The early life immune dynamics and cellular drivers at single-cell resolution in lamb forestomachs and abomasum

Background Four-chambered stomach including the forestomachs(rumen,reticulum,and omasum)and abomasum allows ruminants convert plant fiber into high-quality animal products.The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants,especially the immune development.However,the dynamics of immune development are poorly understood.Results We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep,at 5,10,15,and 25 days of age.We found that forestomachs share similar gene expression patterns,all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25,whereas the metabolic function were significantly downregulated with age.We constructed a cell landscape of the four-chambered stomach using single-cell sequencing.Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells,monocytes and macrophages,as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues.Moreover,the non-immune cells such as epithelial cells play key roles in immune maturation.Cell communication analysis predicted that in addition to immune cells,non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs.Conclusions Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life.We also identified the gene expression patterns and functional cells associated with immune development.Additionally,we identified some key receptors and signaling involved in immune regulation.These results help to understand the early life immune development at single-cell resolution,which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.

Early life migration and population discrimination of the small yellow croaker Larimichthys polyactis from the Yellow Sea: inferences from otolith Sr/Ca ratios

The small yellow croaker Larimichthys polyactis is a benthic marine fish species of high ecological and commercial importance and is widely distributed in the northwestern Pacifi c Ocean,especially in the Chinese coastal waters of the Bohai,Yellow,and East China Seas.As a highly migratory species,the whole life migration of L.polyactis has been intensively studied.However,knowledge about its early life migration is scarce,and population divisions are inconsistent,limiting the ability of fishery scientists and administrators to evaluate the design and potential benefits of thorough conservation and resource-management strategies.In the present study,otolith Sr/Ca was analyzed to investigate the early migratory patterns and discriminate the populations of L.polyactis in the Yellow Sea,including two spawning groups and one overwintering group.The variation in Sr/Ca ratios of ontogenetic growth zones,including the nucleus(N),larval(L),metamorphosis(M),juvenile(J),and edge(E)zones,was measured by electron probe microanalysis.The variation in Sr/Ca ratios in early developmental growth zones was generally characterized by an evident downward trend from the N to J zone,which suggests that the early migratory pattern of L.polyactis might be from inshore to nearshore water.Canonical discriminant analysis,based on the otolith Sr/Ca ratios of the N,L,M,and J zones,allowed the successful discrimination of the two populations,namely,the northern and southern Yellow Sea groups,whose diff erences were mainly reflected in the L and J zones.Compared with previous studies,the traditional geographic boundaries(34°N)separating these two populations might be moving northward.The application of otolith Sr/Ca ratios based on ontogenetic stage could improve our understanding of the migration and population discrimination of L.polyactis from the Yellow Sea.

Early Life Stress as Factor for Use of Psychoactive Substances: Integrative Review

Purpose: To identify, analyze and synthetize the scientific evidences that support Early Life Stress (ELS) diagnosis using the Childhood Trauma Questionnaire (CTQ), since it assumes the use of psychoactive substances later in adolescence and adulthood. Individuals that experienced some form of childhood stress may present, in adulthood, consequences that manifest into mental disorders such as problematic use of psychoactive substances. Methods: An integrative review of the literature on the subject in the databases: PubMed, Web of Science, LILACS and Psycinfo, regards studies that have been indexed in the last ten years (2003-2014). Combination of controlled and uncontrolled factors in the use and abuse of psychoactive substances, CTQ and ELS adapted to each database. Findings: The alcohol was the most used drug by the participating subjects of these research;mostly, the use of psychoactive drugs, started when they were still in adolescence;ELS and the later use of psychoactive drugs can be found more frequently in female;the lack of internal resources for dealing with stress in adulthood after ELS occurrence may have as a consequence the use of psychoactive drugs as a coping mechanism. Conclusions: It was possible to identify scientific evidences that support the ELS diagnosis, measured by the CTQ, as a determining factor for the use and abuse of alcohol and/or other psychoactive drugs in adolescence and adulthood. Implications: Investigate the ELS as a strategy to improve the therapeutic project of patients in nursing care, which will be built based on scientific evidence, so it can be more effective.

