@inproceedings{11816,
  abstract     = {In recent years, significant advances have been made in the design and analysis of fully dynamic maximal matching algorithms. However, these theoretical results have received very little attention from the practical perspective. Few of the algorithms are implemented and tested on real datasets, and their practical potential is far from understood. In this paper, we attempt to bridge the gap between theory and practice that is currently observed for the fully dynamic maximal matching problem. We engineer several algorithms and empirically study those algorithms on an extensive set of dynamic instances.},
  author       = {Henzinger, Monika H and Shahbaz, Khan and Paul, Richard and Schulz, Christian},
  booktitle    = {8th Annual European Symposium on Algorithms},
  isbn         = {9783959771627},
  issn         = {1868-8969},
  location     = {Pisa, Italy},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Dynamic matching algorithms in practice}},
  doi          = {10.4230/LIPIcs.ESA.2020.58},
  volume       = {173},
  year         = {2020},
}

@inproceedings{11818,
  abstract     = {With input sizes becoming massive, coresets - small yet representative summary of the input - are relevant more than ever. A weighted set C_w that is a subset of the input is an ε-coreset if the cost of any feasible solution S with respect to C_w is within [1±ε] of the cost of S with respect to the original input. We give a very general technique to compute coresets in the fully-dynamic setting where input points can be added or deleted. Given a static (i.e., not dynamic) ε-coreset-construction algorithm that runs in time t(n, ε, λ) and computes a coreset of size s(n, ε, λ), where n is the number of input points and 1-λ is the success probability, we give a fully-dynamic algorithm that computes an ε-coreset with worst-case update time O((log n) ⋅ t(s(n, ε/log n, λ/n), ε/log n, λ/n)) (this bound is stated informally), where the success probability is 1-λ. Our technique is a fully-dynamic analog of the merge-and-reduce technique, which is due to Har-Peled and Mazumdar [Har-Peled and Mazumdar, 2004] and is based on a technique of Bentley and Saxe [Jon Louis Bentley and James B. Saxe, 1980], that applies to the insertion-only setting where points can only be added. Although, our space usage is O(n), our technique works in the presence of an adaptive adversary, and we show that Ω(n) space is required when adversary is adaptive.
As a concrete implication of our technique, using the result of Braverman et al. [{Braverman} et al., 2016], we get fully-dynamic ε-coreset-construction algorithms for k-median and k-means with worst-case update time O(ε^{-2} k² log⁵ n log³ k) and coreset size O(ε^{-2} k log n log² k) ignoring log log n and log(1/ε) factors and assuming that ε = Ω(1/poly(n)) and λ = Ω(1/poly(n)) (which are very weak assumptions made only to make these bounds easy to parse). This results in the first fully-dynamic constant-approximation algorithms for k-median and k-means with update times O(poly(k, log n, ε^{-1})). Specifically, the dependence on k is only quadratic, and the bounds are worst-case. The best previous bound for both problems was amortized O(nlog n) by Cohen-Addad et al. [Cohen-Addad et al., 2019] via randomized O(1)-coresets in O(n) space.
We also show that under the OMv conjecture [Monika Henzinger et al., 2015], a fully-dynamic (4 - δ)-approximation algorithm for k-means must either have an amortized update time of Ω(k^{1-γ}) or amortized query time of Ω(k^{2 - γ}), where γ > 0 is a constant.},
  author       = {Henzinger, Monika H and Kale, Sagar},
  booktitle    = {28th Annual European Symposium on Algorithms},
  isbn         = {9783959771627},
  issn         = {1868-8969},
  location     = {Pisa, Italy},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Fully-dynamic coresets}},
  doi          = {10.4230/LIPIcs.ESA.2020.57},
  volume       = {173},
  year         = {2020},
}

