bluuebunny/crossref_metadata_2025 huggingface dataset:
Size-Based Characterization of Freshwater Dissolved Organic Matter finds Similarities within a Water Body Type across Different Canadian Ecozones
Authors: Aukes Pieter J. K. , Schiff Sherry L. , Venkiteswaran Jason J. , Elgood Richard J. , Spoelstra John
Published: April 2020

Dissolved Organic Matter (DOM) represents a mixture of organic molecules that vary due to different source materials and degree of processing. Characterizing how DOM composition evolves along the aquatic continuum can be difficult. Using a size-exclusion chromatography technique (LC-OCD), we assessed the variability in DOM composition from both surface and groundwaters across a number of Canadian ecozones (mean annual temperature spanning −10 to +6 C). A wide range in DOM concentration was found from 0.2 to 120 mg C/L. Proportions of different size-based groupings across ecozones were variable, yet similarities between specific water-body types, regardless of location, suggest commonality in the processes dictating DOM composition. A PCA identified 70% of the variation in LC-OCD derived DOM compositions could be explained by the water-body type. We find that DOM composition within a specific water-body type is similar regardless of the differences in climate or surrounding vegetation where the sample originated from.

Highlights

Size-exclusion chromatography (using LC-OCD) is a fast and effective tool to quantify differences in DOM composition across different environments

Proportions of biopolymers and low molecular weight fractions can distinguish between surface and groundwater DOM

Similar water-body types have comparable DOM size compositions across ecozones that range in annual air temperatures from –10 to 6ºC
A novelAxin2knock-in mouse model for visualization and lineage tracing of WNT/CTNNB1 responsive cells
Authors: van de Moosdijk Anoeska Agatha Alida , van de Grift Yorick Bernardus Cornelis , de Man Saskia Madelon Ada , Zeeman Amber Lisanne , van Amerongen Renée
Published: April 2020

Wnt signal transduction controls tissue morphogenesis, maintenance and regeneration in all multicellular animals. In mammals, the WNT/CTNNB1 (Wnt/β-catenin) pathway controls cell proliferation and cell fate decisions before and after birth. It plays a critical role at multiple stages of embryonic development, but also governs stem cell maintenance and homeostasis in adult tissues. However, it remains challenging to monitor endogenous WNT/CTNNB1 signaling dynamicsin vivo. Here we report the generation and characterization of a new knock-in mouse strain that doubles as a fluorescent reporter and lineage tracing driver for WNT/CTNNB1 responsive cells. We introduced a multi-cistronic targeting cassette at the 3’ end of the universal WNT/CTNNB1 target geneAxin2. The resulting knock-in allele expresses a bright fluorescent reporter (3xNLS-SGFP2) and a doxycycline-inducible driver for lineage tracing (rtTA3). We show that theAxin2P2A-rtTA3-T2A-3xNLS-SGFP2strain labels WNT/CTNNB1 cells at multiple anatomical sites during different stages of embryonic and postnatal development. It faithfully reports the subtle and dynamic changes in physiological WNT/CTNNB1 signaling activity that occurin vivo. We expect this mouse strain to be a useful resource for biologists who want to track and trace the location and developmental fate of WNT/CTNNB1 responsive stem cells in different contexts.

Abstract Figure
Modular genetic control of social status in a cichlid fish
Authors: Alward Beau A. , Laud Vibhav , Skalnik Christopher J. , York Ryan A. , Juntti Scott , Fernald Russell D.
Published: April 2020

Social hierarchies are ubiquitous in social species and profoundly influence physiology and behavior. Androgens like testosterone have been strongly linked to social status, yet the molecular mechanisms regulating social status are not known. The African cichlid fishAstatotilapia burtoniis a powerful model species for elucidating the role of androgens in social status given their rich social hierarchy and genetic tractability. DominantA. burtonimales possess large testes, bright coloration, and perform aggressive and reproductive behaviors while non-dominant males do not. Social status inA. burtoniis in flux, however, as males alter their status depending on the social environment. Due to a teleost-specific whole-genome duplication,A. burtonipossess two androgen receptor (AR) paralogs,ARαandARβ, providing a unique opportunity to disentangle the role of gene duplication in the evolution of social systems. Here, we used CRISPR/Cas9 gene editing to generate AR mutantA. burtoniand performed a suite of experiments to interrogate the mechanistic basis of social dominance. We find thatARβ, but notARα, is required for testes growth and bright coloration, whileARα, but notARβ, is required for the performance of reproductive behavior and aggressive displays. Both receptors are required to reduce flees from females and either AR is sufficient for attacking males. Thus, social status inA. burtoniis inordinately dissociable and under the modular control of two AR paralogs. This type of non-redundancy may be important in facilitating social plasticity inA. burtoniand other species whose social status relies on social experience.

