bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of effect of process variable on dimensional accuracy of FDM component using response surface methodology
Authors: Maurya Nagendra Kumar , Maurya Manish , Dwivedi Shashi Prakash , Srivastava Ashish Kumar , Saxena Ambuj , Chahuan Sandeep , Tiwari Aditya , Mishra Advitya 
Published: April 2021

Purpose
Nowadays, rapid prototyping is emerging as end use product in low volume. The accuracy of the fabricated components depends on various process parameters. Process parameters used in this investigation are layer thickness (150, 200 and 250 µm), infill pattern (linear, hexagonal and star fill), raster angle (0°, 45° and 90°) and infill density (40, 60 and 80%). Linear and radial dimension of knuckle joint are selected for the response factor.

Design/methodology/approach
The experiments are design by using response surface methodology (RSM). Four design variables at three levels are used to examine their influence on percentage error in linear dimension and radial dimension of the component. A prototype Knuckle joint is selected as component. Minitab-14 software is used for the design of experiments.

Findings
Experimental measure data is analyzed by using “smaller is better” quality characteristics. A regression model for the forecasting of percentage error in linear and radial dimension is developed. The developed model is within precision range. The optimum level of process for linear and radial dimensions are obtained: layer thickness of 150 µm, Infill pattern of linear, Raster angle of 90° and infill density of 40%.

Research limitations/implications
It proves that both the mathematical model is significant and can be able to approximate the desired output value close to the accurate dimensions. While comparing the calculated F-values for both linear and radial dimension with the standard table (F-table, 0.05), it is found that at the given set of degree of freedom the standard F-values (6.61) is lower for that regression, linear, square and interaction source of the predicted model, for which p-values have already less than 0.05. It is desirable for significant process parameters.

Practical implications
The dimensional accuracy with respect to average percentage error of FDM produced knuckle joint is successfully examined. The effect of process parameters, namely, layer thickness, infill pattern, raster angle and infill density on average percentage error was investigated by RSM and analysis of variance table.

Social implications
The novelty of this work lies in the fact that only few studies are available in archival literature related to influence of these process parameters on percentage error in linear and radial dimension for Polycarbonate (PC) material.

Originality/value
The novelty of this work lies in the fact only few studies are available in archival literature related to influence of these process parameters on percentage error in linear and radial dimension for Polycarbonate (PC) material.
Numerical investigation into effect of self-healing composite microcapsules thickness and diameter on their failure strength
Authors: Pittala Raj Kumar , B. Satish Ben , Chokka Syam Kumar , Prasad Niranjan 
Published: April 2021

Purpose
Microcapsule-embedded autonomic healing materials have the ability to repair microcracks when they come into contact with the crack by releasing the healing agent. The microcapsules with specific shape and thickness effect in releasing healing agent to the cracked surfaces. Thus, the purpose of this paper is to know the load bearing capacity of the self-healing microcapsules and the stresses developed in the material.

Design/methodology/approach
In the present study, self-healing microcapsule is modelled and integrated with the polymer matrix composite. The aim of the present study is to investigate failure criteria of Poly (methyl methacrylate) microcapsules by varying the shell thickness, capsule diameter and loading conditions. The strength of the capsule is evaluated by keeping the shell thickness as constant and varying the capsule diameter. Uniformly distributed pressure loads were applied on the capsule-reinforced polymer matrix composite to assess the failure strength of capsules and composite.

Findings
It is observed from the results that the load required to break the capsules is increasing with the increase in capsule diameter. The failure strength of microcapsule with 100 µm diameter and 5 µm thickness is observed as 255 MPa. For an applied load range of 40–160 N/mm2 on the capsules embedded composite, the maximum stress developed in the capsules is observed as 308 MPa.

Originality/value
Failure strengths of microcapsules and stresses developed in the microcapsule-reinforced polymer composites were evaluated.
Three dimensional modelling of aluminum foam through computed tomography scan technique
Authors: Sahu Sonika , Ukey Piyush D. , Kumar Narendra , Singh Ravi Pratap , Ansari Mohd. Zahid 
Published: April 2021

Purpose
This study aims to generate different three-dimensional (3D) foam models using computer tomography (CT) scan and solid continuum techniques. The generated foam models were used to study deformation mechanism and the elastic-plastic behaviour with the existing experimental foam behaviour.

