Abstract: The present invention discloses a nitrilase mutant and application thereof in catalytic synthesis of 2-chloronicotinic acid, and belongs to the technical field of enzyme engineering. The nitrilase mutant has an amino acid sequence shown in SEQ ID NO. 4, that is, 167th tryptophan W of a parent nitrilase is mutated into glycine G. According to the nitrilase mutant provided by the present invention, the hydration activity of the parent nitrilase to 2-chloronicotinonitrile is eliminated, a byproduct of 2-chloronicotinamide is not generated in the catalytic process, the nitrile hydrolysis activity is greatly improved, and 2-chloronicotinonitrile can be specifically subjected to catalytic hydrolysis to synthesize 2-chloronicotinic acid. Therefore, the nitrilase mutant has an important potential in enzymatic industrial synthesis of 2-chloronicotinic acid.

Abstract: Methods and systems for enhancing elevation models with landcover feature data are provided.

Abstract: Methods and systems for enhancing elevation models with landcover feature data are provided. An example method involves accessing imagery covering an area of interest that contains an above-ground feature, generating, a digital surface model of the area of interest, extracting three-dimensional landcover feature data representing the above-ground feature that contains one or more actual ground-level points at the base of the above-ground feature, and generating a digital terrain model from the digital surface model at least in part by removing the above-ground feature from the digital surface model and filling at least some of the removed area with one or more of the actual ground-level points from the three-dimensional landcover feature data.

Abstract: The present invention discloses a nitrilase mutant and application thereof in catalytic synthesis of 2-chloronicotinic acid, and belongs to the technical field of enzyme engineering. The nitrilase mutant has an amino acid sequence shown in SEQ ID NO.4, that is, 167th tryptophan W of a parent nitrilase is mutated into glycine G. According to the nitrilase mutant provided by the present invention, the hydration activity of the parent nitrilase to 2-chloronicotinonitrile is eliminated, a byproduct of 2-chloronicotinamide is not generated in the catalytic process, the nitrile hydrolysis activity is greatly improved, and 2-chloronicotinonitrile can be specifically subjected to catalytic hydrolysis to synthesize 2-chloronicotinic acid. Therefore, the nitrilase mutant has an important potential in enzymatic industrial synthesis of 2-chloronicotinic acid.

Abstract: Methods and systems for enhancing elevation models with landcover feature data are provided. An example method involves accessing imagery covering an area of interest that contains an above-ground feature, generating, a digital surface model of the area of interest, extracting three-dimensional landcover feature data representing the above-ground feature that contains one or more actual ground-level points at the base of the above-ground feature, and generating a digital terrain model from the digital surface model at least in part by removing the above-ground feature from the digital surface model and filling at least some of the removed area with one or more of the actual ground-level points from the three-dimensional landcover feature data.