bluuebunny/crossref_metadata_2025 huggingface dataset:
Secondary metabolites from food-derived yeasts inhibit virulence ofCandida albicans
Authors: Kunyeit Lohith , Kurrey Nawneet K , K A Anu-Appaiah , Rao Reeta P
Published: August 2020

Beneficial microbes in the intestine are thought to control pathogen overgrowth by competing for limited nutrients. Our findings modify this prevailing paradigm of a passive, microbial antagonistic mode of action to an active, directed mechanism mediated by specific secondary metabolites. We describe two food-derived yeasts,Saccharomyces cerevisiaeandIssatchenkia occidentalis, that inhibit virulence traits ofCandida albicans, including hyphal morphogenesis, biofilms formation and adhesion to intestinal epithelial cells. These yeasts also protect the model hostCaenorhabditis elegansfromC. albicansinfection. We demonstrate that the protective activity is primarily retained in the secretome of the beneficial yeasts and the protection they provide as a physical barrier is minimal. Mutant analysis demonstrates that phenylethanol and tryptophol are necessary for protection and experiments with commercially procured compounds indicates that they are sufficient to inhibitC. albicansvirulence. We propose food-derived yeasts as an alternative or combination therapy to conventional antifungal therapy forC. albicansinfection.
Limb regeneration modulates reproductive attributes in ladybirds: A case study inPropylea dissectaandCoccinella septempunctata
Authors: Saxena Swati , Mishra Geetanjali , Omkar
Published: August 2020

Regeneration is the capability to regrow or repair the lost or injured body parts. In holometabolous insects, the adult development undergoes through larval and pupal stages. Literature revealed that the limb regeneration has various impact on different life traits of organisms. In the present study, we investigated limb regeneration of two different sized ladybirds affect their life attributes. Fourth instar larvae of small ladybirdPropylea dissectaand the large ladybirdCoccinella septempunctatawere taken from the laboratory stock and were given an ablation treatment,viz. forelegs of larvae were amputated at the base of the coxa. Amputated larvae were observed until the adult emergence. Emerged adults were grouped in different categories on the basis limb regenerationi.e. regenerated adults (incomplete regenerated in case ofP. dissecta), unregenerated, and normal (control) adults. These adults were kept in different mating treatments. The unregenerated adults of both the ladybirds took more time to commence mating with shorter copulation duration and reduced fecundity and percent egg viability. Thus, it can be concluded that regeneration ability modulates the life attributes of the ladybirds irrespective of their body size.
Rational Design of SARS-CoV-2 Spike Glycoproteins To Increase Immunogenicity By T Cell Epitope Engineering
Authors: Ong Edison , Huang Xiaoqiang , Pearce Robin , Zhang Yang , He Yongqun
Published: August 2020

The current COVID-19 pandemic caused by SARS-CoV-2 has resulted in millions of confirmed cases and thousands of deaths globally. Extensive efforts and progress have been made to develop effective and safe vaccines against COVID-19. A primary target of these vaccines is the SARS-CoV-2 spike (S) protein, and many studies utilized structural vaccinology techniques to either stabilize the protein or fix the receptor-binding domain at certain states. In this study, we extended an evolutionary protein design algorithm, EvoDesign, to create thousands of stable S protein variants without perturbing the surface conformation and B cell epitopes of the S protein. We then evaluated the mutated S protein candidates based on predicted MHC-II T cell promiscuous epitopes as well as the epitopes’ similarity to human peptides. The presented strategy aims to improve the S protein’s immunogenicity and antigenicity by inducing stronger CD4 T cell response while maintaining the protein’s native structure and function. The top EvoDesign S protein candidate (Design-10705) recovered 31 out of 32 MHC-II T cell promiscuous epitopes in the native S protein, in which two epitopes were present in all seven human coronaviruses. This newly designed S protein also introduced nine new MHC-II T cell promiscuous epitopes and showed high structural similarity to its native conformation. The proposed structural vaccinology method provides an avenue to rationally design the antigen’s structure with increased immunogenicity, which could be applied to the rational design of new COVID-19 vaccine candidates.
Optimizing checkpoint strategies based on first principles predicts experimental DNA damage checkpoint override times
Authors: Sadeghi Ahmad , Dervey Roxane , Gligorovski Vojislav , Rahi Sahand Jamal
Published: August 2020

