Specific Growth Research Articles

CNSC-43. NEUROTRANSMITTER DEPENDENCY UNDERLIES TUMOR GROWTH IN HUMANIZED PEDIATRIC LOW-GRADE GLIOMA MODELS

Abstract Brain tumors arise in close association with neurons, suggesting that these non-neoplastic cells may be critical stromal drivers of brain tumor initiation and growth. Previously, we have shown that murine low-grade optic glioma formation and progression in the setting of Neurofibromatosis type 1 (NF1) is dictated by neurons and neuronal activity. In these studies, these neuronal dependencies reflected neuronal activity-driven enzymatic cleavage of a growth factor (neuroligin-3) from oligodendrocyte precursors cells (tumor initiation) or neuronal production of a paracrine factor to stimulate T cell support of optic glioma growth (tumor progression). Since neurons typically communicate with other neurons through neurotransmitters, we sought to explore the possibility that neurotransmitters operate to modulate low-grade glioma growth using humanized mouse models of pilocytic astrocytoma (PA). Leveraging single cell RNA sequencing of three independent sets of pediatric PAs, we identified neurotransmitter pathway enrichment in the tumor cells. This neurotransmitter pathway enrichment reflected aberrant expression of specific neurotransmitter receptors, which we confirmed in three independently generated PA tissue microarrays and in five distinct primary PA cell lines grown in vitro. Moreover, this aberrant neurotransmitter receptor expression established differential neurotransmitter PA growth dependencies in vitro. Importantly, interruption of neurotransmitter signaling in human PA xenografts attenuated tumor growth and ERK activation in Rag1-/- mice in vivo. Finally, we discovered crosstalk between neurotransmitter receptor and receptor tyrosine kinase signaling that revealed another target for therapeutic inhibition. Taken together, these findings elucidate a previously unknown neurotransmitter PA growth dependency amenable to therapeutic targeting.

Kinetic modelling and salinity tolerance in Chlorella vulgaris and Desmodesmus communis (Chlorophyta): insights into differential growth responses

Kinetic modelling and salinity tolerance in Chlorella vulgaris and Desmodesmus communis (Chlorophyta): insights into differential growth responses

KIF1A promotes neuroendocrine differentiation in prostate cancer by regulating the OGT-mediated O-GlcNAcylation.

Neuroendocrine prostate cancer (NEPC) arises from prostate adenocarcinoma after endocrine treatment failure and implies lethality and limited therapeutic options. Deciphering the molecular mechanisms underlying transdifferentiation from adenocarcinoma to NEPC may provide valuable therapeutic strategies. We performed a pan-cancer differential mRNA abundance analysis and identified that Kinesin-like protein (KIF1A) was highly expressed in NEPC. KIF1A knockdown impaired neuroendocrine(NE) features, including NE marker gene expression, stemness, and epithelial-mesenchymal transition (EMT), whereas KIF1A overexpression promoted these processes. Targeting KIF1A inhibited the growth of NE differentiated prostate cancer (PCa) cells in vitro and in vivo. Mechanistically, KIF1A bound with O-linked N-acetylglucosamine transferase (OGT) and regulated its protein expression and activity. Nuclear accumulation of OGT induced by KIF1A overexpression promoted intranuclear O-GlcNAcylation of β-catenin and OCT4 in nucleus. More importantly, our data revealed that OGT was critical for KIF1A induced NE differentiation and aggressive tumor growth. An OGT inhibitor, OSMI-1, can significantly inhibited NE differentiated PCa cell proliferation in vitro and tumor growth in vivo. Our findings showed that KIF1A promotes NE differentiation to NEPC by regulating the OGT-mediated O-GlcNAcylation. Targeting O-GlcNAcylation may impede the development of NEPC for a group of PCa patients with elevated KIF1A expression.

ARF alters PAF1 complex integrity to selectively repress oncogenic transcription programs upon p53 loss.

