The 45nm Intels Coret2 family of processors, codename PenrynD, improves upon the performance of Intel Core 2 processors through new microarchitecture features, a larger cache, new instructions, and enhanced powerand thermal-management schemes. This paper presents measured performance data that show the microarchitectural benefits of the Penryn family of processors on key applications and benchm...

We use liquid-phase transmission electron microscopy (LP-TEM) to characterize the structure and dynamics of a solution-phase superlattice assembled from gold nanoprisms at the single particle level. The lamellar structure of the superlattice, determined by a balance of interprism interactions, is maintained and resolved under low-dose imaging conditions typically reserved for biomolecular imagi...

During eukaryotic evolution, genome size has increased disproportionately to nuclear volume, necessitating greater degrees of chromatin compaction in higher eukaryotes, which have evolved several mechanisms for genome compaction. However, it is unknown whether histones themselves have evolved to regulate chromatin compaction. Analysis of histone sequences from 160 eukaryotes revealed that the H...

In eukaryotes, DNA is packaged into chromatin by canonical histone proteins. The specialized histone H3 variant CENP-A provides an epigenetic and structural basis for chromosome segregation by replacing H3 at centromeres. Unlike exclusively octameric canonical H3 nucleosomes, CENP-A nucleosomes have been shown to exist as octamers, hexamers, and tetramers. An intriguing possibility reconciling ...

The ability to control the size, shape, and material of a surface has reinvigorated the field of surface-enhanced Raman spectroscopy (SERS). Because excitation of the localized surface plasmon resonance of a nanostructured surface or nanoparticle lies at the heart of SERS, the ability to reliably control the surface characteristics has taken SERS from an interesting surface phenomenon to a rapi...

Within chromatin, the core histone tail domains play critical roles in regulating the structure and accessibility of nucleosomal DNA within the chromatin fiber. Thus, many nuclear processes are facilitated by concomitant posttranslational modification of these domains. However, elucidation of the mechanisms by which the tails mediate such processes awaits definition of tail interactions within ...

Directional bonding interactions in solid-state atomic lattices dictate the unique symmetries of atomic crystals, resulting in a diverse and complex assortment of three-dimensional structures that exhibit a wide variety of material properties. Methods to create analogous nanoparticle superlattices are beginning to be realized, but the concept of anisotropy is still largely underdeveloped in mos...

Electron-microscope tomography has been used to reconstruct isolated, negatively stained chromatin fibers from Necturus maculosus erythrocytes. Tilt series micrographs from +70 degrees to -70 degrees at 5 degrees intervals were obtained, allowing a reconstruction resolution of 3.3 nm for fibers lying parallel to the tilt axis. The fibers were found to be flattened in the plane of the carbon sup...

CTCF plays a central role in vertebrate insulators and forms part of the Fab-8 insulator in Drosophila. dCTCF is present at hundreds of sites in the Drosophila genome, where it is located at the boundaries between bands and interbands in polytene chromosomes. dCTCF colocalizes with CP190, which is required for proper binding of dCTCF to chromatin, but not with the other gypsy insulator proteins...

Asymmetric assembly of nanomaterials has attracted broad interests because of their unique anisotropic properties that are different from those based on the more widely reported symmetric assemblies. Despite the potential advantages, programmable fabrication of asymmetric structure in nanoscale remains a challenge. We report here a DNA-directed approach for the assembly of asymmetric nanocluste...