2,113 research outputs found
Comparison of Methods for Determining the Composition of Pyrolysis Products from the Degradation of Ablative Composites. Status report.
Determining composition of pyrolysis products from degradation of ablative material
Changes in Understory Woody Vegetation in Red-Cockaded Woodpecker (Picoides Borealis) Nesting Clusters
Understory woody vegetation in red-cockaded woodpecker nesting clusters located in Pinus taeda (L.) and P. echinara (Mill.) dominated stands were inventoried from December 1986 through January 1987 and later in January 1995 to determine what effects court-ordered management schemes had on the composition, abundance, and diversity of these stands. There was a significant difference (Pin the composition between the first sampling period and the second with species diversity increasing and a change from a
P. (aeda/P. echinara dominated community to a P. weda/Rubus spp. understor
Forest pest management on Typic Quartzipsamments: a management dilemma
Pine plantations on Typic Quartzipsamments in East Texas are difficult to establish. Forest management options following clearcutting are limited. A eight year regeneration study of the growth and survival of loblolly, Pinus tuedu, L. shortleaf, P. echinutu Mill., slash, P. elliofii Engelm and longleaf pines P. palustris Mill. was conducted to determine optimum tree species and treatments for reforestation; and to recommend practical alternative land uses and management strategies for Typic Quartzipsamrnents. With successful regeneration also comes insects and pathogens. Impacts of the Nantucket pine tip moth, Rhyacioniujkstrunu, (Comstock) the Deodar weevil, Pissodes nernorensis, Germar, Annosus root rot, Heterobusidion unnosusm (Fr: Fr) Bref, fusiform rust, Cronurtizun quercwn (Berk.) Miyabe ex Shirai f. sp. fisiforme (Hedge and N. Hunt) Burdsall and G. Snow and the Texas leaf-cutting ant, Attu texunu, (Buckley) will be discussed in the context of droughty site management
Advances in targeted Alpha therapy for prostate cancer
BACKGROUND: Amongst therapeutic radiopharmaceuticals, targeted alpha therapy (TαT) can deliver potent and local radiation selectively to cancer cells as well as the tumor microenvironment and thereby control cancer while minimizing toxicity. DESIGN: In this review, we discuss the history, progress, and future potential of TαT in the treatment of prostate cancer, including dosimetry-individualized treatment planning, combinations with small-molecule therapies, and conjugation to molecules directed against antigens expressed by prostate cancer cells, such as prostate-specific membrane antigen (PSMA) or components of the tumor microenvironment. RESULTS: A clinical proof of concept that TαT is efficacious in treating bone-metastatic castration-resistant prostate cancer has been demonstrated by radium-223 via improved overall survival and long-term safety/tolerability in the phase III ALSYMPCA trial. Dosimetry calculation and pharmacokinetic measurements of TαT provide the potential for optimization and individualized treatment planning for a precision medicine-based cancer management paradigm. The ability to combine TαTs with other agents, including chemotherapy, androgen receptor (AR)-targeting agents, DNA repair inhibitors, and immuno-oncology agents, is under investigation. Currently, TαTs that specifically target prostate cancer cells expressing PSMA represents a promising therapeutic approach. Both PSMA-targeted actinium-225 and thorium-227 conjugates are under investigation. CONCLUSIONS: The described clinical benefit, safety and tolerability of radium-223 and the recent progress in TαT trial development suggest that TαT occupies an important new role in prostate cancer treatment. Ongoing studies with newer dosimetry methods, PSMA targeting, and novel approaches to combination therapies should expand the utility of TαT in prostate cancer treatment
Observations and modelling of microphysical variability, aggregation and sedimentation in tropical anvil cirrus outflow regions
Aircraft measurements of the microphysics of a tropical convective anvil (at
temperatures ~−60 °C) forming above the Hector storm, over the
Tiwi Islands, Northern Australia, have been conducted with a view to
determining ice crystal aggregation efficiencies from in situ measurements.
The observed microphysics have been compared to an explicit bin-microphysical
model of the anvil region, which includes crystal growth by vapour diffusion
and aggregation and the process of differential sedimentation.
It has been found in flights made using straight and level runs perpendicular
to the storm that the number of ice crystals initially decreased with
distance from the storm as aggregation took place resulting in larger
crystals, followed by their loss from the cloud layer due to sedimentation.
The net result was that the mass (i.e. Ice Water Content) in the anvil
Ci cloud decreased, but also that the average particle size (weighted by
number) remained relatively constant along the length of the anvil outflow.
