@article{889, abstract = {The function of protein and RNA molecules depends on complex epistatic interactions between sites. Therefore, the deleterious effect of a mutation can be suppressed by a compensatory second-site substitution. In relating a list of 86 pathogenic mutations in human IRNAs encoded by mitochondrial genes to the sequences of their mammalian orthologs, we noted that 52 pathogenic mutations were present in normal tRNAs of one or several nonhuman mammals. We found at least five mechanisms of compensation for 32 pathogenic mutations that destroyed a Watson-Crick pair in one of the four tRNA stems: restoration of the affected Watson-Crick interaction (25 cases), strengthening of another pair (4 cases), creation of a new pair (8 cases), changes of multiple interactions in the affected stem (11 cases) and changes involving the interaction between the loop and stem structures (3 cases). A pathogenic mutation and its compensating substitution are fixed in a lineage in rapid succession, and often a compensatory interaction evolves convergently in different clades. At least 10%, and perhaps as many as 50%, of all nucleotide substitutions in evolving mammalian (RNAs participate in such interactions, indicating that the evolution of tRNAs proceeds along highly epistatic fitness ridges.}, author = {Kern, Andrew D and Fyodor Kondrashov}, journal = {Nature Genetics}, number = {11}, pages = {1207 -- 1212}, publisher = {Nature Publishing Group}, title = {{Mechanisms and convergence of compensatory evolution in mammalian mitochondrial tRNAs}}, doi = {10.1038/ng1451}, volume = {36}, year = {2004}, } @article{898, abstract = {New alleles become fixed owing to random drift of nearly neutral mutations or to positive selection of substantially advantageous mutations. After decades of debate, the fraction of fixations driven by selection remains uncertain. Within 9,390 genes, we analysed 28,196 codons at which rat and mouse differ from each other at two nucleotide sites and 1,982 codons with three differences. At codons where rat-mouse divergence involved two non-synonymous substitutions, both of them occurred in the same lineage, either rat or mouse, in 64% of cases; however, independent substitutions would occur in the same lineage with a probability of only 50%. All three non-synonymous substitutions occurred in the same lineage for 46% of codons, instead of the 25% expected. Furthermore, comparison of 12 pairs of prokaryotic genomes also shows clumping of multiple non-synonymous substitutions in the same lineage. This pattern cannot be explained by correlated mutation or episodes of relaxed negative selection, but instead indicates that positive selection acts at many sites of rapid, successive amino acid replacement.}, author = {Bazykin, Georgii A and Fyodor Kondrashov and Ogurtsov, Aleksey Yu and Sunyaev, Shamil R and Kondrashov, Alexey S}, journal = {Nature}, number = {6991}, pages = {558 -- 562}, publisher = {Nature Publishing Group}, title = {{Positive selection at sites of multiple amino acid replacements since rat-mouse divergence}}, doi = {10.1038/nature02601}, volume = {429}, year = {2004}, } @article{1963, abstract = {The mechanism coupling electron transfer and proton pumping in respiratory complex I (NADH-ubiquinone oxidoreductase) has not been established, but it has been suggested that it involves conformational changes. Here, the influence of substrates on the conformation of purified complex I from Escherichia coli was studied by cross-linking and electron microscopy. When a zero-length cross-linking reagent was used, the presence of NAD(P)H, in contrast to that of NAD+, prevented the formation of cross-links between the hydrophilic subunits of the complex, including NuoB, NuoI, and NuoCD. Comparisons using different cross-linkers suggested that NuoB, which is likely to coordinate the key iron-sulfur cluster N2, is the most mobile subunit. The presence of NAD(P)H led also to enhanced proteolysis of subunit NuoG. These data indicate that upon NAD(P)H binding, the peripheral arm of the complex adopts a more open conformation, with increased distances between subunits. Single particle analysis showed the nature of this conformational change. The enzyme retains its L-shape in the presence of NADH, but exhibits a significantly more open or expanded structure both in the peripheral arm and, unexpectedly, in the membrane domain also.