@inproceedings{11819,
  abstract     = {We present a practically efficient algorithm that finds all global minimum cuts in huge undirected graphs. Our algorithm uses a multitude of kernelization rules to reduce the graph to a small equivalent instance and then finds all minimum cuts using an optimized version of the algorithm of Nagamochi, Nakao and Ibaraki. In shared memory we are able to find all minimum cuts of graphs with up to billions of edges and millions of minimum cuts in a few minutes. We also give a new linear time algorithm to find the most balanced minimum cuts given as input the representation of all minimum cuts.},
  author       = {Henzinger, Monika H and Noe, Alexander and Schulz, Christian and Strash, Darren},
  booktitle    = {28th Annual European Symposium on Algorithms},
  isbn         = {9783959771627},
  issn         = {1868-8969},
  location     = {Pisa, Italy},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Finding all global minimum cuts in practice}},
  doi          = {10.4230/LIPIcs.ESA.2020.59},
  volume       = {173},
  year         = {2020},
}

@inproceedings{11822,
  abstract     = {The fully dynamic transitive closure problem asks to maintain reachability information in a directed graph between arbitrary pairs of vertices, while the graph undergoes a sequence of edge insertions and deletions. The problem has been thoroughly investigated in theory and many specialized algorithms for solving it have been proposed in the last decades. In two large studies [Frigioni ea, 2001; Krommidas and Zaroliagis, 2008], a number of these algorithms have been evaluated experimentally against simple, static algorithms for graph traversal, showing the competitiveness and even superiority of the simple algorithms in practice, except for very dense random graphs or very high ratios of queries. A major drawback of those studies is that only small and mostly randomly generated graphs are considered.
In this paper, we engineer new algorithms to maintain all-pairs reachability information which are simple and space-efficient. Moreover, we perform an extensive experimental evaluation on both generated and real-world instances that are several orders of magnitude larger than those in the previous studies. Our results indicate that our new algorithms outperform all state-of-the-art algorithms on all types of input considerably in practice.},
  author       = {Hanauer, Kathrin and Henzinger, Monika H and Schulz, Christian},
  booktitle    = {18th International Symposium on Experimental Algorithms},
  isbn         = {9783959771481},
  issn         = {1868-8969},
  location     = {Pisa, Italy},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Faster fully dynamic transitive closure in practice}},
  doi          = {10.4230/LIPIcs.SEA.2020.14},
  volume       = {160},
  year         = {2020},
}

@inproceedings{11824,
  abstract     = {Independent set is a fundamental problem in combinatorial optimization. While in general graphs the problem is essentially inapproximable, for many important graph classes there are approximation algorithms known in the offline setting. These graph classes include interval graphs and geometric intersection graphs, where vertices correspond to intervals/geometric objects and an edge indicates that the two corresponding objects intersect.
We present dynamic approximation algorithms for independent set of intervals, hypercubes and hyperrectangles in d dimensions. They work in the fully dynamic model where each update inserts or deletes a geometric object. All our algorithms are deterministic and have worst-case update times that are polylogarithmic for constant d and ε>0, assuming that the coordinates of all input objects are in [0, N]^d and each of their edges has length at least 1. We obtain the following results:
- For weighted intervals, we maintain a (1+ε)-approximate solution.
- For d-dimensional hypercubes we maintain a (1+ε)2^d-approximate solution in the unweighted case and a O(2^d)-approximate solution in the weighted case. Also, we show that for maintaining an unweighted (1+ε)-approximate solution one needs polynomial update time for d ≥ 2 if the ETH holds.
- For weighted d-dimensional hyperrectangles we present a dynamic algorithm with approximation ratio (1+ε)log^{d-1}N.},
  author       = {Henzinger, Monika H and Neumann, Stefan and Wiese, Andreas},
  booktitle    = {36th International Symposium on Computational Geometry},
  isbn         = {9783959771436},
  issn         = {1868-8969},
  location     = {Zurich, Switzerland},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Dynamic approximate maximum independent set of intervals, hypercubes and hyperrectangles}},
  doi          = {10.4230/LIPIcs.SoCG.2020.51},
  volume       = {164},
  year         = {2020},
}

