Petrogenesis of lunar highlands meteorites: Dhofar 025, Dhofar 081, Dar al Gani 262, and Dar al Gani 400

The petrogenesis of four lunar highlands meteorites, Dhofar 025 (Dh-025), Dhofar 081 (Dh-081 ), Dar al Gani 262 (DaG 262), and Dar al Gani 400 (DaG 400) have been studied. For Dh-025, measured oxygen isotopic values (0180 = +5.47%0 and 017 0 = +2.81 %0) and Fe-Mn ratios for mafic minerals (Px-49.7; 01-86) provide corroboratory evidence that it originated on the Moon. Similarly, Fe-Mn ratios in the mafic minerals (Px-52.3; 01-87 .8) of Dh-081 also indicate its lunar origin. Whole-rock Sc and Al2O3 concentrations of Dh-025 (10.2 ppm and 26.1 wt%, resp.), Dh-081 (5.4 ppm and 30.5 wt%, resp.), DaG 262 (7.85 ppm and 27.5 wt%), and DaG 400 (5.40 ppm and 26.2 wt%, resp.; Bischoff et al., 1998) are also indicative of anorthositic lunar highlands material. Each of the four lunar samples is a breccia, with texturally pristine and nonpristine lithologies. Lithologies in Dh-025 and Dh-081 include igneous rocklets, partially recrystallized impact melt rocklets, granulites, and mineral fragments. Some of these lithologies have plagioclase AN and coexisting mafic mineral Mg# that plot within the gap separating ferroan anorthosite suite (FAN) and high-magnesium suite (HMS) rocks. These atypical compositions are more common in recent collections of lunar highlands meteorites, and may indicate the FAN field should be expanded. This is consistent with whole-rock Ti-Sm ratios for Dh-025 (1.5 ppm), Dh-081 (0.63 ppm), and DaG 262 (1.15), which are also intermediate compared to FAN and HMS lithologies. Compared to other lunar highlands meteorites, whole-rock compositions also show that Dh-025 is enriched in Sc and Mg# (70), whereas Dh-081 has the highest A12O3 content measured to date. Systematic depletions (by a factor of 10) in whole-rock Sm concentrations are apparent in Dh-025 (1.5 ppm), Dh-081 (0.63 ppm), and DaG 262 (1.15 ppm), as compared to Apollo 14 and 16 highland regolith breccias. This may indicate that these samples have been derived from an entirely different terrain of highlands regolith, perhaps on the lunar far-side. Ion-microprobe analyses were also performed to evaluate trace-element (including rare earth elements-REE) variations in Dh-025, Dh-081, DaG 262, and DaG 400 clasts and minerals. These analyses show far stronger FAN affinities for these meteorites than whole-rock data suggest, although most clasts indicate admixture of a \u3c=12% HMS component. Ratios of Sc-Sm in all clasts are typical of low-incompatible trace-element abundances in FAN lithologies (\u3e 12). Several analyses of Dh-025 plagioclases indicate redistribution of HREEs due to shock metamorphism. However, the majority of mineral analyses in all these meteorites are typical of FAN lithologies. Coexisting plagioclase-pyroxene REE concentration ratios in several clasts were compared to experimentally determined plagioclasepyroxene REE distribution coefficient ratios. Two Dh-025 clasts have concordant plagioclase-pyroxene profiles indicating that the equilibrium between these minerals has not been modified by shock metamorphism. These clasts plot within the FAN-HMS gap and possibly represent new pristine highland compositions. Since these compositions have not been sampled on the lunar near-side, it is possible they represent far-side rocks and suggest that the FAN or HMS fields should be expanded

Comparison of chicken 7SK and U6 RNA polymerase III promoters for short hairpin RNA expression

