@article{7467,
  abstract     = {Nanomaterials produced from the bottom-up assembly of nanocrystals may incorporate ∼1020–1021 cm–3 not fully coordinated surface atoms, i.e., ∼1020–1021 cm–3 potential donor or acceptor states that can strongly affect transport properties. Therefore, to exploit the full potential of nanocrystal building blocks to produce functional nanomaterials and thin films, a proper control of their surface chemistry is required. Here, we analyze how the ligand stripping procedure influences the charge and heat transport properties of sintered PbSe nanomaterials produced from the bottom-up assembly of colloidal PbSe nanocrystals. First, we show that the removal of the native organic ligands by thermal decomposition in an inert atmosphere leaves relatively large amounts of carbon at the crystal interfaces. This carbon blocks crystal growth during consolidation and at the same time hampers charge and heat transport through the final nanomaterial. Second, we demonstrate that, by stripping ligands from the nanocrystal surface before consolidation, nanomaterials with larger crystal domains, lower porosity, and higher charge carrier concentrations are obtained, thus resulting in nanomaterials with higher electrical and thermal conductivities. In addition, the ligand displacement leaves the nanocrystal surface unprotected, facilitating oxidation and chalcogen evaporation. The influence of the ligand displacement on the nanomaterial charge transport properties is rationalized here using a two-band model based on the standard Boltzmann transport equation with the relaxation time approximation. Finally, we present an application of the produced functional nanomaterials by modeling, fabricating, and testing a simple PbSe-based thermoelectric device with a ring geometry.},
  author       = {Cadavid, Doris and Ortega, Silvia and Illera, Sergio and Liu, Yu and Ibáñez, Maria and Shavel, Alexey and Zhang, Yu and Li, Mengyao and López, Antonio M. and Noriega, Germán and Durá, Oscar Juan and López De La Torre, M. A. and Prades, Joan Daniel and Cabot, Andreu},
  issn         = {2574-0962},
  journal      = {ACS Applied Energy Materials},
  number       = {3},
  pages        = {2120--2129},
  publisher    = {American Chemical Society},
  title        = {{Influence of the ligand stripping on the transport properties of nanoparticle-based PbSe nanomaterials}},
  doi          = {10.1021/acsaem.9b02137},
  volume       = {3},
  year         = {2020},
}

@phdthesis{8589,
  abstract     = {The plant hormone auxin plays indispensable roles in plant growth and development. An essential level of regulation in auxin action is the directional auxin transport within cells. The establishment of auxin gradient in plant tissue has been attributed to local auxin biosynthesis and directional intercellular auxin transport, which both are controlled by various environmental and developmental signals. It is well established that asymmetric auxin distribution in cells is achieved by polarly localized PIN-FORMED (PIN) auxin efflux transporters. Despite the initial insights into cellular mechanisms of PIN polarization obtained from the last decades, the molecular mechanism and specific regulators mediating PIN polarization remains elusive. In this thesis, we aim to find novel players in PIN subcellular polarity regulation during Arabidopsis development. We first characterize the physiological effect of piperonylic acid (PA) on Arabidopsis hypocotyl gravitropic bending and PIN polarization. Secondly, we reveal the importance of SCFTIR1/AFB auxin signaling pathway in shoot gravitropism bending termination. In addition, we also explore the role of myosin XI complex, and actin cytoskeleton in auxin feedback regulation on PIN polarity. In Chapter 1, we give an overview of the current knowledge about PIN-mediated auxin fluxes in various plant tropic responses. In Chapter 2, we study the physiological effect of PA on shoot gravitropic bending. Our results show that PA treatment inhibits auxin-mediated PIN3 repolarization by interfering with PINOID and PIN3 phosphorylation status, ultimately leading to hyperbending hypocotyls. In Chapter 3, we provide evidence to show that the SCFTIR1/AFB nuclear auxin signaling pathway is crucial and required for auxin-mediated PIN3 repolarization and shoot gravitropic bending termination. In Chapter 4, we perform a phosphoproteomics approach and identify the motor protein Myosin XI and its binding protein, the MadB2 family, as an essential regulator of PIN polarity for auxin-canalization related developmental processes. In Chapter 5, we demonstrate the vital role of actin cytoskeleton in auxin feedback on PIN polarity by regulating PIN subcellular trafficking. Overall, the data presented in this PhD thesis brings novel insights into the PIN polar localization regulation that resulted in the (re)establishment of the polar auxin flow and gradient in response to environmental stimuli during plant development.},
  author       = {Han, Huibin},
  issn         = {2663-337X},
  pages        = {164},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Novel insights into PIN polarity regulation during Arabidopsis development}},
  doi          = {10.15479/AT:ISTA:8589},
  year         = {2020},
}

