@inproceedings{10908, abstract = {We present ABC, a software tool for automatically computing symbolic upper bounds on the number of iterations of nested program loops. The system combines static analysis of programs with symbolic summation techniques to derive loop invariant relations between program variables. Iteration bounds are obtained from the inferred invariants, by replacing variables with bounds on their greatest values. We have successfully applied ABC to a large number of examples. The derived symbolic bounds express non-trivial polynomial relations over loop variables. We also report on results to automatically infer symbolic expressions over harmonic numbers as upper bounds on loop iteration counts.}, author = {Blanc, Régis and Henzinger, Thomas A and Hottelier, Thibaud and Kovács, Laura}, booktitle = {Logic for Programming, Artificial Intelligence, and Reasoning}, editor = {Clarke, Edmund M and Voronkov, Andrei}, isbn = {9783642175107}, issn = {1611-3349}, location = {Dakar, Senegal}, pages = {103--118}, publisher = {Springer Nature}, title = {{ABC: Algebraic Bound Computation for loops}}, doi = {10.1007/978-3-642-17511-4_7}, volume = {6355}, year = {2010}, } @inproceedings{10909, abstract = {We address the problem of localizing homology classes, namely, finding the cycle representing a given class with the most concise geometric measure. We focus on the volume measure, that is, the 1-norm of a cycle. Two main results are presented. First, we prove the problem is NP-hard to approximate within any constant factor. Second, we prove that for homology of dimension two or higher, the problem is NP-hard to approximate even when the Betti number is O(1). A side effect is the inapproximability of the problem of computing the nonbounding cycle with the smallest volume, and computing cycles representing a homology basis with the minimal total volume. We also discuss other geometric measures (diameter and radius) and show their disadvantages in homology localization. Our work is restricted to homology over the ℤ2 field.}, author = {Chen, Chao and Freedman, Daniel}, booktitle = {Proceedings of the 2010 Annual ACM-SIAM Symposium on Discrete Algorithms}, location = {Austin, TX, United States}, pages = {1594--1604}, publisher = {Society for Industrial and Applied Mathematics}, title = {{Hardness results for homology localization}}, doi = {10.1137/1.9781611973075.129}, year = {2010}, } @article{11097, abstract = {The nuclear envelope (NE) is a highly regulated membrane barrier that separates the nucleus from the cytoplasm in eukaryotic cells. It contains a large number of different proteins that have been implicated in chromatin organization and gene regulation. Although the nuclear membrane enables complex levels of gene expression, it also poses a challenge when it comes to cell division. To allow access of the mitotic spindle to chromatin, the nucleus of metazoans must completely disassemble during mitosis, generating the need to re-establish the nuclear compartment at the end of each cell division. Here, I summarize our current understanding of the dynamic remodeling of the NE during the cell cycle.}, author = {HETZER, Martin W}, issn = {1943-0264}, journal = {Cold Spring Harbor Perspectives in Biology}, keywords = {General Biochemistry, Genetics and Molecular Biology}, number = {3}, pages = {a000539--a000539}, publisher = {Cold Spring Harbor Laboratory}, title = {{The nuclear envelope}}, doi = {10.1101/cshperspect.a000539}, volume = {2}, year = {2010}, } @article{11098, author = {HETZER, Martin W}, issn = {1945-4589}, journal = {Aging}, keywords = {Cell Biology, Aging}, number = {2}, pages = {74--75}, publisher = {Impact Journals}, title = {{The role of the nuclear pore complex in aging of post-mitotic cells}}, doi = {10.18632/aging.100125}, volume = {2}, year = {2010}, } @article{11099, abstract = {Nuclear pore complexes (NPCs) serve as transport channels across the nuclear membrane, a double lipid bilayer that physically separates the nucleoplasm and cytoplasm of eukaryotic cells. New evidence suggests that the multiprotein nuclear pores also play a role in chromatin organization and gene expression. Given the importance of NPC function, it is not surprising that a growing list of human diseases and developmental defects have been linked to its malfunction. In order to fully understand the functional repertoire of NPCs and their essential role for nuclear organization, it is critical to determine the sequence of events that lead to the formation of nuclear pores. This is particularly relevant since NPC number, and possibly composition, are tightly linked to metabolic activity. Most of our knowledge is derived from NPC formation that occurs in dividing cells at the end of mitosis when the nuclear envelope (NE) and NPCs reform from disassembled precursors. However, NPC assembly also takes place during interphase into an intact NE. Importantly, this process is not restricted to dividing cells but also occurs during cell differentiation. Here, we will review aspects unique to this process, namely the regulation of nuclear expansion and the mechanisms of fusion between the outer and inner nuclear membranes. We will then discuss conserved and diverging mechanisms between post-mitotic and interphase assembly of the proteinaceous structure in light of recently published data.