Key Life Stages Research Articles

Accelerating Research on Chemical Exposures and Child Health Outcomes through ECHO: An Overview

Background: The Environmental Influences on Child Health Outcomes (ECHO) program is a seven-year U.S. National Institutes of Health initiative launched in 2016 to advance knowledge of the effects of a broad range of environmental exposures on child health and development.Objective: To provide an overview of the ECHO program as it relates to understanding relationships between early life chemical exposures and child health outcomes.Methods: We overview ongoing efforts related to chemical exposures and child health outcomes in ECHO by describing existing chemical exposure information and plans for new data collection.Results: ECHO’s observational component leverages data from 84 extant longitudinal cohorts with more than 50,000 children from diverse backgrounds across 44 states, Puerto Rico, and the District of Columbia. The earliest cohort enrolled participants beginning in the 1980s while others have ongoing enrollment. Most cohorts began recruitment during gestation and all cohorts follow children longitudinally and collect biospecimens. ECHO includes working groups dedicated to chemical exposures as well as five outcome focus areas: 1) pre-, peri- and postnatal outcomes; 2) obesity and its consequences; 3) upper and lower airway conditions; 4) neurodevelopment; and 5) positive health. Existing chemical exposures data already collected by some ECHO cohorts includes chemical biomonitoring data, estimates of outdoor air pollution or geographic proxies of air pollution, environmental or personal exposure monitoring, and questionnaire data. In addition, all ECHO cohorts will contribute certain existing and new data as part of the ECHO-wide Cohort data collection protocol, including biospecimens and exposure questionnaires at key life stages of development.Conclusion: By combining rich, longitudinal data with team science approaches, ECHO will accelerate novel and policy-oriented research to address complex environmental health questions.

Balancing resource protection and fishing activity: The case of the European hake in the northern Iberian Peninsula

AbstractOne of the fundamental aims of the Ecosystem Approach to Fisheries Management is to ensure the long‐term sustainability of the fishery by protecting key life‐cycle habitats, such as recruitment areas. In this study, we apply a hurdle Bayesian hierarchical spatio‐temporal model that describes the abundance of European hake (Merluccius merluccius) recruits in the northern continental shelf of the Iberian Peninsula. Our findings clearly show four persistent nurseries, the main one being located along the continental shelf of the Artabrian gulf (off La Coruña). The preferential habitats identified for the hake recruits are areas within a bathymetric range of 120–200 m, with 15–16°C of Sea Surface Temperature, a Chl‐a concentration of 0.8–1.2 mg/m3 and low values of seabed rugosity (unconsolidated substrates). Searching for a compromise with fisheries, we also assess the degree of overlap of the main nursery areas with two fisheries footprints, a local one using Vessel Monitoring System data of trawl fishery of Marín, and a global one using Automatic Identification System data of different type of trawlers (bottom otter, beam and midwater trawls). The two fisheries footprints present different degree of overlapping in distinct areas, highlight the need of specific fleet‐adapted management rules in order to protect juvenile stages. We discuss that understanding the distributional patterns associated with key life stages, such as recruitment, and their interaction with fishing activities, is essential for applying appropriate spatial management measures and improving fishery sustainability.

In vivo effects of 17α-ethinylestradiol, 17β-estradiol and 4-nonylphenol on insulin-like growth-factor binding proteins (igfbps) in Atlantic salmon

Feminizing endocrine disrupting compounds (EDCs) affect the growth and development of teleost fishes. The major regulator of growth performance, the growth hormone (Gh)/insulin-like growth-factor (Igf) system, is sensitive to estrogenic compounds and mediates certain physiological and potentially behavioral consequences of EDC exposure. Igf binding proteins (Igfbps) are key modulators of Igf activity, but their alteration by EDCs has not been examined. We investigated two life-stages (fry and smolts) of Atlantic salmon (Salmo salar), and characterized how the Gh/Igf/Igfbp system responded to waterborne 17α-ethinylestradiol (EE2), 17β-estradiol (E2) and 4-nonylphenol (NP). Fry exposed to EE2 and NP for 21 days had increased hepatic vitellogenin (vtg) mRNA levels while hepatic estrogen receptor α (erα), gh receptor (ghr), igf1 and igf2 mRNA levels were decreased. NP-exposed fry had reduced body mass and total length compared to controls. EE2 and NP reduced hepatic igfbp1b1, -2a, -2b1, -4, -5b2 and -6b1, and stimulated igfbp5a. In smolts, hepatic vtg mRNA levels were induced following 4-day exposures to all three EDCs, while erα only responded to EE2 and E2. EDC exposures did not affect body mass or fork length; however, EE2 diminished plasma Gh and Igf1 levels in parallel with reductions in hepatic ghr and igf1. In smolts, EE2 and E2 diminished hepatic igfbp1b1, -4 and -6b1, and stimulated igfbp5a. There were no signs of compromised ionoregulation in smolts, as indicated by unchanged branchial ion pump/transporter mRNA levels. We conclude that hepatic igfbps respond (directly and/or indirectly) to environmental estrogens during two key life-stages of Atlantic salmon, and thus may modulate the growth and development of exposed individuals.

