@article{1259, abstract = {We consider the Bogolubov–Hartree–Fock functional for a fermionic many-body system with two-body interactions. For suitable interaction potentials that have a strong enough attractive tail in order to allow for two-body bound states, but are otherwise sufficiently repulsive to guarantee stability of the system, we show that in the low-density limit the ground state of this model consists of a Bose–Einstein condensate of fermion pairs. The latter can be described by means of the Gross–Pitaevskii energy functional.}, author = {Bräunlich, Gerhard and Hainzl, Christian and Seiringer, Robert}, journal = {Mathematical Physics, Analysis and Geometry}, number = {2}, publisher = {Springer}, title = {{Bogolubov–Hartree–Fock theory for strongly interacting fermions in the low density limit}}, doi = {10.1007/s11040-016-9209-x}, volume = {19}, year = {2016}, } @article{1260, abstract = {In this work, the Gardner problem of inferring interactions and fields for an Ising neural network from given patterns under a local stability hypothesis is addressed under a dual perspective. By means of duality arguments, an integer linear system is defined whose solution space is the dual of the Gardner space and whose solutions represent mutually unstable patterns. We propose and discuss Monte Carlo methods in order to find and remove unstable patterns and uniformly sample the space of interactions thereafter. We illustrate the problem on a set of real data and perform ensemble calculation that shows how the emergence of phase dominated by unstable patterns can be triggered in a nonlinear discontinuous way.}, author = {De Martino, Daniele}, journal = {International Journal of Modern Physics C}, number = {6}, publisher = {World Scientific Publishing}, title = {{The dual of the space of interactions in neural network models}}, doi = {10.1142/S0129183116500674}, volume = {27}, year = {2016}, } @article{1261, abstract = {We consider a non-standard finite-volume discretization of a strongly non-linear fourth order diffusion equation on the d-dimensional cube, for arbitrary . The scheme preserves two important structural properties of the equation: the first is the interpretation as a gradient flow in a mass transportation metric, and the second is an intimate relation to a linear Fokker-Planck equation. Thanks to these structural properties, the scheme possesses two discrete Lyapunov functionals. These functionals approximate the entropy and the Fisher information, respectively, and their dissipation rates converge to the optimal ones in the discrete-to-continuous limit. Using the dissipation, we derive estimates on the long-time asymptotics of the discrete solutions. Finally, we present results from numerical experiments which indicate that our discretization is able to capture significant features of the complex original dynamics, even with a rather coarse spatial resolution.}, author = {Maas, Jan and Matthes, Daniel}, journal = {Nonlinearity}, number = {7}, pages = {1992 -- 2023}, publisher = {IOP Publishing Ltd.}, title = {{Long-time behavior of a finite volume discretization for a fourth order diffusion equation}}, doi = {10.1088/0951-7715/29/7/1992}, volume = {29}, year = {2016}, } @article{12613, abstract = {We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of evolution emerge: (i) reclining cliffs that flatten during the ablation season; (ii) stable cliffs that maintain a self-similar geometry; and (iii) growing cliffs, expanding laterally. We use the insights from this unique data set to develop a 3-D model of cliff backwasting and evolution that is validated against observations and an independent data set of volume losses. The model includes ablation at the cliff surface driven by energy exchange with the atmosphere, reburial of cliff cells by surrounding debris, and the effect of adjacent ponds. The cliff geometry is updated monthly to account for the modifications induced by each of those processes. Model results indicate that a major factor affecting the survival of steep cliffs is the coupling with ponded water at its base, which prevents progressive flattening and possible disappearance of a cliff. The radial growth observed at one cliff is explained by higher receipts of longwave and shortwave radiation, calculated taking into account atmospheric fluxes, shading, and the emission of longwave radiation from debris surfaces. The model is a clear step forward compared to existing static approaches that calculate atmospheric melt over an invariant cliff geometry and can be used for long-term simulations of cliff evolution and to test existing hypotheses about cliffs' survival.