@inproceedings{8322,
  abstract     = {Reverse firewalls were introduced at Eurocrypt 2015 by Miro-nov and Stephens-Davidowitz, as a method for protecting cryptographic protocols against attacks on the devices of the honest parties. In a nutshell: a reverse firewall is placed outside of a device and its goal is to “sanitize” the messages sent by it, in such a way that a malicious device cannot leak its secrets to the outside world. It is typically assumed that the cryptographic devices are attacked in a “functionality-preserving way” (i.e. informally speaking, the functionality of the protocol remains unchanged under this attacks). In their paper, Mironov and Stephens-Davidowitz construct a protocol for passively-secure two-party computations with firewalls, leaving extension of this result to stronger models as an open question.
In this paper, we address this problem by constructing a protocol for secure computation with firewalls that has two main advantages over the original protocol from Eurocrypt 2015. Firstly, it is a multiparty computation protocol (i.e. it works for an arbitrary number n of the parties, and not just for 2). Secondly, it is secure in much stronger corruption settings, namely in the active corruption model. More precisely: we consider an adversary that can fully corrupt up to 𝑛−1 parties, while the remaining parties are corrupt in a functionality-preserving way.
Our core techniques are: malleable commitments and malleable non-interactive zero-knowledge, which in particular allow us to create a novel protocol for multiparty augmented coin-tossing into the well with reverse firewalls (that is based on a protocol of Lindell from Crypto 2001).},
  author       = {Chakraborty, Suvradip and Dziembowski, Stefan and Nielsen, Jesper Buus},
  booktitle    = {Advances in Cryptology – CRYPTO 2020},
  isbn         = {9783030568795},
  issn         = {1611-3349},
  location     = {Santa Barbara, CA, United States},
  pages        = {732--762},
  publisher    = {Springer Nature},
  title        = {{Reverse firewalls for actively secure MPCs}},
  doi          = {10.1007/978-3-030-56880-1_26},
  volume       = {12171},
  year         = {2020},
}

@inproceedings{7636,
  abstract     = {Balanced search trees typically use key comparisons to guide their operations, and achieve logarithmic running time. By relying on numerical properties of the keys, interpolation search achieves lower search complexity and better performance. Although interpolation-based data structures were investigated in the past, their non-blocking concurrent variants have received very little attention so far.
In this paper, we propose the first non-blocking implementation of the classic interpolation search tree (IST) data structure. For arbitrary key distributions, the data structure ensures worst-case O(log n + p) amortized time for search, insertion and deletion traversals. When the input key distributions are smooth, lookups run in expected O(log log n + p) time, and insertion and deletion run in expected amortized O(log log n + p) time, where p is a bound on the number of threads. To improve the scalability of concurrent insertion and deletion, we propose a novel parallel rebuilding technique, which should be of independent interest.
We evaluate whether the theoretical improvements translate to practice by implementing the concurrent interpolation search tree, and benchmarking it on uniform and nonuniform key distributions, for dataset sizes in the millions to billions of keys. Relative to the state-of-the-art concurrent data structures, the concurrent interpolation search tree achieves performance improvements of up to 15% under high update rates, and of up to 50% under moderate update rates. Further, ISTs exhibit up to 2X less cache-misses, and consume 1.2 -- 2.6X less memory compared to the next best alternative on typical dataset sizes. We find that the results are surprisingly robust to distributional skew, which suggests that our data structure can be a promising alternative to classic concurrent search structures.},
  author       = {Brown, Trevor A and Prokopec, Aleksandar and Alistarh, Dan-Adrian},
  booktitle    = {Proceedings of the ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming},
  isbn         = {9781450368186},
  location     = {San Diego, CA, United States},
  pages        = {276--291},
  publisher    = {Association for Computing Machinery},
  title        = {{Non-blocking interpolation search trees with doubly-logarithmic running time}},
  doi          = {10.1145/3332466.3374542},
  year         = {2020},
}

