The Cretaceous-Tertiary Boundary on the Cape Fear Arch, North Carolina, U.S.A.

Petrologic and faunal study of a 72.5m continuous corehole drilled in southeastern North Carolina has provided an opportunity to study a relatively uninterrupted vertical sequence across the Cretaceous-Tertiary boundary. The following stratographic sequence occurs; upper middle Maastrichtian Peedee Formation, –65.8m to –51.8m below sea-level (BMSL), upper middle Maastrichtian Rocky Point Member of the Peedee Formation, –51.8m to –27.4m BMSL, and middle to upper (?) Eocene Castle Hayne Limestone, –27.4m to 15.2m BMSL (base of casing). The Peedee Formation consists of moderately indurated, very fine to fine, sandy foraminiferal biomicrite and sandy biomicrite. Silt-size zoned dolomite rhombohedra form up to 30% of the upper Peedee Formation and are most abundant where bioturbation is common. A diverse and well-preserved foraminiferal fauna indicates a middle to outer continental shelf environment. The Rocky Point Member conformably overlies typical Peedee Formation lithology and consists of well-indurated sandy, fossiliferous biomicrite that grades upward into sandy, pelecypod biomicrosparite, and finally pelecypod biomicrudite. The Peedee Formation and the Rocky Point Member represent an overall shallowing-upward sequence with the upper surface forming the Cretaceous-Tertiary boundary. The Castle Hayne Limestone disconformably overlies the Rocky Point Member and consists of lithoclast-bearing, bryozoan-molluscan biomicrudite grading upward into bryozoan biomicrudite. The Castle Hayne Limestone was deposited in an open, normal salinity environment between 30m and 100m in water depth

Workgroup Report: National Toxicology Program Workshop on Hormonally Induced Reproductive Tumors—Relevance of Rodent Bioassays

The National Toxicology Program (NTP) is currently reviewing its research portfolio as part of its efforts to implement the NTP Roadmap to achieve the NTP Vision for the 21st century. This review includes a recent workshop, “Hormonally Induced Reproductive Tumors—Relevance of Rodent Bioassays,” held 22–24 May 2006, that was organized to determine the adequacy and relevance to human disease outcome of rodent models currently used in the 2-year bioassay for four types of hormonally induced reproductive tumors (ovary, mammary gland, prostate, and testis). In brief, none of the workshop’s breakout groups felt the currently used models are sufficient. For some types of tumors such as prostate, no adequate animal models exist, and for others such as ovary, the predominant tumors in humans are of different cellular origins than those induced by chemicals in rodents. This inadequacy of current models also applies to the testis, although our more complete understanding of the responses of Leydig cells to hormonal changes in rats may prove predictive for effects in humans other than cancer. All breakout groups recommended that the NTP consider modifying its testing protocols (i.e., age at exposure, additional end points, etc.) and/or using alternative models (i.e., genetically engineered models, in vitro systems, etc.) to improve sensitivity. In this article we briefly review the workshop’s outcome and outline some next steps forward in pursuing the workshop’s recommendations. Breakout group reports and additional information on the workshop, including participants, presentations, public comments and background materials, are posted on the NTP website

Acid-Base Chemical Mechanism of Aspartase From Hafnia alvei

An acid-base chemical mechanism is proposed for Hafnia alvei aspartase in which a proton is abstracted from C-3 of the monoanionic form of L-aspartate by an enzyme general base with a pK of 6.3-6.6 in the absence and presence of Mg2+. The resulting carbanion is presumably stabilized by delocalization of electrons into the β-carboxyl with the assistance of a protonated enzyme group in the vicinity of the β-carboxyl. Ammonia is then expelled with the assistance of a general acid group that traps an initially expelled NH3 as the final NH+4 product. In agreement with the function of the general acid group, potassium, an analog of NH+4, binds optimally when the group is unprotonated. The pK for the general acid is about 7 in the absence of Mg2+, but is increased by about a pH unit in the presence of Mg2+. Since the same pK values are observed in the pKisuccinate and V/K pH profile, both enzyme groups must be in their optimum protonation state for efficient binding of reactant in the presence of Mg2+. At the end of a catalytic cycle, both the general base and general acid groups are in a protonation state opposite that in which they started when aspartate was bound. The presence of Mg2+ causes a pH-dependent activation of aspartase exhibited as a partial change in the V and V/Kasp pH profiles. When the aspartase reaction is run in D2O to greater than 50% completion no deuterium is found in the remaining aspartate, indicating that the site is inaccessible to solvent during the catalytic cycle

Identifying the PECO:A framework for formulating good questions to explore the association of environmental and other exposures with health outcomes

[First paragraph] A clearly-framed question creates the structure and delineates the approach to defining research objectives, conducting systematic reviews and developing health guidance (Guyatt et al., 2011; Armstrong et al., 2007). To assess the association between exposures and outcomes, including in the field of nutrition, environmental and occupational health, the concept of defining the Population (including animal species), Exposure, Comparator, and Outcomes (PECO) as pillars of the question is increasingly accepted (Morgan et al., 2016; Morgan et al., n.d.). Thus, the PECO defines the objectives of the review or guideline. Furthermore, the PECO informs the study design or inclusion and exclusion criteria for a review, as well as facilitating the interpretation of the directness of the findings based on how well the actual research findings represent the original question

The Middle Way: East Asian masters students’ perceptions of critical argumentation in U.K. universities.

