@article{17940, abstract = {Single-molecule conductance studies have traditionally focused on creating highly conducting molecular wires. However, progress in nanoscale electronics demands insulators just as it needs conductors. Here we describe the single-molecule length-dependent conductance properties of the classic silicon dioxide insulator. We synthesize molecular wires consisting of Si–O repeat units and measure their conductance through the scanning tunneling microscope-based break-junction method. These molecules yield conductance lower than alkanes of the same length and the largest length-dependent conductance decay of any molecular systems measured to date. We calculate single-molecule junction transmission and the complex band structure of the infinite 1D material for siloxane, in comparison with silane and alkane, and show that the large conductance decay is intrinsic to the nature of the Si–O bond. This work highlights the potential for siloxanes to function as molecular insulators in electronics.}, author = {Li, Haixing and Garner, Marc H. and Su, Timothy A. and Jensen, Anders and Inkpen, Michael S. and Steigerwald, Michael L. and Venkataraman, Latha and Solomon, Gemma C. and Nuckolls, Colin}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, number = {30}, pages = {10212--10215}, publisher = {American Chemical Society}, title = {{Extreme conductance suppression in molecular siloxanes}}, doi = {10.1021/jacs.7b05599}, volume = {139}, year = {2017}, } @article{17941, abstract = {How heteroatomic substitutions affect electron transport through π-conjugated hydrocarbons has been the subject of some debate. In this paper we investigate the effect of heteroatomic linkers in a molecular junction on the electron-transmission spectrum, focusing on the occurrence of quantum interference (QI) close to the Fermi level, where conductivity can be significantly suppressed. We find that the substitution or addition of heteroatoms to a carbon skeleton at the contact positions does not change the main feature of QI due to the underlying carbon skeleton. QI in the overall system thus remains a robust feature. This empirical observation leads us to derive, in two mathematical ways, that these findings can be generalized. We note that addition or substitution of a carbon atom by a heteroatom at the contact positions will increase or decrease the number of electrons in the π-system, which will lead to a change in the alignment of the molecular orbitals of the isolated system relative to the electrode Fermi level. Both Hückel and density functional theory calculations on model systems probe the effect of this Fermi level change and confirm qualitatively the implications of the underlying mathematical proofs.}, author = {Tsuji, Yuta and Stuyver, Thijs and Gunasekaran, Suman and Venkataraman, Latha}, issn = {1932-7455}, journal = {The Journal of Physical Chemistry C}, number = {27}, pages = {14451--14462}, publisher = {American Chemical Society}, title = {{The influence of linkers on quantum interference: A linker theorem}}, doi = {10.1021/acs.jpcc.7b03493}, volume = {121}, year = {2017}, } @article{17942, abstract = {Quantum interference effects, whether constructive or destructive, are key to predicting and understanding the electrical conductance of single molecules. Here, through theory and experiment, we investigate a family of benzene-like molecules that exhibit both constructive and destructive interference effects arising due to more than one contact between the molecule and each electrode. In particular, we demonstrate that the π-system of meta-coupled benzene can exhibit constructive interference and its para-coupled analog can exhibit destructive interference, and vice versa, depending on the specific through-space interactions. As a peculiarity, this allows a meta-coupled benzene molecule to exhibit higher conductance than a para-coupled benzene. Our results provide design principles for molecular electronic components with high sensitivity to through-space interactions and demonstrate that increasing the number of contacts between the molecule and electrodes can both increase and decrease the conductance.}, author = {Borges, Anders and Xia, Jianlong and Liu, Sheng Hua and Venkataraman, Latha and Solomon, Gemma C.