@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},
}
@inproceedings{8382,
abstract = {We present the first deterministic wait-free long-lived snapshot algorithm, using only read and write operations, that guarantees polylogarithmic amortized step complexity in all executions. This is the first non-blocking snapshot algorithm, using reads and writes only, that has sub-linear amortized step complexity in executions of arbitrary length. The key to our construction is a novel implementation of a 2-component max array object which may be of independent interest.},
author = {Baig, Mirza Ahad and Hendler, Danny and Milani, Alessia and Travers, Corentin},
booktitle = {Proceedings of the 39th Symposium on Principles of Distributed Computing},
isbn = {9781450375825},
location = {Virtual, Italy},
pages = {31--40},
publisher = {Association for Computing Machinery},
title = {{Long-lived snapshots with polylogarithmic amortized step complexity}},
doi = {10.1145/3382734.3406005},
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},
}
@article{22479,
abstract = {AbstractClimate impact studies often require climate data at a higher space–time resolution than is available from global and regional climate models. Weather generator (WG) models, generally designed for mesoscale applications (e.g., 101–105 km2), are popular and widely used tools to downscale climate data to finer resolution. One advantage of using WGs is their ability to generate the necessary climate variables for impact studies in data sparse regions. In this study, we evaluate the ability of a previously established state of the art WG (the AWE‐GEN‐2d model) to perform in data sparse regions that are beyond the mesoscale, using the Zambezi River basin (106 km2) in southeast Africa as a case study. The AWE‐GEN‐2d model was calibrated using data from satellite retrievals and climate re‐analysis products in place of the absent observational data. An 8‐km climate ensemble at hourly resolution, covering the period of 1976–2099 (present climate and RCP4.5 emission scenario from 2020), was then simulated. Using the simulated 30‐member ensemble, climate indices for both present and future climates were computed. The high‐resolution climate indices allow detailed analysis of the effects of climate change on different areas within the basin. For example, the southwestern area of the basin is predicted to experience the greatest change due to increased temperature, while the southeastern area was found to be already so hot that is less affected (e.g., the number of 'very hot days' per year increase by 18 and 9 days, respectively). Rainfall intensities are found to increase most in the eastern areas of the basin (1 mm·d−1) in comparison to the western region (0.3 mm·d−1). As demonstrated in this study, AWE‐GEN‐2d can be calibrated successfully using data from climate reanalysis products in the absence of ground station data and can be applied at larger scales than the mesoscale.},
author = {Peleg, Nadav and Sinclair, Scott and Fatichi, Simone and Burlando, Paolo},
issn = {1097-0088},
journal = {International Journal of Climatology},
number = {15},
pages = {6242--6264},
publisher = {Wiley},
title = {{Downscaling climate projections over large and data sparse regions: Methodological application in the Zambezi River Basin}},
doi = {10.1002/joc.6578},
volume = {40},
year = {2020},
}
@article{22437,
abstract = {Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model‐data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are as follows: (a) Inter‐model variation is generally large and model agreement varies with timescales. In severely water‐limited sites, models only agree on the interannual variability of evapotranspiration and to a smaller extent on gross primary productivity. In more mesic sites, model agreement for both water and carbon fluxes is typically higher on fine (daily–monthly) timescales and reduces on longer (seasonal–annual) scales. (b) Models on average overestimate the relationship between ecosystem productivity and mean rainfall amounts across sites (in space) and have a low capacity in reproducing the temporal (interannual) sensitivity of vegetation productivity to annual rainfall at a given site, even though observation uncertainty is comparable to inter‐model variability. (c) Most models reproduced the sign of the observed patterns in productivity changes in rainfall manipulation experiments but had a low capacity in reproducing the observed magnitude of productivity changes. Models better reproduced the observed productivity responses due to rainfall exclusion than addition. (d) All models attribute ecosystem productivity changes to the intensity of vegetation stress and peak leaf area, whereas the impact of the change in growing season length is negligible. The relative contribution of the peak leaf area and vegetation stress intensity was highly variable among models.},
