1,720,979 research outputs found
Monitoring tropospheric ozone impact on plants in natural and urban areas with a Mediterranean climate
No full textTo investigate the real linkage and effectiveness of using the AOT40 index and ozone stomatal flux (FO3) in the assessment of physiological alteration/leaf injury on clover clones sensitive to ozone and Quercus ilex plants, two statistical techniques Partial Least Squares (PLS) and Neural Net Analysis (NNA)-were applied. Different results were obtained in relation to the statistical method chosen. Linear methodologies applied to clover highlighted the role of temperature (TEMP) and O-3 concentration (O(3)Mean) in affecting photosynthesis (PHOTO), leaf injury, and stomatal conductance (COND). In Quercus plants, COND was linearly correlated to two environmental variables, TEMP and Vapour Pressure Deficit (VPD), and to two physiological variables, PHOTO and Leaf Transpiration (TRASP), whereas PHOTO was correlated with TEMP, sO(3), COND and sub-stomatal CO2/external CO2 ratio (Ci/Ca). These linear relationships were, in part, modified by NNA. In fact, non-linear relationships between environmental variables, and morphological and physiological variables were evident, suggesting caution when risk assessments are made on ozone concentration-based critical levels. Both plant types showed a relationship with FO3 that negatively affected leaf injury and PHOTO in clover and Quercus plants, respectively, suggesting that ozone flux-based critical levels were more effective in linking with leaf injuries or reduction in carbon metabolism
Application of stochastic processes and the random field theory to the resolution of ecological systems from spatial and temporal point of view.
No full textIn this work we will develop approaches having the aim to bu9ild ecological models in the framework of mechanistic and statistical combined approach for spatial scaling and spatial/temporal modelling. The statistical and mathematical tools are stochastic processes and random field theory applied to the prediction and control of ecological systems
Cellular Automata and Random Field: Statistical Analysis of Complex Space-Time Systems
No full textIn the classical approach to the mathematical model specification, for space-time complex system, the usual framework is the Partial Difference-Differential Equations system (PDEs). This approach is very hard from a mathematical point of view, and the search for the (PDEs) solutions, almost in the practical applications, often it is impossible. Our approach is based, on the contrary, on Cellular Automata methodology in the framework of Random Field models. The statistical model building methodology for the Random Fields, is based on very simple statistical and probabilistic reasoning that utilize the concept of divisible distributions and logistic non-linear model. The interaction rules for the Cellular Automata mechanism, are built thorough inferential statistics and data analysis
Statistical analysis of ozone concentration: a forecasting and control model in urban areas
No full textOzone concentration in the urban areas of Rome is studied using statistical methods of multivariate and time series analysis. Data of two sites (a green park and a high motor traffic street) are evaluated and O3g concentration daily and seasonal trends are linked to other variables behaviours. Furthermore the relationship between the full set of pollution variables has analyse
Ionizing radiation and stress: the analysis of the medical ray technician
No full textThe present study aims to analyzing the relation between the work-related distress with the exposition to ionizing radiations in the radiology technicians, in the hospital environment.
Materials and Methods
Our present study has been conducted on a group of 36 sanitary technicians (14 women and 22 man, with an average age of 48±10,1 years) working in the Hospital Radiology Pavilion; 28 of them were less-exposed to radio-active emissions (B Category) and 8 were more exposed to radio-active emissions (A Category). The HSE questionnaire has been administered to all the 36 sanitary technicians. The data analysis and statistical elaboration were conducted using the HSE Tools. After that, the non-parametric Mann-Whitney test was applied to the comparison of the medians of two independent samples.
Results
The HSE tools questionnaire’s analysis (made on the whole population) made evident some criticalities in the domains of the managerial support and of the professionals’ relationships: in the B Category group (less- exposed to radio-emissions) further criticalities emerged, in the domain of peer-support and in the change domain.
The HSE questionnaire analysis, made adopting the Mann-Whitney non-parametric statistical test, significant statistical differences emerged from 2 questions of the 35 sub-administered questions, regarding the mostly radio-exposed workers.
Conclusions
From the research analysis, the authors deducted the small relevance of the emerged criticalities for the two groups of workers; the researchers also believe that, given the (almost complete) homogeneity of the results emerging from the statistical analysis (done with the Mann Whitney test), the perception of the of the work-related distress risk is irrelevant to the dose of ionizing radio-expositio
Kabat rehabilitation for Bell's palsy in the elderly.
No full textCONCLUSIONS: This study has confirmed the importance of combining the physical rehabilitation to the steroid treatment for a better outcome from BP in all age groups, especially in the old HB grade V.
OBJECTIVES: To investigate the role played by aging in the recovery rate from peripheral facial nerve palsy.
METHOD: In the present study, subjects affected by peripheral facial nerve palsy, distributed by age, were randomly assigned to medical treatment, either alone or associated with Kabat physical rehabilitation. Rate and speed of recovery were assessed in the younger and older groups. All the patients were also asked to fill in a specific questionnaire (beta FAce scale). A series of non-parametric tests (McNemar Chi-square and Chi-square) have been applied to verify the hypothesis of dependence of the final recovery level from the variables age and rehabilitation.
RESULTS: The results show that, when treated only by medical therapy, the HB V subjects showed no significant age difference in relation to the achievement of a HB Grade III (100% in the over 65, 80% in the under 65), whilst, in the HB IV subjects, the younger population showed a better recovery, with 89% of a good recovery (HB I or II). In the patients who received the combined protocol, a better recovery rate was found, both in HB IV and V subjects, and the younger population could reach a good recovery in 90% of HB V cases in respect to the older population (50%)
Effect of climate change on tree species distribution assessed by cellular automata model
No full textNatalizumab in multiple sclerosis: Discontinuation, progressive multifocal leukoencephalopathy and possible use in children
No full textIn the early 1990s, attention was drawn to the migration of immune cells into the central nervous system via the blood-brain barrier. The literature showed that lymphocytes binding to the endothelium were successfully inhibited by an antibody against 41 integrin. These biological findings resulted in the development of a humanized antibody to 4 integrin - natalizumab (NTZ) - to treat multiple sclerosis (MS). Here, we provide a systematic review and meta-analysis on the efficacy and safety of natalizumab, trying to answer the question whether its use may be recommended both in adult and in pediatric age groups as standard MS treatment. Our results highlight the improvement of clinical and radiological findings in treated patients (p<0.005), confirming NTZ efficacy. Nevertheless, if NTZ is shown to be efficient, further studies should be performed to evaluate its safety and to target the MS profile that could benefit from this treatment
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