1,062 research outputs found
Galileo Galilei's location, shape and size of Dante's Inferno: an artistic and educational project
Mathematics and Art have a long historical relationship, which goes as far back as the ancient
Greeks. It suffices to think, for instance, to their use of the golden ratio, regarded as an aesthetically
pleasing canon and incorporated into the design of many monuments and temples. With
the Renaissance we can see a rebirth of Classical (Greek and Roman) culture and ideas, and among
them the study of Mathematics as a relevant subject needed to understand the nature and the arts.
Two major reasons drove Renaissance artists towards the pursuit of Mathematics. Firstly, painters
needed to figure out how to depict three-dimensional scenes on a two-dimensional canvas.
Secondly, philosophers and artists alike were convinced that Mathematics was the true essence of
the physical world so that the entire universe, including the arts, could be explained in geometrical
terms. For instance, Galileo Galilei in his Il Saggiatore wrote that “[The universe] is written in the
language of Mathematics, and its characters are triangles, circles, and other geometric figures.”
Thus, there is a close relation between Mathematics and Fine Arts during the Renaissance:
mathematical knowledge is applied in drawings and paintings with the use of symmetry, producing
ratios and proportions.
Within the study of such a context arises the artistic and educational project “Galileo: location,
shape and size of Dante’s Inferno” as a collaboration between the FDS Laboratory for
Mathematical Education and Science Communication at the Department of Mathematics of the
Politecnico di Milano and Accademia di Belle Arti di Brera.
The project is inspired by the first of two lectures held by Galileo Galilei at the Accademia
Fiorentina in 1588. These lectures were commissioned by the Accademia to solve a literary
controversy concerning the interpretation of Dante’s Inferno. In these lessons Galileo took the
opportunity to show his mathematical abilities combined with his strong background in Humanities.
His ultimate aim was to show that Mathematics is not merely useful from a technical point of view,
but can also give a contribution to nobler cultural debates, thus acquiring an intellectual status
comparable to that of the Humanities.
When giving his lectures Galileo probably used drawings to explain how to map Dante’s Inferno,
because of “ la difficoltà del suggetto che non patisce esser con la penna facilmente esplicato” (the
difficulty of the subject which does not admit of easy explication in writing). Galileo’s manuscript
survives and is catalogued in the Filza Rinucciniana 21 of the Biblioteca Nazionale di Firenze, but
the drawings are lost.
The project here presented included an accurate analysis of Galileo’s work and was meant as an
opportunity for the students of Graphic to investigate the relationship between geometric
representation and artistic interpretation. They made scale drawings of the Inferno, by using
different paper media and drawing techniques of their choice. Later they produced original art
works resulting from a personal artistic interpretation of the subject, free of pure scientific
representation. The results reflect various artistic and creative sensibilities: drawings, paintings,
engravings. The students’ works were gathered, accompanied by short sentences associated with the
selected quotes of Inferno and displayed on the exhibition that was held at Politecnico di Milano
(May 2012). After the works were exhibited at the Museo Dantesco of Ravenna (September 2013)
and at the Bergamo Science Festival (XI Edition, October 2013)
Exposure-Tolerant Imaging Solution forCultural Heritage Monitoring
This paper describes a simple and cheap solution specifically designed for monitoring the degradation of thin coatings employed for metal protection. The proposed solution employs a commercial photocamera and a frequency-domain-based approach that is capable of highlighting the surface uniformity changes due to initial corrosion. Even though the proposed solution is specifically designed to monitor the long-time performance of protective coatings employed for the restoration of silver artifacts, it can be successfully used also for assessing the conservation state of other ancient metallic works of art. The proposed solution is made tolerant to exposure changes by using a procedure for sensor nonlinearity identification and correction, does not require a precise lighting control, and employs only free open-source software, so that its overall cost is very low and can be used also by not specifically trained operator
Low-cost electrochemical impedance spectroscopy system for corrosion monitoring of metallic antiquities and works of art
Electrochemical impedance spectroscopy (EIS) is recognized to be a powerful and noninvasive technique to test the integrity of protective coatings on memorials, but commercial EIS systems are rather costly though versatile devices. This paper describes a low cost and portable EIS system that is based on a compact digital signal processor (DSP) board and embeds the potentiostatic function so that it can be used without requiring an external potentiostat. The software that runs on the DSP is designed to analyze the electrochemical impedance only in a reduced frequency range in order to produce a simple corrosion alert result. The device is equipped with a digital interface and can be connected to a personal computer to carry out a complete frequency analysis and perform a more complex data processing
Can the fatty acids profile of Tuber aestivum - T. uncinatum species complex have chemotaxonomic value?
Fatty acid (FA) profiles are considered as chemotaxonomic markers to define groups of various taxonomic ranks in bacteria, yeasts, and fungi. Tuber aestivum is one of the most common European truffles that has environmental and economic values. While genetic studies suggest that T. aestivum Vittad. and T. uncinatum Chatin are synonymous, there is still debate over whether this is a species complex. In this work, we evaluate the differences in the total and individual FAs content of T. aestivum and T. uncinatum morphotypes, and T. melanosporum n-hexane extracts.
