1,040 research outputs found
Hybridized tetraquarks
We propose a new interpretation of the neutral and charged X,Z
exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h -tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the View the MathML source
channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z
particles. Considerations on a state with the same quantum numbers as the X(5568)
are also made
An Extensive Comparison of Static Application Security Testing Tools
Context: Static Application Security Testing Tools (SASTTs) identify software
vulnerabilities to support the security and reliability of software
applications. Interestingly, several studies have suggested that alternative
solutions may be more effective than SASTTs due to their tendency to generate
false alarms, commonly referred to as low Precision. Aim: We aim to
comprehensively evaluate SASTTs, setting a reliable benchmark for assessing and
finding gaps in vulnerability identification mechanisms based on SASTTs or
alternatives. Method: Our SASTTs evaluation is based on a controlled, though
synthetic, Java codebase. It involves an assessment of 1.5 million test
executions, and it features innovative methodological features such as
effort-aware accuracy metrics and method-level analysis. Results: Our findings
reveal that SASTTs detect a tiny range of vulnerabilities. In contrast to
prevailing wisdom, SASTTs exhibit high Precision while falling short in Recall.
Conclusions: The paper suggests that enhancing Recall, alongside expanding the
spectrum of detected vulnerability types, should be the primary focus for
improving SASTTs or alternative approaches, such as machine learning-based
vulnerability identification solutions
Smart Bulbs can be Hacked to Hack into your Household
The IoT is getting more and more pervasive. Even the simplest devices, such
as a light bulb or an electrical plug, are made "smart" and controllable by our
smartphone. This paper describes the findings obtained by applying the PETIoT
kill chain to conduct a Vulnerability Assessment and Penetration Testing
session on a smart bulb, the Tapo L530E by Tp-Link, currently best seller on
Amazon Italy. We found that four vulnerabilities affect the bulb, two of High
severity and two of Medium severity according to the CVSS v3.1 scoring system.
In short, authentication is not well accounted for and confidentiality is
insufficiently achieved by the implemented cryptographic measures. In
consequence, an attacker who is nearby the bulb can operate at will not just
the bulb but all devices of the Tapo family that the user may have on her Tapo
account. Moreover, the attacker can learn the victim's Wi-Fi password, thereby
escalating his malicious potential considerably. The paper terminates with an
outline of possible fixes
L’universo ideologico della Chanson de Jérusalem. Mentalità e propaganda crociata nel XII secolo
Obiettivo di questa tesi è ricostruire l’ideologia presente nella “Chanson de Jérusalem”, chanson de geste della seconda metà del XII secolo riguardante la Prima Crociata, attraverso un’analisi sistematica dei topoi letterari e del ruolo che determinati elementi assumono nella trasfigurazione epica, per descrivere i meccanismi della propaganda crociata in campo letterario, e dimostrare che la “Chanson de Jérusalem” fu, appunto, uno strumento propagandistico teso all’esaltazione dell’ideologia crociata. Opinione del sottoscritto è che l’autore dell’opera caratterizzi la crociata come pellegrinaggio ideale in quanto percorso di “imitatio Christi” compiuto negli stessi luoghi e negli stessi tempi della Passione di Cristo, realizzando in campo letterario la fusione auspicata da Bernardo di Chiaravalle delle due figure del monaco e del guerriero. Tutte le vicende sono guidate dalla Provvidenza divina che dispone la vittoria dei crociati nel modo e nei tempi da essa voluti. Ciò che rende la “Jérusalem” un testo molto originale nel contesto letterario dell’epoca è la capacità di fondere tradizioni diverse in un’ideologia coerente in sé: il modello della nuova cavalleria del “De laude novae militiae”, la valorizzazione del dolore, le tematiche escatologiche tratte da tradizioni apocrife. La “Jérusalem” diffonde un’ideologia che dà grande importanza agli strati più bassi della popolazione e al loro modus vivendi, mettendo l’accento sulla fraternità e sul senso di gruppo, nel seno del contingente crociato. Questi tratti “democratici” e di apertura nei confronti degli ultimi costituiscono gli elementi più originali di un’opera che si differenzia non poco rispetto alle altre “chansons de geste” dell’epoca. La “Jérusalem” è un’opera probabilmente composta entro un secolo dagli avvenimenti che racconta, a dimostrazione dell’eccezionalità della Prima Crociata, che colpì l’immaginario collettivo di tutti gli strati della popolazione medievale, mobilitandoli come mai fino ad allora, facendo forza sulla forte fede cristiana dell’Europa occidentale
Traveling in a fragile world: the value of ecoturism
What is ecotourism and why is it a current topic today more than ever? Tourism represents a significant economic sector and further forecasted to grow at a global level – exceeding even in the first few months of 2018 the most optimistic growth expectations according to WTTC (2018a)1.
