Linking the fate of massive black hole binaries to the active galactic nuclei luminosity function

Massive black hole binaries are naturally predicted in the context of the hierarchical model of structure formation. The binaries that manage to lose most of their angular momentum can coalesce to form a single remnant. In the last stages of this process, the holes undergo an extremely loud phase of gravitational wave emission, possibly detectable by current and future probes. The theoretical effort towards obtaining a coherent physical picture of the binary path down to coalescence is still underway. In this paper, for the first time, we take advantage of observational studies of active galactic nuclei evolution to constrain the efficiency of gas-driven binary decay. Under conservative assumptions we find that gas accretion toward the nuclear black holes can efficiently lead binaries of any mass forming at high redshift (> 2) to coalescence within the current time. The observed "downsizing" trend of the accreting black hole luminosity function further implies that the gas inflow is sufficient to drive light black holes down to coalescence, even if they bind in binaries at lower redshifts, down to z~0.5 for binaries of ~10 million solar masses, and z~0.2 for binaries of ~1 million solar masses. This has strong implications for the detection rates of coalescing black hole binaries of future space-based gravitational wave experiments.Comment: 6 pages, 3 figure, accepted for publication in MNRA

The ATLAS Tile Calorimeter Test Beam Monitoring Program

During 2003 test beam session for ATLAS Tile Calorimeter a monitoring program has been developed to ease the setup of correct running condition and the assessment of data quality. The program has been built using the Online Software services provided by the ATLAS Online Software group. The first part of this note contains a brief overview of these services followed by the full description of Tile Calorimeter monitoring program architecture and features. Performances and future upgrades are discussed in the final part of this note.Comment: 11 pages, 8 figures, ATLAS TILECAL Not

Extending Geant4 Parallelism with External Libraries (MPI, TBB) and Its Use on HPC Resources

With Geant4 Version 10.0, released in December 2013, one of the most widely used Monte-Carlo codes has been ported to take full advantage of multi- and many-core CPUs thanks to the introduction of event-level parallelism via multithreading. In this paper we review recent developments to allow for a better integration of parallel Geant4 jobs with external libraries. We have chosen to develop examples using the popular Intel Threading Building Block (for short TBB) as an alternative parallelization approach to the native Geant4 POSIX. To simplify the scaling of a Geant4 application across nodes on a cluster we are improving the support of MPI in Geant4. In particular it is now possible to run an hybrid MPI/MT application that uses MPI to scale across nodes and MT to scale across cores. %The recent developments allow users to easily implement parallel application resources that scale on a very large number of nodes and cores typical of HPC resources.Comment: conferenc

Multi-threaded Geant4 on the Xeon-Phi with Complex High-Energy Physics Geometry

To study the performance of multi-threaded Geant4 for high-energy physics experiments, an application has been developed which generalizes and extends previous work. A highly-complex detector geometry is used for benchmarking on an Intel Xeon Phi coprocessor. In addition, an implementation of parallel I/O based on Intel SCIF and ROOT technologies is incorporated and studied

Top Quark Mass determination at the ATLAS experiment using early data

The ATLAS experiment will start taking data at the end of 2007. During the very first data taking period it will be possible to make a preliminary measurement of the top quark mass in the semileptonic decay channel of ttbar events. A possible strategy to perform this measurement is presented with particular interest in the role of jet energy scale: a jet calibration algorithm is developed and results are discussed. A detailed discussion of test beam data is also presented together with comparisons of Monte Carlo predicions

Self-assembling reduced graphene oxide and TiO2-based materials for solar photocatalytic wastewater treatment

In this study, we employed a simple and eco-friendly method to prepare self-assembling self-standing membranes of: i) graphene oxide (GO), ii) reduced GO (rGO), iii) rGO and TiO2 (rGO-TiO2). We tested the three membranes for adsorption and solar photodegradation of Imidacloprid in water, obtaining evidence of a remarkable solar photocatalytic activity of rGO. To the best of our knowledge, no other photocatalytic rGO self-standing membranes have been reported yet

Self-standing membranes of reduced graphene oxide, TiO2 and waste-derived TiO2 for water treatment through adsorption and photocatalysis

