2,879 research outputs found

    Berberis microphylla: A species with phenotypic plasticity in different climatic conditions

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    Berberis microphylla G. Forst., commonly called as "calafate" produces small fruits with high content of carbohydrates, phenols and antioxidants. The objective of this work was to characterize the vegetative and reproductive cycle of Berberis microphylla cultivated on Moreno (Buenos Aires province), Argentina in comparison with the results obtained in Ushuaia (Tierra del Fuego) which is its place of origin. Vegetative growth was very different in the two localities. Moreno plants grew with more lax branches than Ushuaia. In effect, length of the shoots was significantly higher for Moreno than Ushuaia plants. Flowering period in Ushuaia plants was concentrated in November while in Moreno it happens earlier and over a longer period. Pollen grains collected from Moreno flowers had a diameter of ~60 ÎŒm, significantly different to pollen grain from Ushuaia (57.11 ÎŒm). Nevertheless, pollen grain vitality was superior in Ushuaia flowers (75%) as compared to Moreno flowers (52%). On the other hand, fruit harvested in Moreno was at 60 days from full bloom while in Ushuaia plants at 120 days. Although the size and compounds measured in the fruits of Moreno were lower than those of Ushuaia, results obtained indicate that B. microphylla grown on Moreno is an interesting option to obtain another nutraceutical fruit near the centers of mass consumption.Fil: Radice, Silvia. Universidad de MorĂłn. Facultad de AgronomĂ­a y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Alonso, Marta. Universidad de MorĂłn. Facultad de AgronomĂ­a y Ciencias Agroalimentarias; ArgentinaFil: Arena, Miriam Elisabet. Universidad de MorĂłn. Facultad de AgronomĂ­a y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentin

    The braincase and inner ear of ‘Metriorhynchus’ cf. ‘M.’ brachyrhynchus – implications for aquatic sensory adaptations in crocodylomorphs

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    During their long evolutionary history crocodylomorphs achieved a great diversity of body sizes, ecomorphotypes and inferred feeding ecologies. One unique group of crocodylomorphs are the thalattosuchians, which lived during the Jurassic and Cretaceous (ca. 191–125 Ma). They transitioned from shallow marine species, like teleosauroids, into fully pelagic forms with paddle shaped limbs and a vertically orientated tail fluke, the metriorhynchids. The osteological adaptations that allowed metriorhynchids to live in the water are generally well understood, but less is known about their neurosensory and endocranial systems, such as the brain, inner ears, sinuses and cranial nerves and how they relate to their aquatic lifestyle. Based on micro-computed tomography (ÎŒCT) data and three-dimensional models, we here describe the braincase and endocranial anatomy of a fully marine metriorhynchid, ‘Metriorhynchus’ cf. ‘M.’ brachyrhynchus (NHMUK PV OR 32617). We found several neuroanatomical features that likely helped this species function in its marine environment. These include a unique flexure in the brain endocast not seen in other thalattosuchians. Other features that have previously been seen in thalattosuchians include enlarged cerebral hemispheres, a hypertrophied venous sinus system, enlarged internal carotid arteries and foramina, and closed/absent lateral pharyngotympanic foramina. The specimen also possesses a pelagic metriorhynchid bony labyrinth morphology, with a compact and dorsoventrally short shape, thick semicircular canals, an enlarged vestibule and potentially a short cochlear duct. A review of character distribution confirms that some of these features evolved at the base of Thalattosuchia in semiaquatic species, long before metriorhynchids became pelagic, suggesting that endocranial anatomy helped allow metriorhynchoids colonize the ocean realm.Fil: Schwab, Julia A.. University of Edinburgh; Reino UnidoFil: Young, Mark T.. University of Edinburgh; Reino UnidoFil: Herrera, Laura Yanina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn PaleontologĂ­a Vertebrados; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata; ArgentinaFil: Witmer, Lawrence. Ohio University; Estados UnidosFil: Walsh, Stig A.. University of Southampton; Reino UnidoFil: Katsamensis, Orestis. Faculty Of Engineering And Physical Sciences; Reino UnidoFil: Brusatte, Stephen L.. University of Edinburgh; Reino Unid

