@article{12646, abstract = {Assessment of water resources from remote mountainous catchments plays a crucial role for the development of rural areas in or in the vicinity of mountain ranges. The scarcity of data, however, prevents the application of standard approaches that are based on data-driven models. The Hindu Kush–Karakoram–Himalaya mountain range is a crucial area in terms of water resources, but our understanding of the response of its high-elevation catchments to a changing climate is hindered by lack of hydro-meteorological and cryospheric data. Hydrological modeling is challenging here because internal inconsistencies—such as an underestimation of precipitation input that can be compensated for by an overestimation of meltwater—might be hidden due to the complexity of feedback mechanisms that govern melt and runoff generation in such basins. Data scarcity adds to this difficulty by preventing the application of systematic calibration procedures that would allow identification of the parameter set that could guarantee internal consistency in the simulation of the single hydrological components. In this work, we use simulations from the Hunza River Basin in the Karakoram region obtained with the hydrological model TOPKAPI to quantify the predictive power of discharge and snow-cover data sets, as well as the combination of both. We also show that short-term measurements of meteorological variables such as radiative fluxes, wind speed, relative humidity, and air temperature from glacio-meteorological experiments are crucial for a correct parameterization of surface melt processes. They enable detailed simulations of the energy fluxes governing glacier–atmosphere interaction and the resulting ablation through energy-balance modeling. These simulations are used to derive calibrated parameters for the simplified snow and glacier routines in TOPKAPI. We demonstrate that such parameters are stable in space and time in similar climatic regions, thus reducing the number of parameters requiring calibration.}, author = {Pellicciotti, Francesca and Buergi, Cyrill and Immerzeel, Walter Willem and Konz, Markus and Shrestha, Arun B.}, issn = {1994-7151}, journal = {Mountain Research and Development}, number = {1}, pages = {39--50}, publisher = {International Mountain Society}, title = {{Challenges and uncertainties in hydrological modeling of remote Hindu Kush–Karakoram–Himalayan (HKH) basins: Suggestions for calibration strategies}}, doi = {10.1659/mrd-journal-d-11-00092.1}, volume = {32}, year = {2012}, } @article{12647, abstract = {Accurate quantification of the spatial distribution of precipitation in mountain regions is crucial for assessments of water resources and for the understanding of high-altitude hydrology, yet it is one of the largest unknowns due to the lack of high-altitude observations. The Hunza basin in Pakistan contains very large glacier systems, which, given the melt, cannot persist unless precipitation (snow input) is much higher than what is observed at the meteorological stations, mostly located in mountain valleys. Several studies, therefore, suggest strong positive vertical precipitation lapse rates; in the present study, we quantify this lapse rate by using glaciers as a proxy. We assume a neutral mass balance for the glaciers for the period from 2001 to 2003, and we inversely model the precipitation lapse by balancing the total accumulation in the catchment area and the ablation over the glacier area for the 50 largest glacier systems in the Hunza basin in the Karakoram. Our results reveal a vertical precipitation lapse rate that equals 0.21 ± 0.12% m−1, with a maximum precipitation at an elevation of 5500 masl. We showed that the total annual basin precipitation (828 mm) is 260% higher than what is estimated based on interpolated observations (319 mm); this has major consequences for hydrological modeling and water resource assessments in general. Our results were validated by using previously published studies on individual glaciers as well as the water balance of the Hunza basin. The approach is more widely applicable in mountain ranges where precipitation measurements at high altitude are lacking.}, author = {Immerzeel, Walter Willem and Pellicciotti, Francesca and Shrestha, Arun B.