Background: RNA polymerase III (pol III) type 3 promoters such as U6 or 7SK are commonly used to express short-hairpin RNA (shRNA) effectors for RNA interference (RNAi). To extend the use of RNAi for studies of development using the chicken as a model system, we have developed a system for expressing shRNAs using the chicken 7SK (ch7SK) promoter. Results: We identified and characterised the ch7SK promoter sequence upstream of the full-length 7SK small nuclear RNA (snRNA) sequence in the chicken genome and used this to construct vectors to express shRNAs targeting enhanced green fluorescent protein (EGFP). We transfected chicken DF-1 cells with these constructs and found that anti-EGFP-shRNAs (shEGFP) expressed from the ch7SK promoter could induce efficient knockdown of EGFP expression. We further compared the efficiency of ch7SK-directed knockdown to that of chicken U6 (cU6) promoters and found that the efficiency of the ch7SK promoter was not greater than, but comparable to the efficiency of cU6 promoters. Conclusion: In this study we have demonstrated that the ch7SK promoter can express shRNAs capable of mediating efficient RNAi in a chicken cell line. However, our finding that RNAi driven by the ch7SK promoter is not more efficient than cU6 promoters contrasts previous comparisons of mammalian U6 and 7SK promoters. Since the ch7SK promoter is the first non-mammalian vertebrate 7SK promoter to be characterised, this finding may be helpful in understanding the divergence of pol III promoter activities between mammalian and non-mammalian vertebrates. This aside, our results clearly indicate that the ch7SK promoter is an efficient alternative to U6-based shRNA expression systems for inducing efficient RNAi activity in chicken cells.<br /

Overcoming the Obstacles of Garrett: An as Applied Saving Construction for the ADA\u27s Title II

Recent Supreme Court cases regarding Congress\u27s abrogation authority have seriously impaired Congress\u27s ability to demonstrate a valid exercise of its Section 5 power under the Fourteenth Amendment to subject nonconsenting states to suit for money damages in federal court. During its 2003 term, the Supreme Court has again granted certiorari to a case involving the proper scope of Congress\u27s section 5 power, Lane v. Tennessee. Lane involves a suit for money damages under Title II of the ADA based on the alleged failure of the State of Tennessee to make its courthouses accessible. Many commentators suggest that the Supreme Court will follow its current precedent and deny a damage remedy in Lane, particularly since the Court barred a suit for damages brought by a state employee for an alleged violation of Title I of the ADA in Board of Trustees of the University of Alabama v. Garrett. This article critiques the Court\u27s current analysis as seen in Garrett and proposes that the Court should evaluate the ADA\u27s Title II damage remedy against the states differently than it did Title I\u27s. It suggests that the Court should adopt an as applied analysis when deciding Title II damage remedy claims. By examining the specific state program or service alleged to discriminate against the disabled, the Court may apply a different level of scrutiny to the state\u27s action than the rational basis scrutiny that applied in Garrett. For example, in Lane, the fundamental right of access to the state court system has been denied to disabled plaintiffs in Tennessee because the courthouses are inaccessible to those who cannot walk up the stairs. Because the Lane case involves a fundamental right, the Court should apply strict scrutiny when evaluating Title II\u27s congruence and proportionality. Analyzing the Lane case, and other Title II damages claims on the facts and with respect to the right that has allegedly been abridged is the appropriate federalism standard

Overcoming the Obstacles of Garrett: An as Applied Saving Construction for the ADA\u27s Title II

Recent Supreme Court cases regarding Congress\u27s abrogation authority have seriously impaired Congress\u27s ability to demonstrate a valid exercise of its Section 5 power under the Fourteenth Amendment to subject nonconsenting states to suit for money damages in federal court. During its 2003 term, the Supreme Court has again granted certiorari to a case involving the proper scope of Congress\u27s section 5 power, Lane v. Tennessee. Lane involves a suit for money damages under Title II of the ADA based on the alleged failure of the State of Tennessee to make its courthouses accessible. Many commentators suggest that the Supreme Court will follow its current precedent and deny a damage remedy in Lane, particularly since the Court barred a suit for damages brought by a state employee for an alleged violation of Title I of the ADA in Board of Trustees of the University of Alabama v. Garrett. This article critiques the Court\u27s current analysis as seen in Garrett and proposes that the Court should evaluate the ADA\u27s Title II damage remedy against the states differently than it did Title I\u27s. It suggests that the Court should adopt an as applied analysis when deciding Title II damage remedy claims. By examining the specific state program or service alleged to discriminate against the disabled, the Court may apply a different level of scrutiny to the state\u27s action than the rational basis scrutiny that applied in Garrett. For example, in Lane, the fundamental right of access to the state court system has been denied to disabled plaintiffs in Tennessee because the courthouses are inaccessible to those who cannot walk up the stairs. Because the Lane case involves a fundamental right, the Court should apply strict scrutiny when evaluating Title II\u27s congruence and proportionality. Analyzing the Lane case, and other Title II damages claims on the facts and with respect to the right that has allegedly been abridged is the appropriate federalism standard