}, author = {Buri, Pascal and Miles, Evan S. and Steiner, Jakob F. and Immerzeel, Walter W. and Wagnon, Patrick and Pellicciotti, Francesca}, issn = {2169-9011}, journal = {Journal of Geophysical Research: Earth Surface}, keywords = {Earth-Surface Processes, Geophysics}, number = {12}, pages = {2471--2493}, publisher = {American Geophysical Union}, title = {{A physically based 3‐D model of ice cliff evolution over debris‐covered glaciers}}, doi = {10.1002/2016jf004039}, volume = {121}, year = {2016}, } @article{12617, abstract = {This study presents volume and mass changes of seven (five partially debris-covered, two debris-free) glaciers in the upper Langtang catchment in Nepal. We use a digital elevation model (DEM) from 1974 stereo Hexagon satellite data and seven DEMs derived from 2006–2015 stereo or tri-stereo satellite imagery (e.g., SPOT6/7). The availability of multiple independent DEM differences allows the identification of a robust signal and narrowing down of the uncertainty about recent volume changes. The volume changes calculated over several multiyear periods between 2006 and 2015 consistently indicate that glacier thinning has accelerated with respect to the period 1974–2006. We calculate an ensemble-mean elevation change rate of –0.45 ± 0.18 m a−1 for 2006–2015, while for the period 1974–2006 we compute a rate of −0.24 ± 0.08 m a−1. However, the behavior of glaciers in the study area is heterogeneous, and the presence or absence of debris does not seem to be a good predictor for mass balance trends. Debris-covered tongues have nonlinear thinning profiles, and we show that recent accelerations in thinning correlate with the presence of supraglacial cliffs and lakes. At stagnating glacier areas near the glacier front, however, thinning rates decreased with time or remained constant. The April 2015 Nepal earthquake triggered large avalanches in the study catchment. Analysis of two post-earthquake DEMs revealed that the avalanche deposit volumes remaining 6 months after the earthquake are negligible in comparison to 2006–2015 elevation changes. However, the deposits compensate about 40 % the mass loss of debris-covered tongues of 1 average year.}, author = {Ragettli, Silvan and Bolch, Tobias and Pellicciotti, Francesca}, issn = {1994-0424}, journal = {The Cryosphere}, keywords = {Earth-Surface Processes, Water Science and Technology}, number = {5}, pages = {2075--2097}, publisher = {Copernicus Publications}, title = {{Heterogeneous glacier thinning patterns over the last 40 years in Langtang Himal, Nepal}}, doi = {10.5194/tc-10-2075-2016}, volume = {10}, year = {2016}, } @article{12618, abstract = {Mountain ranges are the world’s natural water towers and provide water resources for millions of people. However, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility, and the complex interplay between climate, cryosphere, and hydrological processes. Here, we use a state-of-the art glacio-hydrological model informed by data from high-altitude observations and the latest climate change scenarios to quantify the climate change impact on water resources of two contrasting catchments vulnerable to changes in the cryosphere. The two study catchments are located in the Central Andes of Chile and in the Nepalese Himalaya in close vicinity of densely populated areas. Although both sites reveal a strong decrease in glacier area, they show a remarkably different hydrological response to projected climate change. In the Juncal catchment in Chile, runoff is likely to sharply decrease in the future and the runoff seasonality is sensitive to projected climatic changes. In the Langtang catchment in Nepal, future water availability is on the rise for decades to come with limited shifts between seasons. Owing to the high spatiotemporal resolution of the simulations and process complexity included in the modeling, the response times and the mechanisms underlying the variations in glacier area and river flow can be well constrained. The projections indicate that climate change adaptation in Central Chile should focus on dealing with a reduction in water availability, whereas in Nepal preparedness for flood extremes should be the policy priority.