Linking species traits and demography to explain complex temperature responses across levels of organization

Microbial communities regulate ecosystem responses to climate change. However, predicting these responses is challenging because of complex interactions among processes at multiple levels of organization. Organismal traits that determine individual performance and ecological interactions are essential for scaling up environmental responses from individuals to ecosystems. We combine protist microcosm experiments and mathematical models to show that key traits—cell size, shape, and contents—each explain different aspects of species’ demographic responses to changes in temperature. These differences in species’ temperature responses have complex cascading effects across levels of organization—causing nonlinear shifts in total community respiration rates across temperatures via coordinated changes in community composition, equilibrium densities, and community–mean species mass in experimental protist communities that tightly match theoretical predictions. Our results suggest that traits explain variation in population growth, and together, these two factors scale up to influence community- and ecosystem-level processes across temperatures. Connecting the multilevel microbial processes that ultimately influence climate in this way will help refine predictions about complex ecosystem–climate feedbacks and the pace of climate change itself.

Comparative Aspects of Annelid Regeneration: Towards Understanding the Mechanisms of Regeneration

The question of why animals vary in their ability to regenerate remains one of the most intriguing questions in biology. Annelids are a large and diverse phylum, many members of which are capable of extensive regeneration such as regrowth of a complete head or tail and whole-body regeneration, even from few segments. On the other hand, some representatives of both of the two major annelid clades show very limited tissue regeneration and are completely incapable of segmental regeneration. Here we review experimental and descriptive data on annelid regeneration, obtained at different levels of organization, from data on organs and tissues to intracellular and transcriptomic data. Understanding the variety of the cellular and molecular basis of regeneration in annelids can help one to address important questions about the role of stem/dedifferentiated cells and “molecular morphallaxis” in annelid regeneration as well as the evolution of regeneration in general.

On Feasibility of Using Chronotope for Description of Lecture Genre

Any lecture and particularly an academic lecture, as a genre of scientific discourse, is a unique and extremely interesting material for research. Lectures that authors (lecturers) present to students are thought-out, essentially prepared but spontaneous texts as regards the form of their representation. The main purpose of a lecture is the formation of certain scientific ideas, which requires constant interaction with students, constant influence upon them and, most importantly, constant assessment: to what extent functional the speech is. The composition of the lecture is not linear, its narration may contain cross-references to the ideas mentioned before, as well as projections of what will be said later, and every step of such kind is not just a movement forward or backward, these are actions that create a link between the components of the information presented by the lecturer. It is impossible to predict the whole system of such actions. It depends on the specific conditions under which the lecture is given, but the varieties of the steps in the lecture genre given above can be defined and studied. From our perspective for the description of the non-linear structure of the lecture, it is appropriate to use the concept of "chronotope". While creating the lecture, the author generates a model of time and space in which the speech action takes place. The main feature of lecture chronotope is the existence of several levels of organization, since it has its own internal, spatio-temporal coordinates. However, it's included not only in the framework of a whole lecture course but also in the general system of science development. The explication of the lecture chronotope is carried out at different levels of text organization, both at the level of composition, and at the level of vocabulary and grammar, all of which are interconnected.

Homology of process: developmental dynamics in comparative biology

Comparative biology builds up systematic knowledge of the diversity of life, across evolutionary lineages and levels of organization, starting with evidence from a sparse sample of model organisms. In developmental biology, a key obstacle to the growth of comparative approaches is that the concept of homology is not very well defined for levels of organization that are intermediate between individual genes and morphological characters. In this paper, we investigate what it means for ontogenetic processes to be homologous, focusing specifically on the examples of insect segmentation and vertebrate somitogenesis. These processes can be homologous without homology of the underlying genes or gene networks, since the latter can diverge over evolutionary time, while the dynamics of the process remain the same. Ontogenetic processes like these therefore constitute a dissociable level and distinctive unit of comparison requiring their own specific criteria of homology. In addition, such processes are typically complex and nonlinear, such that their rigorous description and comparison requires not only observation and experimentation, but also dynamical modelling. We propose six criteria of process homology, combining recognized indicators (sameness of parts, morphological outcome and topological position) with novel ones derived from dynamical systems modelling (sameness of dynamical properties, dynamical complexity and evidence for transitional forms). We show how these criteria apply to animal segmentation and other ontogenetic processes. We conclude by situating our proposed dynamical framework for homology of process in relation to similar research programmes, such as process structuralism and developmental approaches to morphological homology.

Scarcity of scale-free topology is universal across biochemical networks

Biochemical reactions underlie the functioning of all life. Like many examples of biology or technology, the complex set of interactions among molecules within cells and ecosystems poses a challenge for quantification within simple mathematical objects. A large body of research has indicated many real-world biological and technological systems, including biochemistry, can be described by power-law relationships between the numbers of nodes and edges, often described as “scale-free”. Recently, new statistical analyses have revealed true scale-free networks are rare. We provide a first application of these methods to data sampled from across two distinct levels of biological organization: individuals and ecosystems. We analyze a large ensemble of biochemical networks including networks generated from data of 785 metagenomes and 1082 genomes (sampled from the three domains of life). The results confirm no more than a few biochemical networks are any more than super-weakly scale-free. Additionally, we test the distinguishability of individual and ecosystem-level biochemical networks and show there is no sharp transition in the structure of biochemical networks across these levels of organization moving from individuals to ecosystems. This result holds across different network projections. Our results indicate that while biochemical networks are not scale-free, they nonetheless exhibit common structure across different levels of organization, independent of the projection chosen, suggestive of shared organizing principles across all biochemical networks.

The Effects of Leadership Behaviors on Organization Agility: A Quantitative Study of 126 U.S.-Based Business Units

Researchers have theorized that the behaviors of organization leaders impact organization agility, which is defined as the ability of an organization to swiftly and successfully change in order to achieve long-term success. The purpose of this study was to determine if leadership behaviors as measured by the MLQ-5X predict organization agility as measured by the Agility Survey (short-form). The research sample included 126 U.S.-based business units within 47 organizations with greater than 1,000 employees. The leadership behaviors found to predict higher levels of organization agility included: (a) exploratory leadership behaviors that support discovering new ways to solve problems and conduct business, (b) latitude leadership behaviors that provide employees with a high degree of freedom and responsibility in achieving work results and resolving issues, (c) visionary leadership behaviors that create a clear organization purpose and mission and define the “why” of the organization’s existence, and (d) reflective leadership behaviors that cause leaders to challenge their own assumptions and create mechanisms for the organization to do so as well. The leadership behaviors related to power and structure predicted lower levels of organization agility.