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Biomedical subjects

G Riccio

Publications and source records attributed to G Riccio.

27 records · Page 2Linked to original sources
PubMed1987

Detection of the traversability of surfaces by crawling and walking infants.

In four studies we investigated the perception of the affordance for traversal of a supporting surface. The surface presented was either rigid or deformable, and this property was specified either optically, haptically, or both. In Experiment 1A, crawling and walking infants were presented with two surfaces in succession: a standard surface that both looked and felt rigid and a deforming surface that both looked and felt nonrigid. Latency to initiate locomotion, duration of visual and haptic exploration, and displacement activity were coded from videotapes. Compared with the standard, the deforming surface elicited longer latency, more exploratory behavior, and more displacement in walkers, but not in crawlers, suggesting that typical mode of locomotion influences perceived traversability. These findings were replicated in Experiment 1B, in which the infant was presented with a dual walkway, forcing a choice between the two surfaces. Experiments 2, 3A and B, and 4A and B investigated the use of optical and haptic information in detecting traversability of rigid and nonrigid surfaces. Patterns of exploration varied with the information presented and differed for crawlers and walkers in the case of a deformable surface, as an affordance theory would predict.

Attention↗
PubMed1979

Visual-field asymmetries in letter recognition: evidence for asymmetry in early visual registration.

Two experiments on visual-field differences in tachistoscopic letter recognition are described. In the first, a bright pre-exposure field with a black fixation point was used, and the conventionally expected dominance of the right visual field was found. However, a large number of "blank" trials were observed, in which subjects completely failed to detect the presence of the flashed target. These "blanks" were themselves significantly asymmetric between visual fields, suggesting that asymmetry in early stimulus registration may play an unsuspected role in typical measures of cerebral asymmetry in recognition accuracy. This was confirmed in a second experiment in which use of dark pre-exposure fields eliminated "blanks" and led to higher over-all accuracy, with no visual-field differences. Implications for interpretation of laterality data with normal subjects are discussed.

Adult↗
PubMedDate not supplied

[Carotid atherosclerosis and thrombotic stroke. Diagnostic and therapeutic perspectives].

Carotid atherosclerotic lesions can be studied with color-Doppler ultrasonography vascular systems. Ultrasonography of the carotid plaques at major risk for the development of cerebrovascular ischemic events showed the following characteristics: irregular surface, degree of stenosis > 70%, intimal hemorrhage and ulceration. The plaques with these ultrasonography patterns have to be considered for surgical approach (TEA). The other patients with carotid atherosclerotic lesions will be initially treated with diet and changes of life style to obtain the correction of cardiovascular risk factors (i.e. hypertension, hypercholesterolemia, diabetes). Furthermore, medical therapy with antithrombotic agents will be instituted which, used with good results also in acute cerebral stroke, proved to be effective in the reduction of vascular events in patients with extracranial atherosclerotic plaques. However, it has not been clarified if the positive effect of antiaggregation therapy in carotid atherosclerosis is due to the inhibition of the progression and plaque growth or if other hemorheological factors are involved.

Arteriosclerosis↗
PubMedDate not supplied

[Treatment of surface water].

The present paper describes the most important treatment processes to be used for water for human consumption. Advantages and disadvantages of alternative disinfectants are discussed and a critical assessment of the problem associated to disinfection byproducts is included.

Fresh Water↗
PubMedDate not supplied

[Criteria for assessing severely hot environments: from the WBGT index to the PHS (predicted heat strain) model].

BACKGROUND: The present study deals with the main methods for assessment of hot environments: i.e., WBGT, SWreq and PHS. It is stressed how the WBGT index, which is strictly empirical, although a very practical tool for the assessment of the hot environments, can only be used for a rough evaluation of heat stress, and especially for a not very high metabolic rate (M<175 W/m2). On the contrary, the SWreq method, which is based on both subject-environment heat exchange and the effect of clothing, allows a better assessment of the work situation with a general reduction of the exposure limits with respect to WBGT, especially in non-uniform environments (ta not equal to tr). However, it should be noted that application of SWreq is required by the ISO standard 7243 when the WBGT limit values are exceeded. METHODS: In this study interest was extensively focused on the "Predicted Heat Strain" method, highlighting via a special software the differences in heat stress assessment related to this new approach, which will be adopted by the ISO in the next revision of standard 7933. RESULTS: The PHS method, unlike SWreq, allows the prediction of the time-response of the main physiological variables of interest (i.e., skin temperature, core temperature and sweat rate). Moreover thanks to better modelling of heat exchanges, the PHS method allows account to be taken of both movement and clothing effects, resulting in even more reduced exposure.

Biophysical Phenomena↗
PubMedDate not supplied

[Air quality control systems: heating, ventilating, and air conditioning (HVAC)].

After a brief illustration of the principal layout schemes of Heating, Ventilating, and Air Conditioning (HVAC), the first part of this paper summarizes the standards, both voluntary and compulsory, regulating HVAC facilities design and installation with regard to the question of Indoor Air Quality (IAQ). The paper then examines the problem of ventilation systems maintenance and the essential hygienistic requirements in whose absence HVAC facilities may become a risk factor for people working or living in the building. Lastly, the paper deals with HVAC design strategies and methods, which aim not only to satisfy comfort and air quality requirements, but also to ensure easy and effective maintenance procedures.

Air Conditioning↗
PubMedDate not supplied

Spinal cord involvement and systemic lupus erythematosus: clinical and magnetic resonance findings in 5 patients.

We report the clinical, magnetic resonance imaging (MRI) and laboratory findings in 5 patients with clinical spinal cord involvement with an acute or subacute course; in two of the patients the myelitic episode preceded, in one it was concomitant to, and in two it followed the diagnosis of systemic lupus erythematosus (SLE). The marked clinical and MRI heterogeneity detected in our patients suggests that various factors may be implied in the pathogenesis of spinal cord involvement in SLE. The possibility of a future evolution to SLE should be kept in mind in women presenting spinal cord involvement with no other explanation, and should be assessed by means of extensive and repeated clinical and laboratory evaluations.

Adolescent↗