@article{7472,
  abstract     = {Temporally organized reactivation of experiences during awake immobility periods is thought to underlie cognitive processes like planning and evaluation. While replay of trajectories is well established for the hippocampus, it is unclear whether the medial prefrontal cortex (mPFC) can reactivate sequential behavioral experiences in the awake state to support task execution. We simultaneously recorded from hippocampal and mPFC principal neurons in rats performing a mPFC-dependent rule-switching task on a plus maze. We found that mPFC neuronal activity encoded relative positions between the start and goal. During awake immobility periods, the mPFC replayed temporally organized sequences of these generalized positions, resembling entire spatial trajectories. The occurrence of mPFC trajectory replay positively correlated with rule-switching performance. However, hippocampal and mPFC trajectory replay occurred independently, indicating different functions. These results demonstrate that the mPFC can replay ordered activity patterns representing generalized locations and suggest that mPFC replay might have a role in flexible behavior.},
  author       = {Käfer, Karola and Nardin, Michele and Blahna, Karel and Csicsvari, Jozsef L},
  issn         = {0896-6273},
  journal      = {Neuron},
  number       = {1},
  pages        = {P154--165.e6},
  publisher    = {Elsevier},
  title        = {{Replay of behavioral sequences in the medial prefrontal cortex during rule switching}},
  doi          = {10.1016/j.neuron.2020.01.015},
  volume       = {106},
  year         = {2020},
}

@article{7643,
  author       = {Han, Huibin and Rakusova, Hana and Verstraeten, Inge and Zhang, Yuzhou and Friml, Jiří},
  issn         = {1532-2548},
  journal      = {Plant Physiology},
  number       = {5},
  pages        = {37--40},
  publisher    = {American Society of Plant Biologists},
  title        = {{SCF TIR1/AFB auxin signaling for bending termination during shoot gravitropism}},
  doi          = {10.1104/pp.20.00212},
  volume       = {183},
  year         = {2020},
}

@article{6952,
  abstract     = {We present a unified framework tackling two problems: class-specific 3D reconstruction from a single image, and generation of new 3D shape samples. These tasks have received considerable attention recently; however, most existing approaches rely on 3D supervision, annotation of 2D images with keypoints or poses, and/or training with multiple views of each object instance. Our framework is very general: it can be trained in similar settings to existing approaches, while also supporting weaker supervision. Importantly, it can be trained purely from 2D images, without pose annotations, and with only a single view per instance. We employ meshes as an output representation, instead of voxels used in most prior work. This allows us to reason over lighting parameters and exploit shading information during training, which previous 2D-supervised methods cannot. Thus, our method can learn to generate and reconstruct concave object classes. We evaluate our approach in various settings, showing that: (i) it learns to disentangle shape from pose and lighting; (ii) using shading in the loss improves performance compared to just silhouettes; (iii) when using a standard single white light, our model outperforms state-of-the-art 2D-supervised methods, both with and without pose supervision, thanks to exploiting shading cues; (iv) performance improves further when using multiple coloured lights, even approaching that of state-of-the-art 3D-supervised methods; (v) shapes produced by our model capture smooth surfaces and fine details better than voxel-based approaches; and (vi) our approach supports concave classes such as bathtubs and sofas, which methods based on silhouettes cannot learn.},
  author       = {Henderson, Paul M and Ferrari, Vittorio},
  issn         = {1573-1405},
  journal      = {International Journal of Computer Vision},
  pages        = {835--854},
  publisher    = {Springer Nature},
  title        = {{Learning single-image 3D reconstruction by generative modelling of shape, pose and shading}},
  doi          = {10.1007/s11263-019-01219-8},
  volume       = {128},
  year         = {2020},
}

