Histone H1 is essential for mitotic chromosome architecture and segregation in Xenopus laevis egg extracts.

During cell division, condensation and resolution of chromosome arms and the assembly of a functional kinetochore at the centromere of each sister chromatid are essential steps for accurate segregation of the genome by the mitotic spindle, yet the contribution of individual chromatin proteins to these processes is poorly understood. We have investigated the role of embryonic linker histone H1 during mitosis in Xenopus laevis egg extracts. Immunodepletion of histone H1 caused the assembly of aberrant elongated chromosomes that extended off the metaphase plate and outside the perimeter of the spindle. Although functional kinetochores assembled, aligned, and exhibited poleward movement, long and tangled chromosome arms could not be segregated in anaphase. Histone H1 depletion did not significantly affect the recruitment of known structural or functional chromosomal components such as condensins or chromokinesins, suggesting that the loss of H1 affects chromosome architecture directly. Thus, our results indicate that linker histone H1 plays an important role in the structure and function of vertebrate chromosomes in mitosis

Two Views of the Projective Plane

The projective plane is a mathematical object which can be defined in two ways. In the following paper, I will explain the two definitions and show how they are equivalent by establishing a homeomorphism between the two objects

The condensin complex is required for proper spindle assembly and chromosome segregation in Xenopus egg extracts.

Chromosome condensation is required for the physical resolution and segregation of sister chromatids during cell division, but the precise role of higher order chromatin structure in mitotic chromosome functions is unclear. Here, we address the role of the major condensation machinery, the condensin complex, in spindle assembly and function in Xenopus laevis egg extracts. Immunodepletion of condensin inhibited microtubule growth and organization around chromosomes, reducing the percentage of sperm nuclei capable of forming spindles, and causing dramatic defects in anaphase chromosome segregation. Although the motor CENP-E was recruited to kinetochores pulled poleward during anaphase, the disorganized chromosome mass was not resolved. Inhibition of condensin function during anaphase also inhibited chromosome segregation, indicating its continuous requirement. Spindle assembly around DNA-coated beads in the absence of kinetochores was also impaired upon condensin inhibition. These results support an important role for condensin in establishing chromosomal architecture necessary for proper spindle assembly and chromosome segregation

Systems and methods for altering visual acuity

Provided are systems operable to effect a temporary change in a modulation transfer function (MTF) of a target imaging system. The systems include a light source operable to produce light for transient propagation onto at least a portion of the target imaging system, a power source in operative communication with the light source and configured to effect the production of light from the light source, and a transmission unit in operative communication with the light source and configured to propagate the produced light onto at least a portion of the target imaging system. The propagated light is configured for absorbance by the portion of the target imaging system; the absorbance causes an increase in temperature and a change in a refractive index profile of at least the portion of the imaging system. The change in refractive index profile produces a temporary change in the MTF of the imaging system.Board of Regents, University of Texas Syste

Brain Imaging Correlates of Cognitive Impairment in Depression

This review briefly summarises recent research on the neural basis of cognition in depression. Two broad areas are covered: emotional and non-emotional processing. We consider how research findings support models of depression based on disrupted cortico-limbic circuitry, and how modern connectivity analysis techniques can be used to test such models explicitly. Finally we discuss clinical implications of cognitive imaging in depression, and specifically the possible role for these techniques in diagnosis and treatment planning

High calcium chemically defined culture medium

A high calcium chemically defined animal cell culture medium including vitamins A and D and a fatty acid or its ester. The medium is particularly adapted for the primary or secondary culture of epithelial cells. However, the medium may be utilized for establishing and maintaining cell lines, in particular myelomae and hybridomae.Board of Regents, University of Texas Syste

Comparison of Sport Tourist and Local Participants’ Sponsorship and Charity Recall and Intentions

Running events have proliferated in the last decade and rely on sponsorships for income. However, more needs to be discovered about how effective these sponsorships are in encouraging purchase behavior and connecting to charity organizations. This study aims to develop a stronger understanding of running event participants and their attitudes toward sponsorships and charity organizations. Local participants were compared to sport tourists to determine if differences existed in the recall or potential use of the sponsor’s product. Also, this study used self-determination theory to determine the impact of motivation on sponsorship recall and purchase intentions. A total of 201 respondents completed a survey at a major running event. Results indicated sport participants were likely to recall sponsors with a high level of perceived fit. Additionally, participants intended to purchase products from the running shoe company. Participants also had a high level of recall for the main charity and intended to donate money. Local participants were more likely to donate time to charity and purchase sponsor products than sport event tourists. Finally, autonomously motivated participants were more likely to recall sponsors. Keywords: Sport, Sponsorship, Charit