108 research outputs found
Abstract thoughts of hemostasis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147819/1/jth14375.pd
Identification of a novel nidovirus in an outbreak of fatal respiratory disease in ball pythons (Python regius)
Background: Respiratory infections are important causes of morbidity and mortality in reptiles; however, the causative agents are only infrequently identified. Findings: Pneumonia, tracheitis and esophagitis were reported in a collection of ball pythons (Python regius). Eight of 12 snakes had evidence of bacterial pneumonia. High-throughput sequencing of total extracted nucleic acids from lung, esophagus and spleen revealed a novel nidovirus. PCR indicated the presence of viral RNA in lung, trachea, esophagus, liver, and spleen. In situ hybridization confirmed the presence of intracellular, intracytoplasmic viral nucleic acids in the lungs of infected snakes. Phylogenetic analysis based on a 1,136 amino acid segment of the polyprotein suggests that this virus may represent a new species in the subfamily Torovirinae.
Conclusions: This report of a novel nidovirus in ball pythons may provide insight into the pathogenesis of respiratory disease in this species and enhances our knowledge of the diversity of nidoviruses
A Conserved Stem Loop Motif in the 5′Untranslated Region Regulates Transforming Growth Factor-β1 Translation
Transforming growth factor-β1 (TGF-β1) regulates cellular proliferation, differentiation, migration, and survival. The human TGF-β1 transcript is inherently poorly translated, and translational activation has been documented in relation to several stimuli. In this paper, we have sought to identify in cis regulatory elements within the TGF-β1 5′Untranslated Region (5′UTR). In silico analysis predicted formation of stable secondary structure in a G/C-rich element between nucleotides +77 to +106, and demonstrated that this element is highly conserved across species. Circular dichroism spectroscopy confirmed the presence of secondary structure in this region. The proximal 5′UTR was inhibitory to translation in reporter gene experiments, and mutation of the secondary structure motif increased translational efficiency. Translational regulation of TGF-β1 mRNA is linked to altered binding of YB-1 protein to its 5′UTR. Immunoprecipitation-RT-qPCR demonstrated a high basal association of YB-1 with TGF-β1 mRNA. However, mutation of the secondary structure motif did not prevent interaction of YB-1 with the 5′UTR, suggesting that YB-1 binds to this region due to its G/C-rich composition, rather than a specific, sequence-dependent, binding site. These data identify a highly conserved element within the TGF-β1 5′UTR that forms stable secondary structure, and is responsible for the inherent low translation efficiency of this cytokine
Distributed leadership in organizations: A review of theory and research
The aim of this paper is to review conceptual and empirical literature on the concept of distributed leadership (DL) in order to identify its origins, key arguments, and areas for further work. Consideration is given to the similarities and differences between DL and related concepts including ‘shared’, ‘collective’, ‘collaborative’, ‘emergent’, ‘co-‘ and ‘democratic’ leadership. Findings indicate that whilst there are some common theoretical bases, the relative usage of these concepts varies over time, between countries and between sectors. In particular, DL is a notion that has seen a rapid growth in interest since the year 2000 but research remains largely restricted to the field of school education and of proportionally more interest to UK than US-based academics. Several scholars are increasingly going to lengths to indicate that in order to be ‘distributed’ leadership need not necessarily be widely ‘shared’ or ‘democratic’ and in order to be effective there is a need to balance different ‘hybrid configurations’ of practice. The article highlights a number of areas for further attention, including three factors relating to the context of much work on DL (power and influence; organisational boundaries and context; and ethics and diversity), and three methodological and developmental challenges (ontology; research methods; and leadership development, reward and recognition). It is concluded that descriptive and normative perspectives that dominate the literature should be supplemented by more critical accounts that recognise the rhetorical and discursive significance of DL in (re)constructing leader-follower identities, mobilising collective engagement and challenging or reinforcing traditional forms of organisation
Ecosystem development after mangrove wetland creation : plant–soil change across a 20-year chronosequence
This paper is not subject to U.S. copyright. The definitive version was published in Ecosystems 15 (2012): 848-866, doi:10.1007/s10021-012-9551-1.Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10–30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0–10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses
Minha vida é andar por esse país...: a emigração recente no semiárido setentrional, políticas sociais e meio ambiente
Art and Social Life in Dewey and Hegel
Drawing on John Dewey\u27s philosophy, I argue first that our distinctive human existence depends most fundamentally on practices of communication. I then argue that creative artistic work plays a crucial and inescapable role in shaping and enabling communication. The focus of my dissertation is then on showing the unique and distinctive role that art plays in facilitating the emergence of democratic culture, specifically. To make this argument I draw on Hegel\u27s analysis of two particular artistic media: architecture and painting. I argue first that architecture, though it can serve many different functions, is most essentially the articulation of a shared sense of human dwelling. I then argue that painting, on the contrary, has as its distinctive artistic function the articulation of the distinctive experience of individuality. Turning again to Dewey, I then argue that democratic culture depends essentially on both this communal and this individualistic sense of our existence and, consequently, that in fundamental ways the historical development of the arts of architecture and painting have made possible the emergence of a democratic culture. I conclude, finally, that it is also definitive of the very meaning of democracy that it itself promote the proliferation of transformative practices of creative communication, and hence that, just as it depends inherently on a history of artistic practice, democracy must equally commit itself to the development of new forms of artistic expression
Postintubation Tracheal Stenosis in a Blue and Gold Macaw (Ara ararauna) Resolved With Tracheal Resection and Anastomosis
Estimation of Prothrombin Times of Hispaniolan Amazon Parrots (Amazona ventralis) and Umbrella Cockatoos (Cacatua alba)
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