Variation In Growth Rate Research Articles

Buoyancy and Marangoni effects on horizontal ribbon growth

Unsteady simulations of horizontal ribbon growth of silicon were performed that included both Marangoni and buoyancy effects. A chaotic flow was observed dominated by strong Marangoni-driven jets emerging near the local temperature minima on the free surface. This oscillatory flow caused the vertical position of the leading edge of the sheet to fluctuate, resulting in corrugations on the top surface of the ribbon. Additionally, larger amplitude and wavelength nonuniformities appeared on the bottom of the sheet resulting in a sheet with varying thickness. Lastly, the unsteady flow caused temporal variations in growth rate, which when converted to distance using the pull speed, matched the wavelengths observed on the top surface. All three of these phenomena have been observed experimentally: The median of the surface wavelengths and amplitudes decreased with increasing temperature sensitivity of surface tension and had wavelengths on the same order as experiments for a sensitivity corresponding to uncontaminated silicon. Oscillations in growth rate have been observed using passive antimony demarcation and thickness variations have been measured after sheet removal. These results indicate that the chaotic flow makes producing thin uniform sheets using HRG challenging.

Intraspecific variation in growth‐related traits—from leaf to whole‐tree—in three provenances of Cryptomeria japonica canopy trees grown in a common garden

AbstractTo elucidate the physiological and morphological factors underlying intraspecific variation in growth rate, we examined the variation in leaf and whole‐tree traits for three geographical variations of ca. 45‐year‐old Japanese cedar (Cryptomeria japonica D. Don) with contrasting heights and radial growth in a common garden. Traits that reflect leaf‐level photosynthesis, water relations, and whole‐tree level crown structure in relation to light use and hydraulic architecture were measured. Overall, intraspecific variation in growth characteristics in field‐grown adult trees was regulated by whole‐tree properties rather than leaf properties. Most leaf traits were similar among provenances. Nevertheless, the leaf traits exhibited highest maximum net photosynthetic rate, dark respiration rate, and light compensation point in provenances whose native habitats are most similar to the common garden in the present study. Together with previous reports that this provenance has higher root nutrient acquisition capacity than the other two provenances, it can be said that organ‐level resource use strategies are coupled in a tandem manner. At the whole‐tree level, hydraulic architecture—as explained by axial variation in the hydraulically weighted tracheid diameter—can be linked to leaf distribution with respect to light use strategies as well as water transport capacity, leading to differences in growth characteristics among provenances. The study of intraspecific variation in growth characteristics in trees with a wide range of native habitats is expected to be a useful indicator for predicting changes in growth potential and forest dynamics in response to climate change in each habitat.

FDI and Trade Openness in the Tourism Market in Asian Emerging Market Economies

FDI and trade openness are considered development tools in all sectors, and the tourism sector is no exception. We examine the impact of inward FDI and trade openness on tourism in selected Asian emerging markets using panel data from the Autoregressive Distributed Lag of the Pooled Mean Group model and examine the direction of the causality of inward foreign direct investment and trade openness on tourism using the Granger causality test for the period 1996-2019. In our research model, we employed the number of tourists’ arrivals as the dependent variable and inward foreign direct investment and trade openness as the main independent variables. The control variables are as follows: GDP growth rate, inflation, mobile telephone subscriptions, and the global financial crisis of 2008. According to the pooled mean group ARDL estimation results, inward FDI, trade openness, GDP growth rate, inflation, and mobile telephone subscription variables had long-run significance in explaining tourism, whereas the global financial crisis dummy variable did not explain tourism arrivals. In the short run, an increase in the GDP growth coefficient attracted more international tourists to Asian EMEs, whereas an increase in inflation reduced tourism arrivals. The study found that there is a unidirectional relationship between FDI inflows and tourism arrivals, with the causality flowing from tourism to FDI. Furthermore, the results of the causality test implied that there were bidirectional connections between tourism and trade openness in Asian emerging markets. The study suggests that emerging economies should also promote short-term policies to increase international tourism by increasing trade openness and foreign direct investment.