@article{8755,
  abstract     = {The superconducting circuit community has recently discovered the promising potential of superinductors. These circuit elements have a characteristic impedance exceeding the resistance quantum RQ ≈ 6.45 kΩ which leads to a suppression of ground state charge fluctuations. Applications include the realization of hardware protected qubits for fault tolerant quantum computing, improved coupling to small dipole moment objects and defining a new quantum metrology standard for the ampere. In this work we refute the widespread notion that superinductors can only be implemented based on kinetic inductance, i.e. using disordered superconductors or Josephson junction arrays. We present modeling, fabrication and characterization of 104 planar aluminum coil resonators with a characteristic impedance up to 30.9 kΩ at 5.6 GHz and a capacitance down to ≤ 1 fF, with lowloss and a power handling reaching 108 intra-cavity photons. Geometric superinductors are free of uncontrolled tunneling events and offer high reproducibility, linearity and the ability to couple magnetically - properties that significantly broaden the scope of future quantum circuits. },
  author       = {Peruzzo, Matilda and Trioni, Andrea and Hassani, Farid and Zemlicka, Martin and Fink, Johannes M},
  issn         = {2331-7019},
  journal      = {Physical Review Applied},
  number       = {4},
  publisher    = {American Physical Society},
  title        = {{Surpassing the resistance quantum with a geometric superinductor}},
  doi          = {10.1103/PhysRevApplied.14.044055},
  volume       = {14},
  year         = {2020},
}

@article{6185,
  abstract     = {For complex Wigner-type matrices, i.e. Hermitian random matrices with independent, not necessarily identically distributed entries above the diagonal, we show that at any cusp singularity of the limiting eigenvalue distribution the local eigenvalue statistics are universal and form a Pearcey process. Since the density of states typically exhibits only square root or cubic root cusp singularities, our work complements previous results on the bulk and edge universality and it thus completes the resolution of the Wigner–Dyson–Mehta universality conjecture for the last remaining universality type in the complex Hermitian class. Our analysis holds not only for exact cusps, but approximate cusps as well, where an extended Pearcey process emerges. As a main technical ingredient we prove an optimal local law at the cusp for both symmetry classes. This result is also the key input in the companion paper (Cipolloni et al. in Pure Appl Anal, 2018. arXiv:1811.04055) where the cusp universality for real symmetric Wigner-type matrices is proven. The novel cusp fluctuation mechanism is also essential for the recent results on the spectral radius of non-Hermitian random matrices (Alt et al. in Spectral radius of random matrices with independent entries, 2019. arXiv:1907.13631), and the non-Hermitian edge universality (Cipolloni et al. in Edge universality for non-Hermitian random matrices, 2019. arXiv:1908.00969).},
  author       = {Erdös, László and Krüger, Torben H and Schröder, Dominik J},
  issn         = {1432-0916},
  journal      = {Communications in Mathematical Physics},
  pages        = {1203--1278},
  publisher    = {Springer Nature},
  title        = {{Cusp universality for random matrices I: Local law and the complex Hermitian case}},
  doi          = {10.1007/s00220-019-03657-4},
  volume       = {378},
  year         = {2020},
}

@article{6184,
  abstract     = {We prove edge universality for a general class of correlated real symmetric or complex Hermitian Wigner matrices with arbitrary expectation. Our theorem also applies to internal edges of the self-consistent density of states. In particular, we establish a strong form of band rigidity which excludes mismatches between location and label of eigenvalues close to internal edges in these general models.},
  author       = {Alt, Johannes and Erdös, László and Krüger, Torben H and Schröder, Dominik J},
  issn         = {0091-1798},
  journal      = {Annals of Probability},
  number       = {2},
  pages        = {963--1001},
  publisher    = {Institute of Mathematical Statistics},
  title        = {{Correlated random matrices: Band rigidity and edge universality}},
  doi          = {10.1214/19-AOP1379},
  volume       = {48},
  year         = {2020},
}

@inproceedings{7481,
  abstract     = {We address the following question:  How redundant is the parameterisation of ReLU networks? Specifically, we consider transformations of the weight space which leave the function implemented by the network intact.  Two such transformations are known for feed-forward architectures:  permutation of neurons within a layer, and positive scaling of all incoming weights of a neuron coupled with inverse scaling of its outgoing weights. In this work, we show for architectures with non-increasing widths that permutation and scaling are in fact the only function-preserving weight transformations.  For any eligible architecture we give an explicit construction of a neural network such that any other network that implements the same function can be obtained from the original one by the application of permutations and rescaling.  The proof relies on a geometric understanding of boundaries between linear regions of ReLU networks, and we hope the developed mathematical tools are of independent interest.},
  author       = {Bui Thi Mai, Phuong and Lampert, Christoph},
  booktitle    = {8th International Conference on Learning Representations},
  location     = {Online},
  title        = {{Functional vs. parametric equivalence of ReLU networks}},
  year         = {2020},
}

