@inproceedings{11863, abstract = {Suppose you buy a new laptop and, simply because you like it so much, you recommend it to friends, encouraging them to purchase it as well. What would be an adequate price for the vendor of the laptop to pay for your recommendation? Personal recommendations like this are of considerable commercial interest, but unlike in sponsored search auctions there can be no truthful prices. Despite this "lack of truthfulness" the vendor of the product might still decide to pay you for recommendation e.g. because she wants to (i) provide you with an additional incentive to actually recommend her or to (ii) increase your satisfaction and/or brand loyalty. This leads us to investigate a pricing scheme based on the Shapley value [5] that satisfies certain "axioms of fairness". We find that it is vulnerable to manipulations and show how to overcome these difficulties using the anonymity-proof Shapley value of [4].}, author = {Dütting, Paul and Henzinger, Monika H and Weber, Ingmar}, booktitle = {Proceedings of the 19th international conference on World wide web }, isbn = {9781605587998}, location = {Raleigh, NC, United States}, pages = {1085--1086}, publisher = {Association for Computing Machinery}, title = {{How much is your personal recommendation worth?}}, doi = {10.1145/1772690.1772816}, year = {2010}, } @article{11885, abstract = {Over the last years the h-index has gained popularity as a measure for comparing the impact of scientists. We investigate if ranking according to the h-index is stable with respect to (i) different choices of citation databases, (ii) normalizing citation counts by the number of authors or by removing self-citations, (iii) small amounts of noise created by randomly removing citations or publications and (iv) small changes in the definition of the index. In experiments for 5,283 computer scientists and 1,354 physicists we show that although the ranking of the h-index is stable under most of these changes, it is unstable when different databases are used. Therefore, comparisons based on the h-index should only be trusted when the rankings of multiple citation databases agree.}, author = {Henzinger, Monika H and Suñol, Jacob and Weber, Ingmar}, issn = {1588-2861}, journal = {Scientometrics}, number = {2}, pages = {465--479}, publisher = {Springer Nature}, title = {{The stability of the h-index}}, doi = {10.1007/s11192-009-0098-7}, volume = {84}, year = {2010}, } @article{11975, abstract = {A new method was developed for the quantitative analysis of steryl glycosides in biodiesel (fatty acid methyl esters). This method is much more sensitive than existing methods and has minimum limits of quantification of 50 μg/kg, compared to previously published minimum limits of quantification of about 15 mg/kg. The analysis is based on gas chromatography–mass spectroscopy determination of simple pre-treated and silylated samples via single ion monitoring at 147, 204, 217 m/z, which are specific ions for the silylated sugar moiety. Quantification was carried out using cholesteryl β-d-glucopyranoside as internal standard. The modified synthesis and purification of the internal standard is also presented as well as the characterization by NMR and mass spectroscopy. The advantage of the method compared with other approaches is the simplified sample preparation avoiding extra pre-treatment steps coupled with complete derivatization of the sugar hydroxyl groups by using N,O-bis(trimethylsilyl)acetamide with 5% trimethylchlorosilane as derivatization reagent. On the given conditions high recovery rates ≥89% can be obtained. Evaluation of lab specific variance and intermediate precision underline the robustness of the method which will be further assessed by Round robin tests.}, author = {Pieber, Bartholomäus and Schober, Sigurd and Goebl, Christoph and Mittelbach, Martin}, issn = {0021-9673}, journal = {Journal of Chromatography A}, number = {42}, pages = {6555--6561}, publisher = {Elsevier}, title = {{Novel sensitive determination of steryl glycosides in biodiesel by gas chromatography-mass spectroscopy}}, doi = {10.1016/j.chroma.2010.08.006}, volume = {1217}, year = {2010}, } @article{22023, abstract = {We consider the focusing energy-critical nonlinear Schrödinger equation iut + ∆u = −|u| 4 d−2 u in dimensions d ≥ 5. We prove that if a maximal-lifespan solution u : I × Rd → C obeys supt∈I k∇u(t)k2 < k∇Wk2, then it is global and scatters both forward and backward in time. Here W denotes the ground state, which is a stationary solution of the equation. In particular, if a solution has both energy and kinetic energy less than those of the ground state W at some point in time, then the solution is global and scatters. We also show that any solution that blows up with bounded kinetic energy must concentrate at least the kinetic energy of the ground state. Similar results were obtained by Kenig and Merle in [17, 18] for spherically symmetric initial data and dimensions d = 3, 4, 5.