Enteric methane (CH4) from ruminants is the major driver of global warming and climate change. Successful mitigation efforts entail accurate estimation of on-farm emission and prediction models can be an alternative t...
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Enteric methane (CH4) from ruminants is the major driver of global warming and climate change. Successful mitigation efforts entail accurate estimation of on-farm emission and prediction models can be an alternative to current laborious and costly in vivo CH4 measurement techniques. This study aimed to: (1) collate a database of individual dairy cattle CH4 emission data from studies conducted in the Latin America and Caribbean (LAC) region;(2) identify key variables for predicting CH4 production (g d-1) and yield [g kg-1 of dry matter intake (DMI)];(3) develop and crossvalidate these newly-developed models;and (4) compare models' predictive ability with equations currently used to support national greenhouse gas (GHG) inventories. A total of 42 studies including 1327 individual dairy cattle records were collated. After removing outliers, the final database retained 34 studies and 610 animal records. Production and yield of CH4 were predicted by fitting mixed-effects models with a random effect of study. Evaluation of developed models and fourteen extant equations was assessed on all-data, confined, and grazing cows subsets. Feed intake was the most important predictor of CH4 production. Our best-developed CH4 production models outperformed Tier 2 equations from the Intergovernmental Panel on Climate Change (IPCC) in the all-data and grazing subsets, whereas they had similar performance for confined animals. Developed CH4 production models that include milk yield can be accurate and useful when feed intake is missing. Some extant equations had similar predictive performance to
We present inequalities concerning the entries of correlation matrices, density matrices, and partial isometries through the positivity of 3 x 3 matrices. We extend our discussions to the inequalities concerning the t...
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We present inequalities concerning the entries of correlation matrices, density matrices, and partial isometries through the positivity of 3 x 3 matrices. We extend our discussions to the inequalities concerning the triangle triplets with metric preserving and subadditive functions. (C) 2014 Elsevier Inc. All rights reserved.
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