Early life history affects fish size mainly by indirectly regulating the growth during each stage:a case study in a demersal fish

The complex life histories of demersal fishes are artificially separated into multiple stages along with changes in morphology and habitat.It is worth exploring whether the phenotypes expressed earlier and later during the life cycle are related or decoupled.The life stages of first year Pacific cod(Gadus macrocephalus)were tracked over different hatch years and regions to test whether the early life history had a long-lasting effect on subsequent growth.We further explored the contribution of growth in the early and subsequent life history stages to body size at the end of each stage.In addition to the accessory growth centre and the first annual ring,the other two checks on the otolith possibly related to settlement and entering deeper waters were identified in 75 Pacific cod individuals.The direct and indirect relationships among the life history stages was interpreted based on path analysis.The results showed that growth prior to the formation of the accessory growth centre had a significant effect on the absolute growth of the fish before and after settlement and migration to deep water.However,there was no or moderate evidence that early growth affected the body size at each stage,which was mainly regulated by growth during the stage.This study supports the lasting effect of early growth and clarifies that it affects size mainly by indirectly regulating staged growth.Quantifying the phenotype relationships and identifying the internal mechanisms form the basis for assessing population dynamics and understanding the processes behind the changes.

DNA Methylation,Behavior and Early Life Adversity

The impact of early physical and social environments on life-long phenotypes is well known. Moreover, we have documented evidence for gene-environment interactions where identical gene variants are associated with different phenotypes that are dependent on early life adversity. What are the mechanisms that embed these early life experiences in the genome？ DNA methylation is an enzymatically- catalyzed modification of DNA that serves as a mechanism by which similar sequences acquire cell type identity during cellular differentiation and embryogenesis in the same individual. The hypothesis that will be discussed here proposes that the same mechanism confers environmental-exposure specific identity upon DNA providing a mechanism for embedding environmental experiences in the genome, thus affecting long-term phenotypes. Particularly important is the environment early in life including both the prenatal and postnatal social environments.

Atmospheric and Oceanic Oxygenation and Evolution of Early Life on Earth: New Contributions from China

The buildup of oxygen in the Earth＇s atmosphere and oceans has fundamentally reshaped the dynamics of nearly all major biogeochemical cycles and ultimately paved the way for the diversification of complex life on Earth. Over the past decades there have been sustained efforts to develop a more comprehensive understanding of ocean-atmosphere redox evolution and its relationship to the evolution of early life （Fig. 1）. It is generally accepted that the development of oxygenic photosynthesis at ~2.7 Ga may have been responsible for the Great Oxidation Event （GOE） at the beginning of the Proterozoic Eon, whereas a second big O2 rise at the end of the Proterozoic Eon （the so-called Neoproterozoic Oxidation Event or NOE） was responsible for the diversification of metazoans （Lyons et al., 2014）.

Estrogenic effects of water from the Yangtze River (Nanjing section) on goldfish (Carassius auratus) after an early life stage exposure

Effects of river water from the Yangtze River （Nanjing section） on fish development, vitellogenin （VTG） induction, gonado-somatic index （GSI） and sex ratio were investigated by exposing goldfish （Carassius auratus） in the early life stage （from fertilization to 28 days post-hatch） to water samples （25%, 50% and 100%） collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control （P 0.05）. Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors （CF） of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control （P 0.05）. VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female：male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section （53：47, 56：44 and 54：46, respectively）, but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River （Nanjing section） had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.

Australian Scientists Find New Evidence of Early Life

地球上最早的生命究竟是什么?这是一个长期困扰生物学家的问题。现在,一项新的发现刷“旧”了我们先前所知的生命出现的年代。通过对海底化石的研究,科学家们把生命在地球上出现的时间前移了27亿年。更吸引人的是,生命竟然诞生在沸水里！

Early life adversity as a risk factor for cognitive impairment and Alzheimer’s disease

