24 research outputs found
Distribution and population genetic variation of cryptic species of the Alpine mayfly Baetis alpinus (Ephemeroptera: Baetidae) in the Central Alps
Is the Tax Burden A Generating Factor of Fiscal Evasion in South-East Europe?
Tax evasion is a pernicious phenomenon, very widespread in the world, which is closely linked to the system of taxes and fees. This is considered to be a response to the excessive fiscal pressure exerted on taxpayers. Bypassing the law is also closely related to the phenomenon of corruption and its removal is a difficult target, under the existing conditions. The main purpose of this paper is to study the influence of corruption and fiscal pressure on the phenomenon of tax evasion, materialized by the shadow economy indicator. The analysis is carried out over a period of 18 years, namely 1999-2016, for six countries of South-Eastern Europe, member states of the European Union, divided into two categories, namely developed and emerging states. The research methodology requires a comparative analysis of existing situations in the research countries. Also, we will use the econometric analysis, with the help of statistical package for social sciences, of the relationship between the underground economy and corruption, as well as the correlation between tax burden exerted by the budget revenues and tax evasion. Being difficult to quantify, the level of shadow economy has been taken from Friedrich Schneider's studies, through which he measured underground economy in 157 countries over the period 1999-2013; but also in 36 states, between 2003 and 2016. The level of corruption is measured using the corruption perception index at the International level and the tax burden is calculated as the ratio between tax revenue and gross domestic product.
Keywords: tax burden, shadow economy, corruption, South-East Europe
How long is 3 km for a butterfly?:ecological constraints and functional traits explain high mitochondrial genetic diversity between Sicily and the Italian Peninsula
Abstract
1.Populations inhabiting Mediterranean islands often show contrasting genetic lineages, even on islands that were connected to the mainland during glacial maxima. This pattern is generated by forces acting in historical and contemporary times. Understanding these phenomena requires comparative studies integrating genetic structure, functional traits and dispersal constraints.
2.Using as a model the butterfly species living across the Messina strait (3 km wide) separating Sicily from the Italian Peninsula, we aimed to unravel the mechanisms limiting the dispersal of matrilines and generating genetic differentiation across a narrow sea strait.
3.We analysed the mitochondrial COI gene of 84 butterfly species out of 90 documented in Sicily and compared them with populations from the neighbouring southern Italian Peninsula (1,398 sequences) and from the entire Palaearctic region (8,093 sequences). For each species, we regressed 13 functional traits and 2 ecological constraints to dispersal (winds experienced at the strait and climatic suitability) against genetic differentiation between Sicily and Italian Peninsula to understand the factors limiting dispersal.
4.More than a third of the species showed different haplogroups across the strait and most of them also represented endemic haplogroups for this island. One fifth of Sicilian populations (and 32.3% of endemic lineages) had their closest relatives in distant areas, instead of the neighbouring Italian Peninsula, which suggests high relictuality. Haplotype diversity was significantly explained by the length of the flight period, an intrinsic phenology trait, while genetic differentiation was explained by both intrinsic traits (wingspan and degree of generalism) and contemporary local constraints (winds experienced at the strait and climatic suitability).
5.A relatively narrow sea strait can produce considerable differentiation among butterfly matrilines and this phenomenon showed a largely deterministic fingerprint. Because of unfavourable winds, populations of the less dispersive Sicilian butterflies tended to differentiate into endemic variants or to maintain relict populations. Understanding these phenomena required the integration of DNA sequences, species traits and physical constraints for a large taxon at continental scale. Future studies may reveal if the patterns here shown for mitochondrial DNA are also reflected in the nuclear genome or, alternatively, are the product of limited female dispersal
Radiological risk assessment and spatial distribution of naturally occurring radionuclides within riverbed sediments near uranium deposits: Tulgheș-Grințieș, Eastern Carpathians (Romania)
Cryptic Species or Inadequate Taxonomy? Implementation of 2D Geometric Morphometrics Based on Integumental Organs as Landmarks for Delimitation and Description of Copepod Taxa
Butterfly–parasitoid–hostplant interactions in Western Palaearctic Hesperiidae:a DNA barcoding reference library
Abstract
The study of ecological interactions between plants, phytophagous insects and their natural enemies is an essential but challenging component for understanding ecosystem dynamics. Molecular methods such as DNA barcoding can help elucidate these interactions. In this study, we employed DNA barcoding to establish hostplant and parasitoid interactions with hesperiid butterflies, using a complete reference library for Hesperiidae of continental Europe and north-western Africa (53 species, 100% of those recorded) based on 2934 sequences from 38 countries. A total of 233 hostplant and parasitoid interactions are presented, some recovered by DNA barcoding larval remains or parasitoid cocoons. Combining DNA barcode results with other lines of evidence allowed 94% species-level identification for Hesperiidae, but success was lower for parasitoids, in part due to unresolved taxonomy. Potential cases of cryptic diversity, both in Hesperiidae and Microgastrinae, are discussed. We briefly analyse the resulting interaction networks. Future DNA barcoding initiatives in this region should focus attention on north-western Africa and on parasitoids, because in these cases barcode reference libraries and taxonomy are less well developed