Large-eddy simulation of gusty wind turbulence over a travelling wave

Wind gustiness in the marine atmospheric boundary layer affects significantly the dynamics of air–sea interaction. To understand the impacts of wind gust events, we perform large-eddy simulation of wind turbulence over a travelling wave to investigate the response of the wind field to an impulsive wind speed increase or decrease. It is found that the turbulence fluctuations and the terms in the turbulent kinetic energy budget equation have a delayed response to the change in the mean flow, while the response of the wave-coherent motions is quasi-stationary. The wave-coherent motions are investigated quantitatively through comparison with a viscous curvilinear model developed by Cao et al. (J. Fluid Mech., vol. 901, 2020, A27) and Cao & Shen (J. Fluid Mech., vol. 919, 2021, A38). We observe an asymmetric hysteresis between the growing wind and the decaying wind in the evolution of the form drag and the viscous drag. We find further that the variation of the wave growth rate during the wind gust is related closely to the contribution from the out-of-phase component of the vertical velocity. Our discoveries provide evidence for the necessity of improving non-equilibrium turbulence and wind input modelling to account for the wind gustiness effect in future studies.

470 Investigating modifiers of cutaneous neurofibroma development in adults with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a multi-system genetic disorder involving the cutaneous, nervous, hematopoietic, ocular, and skeletal systems. Almost all individuals with NF1 (>95%) develop benign dermal tumors called cutaneous neurofibromas (cNFs) which frequently lead to significant physical and social morbidity. cNFs exhibit high variability in number, subtype, growth rate, and anatomic location. Despite substantial research into the molecular drivers of cNFs, the genotypic-phenotypic correlation and the factors which modulate cNF development are not well understood.

Individual growth of the Flathead Knob‐scaled Lizard, Xenosaurus platyceps, from tropical and temperate populations

AbstractGrowth rates of ectotherms are frequently affected by environmental conditions, such as temperature, precipitation, and prey availability. However, local adaptation to environmental conditions could influence geographic variation in growth rates. We studied growth rates of the Flathead Knob‐scaled Lizard, Xenosaurus platyceps, from a tropical population and a temperate population in Tamaulipas, Mexico. We used a field study and a common garden experiment to examine the extent and potential causes of variation in individual growth rates between these two populations from contrasting environments. Field‐determined growth rates in the tropical population were greater than those in the temperate population. In a laboratory common garden experiment that manipulated food availability and temperature for neonates from each population, neonates from the tropical population grew faster than those from the temperate population. Neonates kept at higher temperatures grew faster than those kept at lower temperature. In addition, growth rates of neonates from temperate and tropical populations did not differ at low temperature, but neonates from the tropical population grew faster at the higher temperature than did the neonates from the temperate population. Food treatment did not affect individual growth rates in these lizards, although there was a trend for neonates grown with higher food availability to grow faster. Our results suggest that not only does the warm environment of the tropical population contribute to the observed differences in field growth rates, but there is a genetic difference in the ability of the tropical population to take advantage of the warmer temperatures to increase growth ratesAbstract in Spanish is available with online material.

Estimating genotypic richness and proportion of identical multi-locus genotypes in aquatic microalgal populations.

The majority of microalgal species reproduce asexually, yet population genetic studies rarely find identical multi-locus genotypes (MLG) in microalgal blooms. Instead, population genetic studies identify large genotypic diversity in most microalgal species. This paradox of frequent asexual reproduction but low number of identical genotypes hampers interpretations of microalgal genotypic diversity. We present a computer model for estimating, for the first time, the number of distinct MLGs by simulating microalgal population composition after defined exponential growth periods. The simulations highlighted the effects of initial genotypic diversity, sample size and intraspecific differences in growth rates on the probability of isolating identical genotypes. We estimated the genotypic richness for five natural microalgal species with available high-resolution population genetic data and monitoring-based growth rates, indicating 500 000 to 2 000 000 distinct genotypes for species with few observed clonal replicates (<5%). Furthermore, our simulations indicated high variability in genotypic richness over time and among microalgal species. Genotypic richness was also strongly impacted by intraspecific variability in growth rates. The probability of finding identical MLGs and sampling a representative fraction of genotypes decreased noticeably with smaller sample sizes, challenging the detection of differences in genotypic diversity with typical isolate numbers in the field.