}, issn = {1530-6992}, journal = {Nano Letters}, number = {7}, pages = {4436--4442}, publisher = {American Chemical Society}, title = {{The role of through-space interactions in modulating constructive and destructive interference effects in benzene}}, doi = {10.1021/acs.nanolett.7b01592}, volume = {17}, year = {2017}, } @article{17943, abstract = {This Account provides an overview of our recent efforts to uncover the fundamental charge transport properties of Si–Si and Ge–Ge single bonds and introduce useful functions into group 14 molecular wires. We utilize the tools of chemical synthesis and a scanning tunneling microscopy-based break-junction technique to study the mechanism of charge transport in these molecular systems. We evaluated the fundamental ability of silicon, germanium, and carbon molecular wires to transport charge by comparing conductances within families of well-defined structures, the members of which differ only in the number of Si (or Ge or C) atoms in the wire. For each family, this procedure yielded a length-dependent conductance decay parameter, β. Comparison of the different β values demonstrates that Si–Si and Ge–Ge σ bonds are more conductive than the analogous C–C σ bonds. These molecular trends mirror what is seen in the bulk. The conductance decay of Si and Ge-based wires is similar in magnitude to those from π-based molecular wires such as paraphenylenes However, the chemistry of the linkers that attach the molecular wires to the electrodes has a large influence on the resulting β value. For example, Si- and Ge-based wires of many different lengths connected with a methyl–thiomethyl linker give β values of 0.36–0.39 Å–1, whereas Si- and Ge-based wires connected with aryl–thiomethyl groups give drastically different β values for short and long wires. This observation inspired us to study molecular wires that are composed of both π- and σ-orbitals. The sequence and composition of group 14 atoms in the σ chain modulates the electronic coupling between the π end-groups and dictates the molecular conductance. The conductance behavior originates from the coupling between the subunits, which can be understood by considering periodic trends such as bond length, polarizability, and bond polarity. We found that the same periodic trends determine the electric field-induced breakdown properties of individual Si–Si, Ge–Ge, Si–O, Si–C, and C–C bonds. Building from these studies, we have prepared a system that has two different, alternative conductance pathways. In this wire, we can intentionally break a labile, strained silicon–silicon bond and thereby shunt the current through the secondary conduction pathway. This type of in situ bond-rupture provides a new tool to study single molecule reactions that are induced by electric fields. Moreover, these studies provide guidance for designing dielectric materials as well as molecular devices that require stability under high voltage bias. The fundamental studies on the structure/function relationships of the molecular wires have guided the design of new functional systems based on the Si- and Ge-based wires. For example, we exploited the principle of strain-induced Lewis acidity from reaction chemistry to design a single molecule switch that can be controllably switched between two conductive states by varying the distance between the tip and substrate electrodes. We found that the strain intrinsic to the disilaacenaphthene scaffold also creates two state conductance switching. Finally, we demonstrate the first example of a stereoelectronic conductance switch, and we demonstrate that the switching relies crucially on the electronic delocalization in Si–Si and Ge–Ge wire backbones. These studies illustrate the untapped potential in using Si- and Ge-based wires to design and control charge transport at the nanoscale and to allow quantum mechanics to be used as a tool to design ultraminiaturized switches.}, author = {Su, Timothy A. and Li, Haixing and Klausen, Rebekka S. and Kim, Nathaniel T. and Neupane, Madhav and Leighton, James L. and Steigerwald, Michael L. and Venkataraman, Latha and Nuckolls, Colin}, issn = {1520-4898}, journal = {Accounts of Chemical Research}, number = {4}, pages = {1088--1095}, publisher = {American Chemical Society}, title = {{Silane and Germane molecular electronics}}, doi = {10.1021/acs.accounts.7b00059}, volume = {50}, year = {2017}, } @article{17944, abstract = {The electronic, mechanical, and thermoelectric properties of molecular scale devices have fascinated scientists across several disciplines in natural sciences and engineering. The interest is partially technological, driven by the fast miniaturization of integrated circuits that now have reached characteristic features at the nanometer scale. Equally important, a very strong incentive also exists to elucidate the fundamental aspects of structure-function relations for nanoscale devices, which utilize molecular building blocks as functional units. Thus motivated, a rich research field has established itself, broadly termed “Molecular Electronics,” that hosts a plethora of activities devoted to this goal in chemistry, physics, and electrical engineering. This Special Topic on Frontiers of Molecular Scale Electronics captures recent theoretical and experimental advances in the field.