Functional Identity Research Articles

Structural diversity is an important predictor of forest productivity responses to drought

Abstract The response of forest productivity to drought depends on biodiversity and other stand attributes. Biodiversity can regulate productivity through niche complementarity (i.e. greater diversity better utilizes resources to determine ecosystem functioning) and mass‐ratio effects (i.e. dominance drives ecosystem functioning). However, when these forest attributes occur with drought, stress results are mixed. One emerging biodiversity metric is structural diversity, the variation in vegetation size and form. There is a lack of understanding of the interactive effects of structural diversity and drought on forest productivity. Addressing these knowledge gaps can improve the projection of forest dynamics and structural diversity‐based management for drought adaptation. We compiled multiple datasets including repeated survey data of 13,059 trees in 299 plots across southcentral US forests stressed by the 2010–2015 drought. We used the Random Forest algorithm to examine how structural diversity and other factors influenced three aspects of productivity measured by above‐ground wood biomass: ingrowth, growth, and net change accounting for mortality. Our results showed that (1) Among the eight stand attributes studied, structural diversity was among the top three variables showing the greatest main and interactive effects of drought on forest productivity, except for the interactive effect on ingrowth; (2) The drought‐related losses in forest growth and biomass net change were exacerbated in forests with greater structural diversity; (3) Compared with the species and functional diversity metrics, functional identities had greater interactive effects with drought on forest productivity (except for the ingrowth). Synthesis and applications: Productivity losses related to drought increased with greater structural diversity and decreased with functional identities characterized by conservative resource strategies, such as a high leaf carbon–nitrogen ratio. Thus, structural diversity and functional identity could be considered in projecting and managing forest dynamics under climate change. The comparisons between functional identity and the diversity metrics support the important role of the mass‐ratio effect in forest productivity during drought.

Niche-derived Semaphorin 4A safeguards functional identity of myeloid-biased hematopoietic stem cells.

Somatic stem cell pools comprise diverse, highly specialized subsets whose individual contribution is critical for the overall regenerative function. In the bone marrow, myeloid-biased hematopoietic stem cells (myHSCs) are indispensable for replenishment of myeloid cells and platelets during inflammatory response but, at the same time, become irreversibly damaged during inflammation and aging. Here we identify an extrinsic factor, semaphorin 4A (Sema4A), which non-cell-autonomously confers myHSC resilience to inflammatory stress. We show that, in the absence of Sema4A, myHSC inflammatory hyper-responsiveness in young mice drives excessive myHSC expansion, myeloid bias and profound loss of regenerative function with age. Mechanistically, Sema4A is mainly produced by neutrophils, signals via a cell surface receptor, plexin D1, and safeguards the myHSC epigenetic state. Our study shows that, by selectively protecting a distinct stem cell subset, an extrinsic factor preserves functional diversity of somatic stem cell pool throughout organismal lifespan.

Improvements of Hermite-Hadamard-Mercer inequality using k-fractional integral

The well-known Hermite-Hadamard inequality has attracted the attention of several researchers due to the fact that Hermite-Hadamard inequality has many important applications in mathematics as well as in other areas of science. In this article, the authors present new Hermite-Hadamard inequality of the Mercer type containing Riemann-Liouville k-fractional integrals. For these inequalities, we give integral identity for differentiable functions. With the help of the identity and Hermite-Hadamard-Mercer type inequalities, we derive several results for the inequalities. We establish bounds for the difference of the obtain results by applying Hölder's inequality and power-mean inequality. We hope that the proposed result will invigorate further interest in this direction.

Mycodesign: A new collaboration between mycomaterials and product design as a way to promote material identity

The implementation of the new material culture in the industrial field using biomaterials, currently offers solutions that are disconnected from their origin. Primary sources’ alternative offers functional and expressive identities as part of their potential. New dynamics and specific design strategies are emerging to facilitate project thinking around biomaterials’ qualities, in order to use them in their raw form. This paper presents a case study that validates a customized methodology, M4D, focusing on the application of mycelium-based composites in product design, which are yet limited. We provide a journey throughout the creation process of different prototypes in search of a manufacturing strategy that promotes feasibility and reproducibility. Bio-assemblage was identified as a necessary property in the creation of myco-based modular structures. We further discuss how M4D methodology stresses the natural and expressive identities of myco-materials, and how these can blur as you move forward into designing a viable product.