Significance Statement

Social rank along a hierarchy determines physiological state and behavioral performance. A ubiquitous feature of social hierarchies is the communication of rank through non-physical signaling systems (e.g., coloration) and aggression, traits that correlate with the reproductive status of an individual. Despite the links identified between social status, physiology, and behavior, the molecular basis of social status is not known. Here, we genetically dissect social status in the African cichlid fishAstatotilapia burtoniusing CRISPR/Cas9 gene editing. We show that two distinct androgen receptor (AR) genes control social status in a highly modular manner. This type of coordination of social status may be fundamental across species that rely on social information to optimally guide physiology and behavior.
Expansion of the circadian transcriptome inBrassica rapaand genome-wide diversification of paralog expression patterns
Authors: Greenham Kathleen , Sartor Ryan C. , Zorich Stevan , Lou Ping , Mockler Todd C. , McClung C. Robertson
Published: April 2020

An important challenge of crop improvement strategies is assigning function to paralogs in polyploid crops. Gene expression is one method for determining the activity of paralogs; however, the majority of transcript abundance data represents a static point that does not consider the spatial and temporal dynamics of the transcriptome. Studies in Arabidopsis have estimated up to 90% of the transcriptome to be under diel or circadian control depending on the condition. As a result, time of day effects on the transcriptome have major implications on how we characterize gene activity. In this study, we aimed to resolve the circadian transcriptome in the polyploid cropBrassica rapaand explore the fate of multicopy orthologs of Arabidopsis circadian regulated genes. We performed a high-resolution time course study with 2 h sampling density to capture the genes under circadian control. Strikingly, more than two-thirds of expressed genes exhibited rhythmicity indicative of circadian regulation. To compare the expression patterns of paralogous genes, we developed a program in R called DiPALM (Differential Pattern Analysis by Linear Models) that analyzes time course data to identify transcripts with significant pattern differences. Using DiPALM, we identified genome-wide divergence of expression patterns among retained paralogs. Cross-comparison with a previously generated diel drought experiment inB. raparevealed evidence for differential drought response for these diverging paralog pairs. Using gene regulatory network models we compared transcription factor targets betweenB. rapaand Arabidopsis circadian networks to reveal additional evidence for divergence in expression betweenB. rapaparalogs that may be driven in part by variation in conserved non coding sequences. These findings provide new insight into the rapid expansion and divergence of the transcriptional network in a polyploid crop and offer a new method for assessing paralog activity at the transcript level.

Significance

The circadian regulation of the transcriptome leads to time of day changes in gene expression that coordinates environmental conditions with physiological responses.Brassica rapa, a morphologically diverse crop species, has undergone whole genome triplication since diverging from Arabidopsis resulting in an expansion of gene copy number. To examine how this expansion has influenced the circadian transcriptome we developed a new method for comparing gene expression patterns. This method facilitated the discovery of genome-wide expansion of expression patterns for genes present in multiple copies and divergence in temporal abiotic stress response. We find support for conserved sequences outside the gene body contributing to these expression pattern differences and ultimately generating new connections in the gene regulatory network.
Temporal Analysis of T-Cell Receptor-Imposed Forces via Quantitative Single Molecule FRET Measurements
Authors: Göhring Janett , Kellner Florian , Schrangl Lukas , Platzer René , Klotzsch Enrico , Stockinger Hannes , Huppa Johannes B. , Schütz Gerhard J.
Published: April 2020

Mechanical forces acting on ligand-engaged T-cell receptors (TCRs) have previously been implicated in T-cell antigen recognition, yet their magnitude, spread, and temporal behavior are still poorly defined. We here report a FRET-based sensor equipped with a TCR-reactive single chain antibody fragment, which was tethered to planar supported lipid bilayers (SLBs) and informs most directly on the magnitude and kinetics of TCR-imposed forces at the single molecule level. When confronting T-cells with gel-phase SLBs we observed both prior and upon T-cell activation a single, well-resolvable force-peak of approximately 5 pN and force loading rates on the TCR of 1.5 pN per second. When facing fluid SLBs instead, T-cells still exerted tensile forces yet with threefold reduced magnitude and only prior to but not upon activation. Our findings do not only provide first truly molecular information on TCR-imposed forces within the immunological synapse, they also recalibrate their significance in antigen recognition.
A Molecular Mechanism for Turning off IRE1α Signaling During Endoplasmic Reticulum Stress
Authors: Li Xia , Sun Sha , Appathurai Suhila , Sundaram Arunkumar , Plumb Rachel , Mariappan Malaiyalam
Published: April 2020

Misfolded proteins in the endoplasmic reticulum (ER) activate IRE1α endoribonuclease in mammalian cells, which mediates XBP1 mRNA splicing to produce an active transcription factor. This promotes the expression of specific genes to alleviate ER stress and thereby attenuating IRE1α. Although sustained activation of IRE1α is linked to human diseases, it is not clear how IRE1α is attenuated during ER stress. Here, we identify that Sec63 is a subunit of the previously identified IRE1α/Sec61 translocon complex. We find that Sec63 recruits and activates BiP ATPase through its luminal J-domain to bind onto IRE1α. This leads to inhibition of higher-order oligomerization and attenuation of IRE1α RNase activity during prolonged ER stress. In Sec63 deficient cells, IRE1α remains activated for a long time despite the presence of excess BiP in the ER. Thus, our data suggest that the Sec61 translocon bridges IRE1α with Sec63/BiP to regulate the dynamics of IRE1α signaling in cells.
Focused ultrasound stimulates ER localized mechanosensitive PANNEXIN-1 to mediate intracellular calcium release in invasive cancer cells
Authors: Lee Nan Sook , Yoon Chi Woo , Wang Qing , Moon Sunho , Koo Kweon Mo , Jung Hayong , Chen Ruimin , Jiang Laiming , Lu Gengxi , Fernandez Antony , Chow Robert H. , Weitz Andrew C. , Salvaterra Paul M. , Pinaud Fabien , Shung K. Kirk
Published: April 2020