According to the International Ecotourism society2, ecotourism can be defined as a form of responsible tourism that prefers natural areas and that focuses its attention and commitment to conserve the environment and sustain the well-being of local people through interpretation (of heritage, traditions) and education (habitats, animals, cultures).
Ecotourism has the potential to contribute, directly or indirectly, to all the objectives set by the 2030 Agenda3 for Sustainable Development4, which establishes ambitious global targets for people, planet, prosperity and peace through partnerships (UNWTO 2019; WCED 1987). Moreover, it provides the opportunity to preserve natural areas, through natural resources management and increasing environmental awareness and eco-friendly practices; provide sustainable economic growth of local communities in countries like Nepal, Costa Rica or Ecuador; preserve indigenous culture and tradition through educational programs; and reinvest money for conservation efforts like the protection of species or reforestation.
However, critics to Ecotourism claim the negative impacts that this industry has on local people and environments as consequence of long travel distances (like the pollution generated by planes) and the negative impacts deriving from the presence of tourists in delicate environments (and the related production of waste or pollution).
This paper aims to provide a general examination of the available data about the ecotourism activities on a global level, presenting examples from representative countries worldwide.
We consider both the qualitative and quantitative aspects of this industry, trying to focus on what it represents in terms of its impacts and benefits for the country’s natural resources, communities and economy.
In the first part of the manuscript, we compare ecotourism to other forms of natural resources’ use such as trophy hunting and mass tourism, trying to evaluate whether these represent a preferable alternative or not in terms of sustainability and economic benefits.
The next section is divided by regions: Africa, The Americas, Europe, and Australia.
For the study, we used statistics made available mainly by the World Travel and Tourism Council (WTTC) and the UN Environment World Conservation Monitoring Centre (UNEP-WCMC), together with information from specialized international literature
Occurrence of acute oesophageal necrosis (black oesophagus) in a single tertiary centre
Acute oesophageal necrosis (AON) is a rare condition characterised by the endoscopic finding of diffuse, circumferential, black mucosal pigmentation of the oesophagus, which typically stops at the gastro-oesophageal junction. This observational study aimed to assess the occurrence, clinical characteristics and outcomes of AON in a consecutive endoscopic cohort in a single tertiary university centre. A retrospective analysis of endoscopic data of upper gastrointestinal endoscopy (UGE) was carried out from 2008 to 2018. Out of 25,970 UGE, 16 patients (0.06%) had AON; 75.0% were men with a median age of 75 years. Almost all patients underwent diagnosis during emergency UGE performed for gastrointestinal bleeding, but one patient was diagnosed during elective UGE for persistent vomiting and diarrhoea. All patients reported one or more pre-existing comorbidities and concomitant acute events. Two patients had AON as the first presentation of Zollinger-Ellison syndrome (ZES). One patient developed an oesophageal stenosis, and another patient presented a relapse of AON. Mortality was 50%, but no patient died as a direct consequence of AON. AON is a rare cause of gastrointestinal bleeding diagnosed mainly during emergency UGE. Our study showed that ZES might manifest with this critical presentation, and endoscopists must be aware of this evidence
Optimizing Retrieving Performance of an Automated Warehouse for Unconventional Stock Keeping Units
