180 research outputs found
Blended learning and emergency distance learning. How to rethink learning environments at school
The Italian School context, in the current scenario, represent a field in which emerges many innovation possibilities. The activation of emergency distance learning due to the suspension of presence teaching activities, represents the occasion for Italian School to renovate school traditional dynamics. Aware of the fact that virtual learning environments provide different teaching and learning dynamics, it is important to reform learning design practices and organize an integrated learning environment that eases effective learning paths. In this paper we present the design of a research-training-action path in a Secondary Italian School in which it will be activated a training course for teachers and introduced the e-learning platform Moodle in teaching-learning activities
(Down-to-)Earth matter effect in supernova neutrinos
Neutrino oscillations in the Earth matter may introduce peculiar modulations
in the supernova (SN) neutrino spectra. The detection of this effect has been
proposed as diagnostic tool for the neutrino mass hierarchy at "large" 1-3
leptonic mixing angle theta13. We perform an updated study on the observability
of this effect at large next-generation underground detectors (i.e., 0.4 Mton
water Cherenkov, 50 kton scintillation and 100 kton liquid Argon detectors)
based on neutrino fluxes from state-of-the-art SN simulations and accounting
for statistical fluctuations via Montecarlo simulations. Since the average
energies predicted by recent simulations are lower than previously expected and
a tendency towards the equalization of the neutrino fluxes appears during the
SN cooling phase, the detection of the Earth matter effect will be more
challenging than expected from previous studies. We find that none of the
proposed detectors shall be able to detect the Earth modulation for the
neutrino signal of a typical galactic SN at 10 kpc. It should be observable in
a 100 kton liquid Argon detector for a SN at few kpc and all three detectors
would clearly see the Earth signature for very close-by stars only (d ~ 0.2
kpc). Finally, we show that adopting IceCube as co-detector together with a
Mton water Cherenkov detector is not a viable option either.Comment: (14 pages, 5 ps figures
Non-Universal Stellar Initial Mass Functions: Large Uncertainties in Star Formation Rates at and Other Astrophysical Probes
We explore the assumption, widely used in many astrophysical calculations,
that the stellar initial mass function (IMF) is universal across all galaxies.
By considering both a canonical Salpeter-like IMF and a non-universal IMF, we
are able to compare the effect of different IMFs on multiple observables and
derived quantities in astrophysics. Specifically, we consider a non-universal
IMF which varies as a function of the local star formation rate, and explore
the effects on the star formation rate density (SFRD), the extragalactic
background light, the supernova (both core-collapse and thermonuclear) rates,
and the diffuse supernova neutrino background. Our most interesting result is
that our adopted varying IMF leads to much greater uncertainty on the SFRD at
than is usually assumed. Indeed, we find a SFRD (inferred using
observed galaxy luminosity distributions) that is a factor of lower
than canonical results obtained using a universal Salpeter-like IMF. Secondly,
the non-universal IMF we explore implies a reduction in the supernova
core-collapse rate of a factor of , compared against a universal IMF.
The other potential tracers are only slightly affected by changes to the
properties of the IMF. We find that currently available data do not provide a
clear preference for universal or non-universal IMF. However, improvements to
measurements of the star formation rate and core-collapse supernova rate at
redshifts may offer the best prospects for discernment.Comment: 15 pages, 11 figures, 1 appendi
A proposal of quantum-inspired machine learning for medical purposes: An application case
Learning tasks are implemented via mappings of the sampled data set, including both the classical and the quantum framework. Biomedical data characterizing complex diseases such as cancer typically require an algorithmic support for clinical decisions, especially for early stage tumors that typify breast cancer patients, which are still controllable in a therapeutic and surgical way. Our case study consists of the prediction during the pre-operative stage of lymph node metastasis in breast cancer patients resulting in a negative diagnosis after clinical and radiological exams. The classifier adopted to establish a baseline is characterized by the result invariance for the order permutation of the input features, and it exploits stratifications in the training procedure. The quantum one mimics support vector machine mapping in a high-dimensional feature space, yielded by encoding into qubits, while being characterized by complexity. Feature selection is exploited to study the performances associated with a low number of features, thus implemented in a feasible time. Wide variations in sensitivity and specificity are observed in the selected optimal classifiers during cross-validations for both classification system types, with an easier detection of negative or positive cases depending on the choice between the two training schemes. Clinical practice is still far from being reached, even if the flexible structure of quantum-inspired classifier circuits guarantees further developments to rule interactions among features: this preliminary study is solely intended to provide an overview of the particular tree tensor network scheme in a simplified version adopting just product states, as well as to introduce typical machine learning procedures consisting of feature selection and classifier performance evaluation
