40,574 research outputs found
Sequence-Based Mapping and Genome Editing Reveal Mutations in Stickleback Hps5 Cause Oculocutaneous Albinism and the casper Phenotype.
Here, we present and characterize the spontaneous X-linked recessive mutation casper, which causes oculocutaneous albinism in threespine sticklebacks (Gasterosteus aculeatus). In humans, Hermansky-Pudlak syndrome results in pigmentation defects due to disrupted formation of the melanin-containing lysosomal-related organelle (LRO), the melanosome. casper mutants display not only reduced pigmentation of melanosomes in melanophores, but also reductions in the iridescent silver color from iridophores, while the yellow pigmentation from xanthophores appears unaffected. We mapped casper using high-throughput sequencing of genomic DNA from bulked casper mutants to a region of the stickleback X chromosome (chromosome 19) near the stickleback ortholog of Hermansky-Pudlak syndrome 5 (Hps5). casper mutants have an insertion of a single nucleotide in the sixth exon of Hps5, predicted to generate an early frameshift. Genome editing using CRISPR/Cas9 induced lesions in Hps5 and phenocopied the casper mutation. Injecting single or paired Hps5 guide RNAs revealed higher incidences of genomic deletions from paired guide RNAs compared to single gRNAs. Stickleback Hps5 provides a genetic system where a hemizygous locus in XY males and a diploid locus in XX females can be used to generate an easily scored visible phenotype, facilitating quantitative studies of different genome editing approaches. Lastly, we show the ability to better visualize patterns of fluorescent transgenic reporters in Hps5 mutant fish. Thus, Hps5 mutations present an opportunity to study pigmented LROs in the emerging stickleback model system, as well as a tool to aid in assaying genome editing and visualizing enhancer activity in transgenic fish
A Case Report of Folie\u27a Deux: Husband-and-Wife
Shared paranoid disorder is a relatively rare psychiatric disorder in which paranoid delusions are transferred from one individual to one or more other susceptible person(s) in close association. Folie a deux describes a shared paranoid disorder involving two people and is characterized by a complex dependant relationship between the involved individuals. Provided there is no additional underlying psychopathology, there is a good prognosis for the submissive partner. Here we present a case report and discussion off folie a deux involving a husband and wife. Although folie a deux is a relatively uncommon disorder, it is important to recognize such cases due to the potential for recovery in the submissive partner
Modeling the environmental controls on tree water use at different temporal scales
Acknowledgements This study is part of the first author’s PhD projects in 2010–2014, co-funded by the National Centre for Groundwater Research and Training in Australia and the China Scholarship Council. We give thanks to Zijuan Deng and Xiang Xu for their assistance in the field. Constructive comments and suggestion from the anonymous reviewers are appreciated for significant improvement of the manuscript.Peer reviewedPostprin
Multiband radar characterization of forest biomes
The utility of airborne and orbital SAR in classification, assessment, and monitoring of forest biomes is investigated through analysis of orbital synthetic aperature radar (SAR) and multifrequency and multipolarized airborne SAR imagery relying on image tone and texture. Preliminary airborne SAR experiments and truck-mounted scatterometer observations demonstrated that the three dimensional structural complexity of a forest, and the various scales of temporal dynamics in the microwave dielectric properties of both trees and the underlying substrate would severely limit empirical or semi-empirical approaches. As a consequence, it became necessary to develop a more profound understanding of the electromagnetic properties of a forest scene and their temporal dynamics through controlled experimentation coupled with theoretical development and verification. The concatenation of various models into a physically-based composite model treating the entire forest scene became the major objective of the study as this is the key to development of a series of robust retrieval algorithms for forest biophysical properties. In order to verify the performance of the component elements of the composite model, a series of controlled laboratory and field experiments were undertaken to: (1) develop techniques to measure the microwave dielectric properties of vegetation; (2) relate the microwave dielectric properties of vegetation to more readily measured characteristics such as density and moisture content; (3) calculate the radar cross-section of leaves, and cylinders; (4) improve backscatter models for rough surfaces; and (5) relate attenuation and phase delays during propagation through canopies to canopy properties. These modeling efforts, as validated by the measurements, were incorporated within a larger model known as the Michigan Microwave Canopy Scattering (MIMICS) Model
The identification of histidine ligands to cytochrome a in cytochrome c oxidase
A histidine auxotroph of Saccharomyces cerevisiae has been used to metabolically incorporate [1,3-15N2] histidine into yeast cytochrome c oxidase. Electron nuclear double resonance (ENDOR) spectroscopy of cytochrome a in the [15N]histidine-substituted enzyme reveals an ENDOR signal which can be assigned to hyperfine coupling of a histidine 15N with the low-spin heme, thereby unambiguously identifying histidine as an axial ligand to this cytochrome. Comparison of this result with similar ENDOR data obtained on two 15N-substituted bisimidazole model compounds, metmyoglobin-[15N]imidazole and bis[15N]imidazole tetraphenyl porphyrin, provides strong evidence for bisimidazole coordination in cytochrome a
AJAE Appendix: Nonlinear Dynamics and Structural Change in the U.S. Hog-Corn Ratio: A Time-Varying Star Approach
The material contained herein is supplementary to the article named in the title and published in the American Journal of Agricultural Economics, Volume 88, Number 1, February 2006.Agribusiness,
On the Fiscal Implications of Twin Crises
This paper explores the implications of different strategies for financng the fiscal costs of twin crises for inflation and depreciation rates. We use a first-generation type model of speculative attacks which has four key features: (i) the crisis is triggered by prospective deficits; (ii) there exists outstanding non-indexed government debt issued prior to the crisis; (iii) a portion of the government's liabilities are not indexed to inflation; (iv) there are nontradeable goods and costs of distributing tradeable goods, so that the purchasing power parity does not hold. We show that the model can account for the high rates of devaluation and the moderate rates of inflation often observed in the wake of currency crises. We use our model and the data to interpret the recent currency crises in mexico and Korea. Our analysis suggests that the Mexican government is likely to pay for the bulk of the fiscal costs of its crisis through seignorage revenues. in contrast, the Korean government is likely to rely more on a combination of implicit and explicit fiscal reforms.Currency crisis, banking crisis, speculative attacks, seignorage, fiscal reform bailouts
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