Essays on the All-Pay Auction

Three all-pay auction models are examined. The first is a symmetric two-player binary-signal all-pay auction with correlated signals and interdependent valuations. The first chapter provides a complete characterization of each form of equilibrium and gives conditions for their existence. The main finding is that there generically exists a unique equilibrium. The unique equilibrium can only be one of four forms of equilibria. I apply my all-pay auction model to elections, where a candidate that receives good news from the polls behaves in a rationally overconfident manner and reduces her equilibrium effort. Consequently, the other candidate can win the election in an upset. The second chapter extends Chapter 1\u27s model to N signals. In comparison, the binary model allows for a guess-verify approach. However, the number of possible guesses increases rapidly when N increases. Hence such an approach is infeasible. Chapter 2\u27s approach is centered around linear algebra techniques and a novel notion of a weakly monotone equilibrium. In a weakly monotone equilibrium the bid supports are ordered by the strong set order but not necessarily separated like the traditional monotone equilibrium. I classify these weakly monotone equilibria into four primary forms. I characterize each form and find sufficient conditions for their existence. Furthermore, for the model used in Rentschler and Turocy (2016), I provide a novel necessary and sufficient condition for the existence of a traditional monotone equilibrium. The third chapter considers a two-stage game: a negotiation stage followed by a conflict stage in case the negotiations break down. In a setting with multi-dimensional correlated types, two players compete over a good that is of uncertain but common value. Conflict is modeled as an all-pay auction, which endogenizes the cost of conflict. In the literature, which assumes independent private values or costs, a peaceful equilibrium, in which war occurs with zero probability need not exist. I find that in my correlated pure common-value model, a peaceful equilibrium always exists and is essentially unique. Further, I show that adding private values to this model worsens the prospect of peace, and conflict might occur

Microbial adhesion to surface-grafted polyacrylamide brushes after long-term exposure to PBS and reconstituted freeze-dried saliva

Polyacrylamide (PAAm) brushes, covalently grafted from silicon wafer surfaces were examined for their ability to inhibit microbial adhesion after long-term exposure to PBS or reconstituted freeze-dried saliva for time intervals from 48 h up to 1 month at 37 degrees C. Microbial adhesion after exposure was studied in a parallel plate flow chamber. Infrared spectra showed that PAAm brushes exhibit good chemical stability upon incubation in both PBS and reconstituted freeze-dried saliva up to 1 month. Reductions in microbial adhesion on PAAm brushes after exposure to PBS or reconstituted freeze-dried saliva varied from 63 to 93% depending on the microbial strain considered, even after 1 month of exposure of the brushes to reconstituted freeze-dried saliva. (C) 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 94A: 997-1000,2010

Synthesis and characterization of surface-grafted polyacrylamide brushes and their inhibition of microbial adhesion

A method is presented to prevent microbial adhesion to solid surfaces exploiting the unique properties of polymer brushes. Polyacrylamide (PAAm) brushes were grown from silicon wafers by atom transfer radical polymerization (ATRP) using a three-step reaction procedure consisting of immobilization of a coupling agent gamma-aminopropyltriethoxysilane, anchoring of an ATRP initiator 4-(chloromethyl)benzoyl chloride, and controlled radical polymerization of acrylamide. The surfaces were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ellipsometry, and contact-angle measurements. The calculated grafting density pointed to the presence of a dense and homogeneous polymer brush. Initial deposition rates, adhesion after 4 h, and detachment of two bacterial strains (Staphylococcus aureus ATCC 12600 and Streptococcus salivarius GB 24/9) and one yeast strain (Candida albicans GB 1/2) to both PAAm-coated and untreated silicon surfaces were investigated in a parallel plate flow chamber. A high reduction (70-92%) in microbial adhesion to the surface-grafted PAAm brush was observed, as compared with untreated silicon surfaces. Application of the proposed grafting method to silicone rubbers may offer great potential to prevent biomaterials-centered infection of implants.</p