}, author = {Ragettli, Silvan and Immerzeel, Walter W. and Pellicciotti, Francesca}, issn = {1091-6490}, journal = {PNAS}, keywords = {Multidisciplinary}, number = {33}, pages = {9222--9227}, publisher = {Proceedings of the National Academy of Sciences}, title = {{Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains}}, doi = {10.1073/pnas.1606526113}, volume = {113}, year = {2016}, } @article{12619, abstract = {Mass losses originating from supraglacial ice cliffs at the lower tongues of debris-covered glaciers are a potentially large component of the mass balance, but have rarely been quantified. In this study, we develop a method to estimate ice cliff volume losses based on high-resolution topographic data derived from terrestrial and aerial photogrammetry. We apply our method to six cliffs monitored in May and October 2013 and 2014 using four different topographic datasets collected over the debris-covered Lirung Glacier of the Nepalese Himalayas. During the monsoon, the cliff mean backwasting rate was relatively consistent in 2013 (3.8 ± 0.3 cm w.e. d−1) and more heterogeneous among cliffs in 2014 (3.1 ± 0.7 cm w.e. d−1), and the geometric variations between cliffs are larger. Their mean backwasting rate is significantly lower in winter (October 2013–May 2014), at 1.0 ± 0.3 cm w.e. d−1. These results are consistent with estimates of cliff ablation from an energy-balance model developed in a previous study. The ice cliffs lose mass at rates six times higher than estimates of glacier-wide melt under debris, which seems to confirm that ice cliffs provide a large contribution to total glacier melt.}, author = {BRUN, FANNY and BURI, PASCAL and MILES, EVAN S. and WAGNON, PATRICK and STEINER, JAKOB and BERTHIER, ETIENNE and RAGETTLI, SILVAN and KRAAIJENBRINK, PHILIP and IMMERZEEL, WALTER W. and Pellicciotti, Francesca}, issn = {1727-5652}, journal = {Journal of Glaciology}, keywords = {Earth-Surface Processes}, number = {234}, pages = {684--695}, publisher = {Cambridge University Press}, title = {{Quantifying volume loss from ice cliffs on debris-covered glaciers using high-resolution terrestrial and aerial photogrammetry}}, doi = {10.1017/jog.2016.54}, volume = {62}, year = {2016}, } @article{1262, abstract = {Emerging infectious diseases (EIDs) have contributed significantly to the current biodiversity crisis, leading to widespread epidemics and population loss. Owing to genetic variation in pathogen virulence, a complete understanding of species decline requires the accurate identification and characterization of EIDs. We explore this issue in the Western honeybee, where increasing mortality of populations in the Northern Hemisphere has caused major concern. Specifically, we investigate the importance of genetic identity of the main suspect in mortality, deformed wing virus (DWV), in driving honeybee loss. Using laboratory experiments and a systematic field survey, we demonstrate that an emerging DWV genotype (DWV-B) is more virulent than the established DWV genotype (DWV-A) and is widespread in the landscape. Furthermore, we show in a simple model that colonies infected with DWV-B collapse sooner than colonies infected with DWV-A. We also identify potential for rapid DWV evolution by revealing extensive genome-wide recombination in vivo. The emergence of DWV-B in naive honeybee populations, including via recombination with DWV-A, could be of significant ecological and economic importance. Our findings emphasize that knowledge of pathogen genetic identity and diversity is critical to understanding drivers of species decline.}, author = {Mcmahon, Dino and Natsopoulou, Myrsini and Doublet, Vincent and Fürst, Matthias and Weging, Silvio and Brown, Mark and Gogol Döring, Andreas and Paxton, Robert}, journal = {Proceedings of the Royal Society of London Series B Biological Sciences}, number = {1833}, publisher = {Royal Society, The}, title = {{Elevated virulence of an emerging viral genotype as a driver of honeybee loss}}, doi = {10.1098/rspb.2016.0811}, volume = {283}, year = {2016}, } @article{12620, abstract = {Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d’Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the Østrem curve. Its large number of parameters might be a limitation, but we show that the model is transferable in time and space to a second glacier with little loss of performance. We thus suggest that the new DETI model can be included in continuous mass balance models of debris-covered glaciers, because of its limited data requirements. As such, we expect its application to lead to an improvement in simulations of the debris-covered glacier response to climate in comparison with models that simply recalibrate empirical parameters to prescribe a constant across glacier reduction in melt.}, author = {Carenzo, M. and Pellicciotti, Francesca and Mabillard, J. and Reid, T. and Brock, B.W.