Journal Articles

[This Week in Science] Climate change decoupling mutualism

Science - Thu, 09/24/2015 - 23:00
Author: Sacha Vignieri
Categories: Journal Articles

[This Week in Science] Therapeutic opportunity knocks

Science - Thu, 09/24/2015 - 23:00
Author: Angela Colmone
Categories: Journal Articles

[This Week in Science] Transcriptional control of cell senescence

Science - Thu, 09/24/2015 - 23:00
Author: L. Bryan Ray
Categories: Journal Articles

[This Week in Science] A clean and green approach to amines

Science - Thu, 09/24/2015 - 23:00
Author: Jake Yeston
Categories: Journal Articles

[This Week in Science] A solution for scalable-flow batteries

Science - Thu, 09/24/2015 - 23:00
Author: Marc S. Lavine
Categories: Journal Articles

[This Week in Science] A trio helps activate C-H bonds in alcohols

Science - Thu, 09/24/2015 - 23:00
Author: Jake Yeston
Categories: Journal Articles

[This Week in Science] Extreme events under climate change

Science - Thu, 09/24/2015 - 23:00
Author: Julia Fahrenkamp-Uppenbrink
Categories: Journal Articles

[This Week in Science] Flushing the deep ocean

Science - Thu, 09/24/2015 - 23:00
Author: H. Jesse Smith
Categories: Journal Articles

[Editors' Choice] Successional specialism in forests

Science - Thu, 09/24/2015 - 23:00
Author: Andrew M. Sugden
Categories: Journal Articles

[Editors' Choice] A wild hair day for mice

Science - Thu, 09/24/2015 - 23:00
Author: Beverly A. Purnell
Categories: Journal Articles

[Editors' Choice] Traffic noise effects on birds

Science - Thu, 09/24/2015 - 23:00
Author: Julia Fahrenkamp-Uppenbrink
Categories: Journal Articles

[Editors' Choice] Uncovering site selection bias

Science - Thu, 09/24/2015 - 23:00
Author: Brad Wible
Categories: Journal Articles

[Editors' Choice] Giant virus varieties keep growing

Science - Thu, 09/24/2015 - 23:00
Author: Barbara R. Jasny
Categories: Journal Articles

[Editors' Choice] Broadening the source for hot spots

Science - Thu, 09/24/2015 - 23:00
Author: Brent Grocholski
Categories: Journal Articles

[Editors' Choice] Suspicious behavior by a harmless virus

Science - Thu, 09/24/2015 - 23:00
Author: Paula A. Kiberstis
Categories: Journal Articles

[Research Article] The DNA damage response induces inflammation and senescence by inhibiting autophagy of GATA4

Science - Thu, 09/24/2015 - 23:00
Cellular senescence is a terminal stress-activated program controlled by the p53 and p16INK4a tumor suppressor proteins. A striking feature of senescence is the senescence-associated secretory phenotype (SASP), a pro-inflammatory response linked to tumor promotion and aging. We have identified the transcription factor GATA4 as a senescence and SASP regulator. GATA4 is stabilized in cells undergoing senescence and is required for the SASP. Normally, GATA4 is degraded by p62-mediated selective autophagy, but this regulation is suppressed during senescence, thereby stabilizing GATA4. GATA4 in turn activates the transcription factor NF-κB to initiate the SASP and facilitate senescence. GATA4 activation depends on the DNA damage response regulators ATM and ATR, but not on p53 or p16INK4a. GATA4 accumulates in multiple tissues, including the aging brain, and could contribute to aging and its associated inflammation. Authors: Chanhee Kang, Qikai Xu, Timothy D. Martin, Mamie Z. Li, Marco Demaria, Liviu Aron, Tao Lu, Bruce A. Yankner, Judith Campisi, Stephen J. Elledge
Categories: Journal Articles