Central Metabolism and Growth Rate Impacts on Hydrogen and Carbon Isotope Fractionation During Amino Acid Synthesis in E. coli.

Compound specific stable isotope analysis (CSIA) of amino acids from bacterial biomass is a newly emerging powerful tool for exploring central carbon metabolism pathways and fluxes. By comparing isotopic values and fractionations relative to water and growth substrate, the impact of variable flow path for metabolites through different central metabolic pathways, perturbations of these paths, and their resultant consequences on intracellular pools and resultant biomass may be elucidated. Here, we explore the effects that central carbon metabolism and growth rate can have on stable hydrogen (δ2H) and carbon (δ13C) compound specific isotopic values of amino acids, and whether diagnostic isotopic fingerprints are revealed by these paired analyses. We measured δ2H and δ13C in amino acids in the wild type Escherichia coli (MG1655) across a range of growth rates in chemostat cultures to address the unknown isotopic consequences as metabolic fluxes are shuffled between catabolic and anabolic metabolisms. Additionally, two E. coli knockout mutants, one with deficiency in glycolysis –pgi (LC1888) and another inhibiting the oxidative pentose phosphate pathway (OPPP) –zwf (LC1889), were grown on glucose and used as a comparison against the wild type E. coli (MG1655) to address the isotopic changes of amino acids produced in these perturbed metabolic pathways. Amino acid δ2H values, which collectively vary in composition by more than 400‰, are altered along with δ13C values demonstrating fundamental shifts in central metabolic pathways and/or fluxes. Within our linear discriminant analysis with a simple model organism to examine potential amino acid fingerprinting, our knockout strains and variable growth rate samples plot across a wider array of organism classification than merely within the boundaries of other bacterial data.

Emergent evolutionary forces in spatial models of luminal growth and their application to the human gut microbiota

The genetic composition of the gut microbiota is constantly reshaped by ecological and evolutionary forces. These strain-level dynamics are challenging to understand because they depend on complex spatial growth processes that take place within a host. Here we introduce a population genetic framework to predict how stochastic evolutionary forces emerge from simple models of microbial growth in spatially extended environments like the intestinal lumen. Our framework shows how fluid flow and longitudinal variation in growth rate combine to shape the frequencies of genetic variants in simulated fecal samples, yielding analytical expressions for the effective generation times, selection coefficients, and rates of genetic drift. We find that over longer timescales, the emergent evolutionary dynamics can often be captured by well-mixed models that lack explicit spatial structure, even when there is substantial spatial variation in species-level composition. By applying these results to the human colon, we find that continuous fluid flow and simple forms of wall growth alone are unlikely to create sufficient bottlenecks to allow large fluctuations in mutant frequencies within a host. We also find that the effective generation times may be significantly shorter than expected from traditional average growth rate estimates. Our results provide a starting point for quantifying genetic turnover in spatially extended settings like the gut microbiota and may be relevant for other microbial ecosystems where unidirectional fluid flow plays an important role.

French amateur football clubs’ finance and revenue volatility: the determinants of demand shocks

ABSTRACT The article addresses financial troubles in French amateur football clubs and their origins. Previous literature has demonstrated that – in particular in French football – club bankruptcies are triggered by demand shocks. The present research intends highlighting the determinants of demand shocks on those clubs playing French amateur football top two tiers with a longitudinal analysis (2009/2010-2019/2020). Various exogenous elements that influence club demand (i.e. revenues) are taken on board, namely, macroeconomic variables, such as the variation of GDP growth rate between two football seasons, a dummy for the Covid-19 sanitary crisis, and a sport dummy for the effect of the French national team winning the 2018 male football World Cup. The latter is used to check a potential trickle-down effect on amateur elite football. None of these variables do explain demand shocks except if the heterogeneity of clubs’ economic models is taken into account. The determinants of shock demands appear to be clubs’ strategic orientations (towards win maximization vs. a stable economic organization).

