3 research outputs found

    Exploring the butterfly speciation continuum : A study on butterfly speciation in the transition to genomic techniques

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    Butterflies are among the best studied animals, but despite the research efforts carried out during centuries, our knowledge on their diversity and on the mechanisms generating it is still incomplete. In order to understand how butterflies diversify, the speciation continuum of six study cases was examined using morphometrics and several genetic techniques (from sequencing specific markers to genomics). The analysis of phenotypic and genetic variation combined with gene flow evidence allowed to identify the states of the speciation continuum, i.e. to study the relationships between populations. This approach was used as a framework (1) to make grounded taxonomic hypotheses and (2) to extract clues about the mechanisms that drive speciation. As a result, we described and proposed several cases of overlooked and oversplit taxa. We documented the existence of three types of mechanisms producing diversification in butterflies: drift, selection and hybridisation. Selection acted through adaptation to biotic environmental factors, which caused reproductive character displacement, host plant shift and allochrony mediated by adaptation to host plant flowering period. Additionally, the genetic techniques employed were evaluated and their advantages and limitations discussedLes papallones són un dels animals més ben estudiats però, malgrat els esforços dedicats a la seva recerca, el coneixement que tenim sobre la seva diversitat i sobre els mecanismes que la generen és encara incomplet. Per tal d'entendre com les papallones diversifiquen, s'ha examinat el continu de l'especiació en sis casos mitjançant l'ús de la morfometria i de diverses tècniques genètiques (des de la seqüenciació de marcadors específics fins a la genòmica). L'anàlisi de la variació fenotípica i genètica combinada amb evidències sobre el flux genètic ha permès identificar els estats del continu de l'especiació, i.e. l'estudi de les relacions entre poblacions. Aquesta aproximació s'ha usat com a marc (1) per fer hipòtesis taxonòmiques fonamentades i (2) per extreure pistes sobre els mecanismes que dirigeixen l'especiació. Com a resultat, hem descrit i proposat diversos casos de tàxons que havien passat desapercebuts o que s'havien dividit excessivament. Documentem l'existència de tres tipus de mecanismes productors de diversitat en papallones: deriva, selecció i hibridació. La selecció actuà mitjançant l'adaptació a factors ambientals biòtics, que causaren desplaçament de caràcters reproductius, canvi de planta nutrícia i a\ll ocronia produïda per l'adaptació al període de floració de la planta nutrícia. Addicionalment, les tècniques genètiques emprades són avaluades i els seus avantatges i inconvenients discutits

    Tocilizumab in giant cell arteritis. Observational, open-label multicenter study of 134 patients in clinical practice.

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    Tocilizumab (TCZ) has shown efficacy in clinical trials on giant cell arteritis (GCA). Real-world data are scarce. Our objective was to assess efficacy and safety of TCZ in unselected patients with GCA in clinical practice Methods: Observational, open-label multicenter study from 40 national referral centers of GCA patients treated with TCZ due to inefficacy or adverse events of previous therapy. Outcomes variables were improvement of clinical features, acute phase reactants, glucocorticoid-sparing effect, prolonged remission and relapses. A comparative study was performed: (a) TCZ route (SC vs. IV); (b) GCA duration (≤6 vs. >6 months); (c) serious infections (with or without); (d) ≤15 vs. >15 mg/day at TCZ onset. 134 patients; mean age, 73.0 ± 8.8 years. TCZ was started after a median [IQR] time from GCA diagnosis of 13.5 [5.0-33.5] months. Ninety-eight (73.1%) patients had received immunosuppressive agents. After 1 month of TCZ 93.9% experienced clinical improvement. Reduction of CRP from 1.7 [0.4-3.2] to 0.11 [0.05-0.5] mg/dL (p  In clinical practice, TCZ yields a rapid and maintained improvement of refractory GCA. Serious infections appear to be higher than in clinical trials
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