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result(s) for
"Costa, Marco"
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The last complex WIMPs standing
by
Costa, Marco
,
Panci, Paolo
,
Franceschini, Roberto
in
Dark matter
,
Electroweak model
,
Experiments
2022
We continue the study of weakly interacting massive particles (WIMP) started in Bottaro et al. (Eur Phys J C 82:31, 2022), focusing on a single complex electroweak n-plet with non-zero hypercharge added to the Standard Model. The minimal splitting between the Dark Matter and its electroweak neutral partner required to circumvent direct detection constraints allows only multiplets with hypercharge smaller or equal to 1. We compute for the first time all the calculable WIMP masses up to the largest multiplet allowed by perturbative unitarity. For the minimal allowed splitting, most of these multiplets can be fully probed at future large-exposure direct detection experiments, with the notable exception of the doublet with hypercharge 1/2. We show how a future muon collider can fully explore the parameter space of the complex doublet combining missing mass, displaced track and long-lived track searches. In the same spirit, we study how a future muon collider can probe the parameter space of complex WIMPs in regions where the direct detection cross section drops below the neutrino floor. Finally, we comment on how precision observables can provide additional constraints on complex WIMPs.
Journal Article
Closing the window on WIMP Dark Matter
2022
We study scenarios where Dark Matter is a weakly interacting particle (WIMP) embedded in an ElectroWeak multiplet. In particular, we consider real SU(2) representations with zero hypercharge, that automatically avoid direct detection constraints from tree-level Z-exchange. We compute for the first time all the calculable thermal masses for scalar and fermionic WIMPs, including Sommerfeld enhancement and bound states formation at leading order in gauge boson exchange and emission. WIMP masses of few hundred TeV are shown to be compatible both with s-wave unitarity of the annihilation cross-section, and perturbativity. We also provide theory uncertainties on the masses for all multiplets, which are shown to be significant for large SU(2) multiplets. We then outline a strategy to probe these scenarios at future experiments. Electroweak 3-plets and 5-plets have masses up to about 16 TeV and can efficiently be probed at a high energy muon collider. We study various experimental signatures, such as single and double gauge boson emission with missing energy, and disappearing tracks, and determine the collider energy and luminosity required to probe the thermal Dark Matter masses. Larger multiplets are out of reach of any realistic future collider, but can be tested in future γ-ray telescopes and possibly in large-exposure liquid Xenon experiments.
Journal Article
Asymmetric accidental composite dark matter
by
Costa, Marco
,
Popov, Oleg
,
Bottaro, Salvatore
in
Asymmetry
,
Beyond Standard Model
,
Classical and Quantum Gravitation
2021
A
bstract
The goal of this work is to find the simplest UV completion of Accidental Composite Dark Matter Models (ACDM) that can dynamically generate an asymmetry for the DM candidate, the lightest
dark baryon
(DCb), and simultaneously annihilate the symmetric component. In this framework the DCb is a bound state of a confining SU(
N
)
DC
gauge group, and can interact weakly with the visible sector. The constituents of the DCb can possess non-trivial charges under the Standard Model gauge group. The generation of asymmetry for such candidate is a two-flavor variation of the
out-of-equilibrium
decay of a heavy scalar, with mass
M
ϕ
≳ 10
10
GeV. Below the scale of the scalars, the models recover accidental stability, or long-livedness, of the DM candidate. The symmetric component is annihilated by residual confined interactions provided that the mass of the DCb
m
DCb
≲ 75 TeV. We implement the mechanism of asymmetry generation, or a variation of it, in all the original ACDM models, managing to generate the correct asymmetry for DCb of masses in this range. For some of the models found, the stability of the DM candidate is not spoiled even considering generic GUT completions or asymmetry generation mechanisms in the visible sector.
