Quantitative Genetics, Molecular Markers, and Plant Improvement

Quantitative genetics in conjunction with statistics has provided much of the scientific framework for modern plant breeding. Although there has been no specific review of the contributions of quantitative genetics and statistics to plant breeding, the contributions have been undoubtedly profound and lasting. Quantitative genetic theory in many ways is robust to and naive of modern genetic principles. Little is known about the biology or the genetic architecture of quantitative traits. In this paper, five major areas of quantitative genetics -- number of loci controlling quantitative traits, nature of quantitative trait loci, gene action and effects, epistasis, and genotype x environment interaction -- relevant to plant improvement and to molecular marker applications to such improvement are reviewed. Beyond generalities, the conclusion is that quantitative genetics has provided little specific information on the biology or the architecture of quantitative traits. Molecular markers may complement plant breeding in three broad areas. Molecular markers provide reliable estimates of genetic diversity, may improve screening efficiency for many traits through their linkage with alleles with small (quantitative traits) and with large (qualitative traits) effects, and will provide the first understanding of biology and architecture of quantitative traits at the DNA level. Generalities about the usefulness of molecular markers in plant improvement are difficult to make

Giraffes, Ferris Wheels and Royal Reenactments: Hits and Misses in the Reinvention of a Joseon Palace

Thesis (M.A.) - Indiana University, East Asian Languages & Cultures (EALC, 2015)Tourist sites, like national identities, are selectively promoted depictions often made from highly contested perspectives. A site is a self-perpetuating scene created by host and visitors swapping the same images. Olivia Jenkins has described spiraling circles of representation linked to Australia’s iconic symbols, and Herbert Bix, Carol Gluck and Kosaku Yoshino have applied a similar logic to processes facilitating much greater shifts in the image of the entire nation of Japan. Success in both cases requires cropping pieces that do not fit into the newly evolved, prevalent narrative. The speed at which scenes have shifted at one palace in Seoul has meant entire buildings, a park full of fun rides, and one of Korea’s great works of literature – great at least from a Western-trained perspective -- are vanishing from collective memory. Such “a focus on small-scale or localized change can illustrate or embody much broader processes of political transformation,” as Katherine Verdery says, “the Macro is in the Micro.” Consequently this thesis examines manifestations of major changes in Korea’s governing and social structures reflected in the grounds of Changgyeonggung. Discourse and content analyses of guide books, brochures, and websites show how visitors come to absorb the conveniently condensed narratives and imagery as successive administrators place new monuments atop or alongside those of their predecessors to rewrite the geographic scenes

Understanding Disaster Recovery Planning through a Theatre Metaphor: Rehearsing for a Show that Might Never Open

Disaster recovery planning for organizations is fundamental and often urgent. Planning supports the firm\u27s ability to recover the core business functionality of its software, data, and systems after the occurrence of a natural or man-made disaster. Organizations must take steps to protect their software, systems and data backups from natural disasters, power outages, and even terrorist attacks. However the issue of disaster recovery is often awash in checklists or marooned in mundane statistics. Such sterile approaches tend to lead key managers, CEOs, and CIOs to relegate disaster recovery planning to a lower priority when they become overwhelmed with planning minutiae or bored with staid presentations. This paper introduces a theatre metaphor to enable a lively discussion and deeper understanding of disaster recovery planning. Specifically, we introduce the concept of workshopping a play. We explore this new approach from the world of theatrical productions to illuminate and deepen understanding of the importance of testing, evaluation, and reworking of scenarios for each potential disaster

Temporal changes in allele frequencies in two reciprocally selected maize populations

The effects of breeding on allele frequency changes at 82 restriction fragment length polymorphism (RFLP) loci were examined in two maize (Zea mays L.) populations undergoing reciprocal recurrent selection, Iowa Stiff Stalk Synthetic and Iowa Corn Borer Synthetic #1. After 12 cycles of selection, approximately 30% of the alleles were extinct and 10% near fixation in each population. A test of selective neutrality identified several loci in each population whose allele frequency changes cannot be explained by genetic drift; interpopulation mean expected heterozygosity increased for that subset of 28 loci but not for the remaining 54 loci. Mean expected heterozygosity within the two subpopulations decreased 39%, while the between-population component of genetic variation increased from 0.5% to 33.4% of the total. Effective population size is a key parameter for discerning allele frequency changes due to genetic drift versus those resulting from selection and genetic hitchhiking. Empirical estimates of effective population size for each population were within the range predicted by the breeding method

Molecular Genetic Diversity after Reciprocal Recurrent Selection in BSSS and BSCB1 Maize Populations

Iowa Stiff Stalk Synthetic (BSSS) and Iowa Corn Borer Synthetic #1 (BSCB1) are undergoing reciprocal recurrent selection as part of Iowa\u27s Federal-State maize (Zea mays L.) breeding program. This study focused on molecular genetic variation in BSSS(R) and BSCBI(R) cycle 0 (CO) and cycle 12 (C12) populations, as well as the inbred progenitor lines (P) used to synthesize BSSS and BSCB1. The objectives were to quantify amounts of genetic variation within populations, to estimate what proportion remained after selection, and to compare genetic diversities between BSSS and BSCB1 populations. Genotypic data for 82 restriction fragment length polymorphism (RFLP) loci were collected from 100 randomly sampled individuals from each CO and C12 population, 16 BSSS(R) progenitors, and 12 BSCBI(R) progenitors. Progenitor lines were highly homozygous as expected. No single progenitor made excessive genetic contributions to CO or C12. The BSSS and BSCB1 progenitor populations were initially genetically similar (Nei\u27s genetic distance = 0.07). After 12 cycles of selection, they substantially diverged (Nei\u27s distance = 0.66). Gene diversity (expected heterozygosity under random mating) across progenitor populations was very broad (mean gene diversity = 0.6) and remained at that level to C12. Within both populations, the polymorphism level decreased from about 99 to 75%, and gene diversity decreased from about 0.6 to 0.3 between P and C12. The mean number of alleles per locus dropped from about four to less than three. Assuming an effective population size as the mean number of selected S1 lines over 12 cycles, the observed loss of variation was consistent with theoretical expectations resulting from genetic drift of neutral alleles

Polarization characteristics of dye‐laser amplifiers I. Unidirectional molecular distributions

Many practical laser amplifiers exhibit anisotropic gain due to polarization of the pumping fields or to a fixed preferential alignment of the active dipoles. Several specific causes and consequences of gain anisotropy are discussed in detail. In the analysis, the emphasis is placed on dye‐laser systems including arbitrary amplitudes, phases, and polarizations of the pump and signal fields. Analytical results are presented for a unidrectional molecular distribution, and it is found that the polarization states of the pump and signal fields change with distance in the amplifier

Efficient Image Gallery Representations at Scale Through Multi-Task Learning

Image galleries provide a rich source of diverse information about a product which can be leveraged across many recommendation and retrieval applications. We study the problem of building a universal image gallery encoder through multi-task learning (MTL) approach and demonstrate that it is indeed a practical way to achieve generalizability of learned representations to new downstream tasks. Additionally, we analyze the relative predictive performance of MTL-trained solutions against optimal and substantially more expensive solutions, and find signals that MTL can be a useful mechanism to address sparsity in low-resource binary tasks.Comment: Proceedings of the 43rd International ACM SIGIR Conference on Research and Development in Information Retrieva

Artifact Simulating Fracture on Cervical Spine Computed Tomography

We present the case of a 31-year-old trauma patient with computed tomography concerning significant C3–C4 subluxation. The abnormality is due to an artifact with which emergency physicians should be aware