Water Hydrogen-Bond Mediated Layer by Layer Alignment of Lipid Rafts as a Precursor of Intermembrane Processes.

Lipid rafts, which are dynamic nanodomains in the plasma membrane, play a crucial role in intermembrane processes by clustering together and growing in size within the plane of the membrane while also aligning with each other across different membranes. However, the physical origin of layer by layer alignment of lipid rafts remains to be elucidated. Here, by using fluorescence imaging and synchrotron X-ray reflectivity in a phase-separated multilayer system, we find that the alignment of raft-mimicking Lo domains is regulated by the distance between bilayers. Molecular dynamics simulations reveal that the aligned state is energetically preferred when the intermembrane distance is small due to its ability to minimize the volume of surface water, which has fewer water hydrogen bonds (HBs) compared to bulk water. Our results suggest that water HB-driven alignment of lipid rafts plays a role as a precursor of intermembrane processes such as cell-cell fusion, virus entry, and signaling.

Enhancement of ANN-based wind power forecasting by modification of surface roughness parameterization over complex terrain.

Wind energy plays an important role in the sustainable energy transition towards a low-carbon society. Proper assessment of wind energy resources and accurate wind energy prediction are essential prerequisites for balancing electricity supply and demand. However, these remain challenging, especially for onshore wind farms over complex terrains, owing to the interplay between surface heterogeneities and intermittent turbulent flows in the planetary boundary layer. This study aimed to improve wind characteristic assessment and medium-term wind power forecasts over complex hilly terrain using a numerical weather prediction (NWP) model. The NWP model reproduced the wind speed distribution, duration, and spatio-temporal variabilities of the observed hub-height wind speed at 24 wind turbines in onshore wind farms when incorporating more realistic surface roughness effects, such as the subgrid-scale topography, roughness sublayer, and canopy height. This study also emphasizes the good features for machine learning that represent heterogeneities in the surface roughness elements in the atmospheric model. We showed that medium-term forecasting using the NWP model output and a simple artificial neural network (ANN) improved day-ahead wind power forecasts by 14% in terms of annual normalized mean absolute error. Our results suggest that better parameterizations of surface friction in atmospheric models are important for wind power forecasting and resource assessment using NWP models, especially when combined with machine learning techniques, and shed light on onshore wind power forecasting and wind energy assessment in mountainous regions.

Synchrotron X-ray study of intrinsically disordered and polyampholytic Tau 4RS and 4RL under controlled ionic strength.

Aggregated and hyperphosphorylated Tau is one of the pathological hallmarks of Alzheimer's disease. Tau is a polyampholytic and intrinsically disordered protein (IDP). In this paper, we present for the first time experimental results on the ionic strength dependence of the radius of gyration (Rg) of human Tau 4RS and 4RL isoforms. Synchrotron X-ray scattering revealed that 4RS Rg is regulated from 65.4 to 58.5 Å and 4RL Rg is regulated from 70.9 to 57.9 Å by varying ionic strength from 0.01 to 0.592 M. The Rg of 4RL Tau is larger than 4RS at lower ionic strength. This result provides an insight into the ion-responsive nature of intrinsically disordered and polyampholytic Tau, and can be implicated to the further study of Tau-Tau and Tau-tubulin intermolecular structure in ionic environments.

Aerodynamic roughness variation with vegetation: analysis in a suburban neighbourhood and a city park.

Local aerodynamic roughness parameters (zero-plane displacement, z d , and aerodynamic roughness length, z 0 ) are determined for an urban park and a suburban neighbourhood with a new morphometric parameterisation that includes vegetation. Inter-seasonal analysis at the urban park demonstrates z d determined with two anemometric methods is responsive to vegetation state and is 1-4 m greater during leaf-on periods. The seasonal change and directional variability in the magnitude of z d is reproduced by the morphometric methods, which also indicate z 0 can be more than halved during leaf-on periods. In the suburban neighbourhood during leaf-on, the anemometric and morphometric methods have similar directional variability for both z d and z 0 . Wind speeds at approximately 3 times the average roughness-element height are estimated most accurately when using a morphometric method which considers roughness-element height variability. Inclusion of vegetation in the morphometric parameterisation improves wind-speed estimation in all cases. Results indicate that the influence of both vegetation and roughness-element height variability are important for accurate determination of local aerodynamic parameters and the associated wind-speed estimates.

Partitioning of net CO2 exchanges at the city-atmosphere interface into biotic and abiotic components.

Eddy covariance (EC) method has been used to measure CO2 fluxes over various ecosystems. Recently, the EC method has been also deployed in urban areas to measure CO2 fluxes. Urban carbon cycle is complex because of the additional anthropogenic processes unlike natural ecosystems but the EC method only measures the net sum of all CO2 sources and sink. This limitation of the EC method hinders us from the underlying processes of the carbon cycle, and it is necessary to partition the net CO2 fluxes into individual contributions for a better understanding of the urban carbon cycle. Here we propose a statistical method to partition CO2 fluxes into individual components by extending the method of Menzer and McFadden (2017).•Statistical method is proposed to partition CO2 fluxes into gross primary production, ecosystem respiration, anthropogenic emissions from a vehicle and building.•This method uses eddy fluxes and footprint-weighted high-resolution land cover data with temporal subsets that a few components can be negligible.•New partitioning method produces reliable individual components of the urban carbon cycle when compared to inventory data and typical biotic responses to environmental conditions.