Design/methodology/approach
CT scan model was generated by combing 2D images of foam in MIMICS software. Afterwards, it was imported in ABAQUS/CAE software. However, solid continuum model was generated in ABAQUS/CAE software by using crushable foam properties. Then, the generated foam models were sets boundary conditions for a compression test.

Findings
CT scans capture the actual morphology of foam sample which may directly an image based finite element foam model. The sectional views of both the models were used to observe deformation mechanism on compression. The real compressive behaviour of foam was visualised in CT-Scan foam model. It was observed that CT-scan model was the more accurate modelling method than crushable foam model.

Originality/value
The internal structure of foam is very complex and difficult to analyse. Therefore, CT-scanning may be the accurate method for capturing the macro-level detailing of foam structure. A CT-scan foam model can be used for multiple times for mechanical analysis using a simulation software, which may reduce the manufacturing and the experimental cost and time.
Shifting baselines: Physiological legacies contribute to the response of reef corals to frequent heatwaves
Authors: Wall Christopher B. , Ricci Contessa A. , Wen Alexandra D. , Ledbetter Bren E. , Klinger Delania E. , Mydlarz Laura D. , Gates Ruth D. , Putnam Hollie M. 
Published: April 2021

Abstract

Global climate change is altering coral reef ecosystems. Notably, marine heatwaves are producing widespread coral bleaching events that are increasing in frequency, with projections for annual bleaching events on reefs worldwide by mid‐century.

Responses of corals to elevated seawater temperatures are modulated by abiotic factors (e.g. environmental regimes) and dominant Symbiodiniaceae endosymbionts that can shift coral traits and contribute to physiological legacy effects on future response trajectories. It is critical, therefore, to characterize shifting physiological and cellular states driven by these factors and evaluate their influence on in situ bleaching (and recovery) events. We use back‐to‐back bleaching events (2014, 2015) in Hawai'i to characterize the cellular and organismal phenotypes of Montipora capitata corals dominated by heat‐sensitive Cladocopium or heat‐tolerant Durusdinium Symbiodiniaceae at two reef sites.

Despite fewer degree heating weeks in the first‐bleaching event relative to the second (7 vs. 10), M. capitata bleaching severity was greater [bleached cover: ~70% (2014) vs. 50% (2015)] and environmental history (site effects) on coral phenotypes were more pronounced. Symbiodiniaceae affected bleaching responses, but immunity and antioxidant activity was similar in all corals, despite differences in bleaching phenotypes.

We demonstrate that repeat bleaching triggers cellular responses that shift holobiont multivariate phenotypes. These perturbed multivariate phenotypes constitute physiological legacies, which set corals on trajectories (positive and/or negative) that influence future coral performance. Collectively, our data support the need for greater tracking of stress response in a multivariate context to better understand the biology and ecology of corals in the Anthropocene.

A free Plain Language Summary can be found within the Supporting Information of this article.
Sodium addition increases leaf herbivory and fungal damage across four grasslands
Authors: Welti Ellen A. R. , Kaspari Michael 
Published: April 2021

Abstract

Sodium (Na) is an essential element for all animals, but not for plants. Soil Na supplies vary geographically. Animals that primarily consume plants thus have the potential to be Na limited and plants that uptake Na may be subject to higher rates of herbivory, but their high Na content also may attract beneficial partners such as pollinators and seed dispersers.

To test for the effects of Na biogeochemistry on herbivory, we conducted distributed Na press experiments (monthly Na application across the growing season) in four North American grasslands.

Na addition increased soil and plant Na concentrations at all sites. Grasses in Na addition plots had significantly higher herbivore damage by leaf miners and fungal pathogens than those in control plots. Forbs with higher foliar Na concentrations had significantly more chewing insect herbivore and fungal damage.

While no pattern was evident across all species, several forb species had higher Na concentrations in inflorescences compared to leaves, suggesting they may allocate Na to attract beneficial partners.

