julia> DataFrame(CCnt=1:10,Alpha=21:30)
10x2 DataFrame:
CCnt Alpha
[1,] 1 21
[2,] 2 22
[3,] 3 23
[4,] 4 24
[5,] 5 25
[6,] 6 26
[7,] 7 27
[8,] 8 28
[9,] 9 29
[10,] 10 30

julia> samples = DataFrame(CCnt=1:10,Alpha=21:30)
10x2 DataFrame:
CCnt Alpha
[1,] 1 21
[2,] 2 22
[3,] 3 23
[4,] 4 24
[5,] 5 25
[6,] 6 26
[7,] 7 27
[8,] 8 28
[9,] 9 29
[10,] 10 30

julia> samples[:CCnt]
10-element DataArray{Int64,1}:
1
2
3
4
5
6
7
8
9
10

julia> vector(samples[:CCnt])
10-element Array{Int64,1}:
1
2
3
4
5
6
7
8
9
10