Metal Ion Signaling in Biomedicine.

Complex multicellular organisms are composed of distinct tissues involving specialized cells that can perform specific functions, making such life forms possible. Species are defined by their genomes, and differences between individuals within a given species directly result from variations in their genetic codes. While genetic alterations can give rise to disease-causing acquisitions of distinct cell identities, it is now well-established that biochemical imbalances within a cell can also lead to cellular dysfunction and diseases. Specifically, nongenetic chemical events orchestrate cell metabolism and transcriptional programs that govern functional cell identity. Thus, imbalances in cell signaling, which broadly defines the conversion of extracellular signals into intracellular biochemical changes, can also contribute to the acquisition of diseased cell states. Metal ions exhibit unique chemical properties that can be exploited by the cell. For instance, metal ions maintain the ionic balance within the cell, coordinate amino acid residues or nucleobases altering folding and function of biomolecules, or directly catalyze specific chemical reactions. Thus, metals are essential cell signaling effectors in normal physiology and disease. Deciphering metal ion signaling is a challenging endeavor that can illuminate pathways to be targeted for therapeutic intervention. Here, we review key cellular processes where metal ions play essential roles and describe how targeting metal ion signaling pathways has been instrumental to dissecting the biochemistry of the cell and how this has led to the development of effective therapeutic strategies.

Variability and coexistence of sexual and apomictic embryo sac development pathways in Fragaria x ananassa cv. ‘Camino real’

ABSTRACT While most apomictic plants have a defined type of gametophytic apomixis, the cultivars of strawberry reported various mechanisms of unreduced embryo sac formation. In this study, the main events of megasporogenesis and megagametogenesis during the sexual and apomictic processes of embryo sac formation were analyzed in the cultivar “Camino real”. Ovules at different developmental stages were sectioned and cleared and were observed using light microscopy and confocal laser scanning microscopy. Archesporial cells developed asynchronously and had diverse fates. These cells can alternatively be selected as mother cells, apomeiotic initials, persist in a resting stage, or degenerate. Other cells in the nucellus are able to acquire a functional megaspore identity. Apomixis did not involve callose deposition in their initial cells and derivatives. The initiation of apomixis was variable in time and eventually related to the interruption of the sexual process at pre-meiotic and post-meiotic stages of the ovule development. The occurrence of sexuality, apospory and diplospory of Antennaria and Taraxacum types is conserved across cultivars. The comparison with wild Fragaria species suggests that hybridization did not directly cause the observed phenotypic variation in apomixis mechanisms. An overview of the mode and time of unreduced sac formation can contribute to the development and management of clonal seed production in strawberry. The complex phenotypic variation additionally remains to be fully explained in light of emerging concepts regarding the regulatory mechanisms of plant reproductive development.

Functional Traits and Species Identity Drive Decomposition Along a Successional Gradient in Upper Andean Tropical Forests

ABSTRACTLeaf litter decomposition constitutes one of the most vital processes for maintaining productivity and carbon release in ecosystems. However, this remains one of the least understood processes in upper Andean tropical forests (UATF), a highly diverse ecoregion that has undergone extensive transformation over the centuries. In this study, we aimed to determine the relationships between decomposition rates of leaf litter, leaf functional traits, and microclimatic conditions along a successional gradient of UATF. We also tested the “after‐life effect” by analyzing changes between green and senescent leaves. We performed a fully reciprocal translocation experiment with 15 representative species of UATF in a set of 14 permanent plots by using 2520 litterbags distributed across 42 experimental units (three litterbeds per plot), over 1.5 years, with four harvesting times (3, 6, 12, and 18 months). Chemical and physical traits were measured in green and senescent leaves to identify the best predictors of decomposition and to analyze the “after‐life effect.” We found that functional traits and species identity drive litter decomposition in UATF, rather than succession and microclimatic conditions of soil moisture and temperature. The relative importance of traits was prevalent in all stages of decay, despite being stronger in the early phases. Although we found an “after‐life effect” of green leaves in decomposition, changes in chemical composition from green to senescent leaves indicated substantial nitrogen resorption, which is a limiting resource in tropical montane forests. With the increasing landscape transformation in UATF, changes in plant species composition could have profound impacts by altering decomposition rates, nutrient cycling, and global carbon storage.