@phdthesis{7896,
  abstract     = {A search problem lies in the complexity class FNP if a solution to the given instance of the problem can be verified efficiently. The complexity class TFNP consists of all search problems in FNP that are total in the sense that a solution is guaranteed to exist. TFNP contains a host of interesting problems from fields such as algorithmic game theory, computational topology, number theory and combinatorics. Since TFNP is a semantic class, it is unlikely to have a complete problem. Instead, one studies its syntactic subclasses which are defined based on the combinatorial principle used to argue totality. Of particular interest is the subclass PPAD, which contains important problems
like computing Nash equilibrium for bimatrix games and computational counterparts of several fixed-point theorems as complete. In the thesis, we undertake the study of averagecase hardness of TFNP, and in particular its subclass PPAD.
Almost nothing was known about average-case hardness of PPAD before a series of recent results showed how to achieve it using a cryptographic primitive called program obfuscation.
However, it is currently not known how to construct program obfuscation from standard cryptographic assumptions. Therefore, it is desirable to relax the assumption under which average-case hardness of PPAD can be shown. In the thesis we take a step in this direction. First, we show that assuming the (average-case) hardness of a numbertheoretic
problem related to factoring of integers, which we call Iterated-Squaring, PPAD is hard-on-average in the random-oracle model. Then we strengthen this result to show that the average-case hardness of PPAD reduces to the (adaptive) soundness of the Fiat-Shamir Transform, a well-known technique used to compile a public-coin interactive protocol into a non-interactive one. As a corollary, we obtain average-case hardness for PPAD in the random-oracle model assuming the worst-case hardness of #SAT. Moreover, the above results can all be strengthened to obtain average-case hardness for the class CLS ⊆ PPAD.
Our main technical contribution is constructing incrementally-verifiable procedures for computing Iterated-Squaring and #SAT. By incrementally-verifiable, we mean that every intermediate state of the computation includes a proof of its correctness, and the proof can be updated and verified in polynomial time. Previous constructions of such procedures relied on strong, non-standard assumptions. Instead, we introduce a technique called recursive proof-merging to obtain the same from weaker assumptions. },
  author       = {Kamath Hosdurg, Chethan},
  issn         = {2663-337X},
  pages        = {126},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{On the average-case hardness of total search problems}},
  doi          = {10.15479/AT:ISTA:7896},
  year         = {2020},
}

@article{179,
  abstract     = {An asymptotic formula is established for the number of rational points of bounded anticanonical height which lie on a certain Zariski dense subset of the biprojective hypersurface x1y21+⋯+x4y24=0 in ℙ3×ℙ3. This confirms the modified Manin conjecture for this variety, in which the removal of a thin set of rational points is allowed.},
  author       = {Browning, Timothy D and Heath Brown, Roger},
  issn         = {0012-7094},
  journal      = {Duke Mathematical Journal},
  number       = {16},
  pages        = {3099--3165},
  publisher    = {Duke University Press},
  title        = {{Density of rational points on a quadric bundle in ℙ3×ℙ3}},
  doi          = {10.1215/00127094-2020-0031},
  volume       = {169},
  year         = {2020},
}

@article{177,
  abstract     = {We develop a geometric version of the circle method and use it to compute the compactly supported cohomology of the space of rational curves through a point on a smooth affine hypersurface of sufficiently low degree.},
  author       = {Browning, Timothy D and Sawin, Will},
  journal      = {Annals of Mathematics},
  number       = {3},
  pages        = {893--948},
  publisher    = {Princeton University},
  title        = {{A geometric version of the circle method}},
  doi          = {10.4007/annals.2020.191.3.4},
  volume       = {191},
  year         = {2020},
}

