Design Considerations for Embankment Protection During Road Overtopping Events

This report describes the research conducted by the University of Minnesota and project partners on roadway embankment overtopping by flood water. Roadway overtopping is a major safety concern for Minnesota transportation managers because of the potential for rapid soil erosion and mass wasting resulting in partial or complete failure of the roadway embankment. This multi-year research study focused on various aspects of the roadway embankment overtopping. A robust literature survey was performed to identify research, reports and other published knowledge that would inform the project. A field- based research campaign was developed with the goal of collecting data on the hydraulics associated with full-scale overtopping events. Finally, a series of laboratory experiments were conducted at the St. Anthony Falls Laboratory, University of Minnesota to study the hydraulic and erosional processes associated with embankment overtopping and in particular study of three slope protection techniques under overtopping flow. The largest component of the research project was the laboratory hydraulic testing, which focused on bare soil (base case) and three slope protection technologies. A full- scale laboratory facility was constructed to carry out the testing. Three erosion protection techniques were examined including 1) armored sod, 2) turf reinforcement mat, and 3) flexible concrete geogrid mat. Overtopping depths of up to 1-ft were used to determine the failure point of the protection technique and soil on both the 4h:1V and 6V:1H slopes. The full project report details the testing of each protection technique as well as observations and findings made during the testing

Rooting portions of a young pseudosporochnalean from the catskill delta complex of New York

Premise of research. Pseudosporochnales (Cladoxylopsida) were conspicuous elements of the Earth’s earliest forests. Recent evidence has done much to clarify basic aspects of the pseudosporochnalean architecture, but important questions remain about the developmental processes responsible for growth from juvenile individuals to trees of sometimes considerable size. Methodology. Presented here is combined compression/permineralization evidence of a young member of the group from a late Devonian (early Frasnian) locality also containing Eospermatopteris (Wattieza), currently the largest reconstructed pseudosporochnalean tree. Standard pyrite preparations were made and analyzed with reflected light. Pivotal results. The anatomically preserved portion of the trunk with an expanded base lacking a central vascular column shows abundant evidence of appendages with apparent rooting function supplied by traces comprised of primary and often secondary xylem. Traces arise within parenchyma near the trunk center and follow lax courses with multiple divisions outward and downward to the surface, finally enveloping the plant base for some distance. In the upper portion of the specimen, likely near the transition between the base bearing rooting appendages and the aerial shoot, the traces form a vascular plexus toward the periphery of the stem, with the bulk of vascular tissues comprising secondary xylem. Similar but differently oriented vascularization also occurs near the base. Conclusions. Here we hypothesize a unique form of “bipolar” development in this specimen, and potentially all pseudosporochnaleans, by means of a trunk base bearing an appendicular system of positively geotropic rooting appendages. In addition, we hypothesize that diffuse meristematic activity of the base plus the vascular plexus may have a previously unrecognized role in the development of pseudosporochnaleans from the small specimen observed here to large body size. We also suggest that this tissue offers an explanation for the enigmatic genus Xenocladia known from tissue fragments of large size found in coeval marine sediments of New York State. Given current incomplete understanding of development within the Pseudosprochnales, considering the rooting system as sui generis confers the advantage of adequate description of this organ, without necessarily specifying correspondence or homology with other groups

In vitro and In vivo antimycobacterial, hepatoprotective and immunomodulatory activity of Euclea natalensis and its mode of action

