Inequality and Growth: Does Time Change Anything

The econometric analysis of economic growth has always been subject to major flaws and shortcomings. Data scarcity and reliability, parameter heterogeneity, omitted variables bias, endogeneity problems, ... have seriously tainted estimation results. In this paper we propose an alternative framework that explicitly deals with these issues. We investigate the relation between income inequality and economic growth in a number of OECD countries in a cointegrated VAR-setting. Our results suggest that different models seem to hold for different countries. However, for most countries the imperfect markets model better describes reality than the complete markets model.income inequality, economic growth, cointegrated VAR

Exploratory analysis of the association between total T2 lesion volume on brain MRI and resilience in young Patients with Multiple Sclerosis

INTRODUCTION: Multiple Sclerosis is a neurological disorder that affects mostly young adults potentially causing disability due to involvement of motor, sensory, visual and cognitive functions. Frequently patients with multiple sclerosis presents psychological symptoms such as depression and anxiety. Receiving a diagnosis of multiple sclerosis, especially when it happens during young age, represent a challenge for which each individual must face relevant emotional distress. The way in which each person copes to disease seems to be strongly related with resilience. Determinants of resilience include a host of biological, psychological, social, and cultural factors that interact with one another to determine how one respond to stressful experiences. The links between disease-specific variables at diagnosis, resilience, and psychological adjustment of multiple sclerosis patients remain largely unexplored, especially in young adults. AIM OF THE STUDY: to explore the hypothesis that psychological adaptation to multiple sclerosis might be driven not only from personal, social and cognitive factors but also from mechanisms that are intrinsic to the disease process. The primary endpoint of the study was to analyze the correlation between psychological resilience and total T2 lesion volume on brain MRI – i.e. a reliable biomarker of disease severity – in a cohort of young patients newly diagnosed with multiple sclerosis. MATERIALS AND METHODS: we identified eligible patients from an ongoing observational study at University of Verona in which several clinical, psychological, MRI and laboratory measures are collected cross - sectionally in patients with multiple sclerosis aged 18-45 years at enrolment, which occurs in the first two years after diagnosis according to inclusion criteria. For MRI segmentation and lesion volume calculation we used the brain MRI scans obtained from routine investigation for diagnosis or clinical assessment (1.5 or 3 T depending on the machine available at the Center where diagnosis was formulated) within 6 months prior and one month after enrolment. The analysis of total T2 lesion volume (TLV) was made using software open-source ITK-SNAP with semiautomatic segmentation. In order to measure resilience, the Connor-Davidson Resilience Scale (CD – RISC25) was used. The statistical analysis included a descriptive analysis of demographical, psychological and clinical characteristics of participants. A non-parametric approach was applied to compare groups, by using the Kruskal-Wallis test. An explorative correlation analysis was conducted to check possible relationship among variables. RESULTS: our sample consists of 51 consecutive patients, 33 females and 18 males with a mean age of 33.3 years. 88,23% of patients have relapsing-remitting multiple sclerosis and 74,5% a low level of disability (EDSS ≤ 2). The mean T2 lesion volume found was 4.32 cm3 (range 0,21 – 24,79). For resilience (the maximum score on the CD-RISC is 100), the mean value in our sample resulted 65,13 (CI 60,65 – 69,61). Considering data about Quality of Life using the MSQoL- 54 scale, the mean score for physical health resulted 61,48 (CI 58.87 – 64.08) while the mean score for mental health resulted 51,13 (CI 48,22 – 54,03). Other two single scores were calculated; the mean for change in health was 50,19 (CI 45,24 – 55,14); for sexual satisfaction it was 76,73 (CI 70,71 – 82,75). Correlation analysis did not show a significant correlation between T2 total lesion volume and resilience. Despite none of the performed correlation analyses showed statistically significant results, a moderate correlation between resilience and age and between resilience and time from onset of symptoms was numerically observed; a weak inverse correlation was found between EDSS score and resilience. In addition, there was a numerical correlation between resilience and the physical health subscore of MSQoL-54, particularly in the relapsing-remitting multiple sclerosis patients subgroup. CONCLUSION: with reference to the primary outcome, the exploratory analysis we performed in our study showed that total T2 lesion volume on brain MRI of young patients with multiple sclerosis is not significantly associated with resilience. Overall, no significant findings were observed for any of analyzed variables, however some of association examined are worthy of attention. The time that took place between onset of disease and enrollment seems to have a potential moderate correlation with resilience. Among sociodemographic data we have found a possible moderate correlation between resilience and age and also with physical health score in the MSQoL. Also the score regarding physical health on MSQoL numerically shows a moderate correlation with resilience. Our findings show that resilience of young patients with multiple sclerosis, although not statistically associated with disease burden assessed as T2 lesion load on brain MRI, is possibly connected to demographic variables, physical wellbeing, disease duration and possibly disability accumulation in the early stages of the disease. Therefore, all these features deserve to be furtherly examined as possible determinants of resilience, with the ultimate goal of improving quality of life of people with multiple sclerosis

Analysis of selection pressure exerted on Plasmopara viticola by organically based fungicides

Downy mildew is one of the most important grape diseases world-wide. The pathogen is a genetically highly diversified organism with a high capacity of adaptation. A monitoring of changes in population structure of P. viticola subjected to new copper replacing products or strategies, studied and developed within REPCO (Replacement of Copper Fungicides in Organic Production of Grapevine and Apple in Europe) is important for assessing selection pressure which could lead to a reduction of efficacy of these new measures. Therefore P. viticola lesions collected on untreated and treated vines were analyzed by means of microsatellite markers. No significant differences in the populations structure were determined among untreated and treated populations, indicating that the applied products didn’t exerted any selection pressure on the P. viticola populations