@article{8586,
  abstract     = {Cryo-electron microscopy (cryo-EM) of cellular specimens provides insights into biological processes and structures within a native context. However, a major challenge still lies in the efficient and reproducible preparation of adherent cells for subsequent cryo-EM analysis. This is due to the sensitivity of many cellular specimens to the varying seeding and culturing conditions required for EM experiments, the often limited amount of cellular material and also the fragility of EM grids and their substrate. Here, we present low-cost and reusable 3D printed grid holders, designed to improve specimen preparation when culturing challenging cellular samples directly on grids. The described grid holders increase cell culture reproducibility and throughput, and reduce the resources required for cell culturing. We show that grid holders can be integrated into various cryo-EM workflows, including micro-patterning approaches to control cell seeding on grids, and for generating samples for cryo-focused ion beam milling and cryo-electron tomography experiments. Their adaptable design allows for the generation of specialized grid holders customized to a large variety of applications.},
  author       = {Fäßler, Florian and Zens, Bettina and Hauschild, Robert and Schur, Florian KM},
  issn         = {1047-8477},
  journal      = {Journal of Structural Biology},
  keywords     = {electron microscopy, cryo-EM, EM sample preparation, 3D printing, cell culture},
  number       = {3},
  publisher    = {Elsevier},
  title        = {{3D printed cell culture grid holders for improved cellular specimen preparation in cryo-electron microscopy}},
  doi          = {10.1016/j.jsb.2020.107633},
  volume       = {212},
  year         = {2020},
}

@article{7473,
  abstract     = {How structural and functional properties of synapses relate to each other is a fundamental question in neuroscience. Electrophysiology has elucidated mechanisms of synaptic transmission, and electron microscopy (EM) has provided insight into morphological properties of synapses. Here we describe an enhanced method for functional EM (“flash and freeze”), combining optogenetic stimulation with high-pressure freezing. We demonstrate that the improved method can be applied to intact networks in acute brain slices and organotypic slice cultures from mice. As a proof of concept, we probed vesicle pool changes during synaptic transmission at the hippocampal mossy fiber-CA3 pyramidal neuron synapse. Our findings show overlap of the docked vesicle pool and the functionally defined readily releasable pool and provide evidence of fast endocytosis at this synapse. Functional EM with acute slices and slice cultures has the potential to reveal the structural and functional mechanisms of transmission in intact, genetically perturbed, and disease-affected synapses.},
  author       = {Borges Merjane, Carolina and Kim, Olena and Jonas, Peter M},
  issn         = {0896-6273},
  journal      = {Neuron},
  pages        = {992--1006},
  publisher    = {Elsevier},
  title        = {{Functional electron microscopy (“Flash and Freeze”) of identified cortical synapses in acute brain slices}},
  doi          = {10.1016/j.neuron.2019.12.022},
  volume       = {105},
  year         = {2020},
}

@article{7387,
  abstract     = {Most bacteria accomplish cell division with the help of a dynamic protein complex called the divisome, which spans the cell envelope in the plane of division. Assembly and activation of this machinery are coordinated by the tubulin-related GTPase FtsZ, which was found to form treadmilling filaments on supported bilayers in vitro1, as well as in live cells, in which filaments circle around the cell division site2,3. Treadmilling of FtsZ is thought to actively move proteins around the division septum, thereby distributing peptidoglycan synthesis and coordinating the inward growth of the septum to form the new poles of the daughter cells4. However, the molecular mechanisms underlying this function are largely unknown. Here, to study how FtsZ polymerization dynamics are coupled to downstream proteins, we reconstituted part of the bacterial cell division machinery using its purified components FtsZ, FtsA and truncated transmembrane proteins essential for cell division. We found that the membrane-bound cytosolic peptides of FtsN and FtsQ co-migrated with treadmilling FtsZ–FtsA filaments, but despite their directed collective behaviour, individual peptides showed random motion and transient confinement. Our work suggests that divisome proteins follow treadmilling FtsZ filaments by a diffusion-and-capture mechanism, which can give rise to a moving zone of signalling activity at the division site.},
  author       = {Baranova, Natalia S. and Radler, Philipp and Hernández-Rocamora, Víctor M. and Alfonso, Carlos and Lopez Pelegrin, Maria D and Rivas, Germán and Vollmer, Waldemar and Loose, Martin},
  issn         = {2058-5276},
  journal      = {Nature Microbiology},
  pages        = {407--417},
  publisher    = {Springer Nature},
  title        = {{Diffusion and capture permits dynamic coupling between treadmilling FtsZ filaments and cell division proteins}},
  doi          = {10.1038/s41564-019-0657-5},
  volume       = {5},
  year         = {2020},
}

