@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}, } @article{2262, abstract = {Mosaic Analysis with Double Markers (MADM) is a method for generating genetically mosaic mice, in which sibling mutant and wild-type cells are labeled with different fluorescent markers. It is a powerful tool that enables analysis of gene function at the single cell level in vivo. It requires transgenic cassettes to be located between the centromere and the mutation in the gene of interest on the same chromosome. Here we compare procedures for introduction of MADM cassettes into new loci in the mouse genome, and describe new approaches for expanding the utility of MADM. We show that: 1) Targeted homologous recombination outperforms random transgenesis in generation of reliably expressed MADM cassettes, 2) MADM cassettes in new genomic loci need to be validated for biallelic and ubiquitous expression, 3) Recombination between MADM cassettes on different chromosomes can be used to study reciprocal chromosomal deletions/duplications, and 4) MADM can be modified to permit transgene expression by combining it with a binary expression system. The advances described in this study expand current, and enable new and more versatile applications of MADM.}, author = {Tasic, Bosiljka and Miyamichi, Kazunari and Simon Hippenmeyer and Dani, Vardhan S. and Zeng, H. and Joo, William and Zong, Hui and Chen-Tsai, Yanru and Luo, Liqun}, journal = {PLoS One}, number = {3}, publisher = {Public Library of Science}, title = {{Extensions of MADM (Mosaic Analysis with Double Markers) in Mice }}, doi = {10.1371/journal.pone.0033332}, volume = {7}, year = {2012}, } @inproceedings{2267, abstract = {Capturing real-world objects with laser-scanning technology has become an everyday task. Recently, the acquisition of dynamic scenes at interactive frame rates has become feasible. A high-quality visualization of the resulting point cloud stream would require a per-frame reconstruction of object surfaces. Unfortunately, reconstruction computations are still too time-consuming to be applied interactively. In this paper we present a local surface reconstruction and visualization technique that provides interactive feedback for reasonably sized point clouds, while achieving high image quality. Our method is performed entirely on the GPU and in screen pace, exploiting the efficiency of the common rasterization pipeline. The approach is very general, as no assumption is made about point connectivity or sampling density. This naturally allows combining the outputs of multiple scanners in a single visualization, which is useful for many virtual and augmented reality applications. }, author = {Preiner, Reinhold and Jeschke, Stefan and Wimmer, Michael}, location = {Calgari, Italy}, pages = {139 -- 148}, publisher = {Eurographics Association}, title = {{Auto splats: Dynamic point cloud visualization on the GPU}}, doi = {10.2312/EGPGV/EGPGV12/139-148}, year = {2012}, } @inproceedings{2268, abstract = {This paper presents an analytic formulation for anti-aliased sampling of 2D polygons and 3D polyhedra. Our framework allows the exact evaluation of the convolution integral with a linear function defined on the polytopes. The filter is a spherically symmetric polynomial of any order, supporting approximations to refined variants such as the Mitchell-Netravali filter family. This enables high-quality rasterization of triangles and tetrahedra with linearly interpolated vertex values to regular and non-regular grids. A closed form solution of the convolution is presented and an efficient implementation on the GPU using DirectX and CUDA C is described. }, author = {Thomas Auzinger and Guthe, Michael and Stefan Jeschke}, number = {121}, pages = {335 -- 344}, publisher = {Wiley-Blackwell}, title = {{Analytic anti-aliasing of linear functions on polytopes}}, doi = {http://dx.doi.org/10.1111/j.1467-8659.2012.03012.x}, volume = {31}, year = {2012}, } @article{2302, abstract = {We introduce propagation models (PMs), a formalism able to express several kinds of equations that describe the behavior of biochemical reaction networks. Furthermore, we introduce the propagation abstract data type (PADT), which separates concerns regarding different numerical algorithms for the transient analysis of biochemical reaction networks from concerns regarding their implementation, thus allowing for portable and efficient solutions. The state of a propagation abstract data type is given by a vector that assigns mass values to a set of nodes, and its (next) operator propagates mass values through this set of nodes. We propose an approximate implementation of the (next) operator, based on threshold abstraction, which propagates only "significant" mass values and thus achieves a compromise between efficiency and accuracy. Finally, we give three use cases for propagation models: the chemical master equation (CME), the reaction rate equation (RRE), and a hybrid method that combines these two equations. These three applications use propagation models in order to propagate probabilities and/or expected values and variances of the model's variables.