HPLC and 32P‐radiolabeling method for quantification of microbial adenylate concentrations and turnover rates in seawater

AbstractWe optimized a high throughput method to quantify turnover rates of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in marine microbes from simultaneous measures of the respective stocks and phosphorylation rates. We combined a microbial adenylate extraction method using boiling 20 mM Tris buffer with purification and analysis by high pressure liquid chromatography optimized to quantify these intracellular adenylate concentrations in marine microbes. Additionally, we incorporated radiolabeled phosphate (32Pi) incubations to quantify phosphorus (P) uptake rates and the phosphorylation rates for these adenylate compounds in microbial cells. With this method, we can directly assess the variations in microbial growth rates, metabolic turnover rates, energy charge, and adenylate storage. We applied and validated this method application with environmental samples from Biscayne Bay, Florida, and quantified adenylate turnover times of 12, 15, and 73 min, for ATP, ADP, and AMP, respectively. Future incorporation of this method into experiments and geographic surveys across marine environments will allow for direct assessments of changes in microbial metabolic activity in relation to other ecological variables.

Effect of Commercial &amp; Natural Feeds on the Growth Performance of Ostrich (Struthio camelus) in Captivity

In Pakistan, ostrich farming is becoming more popular as a means of obtaining inexpensive meat that is also devoid of cholesterol and other diseases when compared to chicken. In the wild, ostriches dwell in flocks of five to fifty and perform well in captivity. Ostrich chicks' early development rate is critical in preparing the bird for later growth up till the slaughter mass. The original egg mass from which the bird emerges determines the hatching weight. Ostrich chicks lose up to 20% of their weight in the first five to seven days after hatching.The typical carcass weight of an ostrich might be 57-58 percent of the live body weight.On a monthly basis, weight and height were determined, and given feed was calculated on a daily basis. The variation in growth rates between the two farms is due to the fact that the Balouch ostrich farm has far better conditions for birds and provides more food, whilst the Hamayoon ostrich farm has a lower growth rate due to restricted food availability. Furthermore, the death rate is linked to a lack of food.

Land capital and emissions convergence in an extended Green Solow model

AbstractThe main purpose of this paper is to analyze the contribution of land capital to the growth of emissions and income per capita in the long run. We collect new satellite data from the Earth Observatory to obtain estimates of the Enhanced Vegetation Index at the country level for the period 2000–2015. We use these data and the World Bank wealth estimates of natural capital to calibrate and empirically test an extension of the Green Solow model with land degradation and land capital investment. We show that the model is consistent with the cross-country variation in growth rates of carbon emissions per capita and find that there is convergence at the global level, with the contribution of land capital investment to the growth of emissions being negative and significant in all specifications.

Analyzing dynamic species abundance distributions using generalized linear mixed models.

Understanding the mechanisms of ecological community dynamics and how they could be affected by environmental changes is important. Population dynamic models have well known ecological parameters that describe key characteristics of species such as the effect of environmental noise and demographic variance on the dynamics, the long‐term growth rate, and strength of density regulation. These parameters are also central for detecting and understanding changes in communities of species; however, incorporating such vital parameters into models of community dynamics is challenging. In this paper, we demonstrate how generalized linear mixed models specified as intercept‐only models with different random effects can be used to fit dynamic species abundance distributions. Each random effect has an ecologically meaningful interpretation either describing general and species‐specific responses to environmental stochasticity in time or space, or variation in growth rate and carrying capacity among species. We use simulations to show that the accuracy of the estimation depends on the strength of density regulation in discrete population dynamics. The estimation of different covariance and population dynamic parameters, with corresponding statistical uncertainties, is demonstrated for case studies of fish and bat communities. We find that species heterogeneity is the main factor of spatial and temporal community similarity for both case studies.