Neurological conditions,including cognitive impairment and Alzheimer’s disease(AD),impose a huge burden on society,affecting millions of people globally.In addition to genetic factors,recent studies indicate that environmental and experiential factors may contribute to the pathogenesis of these diseases.Early life adversity(ELA)has a profound impact on brain function and health later in life.In rodent models,exposure to ELA results in specific cognitive deficits and aggravated AD pathology.Extensive concerns have been raised regarding the higher risk of developing cognitive impairments in people with a history of ELA.In this review,we scrutinize findings from human and animal studies focusing on the connection of ELA with cognitive impairment and AD.These discoveries suggest that ELA,especially at early postnatal stages,increases susceptibility to cognitive impairment and AD later in life.In terms of mechanisms,ELA could lead to dysregulation of the hypothalamus-pituitary-adrenal axis,altered gut microbiome,persistent inflammation,oligodendrocyte dysfunction,hypomyelination,and aberrant adult hippocampal neurogenesis.Crosstalks among these events may synergistically contribute to cognitive impairment later in life.Additionally,we discuss several interventions that may alleviate adverse consequences of ELA.Further investigation into this crucial area will help improve ELA management and reduce the burden of related neurological conditions.

The succession of fecal bacterial community and its correlation with the changes of serum immune indicators in lambs from birth to 4 months

Early bacterial colonization and succession within the gastrointestinal tract have been suggested to be crucial in the development of host immunity.In this study,we have investigated the changes in live weight and concentrations of selected serum parameters in relation to their fecal bacterial communities as determined by high throughput sequencing of the 16S r RNA gene over the same period in lambs.The results showed that lambs’growth performance,the serum parameters,fecal bacterial community and fecal bacterial functions were all affected(P<0.05)by age of the lambs.Similarity within age groups of fecal microbiota was lower in the preweaning period and increased sharply(P<0.05)after weaning at 60 days.The similarity between the samples collected from birth to 90 days of age and those collected at 120 days of age,increased(P<0.05)sharply after 30 days of age.Some age-associated changes in microbial genera were correlated with the changes in concentrations of immune indicators,including negative(P<0.05)correlations between the relative abundance of Lachnospiraceae UCG-010,Eubacterium coprostanoligenes group,Ruminococcaceae UCG-005,Ruminococcaceae UCG-009,Ruminococcaceae UCG-013,Ruminiclostridium 6,Ruminococcaceae UCG-008,and Oscillibacter with serum concentrations of lipopolysaccharide(LPS),D-lactate dehydrogenase(DLA),immunoglobulin(IgA,IgM,and IgG),and cytokines(interleukin-1β(IL-1β),IL-6,IL-12,and IL-17),tumor necrosis factor-α(TNF-α),and the relative abundance of these genera increased from 45 days of age.In conclusion,these results suggested that the age-related abundances of particular genera were correlated with serum markers of immunity in lambs,and there might be a critical window in the period from birth to 45 days of age which provide an opportunity for potential manipulation of the fecal microbial ecosystems to enhance immune function.

Simulation of the distribution,growth,and survival rate of chub mackerel larvae and juveniles in the East China Sea

In the East China Sea(ECS),chub mackerel Scomber japonicus constitutes an important coastal-pelagic fishery resource that is mainly exploited by Chinese,Japanese,and Korean light-purse seine fisheries.Because the early life history of chub mackerel plays a significant role in its recruitment,we developed an individual-based model to study the distribution,growth,and survival rate of chub mackerel larvae and juveniles in the ECS to improve our understanding of the chub mackerel population structure and recruitment.Our results show that as body length rapidly increases,the swimming capacity of chub mackerel larvae and juveniles improves quickly,and their spatial distribution depends more on their habitat conditions than the ocean currents.Correspondingly,the juveniles from the central and southern ECS spawning ground are scarcely recruited into the Japan/East Sea(JES)or the western Pacific Ocean,but a significant proportion of juveniles from the northern ECS spawning ground still enter the JES and there are exchanges between the stocks in the ECS and JES.Thus,it seems more reasonable to assess and manage the chub mackerels in the ECS and JES as a stock.The water temperature and ocean primary production in the ECS are two important factors influencing the chub mackerel habitat conditions and their spatial and temporal distribution are significantly different as the spawning time changes.Therefore,the spawning time and location play an important role in the growth and survival rate of the larvae and juveniles.Generally,when chub mackerel spawns at the southern ECS spawning ground in March,the larva and juvenile growth and survival rate is relatively high;as spawning time moves forward,higher growth and survival rates would be expected for the chub mackerel spawned coastward or northward.For specific spawning sites,early or delayed spawning will reduce the survival rate.