}, author = {Mamedova, Aygun A and Holt, Peter J and Carroll, Joe D and Leonid Sazanov}, journal = {Journal of Biological Chemistry}, number = {22}, pages = {23830 -- 23836}, publisher = {American Society for Biochemistry and Molecular Biology}, title = {{Substrate-induced conformational change in bacterial complex I}}, doi = {10.1074/jbc.M401539200}, volume = {279}, year = {2004}, } @article{209, author = {Timothy Browning and Heath-Brown, Roger}, journal = {Inventiones Mathematicae}, number = {3}, pages = {553 -- 573}, publisher = {Unknown}, title = {{Equal sums of three powers}}, doi = {10.1007/s00222-004-0360-9}, volume = {157}, year = {2004}, } @article{2308, abstract = {It is widely believed that the inflammatory events mediated by microglial activation contribute to several neurodegenerative processes. Alzheimer's disease, for example, is characterized by an accumulation of β-amyloid protein (Aβ) in neuritic plaques that are infiltrated by reactive microglia and astrocytes. Although Aβ and its fragment 25-35 exert a direct toxic effect on neurons, they also activate microglia. Microglial activation is accompanied by morphological changes, cell proliferation, and release of various cytokines and growth factors. A number of scientific reports suggest that the increased proliferation of microglial cells is dependent on ionic membrane currents and in particular on chloride conductances. An unusual chloride ion channel known to be associated with macrophage activation is the chloride intracellular channel-1 (CLIC1). Here we show that Aβ stimulation of neonatal rat microglia specifically leads to the increase in CLIC1 protein and to the functional expression of CLIC1 chloride conductance, both barely detectable on the plasma membrane of quiescent cells. CLIC1 protein expression in microglia increases after 24 hr of incubation with Aβ, simultaneously with the production of reactive nitrogen intermediates and of tumor necrosis factor-α (TNF-α). We demonstrate that reducing CLIC1 chloride conductance by a specific blocker [IAA-94 (R(+)-[(6,7-dichloro-2-cyclopentyl-2,3-dihydro-2-methyl-1-oxo-1H-inden-5yl)-oxy] acetic acid)] prevents neuronal apoptosis in neurons cocultured with Aβ-treated microglia. Furthermore, we show that small interfering RNAs used to knock down CLIC1 expression prevent TNF-α release induced by Aβ stimulation. These results provide a direct link between Aβ-induced microglial activation and CLIC1 functional expression.}, author = {Gaia Novarino and Fabrizi, Cinzia and Tonini, Raffaella and Denti, Michela A and Malchiodi, Albedi F and Lauro, Giuliana M and Sacchetti, Benedetto and Paradisi, Silvia and Ferroni, Arnaldo and Curmi, Paul M G and Breit, Samuel N and Mazzanti, Michele}, journal = {Journal of Neuroscience}, number = {23}, pages = {5322 -- 5330}, publisher = {Society for Neuroscience}, title = {{Involvement of the intracellular ion channel CLIC1 in microglia-mediated β-amyloid-induced neurotoxicity}}, doi = {10.1523/JNEUROSCI.1170-04.2004}, volume = {24}, year = {2004}, } @article{2355, abstract = {The BMV conjecture for traces, which states that Tr exp(A - λB) is the Laplace transform of a positive measure, is shown to be equivalent to two other statements: (i) The polynomial λ → Tr(A + λB) p has only non-negative coefficients for all A, B ≥ 0, p ∈ ℕ and (ii) λ → Tr(A + λB)-p is the Laplace transform of a positive measure for A, B ≥ 0, p > 0.}, author = {Lieb, Élliott H and Robert Seiringer}, journal = {Journal of Statistical Physics}, number = {1-2}, pages = {185 -- 190}, publisher = {Springer}, title = {{ Equivalent forms of the Bessis-Moussa-Villani conjecture}}, doi = {10.1023/B:JOSS.0000019811.15510.27}, volume = {115}, year = {2004}, } @article{2356, abstract = {Recent experimental and theoretical work has shown that there are conditions in which a trapped, low-density Bose gas behaves like the one-dimensional delta-function Bose gas solved years ago by Lieb and Liniger. This is an intrinsically quantum-mechanical phenomenon because it is not necessary to have a trap width that is the size of an atom - as might have been supposed - but it suffices merely to have a trap width such that the energy gap for motion in the transverse direction is large compared to the energy associated with the motion along the trap. Up to now the theoretical arguments have been based on variational - perturbative ideas or numerical investigations. In contrast, this paper gives a rigorous proof of the one-dimensional behavior as far as the ground state energy and particle density are concerned. There are four parameters involved: the particle number, N, transverse and longitudinal dimensions of the trap, r and L, and the scattering length a of the interaction potential. Our main result is that if r/L → 0 and N → ∞ the ground state energy and density can be obtained by minimizing a one-dimensional density functional involving the Lieb-Liniger energy density with coupling constant ∼ a/r 2. This density functional simplifies in various limiting cases and we identify five asymptotic parameter regions altogether. Three of these, corresponding to the weak coupling regime, can also be obtained as limits of a three-dimensional Gross-Pitaevskii theory. We also show that Bose-Einstein condensation in the ground state persists in a part of this regime. In the strong coupling regime the longitudinal motion of the particles is strongly correlated. The Gross-Pitaevskii description is not valid in this regime and new mathematical methods come into play.