The uptake of Na by plants, and animal responses, has implications for the salinification in the Anthropocene. Increased use of road salt, irrigation with saline groundwater, rising sea levels and increasing temperatures and evapotranspiration rates with climate change can all increase inputs of Na into terrestrial ecosystems.

Our results suggest increasing terrestrial Na availability will benefit insect herbivores and plant fungal pathogens.

A free Plain Language Summary can be found within the Supporting Information of this article.
Diffraction separation by variational mode decomposition
Authors: Lin Peng , Zhao Jingtao , Peng Suping , Cui Xiaoqin 
Published: April 2021

ABSTRACTDiffracted wavefields with superior illumination encode key geologic information about small‐scale geologic discontinuities or inhomogeneities in the subsurface and thus possess great potential for high‐resolution imaging. However, the weak diffracted wavefield is easily masked by the dominant reflected data. Diffraction separation from specular reflected data still plays an important role and plays a major role in diffraction imaging implementation. To solve this problem, a new diffraction‐separation method is proposed that uses variational mode decomposition to suppress reflected data and separate diffracted wavefields in the common‐offset or poststack domains. The variational mode decomposition algorithm targets reflected wavefield by decomposing seismic data into an ensemble of band‐limited intrinsic mode functions representing linear and strong reflected data. This method is based on the principle of energy sparsity and can utilize the kinematic and dynamic differences between reflected and diffracted wavefields to effectively predict linear reflected data. Synthetic and field data examples using complex body geometries demonstrate the effectiveness and performance of the proposed method in enhancing diffracted wavefield and attenuating reflected data as well as increasing the signal‐to‐noise ratio, which helps to clearly image small‐scale subwavelength geologic structures.
The microbiota of intertidal macroalgae Fucus distichus is site‐specific and resistant to change following transplant
Authors: Davis Katherine M. , Mazel Florent , Parfrey Laura Wegener 
Published: April 2021

SummaryIt is unclear how host‐associated microbial communities will be affected by future environmental change. Characterizing how microbiota differ across sites with varying environmental conditions and assessing the stability of the microbiota in response to abiotic variation are critical steps towards predicting outcomes of environmental change. Intertidal organisms are valuable study systems because they experience extreme variation in environmental conditions on tractable timescales such as tide cycles and across small spatial gradients in the intertidal zone. Here we show a widespread intertidal macroalgae, Fucus distichus, hosts site‐specific microbiota over small (meters to kilometres) spatial scales. We demonstrate stability of site‐specific microbial associations by manipulating the host environment and microbial species pool with common garden and reciprocal transplant experiments. We hypothesized that F. distichus microbiota would readily shift to reflect the contemporary environment due to selective filtering by abiotic conditions and/or colonization by microbes from the new environment or nearby hosts. Instead, F. distichus microbiota was stable for days after transplantation in both the laboratory and field. Our findings expand the current understanding of microbiota dynamics on an intertidal foundation species. These results may also point to adaptations for withstanding short‐term environmental variation, in hosts and/or microbes, facilitating stable host–microbial associations.
Astrobiology of life on Earth
Authors: Hallsworth John E. , Mancinelli Rocco L. , Conley Catharine A. , Dallas Tiffany D. , Rinaldi Teresa , Davila Alfonso F. , Benison Kathleen C. , Rapoport Alexander , Cavalazzi Barbara , Selbmann Laura , Changela Hitesh , Westall Frances , Yakimov Michail M. , Amils Ricardo , Madigan Michael T. 
Published: April 2021

