def filter_PIBICs(lattesframe, npibics=1):
    """Returns the rows of the researchers in arg lattesframe that have
    been part of the PIBIC scholarship at least once.
    Args:
        lattesframe: the pandas dataframe to be filtered.
        npibics: the minimum quantity of PIBICs to be filtered.
    """
    if npibics <= 0:
        print('Invalid arg npibics. Reverting to default npibics == 1.')
        npibics = 1

    return lattesframe.loc[lattesframe['quantasVezesPIBIC'] >= npibics]