@inbook{10896, abstract = {Under physiological conditions the brain, via the purine salvage pathway, reuses the preformed purine bases hypoxanthine, derived from ATP degradation, and adenine (Ade), derived from polyamine synthesis, to restore its ATP pool. However, the massive degradation of ATP during ischemia, although providing valuable neuroprotective adenosine, results in the accumulation and loss of diffusible purine metabolites and thereby leads to a protracted reduction in the post-ischemic ATP pool size. In vivo, this may both limit the ability to deploy ATP-dependent reparative mechanisms and reduce the subsequent availability of adenosine, whilst in brain slices results in tissue with substantially lower levels of ATP than in vivo. In the present review, we describe the mechanisms by which brain tissue replenishes its ATP, how this can be improved with the clinically tolerated chemicals D-ribose and adenine, and the functional, and potential therapeutic, implications of doing so.}, author = {zur Nedden, Stephanie and Doney, Alexander S. and Frenguelli, Bruno G.}, booktitle = {Adenosine}, editor = {Masino, Susan and Boison, Detlev}, isbn = {9781461439028}, pages = {109--129}, publisher = {Springer}, title = {{The double-edged sword: Gaining Adenosine at the expense of ATP. How to balance the books}}, doi = {10.1007/978-1-4614-3903-5_6}, year = {2012}, } @inproceedings{10903, abstract = {We propose a logic-based framework for automated reasoning about sequential programs manipulating singly-linked lists and arrays with unbounded data. We introduce the logic SLAD, which allows combining shape constraints, written in a fragment of Separation Logic, with data and size constraints. We address the problem of checking the entailment between SLAD formulas, which is crucial in performing pre-post condition reasoning. Although this problem is undecidable in general for SLAD, we propose a sound and powerful procedure that is able to solve this problem for a large class of formulas, beyond the capabilities of existing techniques and tools. We prove that this procedure is complete, i.e., it is actually a decision procedure for this problem, for an important fragment of SLAD including known decidable logics. We implemented this procedure and shown its preciseness and its efficiency on a significant benchmark of formulas.}, author = {Bouajjani, Ahmed and Dragoi, Cezara and Enea, Constantin and Sighireanu, Mihaela}, booktitle = {Automated Technology for Verification and Analysis}, isbn = {9783642333859}, issn = {1611-3349}, location = {Thiruvananthapuram, India}, pages = {167--182}, publisher = {Springer}, title = {{Accurate invariant checking for programs manipulating lists and arrays with infinite data}}, doi = {10.1007/978-3-642-33386-6_14}, volume = {7561}, year = {2012}, } @article{11089, abstract = {The Nuclear Envelope (NE) contains over 100 different proteins that associate with nuclear components such as chromatin, the lamina and the transcription machinery. Mutations in genes encoding NE proteins have been shown to result in tissue-specific defects and disease, suggesting cell-type specific differences in NE composition and function. Consistent with these observations, recent studies have revealed unexpected functions for numerous NE associated proteins during cell differentiation and development. Here we review the latest insights into the roles played by the NE in cell differentiation, development, disease and aging, focusing primarily on inner nuclear membrane (INM) proteins and nuclear pore components.}, author = {Gomez-Cavazos, J Sebastian and HETZER, Martin W}, issn = {0955-0674}, journal = {Current Opinion in Cell Biology}, keywords = {Cell Biology}, number = {6}, pages = {775--783}, publisher = {Elsevier}, title = {{Outfits for different occasions: tissue-specific roles of Nuclear Envelope proteins}}, doi = {10.1016/j.ceb.2012.08.008}, volume = {24}, year = {2012}, } @article{11090, abstract = {Nuclear export of mRNAs is thought to occur exclusively through nuclear pore complexes. In this issue of Cell, Speese et al. identify an alternate pathway for mRNA export in muscle cells where ribonucleoprotein complexes involved in forming neuromuscular junctions transit the nuclear envelope by fusing with and budding through the nuclear membrane.