}, author = {Henzinger, Thomas A and Mateescu, Maria}, journal = {IEEE ACM Transactions on Computational Biology and Bioinformatics}, number = {2}, pages = {310 -- 322}, publisher = {IEEE}, title = {{The propagation approach for computing biochemical reaction networks}}, doi = {10.1109/TCBB.2012.91}, volume = {10}, year = {2012}, } @article{2313, abstract = {The translation of "next-generation" sequencing directly to the clinic is still being assessed but has the potential for genetic diseases to reduce costs, advance accuracy, and point to unsuspected yet treatable conditions. To study its capability in the clinic, we performed whole-exome sequencing in 118 probands with a diagnosis of a pediatric-onset neurodevelopmental disease in which most known causes had been excluded. Twenty-two genes not previously identified as disease-causing were identified in this study (19% of cohort), further establishing exome sequencing as a useful tool for gene discovery. New genes identified included EXOC8 in Joubert syndrome and GFM2 in a patient with microcephaly, simplified gyral pattern, and insulin-dependent diabetes. Exome sequencing uncovered 10 probands (8% of cohort) with mutations in genes known to cause a disease different from the initial diagnosis. Upon further medical evaluation, these mutations were found to account for each proband's disease, leading to a change in diagnosis, some of which led to changes in patient management. Our data provide proof of principle that genomic strategies are useful in clarifying diagnosis in a proportion of patients with neurodevelopmental disorders.}, author = {Dixon-Salazar, Tracy J and Silhavy, Jennifer L and Udpa, Nitin and Schroth, Jana and Bielas, Stephanie L and Schaffer, Ashleigh E and Olvera, Jesus and Bafna, Vineet K and Zaki, Maha S and Abdel-Salam, Ghada M and Mansour, Lobna A and Selim, Laila A and Abdel-Hadi, Sawsan S and Marzouki, Naima and Ben-Omran, Tawfeg I and Al-Saana, Nouriya A and Sönmez, Fatma M and Celep, Figen and Azam, Matloob and Hill, Kiley J and Collazo, Adrienne and Fenstermaker, Ali G and Gaia Novarino and Akizu, Naiara and Garimella, Kiran V and Sougnez, Carrie L and Russ, Carsten and Gabriel, Stacey B and Gleeson, Joseph G}, journal = {Science Translational Medicine}, number = {138}, publisher = {American Association for the Advancement of Science}, title = {{Exome sequencing can improve diagnosis and alter patient management}}, doi = {10.1126/scitranslmed.3003544}, volume = {4}, year = {2012}, } @article{2314, abstract = {Autism spectrum disorders are a genetically heterogeneous constellation of syndromes characterized by impairments in reciprocal social interaction. Available somatic treatments have limited efficacy. We have identified inactivating mutations in the gene BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) in consanguineous families with autism, epilepsy, and intellectual disability. The encoded protein is responsible for phosphorylation-mediated inactivation of the E1α subunit of branched-chain ketoacid dehydrogenase (BCKDH). Patients with homozygous BCKDK mutations display reductions in BCKDK messenger RNA and protein, E1α phosphorylation, and plasma branched-chain amino acids. Bckdk knockout mice show abnormal brain amino acid profiles and neurobehavioral deficits that respond to dietary supplementation. Thus, autism presenting with intellectual disability and epilepsy caused by BCKDK mutations represents a potentially treatable syndrome.}, author = {Gaia Novarino and El-Fishawy, Paul and Kayserili, Hülya and Meguid, Nagwa A and Scott, Eric M and Schroth, Jana and Silhavy, Jennifer L and Kara, Majdi and Khalil, Rehab O and Ben-Omran, Tawfeg I and Ercan-Sencicek, Adife G and Hashish, Adel F and Sanders, Stephan J and Gupta, Abha R and Hashem, Hebatalla S and Matern, Dietrich and Gabriel, Stacey B and Sweetman, Lawrence and Rahimi, Yasmeen and Harris, Robert A and State, Matthew W and Gleeson, Joseph G}, journal = {Science}, number = {6105}, pages = {394 -- 397}, publisher = {American Association for the Advancement of Science}, title = {{Mutations in BCKD-kinase lead to a potentially treatable form of autism with epilepsy}}, doi = {10.1126/science.1224631}, volume = {338}, year = {2012}, } @inproceedings{2316, abstract = {We summarize our recent results on the ground state energy of multi-polaron systems. In particular, we discuss stability and existence of the thermodynamic limit, and we discuss the absence of binding in the case of large Coulomb repulsion and the corresponding binding-unbinding transition. We also consider the Pekar-Tomasevich approximation to the ground state energy and we study radial symmetry of the ground state density. }, author = {Frank, Rupert L and Lieb, Élliott H and Robert Seiringer and Thomas, Lawrence E}, pages = {477 -- 485}, publisher = {World Scientific Publishing}, title = {{Ground state properties of multi-polaron systems}}, doi = {10.1142/9789814449243_0045}, year = {2012}, }