Estimating the Supply Curve for Nutria Pelts From Coastal Louisiana and the Impacts Associated with Declining Prices

Nutria harvests vary with price. As pelt prices declined, nutria populations - and wetland degradation have risen. This paper develops a nutria supply model to predict harvests at various prices which are incorporated into a wetland loss model to determine how alternative incentive programs affect changes in wetland degradation.Resource /Energy Economics and Policy,

A Conceptual and Empirical Approach for Valuing Biodiversity: An Estimate of the Benefits of Plant and Wildlife Habitat Preservation in the Tensas River Basin.

This research estimated the passive use value of local species biodiversity in the Tensas River basin, a section of the Lower Mississippi River Valley. This research employed the contingent valuation method in eliciting willingness to pay for biodiversity conservation using the habitat needs of an umbrella species as a basis for valuation. This study designed and implemented the Lower Mississippi Valley Plant and Wildlife Survey for primary data collection. The sample included 1,351 households drawn from a hunting permit lottery conducted by the Tensas River National Wildlife Refuge and 3,044 households drawn at random from Louisiana, Arkansas, and Mississippi. The survey distinguished between area users and nonusers to examine differences in valuation. In a probit analysis of the nonuser group\u27s responses to a dichotomous choice willingness to pay question, the value of a biodiversity conservation program was positively related to the respondent\u27s education, income, concern over loss of natural habitat, knowledge of the decline in species\u27 numbers, and attitudes concerning the fragility of the nature. The value of biodiversity conservation was negatively correlated with the number of minors residing in the household. For the user sample, the value of biodiversity was positively related to the respondent\u27s hunting skill, concern for the loss of wild habitat, and knowledge of the decline in plant and animal species. Due to evidence of structural differences between the nonuser and user sample, this study adopts the recommendation of Silberman, Gerlowski, and Williams (1992) to exclude users from passive use valuation. This research conducted multinomial logit analysis to examine the distinction between respondents in the nonuser sample who provided positive, negative and uncertain responses. Positive responses were positively related to education, income, concern for the loss of natural habitat, knowledge of the decline in plant and animal species, and attitudes concerning the fragility of nature and negatively related to the number of minors in the household. Negative responses were negatively related to income, knowledge of the term biodiversity , attitudes regarding the fragility of nature, and anti-anthropocentric attitudes. Uncertain responses were negatively related to knowledge of the decline in species\u27 numbers

In situ formation of suspended graphene windows for lab-based XPS in liquid and gas environments

Environmental cells sealed with photoelectron-transparent graphene windows are promising for extending X-ray photoelectron spectroscopy (XPS) to liquid and high-pressure gas environments for in situ and operando studies. However, the reliable production of graphene windows that are sufficiently leak-tight for extended measurements remains a challenge. Here we demonstrate a PDMS/Au(100 nm)-supported transfer method that reliably produces suspended graphene on perforated silicon nitride membranes without significant contamination. A yield of ~95% is achieved based on single-layer graphene covering >98% of the holes in the silicon nitride membrane. Even higher coverages are achieved for stacked bilayer graphene, allowing wet etching (aqueous KI/I2) of the Au support to be observed in a conventional lab-based XPS system, thereby demonstrating the in situ formation of leak-tight, suspended graphene windows. Furthermore, these windows allow gas-phase measurements at close to atmospheric pressure, showing future promise for XPS under higher-pressure gas environments in conventional lab-based systems

Elucidating the Mechanism of Iron‐Catalyzed Graphitization:The First Observation of Homogeneous Solid‐State Catalysis

Carbon is a critical material for existing and emerging energy applications and there is considerable global effort in generating sustainable carbons. A particularly promising area is iron‐catalyzed graphitization, which is the conversion of organic matter to graphitic carbon nanostructures by an iron catalyst. In this paper, it is reported that iron‐catalyzed graphitization occurs via a new type of mechanism that is called homogeneous solid‐state catalysis. Dark field in situ transmission electron microscopy is used to demonstrate that crystalline iron nanoparticles “burrow” through amorphous carbon to generate multiwalled graphitic nanotubes. The process is remarkably fast, particularly given the solid phase of the catalyst, and in situ synchrotron X‐ray diffraction is used to demonstrate that graphitization is complete within a few minutes

Mice with endogenous TDP-43 mutations exhibit gain of splicing function and characteristics of amyotrophic lateral sclerosis

TDP-43 (encoded by the gene TARDBP) is an RNA binding protein central to the pathogenesis of amyotrophic lateral sclerosis (ALS). However, how TARDBP mutations trigger pathogenesis remains unknown. Here, we use novel mouse mutants carrying point mutations in endogenous Tardbp to dissect TDP-43 function at physiological levels both in vitro and in vivo Interestingly, we find that mutations within the C-terminal domain of TDP-43 lead to a gain of splicing function. Using two different strains, we are able to separate TDP-43 loss- and gain-of-function effects. TDP-43 gain-of-function effects in these mice reveal a novel category of splicing events controlled by TDP-43, referred to as "skiptic" exons, in which skipping of constitutive exons causes changes in gene expression. In vivo, this gain-of-function mutation in endogenous Tardbp causes an adult-onset neuromuscular phenotype accompanied by motor neuron loss and neurodegenerative changes. Furthermore, we have validated the splicing gain-of-function and skiptic exons in ALS patient-derived cells. Our findings provide a novel pathogenic mechanism and highlight how TDP-43 gain of function and loss of function affect RNA processing differently, suggesting they may act at different disease stages

Synthetic Biology: Mapping the Scientific Landscape

This article uses data from Thomson Reuters Web of Science to map and analyse the scientific landscape for synthetic biology. The article draws on recent advances in data visualisation and analytics with the aim of informing upcoming international policy debates on the governance of synthetic biology by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) of the United Nations Convention on Biological Diversity. We use mapping techniques to identify how synthetic biology can best be understood and the range of institutions, researchers and funding agencies involved. Debates under the Convention are likely to focus on a possible moratorium on the field release of synthetic organisms, cells or genomes. Based on the empirical evidence we propose that guidance could be provided to funding agencies to respect the letter and spirit of the Convention on Biological Diversity in making research investments. Building on the recommendations of the United States Presidential Commission for the Study of Bioethical Issues we demonstrate that it is possible to promote independent and transparent monitoring of developments in synthetic biology using modern information tools. In particular, public and policy understanding and engagement with synthetic biology can be enhanced through the use of online interactive tools. As a step forward in this process we make existing data on the scientific literature on synthetic biology available in an online interactive workbook so that researchers, policy makers and civil society can explore the data and draw conclusions for themselves