Ethnopharmacological relevance: The Natal gwarri or Natal ebony (Euclea natalensis A.DC.) is a deciduous tree found widespread throughout southern Africa, especially in Kwazulu-Natal and the southern cost. It has been widely used by indigenous communities such as the Zulus, Tsongas and Vendas for symptoms related to tuberculosis (TB). The decoctions made from the plant parts are administered for chest diseases to treat complications such as chest pains, bronchitis, pleurisy and asthma. TB is prevalent in immune-compromised patients and it is evident that TB-drugs cause hepatotoxicity. The objective of the present study was therefore to evaluate the antimycobacterial activity of the ethanolic extract of E. natalensis against TB and its hepatoprotective and immunomodulatory activities. Materials and methods: The antimycobacterial, antioxidant, hepatoprotective, immunomodulatory activity and cytotoxicity of the ethanolic extract of the shoots of E. natalensis were determined in vitro. The mechanism of action of the antituberculosis activity was determined by investigating the inhibitory effect on mycothiol disulfide reductase enzyme. Furthermore, the acute, sub-acute toxicity (50-2000 mg/kg) and antimycobacterial effect (300 mg/kg) of E. natalensis shoot extract were investigated in Balb/c mice. Hepatoprotective activity of the extract (50-150 mg/kg) was evaluated on isoniazid and rifampicin (50 mg/kg; i.p.) induced hepatic damage in a rat model. Results: The minimum inhibitory concentration of the extract was found to be 125 µg/ml against Mycobacterium tuberculosis. The extracts fifty percent inhibitory concentration (IC50) against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical was found to be 22.55 µg/ml. The plant showed a hepatoprotective effect (50% at 12.5 µg/ml) and the ability to increase T-helper 1 cell cytokines; Interleukin 12, Interleukin 2 and Interferon α by up to 12 fold and the ability to decrease the T-helper 2 cell cytokine Interleukin 10 4 fold when compared to baseline cytokine production. No cellular toxicity was observed in primary peripheral blood mononuclear cells (PBMC's) and two secondary cell lines; U937 monocytes and Chang liver cells (a derivative of the HepG2 cell line). During mechanistic studies, the extract showed a 50% inhibition of mycothiol reductase activity at 38.62 µg/ml. During the acute and sub-acute studies, E. natalensis exhibited no toxic effect and the fifty percent lethal dose (LD50) was established to be above 2000 mg/kg. The extract was able to reduce the mycobacterial load (1.5-fold reduction) in infected mice. Isoniazid and rifampicin caused significant hepatic damage in rats, and the extract was able to reduce the toxicity by 15% and 40% at 50 and 150 mg/kg respectively. Conclusion: The present study supports the traditional usage of the plant against tuberculosis symptoms. The study showed the ability of E. natalensis shoot extract to inhibit mycobacterial growth, stimulate an appropriate immune response and have a hepatic protective effect. Due to the extract's significant results for hepatoprotective, immunomodulatory effects and antimycobacterial activity, it may prove to be effective to serve as an adjuvant for TB-patients

Mid-Devonian Archaeopteris roots signal revolutionary change in earliest fossil forests

The origin of trees and forests in the Mid Devonian (393–383 Ma) was a turning point in Earth history, marking permanent changes to terrestrial ecology, geochemical cycles, atmospheric CO2 levels, and climate. However, how all these factors interrelate remains largely unknown. From a fossil soil (palaeosol) in the Catskill region near Cairo NY, USA, we report evidence of the oldest forest (mid Givetian) yet identified worldwide. Similar to the famous site at Gilboa, NY, we find treefern-like Eospermatopteris (Cladoxylopsida). However, the environment at Cairo appears to have been periodically drier. Along with a single enigmatic root system potentially belonging to a very early rhizomorphic lycopsid, we see spectacularly extensive root systems here assigned to the lignophyte group containing the genus Archaeopteris. This group appears pivotal to the subsequent evolutionary history of forests due to possession of multiple advanced features and likely relationship to subsequently dominant seed plants. Here we show that Archaeopteris had a highly advanced root system essentially comparable to modern seed plants. This suggests a unique ecological role for the group involving greatly expanded energy and resource utilization, with consequent influence on global processes much greater than expected from tree size or rooting depth alone

Overexpression of SIRT1 Protects Pancreatic β-Cells Against Cytokine Toxicity by Suppressing the Nuclear Factor-κB Signaling Pathway