Why biological quality-control systems fail is often mysterious. Specifically, checkpoints such as the DNA damage checkpoint or the spindle assembly checkpoint are overriden after prolonged arrests allowing cells to continue dividing despite the continued presence of errors.1–4Although critical for biological systems, checkpoint override is poorly understood quantitatively by experiment or theory. Override may represent a trade-off between risk and speed, a fundamental principle explaining biological phenomena.5,6Here, we derive the first, general theory of optimal checkpoint strategies, balancing risk and opportunities for growth. We demonstrate that the mathematical problem of finding the optimal strategy maps onto the question of calculating the optimal absorbing boundary for a random walk, which we show can be solved efficiently recursively. The theory predicts the optimal override strategy without any free parameters based on two inputs, the statistics i) of error correction and ii) of survival. We apply the theory to the prominent example of the DNA damage checkpoint in budding yeast (Saccharomyces cerevisiae) experimentally. Using a novel fluorescent construct which allowed cells with DNA breaks to be isolated by flow cytometry, we quantified i) the probability distribution function of repair for a double-strand DNA break (DSB), including for the critically important, rare events deep in the tail of the distribution, as well as ii) the survival probability if the checkpoint was overridden. Based on these two measurements, the optimal checkpoint theory predicted remarkably accurately the DNA damage checkpoint override times as a function of DSB numbers, which we measured precisely at the single-cell level. Our multi-DSB results refine well-known bulk culture measurements7and show that override is a more general phenomenon than previously thought. Further, we show for the first time that override is an advantageous strategy in cells with wild-type DNA repair genes. The universal nature of the balance between risk and self-replication opportunity is in principle relevant to many other systems, including other checkpoints, developmental decisions8, or reprogramming of cancer cells9, suggesting potential further applications of the theory.
Differential methylation as a mediator of COVID-19 susceptibility
Authors: Steyaert Sandra , Trooskens Geert , Delanghe Joris R. , Van Criekinge Wim
Published: August 2020

The COVID-19 outbreak shows a huge variation in prevalence and mortality on geographical level but also within populations1. TheACE2gene, identified as the SARS-CoV2 receptor, has been shown to facilitate the viral invasion and people with higherACE2expression generally are more severely affected2, 3. As there is a lot of variability inACE2expression between individuals we hypothesized that differential DNA methylation profiles could be (one of) the confounding factors explaining this variability. Here we show that epigenetic profiling of host tissue, especially in theACE2promoter region and its homologueACE1, may be important risk factors for COVID-19. Our results propose that variable methylation can explain (part of) the differential susceptibility, symptom severity and death rate for COVID-19. Our findings are a promising starting point to further evaluate the potential ofACE1/2methylation and other candidates as a predictor for clinical outcome upon SARS-CoV2 infection.
A neural signature of choice under sensory conflict inDrosophila
Authors: Sareen Preeti , McCurdy Li Yan , Nitabach Michael N.
Published: August 2020

Feeding decisions are fundamental to survival, and decision making is often disrupted in disease, yet the neuronal and molecular mechanisms of adaptive decision making are not well understood. Here we show that neural activity in a small population of neurons projecting to the fan-shaped body higher-order central brain region ofDrosophilarepresents final food choice during sensory conflict. We found that hungry flies made tradeoffs between appetitive and aversive values of food in a decision making task to choose bittersweet food with high sucrose concentration, but adulterated with bitter quinine, over sweet-only food with less sucrose. Using cell-specific optogenetics and receptor RNAi knockdown during the decision task, we identified an upstream neuropeptidergic and dopaminergic network that relays internal state and other decision-relevant information, such as valence and previous experience, to a specific subset of fan-shaped body neurons. Importantly, calcium imaging revealed that these neurons were strongly inhibited by the taste of the rejected food choice, suggesting that they encode final behavioral food choice. Our findings reveal that fan-shaped body taste responses to food choices are determined not only by taste quality, but also by previous experience (including choice outcome) and hunger state, which are integrated in the fan-shaped body to encode the decision before relay to downstream motor circuits for behavioral implementation. Our results uncover a novel role for the fan-shaped body in choice encoding, and reveal a neural substrate for sensory and internal state integration for decision making in a genetically tractable model organism to enable mechanistic dissection at circuit, cellular, and molecular levels.
The Planarian Anatomy Ontology: A resource to connect data within and across experimental platforms
Authors: Nowotarski Stephanie H. , Davies Erin L. , Robb Sofia M. C. , Ross Eric J. , Matentzoglu Nicolas , Doddihal Viraj , Mir Mol , McClain Melainia , Alvarado Alejandro Sánchez
Published: August 2020

As the planarianSchmidtea mediterranea(Smed) gains popularity as a research organism, the need for standard anatomical nomenclature is increasingly apparent. A controlled vocabulary streamlines data annotation, improves data organization, and enhances cross-platform and cross-species searchability. We created the Planarian Anatomy Ontology (PLANA), an extendable framework of definedSmedanatomical terms organized using relationships. The most current version contains over 800 terms that describeSmedanatomy from subcellular to system-level across all life cycle stages, in intact animals, and regenerating body fragments. Terms from other anatomy ontologies were imported into PLANA to promote ontology interoperability and comparative anatomy studies. To demonstrate the utility of PLANA for data curation, we created web-based resources for planarian embryogenesis, including a staging series and molecular fate mapping atlas, as well as a searchable Planarian Anatomy Gene Expression database, which integrates a variety of published gene expression data and allows retrieval of information of all published sequences associated with specific planarian anatomical regions. Finally, we report methods for continued curation of PLANA, providing a path for expansion and evolution of this community resource.