}, author = {Lieb, Élliott H and Robert Seiringer and Yngvason, Jakob}, journal = {Communications in Mathematical Physics}, number = {2}, pages = {347 -- 393}, publisher = {Springer}, title = {{One-dimensional behavior of dilute, trapped Bose gases}}, doi = {10.1007/s00220-003-0993-3}, volume = {244}, year = {2004}, } @article{2360, abstract = {An optical lattice model developed that is similar to the Bose-Hubbard model to describe the transition between Bose-Einstein condensation (BEC) and a Mott insulator state was analyzed. It was found that the system was a hard core lattice gas at half of the maximum density and the optical lattice was modeled by a periodic potential of strength λ. It was also observed that the interparticle interaction was essential for this transition that occurred even in the ground state. The results show that all the essential features could be proved rigorously such as the existence of BEC for small λ and its suppression for a large λ.}, author = {Aizenman, Michael and Lieb, Élliott H and Robert Seiringer and Solovej, Jan P and Yngvason, Jakob}, journal = {Physical Review A - Atomic, Molecular, and Optical Physics}, number = {2}, pages = {023612 -- 1--0236121--2}, publisher = {American Physical Society}, title = {{Bose-Einstein quantum phase transition in an optical lattice model}}, doi = {10.1103/PhysRevA.70.023612}, volume = {70}, year = {2004}, } @inbook{2417, author = {Lovász, László and Vesztergombi, Katalin and Uli Wagner and Welzl, Emo}, booktitle = {Towards a Theory of Geometric Graphs}, editor = {Pach, János}, pages = {139 -- 148}, publisher = {American Mathematical Society}, title = {{Convex quadrilaterals and k-sets }}, doi = {10.1090/conm/342}, volume = {342}, year = {2004}, } @article{2425, abstract = {A finite set N ⊂ Rd is a weak ε-net for an n-point set X ⊂ Rd (with respect to convex sets) if N intersects every convex set K with |K ∩ X| ≥ εn. We give an alternative, and arguably simpler, proof of the fact, first shown by Chazelle et al., that every point set X in Rd admits a weak ε-net of cardinality O(ε-dpolylog(1/ε)). Moreover, for a number of special point sets (e.g., for points on the moment curve), our method gives substantially better bounds. The construction yields an algorithm to construct such weak ε-nets in time O(n ln(1/ε)).}, author = {Matoušek, Jiří and Uli Wagner}, journal = {Discrete & Computational Geometry}, number = {2}, pages = {195 -- 206}, publisher = {Springer}, title = {{New constructions of weak ε-nets}}, doi = {10.1007/s00454-004-1116-4}, volume = {32}, year = {2004}, } @article{2426, abstract = {We introduce the adaptive neighborhood graph as a data structure for modeling a smooth manifold M embedded in some Euclidean space ℝ d. We assume that M is known to us only through a finite sample P ⊂ M, as is often the case in applications. The adaptive neighborhood graph is a geometric graph on P. Its complexity is at most min{2O(k)n, n2}, where n = P and k = dim M, as opposed to the n[d/2] complexity of the Delaunay triangulation, which is often used to model manifolds. We prove that we can correctly infer the connected components and the dimension of M from the adaptive neighborhood graph provided a certain standard sampling condition is fulfilled. The running time of the dimension detection algorithm is d20(k7 log k) for each connected component of M. If the dimension is considered constant, this is a constant-time operation, and the adaptive neighborhood graph is of linear size. Moreover, the exponential dependence of the constants is only on the intrinsic dimension k, not on the ambient dimension d. This is of particular interest if the co-dimension is high, i.e., if k is much smaller than d, as is the case in many applications. The adaptive neighborhood graph also allows us to approximate the geodesic distances between the points in P.