OBJECTIVE—SIRT1, a class III histone/protein deacetylase, is known to interfere with the nuclear factor-κB (NF-κB) signaling pathway and thereby has an anti-inflammatory function. Because of the central role of NF-κB in cytokine-mediated pancreatic β-cell damage, we postulated that SIRT1 might work in pancreatic β-cell damage models

Extant diversity of bryophytes emerged from successive post-Mesozoic diversification bursts

Unraveling the macroevolutionary history of bryophytes, which arose soon after the origin of land plants but exhibit substantially lower species richness than the more recently derived angiosperms, has been challenged by the scarce fossil record. Here we demonstrate that overall estimates of net species diversification are approximately half those reported in ferns and similar to 30% those described for angiosperms. Nevertheless, statistical rate analyses on time-calibrated large-scale phylogenies reveal that mosses and liverworts underwent bursts of diversification since the mid-Mesozoic. The diversification rates further increase in specific lineages towards the Cenozoic to reach, in the most recently derived lineages, values that are comparable to those reported in angiosperms. This suggests that low diversification rates do not fully account for current patterns of bryophyte species richness, and we hypothesize that, as in gymnosperms, the low extant bryophyte species richness also results from massive extinctions.Assembling the Tree of Life programme at NSF; NSF [EF-0531730-002, EF-0531680, EF-0531750]; Scottish Government's Rural and Environment Science and Analytical Services Division; BeiPD-cofund Marie Curie fellowshipinfo:eu-repo/semantics/publishedVersio

HDAC8 substrates: Histones and beyond

The lysine deacetylase family of enzymes (HDACs) was first demonstrated to catalyze deacetylation of acetyllysine residues on histones. In subsequent years, HDACs have been shown to recognize a large pool of acetylated nonhistone proteins as substrates. Recently, thousands of acetylated proteins have been discovered, yet in most cases, the HDAC that catalyzes deacetylation in vivo has not been identified. This gap has created the need for better in vivo, in vitro, and in silico approaches for determining HDAC substrates. While HDAC8 is the best kinetically and structurally characterized HDAC, few efficient substrates have yet been substantiated in vivo. In this review, we delineate factors that may be important for determining HDAC8 substrate recognition and catalytic activity, including structure, complex formation, and post‐translational modifications. This summary provides insight into the challenges of identifying in vivo substrates for HDAC8, and provides a good vantage point for understanding the variables important for predicting HDAC substrate recognition. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 112–126, 2013.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94512/1/22135_ftp.pd

A Complete Pathway Model for Lipid A Biosynthesis in Escherichia coli.

Lipid A is a highly conserved component of lipopolysaccharide (LPS), itself a major component of the outer membrane of Gram-negative bacteria. Lipid A is essential to cells and elicits a strong immune response from humans and other animals. We developed a quantitative model of the nine enzyme-catalyzed steps of Escherichia coli lipid A biosynthesis, drawing parameters from the experimental literature. This model accounts for biosynthesis regulation, which occurs through regulated degradation of the LpxC and WaaA (also called KdtA) enzymes. The LpxC degradation signal appears to arise from the lipid A disaccharide concentration, which we deduced from prior results, model results, and new LpxK overexpression results. The model agrees reasonably well with many experimental findings, including the lipid A production rate, the behaviors of mutants with defective LpxA enzymes, correlations between LpxC half-lives and cell generation times, and the effects of LpxK overexpression on LpxC concentrations. Its predictions also differ from some experimental results, which suggest modifications to the current understanding of the lipid A pathway, such as the possibility that LpxD can replace LpxA and that there may be metabolic channeling between LpxH and LpxB. The model shows that WaaA regulation may serve to regulate the lipid A production rate when the 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) concentration is low and/or to control the number of KDO residues that get attached to lipid A. Computation of flux control coefficients showed that LpxC is the rate-limiting enzyme if pathway regulation is ignored, but that LpxK is the rate-limiting enzyme if pathway regulation is present, as it is in real cells. Control also shifts to other enzymes if the pathway substrate concentrations are not in excess. Based on these results, we suggest that LpxK may be a much better drug target than LpxC, which has been pursued most often