Summary Statement

We report construction of an anatomy ontology for an emerging research organism and show its use to curate and mine data across multiple experimental platforms.
Comparison of methods for milk pre-processing, exosome isolation, and RNA extraction in bovine and human milk
Authors: Wijenayake Sanoji , Eisha Shafinaz , Tawhidi Zoya , Pitino Michael A. , Steele Michael A. , Fleming Alison S. , McGowan Patrick O.
Published: August 2020

Milk is a highly complex, heterogeneous biological fluid that contains bioactive, membrane-bound extracellular vesicles called exosomes. Characterization of milk-derived exosomes (MDEs) is challenging due to the lack of standardized methods that are currently being used for milk pre-processing, exosome isolation, and RNA extraction. In this study, we tested: 1) three pre-processing methods to remove cream, fat, and casein proteins from bovine milk to determine whether pre-processing of whole milk, prior to long-term storage, improves MDE isolations, 2) two commonly-used exosome isolation methods, and 3) four extraction protocols for obtaining high quality MDE RNA from bovine and human milk. MDEs were characterized via Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA). We also present an optimized method of TEM sample preparation and isolation of total soluble protein from MDEs. Our results indicated that: 1) pre-processing of bovine milk prior to storage does not affect the final exosome yield or the purity, 2) ExoQuick precipitation is better suited for MDE isolation than ultracentrifugation for bovine and human milk, and 3) TRIzol LS produced the highest RNA yield in bovine milk, whereas TRIzol LS, TRIzol+RNA Clean and Concentrator, and TRIzol LS+RNA Clean and Concentrator methods can be used for human milk.
Somite surface tension buffers imprecise segment lengths to ensure left-right symmetry
Authors: Naganathan Sundar R. , Popović Marko , Oates Andrew C.
Published: August 2020

The body axis of vertebrate embryos is periodically segmented into bilaterally symmetric pairs of somites. The anteroposterior (AP) length of somites, their position and left-right symmetry are thought to be molecularly determined prior to somite morphogenesis. Here we discover that in zebrafish embryos, initial somite AP lengths and positions are imprecise and consequently many somite pairs form left-right asymmetrically. Strikingly, these imprecisions are not left unchecked and we find that AP lengths adjust within an hour after somite formation, thereby increasing morphological symmetry. We find that AP length adjustments result entirely from changes in somite shape without change in somite volume, with changes in AP length being compensated by corresponding changes in mediolateral length. The AP adjustment mechanism is facilitated by somite surface tension, which we show by comparingin vivoexperiments andin vitrosingle-somite explant cultures with a mechanical model. Length adjustment is inhibited by perturbation of Integrin and Fibronectin, consistent with their involvement in surface tension. In contrast, the adjustment mechanism is unaffected by perturbations to the segmentation clock, thus revealing a distinct process that determines morphological segment lengths. We propose that tissue surface tension provides a general mechanism to adjust shapes and ensure precision and symmetry of tissues in developing embryos.
Implicit anticipation of probabilistic regularities: Larger CNV emerges for unpredictable events
Authors: Kóbor Andrea , Kardos Zsófia , Horváth Kata , Janacsek Karolina , Takács Ádám , Csépe Valéria , Nemeth Dezso
Published: August 2020

Anticipation of upcoming events plays a crucial role in automatic behaviors. It is, however, still unclear whether the event-related brain potential (ERP) markers of anticipation could track the implicit acquisition of probabilistic regularities that can be considered as building blocks of automatic behaviors. Therefore, in a four-choice reaction time (RT) task performed by young adults (N= 36), the contingent negative variation (CNV) as an ERP marker of anticipation was measured from the onset of a cue stimulus until the presentation of a target stimulus. Due to the probability structure of the task, target stimuli were either predictable or unpredictable, but this was unknown to participants. The cue did not contain predictive information on the upcoming target. Results showed that the CNV amplitude during response preparation was larger before the unpredictable than before the predictable target stimuli. In addition, although RTs increased, the P3 amplitude decreased for the unpredictable as compared with the predictable target stimuli, possibly due to the stronger response preparation that preceded stimulus presentation. These results suggest that enhanced attentional resources are allocated to the implicit anticipation and processing of unpredictable events. This might originate from the formation of internal models on the probabilistic regularities of the stimulus stream, which primarily facilitates the processing of predictable events. Overall, we provide ERP evidence that supports the role of implicit anticipation and predictive processes in the acquisition of probabilistic regularities.
Logical modeling of dendritic cellsin vitrodifferentiation from human monocytes unravels novel transcriptional regulatory interactions
Authors: Nuñez-Reza Karen J. , Naldi Aurélien , Sanchéz-Jiménez Arantza , Leon-Apodaca Ana V. , Santana M. Angélica , Thomas-Chollier Morgane , Thieffry Denis , Medina-Rivera Alejandra
Published: August 2020