In recent years, the diffusion of automated warehouses in different industrial sectors has fostered the design of more complex automated storages and handling solutions. These circumstances, from a technological point of view, have led to the development of automated warehouses that are very different from the classic pallet Automated Storage and Retrieval Systems (AS/RS), both in terms of design and operating logic. A context in which these solutions have spread is the steel sector. Warehouses with innovative layouts and operating logics have been designed to move metal bundles of different sizes, weights and quality levels, instead of standard, interchangeable stock keeping units. Moreover, picking is often not allowed in these warehouses, due to the configuration of the loading units. In this work we propose a meta-heuristic algorithm based on the Simulated Annealing (SA) procedure, which aims to optimize performance during the retrieving phase of an automated warehouse for metal bundles. The algorithm translates the customers’ requests, expressed in terms of item code, quality and weight into a list of jobs. The goal is to optimize the retrieving performance, measured in missions per hour, minimizing the deviations in quality and weight between customer request and the material retrieved. For the validation, a simulation model of an existing warehouse has been created and the performance of the algorithm tested on the simulation model has been compared with the current performance of the warehouse
KCa3.1 channel inhibition sensitizes malignant gliomas to temozolomide treatment
Malignant gliomas are among the most frequent and aggressive cerebral tumors, characterized by high proliferative and invasive indexes. Standard therapy for patients, after surgery and radiotherapy, consists of temozolomide (TMZ), a methylating agent that blocks tumor cell proliferation. Currently, there are no therapies aimed at reducing tumor cell invasion. Ion channels are candidate molecular targets involved in glioma cell migration and infiltration into the brain parenchyma. In this paper we demonstrate that: i) blockade of the calcium-activated potassium channel KCa3.1 with TRAM-34 has co-adjuvant effects with TMZ, reducing GL261 glioma cell migration, invasion and colony forming activity, increasing apoptosis, and forcing cells to pass the G2/M cell cycle phase, likely through cdc2 de-phosphorylation; ii) KCa3.1 silencing potentiates the inhibitory effect of TMZ on glioma cell viability; iii) the combination of TMZ/TRAM-34 attenuates the toxic effects of glioma conditioned medium on neuronal cultures, through a microglia dependent mechanism since the effect is abolished by clodronate-induced microglia killing; iv) TMZ/TRAM-34 co-treatment increases the number of apoptotic tumor cells, and the mean survival time in a syngeneic mouse glioma model (C57BL6 mice implanted with GL261 cells); v) TMZ/TRAM-34 co-treatment reduces cell viability of GBM cells and cancer stem cells (CSC) freshly isolated from patients.Taken together, these data suggest a new therapeutic approach for malignant glioma, targeting both glioma cell proliferating and migration, and demonstrate that TMZ/TRAM-34 co-treatment affects both glioma cells and infiltrating microglia, resulting in an overall reduction of tumor cell progression
A study of the relativistic corrections to tritium -decay
Forthcoming experiments like Project8 and Ptolemy aim at investigating with
high precision the end-point of the tritium -decay spectrum sensitive to
the neutrino mass. In light of this, using the standard parametrization in
terms of nuclear polar form factors, we analyze the complete relativistic
expression for the spectrum of the -electron emitted by a tritium
nucleus. Given the small parameters in the problem, we discuss the
approximations that can be made, and present the first two corrections to the
standard lowest order formula, improving on the few results available in the
literature.Comment: 5 pages, 1 figure, 1 tabl
Photon number statistics uncover the fluctuations in non-equilibrium lattice dynamics
Fluctuations of the atomic positions are at the core of a large class of
unusual material properties ranging from quantum para-electricity to high
temperature superconductivity. Their measurement in solids is the subject of an
intense scientific debate focused on seeking a methodology capable of
establishing a direct link between the variance of the atomic displacements and
experimentally measurable observables. Here we address this issue by means of
non-equilibrium optical experiments performed in shot-noise limited regime. The
variance of the time dependent atomic positions and momenta is directly mapped
into the quantum fluctuations of the photon number of the scattered probing
light. A fully quantum description of the non-linear interaction between
photonic and phononic fields is benchmarked by unveiling the squeezing of
thermal phonons in -quartz.Comment: 7 pages (main text), 5 figures, 11 pages (supplementary information
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