Potential roles of the rectum keystone microbiota in modulating the microbial community and growth performance in goat model

Background Ruminal microbiota in early life plays critical roles in the life-time health and productivity of ruminant animals.However,understanding of the relationship between gut microbiota and ruminant phenotypes is very limited.Here,the relationship between the rectum microbiota,their primary metabolites,and growth rate of a total of 76 young dairy goats(6-month-old)were analyzed,and then 10 goats with the highest or lowest growth rates respectively were further compared for the differences in the rectum microbiota,metabolites,and animal’s immune parameters,to investigate the potential mechanisms by which the rectum microbiota contributes to the health and growth rate.Results The analysis of Spearman correlation and microbial co-occurrence network indicated that some keystone rectum microbiota,including unclassified Prevotellaceae,Faecalibacterium and Succinivibrio,were the key modulators to shape the rectum microbiota and closely correlated with the rectum SCFA production and serum IgG,which contribute to the health and growth rate of young goats.In addition,random forest machine learning analysis suggested that six bacterial taxa in feces could be used as potential biomarkers for differentiating high or low growth rate goats,with 98.3%accuracy of prediction.Moreover,the rectum microbiota played more important roles in gut fermentation in early life(6-month-old)than in adulthood stage(19-month-old)of goats.Conclusion We concluded that the rectum microbiota was associated with the health and growth rate of young goats,and can be a focus on the design of the early-life gut microbial intervention.

Viruses and autism: A Bi-mutual cause and effect

Autism spectrum disorder(ASD)is a group of heterogeneous,multi-factorial,neurodevelopmental disorders resulting from genetic and environmental factors interplay.Infection is a significant trigger of autism,especially during the critical developmental period.There is a strong interplay between the viral infection as a trigger and a result of ASD.We aim to highlight the mutual relationship between autism and viruses.We performed a thorough literature review and included 158 research in this review.Most of the literature agreed on the possible effects of the viral infection during the critical period of development on the risk of developing autism,especially for specific viral infections such as Rubella,Cytomegalovirus,Herpes Simplex virus,Varicella Zoster Virus,Influenza virus,Zika virus,and severe acute respiratory syndrome coronavirus 2.Viral infection directly infects the brain,triggers immune activation,induces epigenetic changes,and raises the risks of having a child with autism.At the same time,there is some evidence of increased risk of infection,including viral infections in children with autism,due to lots of factors.There is an increased risk of developing autism with a specific viral infection during the early developmental period and an increased risk of viral infections in children with autism.In addition,children with autism are at increased risk of infection,including viruses.Every effort should be made to prevent maternal and early-life infections and reduce the risk of autism.Immune modulation of children with autism should be considered to reduce the risk of infection.

Involvement of toll-like receptor 5 in mouse model of colonic hypersensitivity induced by neonatal maternal separation

