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Proceedings of the National Academy of... Sep 2023Cell size and cell count are adaptively regulated and intimately linked to growth and function. Yet, despite their widespread relevance, the relation between cell size...
Cell size and cell count are adaptively regulated and intimately linked to growth and function. Yet, despite their widespread relevance, the relation between cell size and count has never been formally examined over the whole human body. Here, we compile a comprehensive dataset of cell size and count over all major cell types, with data drawn from >1,500 published sources. We consider the body of a representative male (70 kg), which allows further estimates of a female (60 kg) and 10-y-old child (32 kg). We build a hierarchical interface for the cellular organization of the body, giving easy access to data, methods, and sources (https://humancelltreemap.mis.mpg.de/). In total, we estimate total body counts of ≈36 trillion cells in the male, ≈28 trillion in the female, and ≈17 trillion in the child. These data reveal a surprising inverse relation between cell size and count, implying a trade-off between these variables, such that all cells within a given logarithmic size class contribute an equal fraction to the body's total cellular biomass. We also find that the coefficient of variation is approximately independent of mean cell size, implying the existence of cell-size regulation across cell types. Our data serve to establish a holistic quantitative framework for the cells of the human body, and highlight large-scale patterns in cell biology.
Topics: Child; Humans; Female; Male; Cell Count; Biomass; Cell Size; Correlation of Data
PubMed: 37722043
DOI: 10.1073/pnas.2303077120 -
Neuron Nov 2023
Topics: Problem Solving; Mathematics; Neurosciences
PubMed: 37918345
DOI: 10.1016/j.neuron.2023.10.015 -
Neuron Nov 2023David Chalmers is a philosopher who studies consciousness. After sketching his background in mathematics, science, and philosophy, he describes the problems of...
David Chalmers is a philosopher who studies consciousness. After sketching his background in mathematics, science, and philosophy, he describes the problems of consciousness and his collaboration with neuroscientists. He also discusses the roles of neuroscience and philosophy in studying consciousness and other topics as well as the future of these fields.
Topics: Consciousness; Philosophy; Neurosciences; Mathematics
PubMed: 37918347
DOI: 10.1016/j.neuron.2023.10.018 -
Journal of Experimental Child Psychology Aug 2023Identifying the underpinnings of mathematics proficiency is relevant for all societies. A growing literature supports a relation between executive function (EF) and... (Randomized Controlled Trial)
Randomized Controlled Trial
Identifying the underpinnings of mathematics proficiency is relevant for all societies. A growing literature supports a relation between executive function (EF) and mathematics across a wide age range, but causal links are not well understood. In the current study, typically developing preschool children (N = 104) were randomly assigned to one of four training conditions: EF, Number, EF + Number, or an active Control. They participated in three brief training sessions and pretest and posttest sessions measuring EF and mathematics skills. EF training improved EF skills on a task similar to the training but did not extend to an untrained EF task. In addition, the EF training improved number skills but not general mathematics skills. The EF + Number training improved number and general mathematics skills but not EF skills. The EF + Number training did not yield significantly greater benefits for EF and mathematics beyond other training conditions. Finally, differential training effects emerged, such that children with lower pretest EF skills had greater EF benefits on only the trained EF skill. In addition, children from lower versus higher socioeconomic households had greater gains in numerical skills following EF training. No training condition improved verbal knowledge, suggesting that results were specific to the targeted skills. These results extend prior findings on the effectiveness of improving EF and mathematical skills through short-term trainings during early childhood.
Topics: Humans; Child, Preschool; Executive Function; Mathematics
PubMed: 36948040
DOI: 10.1016/j.jecp.2023.105663 -
Cognitive Psychology Nov 2023Mathematical expressions consist of recursive combinations of numbers, variables, and operators. According to theoretical linguists, the syntactic mechanisms of natural... (Review)
Review
Mathematical expressions consist of recursive combinations of numbers, variables, and operators. According to theoretical linguists, the syntactic mechanisms of natural language also provide a basis for mathematics. To date, however, no theoretically rigorous investigation has been conducted to support such arguments. Therefore, this study uses a methodology based on theoretical linguistics to analyze the syntactic properties of mathematical expressions. Through a review of recent behavioral and neuroimaging studies on mathematical syntax, we report several inconsistencies with theoretical linguistics, such as the use of ternary structures. To address these, we propose that a syntactic category called Applicative plays a central role in analyzing mathematical expressions with seemingly ternary structures by combining binary structures. Besides basic arithmetic expressions, we also examine algebraic equations and complex expressions such as integral and differential calculi. This study is the first attempt at building a comprehensive framework for analyzing the syntactic structures of mathematical expressions.
Topics: Humans; Language; Linguistics; Mathematics
PubMed: 37748253
DOI: 10.1016/j.cogpsych.2023.101606 -
Physical Biology Jul 2023Mitochondria serve a wide range of functions within cells, most notably via their production of ATP. Although their morphology is commonly described as bean-like,... (Review)
Review
Mitochondria serve a wide range of functions within cells, most notably via their production of ATP. Although their morphology is commonly described as bean-like, mitochondria often form interconnected networks within cells that exhibit dynamic restructuring through a variety of physical changes. Further, though relationships between form and function in biology are well established, the extant toolkit for understanding mitochondrial morphology is limited. Here, we emphasize new and established methods for quantitatively describing mitochondrial networks, ranging from unweighted graph-theoretic representations to multi-scale approaches from applied topology, in particular persistent homology. We also show fundamental relationships between mitochondrial networks, mathematics, and physics, using ideas of graph planarity and statistical mechanics to better understand the full possible morphological space of mitochondrial network structures. Lastly, we provide suggestions for how examination of mitochondrial network form through the language of mathematics can inform biological understanding, and vice versa.
