157 research outputs found

    Sensitivity of Machine Learning Approaches to Fake and Untrusted Data in Healthcare Domain

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    Machine Learning models are susceptible to attacks, such as noise, privacy invasion, replay, false data injection, and evasion attacks, which affect their reliability and trustworthiness. Evasion attacks performed to probe and identify potential ML-trained models’ vulnerabilities, and poisoning attacks, performed to obtain skewed models whose behavior could be driven when specific inputs are submitted, represent a severe and open issue to face in order to assure security and reliability to critical domains and systems that rely on ML-based or other AI solutions, such as healthcare and justice, for example. In this study, we aimed to perform a comprehensive analysis of the sensitivity of Artificial Intelligence approaches to corrupted data in order to evaluate their reliability and resilience. These systems need to be able to understand what is wrong, figure out how to overcome the resulting problems, and then leverage what they have learned to overcome those challenges and improve their robustness. The main research goal pursued was the evaluation of the sensitivity and responsiveness of Artificial Intelligence algorithms to poisoned signals by comparing several models solicited with both trusted and corrupted data. A case study from the healthcare domain was provided to support the pursued analyses. The results achieved with the experimental campaign were evaluated in terms of accuracy, specificity, sensitivity, F1-score, and ROC area

    La presbiacusia. problematiche, diagnosi e opzioni riabilitative Presbycusis. problems, diagnosis and treatment

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    Presbycusis is sensorineural bilateral symmetrical, progressive hearing loss, caused by the advance of age. It involves mainly the higher frequencies and associated with tinnitus. Presbycusis the most frequent form of sensorineural hearing loss of the adult, characterized by the progressive difficulty following the conversation, especially in noisy environments. It is caused by reduction in the number of Corti cells, induced by genetic and environmental factors. In the elderly communication disorders generate isolation and depression, thereby causing a significant reduction of life quality. An observational study at our hospital in 2010, using questionnaires on verbal-acoustic communication (Self Assessment of Communication), found that older people have a poor perception of disability related to hearing loss. For presbycusis to be diagnosed, tone audiometry and speech and sovraliminary tests have to be carried out and must be integrated with the evaluation of extremely high frequencies (EHFs). In the majority of cases, rehabilitation involves conventional hearing aids. The most commonly used are retroauricular hearing aids, when these are contraindicated partially or totally implantable hearing device scan be used. Careful follow up of the patient is also fundamental, using benefit questionnaires to find the optimal fitting and therefore the best result

    Lysine: N 6 -Hydroxylase: Stability and Interaction with Ligands

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    Recombinant lysine:N 6 -hydroxylase, r IucD, which is isolated as an apoenzyme, requires FAD and NADPH for its catalytic function. r IucD preparations have been found to undergo time-dependent loss in monooxygenase function due to aggregation from the initial tetrameric state to a polytetrameric form(s), a process which is reversible by treatment with thiols. Ligand-in-duced conformational changes in r IucD were assessed by monitoring its CD spectra, DSC profile, and susceptibility to both endo- as well as exopeptidases. The first two methods indicated the absence of any significant conformational change in r IucD, while the last approach revealed that FAD, and its analog ADP, can protect the protein from the deleterious action of proteases. NADPH was partially effective and L-lysine was ineffective in this regard. Deletion of the C-terminal segment, either by treatment with carboxypeptidase Y or by mutagenesis of iucD, results in the loss of r IucD's monooxygenase activity. These findings demonstrate the crucial role of the C-terminal segment in maintaining r IucD in its native conformation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45085/1/10930_2004_Article_409465.pd

    Atmospheric phase correction using CARMA-PACS: high angular resolution observations of the FU Orionis star PP 13S*