The polymerase associated factor 1 (PAF1) complex (PAF1c) promotes RNA polymerase II (RNA Pol II) transcription at the elongation step; however, how PAF1c transcription activity is selectively regulated during cell fate transitions remains poorly understood. Here, we reveal that the alternative reading frame (ARF) tumor suppressor operates at two levels to restrain PAF1c-dependent oncogenic transcriptional programs upon p53 loss in mouse cells. First, ARF assembles into homo-oligomers to bind the PAF1 subunit to promote PAF1c disassembly, consequently dampening PAF1c interaction with RNA Pol II and PAF1c-dependent transcription. Second, ARF targets the RUNX family transcription factor 1 (RUNX1) to selectively tune gene transcription. Consistently, ARF loss triggers RUNX1- and PAF1c-dependent transcriptional activation of pro-growth ligands (growth differentiation factor/bone morphogenetic protein [GDF/BMP]), promoting a cell-intrinsic GDF/BMP-Smad1/5 axis that aberrantly induce cell growth. Notably, pharmacologic inactivation of GDF/BMP signaling and genetic perturbation of RUNX1 significantly attenuate cell proliferation mediated by dual p53 and ARF loss, offering therapeutic utility. Our data underscore the significance of selective ARF-mediated tumor-suppressive functions through a universal transcriptional regulator.

The Wnt/Pyruvate kinase, Muscle axis plays an essential role in the differentiation of mouse neuroblastoma cells

Neuronal differentiation and neurite growth are essential processes in nervous system development and are regulated by several factors. Although all-trans retinoic acid (ATRA) has been shown to mediate the differentiation of mouse neuroblastoma cells via the activation of several pathways, including Wnt/β-catenin signaling, the mechanism remains unclear. The pyruvate kinase, muscle (PKM) plays an important role in the glycolysis of neuroblastoma cells and regulates the Wnt signaling pathway in various cancer cells. In this study, we hypothesized that the Wnt/PKM axis regulates the differentiation of neuroblastoma cells (Neuro-2a and N1E-115). To test this hypothesis, we used inhibitors and activators of the Wnt/β-catenin and glycolytic pathways in ATRA-induced differentiated Neuro-2a and N1E-115 cells and established cell lines with silenced or a mutant replacement of Pkm. Western blot and qPCR showed that ATRA treatment activated the Wnt signaling pathway and inhibited PKM-mediated glycolysis. The oxygen consumption rate (indicating oxidative phosphorylation) significantly increased, whereas the extracellular acidification rate (indicating glycolysis) significantly decreased during differentiation; these effects were reversed upon PKM inhibition. The Wnt inhibitor ICG-001 and PKM activator ML-265 inhibited ATRA-induced Neuro-2a and N1E-115 differentiation, whereas RNA interference-mediated Pkm silencing promoted Neuro-2a and N1E-115 differentiation, which was reversed by PKM overexpression. Treatment with the Wnt activator kenpaullone promoted Neuro-2a and N1E-115 differentiation, which was reversed by ML-265 administration. These results indicate that Wnt/β-catenin signaling promotes Neuro-2a and N1E-115 differentiation by inhibiting PKM-mediated glycolysis during ATRA-induced differentiation. These findings may provide a new theoretical basis for the role of glycolysis in nerve differentiation.

Precommercial Thinning but Not Commercial Thinning Increases the Merchantable and Large Sawlog Volume Production of Lodgepole Pine on Fair Sites

Abstract The effect of thinning on stand structure and volume production is well studied. However, the effect of combinations of precommercial (PCT) and commercial thinning (CT) on the production of different log grades and differential growth responses is less understood, although it is crucial for forest managers to choose an optimal management regime. Starting with actual operational field data from a lodgepole pine (Pinus contorta var.latifolia) PCT trial on fair quality sites (site index: 16–18 m at 50 years), we used an individual tree growth model to forecast development over the entire rotation. We found thinning changed the structure (density, quadratic mean diameter) of the stands but not the total volume production. However, in terms of merchantable volume and large sawlog volume, stands with only PCT provided the largest volume, more than either CT or a combination of PCT and CT, or the unthinned control. Moreover, our study findings also showed that, by doing only PCT, stands reached maximum merchantable or large sawlog mean annual increment earlier than other thinned or unthinned stands. This indicates that PCT might shorten the rotation length and contribute to an enhanced supply of timber. Study Implications: The effect of commercial thinning (CT) on stand structure and volume production is well studied. However, the effect of combinations of precommercial (PCT) and commercial thinning (CT) on the production of different log grades and differential growth responses is less studied, although it is crucial for forest managers to choose a management option. Starting with actual operational field data from a lodgepole pine (Pinus contorta var.latifolia) PCT trial in a fair-quality site (site index [SI]: 16–18), we used an individual tree growth model to develop the stands over the entire rotation. We found thinning changed the structure (density, quadratic mean diameter) of the stands but not the total volume production. However, in terms of merchantable volume and large sawlog volume, stands with only PCT provided the largest volume, more than either CT or a combination of PCT and CT, or the unthinned control. Moreover, our study findings also showed that, by doing only PCT, stands reached maximum merchantable or large sawlog MAI earlier than other thinned or unthinned stands. This indicates that PCT might shorten the rotation length and contribute to the continuous supply of timber production.