Journal Article
Artificial Intelligence in Lung Cancer Screening: The Future Is Now
2023
Lung cancer has one of the worst morbidity and fatality rates of any malignant tumour. Most lung cancers are discovered in the middle and late stages of the disease, when treatment choices are limited, and patients’ survival rate is low. The aim of lung cancer screening is the identification of lung malignancies in the early stage of the disease, when more options for effective treatments are available, to improve the patients’ outcomes. The desire to improve the efficacy and efficiency of clinical care continues to drive multiple innovations into practice for better patient management, and in this context, artificial intelligence (AI) plays a key role. AI may have a role in each process of the lung cancer screening workflow. First, in the acquisition of low-dose computed tomography for screening programs, AI-based reconstruction allows a further dose reduction, while still maintaining an optimal image quality. AI can help the personalization of screening programs through risk stratification based on the collection and analysis of a huge amount of imaging and clinical data. A computer-aided detection (CAD) system provides automatic detection of potential lung nodules with high sensitivity, working as a concurrent or second reader and reducing the time needed for image interpretation. Once a nodule has been detected, it should be characterized as benign or malignant. Two AI-based approaches are available to perform this task: the first one is represented by automatic segmentation with a consequent assessment of the lesion size, volume, and densitometric features; the second consists of segmentation first, followed by radiomic features extraction to characterize the whole abnormalities providing the so-called “virtual biopsy”. This narrative review aims to provide an overview of all possible AI applications in lung cancer screening.
Journal Article
The roles of barriers, refugia, and chromosomal clines underlying diversification in Atlantic Forest social wasps
by
Carvalho, Antônio F.
,
Brady, Seán G.
,
Del Lama, Marco A.
in
631/158/2452
,
631/158/852
,
631/181/2474
2017
Phylogeographic studies have sought to explain the genetic imprints of historical climatic changes and geographic barriers within the Brazilian Atlantic Forest (AF) biota, and consequently two processes of diversification (refugia and barriers) have been proposed. Additionally, there is evidence that eustatic changes influenced the biogeographic history of the AF. Here we evaluate these contrasting diversification processes using two AF social wasp species – the mid-montane
Synoeca cyanea
and the lowland
Synoeca
aff.
septentrionalis
. We analyzed several sources of data including multilocus DNA sequence, climatic niche models and chromosomal features. We find support for idiosyncratic phylogeographic patterns between these wasps, involving different levels of population structure and genetic diversity, contrary suitable climatic conditions during the last glaciation, and contrasting historical movements along the AF. Our data indicate that neotectonics and refugia played distinct roles in shaping the genetic structure of these wasps. However, we argue that eustatic changes influenced the demographic expansion but not population structure in AF biota. Notably, these wasps exhibited chromosomal clines, involving chromosome number and decreasing of GC content, latitudinally oriented along the AF. Together, these results reinforce the need to consider individual organismal histories and indicate that barriers and refugia are significant factors in understanding AF evolution.
Journal Article
Molecular Phylogeny and Historical Biogeography of the Neotropical Swarm-Founding Social Wasp Genus Synoeca (Hymenoptera: Vespidae)
by
Del Lama, Marco Antonio
,
Carvalho, Antônio Freire
,
Costa, Marco Antônio
in
Amphibia
,
Amphibians
,
Animals
2015
The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea) + (S. cyanea + (S. septentrionalis/S. surinama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene.
Journal Article
Change Point Detection by State Space Modeling of Long-Term Air Temperature Series in Europe
by
Costa, Marco
,
Monteiro, Magda
in
air temperature
,
Atmospheric temperature
,
change point detection
2023
This work presents the statistical analysis of a monthly average temperatures time series in several European cities using a state space approach, which considers models with a deterministic seasonal component and a stochastic trend. Temperature rise rates in Europe seem to have increased in the last decades when compared with longer periods. Therefore, change point detection methods, both parametric and non-parametric methods, were applied to the standardized residuals of the state space models (or some other related component) in order to identify these possible changes in the monthly temperature rise rates. All of the used methods have identified at least one change point in each of the temperature time series, particularly in the late 1980s or early 1990s. The differences in the average temperature trend are more evident in Eastern European cities than in Western Europe. The smoother-based t-test framework proposed in this work showed an advantage over the other methods, precisely because it considers the time correlation presented in time series. Moreover, this framework focuses the change point detection on the stochastic trend component.