}, author = {Evers, Ferdinand and Venkataraman, Latha}, issn = {1089-7690}, journal = {The Journal of Chemical Physics}, number = {9}, publisher = {AIP Publishing}, title = {{Preface: Special topic on Frontiers in Molecular Scale Electronics}}, doi = {10.1063/1.4977469}, volume = {146}, year = {2017}, } @article{17945, abstract = {We perform temperature dependent conductance measurements on sub-nanometer sized single molecules bound to gold electrodes using a scanning tunneling microscope-based break junction technique in Ultra-High Vacuum (UHV). We find a threefold increase in the conductance of amine-terminated conjugated molecules when the temperature increases from 4 K to 300 K in UHV. Furthermore, the conductance measured at 300 K in UHV is consistent with solution-based measurements under ambient conditions where the transport mechanism corresponds to off-resonant electron tunneling across the molecule. Our measurements indicate that at 300 K, conductance is largely independent of pressure or solvent around the junction. In addition, our data unambiguously show that temperature can affect the tunneling conductance of single molecule-metal junctions. We show that the structure of the metal electrodes that form in these junctions varies systematically with temperature, and hypothesize that this changing structure of the interface alters electron tunneling probability and propose a mechanism to explain our findings.}, author = {Kamenetska, M. and Widawsky, J. R. and Dell’Angela, M. and Frei, M. and Venkataraman, Latha}, issn = {1089-7690}, journal = {The Journal of Chemical Physics}, number = {9}, publisher = {AIP Publishing}, title = {{Temperature dependent tunneling conductance of single molecule junctions}}, doi = {10.1063/1.4973318}, volume = {146}, year = {2017}, } @article{17947, abstract = {We investigate light-induced conductance enhancement in single-molecule junctions via photon-assisted transport and hot-electron transport. Using 4,4′-bipyridine bound to Au electrodes as a prototypical single-molecule junction, we report a 20–40% enhancement in conductance under illumination with 980 nm wavelength radiation. We probe the effects of subtle changes in the transmission function on light-enhanced current and show that discrete variations in the binding geometry result in a 10% change in enhancement. Importantly, we prove theoretically that the steady-state behavior of photon-assisted transport and hot-electron transport is identical but that hot-electron transport is the dominant mechanism for optically induced conductance enhancement in single-molecule junctions when the wavelength used is absorbed by the electrodes and the hot-electron relaxation time is long. We confirm this experimentally by performing polarization-dependent conductance measurements of illuminated 4,4′-bipyridine junctions. Finally, we perform lock-in type measurements of optical current and conclude that currents due to laser-induced thermal expansion mask optical currents. This work provides a robust experimental framework for studying mechanisms of light-enhanced transport in single-molecule junctions and offers tools for tuning the performance of organic optoelectronic devices by analyzing detailed transport properties of the molecules involved.}, author = {Fung, E-Dean and Adak, Olgun and Lovat, Giacomo and Scarabelli, Diego and Venkataraman, Latha}, issn = {1530-6992}, journal = {Nano Letters}, number = {2}, pages = {1255--1261}, publisher = {American Chemical Society}, title = {{Too hot for photon-assisted transport: Hot-electrons dominate conductance enhancement in illuminated single-molecule junctions}}, doi = {10.1021/acs.nanolett.6b05091}, volume = {17}, year = {2017}, } @article{17949, abstract = {Single-molecule electronic devices provide researchers with an unprecedented ability to relate novel physical phenomena to molecular chemical structures. Typically, conjugated aromatic molecular backbones are relied upon to create electronic devices, where the aromaticity of the building blocks is used to enhance conductivity. We capitalize on the classical physical organic chemistry concept of Hückel antiaromaticity by demonstrating a single-molecule switch that exhibits low conductance in the neutral state and, upon electrochemical oxidation, reversibly switches to an antiaromatic high-conducting structure. We form single-molecule devices using the scanning tunneling microscope–based break-junction technique and observe an on/off ratio of ~70 for a thiophenylidene derivative that switches to an antiaromatic state with 6-4-6-π electrons. Through supporting nuclear magnetic resonance measurements, we show that the doubly oxidized core has antiaromatic character and we use density functional theory calculations to rationalize the origin of the high-conductance state for the oxidized single-molecule junction. Together, our work demonstrates how the concept of antiaromaticity can be exploited to create single-molecule devices that are highly conducting.