Dendritic cells are the major specialized antigen-presenting cells, thereby connecting innate and adaptive immunity. Because of their role in establishing adaptive immunity, they have been used as targets for immunotherapy. Monocytes can differentiate into dendritic cellsin vitroin the presence of colony-stimulating factor 2 (CSF2) and interleukin 4 (IL4), activating four signalling pathways (MAPK, JAK/STAT, NFKB, and PI3K). However, the transcriptional regulation responsible for dendritic cell differentiation from monocytes (moDCs) remains unknown. By curating scientific literature on moDCs differentiation, we established a preliminary logical model that helped us identify missing information for the activation of genes responsible for this differentiation, including missing targets for key transcription factors (TFs). Using ChIP-seq and RNA-seq data from the Blueprint consortium, we defined active and inactive promoters, together with differentially expressed genes in monocytes, moDCs, and macrophages (which correspond to an alternative cell fate). We then used this functional genomic information to predict novel targets for the identified TFs. We established a second logical model integrating this information, which enabled us to recapitulate the main established facts regarding moDCs differentiation. Prospectively, the resulting model should be useful to develop novel immunotherapies based on moDCs regulatory network.
Abortive Intussusceptive Angiogenesis Causes Multi-Cavernous Vascular Malformations
Authors: Li Wenqing , Tran Virginia , Shaked Iftach , Xue Belinda , Moore Thomas , Lightle Rhonda , Kleinfeld David , Awad Issam A. , Ginsberg Mark H.
Published: August 2020

Mosaic inactivation ofCCM2in humans causes cerebral cavernous malformations (CCMs) containing adjacent dilated blood-filled multi-cavernous lesions. We used CRISPR-Cas9 mutagenesis to induce mosaic inactivation of zebrafishccm2resulting in a novel lethal multi-cavernous lesion in the embryonic caudal venous plexus (CVP) caused by obstruction of blood flow by intraluminal pillars. These pillars mimic those that mediate intussusceptive angiogenesis; however, in contrast to the normal process, the pillars failed to fuse to split the pre-existing vessel in two. Abortive intussusceptive angiogenesis stemmed from mosaic inactivation ofccm2leading to patchyklf2aover-expression and resultant aberrant flow signaling. Surviving adult fish manifested histologically-typical hemorrhagic CCM. Formation of mammalian CCM requires the flow-regulated transcription factor KLF2; fish CCM and the embryonic CVP lesion failed to form inklf2anull fish indicating a common pathogenesis with the mammalian lesion. These studies describe a zebrafish CCM model and establish a mechanism that can explain the formation of characteristic multi-cavernous lesions.
Evolution of dosage compensation does not depend on genomic background
Authors: Rovatsos Michail , Kratochvíl Lukáš
Published: August 2020

Organisms evolved various mechanisms to cope with the differences in the gene copy numbers between sexes caused by degeneration of Y and W sex chromosomes. Complete dosage compensation or at least expression balance between sexes was reported predominantly in XX/XY, but rarely in ZZ/ZW systems. However, this often-reported pattern is based on comparisons of lineages where sex chromosomes evolved from non-homologous genomic regions, potentially differing in sensitivity to differences in gene copy numbers. Here we document that two reptilian lineages (XX/XY iguanas and ZZ/ZW softshell turtles), which independently co-opted the same ancestral genomic region for the function of sex chromosomes, evolved different gene dose regulatory mechanisms. The independent co-option of the same genomic region for the role of sex chromosome as in the iguanas and the softshell turtles offers a great opportunity for testing evolutionary scenarios on the sex chromosome evolution under the explicit control for the genomic background and for gene identity. We showed that the parallel loss of functional genes from the Y chromosome of the green anole and the W chromosome of the Florida softshell turtle led to different dosage compensation mechanisms. Our approach controlling for genetic background thus does not support that the variability in the regulation of the gene dose differences is a consequence of ancestral autosomal gene content.
Alterations in bile acid metabolizing gut microbiota and specific bile acid genes as a precision medicine to subclassify NAFLD
Authors: Jiao Na , Loomba Rohit , Yang Zi-Huan , Wu Dingfeng , Fang Sa , Bettencourt Richele , Lan Ping , Zhu Ruixin , Zhu Lixin
Published: August 2020

Background & Aims

Multiple mechanisms for the gut microbiome contributing to the pathogenesis of non-alcoholic fatty liver disease (NAFLD) have been implicated. Here, we aim to investigate the contribution and potential application for altered bile acid (BA) metabolizing microbe in NAFLD using whole metagenome sequencing (WMS) data.

Methods

86 well-characterized biopsy-proven NAFLD patients and 38 healthy controls were included in the discovery cohort. Assembly-based analysis was performed to identify BA-metabolizing microbes. Statistical tests, feature selection and microbial interaction analysis were integrated to identify microbial alterations and markers in NAFLD. An independent validation cohort was subjected to similar analyses.

Results

NAFLD microbiota exhibited decreased diversity and microbial interactions. We established a classifier model with 53 differential species exhibiting a robust diagnostic accuracy (AUC=0.97) for dectecting NAFLD. Next, 8 important differential pathway markers including secondary BA biosynthesis were identified. Specifically, increased abundance of 7α-HSDH, baiA and baiB were detected in NAFLD. Further, 10 of 50 BA-metabolizing metagenome-assembled genomes (MAG)s, fromBacteroides ovatusandEubacterium biforme, were dominant in NAFLD and interplayed as a synergetic ecological guild. Importantly, two subtypes of NAFLD patients were observed according to secondary BA metabolism potentials. Elevated capability for secondary BA biosynthesis was also observed in the validation cohort.

