Floristic composition and comparison of middle Eocene to late Eocene and Oligocene floras in North America

In comparison to the early and middle Eocene, the late Eocene and particularly the Oligocene floral record is sparse in North America. Changing tectonic, environmental and climatic conditions during these times resulted in the development of fewer depositional systems favorable for fossil preservation. Floras are known from the Southeast, the Pacific Northwest and the Rocky Mountains. Each area has a distinct geological history that shaped both the vegetation adjacent to sites of deposition as well as the depositional environments themselves. The floristic change from middle to late Eocene, and then to Oligocene reflects a changing paleoclimate from the thermal maximum to cooler and drier conditions in the late Paleogene. In the present paper, major middle, and then late Eocene and finally Oligocene floras of North America are summarized, with an emphasis on their regional geology, depositional setting, paleoclimate and significant floral elements. The North American occurrences of coryphoid palms (Sabal) and cycads are reviewed in relationship to their biogeographic history. Finally, we suggest several directions for future research that will further illuminate the floristic changes from middle, to late Eocene and Oligocene that occurred in North America

Studies of Paleozoic Seed Ferns: Additional Studies of Microspermopteris aphyllum Baxter

This is the publisher's version, also available electronically from http://www.jstor.org.The genus Microspermopteris is characterized as a small lyginopterid pteridosperm with a pentarch protostele, irregular cortical ridges, and multicellular trichomes. We describe the frond architecture and variability among axillary branches previously unknown for the genus. Fronds are small and delicate, exhibiting three orders of branching. Clasping V-shaped petioles produce primary pinnae alternately to suboppositely from adaxial projections. Primary pinnae in turn produce secondaries that bear two-, three-, or four-lobed ultimate laminar pinnules. Pinnules reconstructed from serial sections are morphologically similar to Sphenopteris-like compressions; however, the overall frond is reduced in size and complexity. While some axillary branches produce secondary xylem, others are composed entirely of primary tissues. Some axillary branches produce scalelike leaves in a tight helix; distally, immature buds are surrounded by flattened bud scales. Although Microspermopteris shows similarities to Heterangium in stelar and cortical anatomy, the two taxa are distinct. Microspermopteris is interpreted as a delicate, scrambling vine, liana, or shrublike plant in contrast to the more robust lyginopterids Lyginopteris, Schopfiastrum, and Heterangium

The influence of burn severity on dissolved organic carbon concentrations across a stream network differs based on seasonal wetness conditions

Large, high-severity wildfires in many regions across the globe have increased concerns about their impacts on carbon cycling in watersheds. Altered sources of carbon and changes in catchment hydrology after wildfire can lead to shifts in dissolved organic carbon (DOC) concentrations in streams, which can have negative impacts on aquatic ecosystem health and downstream drinking-water treatment. Despite its importance, post-fire DOC responses remain relatively unconstrained in the literature, and we lack critical knowledge of how burn severity, landscape elements, and climate interact to affect DOC concentrations. To improve our understanding of the impact of burn severity on DOC concentrations, we measured DOC at 129 sites across a stream network extending upstream, within, and downstream of a large, high-severity wildfire in Oregon, USA. We collected samples across the study sub-basin during four distinct seasonal wetness conditions. We used our high-spatial-resolution data to develop spatial stream network (SSN) models to predict DOC across the stream network and to improve our understanding of the controls on DOC concentrations. Spatially, we found no obvious wildfire signal – instead, we observed a pattern of increasing DOC concentrations from the high-elevation headwaters to the sub-basin outlet, while the mainstem maintained consistently low DOC concentrations. This suggests that effects from large wildfires may be “averaged” out at higher stream orders and larger spatial scales. When we grouped DOC concentrations by burn severity group, we observed a significant decrease in the variability of DOC concentrations in the moderate and high burn severity sub-catchments. However, our SSN models were able to predict decreases in DOC concentrations with increases in burn severity across the stream network. Decreases in DOC concentrations were also highly variable across seasonal wetness conditions, with the greatest (−1.40 to −1.64 mg L−1) decrease occurring in the high-severity group during the wetting season. Additionally, our models indicated that in all seasons, baseflow index was more influential in predicting DOC concentrations than burn severity was, indicating that groundwater discharge can obscure the impacts of wildfire in a stream network. Overall, our results suggested that landscape characteristics can regulate the DOC response to wildfire. Moreover, our results also indicated that the seasonal timing of sampling can influence the observed response of DOC concentrations to wildfire.</p

