190 research outputs found

    Biogeographical patterns of the neotropical genus Battus Scopoli 1777 (Lepidoptera Papilionidae)

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    A phylogenetic approach to the groups of species of the neotropical Troidines currently included in the genus Battus Scopoli 1777 has been conducted. In the light of historical and ecological processes of evolution in the neotropical biota, the cladogram of Battiti is discussed. General vicariance patterns, as well as dispersal events which contributed to the present distribution of the taxa, are suggested to have operated at different spatial and temporal points

    Species, Genera, Families and others, or the Naturality of Taxonomical Categories

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    Conferencia inaugural del máster "Diversidad Biológica y Medio Ambiente" por la Universidad de MálagaTaxonomy, i.e. the science of classifying and naming organisms, has been an activity of man since the invention of language. However, the task of inventorying the Biodiversity on Earth is far from complete. With barely 2,000,000 species catalogued, a conservative estimate of a total of 11,000,000 species claims for exceptional efforts to cope with the task. Furthermore, new methodologies are needed, and possibly new approaches in systematics are required to make taxonomy a more modern discipline. To say it with Willy Hennig: “If systematics is to be a science it must bow to the self-evident requirement that objects to which the same label is given must be comparable in some way”. This has to do with the inconsistet and often ambiguous meaning that higher taxonomic categories (genus, family, order etc…) are given. A genus for an entomologist does not represent a category equivalent to a genus as used by a specialist in mammals, or in fishes: i.e. genera are not comparable across taxa. John Avise has engaged himself in at least two attempts to produce standardization metodologies for taxonomic categories, by referring to the only feature that is certainly shared by all organisms: time. Temporal banding and temporal clipping are discussed as potentially useful methods of standardization of higher taxonomic categories.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    The relationships of the enigmatic gastropod Tritonoharpa (Neogastropoda): New data on early neogastropod evolution?

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    In this paper, the relationships of Tritonoharpa Dall, 1908, within Neogastropoda are discussed. Tritonoharpa is indeed similar to Colubraria in the morphology of its head-foot, pallial complex, reproductive and excretory systems, in the presence of an extremely long and coiled proboscis, and a very large stomach. However, it differs from Colubraria in the rest of its foregut anatomy, revealing a cancellariid affinity, and a typical nematoglossan radula. The molecular data confirms Beu and Maxwell's placement of Tritonoharpa in the Cancellariidae, close to Plesiotriton. It is also suggested that cancellariids may be the sister-group to the rest of neogastropods. Tritonoharpa has a rather large and well developed midgut gland, resembling the gland of Leiblein. As previously studied cancellarioideans have been shown to lack a well differentiated gland of Leiblein, the present study raises some interesting questions about the evolution of the foregut in Neogastropoda. In fact, if this glandular structure were confirmed as a true homologue of the gland of Leiblein, and the cancellarioideans proved to be the sister group to the remaining neogastropods, the possession of the gland should be considered a synapomorphy of the Neogastropoda

    An assessment of the genus Columbella Lamarck, 1799 (Gastropoda: Columbellidae) from eastern Atlantic

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    Three species of the neogastropod genus Columbella Lamarck, 1799 are recognised from the northeastern Atlantic and the Mediterranean. One is the common Mediterranean C. rustica (Linnaeus, 1758), with paucispiral protoconch, extending its range in the Atlantic South to Senegal and North to Portugal. Columbella adansoni Menke, 1853, with multispiral protoconch is restricted to the Macaronesian archipelagoes. A third species, also with multispiral protoconch, from West Africa is recognised through molecular methods, and the name C. xiphitella Duclos, 1840 is employed by correcting the original erroneous locality (“Californie”) to Gabon. Except for protoconch features, no major morphological characters are available to separate the three species; however diagnostic species-level differences in specific positions in the cytochrome c oxidase I (COI) sequences are present between all three species

