61 research outputs found
Enumerative aspects of the Gross-Siebert program
We present enumerative aspects of the Gross-Siebert program in this
introductory survey. After sketching the program's main themes and goals, we
review the basic definitions and results of logarithmic and tropical geometry.
We give examples and a proof for counting algebraic curves via tropical curves.
To illustrate an application of tropical geometry and the Gross-Siebert program
to mirror symmetry, we discuss the mirror symmetry of the projective plane.Comment: A version of these notes will appear as a chapter in an upcoming
Fields Institute volume. 81 page
Ação do cepa e do ácido giberélico na frutificação da videira 'niagara rosada'
Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the Jundiaí Research Station, Agronomic Institute State of São Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersão, do CEPA (ácido 2-cloroetil fosfônico) e do ácido giberélico, 14 dias antes do florescimento, nas características morfológicas da panícula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ácido giberélico foram concluídos com nova aplicação 10 dias após o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panículas com a maioria de características indesejáveis. o tratamento misto CEPA 100 ppm + ácido giberélico 100 ppm também promoveu o aparecimento de panículas subdesenvolvidas. Aplicação de ácido giberélico na concentração de 100 ppm em pré e pós-ílorescimento, resultou médias mais elevadas, com relação ao peso da panícula, comprimento da panícula, peso das bagas e comprimento da ráquis. Ácido giberélico na concentração de 100 ppm aplicado em pós-ílorescimento, promoveu uma tendência de aumento nas médias do tratamento quanto ao comprimento médio das bagas, largura média das bagas, largura do engaço e comprimento da ráquila. Devemos considerar porém, que os resultados obtidos não apresentaram diferenças significativas com relação ao controle, quanto às características das frutificações, nas condições de estudo
Interactions of Microbotryum Violaceum (Ustilago Violacea) with Its Host Plant Silene Alba
Sex expression in Silene alba is determined genetically but can be changed in female plants upon infection with the heterobasidiomycete Microbotryum violaceum. This change is not caused by steroids, the classical plant growth regulators, nor by a diffusible morphogen produced and secreted by the fungus. Nor is the production of stamnes in genotypically female flowers caused by the transmission, incorporation and expression of a fungal plasmid since plants regenerated from diseased tissue of genotypically female S. alba did not yield stamen-producing flowers. Neither density gradient centrifugation nor agarose gel electrophoresis of endonuclease restricted DNA from M. violaceum revealed the presence of a plasmid. Southern blots of DNA from S. alba probed with labeled DNA of M. violaceum, however, indicated the presence of homologous, unique sequences absent in non-host plants. Since the same homologous sequences were identified in male and female S. alba, these DNA fragments are not homologous to the coding sequences for male sex expression in S. alba unless they represent genetic elements of the hypothetical gyndyioecious precursor. Two other aspects of the S. alba-M. violaceum interaction have yielded interesting results. M. violaceum grows as sporidia outside of the host, but as short hyphae in planta. The switch from sporidial to hyphal growth is mediated in vitro by hyphal growth factors (HGFs) isolated from aqueous host plant extracts as well as by α-tocopherol. In addition to changing the fungal growth form. HGFs may serve as host recognition factors. Siderophore mutants of M. violaceum that accumulated less rhodotorulic acid than wild type also showed reduced or no pathogenicity, indicating that siderophores are an important factor in the host-pathogen interaction
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Evidence for downregulation of calcium signaling proteins in advanced mouse adenocarcinoma
BackgroundProstate cancer (PCa) is the leading cancer related death in America. Gleason grading is currently the predominant method for prediction, with only few biomarkers available. More biomarkers, especially as they relate to cancer progression are desirable.MethodsThe abundance of several important proteins in prostate tissue was compared between wild-type mouse dorsal prostate and well-differentiated transgenic adenocarcinoma mouse prostate (TRAMP) mouse dorsal prostates, and between wild-type mouse dorsal prostate and poorly-differentiated TRAMP mouse tumor tissue. 2DIGE method in conjunction with MALDI-ToF and Western blots was used to determine differential expression.ResultsIn TRAMP dorsal prostates with well-differentiated adenocarcinoma, there were few significant changes in the protein abundances compared to wild-type dorsal prostates, with the exception of increases in proliferating cell nuclear antigen (PCNA) and beta tubulin, two proteins implicated in cell proliferation, and a more than 2-fold increase in Hsp60, a protein involved in the suppression of apoptosis. In the poorly-differentiated tumors, the changes in protein abundance were substantial. While some of those changes could be related to the disappearance of stromal tissue or the appearance of epithelial tissue, other changes in protein abundance were more significant to the cancer development itself. Most notable was the overall decrease in calcium homeostasis proteins with a 10-fold decrease in calreticulin and Hsp70 and a 40-fold decrease in creatine kinase bb in the cancerous tissue.ConclusionsProteomics of TRAMP mice provide an excellent method to observe changes in protein abundance, revealing changes in pathways during cancer progression
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