Focused ultrasound (FUS) is a rapidly developing stimulus technology with the potential to uncover novel mechanosensory dependent cellular processes. Since it is noninvasive, it holds great promise for future therapeutic applications in patients used either alone or as a complement to boost existing treatments. For example, FUS stimulation causes invasive but not noninvasive cancer cell lines to exhibit marked activation of calcium signaling pathways. Here, we identify the membrane channel PANNEXIN1 (PANX1) as a mediator for activation of calcium signaling in invasive cancer cells. Knockdown of PANX1 decreases calcium signaling in invasive cells, while PANX1 overexpression enhances calcium elevations in non-invasive cancer cells. We demonstrate that FUS may directly stimulate mechanosensory PANX1 localized in endoplasmic reticulum to evoke calcium release from internal stores. This process does not depend on mechanosensory stimulus transduction through an intact cytoskeleton and does not depend on plasma membrane localized PANX1. Plasma membrane localized PANX1 however plays a different role in mediating the spread of intercellular calcium waves via ATP release. Additionally, we show that FUS stimulation evokes cytokine/chemokine release from invasive cancer cells, suggesting that FUS could be an important new adjuvant treatment to improve cancer immunotherapy.
Nectar-dwelling microbes of common tansy are attractive to its mosquito pollinator,Culex pipiensL
Authors: Peach D. A. H. , Carroll C. , Meraj S. , Gomes S. , Galloway E. , Balcita A. , Coatsworth H. , Young N. , Uriel Y. , Gries R. , Lowenberger C. , Moore M. , Gries G.
Published: April 2020

Background

There is widespread interkingdom signalling between insects and microbes. For example, microbes found in floral nectar may modify its nutritional composition and produce odorants that alter the floral odor bouquet which may attract insect pollinators. Mosquitoes consume nectar and can pollinate flowers. We identified microbes isolated from nectar of common tansy,Tanacetum vulgare,elucidated the microbial odorants, and tested their ability to attract the common house mosquito,Culex pipiens.

Results

We collected 18 microbial isolates fromT. vulgarenectar, representing at least 12 different taxa which we identified with 16S or 26S rDNA sequencing as well as by biochemical and physiological tests. Three microorganisms(Lachancea thermotolerans, Micrococcus lactis, Micrococcus luteus)were grown on culture medium and tested in bioassays. Only the yeastL. thermotoleransgrown on nectar, malt extract agar, or in synthetic nectar broth significantly attractedC. pipiensfemales. The odorant profile produced byL. thermotoleransvaried with the nutritional composition of the culture medium. Surprisingly, all three microbes grown separately, but presented concurrently, attracted fewerC. pipiensfemales thanL. thermotoleransby itself.

Conclusions

Floral nectar ofT. vulgarecontains various microbes whose odorants contribute to the odor profile of inflorescences. In addition,L. thermotoleransproduced odorants that attractCx. pipiensfemales. As the odor profile ofL. thermotoleransvaried with the composition of the culture medium, we hypothesize that microbe odorants inform nectar-foraging mosquitoes about the availability of certain macro-nutrients which, in turn, affect foraging decisions by mosquitoes.
Engineering multiple species-like genetic incompatibilities in insects
Authors: Maselko Maciej , Feltman Nathan , Upadhyay Ambuj , Hayward Amanda , Das Siba , Myslicki Nathan , Peterson Aidan J. , O’Connor Michael B. , Smanski Michael J.
Published: April 2020

Speciation constrains the flow of genetic information between populations of sexually reproducing organisms. Gaining control over mechanisms of speciation would enable new strategies to manage wild populations of disease vectors, agricultural pests, and invasive species. Additionally, such control would provide safe biocontainment of transgenes and gene drives. Natural speciation can be driven by pre-zygotic barriers that prevent fertilization or by post-zygotic genetic incompatibilities that render the hybrid progeny inviable or sterile. Here we demonstrate a general approach to create engineered genetic incompatibilities (EGIs) in the model insectDrosophila melanogaster. Our system couples a dominant lethal transgene with a recessive resistance allele. EGI strains that are homozygous for both elements are fertile and fecund when they mate with similarly engineered strains, but incompatible with wild-type strains that lack resistant alleles. We show that EGI genotypes can be tuned to cause hybrid lethality at different developmental life-stages. Further, we demonstrate that multiple orthogonal EGI strains ofD. melanogastercan be engineered to be mutually incompatible with wild-type and with each other. Our approach to create EGI organisms is simple, robust, and functional in multiple sexually reproducing organisms.
The spectral sensitivity ofDrosophilaphotoreceptors
Authors: Sharkey Camilla R. , Blanco Jorge , Leibowitz Maya M. , Pinto-Benito Daniel , Wardill Trevor J.
Published: April 2020

