code: def main():
      
      logging.basicConfig(level=logging.INFO)
      log.setLevel(logging.INFO)
  
      bms_base = get_bms_base()
      neurommsig_base = get_neurommsig_base()
      neurommsig_excel_dir = os.path.join(neurommsig_base, 'resources', 'excels', 'neurommsig')
  
      nift_values = get_nift_values()
  
      log.info('Starting Alzheimers')
  
      ad_path = os.path.join(neurommsig_excel_dir, 'alzheimers', 'alzheimers.xlsx')
      ad_df = preprocess(ad_path)
      with open(os.path.join(bms_base, 'aetionomy', 'alzheimers', 'neurommsigdb_ad.bel'), 'w') as ad_file:
          write_neurommsig_bel(ad_file, ad_df, mesh_alzheimer, nift_values)
  
      log.info('Starting Parkinsons')
  
      pd_path = os.path.join(neurommsig_excel_dir, 'parkinsons', 'parkinsons.xlsx')
      pd_df = preprocess(pd_path)
      with open(os.path.join(bms_base, 'aetionomy', 'parkinsons', 'neurommsigdb_pd.bel'), 'w') as pd_file:
          write_neurommsig_bel(pd_file, pd_df, mesh_parkinson, nift_values)
docs: Convert the Alzheimer's and Parkinson's disease NeuroMMSig excel sheets to BEL.