Conclusions

We identified novel bacterial BA-metabolizing genes and microbes that may contribute to NAFLD pathogenesis and serve as disease markers. Microbial differences in BA-metabolism and strain-specific differences among patients highlight the potential for precision medicine in NAFLD treatment.
Stage-mediated priority effects and season lengths shape long-term competition dynamics
Authors: Zou Heng-Xing , Schreiber Sebastian J. , Rudolf Volker H.W.
Published: August 2020

The relative arrival time of species can affect their interactions and thus determine which species persist in a community. Although this phenomenon, called priority effect, is widespread in natural communities, it is unclear how it depends on the length of growing season. Using a seasonal stage-structured model, we show that differences in stages of interacting species could generate priority effects by altering the strength of stabilizing and equalizing coexistence mechanisms, changing outcomes between exclusion, coexistence, and positive frequency dependence. However, these priority effects are strongest in systems with just one or a few generations per season and diminish in systems where many overlapping generations per season dilute the importance of stage-specific interactions. Our model reveals a novel link between the number of generations in a season and the consequences of priority effects, suggesting that consequences of phenological shifts driven by climate change should depend on specific life histories of organisms.
Developmental nutrition modulates metabolic responses to projected climate change
Authors: Alton Lesley A. , Kutz Teresa C. , Bywater Candice L. , Beaman Julian E. , Arnold Pieter A. , Mirth Christen K. , Sgrò Carla M. , White Craig R.
Published: August 2020

The current policy has the world on track to experience around 3°C of warming by 2100. The responses of organisms to our warming world will be mediated by changes in physiological processes, including metabolic rate. Metabolic rate represents the energetic cost of living, and is fundamental to understanding the energy required to sustain populations. Current evidence indicates that animals have a limited capacity to adapt to warmer environments by reducing their metabolic rate. Consequently, animals may be more reliant on metabolic plasticity to ameliorate the thermodynamic effect of rising temperatures on physiological rates. However, metabolic plasticity is influenced by other environmental factors, including the nutritional quality of food. Elevated levels of atmospheric CO2 are expected to reduce the protein and increase the carbohydrate concentration in plants, but we do not know how this will affect the response of metabolic rate to climate warming.

Here we test the interactive effects of developmental dietary protein and carbohydrate concentrations on the metabolic plasticity of adult Drosophila melanogaster in response to a 3°C increase in temperature while accounting for variation associated with body mass and activity (resting metabolic rate).

We show that the thermal sensitivity of resting metabolic rate is modulated by developmental nutrition with animals reared on nutritionally poor, low‐protein diets showing the greatest increase in resting metabolic rate in response to simulated climate warming. We also show that if the nutritional quality of resources is unaffected by climate change, then temperature‐induced increases in resting metabolic rate will be offset by decreases in mass, but the absolute energy requirements of animals will be elevated relative to current conditions despite this. If, on the other hand, temperatures rise and resources become more calorie‐dense and carbohydrate‐rich, then the resting metabolic rate of animals will remain relatively unchanged, but decreases in mass and activity may drive down the absolute energy requirements of animals.

In the absence of evolutionary adaptation, these findings suggest that the combined plastic response of physiological, morphological and behavioural traits to temperature and nutrition may be an important determinant of the ultimate outcome of climate change for populations.

A free Plain Language Summary can be found within the Supporting Information of this article.
Trade‐offs between seed size and biotic interactions contribute to coexistence of co‐occurring species that vary in fecundity
Authors: Maron John L. , Hahn Philip G. , Hajek Karyn L. , Pearson Dean E.
Published: August 2020

Despite theoretical advances, the ecological factors and functional traits that enable species varying in seed size and fecundity to coexist remain unclear. Given inherent fecundity advantages, why don't small‐seeded species dominate communities?

In perennial grasslands, we evaluated whether small‐seeded species are less tolerant of competition from the community dominant bunchgrass than large‐seeded species, but also less vulnerable to seed predation by mice. We also explored whether trade‐offs involving competitive tolerance include two other functional traits, height and leaf mass per area (LMA). We added seeds of 17 forb species to plots where bunchgrass competition and rodent seed predation were manipulated across sites varying in bunchgrass productivity and thus competitive intensity. Seeds were added at densities mimicking interspecific variation in fecundity among target species.

Standardizing for differences in fecundity (i.e. seed input, which enabled us to evaluate inherent interspecific differences in susceptibility to biotic interactions), bunchgrass competition more greatly reduced recruitment and establishment of small‐ versus large‐seeded species, whereas rodent seed predation more greatly reduced the recruitment of large‐ versus small‐seeded species. Plant height and LMA were unrelated to the competition effect size.