}, issn = {1994-7151}, journal = {Mountain Research and Development}, keywords = {General Environmental Science, Development, Environmental Chemistry}, number = {1}, pages = {30--38}, publisher = {International Mountain Society}, title = {{Glaciers as a proxy to quantify the spatial distribution of precipitation in the Hunza basin}}, doi = {10.1659/mrd-journal-d-11-00097.1}, volume = {32}, year = {2012}, } @article{12648, abstract = {Distributed glacier melt models generally assume that the glacier surface consists of bare exposed ice and snow. In reality, many glaciers are wholly or partially covered in layers of debris that tend to suppress ablation rates. In this paper, an existing physically based point model for the ablation of debris-covered ice is incorporated in a distributed melt model and applied to Haut Glacier d'Arolla, Switzerland, which has three large patches of debris cover on its surface. The model is based on a 10 m resolution digital elevation model (DEM) of the area; each glacier pixel in the DEM is defined as either bare or debris-covered ice, and may be covered in snow that must be melted off before ice ablation is assumed to occur. Each debris-covered pixel is assigned a debris thickness value using probability distributions based on over 1000 manual thickness measurements. Locally observed meteorological data are used to run energy balance calculations in every pixel, using an approach suitable for snow, bare ice or debris-covered ice as appropriate. The use of the debris model significantly reduces the total ablation in the debris-covered areas, however the precise reduction is sensitive to the temperature extrapolation used in the model distribution because air near the debris surface tends to be slightly warmer than over bare ice. Overall results suggest that the debris patches, which cover 10% of the glacierized area, reduce total runoff from the glacierized part of the basin by up to 7%.}, author = {Reid, T. D. and Carenzo, M. and Pellicciotti, Francesca and Brock, B. W.}, issn = {0148-0227}, journal = {Journal of Geophysical Research: Atmospheres}, keywords = {Paleontology, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Atmospheric Science, Earth-Surface Processes, Geochemistry and Petrology, Soil Science, Water Science and Technology, Ecology, Aquatic Science, Forestry, Oceanography, Geophysics}, number = {D18}, publisher = {American Geophysical Union}, title = {{Including debris cover effects in a distributed model of glacier ablation}}, doi = {10.1029/2012jd017795}, volume = {117}, year = {2012}, } @misc{13075, abstract = {Little is known about the stability of trophic relationships in complex natural communities over evolutionary timescales. Here, we use sequence data from 18 nuclear loci to reconstruct and compare the intraspecific histories of major Pleistocene refugial populations in the Middle East, the Balkans and Iberia in a guild of four Chalcid parasitoids (Cecidostiba fungosa, C. semifascia, Hobbya stenonota and Mesopolobus amaenus) all attacking Cynipid oak galls. We develop a likelihood method to numerically estimate models of divergence between three populations from multilocus data. We investigate the power of this framework on simulated data, and - using triplet alignments of intronic loci - quantify the support for all possible divergence relationships between refugial populations in the four parasitoids. Although an East to West order of population divergence has highest support in all but one species, we cannot rule out alternative population tree topologies. Comparing the estimated times of population splits between species, we find that one species, M. amaenus, has a significantly older history than the rest of the guild and must have arrived in central Europe at least one glacial cycle prior to other guild members. This suggests that although all four species may share a common origin in the East, they expanded westwards into Europe at different times.}, author = {Lohse, Konrad and Barton, Nicholas H and Stone, Graham and Melika, George}, publisher = {Dryad}, title = {{Data from: A likelihood-based comparison of population histories in a parasitoid guild}}, doi = {10.5061/DRYAD.0G0FS}, year = {2012}, } @article{2101, abstract = {Articulated deformable characters are widespread in computer animation. Unfortunately, we lack methods for their automatic fabrication using modern additive manufacturing (AM) technologies. We propose a method that takes a skinned mesh as input, then estimates a fabricatable single-material model that approximates the 3D kinematics of the corresponding virtual articulated character in a piecewise linear manner. We first extract a set of potential joint locations. From this set, together with optional, user-specified range constraints, we then estimate mechanical friction joints that satisfy inter-joint non-penetration and other fabrication constraints. To avoid brittle