Search results for "Labyrinth"
showing 10 items of 54 documents
Dimensional analysis and stage-discharge relationship for weirs: a review
2017
Deducing the weir flow stage-discharge relationship is a classical hydraulic problem. In this regard Buckingham’s theorem of dimensional analysis can be used to find simple and accurate formulas to obtain the rating curves of different weir types. At first, in this review paper the rectangular weir that is a very common hydraulic structure is studied. It is indicated that the crest shape, approach channel width, obliquity (angle between the weir crest and the direction normal to the flow motion) and vertical inclination (pivot weir) are the key-parameters affecting the flow over the rectangular weirs. The flow over the triangular, labyrinth, parabolic, circular, elliptical, and W-weirs are …
European vestibular experiments on the Spacelab-1 mission: 2. Experimental equipment and methods
1986
A series of vestibular experiments were performed in conjunction with the first Spacelab mission, consisting of sets of pre-, in- and postflight tests. A multipurpose experimental apparatus used for the diverse flight and ground tests is presented. Additional apparatus together with the multi-purpose package were used in the baseline data collection facility at the landing site at NASA Dryden Flight Research Facility for the ground tests. The tests involved optokinetic, caloric and mechanical (whole-body or head-alone) stimulation. The latter included linear acceleration in the subject's x, y and z axes, static roll and yaw about an earth-vertical axis. Physiological parameters such as elec…
Città ‘altre’. Le miniere come metafora della rappresentazione.
2014
Lo studio è incentrato sulla rappresentazione di una miniera di zolfo nel cuore della Sicilia. I legami tra gli impianti fuori terra e la fitta rete di gallerie del sottosuolo costituiscono una efficace metafora della struttura urbana e di alcune delle questioni legate alla rappresentazione dell’architettura. Il dualismo tra spazi apollinei e dionisiaci, tra il regno della percezione e quello della tattilità e della memoria, rappresentati rispettivamente dalle strutture fuori terra e dal sottosuolo, costringono alla ricerca di forme della rappresentazione capaci di esprimerne le peculiarità. Tre tavole, disegnate con una tecnica obsoleta, matita su cartoncino, cercano di rappresentare la co…
Un labirinto del tardo Quattrocento nel giardino di Giovan Tomaso Moncada
2017
Da un manoscritto databile intorno al 1550 e un saggio a stampa sulle feste reali celebrate a Palermo, pubblicato nel 1703, sappiamo dell'esistenza di un labirinto nel giardino dell'aristocratico Giovan Tomaso Moncada, costruito negli anni settanta o negli anni ottanta del XV secolo nella campagna vicino Palermo. Si tratta della scena in cui ebbe luogo un ricco banchetto offerto al Viceré Ferdinando de Acuña. Secondo l'autore del manoscritto, Gian Giacomo Adria, modello di riferimento per il labirinto siciliano era quello cretese del Minotauro e lo stesso aveva forma quadrata, con otto circuiti, circondato da un muro decorato con un motivo a chiavi spezzate. Sebbene non abbiamo elementi suf…
Perdersi. Note sul Labirinto
2022
The paper is inspired by a conversation of its author with Sandro Man- cini. Through a series of self-biographical notes, it tries to examine the topological gure of the labyrinth in some of its main mythical- symbolic, mathematical and conceptual articulations. Starting from a famous essay by Italo Calvino, i.e. La s da al labirinto, it seeks in par- ticular to discuss the works of Pierre Rosenstiehl, mathematician and philosopher to whom we owe some of the most re ned analyses on the subject of labyrinth. In the conclusions, after some other short intro- spective remarks, one aims at raising the necessity of more systematic and deepened investigations about this subject.
Sensory reweighting in frail aged adults: Are the balance deficiencies mainly compensated by visual or podal dependences?
2021
Abstract Background Postural control is based on the integration of different sensory inputs. The process of scaling the relative importance of these sensory cues (visual, vestibular and proprioceptive) depends on individuals and creates sensory preferences, leading to sensory dependences when one particular source is preponderant. In this context, the literature showed a frequent visual dependence (visual inputs weighting) in aged adults. However, the somaesthetic inputs can also be prioritised in a podal-dependent profile. In the frail aged adults, none study has shown the distribution of these two dependences. Research question Which sensory orientation profile is preferentially adopted …
Vestibular compensation in cerebellar stroke patients.
2014
Background and purpose There is little evidence about the site where compensatory vestibular mechanisms in patients with cerebellar strokes take place. Methods To determine whether the location of a cerebellar lesion might be a crucial variable in vestibular compensation a sample of 22 patients with cerebellar stroke were tested for graviceptive function in the acute and chronic stage. Results Our statistical anatomical lesion analysis indicated that mainly lesions of the cerebellar hemispheres (lobule V, VI, VIIa) hinder vestibular compensation and might lead to an overcompensation. Conclusions Overcompensation-induced dysfunction can be explained by the absence of cerebellar inhibitory si…
Effects of electrical stimulation in vestibular cortex areas in humans.
2010
The case of a patient with focal epilepsy is reported who underwent presurgical evaluation by stereotactic intracranial electroencephalographic (EEG) recording. A subdural semi-grid electrode, consisting of three multi-channel strip electrodes, was implanted over the temporal lobe and temporo-occipital region; one multi-channel depth electrode was applied towards the posterior insular cortex. During electrical stimulation and EEG monitoring eye movements were recorded by 3-D video-oculography. Stimulation of the medial temporal gyrus induced blurring of vision and horizontal nystagmus. Stimulation of the superior temporal gyrus with low intensities also induced blurring of vision and a simi…
Sudden sensorineural hearing loss associated with inner ear lesions detected by magnetic resonance imaging.
2017
Although recent advances in magnetic resonance imaging (MRI) techniques have contributed to the detection of tiny lesions in the internal auditory canal (IAC) that may be responsible for sudden sensorineural hearing loss (SSNHL), there have been relatively few studies on the clinical characteristics of intra-labyrinthine hemorrhage (ILH) and labyrinthitis versus those regarding IAC tumors. Our purpose was to investigate the frequency of those IAC lesions on MRI and their clinical characteristics. Initial MRIs of 200 patients with SSNHL (93 men, 107 women; mean age = 48.61 years, range: 18-84 years), as well as detailed clinical histories, audiological examinations, and thyroid function, lip…
Nature of a Pigmented Substance in the Labyrinth
1964
The pigment existing in the loose connective tissue of the posterior labyrinth is originated by hemorrhage, pathological or “physiological” inflammations and wearing out of tissues. Such pigment is contained in macrophages.