}, author = {Giesen, Joachim and Uli Wagner}, journal = {Discrete & Computational Geometry}, number = {2}, pages = {245 -- 267}, publisher = {Springer}, title = {{Shape dimension and intrinsic metric from samples of manifolds}}, doi = {10.1007/s00454-004-1120-8}, volume = {32}, year = {2004}, } @article{7333, abstract = {The analysis of the complete H2/air polymer electrolyte fuel cell system shows that process air humidification is one of the biggest obstacles for a high performance portable system in the kW range. Therefore, a new concept, with passive process air humidification integrated into the stack, has been developed. Humidification in each cell makes the process independent from the number of cells and the operation mode, thus making the concept fully scalable. Without external humidification the system is simpler, smaller, and cheaper. The humidification of the process air is achieved by transfer of product water from the exhaust air, through part of the membrane, to the dry intake air. Tests have shown that cells using the concept of internal humidification and operated with dry air at 70 ° have almost the same performance as when operated with external humidification. A 42‐cell stack with this internal humidification concept was built and integrated into a portable 1 kW power generator system.}, author = {Santis, M. and Schmid, D. and Ruge, M. and Freunberger, Stefan Alexander and Büchi, F.N.}, issn = {1615-6846}, journal = {Fuel Cells}, number = {3}, pages = {214--218}, publisher = {Wiley}, title = {{Modular stack-internal air humidification concept-verification in a 1 kW stack}}, doi = {10.1002/fuce.200400028}, volume = {4}, year = {2004}, } @article{7334, abstract = {Fundamental and phenomenological models for cells, stacks, and complete systems of PEFC and SOFC are reviewed and their predictive power is assessed by comparing model simulations against experiments. Computationally efficient models suited for engineering design include the (1+1) dimensionality approach, which decouples the membrane in-plane and through-plane processes, and the volume-averaged-method (VAM) that considers only the lumped effect of pre-selected system components. The former model was shown to capture the measured lateral current density inhomogeneities in a PEFC and the latter was used for the optimization of commercial SOFC systems. State Space Modeling (SSM) was used to identify the main reaction pathways in SOFC and, in conjunction with the implementation of geometrically well-defined electrodes, has opened a new direction for the understanding of electrochemical reactions. Furthermore, SSM has advanced the understanding of the COpoisoning-induced anode impedance in PEFC. Detailed numerical models such as the Lattice Boltzmann (LB) method for transport in porous media and the full 3-D Computational Fluid Dynamics (CFD) Navier-Stokes simulations are addressed. These models contain all components of the relevant physics and they can improve the understanding of the related phenomena, a necessary condition for the development of both appropriate simplified models as well as reliable technologies. Within the LB framework, a technique for the characterization and computer-reconstruction of the porous electrode structure was developed using advanced pattern recognition algorithms. In CFD modeling, 3-D simulations were used to investigate SOFC with internal methane steam reforming and have exemplified the significance of porous and novel fractal channel distributors for the fuel and oxidant delivery, as well as for the cooling of PEFC. As importantly, the novel concept has been put forth of functionally designed, fractal-shaped fuel cells, showing promise of significant performance improvements over the conventional rectangular shaped units. Thermo-economic modeling for the optimization of PEFC is finally addressed. }, author = {Mantzaras, John and Freunberger, Stefan Alexander and Büchi, Felix N. and Roos, Markus and Brandstätter, Wilhelm and Prestat, Michel and Gauckler, Ludwig J. and Andreaus, Bernhard and Hajbolouri, Faegheh and Senn, Stephan M. and Poulikakos, Dimos and Chaniotis, Andreas K. and Larrain, Diego and Autissier, Nordahl and Maréchal, François}, issn = {0009-4293}, journal = {CHIMIA International Journal for Chemistry}, number = {12}, pages = {857--868}, publisher = {Swiss Chemical Society}, title = {{Fuel cell modeling and simulations}}, doi = {10.2533/000942904777677029}, volume = {58}, year = {2004}, } @article{7706, abstract = {The Sir2 deacetylase modulates organismal life-span in various species. However, the molecular mechanisms by which Sir2 increases longevity are largely unknown. We show that in mammalian cells, the Sir2 homolog SIRT1 appears to control the cellular response to stress by regulating the FOXO family of Forkhead transcription factors, a family of proteins that function as sensors of the insulin signaling pathway and as regulators of organismal longevity. SIRT1 and the FOXO transcription factor FOXO3 formed a complex in cells in response to oxidative stress, and SIRT1 deacetylated FOXO3 in vitro and within cells. SIRT1 had a dual effect on FOXO3 function: SIRT1 increased FOXO3's ability to induce cell cycle arrest and resistance to oxidative stress but inhibited FOXO3's ability to induce cell death. Thus, one way in which members of the Sir2 family of proteins may increase organismal longevity is by tipping FOXO-dependent responses away from apoptosis and toward stress resistance.