joint designs, we place joint centers on an approximate medial axis representation of the input geometry, and maximize each joint's minimal cross-sectional area. We provide several demonstrations, manufactured as single, assembled pieces using 3D printers. }, author = {Bac̈her, Moritz and Bernd Bickel and James, Doug L and Pfister, Hanspeter}, journal = {ACM Transactions on Graphics}, number = {4}, publisher = {ACM}, title = {{Fabricating articulated characters from skinned meshes}}, doi = {10.1145/2185520.2185543}, volume = {31}, year = {2012}, } @article{2102, abstract = {We propose a complete process for designing, simulating, and fabricating synthetic skin for an animatronics character that mimics the face of a given subject and its expressions. The process starts with measuring the elastic properties of a material used to manufacture synthetic soft tissue. Given these measurements we use physicsbased simulation to predict the behavior of a face when it is driven by the underlying robotic actuation. Next, we capture 3D facial expressions for a given target subject. As the key component of our process, we present a novel optimization scheme that determines the shape of the synthetic skin as well as the actuation parameters that provide the best match to the target expressions. We demonstrate this computational skin design by physically cloning a real human face onto an animatronics figure. }, author = {Bernd Bickel and Kaufmann, Peter and Skouras, Mélina and Thomaszewski, Bernhard and Bradley, Derek J and Beeler, Thabo and Jackson, Philip V and Marschner, Steve and Matusik, Wojciech and Groß, Markus S}, journal = {ACM Transactions on Graphics}, number = {4}, publisher = {ACM}, title = {{Physical face cloning}}, doi = {10.1145/2185520.2185614}, volume = {31}, year = {2012}, } @article{2103, abstract = {Although facial hair plays an important role in individual expression, facial-hair reconstruction is not addressed by current facecapture systems. Our research addresses this limitation with an algorithm that treats hair and skin surface capture together in a coupled fashion so that a high-quality representation of hair fibers as well as the underlying skin surface can be reconstructed. We propose a passive, camera-based system that is robust against arbitrary motion since all data is acquired within the time period of a single exposure. Our reconstruction algorithm detects and traces hairs in the captured images and reconstructs them in 3D using a multiview stereo approach. Our coupled skin-reconstruction algorithm uses information about the detected hairs to deliver a skin surface that lies underneath all hairs irrespective of occlusions. In dense regions like eyebrows, we employ a hair-synthesis method to create hair fibers that plausibly match the image data. We demonstrate our scanning system on a number of individuals and show that it can successfully reconstruct a variety of facial-hair styles together with the underlying skin surface.}, author = {Beeler, Thabo and Bernd Bickel and Noris, Gioacchino and Beardsley, Paul A and Marschner, Steve and Sumner, Robert W and Groß, Markus S}, journal = {ACM Transactions on Graphics}, number = {4}, publisher = {ACM}, title = {{Coupled 3D reconstruction of sparse facial hair and skin}}, doi = {10.1145/2185520.2185613}, volume = {31}, year = {2012}, } @inproceedings{2104, abstract = {In recent years, various methods have been introduced to exploit pre-recorded data to improve the performance and/or realism of dynamic deformations, but their differences and similarities have not been adequately analyzed or discussed. So far, the proposed methods have been explored mainly in the research context. They have not been adopted by the computer graphics industry. This course bridges the gap between research labs and industry to present a unifying theory and understanding of data-driven methods for dynamic deformations that may inspire development of novel solutions. It focuses on application of data-driven methods to three areas of computer animation: dynamic deformation of faces, soft volumetric tissue, and cloth. And it describes how to approach these challenges in a data-driven manner, classifies the various methods, and demonstrates how data-driven methods can work in other settings. }, author = {Otaduy, Miguel A and Bernd Bickel and Bradley, Derek J and Wang, Huamin}, publisher = {ACM}, title = {{Data-driven simulation methods in computer graphics: Cloth, tissue and faces}}, doi = {10.1145/2343483.2343495}, year = {2012}, } @inproceedings{2105, author = {Skouras, Mélina and Thomaszewski, Bernhard