Topics: Mathematics; Lens, Crystalline; Mitochondria; Physics
PubMed: 37290456
DOI: 10.1088/1478-3975/acdcdb -
Neuroscience and Biobehavioral Reviews Mar 2024Numerical abilities are complex cognitive skills essential for dealing with requirements of the modern world. Although the brain structures and functions underlying... (Review)
Review
Numerical abilities are complex cognitive skills essential for dealing with requirements of the modern world. Although the brain structures and functions underlying numerical cognition in different species have long been appreciated, genetic and molecular techniques have more recently expanded the knowledge about the mechanisms underlying numerical learning. In this review, we discuss the status of the research related to the neurobiological bases of numerical abilities. We consider how genetic factors have been associated with mathematical capacities and how these link to the current knowledge of brain regions underlying these capacities in human and non-human animals. We further discuss the extent to which significant variations in the levels of specific neurotransmitters may be used as potential markers of individual performance and learning difficulties and take into consideration the therapeutic potential of brain stimulation methods to modulate learning and improve interventional outcomes. The implications of this research for formulating a more comprehensive view of the neural basis of mathematical learning are discussed.
Topics: Humans; Learning; Cognition; Brain; Mathematics; Neurobiology
PubMed: 38220032
DOI: 10.1016/j.neubiorev.2024.105545 -
Journal of Experimental Child Psychology Feb 2024The associations between parental mathematics anxiety and attitudes and children's mathematics attainment in early primary school were explored. Initially, parents of...
The associations between parental mathematics anxiety and attitudes and children's mathematics attainment in early primary school were explored. Initially, parents of preschool children (M = 3;11 [years;months]) completed a questionnaire indexing parental mathematics anxiety and attitudes and the frequency of preschool home number experiences. The children completed mathematics assessments in their first year (n = 231, M = 5;2) and second year (n = 119, M = 6;3) of schooling and a mathematics anxiety questionnaire in their third year of schooling (n = 119, M = 6;7). A questionnaire indexing the frequency of primary school home number experiences was completed by 119 of the parents in their children's second year of schooling (M = 6;0). All indices of parental mathematics anxiety and attitudes predicted children's mathematics attainment in their first school year. These associations were independent of parental mathematics attainment and were not mediated by the frequency of preschool home number experiences. Furthermore, the positive association between preschool home number experiences and children's mathematics attainment was not weaker in the context of high parental mathematics anxiety or negative parental mathematics attitudes. One index of parental mathematics attitudes predicted children's mathematics attainment in their second school year, but this association was not significant when prior attainment was controlled. There was a stronger association between maternal mathematics anxiety and girls' attainment versus boys' attainment. Parental mathematics anxiety did not predict children's mathematics anxiety. The findings suggest that children whose parents have high mathematics anxiety or negative mathematics attitudes are more likely to have lower mathematics attainment in their first year of school. However, the mechanism underpinning this association is not yet established.
Topics: Male; Female; Humans; Child, Preschool; Child; Parents; Educational Status; Attitude; Mathematics; Anxiety
PubMed: 37783015
DOI: 10.1016/j.jecp.2023.105779 -
Child Development 2023There is a known association between LEGO® construction ability and mathematics achievement, yet the mechanisms which drive this association are largely unknown. This...
There is a known association between LEGO® construction ability and mathematics achievement, yet the mechanisms which drive this association are largely unknown. This study investigated the spatial mechanisms underlying this association, and whether this differs for concrete versus digital construction. Between January 2020 and July 2021, children aged 7-9 years (N = 358, 189 female, ethnicity not recorded) completed spatial and mathematics tasks, and either a concrete or digital Lego construction task. Mediation analyses examining direct and indirect pathways (through spatial skills) between Lego construction ability and mathematics explained 8.4% to 26.6% of variance in mathematics scores. Exploratory moderated mediation analyses revealed that only the indirect path through mental rotation differed between Lego conditions. Findings are discussed in relation to theories of spatial-numerical associations and the potential of Lego training for mathematics improvement.
Topics: Child; Humans; Female; Mathematics; Achievement
PubMed: 37186278
DOI: 10.1111/cdev.13933 -
Current Biology : CB Dec 2023Cellular responses to environmental changes are often highly heterogeneous and exhibit seemingly random dynamics. The astonishing insight of chaos theory is that such...
Cellular responses to environmental changes are often highly heterogeneous and exhibit seemingly random dynamics. The astonishing insight of chaos theory is that such unpredictable patterns can, in principle, arise without the need for any random processes, i.e., purely deterministically without noise. However, while chaos is well understood in mathematics and physics, its role in cell biology remains unclear because the complexity and noisiness of biological systems make testing difficult. Here, we show that chaos explains the heterogeneous response of Escherichia coli cells to oxidative stress. We developed a theoretical model of the gene expression dynamics and demonstrate that chaotic behavior arises from rapid molecular feedbacks that are coupled with cell growth dynamics and cell-cell interactions. Based on theoretical predictions, we then designed single-cell experiments to show we can shift gene expression from periodic oscillations to chaos on demand. Our work suggests that chaotic gene regulation can be employed by cell populations to generate strong and variable responses to changing environments.
Topics: Nonlinear Dynamics; Models, Theoretical
PubMed: 38029757
DOI: 10.1016/j.cub.2023.11.002