431 resultados para raja-asemat


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This study focused on the role of oceanographic discontinuities and the presence of transitional areas in shaping the population structure and the phylogeography of the Raja miraletus species complex, coupled with the test of the effective occurrence of past speciation events. The comparisons between the Atlantic African and the North-Eastern Atlantic-Mediterranean geographic populations were unravelled using both Cytochrome Oxidase I and eight microsatellite loci. This approach guaranteed a robust dataset for the identification of a speciation event between the Atlantic African clade, corresponding to the ex Raja ocellifera nominal species, and the NE Atlantic-Mediterranean R. miraletus clade. As a matter of fact, the origin of the Atlantic Africa and the NE Atlantic-Mediterranean deep split dated about 11.74MYA and was likely due to the synergic influence currents and two upwelling areas crossing the Western African Waters. Within the Mediterranean Sea, particular attention was also paid to the transitional area represented by Adventura and Maltese Bank, that might have contributed in sustaining the connectivity of the Western and the Eastern Mediterranean geographical populations. Furthermore, the geology of the easternmost part of Sicily and the geo-morphological depression of the Calabrian Arc could have driven the differentiation of the Eastern Mediterranean Sea. Although bathymetric and oceanographic discontinuity could represent barriers to dispersal and migration between Eastern and Western Mediterranean samples, a clear and complete genetic separation among them was not detected. Results produced by this work identified a speciation event defining Raja ocellifera and R. miraletus as two different species, and describing the R. miraletus species complex as the most ancient cryptic speciation event in the family Rajidae, representing another example of how strictly connected the environment, the behavioural habits and the evolutionary and ecologic drivers are.

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We are grateful to all those who helped with sample collection. This includes the MEDITS survey programme (IEO Mallorca) for Mediterranean samples. Portugal mainland samples were collected under the EU Data Collection Framework (DCF, PNAB). Azores specimens from the Department of Oceanography and Fisheries (DOP) of the University of the Azores (UAc) were collected under the project DEMERSAIS “Monitorização das espécies demersais dos Açores” financed by the Azorean government, and the project DEECON “Unravelling population connectivity for sustainable fisheries in the Deep Sea” project approved by the European Science Foundation (ESF) under the EUROCORES programme (proposal No 06-EuroDEEP-FP-008 & SFRH-EuroDEEP/0002/2007). This study was funded by the UK Natural Environment Research Council (NERC) Oceans 2025 Strategic Research Programme Theme 6 (Science for Sustainable Marine Resources). REB was supported by the Fisheries Society of the British Isles (FSBI), BSP was funded by the Fundação para a Ciência e a Tecnologia, SFRH/BPD/72351/2010 and JL was supported by The Alasdair Downes Marine Conservation Fund.

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Title from f. 1r.

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Skates and rays constitute the most speciose group of chondrichthyan fishes, yet are characterised by remarkable levels of morphological and ecological conservatism. They can be challenging to identify, which makes monitoring species compositions for fisheries management purposes problematic. Owing to their slow growth and low fecundity, skates are vulnerable to exploitation and species exhibiting endemism or limited ranges are considered to be the most at risk. The Madeira skate Raja maderensis is endemic and classified as ‘Data Deficient’ by the IUCN, yet its taxonomic distinctiveness from the morphologically similar and more wide-ranging thornback ray Raja clavata is unresolved. This study evaluated the sequence divergence of both the variable control region and cytochrome oxidase I ‘DNA barcode’ gene of the mitochondrial genome to elucidate the genetic differentiation of specimens identified as R. maderensis and R. clavata collected across much of their geographic ranges. Genetic evidence was insufficient to support the different species designations. However regardless of putative species identification, individuals occupying waters around the Azores and North African Seamounts represent an evolutionarily significant unit worthy of special consideration for conservation management.

