221 research outputs found

    Cranial size and shape sexual dimorphism in the Kangal dog from Turkey

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    This study has so far been the first attempt to characterize and quantify skull sexual variation in Kangal dog, by means of geometric morphometric techniques. A sample of 16 adult Kangal crania has been analyzed with this purpose. To obtain a full image of morphological pattern, digital pictures were taken from the ventral, left lateral, and dorsal sides of each skull, and a total of 16, 15, and 16 landmarks respectively were obtained on each image. Skull size and shape differed significantly in all aspects among different sexes, male skulls being bigger. Shape differences were observed mainly on zygomatic arch and muzzle on the dorsal view, pterygoid bone and articular surface to mandibular condyle in the lateral aspect, and cranial width and maxillary bone on the ventral view. Although the sample was comparatively small in number, being the first geometric morphometric approach applied on the Kangal dog, the obtained results will add vital information particularly to understand the cranial shape sexual dimorphism of this unique dog breed in Turkey

    Craneometric canine types are well expressed at the level of the zygomatic arch conformation

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    Dentro del espectro de conformación del cráneo, se reconocen generalmente tres amplias categorías que se corresponden con el concepto de biotipo cefálico, determinado por el Índice Cefálico. El Estos tres biotipos cefálicos son: el braquiocefálico, mesaticefálico y dolicocefálico, pero están basados en medidas lineales. A fin de revisar esta clasificación en base a su geometría, se estudiaron 53 cráneos de perros adultos, correspondientes a los tres grupos craneométricos descritos: 16 braquicéfalos, 20 mesaticéfalos y 17 dolicocéfalos. Para ello se obtuvieron fotografías en el plano ventral, en las que posteriormente se ubicaron 17 hitos anatómicos que se analizaron mediante técnicas de morfometría geométrica. De estos hitos, 5 correspondían a la zona neurocraneal y el resto al esplacnocráneo. Los tres grupos craneométricos mostraron diferencias estadísticamente significativas entre ellos tanto por el tamaño como por la forma. Las variables que contribuyeron más a explicar la diferenciación fueron las ubicadas en el margen más lateral de los arcos cigomáticos y en la base de este mismo arco. Las variables esplacnocraneales presentaban una alometría mucho más marcada que las neurocráneos. Puesto que el arco cigomático debe ser considerado como parte del esplacnocráneo, sugerimos que es tan importante el índice cefálico (que tiene en cuenta la máxima anchura de la cabeza) como el facial (que tiene en cuenta la máxima anchura de la cara). La conformación neurocraneal sería mucho más conservativa y por ende el índice craneal, de mucho menor poder discriminatorio entre grupos. El cambio entre tipos se debería a los músculos masetero y temporal, que tienen su inserción en el arco.Within the wide conformation of skull spectrum, there are generally three recognized broad categories that correspond to the concept of cephalic biotype, determined by the cephalic index. The three cephalic biotypes are: brachiocephalic, mesaticephalic and dolichocephalic, which are based on linear measures. In order to revise this classification based on its geometry, we studied 53 skulls of adult dogs, corresponding to the three craneometric groups previously described: 16 brachycephalic, 20 mesaticephalic and 17 dolichocephalic. Images on ventral plane were obtained and 17 anatomical landmarks were subsequently located and analyzed by means of geometric morphometric techniques. Five of those landmarks corresponded to the neurocraneal area and the rest of the splanchnocranium. The three craneometric groups showed statistically significant differences between them for both size and shape. The variables that contributed to the differentiation between them were located along the edge of the zygomatic arches and on the basis of this arch. Splanchnocranial variables also presented a much more marked allometry than the neurocraneal variables. Since the zygomatic arch should be considered as part of the splanchnocranium, we suggest that the cephalic index (which takes into account the maximum width of the head) is as important as the facial index (which takes into account the maximum width of the face). The neurocraneal index would be much more conservative, and therefore less discriminatory between the groups

    Isotopic life-history signatures are retained in modern and ancient Atlantic bluefin tuna vertebrae

