4 resultados para Astronautics and state
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
The Ecosystem Approach to Fisheries represents the most recent research line in the international context, showing interest both towards the whole community and toward the identification and protection of all the “critical habitats” in which marine resources complete their life cycles. Using data coming from trawl surveys performed in the Northern and Central Adriatic from 1996 to 2010, this study provides the first attempt to appraise the status of the whole demersal community. It took into account not only fishery target species but also by-catch and discharge species by the use of a suite of biological indicators both at population and multi-specific level, allowing to have a global picture of the status of the demersal system. This study underlined the decline of extremely important species for the Adriatic fishery in recent years; adverse impact on catches is expected for these species in the coming years, since also minimum values of recruits recently were recorded. Both the excessive exploitation and environmental factors affected availability of resources. Moreover both distribution and nursery areas of the most important resources were pinpointed by means of geostatistical methods. The geospatial analysis also confirmed the presence of relevant recruitment areas in the North and Central Adriatic for several commercial species, as reported in the literature. The morphological and oceanographic features, the relevant rivers inflow together with the mosaic pattern of biocenoses with different food availability affected the location of the observed relevant nursery areas.
Resumo:
Obesity often predisposes to coronary heart disease, heart failure, and sudden death. Also, several studies suggest a reciprocal enhancing interaction between obesity and sleep curtailment. Aim of the present study was to go deeper in the understanding of sleep and cardiovascular regulation in an animal model of diet-induced obesity (DIO). According to this, Wake-Sleep (W-S) regulation, and W-S dependent regulation of cardiovascular and metabolic/thermoregulatory function was studied in DIO rats, under normal laboratory conditions and during sleep deprivation and the following recovery period, enhancing either wake or sleep, respectively. After 8 weeks of the delivery of a hypercaloric (HC) diet, treated animals were heavier than those fed a normocaloric (NC) diet (NC: 441 ±17g; HC: 557±17g). HC rats slept more than NC ones during the activity period (Dark) of the normal 12h:12h light-dark (LD) cycle (Wake: 67.3±1.2% and 57.2 ±1.6%; NREM sleep (NREMS): 26.8±1.0% and 34.0±1.4%; REM sleep (REMS): 5.7±0. 6% and 8.6±0.7%; for NC and HC, respectively; p<0.05 for all). HC rats were hypertensive throughout the W-S states, as shown by the mean arterial blood pressure values across the 24-h period (Wake: 90.0±5.3 and 97.3±1.3; NREMS: 85.1±5.5 and 92.2±1.2; REMS: 87.2±4.5 and 96.5±1.1, mmHg for NC and HC, respectively; p<0.05 for all). Also, HC rats appeared to be slightly bradycardic compared to NC ones (Wake: 359.8±9.3 and 352.4±7.7; NREMS: 332.5±10.1 and 328.9±5.4; REMS: 338.5±9.3 and 334.4±5.8; bpm for NC and HC, respectively; p<0.05 for Wake). In HC animals, sleep regulation was not apparently altered during the sleep rebound observed in the recovery period following sleep deprivation, although REMS rebound appeared to be quicker in NC animals. In conclusion, these results indicate that in the rat obesity interfere with W-S and cardiovascular regulation and that DIO rats are suitable for further studies aimed at a better understanding of obesity comorbidities.
Resumo:
Spinal cord injury (SCI) results not only in paralysis; but it is also associated with a range of autonomic dysregulation that can interfere with cardiovascular, bladder, bowel, temperature, and sexual function. The entity of the autonomic dysfunction is related to the level and severity of injury to descending autonomic (sympathetic) pathways. For many years there was limited awareness of these issues and the attention given to them by the scientific and medical community was scarce. Yet, even if a new system to document the impact of SCI on autonomic function has recently been proposed, the current standard of assessment of SCI (American Spinal Injury Association (ASIA) examination) evaluates motor and sensory pathways, but not severity of injury to autonomic pathways. Beside the severe impact on quality of life, autonomic dysfunction in persons with SCI is associated with increased risk of cardiovascular disease and mortality. Therefore, obtaining information regarding autonomic function in persons with SCI is pivotal and clinical examinations and laboratory evaluations to detect the presence of autonomic dysfunction and quantitate its severity are mandatory. Furthermore, previous studies demonstrated that there is an intimate relationship between the autonomic nervous system and sleep from anatomical, physiological, and neurochemical points of view. Although, even if previous epidemiological studies demonstrated that sleep problems are common in spinal cord injury (SCI), so far only limited polysomnographic (PSG) data are available. Finally, until now, circadian and state dependent autonomic regulation of blood pressure (BP), heart rate (HR) and body core temperature (BcT) were never assessed in SCI patients. Aim of the current study was to establish the association between the autonomic control of the cardiovascular function and thermoregulation, sleep parameters and increased cardiovascular risk in SCI patients.
Resumo:
In this research work I analyzed the instrumental seismicity of Southern Italy in the area including the Lucanian Apennines and Bradano foredeep, making use of the most recent seismological database available so far. I examined the seismicity occurred during the period between 2001 and 2006, considering 514 events with magnitudes M ≥ 2.0. In the first part of the work, P- and S-wave arrival times, recorded by the Italian National Seismic Network (RSNC) operated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV), were re-picked along with those of the SAPTEX temporary array (2001–2004). For some events located in the Upper Val d'Agri, I also used data from the Eni-Agip oil company seismic network. I computed the VP/VS ratio obtaining a value of 1.83 and I carried out an analysis for the one-dimensional (1D) velocity model that approximates the seismic structure of the study area. After this preliminary analysis, making use of the records obtained in the SeSCAL experiment, I incremented the database by handpicking new arrival times. My final dataset consists of 15,666 P- and 9228 S-arrival times associated to 1047 earthquakes with magnitude ML ≥ 1.5. I computed 162 fault-plane solutions and composite focal mechanisms for closely located events. I investigated stress field orientation inverting focal mechanism belonging to the Lucanian Apennine and the Pollino Range, both areas characterized by more concentrated background seismicity. Moreover, I applied the double difference technique (DD) to improve the earthquake locations. Considering these results and different datasets available in the literature, I carried out a detailed analysis of single sub-areas and of a swarm (November 2008) recorded by SeSCAL array. The relocated seismicity appears more concentrated within the upper crust and it is mostly clustered along the Lucanian Apennine chain. In particular, two well-defined clusters were located in the Potentino and in the Abriola-Pietrapertosa sector (central Lucanian region). Their hypocentral depths are slightly deeper than those observed beneath the chain. I suggest that these two seismic features are representative of the transition from the inner portion of the chain with NE-SW extension to the external margin characterized by dextral strike-slip kinematics. In the easternmost part of the study area, below the Bradano foredeep and the Apulia foreland, the seismicity is generally deeper and more scattered and is associated to the Murge uplift and to the small structures present in the area. I also observed a small structure NE-SW oriented in the Abriola-Pietrapertosa area (activated with a swarm in November 2008) that could be considered to act as a barrier to the propagation of a potential rupture of an active NW-SE striking faults system. Focal mechanisms computed in this study are in large part normal and strike-slip solutions and their tensional axes (T-axes) have a generalized NE-SW orientation. Thanks to denser coverage of seismic stations and the detailed analysis, this study is a further contribution to the comprehension of the seismogenesis and state of stress of the Southern Apennines region, giving important contributions to seismotectonic zoning and seismic hazard assessment.