Bheemanahalli R.,International Rice Research Institute |
Sathishraj R.,Tamil Nadu Agricultural University |
Tack J.,Mississippi State University |
Nalley L.L.,University of Arkansas |
And 3 more authors.
Agricultural and Forest Meteorology | Year: 2016
Identifying a reliable and robust temperature threshold inducing rice spikelet sterility under field conditions involving cultivars with highly varying phenology has been a major limitation. This challenge has been a consistent bottleneck in devising a phenotyping strategy for rice breeders and to accurately estimate heat stress impacts by the climate and crop modeling communities. In an attempt to address this challenge, we used 292 diverse indica cultivars, recorded 15 min air temperature data during the key flowering period across wet season and two consecutive dry (summer) seasons. We identified 33 °C as the critical threshold beyond which large sterility increases were observed. This is the first report that demonstrates the need to consider cultivar and seasonal fixed effects in a regression model framework to derive meaningful temperature thresholds. We find that an additional growing degree hour (GDH) above 33 °C is associated with a 0.26 percentage point increase in sterility. The average and maximum exposures above this threshold in the sample data are 13.0 and 46.5 h, respectively, corresponding to a 3.4 and 12.0 percentage point increase in sterility. We simulate warming impacts between 0.5-2.0 °C increase in daily temperatures, which increases sterility between 2.9-13.1 percentage points for the dry summer season and 0.2-3.2 percentage points for the wet season. Evidence for threshold heterogeneity across different sterility classes - low, medium and high sterility cultivar groups is tested and we find limited evidence for this extension of the model. The identified threshold can be utilized by breeders to test contrasting cultivars or segregating mapping populations in an unbiased set up and for precise heat stress impact modeling exercises. Heat sensitivity analysis indicated substantial genetic variability for heat induced spikelet sterility, providing ample evidence for producer adaptation to a warming climate by developing and switching to more heat stress resilient cultivars. © 2016 Elsevier B.V.
De-la-Torre P.,University of Talca |
Treuer A.V.,University of Talca |
Gutierrez M.,University of Talca |
Poblete H.,University of Talca |
And 5 more authors.
Revista Mexicana de Urologia | Year: 2016
Alzheimer disease (AD) is a neurodegenerative disorder that causes damages in brain due to factors such as oxidative stress, low-levels of the neurotransmitter acetylcholine, β-amyloid protein aggregation, etc. It is necessary the design of novel efficient drugs for AD treatment to counteract the increase of people suffering from AD. Recently, heteroaryl-acrylonitrile derivatives have emerged as a new family of acetylcholinesterase inhibitors (AChEIs). The analysis of the structure-activity relationship of these compounds could help to elucidate the main molecular features that contribute to the activity of these compounds. In this paper, we performed 3D-QSAR analyses through a Comparative Similarity Indices Analysis (CoMSIA) to determine the key-factors for the activity of E/Z-heteroaryl-acrylonitriles reported in literature and novel derivatives that are reported in this work for the first time. The novel derivatives were synthetized in order to enlarge the library of compounds available in literature. They were synthetized via microwave-assisted Knoevenagel reaction and their biological activities as AChE/BuChE inhibitors were explored by the Ellman's spectrophotometric method. The best CoMSIA model included both electrostatic and hydrogen bond donor fields (CoMSIA-ED model) and provided the best statistical results with a highest Q2 value of 0.901. The model also had satisfactory predictions of external compounds. Our in silico study provided a new tool for predicting the affinity of heteroaryl-acrylonitriles as AChEIs to the scientific community. It can be used for guiding the design and synthesis of novel, selective, and more potent AChEIs. © 2015 Taiwan Institute of Chemical Engineers.
Bremer D.J.,Kansas StateUniversity |
Keeley S.J.,Kansas StateUniversity |
Jager A.,Kansas State University
HortTechnology | Year: 2015
Urbanization is increasing the land area covered with turfgrasses, which may affect water quantity and quality. Our objective was to understand lawnwatering habits of homeowners in Olathe and Wichita, KS, based on home value, home age, and lot size. Surveys were mailed to 9992 homeowners in Olathe and 15,534 in Wichita, with a return rate of 12%. Owners of more expensive and/or newer homes were more likely to water frequently, water on a routine schedule, feel it was important to have a green lawn, have an in-ground sprinkler system, and sweep or blow grass clippings and lawn care products off impervious surfaces. Owners of less expensive and/or older homes were more likely to never water or water infrequently, water based on the lawn’s appearance rather than on a routine schedule, consider it less important to have a green lawn; not have an in-ground sprinkler system, and leave grass clippings and lawn care products on impervious surfaces rather than blowing them off. A small percentage of homeowners who swept or blew clippings and/or lawn-care products did so into streets/storm drains. Owners of less expensive and/or older homes were somewhat more likely to engage in this practice. Educational efforts to improve lawn water conservation should be concentrated on homeowners in more expensive and/or newer homes because they water more frequently and routinely. Efforts to protect surface water quality should include homeowners of less expensive and/or older homes. © 2015, Hort Technology. All rights reserved.