Small‐seeded species abundance decreased across sites increasing in bunchgrass productivity, whereas this was not the case for large‐seeded species. For adult plants but not seedlings, community‐weighted functional trait means (CWM) for seed size, height and LMA increased in plots with versus without bunchgrass competition and the CWM for seed size and height also increased at sites with greater bunchgrass productivity (for adults only). In contrast, rodent seed predation had no significant effects on CWM seed size.

At the end of the experiment, adult abundance positively correlated with plant fecundity in plots lacking bunchgrass, indicating the inherent advantages accrued to high fecundity small‐seeded species. However, with bunchgrass competition, abundances were equalized across species due to reduced competitive tolerance of high fecundity small‐seeded species.

Synthesis. Our results suggest that coexistence among subordinate forb species varying in seed size and fecundity is in‐part due to a trade‐off involving competitive tolerance and fecundity, mediated by seed size and associated functional traits.
Climate manipulations differentially affect plant population dynamics within versus beyond northern range limits
Authors: Reed Paul B. , Peterson Megan L. , Pfeifer‐Meister Laurel E. , Morris William F. , Doak Daniel F. , Roy Bitty A. , Johnson Bart R. , Bailes Graham T. , Nelson Aaron A. , Bridgham Scott D.
Published: August 2020

Predicting species' range shifts under future climate is a central goal of conservation ecology. Studying populations within and beyond multiple species' current ranges can help identify whether demographic responses to climate change exhibit directionality, indicative of range shifts, and whether responses are uniform across a suite of species.

We quantified the demographic responses of six native perennial prairie species planted within and, for two species, beyond their northern range limits to a 3‐year experimental manipulation of temperature and precipitation at three sites spanning a latitudinal climate gradient in the Pacific Northwest, USA. We estimated population growth rates (λ) using integral projection models and tested for opposing responses to climate in different demographic vital rates (demographic compensation).

Where species successfully established reproductive populations, warming negatively affected λ at sites within species' current ranges. Contrarily, warming and drought positively affected λ for the two species planted beyond their northern range limits. Most species failed to establish a reproductive population at one or more sites within their current ranges, due to extremely low germination and seedling survival. We found little evidence of demographic compensation buffering populations to the climate treatments.

Synthesis. These results support predictions across a suite of species that ranges will need to shift with climate change as populations within current ranges become increasingly vulnerable to decline. Species capable of dispersing beyond their leading edges may be more likely to persist, as our evidence suggests that projected changes in climate may benefit such populations. If species are unable to disperse to new habitat on their own, assisted migration may need to be considered to prevent the widespread loss of vulnerable species.
A Community of Practice of primary health care occupational therapists: Advancing practice‐based knowledge
Authors: Marcolino Taís Q. , Kinsella Elizabeth A. , Araujo Angélica da S. , Fantinatti Eliane N. , Takayama Gabriela M. , Vieira Natália M. U. , Pereira Ana J. A. T. , Gomes Laysla D. , Galheigo Sandra M. , Ferigato Sabrina H.
Published: August 2020

Introduction

New contexts of practice demand that professionals engage in critical reflection to handle new situations and to create new knowledge that is responsive to professional practices situated in unique historical and social contexts. Community of Practice offers a framework for professions to reflect together on practice dilemmas and to generate practical solutions.

Methods

This paper presents a participatory action research project that traces the trajectory of a Community of Practice made up of seven occupational therapists working in primary health care and a researcher team, in Brazil. This study mapped the Community of Practice's trajectory between 2013 and 2017 through a group timeline analysis, which occurred gradually, in a collaborative mode.

Results

Three distinct phases in the trajectory of the development of the Community of Practice were identified: narrative perspectives were utilised as a means to identify dilemmas and difficulties in practice; the investigation of clients' needs and identification of issues was an ongoing process; and the generation of practice‐based knowledge through the development of instruments to sustain clinical reasoning was a creative solution to practical dilemmas.

Conclusion

Three main aspects were highlighted: the partnership between researchers and practitioners as a potential avenue for the production of knowledge relevant to professional practice; the negotiation of the dilemma of "putting practice into words" in the context of constantly changing local and global perspectives; and the investigation of situated practice as an important element that can strengthen, strain, resist or even modify hegemonic perspectives of knowledge production in our field.
Making Original Men: Elijah Muhammad, The Nation of Islam, and The Fruit of Islam
Authors: Gibson Dawn‐Marie
Published: August 2020

Elijah Muhammad's Nation of Islam converted thousands of African American men to Islam during the height of the Civil Rights Movement and the Black Power Movement. Muhammad's men neither protested for Civil Rights nor subscribed to the militancy of the Black Power Movement. Indeed, they construed both to be fundamentally flawed routes to justice, freedom, and equality. Nation men, or Fruit of Islam (FOI) as they are more commonly known, believed that through Islam, racial separation, and community building initiatives they could ultimately reclaim their freedom, self‐respect, and manhood. The NOI provided men with a newfound sense of self and purpose and in doing so imbued them with a deep‐rooted appreciation for Islam, as taught by Elijah Muhammad. Rank‐and‐file male members of the faith community remain largely overlooked in the extant scholarship on the NOI. This article seeks to recover the stories of rank‐and‐file FOI. It assesses the organisation's appeal to men, the varied means by which it challenged them and the burdens the community placed on FOI.
The impact of coal and non‐coal consumption on China's energy performance improvement
Authors: Teng Xiangyu , Liu Fan‐peng , Chiu Yung‐ho
Published: August 2020