}, author = {Killip, Rowan and Visan, Monica}, issn = {1080-6377}, journal = {American Journal of Mathematics}, number = {2}, pages = {361--424}, publisher = {Johns Hopkins University Press}, title = {{The focusing energy-critical nonlinear Schrödinger equation in dimensions five and higher}}, doi = {10.1353/ajm.0.0107}, volume = {132}, year = {2010}, } @inbook{2309, abstract = {The importance of chloride ions in cell physiology has not been fully recognized until recently, in spite of the fact that chloride (Cl-), together with bicarbonate, is the most abundant free anion in animal cells, and performs or determines fundamental biological functions in all tissues. For many years it was thought that Cl- was distributed in thermodynamic equilibrium across the plasma membrane of most cells. Research carried out during the last couple of decades has led to a dramatic change in this simplistic view. We now know that most animal cells, neurons included, exhibit a non-equilibrium distribution of Cl- across their plasma membranes. Over the last 10 to 15 years, with the growth of molecular biology and the advent of new optical methods, an enormous amount of exciting new information has become available on the molecular structure and function of Cl- channels and carriers. In nerve cells, Cl- channels and carriers play key functional roles in GABA- and glycine-mediated synaptic inhibition, neuronal growth and development, extracellular potassium scavenging, sensory-transduction, neurotransmitter uptake and cell volume control. Disruption of Cl- homeostasis in neurons underlies pathological conditions such as epilepsy, deafness, imbalance, brain edema and ischemia, pain and neurogenic inflammation. This book is about how chloride ions are regulated and how they cross the plasma membrane of neurons. It spans from molecular structure and function of carriers and channels involved in Cl- transport to their role in various diseases. * The first comprehensive book on the structure, molecular biology, cell physiology, and role in diseases of chloride transporters / channels in the nervous system in almost 20 years * Chloride is the most abundant free anion in animal cells. THis book summarizes and integrates for the first time the important research of the past two decades that has shown that Cl- channels and carriers play key functional roles in GABA- and glycine-mediated synaptic inhibition, neuronal growth and development, extracellular potassium scavenging, sensory-transduction, neurotransmitter uptake and cell volume control. * The first book that systematically discusses the result of disruption of Cl- homeostasis in neurons which underlies pathological conditions such as epilepsy, deafness, imbalance, brain edema and ischemia, pain and neurogenic inflammation. * Spanning topics from molecular structure and function of carriers and channels involved in Cl- transport to their role in various diseases. * Involves all of the leading researchers in the field. * INcludes an extensive introductory section that covers basic thermodynamic and kinetics aspects of Cl- transport, as well as current methods for studying Cl- regulation, spanning from fluorescent dyes in single cells to knock-out models to make the book available for a growing population of graduate students and postdocs entering the field.}, author = {Stauber, Tobias and Gaia Novarino and Jentsch, Thomas J}, booktitle = {Physiology and Pathology of chloride transporters and channels in the nervous system}, pages = {209 -- 231}, publisher = {Elsevier}, title = {{The CLC family of chloride channels and transporters}}, doi = {10.1016/B978-0-12-374373-2.00012-1}, year = {2010}, } @article{231, abstract = {Let X be a projective cubic hypersurface of dimension 11 or more, which is defined over ℚ. We show that X(ℚ) is non-empty provided that the cubic form defining X can be written as the sum of two forms that share no common variables.}, author = {Timothy Browning and Colliot-Thélène, Jean-Louis}, journal = {Compositio Mathematica}, number = {4}, pages = {853 -- 885}, publisher = {Cambridge University Press}, title = {{Rational points on cubic hypersurfaces that split off a form. With an appendix by J-L Colliot-Thélène}}, doi = {10.1112/S0010437X0900459X}, volume = {146}, year = {2010}, } @article{2310, abstract = {Loss of the endosomal anion transport protein ClC-5 impairs renal endocytosis and underlies human Dent's disease. ClC-5 is thought to promote endocytosis by facilitating endosomal acidification through the neutralization of proton pump currents. However, ClC-5 is a 2 chloride (Cl-)/proton (H+) exchanger rather than a Cl- channel. We generated mice that carry the uncoupling E211A (unc) mutation that converts CLC-5 into a pure CL- conductor. Adenosine triphosphate (ATP)-dependent acidification of renal endosomes was reduced in mice in which ClC-5 was knocked out, but normal in Clcn5unc mice. However, their proximal tubular endocytosis was also impaired. Thus, endosomal chloride concentration, which is raised by CLC-5 in exchange for protons accumulated by the H+-ATPase, may play a role in endocytosis.