Highly Multiplexed Confocal Fluorescence Lifetime Microscope Designed for Screening Applications
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
Authors: Hirmiz, Nehad; Tsikouras, Anthony; Osterlund, Elizabeth J.; Richards, Morgan; Andrews, David W.; Fang, Qiyin
Abstract
Protein-protein interactions can be measured in live cells, at nanometer scale, using Fluorescence Lifetime Imaging Microscopy (FLIM) enabled Forster Resonance Energy Transfer (FRET). There are growing interests in exploring protein-protein interactions in drug discovery applications. Traditional single point confocal microscopes, however, are slow and unsuited to small molecule screening, especially when combined with FLIM-FRET. We developed a 32 x 32 multiplexed confocal microscope, which employs a single-photon avalanche photodiode array with time gating capabilities for rapid FLIM acquisition. It has been demonstrated that such multiplexing technique can capture a 960 x 960 pixel multi-channel confocal fluorescence lifetime images in less than 1.5 seconds. Binding curves of two Bcl-2 family proteins: Bcl-XL and Bad were generated in live cells imaging experiments. The results show that the small molecule inhibitor A-1131852 is a more effective compound for disrupting Bcl-XL binding to Bad than ABT-263, which demonstrated the feasibility of screening of protein-protein interactions in high density well-plates.
Relationship between quality of facilities, animal-based welfare indicators and measures of reproductive and productive performances on dairy farms in the northwest of Spain
ITALIAN JOURNAL OF ANIMAL SCIENCE
Authors: Verdes, Sonia; Trillo, Yolanda; Pena, Ana, I; Herradon, Pedro G.; Becerra, Juan J.; Quintela, Luis A.
Abstract
The aim of the present study was to evaluate the effect of facility comfort level on animal-based welfare indicators as well as on productive and reproductive parameters of 187 dairy farms in the northwest of Spain. Fifty-eight facility-based parameters, which included both housing facilities and management parameters, were evaluated in each farm and used to classify the 187 farms in 5 groups (from 1: top farms to 5: worst farms). Animal-based welfare indicators and reproductive and productive parameters were compared among farm groups. Lameness score significantly differed (p < .005) in top farms (67% of cows having normal gait) versus groups 4 (55%) and 5 (53%). The proportion of cows with dirty lower legs and udder was lower (p < .05) in top farms (80% and 31%, respectively) than in groups 4 (92% and 51%) and 5 (95% and 56%). Other animal-based indicators were not different among farm groups. Heat detection rate was higher (p < .001) in top farms (56.5%) versus groups 4 (51%) and 5 (47%), and milk production/cow/day was also significantly higher (p < .001) in top farms (34.4 L) versus groups 3 (31.2 L), 4 (30.5 L) and 5 (27.4 L). Other reproductive or productive parameters were not different among farm groups. Facility-based measures were compared only between the top and worst farms. In top farms, most facility-based parameters met the welfare-related objectives, whereas in the worst farms only a few facility-based parameters met the welfare objectives.