Sorting records in descending manner is possible using ottoman?

export function PaginationModel_test(columnName){
var paginationModel={
     filter:[],
    limit:10,
    skip:0,
    consistency:ottoman.Consistency.LOCAL,
    sort:columnName
};

return paginationModel; };

I have sort property,which by default sorts in a ascending way.Is it possible to sort the records in a descending manner???