}, author = {Gaia Novarino and Weinert, Stefanie and Rickheit, Gesa and Jentsch, Thomas J}, journal = {Science}, number = {5984}, pages = {1398 -- 1401}, publisher = {American Association for the Advancement of Science}, title = {{Endosomal chloride-proton exchange rather than chloride conductance is crucial for renal endocytosis}}, doi = {10.1126/science.1188070}, volume = {328}, year = {2010}, } @article{2311, abstract = {Inactivation of the mainly endosomal 2Cl-/H+- exchanger ClC-5 severely impairs endocytosis in renal proximal tubules and underlies the human kidney stone disorder Dent's disease. In heterologous expression systems, interaction of the E3 ubiquitin ligasesWWP2and Nedd4-2 with a "PY-motif" in the cytoplasmic C terminus of ClC-5 stimulates its internalization from the plasma membrane and may influence receptor-mediated endocytosis. We asked whether this interaction is relevant in vivo and generated mice in which the PY-motif was destroyed by a point mutation. Unlike ClC-5 knock-out mice, these knock-in mice displayed neither low molecular weight proteinuria nor hyperphosphaturia, and both receptor-mediated and fluid-phase endocytosis were normal. The abundances and localizations of the endocytic receptor megalin and of the Na+-coupled phosphate transporter NaPi-2a (Npt2) were not changed, either. To explore whether the discrepancy in results from heterologous expression studies might be due to heteromerization of ClC-5 with ClC-3 or ClC-4 in vivo, we studied knock-in mice additionally deleted for those related transporters. Disruption of neither ClC-3 nor ClC-4 led to proteinuria or impaired proximal tubular endocytosis by itself, nor in combination with the PY-mutant of ClC-5. Endocytosis of cells lacking ClC-5 was not impaired further when ClC-3 or ClC-4 was additionally deleted. We conclude that ClC-5 is unique among CLC proteins in being crucial for proximal tubular endocytosis and that PY-motif-dependent ubiquitylation of ClC-5 is dispensable for this role.}, author = {Rickheit, Gesa and Wartosch, Lena and Schaffer, Sven and Stobrawa, Sandra M and Gaia Novarino and Weinert, Stefanie and Jentsch, Thomas J}, journal = {Journal of Biological Chemistry}, number = {23}, pages = {17595 -- 17603}, publisher = {American Society for Biochemistry and Molecular Biology}, title = {{Role of ClC-5 in renal endocytosis is unique among ClC exchangers and does not require PY-motif-dependent ubiquitylation}}, doi = {10.1074/jbc.M110.115600}, volume = {285}, year = {2010}, } @article{232, abstract = {We study the average order of the divisor function, as it ranges over the values of binary quartic forms that are reducible over ℚ.}, author = {De La Bretèche, Régis and Browning, Timothy D}, journal = {Journal fur die Reine und Angewandte Mathematik}, number = {646}, pages = {1 -- 44}, publisher = {Walter de Gruyter}, title = {{Le problème des diviseurs pour des formes binaires de degré 4}}, doi = {10.1515/CRELLE.2010.064}, year = {2010}, } @inproceedings{2322, author = {Frank, Rupert L and Lieb, Élliott H and Robert Seiringer}, pages = {523 -- 535}, publisher = {World Scientific Publishing}, title = {{ Equivalence of Sobolev inequalities and Lieb-Thirring inequalities}}, doi = {10.1142/9789814304634_0045 }, year = {2010}, } @inproceedings{2323, abstract = {Since the first experimental realization of Bose-Einstein condensation in cold atomic gases in 1995 there has been a surge of activity in this field. Ingenious experiments have allowed us to probe matter close to zero temperature and reveal some of the fascinating effects quantum mechanics has bestowed on nature. It is a challenge for mathematical physicists to understand these various phenomena from first principles, that is, starting from the underlying many-body Schrödinger equation. Recent progress in this direction concerns mainly equilibrium properties of dilute, cold quantum gases. We shall explain some of the results in this article, and describe the mathematics involved in understanding these phenomena. Topics include the ground state energy and the free energy at positive temperature, the effect of interparticle interaction on the critical temperature for Bose-Einstein condensation, as well as the occurrence of superfluidity and quantized vortices in rapidly rotating gases.