    Kilo-instruction processors: overcoming the memory wall

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    Historically, advances in integrated circuit technology have driven improvements in processor microarchitecture and led to todays microprocessors with sophisticated pipelines operating at very high clock frequencies. However, performance improvements achievable by high-frequency microprocessors have become seriously limited by main-memory access latencies because main-memory speeds have improved at a much slower pace than microprocessor speeds. Its crucial to deal with this performance disparity, commonly known as the memory wall, to enable future high-frequency microprocessors to achieve their performance potential. To overcome the memory wall, we propose kilo-instruction processors-superscalar processors that can maintain a thousand or more simultaneous in-flight instructions. Doing so means designing key hardware structures so that the processor can satisfy the high resource requirements without significantly decreasing processor efficiency or increasing energy consumption.Peer ReviewedPostprint (published version

    DNA mitocondrial revela la importancia regional e interregional de la plataforma continental mediterránea africana para la tortuga boba (Caretta caretta)

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    The wide north African continental shelf in the central Mediterranean is known to be one of the few important areas in the basin for loggerhead turtles in the neritic stage. In order to assess the origin of these turtles, sequences of the mtDNA control region were obtained from 70 turtles caught by bottom trawlers in the area, and compared with known sequences from turtles from Mediterranean and Atlantic nesting sites. Five haplotypes were identified (Haplotype diversity = 0.262; nucleotide diversity = 5.4×10-3). Specific haplotypes indicate contributions from distant rookeries such as Turkey and the Atlantic, which shows that Atlantic turtles entering the Mediterranean while in the oceanic phase use at least one Mediterranean continental shelf as a neritic foraging ground. A new haplotype and another one previously found only in foraging areas, highlight the genetic information gaps for nesting sites, which undermine powerful mixed stock analyses. Despite these limitations, the results reveal the regional importance of the study area as a neritic foraging ground for turtles that are probably from most of the Mediterranean nesting aggregates. Therefore, reducing turtle mortality resulting from the high fishing effort in the area should be regarded as key for Mediterranean turtle conservation and is also possibly important for Atlantic populations.La amplia plataforma continental africana en el Mediterráneo se reconoce como una de las pocas áreas importantes en la cuenca para la tortuga boba en su estadio nerítico. Para evaluar el origen de estas tortugas se obtuvieron secuencias de mtDNA de la región control de 70 tortugas capturadas en el área por arrastreros y se compararon con las conocidas de localidades de anidación en el Mediterráneo y el Atlántico. Se identificaron cinco haplotipos (diversidad de haplotipos = 0.262; diversidad de nucleótidos = 5.4×10-3). Los haplotipos específicos indican contribución de localidades alejadas como Turquía y el Atlántico, mostrando que las tortugas atlánticas que entran en el Mediterráneo en la fase oceánica usan, al menos, una plataforma continental mediterránea como territorio de anidación y alimentación. Un nuevo haplotipo y otro más, previamente encontrado sólo en áreas de alimentación, destacan el vacío de información genética de los sitios de anidación, lo que socava el poder de los análisis de stocks mixtos. A pesar de estas limitaciones, los resultados revelan la importancia regional del área de estudio como área de alimentación para las tortugas de, probablemente, la mayor parte de los agregados de anidación mediterráneos. Por tanto, la reducción de la mortalidad de tortugas debida al alto esfuerzo de pesca en el área debería ser considerado clave para la conservación de la tortuga mediterránea y, posiblemente, importante también para la poblaciones atlánticas

    Mitochondrial DNA reveals regional and interregional importance of the central Mediterranean African shelf for loggerhead sea turtles (<em>Caretta caretta</em>)

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    The wide north African continental shelf in the central Mediterranean is known to be one of the few important areas in the basin for loggerhead turtles in the neritic stage. In order to assess the origin of these turtles, sequences of the mtDNA control region were obtained from 70 turtles caught by bottom trawlers in the area, and compared with known sequences from turtles from Mediterranean and Atlantic nesting sites. Five haplotypes were identified (Haplotype diversity = 0.262; nucleotide diversity = 5.4×10-3). Specific haplotypes indicate contributions from distant rookeries such as Turkey and the Atlantic, which shows that Atlantic turtles entering the Mediterranean while in the oceanic phase use at least one Mediterranean continental shelf as a neritic foraging ground. A new haplotype and another one previously found only in foraging areas, highlight the genetic information gaps for nesting sites, which undermine powerful mixed stock analyses. Despite these limitations, the results reveal the regional importance of the study area as a neritic foraging ground for turtles that are probably from most of the Mediterranean nesting aggregates. Therefore, reducing turtle mortality resulting from the high fishing effort in the area should be regarded as key for Mediterranean turtle conservation and is also possibly important for Atlantic populations