}, author = {Hatch, Emily M. and HETZER, Martin W}, issn = {0092-8674}, journal = {Cell}, keywords = {General Biochemistry, Genetics and Molecular Biology}, number = {4}, pages = {733--735}, publisher = {Elsevier}, title = {{RNP export by nuclear envelope budding}}, doi = {10.1016/j.cell.2012.04.018}, volume = {149}, year = {2012}, } @article{11091, abstract = {Neoplastic cells are often characterized by specific morphological abnormalities of the nuclear envelope (NE), which have been used for cancer diagnosis for more than a century. The NE is a double phospholipid bilayer that encapsulates the nuclear genome, regulates all nuclear trafficking of RNAs and proteins and prevents the passive diffusion of macromolecules between the nucleoplasm and the cytoplasm. Whether there is a consequence to the proper functioning of the cell and loss of structural integrity of the nucleus remains unclear. Using live cell imaging, we characterize a phenomenon wherein nuclei of several proliferating human cancer cell lines become temporarily ruptured during interphase. Strikingly, NE rupturing was associated with the mislocalization of nucleoplasmic and cytoplasmic proteins and, in the most extreme cases, the entrapment of cytoplasmic organelles in the nuclear interior. In addition, we observed the formation of micronuclei-like structures during interphase and the movement of chromatin out of the nuclear space. The frequency of these NE rupturing events was higher in cells in which the nuclear lamina, a network of intermediate filaments providing mechanical support to the NE, was not properly formed. Our data uncover the existence of a NE instability that has the potential to change the genomic landscape of cancer cells.}, author = {Vargas, Jesse D. and Hatch, Emily M. and Anderson, Daniel J. and HETZER, Martin W}, issn = {1949-1042}, journal = {Nucleus}, keywords = {Cell Biology}, number = {1}, pages = {88--100}, publisher = {Taylor & Francis}, title = {{Transient nuclear envelope rupturing during interphase in human cancer cells}}, doi = {10.4161/nucl.18954}, volume = {3}, year = {2012}, } @article{11092, abstract = {To combat the functional decline of the proteome, cells use the process of protein turnover to replace potentially impaired polypeptides with new functional copies. We found that extremely long-lived proteins (ELLPs) did not turn over in postmitotic cells of the rat central nervous system. These ELLPs were associated with chromatin and the nuclear pore complex, the central transport channels that mediate all molecular trafficking in and out of the nucleus. The longevity of these proteins would be expected to expose them to potentially harmful metabolites, putting them at risk of accumulating damage over extended periods of time. Thus, it is possible that failure to maintain proper levels and functional integrity of ELLPs in nonproliferative cells might contribute to age-related deterioration in cell and tissue function.}, author = {Savas, Jeffrey N. and Toyama, Brandon H. and Xu, Tao and Yates, John R. and HETZER, Martin W}, issn = {1095-9203}, journal = {Science}, number = {6071}, pages = {942--942}, publisher = {American Association for the Advancement of Science}, title = {{Extremely long-lived nuclear pore proteins in the rat brain}}, doi = {10.1126/science.1217421}, volume = {335}, year = {2012}, } @article{11093, abstract = {Nuclear pore complexes (NPCs) are built from ∼30 different proteins called nucleoporins or Nups. Previous studies have shown that several Nups exhibit cell-type-specific expression and that mutations in NPC components result in tissue-specific diseases. Here we show that a specific change in NPC composition is required for both myogenic and neuronal differentiation. The transmembrane nucleoporin Nup210 is absent in proliferating myoblasts and embryonic stem cells (ESCs) but becomes expressed and incorporated into NPCs during cell differentiation. Preventing Nup210 production by RNAi blocks myogenesis and the differentiation of ESCs into neuroprogenitors. We found that the addition of Nup210 to NPCs does not affect nuclear transport but is required for the induction of genes that are essential for cell differentiation. Our results identify a single change in NPC composition as an essential step in cell differentiation and establish a role for Nup210 in gene expression regulation and cell fate determination.}, author = {D'Angelo, Maximiliano A. and Gomez-Cavazos, J. Sebastian and Mei, Arianna and Lackner, Daniel H. and HETZER, Martin W}, issn = {1534-5807}, journal = {Developmental Cell}, keywords = {Developmental Biology, Cell Biology, General Biochemistry, Genetics and Molecular Biology, Molecular Biology}, number = {2}, pages = {446--458}, publisher = {Elsevier}, title = {{A change in nuclear pore complex composition regulates cell differentiation}}, doi = {10.1016/j.devcel.2011.11.021}, volume = {22}, year = {2012}, } @article{113, abstract = {Although liquids typically flow around intruding objects, a counterintuitive phenomenon occurs in dense suspensions of micrometre-sized particles: they become liquid-like when perturbed lightly, but harden when driven strongly. Rheological experiments have investigated how such thickening arises under shear, and linked it to hydrodynamic interactions or granular dilation. However, neither of these mechanisms alone can explain the ability of suspensions to generate very large, positive normal stresses under impact. To illustrate the phenomenon, such stresses can be large enough to allow a person to run across a suspension without sinking, and far exceed the