@inproceedings{11825,
  abstract     = {We give a fully dynamic (Las-Vegas style) algorithm with constant expected amortized time per update that maintains a proper (Δ+1)-vertex coloring of a graph with maximum degree at most Δ. This improves upon the previous O(log Δ)-time algorithm by Bhattacharya et al. (SODA 2018). Our algorithm uses an approach based on assigning random ranks to vertices and does not need to maintain a hierarchical graph decomposition. We show that our result does not only have optimal running time, but is also optimal in the sense that already deciding whether a Δ-coloring exists in a dynamically changing graph with maximum degree at most Δ takes Ω(log n) time per operation.},
  author       = {Henzinger, Monika H and Peng, Pan},
  booktitle    = {37th International Symposium on Theoretical Aspects of Computer Science},
  isbn         = {9783959771405},
  issn         = {1868-8969},
  location     = {Montpellier, France},
  publisher    = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
  title        = {{Constant-time dynamic (Δ+1)-coloring}},
  doi          = {10.4230/LIPIcs.STACS.2020.53},
  volume       = {154},
  year         = {2020},
}

@inproceedings{11852,
  abstract     = {We present a general framework of designing efficient dynamic approximate algorithms for optimization problems on undirected graphs. In particular, we develop a technique that, given any problem that admits a certain notion of vertex sparsifiers, gives data structures that maintain approximate solutions in sub-linear update and query time. We illustrate the applicability of our paradigm to the following problems. (1)A fully-dynamic algorithm that approximates all-pair maximum-flows/minimum-cuts up to a nearly logarithmic factor in O~(n2/3) 11The O~(⋅) notation is used in this paper to hide poly-logarithmic factors. amortized time against an oblivious adversary, and O~(m3/4) time against an adaptive adversary. (2)An incremental data structure that maintains O(1) - approximate shortest path in no(1) time per operation, as well as fully dynamic approximate all-pair shortest path and transshipment in O~(n2/3+o(1)) amortized time per operation. (3)A fully-dynamic algorithm that approximates all-pair effective resistance up to an (1+ϵ) factor in O~(n2/3+o(1)ϵ−O(1)) amortized update time per operation. The key tool behind result (1) is the dynamic maintenance of an algorithmic construction due to Madry [FOCS' 10], which partitions a graph into a collection of simpler graph structures (known as j-trees) and approximately captures the cut-flow and metric structure of the graph. The O(1)-approximation guarantee of (2) is by adapting the distance oracles by [Thorup-Zwick JACM '05]. Result (3) is obtained by invoking the random-walk based spectral vertex sparsifier by [Durfee et al. STOC '19] in a hierarchical manner, while carefully keeping track of the recourse among levels in the hierarchy. See https://arxiv.org/pdf/2005.02368.pdf for the full version of this paper.},
  author       = {Chen, Li and Goranci, Gramoz and Henzinger, Monika H and Peng, Richard and Saranurak, Thatchaphol},
  booktitle    = {61st Annual Symposium on Foundations of Computer Science},
  isbn         = {978-1-7281-9622-0},
  issn         = {2575-8454},
  location     = {Durham, NC, United States},
  pages        = {1135--1146},
  publisher    = {Institute of Electrical and Electronics Engineers},
  title        = {{Fast dynamic cuts, distances and effective resistances via vertex sparsifiers}},
  doi          = {10.1109/focs46700.2020.00109},
  year         = {2020},
}

@inproceedings{11880,
  abstract     = {Given a directed graph and a source vertex, the fully dynamic single-source reachability problem is to maintain the set of vertices that are reachable from the given vertex, subject to edge deletions and insertions. It is one of the most fundamental problems on graphs and appears directly or indirectly in many and varied applications. While there has been theoretical work on this problem, showing both linear conditional lower bounds for the fully dynamic problem and insertions-only and deletions-only upper bounds beating these conditional lower bounds, there has been no experimental study that compares the performance of fully dynamic reachability algorithms in practice. Previous experimental studies in this area concentrated only on the more general all-pairs reachability or transitive closure problem and did not use real-world dynamic graphs.

