9 research outputs found

    Supplementary descriptions and DNA barcodes of two rarely encountered Trisetacus species (Eriophyoidea, Phytoptidae) associated with Tertiary relict conifers from the Mediterranean region

    Get PDF
    New records and supplementary morphological descriptions of two rarely encountered Trisetacus species from Pinaceae, T. abietis Postner 1968 and T. cedri (Nalepa 1920), are reported. Trisetacus abietis was found in Abkhazia under the needle epidermis of Abies nordmanniana (Steven) Spach, a conifer endemic to the mountainous Asian coast of the Black Sea. Trisetacus cedri was found in buds of introduced Cedrus deodara(Roxb. ex D. Don) G. Don in Abkhazia and South Africa. It is the only member of Trisetacus known from Cedrus spp. For the first time we provide sequences of two genes (COI and D1ā€“D2 28S) of T. abietis(MN022221, MN025333) and T. cedri (MN022222, MN022223, MN025334, MN025335), along with microphotographs of the damage caused by these mites on their coniferous hosts. Sequences of D1ā€“D2 28S of T. cedri from Abkhazian and South African populations are identical; COI sequences from different populations differ by only one synonymous substitution in a codon for asparagine. Females of T. abietis have long asymmetrical 8/7-rayed empodia, whereas males have shorter symmetrical 6/6-rayed empodia and shorter solenidia Ļ‰ I. Similar sexual dimorphism in tarsal appendages was previously reported in Novophytoptus, representing an endoparasitic lineage of phytoptids on monocots. In T. cedri, a ā€œlong formā€ and a ā€œshort formā€ of both males and females were detected, suggesting a complex life cycle in this species. The evolution of Trisetacus is discussed within the broader context of the molecular phylogenies of Pinaceae and Eriophyoidea, including estimations of divergence times.The Russian Foundation for Basic Research; ZIN RAS (project ŠŠŠŠ-Š19-119020790133-6) and the Russian Science Foundation.https://www.biotaxa.org/saaam2019Forestry and Agricultural Biotechnology Institute (FABI

    Toward video-based navigation for endoscopic endonasal skull base surgery

    No full text
    Endoscopic endonasal skull base surgery (ESBS) requires high accuracy to ensure safe navigation of the critical anatomy at the anterior skull base. Current navigation systems provide approximately 2mm accuracy. This level of registration error is due in part from the indirect nature of tracking used. We propose a method to directly track the position of the endoscope using video data. Our method first reconstructs image feature points from video in 3D, and then registers the reconstructed point cloud to pre-operative data (e.g. CT/MRI). After the initial registration, the system tracks image features and maintains the 2D-3D correspondence of image features and 3D locations. These data are then used to update the current camera pose. We present registration results within 1mm, which matches the accuracy of our validation framework.Daniel Mirota, Hanzi Wang, Russell H. Taylor, Masaru Ishii and Gregory D. Hage

    Evolutionary significance of phenotypic accommodation in novel environments: an empirical test of the Baldwin effect

    No full text
    When faced with changing environments, organisms rapidly mount physiological and behavioural responses, accommodating new environmental inputs in their functioning. The ubiquity of this process contrasts with our ignorance of its evolutionary significance: whereas within-generation accommodation of novel external inputs has clear fitness consequences, current evolutionary theory cannot easily link functional importance and inheritance of novel accommodations. One hundred and twelve years ago, J. M. Baldwin, H. F. Osborn and C. L. Morgan proposed a process (later termed the Baldwin effect) by which non-heritable developmental accommodation of novel inputs, which makes an organism fit in its current environment, can become internalized in a lineage and affect the course of evolution. The defining features of this process are initial overproduction of random (with respect to fitness) developmental variation, followed by within-generation accommodation of a subset of this variation by developmental or functional systems (ā€˜organic selectionā€™), ensuring the organism's fit and survival. Subsequent natural selection sorts among resultant developmental variants, which, if recurrent and consistently favoured, can be inherited when existing genetic variance includes developmental components of individual modifications or when the ability to accommodate novel inputs is itself heritable. Here, I show that this process is consistent with the origin of novel adaptations during colonization of North America by the house finch. The induction of developmental variation by novel environments of this species's expanding range was followed by homeostatic channelling, phenotypic accommodation and directional cross-generational transfer of a subset of induced developmental outcomes favoured by natural selection. These results emphasize three principal points. First, contemporary novel adaptations result mostly from reorganization of existing structures that shape newly expressed variation, giving natural selection an appearance of a creative force. Second, evolutionary innovations and maintenance of adaptations are different processes. Third, both the Baldwin and parental effects are probably a transient state in an evolutionary cycle connecting initial phenotypic retention of adaptive changes and their eventual genetic determination and, thus, the origin of adaptation and evolutionary change

    Phenotypic parallelism of color aberrations in the Northern fur seal (Callorhinus ursinus), American mink (Mustela vison), and sable (Martes zibellina)

    No full text
    corecore