Grass competition overwhelms effects of herbivores and precipitation on early tree establishment in Serengeti

Abstract Savanna ecosystems span a diverse range of climates, edaphic conditions, and disturbance regimes, the complexity of which has stimulated long‐standing interest in the mechanisms that maintain tree–grass coexistence. One hypothesis suggests that tree establishment is strongly limited by one or several demographic bottlenecks at early stages of the tree life cycle. A major impediment to testing this hypothesis is the lack of data on the relative strengths of different bottlenecks across key environmental gradients. To identify demographic bottlenecks that limit early tree establishment (0–18 months), we conducted a series of transplant experiments with two savanna trees species (Acacia robusta and Acacia tortilis) across a natural rainfall and soil fertility gradient in the Serengeti ecosystem, Tanzania. We tested the interactive effects of precipitation, herbivory, seed scarification, grass competition, water limitation, and tree species identity on two key life stages: germination and early seedling survival (0–2 months), and juvenile seedling survival (2–18 months). Germination and early seedling survival increased as a function of rainfall, in the absence of herbivores and when seeds were scarified. Juvenile seedling survival, in contrast, decreased with rainfall but increased in the absence of herbivores. Grass removal had the single strongest (positive) effect on juvenile seedling survival of any treatment. Soil moisture monitoring and grass‐addition treatments revealed that grasses negatively affected seedlings in ways that were not necessarily linked to soil moisture. A demographic model combining all effects across early life stages showed that the strength of grass competition on juvenile seedling survival was the key factor limiting early tree establishment. While rainfall had an unexpected opposing effect on the two life stages, the net effect of mean annual precipitation on early tree establishment was positive. Synthesis. Successful tree establishment in Serengeti is maximized by a seemingly unlikely sequence of events: (a) scarification of seeds by browsers, (b) heavy rainfall to promote germination, (c) intensive grazing (but absence of browsers), and (d) dry conditions during juvenile seedling growth (>2 months) to reduce competition with grasses. By considering a wide suite of conditions and their interactions, our experimental results are relevant to ongoing debates about savanna vegetation dynamics and structural shifts in tree:grass ratios.

Risk of vector tick exposure initially increases, then declines through time in response to wildfire in California

AbstractIdentifying the effects of human‐driven perturbations, such as species introductions or habitat fragmentation, on the ecology and dynamics of infectious disease has become a central focus of disease ecologists. Yet, comparatively little is known about how the ecology of zoonotic disease systems responds to catastrophic disturbance events such as wildfires or hurricanes. In California, wildfire disturbance is centrally important to the ecology of forests and oak woodlands and is projected to increase in severity and extent under future climate change. Here, taking advantage of a recent wildfire as a natural experiment, we investigate the effects of wildfire disturbance on the ecology of tick‐borne disease in California oak woodlands. We find that wildfire leads to elevated abundance of questing adult and nymphal western blacklegged ticks (Ixodes pacificus) in the year following fire, relative to unburned control plots, but that vector tick abundance declines sharply in the following two years. We find that the abundance of non‐competent hosts (western fence lizards) for the Lyme disease bacterium is unaffected by fire, but that the abundances of important reproductive hosts (deer) for ticks and reservoir hosts (dusky‐footed woodrats) for tick‐borne pathogens are significantly negatively affected by fire. We found ticks and hosts infected with Borrelia burgdorferi sensu lato only within the burn extent and only in the year following the wildfire, though rates of infection were exceedingly low representing little risk to humans. In aggregate, due to the differential effects of this catastrophic disturbance event on different key host species and vector tick life stages in the transmission of tick‐borne pathogens, we conclude that wildfire may potentially increase risk of exposure to vector ticks in the first year following wildfire in California, but that risk is dampened substantially in following years due to tick population declines and loss of key reservoir hosts from the system.