In this paper, we bridge this gap by empirically studying an extensive set of algorithms for the single-source reachability problem in the fully dynamic setting. In particular, we design several fully dynamic variants of well-known approaches to obtain and maintain reachability information with respect to a distinguished source. Moreover, we extend the existing insertions-only or deletions-only upper bounds into fully dynamic algorithms. Even though the worst-case time per operation of all the fully dynamic algorithms we evaluate is at least linear in the number of edges in the graph (as is to be expected given the conditional lower bounds) we show in our extensive experimental evaluation that their performance differs greatly, both on generated as well as on real-world instances.},
  author       = {Hanauer, Kathrin and Henzinger, Monika H and Schulz, Christian},
  booktitle    = {2020 Symposium on Algorithm Engineering and Experiments},
  location     = {Salt Lake City, UT, United States},
  pages        = {106--119},
  publisher    = {Society for Industrial and Applied Mathematics},
  title        = {{Fully dynamic single-source reachability in practice: An experimental study}},
  doi          = {10.1137/1.9781611976007.9},
  year         = {2020},
}

@inproceedings{11881,
  abstract     = {We introduce the fastest known exact algorithm for the multiterminal cut problem with k terminals. In particular, we engineer existing as well as new data reduction rules. We use the rules within a branch-and-reduce framework and to boost the performance of an ILP formulation. Our algorithms achieve improvements in running time of up to multiple orders of magnitudes over the ILP formulation without data reductions, which has been the de facto standard used by practitioners. This allows us to solve instances to optimality that are significantly larger than was previously possible.},
  author       = {Henzinger, Monika H and Noe, Alexander and Schulz, Christian},
  booktitle    = {2020 Symposium on Algorithm Engineering and Experiments},
  location     = {Salt Lake City, UT, United States},
  pages        = {42--55},
  publisher    = {Society for Industrial and Applied Mathematics},
  title        = {{Shared-memory branch-and-reduce for multiterminal cuts}},
  doi          = {10.1137/1.9781611976007.4},
  year         = {2020},
}

@article{11894,
  abstract     = {Graph sparsification aims at compressing large graphs into smaller ones while preserving important characteristics of the input graph. In this work we study vertex sparsifiers, i.e., sparsifiers whose goal is to reduce the number of vertices. We focus on the following notions: (1) Given a digraph 𝐺=(𝑉,𝐸) and terminal vertices 𝐾⊂𝑉 with |𝐾|=𝑘, a (vertex) reachability sparsifier of 𝐺 is a digraph 𝐻=(𝑉𝐻,𝐸𝐻), 𝐾⊂𝑉𝐻 that preserves all reachability information among terminal pairs. Let |𝑉𝐻| denote the size of 𝐻. In this work we introduce the notion of reachability-preserving minors (RPMs), i.e., we require 𝐻 to be a minor of 𝐺. We show any directed graph 𝐺 admits an RPM 𝐻 of size 𝑂(𝑘3), and if 𝐺 is planar, then the size of 𝐻 improves to 𝑂(𝑘2log𝑘). We complement our upper bound by showing that there exists an infinite family of grids such that any RPM must have Ω(𝑘2) vertices. (2) Given a weighted undirected graph 𝐺=(𝑉,𝐸) and terminal vertices 𝐾 with |𝐾|=𝑘, an exact (vertex) cut sparsifier of 𝐺 is a graph 𝐻 with 𝐾⊂𝑉𝐻 that preserves the value of minimum cuts separating any bipartition of 𝐾. We show that planar graphs with all the 𝑘 terminals lying on the same face admit exact cut sparsifiers of size 𝑂(𝑘2) that are also planar. Our result extends to flow and distance sparsifiers. It improves the previous best-known bound of 𝑂(𝑘222𝑘) for cut and flow sparsifiers by an exponential factor and matches an Ω(𝑘2) lower-bound for this class of graphs.},
  author       = {Goranci, Gramoz and Henzinger, Monika H and Peng, Pan},
  issn         = {1095-7146},
  journal      = {SIAM Journal on Discrete Mathematics},
  number       = {1},
  pages        = {130--162},
  publisher    = {Society for Industrial & Applied Mathematics},
  title        = {{Improved guarantees for vertex sparsification in planar graphs}},
  doi          = {10.1137/17m1163153},
  volume       = {34},
  year         = {2020},
}