    Diversidad críptica en gasterópodos mediterráneos del género Aplus (Neogastropoda: Buccinidae)

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    Northeastern Atlantic and Mediterranean gastropods previously ascribed to the buccinid genus Pollia Gray, 1837 are more correctly classified in the genus Aplus de Gregorio, 1885. Using an integrative taxonomy approach combining molecular, morphological and geographic data, we revisit the limits of the extant species in the area, and propose a molecular phylogenetic hypothesis based on 66 specimens from various localities in the Mediterranean Sea, including type localities of some nominal taxa. We used a preliminary morphological inspection, followed by a DNA-barcoding approach to propose species hypotheses, subsequently consolidated using additional data (phylogenetic, geographic and refined morphological data). Seven species hypotheses were eventually retained within our molecularly assayed samples, versus three classical morphologically recognized species. Among these, three correspond to Aplus dorbignyi (Payreaudeau, 1826) with its hitherto unrecognized geographical cognates A. gaillardoti (Puton, 1856) (eastern Mediterranean) and Aplus nodulosus (Bivona Ant., 1832) (Sicily); two closely related, yet considerably divergent, lineages are treated as a single species under Aplus scaber (Locard, 1892); the classically admitted Aplus scacchianus (Philippi, 1844) is confirmed by molecular evidence; Mediterranean populations attributable to Aplus assimilis (Reeve, 1846) may represent either cryptic native populations or an ongoing invasion of the Mediterranean by what was hitherto considered to be a West African species; finally, specimens from the Strait of Gibraltar may represent an undescribed species, but we conservatively refrain from formally introducing it pending the analysis of more material, and it is compared with the similar Aplus campisii (Ardovini, 2014), recently described from Sicily and not assayed molecularly, and Aplus scaber.Los gasterópodos mediterráneos y del Atlántico nordeste previamente asignados al género Pollia Gray, 1837 deben ser más correctamente incluidos en el género Aplus de Gregorio, 1885. Se revisan aquí los límites de las especies recientes de este género en el área estudiada por medio de un enfoque de taxonomía integrativa. En base a ello se propone una hipótesis filogenética basada en 66 ejemplares procedentes de varias localidades del Mediterráneo, incluyendo las localidades tipo de algunos taxones nominales. Primero se realizó una diferenciación morfológica, seguida de la aplicación del marcador molecular COI para proponer las especies a modo de hipótesis, que finalmente fueron validadas con datos adicionales (filogenéticos, geográficos y detalles morfológicos). Como resultado se reconocieron siete especies válidas entre los ejemplares analizados molecularmente, en contraste con las tres especies previamente reconocidas morfológicamente. Tres de ellas corresponden a Aplus dorbignyi (Payreaudeau, 1826) y a sus afines geográficos no reconocidas hasta ahora A. gaillardoti (Puton, 1856) [del Mediterráneo oriental] y Aplus nodulosus (Bivona Ant., 1832) [de Sicilia]; dos linajes estrechamente relacionados, aunque divergentes, son considerados como una misma especie con el nombre de Aplus scaber (Locard, 1892); la especie tradicionalmente admitida Aplus scacchianus (Philippi, 1844) se confirma en base a evidencias moleculares; las poblaciones mediterráneas atribuibles a Aplusas similis (Reeve, 1846) pueden ser crípticas nativas o corresponder a una invasión en curso por parte de esta especie del noroeste africano; finalmente los ejemplares del Estrecho de Gibraltar pueden representar una especie no descrita, pero se ha preferido optar por una posición conservadora y no introducir un nuevo nombre a la espera del estudio de material adicional y compararla con Aplus campisii (Ardovini, 2014), especie descrita recientemente de Sicilia y pendiente de su análisis molecular, y con Aplus scaber

