Growth-limiting Conditions Research Articles

Using Mycobacterium smegmatis as a Bioindicator for Zinc-limited Growth Conditions in Mycobacteria.

Many bacteria build alternative ribosomes in Zn2+-limiting growth conditions by replacing Zn2+-binding ribosomal proteins with Zn2+-independent paralogs. Defining a system to study these alternative ribosomes has proven difficult because Zn2+ contamination in the laboratory is common. To address this issue, chelating agents are sometimes added to growth media, but this approach convolutes the biological response to gradual Zn2+limitation and is associated with ribosome hibernation. Here, detailed instructions are outlined for preparing media and seeding cultures for Zn2+-limited growth without adding chelators. Following this method, the model bacterium, Mycobacterium smegmatis, undergoes morphogenesis, which depends on alternative ribosomes. Because morphogenesis is tractable and only occurs in Zn2+-limiting conditions, M. smegmatis can be used as a bioindicator to verify biologically relevant growth conditions. Three bioindicator phenotypes (cell density, cell length, and coenzyme F420 fluorescence) that indicate Zn2+ limitation in the wild-type are described, and changes in these bioindicators for a deletion mutant that cannot build alternative ribosomes are outlined. Since trace Zn2+ contamination is difficult to control for each batch of media, and precise quantification of Zn2+ in each media preparation is overly burdensome, following this bioindicator phenotype is an accessible way to validate the preparation of Zn2+-limited growth media. To help identify proper conditions for Zn2+-limiting growth and alternative ribosome production, changes in the bioindicator phenotypes were profiled for Zn2+-contaminated or severely Zn2+-depleted preparations of Zn2+-limited media as well. Further details to achieve Zn2+-limiting growth and alternative ribosome production in M. tuberculosis are presented, along with the associated bioindicator phenotype. Overall, the detailed instructions and bioindicator phenotypes described here will help standardize the production of translationally active alternative ribosomes in mycobacteria.

Contrasting impacts of climate warming on Himalayan Hemlock growth: Seasonal and elevational variations

Ongoing climate change can have varying impacts on tree growth within the growing season and across their elevation ranges, with important implications for forest ecosystem functions and services. However, our knowledge of these effects on climate-sensitive Himalayan forests is still limited. Here, we explore the elevational changes in climatic factors driving long-term changes in the radial growth of Himalayan Hemlock (Tsuga dumosa), including recent responses to unprecedented climate warming in the central Himalayas. We evaluated several growth parameters, including total ring width, earlywood width, adjusted latewood width, and maximum latewood density, in unique > 400-year-old forests along an elevational gradient of 2500–3100 m on the southern slopes of Dhaulagiri, Nepal. Our findings show that changing climatic conditions, characterized by increasing temperatures and variable precipitation patterns, had a more detrimental effect on Tsuga growth at the edge of its elevation range compared to the optimal mid-elevation zone. Specifically, at lower elevations, the combination of spring and preceding autumn warming restricted earlywood growth, while warmer temperatures in late summer stimulated growth at the mid-elevation site by alleviating the cool growth-limiting conditions caused by high monsoonal precipitation. Furthermore, increased spring temperatures enhance latewood density, while summer warming promotes latewood growth at higher elevations. Additionally, we observed that the recent rise in autumn temperatures has begun to impede Tsuga growth across all elevations. In conclusion, our study reveals that the growth of Tsuga trees is influenced by multiple climatic factors that vary within the growing season and across different parts of its elevation range. Recent spring warming has constrained growth in lower elevations, while higher previous autumn temperatures have reduced growth at both higher and lower boundaries of the species' range. These findings contribute to a better understanding of the complex relationship between climate change and tree growth dynamics, particularly in vulnerable Himalayan forests.