Drosophila melanogasterhas long been a popular model insect species, due in large part to the availability of genetic tools and is fast becoming the model for insect colour vision. Key to understanding colour reception inDrosophilais in-depth knowledge of spectral inputs and downstream neural processing. While recent studies have sparked renewed interest in colour processing inDrosophila, photoreceptor spectral sensitivity measurements have yet to be carried outin vivo. We have fully characterised the spectral input to the motion and colour vision pathways, and directly measured the effects of spectral modulating factors, screening pigment density and carotenoid-based ocular pigments. All receptor sensitivities had significant shifts in spectral sensitivity compared to previous measurements. Notably, the spectral range of the Rh6 visual pigment is substantially broadened and its peak sensitivity is shifted by 92 nm from 508 to 600 nm. We propose that this deviation can be explained by transmission of long wavelengths through the red screening pigment and by the presence of the blue-absorbing filter in the R7y receptors. Further, we tested direct interactions between photoreceptors and found evidence of interactions between inner and outer receptors, in agreement with previous findings of cross-modulation between receptor outputs in the lamina.
The role of Kabuki Syndrome genesKMT2DandKDM6Ain development: Analysis in Human sequencing data and compared to mice and zebrafish
Authors: Sen Rwik , Lencer Ezra , Geiger Elizabeth A. , Jones Kenneth , Shaikh Tamim H. , Artinger Kristin Bruk
Published: April 2020

KMT2DandKDM6Aare epigenetic regulators that have been implicated in Kabuki Syndrome, a rare congenital birth defect with multiple tissue and organ abnormalities, including craniofacial and heart defects. Our previous study identified human families with mutations in the epigenetic modifiers KMT2D and KDM6A, which is implicated in 32% and 10% of Kabuki Syndrome patients respectively. To understand the connection to Kabuki syndrome patients, and the transcriptional targets of KMT2D and KDM6A in humans, we performed RNA sequencing (seq) of lymphoblastoid cells from Kabuki Syndrome patients carrying mutations inKMT2DandKDM6A. We identified 1995 significant changes in transcriptional targets forKMT2Dand 1917 forKDM6A, as compared to control. When compared with RNA-seq datasets obtained from other mouse and zebrafish studies, our analysis revealedKMT2Dmutations affect the expression of 76 orthologous genes across all three datasets. Similarliy,KDM6Aafftects the expprssion of 7 orthologous genes across three datasets. Despite the differences in cell types, stages, and species in the comparison between the transcriptomic datasets, there are common gene expression changes associated with KMT2D and KDM6A mutations. qPCR on novel zebrafish mutants confirmed the differentially expression in KMT2D or KDM6A mutant backgrounds. Taken together, our results show thatKMT2DandKDM6Aregulate common and unique genes across humans, mice, and zebrafish for early craniofacial and cardiac development and this information contributes to the understanding of epigenetic dysregulation during development of Kabuki syndrome.
From simplicity to complexity: The gain or loss of spot rows underlies the morphological diversity of threeDrosophilaspecies
Authors: Dion William A. , Shittu Mujeeb O. , Steenwinkel Tessa E. , Raja Komal K. B. , Kokate Prajakta P. , Werner Thomas
Published: April 2020

To understand how novel animal patterning emerged, one needs to ask how the development of color patterns has changed among diverging species. Here we examine three species of fruit flies –Drosophila guttifera(D. guttifera),Drosophila palustris(D. palustris), andDrosophila subpalustris(D. subpalustris) – displaying a varying number of abdominal spot rows that were either gained or lost throughout evolutionary time. Throughin situhybridization, we examine the mRNA expression patterns for the pigmentation genesDopa decarboxylase(Ddc),tan(t), andyellow(y) during pupal development. Our results show thatDdc,t, andyare co-expressed in identical patterns, each foreshadowing the adult abdominal spots inD. guttifera,D. palustris, andD. subpalustris.
Cell culture system to efficiently test candidate genes and molecular pathways implicated in congenital diaphragmatic hernias
Authors: Bogenschutz Eric L. , Sefton Elizabeth M. , Kardon Gabrielle
Published: April 2020

The mammalian muscularized diaphragm is essential for respiration and defects in the developing diaphragm cause a common and frequently lethal birth defect, congenital diaphragmatic hernia (CDH). Human genetic studies have implicated more than 150 genes and multiple molecular pathways in CDH, but few of these have been validated because of the expense and time to generate mouse mutants. The pleuroperitoneal folds (PPFs) are transient embryonic structures in diaphragm development and a critical cellular source of CDH. We have developed a system to culture PPF fibroblasts from E12.5 mouse embryos and show that these fibroblasts, in contrast to the commonly used NIH 3T3 fibroblasts, maintain expression of key genes in normal diaphragm development. Using pharmacological and genetic manipulations that result in CDHin vivo, we also demonstrate that differences in proliferation provide a rapid means of distinguishing healthy and impaired PPF fibroblasts. Thus, the PPF fibroblast cell culture system is an efficient tool for testing the functional significance of CDH candidate genes and molecular pathways and will be an important resource for elucidating the complex etiology of CDH.

