Mirroring doubly excited resonances in argon.

New features are revealed in the low-energy photoionization spectrum of Ar by critically combining high photon resolution and differential photoelectron spectroscopic techniques. Two LS-forbidden doubly excited resonances are seen in the 3p−13/2,1/2 partial cross sections which exhibit mirroring profiles, resulting in complete cancellation in the total photoionization cross section, as was predicted by Liu and Starace [Phys. Rev. A 59, R1731 (1999)]. These results demonstrate that a new class of weakly spin-orbit induced, mirroring resonances should be observable in partial, but not in total, collisional cross sections involving atoms, molecules, and solids in general

Suitability of winter canola (Brassica napus) for enhancing summer annual crop rotations in Iowa

What are the prospects for winter canola as an alternative crop for Iowa farmers? This project examined the economics and costs/benefits of adding canola as a third crop or a cover crop in rotations

Radiocarbon dating wooden carvings and skeletal remains from Pitch Lake, Trinidad

Since the mid 19th century, rare prehistoric wooden carvings and human skeletal remains have been dredged from Pitch Lake, Trinidad, during commercial asphalt mining. Establishing a chronology for these objects is challenging, due to both a lack of stratigraphic and contextual information and the necessity to completely remove any pitch to ensure accurate radiocarbon dates. A range of solvent extraction protocols was tested to identify the most suitable one for pretreating the Pitch Lake artefacts, and then applied to ten wooden objects and a human cranium recovered from the lake. Several of these objects yielded earlier dates than expected, raising concerns that pitch had remained after pretreatment and had affected the dates. Pyrolysis-GC/MS and optical microscopy techniques were applied to material from the human cranium, a weaving tool, and a small bowl. These techniques, as well as routinely applied laboratory quality assurance procedures, indicated that there was no residual pitch within the cranium or the weaving tool after pretreatment, giving confidence to the dates. However, the small bowl was observed to still be contaminated with pitch after extensive pretreatment, indicating that the date is too old and can only be considered as a terminus post quem

Opportunities for improved transparency in the timber trade through scientific verification

Published: 09 November 2016In May 2014, the Member States of the United Nations adopted Resolution 23/1 on “strengthening a targeted crime prevention and criminal justice response to combat illicit trafficking in forest products, including timber.” The resolution promotes the development of tools and technologies that can be used to combat the illicit trafficking of timber. Stopping illegal logging worldwide could substantially increase revenue from the legal trade in timber and halt the associated environmental degradation, but law enforcement and timber traders themselves are hampered by the lack of available tools to verify timber legality. Here, we outline how scientific methods can be used to verify global timber supply chains. We advocate that scientific methods are capable of supporting both enforcement and compliance with respect to timber laws but that work is required to expand the applicability of these methods and provide the certification, policy, and enforcement frameworks needed for effective routine implementation.Andrew J. Lowe, Eleanor E. Dormontt, Matthew J. Bowie, Bernd Degen, Shelley Gardner, Darren Thomas, Caitlin Clarke, Anto Rimbawanto, Alex Wiedenhoeft, Yafang Yin, and Nophea Sasak

Evolution of protein domain architectures

This chapter reviews current research on how protein domain architectures evolve. We begin by summarizing work on the phylogenetic distribution of proteins, as this will directly impact which domain architectures can be formed in different species. Studies relating domain family size to occurrence have shown that they generally follow power law distributions, both within genomes and larger evolutionary groups. These findings were subsequently extended to multi-domain architectures. Genome evolution models that have been suggested to explain the shape of these distributions are reviewed, as well as evidence for selective pressure to expand certain domain families more than others. Each domain has an intrinsic combinatorial propensity, and the effects of this have been studied using measures of domain versatility or promiscuity. Next, we study the principles of protein domain architecture evolution and how these have been inferred from distributions of extant domain arrangements. Following this, we review inferences of ancestral domain architecture and the conclusions concerning domain architecture evolution mechanisms that can be drawn from these. Finally, we examine whether all known cases of a given domain architecture can be assumed to have a single common origin (monophyly) or have evolved convergently (polyphyly). We end by a discussion of some available tools for computational analysis or exploitation of protein domain architectures and their evolution

The origins of Tradescant's 'India Occidentali' wooden clubs: 14C dating, material identification and strontium isotope studies

This paper focuses on the material study (radiocarbon dating, wood identification and strontium isotope analyses) of four large ‘India occidentali’ clubs, part of the founding collections of the Ashmolean Museum, in Oxford, and originally part of John Tradescant’s ‘Ark’, in Lambeth (1656). During the seventeenth century, the term ‘India occidentali/occidentales’ referred not only to the ‘West Indies’ (its literal translation), but to the Americas as a whole; hence, the Ashmolean clubs and, indeed, the ca forty examples of similarly large, decorated clubs known in international museum collections had no firm provenance and lacked even the most basic information. Previous attempts at attribution, based on stylistic comparisons with nineteenth- to twentieth-century Brazilian and Guyanese clubs, have proved inconclusive given the unique features of this club style, raising the intriguing possibility that these may be exceptionally rare examples of ‘Island Carib’ (Kalinago) material culture, particularly as images of such clubs appear in seventeenth-century ethnographic accounts from the LesserAntilles. This paper provides new data for these poorly known objects fromearly collections, revealing not only the type of wood from which they were carved (Platymiscium sp. and Brosimum cf guianense) and their probable dates of manufacture (c AD 1300–1640), but also their possible provenance (strontium results are consistent with a possible range from Trinidad south to French Guiana)

Habitat Capacity for Cougar Recolonization in the Upper Great Lakes Region

BACKGROUND: Recent findings indicate that cougars (Puma concolor) are expanding their range into the midwestern United States. Confirmed reports of cougar in Michigan, Minnesota, and Wisconsin have increased dramatically in frequency during the last five years, leading to speculation that cougars may re-establish in the Upper Great Lakes (UGL) region, USA. Recent work showed favorable cougar habitat in northeastern Minnesota, suggesting that the northern forested regions of Michigan and Wisconsin may have similar potential. Recolonization of cougars in the UGL states would have important ecological, social, and political impacts that will require effective management. METHODOLOGY/PRINCIPAL FINDINGS: Using Geographic Information Systems (GIS), we extended a cougar habitat model to Michigan and Wisconsin and incorporated primary prey densities to estimate the capacity of the region to support cougars. Results suggest that approximately 39% (>58,000 km2) of the study area could support cougars, and that there is potential for a population of approximately 500 or more animals. An exploratory validation of this habitat model revealed strong association with 58 verified cougar locations occurring in the study area between 2008 and 2013. CONCLUSIONS/SIGNIFICANCE: Spatially explicit information derived from this study could potentially lead to estimation of a viable population, delineation of possible cougar-human conflict areas, and the targeting of site locations for current monitoring. Understanding predator-prey interactions, interspecific competition, and human-wildlife relationships is becoming increasingly critical as top carnivores continue to recolonize the UGL region