Global variation in early epidemic growth rates and reproduction number of seasonal influenza

BackgroundLittle is known about global variation in early epidemic growth rates and effective reproduction numbers (Re) of seasonal influenza. We aimed to estimate global variation in Re of influenza type A and B during a single period. MethodsCountry influenza detection time series from September 2017 through January 2019 were obtained from an international database. Type A and B epidemics by country were selected on the basis of Re estimates for a five-week moving window, advanced by week. Associations of Re with absolute latitude, human development index, percent of the population aged <15 years, and percent of those living in rural areas in each country were assessed. ResultsTime series were included for 119 of 169 available countries. There were 100 countries with influenza A and 79 with B epidemics. Median Re for both influenza A and B epidemics was 1.23 (ranges: A 1.10, 1.60; B 1.06, 1.58). Re of influenza B but not A was independently associated with absolute latitude, increasing by 0.022 (95% confidence interval 0.002, 0.043) per 10 degrees. ConclusionThe Re of influenza A and B were similar. Only the Re of influenza B was associated with country characteristics, which was increasing with distance from the equator. The approach may be suitable for continuous Re surveillance.

Pinangapalms revisited 20 years on: what can changes inPinangaspecies populations tell us about rainforest understory palm persistence?

AbstractBorneo is the centre of diversity of the palm genusPinanga. At least 13 understory species have been recorded in the Ulu Temburong National Park in Brunei, but little is known of their persistence. Changes in populations ofPinangaunderstory palms may be indicative of more widespread changes due to climate change, such as changes in rainfall, which may be important for the palm diversity in the protected area. However, we know little about the population dynamics of these palms, how persistent their populations are or if they behave similarly over long time frames. In 1998, populations of five co-occurring species ofPinangaat several locations in the Ulu Temburong National Park were documented. This project aimed to undertake a comprehensive resurvey of the original fivePinangapalm species populations in order to assess if they showed similar population changes across sites and species after two decades. Overall, most species maintained their population size in the surveyed region but not consistently among sites, and one species significantly declined in abundance. There was considerable variation in population growth rate (R) within and among species and sites that was significantly correlated with density and the percentage of multi-stemmed plants. There was evidence of pulsed recruitment in some species and or sites rather than steady or exponential patterns of population growth.

Abstract 5988: Intra-carotid artery brain metastasis models for evaluation of lung and breast cancer drugs

Abstract Non-CNS metastatic brain cancer is about 10 times more common than CNS cancer. Lung cancer and breast cancer account for most brain metastasis. KRAS-mutant NSCLC compose a third lung adenocarcinoma, among which 17% to 55% will develop brain metastases. Likewise, more than a third HER2-positive breast cancer will develop brain metastasis. Among existing animal models, the ectopic injection in brain cannot reflect the mechanism of tumor invasion and metastasis, while tail vein and intra-cardiac injection usually produces extra-cerebral metastatic disease and the animals have to be sacrificed before brain metastases appeared. Here we developed several metastasis models injected by intra-carotid artery (ICA) to address these problems. Two KRAS-mutant lung cancer cells and two HER2-positive breast cancer cells selected by their metastasize potential were luciferase labeled for in vivo imaging and drug evaluation. The tumor pathology in brain was evaluated by H&amp;E staining. Compared to ectopic models, these ICA models have natural dissemination and progression in the brain, which recapitulate the different pattern of metastatic lesions in the clinic. With synchronized growth rate and little variation compared to tail vein and intra-cardiac models, these tumor growth kinetics allow for more appropriate animal efficacy study. Both KRAS-sensitive and insensitive models have been developed and validated for the next generation drug development; HER-2 positive breast models with ICA method also showed a good discriminative power on anti-HER2 modalities including antibodies, small molecules and ADC. Meanwhile, ICA models with human immune cell reconstitution were also developed to support immune therapies in pre-clinical stage. In summary, we have developed a panel of intra-carotid artery brain metastatic models for drug evaluation, and demonstrated their superiority in growth kinetics, brain microenvironment, drug selectivity and immune component. These models can be a promising predictive tool for novel drug/modality discovery to target brain metastasis. Citation Format: Fuyang Wang, Yuying Yang, Haoxia Zhao, Chunlei Dai, Bingrui Han, Mengyao Zhang, Xia Xiong, Chao Zhang, Xuzhen Tang, Qunsheng Ji. Intra-carotid artery brain metastasis models for evaluation of lung and breast cancer drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5988.