}, author = {Yin, Xiaodong and Zang, Yaping and Zhu, Liangliang and Low, Jonathan Z. and Liu, Zhen-Fei and Cui, Jing and Neaton, Jeffrey B. and Venkataraman, Latha and Campos, Luis M.}, issn = {2375-2548}, journal = {Science Advances}, number = {10}, publisher = {American Association for the Advancement of Science}, title = {{A reversible single-molecule switch based on activated antiaromaticity}}, doi = {10.1126/sciadv.aao2615}, volume = {3}, year = {2017}, } @article{17950, abstract = {Whilst most studies in single-molecule electronics involve components first synthesized ex situ, there is also great potential in exploiting chemical transformations to prepare devices in situ. Here, as a first step towards this goal, we conduct reversible reactions on monolayers to make and break covalent bonds between alkanes of different lengths, then measure the conductance of these molecules connected between electrodes using the scanning tunneling microscopy-based break junction (STM-BJ) method. In doing so, we develop the critical methodology required for assembling and disassembling surface-bound single-molecule circuits. We identify effective reaction conditions for surface-bound reagents, and importantly demonstrate that the electronic characteristics of wires created in situ agree with those created ex situ. Finally, we show that the STM-BJ technique is unique in its ability to definitively probe surface reaction yields both on a local (∼50 nm2) and pseudo-global (≥10 mm2) level. This investigation thus highlights a route to the construction and integration of more complex, and ultimately functional, surface-based single-molecule circuitry, as well as advancing a methodology that facilitates studies beyond the reach of traditional ex situ synthetic approaches.}, author = {Inkpen, Michael S. and Leroux, Yann R. and Hapiot, Philippe and Campos, Luis M. and Venkataraman, Latha}, issn = {2041-6539}, journal = {Chemical Science}, number = {6}, pages = {4340--4346}, publisher = {Royal Society of Chemistry}, title = {{Reversible on-surface wiring of resistive circuits}}, doi = {10.1039/c7sc00599g}, volume = {8}, year = {2017}, } @article{17951, abstract = {Thiophene-1,1-dioxide (TDO) oligomers have fascinating electronic properties. We previously used thermopower measurements to show that a change in charge carrier from hole to electron occurs with increasing length of TDO oligomers when single-molecule junctions are formed between gold electrodes. In this article, we show for the first time that the dominant conducting orbitals for thiophene/TDO oligomers of fixed length can be tuned by altering the strength of the electron acceptors incorporated into the backbone. We use the scanning tunneling microscope break-junction (STM-BJ) technique and apply a recently developed method to determine the dominant transport channel in single-molecule junctions formed with these systems. Through these measurements, we find that increasing the electron affinity of thiophene derivatives, within a family of pentamers, changes the polarity of the charge carriers systematically from holes to electrons, with some systems even showing mid-gap transport characteristics.}, author = {Low, Jonathan Z. and Capozzi, Brian and Cui, Jing and Wei, Sujun and Venkataraman, Latha and Campos, Luis M.}, issn = {2041-6539}, journal = {Chemical Science}, number = {4}, pages = {3254--3259}, publisher = {Royal Society of Chemistry}, title = {{Tuning the polarity of charge carriers using electron deficient thiophenes}}, doi = {10.1039/c6sc05283e}, volume = {8}, year = {2017}, } @article{18198, abstract = {Higgs and Goldstone modes are collective excitations of the amplitude and phase of an order parameter that is related to the breaking of a continuous symmetry. We directly studied these modes in a supersolid quantum gas created by coupling a Bose-Einstein condensate to two optical cavities, whose field amplitudes form the real and imaginary parts of a U(1)-symmetric order parameter. Monitoring the cavity fields in real time allowed us to observe the dynamics of the associated Higgs and Goldstone modes and revealed their amplitude and phase nature. We used a spectroscopic method to measure their frequencies, and we gave a tunable mass to the Goldstone mode by exploring the crossover between continuous and discrete symmetry. Our experiments link spectroscopic measurements to the theoretical concept of Higgs and Goldstone modes.