Experimental study of vapor-cell magneto-optical traps for efficient trapping of radioactive atoms

We have studied magneto-optical traps (MOTs) for efficient on-line trapping of radioactive atoms. After discussing a model of the trapping process in a vapor cell and its efficiency, we present the results of detailed experimental studies on Rb MOTs. Three spherical cells of different sizes were used. These cells can be easily replaced, while keeping the rest of the apparatus unchanged: atomic sources, vacuum conditions, magnetic field gradients, sizes and power of the laser beams, detection system. By direct comparison, we find that the trapping efficiency only weakly depends on the MOT cell size. It is also found that the trapping efficiency of the MOT with the smallest cell, whose diameter is equal to the diameter of the trapping beams, is about 40% smaller than the efficiency of larger cells. Furthermore, we also demonstrate the importance of two factors: a long coated tube at the entrance of the MOT cell, used instead of a diaphragm; and the passivation with an alkali vapor of the coating on the cell walls, in order to minimize the losses of trappable atoms. These results guided us in the construction of an efficient large-diameter cell, which has been successfully employed for on-line trapping of Fr isotopes at INFN's national laboratories in Legnaro, Italy.Comment: 9 pages, 7 figures, submitted to Eur. Phys. J.

The Modal mu-Calculus and The Gödel-Löb Logic

We show that the modal µ-calculus over GL collapses to the modal fragment by showing that the fixpoint formula is reached after two iterations and answer to a question posed by van Benthem in [vBe06]. Further, we introduce the modal µ∼-calculus by allowing fixpoint constructors for any formula where the fixpoint variable appears guarded but not necessarily positive and show that this calculus over GL collapses to the modal fragment, too. The latter result allows us a new proof of the de Jongh, Sambin Theorem and provides a simple algorithm to construct the fixpoint formula

The Modal μ-Calculus Hierarchy on Restricted Classes of Transition Systems

We discuss the strictness of the modal µ-calculus hierarchy over some restricted classes of transition systems. First, we show that the hierarchy is strict over reflexive frames. By proving the finite model theorem for reflexive systems the same results holds for finite models. Second, we prove that over transitive systems the hierarchy collapses to the alternation-free fragment. In order to do this the finite model theorem for transitive transition systems is also proved. Further, we verify that if symmetry is added to transitivity the hierarchy collapses to the purely modal fragment

Nonresidential Fathers Parenting Their Children Residing in Shelters: A Phenomenological Study

This phenomenological qualitative study explored the parenting role of nonresidential fathers of children living in shelters. Special attention was paid to the perceived contributions of these fathers to the overall health and general well-being of their children residing in shelters. Often separations of nonresidential fathers from their children in shelters decreased their contributions to their children\u27s health and well-being. Increased knowledge of these parental roles and contributions can enhance programs and policies to support these fathers in improving the health and well-being of their children. In-depth semistructured interviews were conducted with 6 demographically diverse nonresidential fathers living in Philadelphia. The health-belief model, in conjunction with the revised health-belief model, was used as a theoretical framework for this study. The research questions were designed to explore nonresidential fathers\u27 parenting roles, perceptions of their contributions, and the facilitators of and barriers to their parenting while their children resided in shelters. An inductive approach to data analysis informed study findings of nonresidential fathers\u27 active participation and engagement in their children\u27s lives, including involvement in their healthcare and health promotion. Perceived facilitators to their parenting role included internal and external motivators, whereas perceived challenges and barriers to their parenting role were externally based. Finally, study findings showed these fathers to be present and making significant contributions to the improved health and overall well-being of their children while they resided in homeless shelters

A FORTRESS BETWEEN ARTIFICE AND NATURE: THE LASER SCANNING SURVEY OF THE CASTLE OF PESCOPAGANO AS AN INSTRUMENT OF KNOWLEDGE, CONSERVATION AND ENHANCEMENT

Abstract. The castle of Pescopagano, a small village located on the border between Basilicata and Campania, is a complex of great historical and landscape value, for the inseparable combination that binds its stones to the rock where it stands. Founded perhaps in the Byzantine times, but certainly renovated and built in its current forms between the 11th and 12th century, the castle had considerable military importance under Frederick II of Swabia. Seriously damaged by the earthquake of 1694, the fortress underwent a partial reconstruction, but ended up suffering further collapses caused by the Irpinia earthquake of 1980, such as to motivate the first interventions of securing and, above all, the application of the listing process. Today the castle is still largely in ruins and is only partially accessible thanks to a limited intervention on the paths. The present research aims at deepening the knowledge of the state of conservation, the damage mechanisms and the previous restoration interventions of the castle, in order to define possible strategies for its restoration and enhancement. The analysis work uses the most advanced laser scanning and drone detection systems, in order to document, as accurately as possible, the complex patrimonial system of the castle. Thanks to the combined use of these techniques, the objective is also to define methods that can be replicated in other contexts where the relationship between geomorphology and construction is so relevant that it jeopardizes the use of any other traditional survey system

Gaia DR2 view of the Lupus V-VI clouds: the candidate diskless young stellar objects are mainly background contaminants

Extensive surveys of star-forming regions with Spitzer have revealed populations of disk-bearing young stellar objects. These have provided crucial constraints, such as the timescale of dispersal of protoplanetary disks, obtained by carefully combining infrared data with spectroscopic or X-ray data. While observations in various regions agree with the general trend of decreasing disk fraction with age, the Lupus V and VI regions appeared to have been at odds, having an extremely low disk fraction. Here we show, using the recent Gaia data release 2 (DR2), that these extremely low disk fractions are actually due to a very high contamination by background giants. Out of the 83 candidate young stellar objects (YSOs) in these clouds observed by Gaia, only five have distances of 150 pc, similar to YSOs in the other Lupus clouds, and have similar proper motions to other members in this star-forming complex. Of these five targets, four have optically thick (Class II) disks. On the one hand, this result resolves the conundrum of the puzzling low disk fraction in these clouds, while, on the other hand, it further clarifies the need to confirm the Spitzer selected diskless population with other tracers, especially in regions at low galactic latitude like Lupus V and VI. The use of Gaia astrometry is now an independent and reliable way to further assess the membership of candidate YSOs in these, and potentially other, star-forming regions.Comment: Accepted for publication on Astronomy&Astrophysics Letter

Toward a personalized therapy in soft-tissue sarcomas: State of the art and future directions

Soft-tissue sarcomas are rare tumors characterized by pathogenetic, morphological, and clinical intrinsic variability. Median survival of patients with advanced tumors are usually chemo-and radio-resistant, and standard treatments yield low response rates and poor survival results. The identification of defined genomic alterations in sarcoma could represent the premise for targeted treatments. Summarizing, soft-tissue sarcomas can be differentiated into histotypes with reciprocal chromosomal translocations, with defined oncogenic mutations and complex karyotypes. If the latter are improbably approached with targeted treatments, many suggest that innovative therapies interfering with the identified fusion oncoproteins and altered pathways could be potentially resolu-tive. In most cases, the characteristic genetic signature is discouragingly defined as “undruggable”, which poses a challenge for the development of novel pharmacological approaches. In this review, a summary of genomic alterations recognized in most common soft-tissue sarcoma is reported together with current and future therapeutic opportunities