185 research outputs found
Chemical and molecular genetic strategies to block ethylene perception for increased flower life
Ethylene has been known to cause many undesirable effects in a range of ornamental species. Blocking ethylene responses has been proved as an efficient strategy to enhance the longevity of the flowers. The most effective ways to conduct such interference are using chemical compounds or genetic manipulation. In the last 15 years a large number of volatile chemical compounds have been evaluated for their effects on ethylene production and perception. This has resulted in the discovery that cyclopropenes effectively block ethylene responses at the receptor level. The most promising among them are 1-methylcyclopropene (1-MCP) and a number of other substituted cyclopropenes. A lot of testing remains to be done to uncover the full potential of these compounds, but they do offer promising new ways to improve the postharvest quality and longevity of ornamentals. Another very effective way for controlling ethylene synthesis and perception is genetic modification. The most promising strategy seems to be the use of the mutant ethylene receptor gene, etr1-1, from Arabidopsis thaliana, especially when it is expressed under the control of a flower specific promoter
Stitching Life Together” A Capstone Project
Our Sophomore Scholars in Residence class, Longevity and Happiness, made a quilt for its capstone project. Each member of the class (15 students, 1 faculty) designed and then sewed together a 12 x 12 inch square, based on a particular person or theme from the course. Most of the squares depict the lives of individuals we met and interviewed over the year, including several from Canada, where we traveled for fall break to interview the exceptionally long-lived individuals in Lunenburg, Nova Scotia. We also interviewed several individuals from Richmond, VA. Throughout the spring semester, we learned and practiced our sewing skills, bought fabric, visited quilting stores, and finally stitched together the squares to batting and backing to create our capstone quilt for its presentation as part of the 2018 Arts & Sciences Student Symposium. The quilt traveled to Nova Scotia in June 2018 as part of a Summer Research Fellowship project awarded to SSIR students Elizabeth Cooper, Mallory Haskins, and Peter Kade. These students returned to Lunenburg to conduct follow-up research based on their coursework in Longevity and Happiness, and shared the quilt with some of our interviewees from the trip to Nova Scotia in October 2018. The quilt will hang in Richmond Hall, Department of Psychology, University of Richmond.https://scholarship.richmond.edu/ssir-presentations-2018/1004/thumbnail.jp
Placental growth hormone (GH), GH-binding protein, and insulin-like growth factor axis in normal, growth-retarded, and diabetic pregnancies: Correlations with fetal growth
We previously described significant changes in GH-binding protein (GHBP) in pathological human pregnancy. There was a substantial elevation of GHBP in cases of noninsulin-dependent diabetes mellitus and a reduction in insulin-dependent diabetes mellitus. GHBP has the potential to modulate the proportion of free placental GH (PGH) and hence the impact on the maternal GH/insulin-like growth factor I (IGF-I) axis, fetal growth, and maternal glycemic status. The present study was undertaken to investigate the relationship among glycemia, GHBP, and PGH during pregnancy and to assess the impact of GHBP on the concentration of free PGH. We have extended the analysis of specimens to include measurements of GHBP, PGH, IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), IGFSP-2, and IGFBP-3 and have related these to maternal characteristics, fetal growth, and glycemia. The simultaneous measurement of GHBP and PGH has for the first time allowed calculation of the free component of PGH and correlation of the free component to indexes of fetal growth and other endocrine markers. PGH, free PGH, IGF-I, and IGF-II were substantially decreased in IUGR at 28-30 weeks gestation (K28) and 36-38 weeks gestation (K36). The mean concentration (+/-SEM) of total PGH increased significantly from K28 to K36 (30.0 +/- 2.2 to 50.7 +/- 6.2 ng/mL; n = 40), as did the concentration of free PGH (23.4 +/- 2.3 to 43.7 +/- 6.0 ng/mL; n = 38). The mean percentage of free PGH was significantly less in IUGR than in normal subjects (67% vs. 79%; P < 0.01). Macrosomia was associated with an increase in these parameters that did not reach statistical significance. Multiple regression analysis revealed that PGH/IGF-I and IGFBP-5 account for 40% of the variance in birth weight. IGFBP-3 showed a significant correlation with IGF-I, IGF-II, and free and total PGK at K28 and K36. Noninsulin-dependent diabetes mellitus patients had a lower mean percentage of free PGH (65%; P < 0.01), and insulin-dependent diabetics had a higher mean percentage of free PGH (87%; P < 0.01) than normal subjects. Mean postprandial glucose at K28 correlated positively with PGH and free PGH (consistent with the hyperglycemic action of GH). GHBP correlated negatively with both postprandial and fasting glucose. Although GHBP correlated negatively with PGH (r = -0.52; P <.001), free PGH and total PGH correlated very closely (r = 0.98). The results are consistent with an inhibitory function for GHBP in vivo and support a critical role for placental GH and IGF-I in driving normal fetal growth
Adolescents' perspectives on traditional, nontraditional, and direct political activities: The role of identity-processing styles and political beliefs
The study examined whether adolescents’ tendency to employ informational, or normative identity-processing style predicts their perceived effectiveness of different political activities. Data were taken from the broader longitudinal study conducted in the Czech Republic, and included reports from 179 participants (Time 1 = age 17; Time 2 = age 19). Path analyses suggested that adolescents who sought information tended to perceive non-traditional political activity (e.g., in civic organizations) as effective, while participants’ normative conformism predicted disbelief in direct activity (e.g., petitions). Perceived effectiveness of traditional activity (e.g., voting) reflected adolescents’ actual political trust rather than their identity-processing styles. These results complement previous findings on the correlates of identity-processing styles and adolescents’ political thinking
Longevity of Oncidium varicosum (Orchidaceae) inflorescences treated with 1-methylciclopropene
Firmeza de mangas 'Palmer' tratadas com 1-metilciclopropeno e armazenadas sob refrigeração
Correlation between morphoagronomic traits and resistance to ethylene action in ornamental peppers.
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