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RUBylation plays essential roles in plant growth and development through regulating Cullin-RING ubiquitin E3 ligase (CRL) activities and the CRL-mediated protein degradations. However, the function of RUBylation in regulating kernel development remains unclear. Through genetic and molecular analyses of a small kernel 501 (smk501) mutant in maize (Zea mays L.), we cloned the smk501 gene, revealed its molecular function, and defined its roles in RUBylation pathway and seed development. Smk501 encodes a RUBylation activating enzyme E1 subunit ZmECR1 (E1 C-TERMINAL RELATED 1) protein. Destruction in RUBylation by smk501 mutation resulted in less embryo and endosperm cell number and smaller kernel size. The transcriptome and proteome profiling, hormone evaluation and cell proliferation observation revealed that disturbing ZmECR1 expression mainly affects pathways on hormone signal transduction, cell cycle progression and starch accumulation during kernel development. In addition, mutant in zmaxr1 (Auxin resistant 1), another RUB E1 subunit, also showed similar defects in kernel development. Double mutation of zmecr1 and zmaxr1 lead to empty pericarp kernel phenotype. RUBylation is a novel regulatory pathway affecting maize kernel development, majorly through its functions in modifying multiple cellular progresses.

This study employed basic demand estimation, field observation, text analysis, and spatial analysis methods to examine the adequacy of the existing supply of commercial dedicated parking space in high-density areas of New York City to accommodate expected demand for direct-to-home deliveries. The study also examined the proximity of available commercial dedicated parking space to end delivery locations. The study estimated and mapped two performance metrics: (1) the share of on-street commercial dedicated parking demanded for expected U.S. Postal Service residential freight deliveries, and (2) the share of these package deliveries expected to occur within a reasonable walking distance of a commercial dedicated parking space. The study relies on a variety of open data sources and on limited field observations; owing to data limitations, and resulting assumptions for baseline analysis, sensitivity analysis was also conducted. Results suggest that there is currently both a spatial and temporal mismatch between the commercial dedicated parking supply and expected residential delivery demand, and that shifts toward express deliveries may exacerbate this mismatch. Future research needs are also discussed.

The black layer (BL) is traditionally used as an indicator for kernel harvesting in maize, as it turns visibly dark when the kernel reaches physiological maturity. However, the molecular roles of BL in kernel development have not been fully elucidated. In this work, microscopy images showed that BL began to appear at a growth stage earlier than 10 days after pollination (DAP), and its color gradually deepened to become dark as the development period progressed. Scanning electron microscopy observations revealed that BL is a tissue structure composed of several layers of cells that are gradually squeezed and compressed during kernel development. Laser-capture microdissection (LCM) was used to sample BL and its neighboring inner tissue, basal endosperm transfer layer (BETL), and outer tissue, inner epidermis (IEP), from 20 DAP of kernels. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling (MALDI-TOF MS profiling) detected 41, 104, and 120 proteins from LCM-sampled BL, BETL, and IEP, respectively. Gene ontology (GO) analysis indicated that the 41 BL proteins were primarily involved in the response to stress and stimuli. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that the BL proteins were enriched in several defense pathways, such as the ascorbate and aldarate metabolic pathways. Among the 41 BL proteins, six were BL-specific proteins that were only detected from BL. Annotations of five BL-specific proteins were related to stress responses. During kernel development, transcriptional expression of most BL proteins showed an increase, followed by a decrease, and reached a maximum zero to 20 DAP. These results suggest a role for BL in stress responses for protecting filial tissue against threats from maternal sides, which helps to elucidate the biological functions of BL.

Increasing demand for direct-to-home deliveries requires frequent delivery of small volumes; these deliveries generate growth in commercial vehicle curb side parking activities in dense urban areas. In New York City, which has extremely densely developed, mixed land uses, this new demand is only exacerbating already challenging conditions for urban delivery. This study utilizes a number of existing “open” datasets from New York City to compare commercial vehicle parking regulations and violations in commercial, mixed-use, and residential land use areas in New York City. Results suggest that parking availability – and resulting violation rates – vary considerably by area and roadway type, and that current curb parking regulations are not adequate to accommodate growing residential demand.

Parking in big cities is never easy. Policy-makers and transportation planners have developed many strategies to accommodate increasing parking demand. However, most of them focus on passenger vehicles, and analysis of delivery vehicle parking is still limited. This study uses recent disaggregate data of freight delivery patterns collected in the Manhattan area, which is rarely available in freight studies, to explore the factors influencing delivery vehicle on-street parking characteristics and drivers’ behavior. A duration model is used to analyze delivery vehicle on-street parking duration, and a count data model is used to analyze the parking frequency of delivery tours. With the outputs of these models, the effectiveness of different traffic-management and parking-management strategies are assessed. The results show that policies encouraging smaller delivery vehicle, higher loading efficiency, and shorter parking duration will reduce congestion and economic losses. The results also demonstrat...