    Chaste: a test-driven approach to software development for biological modelling

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    Chaste (‘Cancer, heart and soft-tissue environment’) is a software library and a set of test suites for computational simulations in the domain of biology. Current functionality has arisen from modelling in the fields of cancer, cardiac physiology and soft-tissue mechanics. It is released under the LGPL 2.1 licence.\ud \ud Chaste has been developed using agile programming methods. The project began in 2005 when it was reasoned that the modelling of a variety of physiological phenomena required both a generic mathematical modelling framework, and a generic computational/simulation framework. The Chaste project evolved from the Integrative Biology (IB) e-Science Project, an inter-institutional project aimed at developing a suitable IT infrastructure to support physiome-level computational modelling, with a primary focus on cardiac and cancer modelling

    Morphological evolution of the mammalian jaw adductor complex

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    The evolution of the mammalian jaw during the transition from non-mammalian synapsids to crown mammals is a key event in vertebrate history and characterised by the gradual reduction of its individual bones into a single element and the concomitant transformation of the jaw joint and its incorporation into the middle ear complex. This osteological transformation is accompanied by a rearrangement and modification of the jaw adductor musculature, which is thought to have allowed the evolution of a more-efficient masticatory system in comparison to the plesiomorphic synapsid condition. While osteological characters relating to this transition are well documented in the fossil record, the exact arrangement and modifications of the individual adductor muscles during the cynodont–mammaliaform transition have been debated for nearly a century. We review the existing knowledge about the musculoskeletal evolution of the mammalian jaw adductor complex and evaluate previous hypotheses in the light of recently documented fossils that represent new specimens of existing species, which are of central importance to the mammalian origins debate. By employing computed tomography (CT) and digital reconstruction techniques to create three-dimensional models of the jaw adductor musculature in a number of representative non-mammalian cynodonts and mammaliaforms, we provide an updated perspective on mammalian jaw muscle evolution. As an emerging consensus, current evidence suggests that the mammal-like division of the jaw adductor musculature (into deep and superficial components of the m. masseter, the m. temporalis and the m. pterygoideus) was completed in Eucynodontia. The arrangement of the jaw adductor musculature in a mammalian fashion, with the m. pterygoideus group inserting on the dentary was completed in basal Mammaliaformes as suggested by the muscle reconstruction of Morganucodon oehleri. Consequently, transformation of the jaw adductor musculature from the ancestral (‘reptilian’) to the mammalian condition must have preceded the emergence of Mammalia and the full formation of the mammalian jaw joint. This suggests that the modification of the jaw adductor system played a pivotal role in the functional morphology and biomechanical stability of the jaw joint

    Long bone and vertebral microanatomy and osteo-histology of ’Platecarpus’ ptychodon (Reptilia, Mosasauridae) : implications for marine adaptations

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    The inner bone architecture and histology provide information about life history traits of extant as well as extinct animals. Mosasaurs (family Mosasauridae) are a group of secondarily adapted marine squamates that radiated in the Late Cretaceous, resulting in the evolution of a body plan adapted for pelagic habitats. Specialisa-tions in this group can be observed at different levels of skeletal anatomy, including bone microstructures and osteo-histology. This study describes the histological features and microanatomy observed in bone sections of a vertebra and a long bone (humerus) from derived mosasaur ’Platecarpus’ ptychodon. Bone sections consist mainly of can-cellous bone with a gradual transition to a rather thin outer layer of cortical bone. The bone histology in both sec-tions is characterised by poorly organised tissue; fibro-lamellar bone is abundant throughout the sections, display-ing randomly organised lacunae and lamellar bone in osteons, whereas parallel-fibered bone (lamellar-zonal bone) is observed only in one area of the vertebra. This implies a rapid growth rate possibly similar to some ichthyosaurs and plesiosaurs. The present contribution demonstrates that ’P’. ptychodon exhibit microstructures consistent with life in pelagic environments and show evidence for rapid growth rate and an active marine lifestyle. Furthermore, a structure found in the vertebra is probably related to avascular necrosis, a disease caused by decompression sick-ness, which adds information about the ecology of this species.Den inre strukturen och vĂ€vnaden hos ben ger information om livsstil hos nutida och utdöda djur. Mosasaurier (familj Mosasauridae) Ă€r en grupp sekundĂ€rt anpassade marina reptiler som utvecklades och spred sig under sen krita, vilket resulterade i en kropp vĂ€l anpassad för marina miljöer. Marina anpassningar hos den hĂ€r gruppen kan observeras pĂ„ olika nivĂ„er i skelettanatomin, exempelvis mikrostrukturer och benvĂ€vnad. Den hĂ€r studien beskriver histologiska och mikroanatomiska kĂ€nnetecken i ett överarmsben och en ryggkota hos den vĂ€l anpassade mosasaurien ’Platecarpus’ ptychodon. Tunnslip visar att benen till stor del bestĂ„r av trabekulĂ€rt ben med en gradvis övergĂ„ng till det mer kompakta yttre benlagret. Detta Ă€r jĂ€mförbart med mĂ„nga moderna valar. Benhisto-login karaktĂ€riseras av en avsaknad av organiserad vĂ€vnad. Fibro-laminĂ€rt ben med slumpmĂ€ssigt orienterade laku-ner finns rikligt i bĂ„da benen och laminĂ€rt ben finns i osteoner. Parallellfibröst ben observeras endast i en del av ryggkotan. Detta antyder en snabb tillvĂ€xthastighet, eventuellt liknande den hos vissa ichthyosaurier och plesiosau-rier. Den hĂ€r studien visar att ’P’ ptychodon har mikrostrukturer som stĂ€mmer överens med en aktiv pelagisk livs-stil. Den uppvisar Ă€ven tecken pĂ„ en snabb tillvĂ€xthastighet. En struktur i ryggkotan Ă€r troligtvis relaterad till osteo-nekros, en sjukdom som orsakas av tryckfallssjuka, vilket bidrar till förstĂ„elsen av den hĂ€r artens ekologi