Biogeochemistry of upland to wetland soils, sediments, and surface waters across Mid-Atlantic and Great Lakes coastal interfaces

Transferable and mechanistic understanding of cross-scale interactions is necessary to predict how coastal systems respond to global change. Cohesive datasets across geographically distributed sites can be used to examine how transferable a mechanistic understanding of coastal ecosystem control points is. To address the above research objectives, data were collected by the EXploration of Coastal Hydrobiogeochemistry Across a Network of Gradients and Experiments (EXCHANGE) Consortium – a regionally distributed network of researchers that collaborated on experimental design, methodology, collection, analysis, and publication. The EXCHANGE Consortium collected samples from 52 coastal terrestrial-aquatic interfaces (TAIs) during Fall of 2021. At each TAI, samples collected include soils from across a transverse elevation gradient (i.e., coastal upland forest, transitional forest, and wetland soils), surface waters, and nearshore sediments across research sites in the Great Lakes and Mid-Atlantic regions (Chesapeake and Delaware Bays) of the continental USA. The first campaign measures surface water quality parameters, bulk geochemical parameters on water, soil, and sediment samples, and physicochemical parameters of sediment and soil

Potential bioavailability of representative pyrogenic organic matter compounds in comparison to natural dissolved organic matter pools

Pyrogenic organic matter (PyOM) from wildfires impacts river corridors globally and is widely regarded as resistant to biological degradation. Though recent work suggests PyOM may be more bioavailable than historically perceived, estimating bioavailability across its chemical spectrum remains elusive. To address this knowledge gap, we assessed potential bioavailability of representative PyOM compounds relative to ubiquitous dissolved organic matter (DOM) with a substrate-explicit model. The range of potential bioavailability of PyOM was greater than natural DOM; however, the predicted thermodynamics, metabolic rates, and carbon use efficiencies (CUEs) overlapped significantly between all OM pools. Compound type (e.g., natural versus PyOM) had approximately 6-fold less impact on predicted respiration rates than simulated carbon and oxygen limitations. Within PyOM, the metabolism of specific chemistries differed strongly between unlimited and oxygen-limited conditions – degradations of anhydrosugars, phenols, and polycyclic aromatic hydrocarbons (PAHs) were more favorable under oxygen limitation than other molecules. Notably, amino sugar-like, protein-like, and lignin-like PyOM had lower carbon use efficiencies relative to natural DOM of the same classes, indicating potential impacts in process-based model representations. Overall, our work illustrates how similar PyOM bioavailability may be to that of natural DOM in the river corridor, furthering our understanding of how PyOM may influence riverine biogeochemical cycling.</p

Polar opposites? NGOs, left parties and the fight for social change in Nepal

In the early 1990s, when NGOs were rising to prominence as an ostensible force for social change in Nepal, the Maoists were also beginning to organise, and denounced NGOs as agents of imperialism. The Maoists came to prominence by fighting a People’s War launched in 1996, with the intention of improving life for the poor peasant and working-class majority. But after a decade-long struggle, the Maoists became incorporated into the parliamentary system. While Nepal’s first democratic revolution in 1990 met formal, popular political demands, which were consolidated in a subsequent revolution in 2006 overthrowing the monarchy and bringing the People’s War to an end, there was little socio-economic progress for the vast majority. The argument advanced in this article is that this lack of progress relied on the interplay of two phenomena: an anti-Maoist alliance consisting of the international community, the domestic ruling elite and NGOs, and a fundamental ambiguity at the heart of the Maoists’ political theory

PRIRATE 2020 guidelines for reporting randomized trials in endodontics: a consensus-based development

