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Artificial Intelligence for the Modeling and Prediction ...   291

                       respective anti-inflammatory properties by a genetic algorithm. After further study using
                       a  decision  tree  classifier,  some  11  chemical  compounds  were  determined  to  be
                       ‘biomarkers’  of  the  putative  anti-inflammatory  potential.  From  these  data,  an
                       unsupervised model to predict new biologically active extracts from Asteraceae species
                       using  HPLC-MS-MS  information  was  built  using  an  ANN  with  the  back-propagation
                       algorithm using the biomarker data resulting in a high percentage of correct predictions
                       for dual inhibition.
                          Nagahama et al. (2011) proposed the simultaneous estimation of the multiple health-
                       promoting effects of food constituents using ANNs. The model utilizes expression data of
                       intracellular marker proteins as descriptors that reply to stimulation of a constituent. To
                       estimate three health-promoting effects, namely, cancer cell growth suppression activity,
                       antiviral  activity,  and  antioxidant  stress  activity,  each  model  was  constructed  using
                       expression  data  of  marker  proteins  as  input  data  and  health-promoting  effects  as  the
                       output value.
                          Goodacre  et  al.  (1998)  used  unsupervised  methods  of  discriminant  function  and
                       hierarchical  cluster  analyses  to  group  the  spectral  fingerprints,  of  clinical  bacterial
                       isolates  associated  with  urinary  tract  infection.  ANNs  trained  with  Raman  spectra
                       correctly  identified  some  80%  of  the  same  test  set,  thus  providing  rapid  accurate
                       microbial  characterization  techniques,  but  only  when  combined  with  appropriate
                       chemometrics.
                          Zeraatpishe et al. (2011) studied the effects of Lemon balm infusions (30 days, twice
                       daily, a tea bag of 1.5 g in 100 mL water) on the oxidative stress status in radiology staff
                       exposed to persistent low-dose radiation during work. They measured lipid peroxidation,
                       DNA  damage,  catalase,  superoxide  dismutase,  myeloperoxidase,  and  glutathione
                       peroxidase activity in plasma samples. The treatment markedly improved oxidative stress
                       condition and DNA damage in radiology staff. The authors posed the question whether
                       our  approach  to  apply  ANNs  to  correlate  with  the  antioxidant  essential  oils  (Cortes-
                       Cabrera & Prieto, 2010) was to be applied to the protective activities of Lemon balm in
                       order to improve this intervention.


                                     FACTORS INFLUENCING THE ACCURACY OF

                                THE PREDICTIONS: STRATEGIES TO MINIMISE THEM

                       Internal Factors

                          Some  of  the  reported  problems  in  the  application  of  ANNs  are  caused  by  their
                       inherent  structure  and  the  most  important  are  ‘overtraining’,  ‘peaking  effect’,  and
                       ‘network paralysis’. Overtraining the ANN may lead to the noise of data used for training
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