}, author = {Doucet, Christine M. and HETZER, Martin W}, issn = {1432-0886}, journal = {Chromosoma}, keywords = {Genetics (clinical), Genetics}, pages = {469--477}, publisher = {Springer Nature}, title = {{Nuclear pore biogenesis into an intact nuclear envelope}}, doi = {10.1007/s00412-010-0289-2}, volume = {119}, year = {2010}, } @article{11101, abstract = {In metazoa, nuclear pore complexes (NPCs) assemble from disassembled precursors into a reforming nuclear envelope (NE) at the end of mitosis and into growing intact NEs during interphase. Here, we show via RNAi-mediated knockdown that ELYS, a nucleoporin critical for the recruitment of the essential Nup107/160 complex to chromatin, is required for NPC assembly at the end of mitosis but not during interphase. Conversely, the transmembrane nucleoporin POM121 is critical for the incorporation of the Nup107/160 complex into new assembly sites specifically during interphase. Strikingly, recruitment of the Nup107/160 complex to an intact NE involves a membrane curvature-sensing domain of its constituent Nup133, which is not required for postmitotic NPC formation. Our results suggest that in organisms with open mitosis, NPCs assemble via two distinct mechanisms to accommodate cell cycle-dependent differences in NE topology.}, author = {Doucet, Christine M. and Talamas, Jessica A. and HETZER, Martin W}, issn = {0092-8674}, journal = {Cell}, keywords = {General Biochemistry, Genetics and Molecular Biology}, number = {6}, pages = {1030--1041}, publisher = {Elsevier}, title = {{Cell cycle-dependent differences in nuclear pore complex assembly in metazoa}}, doi = {10.1016/j.cell.2010.04.036}, volume = {141}, year = {2010}, } @article{11102, abstract = {Nuclear pore complexes have recently been shown to play roles in gene activation; however their potential involvement in metazoan transcription remains unclear. Here we show that the nucleoporins Sec13, Nup98, and Nup88, as well as a group of FG-repeat nucleoporins, bind to the Drosophila genome at functionally distinct loci that often do not represent nuclear envelope contact sites. Whereas Nup88 localizes to silent loci, Sec13, Nup98, and a subset of FG-repeat nucleoporins bind to developmentally regulated genes undergoing transcription induction. Strikingly, RNAi-mediated knockdown of intranuclear Sec13 and Nup98 specifically inhibits transcription of their target genes and prevents efficient reactivation of transcription after heat shock, suggesting an essential role of NPC components in regulating complex gene expression programs of multicellular organisms.}, author = {Capelson, Maya and Liang, Yun and Schulte, Roberta and Mair, William and Wagner, Ulrich and HETZER, Martin W}, issn = {0092-8674}, journal = {Cell}, keywords = {General Biochemistry, Genetics and Molecular Biology}, number = {3}, pages = {372--383}, publisher = {Elsevier}, title = {{Chromatin-bound nuclear pore components regulate gene expression in higher eukaryotes}}, doi = {10.1016/j.cell.2009.12.054}, volume = {140}, year = {2010}, } @inproceedings{11753, abstract = {Ferroelectric ceramic materials have a wide range of applications because of their piezoelectric and pyroelectric properties. One of their most important physical properties is the specific heat. In this study, the specific heats of a series of lead-zirconate-titanate (PZT) compositions in the vicinity of the morphotropic phase boundary (MPB) were measured. The temperature range was from 1.8 to 300 K. It is believed that these are the lowest temperature measurements ever made on PZT. Differences between the specific heats of the different compositions were very small. However, the calculated Debye temperatures were slightly different. The results are useful in computing design parameters for technical devices.}, author = {Lang, S. B. and Lashley, J. C. and Modic, Kimberly A and Fisher, R. A. and Zhu, W. M. and Ye, Z. G.