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

Signatures for Black Hole production from hadronic observables at the Large Hadron Collider

The concept of Large Extra Dimensions (LED) provides a way of solving the Hierarchy Problem which concerns the weakness of gravity compared with the strong and electro-weak forces. A consequence of LED is that miniature Black Holes (mini-BHs) may be produced at the Large Hadron Collider in p+p collisions. The present work uses the CHARYBDIS mini-BH generator code to simulate the hadronic signal which might be expected in a mid-rapidity particle tracking detector from the decay of these exotic objects if indeed they are produced. An estimate is also given for Pb+Pb collisions.Comment: 11 pages, 9 figures, ISHIP 2006 conference proceedin

Mining Association Rules between Credits in the Leadership in Energy and Environmental Design for New Construction (LEED-NC) Green Building Assessment System

The Leadership in Energy and Environmental Design (LEED) Building Assessment System is a performance-based tool for determining the environmental impact of a facility from the whole-building perspective. Taking this vision into account, the individual credits that comprise LEED are designed to reward design teams for employing sustainable design strategies that reduce the total environmental impact across several sustainability issues. This study analyzed projects that have been certified in LEED for New Construction (LEED-NC) versions 2.0 and 2.1. Data on the credits achieved by the projects were mined using the Apriori algorithm which produced 641 association rules. These results were then subjectively reduced to the 24 most synergistic credit combinations and were subsequently identified as credit bundles. This study provided insight into credit interplay and its effect on high-scoring sustainable design strategies. Additionally, it shows that no one strategy is systematically employed by sustainable design professionals in the pursuit of LEED certification. This research lays the foundation for the application of data mining techniques to future LEED data sets. Finally, the revealed credit bundles support the assertion that LEED is a tool that rewards whole-building design and reinforces the perception that integrated design teams are a critical element in successful LEED project delivery