Electropermanent magnetic anchoring for surgery and endoscopy

The use of magnets for anchoring of instrumentation in minimally invasive surgery and endoscopy has become of increased interest in recent years. Permanent magnets have significant advantages over electromagnets for these applications; larger anchoring and retraction force for comparable size and volume without the need for any external power supply. However, permanent magnets represent a potential hazard in the operating field where inadvertent attraction to surgical instrumentation is often undesirable. The current work proposes an interesting hybrid approach which marries the high forces of permanent magnets with the control of electromagnetic technology including the ability to turn the magnet OFF when necessary. This is achieved through the use of an electropermanent magnet, which is designed for surgical retraction across the abdominal and gastric walls. Our electropermanent magnet, which is hand-held and does not require continuous power, is designed with a center lumen which may be used for trocar or needle insertion. The device in this application has been demonstrated successfully in the porcine model where coupling between an intraluminal ring magnet and our electropermanent magnet facilitated guided insertion of an 18 Fr Tuohy needle for guidewire placement. Subsequent investigations have demonstrated the ability to control the coupling distance of the system alleviating shortcomings with current methods of magnetic coupling due to variation in transabdominal wall thicknesses. With further refinement, the magnet may find application in the anchoring of endoscopic and surgical instrumentation for minimally invasive interventions in the gastrointestinal tract

Incorporating temporal and spatial variability of salt-marsh foraminifera into sea-level reconstructions

Foraminifera from salt-marsh environments have been used extensively in quantitative relative sea-level reconstructions due to their strong relationship with tidal level. However, the influence of temporal and spatial variability of salt-marsh foraminifera on quantitative reconstructions remains unconstrained. Here, we conducted a monitoring study of foraminifera from four intertidal monitoring stations in New Jersey from high marsh environments over three years that included several extreme weather (temperature, precipitation, and storm surge) events. We sampled four replicates from each station seasonally (four times per year) for a total of 188 samples. The dead foraminiferal assemblages were separated into four site-specific assemblages. After accounting for systematic trends in changes in foraminifera over time among stations, the distribution of foraminiferal assemblages across monitoring stations explained ~87% of the remaining variation, while ~13% can be explained by temporal and/or spatial variability among the replicate samples. We applied a Bayesian transfer function to estimate the elevation of the four monitoring stations. All samples from each station predicted an elevation estimate within a 95% uncertainty interval consistent with the observed elevation of that station. Combining samples into replicate- and seasonal-aggregate datasets decreased elevation estimate uncertainty, with the greatest decrease in aggregate datasets from Fall and Winter. Information about the temporal and spatial variability of modern foraminiferal distributions was formally incorporated into the Bayesian transfer function through informative foraminifera variability priors and was applied to a Common Era relative sea-level record in New Jersey. The average difference in paleomarsh elevation estimates and uncertainties using an informative vs uninformative prior was minimal

Author Correction: Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey

Correction to: NPJ Climate and Atmospheric Science https://doi.org/10.1038/s41612-020-0121-5, published online 08 May 202

Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey

Sea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions. To elicit projections from members of the scientific community regarding future global mean sea-level (GMSL) rise, we repeated a survey originally conducted five years ago. Under Representative Concentration Pathway (RCP) 2.6, 106 experts projected a likely (central 66% probability) GMSL rise of 0.30–0.65 m by 2100, and 0.54–2.15 m by 2300, relative to 1986–2005. Under RCP 8.5, the same experts projected a likely GMSL rise of 0.63–1.32 m by 2100, and 1.67–5.61 m by 2300. Expert projections for 2100 are similar to those from the original survey, although the projection for 2300 has extended tails and is higher than the original survey. Experts give a likelihood of 42% (original survey) and 45% (current survey) that under the high-emissions scenario GMSL rise will exceed the upper bound (0.98 m) of the likely range estimated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which is considered to have an exceedance likelihood of 17%. Responses to open-ended questions suggest that the increases in upper-end estimates and uncertainties arose from recent influential studies about the impact of marine ice cliff instability on the meltwater contribution to GMSL rise from the Antarctic Ice Sheet. © 2020, The Author(s)