BACKGROUND Chronic abdominal pain is the most common cause for gastroenterology consultation and is frequently associated with functional gastrointestinal disorders including irritable bowel syndrome and inflammatory bowel disease. These disorders present similar brain/gut/microbiota trialogue alterations, associated with abnormal intestinal permeability, intestinal dysbiosis and colonic hypersensitivity(CHS). Intestinal dysbiosis can alter colon homeostasis leading to abnormal activation of the innate immunity that promotes CHS, perhaps involving the toll-like receptors(TLRs), which play a central role in innate immunity.AIM To understand the mechanisms between early life event paradigm on intestinal permeability, fecal microbiota composition and CHS development in mice with TLRs expression in colonocytes.METHODS Maternal separation model(NMS) CHS model, which mimics deleterious events in childhood that can induce a wide range of chronic disorders during adulthood were used. Colonic sensitivity of NMS mice was evaluated by colorectal distension(CRD) coupled with intracolonic pressure variation(IPV) measurement. Fecal microbiota composition was analyzed by 16S rRNA sequencing from weaning to CRD periods. TLR mRNA expression was evaluated in colonocytes.Additionally, the effect of acute intrarectal instillation of the TLR5 agonist flagellin(FliC) on CHS in adult naive wildtype mice was analyzed.RESULTS Around 50% of NMS mice exhibited increased intestinal permeability and CHS associated with intestinal dysbiosis, characterized by a significant decrease of species richness, an alteration of the core fecal microbiota and a specific increased relative abundance of flagellated bacteria. Only TLR5mRNA expression was increased in colonocytes of NMS mice with CHS. Acute intrarectal instillation of FliC induced transient increase of IPV, reflecting transient CHS appearance.CONCLUSION Altogether, these data suggest a pathophysiological continuum between intestinal dysbiosis and CHS, with a role for TLR5.

Music in depression: Neural correlates of emotional experience in remitted depression

AIM: To investigate neural and behavioral correlates of emotional experiences as potential vulnerability markers in remitted depression. METHODS: Fourteen remitted participants with a history of major depression and fourteen closely matched healthy control participants took part in the study. We used two psychiatric interviews(Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale) and one self-report scale(Beck Depression Inventory) to assess remission. Healthy control participants were interviewed by an experienced psychiatrist to exclude those who showed any current or lifetime psychiatric or neurological disorders. To explore psychosocialand cognitive-interpersonal underpinnings of potential vulnerability markers of depression, early life stress, coping styles and alexithymia were also assessed. We induced pleasant and unpleasant emotional states using congruent combinations of music and human emotional faces to investigate neural and behavioral correlates of emotional experiences; neutral stimuli were used as a control condition. Brain responses were recorded using functional magnetic resonance imaging. Behavioral responses of pleasantness, arousal, joy and fear were measured via button-press inside the resonance imaging scanner. RESULTS: The mean age of the sample was 54.9(± 11.3) years. There were no differences between remitted depressed(RD)(n = 14; 9 females and 5 males) and healthy participants(n = 14; 8 females and 6 males) regarding age, current degree of depression, early life stress, coping styles and alexithymia. On a neural level, RD participants showed reduced activations in the pregenual anterior cingulate cortex(pg ACC) in response to pleasant [parameter estimates:-0.78 vs 0.32; t(26) =-3.41, P < 0.05] and unpleasant [parameter estimates:-0.88 vs 0.56; t(26)=-4.02, P < 0.05] emotional stimuli. Linear regression analysis revealed that pg ACC activity was modulated by early life stress [β =-0.48; R2 = 0.23, F(1,27) = 7.83, P < 0.01] and taskoriented coping style [β = 0.63; R2 = 0.37, F(1,27) = 16.91, P < 0.001]. Trait anxiety modulated hippocampal responses to unpleasant stimuli [β = 0.62; R2= 0.38, F(1,27) = 15.95, P < 0.001]. Interestingly, in their reported experiences of pleasantness, arousal, happiness and fear in response to pleasant, unpleasant and neutral stimuli, RD participants did not differ significantly from healthy control participants. Adding trait anxiety or alexithymia as a covariate did not change the results.CONCLUSION: The present study indicates that, in euthymic individuals, depression history alters neural correlates, but not the subjective dimension of pleasant and unpleasant emotional experiences.

Prey life stages modulate effects of predation stress on prey lifespan,development,and reproduction in mites

The non-consumptive effects of predator-induced stress can influence a variety of life-history traits.Many previous studies focused only on short-term effects such as development and reproductive rates.Recent studies have showed that long-term predation stress(given during the whole life of the prey)and short-term predation stress(provided during the immature stage of the prey)could generate completely opposite results:the former could decrease lifespan,whereas the later could increase lifespan.However,it is still unclear whether the advantage is because of the short duration of exposure or the early stage of life during which exposure was exerted.Thus,in this study,the prey(Tyrophagus putrescentiae)was exposed to predation stress from the predator(Neoseiulus cucumeris)during different life stages(larva,protonymph,tritonymph,first 5 d of oviposition,the full lifespan or none of the above).The results showed that the predation stress supplied during larval and protonymphal stage delayed development,reduced fecundity and prolonged lifespan of the prey,while the stress given during tritonymphal stage only reduced lifespan slightly and the stress given during the first 5 d of oviposition did not change lifespan but reduced fecundity.This study indicated that the effects of predation stress are dependent on prey life stage and the predation stress experienced in the early life stages is important to lifespan modulation.

