Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Land Utilization, Landscape Pattern, and Ecological Efficiency: An Empirical Analysis of Discrimination and Overlap from Suining, China

The rapid urbanization in recent decades has highlighted the impact of rural land utilization, which further affects the spatial structure and efficiency of rural ecosystems. Optimizing the structure of urban green infrastructure is an effective way to alleviate the fragmentation of rural landscapes, coordinate the relationship between rural development and ecosystem services, and ensure sustainable rural development. The purpose of this paper is to provide a clear direction for the optimization of construction for the sustainable development of rural green infrastructure (RGI). This study provides a new method for RGI identification and analysis by taking Suining County, a typical rural area on the North China Plain, as an example. Morphological spatial pattern analysis (MSPA) was used to distinguish different space scenery elements in RGI and combine them with land utilization elements, so as to obtain two types of overlapping degree data in each village and town. We further combined the overlapping degree data with ecological efficiency indicators to evaluate the spatial structure construction priorities of different land use components in the RGI system. The results show that the MSPA and ecological efficiency analysis method proposed in this paper are conducive to qualitative and quantitative analysis of the relationship between land use type, spatial structure, and ecological efficiency in the RGI system and are suitable for the construction of a green infrastructure network. This method can be used to better understand the spatial distribution and priority of green infrastructure networks to achieve sustainable rural development on the North China Plain

Land Utilization, Landscape Pattern, and Ecological Efficiency: An Empirical Analysis of Discrimination and Overlap from Suining, China

The rapid urbanization in recent decades has highlighted the impact of rural land utilization, which further affects the spatial structure and efficiency of rural ecosystems. Optimizing the structure of urban green infrastructure is an effective way to alleviate the fragmentation of rural landscapes, coordinate the relationship between rural development and ecosystem services, and ensure sustainable rural development. The purpose of this paper is to provide a clear direction for the optimization of construction for the sustainable development of rural green infrastructure (RGI). This study provides a new method for RGI identification and analysis by taking Suining County, a typical rural area on the North China Plain, as an example. Morphological spatial pattern analysis (MSPA) was used to distinguish different space scenery elements in RGI and combine them with land utilization elements, so as to obtain two types of overlapping degree data in each village and town. We further combined the overlapping degree data with ecological efficiency indicators to evaluate the spatial structure construction priorities of different land use components in the RGI system. The results show that the MSPA and ecological efficiency analysis method proposed in this paper are conducive to qualitative and quantitative analysis of the relationship between land use type, spatial structure, and ecological efficiency in the RGI system and are suitable for the construction of a green infrastructure network. This method can be used to better understand the spatial distribution and priority of green infrastructure networks to achieve sustainable rural development on the North China Plain

Dynamic Concentrated Solar Building Skin Design Based on Multiobjective Optimization

Building skin can provide comprehensive functions of energy production, daylighting, and shading with an integrated transmissive solar-concentrating panel. In this study, Rhino Grasshopper parametric modeling, Ladybug tool performance simulation, and Octopus multiobjective optimization platforms are used to carry out experimental research. This study establishes the optimal relationship between the conflicting objectives of light environment creation and energy production efficiency of solar-concentrating skin by controlling three variables, namely the size of the solar-concentrating module, the rotation angle, and the number of modules, aiming to design the optimal solution and build a multiobjective optimization technology framework for the solar-concentrating skin of an office space. A comparison and analysis of the scenarios indicate a dynamic concentrating skin that can effectively reduce the daylight glare probability (DGP) by 70% and increase the useful daylight illuminance (UDI) by 10%, while achieving energy production. The correlation between the variables and the performance indices of the solar-concentrating skin was obtained as angle > width > length > amount, and the optimal design interval for each parameter variable. This study reveals the laws of how parameter changes affect individual indicators, which can provide ideas for the design of dynamic concentrating skins and building integration, methods for improving the balanced design of indoor light environments and building capacity, and a technical framework for multiobjective optimization processes