DEAR EDITOR,The composition and diversity of the human vaginal microbial community have been investigated intensively due to the diversity-stability relationship (DSR)-based hypothesis for bacterial vaginosis (BV) eti...DEAR EDITOR,The composition and diversity of the human vaginal microbial community have been investigated intensively due to the diversity-stability relationship (DSR)-based hypothesis for bacterial vaginosis (BV) etiology, which was first proposed in the 1990s and has received renewed interest in recent years. Nevertheless, diversity changes (scaling) across individuals in a cohort or population have not yet been addressed, which is significant both theoretically and practically. Theoretically, biodiversity scaling is the core of biogeography, and practically, inter-subject heterogeneity is critical for understanding the etiology and epidemiology of human microbiome-associated diseases such as BV. Here we applied the diversity-area relationship (DAR), a recent extension to the classic species-area relationship (SAR), to study diversity scaling of the vaginal microbiome by reanalyzing reported data collected from 1 107 postpartum women. The model used here characterized the power-law (or its extension) relationships between accrued diversity and areas (numbers of individuals), upon which four biogeographic profiles were thus defined. Specifically, we established the DAR profile (relationship between diversity scaling parameter and so-termed diversity order (q)), similarly pair-wise diversity overlap (PDO) profile, maximal accrual diversity (MAD) profile, and ratio of individual-level to population-level diversity (RIP) profile. These four profiles offer valuable tools to assess and predict diversity scaling (changes) in the human vaginal microbiome across individuals, as well as to understand the dynamics of vaginal microbiomes in healthy women.展开更多
The purpose of this research is to find a method that can improve the cost and efficiency of sludge treatment. Currently, large amounts of sludge are produced every day, but sludge treatment is neither efficient nor p...The purpose of this research is to find a method that can improve the cost and efficiency of sludge treatment. Currently, large amounts of sludge are produced every day, but sludge treatment is neither efficient nor profitable. To improve the sludge treatment process, we proposed the method of using microwave technology to treat sludge. We hypothesized that using microwave technology, we can reduce the volume of the sludge up to 90%, and can save more energy and time comparing to the traditional methods that we are currently using to treat the sludge. To prove our hypothesis, we designed an experiment to compare the solid-liquid boundary height and the solid-liquid mass ratio of the sludge treated by the conventional method and the microwave technology. Prime temperature and time found for dewatering sludge are 70 Celsius degrees and five minutes. The results were rather surprising, as microwave heating demonstrated no significant advantage over conventional heating. The solid-liquid boundary height of sludge heated by conventional and by microwave methods are 22.34 mL and 22.56 mL;the solid-liquid mass ratio of sludge using conventional heating and microwave heating at 70 Celsius degrees are 14.28% and 14.55% (by separation with filter press), or 9.82% and 9.89% (by centrifugation). In conclusion, the difference is negligible.展开更多
文摘DEAR EDITOR,The composition and diversity of the human vaginal microbial community have been investigated intensively due to the diversity-stability relationship (DSR)-based hypothesis for bacterial vaginosis (BV) etiology, which was first proposed in the 1990s and has received renewed interest in recent years. Nevertheless, diversity changes (scaling) across individuals in a cohort or population have not yet been addressed, which is significant both theoretically and practically. Theoretically, biodiversity scaling is the core of biogeography, and practically, inter-subject heterogeneity is critical for understanding the etiology and epidemiology of human microbiome-associated diseases such as BV. Here we applied the diversity-area relationship (DAR), a recent extension to the classic species-area relationship (SAR), to study diversity scaling of the vaginal microbiome by reanalyzing reported data collected from 1 107 postpartum women. The model used here characterized the power-law (or its extension) relationships between accrued diversity and areas (numbers of individuals), upon which four biogeographic profiles were thus defined. Specifically, we established the DAR profile (relationship between diversity scaling parameter and so-termed diversity order (q)), similarly pair-wise diversity overlap (PDO) profile, maximal accrual diversity (MAD) profile, and ratio of individual-level to population-level diversity (RIP) profile. These four profiles offer valuable tools to assess and predict diversity scaling (changes) in the human vaginal microbiome across individuals, as well as to understand the dynamics of vaginal microbiomes in healthy women.
文摘The purpose of this research is to find a method that can improve the cost and efficiency of sludge treatment. Currently, large amounts of sludge are produced every day, but sludge treatment is neither efficient nor profitable. To improve the sludge treatment process, we proposed the method of using microwave technology to treat sludge. We hypothesized that using microwave technology, we can reduce the volume of the sludge up to 90%, and can save more energy and time comparing to the traditional methods that we are currently using to treat the sludge. To prove our hypothesis, we designed an experiment to compare the solid-liquid boundary height and the solid-liquid mass ratio of the sludge treated by the conventional method and the microwave technology. Prime temperature and time found for dewatering sludge are 70 Celsius degrees and five minutes. The results were rather surprising, as microwave heating demonstrated no significant advantage over conventional heating. The solid-liquid boundary height of sludge heated by conventional and by microwave methods are 22.34 mL and 22.56 mL;the solid-liquid mass ratio of sludge using conventional heating and microwave heating at 70 Celsius degrees are 14.28% and 14.55% (by separation with filter press), or 9.82% and 9.89% (by centrifugation). In conclusion, the difference is negligible.
