I confini di Cipro: il muro di Nicosia

Il muro di Nicosia e di tutta l'isola è solo un segno verde tracciato su una mappa, eppure ha una sua fisicità che non si può non percepire, o subire, nel percorrere il territorio. Il muro è un luogo da non attraversare - per tutti i ciprioti - che taglia in due un'unica popolazione, separandola attraverso i temi della cultura, della religione e della lingua. La storia del muro di Cipro, confine tra Nord e Sud, nasce nel 1974: da quel momento in poi saranno evidenziate in modo prevalente le differenze tra greco-ciprioti e turco-ciprioti. Con la separazione nascono due modi di gestire il territorio, attraverso la formazione di nuovi centri all'interno delle due regioni. Muta la percezione di cosa sia il centro e di dove si trovi il fulcro attivo della vita comunitaria; nasce la memoria del tempo dell'unione e si fa strada, contemporaneamente, il bisogno di avere nuovi punti di identificazione.The wall of Nicosia and of the island of Cyprus is just a green line on a map and yet has a physical concreteness which you have to perceive, or suffer, while getting around the country. The wall is an area that cannot be crossed - by no one, not even the Cypriots - that divides a single population and separates it because of culture, religion and language. The history of the wall of Cyprus, border between North and South, started in 1974: from then on differences between Greek-Cypriots and Turkish-Cypriots would have been made clear in a predominant way. After the separation two different ways of managing the territory begin through the formation of new centres in the two regions. The perception of what the centre is and where the active heart of community life lies, changes; reminiscence of a united country lies in the air and at the same time rises the need for new points of identification

Estimating Improved Partitioning Schemes for Ultraconserved Elements

Ultraconserved (UCEs) are popular markers for phylogenomic studies. They are relatively simple to collect from distantly-related organisms, and contain sufficient information to infer relationships at almost all taxonomic levels. Most studies of UCEs use partitioning to account for variation in rates and patterns of molecular evolution among sites, for example by estimating an independent model of molecular evolution for each UCE. However, rates and patterns of molecular evolution vary substantially within as well as between UCEs, suggesting that there may be opportunities to improve how UCEs are partitioned for phylogenetic inference. We propose and evaluate new partitioning methods for phylogenomic studies of UCEs: Sliding-Window Site Characteristics (SWSC), and UCE Site Position (UCESP). The first method uses site characteristics such as entropy, multinomial likelihood, and GC content to generate partitions that account for heterogeneity in rates and patterns of molecular evolution within each UCE. The second method groups together nucleotides that are found in similar physical locations within the UCEs. We examined the new methods with seven published data sets from a variety of taxa. We demonstrate the UCESP method generates partitions that are worse than other strategies used to partition UCE data sets (e.g., one partition per UCE). The SWSC method, particularly when based on site entropies, generates partitions that account for within-UCE heterogeneity and leads to large increases in the model fit. All of the methods, code, and data used in this study, are available from https://github.com/Tagliacollo/PartitionUCE. Simplified code for implementing the best method, the SWSC-EN, is available from https://github.com/Tagliacollo/PFinderUCE-SWSC-EN.National Postdoctoral Program (PNPD/CAPES) and Australian Endeavour Program. RL was supported by an Australian Research Council Future Fellowship

Why the short face? Developmental disintegration of the neurocranium drives convergent evolution in neotropical electric fishes

© 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Convergent evolution is widely viewed as strong evidence for the influence of natural selection on the origin of phenotypic design. However, the emerging evo-devo synthesis has highlighted other processes that may bias and direct phenotypic evolution in the presence of environmental and genetic variation. Developmental biases on the production of phenotypic variation may channel the evolution of convergent forms by limiting the range of phenotypes produced during ontogeny. Here, we study the evolution and convergence of brachycephalic and dolichocephalic skull shapes among 133 species of Neotropical electric fishes (Gymnotiformes: Teleostei) and identify potential developmental biases on phenotypic evolution. We plot the ontogenetic trajectories of neurocranial phenotypes in 17 species and document developmental modularity between the face and braincase regions of the skull. We recover a significant relationship between developmental covariation and relative skull length and a significant relationship between developmental covariation and ontogenetic disparity. We demonstrate that modularity and integration bias the production of phenotypes along the brachycephalic and dolichocephalic skull axis and contribute to multiple, independent evolutionary transformations to highly brachycephalic and dolichocephalic skull morphologies

