Population dynamics was studied in a 52-l biotrickling filter (BTF) operated for 182 days and used to clean air contaminated with styrene vapors. In the BTF, biomass grew either as free-floating (planktonic) or attached (sessile) microorganisms. PCR-amplified 16S rDNA fragments from planktonic and sessile cells within the bioreactor were analyzed using denaturing gradient gel electrophoresis (DGGE). The results indicated that the complexity of biofilm community was always more pronounced than the complexity of the planktonic cell community. Notably, Rhodococcus erythropolis was identified, based on DNA sequence analysis, as one of the biofilm-specific strains. It was also shown that the inoculum, even when enriched with styrene-degrading bacteria, was not adapted to the growth conditions imposed by the BTF. After a 35-day microbial acclimation period, the DGGE analysis also showed less variation in the banding pattern representing the microbial complexity of the biofilm. In addition, the phylogenic fingerprinting method used demonstrated similar banding profiles in the biofilm along the filter bed.
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http://dx.doi.org/10.1007/s00253-002-1039-z | DOI Listing |
Introduction: China implemented a dynamic zero-COVID strategy to curb viral transmission in response to the coronavirus disease 2019 (COVID-19) pandemic. This strategy was designed to inhibit mutation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19. This study explores the dynamics of viral evolution under stringent non-pharmaceutical interventions (NPIs) through real-world observations.
View Article and Find Full Text PDFBMC Public Health
January 2025
Amsterdam UMC location Vrije Universiteit Amsterdam, Public and Occupational Health, De Boelelaan 1117, Amsterdam, the Netherlands.
Background: Developing interventions along with the population of interest using systems thinking is a promising method to address the underlying system dynamics of overweight. The purpose of this study is twofold: to gain insight into the perspectives of adolescents regarding: (1) the system dynamics of energy balance-related behaviours (EBRBs) (physical activity, screen use, sleep behaviour and dietary behaviour); and (2) underlying mechanisms and overarching drivers of unhealthy EBRBs.
Methods: We conducted Participatory Action Research (PAR) to map the system dynamics of EBRBs together with adolescents aged 10-14 years old living in a lower socioeconomic, ethnically diverse neighbourhood in Amsterdam East, the Netherlands.
J Math Biol
January 2025
Department of Integrative Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
In the past several decades, much attention has been focused on the effects of dispersal on total populations of species. In Zhang (EL 20:1118-1128, 2017), a rigorous biological experiment was performed to confirm the mathematical conclusion: Dispersal tends to enhance populations under a suitable hypothesis. In addition, mathematical models keeping track of resource dynamics in population growth were also proposed in Zhang (EL 20:1118-1128, 2017) to understand this remarkable phenomenon.
View Article and Find Full Text PDFSci Rep
January 2025
Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, 622 West 168th Street, Ste. 876, New York, NY, 10032, USA.
The COVID-19 pandemic may have exacerbated mental health conditions by introducing and/or modifying stressors, particularly in university populations. We examined longitudinal patterns, time-varying predictors, and contemporaneous correlates of moderate-severe psychological distress (MS-PD) among college students. During 2020-2021, participants completed self-administered questionnaires quarterly (T1 = 562, T2 = 334, T3 = 221, and T4 = 169).
View Article and Find Full Text PDFNat Commun
January 2025
Sorbonne Université, CNRS, Laboratory of Computational and Quantitative Biology, LCQB, Paris, France.
Telomere shortening ultimately causes replicative senescence. However, identifying the mechanisms driving replicative senescence in cell populations is challenging due to the heterogeneity of telomere lengths and the asynchrony of senescence onset. Here, we present a mathematical model of telomere shortening and replicative senescence in Saccharomyces cerevisiae which is quantitatively calibrated and validated using data of telomerase-deficient single cells.
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