163 research outputs found
Properties And Mechanisms: Physical And Chemical Investigations Of Bis(imino)pyridine Ruthenium Complexes
Interesting chemical transformations and reactivities of metal complexes bearing the bis(imino)pyridine ligand have been observed. These transformations and reactivities have often been attributed to interesting electronic structures induced by the ligand. Developing a better understanding of the nature of the bis(imino)pyridine ligand and how to tune it has become an area of great interest. Ruthenium complexes bearing the bis(imino)pyridine ligand have been synthesized and probed using various analytical techniques to investigate electronic structure. Similarly, chemical transformations and reactivities involving ruthenium bis(imino)pyridine complexes have been investigated. The coordination number appears to significantly affect the mode by which the chemistry of these complexes occurs, whether through radical chemistry or traditional 2 e– chemistry
Ecological characterization of the Florida springs coast: Pithlachascotee to Waccasassa Rivers
This report covers the upper coast of west-central Florida. This region includes the drainage basins and nearshore waters of the west coast of Florida between, but not including, the Anclote River basin and the Suwannee River basin. The name Springs Coast wash chosen because this area contains a multitude of springs, both named and too small or inaccessible to have been names. Much of the area is karstic limestone. Most recognizable among the springs are the famous Crystal river, Weeki Wachee, and Homosassa. This territory includes large expanses of
marsh and wetland and, along its shores, the southern end of the largest area of seagrass beds in the state -- the Florida Big Bend Seagrass Beds preserve. It also possesses numerous spring-fed rivers and streams along the coast, whose constant discharges provide unique, relatively stable estuarine environments. This document is a summary of the available
information on the Springs Coast area of Florida, for
use by planners, developers, regulatory authorities,
and other interested parties. An understanding of the
factors affecting their plans and the possibly unexpected
impacts of their actions on others will, it is
hoped, promote intelligent development in areas
capable of supporting it. We have tried to provide a
clear, coherent picture of what is currently known
about how the physical, chemical, and biological
factors of the environment interact. (343 pp.
A Vulnerability Assessment of 300 Species in Florida: Threats from Sea Level Rise, Land Use, and Climate Change
Species face many threats, including accelerated climate change, sea level rise, and conversion and degradation of habitat from human land uses. Vulnerability assessments and prioritization protocols have been proposed to assess these threats, often in combination with information such as species rarity; ecological, evolutionary or economic value; and likelihood of success. Nevertheless, few vulnerability assessments or prioritization protocols simultaneously account for multiple threats or conservation values. We applied a novel vulnerability assessment tool, the Standardized Index of Vulnerability and Value, to assess the conservation priority of 300 species of plants and animals in Florida given projections of climate change, human land-use patterns, and sea level rise by the year 2100. We account for multiple sources of uncertainty and prioritize species under five different systems of value, ranging from a primary emphasis on vulnerability to threats to an emphasis on metrics of conservation value such as phylogenetic distinctiveness. Our results reveal remarkable consistency in the prioritization of species across different conservation value systems. Species of high priority include the Miami blue butterfly (Cyclargus thomasi bethunebakeri), Key tree cactus (Pilosocereus robinii), Florida duskywing butterfly (Ephyriades brunnea floridensis), and Key deer (Odocoileus virginianus clavium). We also identify sources of uncertainty and the types of life history information consistently missing across taxonomic groups. This study characterizes the vulnerabilities to major threats of a broad swath of Florida\u27s biodiversity and provides a system for prioritizing conservation efforts that is quantitative, flexible, and free from hidden value judgments
Connectivity Conservation and Endangered Species Recovery: A Study in the Challenges of Defining Conservation-Reliant Species
Many species listed under the US Endangered Species Act (ESA) face continuing threats and will require intervention to address those threats for decades. These species, which have been termed conservation-reliant, pose a challenge to the ESA\u27s mandate for recovery of self-sustaining populations. Most references to conservation-reliant species by federal agencies involve the restoration of population connectivity. However, the diverse threats to connectivity faced by different species have contrasting implications in the context of the ESA\u27s mandate. For species facing long-term threats from invasive species or climate change, restoration of natural dispersal may not be technically feasible in the foreseeable future. For other species, restoration of natural dispersal is feasible, but carries economic and political cost. Federal agencies have used a broad definition of conservation reliance to justify delisting of species in the latter group even if they remain dependent on artificial translocation. Distinguishing the two groups better informs policy by distinguishing the technical challenges posed by novel ecological stressors from normative questions such as the price society is willing to pay to protect biodiversity, and the degree to which we should grow accustomed to direct human intervention in species\u27 life cycles as a component of conservation in the Anthropocene Epoch
Cellular and Molecular Mechanisms of Fungal β-(1→6)-Glucan in Macrophages
Over the last 40-yr, the majority of research on glucans has focused on β-(1→3)-glucans. Recent studies indicate that β-(1→6)-glucans may be even more potent immune modulators than β-(1→3)-glucans. Mechanisms by which β-(1→6)-glucans are recognized and modulate immunity are unknown. In this study, we examined the interaction of purified water-soluble β-(1→6)-glucans with macrophage cell lines and primary peritoneal macrophages and the cellular and molecular consequences of this interaction. Our results indicate the existence of a specific β-(1→6)-glucan receptor that internalizes the glucan ligand via a clathrin-dependent mechanism. We show that the known β-(1→3)-glucans receptors are not responsible for β-(1→6)-glucan recognition and interaction. The receptor-ligand uptake/interaction has an apparent dissociation constant (KD) of ∼4-μM, and was associated with phosphorylation of ERK and JNK but not Iκ-α or p38. Our results indicate that macrophage interaction with β-(1→6)-glucans may lead to modulation of genes associated with anti-fungal immunity and recruitment/activation of neutrophils. In summary, we show that macrophages specifically bind and internalize β-(1→6)-glucans followed by activation of intracellular signaling and modulation of anti-fungal immune response-related gene regulation. Thus, we conclude that the interaction between innate immunity and β-(1→6)-glucans may play an important role in shaping the anti-fungal immune response