author = {Paschalis, Athanasios and Fatichi, Simone and Zscheischler, Jakob and Ciais, Philippe and Bahn, Michael and Boysen, Lena and Chang, Jinfeng and De Kauwe, Martin and Estiarte, Marc and Goll, Daniel and Hanson, Paul J. and Harper, Anna B. and Hou, Enqing and Kigel, Jaime and Knapp, Alan K. and Larsen, Klaus S. and Li, Wei and Lienert, Sebastian and Luo, Yiqi and Meir, Patrick and Nabel, Julia E. M. S. and Ogaya, Romà and Parolari, Anthony J. and Peng, Changhui and Peñuelas, Josep and Pongratz, Julia and Rambal, Serge and Schmidt, Inger K. and Shi, Hao and Sternberg, Marcelo and Tian, Hanqin and Tschumi, Elisabeth and Ukkola, Anna and Vicca, Sara and Viovy, Nicolas and Wang, Ying‐Ping and Wang, Zhuonan and Williams, Karina and Wu, Donghai and Zhu, Qiuan},
issn = {1365-2486},
journal = {Global Change Biology},
number = {6},
pages = {3336--3355},
publisher = {Wiley},
title = {{Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand?}},
doi = {10.1111/gcb.15024},
volume = {26},
year = {2020},
}
@article{22473,
abstract = {The vadose zone is a zone sensitive to environmental
changes and exerts a crucial control in ecosystem functioning and even more
so in cold regions considering the rapid change in seasonally frozen ground
under climate warming. While the way in representing the underlying physical
process of the vadose zone differs among models, the effect of such differences
on ecosystem functioning and its ecohydrological response to freeze–thaw
cycles are seldom reported. Here, the detailed vadose zone process model
STEMMUS (Simultaneous Transfer of Energy, Mass
and Momentum in Unsaturated Soil) was coupled with the ecohydrological model Tethys–Chloris (T&C) to investigate the
role of influential physical processes during freeze–thaw cycles. The
physical representation is increased from using T&C coupling without STEMMUS enabling the
simultaneous mass and energy transfer in the soil system (liquid, vapor,
ice) – and with
explicit consideration of the impact of soil ice content on energy and water
transfer properties – to using T&C coupling with it. We tested model performance with the aid of a comprehensive
observation dataset collected at a typical meadow ecosystem on the Tibetan
Plateau. Results indicated that (i) explicitly considering the frozen soil
process significantly improved the soil moisture/temperature profile
simulations and facilitated our understanding of the water transfer
processes within the soil–plant–atmosphere continuum; (ii) the difference
among various representations of vadose zone physics have an impact on the
vegetation dynamics mainly at the beginning of the growing season; and (iii) models with different vadose zone physics can predict similar interannual
vegetation dynamics, as well as energy, water, and carbon exchanges, at the land
surface. This research highlights the important role of vadose zone physics
for ecosystem functioning in cold regions and can support the development
and application of future Earth system models.},
author = {Yu, Lianyu and Fatichi, Simone and Zeng, Yijian and Su, Zhongbo},
issn = {1994-0424},
journal = {The Cryosphere},
number = {12},
pages = {4653--4673},
publisher = {Copernicus Publications},
title = {{The role of vadose zone physics in the ecohydrological response of a Tibetan meadow to freeze–thaw cycles}},
doi = {10.5194/tc-14-4653-2020},
volume = {14},
year = {2020},
}
@article{22458,
abstract = {Groundwater can have a critical role in sustaining the functioning of natural ecosystems during droughts, especially in dry and seasonally dry climates. However, the response to droughts of ecosystems embedded in urban areas is not well known. This study investigates how different scenarios of groundwater availability control the water balance and vegetation productivity of two urban reserves hosting native vegetation in the Melbourne metropolitan area, Australia. Using a mechanistic ecohydrological model supported by field observations, long-term simulations were run to explore the impact of groundwater flow on water, carbon, and energy fluxes under present climatic conditions, including the Millennium Drought (2001–2009), and in response to perturbations in key environmental variables (air temperature, atmospheric CO2 concentrations, and rainfall). It was found that the presence of a water table and its capillary fringe within the root depths supports ecosystem transpiration