upper limit observed under shear or extension. Here we show that these stresses originate from an impact-generated solidification front that transforms an initially compressible particle matrix into a rapidly growing jammed region, ultimately leading to extraordinary amounts of momentum absorption. Using high-speed videography, embedded force sensing and X-ray imaging, we capture the detailed dynamics of this process as it decelerates a metal rod hitting a suspension of cornflour (cornstarch) in water. We develop a model for the dynamic solidification and its effect on the surrounding suspension that reproduces the observed behaviour quantitatively. Our findings suggest that prior interpretations of the impact resistance as dominated by shear thickening need to be revisited.}, author = {Waitukaitis, Scott R and Jaeger, Heinrich}, journal = {Nature}, number = {7406}, pages = {205 -- 209}, publisher = {Nature Publishing Group}, title = {{Impact-activated solidification of dense suspensions via dynamic jamming fronts}}, doi = {10.1038/nature11187}, volume = {487}, year = {2012}, } @article{114, abstract = {We report on an investigation of the solidification of a cornstarch and water suspension during normal impact on its surface. We find that a finite time after impact, the suspension displays characteristics reminiscent of a solid, including localized stress transmission, the development of a yield stress, and some elastic energy storage. The time dependence of these characteristics depends on the thickness of the cornstarch layer, showing that the solidification is a dynamic process driven by the impacting object. These findings confirm previous speculations that rapidly applied normal stress transforms the normally fluid-like suspension into a temporarily jammed solid and draw a clear distinction between the effects of normal stress and shear stress in dense suspensions.}, author = {Waitukaitis, Scott R and Jaeger, Heinrich}, journal = {Revista Cubana de Fisica}, number = {1E}, pages = {1E31 -- 1E33}, publisher = {Universidad de La Habana}, title = {{Solidification of a cornstarch and water suspension}}, volume = {29}, year = {2012}, } @inproceedings{11656, abstract = {Suppose your sole interest in recommending a product to me is to maximize the amount paid to you by the seller for a sequence of recommendations. How should you recommend optimally if I become more inclined to ignore you with each irrelevant recommendation you make? Finding an answer to this question is a key challenge in all forms of marketing that rely on and explore social ties; ranging from personal recommendations to viral marketing. We prove that even if the recommendee regains her initial trust on each successful recommendation, the expected revenue the recommender can make over an infinite period due to payments by the seller is bounded. This can only be overcome when the recommendee also incrementally regains trust during periods without any recommendation. Here, we see a connection to "banner blindness," suggesting that showing fewer ads can lead to a higher long-term revenue.}, author = {Dütting, Paul and Henzinger, Monika H and Weber, Ingmar}, booktitle = {Proceedings of the 21st ACM international conference on Information and knowledge management}, isbn = {9781450311564}, location = {Maui, HI, United States}, pages = {2268--2286}, publisher = {Association for Computing Machinery}, title = {{Maximizing revenue from strategic recommendations under decaying trust}}, doi = {10.1145/2396761.2398621}, year = {2012}, } @article{11751, abstract = {The Seebeck coefficients, electrical resistivities, total thermal conductivities, and magnetization are reported for temperatures between 5 and 350 K for n-type Bi0.88Sb0.12 nano-composite alloys made by Ho-doping at the 0, 1, and 3 % atomic levels. The alloys were prepared using a dc hot-pressing method, and are shown to be single phase for both Ho contents with grain sizes on the average of 900 nm. We find the parent compound has a maximum of ZT = 0.28 at 231 K, while doping 1 % Ho increases the maximum ZT to 0.31 at 221 K and the 3 % doped sample suppresses the maximum ZT = 0.24 at a temperature of 260 K.}, author = {Lukas, K. C. and Joshi, G. and Modic, Kimberly A and Ren, Z. F. and Opeil, C. P.}, issn = {1573-4803}, journal = {Journal of Materials Science}, number = {15}, pages = {5729--5734}, publisher = {Springer Nature}, title = {{Thermoelectric properties of Ho-doped Bi0.88Sb0.12}}, doi = {10.1007/s10853-012-6463-6}, volume = {47}, year = {2012}, } @inproceedings{11794, abstract = {We study individual rational, Pareto optimal, and incentive compatible mechanisms for auctions with heterogeneous items and budget limits. For multi-dimensional valuations we show that there can be no deterministic mechanism with these properties for divisible items. We use this to show that there can also be no randomized mechanism that achieves this for either divisible or indivisible items. For single-dimensional valuations we show that there can be no deterministic mechanism with these properties for indivisible items, but that there is a randomized mechanism that achieves this for either divisible or indivisible items. The impossibility results hold for public budgets, while the mechanism allows private budgets, which is in both cases the harder variant to show. While all positive results are polynomial-time algorithms, all negative results hold independent of complexity considerations.