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Skates and rays constitute the most speciose group of chondrichthyan fishes, yet are characterised by remarkable levels of morphological and ecological conservatism. They can be challenging to identify, which makes monitoring species compositions for fisheries management purposes problematic. Owing to their slow growth and low fecundity, skates are vulnerable to exploitation and species exhibiting endemism or limited ranges are considered to be the most at risk. The Madeira skate Raja maderensis is endemic and classified as ‘Data Deficient’ by the IUCN, yet its taxonomic distinctiveness from the morphologically similar and more wide-ranging thornback ray Raja clavata is unresolved. This study evaluated the sequence divergence of both the variable control region and cytochrome oxidase I ‘DNA barcode’ gene of the mitochondrial genome to elucidate the genetic differentiation of specimens identified as R. maderensis and R. clavata collected across much of their geographic ranges. Genetic evidence was insufficient to support the different species designations. However regardless of putative species identification, individuals occupying waters around the Azores and North African Seamounts represent an evolutionarily significant unit worthy of special consideration for conservation management.

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Tässä työssä on asetettu Riihimäen seudullisen joukkoliikenteen palvelutasotavoitteet nykyisen, aikavälille 2010–2016 asetetun palve-lutason jälkeiseen aikaan. Palvelutasomäärittelyssä on sovellettu uutta Liikenneviraston julkaisun 31/2015 mukaista joukkoliikenteen palvelutason määrittelyohjetta. Ohjeen mukaisesti määritellyn palvelutason lisäksi työssä esitetään alueen kaikkien avoimien henkilö-kuljetusten muodostama seudullinen palvelutaso, johon on otettu muukaan myös ne liikenteet, joiden asiakaspohja ei täytä palvelu-tasoluokitellun joukkoliikenteen mukaisia numeerisia kriteerejä. Käytännössä tämä tarkoittaa kyliä tai tiesuuntia joiden asukasluku on alle 650. Seudullisen liikenteen pysäkit on luokiteltu työssä Digiroad -tietokantaan tallennettuja tietoja hyödyntäen neljään eri luokaan. Termi-naali -tasoisina pysäkkeinä on esitetty Riihimäen matkakeskus ja Hyvinkään linja-autoasema. Toiseksi korkeimpaan luokkaan valittiin Lopen linja-autoasema, Oitin keskustaajaman katoksellinen pysäkki sekä VT3 rampeilla sijaitsevat pikavuoropysäkit Riihimäellä ja Hyvinkäällä. Muut pysäkit on jaettu vilkkaisiin ja peruspysäkkeihin. Lisäksi työn aikaan on otettu kantaa suunnittelualueella vuonna 2015 päättyneiden Uudenmaan ELY-keskuksen toimivaltaan kuulu-neiden liikenteiden toteutukseen sekä laadittu hankintasuunnitelma vuonna 2016 päättyvien liikenteiden toteutuksesta jatkosta. Näiden akuuttien tarpeiden lisäksi työn lopussa ideoitiin uudenlaista, nykyistä voimakkaammin eri toimijoiden tarpeita huomioivaa tapaa suun-nitella ja kilpailuttaa alueen joukkoliikennettä ja henkilökuljetuksia alueellisina kokonaisuuksina innovaatiokumppanuuteen perustuvaa hankintaprosessia hyödyntäen. Työn aikana opiskelijatyönä toteutetun käyttäjäkyselyn tuloksia voitiin huomioida erityisesti Riihimäen paikallisliikenteeseen suunnitel-luissa pienissä reittimuutoksissa, joista keskeisimpiä olivat Merkoksen kaupallisten palveluiden alueen sekä Valion tehtaan kytkeminen mukaan paikallisliikenteen reitteihin. Riihimäen palveluliikenteen osalta keskeisimmäksi kehittämistarpeeksi osoittautui tiedottamisen lisääminen niin kaupungin organisaation sisällä kuin myös ulospäin asiakkaille.