New Directions in Conservation for the National Wildlife Refuge System
The National Wildlife Refuge System Improvement Act of 1997 includes the nation’s broadest statutory commitment to ecosystem protection: to “ensure that the biological integrity, diversity, and environmental health of the system are maintained.” The act also directs the US Fish and Wildlife Service (FWS) to expand the scope of conservation monitoring, assessment, and management beyond refuge boundaries to encompass surrounding landscapes. The act thus gives the FWS a leadership role in developing research and management partnerships with other agencies, organizations, and neighboring landowners. Increasing research capacity and scientific expertise, and strengthening institutional resolve to limit activities that impede the attainment of this directive, are challenges for the FWS. Success requires reexamination of existing priorities, refocused training, the acquisition of new funding and technical expertise, and creative application of those new skills to meet the law’s broad mandat
Consolidating diverse modeling methods and spatial prioritization for multispecies connectivity planning
IntroductionGiven the different life histories and movement behaviors of diverse species, reconciling conservation measures to benefit all species is a critical concern for landscape conservation planning. Understanding land cover composition and finding multispecies movement routes across heterogeneous landscapes are crucial to maintaining many target species. The primary objectives of this study were to determine the optimal environment in Florida that promotes multispecies connectivity in landscapes increasingly threatened by rapid suburban development and to enhance methods for delineating the state’s ecological networks.MethodsPotential functional connectivity of the focal species with statewide distributions and are considered priorities because of the historical and current threats to their population viability, such as the Florida black bear (Ursus americanus floridanus), Florida panther (Puma concolor coryi), eastern indigo snake (Drymarchon couperi), and southern fox squirrel (Sciurus niger niger), were modeled using Linkage Mapper, Omniscape, and resistant kernels. We combined quantiles from each method for a single species combination approach to leverage the results from the three models for planning purposes. Subsequently, we integrated the results into a novel multiple species, multi-model connectivity mapping approach. Following the corridor analysis, a comparison was made between multispecies connectivity maps, current managed conservation lands, and the main priority areas for the Florida Wildlife Corridor, a previously developed planning network of natural hubs and corridors. Finally, we used the spatial prioritization software Zonation to identify areas of conservation priority, while also illustrating the impacts of infrastructure (built infrastructure, roadways, mining, and future development 2040 and 2070 projections) and threats from human activity (landscape fragmentation, recreation, pollution, contamination, and clean-up sites).ResultsThe study identified priority areas for all four species, with a particular focus on areas not currently protected. The connectivity models showed significant overlap with current managed conservation lands and the main priority areas for the Florida Wildlife Corridor. Pinchpoint areas or bottlenecks were identified as needing fine-scale incorporation into spatial planning. Using the spatial prioritization software Zonation, we identified areas of conservation priority and illustrated the impacts of infrastructure and threats.DiscussionThe results indicate that species-relevant connectivity models incorporating a group of focal species with both complementary and opposing habitat requirements can better inform biodiversity conservation and landscape design decisions. This multi-model approach provides a robust framework for identifying and prioritizing areas for conservation, particularly in landscapes facing rapid suburban development. Integrating multispecies connectivity models into conservation planning can enhance the effectiveness of ecological networks and contribute to the long-term viability of diverse species in Florida
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Cadherin-11 regulates synovial fibroblast behavior in health and disease
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Evidence for cadherin-11 cleavage in the synovium and partial characterization of its mechanism
Introduction: Engagement of the homotypic cell-to-cell adhesion molecule cadherin-11 on rheumatoid arthritis (RA) synovial fibroblasts with a chimeric molecule containing the cadherin-11 extracellular binding domain stimulated cytokine, chemokine, and matrix metalloproteinases (MMP) release, implicating cadherin-11 signaling in RA pathogenesis. The objective of this study was to determine if cadherin-11 extracellular domain fragments are found inside the joint and if a physiologic synovial fibroblast cleavage pathway releases those fragments. Methods: Cadherin-11 cleavage fragments were detected by western blot in cell media or lysates. Cleavage was interrupted using chemical inhibitors or short-interfering RNA (siRNA) gene silencing. The amount of cadherin-11 fragments in synovial fluid was measured by western blot and ELISA. Results: Soluble cadherin-11 extracellular fragments were detected in human synovial fluid at significantly higher levels in RA samples compared to osteoarthritis (OA) samples. A cadherin-11 N-terminal extracellular binding domain fragment was shed from synovial fibroblasts after ionomycin stimulation, followed by presenilin 1 (PSN1)-dependent regulated intramembrane proteolysis of the retained membrane-bound C-terminal fragments. In addition to ionomycin-induced calcium flux, tumor necrosis factor (TNF)-α also stimulated cleavage in both two- and three-dimensional fibroblast cultures. Although cadherin-11 extracellular domains were shed by a disintegrin and metalloproteinase (ADAM) 10 in several cell types, a novel ADAM- and metalloproteinase-independent activity mediated shedding in primary human fibroblasts. Conclusions: Cadherin-11 undergoes ectodomain shedding followed by regulated intramembrane proteolysis in synovial fibroblasts, triggered by a novel sheddase that generates extracelluar cadherin-11 fragments. Cadherin-11 fragments were enriched in RA synovial fluid, suggesting they may be a marker of synovial burden and may function to modify cadherin-11 interactions between synovial fibroblasts. Electronic supplementary material The online version of this article (doi:10.1186/s13075-015-0647-9) contains supplementary material, which is available to authorized users
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