good spatial resolution coupled with better-than average sensitivity and the ability to produce good
quality animal images when administering low activities