The higher amounts of total linoleic acid and total oleic acid are found in T. uncinatum and characterize it from the T. aestivum. The composition of FA profiles of T. uncinatum-T. aestivum were distinguished by the presence of free palmitoleic acid (a chemotaxonomic marker) in T. uncinatum and absent in T. aestivum. Cluster analysis indicated that there were two groups for the FA profiles of the Tuber spp. hexanic extract: T. aestivum extract and T. uncinatum and T. melanosporum extracts.
Our results indicate that T. aestivum and T. uncinatum have to be considered as two different taxa within the T. aestivum species complex
Handheld-Impedance-Measurement System with seven-decade capability and potentiostatic function
This paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 kΩ to 100 GΩ. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligibl
Archaeology and virtual acoustics. A pan flute from ancient Egypt
This paper presents the early developments of a recently started research project, aimed at studying from a multidisciplinary perspective an exceptionally well preserved ancient pan flute. A brief discussion of the history and
iconography of pan flutes is provided, with a focus on Classical Greece. Then a set of non-invasive analyses are presented, which are based on 3D scanning andmaterials chemistry, and are the starting point to inspect the geometry, construction, age and geographical origin of the instrument. Based on the available measurements, a preliminary analysis of the instrument tuning is provided, which is also informed with elements of theory of ancient Greek music. Finally, the paper presents current work aimed at realizing an interactive museum installation that recreates a virtual flute and allows intuitive access to all these research facets
Genetic modifiers of Duchenne muscular dystrophy and dilated cardiomyopathy
OBJECTIVE:
Dilated cardiomyopathy (DCM) is a major complication and leading cause of death in Duchenne muscular dystrophy (DMD). DCM onset is variable, suggesting modifier effects of genetic or environmental factors. We aimed to determine if polymorphisms previously associated with age at loss of independent ambulation (LoA) in DMD (rs28357094 in the SPP1 promoter, rs10880 and the VTTT/IAAM haplotype in LTBP4) also modify DCM onset.
METHODS:
A multicentric cohort of 178 DMD patients was genotyped by TaqMan assays. We performed a time-to-event analysis of DCM onset, with age as time variable, and finding of left ventricular ejection fraction 70 mL/m2 as event (confirmed by a previous normal exam < 12 months prior); DCM-free patients were censored at the age of last echocardiographic follow-up.
RESULTS:
Patients were followed up to an average age of 15.9 \ub1 6.7 years. Seventy-one/178 patients developed DCM, and median age at onset was 20.0 years. Glucocorticoid corticosteroid treatment (n = 88 untreated; n = 75 treated; n = 15 unknown) did not have a significant independent effect on DCM onset. Cardiological medications were not administered before DCM onset in this population. We observed trends towards a protective effect of the dominant G allele at SPP1 rs28357094 and recessive T allele at LTBP4 rs10880, which was statistically significant in steroid-treated patients for LTBP4 rs10880 (< 50% T/T patients developing DCM during follow-up [n = 13]; median DCM onset 17.6 years for C/C-C/T, log-rank p = 0.027).
CONCLUSIONS:
We report a putative protective effect of DMD genetic modifiers on the development of cardiac complications, that might aid in risk stratification if confirmed in independent cohorts
Renal function and physical fitness after 12-mo supervised training in kidney transplant recipients
To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations
Non-neural phenotype of spinal and bulbar muscular atrophy: Results from a large cohort of Italian patients
Objective: To carry out a deep characterisation of the main androgen-responsive tissues involved in spinal and bulbar muscular atrophy (SBMA). Methods: 73 consecutive Italian patients underwent a full clinical protocol including biochemical and hormonal analyses, genitourinary examination, bone metabolism and densitometry, cardiological evaluation and muscle pathology. Results: Creatine kinase levels were slightly to markedly elevated in almost all cases (68 of the 73; 94%). 30 (41%) patients had fasting glucose above the reference limit, and many patients had total cholesterol (40; 54.7%), low-density lipoproteins cholesterol (29; 39.7%) and triglyceride (35; 48%) levels above the recommended values. Although testosterone, luteinising hormone and follicle-stimulating hormone values were generally normal, in one-third of cases we calculated an increased Androgen Sensitivity Index reflecting the presence of androgen resistance in these patients. According to the International Prostate Symptom Score (IPSS), 7/70 (10%) patients reported severe lower urinal tract symptoms (IPSS score >19), and 21/73 (30%) patients were moderately symptomatic (IPSS score from 8 to 19). In addition, 3 patients were carriers of an indwelling bladder catheter. Videourodynamic evaluation indicated that 4 of the 7 patients reporting severe urinary symptoms had an overt prostate-unrelated bladder outlet obstruction. Dual-energy X-ray absorptiometry scan data were consistent with low bone mass in 25/61 (41%) patients. Low bone mass was more frequent at the femoral than at the lumbar level. Skeletal muscle biopsy was carried out in 20 patients and myogenic changes in addition to the neurogenic atrophy were mostly observed. Conclusions: Our study provides evidence of a wide non-neural clinical phenotype in SBMA, suggesting the need for comprehensive multidisciplinary protocols for these patients. \ua9 2016 Published by the BMJ Publishing Group Limited
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