Commercial inpatient hospital price growth driven by system affiliation and nonprofit-status hospitals.

As policymakers continue to grapple with rising health care costs and prices, understanding trends and variations in inpatient prices among hospital characteristics is an important benchmark to allow policymakers to craft targeted policies. In this study, we provide descriptive trends on variation in inpatient prices paid by commercial health plans stratified by hospital characteristics using data from Health Care Cost Institute's employer-sponsored insured claims data. Our analyses found evidence of considerable variation among inpatient price levels and growth among system affiliation and profitability. Prices among system-affiliated hospitals grew from $14 281.74 in 2012 to $20 731.95 in 2021, corresponding to a 45.2% increase during this period. On the other hand, prices among independent hospitals grew more slowly, from $13 460.50 in 2012 to $18 196.90 in 2021, corresponding to a 35.2% increase. We did not observe a similar trend in growth rates among case mix index by hospital characteristics, implying that differential inpatient price growth is not driven by changes in case mix by hospital characteristics. Heterogeneity in hospital prices and price growth by type of hospital suggests that public and private policymakers aiming to rein in health spending should consider policies that address this variation.

Mapping and evaluating spatiotemporal patterns of urban expansion in global earthquake-affected areas: a nighttime light remote sensing perspective

ABSTRACT Amidst the backdrop of frequent global earthquakes, assessing the spatiotemporal dynamics of urban expansion in earthquake-affected areas is imperative for sustainable development insights. The current analyses, however, are primarily focused on administrative units or some specific natural units. Here, we quantified spatiotemporal patterns of urban expansion from 2000 to 2020 in global earthquake-affected areas globally. Specifically, we delineated such areas using data from earthquakes of magnitude 5.5 and above since 1965. Then, employing nighttime light remote sensing data, we extracted urban entities and systematically evaluated the spatiotemporal patterns of urban expansion in earthquake-affected areas. The findings indicate a phase-based differential growth in urban expansion in earthquake-affected areas from 2000 to 2020. The average deceleration factor for urban areas in earthquake-affected areas over the past 20 years is 128.67%. Urban expansion in earthquake-affected areas is growing at a rapid pace, except for Europe and North America. In addition, 66.7% of urban expansion in global earthquake-affected areas presents low-density sprawl and solitary edge expansion trends, potentially affecting population density and land use efficiency. This study offers the most exhaustive analysis of urban expansion in earthquake-affected areas in recent decades and calls for administration beyond administrative boundaries to some extent.

Growth performances of Clarias gariepinus juveniles fed with Jatropha curcas seed meal

