471 research outputs found

    Topological mass mechanism and exact fields mapping

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    We present a class of mappings between models with topological mass mechanism and purely topological models in arbitrary dimensions. These mappings are established by directly mapping the fields of one model in terms of the fields of the other model in closed expressions. These expressions provide the mappings of their actions as well as the mappings of their propagators. For a general class of models in which the topological model becomes the BF model the mappings present arbitrary functions which otherwise are absent for Chern-Simons like actions. This work generalizes the results of [1] for arbitrary dimensions.Comment: 11 page

    The MADS-box gene Agamous-like 11 is essential for seed morphogenesis in grapevine.

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    Despite the wide appreciation of seedless grapes, little is known about the molecular mechanisms that drive the stenospermocarpic seedless-type phenotype in grapevine. In order to address the molecular mechanisms that control seedlessness in grapevine, our study aimed to characterize VviAGL11, a class D MADS-box transcription factor gene that has been proposed as the major candidate gene involved in Vitis vinifera seed morphogenesis. VviAGL11 allelic variations in seeded and seedless grapevine cultivars were determined, and its correlations with allele-specific steady-state mRNA levels were investigated. VviAGL11 relative expression was significantly higher in seeds at 2, 4, and 6 weeks after fruit set, whereas in the seedless grape its transcript levels were extremely low in all stages analyzed. In situ hybridization revealed transcript accumulation specifically in the dual endotesta layer of the seeds, which is responsible for elongation and an increase of cell number, a necessary step to determine the lignification and the final seed size. No hybridization signals were visible in the seedless grapevine tissues, and a morphoanatomical analysis showed an apparent loss of identity of the endotesta layer of the seed traces. Ectopic expression of VviAGL11 in the Arabidopsis SEEDSTICK mutant background restored the wild-type phenotype and confirmed the direct role of VviAGL11 in seed morphogenesis, suggesting that depletion of its expression is responsible for the erroneous development of a highly essential seed layer, therefore culminating in the typical apirenic phenotype. Key words: Apireny, grapevine, in situ hybridization, seedlessness, Sultanine, VviAGL11

    Differential transcriptional profiles of dormancy-related genes in apple buds

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    The production of temperate fruit crops depends on plant developmental processes, primarily the shift from the juvenile phase to the reproductive phase, dormancy transitions and flowering. Apple tree (Malus ×domestica Borkh.) development is regulated by chilling temperatures, which are required for bud dormancy progression. The apple cultivar Castel Gala is a spontaneous mutation of "Gala Standard". "Castel Gala" is characterized by a 50 % decrease in the chilling requirement (CR) for dormancy release, which results in an earlier budbreak. This work explores the contrasting phenotypes of these cultivars using suppression subtractive hybridization (SSH). From 1,019 unigenes identified by SSH, we selected 28 candidate genes putatively associated with dormancy cycling. Reverse transcription-quantitative polymerase chain reaction was used to validate the differential expression profiles and to transcriptionally characterize these genes in three distinct apple cultivars ("Castel Gala", "Royal Gala" and "Fuji Standard") during a cycle comprising growth to dormancy. Of the 28 candidate genes analyzed, 17 confirmed the differences in expression predicted by SSH. Seasonal transcript accumulation during the winter was observed for several genes, with higher steady-state mRNA levels maintained longer in cultivars with a high CR. The transcription profiles suggest that these genes may be associated with dormancy establishment and maintenance. Of the 17 candidate genes, transcripts coding for dormancy-associated MADS-box (DAM), dehydrins, GAST1, LTI65, NAC, HTA8, HTA12 and RAP2.12-like proteins displayed major differences in gene expression between cultivars through the winter. These genes were therefore considered good candidates for key roles in the dormancy process in apple trees.DOI 10.1007/s11105-013-0690-

    Enhanced Response of Blood Monocytes to In Vitro Lipopolysaccharide-Challenge in Patients With Recurrent Unstable Angina

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    Background—C-reactive protein (CRP) plasma levels have been associated with short- and long-term occurrence of coronary events. We investigated whether circulating inflammatory cell responsiveness to low-grade stimuli could contribute to the reported association between CRP and coronary events.Methods and Results—We studied 32 patients with unstable angina who were followed for 24 months and were free of symptoms for 6 months (group 1): 19 patients had persistently high CRP levels (>0.3 mg/dL) (group 1A); 13 patients had normal CRP levels (group 1B). During the follow-up, 12 (63%) group 1A but no group 1B patients developed an infarction or recurrence of unstable angina (P<0.001). Eighteen patients with chronic stable angina (group 2) and 18 healthy subjects (group 3) were studied as controls. Interleukin (IL)-6 production (median, range) by peripheral blood mononuclear cells after 4 hours of in vitro stimulation with 1 ng/mL lipopolysaccharide (LPS) was significantly higher in group 1A (4526 pg/mL, 3042 to 10 583 pg/mL) than in group 1B (1752 pg/mL, 75 to 3981 pg/mL), group 2 (707 pg/mL, 41 to 3275 pg/mL), and group 3 (488 pg/mL, 92 to 3503 pg/mL) (allP<0.001). No significant differences were observed among the other groups. IL-6 production after LPS-challenge was correlated with baseline CRP levels (r=0.42,P=0.005).Conclusions—Mononuclear cells of patients with recurrent phases of instability exhibit an enhanced production of IL-6 in response to low-dose of LPS, correlated with baseline CRP levels, 6 months after the last acute event. This persisting enhanced acute-phase responsiveness may help explain the association between CRP and acute coronary events

    The 9p21 Rs 1333040 polymorphism is associated with coronary microvascular obstruction in ST-segment elevation myocardial infarction treated by primary angioplasty

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    Background: Microvascular obstruction (MVO) after primary percutaneous coronary intervention (pPCI) leads to higher incidence of both early and late complications. A number of single nucleotide polymorphisms in 9p21 chromosome have been shown to affect angiogenesis in response to ischaemia. In particular, Rs1333040 with its three genotypic vriants C/C, T/C and T/T might influence the occurrence of MVO after pPCI. Methods: We enrolled ST-elevation myocardial infarction (STEMI) patients undergoing pPCI. The Rs1333040 polymorphism was evaluated by polymerase chain reaction-restriction fragment length polymorphism using restriction endonucleases (Bsml). Two expert operators unaware of the patients' identity performed the angiographic analysis; collaterals were assessed applying Rentrop's classification. Angiographic MVO was defined as a post-pPCI Thrombolysis In Myocardial Infarction (TIMI)&lt;3 or TIMI 3 with myocardial blush grade 0 or 1, whereas electrocardiographic MVO was defined as ST segment resolution Results: Among our 133 STEMI patients (mean age 63 +/- 11 years, men 72%), 35 (26%) and 53 (40%) respectively experienced angiographic or electrocardiographic MVO. Angiographic and electrocardiographic MVO were different among the three variants (p= 0.03 and p=0.02 respectively). In particular, T/T genotype was associated with a higher incidence of both angiographic and electrocardiographic MVO compared with C/C genotype (p=0.04 and p=0.03 respectively). Moreover, Rentrop score &lt;2 detection rate differed among the three genotypes (p=0.03). In particular T/T genotype was associated with a higher incidence of a Rentrop score &lt;2 as compared with C/C genotype (p= 0.02). Conclusion: Rs1333040 polymorphism genetic variants portend different MVO incidence. In particular, T/T genotype is related to angiographic and electrocardiographic MVO and to worse collaterals towards the culprit artery
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