Epitaxy and transport properties of alkali-earth palladate thin films

ABSTRACT Topological insulators and semimetals are an interesting class of materials for new electronic and optical applications owing to their characteristic electromagnetic responses originating from the spin-orbit coupled band structures. However, topological electronic structures are rare in oxide materials despite their chemical stability being preferable for applications. In this study, given the theoretical prediction of Dirac bands in CaPd3O4, we investigate the fabrication and transport properties of SrPd3O4 and CaPd3O4 thin films as candidates of oxide Dirac semimetals. We have found that these materials are epitaxially grown on MgO (100) substrate under limited growth conditions by pulsed laser deposition. The transport properties show a weak temperature dependence, suggestive of narrow-gap properties, although unintentionally doped holes hinder us from revealing the presence of the Dirac band. Our study establishes the basic thermodynamics of thin-film fabrication of these materials and will lead to interesting properties characteristic of topological band structure by modulating the electronic structure by, for example, chemical substitutions or pressure.

Constitutive basis of root system architecture: uncovering a promising trait for breeding nutrient- and drought-resilient crops

Root system architecture (RSA) plays a pivotal role in efficient uptake of essential nutrients, such as phosphorous (P), nitrogen (N), and water. In soils with heterogeneous nutrient distribution, root plasticity can optimize acquisition and plant growth. Here, we present evidence that a constitutive RSA can confer benefits for sorghum grown under both sufficient and limiting growth conditions. Our studies, using P efficient SC103 and inefficient BTx635 sorghum cultivars, identified significant differences in root traits, with SC103 developing a larger root system with more and longer lateral roots, and enhanced shoot biomass, under both nutrient sufficient and deficient conditions. In addition to this constitutive attribute, under P deficiency, both cultivars exhibited an initial increase in lateral root development; however, SC103 still maintained the larger root biomass. Although N deficiency and drought stress inhibited both root and shoot growth, for both sorghum cultivars, SC103 again maintained the better performance. These findings reveal that SC103, a P efficient sorghum cultivar, also exhibited enhanced growth performance under N deficiency and drought. Our results provide evidence that this constitutive nature of RSA can provide an avenue for breeding nutrient- and drought-resilient crops.

A truncated antenna mutant of the unicellular green alga Coccomyxa sp. strain Obi shows better biomass productivity than the wild-type strain under higher irradiance, at higher cell density, and in greater depth of culture

Mutants with reduced chlorophyll contents were isolated from the industrial green alga Coccomyxa sp. strain Obi after chemical mutagenesis. The growth of most of the isolates was slower than that of the parental strain with one exception, which was named strain 5P. Chlorophyll a (Chl a) content in rapidly growing cells of strain 5P was >30 % lower than the wild-type level, while its chlorophyll b (Chl b) content was below 20 %. Strain 5P did not have trimeric light-harvesting antenna complexes (LHCs) for photosystem (PS) II, but its reaction centers for PSI and PSII were intact. Whole-genome resequencing of strain 5P identified many mutations, including a nonsynonymous mutation in the gene encoding chlorophyllide a oxygenase (CAO) involved in the biosynthesis of Chl b. Chl b is present only in LHCs, and the reduction of Chl b confers the reduction of LHCs that accompanies the reduction of Chl a. Genetic complementation of strain 5P with the genomic CAO gene (CAO) resulted in the full recovery of Chl a and Chl b contents. Thus, the low-chlorophyll phenotype of strain 5P was caused by the CAO mutation. The growth yields of strain 5P were superior to those of the wild-type strain in deeper cultures, and in nutrient-rich culture medium that supported cell growth to higher densities. The growth advantage over the wild-type strain was not observed in the CAO-complemented strains. We concluded that the mutant possessing a smaller antenna size exhibits a growth advantage under limited growth conditions.

Microbial Growth under Limiting Conditions-Future Perspectives.

Microorganisms rule the functioning of our planet and each one of the individual macroscopic living creature. Nevertheless, microbial activity and growth status have always been challenging tasks to determine both in situ and in vivo. Microbial activity is generally related to growth, and the growth rate is a result of the availability of nutrients under adequate or adverse conditions faced by microbial cells in a changing environment. Most studies on microorganisms have been carried out under optimum or near-optimum growth conditions, but scarce information is available about microorganisms at slow-growing states (i.e., near-zero growth and maintenance metabolism). This study aims to better understand microorganisms under growth-limiting conditions. This is expected to provide new perspectives on the functions and relevance of the microbial world. This is because (i) microorganisms in nature frequently face conditions of severe growth limitation, (ii) microorganisms activate singular pathways (mostly genes remaining to be functionally annotated), resulting in a broad range of secondary metabolites, and (iii) the response of microorganisms to slow-growth conditions remains to be understood, including persistence strategies, gene expression, and cell differentiation both within clonal populations and due to the complexity of the environment.