and Bernd Bickel and Groß, Markus S}, number = {2}, pages = {835 -- 844}, publisher = {Wiley-Blackwell}, title = {{Computational design of rubber balloons}}, doi = {10.1111/j.1467-8659.2012.03064.x}, volume = {31}, year = {2012}, } @inproceedings{2106, abstract = {Progress in cloth simulation for computer animation and apparel design has led to a multitude of deformation models, each with its own way of relating geometry, deformation, and forces. As simulators improve, differences between these models become more important, but it is difficult to choose a model and a set of parameters to match a given real material simply by looking at simulation results. This paper provides measurement and fitting methods that allow nonlinear models to be fit to the observed deformation of a particular cloth sample. Unlike standard textile testing, our system measures complex 3D deformations of a sheet of cloth, not just one-dimensional force-displacement curves, so it works under a wider range of deformation conditions. The fitted models are then evaluated by comparison to measured deformations with motions very different from those used for fitting.}, author = {Miguel, Eder and Bradley, Derek J and Thomaszewski, Bernhard and Bernd Bickel and Matusik, Wojciech and Otaduy, Miguel A and Marschner, Steve}, number = {2}, pages = {519 -- 528}, publisher = {Wiley-Blackwell}, title = {{Data-driven estimation of cloth simulation models}}, doi = {10.1111/j.1467-8659.2012.03031.x}, volume = {31}, year = {2012}, } @article{21104, abstract = {Crystal structures of the hexanucleotide d(CACGCG)·d(CGCGTG) were determined in two crystal lattices when different concentrations of the counterion Mn2+ were used in crystallization. The availability of Mn2+ during the crystallization process appears to play an important role in inducing different crystal packings that lead to crystals belonging to the two space groups P21 and P65. Analysis of the molecular interactions of Mn2+ with the Z-form duplexes shows direct coordination to the purine residues G and A.}, author = {Mandal, Pradeep K and Venkadesh, S. and Gautham, N.}, issn = {1744-3091}, journal = {Acta Crystallographica Section F Structural Biology Communications}, number = {12}, pages = {1420--1426}, publisher = {International Union of Crystallography}, title = {{Interactions of Mn2+ with a non-self-complementary Z-type DNA duplex}}, doi = {10.1107/s1744309112041759}, volume = {68}, year = {2012}, } @article{21105, abstract = {The hexamer duplex d(CACGCG).d(CGCGTG) produces unusual hexagonal ring shaped crystals when crystallized in the presence of cobalt hexammine chloride. Observation of the growth of these crystals over a period of about 6 days indicated that this morphology resulted from radial dissolution of the crystal from the center of the well-formed hexagonal plates. X-ray diffraction studies were carried out for crystals of four stages in the ring crystal morphology. The structure of the DNA in all four crystals was the Z type DNA double helix. The packing mode of the Z DNA duplex in all four crystal structures was that of the ‘spermine’ form. The crystal morphology changes from hexagonal plates to hexagonal rings without any apparent change in the molecular structure of the oligonucleotide or helical packing of the duplexes.}, author = {Mandal, Pradeep K and Chandrasekaran, Arun Richard and Madhanagopal, Bharath Raj and Venkadesh, Sarkarai and Gautham, Namasivayam}, issn = {0022-0248}, journal = {Journal of Crystal Growth}, number = {1}, pages = {20--26}, publisher = {Elsevier}, title = {{Ring crystals of oligonucleotides: Growth stages and X-ray diffraction studies}}, doi = {10.1016/j.jcrysgro.2012.05.029}, volume = {354}, year = {2012}, } @article{21106, abstract = {The crystal structure of the tetradecanucleotide sequence d(CCCCGGTACC­GGGG)2 has been determined at 2.5 Å resolution in the tetragonal space group P41. This sequence was designed with the expectation of a four-way junction. However, the sequence crystallized as an A-DNA duplex and represents more than one full turn of the A-helix. The crystallographic asymmetric unit consists of one tetradecanucleotide duplex. The structural parameters of the A-type DNA duplex structure and the crystal-packing arrangement are described. One Mn2+ ion was identified with direct coordination to the N7 position of G13 and a water molecule at the major-groove side of the C2·G13 base pair.