@article{7888,
  abstract     = {Embryonic stem cell cultures are thought to self-organize into embryoid bodies, able to undergo symmetry-breaking, germ layer specification and even morphogenesis. Yet, it is unclear how to reconcile this remarkable self-organization capacity with classical experiments demonstrating key roles for extrinsic biases by maternal factors and/or extraembryonic tissues in embryogenesis. Here, we show that zebrafish embryonic tissue explants, prepared prior to germ layer induction and lacking extraembryonic tissues, can specify all germ layers and form a seemingly complete mesendoderm anlage. Importantly, explant organization requires polarized inheritance of maternal factors from dorsal-marginal regions of the blastoderm. Moreover, induction of endoderm and head-mesoderm, which require peak Nodal-signaling levels, is highly variable in explants, reminiscent of embryos with reduced Nodal signals from the extraembryonic tissues. Together, these data suggest that zebrafish explants do not undergo bona fide self-organization, but rather display features of genetically encoded self-assembly, where intrinsic genetic programs control the emergence of order.},
  author       = {Schauer, Alexandra and Nunes Pinheiro, Diana C and Hauschild, Robert and Heisenberg, Carl-Philipp J},
  issn         = {2050-084X},
  journal      = {eLife},
  publisher    = {eLife Sciences Publications},
  title        = {{Zebrafish embryonic explants undergo genetically encoded self-assembly}},
  doi          = {10.7554/elife.55190},
  volume       = {9},
  year         = {2020},
}

@article{7885,
  abstract     = {Eukaryotic cells migrate by coupling the intracellular force of the actin cytoskeleton to the environment. While force coupling is usually mediated by transmembrane adhesion receptors, especially those of the integrin family, amoeboid cells such as leukocytes can migrate extremely fast despite very low adhesive forces1. Here we show that leukocytes cannot only migrate under low adhesion but can also transmit forces in the complete absence of transmembrane force coupling. When confined within three-dimensional environments, they use the topographical features of the substrate to propel themselves. Here the retrograde flow of the actin cytoskeleton follows the texture of the substrate, creating retrograde shear forces that are sufficient to drive the cell body forwards. Notably, adhesion-dependent and adhesion-independent migration are not mutually exclusive, but rather are variants of the same principle of coupling retrograde actin flow to the environment and thus can potentially operate interchangeably and simultaneously. As adhesion-free migration is independent of the chemical composition of the environment, it renders cells completely autonomous in their locomotive behaviour.},
  author       = {Reversat, Anne and Gärtner, Florian R and Merrin, Jack and Stopp, Julian A and Tasciyan, Saren and Aguilera Servin, Juan L and De Vries, Ingrid and Hauschild, Robert and Hons, Miroslav and Piel, Matthieu and Callan-Jones, Andrew and Voituriez, Raphael and Sixt, Michael K},
  issn         = {1476-4687},
  journal      = {Nature},
  pages        = {582–585},
  publisher    = {Springer Nature},
  title        = {{Cellular locomotion using environmental topography}},
  doi          = {10.1038/s41586-020-2283-z},
  volume       = {582},
  year         = {2020},
}

@inproceedings{9198,
  abstract     = {The optimization of multilayer neural networks typically leads to a solution
with zero training error, yet the landscape can exhibit spurious local minima
and the minima can be disconnected. In this paper, we shed light on this
phenomenon: we show that the combination of stochastic gradient descent (SGD)
and over-parameterization makes the landscape of multilayer neural networks
approximately connected and thus more favorable to optimization. More
specifically, we prove that SGD solutions are connected via a piecewise linear
path, and the increase in loss along this path vanishes as the number of
neurons grows large. This result is a consequence of the fact that the
parameters found by SGD are increasingly dropout stable as the network becomes
wider. We show that, if we remove part of the neurons (and suitably rescale the
remaining ones), the change in loss is independent of the total number of
neurons, and it depends only on how many neurons are left. Our results exhibit
a mild dependence on the input dimension: they are dimension-free for two-layer
networks and depend linearly on the dimension for multilayer networks. We
validate our theoretical findings with numerical experiments for different
architectures and classification tasks.},
  author       = {Shevchenko, Aleksandr and Mondelli, Marco},
  booktitle    = {Proceedings of the 37th International Conference on Machine Learning},
  pages        = {8773--8784},
  publisher    = {ML Research Press},
  title        = {{Landscape connectivity and dropout stability of SGD solutions for over-parameterized neural networks}},
  volume       = {119},
  year         = {2020},
}