Search results for "Multiple"

Spectral properties of correlation matrices for some hierarchically nested factor models

2007

We show that spectral methods, such as Principal Component Analysis and Random Matrix Theory, are unable to reveal the hierarchical (or nested) structure of a set of mutivariate data. We consider the method introduced in M. Tumminello et al., EPL 78, 30006 (2007) to associate a hierarchical factor model with a set of data by making use of clustering algorithms. This is done by proving the existence of a bijective correspondence between a hierarchical tree and a factor model.

Building Composite Indicators With Unweighted-TOPSIS

2023

Composite indicators have been widely used in a large number of fields, including innovation and entrepreneurship as a useful tool for conveying summary information about overall performance in a relatively simple way. The construction of composite indicators implies several stages concerning collection of data, selection of criteria and individual indicators, normalization and weighting of criteria and indicators, aggregation, and comparison of overall performance of the alternatives or options. This article aims at contributing to the construction of synthetic indicators by showing with a real example, how the proposed methodology can overcome the problem of the establisment of the decisi…

A new method for detecting viruses that cause tomato yellow leaf curl disease in the Mediterranean region and their recombinants.

2007

Zymographic Analysis of Matrix Metalloproteinases (MMP-2 and MMP-9) in Cerebrospinal Fluid and Sera from Patients with Multiple Sclerosis

2023

Cumulative climatic stressors strangles marine aquaculture: Ancillary effects of COVID 19 on Spanish mariculture

2021

9 pages, 8 figures

Integrating multiple stressors in aquaculture to build the blue growth in a changing sea

2017

Fisheries currently represent the main source of animal protein intake worldwide, although catches of most commercial species are at or beyond maximum sustainable yields. Increasing production would require an excess of exploitation levels and aquaculture is expected to become crucial in sustaining a growing seafood demand. Nonetheless, many threats are expected to affect aquaculture and the increased production must evolve in a way that minimizes environmental and socio-economic impacts. The claimed sustainable development of human activities at sea (blue growth and economy) seeks for new joint analyses and solutions at (trans-)national systemic level should be planned and applied. To meet…

Short-term exposure to concurrent biotic and abiotic stressors may impair farmed molluscs performance

2022

Global warming, through increasing temperatures, may facilitate the spread and proliferation of outbreak-forming species which may find favourable substrate conditions on artificial aquaculture structures. The presence of stinging organisms (cnidarian hydroids) in the facilities fouling community are a source of pollution that can cause critical problems when in-situ underwater cleaning processes are performed. Multiple stressor experiments were carried out to investigate the cumulative effect on farmed mussels' functional traits when exposed to realistic stressful conditions, including presence of harmful cnidarian cells and environmental conditions of increasing temperature and short-term…

MACROALGAL BIODIVERSITY RESPONSE UNDER A MULTIPLE STRESSOR SCENARIO

2019

Biodiversity-Ecosystem Function experimental stu- dies focusing on marine systems are few and produce contrasting outcomes. Here, we provide experimental proofs on how communities, on a natural gradient of diversity, respond under stressful conditions in inter- tidal habitats. In August 2017 a field experiment was performed in Western Sicily (Italy) in a site charac- terized by tidal pools whose biodiversity structure and composition change as a function of the distance from the low tide mark. The pools closer to the sea are more stable from a thermal and oxic point of view and characterized by high algal biodiversity. Those further from the sea are highly variable with extreme conditions a…

Blood lipid, homocysteine, uric acid and vitamins in clinically stable Multiple Sclerosis patients

2008

A decrease of antioxidants, of neuroprotective and immunoregulatory vitamins and an increase of total-Homocysteine, Cholesterol, HDL-cholesterol, and of cellular stress markers [1] was reported in patients affected by Multiple Sclerosis. Recently, considering their unreliability, mainly due to the variability of the samples investigated, the attention focused on clinical relapse that results associated to a decrease of Uric acid and an increase of Cholesterol and stress markers. Aim. To identify the biochemical status during Multiple Sclerosis (MS) in a phase of clinical stability (PCS), we compared the blood levels of Urico acid (UA), Folic acid (FA), vitamins B12, A, and E, total-Homocyst…

MULTIPLE SCLEROSIS: PHYSICAL ACTIVITY AND WELL-BEING

2017

Multiple sclerosis (MS) is a chronic disease that affects central nervous system (CNS) – coexists in brain, spinal cord and optic nerves. It can process in three different courses: remitting, progressive and progressive-relapsing. Although there is still no cure for MS, effective strategies are available to modify the disease course, reduce number of relapses, rate of progressions and development of new lesions. Nowadays, moderate physical performance is strongly recommended: besides having positive effects on the body, it can have a positive effect on the psychophysical wellbeing. Essentially there are 3 types of training protocols: aerobic (endurance training), strength training (resistan…