and vegetation productivity. The effects of declining groundwater were found to be more severe in predominantly sandy soils because of the lower water holding capacity, identifying that the water status of vegetation differs significantly depending on soil type. Differences in rooting strategies and groundwater availability also had a pivotal role in helping plants soften the impacts of increased air temperature (Ta) and make use of higher atmospheric CO2 concentrations. Increased Ta strongly affected evapotranspiration, enhancing the competition for water between different vegetation types. These results provide quantitative insights of how vegetation responds to groundwater depletion and climate variability, highlighting the essential role of groundwater resources in urban ecosystems characterized by seasonally dry climates.},
author = {Marchionni, V. and Daly, E. and Manoli, G. and Tapper, N. J. and Walker, J. P. and Fatichi, Simone},
issn = {1944-7973},
journal = {Water Resources Research},
number = {5},
publisher = {American Geophysical Union},
title = {{Groundwater buffers drought effects and climate variability in urban reserves}},
doi = {10.1029/2019wr026192},
volume = {56},
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{22558,
abstract = {Heavy rainfall is expected to intensify with increasing
temperatures, which will likely affect rainfall spatial characteristics. The
spatial variability of rainfall can affect streamflow and sediment transport
volumes and peaks. Yet, the effect of climate change on the small-scale
spatial structure of heavy rainfall and subsequent impacts on hydrology and
geomorphology remain largely unexplored. In this study, the sensitivity of
the hydro-morphological response to heavy rainfall at the small-scale
resolution of minutes and hundreds of metres was investigated. A numerical
experiment was conducted in which synthetic rainfall fields representing
heavy rainfall events of two types, stratiform and convective, were
simulated using a space-time rainfall generator model. The rainfall fields
were modified to follow different spatial rainfall scenarios associated
with increasing temperatures and used as inputs into a landscape evolution
model. The experiment was conducted over a complex topography, a medium-sized
(477 km2) Alpine catchment in central Switzerland. It was found that
the responses of the streamflow and sediment yields are highly sensitive to
changes in total rainfall volume and to a lesser extent to changes in local
peak rainfall intensities. The results highlight that the morphological
components are more sensitive to changes in rainfall spatial structure in
comparison to the hydrological components. The hydro-morphological features
were found to respond more to convective rainfall than stratiform rainfall
because of localized runoff and erosion production. It is further shown that
assuming heavy rainfall to intensify with increasing temperatures without
introducing changes in the rainfall spatial structure might lead to
overestimation of future climate impacts on basin hydro-morphology.},
author = {Peleg, Nadav and Skinner, Chris and Fatichi, Simone and Molnar, Peter},
issn = {2196-632X},
journal = {Earth Surface Dynamics},
number = {1},
pages = {17--36},
publisher = {Copernicus Publications},
title = {{Temperature effects on the spatial structure of heavy rainfall modify catchment hydro-morphological response}},
doi = {10.5194/esurf-8-17-2020},
volume = {8},
year = {2020},
}
@article{22567,
abstract = {Most soil hydraulic information used in Earth System Models (ESMs) is derived from pedo-transfer functions that use easy-to-measure soil attributes to estimate hydraulic parameters. This parameterization relies heavily on soil texture, but overlooks the critical role of soil structure originated by soil biophysical activity. Soil structure omission is pervasive also in sampling and measurement methods used to train pedotransfer functions. Here we show how systematic inclusion of salient soil structural features of biophysical origin affect local and global hydrologic and climatic responses. Locally, including soil structure in models significantly alters infiltration-runoff partitioning and recharge in wet and vegetated regions. Globally, the coarse spatial resolution of ESMs and their inability to simulate intense and short rainfall events mask effects of soil structure on surface fluxes and climate. Results suggest that although soil structure affects local hydrologic response, its implications on global-scale climate remains elusive in current ESMs.},