Comparisons with the explicit microphysics model showed that the changes in
the shapes of the ice crystal spectra as a function of distance from the
storm could be explained by the model if the aggregation efficiency was set
to values of Eagg~0.5 and higher. This result is supported by
recent literature on aggregation efficiencies for complex ice particles and
suggests that either the mechanism of particle interlocking is important to
the aggregation process, or that other effects are occuring, such as
enhancement of ice-aggregation by high electric fields that arise as a
consequence of charge separation within the storm.
It is noteworthy that this value of the ice crystal aggregation efficiency is
much larger than values used in cloud resolving models at these temperatures,
which typically use E~0.0016. These results are important to
understanding how cold clouds evolve in time and for the treatment of the
evolution of tropical Ci in numerical models
Complex Tissue Regeneration in Mammals Is Associated with Reduced Inflammatory Cytokines and an Influx of T Cells
While mammals tend to repair injuries, other adult vertebrates like salamanders and fish regenerate damaged tissue. One prominent hypothesis offered to explain an inability to regenerate complex tissue in mammals is a bias during healing toward strong adaptive immunity and inflammatory responses. Here we directly test this hypothesis by characterizing part of the immune response during regeneration in spiny mice (Acomys cahirinus and Acomys percivali) vs. fibrotic repair in Mus musculus. By directly quantifying cytokines during tissue healing, we found that fibrotic repair was associated with a greater release of pro-inflammatory cytokines (i.e., IL-6, CCL2, and CXCL1) during acute inflammation in the wound microenvironment. However, reducing inflammation via COX-2 inhibition was not sufficient to reduce fibrosis or induce a regenerative response, suggesting that inflammatory strength does not control how an injury heals. Although regeneration was associated with lower concentrations of many inflammatory markers, we measured a comparatively larger influx of T cells into regenerating ear tissue and detected a local increase in the T cell associated cytokines IL-12 and IL-17 during the proliferative phase of regeneration. Taken together, our data demonstrate that a strong adaptive immune response is not antagonistic to regeneration and that other mechanisms likely explain the distribution of regenerative ability in vertebrates
Delivering reform in English healthcare: an ideational perspective
A variety of perspectives has been put forward to understand reform across healthcare systems. Recently, some have called for these perspectives to give greater recognition to the role of ideational processes. The purpose of this article is to present an ideational approach to understanding the delivery of healthcare reform. It draws on a case of English healthcare reform – the Next Stage Review led by Lord Darzi – to show how the delivery of its reform proposals was associated with four ideational frames. These frames built on the idea of “progress” in responding to existing problems; the idea of “prevailing policy” in forming part of a bricolage of ideas within institutional contexts; the idea of “prescription” as top-down structural change at odds with local contexts; and the idea of “professional disputes” in challenging the notion of clinical engagement across professional groups. The article discusses the implications of these ideas in furthering our understanding of policy change, conflict and continuity across healthcare settings
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Coastal protection and conservation on sandy beaches and dunes : Context-dependent tradeoffs in ecosystem service supply
Managing multiple ecosystem services (ESs) across landscapes presents a central challenge for ecosystem-based management, because services often exhibit spatiotemporal variation and weak associations with co-occurring ESs. Further focus on the mechanistic relationships among ESs and their underlying biophysical processes provides greater insight into the causes of variation and covariation among ESs, thus serving as a guide to enhance their supply while preventing adverse outcomes. Here, we used the U.S. Pacific Northwest coastal dune ecosystem to examine how invasive beachgrass management affects three ESs: coastal protection, western snowy plover conservation, and endemic foredune plant conservation. At seven coastal dune habitat restoration areas, we observed spatial variation in the supply of each ES and further identified a tradeoff between western snowy plover conservation and coastal protection. While the ESs were collectively influenced by the invasive beachgrasses and the foredunes they create, the magnitude of the synergies and tradeoffs were influenced by numerous non-shared drivers, including nearshore geomorphology, changes in foredune shape as a result of restoration, and other management actions irrespective of restoration. Incorporation of these shared and non-shared drivers into future coastal management planning may reduce tradeoffs among Pacific Northwest dune ESs. With better understanding of ES relationships, it becomes possible to identify management actions that may enhance synergies and mitigate tradeoffs, leading to better decisions for nature and people. Key words: coastal protection; conservation; ecosystem management; ecosystem services; natural capital; restoration
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