Phase formation in CrFeCoNi nitride thin films

As a single-phase alloy, CrFeCoNi is a face centered cubic (fcc) material related to the archetypical high-entropy Cantor alloy CrFeCoNiMn. For thin films, CrFeCoNi of approximately equimolar composition tends to assume an fcc structure when grown at room temperature by magnetron sputtering. However, the single-phase solid solution state is typically not achieved for thin films grown at higher temperatures. The same holds true for Cantor alloy-based ceramics (nitrides and oxides), where phase formation is extremely sensitive to process parameters such as the amount of reactive gas. This study combines theoretical and experimental methods to understand the phase formation in nitrogen-containing CrFeCoNi thin films. Density functional theory calculations considering three competing phases (CrN, Fe-Ni and Co) show that the free energy of mixing, \ensuremath{\Delta}$G$ of ${(\mathrm{CrFeCoNi})}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ solid solutions has a maximum at $x=0.20\ensuremath{-}0.25$, and \ensuremath{\Delta}$G$ becomes lower when $x<0.20$ and $x>0.25$. Thin films of ${(\mathrm{CrFeCoNi})}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ ($0.14\ensuremath{\ge}x\ensuremath{\le}0.41$) grown by magnetron sputtering show stabilization of the metallic fcc when $x\ensuremath{\le}0.22$ and the stabilization of the NaCl B1 structure when $x>0.33$, consistent with the theoretical prediction. In contrast, films with intermediate amounts of nitrogen $(x=0.22)$ grown at higher temperatures show segregation into multiple phases of CrN, Fe-Ni-rich and Co. These results offer an explanation for the requirement of kinetically limited growth conditions at low temperature for obtaining single-phase CrFeCoNi Cantor-like nitrogen-containing thin films and are of importance for understanding the phase-formation mechanisms in multicomponent ceramics. The results from the study further aid in making correlations between the observed mechanical properties and the crystal structure of the films.

Opportunities to diversify the activities of wholesale and retail trade organizations in modern conditions

There are presents the results of a study of promising areas of diversification of the activities of wholesale and retail trade enterprises in the conditions of economic transformation. The purpose of this study is to identify and substantiate the possibilities of diversifying the activities of wholesale and retail companies in conditions of limited economic growth. The relevance of the research on the chosen problem is due to the need to find solutions to the problems of import substitution of enterprises that are interested in expanding their activities, including on the basis of diversification of activities. The methodology of the research is based on the analysis of modern theoretical provisions on the diversification of the activities of leading Russian scientists and economists. The main research methods used in the preparation of the materials of the article: system analysis, methods of expert evaluation, comparison, analogy, analysis of absolute and relative indicators, and others. Additional research methods include: traditional literature analysis, document analysis, design, synthesis, analysis of the data obtained. Within the framework of the article, the directions of diversification of the activities of wholesale and retail trade organizations are considered, as well as a multifactorial model is proposed that allows assessing the potential for increasing sales volumes based on diversification. The value of the conducted research lies in the consideration and detailed analysis of the state of the trade industry of the Russian Federation in the conditions of sanctions and restrictions. Also, this study shows development options in the field of diversification for wholesale and retail trade enterprises that depend directly on foreign supplies. The practical significance of this article is that the results of the study can be used by domestic enterprises specializing in the implementation of both wholesale and retail sales in the Russian market.

