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Thierra K. Nalley Neysa Grider-Potter 《American journal of physical anthropology》2015,156(4):531-542
The vertebral column plays a key role in maintaining posture, locomotion, and transmitting loads between body components. Cervical vertebrae act as a bridge between the torso and head and play a crucial role in the maintenance of head position and the visual field. Despite its importance in positional behaviors, the functional morphology of the cervical region remains poorly understood, particularly in comparison to the thoracic and lumbar sections of the spinal column. This study tests whether morphological variation in the primate cervical vertebrae correlates with differences in postural behavior. Phylogenetic generalized least-squares analyses were performed on a taxonomically broad sample of 26 extant primate taxa to test the link between vertebral morphology and posture. Kinematic data on primate head and neck postures were used instead of behavioral categories in an effort to provide a more direct analysis of our functional hypothesis. Results provide evidence for a function-form link between cervical vertebral shape and postural behaviors. Specifically, taxa with more pronograde heads and necks and less kyphotic orbits exhibit cervical vertebrae with longer spinous processes, indicating increased mechanical advantage for deep nuchal musculature, and craniocaudally longer vertebral bodies and more coronally oriented zygapophyseal articular facets, suggesting an emphasis on curve formation and maintenance within the cervical lordosis, coupled with a greater resistance to translation and ventral displacement. These results not only document support for functional relationships in cervical vertebrae features across a wide range of primate taxa, but highlight the utility of quantitative behavioral data in functional investigations. Am J Phys Anthropol 156:531–542, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
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Luo L Parrish CA Nevins N McNulty DE Chaudhari AM Carson JD Sudakin V Shaw AN Lehr R Zhao H Sweitzer S Lad L Wood KW Sakowicz R Annan RS Huang PS Jackson JR Dhanak D Copeland RA Auger KR 《Nature chemical biology》2007,3(11):722-726
The mitotic kinesin KSP (kinesin spindle protein, or Eg5) has an essential role in centrosome separation and formation of the bipolar mitotic spindle. Its exclusive involvement in the mitotic spindle of proliferating cells presents an opportunity for developing new anticancer agents with reduced side effects relative to antimitotics that target tubulin. Ispinesib is an allosteric small-molecule KSP inhibitor in phase 2 clinical trials. Mutations that attenuate ispinesib binding to KSP have been identified, which highlights the need for inhibitors that target different binding sites. We describe a new class of selective KSP inhibitors that are active against ispinesib-resistant forms of KSP. These ATP-competitive KSP inhibitors do not bind in the nucleotide binding pocket. Cumulative data from generation of resistant cells, site-directed mutagenesis and photo-affinity labeling suggest that they compete with ATP binding via a novel allosteric mechanism. 相似文献
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Maria Neysa Silva Stort 《American journal of botany》1984,71(3):309-318
Microsporogenesis, pollen germination and fertility of males gametes were studied in 24 artificial intergeneric and interspecific F1 hybrids of orchids. Although parental species had the same chromosome number (2n = 40), microsporogenesis of the hybrids was irregular due to the lack of homology of the chromosomes of the parental species. This led to formation of tetrads of microspores without micronuclei, tetrads with 1–8 micronuclei, triads, dyads with and without micronuclei, and monads. Chromosomes numbers found in haploid microsporocytes ranged from 7 to 40; in micronuclei the chromosome number varied between 1 and 5. In terms of pollen germination, three situations were observed: 1) hybrids whose pollen grains did not germinate in the stigma; 2) hybrids in which the pollen tubes grew down in the style, but did not penetrate into the ovary; 3) hybrids in which the pollen tubes grew down normally through the ovary, reaching the ovules. When the pollen tubes did not penetrate the ovary no fruit was formed. Therefore germination tests carried out in vitro may not indicate pollen fertility, because pollen tube growth in the style of the flower may be insufficient to induce fruit formation or to accomplish fertilization. 相似文献
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Kerns JK Nie H Bondinell W Widdowson KL Yamashita DS Rahman A Podolin PL Carpenter DC Jin Q Riflade B Dong X Nevins N Keller PM Mitchell L Tomaszek T 《Bioorganic & medicinal chemistry letters》2011,21(15):4409-4415
A series of azepanone inhibitors of cathepsin S is described. Selectivity over both cathepsin K and cathepsin L was achieved by varying the P2 substituent. Ultimately, a balanced potency and selectivity profile was achieved in compound 39 possessing a 1-methylcyclohexyl alanine at P2 and nicotinamide as the P′ substituent. The cellular potency of selected analogs is also described. 相似文献
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Robert M. Chin Devin Maurer Neysa Allworth Daniel Sullivan William Brennessel 《Inorganica chimica acta》2009,362(2):389-3875
The dimerization of 6,6-dimethylfulvene with Ni(cod)2 yields the 4,4,8,8-tetramethyl-3a,4,7a,8-tetrahydro-s-indacene isomer (1a). Heating a solution of 1a converts it to the 1,4,5,8 (1b) and 1,4,7,8 (1c) tetrahydro-s-indacene isomers. The activation energy for the isomerization is 23(1) kcal/mol. 1b and 1c can be deprotonated with n-BuLi and the reaction of the dianion with [ClIr(C2H4)2]2 gives two isomers, cis-[(η5-C5H3)(CMe2)Ir(C2H4)2]2 (cis-2) and trans-[(η5-C5H3)(CMe2)Ir(C2H4)2]2 (trans-2). Reaction of 1b and 1c with RhCl3 · xH2O in refluxing methanol yields a red-orange solid, which was consistent with the empirical formula, [(C5H3)(CMe2)RhCl2]n (3). Reaction of 3 with C2H4 in a Na2CO3/ethanol mixture afforded cis-[(η5-C5H3)(CMe2)Rh(C2H4)2]2 in 5% yield. 相似文献
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