@article{11954,
  abstract     = {The combination of nickel and photocatalysis has unlocked a variety of cross-couplings. These protocols rely on a few photocatalysts that can only convert a small portion of visible light (<500 nm) into chemical energy. The high-energy photons that excite the photocatalyst can result in unwanted side reactions. Dyes that absorb a much broader spectrum of light are not applicable because of their short-lived singlet excited states. Here, we describe a self-assembling catalyst system that overcomes this limitation. Immobilization of a nickel catalyst on dye-sensitized titanium dioxide results in a material that catalyzes carbon–heteroatom and carbon–carbon bond formations. The modular approach of dye-sensitized metallaphotocatalysts accesses the entire visible light spectrum and allows tackling selectivity issues resulting from low wavelengths strategically. The concept overcomes current limitations of metallaphotocatalysis by unlocking the potential of dyes that were previously unsuitable.},
  author       = {Reischauer, Susanne and Strauss, Volker and Pieber, Bartholomäus},
  issn         = {2155-5435},
  journal      = {ACS Catalysis},
  number       = {22},
  pages        = {13269–13274},
  publisher    = {American Chemical Society},
  title        = {{Modular, self-assembling metallaphotocatalyst for cross-couplings using the full visible-light spectrum}},
  doi          = {10.1021/acscatal.0c03950},
  volume       = {10},
  year         = {2020},
}

@article{11969,
  abstract     = {Photochemistry enables new synthetic means to form carbon–heteroatom bonds. Photocatalysts can catalyze carbon–heteroatom cross-couplings by electron or energy transfer either alone or in combination with a second catalyst. Photocatalyst-free methods are possible using photolabile substrates or by generating photoactive electron donor-acceptor complexes. This review summarizes and discusses the strategies used in light-mediated carbon–heteroatom bond formations based on the proposed mechanisms.},
  author       = {Cavedon, Cristian and Seeberger, Peter H. and Pieber, Bartholomäus},
  issn         = {1099-0690},
  journal      = {European Journal of Organic Chemistry},
  number       = {10},
  pages        = {1379--1392},
  publisher    = {Wiley},
  title        = {{Photochemical strategies for carbon–heteroatom bond formation}},
  doi          = {10.1002/ejoc.201901173},
  volume       = {2020},
  year         = {2020},
}

@article{11978,
  abstract     = {Dual photocatalysis and nickel catalysis can effect cross-coupling under mild conditions, but little is known about the in situ kinetics of this class of reactions. We report a comprehensive kinetic examination of a model carboxylate O-arylation, comparing a state-of-the-art homogeneous photocatalyst (Ir(ppy)3) with a competitive heterogeneous photocatalyst (graphitic carbon nitride). Experimental conditions were adjusted such that the nickel catalytic cycle is saturated with excited photocatalyst. This approach was designed to remove the role of the photocatalyst, by which only the intrinsic behaviors of the nickel catalytic cycles are observed. The two reactions did not display identical kinetics. Ir(ppy)3 deactivates the nickel catalytic cycle and creates more dehalogenated side product. Kinetic data for the reaction using Ir(ppy)3 supports a turnover-limiting reductive elimination. Graphitic carbon nitride gave higher selectivity, even at high photocatalyst-to-nickel ratios. The heterogeneous reaction also showed a rate dependence on aryl halide, indicating that oxidative addition plays a role in rate determination. The results argue against the current mechanistic hypothesis, which states that the photocatalyst is only involved to trigger reductive elimination.},
  author       = {Malik, Jamal A. and Madani, Amiera and Pieber, Bartholomäus and Seeberger, Peter H.},
  issn         = {1520-5126},
  journal      = {Journal of the American Chemical Society},
  number       = {25},
  pages        = {11042--11049},
  publisher    = {American Chemical Society},
  title        = {{Evidence for photocatalyst involvement in oxidative additions of nickel-catalyzed carboxylate O-arylations}},
  doi          = {10.1021/jacs.0c02848},
  volume       = {142},
  year         = {2020},
}