}, issn = {0309-1708}, journal = {Advances in Water Resources}, keywords = {Water Science and Technology}, pages = {457--469}, publisher = {Elsevier}, title = {{An enhanced temperature index model for debris-covered glaciers accounting for thickness effect}}, doi = {10.1016/j.advwatres.2016.05.001}, volume = {94}, year = {2016}, } @article{12621, abstract = {Near-surface air temperature is an important determinant of the surface energy balance of glaciers and is often represented by a constant linear temperature gradients (TGs) in models. Spatio-temporal variability in 2 m air temperature was measured across the debris-covered Miage Glacier, Italy, over an 89 d period during the 2014 ablation season using a network of 19 stations. Air temperature was found to be strongly dependent upon elevation for most stations, even under varying meteorological conditions and at different times of day, and its spatial variability was well explained by a locally derived mean linear TG (MG–TG) of −0.0088°C m−1. However, local temperature depressions occurred over areas of very thin or patchy debris cover. The MG–TG, together with other air TGs, extrapolated from both on- and off-glacier sites, were applied in a distributed energy-balance model. Compared with piecewise air temperature extrapolation from all on-glacier stations, modelled ablation, using the MG–TG, increased by <1%, increasing to >4% using the environmental ‘lapse rate’. Ice melt under thick debris was relatively insensitive to air temperature, while the effects of different temperature extrapolation methods were strongest at high elevation sites of thin and patchy debris cover.}, author = {SHAW, THOMAS E. and BROCK, BEN W. and FYFFE, CATRIONA L. and Pellicciotti, Francesca and RUTTER, NICK and DIOTRI, FABRIZIO}, issn = {1727-5652}, journal = {Journal of Glaciology}, keywords = {Earth-Surface Processes}, number = {231}, pages = {185--198}, publisher = {Cambridge University Press}, title = {{Air temperature distribution and energy-balance modelling of a debris-covered glacier}}, doi = {10.1017/jog.2016.31}, volume = {62}, year = {2016}, } @article{12622, abstract = {Air temperature is a key control of processes affecting snow and glaciers in high-elevation catchments, including melt, snowfall and sublimation. It is therefore a key input variable to models of land–surface–atmosphere interaction. Despite this importance, its spatial variability is poorly understood and simple assumptions are made to extrapolate it from point observations to the catchment scale. We use a dataset of 2.75 years of air temperature measurements (from May 2012 to November 2014) at a network of up to 27 locations in the Langtang River, Nepal, catchment to investigate air temperature seasonality and consistency between years. We use observations from high elevations and from the easternmost section of the basin to corroborate previous findings of shallow lapse rates. Seasonal variability is strong, with shallowest lapse rates during the monsoon season. Diurnal variability is also strong and should be taken into account since processes such as melt have a pronounced diurnal variability. Use of seasonal lapse rates seems crucial for glacio-hydrological modelling, but seasonal lapse rates seem stable over the 2–3 years investigated. Lateral variability at transects across valley is high and dominated by aspect, with south-facing sites being warmer than north-facing sites and deviations from the fitted lapse rates of up to several degrees. Local factors (e.g. topographic shading) can reduce or enhance this effect. The interplay of radiation, aspect and elevation should be further investigated with high-elevation transects.}, author = {Heynen, Martin and Miles, Evan and Ragettli, Silvan and Buri, Pascal and Immerzeel, Walter W. and Pellicciotti, Francesca}, issn = {1727-5644}, journal = {Annals of Glaciology}, keywords = {Earth-Surface Processes}, number = {71}, pages = {212--222}, publisher = {International Glaciological Society}, title = {{Air temperature variability in a high-elevation Himalayan catchment}}, doi = {10.3189/2016aog71a076}, volume = {57}, year = {2016}, } @article{12623, abstract = {Ice cliffs might be partly responsible for the high mass losses of debris-covered glaciers in the Hindu Kush-Karakoram-Himalaya region. The few existing models of cliff backwasting are point-scale models applied at few locations or assume cliffs to be planes with constant slope and aspect, a major simplification given the complex surfaces of most cliffs. We develop the first grid-based model of cliff backwasting for two cliffs on debris-covered Lirung