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    Isotopic, tagging and diet studies of modern-day teleosts lacked the ability to contextualise life-history and trophic dynamics with a historical perspective, when exploitation rates were lower and climatic conditions differed. Isotopic analysis of vertebrae, the most plentiful hard-part in archaeological and museum collections, can potentially fill this data-gap. Chemical signatures of habitat and diet use during growth are retained by vertebrae during bone formation. Nonetheless, to fulfil their potential to reveal life-history and trophic dynamics, we need a better understanding of the time frame recorded by vertebrae, currently lacking due to a poor understanding of fish bone remodelling. To address this issue, the authors serially-sectioned four vertebral centra of the highly migratory Atlantic bluefin tuna (Thunnus thynnus; BFT) captured off Sardinia (Italy) and analysed their isotopic composition. They show how carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) isotope values can vary significantly across BFT vertebrae growth-axes, revealing patterning in dietary life histories. Further, they find that similar patterns are revealed through incremental isotopic analysis of inner and outer vertebrae centra samples from 13 archaeological BFT vertebrae dating between the 9th and13th centuries CE. The results indicate that multi-year foraging signatures are retained in vertebrae and allow for the study of life histories in both modern and paleo-environments. These novel methods can be extended across teleost taxa owing to their potential to inform management and conservation on how teleost trophic dynamics change over time and what their long-term environmental, ecological and anthropological drivers are

    Türkiye'nin Akdeniz ve Ege Denizi'ndeki kılıçbalığı populasyonlarının mitokondriyal Dna (Mtdna) kullanılarak incelenmesi

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    TÜBİTAK KBAG15.07.2014Kılıç balığı (Xiphias gladius) hem dünya hem de Türkiye için önemli besin kaynaklarından biridir. Çeşitli moleküler belirteçler kullanılarak yapılan genetik çalışmalar, kılıç balıklarının Kuzey Atlantik, Güney Atlantik, Akdeniz ve Hint-Pasifik olmak üzere 4 ana stoktan oluştuğunu göstermektedir. Şu ana kadar tek bir stok olarak kabul edilen Akdeniz için tek bir koruma ve yönetim senaryosu önerilmiştir. Türkiye’deki kılıç balığı popülasyonları Akdeniz stoğunun bir parçası olarak kabul edilir. Fakat Türkiye’nin Ege ve Akdeniz kıyılarını içeren herhangi bir genetik çalışma yapılmamıştır. Bu projede, Türkiye’nin Akdeniz (Antalya Körfezi civarından) ve Kıbrıs’ın Karşıyaka kıyısından, Kuzey Levant Denizi’ni temsilen, (n= 42) ve Türkiye’nin Ege Denizi kıyısından Gökçeada ve Çanakkale civarından (n=26) kılıç balığı örnekleri toplanmıştır. Bu örneklerden DNA izole edilerek, mtDNA kontrol bölgesinin 450 baz çiftlik (bç) dizi analizi yapılmıştır. Ayrıca Yenikapı kazılarından çıkartılan örneklerden antik DNA (aDNA) izole edilmiş ve 450 bç’lik bölgesi 5 parça halinde analiz edilmiştir. Sonuçlar birbirleri ve literatürdeki dizi örnekleri ile karşılaştırılarak incelendiğinde Akdeniz’de batıdan doğuya gidildikçe genel olarak genetik çeşitliliğin ve etkin popülasyon sayısının düştüğü ve soy I diye tanımlanan soya ait alt soyların frekansları açısından Ege Denizi kılıç balıklarının Kuzey Levant havzasından değil ama diğer Akdeniz örneklerinden düşük anlamlılık (p0.05). Again, based on clade I, there is no implicit differentiation between east and west populations that overlap with two spawning areas (around South Italy- Sardinia Island and Crete Island-Fethiye) in the Mediterranean, but it is very likely that these two groups are mixed around the middle of the Mediterranean. The frequencies of the clades observed in ancient samples are similar to modern swordfish populations. Production of swordfish in Turkey has been increasing every year since 1980s. İt is observed that, this increase and disappearance of swordfish from Marmara and Black Sea has not been expressed as a decline in the population size, yet. Data obtained from this study can contribute to conservation and management of swordfish populations inhabiting Turkish coasts

