Atti del Workshop: Tecniche Speciali e Avanzate di Dosimetria e Radioprotezione

Atti del Workshop organizzato dall'Associazione Italiana di Radioprotezione (AIRP) in collaborazione con l'Università degli Studi di Palermo, dal titolo "Tecniche Speciali e Avanzate in Dosimetria e Radioprotezione" che si svolgerà venerdì 24 Giugno a Palermo presso l'Aula Magna del Dipartimento di Fisica e Chimica, Viale delle Scienze Edificio 18. L'evento rientra tra i 210 Eventi organizzati per i 210 anni dalla fondazione dell'Ateneo palermitano su iniziativa del Magnifico Rettore, Prof. Fabrizio Micari. L’evento prevede la discussione di 4 tematiche in ambito della dosimetria e della radioprotezione in campo sanitario ed ambientale (Dosimetria Clinica, Dosimetria Ambientale, Dosimetria Retrospettiva e Tecniche Dosimetriche avanzate in Radioprotezione) ciascuna delle quali ha una relazione generale ad invito e alcune brevi comunicazioni orali. Le sessioni sono moderate da Dirigenti Fisici medici di due delle più importanti Aziende Ospedaliere Siciliane, Dirigenti dell’Istituto Superiore di Sanità e l’ex Rettore dell’Ateneo e membro del CdA del CNR, il Prof. Roberto Lagalla. Interverranno il magnifico Rettore dell’Università di Palermo, l’Assessore alla Sanità della Regione Sicilia, il Direttore dell’Istituto Zooprofilattico Sperimentale di Sicilia, il Direttore Generale dell’Agenzia per la Protezione dell’Ambiente Sicilia, il Direttore del Dipartimento di Fisica e Chimica, il Direttore di ATeN Center (Advanced Technologies Network), Dirigenti Fisici dell’Istituto Superiore di Sanità e dell’Istituto Europeo Oncologico di Milano. Hanno contribuito alla parte organizzativa e scientifica Dirigenti dell’ARPA Sicilia, Dirigenti dell’ARNAS Civico di Palermo, Docenti dell’Università di Palermo e di Milano, Ricercatori del CNR e Specializzandi UniPa. Questo evento è di grande rilevanza nazionale in termini di divulgazione scientifica vista la presenza dei relatori e moderatori invitati che ne danno lustro e rilevanza. Sarà un'occasione di confronto e di analisi retrospettiva a quarant'anni della giornata di studio “Problemi e prospettive della Fisica Sanitaria nel settore medico” organizzata dalla Prof.ssa Maria Brai

Formation of Supermassive Black Holes

Evidence shows that massive black holes reside in most local galaxies. Studies have also established a number of relations between the MBH mass and properties of the host galaxy such as bulge mass and velocity dispersion. These results suggest that central MBHs, while much less massive than the host (~ 0.1%), are linked to the evolution of galactic structure. In hierarchical cosmologies, a single big galaxy today can be traced back to the stage when it was split up in hundreds of smaller components. Did MBH seeds form with the same efficiency in small proto-galaxies, or did their formation had to await the buildup of substantial galaxies with deeper potential wells? I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I will discuss black hole formation processes for `seed' black holes that are likely to place at early cosmic epochs, and possible observational tests of these scenarios.Comment: To appear in The Astronomy and Astrophysics Review. The final publication is available at http://www.springerlink.co

Prevalence of polycystic ovary syndrome in young women who had idiopathic central precocious puberty.

To assess the prevalence of polycystic ovary syndrome (PCOS) in a cohort of young women with previous idiopathic central precocious puberty (ICPP) at least 3 years after menarche, and to look for any predictive factors of PCOS at the time ICPP was diagnosed. DESIGN: Longitudinal study. PATIENT(S): Forty-six young women (18.1 +/- 3.0 years) who had been treated with GnRH analogues during childhood, observed at gynecologic age of 6.23 +/- 3.3 years. INTERVENTION(S): Semistructured interview concerning cycles, physical exam, blood sampling, and transabdominal pelvic ultrasound. MAIN OUTCOME MEASURE(S): Oligomenorrhea, LH, FSH, E(2), T, DHEAS, free T, delta4-androstenedione, 17-OHP, P, polycystic ovary morphology (PCOM). RESULT(S): Fifteen percent of the young women had oligomenorrhea, 28% clinical hyperandrogenism, 48% biochemical hyperandrogenism, and 37% PCOM. A total of 32% of the patients had PCOS according to the Rotterdam definition and 30% had PCOS according to the Androgen Exess Society. The prevalent phenotype of PCOS was characterized by clinical and/or biochemical hyperandrogenism and PCOM. We did not find any predictive factors for PCOS at the time ICPP was diagnosed. CONCLUSION(S): Patients with ICCP are prone to developing PCOS. The prominent phenotype in this cohort was PCOM associated with clinical and/or biochemical hyperandrogenism. Further follow-ups of these young adult patients will clarify whether this phenotype persists and if it will have important long-term implications regarding increased risk of infertility or metabolic complications

A Model for Emission from Jets in X-ray Binaries: Consequences of a Single Acceleration Episode

