Generic diversity dynamics of the Phanerozoic marine animals is far better described by the hyperbolic model, widely used in demography and macrosociology, than by the exponential and logistic models from population dynamics traditionally employed for this purpose. Exponential and logistic models imply zero influence of interactions between taxa on the dynamics of diversity, with the exception of competing for unoccupied ecological space, whereas the hyperbolic model implies non-linear second-order positive feedback in the development of the biota. The hyperbolic human population growth is caused by positive feedback between population size and the rate of technological and cultural development (the more individuals, the more inventors, the more rapid progress, the more rapid growth of the Earth's bearing capacity; the smaller death-rate, the more accelerated growth-rate of the population). Probably there is also non-linear second-order positive feedback between diversity and community structure (the more genera, the higher alpha-diversity, which is defined as average number of genera per community, the more complicated and stable, "buffered" communities, the greater "taxonomic capacity of the environment" and average duration of the existence of genera; extinction rate dencreases, biodiversity growth-rate increases). The simplest mathematical model of biodiversity dynamics based on this assumption is confirmed by empirical data on alpha-diversity dynamics. Progressive complexification of marine communities during the Phanerozoic is also confirmed by the growing evennes of generic abundance distribution in paleocommunities.
Download full-text PDF |
Source |
---|
J Cell Mol Med
January 2025
NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Institute of Endocrinology, Tianjin, China.
Proper differentiation of bone marrow stromal cells (BMSCs) into adipocytes is crucial for maintaining skeletal homeostasis. However, the underlying regulatory mechanisms remain incompletely understood, posing a challenge for the treatment of age-related osteopenia and osteoporosis. Here, through comprehensive gene expression analysis during BMSC differentiation into adipocytes, we identified the forkhead transcription factor Foxk2 as a key regulator of this process.
View Article and Find Full Text PDFNat Struct Mol Biol
January 2025
Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.
Infection of cells with high-risk strains of the human papillomavirus (HPV) causes cancer in various types of epithelial tissue. HPV infections are responsible for ~4.5% of all cancers worldwide.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, People's Republic of China; Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan, People's Republic of China; Hubei Engineering Center for Infectious Disease Prevention, Control and Treatment, Wuhan, People's Republic of China. Electronic address:
Background: In current years, the CRISPR (clustered regularly interspaced short palindromic repeats) based strategies have emerged as the most promising molecular tool in the field of gene editing, intracellular imaging, transcriptional regulation and biosensing. However, the recent CRISPR-based diagnostic technologies still require the incorporation of other amplification strategies (such as polymerase chain reaction) to improve the cis/trans cleavage activity of Cas12a, which complicates the detection workflow and lack of a uniform compatible system to respond to the target in one pot.
Results: To better fully-functioning CRISPR/Cas12a, we reported a novel technique for straightforward nucleic acid detection by incorporating enzyme-responsive steric hindrance-based branched inhibitors with CRISPR/AsCas12a methodology.
Surgery
January 2025
Experimental Surgery and Simulation Center, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; Department of Digestive Surgery, Pontificia Universidad Católica de Chile, Santiago, Chile. Electronic address:
Distance and remote simulation have emerged as vital tools in modern surgical education, offering solutions to challenges such as limited operating hours, growing clinical demands, and the need for consistent, high-quality training. This review examines the benefits, limitations, and strategies for implementing sustainable distance simulation, structured around 3 foundational pillars: (1) effective hardware and infrastructure, including simulators and realistic scenarios that enable trainees to develop essential skills; (2) validated training programs grounded in educational theory with a clear focus on skill transfer and predictive validity; and (3) timely access to effective feedback. Distance simulation permits adaptable, scalable training environments, but the addition of remote and deferred feedback has further broadened its impact, helping to overcome the challenges posed by faculty availability and clinician time constraints.
View Article and Find Full Text PDFHistoric cultural blocks are areas where a city's material cultural heritage and humanistic characteristics converge, showcasing the city's unique features and preserving rich and complete urban memories. Research on historic blocks primarily involves strategies related to protection, renewal, planning, and enhancement. However, there is a paucity of studies that explore the relationship between landscape value perception and tourist behavioral intentions from the perspective of recreation participants during the development and renewal of historic cultural blocks.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!