Assessing three industrially produced fungi for the bioremediation of diclofenac

Diclofenac is an emerging pollutant: toxic, persistent, and bioaccumulative, present in several environmental niches in a concentration of parts per million. This pharmaceutical’s biological removal was reported with various fungal species, showing promissory results. This work aimed at diclofenac removal by individually challenging the fungal species Pleurotus ostreatus, Aspergillus niger, and Penicillium roquefortii but triying to lower the biosorption nature of cell walls by NaCl addition. P. ostreatus removed 100% of the initial diclofenac concentration, whereas A. niger and P. roqueforti removed 74% and 32%, respectively. In all three cases, biosorption by polar interactions was negligible. We demonstrated that stressful environments, such as mineral media, force the fungus to take advantage of its metabolic tools to survive, hence showing higher removal capacity when limiting growth conditions. Bioremediation is an excellent alternative to give residual fungal biomass a secondary use.

Concomitant Activation of OsNAS2 and OsNAS3 Contributes to the Enhanced Accumulation of Iron and Zinc in Rice

Nicotianamine (NA) is produced by NA synthase (NAS), which contains three genes in rice and is responsible for chelating metals such as iron (Fe) and zinc (Zn), as well as preserving metal homeostasis. In this study, we generated a transgenic plant (23D) that shows simultaneous activation of OsNAS2 and OsNAS3 by crossing two previously identified activation-tagged mutants, OsNAS2-D1 (2D) and OsNAS3-D1 (3D). Concomitant activation of both genes resulted in the highest Fe and Zn concentrations in shoots and roots of the 23D plants grown under normal conditions and Fe and Zn limited growth conditions. Expression of genes for the biosynthesis of mugineic acid family phytosiderophores (MAs) and Fe and Zn uptake were enhanced in 23D roots. Additionally, 23D plants displayed superior growth to other plants at higher pH levels. Importantly, 23D seeds had NA and 2'-deoxymugineic acid (DMA) concentrations that were 50.6- and 10.0-fold higher than those of the WT. As a result, the mature grain Fe and Zn concentrations of the 23D plant were 4.0 and 3.5 times greater, respectively, than those of the WT. Furthermore, 23D plants exhibited the greatest resistance to excess metals. Our research suggests that simultaneous activation of OsNAS2 and OsNAS3 can enhance Fe and Zn accumulation in rice grains while also increasing plant tolerance to growing situations with metal deficiency and excess metal availability.

Biofilm formation is correlated with low nutrient and simulated microgravity conditions in a Burkholderia isolate from the ISS water processor assembly

The International Space Station (ISS) Water Processor Assembly (WPA) experiences intermittent dormancy in the WPA wastewater tank during water recycling events which promotes biofilm formation within the system. In this work we aimed to gain a deeper understanding of the impact of nutrient limitation on bacterial growth and biofilm formation under microgravity in support of biofilm mitigation efforts in exploration water recovery systems. A representative species of bacteria that is commonly cultured from the ISS WPA was cultured in an WPA influent water ersatz formulation tailored for microbiological studies. An isolate of Burkholderia contaminans was cultured under a simulated microgravity (SμG) treatment in a vertically rotating high-aspect rotating vessel (HARV) to create the low shear modeled microgravity (LSMMG) environment on a rotating wall vessel (RWV), with a rotating control (R) in the horizontal plane at the predetermined optimal rotation per minute (rpm) speed of 20. Over the course of the growth curve, the bacterial culture in ersatz media was harvested for bacterial counts, and transcriptomic and nutrient content analyses. The cultures under SμG treatment showed a transcriptomic signature indicative of nutrient stress and biofilm formation as compared to the R control treatment. Further analysis of the WPA ersatz over the course of the growth curve suggests that the essential nutrients of the media were consumed faster in the early stages of growth for the SμG treatment and thus approached a nutrient limited growth condition earlier than in the R control culture. The observed limited nutrient response may serve as one element to explain a moderate enhancement of adherent biofilm formation in the SμG treatment after 24 h. While nutrients levels can be modulated, one implication of this investigation is that biofilm mitigation in the ISS environment could benefit from methods such as mixing or the maintenance of minimum flow within a dormant water system in order to force convection and offset the response of microbes to the secondary effects of microgravity.

Stress-Associated and Growth-Dependent Mutagenesis Are Divergently Regulated by c-di-AMP Levels in Bacillus subtilis.