@article{11979,
  abstract     = {Dual photoredox/nickel-catalysed C–N cross-couplings suffer from low yields for electron-rich aryl halides. The formation of catalytically inactive nickel-black is responsible for this limitation and causes severe reproducibility issues. Here, we demonstrate that catalyst deactivation can be avoided by using a carbon nitride photocatalyst. The broad absorption of the heterogeneous photocatalyst enables wavelength-dependent control of the rate of reductive elimination to prevent nickel-black formation during the coupling of cyclic, secondary amines and aryl halides. A second approach, which is applicable to a broader set of electron-rich aryl halides, is to run the reactions at high concentrations to increase the rate of oxidative addition. Less nucleophilic, primary amines can be coupled with electron-rich aryl halides by stabilizing low-valent nickel intermediates with a suitable additive. The developed protocols enable reproducible, selective C–N cross-couplings of electron-rich aryl bromides and can also be applied for electron-poor aryl chlorides.},
  author       = {Gisbertz, Sebastian and Reischauer, Susanne and Pieber, Bartholomäus},
  issn         = {2520-1158},
  journal      = {Nature Catalysis},
  number       = {8},
  pages        = {611--620},
  publisher    = {Springer Nature},
  title        = {{Overcoming limitations in dual photoredox/nickel-catalysed C–N cross-couplings due to catalyst deactivation}},
  doi          = {10.1038/s41929-020-0473-6},
  volume       = {3},
  year         = {2020},
}

@article{11980,
  abstract     = {Small organic radicals are ubiquitous intermediates in photocatalysis and are used in organic synthesis to install functional groups and to tune electronic properties and pharmacokinetic parameters of the final molecule. Development of new methods to generate small organic radicals with added functionality can further extend the utility of photocatalysis for synthetic needs. Herein, we present a method to generate dichloromethyl radicals from chloroform using a heterogeneous potassium poly(heptazine imide) (K-PHI) photocatalyst under visible light irradiation for C1-extension of the enone backbone. The method is applied on 15 enones, with γ,γ-dichloroketones yields of 18–89%. Due to negative zeta-potential (−40 mV) and small particle size (100 nm) K-PHI suspension is used in quasi-homogeneous flow-photoreactor increasing the productivity by 19 times compared to the batch approach. The resulting γ,γ-dichloroketones, are used as bifunctional building blocks to access value-added organic compounds such as substituted furans and pyrroles.},
  author       = {Mazzanti, Stefano and Kurpil, Bogdan and Pieber, Bartholomäus and Antonietti, Markus and Savateev, Aleksandr},
  issn         = {2041-1723},
  journal      = {Nature Communications},
  publisher    = {Springer Nature},
  title        = {{Dichloromethylation of enones by carbon nitride photocatalysis}},
  doi          = {10.1038/s41467-020-15131-0},
  volume       = {11},
  year         = {2020},
}

@article{11986,
  abstract     = {Carbon nitride materials have emerged as an efficient and sustainable class of heterogeneous photocatalysts, particularly when paired with nickel in dual catalytic cross-coupling reactions. Performing these transformations on larger scales using a continuous process is difficult due to the problems associated with handling solids in flow. By combining an oscillatory pump with a microstructured plug flow photoreactor, a stable suspension of the photocatalyst can be maintained, circumventing clogging of the reactor channels. Through careful tuning of the oscillator properties, the residence time distribution (RTD) was optimized, whilst maintaining a stable catalyst suspension. Short residence times (20 min) were achieved using optimized conditions and the recyclability of the photocatalyst was demonstrated over 10 cycles with no loss of activity. During a stable 4.5 hour scale-out demonstration, the model substrate could be isolated on 12 g scale (90% yield, 2.67 g h−1). Moreover, the method was applied for the gram scale synthesis of an intermediate of the active pharmaceutical ingredient tetracaine.},
  author       = {Rosso, Cristian and Gisbertz, Sebastian and Williams, Jason D. and Gemoets, Hannes P. L. and Debrouwer, Wouter and Pieber, Bartholomäus and Kappe, C. Oliver},
  issn         = {2058-9883},
  journal      = {Reaction Chemistry and Engineering},
  number       = {3},
  pages        = {597--604},
  publisher    = {Royal Society of Chemistry},
  title        = {{An oscillatory plug flow photoreactor facilitates semi-heterogeneous dual nickel/carbon nitride photocatalytic C–N couplings}},
  doi          = {10.1039/d0re00036a},
  volume       = {5},
  year         = {2020},
}