There are strong evidence for powerful jets in the low/hard state of black-hole X-ray binaries (BHXRBs). Here, we present a model in which electrons are accelerated once at the base of the jet, and are cooled by synchrotron emission and possible adiabatic energy losses. The accelerated electrons assume a Maxwellian distribution at low energies and possible energetic power law tail. These assumptions yield to a wealth of spectra, which we study in details. We identify critical values of the magnetic field, and five transition frequencies in the spectra. In particular, we show that: (I) the decay of the magnetic field along the jet enables, for wide jets, production of flat radio spectra without the need for electrons re-acceleration along the jet. (II) An increase of the magnetic field above a critical value of ~10^5 G leads to a sharp decrease in the flux at the radio band, while the flux at higher frequencies saturates to a constant value. (III) For strong magnetic field, the flux decays in the optical/UV band as F_nu ~ nu^{-1/2}, irrespective of the electrons initial distribution. (IV) For B_0 ~ 10^4 G, the X-ray flux gradually steepens. (V) With adiabatic energy losses, flat spectrum can be obtained only at a limited frequency range, and under certain conditions (VI) For narrow jets, r(x) ~ x^{alpha} with alpha < 1/2, flat radio spectrum cannot be obtained. We provide full description of the spectrum in the different scenarios, and show that our model is consistent with the key observed properties of BHXRBs.Comment: Slightly shortened; references added; accepted for publication in Ap

The association of financial difficulties with clinical outcomes in cancer patients: secondary analysis of 16 academic prospective clinical trials conducted in Italy

Background: Cancer may cause financial difficulties, but its impact in countries with public health systems is unknown. We evaluated the association of financial difficulties with clinical outcomes of cancer patients enrolled in academic clinical trials performed within the Italian public health system. Patients and methods: Data were pooled from 16 prospective multicentre trials in lung, breast or ovarian cancer, using the EORTC quality of life (QOL) C30 questionnaire. Question 28 scores financial difficulties related to disease or treatment in four categories from 'not at all' to 'very much'. We defined financial burden (FB) as any financial difficulty reported at baseline questionnaire, and financial toxicity (FT) as score worsening in a subsequent questionnaire. We investigated (i) the association of FB with clinical outcomes (survival, global QOL response [questions 29/30] and severe toxicity), and (ii) the association of FT with survival. Multivariable analyses were performed using logistic regression models or the Cox model adjusting for trial, gender, age, region and period of enrolment, baseline global QOL and, where appropriate, FB and global QOL response. Results are reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CI). Results: At baseline 26% of the 3670 study patients reported FB, significantly correlated with worse baseline global QOL. FB was not associated with risks of death (HR 0.94, 95% CI 0.85-1.04, P = 0.23) and severe toxicity (OR 0.90, 95% CI 0.76-1.06, P = 0.19) but was predictive of a higher chance of worse global QOL response (OR 1.35, 95% CI 1.08-1.70, P = 0.009). During treatment, 2735 (74.5%) patients filled in subsequent questionnaires and 616 (22.5%) developed FT that was significantly associated with an increased risk of death (HR 1.20, 95% CI 1.05-1.37, P = 0.007). Several sensitivity analyses confirmed these findings. Conclusion: Even in a public health system, financial difficulties are associated with relevant cancer patients outcomes like QOL and survival

Intergenerational and intrafamilial phenotypic variability in 22q11.2 deletion syndrome subjects

BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) is a common microdeletion syndrome, which occurs in approximately 1:4000 births. Familial autosomal dominant recurrence of the syndrome is detected in about 8-28% of the cases. Aim of this study is to evaluate the intergenerational and intrafamilial phenotypic variability in a cohort of familial cases carrying a 22q11.2 deletion. METHODS: Thirty-two 22q11.2DS subjects among 26 families were enrolled. RESULTS: Second generation subjects showed a significantly higher number of features than their transmitting parents (212 vs 129, P = 0.0015). Congenital heart defect, calcium-phosphorus metabolism abnormalities, developmental and speech delay were more represented in the second generation (P < 0.05). Ocular disorders were more frequent in the parent group. No significant difference was observed for the other clinical variables. Intrafamilial phenotypic heterogeneity was identified in the pedigrees. In 23/32 families, a higher number of features were found in individuals from the second generation and a more severe phenotype was observed in almost all of them, indicating the worsening of the phenotype over generations. Both genetic and epigenetic mechanisms may be involved in the phenotypic variability. CONCLUSIONS: Second generation subjects showed a more complex phenotype in comparison to those from the first generation. Both ascertainment bias related to patient selection or to the low rate of reproductive fitness of adults with a more severe phenotype, and several not well defined molecular mechanism, could explain intergenerational and intrafamilial phenotypic variability in this syndrome

Formation of regulatory modules by local sequence duplication

Turnover of regulatory sequence and function is an important part of molecular evolution. But what are the modes of sequence evolution leading to rapid formation and loss of regulatory sites? Here, we show that a large fraction of neighboring transcription factor binding sites in the fly genome have formed from a common sequence origin by local duplications. This mode of evolution is found to produce regulatory information: duplications can seed new sites in the neighborhood of existing sites. Duplicate seeds evolve subsequently by point mutations, often towards binding a different factor than their ancestral neighbor sites. These results are based on a statistical analysis of 346 cis-regulatory modules in the Drosophila melanogaster genome, and a comparison set of intergenic regulatory sequence in Saccharomyces cerevisiae. In fly regulatory modules, pairs of binding sites show significantly enhanced sequence similarity up to distances of about 50 bp. We analyze these data in terms of an evolutionary model with two distinct modes of site formation: (i) evolution from independent sequence origin and (ii) divergent evolution following duplication of a common ancestor sequence. Our results suggest that pervasive formation of binding sites by local sequence duplications distinguishes the complex regulatory architecture of higher eukaryotes from the simpler architecture of unicellular organisms