Glacier, Nepal. The model includes an improved representation of shortwave and longwave radiation, and their interplay with the glacier topography. Shortwave radiation varies considerably across the two cliffs, mostly due to direct radiation. Diffuse radiation is the major shortwave component, as the direct component is strongly reduced by the cliffs’ aspect and slope through self-shading. Incoming longwave radiation is higher than the total incoming shortwave flux, due to radiation emitted by the surrounding terrain, which is 25% of the incoming flux. Melt is highly variable in space, suggesting that simple models provide inaccurate estimates of total melt volumes. Although only representing 0.09% of the glacier tongue area, the total melt at the two cliffs over the measurement period is 2313 and 8282 m3, 1.23% of the total melt simulated by a glacio-hydrological model for the glacier’s tongue.}, author = {Buri, Pascal and Pellicciotti, Francesca and Steiner, Jakob F. and Miles, Evan S. and Immerzeel, Walter W.}, issn = {1727-5644}, journal = {Annals of Glaciology}, keywords = {Earth-Surface Processes}, number = {71}, pages = {199--211}, publisher = {International Glaciological Society}, title = {{A grid-based model of backwasting of supraglacial ice cliffs on debris-covered glaciers}}, doi = {10.3189/2016aog71a059}, volume = {57}, year = {2016}, } @article{12624, abstract = {Supraglacial ponds on debris-covered glaciers present a mechanism of atmosphere/glacier energy transfer that is poorly studied, and only conceptually included in mass-balance studies of debris-covered glaciers. This research advances previous efforts to develop a model of mass and energy balance for supraglacial ponds by applying a free-convection approach to account for energy exchanges at the subaqueous bare-ice surfaces. We develop the model using field data from a pond on Lirung Glacier, Nepal, that was monitored during the 2013 and 2014 monsoon periods. Sensitivity testing is performed for several key parameters, and alternative melt algorithms are compared with the model. The pond acts as a significant recipient of energy for the glacier system, and actively participates in the glacier’s hydrologic system during the monsoon. Melt rates are 2-4 cm d-1 (total of 98.5 m3 over the study period) for bare ice in contact with the pond, and <1 mmd-1 (total of 10.6m3) for the saturated debris zone. The majority of absorbed atmospheric energy leaves the pond system through englacial conduits, delivering sufficient energy to melt 2612 m3 additional ice over the study period (38.4 m3 d-1). Such melting might be expected to lead to subsidence of the glacier surface. Supraglacial ponds efficiently convey atmospheric energy to the glacier’s interior and rapidly promote the downwasting process.}, author = {Miles, Evan S. and Pellicciotti, Francesca and Willis, Ian C. and Steiner, Jakob F. and Buri, Pascal and Arnold, Neil S.}, issn = {1727-5644}, journal = {Annals of Glaciology}, keywords = {Earth-Surface Processes}, number = {71}, pages = {29--40}, publisher = {International Glaciological Society}, title = {{Refined energy-balance modelling of a supraglacial pond, Langtang Khola, Nepal}}, doi = {10.3189/2016aog71a421}, volume = {57}, year = {2016}, } @article{12625, abstract = {Debris-covered glaciers play an important role in the high-altitude water cycle in the Himalaya, yet their dynamics are poorly understood, partly because of the difficult fieldwork conditions. In this study we therefore deploy an unmanned aerial vehicle (UAV) three times (May 2013, October 2013 and May 2014) over the debris-covered Lirung Glacier in Nepal. The acquired data are processed into orthomosaics and elevation models by a Structure from Motion workflow, and seasonal surface velocity is derived using frequency cross-correlation. In order to obtain optimal surface velocity products, the effects of different input data and correlator configurations are evaluated, which reveals that the orthomosaic as input paired with moderate correlator settings provides the best results. The glacier has considerable spatial and seasonal differences in surface velocity, with maximum summer and winter velocities 6 and 2.5 m a-1, respectively, in the upper part of the tongue, while the lower part is nearly stagnant. It is hypothesized that the higher velocities during summer are caused by basal sliding due to increased lubrication of the bed. We conclude that UAVs have great potential to quantify seasonal and annual variations in flow and can help to further our understanding of debris-covered glaciers.