Trait diversity and spider community composition are associated with lower herbivory in young forest plantations

Spiders constitute a numerically dominant group of generalist predators in forest ecosystems, but their biocontrol function in forest plantations is not well understood. The biocontrol potential of spiders may depend upon interaction among pest type, forest type, season, trait composition, and spider community diversity. Using a correlative approach, we addressed this gap in knowledge in young (10–15 years) oak (Quercus spp.) and ash (Fraxinus spp.) forest plantations. We sampled (N = 103 samples) foliage-dwelling arthropods and leaves during late spring and autumn. We then measured traits of spiders (body size and hunting strategy) and examined two indicators of herbivory (leaf damage and leaf dry biomass). In oak plantations, abundances of Hemiptera negatively correlated with functional diversity of spiders consistently during the two seasons. Abundances of caterpillars negatively correlated with abundances of ambushers and marginally with abundances of orb-web building spiders during late spring. Abundances of herbivorous Coleoptera negatively correlated with functional evenness of spiders in autumn. Moreover, herbivory negatively correlated with abundances of Space-web builders and functional diversity of spiders in spring but with mean spider body size in autumn. In ash plantations, herbivory negatively correlated with spider abundances in autumn. Our findings provide indirect evidence that foliage-dwelling spiders can be useful for the biological control of forest pests. The biocontrol potential of spiders seems to depend on both functional diversity and identity. Therefore, forest pest management should focus not only on spider community composition but also functional trait diversity of spiders.

Sum and Weighted Sum Formulas for Fibonacci and Lucas Quaternions

Fibonacci and Lucas quaternions are deeply studied in the literature after its definition by Horadam in 1963. Binet formula, generation function, Cassini, Catalan, Honsberger, and other identities for these sequences studied in different quaternion algebra types like split quaternion algebra, dual quaternion algebra, etc. Additionally, some of the generalizations for Fibonacci and Lucas quaternions are studied like k-Fibonacci quaternions, k-Lucas quaternions, Horadam quaternions, and more. However, despite being researched intensively, the summation formulas or weighted summation formulas for these sequences are not examined thoroughly. In this study, after briefly summarizing the literature, we focused on the summation and the weighted summation formulas for the Fibonacci and the Lucas quaternions. In addition, we provided generalized weighted summation formulas for the Fibonacci and Lucas quaternions. Moreover, we calculated generalized weighted summation formulas for the double coefficient Fibonacci and double coefficient Lucas quaternions which have two Fibonacci and Lucas coefficient in every unit of the quaternion, respectively.

Characterizing multiplicative (generalized)-derivations on semiprime rings satisfying specific functional identities

Characterizing multiplicative (generalized)-derivations on semiprime rings satisfying specific functional identities

A POSTERIORI ERROR ESTIMATES FOR APPROXIMATE SOLUTIONS OF THE OBSTACLE PROBLEM FOR THE 𝑝-LAPLACIAN

The paper is concerned with a functional identity and estimates which are fulfilled for the measures of deviations from exact solutions of the obstacle problem for the 𝑝-Laplacian. They hold true for any functions from the corresponding (energy) functional class, which contains the generalised solution of the problem as well. We do not use any special properties of approximations or numerical methods nor information of the exact configuration of the coincidence set. The right-hand side of the identities and estimates contains only known functions and can be explicitly calculated, and the left side represents a certain measure of the deviation of the approximate solution from the exact solution. The right-hand side of the identity and estimates contains only known functions and can be explicitly calculated, while and the left side represents a certain measure of the deviation of the approximate solution from the exact one. The obtained functional relations allow to estimate the error of of any approximate solutions of the problem regardless of the method of their obtaining. In addition, they enable to compare the exact solutions of problems with different data. The latter provides the possibility to estimate the errors of mathematical models.

A Study of the Impact of Social Media on Family Structure Change

With the rapid development of Internet technology, social media has become an indispensable part of modern society. The popularization of social media has profoundly affected all aspects of family life, and traditional family structures and interaction patterns are facing unprecedented challenges and opportunities. The impact of social media on family structure is a complex process, which not only breaks down geographical boundaries to a certain extent and creates opportunities for family members to strengthen their ties with each other, but also reduces the number of face-to-face exchanges to a certain extent, which obviously affects the mode of communication and frequency of interaction of modern families. In such a context, it is of great theoretical and practical importance to study in depth the changing family structure in the era of social media. This study aims to explore and reveal the influence of social media on family power structure, boundary function and emotional identity from different perspectives through the questionnaire method, so as to grasp the law of change of family structure in the era of social media. Through this study, it can be found that the current development of social media plays a role in reshaping and negotiating boundaries, as well as changing and balancing the power structure of Chinese families.