@article{12192,
  abstract     = {Transposable elements (TEs), the movement of which can damage the genome, are epigenetically silenced in eukaryotes. Intriguingly, TEs are activated in the sperm companion cell – vegetative cell (VC) – of the flowering plant Arabidopsis thaliana. However, the extent and mechanism of this activation are unknown. Here we show that about 100 heterochromatic TEs are activated in VCs, mostly by DEMETER-catalyzed DNA demethylation. We further demonstrate that DEMETER access to some of these TEs is permitted by the natural depletion of linker histone H1 in VCs. Ectopically expressed H1 suppresses TEs in VCs by reducing DNA demethylation and via a methylation-independent mechanism. We demonstrate that H1 is required for heterochromatin condensation in plant cells and show that H1 overexpression creates heterochromatic foci in the VC progenitor cell. Taken together, our results demonstrate that the natural depletion of H1 during male gametogenesis facilitates DEMETER-directed DNA demethylation, heterochromatin relaxation, and TE activation.},
  author       = {He, Shengbo and Vickers, Martin and Zhang, Jingyi and Feng, Xiaoqi},
  issn         = {2050-084X},
  journal      = {eLife},
  keywords     = {General Immunology and Microbiology, General Biochemistry, Genetics and Molecular Biology, General Medicine, General Neuroscience},
  publisher    = {eLife Sciences Publications, Ltd},
  title        = {{Natural depletion of histone H1 in sex cells causes DNA demethylation, heterochromatin decondensation and transposon activation}},
  doi          = {10.7554/elife.42530},
  volume       = {8},
  year         = {2019},
}

@article{12600,
  abstract     = {The snow cover dynamics of High Mountain Asia are usually assessed at spatial resolutions of 250 m or greater, but this scale is too coarse to clearly represent the rugged topography common to the region. Higher-resolution measurement of snow-covered area often results in biased sampling due to cloud cover and deep shadows. We therefore develop a Normalized Difference Snow Index-based workflow to delineate snow lines from Landsat Thematic Mapper/Enhanced Thematic Mapper+ imagery and apply it to the upper Langtang Valley in Nepal, processing 194 scenes spanning 1999 to 2013. For each scene, we determine the spatial distribution of snow line altitudes (SLAs) with respect to aspect and across six subcatchments. Our results show that the mean SLA exhibits distinct seasonal behavior based on aspect and subcatchment position. We find that SLA dynamics respond to spatial and seasonal trade-offs in precipitation, temperature, and solar radiation, which act as primary controls. We identify two SLA spatial gradients, which we attribute to the effect of spatially variable precipitation. Our results also reveal that aspect-related SLA differences vary seasonally and are influenced by solar radiation. In terms of seasonal dominant controls, we demonstrate that the snow line is controlled by snow precipitation in winter, melt in premonsoon, a combination of both in postmonsoon, and temperature in monsoon, explaining to a large extent the spatial and seasonal variability of the SLA in the upper Langtang Valley. We conclude that while SLA and snow-covered area are complementary metrics, the SLA has a strong potential for understanding local-scale snow cover dynamics and their controlling mechanisms.},
  author       = {Girona‐Mata, Marc and Miles, Evan S. and Ragettli, Silvan and Pellicciotti, Francesca},
  issn         = {1944-7973},
  journal      = {Water Resources Research},
  keywords     = {Water Science and Technology},
  number       = {8},
  pages        = {6754--6772},
  publisher    = {American Geophysical Union},
  title        = {{High‐resolution snowline delineation from Landsat imagery to infer snow cover controls in a Himalayan catchment}},
  doi          = {10.1029/2019wr024935},
  volume       = {55},
  year         = {2019},
}