}, author = {Mandal, Pradeep K and Venkadesh, Sarkarai and Gautham, Namasivayam}, issn = {1744-3091}, journal = {Acta Crystallographica Section F Structural Biology Communications}, number = {4}, pages = {393--399}, publisher = {International Union of Crystallography}, title = {{Structure of the tetradecanucleotide d(CCCCGGTACCGGGG)2 as an A-DNA duplex}}, doi = {10.1107/s174430911200869x}, volume = {68}, year = {2012}, } @article{21111, abstract = {Inhibiting PLA2 activity should, in theory, be an effective approach to control the inflammation. Several naturally occurring polyphenolic compounds have been reported as inhibitors of PLA2. Among the naturally occurring polyphenols, catechol (1,2-dihydroxybenzene) possesses anti-inflammatory activity. Catechol can inhibit cyclooxygenase and lipo-oxygenase. By means of enzyme kinetic study, it was revealed that catechol can inhibit PLA2 also. Crystal structure showed that catechol binds to PLA2 at the opening of the active site cleft. This might stop the entry of substrate into the active site. Hence, catechol can be used as a lead compound for the development of novel anti-inflammatory drugs with PLA2 as the target.}, author = {Dileep, Kalarickal V. and Tintu, Ignatius and Mandal, Pradeep K and Karthe, Ponnuraj and Haridas, Madathilkovilakathu and Sadasivan, Chittalakkottu}, issn = {1747-0285}, journal = {Chemical Biology & Drug Design}, number = {1}, pages = {143--147}, publisher = {Wiley}, title = {{Binding to PLA2 may contribute to the anti‐inflammatory activity of catechol}}, doi = {10.1111/j.1747-0285.2011.01258.x}, volume = {79}, year = {2012}, } @article{21112, abstract = {Ester bond hydrolysis of membrane phospholipids by Phospholipase A2 and consequent release of fatty acids are the initiating steps of inflammation. It is proposed in this study that the inhibition of phospholipase A2 is one of the ways to control inflammation. Investigations are carried out to identify the mode of inhibition of phospholipase A2 by the n‐hexadecanoic acid. It may help in designing of specific inhibitors of phospholipase A2 as anti‐inflammatory agents. The enzyme kinetics study proved that n‐hexadecanoic acid inhibits phospholipase A2 in a competitive manner. It was identified from the crystal structure at 2.5Å resolution that the position of n‐hexadecanoic acid is in the active site of the phospholipase A2. The binding constant and binding energy have also been calculated using Isothermal Titration Calorimetry. Also, the binding energy of n‐hexadecanoic acid to phospholipase A2 was calculated by in silico method and compared with known inhibitors. It may be concluded from the structural and kinetics studies that the fatty acid, n‐hexadecanoic acid, is an inhibitor of phospholipase A2, hence, an anti‐inflammatory compound. The inferences from the present study validate the rigorous use of medicated oils rich in n‐hexadecanoic acid for the treatment of rheumatic symptoms in the traditional medical system of India, Ayurveda.}, author = {Aparna, Vasudevan and Dileep, Kalarickal V. and Mandal, Pradeep K and Karthe, Ponnuraj and Sadasivan, Chittalakkottu and Haridas, Madathilkovilakathu}, issn = {1747-0285}, journal = {Chemical Biology & Drug Design}, number = {3}, pages = {434--439}, publisher = {Wiley}, title = {{Anti-inflammatory property of n-hexadecanoic acid: Structural evidence and kinetic assessment}}, doi = {10.1111/j.1747-0285.2012.01418.x}, volume = {80}, year = {2012}, } @article{21151, abstract = {The decanucleotide sequence d(CCGGTACCGG) crystallizes as a four-way junction at low cobalt ion concentrations (i.e., 1 mM). When the cobalt concentration in the crystallization solution is increased to 5 mM, the sequence crystallizes as resolved B-DNA duplexes. Gel retardation studies of the decamer show both a faint slow-moving band and a much thicker fast-moving band at low cobalt ion concentrations, and only the intense fast-moving band at higher ion concentration. Circular dichroism (CD) spectroscopy of the decamer indicates a structural transition as the cobalt ion concentration in the solution is increased, probably from B-type to A-type DNA. These studies revealed that the oligomer sequence has several conformations and structures accessible to it, in a manner dependent on sequence, ion concentration, and DNA concentration.}, author = {Venkadesh, S. and Mandal, Pradeep K and Gautham, N.