China is the world's largest energy consumer, and coal accounts for a higher proportion of the country's total energy consumption, yet during its 12th five‐year plan (2011–2015), the coal share among total energy consumption significantly decreased. Previous studies exploring energy performance typically used energy consumption as an input, but this lacks the analytical capacity for the structure of energy consumption. Thus, this study splits energy input into two different inputs, coal consumption and non‐coal energy consumption, and based on their differences with other variables, uses the hybrid dynamic data envelopment analysis model to assess the energy performance of China's provincial industrial sector during the period 2011 to 2015. We then compare coal consumption's and non‐coal consumption's rooms for improvement and conclude that provinces in eastern and central China should reduce the amount of coal consumption, thereby improving energy performance. Conversely, provinces in the western region should target a balance between energy utilization efficiency and coal consumption.
Combined transcriptomic and proteomic analysis of flubendiamide resistance in Plutella xylostella
Authors: Li Jing‐Jing , Jin Ming‐Hui , Wang Nian‐Meng , Yu Qi‐Tong , Shang Ze‐Yu , Xue Chao‐Bin
Published: August 2020

Diamondback moth (DBM), Plutella xylostella, is an important pest of crucifers worldwide. The extensive use of diamide insecticides has led to DBM resistance in the world, and this presents a serious threat to vegetable production. In the present study, transcriptomic and proteomic analyses were combined to investigate the potential flubendiamide‐resistance mechanism in DBM. The lab‐selected (Rh) and field‐collected (Rb) flubendiamide‐resistant lines of P. xylostella with resistance ratios of 1889.92‐fold and 1250.97‐fold, respectively, were used, as well as a lab‐reared flubendiamide‐susceptible line (S). Compared with the S group, the transcriptomic analysis revealed 151 upregulated and 287 downregulated gene messengers in the Rh group and 432 upregulated and 565 downregulated gene messengers in the Rb group. The most frequently enriched pathways of differentially expressed genes (DEGs) were mainly involved in metabolic pathways. Metabolism related genes, including two P450, two ABC transporters, and three trypsins, were upregulated in the Rh line. Additionally, some P450 genes, trypsin, juvenile hormone (JH), and mucin genes were also upregulated in the Rb line. In proteomic analysis comparisons with the S group, there were 78 upregulated and 90 downregulated proteins in the Rh group and 221 upregulated and 155 downregulated proteins in the Rb group. Further analyses found that three CYP and 11 CYP proteins were over‐expressed in Rh and Rb lines, respectively. Four glutathione S‐transferase (GST) and four UGTs were over‐expressed in Rb line. So, we deduced that the detoxification metabolism may be the main mechanism of flubendiamide resistance in P. xylostella.
Saccharomyces cerevisiae may serve as a probiotic in colorectal cancer by promoting cancer cell apoptosis
Authors: Li Jia Qi , Li Jia Lu , Xie Yuan Hong , Wang Yao , Shen Xiao Nan , Qian Yun , Han Ji Xuan , Chen Ying Xuan , Fang Jing‐Yuan
Published: August 2020

Objectives

Shotgun metagenomic sequencing of human fecal samples has shown that Saccharomyces cerevisiae (S. cerevisiae) is significantly suppressed in colorectal cancer (CRC) and probably plays an important role in CRC progression. However, these results need to be validated. Here we aimed to confirm the results of high‐throughput sequencing and demonstrate the mechanisms mediating the effect of S. cerevisiae on progression from colorectal adenoma (CRA) to CRC.

Methods

We used a quantitative polymerase chain reaction (qPCR) assay to examine the relative abundance of S. cerevisiae in 281 fecal samples collected from 106 healthy controls, 108 patients with CRA and 67 with CRC. C57BL/6 and APCMin/+ mouse models and in vitro cell assays were subsequntly used for additional analyses. The mouse models were treated or not treated with broad‐spectrum antibiotics and given an S. cerevisiae gavage for 8 weeks. Western blot, 16S rRNA sequencing, qPCR, immunohistochemistry, RNA sequencing, cell counting kit‐8 assay, colony formation assay and flow cytometry were performed.

Results

S. cerevisiae was 2.68‐fold and 3.94‐fold less abundant in patients with CRA and CRC, respectively, than in the controls. In vivo experiments showed that S. cerevisiae reduced colorectal tumor progression by promoting epithelial cell apoptosis and modulated gut microbial structure and intestinal immunity. S. cerevisiae downregulated nuclear factor kappa light chain enhancer of activated B cells and the mechanistic target of rapamycin signaling pathways. Cell assays confirmed the pro‐apoptotic effect of S. cerevisiae.