Assessment of Ozone or Not-Treated Wastewater Ecotoxicity Using Mechanism-Based and Zebrafish Embryo Bioassays

Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more adapted tests. The present work aimed to add the recording of several sub-lethal endpoints in exposed zebrafish embryo-larval stages in order to increase the sensitivity of residual toxicity evaluation of WWTP effluents using a semi-quantitative method (iFET score). This approach was complemented with the genotoxicity assessment on the exposed embryos, a sub-acute hazard particularly relevant to evaluate a potential chronic toxicity risk of low and multi-contaminated environmental matrices. Additionally, endocrine activities of effluents were quantified using human reporter cell lines. This test battery was applied to the assessment of the residual toxicity of five biological treatment effluents, further treated or not using various ozonation treatments intended to improve pharmaceutical compounds removal. Acute toxicity towards zebrafish embryos was very low. However, iFET score approach proposed was able to reveal residual toxicity through the presence of developmental abnormalities in all samples tested. Additionally, a low residual genotoxicity was measured in embryos exposed to two of the WWTP effluents when all excepted one exhibited a residual endocrine activity potential in the ng/L range providing complementary information on the occurrence of endocrine active chemicals and their reduction by different processes. To sum up, such a simplified and ecologically relevant test battery was found sensitive enough to characterize and differentiate various residual effluent’s ecotoxicity at contaminant levels of environmental concern.

Epigenetic clocks in the pediatric population:when and why they tick?

Recent research efforts have provided compelling evidence of genome-wide DNA methylation alterations in pediatrics.It is currently well established that epigenetic clocks,composed of DNA methylation sites,can estimate the gestational and chronological age of cells and tissues from different ages.Also,extensive research is aimed at their correlation with early life exposure and pediatric diseases.This review aimed to systematically summarize the epigenetic clocks in the pediatric population.Publications were collected from PubMed and Web of Science databases up to Apr 2021.Epigenetic clocks,DNA methylation clocks,epigenetic age acceleration or deceleration,pediatric and the pediatric population were used as search criteria.Here,we first review the currently applicative pediatric epigenetic clocks.We then highlight the interpretation for epigenetic age deviations in the pediatric population and their association with external factors,developmental trajectories,and pediatric diseases.Considering the remaining unknown of pediatric clocks,research strategies into them are also discussed.In all,pediatric epigenetic clocks may act as potent tools to understand development,growth and diseases in early life.

Plastic ingestion and associated additives in Faroe Islands chicks of the Northern Fulmar Fulmarus glacialis

Northern Fulmars(Fulmarus glacialis)are a pelagic seabird species distributed at northern and polar latitudes.They are often used as an indicator of plastic pollution in the North Sea region,but data are lacking from higher latitudes,especially when it comes to chicks.Here,we investigated amounts of ingested plastic and their characteristics in fulmar chicks from the Faroe Islands.Plastic particles(≥1 mm)in chicks of two age classes were searched using a digestion method with KOH.In addition,to evaluate if additive tissue burden reflects plastic ingestion,we measured liver tissue concentrations of two pollutant classes associated with plastic materials:polybrominated diphenyl ethers(PBDEs)and several dechloranes,using gas chromatography with high-resolution mass spectrometry.The most common shape was hard fragment(81%)and the most common polymer was polyethylene(73%).Plastic contamination did not differ between either age class,and we found no correlation between neither the amount and mass of plastic particles and the concentration of additives.After comparison with previous studies on adult fulmars,we do not recommend using chicks for biomonitoring adults because chicks seem to ingest more plastics than adults.