Search

Abstract: The cellular molecular motor kinesin-1 mediates the microtubule-dependent transport of a range of cargo. We have previously identified an interaction between the cargo-binding domain of kinesin-1 heavy chain KIF5B and the membrane-associated SNARE proteins SNAP-25 and SNAP-23. In this study we further defined the minimal SNAP-25 binding domain in KIF5B to residues 874–894. Overexpression of a fragment of KIF5B (residues 594–910) resulted in significant colocalization with SNAP-25 with resulting blockage of the trafficking of SNAP-25 to the periphery of cells. This indicates that kinesin-1 facilitates the transport of SNAP-25 containing vesicles as a prerequisite to SNAP-25 driven membrane fusion events. [Copyright &y& Elsevier]

Active transportation modes–walk and bicycle–are central for low carbon transport, healthy living, and complete streets initiative. Building a community with amenable walk and bicycle facilities asks for smart planning and investments. It is critical to investigate the impact of infrastructure building or expansion on the overall walk and bicycle mode usage prior to making investment choices utilizing public tax money. This research developed a high performance agent-based model to support investment decisions that allows to assess the impact of changes in walk-bike infrastructures at a fine spatial resolution ( e.g. , block group level). We built the agent-based model (ABM) in Repast-HPC platform and calibrated the model using Simultaneous Perturbation Stochastic Simulation (SPSA) technique. The ABM utilizes data from a synthetic population simulator that generates agents with corresponding socio-demographic characteristics, and integrates facility attributes regarding walking and bicycling such as sidewalk width and total length bike lane into the mode choice decision making process. Moreover, the ABM accounts for the effect of social interactions among agents who share identical home and work geographic locations. Finally, GIS-based maps are developed at block group resolution that allows examining the effect of walk-bike infrastructure related investments. The results from New York City case study indicate that infrastructure investments such as widening sidewalk and increasing bike lane network can positively influence the active transportation mode choices. Also, the impact varies with geographic locations–different boroughs of New York City will have different impacts. Our ABM simulation results also indicate that social promotions foucsing on active transportation can positively reinforce the impacts of infrastructure changes. [ABSTRACT FROM AUTHOR]

Cities are concentrations of sociopolitical power and prime architects of land transformation, while also serving as consumption hubs of "hard" water and energy infrastructures. These infrastructures extend well outside metropolitan boundaries and impact distal river ecosystems. We used a comprehensive model to quantify the roles of anthropogenic stressors on hydrologic alteration and biodiversity in US streams and isolate the impacts stemming from hard infrastructure developments in cities. Across the contiguous United States, cities' hard infrastructures have significantly altered at least 7% of streams, which influence habitats for over 60% of North America's fish, mussel, and crayfish species. Additionally, city infrastructures have contributed to local extinctions in 260 species and currently influence 970 indigenous species, 27% of which are in jeopardy. We find that ecosystem impacts do not scale with city size but are instead proportionate to infrastructure decisions. For example, Atlanta's impacts by hard infrastructures extend across four major river basins, 12,500 stream km, and contribute to 100 local extinctions of aquatic species. In contrast, Las Vegas, a similar size city, impacts <1,000 stream km, leading to only seven local extinctions. So, cities have local policy choices that can reduce future impacts to regional aquatic ecosystems as they grow. By coordinating policy and communication between hard infrastructure sectors, local city governments and utilities can directly improve environmental quality in a significant fraction of the nation's streams reaching far beyond their city boundaries. [ABSTRACT FROM AUTHOR]