The role of parasites in host speciation. Testing for parasite-mediated divergent selection at different stages of speciation in cichlid fish

Parasites represent one of the most successful modes of life in nature and are an important component of ecosystems. By imposing fitness costs on their hosts, parasites constitute a major agent of ecological selection. The host-parasite coevolutionary dynamics of adaptation and counter-adaptation may promote host diversification. The cichlid fish of Lake Victoria have rapidly diversified into hundreds of species, making them a good model system for studying the early stages of speciation. I investigate whether parasites drive or contribute to host speciation by analysing infection patterns in closely related cichlid populations. I found support for two prerequisites for parasite-mediated selection: host species differed in their infection profiles and these infection differences were maintained over multiple sampling years. Different parasites were located in different microhabitats in the fish gills, also depending on the host species. Since microhabitat segregation constitutes another axis of infection heterogeneity, I suggest to include it in future studies. Host species variation in infection was not fully explained by exposure to parasites, suggesting that other intrinsic host properties (i.e. immunity) also play a role. Incipient cichlid species reared in aquaria with uniform parasite exposure did not differ in infection, indicating they have not (yet) evolved differences in immunity. This is inconsistent with a role of parasites in driving host divergence. Infection differences accumulate as hosts become more genetically differentiated, but only reproductive isolated host species display a significant difference in infection. This suggests that parasites may contribute to host divergence but they are not initiating it

The role of parasites in host speciation:Testing for parasite-mediated divergent selection at different stages of speciation in cichlid fish

Parasites represent one of the most successful modes of life in nature and are an important component of ecosystems. By imposing fitness costs on their hosts, parasites constitute a major agent of ecological selection. The host-parasite coevolutionary dynamics of adaptation and counter-adaptation may promote host diversification. The cichlid fish of Lake Victoria have rapidly diversified into hundreds of species, making them a good model system for studying the early stages of speciation. I investigate whether parasites drive or contribute to host speciation by analysing infection patterns in closely related cichlid populations. I found support for two prerequisites for parasite-mediated selection: host species differed in their infection profiles and these infection differences were maintained over multiple sampling years. Different parasites were located in different microhabitats in the fish gills, also depending on the host species. Since microhabitat segregation constitutes another axis of infection heterogeneity, I suggest to include it in future studies. Host species variation in infection was not fully explained by exposure to parasites, suggesting that other intrinsic host properties (i.e. immunity) also play a role. Incipient cichlid species reared in aquaria with uniform parasite exposure did not differ in infection, indicating they have not (yet) evolved differences in immunity. This is inconsistent with a role of parasites in driving host divergence. Infection differences accumulate as hosts become more genetically differentiated, but only reproductive isolated host species display a significant difference in infection. This suggests that parasites may contribute to host divergence but they are not initiating it

Identification of Microsatellite Markers for Plasmopara viticola and Establishment of High throughput Method for SSR Analysis

The Oomycete Plasmopara viticola is the causal organism of downy mildew on grapevine (Vitis spp.). In order to set up the techniques for investigating downy mildew disease dynamics and genetic structure, co-dominant, neutral, highly reproducible and polymorphic microsatellite markers for P. viticola were developed. Five markers, two with a (TC)n repeat (loci BER and ISA), two with a (TC)n(AC)n repeat (loci CES and REX) and one with a (CT)n(CTAT)n repeat (locus GOB), were selected. Simple sequence repeat (SSR) markers revealed different degrees of polymorphism within 190 oil spots (disease symptoms) collected from an infected Italian vineyard. The most polymorphic SSR marker GOB showed 43 alleles (Nei's expected gene diversity He = 0.89) while CES, ISA, BER and REX showed 14 (He = 0.71), 4 (He = 0.57), 3 (He = 0.24) and 1 allele (He = 0), respectively. A high throughput DNA extraction method, that allowed molecular analysis of this obligate pathogen directly in the host without any isolation procedure, was developed. The quality and quantity of oil spots did not influence the SSR analysis. Amplified SSR loci were separated by electrophoresis on a Beckman-Coulter 2000XL sequencer and automatically analysed. The objective of this study was to develop molecular biological tools and methods that allow high throughput analysis of the downy mildew population

Microsatellite based population structure of Plasmopara viticola at single vine scale

The genetic structure of a Plasmopara viticola population was characterized on five single vines, one for each cultivar Regent, Merlot, Isabella, Müller-Thurgau and Solaris, using four neutral specific polymorphic microsatellite markers. Five-hundred and seventy samples were collected at four dates in the period between the 10th of July and the 23rd of August 2006. On average over all five cultivars, 67% of the genotypes present on the single selected vines derived from primary infections and caused 37% of the lesions genotyped. Fifty-three percent of these genotypes occurred only once on the vine throughout the survey period, while 14% were able to asexually reproduce on the selected single vine throughout the survey period, causing 23% of the lesions. Thirty-three percent of the genotypes on the single vine derived from other vines, 28% from vines of other cultivars in the other rows, and 5% from vines of the same cultivar in the same row. New primary infections appear all along the sampling dates. The overwhelmingly quantitative role of primary infections at vineyard scale was known, however here we observed the phenomenon also at the single vine scale and the reduced contribution of secondary lesions to the populations present on more resistant cultivars compared to the susceptible cultivars. As the sampling extended almost to defoliation, the results are judged to be representative of a typical P. viticola epidemi