Conclusions

S. cerevisiae may play a probiotic role in CRC by promoting cancer cell apoptosis. It can reduce CRC progression by modulating the mucosal microbial structure.
Comparative secretome of white‐rot fungi reveals co‐regulated carbohydrate‐active enzymes associated with selective ligninolysis of ramie stalks
Authors: Xie Chunliang , Gong Wenbing , Zhu Zuohua , Zhou Yingjun , Xu Chao , Yan Li , Hu Zhenxiu , Ai Lianzhong , Peng Yuande
Published: August 2020

In the present research, Phanerochaete chrysosporium and Irpex Lacteus simultaneously degraded lignin and cellulose in ramie stalks, whereas Pleurotus ostreatus and Pleurotus eryngii could depolymerize lignin but little cellulose. Comparative proteomic analysis of these four white‐rot fungi was used to investigate the molecular mechanism of this selective ligninolysis. 292 proteins, including CAZymes, sugar transporters, cytochrome P450, proteases, phosphatases and proteins with other function, were successfully identified. A total of 58 CAZyme proteins were differentially expressed, and at the same time, oxidoreductases participated in lignin degradation were expressed at higher levels in P. eryngii and P. ostreatus. Enzyme activity results indicated that cellulase activities were higher in P. chrysosporium and I. lacteus, while the activities of lignin‐degrading enzymes were higher in P. eryngii and P. ostreatus. In addition to the lignocellulosic degrading enzymes, several proteins including sugar transporters, cytochrome P450 monooxygenases, peptidases, proteinases, phosphatases and kinases were also found to be differentially expressed among these four species of white‐rot fungi. In summary, the protein expression patterns of P. eryngii and P. ostreatus exhibit co‐upregulated oxidoreductase potential and co‐downregulated cellulolytic capability relative to those of P. chrysosporium and I. lacteus, providing a mechanism consistent with selective ligninolysis by P. eryngii and P. ostreatus.
The curse of knowledge: having access to customer information can reduce monopoly profits
Authors: Laussel Didier , Long Ngo V. , Resende Joana
Published: August 2020

We show that a monopolist's profit is higher if he refrains from collecting coarse information on his customers, sticking to constant uniform pricing rather than recognizing customers' segments through their purchase history. In the Markov perfect equilibrium with coarse information collection, after each commitment period, a new introductory price is offered to attract new customers, creating a new market segment for price discrimination. Eventually, the whole market is covered. Shortening the commitment period results in lower profits. These results sharply differ from the ones obtained when the firm can uncover the exact willingness‐to‐pay of each previous customer.
Not knowing the competition: evidence and implications for auction design
Authors: Kong Yunmi
Published: August 2020

In a government auction program where first‐price auctions generate significantly higher revenue than English auctions, I document evidence that bidders are uncertain about the number of auction entrants. Motivated by additional data evidence, I estimate a structural model of auctions in which rivals' participation is stochastic, allowing for bidders' risk aversion and asymmetry. Counterfactual simulations reveal that bidders' uncertainty about the number of entrants, combined with risk aversion, substantially softens the revenue impact of low competition in first‐price auctions. This explains the observed revenue patterns and uncovers an empirically important reason for sellers to favor first‐price auctions over English auctions.
Intermediaries and product quality in used car markets
Authors: Biglaiser Gary , Li Fei , Murry Charles , Zhou Yiyi
Published: August 2020

We present empirical evidence supporting that used cars sold by dealers have higher quality: (i) dealer transaction prices are higher than unmediated market prices, and this dealer premium increases in the age of the car as a ratio and is hump‐shaped in dollar value, and (ii) used cars purchased from dealers are less likely to be resold. In a model, we show that these empirical facts can be rationalized either when dealers alleviate information asymmetry, or when dealers facilitate assortative matching. The model predictions allow us to distinguish these two theories in the data, and we find evidence for both.
Intermittent self‐administration of fentanyl induces a multifaceted addiction state associated with persistent changes in the orexin system
Authors: Fragale Jennifer E. , James Morgan H. , Aston‐Jones Gary
Published: August 2020

The orexin (hypocretin) system plays a critical role in motivated drug taking. Cocaine self‐administration with the intermittent access (IntA) procedure produces a robust addiction‐like state that is orexin‐dependent. Here, we sought to determine the role of the orexin system in opioid addiction using IntA self‐administration of fentanyl. Different groups of male rats were either given continuous access in 1‐h period (short access [ShA]), 6‐h period (long access [LgA]), or IntA (5 min of access separated by 25 min of no access for 6 h) to fentanyl for 14 days. IntA produced a greater escalation of fentanyl intake, increased motivation for fentanyl on a behavioral economics task, persistent drug seeking during abstinence, and stronger cue‐induced reinstatement compared with rats given ShA or LgA. We found that addiction behaviors induced by IntA to fentanyl were reversed by the orexin‐1 receptor antagonist SB‐334867. IntA to fentanyl was also associated with a persistent increase in the number of orexin neurons. Together, these results indicate that the IntA model is a useful tool in the study of opioid addiction and that the orexin system is critical for the maintenance of addiction behaviors induced by IntA self‐administration of fentanyl.