Previous studies suggest that the atmospheric precursor of E1 Nifio-Southern Oscillation （ENSO） in the extratropical Southern Hemisphere （SH） might trigger a quadrapole sea surface temperature anomaly （SSTA） in ...Previous studies suggest that the atmospheric precursor of E1 Nifio-Southern Oscillation （ENSO） in the extratropical Southern Hemisphere （SH） might trigger a quadrapole sea surface temperature anomaly （SSTA） in the South Pacific and subsequently influence the following ENSO. Such a quadrapole SSTA is referred to as the South Pacific quadrapole （SPQ）. The present study investigated the relationships between the atmospheric precursor signal of ENSO and leading modes of atmospheric variability in the extratropical SH [including the SH annular mode （SAM）, the first Pacific-South America （PSA1） mode, and the second Pacific-South America （PSA2） mode]. The results showed that the atmospheric precursor signal in the extratropical SH basically exhibits a barotropic wavenumber-3 structure over the South Pacific and is significantly correlated with the SAM and the PSA2 mode during austral summer. Nevertheless, only the PSA2 mode was found to be a precursor for the following ENSO. It leads the SPQ-like SSTA by around one month, while the SAM and the PSA1 mode do not show any obvious linkage with either ENSO or the SPQ. This suggests that the PSA2 mode may provide a bridge between the preceding circulation anomalies over the extratropical SH and the following ENSO through the SPQ-like SSTA.展开更多
For the past few decades, intensive studies have been carried out in an attempt to under- stand how the amino acid sequences of proteins encode their three dimensional structures to perform their specific functions. I...For the past few decades, intensive studies have been carried out in an attempt to under- stand how the amino acid sequences of proteins encode their three dimensional structures to perform their specific functions. In order to understand the sequence-structure relationship of proteins, sev- eral sub-sequence search studies in non-redundant sequence-structure databases have been under- taken which have given some fruitful clues. In our earlier work, we analyzed a set of 3124 non- redundant protein sequences from the Protein Data Bank （PDB） and retrieved 30 identical octapep- tides having different secondary structures. These octapeptides were characterized by using different computational procedures. This prompted us to explore the presence of octapeptides with reverse sequences and to analyze whether these octapeptides would adopt similar structures as that of their parent octapeptides. Our identical reverse octapeptide search resulted in the finding of eight octapep- tide pairs （octapeptide and reverse octapeptide） with similar secondary structure and 23 octapeptide pairs with different secondary structures. In the present work, the geometrical and biophysical char- acteristics of identical reverse octapeptides were explored and compared with unrelated octapeptide pairs by using various computational tools. We thus conclude that proteins containing identical reverse octapeptides are not very abundant and residues in the octapeptide pairs do not contribute to the stability of the protein. Furthermore, compared to unrelated octapeptides, identical reverse octapeptides do not show certain biophysical and geometrical properties.展开更多
基金jointly supported by the China Special Fund for Meteorological Research in the Public Interest(Grant No.GYHY201506013)the 973 project of China(Grant No.2012CB955200)+2 种基金the National Natural Science Foundation of China for Excellent Young Scholars(Grant No.41522502)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA11010303)the National Natural Science Foundation of China(Grant Nos.41575075,91437216 and 91637312)
文摘Previous studies suggest that the atmospheric precursor of E1 Nifio-Southern Oscillation （ENSO） in the extratropical Southern Hemisphere （SH） might trigger a quadrapole sea surface temperature anomaly （SSTA） in the South Pacific and subsequently influence the following ENSO. Such a quadrapole SSTA is referred to as the South Pacific quadrapole （SPQ）. The present study investigated the relationships between the atmospheric precursor signal of ENSO and leading modes of atmospheric variability in the extratropical SH [including the SH annular mode （SAM）, the first Pacific-South America （PSA1） mode, and the second Pacific-South America （PSA2） mode]. The results showed that the atmospheric precursor signal in the extratropical SH basically exhibits a barotropic wavenumber-3 structure over the South Pacific and is significantly correlated with the SAM and the PSA2 mode during austral summer. Nevertheless, only the PSA2 mode was found to be a precursor for the following ENSO. It leads the SPQ-like SSTA by around one month, while the SAM and the PSA1 mode do not show any obvious linkage with either ENSO or the SPQ. This suggests that the PSA2 mode may provide a bridge between the preceding circulation anomalies over the extratropical SH and the following ENSO through the SPQ-like SSTA.
基金the Council of Scientific and Industrial Research (CSIR) for the award of Senior Research Fellowship (Grant No. 09/475(0157)/2010-EMR-I)
文摘For the past few decades, intensive studies have been carried out in an attempt to under- stand how the amino acid sequences of proteins encode their three dimensional structures to perform their specific functions. In order to understand the sequence-structure relationship of proteins, sev- eral sub-sequence search studies in non-redundant sequence-structure databases have been under- taken which have given some fruitful clues. In our earlier work, we analyzed a set of 3124 non- redundant protein sequences from the Protein Data Bank （PDB） and retrieved 30 identical octapep- tides having different secondary structures. These octapeptides were characterized by using different computational procedures. This prompted us to explore the presence of octapeptides with reverse sequences and to analyze whether these octapeptides would adopt similar structures as that of their parent octapeptides. Our identical reverse octapeptide search resulted in the finding of eight octapep- tide pairs （octapeptide and reverse octapeptide） with similar secondary structure and 23 octapeptide pairs with different secondary structures. In the present work, the geometrical and biophysical char- acteristics of identical reverse octapeptides were explored and compared with unrelated octapeptide pairs by using various computational tools. We thus conclude that proteins containing identical reverse octapeptides are not very abundant and residues in the octapeptide pairs do not contribute to the stability of the protein. Furthermore, compared to unrelated octapeptides, identical reverse octapeptides do not show certain biophysical and geometrical properties.