As stated in United Nations SDG 6, improvement of wastewater treatment and reuse is an urgent necessity. In this context, titanium dioxide (TiO2) and reduced graphene oxide (rGO) deserve a particular attention. The former is a well-known photocatalytic material, the latter shows a significant capture ability toward metal ions and organic molecules. Compared to pure TiO2, rGO-TiO2 composites are proved to have a reduced bandgap, which allows to exploit lower-energy photons for photocatalysis. In this work, we developed composite self-assembling membranes of rGO and TiO2. Our purpose is to obtain a self-standing material having the double functionality of adsorbent and photocatalyst, able to decontaminate wastewater from both inorganic and organic pollutants. To the best of our knowledge, no other self-standing membranes of rGO and TiO2 have been reported in literature yet. Fulfilling a circular economy approach, we also investigated the replacement of TiO2 with tionite (TIO), a waste-derived TiO2-containing material. Composite rGO-TiO2 and rGO-TIO membranes, with 2:1, 1:1 or 1:2 mass ratio, were simply prepared by mixing of an rGO aqueous suspension with commercial TiO2 nanopowder or tionite, followed by vacuum filtration and mild drying. The resulting self-assembling membranes were extensively characterized through XRD, SEMEDX, thermogravimetry, Raman and UV-Vis spectroscopy. Their water remediation properties were evaluated toward contaminants of different nature. Membranes were employed as filters for aqueous solutions of Fe3+ and Cu2+, representative of heavy metals contaminated wastewater. Then, membranes were tested for adsorption and photodegradation of organic molecules, namely the pesticide Imidacloprid, the dye methylene blue and the analgesic drug paracetamol. Experiments were carried out in dynamic and static conditions for 5 h, irradiating the membranes with UV-A, visible and simulated solar light. All the membranes exhibited a significant adsorption capacity (75%) toward the three molecules. In addition, composite membranes were responsible for pollutants photodegradation. Despite being limited (between 10% and 20%), the photocatalytic activity of these membranes is notable, considering the small amount of TiO2 and TIO contained. Moreover, the anatase content of tionite is as low as 1/6 of the one of commercial TiO2

Primary familial brain calcification: update on molecular genetics

Primary familial brain calcification is a neuropsychiatric disorder with calcium deposits in the brain, especially in basal ganglia, cerebellum and subcortical white matter. The disease is characterized by a clinical heterogeneity, with a various combination of symptoms that include movement disorders and psychiatric disturbances; asymptomatic patients have been also reported. To date, three causative genes have been found: SLC20A2, PDGFRB and PDGFB. SLC20A2 gene codes for the 'sodium-dependent phosphate transporter 2' (PiT-2), a cell membrane transporters of inorganic phosphate, involved in Pi uptake by cells and maintenance of Pi body levels. Over 40 pathogenic variants of SLC20A2 have been reported, affecting the regulation of Pi homeostasis. It was hypothesized that SLC20A2 mutations cause brain calcification most likely through haploinsufficiency. PDGFRB encodes for the platelet-derived growth factor receptor-β (PDGFRβ), a cell-surface tyrosine-kinase (RTK) receptor that regulates cell proliferation, migration, survival and differentiation. PDGFB encodes for the 'platelet-derived growth factor beta' (PDGFβ), the ligand of PDGFRβ. The loss of function of PDGFRβ and PDGFβ could lead to the impairment of the pericytes function and blood brain barrier integrity, causing vascular and perivascular calcium accumulation. SLC20A2 accounts for about 40 % of familial form and 14 % of sporadic cases, while PDGFRB and PDGFB mutations are likely rare. However, approximately 50 % of patients are not genetically defined and there should be at least another causative gene

Explorations of the viability of ARM and Xeon Phi for physics processing

We report on our investigations into the viability of the ARM processor and the Intel Xeon Phi co-processor for scientific computing. We describe our experience porting software to these processors and running benchmarks using real physics applications to explore the potential of these processors for production physics processing.Comment: Submitted to proceedings of the 20th International Conference on Computing in High Energy and Nuclear Physics (CHEP13), Amsterda

Health monitoring program for the control of laboratory animal diseases

Pathogens present in the environment are the biggest source of diseases and epidemics in the breeding of laboratory animals. In fact, the presence of microorganisms can critically influence the animal health status and, consequently, the validity and reproducibility of experimental data. In accordance with the 3Rs principle (Refinement, Reduction, Replacement), this study is part of the Refinement concept. The FELASA guidelines, formulated with the aim of guaranteeing the best animal health state, are a valid support for researchers. In this preliminary study, health-monitoring program was carried out within the breeding of laboratory animals in IZSLER facility. The main murine viruses were analyzed through molecular biology techniques (PCR, RT-PCR) and enzyme immunoassays (indirect ELISA). The established surveillance program steadily guarantees animal health and ensures the most controlled environmental and sanitary conditions. Further investigations will be needed to develop virus control strategies