}, author = {Brunet, Anne and Sweeney, Lora Beatrice Jaeger and Sturgill, J Fitzhugh and Chua, Katrin and Greer, Paul and Lin, Yingxi and Tran, Hien and Ross, Sarah and Mostoslavsky, Raul and Cohen, Haim and Hu, Linda and Chen, Hwei-Ling and Jedrychowski, Mark and Gygi, Steven and Sinclair, David and Alt, Frederick and Greenberg, Michael}, issn = {0036-8075}, journal = {Science}, number = {5666}, pages = {2011--2015}, publisher = {American Association for the Advancement of Science}, title = {{Stress-dependent regulation of FOXO transcription factors by the SIRT1 deacetylase}}, doi = {10.1126/science.1094637}, volume = {303}, year = {2004}, } @inproceedings{4577, abstract = {While model checking has been successful in uncovering subtle bugs in code, its adoption in software engineering practice has been hampered by the absence of a simple interface to the programmer in an integrated development environment. We describe an integration of the software model checker BLAST into the Eclipse development environment. We provide a verification interface for practical solutions for some typical program analysis problems - assertion checking, reachability analysis, dead code analysis, and test generation - directly on the source code. The analysis is completely automatic, and assumes no knowledge of model checking or formal notation. Moreover, the interface supports incremental program verification to support incremental design and evolution of code.}, author = {Beyer, Dirk and Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S}, pages = {251 -- 255}, publisher = {IEEE}, title = {{An eclipse plug-in for model checking}}, doi = {10.1109/WPC.2004.1311069 }, year = {2004}, } @inproceedings{4578, abstract = {BLAST is an automatic verification tool for checking temporal safety properties of C programs. Blast is based on lazy predicate abstraction driven by interpolation-based predicate discovery. In this paper, we present the Blast specification language. The language specifies program properties at two levels of precision. At the lower level, monitor automata are used to specify temporal safety properties of program executions (traces). At the higher level, relational reachability queries over program locations are used to combine lower-level trace properties. The two-level specification language can be used to break down a verification task into several independent calls of the model-checking engine. In this way, each call to the model checker may have to analyze only part of the program, or part of the specification, and may thus succeed in a reduction of the number of predicates needed for the analysis. In addition, the two-level specification language provides a means for structuring and maintaining specifications. }, author = {Beyer, Dirk and Chlipala, Adam J and Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S}, pages = {2 -- 18}, publisher = {Springer}, title = {{The BLAST query language for software verification}}, doi = {10.1007/978-3-540-27864-1_2}, volume = {3148}, year = {2004}, } @inproceedings{4581, abstract = {We have extended the software model checker BLAST to automatically generate test suites that guarantee full coverage with respect to a given predicate. More precisely, given a C program and a target predicate p, BLAST determines the set L of program locations which program execution can reach with p true, and automatically generates a set of test vectors that exhibit the truth of p at all locations in L. We have used BLAST to generate test suites and to detect dead code in C programs with up to 30 K lines of code. The analysis and test vector generation is fully automatic (no user intervention) and exact (no false positives).