Radiomic analysis in contrast-enhanced spectral mammography for predicting breast cancer histological outcome
Contrast-Enhanced Spectral Mammography (CESM) is a recently introduced mammographic method with characteristics particularly suitable for breast cancer radiomic analysis. This work aims to evaluate radiomic features for predicting histological outcome and two cancer molecular subtypes, namely Human Epidermal growth factor Receptor 2 (HER2)-positive and triple-negative. From 52 patients, 68 lesions were identified and confirmed on histological examination. Radiomic analysis was performed on regions of interest (ROIs) selected from both low-energy (LE) and ReCombined (RC) CESM images. Fourteen statistical features were extracted from each ROI. Expression of estrogen receptor (ER) was significantly correlated with variation coefficient and variation range calculated on both LE and RC images; progesterone receptor (PR) with skewness index calculated on LE images; and Ki67 with variation coefficient, variation range, entropy and relative smoothness indices calculated on RC images. HER2 was significantly associated with relative smoothness calculated on LE images, and grading tumor with variation coefficient, entropy and relative smoothness calculated on RC images. Encouraging results for differentiation between ER+/ERâ, PR+/PRâ, HER2+/HER2â, Ki67+/Ki67â, High-Grade/Low-Grade and TN/NTN were obtained. Specifically, the highest performances were obtained for discriminating HER2+/HER2â (90.87%), ER+/ERâ (83.79%) and Ki67+/Ki67â (84.80%). Our results suggest an interesting role for radiomics in CESM to predict histological outcomes and particular tumorsâ molecular subtype
A roadmap towards breast cancer therapies supported by explainable artificial intelligence
In recent years personalized medicine reached an increasing importance, especially in the design of oncological therapies. In particular, the development of patientsâ profiling strategies suggests the possibility of promising rewards. In this work, we present an explainable artificial intelligence (XAI) framework based on an adaptive dimensional reduction which (i) outlines the most important clinical features for oncological patientsâ profiling and (ii), based on these features, determines the profile, i.e., the cluster a patient belongs to. For these purposes, we collected a cohort of 267 breast cancer patients. The adopted dimensional reduction method determines the relevant subspace where distances among patients are used by a hierarchical clustering procedure to identify the corresponding optimal categories. Our results demonstrate how the molecular subtype is the most important feature for clustering. Then, we assessed the robustness of current therapies and guidelines; our findings show a striking correspondence between available patientsâ profiles determined in an unsupervised way and either molecular subtypes or therapies chosen according to guidelines, which guarantees the interpretability characterizing explainable approaches to machine learning techniques. Accordingly, our work suggests the possibility to design data-driven therapies to emphasize the differences observed among the patients
A Gradient-Based Approach for Breast DCE-MRI Analysis
Breast cancer is the main cause of female malignancy worldwide. Effective early detection by imaging studies remains critical to decrease mortality rates, particularly in women at high risk for developing breast cancer. Breast Magnetic Resonance Imaging (MRI) is a common diagnostic tool in the management of breast diseases, especially for high-risk women. However, during this examination, both normal and abnormal breast tissues enhance after contrast material administration. Specifically, the normal breast tissue enhancement is known as background parenchymal enhancement: it may represent breast activity and depends on several factors, varying in degree and distribution in different patients as well as in the same patient over time. While a light degree of normal breast tissue enhancement generally causes no interpretative difficulties, a higher degree may cause difficulty to detect and classify breast lesions at Magnetic Resonance Imaging even for experienced radiologists. In this work, we intend to investigate the exploitation of some statistical measurements to automatically characterize the enhancement trend of the whole breast area in both normal and abnormal tissues independently from the presence of a background parenchymal enhancement thus to provide a diagnostic support tool for radiologists in the MRI analysis
Light Sterile Neutrinos: A White Paper
This white paper addresses the hypothesis of light sterile neutrinos based on
recent anomalies observed in neutrino experiments and the latest astrophysical
data
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