Characterization of branched monounsaturated hydrocarbons ofSarcina lutea andSarcina flava

The exact position of the double bond and the probable branch assignments of each hydrocarbon isomer ofSarcina lutea andSarcina flava were determined by derivatives and gas chromatography and combined gas chromatography-mass spectrometry. It was shown by mass spectral data that in all isomers the double bond position was in or near the center of the molecule and, that some of the resolved isomers contained an additional positional isomer. The hydrocarbons were identified as containing methyl branches in the iso or anteiso or both configurations, symmetrically and asymmetrically disposed on the ends of the isomers. The assignment of the methyl branches for each tetrad of four isomers as the isomers emerged from the gas chromatographic column was iso-iso’; anteiso-iso; anteiso-anteiso’; and isonormal for odd carbon-numbered chains, and iso-iso’; anteiso-iso; iso-normal; and anteiso-normal for even carbon-numbered chains. A fifth isomer was identified as a normal-olefin.     

Pornography-seeking behaviors following midterm political elections in the United States: A replication of the challenge hypothesis

The current study examined a prediction derived from the challenge hypothesis; individuals who viciously win a competition of rank order will seek out pornography relatively more often than individuals who viciously lose a competition. By examining Google keyword searches during the 2006 and 2010 midterm elections in the United States, the relative popularity of various pornography keyword searches was computed for each state and the District of Columbia the week after each midterm election. Consistent with previous research examining presidential elections and the challenge hypothesis, individuals located in traditionally Republican states tended to search for pornography keywords relatively more often after the 2010 midterm election (a Republican victory) than after the 2006 midterm election (a Democratic victory). Conversely, individuals located in traditionally Democratic states tended to search for pornography relatively less often following the 2010 midterm election than they did following the 2006 midterm election.     

Complex Wavelet Structural Similarity: A New Image Similarity Index

We introduce a new measure of image similarity called the complex wavelet structural similarity (CW-SSIM) index and show its applicability as a general purpose image similarity index. The key idea behind CW-SSIM is that certain image distortions lead to consistent phase changes in the local wavelet coefficients, and that a consistent phase shift of the coefficients does not change the structural content of the image. By conducting four case studies, we have demonstrated the superiority of the CW-SSIM index against other indices (e.g., Dice, Hausdorff distance) commonly used for assessing the similarity of a given pair of images. In addition, we show that the CW-SSIM index has a number of advantages. It is robust to small rotations and translations. It provides useful comparisons even without a preprocessing image registration step, which is essential for other indices. Moreover, it is computationally less expensive.     

Conformational changes of an Hsp70 molecular chaperone induced by nucleotides, polypeptides, and N-ethylmaleimide

Hsp70 molecular chaperones are highly conserved ATPases that guide the folding and assembly of proteins in many cellular pathways. They use the energy of ATP binding and hydrolysis to regulate their interactions with hydrophobic regions of unfolded proteins. The activities and the conformations of the N-terminal nucleotide- and C-terminal polypeptide-binding domains of Hsp70s are coupled. We recently reported that the sulfhydryl-modifying reagent N-ethylmaleimide (NEM) inactivates the yeast Hsp70 Ssa1p by reacting with its three cysteine residues which are located in the nucleotide-binding domain. To further characterize conformational changes associated with interdomain coupling and to determine whether NEM alters Ssa1p's conformation, the structures of Ssa1p and NEM-modified Ssa1p (NEM-Ssa1p) were compared using a variety of biophysical techniques. Size exclusion chromatography revealed that NEM-Ssa1p is more oligomeric and more resistant to nucleotide- or polypeptide-dependent depolymerization than Ssa1p. Measurement of the thermal stability indicated that NEM modification has an effect very similar to that of binding of nucleotides to the unmodified protein. Circular dichroism demonstrated small differences in the secondary structure of Ssa1p and NEM-Ssa1p, and in their complexes with nucleotides. NEM modification increased the ANS fluorescence of Ssa1p and exposed numerous trypsin-sensitive sites in its nucleotide-binding domain. The intrinsic fluorescence of Ssa1p's only tryptophan residue, which is located in a C-terminal alpha-helical region adjacent to the polypeptide-binding cleft, was quenched in the presence of ATP, but not ADP. NEM modification altered nucleotide-dependent changes in the intrinsic fluorescence of Ssa1p. Together, these results demonstrate that NEM alters the conformation of Ssa1p and disrupts, but does not eliminate, interdomain communication. Furthermore, the results provide evidence for a model in which the polypeptide-binding cleft of Hsp70s is covered by an alpha-helical lid that is open in the presence of ATP, but closed in the presence of ADP.     