}, author = {Dütting, Paul and Henzinger, Monika H and Starnberger, Martin}, booktitle = {8th International Workshop on Internet and Network Economics}, isbn = {9783642353109}, issn = {1611-3349}, location = {Liverpool, United Kingdom}, pages = {44–57}, publisher = {Springer Nature}, title = {{Auctions with heterogeneous items and budget limits}}, doi = {10.1007/978-3-642-35311-6_4}, volume = {7695}, year = {2012}, } @inproceedings{11795, abstract = {We study multiple keyword sponsored search auctions with budgets. Each keyword has multiple ad slots with a click-through rate. The bidders have additive valuations, which are linear in the click-through rates, and budgets, which are restricting their overall payments. Additionally, the number of slots per keyword assigned to a bidder is bounded. We show the following results: (1) We give the first mechanism for multiple keywords, where click-through rates differ among slots. Our mechanism is incentive compatible in expectation, individually rational in expectation, and Pareto optimal. (2) We study the combinatorial setting, where each bidder is only interested in a subset of the keywords. We give an incentive compatible, individually rational, Pareto optimal, and deterministic mechanism for identical click-through rates. (3) We give an impossibility result for incentive compatible, individually rational, Pareto optimal, and deterministic mechanisms for bidders with diminishing marginal valuations.}, author = {Colini-Baldeschi, Riccardo and Henzinger, Monika H and Leonardi, Stefano and Starnberger, Martin}, booktitle = {39th International Colloquium on Automata, Languages, and Programming}, isbn = {9783642315848}, issn = {0302-9743}, location = {Warwick, United Kingdom}, pages = {1–12}, publisher = {Springer Nature}, title = {{On multiple keyword sponsored search auctions with budgets}}, doi = {10.1007/978-3-642-31585-5_1}, volume = {7392}, year = {2012}, } @article{11963, abstract = {Peroxides and ethers in flow: 2-Carbonyl-substituted phenols and β-ketoesters react safely with ethers in a microreactor environment using a copper catalyst and an organic peroxide (TBHP). This protocol results in unsymmetrical acetal scaffolds not easily available otherwise (see scheme).}, author = {Kumar, G. Sathish and Pieber, Bartholomäus and Reddy, K. Rajender and Kappe, C. Oliver}, issn = {1521-3765}, journal = {Chemistry - A European Journal}, number = {20}, pages = {6124--6128}, publisher = {Wiley}, title = {{Copper-catalyzed formation of C-O bonds by direct α-C-H bond activation of ethers using stoichiometric amounts of peroxide in batch and continuous-flow formats}}, doi = {10.1002/chem.201200815}, volume = {18}, year = {2012}, } @article{11964, abstract = {A detailed investigation on the direct arylation of benzene with aryl bromides by using first-row transition metals under high-temperature/high-pressure (high-T/p) conditions is described. By employing a parallel reactor platform for rapid reaction screening and discovery at elevated temperatures, various metal/ligand/base combinations were evaluated for their ability to enable biaryl formation through C-H activation. The combination of cobalt(III) acetylacetonate and lithium bis(trimethylsilyl)amide was subjected to further process intensification at 200 °C (15 bar), allowing a significant reduction of the catalyst/base loading and a dramatic increase in catalytic efficiency (turnover frequency) by a factor of 1000 compared to traditional protocols. The high-throughput screening additionally identified novel nickel- and copper-based metal/ligand combinations that favored an amination pathway competing with C-H activation, with the addition of ligands, such as 1,10-phenanthroline, having a profound influence on the selectivity. In addition to metal-based catalysts, high-T/p process windows were also successfully applied to transition-metal-free systems, utilizing 1,10-phenanthroline as organocatalyst.