Stress protein expression in early phase spinal cord ischemia/reperfusion injury

Spinal cord ischemia/reperfusion injury is a stress injury to the spinal cord. Our previous studies using differential proteomics identified 21 differentially expressed proteins （n 〉 2） in rabbits with spinal cord ischemia/reperfusion injury. Of these proteins, stress-related proteins included protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70. In this study, we established New Zealand rabbit models of spinal cord ischemia/reperfusion injury by abdominal aorta occlusion. Results demonstrated that hind limb function initially improved after spinal cord ischemia/reperfusion injury, but then deteriorated. The pathological morphology of the spinal cord became aggravated, but lessened 24 hours after reperfusion. However, the numbers of motor neurons and interneurons in the spinal cord gradually decreased. The expression of protein disulfide isomerase A3, stress-induced-phosphoprotein 1 and heat shock cognate protein 70 was induced by ischemia/reperfusion injury. The expression of these proteins increased within 12 hours after reperfusion, and then decreased, reached a minimum at 24 hours, but subsequently increased again to similar levels seen at 6-12 hours, showing a characterization of induction-inhibition-induc- tion. These three proteins were expressed only in cytoplasm but not in the nuclei. Moreover, the expression was higher in interneurons than in motor neurons, and the survival rate of interneurons was greater than that of motor neurons. It is assumed that the expression of stress-related proteins exhibited a protective effect on neurons.

Argobba and Amharic： Putting a Stop to a Quandary

This paper aims at producing and analyzing substantial linguistic data to point up differences between Argobba and Amharic. The paper argues against prior studies (Bender, 1976; Bender and Fulas, 1978; Zelealem, 1994; Leslau, 1997) which consider Argobba as a dialect of Amharic. There are also a few works which suggest that Argobba is an independent language of its own (Waldron, 1984; Wetter, 2006).These works, however,have not produced concrete linguistic evidence to substantiate their claim. This brings about the relation between Amharic and Argobba not to be comprehensible. This study,thus, intends to make this hazy issue to come to an end by providing comparable grammatical facts from both languages. The paper also provides counter examples which challenge the claims in Hudson (1997). The paper presents concrete linguistic facts that clearly show that Argobba and Amharic are not dialects of one another, but independent sister languages. It is strongly believed that this will finish off the problem about the relation between the two languages and brings the full picture of Argobba as an independent language in Ethio-Semitic subfamily.

Structural Implications of Universal Complementarities in Translation—High Accuracy at the Decoding Site

X-ray structures of transfer RNAs (tRNAs) bound to the whole ribosome do not fully explain the mechanism of translation. The cause of the failure seems to come mainly from a high Mg2+ ion concentration compared to that in the living cells. There exists a wide range of nucleotide sequence conservation in tRNA and ribosomal RNAs (rRNAs) of small and large subunits as well as sequence complementarities, that seems to explain how high accuracy in translation can be achieved at the decoding site. Conformational transition between U33-folded and U33-extended forms of anticodon loops of tRNAs and G-C pair formation and disruption between C1399 and G1504 of 16S rRNA, etc. play the central role in explaining why E-site tRNA can automatically be expelled when an aminoacyl-tRNA at the A site turns out to be cognate.

Relationship between coupler curve properties of a 4-bar linkage and its dimensional types

Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characteristic parameters of the coupler curve of the linkage, it was found that six types of linkages are related to the same coupler curve, and they belong to two groups of cognate mechanisms, in which the coupler curves have the same shape and are symmetric. The relationships among the dimensional types of these six mechanisms are presented. The corresponding examples have also proved these conclusions. This work enriches the cognate mechanism law, and can result in more candidate mechanisms for mechanism dimensional synthesis.