Cosmological amplitudes in power-law FRW universe

The correlators of large-scale fluctuations belong to the most important observables in modern cosmology. Recently, there have been considerable efforts in analytically understanding the cosmological correlators and the related wavefunction coefficients, which we collectively call cosmological amplitudes. In this work, we provide a set of simple rules to directly write down analytical answers for arbitrary tree-level amplitudes of conformal scalars with time-dependent interactions in power-law FRW universe. With the recently proposed family-tree decomposition method, we identify an over-complete set of multivariate hypergeometric functions, called family trees, to which all tree-level conformal scalar amplitudes can be easily reduced. Our method yields series expansions and monodromies of family trees in various kinematic limits, together with a large number of functional identities. The family trees are in a sense generalizations of polylogarithms and do reduce to polylogarithmic expressions for the cubic coupling in inflationary limit. We further show that all family trees can be decomposed into linear chains by taking shuffle products of all subfamilies, with which we find simple connection between bulk time integrals and boundary energy integrals.

Enhanced prediction of protein functional identity through the integration of sequence and structural features

Although over 300 million protein sequences are registered in a reference sequence database, only 0.2 % have experimentally determined functions. This suggests that many valuable proteins, potentially catalyzing novel enzymatic reactions, remain undiscovered among the vast number of function-unknown proteins. In this study, we developed a method to predict whether two proteins catalyze the same enzymatic reaction by analyzing sequence and structural similarities, utilizing structural models predicted by AlphaFold2. We performed pocket detection and domain decomposition for each structural model. The similarity between protein pairs was assessed using features such as full-length sequence similarity, domain structural similarity, and pocket similarity. We developed several models using conventional machine learning algorithms and found that the LightGBM-based model outperformed the models. Our method also surpassed existing approaches, including those based solely on full-length sequence similarity and state-of-the-art deep learning models. Feature importance analysis revealed that domain sequence identity, calculated through structural alignment, had the greatest influence on the prediction. Therefore, our findings demonstrate that integrating sequence and structural information improves the accuracy of protein function prediction.

Proof of a conjecture on congruences of the sum of minimal excludants

Very recently, Baruah et al. refined a result of Andrews and Newman on the sum of minimal excludants over all the partitions of a positive integer [Formula: see text] by establishing the generating functions of two functions [Formula: see text] and [Formula: see text] which denote the sum of odd minimal excludants and the sum of even minimal excludants, respectively. They proved some congruences on [Formula: see text] and [Formula: see text] modulo 4 and 8 and posed a conjecture on [Formula: see text] and [Formula: see text] at the end of their paper. In this paper, we confirm this conjecture by using theta function identities.

Few Identities of Rogers-Ramanujan Type and Some q-Product Identities Arising from Theta Function Identities

Few Identities of Rogers-Ramanujan Type and Some q-Product Identities Arising from Theta Function Identities

Proofs of three conjectured internal congruences modulo 32 for Schur-type overpartitions

Let S(n) denote the number of overpartitions of Schur-type. Recently, Chern, da Silva and Sellers proved many congruences modulo 8 and 16 for S(n). At the end of their paper, they also posed a conjecture on internal congruences modulo 32 for S(n). In this paper, we confirm their conjecture by using theta function identities and the (p, k)-parameterization of theta functions given by Alaca and Williams. In particular, we show that for any integer j with 0 ≤ j ≤ 31, there are infinitely many integers uj such that S(uj ) ≡ j (mod 32).

Symmetric Reverse n-Derivations on Ideals of Semiprime Rings

This paper focuses on examining a new type of n-additive map called the symmetric reverse n-derivation. As implied by its name, it combines the ideas of n-additive maps and reverse derivations, with a 1-reverse derivation being the ordinary reverse derivation. We explore several findings that expand our knowledge of these maps, particularly their presence in semiprime rings and the way rings respond to specific functional identities involving elements of ideals. Also, we provide examples to help clarify the concept of symmetric reverse n-derivations. This study aims to deepen our understanding of these symmetric maps and their properties within mathematical structures.

