def capitalize_some_column_names(dataframe):
    """
    Rename columns as per Mila's preferences.

    :param dataframe: dataframe to modify
    :return: dataframe with modified column names.
    """
    if "week" in dataframe.columns:
        dataframe.rename(columns={'week':'Week'}, inplace=True)
    if "oxy" in dataframe.columns:
        dataframe.rename(columns={'oxy': '$O_2$'}, inplace=True)
    if "rep" in dataframe.columns:
        dataframe.rename(columns={'rep': 'Replicate'}, inplace=True)
    return dataframe