[Research Article] Structural origin of slow diffusion in protein folding

Science - Thu, 09/24/2015 - 23:00
Experimental, theoretical, and computational studies of small proteins suggest that interresidue contacts not present in the folded structure play little or no role in the self-assembly mechanism. Non-native contacts can, however, influence folding kinetics by introducing additional local minima that slow diffusion over the global free-energy barrier between folded and unfolded states. Here, we combine single-molecule fluorescence with all-atom molecular dynamics simulations to discover the structural origin for the slow diffusion that markedly decreases the folding rate for a designed α-helical protein. Our experimental determination of transition path times and our analysis of the simulations point to non-native salt bridges between helices as the source, which provides a quantitative glimpse of how specific intramolecular interactions influence protein folding rates by altering dynamics and not activation free energies. Authors: Hoi Sung Chung, Stefano Piana-Agostinetti, David E. Shaw, William A. Eaton
Categories: Journal Articles

[Report] Observation of chiral edge states with neutral fermions in synthetic Hall ribbons

Science - Thu, 09/24/2015 - 23:00
Chiral edge states are a hallmark of quantum Hall physics. In electronic systems, they appear as a macroscopic consequence of the cyclotron orbits induced by a magnetic field, which are naturally truncated at the physical boundary of the sample. Here we report on the experimental realization of chiral edge states in a ribbon geometry with an ultracold gas of neutral fermions subjected to an artificial gauge field. By imaging individual sites along a synthetic dimension, encoded in the nuclear spin of the atoms, we detect the existence of the edge states and observe the edge-cyclotron orbits induced during quench dynamics. The realization of fermionic chiral edge states opens the door for edge state interferometry and the study of non-Abelian anyons in atomic systems. Authors: M. Mancini, G. Pagano, G. Cappellini, L. Livi, M. Rider, J. Catani, C. Sias, P. Zoller, M. Inguscio, M. Dalmonte, L. Fallani
Categories: Journal Articles

[Report] Visualizing edge states with an atomic Bose gas in the quantum Hall regime

Science - Thu, 09/24/2015 - 23:00
Bringing ultracold atomic gases into the quantum Hall regime is challenging. We engineered an effective magnetic field in a two-dimensional lattice with an elongated-strip geometry, consisting of the sites of an optical lattice in the long direction and of three internal atomic spin states in the short direction. We imaged the localized states of atomic Bose-Einstein condensates in this strip; via excitation dynamics, we further observed both the skipping orbits of excited atoms traveling down the system’s edges, analogous to edge magnetoplasmons in two-dimensional electron systems, and a dynamical Hall effect for bulk excitations. Our technique involves minimal heating, which will be important for spectroscopic measurements of the Hofstadter butterfly and realizations of Laughlin’s charge pump. Authors: B. K. Stuhl, H.-I. Lu, L. M. Aycock, D. Genkina, I. B. Spielman
Categories: Journal Articles

[Report] Atomically thin two-dimensional organic-inorganic hybrid perovskites

Science - Thu, 09/24/2015 - 23:00
Organic-inorganic hybrid perovskites, which have proved to be promising semiconductor materials for photovoltaic applications, have been made into atomically thin two-dimensional (2D) sheets. We report the solution-phase growth of single- and few-unit-cell-thick single-crystalline 2D hybrid perovskites of (C4H9NH3)2PbBr4 with well-defined square shape and large size. In contrast to other 2D materials, the hybrid perovskite sheets exhibit an unusual structural relaxation, and this structural change leads to a band gap shift as compared to the bulk crystal. The high-quality 2D crystals exhibit efficient photoluminescence, and color tuning could be achieved by changing sheet thickness as well as composition via the synthesis of related materials. Authors: Letian Dou, Andrew B. Wong, Yi Yu, Minliang Lai, Nikolay Kornienko, Samuel W. Eaton, Anthony Fu, Connor G. Bischak, Jie Ma, Tina Ding, Naomi S. Ginsberg, Lin-Wang Wang, A. Paul Alivisatos, Peidong Yang
Categories: Journal Articles
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