A methodological note on the study of personal space.

Considers that direct comparability of results of research on the concept of personal space has been hampered by the use of diverse methodologies, and presents empirical evidence on the relationships among 4 common methodologies in the measurement of personal space. Methods of live participation, observation of live actors, felt-board placement, and judgment of photographs were compared across 36 undergraduate Ss. Interrelationships suggest that the live observation and felt-board techniques are more reflective of Ss' actual behavior than are photograph judgments. A cluster analysis performed on the data reveals 2 distinct classes of methodologies for the study of personal space. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introducing a biosensor based technology for real-time biospecific interaction analysis

The peptido-leukotriene receptor(s) (PL) on the ferret isolated spleen strip have been characterised by functional studies using the naturally occurring leukotrienes (LTs), a range of structurally distinct PL antagonists, and by ligand binding studies. LTB4 (0.01-10 microM) was inactive on ferret spleen whereas LTC4, LTD4 and LTE4 produced concentration-related contractions with maximal responses, relative to noradrenaline, of 57% (EC50 0.28 microM), 60% (EC50 0.5 microM) and 7% respectively. The leukotriene responses were unaltered by L-serine borate, L-cysteine, indomethacin, phentolamine, propranolol, mepyramine, methysergide or atropine, suggesting that the peptido-leukotrienes were acting through distinct PL receptors. The PL1 antagonists, FPL 55712 (0.01-10 microM), ICI 198615 (10 microM), SK&F 104353 (10 microM) and MK541 (10 microM) were all inactive against LTC4- or LTD4-induced contractile responses. LTE4 was a partial agonist with respect to LTC4 and LTD4 with pKB values of 5.8 and 5.5 respectively. Nifedipine (0.1 microM) produced a rightward shift of the concentration-response curves to both LTC4 and LTD4 and depressed their maximal responses. An unacceptably high level of non-specific binding of [3H]LTD4 to membrane preparations of ferret spleen prevented characterisation of this receptor by ligand binding. These results suggest that the ferret spleen has a homogeneous population of a PL receptor type which is insensitive to existing PL1 receptor antagonists. The functional characteristics of this PL receptor type are similar to those of the PL2 receptor on other tissues. The absence of PL1 receptors on this tissue makes it particularly useful in identifying new and selective drug tools for the PL2 receptor.     

Design and Characterization of Dielectric-Loaded Plasmonic Directional Couplers

Ultracompact directional couplers (DCs) based on dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs) are analyzed using the effective index method (EIM), with the coupling, both in the parallel interaction region and in- and out-coupling regions, being taken into account. Near-field characterization of fabricated DCs performed with a scanning near-field optical microscope verifies the applicability of the EIM in the analysis and design of DLSPPW-based wavelength-selective DCs. The design approach applicable to a large variety of integrated optical waveguides is developed, enabling the realization of DCs in which optical signals at two different wavelengths are coupled into two separate output channels. The developed approach ensures minimization of the crosstalk and overall DC length via simultaneous adjustment of the waveguide separation and length of the interaction region. As an example, the design of a DLSPPW-based DC for complete separation of telecommunication signals at the wavelengths lambda = 1400 nm and lambda = 1600 nm between two output channels separated by 6 mum is worked out, resulting in the total device length of 52.3 mum. In addition, the design of an ultracompact DLSPPW-based DC waveguide crossing that ensures a very low crosstalk over a large wavelength band in the telecommunication range is considered.