Jatropha curcas is an oil producing seed with high nutritional qualities for consumption. However, due to inherent anti-nutritional factors, appropriate processing is necessary to improve its nutrients utilization. This study was aimed at processing J. curcas using solvent-extraction method and evaluating its inclusion effects in the diet for Clarias gariepinus on its growth status. J. curcas meal was extracted using 80 % methanol to remove phorbol esters and other anti-nutrients. Thereafter, five iso-nitrogenous diets (40 % crude protein) were formulated containing J. curcas meal replacements of soybeans meal at 0 % (TRT0), 25 % (TRT25), 50 % (TRT50), 75 % (TRT75) and 100 % (TRT100) and fed to C. gariepinus for 70 days. Results showed that TRT25 fish had the highest mean weight gain and specific growth. The serum alkaline phosphate, alanine aminotransferase, and aspartate aminotransferase levels began to rise significantly (p ≤ 0.05) at 50 % replacement. Likewise, the assessment of gut ecology and morphology indicated that TRT25 had significantly (p ≤ 0.05) the highest gut bacteria colony forming unit (2.60 ×104±0.02cfu/g) and most favorable area of absorption (0.16±0.01 cm2). The histopathological observation of the fish intestine, liver and gills indicated no visible deformity in TRT0 and TRT25 fish. However, various degrees of degenerations were observed in the fish fed with 50 % and higher inclusion of J. curcas. This study showed that methanol-extracted J. curcas meal can be effectively utilized for C. gariepinus at 25 % of replacement.

The Modulation of Growth and Metabolism in Solanum lycopersicum Contrast With the Leaf-Specific Regulation of Wild Tomato Species.

Plant organs harbour diverse components that connect their physiology to the whole organism. The turnover of metabolites may be higher in some organs than in others, triggering differential growth patterns throughout the organism. We revealed that Solanum lycopersicum exhibits more coordinated growth and physiology across the entire plant compared to wild tomato species. Specifically, young leaves of S. lycopersicum develop more slowly than mature leaves, whereas wild species do not exhibit this pattern. Wild tomato Solanum pennellii displays young leaves with higher photosynthetic rates than mature leaves. Consequently, sucrose metabolism in S. pennellii is quite similar between young and mature leaves, while expression patterns of circadian clock genes differ significantly between leaves of different ages. Additionally, we demonstrated that introducing alleles related to tomato domestication into the wild tomato Solanum pimpinellifolium promotes coordinated growth between young and mature leaves, resulting in similar patterns to those observed in S. lycopersicum. Collectively, S. lycopersicum appears to exhibit more coordinated regulation of growth and metabolism, and understanding this process is likely fundamental to explaining its elevated harvest index.

Chemical Characteristics of Zirconium Chloride and Zirconium Oxide Nanoparticles Driving Toxicity on Lemna minor

The increasing global production and utilization of zirconium (Zr) compounds, including zirconium chloride (ZrCl4) and zirconium oxide nanoparticles (NPs-ZrO2), raises concerns about their potential environmental impact. This study investigated the toxicity mechanisms of ZrCl4 and NPs-ZrO2 on the aquatic plant Lemna minor. The physicochemical properties of NPs-ZrO2 in the test medium were characterized, revealing concentration-dependent changes in the hydrodynamic diameter, zeta potential, and solubility over time. The analysis of Zr speciation showed the predominance of Zr(OH)4(aq) species from ZrCl4. Plants of L. minor exposed to ZrCl4 and NPs-ZrO2 exhibited differential Zr bioaccumulation, growth inhibition, oxidative stress, and antioxidant responses. ZrCl4 induced a higher toxicity than NPs-ZrO2, with bioaccumulation strongly correlating with adverse effects. The differential toxicity impact between these two Zr-compounds was also determined by the lowest observed-effect doses for growth and biochemical parameters. The scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy confirmed internalization of NPs-ZrO2 and Zr uptake in the L. minor plant. Therefore, these findings highlighted the importance of chemical speciation, environmental transformations, and biological responses in assessing the ecological impact of Zr-compounds for effective risk assessment and management strategies for protecting aquatic ecosystems.

Distribution of genotypes by the growth diferential factor 9 (GDF-9) gene locus in the romanov breed sheep population