Independent effects of tree diversity on aboveground and soil carbon pools after six years of experimental afforestation.

Planting diverse forests has been proposed as a means to increase long-term carbon (C) sequestration while providing many co-benefits. Positive tree diversity-productivity relationships are well established, suggesting more diverse forests will lead to greater aboveground C sequestration. However, the effects of tree diversity on belowground C storage have the potential to either complement or offset aboveground gains, especially during early stages of afforestation when potential exists for large losses in soil C due to soil decomposition. Thus, experimental tests of the effects of planted tree biodiversity on changes in whole-ecosystem C balance are needed. Here, we present changes in above- and belowground C pools 6 years after the initiation of the Forests and Biodiversity experiment (FAB1), consisting of high-density plots of one, two, five, or 12 tree species planted in a common garden. The trees included a diverse range of native species, including both needle-leaf conifer and broadleaf angiosperm species, and both ectomycorrhizal and arbuscular mycorrhizal species. We quantified the effects of species richness, phylogenetic diversity, and functional diversity on aboveground woody C, as well as on mineral soil C accumulation, fine root C, and soil aggregation. Surprisingly, changes in aboveground woody C pools were uncorrelated to changes in mineral soil C pools, suggesting that variation in soil C accumulation was not driven by the quantity of plant litter inputs. Aboveground woody C accumulation was strongly driven by species and functional identity; however, plots with higher species richness and functional diversity accumulated more C in aboveground wood than expected based on monocultures. We also found weak but significant effects of tree species richness, identity, and mycorrhizal type on soil C accumulation. To assess the role of the microbial community in mediating these effects, we further compared changes in soil C pools to phospholipid fatty acid (PLFA) profiles. Soil C pools and accumulation were more strongly correlated with specific microbial clades than with total microbial biomass or plant diversity. Our results highlight rapidly emerging and microbially mediated effects of tree biodiversity on soil C storage in the early years of afforestation that are independent of gains in aboveground woody biomass.

Interpreting the shifts in forest structure, plant community composition, diversity, and functional identity by using remote sensing-derived wildfire severity

BackgroundWildfires are increasingly impacting ecosystems worldwide especially in temperate dry habitats, often interplaying with other global changes (e.g., alien plant invasions). Understanding the ecological consequences of wildfires is crucial for effective conservation and management strategies. The aim of this study was to investigate the impacts of wildfire severity on plant community (both the canopy trees and herbaceous layer) and alien plant invasion, combining field observations and remotely sensed data.We conducted an observational study in the Karst forests (North-East Italy) 1 year after the large wildfire which affected the area in 2022. We assessed the impact through 35 field plots (200 m2 each) distributed among different fire severity (i.e., the loss of organic matter) classes assessed using the differenced normalized burn ratio (dNBR) calculated from satellite images. In each plot, tree species, diameter, vitality, resprouting capacity, and seedling density were measured. In addition, herb species richness (taxonomical diversity) was quantified, and plant cover was visually estimated. Functional diversity was also assessed considering six functional traits retrieved from databases.ResultsSome woody species (e.g., Quercus pubescens) showed a higher resistance to the fire (i.e., lower mortality rate), while others showed a higher resilience (i.e., recovery after fire through resprouting or seedlings, e.g., Cotinus coggygria). The transition to a shrub-dominated community (i.e., Cotinus coggygria) where fire severity was the highest underlines the dynamic nature of the post-fire succession. We detected a significant variation in the herbaceous plant community composition, diversity, and functional identity (i.e., community-weighted mean of trait) along the fire severity gradient. In particular, high-fire severity areas exhibited higher species richness compared to low-severity or unburned areas. Total alien plant cover increased with fire severity, while native cover remained constant. We also found shifts in species that enhance traits related to germination potential and growth strategy.ConclusionsOur results highlight the vulnerability of the forest stands to an increase in wildfire severity, resulting in significant mortality and changes in tree community structure. This study contributes to the understanding of ecological processes after wildfires using a novel remote sensing approach in a temperate forest, emphasizing the need for conservation strategies aimed at mitigating high severity wildfires.