Effects of sediment organic matter on mortality, growth and development of the polychaetes Capitella teleta and Capitella sp. (Annelida: Capitellidae) in laboratory conditions

The endobenthic deposit-feeder polychaetes of the Capitella capitata species complex have a strong relation with organically enriched sediments (OES). The effect of non-organically enriched sediments (NOES, 0.09% of organic content) and OES (6.26% of organic content) on mortality, growth and development of juveniles and adults of Capitella teleta (cultured for more than 40 years) and Capitella sp. from Alfacs Bay, Tarragona, Spain (acclimatized for one month) were analysed in laboratory conditions. Juveniles and adults were exposed (all individuals separately in different dishes) to the two treatments, periodically observed and measured until death. NOES considerably impaired survival, growth rates and development of juveniles and adults of both species, which showed highly variable negative growth rates under OES. Juvenile and adult C. teleta showed an improved maturity under OES, even producing two protandrous and one protogynous individuals, whereas no Capitella sp. reached maturity during the experiment.

Production and competitiveness of Mexican floriculture

Objective: To analyze the international commercialization competitiveness of the main flowers grown in Mexico compared to United States of America (USA). Design/methodology/approach: The cumulative growth rate of the production variables of the main flowers cultivated in Mexico from 2000 to 2020 was calculated. The country’s flower trade balance was evaluated. The revealed comparative advantage index (IVCR) of the Mexican floricultural sector was compared with the American IVCR. Results: Mexican floriculture has expanded in the last two decades; therefore, the 2000-2020 cumulative growth rates of the production variables in most of the flowers studied were positive. It is also a high-income activity. Although only 10.11 thousand ha are used by this sector, the four species of flowers analyzed had a 5.51-billion Mexican pesos production value (2020). Likewise, its trade balance has been in surplus and, in most of the years analyzed, its balance was greater than 90% of the value of exports. In addition, it is competitive in the international market: in 2020, the IVCR of Mexican flowers in the US market was 0.96 and, in the overall period of this study, it has been greater than 0.8. Study Limitations/Implications: Changes to the Harmonized System Codes hinder the evolutionary analysis of the tariff codes. The IVCR determines if the national market is competitive or not in the international market, but it does not establish which factors would provide competitiveness to the country. Findings/Conclusions: Floriculture in Mexico has increased in the last two decades. The production value of all the flowers studied increased during the period analyzed. In general terms, the Mexican floricultural market is competitive in the international market; additionally, the different Mexican flowers included in this research have a competitive advantage in the US market.

Enhancer-promoter interaction maps provide insights into skeletal muscle-related traits in pig genome

BackgroundGene expression programs are intimately linked to the interplay of active cis regulatory elements mediated by chromatin contacts and associated RNAs. Genome-wide association studies (GWAS) have identified many variants in these regulatory elements that can contribute to phenotypic diversity. However, the functional interpretation of these variants remains nontrivial due to the lack of chromatin contact information or limited contact resolution. Furthermore, the distribution and role of chromatin-associated RNAs in gene expression and chromatin conformation remain poorly understood. To address this, we first present a comprehensive interaction map of nuclear dynamics of 3D chromatin-chromatin interactions (H3K27ac BL-HiChIP) and RNA-chromatin interactions (GRID-seq) to reveal genomic variants that contribute to complex skeletal muscle traits.ResultsIn a genome-wide scan, we provide systematic fine mapping and gene prioritization from GWAS leading signals that underlie phenotypic variability of growth rate, meat quality, and carcass performance. A set of candidate functional variants and 54 target genes previously not detected were identified, with 71% of these candidate functional variants choosing to skip over their nearest gene to regulate the target gene in a long-range manner. The effects of three functional variants regulating KLF6 (related to days to 100 kg), MXRA8 (related to lean meat percentage), and TAF11 (related to loin muscle depth) were observed in two pig populations. Moreover, we find that this multi-omics interaction map consists of functional communities that are enriched in specific biological functions, and GWAS target genes can serve as core genes for exploring peripheral trait-relevant genes.ConclusionsOur results provide a valuable resource of candidate functional variants for complex skeletal muscle-related traits and establish an integrated approach to complement existing 3D genomics by exploiting RNA-chromatin and chromatin-chromatin interactions for future association studies.