71 research outputs found
Informatics and data mining tools and strategies for the Human Connectome Project
The Human Connectome Project (HCP) is a major endeavor that will acquire and analyze connectivity data plus other neuroimaging, behavioral, and genetic data from 1,200 healthy adults. It will serve as a key resource for the neuroscience research community, enabling discoveries of how the brain is wired and how it functions in different individuals. To fulfill its potential, the HCP consortium is developing an informatics platform that will handle: 1) storage of primary and processed data, 2) systematic processing and analysis of the data, 3) open access data sharing, and 4) mining and exploration of the data. This informatics platform will include two primary components. ConnectomeDB will provide database services for storing and distributing the data, as well as data analysis pipelines. Connectome Workbench will provide visualization and exploration capabilities. The platform will be based on standard data formats and provide an open set of application programming interfaces (APIs) that will facilitate broad utilization of the data and integration of HCP services into a variety of external applications. Primary and processed data generated by the HCP will be openly shared with the scientific community, and the informatics platform will be available under an open source license. This paper describes the HCP informatics platform as currently envisioned and places it into the context of the overall HCP vision and agenda
MVB-12, a Fourth Subunit of Metazoan ESCRT-I, Functions in Receptor Downregulation
After ligand binding and endocytosis, cell surface receptors can continue to signal from endosomal compartments until sequestered from the cytoplasm. An important mechanism for receptor downregulation in vivo is via the inward budding of receptors into intralumenal vesicles to form specialized endosomes called multivesicular bodies (MVBs) that subsequently fuse with lysosomes, degrading their cargo. This process requires four heterooligomeric protein complexes collectively termed the ESCRT machinery. In yeast, ESCRT-I is a heterotetrameric complex comprised of three conserved subunits and a fourth subunit for which identifiable metazoan homologs were lacking. Using C. elegans, we identify MVB-12, a fourth metazoan ESCRT-I subunit. Depletion of MVB-12 slows the kinetics of receptor downregulation in vivo, but to a lesser extent than inhibition of other ESCRT-I subunits. Consistent with these findings, targeting of MVB-12 to membranes requires the other ESCRT-I subunits, but MVB-12 is not required to target the remaining ESCRT-I components. Both endogenous and recombinant ESCRT-I are stable complexes with a 1:1:1:1 subunit stoichiometry. MVB-12 has two human homologs that co-localize and co-immunoprecipitate with the ESCRT-I component TSG101. Thus, MVB-12 is a conserved core component of metazoan ESCRT-I that regulates its activity during MVB biogenesis
Synthesis of Pyridine– and Pyrazine–BF<sub>3</sub> Complexes and Their Characterization in Solution and Solid State
Following
the discovery of the redox-active 1,4-bis-BF<sub>3</sub>-quinoxaline
complex, we undertook a structure–activity study
with the objective to understand the active nature of the quinoxaline
complex. Through systematic synthesis and characterization, we have
compared complexes prepared from pyridine and pyrazine derivatives,
as heterocyclic core analogues. This paper reports the structural
requirements that give rise to the electrochemical features of the
1,4-bis-BF<sub>3</sub>-quinoxaline adduct. Using solution and solid-state
NMR spectroscopy, the role of aromatic ring fusion and nitrogen incorporation
in bonding and electronics was elucidated. We establish the boron
atom location and its interaction with its environment from 1D and
2D solution NMR, X-ray diffraction analysis, and <sup>11</sup>B solid-state
NMR experiments. Crystallographic analysis of single crystals helped
to correlate the boron geometry with <sup>11</sup>B quadrupolar coupling
constant (<i>C</i><sub>Q</sub>) and asymmetry parameter
(η<sub>Q</sub>), extracted from <sup>11</sup>B solid-state NMR
spectra. Additionally, computations based on density functional theory
were performed to predict electrochemical behavior of the BF<sub>3</sub>–heteroaromatic complexes. We then experimentally measured
electrochemical potential using cyclic voltammetry and found that
the redox potentials and <i>C</i><sub>Q</sub> values are
similarly affected by electronic changes in the complexes
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