    Avian cerebellar floccular fossa size is not a proxy for flying ability in birds

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    Extinct animal behavior has often been inferred from qualitative assessments of relative brain region size in fossil endocranial casts. For instance, flight capability in pterosaurs and early birds has been inferred from the relative size of the cerebellar flocculus, which in life protrudes from the lateral surface of the cerebellum. A primary role of the flocculus is to integrate sensory information about head rotation and translation to stabilize visual gaze via the vestibulo-occular reflex (VOR). Because gaze stabilization is a critical aspect of flight, some authors have suggested that the flocculus is enlarged in flying species. Whether this can be further extended to a floccular expansion in highly maneuverable flying species or floccular reduction in flightless species is unknown. Here, we used micro computed-tomography to reconstruct “virtual” endocranial casts of 60 extant bird species, to extract the same level of anatomical information offered by fossils. Volumes of the floccular fossa and entire brain cavity were measured and these values correlated with four indices of flying behavior. Although a weak positive relationship was found between floccular fossa size and brachial index, no significant relationship was found between floccular fossa size and any other flight mode classification. These findings could be the result of the bony endocranium inaccurately reflecting the size of the neural flocculus, but might also reflect the importance of the flocculus for all modes of locomotion in birds. We therefore conclude that the relative size of the flocculus of endocranial casts is an unreliable predictor of locomotor behavior in extinct birds, and probably also pterosaurs and non-avian dinosaurs

    Knowledge in transition in healthcare

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    Organizations are challenged by the need to transform Dynamic Knowledge, embedded in each worker, into Static Knowledge, rooted in factual documental information. However, innovation and knowledge creation seem to be facilitated by the personal knowledge and life experiences of people, which appear to be dynamic. The tensions between Dynamic and Static Knowledge in facilitating the transfer and sharing of knowledge arise as compelling research as well as practical topic for organizations. Our paper aims to investigate such tensions by employing a case study. We decided to deepen such dynamics in the healthcare field, given its importance for business and society. In more detail, we analyzed one Emergency Room (ER) department through a series of interviews. Our findings highlight the importance of the right balance between Static and Dynamic Knowledge. On the one hand, the healthcare organization recognized the need to incorporate knowledge into practical and tangible instruments. On the other hand, the flows of Dynamic Knowledge must be fostered through a culture of knowledge translation and sharing, and the development of soft skills

    Voice classification and Fach : recent, historical and conflicting systems of voice categorization

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    "While the body of critical and analytic texts concerning voice training grows, so, too, does the discourse continue to develop its on-going debate as to the importance of various criteria involved in voice classification. There exist also numerous documents from previous centuries which may be explored for insight into historical conceptions of voice classification. Yet as this body of literature on physiology and pedagogy continues to grow, there remains a lack of critical writings examining the Fach system. Indeed, the Fach system continues to be considered primarily a listing of roles organized by appropriate voice type, though the fluid nature of the system alone is enough to question the possibility of voice type as the true and constant categorization principle. Without any critical studies of the system, Fach is bound to remain a controversial subject over which pedagogues argue in vain. This paper offers a suggestion for approaching the system from two different angles: first, from a historical perspective which will allow for an overview of the fluidity of the system; second, with a tessitura study of a group of roles considered all part of one Fach."--Abstract from author supplied metadata
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