SummaryAstrobiology is mistakenly regarded by some as a field confined to studies of life beyond Earth. Here, we consider life on Earth through an astrobiological lens. Whereas classical studies of microbiology historically focused on various anthropocentric sub‐fields (such as fermented foods or commensals and pathogens of crop plants, livestock and humans), addressing key biological questions via astrobiological approaches can further our understanding of all life on Earth. We highlight potential implications of this approach through the articles in this Environmental Microbiology special issue ‘Ecophysiology of Extremophiles’. They report on the microbiology of places/processes including low‐temperature environments and chemically diverse saline‐ and hypersaline habitats; aspects of sulphur metabolism in hypersaline lakes, dysoxic marine waters, and thermal acidic springs; biology of extremophile viruses; the survival of terrestrial extremophiles on the surface of Mars; biological soils crusts and rock‐associated microbes of deserts; subsurface and deep biosphere, including a salticle formed within Triassic halite; and interactions of microbes with igneous and sedimentary rocks. These studies, some of which we highlight here, contribute to our understanding of the spatiotemporal reach of Earth'sfunctional biosphere, and the tenacity of terrestrial life. Their findings will help set the stage for future work focused on the constraints for life, and how organisms adapt and evolve to circumvent these constraints.
Distinctive role of fluG in the adaptation of Beauveria bassiana to insect‐pathogenic lifecycle and environmental stresses
Authors: Guo Chong‐Tao , Peng Han , Tong Sen‐Miao , Ying Sheng‐Hua , Feng Ming‐Guang 
Published: April 2021

SummaryThe upstream developmental activation (UDA) pathway comprises three fluG‐cored cascades (fluG‐flbA, fluG‐flbE/B/D and fluG‐flbC) that activate the key gene brlA of central developmental pathway (CDP) to initiate conidiation in aspergilli. However, the core role of fluG remains poorly understood in other fungi. Here, we report distinctive role of fluG in the insect‐pathogenic lifecycle of Beauveria bassiana. Disruption of fluG resulted in limited conidiation defect, which was mitigated with incubation time and associated with time‐course up‐regulation/down‐regulation of all flb and CDP genes and another fluG‐like gene (BBA_06309). In ΔfluG, increased sensitivities to various stresses correlated with repression of corresponding stress‐responsive genes. Its virulence through normal cuticle infection was attenuated greatly due to blocked secretion of cuticle‐degrading enzymes and delayed formation of hyphal bodies (blastospores) to accelerate proliferation in vivo and host death. In submerged ΔfluG cultures mimicking insect haemolymph, largely increased blastospore production concurred with drastic up‐regulation of the CDP genes brlA and abaA, which was associated with earlier up‐regulation of most flb genes in the cultures. Our results unveil an essentiality of fluG for fungal adaptation to insect‐pathogenic lifecycle and suggest the other fluG‐like gene to act as an alternative player in the UDA pathway of B. bassiana.
Seasonal dynamics of natural Ostreococcus viral infection at the single cell level using VirusFISH
Authors: Castillo Yaiza M. , Forn Irene , Yau Sheree , Morán Xosé Anxelu G. , Alonso‐Sáez Laura , Arandia‐Gorostidi Néstor , Vaqué Dolors , Sebastián Marta 
Published: April 2021

SummaryOstreococcus is a cosmopolitan marine genus of phytoplankton found in mesotrophic and oligotrophic waters, and the smallest free‐living eukaryotes known to date, with a cell diameter close to 1 μm. Ostreococcus has been extensively studied as a model system to investigate viral–host dynamics in culture, yet the impact of viruses in naturally occurring populations is largely unknown. Here, we used Virus Fluorescence in situ Hybridization (VirusFISH) to visualize and quantify viral‐host dynamics in natural populations of Ostreococcus during a seasonal cycle in the central Cantabrian Sea (Southern Bay of Biscay). Ostreococcus were predominantly found during summer and autumn at surface and 50 m depth, in coastal, mid‐shelf and shelf waters, representing up to 21% of the picoeukaryotic communities. Viral infection was only detected in surface waters, and its impact was variable but highest from May to July and November to December, when up to half of the population was infected. Metatranscriptomic data available from the mid‐shelf station unveiled that the Ostreococcus population was dominated by the species O. lucimarinus. This work represents a proof of concept that the VirusFISH technique can be used to quantify the impact of viruses on targeted populations of key microbes from complex natural communities.
Special roles for efflux systems in iron homeostasis of non‐siderophore‐producing cyanobacteria
Authors: Liu Ling‐Mei , Li Ding‐Lan , Deng Bin , Wang Xin‐Wei , Jiang Hai‐Bo 
Published: April 2021