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    We present 0".15 resolution observations of the 227 GHz continuum emission from the circumstellar disk around the FU Orionis star PP 13S*. The data were obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) Paired Antenna Calibration System (C-PACS), which measures and corrects the atmospheric delay fluctuations on the longest baselines of the array in order to improve the sensitivity and angular resolution of the observations. A description of the C-PACS technique and the data reduction procedures are presented. C-PACS was applied to CARMA observations of PP 13S*, which led to a factor of 1.6 increase in the observed peak flux of the source, a 36% reduction in the noise of the image, and a 52% decrease in the measured size of the source major axis. The calibrated complex visibilities were fitted with a theoretical disk model to constrain the disk surface density. The total disk mass from the best-fit model corresponds to 0.06 M_⊙, which is larger than the median mass of a disk around a classical T Tauri star. The disk is optically thick at a wavelength of 1.3 mm for orbital radii less than 48 AU. At larger radii, the inferred surface density of the PP 13S* disk is an order of magnitude lower than that needed to develop a gravitational instability

    Atmospheric phase correction using the CARMA paired antennas calibration system

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    High angular resolution observations are essential to understand a variety of astrophysical phenomena. The resolution of millimeter wave interferometers is limited by large and rapid differential atmospheric delay fluctuations. At the Combined Array for Research in Millimeter-wave Astronomy (CARMA) we have employed a Paired Antenna Calibration System (C-PACS) for atmospheric phase compensation in the extended array configurations (up to 2 km baselines). We present a description of C-PACS and its application. We also present successful atmospheric delay corrections applied to science observations with dramatic improvements in sensitivity and angular resolution

    Molecular basis of mucopolysaccharidosis IVA (Morquio A syndrome) : a review and classification of GALNS gene variants and reporting of 68 novel variants

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    Mucopolysaccharidosis IVA (MPS IVA, Morquio A syndrome) is a rare autosomal recessive lysosomal storage disorder caused by mutations in the N-acetylgalactosamine-6-sulfatase (GALNS) gene. We collected, analyzed, and uniformly summarized all published GALNS gene variants, thus updating the previous mutation review (published in 2014). In addition, new variants were communicated by seven reference laboratories in Europe, the Middle East, Latin America, Asia, and the United States. All data were analyzed to determine common alleles, geographic distribution, level of homozygosity, and genotype-phenotype correlation. Moreover, variants were classified according to their pathogenicity as suggested by ACMG. Including those previously published, we assembled 446 unique variants, among which 68 were novel, from 1190 subjects (including newborn screening positive subjects). Variants' distribution was missense (65.0%), followed by nonsense (8.1%), splicing (7.2%), small frameshift deletions(del)/insertions(ins) (7.0%), intronic (4.0%), and large del/ins and complex rearrangements (3.8%). Half (50.4%) of the subjects were homozygous, 37.1% were compound heterozygous, and 10.7% had only one variant detected. The novel variants underwent in silico analysis to evaluate their pathogenicity. All variants were submitted to ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/) to make them publicly available. Mutation updates are essential for the correct molecular diagnoses, genetic counseling, prenatal and preimplantation diagnosis, and disease management

    A VLBI receiving system for the South Pole Telescope

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    The Event Horizon Telescope (EHT) is a very-long-baseline interferometry (VLBI) experiment that aims to observe supermassive black holes with an angular resolution that is comparable to the event horizon scale. The South Pole occupies an important position in the array, greatly increasing its north-south extent and therefore its resolution. The South Pole Telescope (SPT) is a 10-meter diameter, millimeter-wavelength telescope equipped for bolometric observations of the cosmic microwave background. To enable VLBI observations with the SPT we have constructed a coherent signal chain suitable for the South Pole environment. The dual-frequency receiver incorporates state-of-the-art SIS mixers and is installed in the SPT receiver cabin. The VLBI signal chain also includes a recording system and reference frequency generator tied to a hydrogen maser. Here we describe the SPT VLBI system design in detail and present both the lab measurements and on-sky results.Comment: 14 pages, 11 figures, to appear in the Proceedings of the SPIE (SPIE Astronomical Telescopes + Instrumentation 2018; Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX
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