SUMMARY STATEMENT

Multiple candidate genes and molecular pathways have been identified as potentially contributing to the etiology of congenital diaphragmatic hernias. We describe a cell culture system to efficiently functionally test these candidates.
Intrinsically disordered linkers control tethered kinases via effective concentration
Authors: Dyla Mateusz , Kjaergaard Magnus
Published: April 2020

Kinase specificity is crucial to the fidelity of signalling pathways, yet many pathways use the same kinases to achieve widely different effects. Specificity arises in part from the enzymatic domain, but also from the physical tethering of kinases to their substrates. Such tethering can occur via protein interaction domains in the kinase or via anchoring and scaffolding proteins, and can drastically increase the kinetics of phosphorylation. However, we do not know how such intra-complex reactions depend on the link between enzyme and substrate. Here we show that the kinetics of tethered kinases follow a Michaelis-Menten like dependence on effective concentration. We find that phosphorylation kinetics scale with the length of the intrinsically disordered linkers that join the enzyme and substrate, but that the scaling differs between substrates. Steady-state kinetics can only partially predict rates of tethered reactions as product release may obscure the rate of phospho-transfer. Our results suggest that changes in signalling complex architecture not only enhance the rates of phosphorylation reactions, but may also alter the relative substrate usage. This suggests a mechanism for how scaffolding proteins can allosterically modify the output from a signalling pathway.
From winter to summer and back: Lessons from the parameterization of a seasonal food web model for the Białowieża forest
Authors: Sauve Alix M. C. , Barraquand Frederic
Published: April 2020

Dynamic food web models describe how species abundances change over time as a function of trophic and life‐history parameters. They are essential to predicting the response of ecosystems to perturbations. However, they are notoriously difficult to parameterize, so that most models rely heavily either on allometric scaling of parameters or inverse estimation of biomass flows. The allometric approach makes species of comparable body mass have near‐identical parameters which can generate extinctions within a trophic level. The biomass flow approach is more precise, but is restricted to steady‐states, which is not appropriate for time‐varying environments.

Adequately parameterizing large food webs of temperate and arctic environments requires dealing both with many species of similar sizes and a strongly seasonal environment. Inspired by the rich empirical knowledge on the vertebrate food web of the Białowieża forest, we parameterize a bipartite food web model comprising 21 predators and 124 prey species. Our model is a non‐autonomous coupled ordinary differential equations system that allows for seasonality in life‐history and predation parameters.

Birth and death rates, seasonal descriptions of diet for each species, food requirements and biomass information are combined into a seasonal parameterization of a dynamic food web model. Food web seasonality is implemented with time‐varying intrinsic growth rate and interaction parameters, while predation is modelled with both type I and type II functional responses.

All our model variants allow for >80% persistence in spite of massive apparent competition, and a quantitative match to observed (seasonal) biomasses. We also identify trade‐offs between maximizing persistence, reproducing observed biomasses, and ensuring model robustness to sampling errors. Although multi‐annual cycles are expected with type II functional responses, they are here prevented by a strong predator self‐regulation. We discuss these results and possible improvements on the model.

We provide a general workflow to parameterize dynamic food web models in seasonal environments, based on a real case study. This may help to better predict how biodiverse food webs respond to changing environments.
Applying the core microbiome to understand host–microbe systems
Authors: Risely Alice
Published: April 2020

The host‐associated core microbiome was originally coined to refer to common groups of microbes or genes that were likely to be particularly important for host biological function. However, the term has evolved to encompass variable definitions across studies, often identifying key microbes with respect to their spatial distribution, temporal stability or ecological influence, as well as their contribution to host function and fitness.

A major barrier to reaching a consensus over how to define the core microbiome and its relevance to biological, ecological and evolutionary theory is a lack of precise terminology and associated definitions, as well the persistent association of the core microbiome with host function. Common, temporal and ecological core microbiomes can together generate insights into ecological processes that act independently of host function, while functional and host‐adapted cores distinguish between facultative and near‐obligate symbionts that differ in their effects on host fitness.

This commentary summarizes five broad definitions of the core microbiome that have been applied across the literature, highlighting their strengths and limitations for advancing our understanding of host–microbe systems, noting where they are likely to overlap, and discussing their potential relevance to host function and fitness.

No one definition of the core microbiome is likely to capture the range of key microbes across a host population. Applied together, they have the potential to reveal different layers of microbial organization from which we can begin to understand the ecological and evolutionary processes that govern host–microbe interactions.
Long‐term research and hierarchical models reveal consistent fitness costs of being the last egg in a clutch
Authors: Acevedo Cheyenne R. , Riecke Thomas V. , Leach Alan G. , Lohman Madeleine G. , Williams Perry J. , Sedinger James S.
Published: April 2020

Maintenance of phenotypic heterogeneity in the face of strong selection is an important component of evolutionary ecology, as are the consequences of such heterogeneity. Organisms may experience diminishing returns of increased reproductive allocation as clutch or litter size increases, affecting current and residual reproductive success. Given existing uncertainty regarding trade‐offs between the quantity and quality of offspring, we sought to examine the potential for diminishing returns on increased reproductive allocation in a long‐lived species of goose, with a particular emphasis on the effect of position in the laying sequence on offspring quality.

To better understand the effects of maternal allocation on offspring survival and growth, we estimated the effects of egg size, timing of breeding, inter‐ and intra‐annual variation, and position in the laying sequence on gosling survival and growth rates of black brant Branta bernicla nigricans breeding in western Alaska from 1987 to 2007.

We found that gosling growth rates and survival decreased with position in the laying sequence, regardless of clutch size. Mean egg volume of the clutch a gosling originated from had a positive effect on gosling survival (β = 0.095, 95% CRI: 0.024, 0.165) and gosling growth rates (β = 0.626, 95% CRI: 0.469, 0.738). Gosling survival (β = −0.146, 95% CRI: −0.214, −0.079) and growth rates (β = −1.286, 95% CRI: −1.435, −1.132) were negatively related to hatching date.