}, author = {Robert Seiringer}, pages = {231 -- 245}, publisher = {World Scientific Publishing}, title = {{Hot topics on cold gases}}, doi = {10.1142/9789814304634_0013}, year = {2010}, } @inbook{2324, abstract = {We determine the sharp constant in the Hardy inequality for fractional Sobolev spaces on half-spaces. Our proof relies on a nonlinear and nonlocal version of the ground state representation.}, author = {Frank, Rupert L and Robert Seiringer}, booktitle = {Around the Research of Vladimir Maz'ya I}, pages = {161 -- 167}, publisher = {Springer}, title = {{Sharp fractional Hardy inequalities in half-spaces}}, doi = {10.1007/978-1-4419-1341-8_6}, volume = {11}, year = {2010}, } @article{2389, abstract = {We study the eigenvalues of Schrödinger type operators T + λV and their asymptotic behavior in the small coupling limit λ → 0, in the case where the symbol of the kinetic energy, T (p), strongly degenerates on a non-trivial manifold of codimension one.}, author = {Hainzl, Christian and Robert Seiringer}, journal = {Mathematische Nachrichten}, number = {3}, pages = {489 -- 499}, publisher = {Wiley-Blackwell}, title = {{Asymptotic behavior of eigenvalues of Schrödinger type operators with degenerate kinetic energy}}, doi = {10.1002/mana.200810195}, volume = {283}, year = {2010}, } @article{2392, abstract = {The binding of polarons, or its absence, is an old and subtle topic. Here we prove two things rigorously. First, the transition from many-body collapse to the existence of a thermodynamic limit for N polarons occurs precisely at U=2α, where U is the electronic Coulomb repulsion and α is the polaron coupling constant. Second, if U is large enough, there is no multipolaron binding of any kind. Considering the known fact that there is binding for some U>2α, these conclusions are not obvious and their proof has been an open problem for some time.}, author = {Frank, Rupert L and Lieb, Élliott H and Robert Seiringer and Thomas, Lawrence E}, journal = {Physical Review Letters}, number = {21}, publisher = {American Physical Society}, title = {{Bipolaron and N-polaron binding energies}}, doi = {10.1103/PhysRevLett.104.210402}, volume = {104}, year = {2010}, } @article{2409, abstract = {Background: The availability of many gene alignments with overlapping taxon sets raises the question of which strategy is the best to infer species phylogenies from multiple gene information. Methods and programs abound that use the gene alignment in different ways to reconstruct the species tree. In particular, different methods combine the original data at different points along the way from the underlying sequences to the final tree. Accordingly, they are classified into superalignment, supertree and medium-level approaches. Here, we present a simulation study to compare different methods from each of these three approaches. Results: We observe that superalignment methods usually outperform the other approaches over a wide range of parameters including sparse data and gene-specific evolutionary parameters. In the presence of high incongruency among gene trees, however, other combination methods show better performance than the superalignment approach. Surprisingly, some supertree and medium-level methods exhibit, on average, worse results than a single gene phylogeny with complete taxon information. Conclusions: For some methods, using the reconstructed gene tree as an estimation of the species tree is superior to the combination of incomplete information. Superalignment usually performs best since it is less susceptible to stochastic error. Supertree methods can outperform superalignment in the presence of gene-tree conflict.}, author = {Kupczok, Anne and Schmidt, Heiko and Von Haeseler, Arndt}, journal = {Algorithms for Molecular Biology}, number = {1}, publisher = {BioMed Central}, title = {{Accuracy of phylogeny reconstruction methods combining overlapping gene data sets}}, doi = {10.1186/1748-7188-5-37}, volume = {5}, year = {2010}, } @article{2435, abstract = {We consider a generalization of the van Kampen-Flores Theorem and relate it to the long-standing g-conjecture for simplicial spheres. }, author = {Nevo, Eran and Uli Wagner}, journal = {Israel Journal of Mathematics}, number = {1}, pages = {381 -- 402}, publisher = {Springer}, title = {{On the embeddability of skeleta of spheres}}, doi = {10.1007/s11856-009-0119-5}, volume = {174}, year = {2010}, } @article{2442, abstract = {In a new study published in this issue of Developmental Cell, Krouk et al. reveal a surprising mechanism by which plant root systems adapt their architecture for soil exploitation. The dual transporter NRT1.1 uses both nitrate and the plant hormone auxin as substrates, enabling soil nitrate availability to regulate auxin-driven lateral root development.