In evidence-based healthcare, randomized clinical trials provide the most accurate and reliable information on the effectiveness of an intervention. This project aimed to develop reporting guidelines, exclusively for randomized clinical trials in the dental specialty of Endodontology, using a well-documented, validated consensus-based methodology. The guidelines have been named: Preferred Reporting Items for RAndomized Trials in Endodontics (PRIRATE) 2020. A total of eight individuals (PD, VN, HD, LB, TK, JJ, EP, SP), including the project leaders (PD, VN) formed a steering committee. The committee developed a checklist based on the items in the Consolidated Standards for Reporting Trials (CONSORT) guidelines and Clinical and Laboratory Images in Publications (CLIP) principles. A PRIRATE Delphi Group (PDG) and PRIRATE Face-to-Face Meeting group (PFMG) were also formed. Thirty PDG members participated in the online Delphi process and achieved consensus on the checklist items and flowchart that make up the PRIRATE guidelines. The guidelines were discussed at a meeting of the PFMG at the 19th European Society of Endodontology (ESE) Biennial congress, held on 13th September 2019 in Vienna, Austria. A total of 21 individuals from across the globe and four steering committee members (PD, VN, HD, LB) attended the meeting. As a consequence of the discussions, the guidelines were modified and then piloted by several authors whilst writing a manuscript. The PRIRATE 2020 guidelines contain a checklist consisting of 11 sections and 58 individual items as well as a flowchart, considered essential for authors to include when writing manuscripts for randomized clinical trials in Endodontics

PRIDASE 2024 guidelines for reporting diagnostic accuracy studies in endodontics: Explanation and elaboration

The Preferred Reporting Items for Diagnostic Accuracy Studies in Endodontics (PRIDASE) 2024 guidelines are based on the Standards for Reporting of Diagnostic Accuracy Studies (STARD) 2015 guidelines and the Clinical and Laboratory Images in Publications (CLIP) principles, with the addition of items specifically related to endodontics. The use of the PRIDASE 2024 guidelines by authors and their application by journals during the peer review process will reduce the possibility of bias and enhance the quality of future diagnostic accuracy studies. The PRIDASE 2024 guidelines consist of a checklist containing 11 domains and 66 individual items. The purpose of the current document is to provide an explanation for each item on the PRIDASE 2024 checklist, along with examples from the literature to help readers understand their importance and offer advice to those developing manuscripts. A link to the PRIDASE 2024 explanation and elaboration document is available on the Preferred Reporting Items for study Designs in Endodontology (PRIDE) website (https://pride‐endodonticguidelines.org/pridase/) and on the International Endodontic Journal website (https://onlinelibrary.wiley.com/page/journal/13652591/homepage/pride‐guidelines.htm)

Ficaria verna Huds. extracts and their β-cyclodextrin supramolecular systems

<p>Abstract</p> <p>Background</p> <p>Obtaining new pharmaceutical materials with enhanced properties by using natural compounds and environment-friendly methods is a continuous goal for scientists. <it>Ficaria verna </it>Huds. is a widespread perennial plant with applications in the treat of haemorrhoids and to cure piles; it has also anti-inflammatory, astringent, and antibiotic properties. The goal of the present study is the obtaining and characterization of new <it>F. verna </it>extract/β-cyclodextrin complexes by using only natural compounds, solvents, and environment-friendly methods in order to increase the quality and acceptability versus toxicity indicator. Thus, the flavonoid content (as quercetin) of <it>Ficaria verna </it>Huds. flowers and leaves from the West side of Romania was determined and correlated with their antioxidant activity. Further, the possibility of obtaining β-cyclodextrin supramolecular systems was studied.</p> <p>Results</p> <p><it>F. verna </it>flowers and leaves extracts were obtained by semi-continuous solid-liquid extraction. The raw concentrated extract was spectrophotometrically analyzed in order to quantify the flavonoids from plant parts and to evaluate the antioxidant activity of these extracts. The <it>F. verna </it>extracts were used for obtaining β-cyclodextrin complexes; these were analyzed by scanning electron microscopy and Karl Fischer water titration; spectrophotometry was used in order to quantifying the flavonoids and evaluates the antioxidant activity. A higher concentration of flavonoids of 0.5% was determined in complexes obtained by crystallisation method, while only a half of this value was calculated for kneading method. The antioxidant activity of these complexes was correlated with the flavonoid content and this parameter reveals possible controlled release properties.</p> <p>Conclusions</p> <p>The flavonoid content of <it>F. verna </it>Huds. from the West side of Romania (Banat county) is approximately the same in flowers and leaves, being situated at a medium value among other studies. β-Cyclodextrin complexes of <it>F. verna </it>extracts are obtained with lower yields by crystallisation than kneading methods, but the flavonoids (as quercetin) are better encapsulated in the first case most probably due to the possibility to attain the <it>host</it>-<it>guest </it>equilibrium in the slower crystallisation process. <it>F. verna </it>extracts and their β-cyclodextrin complexes have antioxidant activity even at very low concentrations and could be used in proper and valuable pharmaceutical formulations with enhanced bioactivity.</p

