Roma Tre University

About: Roma Tre University is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 4434 authors who have published 15352 publications receiving 374888 citations. The organization is also known as: Universita degli Studi Roma Tre & RomaTre.

Search for dark matter in events with heavy quarks and missing transverse momentum in $pp$ collisions with the ATLAS detector

Abstract: This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb−1 of pp collisions collected at s√=8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing b-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter--nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter.

Child nutrition in Mozambique in 2003: the role of mother's schooling and nutrition knowledge.

Abstract: This paper is a study of the determinants of the anthropometric status of preschool children in Mozambique. Using the 2003 Demographic and Health Survey, we provide insights into two main explanatory factors: the mother's schooling and the mother's nutrition knowledge. Rather than treating the mother's schooling as a black box, we analyze its interaction with the mother's nutrition knowledge and household wealth in order to elucidate the mechanisms underlying their ultimate effect on child height. The estimates obtained through instrumental variable regression show that the direct effect of the mother's schooling is large but that the rate at which it increases declines as her educational level rises. Primary education seems to be a key to enhance the mothers’ general knowledge, which then improves the allocation of resources in regard to children's well-being and the care for the child. A higher educational level attained by the mother is likely to play only a minimal and indirect role in her child's nutrition, by expanding her economic opportunities. This is because more educated mothers have also more qualified and time-consuming jobs, which reduces the time spent for childcare. Mothers with higher levels of nutrition knowledge, acquired primarily outside of school, are able to choose a more diversified diet for their children and, broadly speaking, to utilize food more effectively. Based on a second technique, the instrumental variable quantile regression, we are able to draw a double conclusion: that mothers’ nutrition knowledge contributes to height increases among extremely deprived children, and that mothers’ formal education and household wealth are slightly more important for relatively well-off children.

Antimicrobial Activity of Gallium Compounds on ESKAPE Pathogens

Abstract: ESKAPE bacteria are a major cause of multidrug-resistant infections, and new drugs are urgently needed to combat these pathogens. Given the importance of iron in bacterial physiology and pathogenicity, iron uptake and metabolism have become attractive targets for the development of new antibacterial drugs. In this scenario, the FDA-approved iron mimetic metal Gallium [Ga(III)] has been successfully repurposed as an antimicrobial drug. Ga(III) disrupts ferric iron-dependent metabolic pathways, thereby inhibiting microbial growth. This work provides the first comparative assessment of the antibacterial activity of Ga(NO3)3 (GaN), Ga(III)-maltolate (GaM), and Ga(III)-protoporphyrin IX (GaPPIX), belonging to the first-, second- and third-generation of Ga(III) formulations, respectively, on ESKAPE species, including reference strains and multidrug-resistant (MDR) clinical isolates. In addition to the standard culture medium Mueller Hinton broth (MHB), iron-depleted MHB (DMHB) and RPMI-1640 supplemented with 10% human serum (HS) (RPMI-HS) were also included in Ga(III)-susceptibility tests, because of their different nutrient and iron contents. All ESKAPE species were resistant to all Ga(III) compounds in MHB and DMHB (MIC > 32 μM), except Staphylococcus aureus and Acinetobacter baumannii, which were susceptible to GaPPIX. Conversely, the antibacterial activity of GaN and GaM was very evident in RPMI-HS, in which the low iron content and the presence of HS better mimic the in vivo environment. In RPMI-HS about 50% of the strains were sensitive (MIC < 32) to GaN and GaM, both compounds showing a similar spectrum of activity, although GaM was more effective than GaN. In contrast, GaPPIX lost its antibacterial activity in RPMI-HS likely due to the presence of albumin, which binds GaPPIX and counteracts its inhibitory effect. We also demonstrated that the presence of multiple heme-uptake systems strongly influences GaPPIX susceptibility in A. baumannii. Interestingly, GaN and GaM showed only a bacteriostatic effect, whereas GaPPIX exerted a bactericidal activity on susceptible strains. Altogether, our findings raise hope for the future development of Ga(III)-based compounds in the treatment of infections caused by multidrug-resistant ESKAPE pathogens.

Robust digital watermarking in the ridgelet domain

Abstract: In this letter, we propose a multiplicative watermarking method operating in the ridgelet domain. We employ the directional sensitivity and the anisotropy of the ridgelet transform (RT) in order to obtain a sparse image representation, where the most significant coefficients represent the most energetic direction of an image with straight edges. Therefore, given a natural image, the associated edge image is obtained by means of a filter bank designed using the circular harmonic functions, then the edge image is partitioned into small blocks in order to deal with straight edges. Finally, the RT is performed for each block, the most relevant coefficients are selected, and eventually the watermark is embedded. Robustness and transparency are proven by experimental results.

Effect of penguin operators in the B0 --> J/psiK0 CP asymmetry.

Abstract: Performing a fit to the available experimental data, we quantify the effect of long-distance contributions from penguin contractions in ${B}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{0}$ decays. We estimate the deviation of the measured ${\mathcal{S}}_{CP}$ term of the time-dependent $CP$ asymmetry from $\mathrm{sin} 2\ensuremath{\beta}$ induced by these contributions and by the penguin operators. We find $\ensuremath{\Delta}\mathcal{S}\ensuremath{\equiv}{\mathcal{S}}_{CP}(J/\ensuremath{\psi}K)\ensuremath{-}\mathrm{sin} 2\ensuremath{\beta}=0.000\ifmmode\pm\else\textpm\fi{}0.012$ ($[\ensuremath{-}0.025,0.024]@95%$ probability), an uncertainty much larger than previous estimates and comparable to the present systematic error quoted by the experiments at the $B$ factories.