}, author = {Beeckman, Tom and Friml, Jirí}, journal = {Developmental Cell}, number = {6}, pages = {877 -- 878}, publisher = {Cell Press}, title = {{Nitrate Contra Auxin: Nutrient Sensing by roots}}, doi = {10.1016/j.devcel.2010.05.020}, volume = {18}, year = {2010}, } @article{2503, abstract = {Epilepsy is a devastating and poorly understood disease. Mutations in a secreted neuronal protein, leucine-rich glioma inactivated 1 (LGI1), were reported in patients with an inherited form of human epilepsy, autosomal dominant partial epilepsy with auditory features (ADPEAF). Here, we report an essential role of LGI1 as an antiepileptogenic ligand. We find that loss of LGI1 in mice (LGI1-/-) causes lethal epilepsy, which is specifically rescued by the neuronal expression of LGI1 transgene, but not LGI3. Moreover, heterozygous mice for the LGI1 mutation (LGI1+/-) show lowered seizure thresholds. Extracellularly secreted LGI1 links two epilepsy-related receptors, ADAM22 and ADAM23, in the brain and organizes a transsynaptic protein complex that includes presynaptic potassium channels and postsynaptic AMPA receptor scaffolds. A lack of LGI1 disrupts this synaptic protein connection and selectively reduces AMPA receptor-mediated synaptic transmission in the hippocampus. Thus, LGI1 may serve as a major determinant of brain excitation, and the LGI1 gene-targeted mouse provides a good model for human epilepsy.}, author = {Fukata, Yuko and Lovero, Kathryn L and Iwanaga, Tsuyoshi and Watanabe, Atsushi and Yokoi, Norihiko and Tabuchi, Katsuhiko and Ryuichi Shigemoto and Nicoll, Roger A and Fukata, Masaki}, journal = {PNAS}, number = {8}, pages = {3799 -- 3804}, publisher = {National Academy of Sciences}, title = {{Disruption of LGI1-linked synaptic complex causes abnormal synaptic transmission and epilepsy}}, doi = {10.1073/pnas.0914537107}, volume = {107}, year = {2010}, } @article{2504, abstract = {We present a method for immunolabeling of multiple species of membrane proteins with high spatial resolution. It allows differentiation of equally sized very small markers with different chemical compositions, which leads to high labeling efficiency and reduces steric hindrance of closely spaced immunolabeled biomolecules. Markers such as CdSe/ZnS semiconductor quantum dots and colloidal gold particles are distinguished by differential contrast in high-angle annular detector dark-field STEM mode or by EDX microanalysis of their elemental contents. This method was tested by observation of labeled AMPA- and NMDA-type glutamate receptors on sodium-dodecyl-sulfate-digested replica prepared from rat hippocampus. To improve particle visibility and detectability, the replica films were made exclusively with carbon to avoid the high background of conventional platinum/carbon replica. Extension of the method is suggested by detection of 1.4 nm nanogold particles and its potential application in the biological imaging research.}, author = {Loukanov, Alexandre R and Kamasawa, Naomi and Danev, Radostin S and Ryuichi Shigemoto and Nagayama, Kuniaki}, journal = {Ultramicroscopy}, number = {4}, pages = {366 -- 374}, publisher = {Elsevier}, title = {{Immunolocalization of multiple membrane proteins on a carbon replica with STEM and EDX}}, doi = {10.1016/j.ultramic.2010.01.016}, volume = {110}, year = {2010}, } @article{2505, abstract = {Cbln1, secreted from cerebellar granule cells, and the orphan glutamate receptor 52 (GluD2), expressed by Purkinje cells, are essential for synapse integrity between these neurons in adult mice. Nevertheless, no endogenous binding partners for these molecules have been identified. We found that Cblnl binds directly to the N-terminal domain of GluD2. GluD2 expression by postsynaptic cells, combined with exogenously applied Cbln1, was necessary and sufficient to induce new synapses in vitro and in the adult cerebellum in vivo. Further, beads coated with recombinant Cbln1 directly induced presynaptic differentiation and indirectly caused clustering of postsynaptic molecules via GluD2. These results indicate that the Cbln1-GluD2 complex is a unique synapse organizer that acts bidirectionally on both pre- and postsynaptic components.}, author = {Matsuda, Keiko and Miura, Eriko and Miyazaki, Taisuke and Kakegawa, Wataru and Emi, Kyoichi and Narumi, Sakae and Fukazawa, Yugo and Ito-lshida, Aya and Kondo, Tetsuro and Ryuichi Shigemoto and Watanabe, Masahiko and Yuzaki, Michisuke}, journal = {Science}, number = {5976}, pages = {363 -- 368}, publisher = {American Association for the Advancement of Science}, title = {{Cbln1 is a ligand for an orphan glutamate receptor δ2, a bidirectional synapse organizer}}, doi = {10.1126/science.1185152}, volume = {328}, year = {2010}, }