Representing the function and sensitivity of coastal interfaces in earth system models

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ward, N. D., Megonigal, J. P., Bond-Lamberty, B., Bailey, V. L., Butman, D., Canuel, E. A., Diefenderfer, H., Ganju, N. K., Goni, M. A., Graham, E. B., Hopkinson, C. S., Khangaonkar, T., Langley, J. A., McDowell, N. G., Myers-Pigg, A. N., Neumann, R. B., Osburn, C. L., Price, R. M., Rowland, J., Sengupta, A., Simard, M., Thornton, P. E., Tzortziou, M., Vargas, R., Weisenhorn, P. B., & Windham-Myers, L. Representing the function and sensitivity of coastal interfaces in earth system models. Nature Communications, 11(1), (2020): 2458, doi:10.1038/s41467-020-16236-2.Between the land and ocean, diverse coastal ecosystems transform, store, and transport material. Across these interfaces, the dynamic exchange of energy and matter is driven by hydrological and hydrodynamic processes such as river and groundwater discharge, tides, waves, and storms. These dynamics regulate ecosystem functions and Earth’s climate, yet global models lack representation of coastal processes and related feedbacks, impeding their predictions of coastal and global responses to change. Here, we assess existing coastal monitoring networks and regional models, existing challenges in these efforts, and recommend a path towards development of global models that more robustly reflect the coastal interface.Funding for this work was provided by Pacific Northwest National Laboratory (PNNL) Laboratory Directed Research & Development (LDRD) as part of the Predicting Ecosystem Resilience through Multiscale Integrative Science (PREMIS) Initiative. PNNL is operated by Battelle for the U.S. Department of Energy under Contract DE-AC05-76RL01830. Additional support to J.P.M. was provided by the NSF-LTREB program (DEB-0950080, DEB-1457100, DEB-1557009), DOE-TES Program (DE-SC0008339), and the Smithsonian Institution. This manuscript was motivated by discussions held by co-authors during a three-day workshop at PNNL in Richland, WA: The System for Terrestrial Aquatic Research (STAR) Workshop: Terrestrial-Aquatic Research in Coastal Systems. The authors thank PNNL artist Nathan Johnson for preparing the figures in this manuscript and Terry Clark, Dr. Charlette Geffen, and Dr. Nancy Hess for their aid in organizing the STAR workshop. The authors thank all workshop participants not listed as authors for their valuable insight: Lihini Aluwihare (contributed to biogeochemistry discussions and development of concept for Fig. 3), Gautam Bisht (contributed to modeling discussion), Emmett Duffy (contributed to observational network discussions), Yilin Fang (contributed to modeling discussion), Jeremy Jones (contributed to biogeochemistry discussions), Roser Matamala (contributed to biogeochemistry discussions), James Morris (contributed to biogeochemistry discussions), Robert Twilley (contributed to biogeochemistry discussions), and Jesse Vance (contributed to observational network discussions). A full report on the workshop discussions can be found at https://www.pnnl.gov/publications/star-workshop-terrestrial-aquatic-research-coastal-systems