You can do this way...
$new_arr=array();
$arkeys = array_unique(array_map(function ($v){ return $v[0];},$arr));
foreach($arr as $k=>$arr1)
{
$new_arr[$arr1[0]][]=array_slice($arr1,0,count($arr1)-1);
}
foreach($arkeys as $v)
{
$new_arr[$v] = call_user_func_array('array_merge', $new_arr[$v]);
}
print_r($new_arr);
OUTPUT :
Array
(
[Analyst] => Array
(
[0] => 21
[1] => 3
[2] => 12
[3] => 2
[4] => 12
[5] => 2
)
[Catalysis] => Array
(
[0] => 47
[1] => 8
)
[Biomaterials] => Array
(
[0] => 1
[1] => 0
)
)