Showing 21 - 30 of 5709 Items
The Sacralization of Absolute Power: God's Power and Women's Subordination in the Southern Baptist Convention
Date: 2019-05-01
Creator: Sydney Smith
Access: Open access
Stolen Future, Broken Present: The Human Significance of Climate Change
Date: 2014-01-01
Creator: David A Collings
Access: Open access
- This book argues that climate change has a devastating effect on how we think about the future. Once several positive feedback loops in Earth’s dynamic systems, such as the melting of the Arctic icecap or the drying of the Amazon, cross the point of no return, the biosphere is likely to undergo severe and irreversible warming. Nearly everything we do is premised on the assumption that the world we know will endure into the future and provide a sustaining context for our activities. But today the future of a viable biosphere, and thus the purpose of our present activities, is put into question. A disappearing future leads to a broken present, a strange incoherence in the feel of everyday life. We thus face the unprecedented challenge of salvaging a basis for our lives today. That basis, this book argues, may be found in our capacity to assume an infinite responsibility for ecological disaster and, like the biblical Job, to respond with awe to the alien voice that speaks from the whirlwind. By owning disaster and accepting our small place within the inhuman forces of the biosphere, we may discover how to live with responsibility and serenity whatever may come. (Publisher's Description) Freely available online at: http://dx.doi.org/10.3998/ohp.12832550.0001.001
Conical wave propagation and diffraction in two-dimensional hexagonally packed granular lattices
Date: 2016-01-25
Creator: C. Chong, P. G. Kevrekidis, M. J. Ablowitz, Yi Ping Ma
Access: Open access
- Linear and nonlinear mechanisms for conical wave propagation in two-dimensional lattices are explored in the realm of phononic crystals. As a prototypical example, a statically compressed granular lattice of spherical particles arranged in a hexagonal packing configuration is analyzed. Upon identifying the dispersion relation of the underlying linear problem, the resulting diffraction properties are considered. Analysis both via a heuristic argument for the linear propagation of a wave packet and via asymptotic analysis leading to the derivation of a Dirac system suggests the occurrence of conical diffraction. This analysis is valid for strong precompression, i.e., near the linear regime. For weak precompression, conical wave propagation is still possible, but the resulting expanding circular wave front is of a nonoscillatory nature, resulting from the complex interplay among the discreteness, nonlinearity, and geometry of the packing. The transition between these two types of propagation is explored.
“The Spirit of Turbulence”: East Indian Political Imaginaries in Early 20th Century British Guiana
Date: 2020-01-01
Creator: Faria A Nasruddin
Access: Open access
- After the abolition of slavery, the Colonial Office instituted an indentured labor scheme that lasted from 1838 to 1917, in which they brought East Indians to the plantation colonies as laborers under five year contracts. Due to the planter class’ desire for permanent sources of labor in British Guiana, the Colonial Government incentivized East Indians to permanently settle. East Indians thus dominated the British Guiana’s agricultural landscape and became the single largest ethnicity in the Colony by 1920. This thesis explores the early negotiations of the meaning of diaspora and diasporic citizenship for East Indians in British Guiana. They comprised a diverse conglomerate of different socio-economic positions: agricultural estate laborers, village residents, and middle-class business professionals. Each socioeconomic group had a different lived experience in the colony and different outlook on what it meant to be a creole-born East Indian. This thesis traces the multiple and contingent ideas of citizenship and nationality that were circulating at the time. Against a backdrop of changing imperial politics that promoted modernity and the discourse of the nation, East Indian visions centered around how to construct permanence, and negotiate belonging. By drawing on colonial documentation–local reports, commission transcripts, personal correspondence–and documentation produced by East Indians–memorandums, speeches, and books–this thesis ultimately argues that East Indians came to view culture as integral to their self-worth and definitions of place within the imperial system. Culture thus became the primary lens to negotiate the various meaning of citizenship and place in the imperial-national moment.
Multistable solitons in higher-dimensional cubic-quintic nonlinear Schrödinger lattices
Date: 2009-01-15
Creator: C. Chong, R. Carretero-González, B. A. Malomed, P. G. Kevrekidis
Access: Open access
- We study the existence, stability, and mobility of fundamental discrete solitons in two- and three-dimensional nonlinear Schrödinger lattices with a combination of cubic self-focusing and quintic self-defocusing onsite nonlinearities. Several species of stationary solutions are constructed, and bifurcations linking their families are investigated using parameter continuation starting from the anti-continuum limit, and also with the help of a variational approximation. In particular, a species of hybrid solitons, intermediate between the site- and bond-centered types of the localized states (with no counterpart in the 1D model), is analyzed in 2D and 3D lattices. We also discuss the mobility of multi-dimensional discrete solitons that can be set in motion by lending them kinetic energy exceeding the appropriately defined Peierls-Nabarro barrier; however, they eventually come to a halt, due to radiation loss. © 2008 Elsevier B.V. All rights reserved.