    Molecular systematics and biogeography of the western Mediterranean stonefly genus Tyrrhenoleuctra (Insecta, Plecoptera)

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    The stonefly genus Tyrrhenoleuctra includes species living in western Mediterranean temporary freshwater streams, sometimes also at sea level, a very unusual habitat for most Plecoptera. Traditional morphological approaches proved unsuccessful in drawing both taxonomic and phylogenetic patterns, thus hampering discussion of biogeographical patterns for this interesting group. We aimed at: (a) assessing the taxonomic status of populations of Tyrrhenoleuctra covering the geographic range of the genus; (b) studying the phylogenetic relationships among the recognized species; and (c) describing biogeographic patterns. We used phylogenetic analyses to infer the phylogenetic history of this group of stoneflies based on a combined data set of 1666 bp including fragments of the 12S ribosomal (12S) and cytochrome oxidase I (CO-I) mtDNA genes, with maximum likelihood and Bayesian methods. Two main clades have been identified: a Sardo-Corsican one, including Tyrrhenoleuctra zavattarii, and an Ibero-Maghrebian one including four lineages of unkown taxonomic rank from the Balearic Islands (Maiorca), from northern Africa (Ceuta) and southernmost Spain (Algeciras), and a complex preliminarily referred herein to T. minuta (Klapálek, 1901), which includes two lineages, one from Cordoba, and one from Sierra de Grazalema (El Cerro) and Portugal (Tellhares) respectively. Dating the nodes by fixing the split of the Ibero-Maghrebian clade from the Sardo-Corsican one at 29 million years ago (Mya), yielded dates referring to the major geological events in the Mediterranean basin. Estimated molecular evolutionary rates ranged from 0.02-0.09% per million years (my) in the T. zavattarii lineages, to 0.2-0.7% per MY in the Ibero-Maghrebian clade. The phylogenetic pattern emerged from the present study is congruent with the known paleo-history of the western Mediterranean basin, with the divergence of the two main Tyrrhenoleuctra lineages corresponding to the split of the Sardo-Corsican microplate from the Iberian block. Vicariance events have characterized the history of this stonefly group along its entire biogeographical history. Surprisingly low evolutionary rates, previously supposed by Fochetti (1991, 1994) and Fochetti et al. (2004) based on nuclear markers (allozymes), have been herein found also in mitochondrial markers.L'articolo è disponibile sul sito dell'edditore http://onlinelibrary.wiley.com

    Selective transepithelial ablation with simultaneous accelerated corneal crosslinking for corneal regularization of keratoconus : STARE-X protocol

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    Publisher Copyright: Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS.PURPOSE: To evaluate the changes in refractive outcomes and corneal aberrations in central and paracentral keratoconus after selective transepithelial topography-guided photorefractive keratectomy combined with accelerated corneal crosslinking (STARE-X). SETTINGS: Centro Polispecialistico Mediterraneo, Siena Crosslinking Center, and University of Messina, Italy. DESIGN: Prospective, interventional, multicentric study. METHODS: Patients were subdivided into 2 groups: Group 1 with cone located within the central 3 mm zone (50 eyes) and Group 2 (50 eyes) with cone located outside the central 3 mm zone. Follow-up was 2 years at least for all eyes. Outcome parameters included uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). Corneal tomography and corneal wavefront aberrations were assessed and compared before and 2 years after the treatment. RESULTS: 100 eyes of 100 patients underwent STARE-X protocol. At 2 years, UDVA and CDVA improved, and sphere, cylinder, and Kmax reduced after treatment in both groups (P < .001, respectively). Moreover, a statistically significant reduction was observed of total higher-order aberrations root main square (RMS), coma RMS, and spherical aberration RMS in both groups (P < .001, respectively). However, CDVA improved more in Group 1 than in Group 2 (P < .02). CONCLUSIONS: The STARE-X protocol demonstrated effective results in halting keratoconus progression and improving corneal regularity with a safe and effective profile. STARE-X improved both visual acuity and corneal aberration at 2 years. Longer follow-up studies are warranted to observe further long-term CXL flattening effect on the cone.Peer reviewe
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