The FecG gene, also known as GDF-9 (growth factor differentiation factor 9), plays an important role in regulating reproductive function in mammals. This paper presents the results of a study of a point mutation in the differential growth factor gene in Romanov breed sheep. Mutations in exon 1 of the GDF-9 gene can lead to disturbances in ovarian development and ovulation, resulting in infertility or reduced reproductive capacity in animals. The object of the study was Romanov breed sheep in a sample of 30 individuals. For DNA extraction, venous blood samples were taken from the jugular vein. In Romanov breed sheep for the GDF-9 gene, it was found that at the G1 locus of this gene there are two alleles – G and A. Three genotypes were also identified: GG (254 bp/117 bp), AG (410bp/254/117 bp) and AA (410 bp/410 bp). The observed χ2 criterion was less than expected, therefore, the empirical and theoretical frequencies do not differ significantly, and deviations from the distribution according to the Hardy-Weinberg law are not observed. The observed heterozygosity index (Ho) was 0.27. Allele frequencies were 0,8 for G and 0,2 for A. For genotypes the following were obtained: GG – 0,66, GA – 0,27 and AA – 0,07.It can be noted that the data on the frequencies of alleles and genotypes in the population of Romanov breed sheep differ from the results for the Kulunda fine-wool, Dagestan mountain, Salsk, Lacaune and Merino breeds. The research results can be used to monitor changes in allele frequencies and genotypes in sheep during the selection process.

Super-enhancer-driven ZFP36L1 promotes PD-L1 expression in infiltrative gastric cancer

Gastric cancer (GC) is a major cause of cancer-related mortality worldwide. Despite the widespread recognition of tumor immunotherapy in treating unresectable GC, challenges, including ineffective immunotherapy and drug resistance, persist. Therefore, understanding the regulatory mechanisms of PD-L1, particularly in the context of super-enhancers (SEs) and zinc finger protein 36 ring finger protein-like 1 (ZFP36L1) RNA-binding protein, is crucial. In this study, we performed H3K27ac Cleavage Under Targets and Tagmentation (CUT&Tag) sequencing, investigated the heterogeneity of SEs between two GC subtypes with differential growth patterns, and revealed the immune escape signatures driven by ZFP36L1-SE in infiltrative GC through SEs inhibitors treatment. The regulation of ZFP36L1 to PD-L1 was evaluated by quantitative PCR, western blot, flow cytometry, and immunohistochemistry. Furthermore, we explored its regulatory mechanisms using a combination of molecular biology techniques, including luciferase reporter assay, GST/RNA pull-down, chromatin immunoprecipitation (ChIP)/RIP experiments, and in vivo functional assays. We demonstrated that ZFP36L1, driven by an SE, enhances IFN-γ-induced PD-L1 expression, with SPI1 identified as the specific transcription factor binding to ZFP36L1-SE. Mechanistically, ZFP36L1 binds to the adenylate uridylate-rich element in the 3ʹ untranslated region (3ʹUTR) of HDAC3 mRNA, exacerbating its mRNA decay, and thereby facilitating PD-L1 abnormal transcriptional activation. Collectively, our findings provide mechanistic insights into the role of the SPI1-ZFP36L1-HDAC3-PD-L1 signaling axis in orchestrating immune escape mechanisms in GC, thereby offering valuable insights into the potential targets for immune checkpoint therapy in GC management.

Super-enhancer-driven ZFP36L1 promotes PD-L1 expression in infiltrative gastric cancer.

Gastric cancer (GC) is a major cause of cancer-related mortality worldwide. Despite the widespread recognition of tumor immunotherapy in treating unresectable GC, challenges, including ineffective immunotherapy and drug resistance, persist. Therefore, understanding the regulatory mechanisms of PD-L1, particularly in the context of super-enhancers (SEs) and zinc finger protein 36 ring finger protein-like 1 (ZFP36L1) RNA-binding protein, is crucial. In this study, we performed H3K27ac Cleavage Under Targets and Tagmentation (CUT&Tag) sequencing, investigated the heterogeneity of SEs between two GC subtypes with differential growth patterns, and revealed the immune escape signatures driven by ZFP36L1-SE in infiltrative GC through SEs inhibitors treatment. The regulation of ZFP36L1 to PD-L1 was evaluated by quantitative PCR, western blot, flow cytometry, and immunohistochemistry. Furthermore, we explored its regulatory mechanisms using a combination of molecular biology techniques, including luciferase reporter assay, GST/RNA pull-down, chromatin immunoprecipitation (ChIP)/RIP experiments, and in vivo functional assays. We demonstrated that ZFP36L1, driven by an SE, enhances IFN-γ-induced PD-L1 expression, with SPI1 identified as the specific transcription factor binding to ZFP36L1-SE. Mechanistically, ZFP36L1 binds to the adenylate uridylate-rich element in the 3' untranslated region (3'UTR) of HDAC3 mRNA, exacerbating its mRNA decay, and thereby facilitating PD-L1 abnormal transcriptional activation. Collectively, our findings provide mechanistic insights into the role of the SPI1-ZFP36L1-HDAC3-PD-L1 signaling axis in orchestrating immune escape mechanisms in GC, thereby offering valuable insights into the potential targets for immune checkpoint therapy in GC management.

