512 research outputs found

    Interactive management of time series

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    The main purpose of this data base is to offer the researcher a supply of information which can be analyzed, revised and updated in a repetitive way. This can be accomplished by an interactive approach. It is possible to use data from the central file (official data) and from a private single user file. It is possible to write regression equations, as well as algebraic expressions defining transformations of the economic variables.Economic data base; interactive access; transformation of variables; regression analysis

    Interactive management of time series

    Get PDF
    The main purpose of this data base is to offer the researcher a supply of information which can be analyzed, revised and updated in a repetitive way. This can be accomplished by an interactive approach. It is possible to use data from the central file (official data) and from a private single user file. It is possible to write regression equations, as well as algebraic expressions defining transformations of the economic variables

    On the Origins and Admixture of Malagasy: New Evidence from High-Resolution Analyses of Paternal and Maternal Lineages

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    The Malagasy have been shown to be a genetically admixed population combining parental lineages with African and South East Asian ancestry. In the present paper, we fit the Malagasy admixture history in a highly resolved phylogeographic framework by typing a large set of mitochondrial DNA and Y DNA markers in unrelated individuals from inland (Merina) and coastal (Antandroy, Antanosy, and Antaisaka) ethnic groups. This allowed performance of a multilevel analysis in which the diversity among main ethnic divisions, lineage ancestries, and modes of inheritance could be concurrently evaluated. Admixture was confirmed to result from the encounter of African and Southeast Asian people with minor recent male contributions from Europe. However, new scenarios are depicted about Malagasy admixture history. The distribution of ancestral components was ethnic and sex biased, with the Asian ancestry appearing more conserved in the female than in the male gene pool and in inland than in coastal groups. A statistic based on haplotype sharing (D(HS)), showing low sampling error and time linearity over the last 200 generations, was introduced here for the first time and helped to integrate our results with linguistic and archeological data. The focus about the origin of Malagasy lineages was enlarged in space and pushed back in time. Homelands could not be pinpointed but appeared to comprise two vast areas containing different populations from sub-Saharan Africa and South East Asia. The pattern of diffusion of uniparental lineages was compatible with at least two events: a primary admixture of proto-Malay people with Bantu speakers bearing a western-like pool of haplotypes, followed by a secondary flow of Southeastern Bantu speakers unpaired for gender (mainly male driven) and geography (mainly coastal)

    Surname analysis of the Corsican population reveals an agreement with geographical and linguistic structure

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    The surname is a cultural trait that is extremely useful for historical and linguistic studies and can effectively be used as a genetic marker. In many human populations the surname is inherited in the paternal lineage, and can therefore be considered a marker for the Y chromosome. In this study, surnames were recorded from the white pages of telephone directories in current use in Corsica in 1993. All surnames present in thirteen villages scattered over the whole island and covering the main historical regions were transcribed. Surname variability was found to be higher in coastal villages, and lower in more isolated communities. The isonymy detected among the thirteen villages allowed the calculation of kinship values, visualized in a tree showing two main clusters, one referring to the northern villages and one encompassing the villages of the south. The pattern reflects the administrative division of the island, with the exception of Vico, which belongs to the southern administrative region but is geographically close to the northern villages, and Ghisoni, which belongs to the northern district but is more similar to the village of Bastelica in the southern district. The data presented here show a structure in the surname distribution that is in substantial agreement with the geographical patterns. The kinship values are consistent with a moderated gene flow among villages producing a surname structure according to the geographic features of the territory

    Estimating Sampling Selection Bias in Human Genetics: A Phenomenological Approach

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    This research is the first empirical attempt to calculate the various components of the hidden bias associated with the sampling strategies routinely-used in human genetics, with special reference to surname-based strategies. We reconstructed surname distributions of 26 Italian communities with different demographic features across the last six centuries (years 1447-2001). The degree of overlapping between "reference founding core" distributions and the distributions obtained from sampling the present day communities by probabilistic and selective methods was quantified under different conditions and models. When taking into account only one individual per surname (low kinship model), the average discrepancy was 59.5%, with a peak of 84% by random sampling. When multiple individuals per surname were considered (high kinship model), the discrepancy decreased by 8-30% at the cost of a larger variance. Criteria aimed at maximizing locally-spread patrilineages and long-term residency appeared to be affected by recent gene flows much more than expected. Selection of the more frequent family names following low kinship criteria proved to be a suitable approach only for historically stable communities. In any other case true random sampling, despite its high variance, did not return more biased estimates than other selective methods. Our results indicate that the sampling of individuals bearing historically documented surnames (founders' method) should be applied, especially when studying the male-specific genome, to prevent an over-stratification of ancient and recent genetic components that heavily biases inferences and statistics