}, author = {Leonard, Julian and Morales, Andrea and Zupancic, Philip and Donner, Tobias and Esslinger, Tilman}, issn = {1095-9203}, journal = {Science}, number = {6369}, pages = {1415--1418}, publisher = {American Association for the Advancement of Science}, title = {{Monitoring and manipulating Higgs and Goldstone modes in a supersolid quantum gas}}, doi = {10.1126/science.aan2608}, volume = {358}, year = {2017}, } @article{18199, abstract = {The concept of a supersolid state combines the crystallization of a many-body system with dissipationless flow of the atoms from which it is built. This quantum phase requires the breaking of two continuous symmetries: the phase invariance of a superfluid and the continuous translational invariance to form the crystal1,2. Despite having been proposed for helium almost 50 years ago3,4, experimental verification of supersolidity remains elusive5,6. A variant with only discrete translational symmetry breaking on a preimposed lattice structure—the ‘lattice supersolid’7—has been realized, based on self-organization of a Bose–Einstein condensate8,9. However, lattice supersolids do not feature the continuous ground-state degeneracy that characterizes the supersolid state as originally proposed. Here we report the realization of a supersolid with continuous translational symmetry breaking along one direction in a quantum gas. The continuous symmetry that is broken emerges from two discrete spatial symmetries by symmetrically coupling a Bose–Einstein condensate to the modes of two optical cavities. We establish the phase coherence of the supersolid and find a high ground-state degeneracy by measuring the crystal position over many realizations through the light fields that leak from the cavities. These light fields are also used to monitor the position fluctuations in real time. Our concept provides a route to creating and studying glassy many-body systems with controllably lifted ground-state degeneracies, such as supersolids in the presence of disorder.}, author = {Leonard, Julian and Morales, Andrea and Zupancic, Philip and Esslinger, Tilman and Donner, Tobias}, issn = {0028-0836}, journal = {Nature}, number = {7643}, pages = {87--90}, publisher = {Springer Science and Business Media LLC}, title = {{Supersolid formation in a quantum gas breaking a continuous translational symmetry}}, doi = {10.1038/nature21067}, volume = {543}, year = {2017}, } @inproceedings{18286, abstract = {We introduce a new framework for learning dense correspondence between deformable 3D shapes. Existing learning based approaches model shape correspondence as a labelling problem, where each point of a query shape receives a label identifying a point on some reference domain; the correspondence is then constructed a posteriori by composing the label predictions of two input shapes. We propose a paradigm shift and design a structured prediction model in the space of functional maps, linear operators that provide a compact representation of the correspondence. We model the learning process via a deep residual network which takes dense descriptor fields defined on two shapes as input, and outputs a soft map between the two given objects. The resulting correspondence is shown to be accurate on several challenging benchmarks comprising multiple categories, synthetic models, real scans with acquisition artifacts, topological noise, and partiality.}, author = {Litany, Or and Remez, Tal and Rodola, Emanuele and Bronstein, Alexander and Bronstein, Michael}, booktitle = {2017 IEEE International Conference on Computer Vision (ICCV)}, issn = {9781538610329}, publisher = {IEEE}, title = {{Deep functional maps: Structured prediction for dense shape correspondence}}, doi = {10.1109/iccv.2017.603}, volume = {31}, year = {2017}, } @inproceedings{18287, abstract = {Many algorithms for the computation of correspondences between deformable shapes rely on some variant of nearest neighbor matching in a descriptor space. Such are, for example, various point-wise correspondence recovery algorithms used as a post-processing stage in the functional correspondence framework. Such frequently used techniques implicitly make restrictive assumptions (e.g., nearisometry) on the considered shapes and in practice suffer from lack of accuracy and result in poor surjectivity. We propose an alternative recovery technique capable of guaranteeing a bijective correspondence and producing significantly higher accuracy and smoothness. Unlike other methods our approach does not depend on the assumption that the analyzed shapes are isometric. We derive the proposed method from the statistical framework of kernel density estimation and demonstrate its performance on several challenging deformable 3D shape matching datasets.