A multiple approach for the evaluation of the spatial distribution and dynamics of a forest habitat: the case of Apennine beech forests with Taxus baccata and Ilex aquifolium

An approach integrating phytosociological and stand structure surveys with the predictive modelling of species distribution was applied to analyse the spatial distribution and dynamics of the Apennine beech forests with Taxus and Ilex, a high conservation priority forest habitat in Europe. The homogeneity of the habitat was tested trough a Mann–Whitney test between beech woods with Taxus and those with Ilex with respect to climatic, topographic, structural and environmental parameters: the former have proven to be more microthermic, mesophilous and characterised by a closer canopy. Five statistical models were compared to analyse the relationship between bioclimatic parameters and Taxus and Ilex spatial distribution: Regression Tree Analysis, the most efficient model, has shown that the distribution of Taxus is influenced by precipitation variables, while Ilex is mainly influenced by temperature variables. This model highlighted that Ilex has a potential area that surrounds, at lower altitudes, that of Taxus. A stepwise multiple regression analysis has been applied to identify the factors influencing the regeneration of the two species: beside climatic parameters, Taxus regeneration is negatively influenced by soil nitrate concentration (an indicator of livestock disturbance) while Ilex is negatively influenced by beech forest cover. Traditional management practices seem to have an effect on the regeneration of the two species: frequent cuts favour the regeneration of Ilex, reducing the forest cover and allowing more light penetration, while Taxus, less resistant to grazing livestock, is confined to more inaccessible places. The multiple approach has proven to be useful for the elaboration of two differentiated conservation strategies for the two beech forest types.     

Assessing the impact of ecological and economic factors on land degradation vulnerability through multiway analysis

Land degradation (LD) is a global problem which involves climate, soil, vegetation, economic, and population conditions. In Mediterranean Europe climatic variability and human pressure combine to produce soil sealing, erosion, salinisation, fire risk, and landscape fragmentation, all regarded as important factors to start LD. The aim of this paper is to introduce a time-series evaluation of land vulnerability to degradation based on nine ecological and economic variables. The analysis was carried out over 1970–2000 at the municipality level in Latium (central Italy), a region which has shown increasing land vulnerability in the last years. A multiway data analysis (MDA) was applied in order to explore the relationship among indicators over the study period. Their importance in determining LD vulnerability was estimated through a weighting system based on MDA results. A composite index of land vulnerability (LVI) was obtained as the weighted average of the nine variables transformed into single indicators, according to their relationship with LD. Considerable increases in LVI were observed in dry coastal and lowland municipalities close to Rome, thus indicating that climate aridity, population growth, and land use changes are important determinants of land vulnerability in Latium. LVI was positively correlated to the environmental sensitive area index (ESAI) measured on the same spatial and time scales, thus suggesting that a sound evaluation of land vulnerability is possible through LVI score.     

Improper excess light energy dissipation in Arabidopsis results in a metabolic reprogramming

Background  

Plant performance is affected by the level of expression of PsbS, a key photoprotective protein involved in the process of feedback de-excitation (FDE), or the qE component of non-photochemical quenching, NPQ.     

Definition of an automated Content-Based Image Retrieval (CBIR) system for the comparison of dermoscopic images of pigmented skin lesions

Background  

New generations of image-based diagnostic machines are based on digital technologies for data acquisition; consequently, the diffusion of digital archiving systems for diagnostic exams preservation and cataloguing is rapidly increasing. To overcome the limits of current state of art text-based access methods, we have developed a novel content-based search engine for dermoscopic images to support clinical decision making.     

Association between Protective and Deleterious HLA Alleles with Multiple Sclerosis in Central East Sardinia

The human leukocyte antigen (HLA) complex on chromosome 6p21 has been unambiguously associated with multiple sclerosis (MS). The complex features of the HLA region, especially its high genic content, extreme polymorphism, and extensive linkage disequilibrium, has prevented to resolve the nature of HLA association in MS. We performed a family based association study on the isolated population of the Nuoro province (Sardinia) to clarify the role of HLA genes in MS. The main stage of our study involved an analysis of the ancestral haplotypes A2Cw7B58DR2DQ1 and A30Cw5B18DR3DQ2. On the basis of a multiplicative model, the effect of the first haplotype is protective with an odds ratio (OR) = 0.27 (95% confidence interval CI 0.13–0.57), while that of the second is deleterious, OR 1.78 (95% CI 1.26–2.50). We found both class I (A, Cw, B) and class II (DR, DQ) loci to have an effect on MS susceptibility, but we saw that they act independently from each other. We also performed an exploratory analysis on a set of 796 SNPs in the same HLA region. Our study supports the claim that Class I and Class II loci act independently on MS susceptibility and this has a biological explanation. Also, the analysis of SNPs suggests that there are other HLA genes involved in MS, but replication is needed. This opens up new perspective on the study of MS.     

Increasing Clinical Virulence in Two Decades of the Italian HIV Epidemic

The recent origin and great evolutionary potential of HIV imply that the virulence of the virus might still be changing, which could greatly affect the future of the pandemic. However, previous studies of time trends of HIV virulence have yielded conflicting results. Here we used an established methodology to assess time trends in the severity (virulence) of untreated HIV infections in a large Italian cohort. We characterized clinical virulence by the decline slope of the CD4 count (n = 1423 patients) and the viral setpoint (n = 785 patients) in untreated patients with sufficient data points. We used linear regression models to detect correlations between the date of diagnosis (ranging 1984–2006) and the virulence markers, controlling for gender, exposure category, age, and CD4 count at entry. The decline slope of the CD4 count and the viral setpoint displayed highly significant correlation with the date of diagnosis pointing in the direction of increasing virulence. A detailed analysis of riskgroups revealed that the epidemics of intravenous drug users started with an apparently less virulent virus, but experienced the strongest trend towards steeper CD4 decline among the major exposure categories. While our study did not allow us to exclude the effect of potential time trends in host factors, our findings are consistent with the hypothesis of increasing HIV virulence. Importantly, the use of an established methodology allowed for a comparison with earlier results, which confirmed that genuine differences exist in the time trends of HIV virulence between different epidemics. We thus conclude that there is not a single global trend of HIV virulence, and results obtained in one epidemic cannot be extrapolated to others. Comparison of discordant patterns between riskgroups and epidemics hints at a converging trend, which might indicate that an optimal level of virulence might exist for the virus.