Feeding habits of extant and fossil canids as determined by their skull geometry

The canids belong to one of the most prominent families of mammalian carnivores. Feeding adaptations of extant species is well documented by field observations; however, we are still missing palaeoecological insights for many enigmatic fossil specimens. We employ geometric morphometrics to quantify skull size and shape in extant and fossil members of the Canini tribe, inclusive of jackals and wolf-like taxa. Skull data are tested to identify correlates of dietary adaptations in extant species for predicting adaptations in fossils. Main vectors of shape variation correlate with the relative skull-palatal length, the position of the upper carnassial tooth and the anterior tip of the secondary palate. Allometry occurs in the palatal shape but size explains only a small fraction (about 4%) of shape variance. Although we quantified only palatal and tooth shape for the inclusion of fragmentary fossils, discriminant function analysis successfully classify extant Canini in dietary groups (small, medium and large prey specialist) with 89% of accuracy. The discriminant functions provide insights into many enigmatic specimens such as Eucyon adoxus (=small prey), fossil jackal-like from Koobi Fora formation (=small prey) and the Plio-Pleistocene Old World canid guild (Canis etruscus, C. arnensis and Lycaon falconeri). Clearly, both skull size and shape are excellent predictors of feeding habits in Canini thus also provide information about fossil taxonomic affinities

Antara Dayak dan Belanda : Sejarah Ekonomi Kalimantan Timur dan Kalimantan Selatan 1880-1942

xvi, 264 hlm,; 23 c

Expanded trinucleotide CAG repeats in families with bipolar affective disorder

Clinical anticipation has been reported in bipolar affective disorder (BPAD). The hypothesis that expanded trinucleotide repeats are related to anticipation and transmission pattern in families with bipolar affective disorder is tested in this study. Eighty-seven two-generation pairs of patients recruited from 29 bipolar families were analyzed. The repeat expansion detection method was used to detect CAG repeat expansions between successive generations. Significant changes in age at onset and episode frequency in successive generations were observed. Mean trinucleotide CAG repeat length between parental and offspring generation significantly increased when the phenotype increased in severity, i.e. changed from major depression, single episode or unipolar recurrent depression to BPAD. A parent-of-origin effect was also observed with a significant increase in median length CAG between G1 and G2 with maternal inheritance. This increase was observed notably in female offspring. Our findings indicate for the first time that expansion of CAG repeat length could explain the clinical observation of anticipation in families with BPAD. These results provide further support for expanded trinucleotide repeat sequences as risk factors in major affective disorders.SCOPUS: ar.jinfo:eu-repo/semantics/publishe