}, author = {Vestner, Matthias and Litman, Roee and Rodola, Emanuele and Bronstein, Alexander and Cremers, Daniel}, booktitle = {2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)}, isbn = {9781538604588}, issn = {1063-6919}, location = {Honolulu, HI, United States}, pages = {6681 -- 6690}, publisher = {IEEE}, title = {{Product manifold filter: Non-rigid shape correspondence via kernel density estimation in the product space}}, doi = {10.1109/cvpr.2017.707}, year = {2017}, } @inproceedings{18288, abstract = {The increasing demand for high image quality in mobile devices brings forth the need for better computational enhancement techniques, and image denoising in particular. To this end, we propose a new fully convolutional deep neural network architecture which is simple yet powerful and achieves state-of-the-art performance for additive Gaussian noise removal. Furthermore, we claim that the personal photo-collections can usually be categorized into a small set of semantic classes. However simple, this observation has not been exploited in image denoising until now. We show that a significant boost in performance of up to 0.4dB PSNR can be achieved by making our network class-aware, namely, by fine-tuning it for images belonging to a specific semantic class. Relying on the hugely successful existing image classifiers, this research advocates for using a class-aware approach in all image enhancement tasks.}, author = {Remez, Tal and Litany, Or and Giryes, Raja and Bronstein, Alexander}, booktitle = {2017 International Conference on Sampling Theory and Applications (SampTA)}, location = {Tallinn, Estonia}, publisher = {IEEE}, title = {{Deep class-aware image denoising}}, doi = {10.1109/sampta.2017.8024474}, year = {2017}, } @inproceedings{18329, abstract = {Multidimensional Scaling (MDS) is one of the most popular methods for dimensionality reduction and visualization of high dimensional data. Apart from these tasks, it also found applications in the field of geometry processing for the analysis and reconstruction of non-rigid shapes. In this regard, MDS can be thought of as a shape from metric algorithm, consisting of finding a configuration of points in the Euclidean space that realize, as isometrically as possible, some given distance structure. In the present work we cast the least squares variant of MDS (LS-MDS) in the spectral domain. This uncovers a multiresolution property of distance scaling which speeds up the optimization by a significant amount, while producing comparable, and sometimes even better, embeddings.}, author = {Boyarski, Amit and Bronstein, Alexander and Bronstein, Michael M.}, booktitle = {International Conference on Scale Space and Variational Methods in Computer Vision}, isbn = {9783319587707}, issn = {1611-3349}, location = {Kolding, Denmark}, pages = {681--693}, publisher = {Springer Nature}, title = {{Subspace least squares multidimensional scaling}}, doi = {10.1007/978-3-319-58771-4_54}, volume = {10302}, year = {2017}, } @inproceedings{18330, abstract = {With increasingly sophisticated Diffusion Weighted MRI acquisition methods and modeling techniques, very large sets of streamlines (fibers) are presently generated per imaged brain. These reconstructions of white matter architecture, which are important for human brain research and pre-surgical planning, require a large amount of storage and are often unwieldy and difficult to manipulate and analyze. This work proposes a novel continuous parsimonious framework in which signals are sparsely represented in a dictionary with continuous atoms. The significant innovation in our new methodology is the ability to train such continuous dictionaries, unlike previous approaches that either used pre-fixed continuous transforms or training with finite atoms. This leads to an innovative fiber representation method, which uses Continuous Dictionary Learning to sparsely code each fiber with high accuracy. This method is tested on numerous tractograms produced from the Human Connectome Project data and achieves state-of-the-art performances in compression ratio and reconstruction error.