Differential growth is an emergent property of mechanochemical feedback mechanisms in curved plant organs.

Differential growth is central to eukaryotic morphogenesis. We showed using cellular imaging, simulations, and perturbations that light-induced differential growth in a curved organ, the Arabidopsis thaliana apical hook, emerges from the longitudinal expansion of subepidermal cells, acting in parallel with a differential in the material properties of epidermal cell walls that resist expansion. The greater expansion of inner hook cells that results in apical hook opening is gated by wall alkalinity and auxin, both of which are depleted upon illumination. We further identified mechanochemical feedback from wall mechanics to light stimulated auxin depletion, which may contribute to gating hook opening under mechanical restraint. These results highlight how plant cells coordinate growth among tissue layers by linking mechanics and hormonal gradients with the cell wall remodeling required for differential growth.

On Population and the International Order

AbstractThis essay expores demographic effects on the international order over the postwar decades and potentially through the next half‐century. Such effects derive from the relative sizes of populations and labor forces among states, contrasts in age distributions (resulting from the regionally staggered timing of fertility decline), and high levels of international migration, fueled by economic disparities and civil conflict. In coming decades, differential population growth and aging—in some states, entrenchment of population decline—will shift the global distribution of labor away from East Asia and Europe and toward South and West Asia and especially Africa. Short‐range migration may be pressed by environmental change; longer‐range migration toward rich countries, much of it illicit and already an intractable public policy issue in many of them, will face increased societal resistance and stronger efforts to police entry. The future international order will see a states system with the Global North further demographically marginalized; India as an emerging economic‐demographic superpower, joining a fast‐aging China and plausibly a less internationally engaged United States; and a demographically dominant Africa with as yet a wholly unclear place in the global political economy. Although not part of standard demographic projections, there are extreme global warming scenarios and other disaster eventualities that could be radically transformative of this order.

Laser powder bed fusion printed poly-ether-ether-ketone/bioactive glass composite scaffolds with dual-scale pores for enhanced osseointegration and bone ingrowth

Although poly-ether-ether-ketone (PEEK) implants hold significant medical promise, their bioinert nature presents challenges in osseointegration and bone ingrowth within clinical contexts. To mitigate these challenges, the present study introduces Diamond PEEK/bioactive glass (BG) composite scaffolds, characterized by macro/micro dual-porous structures, precisely fabricated via laser powder bed fusion (LPBF) technology. The findings indicate that an increase in BG content within these scaffolds significantly augments their hydrophilicity and hydroxyapatite formation capacities. Stress-strain curve analysis demonstrates reliable load-bearing stability across all scaffold types. In vitro assessments confirmed the non-cytotoxicity of PEEK/BG samples and demonstrated improved osteogenic differentiation and mineralization with increased BG incorporation. Further, in vivo experiments illustrated that the Diamond porous structure of these scaffolds facilitated bone growth, an effect notably amplified with higher BG content. Particularly in groups with 15 wt% and 25 wt% BG scaffolds, new bone formation was observed not only within the macropores of the Diamond structure but also within the micropores inside the scaffold rod, suggesting an almost seamless fusion with the new bone. This demonstrates the scaffolds’ effective osteointegration and bone ingrowth properties. This study conclusively established the effectiveness of Diamond-structured PEEK/BG composite scaffolds, fabricated via LPBF, in bone repair. It highlights the crucial role of BG in enhancing osteogenic potential through interaction with the macro/micro pores of the scaffold. Statement of significanceThis study addresses the bioinert nature of PEEK implants by developing Diamond-structured PEEK/bioactive glass (BG) composite scaffolds by laser powder bed fusion. The dual-porous macro/microstructure enhances hydrophilicity and hydroxyapatite formation, vital for bone regeneration. By adjusting the BG content, we controlled the melt viscosity and sintering rate, leading to the formation of beneficial microscale pores. These pores resolve the issue of ineffective bioactive fillers in previous LPBF-fabricated scaffolds, enhancing the osteogenic potential of BG and inducing superior bone ingrowth and osseointegration. In vitro and in vivo analyses show enhanced osteogenic differentiation, mineralization, and bone growth, underscoring the clinical potential of these scaffolds for bone repair.