}, author = {Kraaijenbrink, Philip and Meijer, Sander W. and Shea, Joseph M. and Pellicciotti, Francesca and De Jong, Steven M. and Immerzeel, Walter W.}, issn = {1727-5644}, journal = {Annals of Glaciology}, keywords = {Earth-Surface Processes}, number = {71}, pages = {103--113}, publisher = {International Glaciological Society}, title = {{Seasonal surface velocities of a Himalayan glacier derived by automated correlation of unmanned aerial vehicle imagery}}, doi = {10.3189/2016aog71a072}, volume = {57}, year = {2016}, } @article{1263, abstract = {Linking classical microwave electrical circuits to the optical telecommunication band is at the core of modern communication. Future quantum information networks will require coherent microwave-to-optical conversion to link electronic quantum processors and memories via low-loss optical telecommunication networks. Efficient conversion can be achieved with electro-optical modulators operating at the single microwave photon level. In the standard electro-optic modulation scheme, this is impossible because both up- and down-converted sidebands are necessarily present. Here, we demonstrate true single-sideband up- or down-conversion in a triply resonant whispering gallery mode resonator by explicitly addressing modes with asymmetric free spectral range. Compared to previous experiments, we show a 3 orders of magnitude improvement of the electro-optical conversion efficiency, reaching 0.1% photon number conversion for a 10 GHz microwave tone at 0.42 mW of optical pump power. The presented scheme is fully compatible with existing superconducting 3D circuit quantum electrodynamics technology and can be used for nonclassical state conversion and communication. Our conversion bandwidth is larger than 1 MHz and is not fundamentally limited.}, author = {Rueda, Alfredo and Sedlmeir, Florian and Collodo, Michele and Vogl, Ulrich and Stiller, Birgit and Schunk, Gerhard and Strekalov, Dmitry and Marquardt, Christoph and Fink, Johannes M and Painter, Oskar and Leuchs, Gerd and Schwefel, Harald}, journal = {Optica}, number = {6}, pages = {597 -- 604}, publisher = {Optica Publishing Group}, title = {{Efficient microwave to optical photon conversion: An electro-optical realization}}, doi = {10.1364/OPTICA.3.000597}, volume = {3}, year = {2016}, } @article{1264, abstract = {n contrast with the wealth of recent reports about the function of μ-adaptins and clathrin adaptor protein (AP) complexes, there is very little information about the motifs that determine the sorting of membrane proteins within clathrin-coated vesicles in plants. Here, we investigated putative sorting signals in the large cytosolic loop of the Arabidopsis (Arabidopsis thaliana) PIN-FORMED1 (PIN1) auxin transporter, which are involved in binding μ-adaptins and thus in PIN1 trafficking and localization. We found that Phe-165 and Tyr-280, Tyr-328, and Tyr-394 are involved in the binding of different μ-adaptins in vitro. However, only Phe-165, which binds μA(μ2)- and μD(μ3)-adaptin, was found to be essential for PIN1 trafficking and localization in vivo. The PIN1:GFP-F165A mutant showed reduced endocytosis but also localized to intracellular structures containing several layers of membranes and endoplasmic reticulum (ER) markers, suggesting that they correspond to ER or ER-derived membranes. While PIN1:GFP localized normally in a μA (μ2)-adaptin mutant, it accumulated in big intracellular structures containing LysoTracker in a μD (μ3)-adaptin mutant, consistent with previous results obtained with mutants of other subunits of the AP-3 complex. Our data suggest that Phe-165, through the binding of μA (μ2)- and μD (μ3)-adaptin, is important for PIN1 endocytosis and for PIN1 trafficking along the secretory pathway, respectively.}, author = {Sancho Andrés, Gloria and Soriano Ortega, Esther and Gao, Caiji and Bernabé Orts, Joan and Narasimhan, Madhumitha and Müller, Anna and Tejos, Ricardo and Jiang, Liwen and Friml, Jirí and Aniento, Fernando and Marcote, Maria}, journal = {Plant Physiology}, number = {3}, pages = {1965 -- 1982}, publisher = {American Society of Plant Biologists}, title = {{Sorting motifs involved in the trafficking and localization of the PIN1 auxin efflux carrier}}, doi = {10.1104/pp.16.00373}, volume = {171}, year = {2016}, } @article{1266, abstract = {Cortical networks exhibit ‘global oscillations’, in which neural spike times are entrained to an underlying oscillatory rhythm, but where individual neurons fire irregularly, on only a fraction of cycles. While the network dynamics underlying global oscillations have