The paper explores the learning experiences of East Asian masters students in dealing with Western academic norms of critical thinking in classroom debate and assignment writing. The research takes a cultural approach, and employs grounded theory and case study methodology, the aims being for students to explain their perceptions of their personal learning journeys. The data suggest that the majority of students interviewed rejected full academic acculturation into Western norms of argumentation. They instead opted for a ‘Middle Way’ that synergizes the traditional cultural academic values held by many East Asian students with those elements of Western academic norms that are perceived to be aligned with these. This is a relatively new area of research which represents a challenge for British lecturers and students

Inhibition of Bone Morphogenetic Protein Signal Transduction Prevents the Medial Vascular Calcification Associated with Matrix Gla Protein Deficiency

Objective: Matrix Gla protein (MGP) is reported to inhibit bone morphogenetic protein (BMP) signal transduction. MGP deficiency is associated with medial calcification of the arterial wall, in a process that involves both osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs) and mesenchymal transition of endothelial cells (EndMT). In this study, we investigated the contribution of BMP signal transduction to the medial calcification that develops in MGP-deficient mice. Approach and Results MGP-deficient mice (MGP-/-) were treated with one of two BMP signaling inhibitors, LDN-193189 or ALK3-Fc, beginning one day after birth. Aortic calcification was assessed in 28-day-old mice by measuring the uptake of a fluorescent bisphosphonate probe and by staining tissue sections with Alizarin red. Aortic calcification was 80% less in MGP-/- mice treated with LDN-193189 or ALK3-Fc compared with vehicle-treated control animals (P<0.001 for both). LDN-193189-treated MGP-/- mice survived longer than vehicle-treated MGP-/- mice. Levels of phosphorylated Smad1/5 and Id1 mRNA (markers of BMP signaling) did not differ in the aortas from MGP-/- and wild-type mice. Markers of EndMT and osteogenesis were increased in MGP-/- aortas, an effect that was prevented by LDN-193189. Calcification of isolated VSMCs was also inhibited by LDN-193189. Conclusions: Inhibition of BMP signaling leads to reduced vascular calcification and improved survival in MGP-/- mice. The EndMT and osteogenic transdifferentiation associated with MGP deficiency is dependent upon BMP signaling. These results suggest that BMP signal transduction has critical roles in the development of vascular calcification in MGP-deficient mice

Fluid-bicontinuous gels stabilized by interfacial colloids: low and high molecular weight fluids

Carefully tuned composite materials can have properties wholly unlike their separate constituents. We review the development of one example: colloid-stabilized emulsions with bicontinuous liquid domains. These non-equilibrium structures resemble the sponge mesophase of surfactants; however, in the colloid-stabilized case the interface separating the liquid domains is itself semi-solid. The arrangement of domains is created by arresting liquid-liquid phase separation via spinodal decomposition. Dispersed colloids exhibiting partial wettability become trapped on the newly created interface and jam together as the domains coarsen. Similar structures have been created in polymer blends stabilized using either interfacial nanoparticles or clay platelets. Here it has been possible to create the domain arrangement either by phase separation or by direct mixing of the melt. The low molecular-weight liquid and polymer based structures have been developed independently and much can be learnt by comparing the two.Comment: Topical Review, 17 pages, 10 figure

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

Artificial intelligence, systemic risks, and sustainability

Automated decision making and predictive analytics through artificial intelligence, in combination with rapid progress in technologies such as sensor technology and robotics are likely to change the way individuals, communities, governments and private actors perceive and respond to climate and ecological change. Methods based on various forms of artificial intelligence are already today being applied in a number of research fields related to climate change and environmental monitoring. Investments into applications of these technologies in agriculture, forestry and the extraction of marine resources also seem to be increasing rapidly. Despite a growing interest in, and deployment of AI-technologies in domains critical for sustainability, few have explored possible systemic risks in depth. This article offers a global overview of the progress of such technologies in sectors with high impact potential for sustainability like farming, forestry and the extraction of marine resources. We also identify possible systemic risks in these domains including a) algorithmic bias and allocative harms; b) unequal access and benefits; c) cascading failures and external disruptions, and d) trade-offs between efficiency and resilience. We explore these emerging risks, identify critical questions, and discuss the limitations of current governance mechanisms in addressing AI sustainability risks in these sectors