Coordinated dispersal and pre-isthmian assembly of the central American ichthyofauna

© The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in LAGRANGE+, a modified version of the ML-based parametric biogeographic program LAGRANGE. DO is measured in units of wallaces (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto-Orinoco-Amazon river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America during the Paleocene-Eocene (ca. 58-45 Ma), potentially during the existence of an incomplete Paleogene Arc (∼59 Ma) or Lesser Antilles Arc (∼45 Ma), but predating the GAARlandia land bridge (∼34-33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) platemargin did not serve as a dispersal corridor until the LateNeogene (12-0 Ma), and contributed relatively little to the formation of modern distributions

Using community phylogenetics to assess phylogenetic structure in the fitzcarrald region of Western Amazonia

© 2020 The Authors. Di versity and Distributions Published by SBI. Here we explore the use of community phylogenetics as a tool to document patterns of biodiversity in the Fitzcarrald region, a remote area in Southwestern Amazonia. For these analyses, we subdivide the region into basin-wide assemblages encompassing the headwaters of four Amazonian tributaries (Urubamba, Yuruá, Purús and Las Piedras basins), and habitat types: river channels, terra firme (non-floodplain) streams, and floodplain lakes. We present a robust, well-documented collection of fishes from the region including 272 species collected from 132 field sites over 63 field days and four years, comprising the most extensive collection of fishes from this region to date. We conduct a preliminary community phylogenetic analysis based on this collection and recover results largely statistically indistinguishable from the random expectation, with only a few instances of phylogenetic structure. Based on these results, and of those published in other recent biogeographic studies, we conclude that the Fitzcarrald fish species pool accumulated over a period of several million years, plausibly as a result of dispersal from the larger species pool of Greater Amazonia

The effect of seating preferences of the medical students on educational achievement

Background: The seat selection and classroom dynamics may have mutual influence on the student performance and participation in both assigned and random seating arrangement. Purpose: The aim of the study was to understand the influence of seat selection on educational achievement. Methods: The seating positions of the medical students were recorded on an architectural plan during each class session and the means and standard deviations of the students’ locations were calculated in X and Y orientations. The locations of the students in the class were analyzed based on three architectural classifications: interactional zone, distance from the board, and access to the aisles. Final exam scores were used to measure the students’ educational achievement. Results: Our results demonstrate that there is a statistically significant relationship between the student's locations in the class and their attendance and educational achievements. Conclusion: Two factors may effect on educational achievement: student seating in the high interactional zone and minimal changes in seating location. Seating in the high interaction zone was directly associated with higher performance and inversely correlated with the percentage of absences. This observation is consistent with the view that students in the front of the classroom are likely more motivated and interact with the lecturer more than their classmates

Fluctuations in Evolutionary Integration Allow for Big Brains and Disparate Faces

In theory, evolutionary modularity allows anatomical structures to respond differently to selective regimes, thus promoting morphological diversification. These differences can then influence the rate and direction of phenotypic evolution among structures. Here we use geometric morphometrics and phenotypic matrix statistics to compare rates of craniofacial evolution and estimate evolvability in the face and braincase modules of a clade of teleost fishes (Gymnotiformes) and a clade of mammals (Carnivora), both of which exhibit substantial craniofacial diversity. We find that the face and braincase regions of both clades display different degrees of integration. We find that the face and braincase evolve at similar rates in Gymnotiformes and the reverse in Carnivora with the braincase evolving twice as fast as the face. Estimates of evolvability and constraints in these modules suggest differential responses to selection arising from fluctuations in phylogenetic integration, thus influencing differential rates of skull-shape evolution in these two clades

Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes—the most species-rich continental vertebrate fauna on Earth—to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish fauna