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Aspects of the population dynamics of the undulate ray, Raja undulata (Chondrichthyes: Rajidae), one of the more abundant elasmobranch fish captured along the Portuguese south coast (Algarve), were studied for the first time. Some traditional elasmobranch vertebral enhancing techniques were compared and the most precise for this species determined to be the cedar wood oil immersion and the alizarin red S stain. The sample consisted of 14 age-classes, with age-classes 3 to 8 being the most represented. Evidence of an annual deposition pattern of a pair of bands (one opaque and one translucent) was found by marginal increment analyses. Von Bertalanffy growth parameters were estimated and no differences found between males and females (all data: L-inf=110.22 cm, K=0.11 y(-1) and t(0)=-1.58 y).

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The maturity of the undulate ray, Raja undulata, one of the most important by-catch elasmobranch species captured in south Portugal, was studied for the first time. Females ranged in total length (TL) from 19.4 to 88.2 cm and males from 23.0 to 83.2 cm. The gonadosomatic index for females was higher during the winter, meaning that this species reproduces during this season. Females matured at significantly larger sizes and older ages than males, with 50% of the females mature at 76.2 cm TL at an age of 8.98 years while 50% maturity for males was achieved at 73.6 cm TL and 7.66 years. Females were mature at 86.3% of the maximum observed size and 69.1% of the maximum observed age while males matured at 88.5% of the maximum observed size and 63.8% of the maximum observed age, making this a very late maturing species, with important consequences in terms of fisheries management and conservation. (c) 2006 Elsevier B.V. All rights reserved.

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Efforts to improve mathematics and science content knowledge have in many institutions required redefining teacher education through new teaching and learning. See, for example, Peard & Pumadevi (2007) for an account of one such attempt involving the development of a Foundations Unit, Scientific and Quantitative Literacy. This unit is core for all first year pre-service primary teacher education students at Queensland University of Technology (QUT) and two Education Institutes in Malaysia, Institute Perguruan Raja Melewar (IPRM), and Institute Perguruan Teknik (IPT) Kuala Lumpur. Since then, QUT has modified the unit to adopt a thematic approach to the same content. An aim of the unit rewrite was the development of a positive attitude and disposition to the teaching and learning of mathematics and science, with a curiosity and willingness to speculate about and explore the world. Numeracy was specifically identified within the mathematics encountered and appropriately embedded in the science learning area. The importance of the ability to engage in communication of and about mathematics and science was considered crucial to the development of pre-service primary teachers. Cognisance was given to the appropriate selection and use of technology to enhance learning - digital technologies were embedded in the teaching, learning and assessment of the unit to avoid being considered as an optional extra. This was achieved around the theme of “the sustainable school”. This „sustainability‟ theme was selected due to its prominence in Australia‟s futures-oriented National Curriculum which will be implemented in 2011. This paper outlines the approach taken to the implementation of the unit and discusses early indicators of its effectiveness.

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Efforts to improve mathematics and science content knowledge have in many institutions required redefining teacher education through new teaching and learning. See, for example, Peard & Pumadevi (2007) for an account of one such attempt involving the development of a Foundations Unit, Scientific and Quantitative Literacy. This unit is core for all first year pre-service primary teacher education students at Queensland University of Technology (QUT) and two Education Institutes in Malaysia, Institute Perguruan Raja Melewar (IPRM), and Institute Perguruan Teknik (IPT) Kuala Lumpur. Since then, QUT has modified the unit to adopt a thematic approach to the same content. An aim of the unit rewrite was the development of a positive attitude and disposition to the teaching and learning of mathematics and science, with a curiosity and willingness to speculate about and explore the world. Numeracy was specifically identified within the mathematics encountered and appropriately embedded in the science learning area. The importance of the ability to engage in communication of and about mathematics and science was considered crucial to the development of pre-service primary teachers. Cognisance was given to the appropriate selection and use of technology to enhance learning - digital technologies were embedded in the teaching, learning and assessment of the unit to avoid being considered as an optional extra. This was achieved around the theme of “the sustainable school”. This ‘sustainability’ theme was selected due to its prominence in Australia’s futures-oriented National Curriculum which will be implemented in 2011. This paper outlines the approach taken to the implementation of the unit and discusses early indicators of its effectiveness.