A previous proteomic study uncovered a relationship between nutritional stress and fluctuations in levels of diadenylate cyclases (DACs) and other proteins that regulate DAC activity, degrade, or interact with c-di-AMP, suggesting a possible role of this second messenger in B. subtilis stress-associated mutagenesis (SAM). Here, we investigated a possible role of c-di-AMP in SAM and growth-associated mutagenesis (GAM). Our results showed that in growing cells of B. subtilis YB955 (hisC952, metB25 and leuC427), the DACs CdaA and DisA, which play crucial roles in cell wall homeostasis and chromosomal fidelity, respectively, counteracted spontaneous and Mitomycin-C-induced mutagenesis. However, experiments in which hydrogen peroxide was used to induce mutations showed that single deficiencies in DACs caused opposite effects compared to each other. In contrast, in the stationary-phase, DACs promoted mutations in conditions of nutritional stress. These results tracked with intracellular levels of c-di-AMP, which are significantly lower in cdaA- and disA-deficient strains. The restoration of DAC-deficient strains with single functional copies of the cdaA and/or disA returned SAM and GAM levels to those observed in the parental strain. Taken together, these results reveal a role for c-di-AMP in promoting genetic diversity in growth-limiting conditions in B. subtilis. Finally, we postulate that this novel function of c-di-AMP can be exerted through proteins that possess binding domains for this second messenger and play roles in DNA repair, ion transport, transcriptional regulation, as well as oxidative stress protection.

Occurrence and Roles of Comammox Bacteria in Water and Wastewater Treatment Systems: A Critical Review

Nitrogen removal is a critical process in water treatment plants (WTPs) and wastewater treatment plants (WWTPs). The recent discovery of a novel bacterial process, complete ammonia oxidation (comammox, CMX), has refuted a century-long perception of the two-step conversion of NH3 to NO3–. Compared with canonical nitrifiers, CMX bacteria offer undeniable advantages, such as a high growth yield propensity and adaptability to nutrient- and growth-limiting conditions, which collectively draw attention to validate the aptness of CMX bacteria to wastewater treatment. As there has been no comprehensive review on the relevance of CMX bacteria for sustainable water and wastewater treatment, this review is intended to discuss the roles and applications of CMX in the removal of nitrogen and pollutants from water and wastewater. We took into account insights into the metabolic versatilities of CMX bacteria at the clade and subclade levels. We focused on the distribution of CMX bacteria in engineered systems, niche differentiation, co-occurrence and interactions with canonical nitrifiers for a better understanding of CMX bacteria in terms of their ecophysiology. Conceptualized details on the reactor adaptability and stress response of CMX bacteria are provided. The potential of CMX bacteria to degrade micropollutants either directly or co-metabolically was evaluated, and these insights would be an indispensable advantage in opening the doors for wider applications of CMX bacteria in WWTPs. Finally, we summarized future directions of research that are imperative in improving the understanding of CMX biology.

Linear Growth Spurts are Preceded by Higher Weight Gain Velocity and Followed by Weight Slowdowns Among Rural Children in Burkina Faso: A Longitudinal Study

BackgroundThe temporal relationship between length (linear) and weight (ponderal) growth in early life is important to support optimal nutrition program design. Studies based on measures of attained size have established that wasting often precedes stunting, but such studies do not capture responsiveness of growth to previous compared with current conditions. As a result, the temporality of linear and ponderal growth relationships remain unclear. ObjectivesWe used growth velocity indicators to assess the temporal bidirectional relationships between linear and ponderal growth in children. MethodsUsing monthly anthropometric measurements from 5039 Burkinabè children enrolled at 6 months of age and followed until 28 months from August 2014 to December 2016, we employed multilevel mixed-effects models to investigate concurrent and lagged associations between linear and ponderal growth velocity, controlling for time trends, seasonality, and morbidity. ResultsFaster ponderal growth is associated with faster concurrent and subsequent linear growth (0.21–0.72 increase in length velocity z-score per unit increase in weight velocity z-score), while faster linear growth is associated with slower future weight gain (0.009–0.02 decrease in weight velocity z-score per unit increase in length velocity z-score), especially among children 9–14 months. Ponderal growth slows around the same time as peaks in morbidity, followed roughly a month later by slower linear growth. ConclusionsUse of velocity measures to assess temporal dependencies between linear and ponderal growth demonstrate that the same growth-limiting conditions likely affect both length and weight velocity, that slow ponderal growth likely limits subsequent linear growth, and that linear growth spurts may not be accompanied by sufficient increases in dietary intake to avoid slowdowns in weight gain.

