52 research outputs found
BIOPHYSICAL CONTROLS OF MARSH SOIL SHEAR STRENGTH ALONG AN ESTUARINE SALINITY GRADIENT
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gillen, M. N., Messerschmidt, T. C., & Kirwan, M. L. Biophysical controls of marsh soil shear strength along an estuarine salinity gradient. Earth Surface Dynamics, 9(3),(2021): 413-421, https://doi.org/10.5194/esurf-9-413-2021.Sea-level rise, saltwater intrusion, and wave erosion threaten coastal marshes, but the influence of salinity on marsh erodibility remains poorly understood. We measured the shear strength of marsh soils along a salinity and biodiversity gradient in the York River estuary in Virginia to assess the direct and indirect impacts of salinity on potential marsh erodibility. We found that soil shear strength was higher in monospecific salt marshes (5–36 kPa) than in biodiverse freshwater marshes (4–8 kPa), likely driven by differences in belowground biomass. However, we also found that shear strength at the marsh edge was controlled by sediment characteristics, rather than vegetation or salinity, suggesting that inherent relationships may be obscured in more dynamic environments. Our results indicate that York River freshwater marsh soils are weaker than salt marsh soils, and suggest that salinization of these freshwater marshes may lead to simultaneous losses in biodiversity and erodibility.This research has been supported by the US National Science Foundation (grant nos. 1654374, 1426981, 1529245, and 1832221)
J.B. [Production]
No full textCAST: Heather Bell (Mrs. Lesure), Lisa Berson (Sarah), Jim Black (Bildad), Leda Califf (Rebecca), Bob Conrad (Zuss), Tom Cotter (Eliphaz), Erin Finn (Mrs. Adams), Patty Guenthner (First Maid), Don Haley (Second Messenger), Bob Livolsy (Nickles), William Loennett (Zophar), Susan Looker (Mary), Bert Lyons (David), Charles Malin (Jonathan), Denise Messerschmidt (Second Maid), Sunday Palmer (Mrs. Botticellie), Jenny Reno (Ruth), David Ritter (First Messenger), Miriam Saggus (Mrs. Murphy), Betsy Shimek (The Girl), Wesley Smith (Distant Voice), Paul Wallace (Billy Adams), Wally Wulff (J.B.).CREW: David Califf (Director), John Burke (Assistant Director), Bill Weatherford (Stage Manager), Bob Behling (Master Carpenter), Lauriston Hardin (Lighting Designer), William 'Bill' Landolina (Resident Master Electrician), Robert Cole (Master Electrician), Stephen L 'Steve' Peet (Lighting), Jim Chalmers (Sound), Denise Messerschmidt (Properties), Erin Finn (Costumes), Susan Bailey (Makeup), Frankie Little (Publicity), Kevin Patton (House Manager), John Burke (Box Office Manager)
Cancer Clonal Theory, Immune Escape, and Their Evolving Roles in Cancer Multi-Agent Therapeutics
No full textCancer Clonal Theory, Immune Escape, and Their Evolving Roles in Cancer Multi-Agent Therapeutics
No full textHow Cancers Escape Immune Destruction and Mechanisms of Action for the New Significantly Active Immune Therapies: Helping Nonimmunologists Decipher Recent Advances
No full textAbstract
With the Food and Drug Administration and other worldwide regulatory authorities’ approval of ipilimumab (Yervoy), sipuleucel-T (Provenge), nivolumab (Opdivo), and pembrolizumab (Keytruda), oncologic therapy has now moved into noncancer cell targets within the immune system. For many nonimmunologists, understanding how these vastly different therapies work to improve survival, like no other therapies have in the past, is a challenge. The present report reviews the normal function of the immune system, how cancers escape the normal immune system, and how these new therapies improve immune system reactions against cancers.</jats:p
Rejection of benign melanocytic nevi by nevus-resident CD4(+) T cells
No full textMelanoma and melanocytic nevi harbor shared lineage-specific antigens and oncogenic mutations. Yet, the relationship between the immune system and melanocytic nevi is unclear. Using a patient-derived xenograft (PDX) model, we found that 81.8% of the transplanted nevi underwent spontaneous regression, while peripheral skin remained intact. Nevus-resident CD4(+) T helper 1 cells, which exhibited a massive clonal expansion to melanocyte-specific antigens, were responsible for nevus rejection. Boosting regulatory T cell suppressive function with low-dose exogenous human interleukin-2 injection or treatment with a human leukocyte antigen (HLA) class II-blocking antibody prevented nevus rejection. Notably, mice with rejected nevus PDXs were protected from melanoma tumor growth. We detected a parallel CD4(+) T cell-dominant immunity in clinically regressing melanocytic nevi. These findings reveal a mechanistic explanation for spontaneous nevus regression in humans and posit the activation of nevus-resident CD4(+) effector T cells as a novel strategy for melanoma immunoprevention and treatment.
