Tensile Strength of Malosma Laurina Leaves in Wet and Dry Conditions

Pepperdine University is one located in one of the most diverse places of the world. It is located in the Mediterranean which occupies less than 5% of the earth\u27s landmass and is only found in five areas which includes California. On the campus there are several canyons. One of the canyons is called Winter Canyon. The canyon contained a plant called Malosma laurina which is located in a riparian environment and a chaparral environment. The plant grows in both areas however, our hypothesis was that the dry plants\u27 leaves would demonstrate more plasticity. The soil humidity was also measured to compare the difference between the two and there was a significant difference. The average humidity for the wet soil was 43.5% and the dry was 22.5%. Our hypothesis was proven to be true after analyzing the results of the instron machine. The tensile strength was higher among dry leaves

Sphingosine 1-phosphate analogue recognition and selectivity at S1P(4) within the endothelial differentiation gene family of receptors

Synergistic computational and experimental studies provided previously unforeseen details concerning the structural basis of S1P (sphingosine 1-phosphate) recognition by the S1P(4) G-protein-coupled receptor. Similarly to reports on the S1P(1) receptor, cationic and anionic residues in the third transmembrane domain (R3.28 and E3.29 at positions 124 and 125) form ion pairs with the phosphate and ammonium of S1P, and alanine mutations at these positions abolished specific S1P binding, S1P-induced receptor activation and cell migration. Unlike findings on the S1P(1) receptor, no cationic residue in the seventh transmembrane domain interacts with the phosphate. Additionally, two previously undiscovered interactions with the S1P polar headgroup have been identified. Trp(186) at position 4.64 in the fourth transmembrane domain interacts by a cation-π interaction with the ammonium group of S1P. Lys(204) at position 5.38 forms an ion pair with the S1P. The S1P(4) and S1P(1) receptors show differences in binding-pocket shape and electrostatic distributions that correlate with the published structure–activity relationships. In particular, the binding pocket of mS1P(4) (mouse S1P(4)) has recognition sites for the anionic phosphate and cationic ammonium groups that are equidistant from the end of the non-polar tail. In contrast, the binding pocket of hS1P(1) (human S1P(4)) places the ammonium recognition site 2 Å (1 Å=0.1 nm) closer to the end of the non-polar tail than the phosphate recognition site