These findings indicate substantial heterogeneity in offspring quality associated with their position in the laying sequence. They also potentially suggest a trade‐off mechanism for females whose total reproductive investment is governed by pre‐breeding state.
Associational resistance to both insect and pathogen damage in mixed forests is modulated by tree neighbour identity and drought
Authors: Field Elsa , Castagneyrol Bastien , Gibbs Melanie , Jactel Hervé , Barsoum Nadia , Schönrogge Karsten , Hector Andrew
Published: April 2020

Tree health declines can be caused by interactions between pests and pathogens and many studies have shown a reduction in their damage in mixed species forests compared to monocultures. Yet few authors have considered tree diversity effects on both groups simultaneously. Moreover, it is unclear whether diversity effects on tree pests and pathogens are robust to changes in abiotic conditions, such as drought.

We addressed tree diversity effects on foliar insect herbivory, oak powdery mildew and their interaction under contrasting water regimes in a large-scale tree diversity experiment in SW France. Using an irrigation treatment that alleviated drought conditions, we were able to experimentally assess the effects of tree diversity under contrasting abiotic environments. We surveyed plots along a richness gradient from one to four tree species, in which a focal study species of oak (Quercus robur) was mixed with other oak species (Q. pyrenaica and Q. ilex) and a taller, broadleaved species (Betula pendula).

Increasing tree species richness lowered leaf miner abundance, leaf chewer damage and oak powdery mildew infection, consistent with a protective effect of resource dilution. However, richness effects on leaf miners were stronger in irrigated compared to non-irrigated blocks, indicating that environmental conditions can modulate diversity effects. Separate from the effect of tree species richness, the presence of birch in a plot increased damage by leaf chewers and powdery mildew, but lowered leaf miner damage, suggesting additional tree neighbour identity effects potentially linked to modulation of microclimate. We found a negative association between leaf miner abundance and oak powdery mildew, consistent with antagonism between oak damage agents.

Synthesis. Overall, our study illustrates the importance of considering both tree diversity and composition (neighbour identity) in designing forests more resistant to pest and pathogen damage.
Patterns of pollen dispersal and mating in a population of the clonal plant Sagittaria latifolia
Authors: Stephens Samantha , van Kleunen Mark , Dorken Marcel E.
Published: April 2020

Increased plant size is generally expected to have negative consequences for mating by increasing pollen transfer between flowers of the same plant. Such geitonogamous self‐pollination would then reduce sexual fitness through both female and male function. However, recent theoretical work has indicated that when plants grow clonally, the outward expansion of plants caused by clonal growth might have positive effects on siring without substantially increasing rates of self‐pollination.

We investigated patterns of pollen dispersal, selfing and siring in a monoecious population of the clonal plant Sagittaria latifolia, in which clones varied in size and the extent of intermingling with other clones. A spatially explicit statistical model based on the inferred pollen dispersal kernel was constructed to examine the mechanisms underlying observed mating patterns.

Pollen dispersal typically occurred over distances that exceeded the spatial extent of clones. There was a positive association between clone size (measured as the number of ramets per genet) and the likelihood that clones were intermingled with the shoots of other clones. Together, these patterns of pollen dispersal and clonal intermingling resulted in a weak positive association between clone size and selfing rates and a strong positive association between clone size and outcross siring success. These patterns were replicated in the spatially explicit model, indicating that the intermingling of clones is an important determinant of mating patterns in this population.

Synthesis. Our study provides the first examination of the pollen dispersal kernel for a clonal plant. It is the first study providing empirical support for model predictions that potentially negative effects of increased selfing in large clones might be offset by increased siring success. This implies that the negative consequences of becoming large do not necessarily apply to clonal plants.
MiR‐342 attenuates lipopolysaccharide‐induced acute lung injury via inhibiting MAPK1 expression
Authors: Zhu Siliang , Song Wenke , Sun Yanqi , Zhou Yongqin , Kong Fanpo
Published: April 2020

Micro RNA (miRNA) and mitogen‐activated protein kinase (MAPK) are reported as the crucial regulators of inflammatory responses in acute lung injury (ALI). This study will explore the role of the miR‐342/MAPK1 axis in regulation of lipopolysaccharide (LPS)‐induced ALI. We found that miR‐342 was down‐regulated in LPS‐induced A549 cells compared with the control group with DMSO, accompanied by elevated inflammatory cytokines and apoptosis. Over‐expression of miR‐342 reduced LPS‐induced inflammatory responses and apoptosis in LPS‐stimulated A549 cells, and had a protective role in LPS‐treated mice with ALI by decreasing levels of inflammatory cytokines, improving survival of mice with ALI, and ameliorating the lung permeability. Dual‐luciferase reporter gene assay demonstrated that miR‐342 regulated the expression of MAPK1 by directly targeting its 3′ untranslated region (3′‐UTR). Mechanistically, MAPK1 silencing abrogated LPS‐induced inflammatory injury in A549 cells, and partially enhanced the protective effect of miR‐342. Therefore, miR‐342 attenuates LPS‐induced ALI by targeting MAPK1 expression, thereby protecting against A549 cell injury induced by LPS and lung injury of mice with ALI.
MiR‐599 regulates LPS‐mediated apoptosis and inflammatory responses through the JAK2/STAT3 signalling pathway via targeting ROCK1 in human umbilical vein endothelial cells
Authors: Wang Jia , Du Aolin , Wang Hexilin , Li Yang
Published: April 2020