@article{12601,
  abstract     = {Ice cliffs and ponds on debris-covered glaciers have received increased attention due to their role in amplifying local melt. However, very few studies have looked at these features on the catchment scale to determine their patterns and changes in space and time. We have compiled a detailed inventory of cliffs and ponds in the Langtang catchment, central Himalaya, from six high-resolution satellite orthoimages and DEMs between 2006 and 2015, and a historic orthophoto from 1974. Cliffs cover between 1.4% (± 0.4%) in the dry and 3.4% (± 0.9%) in the wet seasons and ponds between 0.6% (± 0.1%) and 1.6% (± 0.3%) of the total debris-covered tongues. We find large variations between seasons, as cliffs and ponds tend to grow in the wetter monsoon period, but there is no obvious trend in total area over the study period. The inventory further shows that cliffs are predominately north-facing irrespective of the glacier flow direction. Both cliffs and ponds appear in higher densities several hundred metres from the terminus in areas where tributaries reach the main glacier tongue. On the largest glacier in the catchment ~10% of all cliffs and ponds persisted over nearly a decade.},
  author       = {STEINER, JAKOB F. and BURI, PASCAL and MILES, EVAN S. and RAGETTLI, SILVAN and Pellicciotti, Francesca},
  issn         = {1727-5652},
  journal      = {Journal of Glaciology},
  number       = {252},
  pages        = {617--632},
  publisher    = {Cambridge University Press},
  title        = {{Supraglacial ice cliffs and ponds on debris-covered glaciers: Spatio-temporal distribution and characteristics}},
  doi          = {10.1017/jog.2019.40},
  volume       = {65},
  year         = {2019},
}

@article{12602,
  abstract     = {This study aims at developing and applying a spatially-distributed coupled glacier mass balance and ice-flow model to attribute the response of glaciers to natural and anthropogenic climate change. We focus on two glaciers with contrasting surface characteristics: a debris-covered glacier (Langtang Glacier in Nepal) and a clean-ice glacier (Hintereisferner in Austria). The model is applied from the end of the Little Ice Age (1850) to the present-day (2016) and is forced with four bias-corrected General Circulation Models (GCMs) from the historical experiment of the CMIP5 archive. The selected GCMs represent region-specific warm-dry, warm-wet, cold-dry, and cold-wet climate conditions. To isolate the effects of anthropogenic climate change on glacier mass balance and flow runs from these GCMs with and without further anthropogenic forcing after 1970 until 2016 are selected. The outcomes indicate that both glaciers experience the largest reduction in area and volume under warm climate conditions, whereas area and volume reductions are smaller under cold climate conditions. Simultaneously with changes in glacier area and volume, surface velocities generally decrease over time. Without further anthropogenic forcing the results reveal a 3% (9%) smaller decline in glacier area (volume) for the debris-covered glacier and a 18% (39%) smaller decline in glacier area (volume) for the clean-ice glacier. The difference in the magnitude between the two glaciers can mainly be attributed to differences in the response time of the glaciers, where the clean-ice glacier shows a much faster response to climate change. We conclude that the response of the two glaciers can mainly be attributed to anthropogenic climate change and that the impact is larger on the clean-ice glacier. The outcomes show that the model performs well under different climate conditions and that the developed approach can be used for regional-scale glacio-hydrological modeling.},
  author       = {Wijngaard, René R. and Steiner, Jakob F. and Kraaijenbrink, Philip D. A. and Klug, Christoph and Adhikari, Surendra and Banerjee, Argha and Pellicciotti, Francesca and van Beek, Ludovicus P. H. and Bierkens, Marc F. P. and Lutz, Arthur F. and Immerzeel, Walter W.},
  issn         = {2296-6463},
  journal      = {Frontiers in Earth Science},
  publisher    = {Frontiers Media},
  title        = {{Modeling the response of the Langtang Glacier and the Hintereisferner to a changing climate since the Little Ice Age}},
  doi          = {10.3389/feart.2019.00143},
  volume       = {7},
  year         = {2019},
}