SummaryIn oligotrophic oceans, low bioavailability of Fe is a key factor limiting primary productivity. However, excessive Fe in cells leads to the Fenton reaction, which is toxic to cells. Cyanobacteria must strictly maintain intracellular Fe homeostasis. Here, we knocked out a series of genes encoding efflux systems in Synechocystis sp. PCC 6803, and found eight genes that are required for high Fe detoxification. Unexpectedly, the HlyBD‐TolC efflux system plays an important role in the adaptation of Synechocystis under Fe‐deficient conditions. Mutants of HlyD and TolC grew worse than the wild‐type strain under low‐Fe conditions and showed significantly lower intracellular Fe contents than the wild‐type strain. We excluded the possibility that the low Fe sensitivity of the HlyBD‐TolC mutants was caused by a loss of the S‐layer, the main extracellular protein secreted via this efflux system. Inactivation of the HlyD protein influenced type IV pili formation and direct inactivation of type IV pili related genes affected the adaptation to low‐Fe conditions. HlyBD‐TolC system is likely involved in the formation of type IV pili and indirectly influenced Fe acquisition. Our findings suggest that efflux system in non‐siderophore‐producing cyanobacteria can facilitate Fe uptake and help cells adapt to Fe‐deficient conditions via novel pathways.
Termite mounds reduce soil microbial diversity by filtering rare microbial taxa
Authors: Chen Qing‐Lin , Hu Hang‐Wei , Yan Zhen‐Zhen , Li Chao‐Yu , Nguyen Bao‐Anh Thi , Zheng Yong , Zhu Yong‐Guan , He Ji‐Zheng 
Published: April 2021

SummaryTermites are ubiquitous insects in tropical and subtropical habitats, and some of them construct massive nests (‘mounds’), which substantially promote substrate heterogeneity by altering soil properties. Yet, the role of termite nesting process in regulating the distribution and diversity of soil microbial communities remains poorly understood, which introduces uncertainty in predictions of ecosystem functions of termite mounds in a changing environment. Here, by using amplicon sequencing, we conducted a survey of 134 termite mounds across >1500 km in northern Australia and found that termite mounds significantly differed from bulk soils in the microbial diversity and community compositions. Compared with bulk soils, termite nesting process decreased the microbial diversity and the relative abundance of rare taxa. Rare taxa had a narrower habitat niche breadth than dominant taxa and might be easier to be filtered by the potential intensive microbial competition during the nesting processes. We further demonstrated that the shift in pH induced by termite nesting process was a major driver shaping the microbial community profiles in termite mounds. Together, our work provides novel evidence that termite nesting is an important process in regulating soil microbial diversity, which advances our understanding of the functioning of termite mounds.
Discovery of inhibitors of Pseudomonas aeruginosa virulence through the search for natural‐like compounds with a dual role as inducers and substrates of efflux pumps
Authors: Laborda Pablo , Alcalde‐Rico Manuel , Chini Andrea , Martínez José L. , Hernando‐Amado Sara 
Published: April 2021

SummaryMultidrug efflux pumps are ancient elements encoded in every genome, from bacteria to humans. In bacteria, in addition to antibiotics, efflux pumps extrude a wide range of substrates, including quorum sensing signals, bacterial metabolites, or plant‐produced compounds. This indicates that their original functions may differ from their recently acquired role in the extrusion of antibiotics during human infection. Concerning plant‐produced compounds, some of them are substrates and inducers of the same efflux pump, suggesting a coordinated plant/bacteria coevolution. Herein we analyse the ability of 1243 compounds from a Natural Product‐Like library to induce the expression of P. aeruginosa mexCD‐oprJ or mexAB‐oprM efflux pumps' encoding genes. We further characterized natural‐like compounds that do not trigger antibiotic resistance in P. aeruginosa and that act as virulence inhibitors, choosing those that were not only inducers but substrates of the same efflux pump. Four compounds impair swarming motility, exotoxin secretion through the Type 3 Secretion System (T3SS) and the ability to kill Caenorhabditis elegans, which might be explained by the downregulation of genes encoding flagellum and T3SS. Our results emphasize the possibility of discovering new anti‐virulence drugs by screening natural or natural‐like libraries for compounds that behave as both, inducers and substrates of efflux pumps.