}, issn = {1532-2335}, journal = {Nucleosides, Nucleotides and Nucleic Acids}, number = {3}, pages = {184--196}, publisher = {Informa UK Limited}, title = {{Crystallographic and spectroscopic studies of d(CCGGTACCGG)}}, doi = {10.1080/15257770.2011.648363}, volume = {31}, year = {2012}, } @article{21153, abstract = {Curcumin possess anti-inflammatory activity. In this study, the binding of curcumin with PLA2 was studied using X-ray crystallography. Since the electron density found at the active site did not match with curcumin, 2-methoxycyclohexa-2-5-diene-1,4-dione (MCW) (the photodegraded product of curcumin) was fitted in the unexplained electron density. To understand the binding mode of actual curcumin, molecular docking study was carried out. The crystallographic and docked structures were superimposed with respect to the ligand position and it was found that curcumin was binding in the hydrophobic cavity of PLA2 with a binding energy of−16.81 Kcal/mol. The binding mode was of such a nature that it prevented the entry of the substrate to the hydrophobic active site. This study indicates that curcumin can act as an inhibitor of PLA2. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:FLS:1.}, author = {Dileep, K. V. and Tintu, I. and Mandal, Pradeep K and Karthe, P. and Haridas, M. and Sadasivan, C.}, issn = {2155-3769}, journal = {Frontiers in Life Science}, number = {3-4}, pages = {135--139}, publisher = {Informa UK Limited}, title = {{Crystal structure of porcine pancreatic phospholipase A2 in complex with 2-methoxycyclohexa-2-5-diene-1,4-dione}}, doi = {10.1080/21553769.2012.689262}, volume = {5}, year = {2012}, } @article{21154, abstract = {The crystal structure of the decamer sequence d(CCGGGACCGG)4 has previously been reported at 2.16 Å resolution as a four-way junction. Here, the structure of this sequence is reported at the significantly higher resolution of 1.6 Å, which is the highest resolution reported for a four-way junction. This allowed the unambiguous identification of an extensive hydration network with distinct patterns and solvent-mediated interactions that shed new light on the role of water in the formation and stabilization of junction structures.}, author = {Chakraborty, Arka and Mandal, Pradeep K and Gautham, Namasivayam}, issn = {1744-3091}, journal = {Acta Crystallographica Section F Structural Biology Communications}, number = {10}, pages = {1169--1174}, publisher = {International Union of Crystallography}, title = {{Structure of d(CCGGGACCGG)4 as a four-way junction at 1.6 Å resolution: New insights into solvent interactions}}, doi = {10.1107/s1744309112034926}, volume = {68}, year = {2012}, } @article{2125, abstract = {We consider a class of stochastic PDEs of Burgers type in spatial dimension 1, driven by space–time white noise. Even though it is well known that these equations are well posed, it turns out that if one performs a spatial discretization of the nonlinearity in the “wrong” way, then the sequence of approximate equations does converge to a limit, but this limit exhibits an additional correction term. This correction term is proportional to the local quadratic cross-variation (in space) of the gradient of the conserved quantity with the solution itself. This can be understood as a consequence of the fact that for any fixed time, the law of the solution is locally equivalent to Wiener measure, where space plays the role of time. In this sense, the correction term is similar to the usual Itô–Stratonovich correction term that arises when one considers different temporal discretizations of stochastic ODEs.}, author = {Hairer, Martin M and Jan Maas}, journal = {Annals of Probability}, number = {4}, pages = {1675 -- 1714}, publisher = {Institute of Mathematical Statistics}, title = {{A spatial version of the Itô-Stratonovich correction}}, doi = {10.1214/11-AOP662}, volume = {40}, year = {2012}, } @article{2127, abstract = {We study a new notion of Ricci curvature that applies to Markov chains on discrete spaces. This notion relies on geodesic convexity of the entropy and is analogous to the one introduced by Lott, Sturm, and Villani for geodesic measure spaces. In order to apply to the discrete setting, the role of the Wasserstein metric is taken over by a different metric, having the property that continuous time Markov chains are gradient flows of the entropy. Using this notion of Ricci curvature we prove discrete analogues of fundamental results by Bakry–Émery and Otto–Villani. Further, we show that Ricci curvature bounds are preserved under tensorisation. As a special case we obtain the sharp Ricci curvature lower bound for the discrete hypercube.}, author = {Erbar, Matthias and Jan Maas}, journal = {Archive for Rational Mechanics and Analysis}, number = {3}, pages = {997 -- 1038}, publisher = {Springer}, title = {{Ricci curvature of finite Markov chains via convexity of the entropy}}, doi = {10.1007/s00205-012-0554-z}, volume = {206}, year = {2012}, }