MicroRNA plays an integral role in the development of atherosclerosis. Our study aimed to investigate the roles of miR‐599 in lipopolysaccharide (LPS)‐induced endothelial damage in human umbilical vein endothelial cells (HUVECs). HUVECs were transfected with a miR‐599 mimic and negative control, and then exposed to LPS. The expression of miR‐599 was detected by quantitative real time‐polymerase chain reaction (RT‐qPCR). Cell viability was analyzed by CCK‐8 assay and trypan blue exclusion assay; the formation of DNA fragments was tested by Cell Death Detection ELISA Plus kit; the incidence of apoptosis was detected by flow cytometry; the expression of p53 and cleaved‐caspase 3 (c‐caspase 3) was evaluated by western blot. Moreover, the mRNA levels and concentrations of tumour necrosis factor (TNF)‐α, interleukin (IL)‐6, ICAM‐1 and VCAM‐1 were assayed by RT‐qPCR and ELISA. The results showed that overexpression of miR‐599 increased cell viability, reduced DNA fragments, the incidence of apoptosis, as well as the protein levels of p53 and c‐caspase 3 in the presence of LPS. TNF‐α, IL‐6, ICAM‐1 and VCAM‐1 mRNA levels and concentrations were also decreased upon miR‐599 upregulation. In addition, the dual luciferase reporter assay demonstrated that ROCK1 is a direct target of miR‐599. MiR‐599 overexpression inhibited ROCK1 expression. Induced expression of ROCK1 reversed the roles of miR‐599 in apoptosis and inflammation. The gain function of miR‐599 function inhibited activation of the JAK2/STAT3 signalling pathway, which was abrogated by overexpression of ROCK1. Taken together, our results indicate that miR‐599 attenuates LPS‐caused cell apoptosis and inflammatory responses through the JAK2/STAT3 signalling pathway via targeting ROCK1.
Characterization of B cell‐mediated PD‐1/PD‐L1 interaction in pancreatic cancer patients
Authors: Tong Da‐Nian , Guan Jiao , Sun Jian‐Hua , Zhao Chong‐Yue , Chen Shi‐Geng , Zhang Zheng‐Yun , Zhou Zun‐Qiang
Published: April 2020

Pancreatic ductal adenocarcinoma (PDAC) is a common type of pancreatic cancer with one of the worst survival rate of all malignancies. Recent studies have identified that immunosuppressive B cells could employ the PD‐1/PD‐L1 pathway to suppress antitumour T cell responses; hence, we examined the expression and function of PD‐L1 in B cells. We found that the PD‐L1 expression was significantly enriched in tumour‐infiltrating (TI) B cells than in peripheral blood (PB) B cells from the same patients. Additionally, the PB B cells from stage III and stage IV PDAC patients presented significantly higher PD‐L1 than the PB B cells from healthy controls. High PD‐L1 expression in PB B cells could be achieved by stimulation via CpG and less effectively via anti‐BCR plus CD40L, but not by coculture with pancreatic cancer cell lines in vitro. Also, STAT1 and STAT3 inhibition significantly suppressed PD‐L1 upregulation in stimulated B cells. CpG‐stimulated PB B cells could inhibit the IFN‐γ expression and proliferation of CD8 T cells in a PD‐L1‐dependent manner. Also, TI CD8 T cells incubated with whole TI B cells presented significantly lower IFN‐γ expression and lower proliferation, than TI CD8 T cells incubated with PD‐L1+ cell‐depleted TI B cells, suggesting that PD‐L1+ B cells could also suppress CD8 T cells in the tumour. Overall, this study identified that B cells could suppress CD8 T cells via PD‐L1 expression, indicating a novel pathway of immuno‐regulation in pancreatic cancer.
Managing and Measuring Emergency Department Care: Results of the Fourth Emergency Department Benchmarking Definitions Summit
Authors: Yiadom Maame Y. A. B. , Napoli Anthony , Granovsky Michael , Parker Rebecca B. , Pilgrim Randy , Pines Jesse M. , Schuur Jeremiah , Augustine James , Jouriles Nicholas , Welch Shari
Published: April 2020

Background

A shared language and vocabulary are essential for managing emergency department (ED) operations. This Fourth Emergency Department Benchmarking Alliance (EDBA) Summit brought together experts in the field to review, update, and add to key definitions and metrics of ED operations.

Objective

Summit objectives were to review and revise existing definitions, define and characterize new practices related to ED operations, and introduce financial and regulatory definitions affecting ED reimbursement.

Methods

Forty‐six ED operations, data management, and benchmarking experts were invited to participate in the EDBA summit. Before arrival, experts were provided with documents from the three prior summits and assigned to update the terminology. Materials and publications related to standards of ED operations were considered and discussed. Each group submitted a revised set of definitions prior to the summit. Significantly revised, topical, or controversial recommendations were discussed among all summit participants. The goal of the in‐person discussion was to reach consensus on definitions. Work group leaders made changes to reflect the discussion, which was revised with public and stakeholder feedback.

Results

The entire EDBA dictionary was updated and expanded. This article focuses on an update and discussion of definitions related to specific topics that changed since the last summit, specifically ED intake, boarding, diversion, and observation care. In addition, an extensive new glossary of financial and regulatory terminology germane to the practice of emergency medicine is included.

