System test approach for the SAX satellite

SAX satellite verification is based on a protoflight approach, in which only one system model is realized at flight standard level, taking into account the utilization of hardware already qualified for other space programs and the necessity to respect the schedule constraints for a scientific objective. In any case, this approach was tailored with some deviations in order to reduce risks inherent in such a choice. The protoflight approach was also pursued at subsystem/unit level in particular for those subsystems and units considered critical from the schedule point of view. Payload Instruments followed the same approach but complete spare units were developed to reduce the risks associated with such an approach. A description of the model philosophy is provided and then, at satellite level, the testing approach and rationale for each model is presented. Finally, a brief description of each test will be given, highlighting objectives, methodologies, and test configurations. Moreover, for the major tests, problems encountered and solutions applied in establishing a correct approach are described

Screening and Genetic Diagnosis of Hemoglobinopathies in Southern and Northern Europe: Two Examples

Prevention of Hemoglobinopathies has developed around the world based upon the experience done in pioneering endemic countries and is now facing a new phase in non-endemic areas with a recent immigration history. We describe two situations, taking Latium (central Italy) and The Netherlands as two models for endemic and non-endemic countries both confronted with a large multi-ethnic immigrant society. We present prevention results and discuss aspects such as local knowledge and organization. We illustrate the importance of issues like information, carrier diagnostics, screening, counseling and prenatal diagnosis in particular situation of contrasting interest an different ethical opinions. We conclude by underlining the importance of implementing primary prevention at the European level, based upon better information, diagnostics and counseling

Small-angle neutron scattering of percolative perfluoropolyether water-in-oil microemulsions

A water in oil microemulsion system composed of water, surfactant, and oil, the latter two components of perfluoropolyether (PFPE) type, has been studied by small-angle neutron scattering (SANS) with the aim of knowing the microstructure of the system and to have an insight on the connection between microstructure characterization and percolation behavior. In fact, along the dilution line W/S = 11 of the phase diagram, dielectric spectroscopy and conductivity studies revealed a dynamic percolation process taking place approaching and above the dynamic percolation threshold, leading to a system composed of droplet clusters with percolation thresholds varying with temperature from a 0.501 volume fraction of the dispersed phase at 9.3 °C to 0.205 at 32.5 °C. The SANS experimental spectra of this work have been studied by modeling the microemulsion droplets as adhesive hard spheres. For all of the samples, the surfactant area per polar head has been also measured in the Porod region of the SANS spectra. Geometric and potential parameters as well as the osmotic pressure, the second virial coefficient, and the distance between droplets have been extracted from data as a function of droplets concentration. At low concentration, that is, below percolation thresholds, the droplets behave as hard spheres, whereas at threshold and above, adhesion changes significantly the samples. In fact, for each temperature, the measured size increases versus concentration from 30 to 50 Å, and the area per polar head decreases correspondingly, suggesting that a process of dynamic fusion of droplets occurs in the system above threshold, that is, couples of droplets stick and unstick continuously with interdigitation of the surfactant tails.The EC for support via the ”Human Capital and Mobility - Access to Large Scale Facilities” Program, Contract ERB CHGECT920001, and the Italian MIUR, PRIN 2005, INFM, and CSGI for financial support.Peer reviewe

Gender differences and aging: Effects on the human heart

Objectives.This study investigated the changes in myocyte size and number in the left and right ventricles that occur with aging in the female and male heart.Background.Differences in life span between women and men may be related to a better preservation of myocardial structure in the female heart with aging. On this basis, the hypothesis was advanced that the aging process has a different impact on the integrity of the myocardium in the two genders.Methods.Morphometric methodologies were applied to analyze the changes in number and size of ventricular myocytes in the hearts of 53 women and 53 men. The changes in mononucleated and binucleated myocytes with age were determined in enzymatically dissociated cells. The age interval examined varied from 17 to 95 years.Results.Aging was associated with a preservation of ventricular myocardial mass, aggregate number of mononucleated and binucleated myocytes, average cell diameter and volume in the female heart. In contrast, nearly 1 g/year of myocardium was lost in the male heart, and this phenomenon accounted for the loss of ∼64 million cells. This detrimental effect involved the left and right sides of the heart. In the remaining cells, myocyte cell volume increased at a rate of 158 μm3/year in the left and 167 μm3/year in the right ventricle.Conclusions.Aging does not lead to myocyte cell loss and myocyte cellular reactive hypertrophy in women, indicating that gender differences may play a significant role in the detrimental effects of the aging process on the heart