Heterogeneity, distribution, and cooperation in common property resource management
No full textThe report considers the role of group heterogeneity in the success or failure of common property resource management. The author argues that cooperative agreements are less likely to come about when agents are highly heterogeneous along relevant dimensions - and existing agreements are more likely to break down as a group becomes more heterogeneous. The author crystallizes his argument in simple numerical examples and illustrates by reference to case studies on common property resource management, in particular, cases involving fisheries and irrigation systems. More work is needed to substantiate the author's argument, but his analysis so far supports the argument that equity and efficiency complement rather than oppose each other.Agricultural Research,Agricultural Knowledge&Information Systems,Poverty Assessment,Common Property Resource Development,Environmental Economics&Policies
Sediment Delivery to a Tidal Marsh Platform Is Minimized by Source Decoupling and Flux Convergence
No full textAuthor Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 125(8),(2020): e2020JF005558, doi:10.1029/2020JF005558.Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. However, understanding sediment transport across the marsh itself remains limited by discontinuous measurements of SSC over individual tidal cycles. Here, we use an array of optical turbidity sensors to build a long‐term, continuous record of SSC across a marsh platform and adjacent tidal channel. We find that channel and marsh concentrations are correlated (i.e., coupled) within tidal cycles but are largely decoupled over longer time scales. We also find that net sediment fluxes decline to near zero within 10 m of the marsh edge. Together, these results suggest that large sections of the marsh platform receive minimal sediment independent of flooding frequency or channel sediment supply. Marsh‐centric, as opposed to channel‐centric, measures of sediment supply may better characterize marsh platform vulnerability.This work was funded by NSF Awards 1529245, 1654374, 1426981, 1637630, and 1832221, the NSF Graduate Research Fellowship Program, and the USGS Climate and Land Use Research and Development program. We thank D. Walters, J. Himmelstein, D. Nicks, R. Walker, T. Messerschmidt, and the Plum Island Ecosystems LTER, especially S. Kelsey for laboratory and field assistance. Additionally, we thank C. Friedrichs, G. Guntenspergen, and O. Duran Vinent for contributing ideas that helped develop the work, and the reviewers who helped improve the manuscript. This work is Contribution Number 3928 of the Virginia Institute of Marine Science. In memoriam of David Nicks.2021-01-2
Diffraction data of core-shell nanoparticles from an X-ray free electron laser
No full textabstract: X-ray free-electron lasers provide novel opportunities to conduct single particle analysis on nanoscale particles. Coherent diffractive imaging experiments were performed at the Linac Coherent Light Source (LCLS), SLAC National Laboratory, exposing single inorganic core-shell nanoparticles to femtosecond hard-X-ray pulses. Each facetted nanoparticle consisted of a crystalline gold core and a differently shaped palladium shell. Scattered intensities were observed up to about 7 nm resolution. Analysis of the scattering patterns revealed the size distribution of the samples, which is consistent with that obtained from direct real-space imaging by electron microscopy. Scattering patterns resulting from single particles were selected and compiled into a dataset which can be valuable for algorithm developments in single particle scattering research.The final version of this article, as published in Scientific Data, can be viewed online at: https://www.nature.com/articles/sdata20174
- …