Conclusions

A complete and precise set of operational definitions, time intervals, and utilization measures is necessary for timely and effective ED care. A common language of financial and regulatory definitions that affect ED operations is included for the first time. This article and its companion dictionary should serve as a resource to ED leadership, researchers, informatics and health policy leaders, and regulatory bodies.
Radiography and computed tomography of the heart and lower respiratory tract in toco toucans (Ramphastos toco)
Authors: da Silva Jeana Pereira , Rahal Sheila Canevese , Castiglioni Maria Cristina Reis , Baldissera Gonçalves Raphael Augusto , Doiche Danuta Pulz , Moresco Anneke , Mamprim Maria Jaqueline , Vulcano Luiz Carlos
Published: April 2020

This study aimed to evaluate normal features of the heart and lower respiratory tract in toco toucans by means of radiography and helical computed tomography (CT) scanner. Fifteen healthy adult toco toucans (Ramphastos toco), 10 females and 5 males, average body mass of 650 g were studied. CT examination as well as right lateral and ventrodorsal radiographic examinations of the coelomic cavity were performed under chemical restraint. Heart, lungs, air sacs, trachea and syrinx were analysed. The mean values of heart length, heart width and thoracic cavity in radiographs were, respectively, 23.76 mm, 25.94 mm and 48.87 mm. In both X‐rays and CT scans, the lung parenchyma had honeycomb‐like pattern. The topographic areas of the anterior and posterior air sacs were visualized as dark and air‐filled spaces in X‐rays. On CT evaluation, the air sacs occupied a larger area in the coelomic cavity compared to X‐ray. In the lateral radiographic view, the cervical part of the trachea was positioned more ventrally in the transition from cervical to thoracic regions showing a V‐shaped appearance. In all CT planes was visible division of the trachea into the right and left main bronchi at the level of 3rd thoracic vertebra. The syrinx was difficult to visualize in X‐rays, but on CT it was easily identified in axial slice. In conclusion, the normal features of toco toucan's heart and lower respiratory tract that were determined on X‐rays and CT scans are useful to compare with sick toco toucans, as well as other bird species.
Intrauterine perfusion immunotherapies in recurrent implantation failures: Systematic review
Authors: Cavalcante Marcelo Borges , Cavalcante Candice Torres de Melo Bezerra , Sarno Manoel , Barini Ricardo
Published: April 2020

Studies have investigated the gestational outcomes of new immunological therapies in the treatment of patients with recurrent implantation failure (RIF) in assisted reproductive technology (ART). The objective of this article is to assess the current state of evidence available in the literature on intrauterine perfusion immunotherapies in women undergoing ART treatments. By considering the guidelines of Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA), the authors performed systematic review by searching the databases of PubMed/MEDLINE and Scopus using the following key words: “recurrent implantation failure,” “intrauterine infusion,” “Platelet‐Rich Plasma (PRP),” “Peripheral Blood Mononuclear Cells (PBMC),” “Granulocyte Colony‐Stimulating Factor (G‐CSF),” and “Human Chorionic Gonadotropin (hCG).” The authors analyzed the indications and the impact of new immunological therapies with intrauterine infusions on the pregnancy outcomes of patients undergoing ART. PRP, PBMC, G‐CSF, and hCG were the four most used immunological therapies with intrauterine infusion. These new therapies appear to improve the results of ART treatments in cases of RIF. However, the small number of studies does not allow definitive conclusions about the effectiveness of these therapies.
IgE to epitopes of Ara h 2 enhance the diagnostic accuracy of Ara h 2‐specific IgE
Authors: Santos Alexandra F. , Barbosa‐Morais Nuno L. , Hurlburt Barry K. , Ramaswamy Sneha , Hemmings Oliver , Kwok Matthew , O’Rourke Colin , Bahnson Henry T. , Cheng Hsiaopo , James Louisa , Gould Hannah J. , Sutton Brian J. , Maleki Soheila J. , Lack Gideon
Published: April 2020

Background

Understanding the discrepancy between IgE sensitization and allergic reactions to peanut could facilitate diagnosis and lead to novel means of treating peanut allergy.

Objective

To identify differences in IgE and IgG4 binding to peanut peptides between peanut‐allergic (PA) and peanut‐sensitized but tolerant (PS) children.

Methods

PA (n = 56), PS (n = 42) and nonsensitized nonallergic (NA, n = 10) patients were studied. Synthetic overlapping 15‐mer peptides of peanut allergens (Ara h 1‐11) were spotted onto microarray slides, and patients’ samples were tested for IgE and IgG4 binding using immunofluorescence. IgE and IgG4 levels to selected peptides were quantified using ImmunoCAP. Diagnostic model comparisons were performed using likelihood‐ratio tests between each specified nominal logistic regression models.

Results

Seven peptides on Ara h 1, Ara h 2, and Ara h 3 were bound more by IgE of PA compared to PS patients on the microarray. IgE binding to one peptide on Ara h 5 and IgG4 binding to one Ara h 9 peptide were greater in PS than in PA patients. Using ImmunoCAP, IgE to the Ara h 2 peptides enhanced the diagnostic accuracy of Ara h 2‐specific IgE. Ratios of IgG4/IgE to 4 out of the 7 peptides were higher in PS than in PA subjects.

Conclusions

Ara h 2 peptide‐specific IgE added diagnostic value to Ara h 2‐specific IgE. Ability of peptide‐specific IgG4 to surmount their IgE counterpart seems to be important in established peanut tolerance.