}, booktitle = {Proceedings of the 2010 IEEE International Conference on Solid Dielectrics}, issn = {2159-1687}, location = {Potsdam, Germany}, publisher = {Institute of Electrical and Electronics Engineers}, title = {{Specific heat of a ferroelectric PZT ceramic at the morphotropic phase boundary}}, doi = {10.1109/icsd.2010.5568033}, year = {2010}, } @inproceedings{11754, abstract = {Ferroelectric ceramic materials have a wide range of applications because of their piezoelectric and pyroelectric properties. One of their most important physical properties is the specific heat. In this study, the specific heats of a series of lead-zirconate-titanate (PZT) compositions in the vicinity of the morphotropic phase boundary (MPB) were measured. The temperature range was from 1.8 to 300 K. It is believed that these are the lowest temperature measurements ever made on PZT. Differences between the specific heats of the different compositions were very small. However, the calculated Debye temperatures were slightly different. The results are useful in computing design parameters for technical devices.}, author = {Lang, S.B. and Lashley, J.C. and Modic, Kimberly A and Fisher, R.A. and Zhu, W.M. and Ye, Z.G.}, booktitle = {15th IEEE Mediterranean Electrotechnical Conference}, isbn = {978-142445795-3}, location = {Valletta, Malta}, publisher = {Institute of Electrical and Electronics Engineers}, title = {{Specific heat of a ferroelectric PZT ceramic at the morphotropic phase boundary}}, doi = {10.1109/melcon.2010.5476345}, year = {2010}, } @inproceedings{11797, abstract = {Inspired by online ad allocation, we study online stochastic packing integer programs from theoretical and practical standpoints. We first present a near-optimal online algorithm for a general class of packing integer programs which model various online resource allocation problems including online variants of routing, ad allocations, generalized assignment, and combinatorial auctions. As our main theoretical result, we prove that a simple dual training-based algorithm achieves a (1 − o(1))-approximation guarantee in the random order stochastic model. This is a significant improvement over logarithmic or constant-factor approximations for the adversarial variants of the same problems (e.g. factor 1−1𝑒 for online ad allocation, and log(m) for online routing). We then focus on the online display ad allocation problem and study the efficiency and fairness of various training-based and online allocation algorithms on data sets collected from real-life display ad allocation system. Our experimental evaluation confirms the effectiveness of training-based algorithms on real data sets, and also indicates an intrinsic trade-off between fairness and efficiency.}, author = {Feldman, Jon and Henzinger, Monika H and Korula, Nitish and Mirrokni, Vahab S. and Stein, Cliff}, booktitle = {18th Annual European Symposium on Algorithms}, isbn = {3642157742}, issn = {1611-3349}, location = {Liverpool, United Kingdom}, pages = {182–194}, publisher = {Springer Nature}, title = {{Online stochastic packing applied to display ad allocation}}, doi = {10.1007/978-3-642-15775-2_16}, volume = {6346}, year = {2010}, } @inproceedings{11798, abstract = {Starting with two models fifty years ago, the discrete marriage game [1] and the continuous assignment game [2], the study of stable matchings has evolved into a rich theory with applications in many areas. Most notably, it has lead to a number of truthful mechanisms that have seen a recent rejuvenation in the context of sponsored search. In this paper we survey the history of these problems and provide several links to ongoing research in the field.}, author = {Dütting, Paul and Henzinger, Monika H}, booktitle = {7th International Conference on Algorithms and Complexity}, isbn = {9783642130724}, issn = {1611-3349}, location = {Rome, Italy}, pages = {6–12}, publisher = {Springer Nature}, title = {{Mechanisms for the marriage and the assignment game}}, doi = {10.1007/978-3-642-13073-1_2}, volume = {6078}, year = {2010}, } @inproceedings{11838, abstract = {Two-sided matching markets play a prominent role in economic theory. A prime example of such a market is the sponsored search market where $n$ advertisers compete for the assignment of one of $k$ sponsored search results, also known as ``slots'', for certain keywords they are interested in. Here, as in other markets of that kind, market equilibria correspond to stable matchings. In this paper, we show how to modify Kuhn's Hungarian Method (Kuhn, 1955) so that it finds an optimal stable matching between advertisers and advertising slots in settings with generalized linear utilities, per-bidder-item reserve prices, and per-bidder-item maximum prices. The only algorithm for this problem presented so far (Aggarwal et al., 2009) requires the market to be in ''general position''. We do not make this assumption.}, author = {Dütting, Paul and Henzinger, Monika H and Weber, Ingmar}, booktitle = {27th International Symposium on Theoretical Aspects of Computer Science}, isbn = {978-3-939897-16-3}, issn = {1868-8969}, location = {Nancy, France}, pages = {287--298}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Sponsored search, market equilibria, and the Hungarian Method}}, doi = {10.4230/LIPICS.STACS.2010.2463}, volume = {5}, year = {2010}, } @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}, }