Journal Article
Assessing Comfort and Safety in Use of Elevators’ Human–Machine Interaction Devices
by
Costa, Marco
,
Perrucci, Giovanni
,
Trabucco, Dario
in
Accessibility
,
Architectural design
,
Blindness
2025
Elevators are essential for accessibility and play a key role in a building’s functionality. Normally mass-produced and purchased from catalogs, elevators require thoughtful integration into architectural design to meet ergonomic, aesthetic, and safety standards. Proper design ensures accessibility, comfort, and efficiency for all users. Internal elements, such as the control panel, influence the user experience within the cabin and should be designed for ease of use, particularly for individuals with disabilities. Two experiments were conducted in a static elevator cabin, installed at the University of Bologna to evaluate user interaction. The first experiment assessed user preferences for different control panel layouts, while the second experiment tested emergency procedures, comparing the standard long-press with a double-press method. Both procedures were also tested with participants with hearing impairments to explore accessibility perceptions among disabled users. An urgent need for an alternative emergency procedure, including a double press to initiate the call and a video–textual device for visual–written communication, was identified to ensure both comfort and safety in elevator use.
Journal Article
Chromosome evolution in lophyohylini (amphibia, anura, hylinae)
2020
The hyline tribe Lophyohylini includes 87 species of treefrogs, of which cytogenetics aspects have been studied in less than 20% of them. In order to evaluate the evolution of some of its chromosome characters (NOR position, C-bands, and DAPI/CMA3 bands), we studied the karyotypes of 21 lophyohylines, 16 of them for the first time, and analyzed them in a phylogenetic context. Most species showed similar karyotypes regarding chromosome number (2n = 24) and morphology (FN = 48), excepting Phyllodytes edelmoi and Osteocephalus buckleyi with 2n = 22 (FN = 44) and 2n = 28 (FN = 50), respectively. The NOR location was variable among species and provided valuable phylogenetic information. This marker was located in pair 11 in all species of Trachycephalus, Itapotihyla langsdorffii, and Nyctimantis arapapa, representing the plesiomorphic condition of Lophyohylini. Besides, other apomorphic states were recovered for the clades comprising N. rugiceps and N. siemersi (NOR in pair 5), and Dryaderces pearsoni, Osteocephalus, and Osteopilus (NOR in pair 9). Phyllodytes presented variation for NORs position; they were in pair 2 in P. edelmoi, pair 7 in P. melanomystax, and pair 8 in P. gyrinaethes and P. praeceptor. Polymorphisms in size, number, and activity of this marker were observed for N. siemersi, Osteocephalus fuscifacies, and some species of Trachycephalus. Remarkably, in N. siemersi NORs were detected on a single chromosome in the two specimens studied by this technique, raising the question of how this complex polymorphism is maintained. Interstitial telomeric sequences were found in P. edelmoi,P. melanomystax, and Osteocephalus buckleyi, and their presence seems to be not related to the chromosome reorganization events. Finally, some species showed spontaneous rearrangements, possibly as a consequence of an uncommon phenomenon in anuran cytogenetics: the presence of fragile sites or secondary constrictions not associated with NORs. We propose that this rare feature would have played an important role in the evolution of this group of frogs. From the evidence obtained in this and previous studies, we conclude that Lophyohylini presents a complex chromosome evolution.
Journal Article
Needs of Deaf People Using Elevators: Identification of Accessibility and Safety Requirements
by
Costa, Marco
,
Perrucci, Giovanni
,
Trabucco, Dario
in
Accessibility
,
accessible buildings
,
Alarm systems
2024
As urbanization and population growth continue, cities concentrate an increasing amount of people, energy, and economy. Multi-story buildings enable densification, requiring vertical transport for access to upper floors. This is crucial for people with disabilities, who may face barriers in the built environment. Elevators are essential for accessibility, allowing everyone, including people with disabilities, to comfortably access multi-story buildings. However, barriers to inclusivity remain, often subtle and hard to define. This paper highlights one such example, focusing on elevator use by individuals with varying degrees of hearing loss. Currently, they cannot establish one-to-one communication with the outside world if trapped in an elevator. Under EN standards, this issue stems from alarm system requirements that lack effective alternatives to voice communication. Based on this evidence, the research was carried out in two steps, with the aim of understanding the needs of deaf individuals when using elevators by directly involving them in the study. First, a questionnaire conducted in Italy collected information regarding the safety and usability of elevators. Second, a test campaign involving both deaf and normal-hearing participants was carried out to quantify the severity of the issue and evaluate potential solutions to address the identified challenges. The conclusions indicate that current alarm systems in elevators are inadequate for individuals with hearing impairments, and effective alternatives must be implemented.
Journal Article