}, author = {Beyer, Dirk and Chlipala, Adam J and Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S}, pages = {326 -- 335}, publisher = {IEEE}, title = {{Generating tests from counterexamples}}, doi = {10.1109/ICSE.2004.1317455}, year = {2004}, } @inproceedings{4629, abstract = {Temporal logic is two-valued: a property is either true or false. When applied to the analysis of stochastic systems, or systems with imprecise formal models, temporal logic is therefore fragile: even small changes in the model can lead to opposite truth values for a specification. We present a generalization of the branching-time logic Ctl which achieves robustness with respect to model perturbations by giving a quantitative interpretation to predicates and logical operators, and by discounting the importance of events according to how late they occur. In every state, the value of a formula is a real number in the interval [0,1], where 1 corresponds to truth and 0 to falsehood. The boolean operators and and or are replaced by min and max, the path quantifiers ∃ and ∀ determine sup and inf over all paths from a given state, and the temporal operators and □ specify sup and inf over a given path; a new operator averages all values along a path. Furthermore, all path operators are discounted by a parameter that can be chosen to give more weight to states that are closer to the beginning of the path. We interpret the resulting logic Dctl over transition systems, Markov chains, and Markov decision processes. We present two semantics for Dctl: a path semantics, inspired by the standard interpretation of state and path formulas in CTL, and a fixpoint semantics, inspired by the μ-calculus evaluation of CTL formulas. We show that, while these semantics coincide for CTL, they differ for Dctl, and we provide model-checking algorithms for both semantics.}, author = {de Alfaro, Luca and Faella, Marco and Thomas Henzinger and Majumdar, Ritankar S and Stoelinga, Mariëlle}, pages = {77 -- 92}, publisher = {Springer}, title = {{Model checking discounted temporal properties}}, doi = {10.1007/978-3-540-24730-2_6}, volume = {2988}, year = {2004}, } @article{6155, abstract = {The genome of the nematode Caenorhabditis elegans encodes seven soluble guanylate cyclases (sGCs) [1]. In mammals, sGCs function as α/β heterodimers activated by gaseous ligands binding to a haem prosthetic group 2, 3. The principal activator is nitric oxide, which acts through sGCs to regulate diverse cellular events. In C. elegans the function of sGCs is mysterious: the worm genome does not appear to encode nitric oxide synthase, and all C. elegans sGC subunits are more closely related to mammalian β than α subunits [1]. Here, we show that two of the seven C. elegans sGCs, GCY-35 and GCY-36, promote aggregation behavior. gcy-35 and gcy-36 are expressed in a small number of neurons. These include the body cavity neurons AQR, PQR, and URX, which are directly exposed to the blood equivalent of C. elegans and regulate aggregation behavior [4]. We show that GCY-35 and GCY-36 act as α-like and β-like sGC subunits and that their function in the URX sensory neurons is sufficient for strong nematode aggregation. Neither GCY-35 nor GCY-36 is absolutely required for C. elegans to aggregate. Instead, these molecules may transduce one of several pathways that induce C. elegans to aggregate or may modulate aggregation by responding to cues in C. elegans body fluid.}, author = {Cheung, Benny H.H and Arellano-Carbajal, Fausto and Rybicki, Irene and de Bono, Mario}, issn = {0960-9822}, journal = {Current Biology}, number = {12}, pages = {1105--1111}, publisher = {Elsevier}, title = {{Soluble guanylate cyclases act in neurons exposed to the body fluid to promote C. elegans aggregation behavior}}, doi = {10.1016/j.cub.2004.06.027}, volume = {14}, year = {2004}, } @article{1456, abstract = {We study the space of L2 harmonic forms on complete manifolds with metrics of fibred boundary or fibred cusp type. These metrics generalize the geometric structures at infinity of several different well-known classes of metrics, including asymptotically locally Euclidean manifolds, the (known types of) gravitational instantons, and also Poincaré metrics on ℚ-rank 1 ends of locally symmetric spaces and on the complements of smooth divisors in Kähler manifolds. The answer in all cases is given in terms of intersection cohomology of a stratified compactification of the manifold. The L2 signature formula implied by our result is closely related to the one proved by Dai and more generally by Vaillant and identifies Dai's τ-invariant directly in terms of intersection cohomology of differing perversities. This work is also closely related to a recent paper of Carron and the forthcoming paper of Cheeger and Dai. We apply our results to a number of examples, gravitational instantons among them, arising in predictions about L2 harmonic forms in duality theories in string theory.}, author = {Tamas Hausel and Hunsicker, Eugénie and Mazzeo, Rafe R}, journal = {Duke Mathematical Journal}, number = {3}, pages = {485 -- 548}, publisher = {Duke University Press}, title = {{Hodge cohomology of gravitational instantons}}, doi = {10.1215/S0012-7094-04-12233-X}, volume = {122}, year = {2004}, }