Patterns of early embryogenesis and growth in the olfactory system of chick (Gallus gallus domesticus) based on iodine-enhanced micro-computed tomography.

The vertebrate olfactory system entails a complex set of neural/support structures that bridge morphogenetic regions. The developmental mechanisms coordinating this bridge remain unclear, even for model organisms such as chick, Gallus gallus. Here, we combine previous growth data on the chick olfactory apparatus with new samples targeting its early embryogenesis. The purpose is to illuminate how early developmental dynamics integrate with scaling relationships to produce adult form and, potentially, evolutionary patterns. Olfactory structures, including epithelium, turbinate, nerve, and olfactory bulb, are considered in the context of neighboring nasal and brain structures. Axonal outgrowth from the olfactory epithelium, which eventually connects receptor neurons with the brain, begins earlier than previously established. This dynamic marks the beginning of a complex pattern of early differential growth wherein the olfactory bulbs scale with positive allometry relative to both brain volume and turbinate area, which in turn scale isometrically with one another. The mechanisms driving observed patterns of organogenesis and growth remain unclear awaiting experimental evidence. We discuss competing hypotheses, including the possibility that broad-based isometry of olfactory components reflects constraints imposed by high levels of functional/structural integration. Such integration would include the frontonasal prominence having a strong influence on telencephalic patterning.

Historical forest use constrains tree growth responses to drought: A case study on tapped maritime pine (Pinus pinaster)

Resin extraction from Pinus pinaster (maritime pine) trees was an important economic activity for most of the 20th century in Mediterranean forests, until the decrease in resin prices that led to their abandonment in the 1960s-1970s. Reduced tree growth is often observed after long periods of resin tapping, but it is unknown how these formerly tapped stands respond to recent climate warming and aridification. We sampled three historically tapped maritime pine stands in Teruel, eastern Spain, to understand differential growth and responses to climate in resin tapped and non-tapped trees. Using dendrochronological methods, we compared tree growth trends and responses to climate in tapped and non-tapped trees. Overall, tree growth was higher in resin tapped trees than in non-tapped trees, which were generally younger. However, tree growth decreased over time, increasing the negative effects of late spring temperatures, summer drought and reduced summer precipitation, with increased sensitivity to drought in tapped than non-tapped trees. Among tapped trees, those with larger wound area grew more than those less tapped, and were more sensitive to drought, particularly after the 80 s. Our results suggest that the legacy effects of previous management can constrain tree responses to climate change by increasing the sensitivity of tree growth to drought.

Differential growth and shape formation of a flower-shaped structure

Morphogenesis, which is a complex interplay of biological, chemical, and physical processes, facilitates differential growth in various biological systems, particularly in plant organs, such as petals and leaves. Although recent studies have increasingly delved into the mechanical aspects of these biological structures, there remains a lack of a comprehensive quantitative understanding of shape formation induced by differential growth in plant organs. Thus, this study addressed this gap by employing a multifaceted approach encompassing theoretical analyses and comprehensive finite element analysis of the effect of differential growth on the shape of a cylinder into a flower shape. Based on the derivation of the strain energy expressions for the axisymmetric and asymmetric configurations, the shape function of the growing flower-like structures were calculated through mathematical optimization. The findings of this study shed light on the influence of the growth function, geometric characteristics, and material properties. As the wave number increased, the final configuration tended to have smaller waves, whereas a longer cylinder buckled more easily and the thickness had a minimal effect. This study offers insights that can pave the way for innovative geometrical designs, thereby providing inspiration for applications on both micro-and macroscales, such as in the realms of self-assembly of soft robotics and flexible electronics.