}, author = {Alexandroni, Guy and Podolsky, Yana and Greenspan, Hayit and Remez, Tal and Litany, Or and Bronstein, Alexander and Giryes, Raja}, booktitle = {20th International Conference on Medical Image Computing and Computer-Assisted Intervention}, isbn = {9783319661810}, issn = {1611-3349}, location = {Quebec City, QC, Canada}, number = {Part 1}, pages = {566 -- 574}, publisher = {Springer Nature}, title = {{White matter fiber representation using continuous dictionary learning}}, doi = {10.1007/978-3-319-66182-7_65}, volume = {10433}, year = {2017}, } @article{18366, abstract = {We present ASIST, a technique for transforming point clouds by replacing objects with their semantically equivalent counterparts. Transformations of this kind have applications in virtual reality, repair of fused scans, and robotics. ASIST is based on a unified formulation of semantic labeling and object replacement; both result from minimizing a single objective. We present numerical tools for the efficient solution of this optimization problem. The method is experimentally assessed on new datasets of both synthetic and real point clouds, and is additionally compared to two recent works on object replacement on data from the corresponding papers.}, author = {Litany, Or and Remez, Tal and Freedman, Daniel and Shapira, Lior and Bronstein, Alexander and Gal, Ran}, issn = {1077-3142}, journal = {Computer Vision and Image Understanding}, pages = {284--299}, publisher = {Elsevier}, title = {{ASIST: Automatic semantically invariant scene transformation}}, doi = {10.1016/j.cviu.2016.08.002}, volume = {157}, year = {2017}, } @article{18372, abstract = {The sliding clamp, PCNA, plays a central role in DNA replication and repair. In the moving replication fork, PCNA is present at the leading strand and at each of the Okazaki fragments that are formed on the lagging strand. PCNA enhances the processivity of the replicative polymerases and provides a landing platform for other proteins and enzymes. The loading of the clamp onto DNA is performed by the Replication Factor C (RFC) complex, whereas its unloading can be carried out by an RFC-like complex containing Elg1. Mutations in ELG1 lead to DNA damage sensitivity and genome instability. To characterize the role of Elg1 in maintaining genomic integrity, we used homology modeling to generate a number of site-specific mutations in ELG1 that exhibit different PCNA unloading capabilities. We show that the sensitivity to DNA damaging agents and hyper-recombination of these alleles correlate with their ability to unload PCNA from the chromatin. Our results indicate that retention of modified and unmodified PCNA on the chromatin causes genomic instability. We also show, using purified proteins, that the Elg1 complex inhibits DNA synthesis by unloading SUMOylated PCNA from the DNA. Additionally, we find that mutations in ELG1 suppress the sensitivity of rad5Δ mutants to DNA damage by allowing trans-lesion synthesis to take place. Taken together, the data indicate that the Elg1–RLC complex plays an important role in the maintenance of genomic stability by unloading PCNA from the chromatin.}, author = {Shemesh, Keren and Sebesta, Marek and Pacesa, Martin and Sau, Soumitra and Bronstein, Alexander and Parnas, Oren and Liefshitz, Batia and Venclovas, Česlovas and Krejci, Lumir and Kupiec, Martin}, issn = {0305-1048}, journal = {Nucleic Acids Research}, number = {6}, pages = {3189 -- 3203}, publisher = {Oxford University Press (OUP)}, title = {{A structure-function analysis of the yeast Elg1 protein reveals the importance of PCNA unloading in genome stability maintenance}}, doi = {10.1093/nar/gkw1348}, volume = {45}, year = {2017}, } @inproceedings{18403, abstract = {Recent studies validated the feasibility of estimating heart rate from human faces in RGB video. However, test subjects are often recorded under controlled conditions, as illumination variations significantly affect the RGB-based heart rate estimation accuracy. Intel newly-announced low-cost RealSense 3D (RGBD) camera is becoming ubiquitous in laptops and mobile devices starting this year, opening the door to new and more robust computer vision. RealSense cameras produce RGB images with extra depth information inferred from a latent near-infrared (NIR) channel. In this paper, we experimentally demonstrate, for the first time, that heart rate can be reliably estimated from RealSense near-infrared images. This enables illumination invariant heart rate estimation, extending the heart rate from video feasibility to low-light applications, such as night driving. With the (coming) ubiquitous presence of RealSense devices, the proposed method not only utilizes its near-infrared channel, designed originally to be hidden from consumers; but also exploits the associated depth information for improved robustness to head pose.}, author = {Chen, Jie and Chang, Zhuoqing and Qiu, Qiang and Li, Xiaobai and Sapiro, Guillermo and Bronstein, Alexander and Pietikainen, Matti}, booktitle = {2016 Sixth International Conference on Image Processing Theory, Tools and Applications (IPTA)}, isbn = {9781467389112}, issn = {2154-512X}, location = {Oulu, Finland}, publisher = {IEEE}, title = {{RealSense = real heart rate: Illumination invariant heart rate estimation from videos}}, doi = {10.1109/ipta.2016.7820970}, year = {2017}, }