Seasonality of Child Growth: High Temperatures Coincide with Growth Faltering among Young Children in Burkina Faso

ObjectivesSeasonal cycles in climatic factors such as temperature and precipitation affect the drivers of child growth and contribute to seasonal fluctuations in undernutrition. Current growth seasonality models are limited by categorical definitions of seasons that rely on assumptions about their timing and fail to consider their magnitude. In this study, we disentangle the relationship between climatic factors and growth indicators, using harmonic regression models to determine how child growth is related to peaks in temperature, precipitation, and vegetation. MethodsLongitudinal anthropometric data collected between August 2014-December 2016 from 5,039 Burkinabè children measured monthly from age 6–28 months were linked with remotely sensed daily precipitation, vegetation, and maximum air temperature. Using harmonic regression models, we compared the magnitude and timing of seasonal peaks in climatic factors and morbidity with that of nadirs in growth velocity (cm/month, kg/month). ResultsLength and weight velocity were slowest twice a year, coinciding both times with the highest temperatures, as rains start and end, and with peak fever and diarrhea incidence. ConclusionsOur results suggest that child health and development are more affected by high temperatures than by other aspects of climatic seasonality such as rainfall. Pathogens causing diarrheal disease and fever thrive and have more opportunities to infect children while temperatures are high, and precipitation is low. Emerging shifts in climatic conditions will pose challenges to optimal growth, highlighting the importance of programmatic and policy-level changes that optimize timing of nutrition interventions and address environmental growth-limiting conditions. Funding SourcesUnited States Agency for International Development.

Light Stress after Heterotrophic Cultivation Enhances Lutein and Biofuel Production from a Novel Algal Strain Scenedesmus obliquus ABC-009.

Scenedesmus obliquus ABC-009 is a microalgal strain that accumulates large amounts of lutein, particularly when subjected to growth-limiting conditions. Here, the performance of this strain was evaluated for the simultaneous production of lutein and biofuels under three different modes of cultivation - photoautotrophic mode using BG-11 medium with air or 2% CO2 and heterotrophic mode using YM medium. While it was found that the highest fatty acid methyl ester (FAME) level and lutein content per biomass (%) were achieved in BG-11 medium with CO2 and air, respectively, heterotrophic cultivation resulted in much higher biomass productivity. While the cell concentrations of the cultures grown under BG-11 and CO2 were largely similar to those grown in YM medium, the disparity in the biomass yield was largely attributed to the larger cell volume in heterotrophically cultivated cells. Post-cultivation light treatment was found to further enhance the biomass productivity in all three cases and lutein content in heterotrophic conditions. Consequently, the maximum biomass (757.14 ± 20.20 mg/l/d), FAME (92.78 ± 0.08 mg/l/d), and lutein (1.006 ± 0.23 mg/l/d) productivities were obtained under heterotrophic cultivation. Next, large-scale lutein production using microalgae was demonstrated using a 1-ton open raceway pond cultivation system and a low-cost fertilizer (Eco-Sol). The overall biomass yields were similar in both media, while slightly higher lutein content was obtained using the fertilizer owing to the higher nitrogen content.