}, author = {Pieber, Bartholomäus and Cantillo, David and Kappe, C. Oliver}, issn = {1521-3765}, journal = {Chemistry – A European Journal}, number = {16}, pages = {5047--5055}, publisher = {Wiley}, title = {{Direct arylation of benzene with aryl bromides using high‐temperature/high‐pressure process windows: Expanding the scope of C-H activation chemistry}}, doi = {10.1002/chem.201103748}, volume = {18}, year = {2012}, } @article{2201, abstract = {We study the growth dynamics of ordered structures of strongly interacting polar molecules in optical lattices. Using a dipole blockade of microwave excitations, we map the system onto an interacting spin-1/2 model possessing ground states with crystalline order, and describe a way to prepare these states by nonadiabatically driving the transitions between molecular rotational levels. The proposed technique bypasses the need to cross a phase transition and allows for the creation of ordered domains of considerably larger size compared to approaches relying on adiabatic preparation.}, author = {Lemeshko, Mikhail and Krems, Roman and Weimer, Hendrik}, journal = {Physical Review Letters}, number = {3}, publisher = {American Physical Society}, title = {{Nonadiabatic preparation of spin crystals with ultracold polar molecules}}, doi = {10.1103/PhysRevLett.109.035301}, volume = {109}, year = {2012}, } @article{2202, abstract = {We propose a method for sensitive parallel detection of low-frequency electromagnetic fields based on the fine structure interactions in paramagnetic polar molecules. Compared to the recently implemented scheme employing ultracold 87Rb atoms by Böhi, the technique based on molecules offers a 100-fold higher sensitivity, the possibility to measure both the electric and magnetic field components, and a probe of a wide range of frequencies from the dc limit to the THz regime.}, author = {Alyabyshev, Sergey V and Mikhail Lemeshko and Krems, Roman V}, journal = {Physical Review A - Atomic, Molecular, and Optical Physics}, number = {1}, publisher = {American Physical Society}, title = {{Sensitive imaging of electromagnetic fields with paramagnetic polar molecules}}, doi = {10.1103/PhysRevA.86.013409}, volume = {86}, year = {2012}, } @article{22022, abstract = {We consider both the defocusing and focusing cubic nonlinear Klein–Gordon equations utt − Δu + u ± u3 =0 in two space dimensions for real-valued initial data u(0) ∈ H1/x and ut(0) ∈ L2/x. We show that in the defocusing case, solutions are global and have finite global L4/t,x spacetime bounds. In the focusing case, we characterize the dichotomy between this behaviour and blowup for initial data with energy less than that of the ground state. These results rely on analogous statements for the two-dimensional cubic nonlinear Schr¨odinger equation, which are known in the defocusing case and for spherically-symmetric initial data in the focusing case. Thus, our results are mostly unconditional. It was previously shown by Nakanishi that spacetime bounds for Klein– Gordon equations imply the same for nonlinear Schr¨odinger equations.}, author = {Killip, Rowan and Stovall, Betsy and Visan, Monica}, issn = {1088-6850}, journal = {Transactions of the American Mathematical Society}, number = {3}, pages = {1571--1631}, publisher = {American Mathematical Society}, title = {{Scattering for the cubic Klein-Gordon equation in two space dimensions}}, doi = {10.1090/s0002-9947-2011-05536-4}, volume = {364}, year = {2012}, } @article{22024, abstract = {We revisit the proof of global well-posedness and scattering for the defocusing energy-critical NLS in three space dimensions in light of recent developments. This result was obtained previously by Colliander, Keel, Staffilani, Takaoka, and Tao.}, author = {Killip, Rowan and Visan, Monica}, issn = {1948-206X}, journal = {Analysis & PDE}, keywords = {energy critical, nonlinear Schrödinger}, number = {4}, pages = {855--885}, publisher = {Mathematical Sciences Publishers}, title = {{Global well-posedness and scattering for the defocusing quintic NLS in three dimensions}}, doi = {10.2140/apde.2012.5.855}, volume = {5}, year = {2012}, } @article{2203, abstract = {We show that the electric dipole-dipole interaction between a pair of polar molecules undergoes an all-out transformation when superimposed by a far-off-resonant optical field. The combined interaction potential becomes tunable by variation of wavelength, polarisation and intensity of the optical field and its dependence on the intermolecular separation exhibits a crossover from an inverse-power to an oscillating behaviour. The ability thereby offered to control molecular interactions opens up avenues toward the creation and manipulation of novel phases of ultracold polar gases among whose characteristics is a long-range entanglement of the dipoles' mutual orientation. We devised an accurate analytic model of such optical-field-dressed dipole-dipole interaction potentials, which enables a straightforward access to the optical-field parameters required for the design of intermolecular interactions in the laboratory.}, author = {Mikhail Lemeshko and Friedrich, Břetislav}, journal = {Molecular Physics}, number = {15-16}, pages = {1873 -- 1881}, publisher = {Taylor & Francis}, title = {{Interaction between polar molecules subject to a far-off-resonant optical field: Entangled dipoles up- or down-holding each other}}, doi = {10.1080/00268976.2012.689868}, volume = {110}, year = {2012}, }