    The Reconstruction of Nasal Septal Perforation with High Density Porous Polyethylene Covered with Fascia Lata: An Experimental Study on Rabbit Model

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    ObjectivesEvaluation of a new material, high-density porous polyethylene (HDPP), which is covered with fascia lata, for experimental nasal septal perforation closure.MethodsTwenty New Zealand albino rabbits were included and divided into study and control groups. A lateral incision was made from the lateral aspect of the left nares to the incisura nasomaxillaris. After exposure of the cavum nasi, the nasal mucoperichondrium was elevated bilaterally. A full-thickness 0.5×0.5-cm perforation was created over the septum nasi with a No. 11 surgical blade. A fascia lata graft was used for the study group. The HDPP was covered with fascia lata and placed under the elevated mucosa. HDPP without a fascial covering was used in the control group. Four months after the procedure, magnetic resonance imaging was performed to evaluate resorption of the material. The animals were sacrificed, and the nasal septum was completely removed. Macroscopic and histopathological examinations were performed on the nasal septum.ResultsAll rabbits had survived after the 4-month period. Macroscopically, nine of 10 (90%) perforations were closed in the fascia lata-covered HDPP group. Histopathological examination of these nine rabbits revealed that the continuity of cartilage was disturbed in the perforation areas. Granulation tissue was inverted in areas in which the cartilage continuity was disturbed. The HDPP had remained intact at the edge of the perforation. In the HDPP group, six of 10 implants were still perforated (60%) and four (40%) were closed. The fascia lata-covered HDPP implant had a significantly higher perforation closure rate than that of the HDPP implant alone (P<0.05).ConclusionIn cases of septal perforation, it is better to cover the HDPP implant with fascia lata. This covered implant can be used for the repair of nasal septal perforations. HDPP implants are easy to work with and avoid the increased operative time and morbidity associated with harvesting autografts

    Exploitation shifted trophic ecology and habitat preferences of Mediterranean and Black Sea bluefin tuna over centuries

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    During recent decades, the health of ocean ecosystems and fish populations has been threatened by overexploitation, pollution and anthropogenic-driven climate change. Due to a lack of long-term ecological data, we have a poor grasp of the true impact on the diet and habitat use of fishes. This information is vital if we are to recover depleted fish populations and predict their future dynamics. Here, we trace the long-term diet and habitat use of Atlantic bluefin tuna (BFT), Thunnus thynnus, a species that has had one of the longest and most intense exploitation histories, owing to its tremendous cultural and economic importance. Using carbon, nitrogen and sulphur stable isotope analyses of modern and ancient BFT including 98 archaeological and archival bones from 11 Mediterranean locations ca. 1st century to 1941 CE, we infer a shift to increased pelagic foraging around the 16th century in Mediterranean BFT. This likely reflects the early anthropogenic exploitation of inshore coastal ecosystems, as attested by historical literature sources. Further, we reveal that BFT which migrated to the Black Sea–and that disappeared during a period of intense exploitation and ecosystem changes in the 1980s–represented a unique component, isotopically distinct from BFT of NE Atlantic and Mediterranean locations. These data suggest that anthropogenic activities had the ability to alter the diet and habitat use of fishes in conditions prior to those of recent decades. Consequently, long-term data provide novel perspectives on when marine ecosystem modification began and the responses of marine populations, with which to guide conservation policy

    Origins and genetic legacy of prehistoric dogs

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    Dogs were the first domestic animal, but little is known about their population history and to what extent it was linked to humans. We sequenced 27 ancient dog genomes and found that all dogs share a common ancestry distinct from present-day wolves, with limited gene flow from wolves since domestication but substantial dog-to-wolf gene flow. By 11,000 years ago, at least five major ancestry lineages had diversified, demonstrating a deep genetic history of dogs during the Paleolithic. Coanalysis with human genomes reveals aspects of dog population history that mirror humans, including Levant-related ancestry in Africa and early agricultural Europe. Other aspects differ, including the impacts of steppe pastoralist expansions in West and East Eurasia and a near-complete turnover of Neolithic European dog ancestry
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