author = {Fatichi, Simone and Or, Dani and Walko, Robert and Vereecken, Harry and Young, Michael H. and Ghezzehei, Teamrat A. and Hengl, Tomislav and Kollet, Stefan and Agam, Nurit and Avissar, Roni},
issn = {2041-1723},
journal = {Nature Communications},
publisher = {Springer Nature},
title = {{Soil structure is an important omission in Earth System Models}},
doi = {10.1038/s41467-020-14411-z},
volume = {11},
year = {2020},
}
@article{22565,
abstract = {Solutes in rivers often come from multiple sources, notably precipitation (above) and generation from the subsurface (below). The question of which source is more influential in shaping the dynamics of solute concentration cannot be easily addressed due to the general lack of input data. An analysis of solute concentrations and their dependence on discharge across 585 catchments in nine countries leads us to hypothesize that both the timing and the vertical distribution of the solute generation are important drivers of solute export dynamics at the catchment scale. We test this hypothesis running synthetic experiments with a tracer-aided distributed hydrological model. The results reveal that the depth of solute generation is the most important control of the concentration-discharge (C-Q) relation for a number of solutes. Such relation shows that C-Q patterns of solute export vary from dilution (Ca2+, Mg2+, K+, Na+, and Cl−) to weakly enriching (dissolved organic carbon). The timing of the input imposes a signature on temporal dynamics, most evident for nutrients, and adds uncertainty in the exponent of the C-Q relation.},
author = {Botter, M. and Li, L. and Hartmann, J. and Burlando, P. and Fatichi, Simone},
issn = {1944-7973},
journal = {Water Resources Research},
number = {8},
publisher = {American Geophysical Union},
title = {{Depth of solute generation is a dominant control on concentration‐discharge relations}},
doi = {10.1029/2019wr026695},
volume = {56},
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{22520,
abstract = {Increasing urbanization is likely to intensify the urban heat island effect, decrease outdoor thermal comfort, and enhance runoff generation in cities. Urban green spaces are often proposed as a mitigation strategy to counteract these adverse effects, and many recent developments of urban climate models focus on the inclusion of green and blue infrastructure to inform urban planning. However, many models still lack the ability to account for different plant types and oversimplify the interactions between the built environment, vegetation, and hydrology. In this study, we present an urban ecohydrological model, Urban Tethys-Chloris (UT&C), that combines principles of ecosystem modelling with an urban canopy scheme accounting for the biophysical and ecophysiological characteristics of roof vegetation, ground vegetation, and urban trees. UT&C is a fully coupled energy and water balance model that calculates 2 m air temperature, 2 m humidity, and surface temperatures based on the infinite urban canyon approach. It further calculates the urban hydrological fluxes in the absence of snow, including transpiration as a function of plant photosynthesis. Hence, UT&C accounts for the effects of different plant types on the urban climate and hydrology, as well as the effects of the urban environment on plant well-being and performance. UT&C performs well when compared against energy flux measurements of eddy-covariance towers located in three cities in different climates (Singapore, Melbourne, and Phoenix). A sensitivity analysis, performed as a proof of concept for the city of Singapore, shows a mean decrease in 2 m air temperature of 1.1 ∘C for fully grass-covered ground, 0.2 ∘C for high values of leaf area index (LAI), and 0.3 ∘C for high values of Vc,max (an expression of photosynthetic capacity). These reductions in temperature were combined with a simultaneous increase in relative humidity by 6.5 %, 2.1 %, and 1.6 %, for fully grass-covered ground, high values of LAI, and high values of Vc,max, respectively. Furthermore, the increase of pervious vegetated ground is able to significantly reduce surface runoff.},
author = {Meili, Naika and Manoli, Gabriele and Burlando, Paolo and Bou-Zeid, Elie and Chow, Winston T. L. and Coutts, Andrew M. and Daly, Edoardo and Nice, Kerry A. and Roth, Matthias and Tapper, Nigel J. and Velasco, Erik and Vivoni, Enrique R. and Fatichi, Simone},
issn = {1991-9603},
journal = {Geoscientific Model Development},
number = {1},
pages = {335--362},
publisher = {Copernicus Publications},
title = {{An urban ecohydrological model to quantify the effect of vegetation on urban climate and hydrology (UT&C v1.0)}},
doi = {10.5194/gmd-13-335-2020},
volume = {13},
year = {2020},
}