    Modelling plant yield and quality response of fresh-market spinach (Spinacia oleracea L.) to mineral nitrogen availability in the root zone

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    Spinach is one of the most important green-leafy vegetables, consumed worldwide, and its intake is beneficial for human beings. In this crop, produce yield and quality are closely related to plant nitrogen (N) nutrition. A precise supply of N is also essential for high environmental and economic sustainability. Main aims of the work were: i) to establish relationships between produce yield or quality and mineral N availability in the root zone; and ii) to define an optimal mineral N level to be maintained in the root zone for spinach. Eight experiments were carried out during a four-year-long period under typical Mediterranean climate conditions. Different amounts of N fertilisers were supplied leading to twenty different levels of mineral N in the root zone. Experimental measurements included climate parameters, plant growth, tissue and soil analyses, produce yield and quality indicators. A segmented linear model significantly represented the relationship between crop yield (1.7 to 21.7 t ha–1) and soil mineral N concentration (7.6 to 41.0 mg kg–1). Basing on this model, an optimal mineral N threshold was fixed at 23.4 mg kg–1. Above this threshold, crop yield did not show any significant variations as well as tissue characteristics and produce quality. Plants grown under suboptimal N levels showed reduction in growth, tissue mineral (nutrients) content, and SPAD index. The proposed models could be implemented in fertilisation protocols for the optimization of N supply and the estimation of spinach growth and yield

    Lobaria pulmonaria (L.) Hoffm.: The Multifaceted Suitability of the Lung Lichen to Monitor Forest Ecosystems

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    Lobaria pulmonaria (L.) Hoffm. is a tripartite, broad-lobed foliose lichen usually found on bark and on epiphytic and epilithic mosses in humid forests. Currently, the species is threatened in most European countries because of its sensitivity to environmental alterations. In this paper, a total of 107 previous studies across more than 50 years were analysed to gain insight into the multiple roles that L. pulmonaria plays in forest habitats, specifically relating to ecosystem services and as environmental bioindicator. Content analysis was employed to systematically characterise and classify the existing papers on the functions performed by L. pulmonaria into several groups mostly based on research topic and scope. Two main types of ecosystem services (N2 fixation and feeding) offered by L. pulmonaria have been identified, with varying research aims and types of parameters measured in the studies. Two aspects of current biomonitoring applications using L. pulmonaria in forest habitats (concerning atmospheric pollution and forest management) were analysed, and it was found that the number of related studies increased significantly in recent years. Finally, the current practices of monitoring using L. pulmonaria as a biological indicator are discussed, and recommendations are provided

    High altitude adaptation in Daghestani populations from the Caucasus

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    We have surveyed 15 high-altitude adaptation candidate genes for signals of positive selection in North Caucasian highlanders using targeted re-sequencing. A total of 49 unrelated Daghestani from three ethnic groups (Avars, Kubachians, and Laks) living in ancient villages located at around 2,000 m above sea level were chosen as the study population. Caucasian (Adygei living at sea level, N = 20) and CEU (CEPH Utah residents with ancestry from northern and western Europe; N = 20) were used as controls. Candidate genes were compared with 20 putatively neutral control regions resequenced in the same individuals. The regions of interest were amplified by long-PCR, pooled according to individual, indexed by adding an eight-nucleotide tag, and sequenced using the Illumina GAII platform. 1,066 SNPs were called using false discovery and false negative thresholds of ~6%. The neutral regions provided an empirical null distribution to compare with the candidate genes for signals of selection. Two genes stood out. In Laks, a non-synonymous variant within HIF1A already known to be associated with improvement in oxygen metabolism was rediscovered, and in Kubachians a cluster of 13 SNPs located in a conserved intronic region within EGLN1 showing high population differentiation was found. These variants illustrate both the common pathways of adaptation to high altitude in different populations and features specific to the Daghestani populations, showing how even a mildly hypoxic environment can lead to genetic adaptation

    Elderly with COPD: comoborbitidies and systemic consequences

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    Chronic obstructive pulmonary disease (COPD) represents a comple respiratory disorder characterized by persistent respiratory symptoms due to chronic airflow limitation caused by exposure to noxious particles/gases with an increased inflammatory response of the airways. COPD is common in older people, with an estimated prevalence of 10% in the US population aged > 75 years and is often accompanied by other concomitant chronic conditions that negatively impact prognosis and health status. The aim of this paper is to highlight the relationship between COPD and other comorbidities in elderly population. We focus our attention on the relationship existing between COPD and cardiovascular diseases, lung cancer, obstructive sleep apnoea syndrome, malnutrition/sarcopenia and osteoporosis with particular attention to adipokines, considering that adipose tissue plays a relevant role in the cross-talk between organs
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