Mathematical Analysis of Cyclic and Sampled Current Voltammetries for the Description of Nucleation and Growth Processes of Metallic Nanoparticles

The electrodeposition of metallic nanoparticles was studied using numerical methods under progressive and instantaneous nucleation regimes to calculate cyclic and sampled current voltammetries. The cyclic voltammograms (CV) for both types of nucleation were calculated using diffusion and kinetics limited growth conditions. The sampled current voltammograms (SCV) were built from numerically generated chronoamperometric curves. Comparison of the SCV and CV curves shows that the current response corresponding to the progressive nucleation was similar under both growth regimes, although the nuclei density was considerably different. Under instantaneous nucleation, the CV and SCV showed similar current responses only under kinetic control due to similar cluster growth, and the diffusion-controlled growth showed a similar cluster growth, but a different current response. The comparison made in this work provides a guideline to understand experimental electrodeposition results and makes a good argument for using SCV to complement the CV curves.

A metabolic perspective into antimicrobial tolerance and resistance

A metabolic perspective into antimicrobial tolerance and resistance

Monthly measurement of child lengths between 6 and 27 months of age in Burkina Faso reveals both chronic and episodic growth faltering

ABSTRACTBackgroundLinear growth faltering is determined primarily by attained heights in infancy, but available data consist mainly of cross-sectional heights at each age.ObjectivesThis study used longitudinal data to test whether faltering occurs episodically in a few months of very low growth, which could potentially be prevented by timely intervention, or is a chronic condition with slower growth in every month of infancy and early childhood.MethodsUsing anthropometric data collected monthly between August 2014 and December 2016, we investigated individual growth curves of 5039 children ages 6–27 mo in Burkina Faso (108,580 observations). We evaluated growth-curve smoothness by level of attained length at ∼27 mo by analyzing variation in changes in monthly growth rates and using 2-stage regressions: 1) regressing each child's length on their age and extracting R2 to represent curve smoothness, initial length, and average velocity by age; and 2) regressing extracted parameters on individual-level attained length.ResultsShort children started smaller and remained on their initial trajectories, continuously growing slower than taller children. Growth between 9 and 11 mo was the most influential on attained length; for each 1-cm/mo increase in growth velocity during this period, attained length increased by 6.71 cm (95% CI: 6.59, 6.83 cm). Furthermore, a 0.01 increase in R2 from individual regression of length on age was associated with a 3.10-cm higher attained length (95% CI: 2.80, 3.41 cm), and having 2 consecutive months of slow growth (<15th centile relative to the sample) was associated with 1.7-cm lower attained length (95% CI: −1.80, −1.59 cm), with larger effects in younger children, suggesting that smoother growth patterns were also associated with higher attained length.ConclusionsChildren who experience extreme growth faltering are likely less resilient to systematic growth-limiting conditions as well as episodic insults to their growth.This trial was registered at clinicaltrials.gov as NCT02071563.

The metabolic core of the prokaryotic community from deep-sea sediments of the southern Gulf of Mexico shows different functional signatures between the continental slope and abyssal plain.

Marine sediments harbor an outstanding level of microbial diversity supporting diverse metabolic activities. Sediments in the Gulf of Mexico (GoM) are subjected to anthropic stressors including oil pollution with potential effects on microbial community structure and function that impact biogeochemical cycling. We used metagenomic analyses to provide significant insight into the potential metabolic capacity of the microbial community in Southern GoM deep sediments. We identified genes for hydrocarbon, nitrogen and sulfur metabolism mostly affiliated with Alpha and Betaproteobacteria, Acidobacteria, Chloroflexi and Firmicutes, in relation to the use of alternative carbon and energy sources to thrive under limiting growth conditions, and metabolic strategies to cope with environmental stressors. In addition, results show amino acids metabolism could be associated with sulfur metabolism carried out by Acidobacteria, Chloroflexi and Firmicutes, and may play a crucial role as a central carbon source to favor bacterial growth. We identified the tricarboxylic acid cycle (TCA) and aspartate, glutamate, glyoxylate and leucine degradation pathways, as part of the core carbon metabolism across samples. Further, microbial communities from the continental slope and abyssal plain show differential metabolic capacities to cope with environmental stressors such as oxidative stress and carbon limiting growth conditions, respectively. This research combined taxonomic and functional information of the microbial community from Southern GoM sediments to provide fundamental knowledge that links the prokaryotic structure to its potential function and which can be used as a baseline for future studies to model microbial community responses to environmental perturbations, as well as to develop more accurate mitigation and conservation strategies.