Tumor Vascular Morphology Undergoes Dramatic Changes during Outgrowth of B16 Melanoma While Proangiogenic Gene Expression Remains Unchanged

In established tumors, angiogenic endothelial cells (ECs) coexist next to “quiescent” EC in matured vessels. We hypothesized that angio-gene expression of B16.F10 melanoma would differ depending on the growth stage. Unraveling the spatiotemporal nature thereof is essential for drug regimen design aimed to affect multiple neovascularization stages. We determined the angiogenic phenotype—represented by 52 angio-genes—and vascular morphology of small, intermediate, and large s.c. growing mouse B16.F10 tumors and demonstrated that expression of these genes did not differ between the different growth stages. Yet vascular morphology changed dramatically from small vessels without lumen in small to larger vessels with increased lumen size in intermediate/large tumors. Separate analysis of these vascular morphologies revealed a significant difference in αSMA expression in relation to vessel morphology, while no relation with VEGF, HIF-1α, nor Dll4 expression levels was observed. We conclude that the tumor vasculature remains actively engaged in angiogenesis during B16.F10 melanoma outgrowth and that the major change in tumor vascular morphology does not follow molecular concepts generated in other angiogenesis models

Аудит промышленной безопасности организации

Цель выпускной квалификационной работы: Разработка способа быстрого перерасчета пожарного риска для зданий класса функциональной пожарной опасности Ф4.3 офисного типа. В процессе исследования проводилась теоретическая подготовка в исследовании пожарного аудита, анализ литературы в области проведения аудита по пожарной безопасности, разработка способа быстрого перерасчета пожарных рисков на основе "Методика определения расчетных величин пожарного риска в зданиях, сооружениях и строениях различных классов функциональной пожарной опасности".The purpose of the final qualifying work: the Development of a method of rapid recalculation of fire risk for buildings of functional fire hazard class F4.3 office type. In the course of the study, theoretical training was conducted in the study of fire audit, literature analysis in the field of fire safety audit, development of a method for rapid recalculation of fire risks based on the "Method of determining the calculated values of fire risk in buildings, structures and buildings of various classes of functional fire danger"

Meiosis Drives Extraordinary Genome Plasticity in the Haploid Fungal Plant Pathogen Mycosphaerella graminicola

Meiosis in the haploid plant-pathogenic fungus Mycosphaerella graminicola results in eight ascospores due to a mitotic division following the two meiotic divisions. The transient diploid phase allows for recombination among homologous chromosomes. However, some chromosomes of M. graminicola lack homologs and do not pair during meiosis. Because these chromosomes are not present universally in the genome of the organism they can be considered to be dispensable. To analyze the meiotic transmission of unequal chromosome numbers, two segregating populations were generated by crossing genetically unrelated parent isolates originating from Algeria and The Netherlands that had pathogenicity towards durum or bread wheat, respectively. Detailed genetic analyses of these progenies using high-density mapping (1793 DArT, 258 AFLP and 25 SSR markers) and graphical genotyping revealed that M. graminicola has up to eight dispensable chromosomes, the highest number reported in filamentous fungi. These chromosomes vary from 0.39 to 0.77 Mb in size, and represent up to 38% of the chromosomal complement. Chromosome numbers among progeny isolates varied widely, with some progeny missing up to three chromosomes, while other strains were disomic for one or more chromosomes. Between 15–20% of the progeny isolates lacked one or more chromosomes that were present in both parents. The two high-density maps showed no recombination of dispensable chromosomes and hence, their meiotic processing may require distributive disjunction, a phenomenon that is rarely observed in fungi. The maps also enabled the identification of individual twin isolates from a single ascus that shared the same missing or doubled chromosomes indicating that the chromosomal polymorphisms were mitotically stable and originated from nondisjunction during the second division and, less frequently, during the first division of fungal meiosis. High genome plasticity could be among the strategies enabling this versatile pathogen to quickly overcome adverse biotic and abiotic conditions in wheat field