All-loop infrared-divergent behavior of most-subleading-color gauge-theory amplitudes
Date: 2013-04-19
Creator: Stephen G. Naculich, Horatiu Nastase, Howard J. Schnitzer
Access: Open access
- The infrared singularities of gravitational amplitudes are one-loop exact, in that higher-loop divergences are characterized by the exponential of the one-loop divergence. We show that the contributions to SU(N) gauge-theory amplitudes that are mostsubleading in the 1/N expansion are also one-loop exact, provided that the dipole conjecture holds. Possible corrections to the dipole conjecture, beginning at three loops, could violate one-loop-exactness, though would still maintain the absence of collinear divergences. We also demonstrate a relation between L-loop four-point N = 8 supergravity and mostsubleading-color N = 4 SYM amplitudes that holds for the two leading IR divergences, (Formula presented.) and (Formula presented.), but breaks down at (Formula presented.).
Neural correlates of behavior therapy for Tourette's disorder
Date: 2014-01-01
Creator: Thilo Deckersbach, Tina Chou, Jennifer C. Britton, Lindsay E. Carlson, Hannah E., Reese, Jedidiah Siev, Lawrence Scahill, John C. Piacentini, Douglas W. Woods, John T. Walkup, Alan L. Peterson, Darin D. Dougherty, Sabine Wilhelm
Access: Open access
- Tourette's disorder, also called Tourette syndrome (TS), is characterized by motor and vocal tics that can cause significant impairment in daily functioning. Tics are believed to be due to failed inhibition of both associative and motor cortico-striato-thalamo-cortical pathways. Comprehensive Behavioral Intervention for Tics (CBIT), which is an extension of Habit Reversal Therapy (HRT), teaches patients to become more aware of sensations that reliably precede tics (premonitory urges) and to initiate competing movements that inhibit the occurrence of tics. In this study, we used functional magnetic resonance imaging (fMRI) to investigate the neural changes associated with CBIT treatment in subjects with TS. Eight subjects with TS were matched with eight healthy controls in gender, education, age, and handedness. Subjects completed the Visuospatial Priming (VSP) task, a measure of response inhibition, during fMRI scanning before and after CBIT treatment (or waiting period for controls). For TS subjects, we found a significant decrease in striatal (putamen) activation from pre- to post-treatment. Change in VSP task-related activation from pre- to post-treatment in Brodmann's area 47 (the inferior frontal gyrus) was negatively correlated with changes in tic severity. CBIT may promote normalization of aberrant cortico-striato-thalamo-cortical associative and motor pathways in individuals with TS.
Genome plasticity in candida albicans is driven by long repeat sequences
Date: 2019-06-01
Creator: Robert T. Todd, Tyler D. Wikoff, Anja Forche, Anna Selmecki
Access: Open access
- Genome rearrangements resulting in copy number variation (CNV) and loss of heterozygosity (LOH) are frequently observed during the somatic evolution of cancer and promote rapid adaptation of fungi to novel environments. In the human fungal pathogen Candida albicans, CNV and LOH confer increased virulence and antifungal drug resistance, yet the mechanisms driving these rearrangements are not completely understood. Here, we unveil an extensive array of long repeat sequences (65–6499 bp) that are associated with CNV, LOH, and chromosomal inversions. Many of these long repeat sequences are uncharacterized and encompass one or more coding sequences that are actively transcribed. Repeats associated with genome rearrangements are predominantly inverted and separated by up to ~1.6 Mb, an extraordinary distance for homology-based DNA repair/recombination in yeast. These repeat sequences are a significant source of genome plasticity across diverse strain backgrounds including clinical, environmental, and experimentally evolved isolates, and represent previously uncharacterized variation in the reference genome.
Fgf signaling is required for zebrafish tooth development
Date: 2004-10-01
Creator: William R. Jackman, Bruce W. Draper, David W. Stock
Access: Open access
- We have investigated fibroblast growth factor (FGF) signaling during the development of the zebrafish pharyngeal dentition with the goal of uncovering novel roles for FGFs in tooth development as well as phylogenetic and topographic diversity in the tooth developmental pathway. We found that the tooth-related expression of several zebrafish genes is similar to that of their mouse orthologs, including both epithelial and mesenchymal markers. Additionally, significant differences in gene expression between zebrafish and mouse teeth are indicated by the apparent lack of fgf8 and pax9 expression in zebrafish tooth germs. FGF receptor inhibition with SU5402 at 32 h blocked dental epithelial morphogenesis and tooth mineralization. While the pharyngeal epithelium remained intact as judged by normal pitx2 expression, not only was the mesenchymal expression of lhx6 and lhx7 eliminated as expected from mouse studies, but the epithelial expression of dlx2a, dlx2b, fgf3, and fgf4 was as well. This latter result provides novel evidence that the dental epithelium is a target of FGF signaling. However, the failure of SU5402 to block localized expression of pitx2 suggests that the earliest steps of tooth initiation are FGF-independent. Investigations of specific FGF ligands with morpholino antisense oligonucleotides revealed only a mild tooth shape phenotype following fgf4 knockdown, while fgf8 inhibition revealed only a subtle down-regulation of dental dlx2b expression with no apparent effect on tooth morphology. Our results suggest redundant FGF signals target the dental epithelium and together are required for dental morphogenesis. Further work will be required to elucidate the nature of these signals, particularly with respect to their origins and whether they act through the mesenchyme. © 2004 Elsevier Inc. All rights reserved.