Browsing FAS Scholarly Articles by Title
Now showing items 3033-3052 of 14421
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A Direct Comparison of Scan and Focal Sampling Methods for Measuring Wild Chimpanzee Feeding Behaviour
(Karger, 2010)Focal sampling is the most accurate method for measuring primate activity budgets, but is sometimes impractical. An alternative is scan sampling, in which the behaviour of the group is recorded at regular intervals. The ... -
Direct Estimation of Single- and Two-Qubit Hamiltonians and Relaxation Rates
(The American Physical Society, 2008)We provide an approach for characterization of quantum Hamiltonian systems via utilizing a single measurement device. Specifically, we demonstrate how external quantum correlations can be used for Hamiltonian identification ... -
Direct Gamete Sequencing Reveals No Evidence for Segregation Distortion in House Mouse Hybrids
(Public Library of Science, 2015)Understanding the molecular basis of species formation is an important goal in evolutionary genetics, and Dobzhansky-Muller incompatibilities are thought to be a common source of postzygotic reproductive isolation between ... -
Direct Graphene Growth on Insulator
(Wiley, 2011)Fabrication of graphene devices is often hindered by incompatibility between the silicon technology and the methods of graphene growth. Exfoliation from graphite yields excellent films but is good mainly for research. ... -
Direct haplotyping of kilobase-size DNA using carbon nanotube probes
(Nature Publishing Group, 2000)We have implemented a method for multiplexed detection of polymorphic sites and direct determination of haplotypes in 10-kilobase- size DNA fragments using single-walled carbon nanotube (SWNT) atomic force microscopy ... -
Direct Imaging of Atomic-Scale Ripples in Few-Layer Graphene
(American Chemical Society, 2012)Graphene has been touted as the prototypical two-dimensional solid of extraordinary stability and strength. However, its very existence relies on out-of-plane ripples as predicted by theory and confirmed by experiments. ... -
Direct Imaging of Human SWI/SNF-Remodeled Mono- and Polynucleosomes by Atomic Force Microscopy Employing Carbon Nanotube Tips
(American Society for Microbiology, 2001)Chromatin-remodeling complexes alter chromatin structure to facilitate, or in some cases repress, gene expression. Recent studies have suggested two potential pathways by which such regulation might occur. In the first, ... -
Direct Injection Tunnel Spectroscopy of a p-n Junction
(American Institute of Physics, 2009)We demonstrate spectroscopic measurements on an InGaAs p-n junction using direct tunnel injection of electrons. In contrast to the metal-base transistor design of conventional ballistic electron emission spectroscopy (BEES), ... -
Direct Interaction of FliX and FlbD is Required for Their Regulatory Activity in Caulobacter crescentus
(BioMed Central, 2011)Background: The temporal and spatial expression of late flagellar genes in Caulobacter crescentus is activated by the transcription factor FlbD and its partner trans-acting factor FliX. The physical interaction of these ... -
Direct Interfacial Y731 Oxidation in α2 by a Photoβ2 Subunit of E. Coli Class Ia Ribonucleotide Reductase
(Royal Society of Chemistry (RSC), 2015)Proton-coupled electron transfer (PCET) is a fundamental mechanism important in a wide range of biological processes including the universal reaction catalysed by ribonucleotide reductases (RNRs) in making de novo, the ... -
Direct measurement of crystal surface stress
(American Physical Society (APS), 1990)We have measured surface stresses on clean Si(111) 7×7 by comparing this surface to a reference surface on which gallium atoms are adsorbed under UHV conditions. Stresses are determined by optically measuring the macroscopic ... -
Direct measurement of local oxygen concentration in the bone marrow of live animals
(2014)Characterizing how the microenvironment, or niche, regulates stem cell activity is central to understanding stem cell biology and to developing strategies for therapeutic manipulation of stem cells1. Low oxygen tension ... -
Direct measurement of the Zak phase in topological Bloch bands
(Nature Publishing Group, 2013)Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the band theory of solids. Here we report on the measurement of the geometric phase acquired by cold atoms moving in ... -
Direct Observation of a Long-Lived Single-Atom Catalyst Chiseling Atomic Structures in Graphene
(American Chemical Society (ACS), 2014)Fabricating stable functional devices at the atomic scale is an ultimate goal of nanotechnology. In biological processes, such high-precision operations are accomplished by enzymes. A counterpart molecular catalyst that ... -
Direct Observation of a Sharp Transition to Coherence in Dense Cores
(American Astronomical Society, 2010)We present \(NH_3\) observations of the B5 region in Perseus obtained with the Green Bank Telescope. The map covers a region large enough \((\sim 11'×14')\) that it contains the entire dense core observed in previous dust ... -
Direct parsing of ID/LP grammars
(Springer, 1984)The Immediate Dominance/Linear Precedence (ID/LP) formalism is a recent extension of Generalized Phrase Structure Grammar (GPSG) designed to perform some of the tasks previously assigned to metarules--for example, modeling ... -
Direct phase-sensitive identification of a d-form factor density wave in underdoped cuprates
(Proceedings of the National Academy of Sciences, 2014)The identity of the fundamental broken symmetry (if any) in the underdoped cuprates is unresolved. However, evidence has been accumulating that this state may be an unconventional density wave. Here we carry out site-specific ... -
Direct Photon Production With Effective Field Theory
(Springer Verlag, 2010)The production of hard photons in hadronic collisions is studied using Soft-Collinear Effective Theory (SCET). This is the first application of SCET to a physical, observable cross section involving energetic partons in ... -
Direct Realism and Perceptual Consciousness.
(Wiley-Blackwell, 2006) -
Direct Reciprocity on Graphs
(Elsevier, 2007)Direct reciprocity is a mechanism for the evolution of cooperation based on the idea of repeated encounters between the same two individuals. Here we examine direct reciprocity in structured populations, where individuals ...