Spatiotemporal Variation of Urban Plant Diversity and above Ground Biomass in Haikou, China

Understanding the drivers of urban plant diversity (UPD) and above ground biomass (AGB) in urbanized areas is critical for urban ecosystem services and biodiversity protection. The relationships between UPD and AGB have been investigated simultaneously. However, the drivers of UPD and AGB have been explored independently in tropical coastal areas at different time points. To fill this gap, we conducted a remote sensing interpretation, field plant plot surveys, and compiled socioeconomic and urban greening management survey data. We conducted spatial analyses to investigate the relationships among UPD and socioeconomic variables across different primary and secondary urban functional units (UFUs) in the tropical urban ecosystems of the coastal city of Haikou, China. The primary UFUs with the highest AGB were the recreation and leisure districts in 2015 and 2021. In 2015, AGB was mainly correlated with the number of herb species in undeveloped land and the districts of industry, business, recreation, and leisure. In 2021, AGB was affected primarily by the frequency of fertilizing, maintenance, and watering. Our study found that the relationship between UPD and AGB varied across time and space in Haikou. The plant diversity and AGB's response to human activities and socioeconomics appear to have a time-lag effect. These results provide new insights in understanding how management decisions affect urban vegetation and could be used to guide future urban green space planning in Haikou.

Development and Characterization of Defect-Free Matrimid® Mixed-Matrix Membranes Containing Activated Carbon Particles for Gas Separation

In this work, mixed-matrix membranes (MMMs) for gas separation in the form of thick films were prepared via the combination of the polymer Matrimid® 5218 and activated carbons (AC). The AC particles had a mean particle size of 1.5 μm and a mean pore diameter of 1.9 nm. The films were prepared by slow solvent evaporation from casting solutions in chloroform, which had a varying polymer⁻AC ratio. It was possible to produce stable films with up to a content of 50 vol % of AC. Thorough characterization experiments were accomplished via differential scanning calorimetry and thermogravimetric analysis, while the morphology of the MMMs was also investigated via scanning electron microscopy. The gas transport properties were revealed by employing time-lag measurements for different pure gases as well as sorption balance experiments for the filler particles. It was found that defect free Matrimid® MMMs with AC were prepared and the increase of the filler content led to a higher effective permeability for different gases. The single gas selectivity αij of different gas pairs maintained stable values with the increase of AC content, regardless of the steep increase in the effective permeability of the pure gases. Estimation of the solubilities and the diffusivities of the Matrimid®, AC, and MMMs allowed for the explanation of the increasing permeabilities of the MMMs, with the increase of AC content by modelling.

Changes in 10-year-old children's body esteem: a time-lag study between 2000 and 2010

This time-lag study examined if there has been any changes in body esteem over a 10-year period for 10-year old children in Gothenburg, Sweden. Two cohorts of children, one in year 2000 and one in 2010, answered the same questionnaire about body esteem. A total of 960 children, 515 girls and 445 boys, participated in the first wave in 2000 and a total of 342 children, 171 girls and 171 boys participated in the second wave in 2010. The results showed a general stability in levels of body esteem for both girls and boys over the past 10 years. The gender differences, with boys being more satisfied with their appearance and weight compared to girls also seems to be stable over the years. In addition, the results also showed a somewhat positive development among the overweight girls with enhanced body esteem for the overweight girls compared to the non-overweight girls during the ten years studied. Unfortunately, the same pattern was not found for overweight boys. For them the discrepancy in body esteem compared to non-overweight boys, with the overweight boys being more dissatisfied, found in 2000 remained in 2010.

Environmental change preceded Caribbean extinction by 2 million years

Paleontologists typically treat major episodes of extinction as single and distinct events in which a major environmental perturbation results in a synchronous evolutionary response. Alternatively, the causes of biotic change may be multifaceted and extinction may lag behind the changes ultimately responsible because of nonlinear ecological dynamics. We examined these alternatives for the major episode of Caribbean extinction 2 million years ago (Ma). Isolation of the Caribbean from the Eastern Pacific by uplift of the Panamanian Isthmus was associated with synchronous changes in Caribbean near shore environments and community composition between 4.25 and 3.45 Ma. Seasonal fluctuations in Caribbean seawater temperature decreased 3-fold, carbonate deposition increased, and there was a striking, albeit patchy, shift in dominance of benthic ecosystems from heterotrophic mollusks to mixotrophic reef corals and calcareous algae. All of these changes correspond well with a simple model of decreased upwelling and collapse in planktonic productivity associated with the final stages of the closure of the isthmian barrier. However, extinction rates of mollusks and corals did not increase until 3-2 Ma and sharply peaked between 2 and 1 Ma, even though extinction overwhelmingly affected taxa commonly associated with high productivity. This time lag suggests that something other than environmental change per se was involved in extinction that does not occur as a single event. Understanding cause and effect will require more taxonomically refined analysis of the changing abundance and distribution patterns of different ecological guilds in the 2 million years leading up to the relatively sudden peak in extinction.