been well characterised, their function is debated. Here, we show that such global oscillations are a direct consequence of optimal efficient coding in spiking networks with synaptic delays and noise. To avoid firing unnecessary spikes, neurons need to share information about the network state. Ideally, membrane potentials should be strongly correlated and reflect a ‘prediction error’ while the spikes themselves are uncorrelated and occur rarely. We show that the most efficient representation is when: (i) spike times are entrained to a global Gamma rhythm (implying a consistent representation of the error); but (ii) few neurons fire on each cycle (implying high efficiency), while (iii) excitation and inhibition are tightly balanced. This suggests that cortical networks exhibiting such dynamics are tuned to achieve a maximally efficient population code.}, author = {Chalk, Matthew J and Gutkin, Boris and Denève, Sophie}, journal = {eLife}, number = {2016JULY}, publisher = {eLife Sciences Publications}, title = {{Neural oscillations as a signature of efficient coding in the presence of synaptic delays}}, doi = {10.7554/eLife.13824}, volume = {5}, year = {2016}, } @article{1267, abstract = {We give a simplified proof of the nonexistence of large nuclei in the liquid drop model and provide an explicit bound. Our bound is within a factor of 2.3 of the conjectured value and seems to be the first quantitative result.}, author = {Frank, Rupert and Killip, Rowan and Nam, Phan}, journal = {Letters in Mathematical Physics}, number = {8}, pages = {1033 -- 1036}, publisher = {Springer}, title = {{Nonexistence of large nuclei in the liquid drop model}}, doi = {10.1007/s11005-016-0860-8}, volume = {106}, year = {2016}, } @article{1269, abstract = {Plants are continuously exposed to a myriad of external signals such as fluctuating nutrients availability, drought, heat, cold, high salinity, or pathogen/pest attacks that can severely affect their development, growth, and fertility. As sessile organisms, plants must therefore be able to sense and rapidly react to these external inputs, activate efficient responses, and adjust development to changing conditions. In recent years, significant progress has been made towards understanding the molecular mechanisms underlying the intricate and complex communication between plants and the environment. It is now becoming increasingly evident that hormones have an important regulatory role in plant adaptation and defense mechanisms.}, author = {Benková, Eva}, journal = {Plant Molecular Biology}, number = {6}, pages = {597}, publisher = {Springer}, title = {{Plant hormones in interactions with the environment}}, doi = {10.1007/s11103-016-0501-8}, volume = {91}, year = {2016}, } @article{1270, abstract = {A crucial step in the early development of multicellular organisms involves the establishment of spatial patterns of gene expression which later direct proliferating cells to take on different cell fates. These patterns enable the cells to infer their global position within a tissue or an organism by reading out local gene expression levels. The patterning system is thus said to encode positional information, a concept that was formalized recently in the framework of information theory. Here we introduce a toy model of patterning in one spatial dimension, which can be seen as an extension of Wolpert's paradigmatic "French Flag" model, to patterning by several interacting, spatially coupled genes subject to intrinsic and extrinsic noise. Our model, a variant of an Ising spin system, allows us to systematically explore expression patterns that optimally encode positional information. We find that optimal patterning systems use positional cues, as in the French Flag model, together with gene-gene interactions to generate combinatorial codes for position which we call "Counter" patterns. Counter patterns can also be stabilized against noise and variations in system size or morphogen dosage by longer-range spatial interactions of the type invoked in the Turing model. The simple setup proposed here qualitatively captures many of the experimentally observed properties of biological patterning systems and allows them to be studied in a single, theoretically consistent framework.}, author = {Hillenbrand, Patrick and Gerland, Ulrich and Tkacik, Gasper}, journal = {PLoS One}, number = {9}, publisher = {Public Library of Science}, title = {{Beyond the French flag model: Exploiting spatial and gene regulatory interactions for positional information}}, doi = {10.1371/journal.pone.0163628}, volume = {11}, year = {2016}, }