Vessel sound cuts down communication space for vocalising fish and marine mammals

Anthropogenic noise across the world’s oceans threatens the ability of vocalizing marine species to communicate. Some species vocalize at key life stages or whilst foraging, and disruption to the acoustic habitat at these times could lead to adverse consequences at the population level. To explore the risk of such impacts, we investigated the effect of vessel noise on the communication space of the Bryde’s whale Balaenoptera edeni, an endangered species which vocalizes at low frequencies and bigeye Pempheris adspersa, a nocturnal fish species which uses contact calls to maintain group cohesion while foraging. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic propagation modelling, a quantitative method for determining the impact of vessel noise on their communication space was established. Routine vessel passages cut down communication space by up to 61.5% for bigeyes and 87.4% for Bryde’s whales. The influence of vessel noise on communication space also exceeded natural variability between 3.9 and 18.9% of the monitoring period. To combat potential effects of vessel sound, we propose the application or extension of ship speed restrictions in ecologically significant areas, since our results indicate a reduction in sound source levels for vessels transiting at lower speeds.

Unravelling warming sensitivity across fish coastal life-cycle stages: from cellular biology to ecological patterns

Event Abstract Back to Event Unravelling warming sensitivity across fish coastal life-cycle stages: from cellular biology to ecological patterns Diana S. Madeira1, 2*, Carolina Madeira3, Pedro M. Costa4, Catarina Vinagre3, Hans Poertner5 and Mário S. Diniz2 1 University of Aveiro, Biology, Portugal 2 Universidade Nova de Lisboa, Chemistry, Portugal 3 Universidade de Lisboa, MARE, Portugal 4 Universidade Nova de Lisboa, Life Sciences, Portugal 5 Alfred Wegener Institut Helmholtz Zentrum für Polar und Meeresforschung, Germany Accurate projections of global change impacts on biota are hampered due to the lack of eco-physiological data for the key life stages of a species. Here we experimentally tested the vulnerability of a demersal predatory fish (Sparus aurata) to ocean warming, focusing on larval, juvenile and adult life-stages that inhabit shallow coastal waters. We combined a set of organism level indicators (mortality; condition index) with cellular stress response end-points (hsp70, ubiquitin, antioxidant enzymes, lipid peroxidation and histopathology evaluation). The vulnerability of life cycle stages, defined by tissue damage and mortality can be ranked as larvae>adults >juveniles. Larvae were very sensitive to warming, showing reduced acclimation capacity that resulted in damage to muscle and kidneys and elevated mortality rates. Juvenile fish were the most resistant, inducing cyto-protective proteins that maintained the integrity of vital organs. Adults were sensitive to warming, showing greater tissue harm in vital organs (protein damage, inflammation) suggesting low plasticity. The effort to protect against thermal challenge differed between organs depending on developmental stage. The larval phase is a key developmental stage that will determine life cycle closure of demersal sea breams under projected ocean warming scenarios. Life-cycle assessments are crucial to understand global change impacts on biodiversity and improve conservation strategies. Acknowledgements MARESA, Fundação para a Ciência e a Tecnologia (FCT) [individual grants: senior researcher position to C.V. and P.M.C., SFRH/BD/80613/2011 to D.M.; SFRH/BPD/117491/2016 to D.M., SFRH/BD/92975/2013 to CM; project grants PTDC/MAR/119068/2010 and PTDC/AAG-REC/2139/2012], UCIBIO [FCT/MEC UID/Multi/04378/2013] and [POCI-01-0145-FEDER-00], MARE [FCT/MEC UID/MAR/04292/20], CESAM [FCT/MEC UID/AMB/50017/2013]. Keywords: temperature, phenotypic plasticity, Life-cycle, biomarkers, Climate Change, comparative physiology Conference: IMMR'18 | International Meeting on Marine Research 2018, Peniche, Portugal, 5 Jul - 6 Jul, 2018. Presentation Type: Poster Presentation Topic: Biodiversity, Conservation and Coastal Management Citation: Madeira DS, Madeira C, Costa PM, Vinagre C, Poertner H and Diniz MS (2019). Unravelling warming sensitivity across fish coastal life-cycle stages: from cellular biology to ecological patterns. Front. Mar. Sci. Conference Abstract: IMMR'18 | International Meeting on Marine Research 2018. doi: 10.3389/conf.FMARS.2018.06.00055 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 May 2018; Published Online: 07 Jan 2019. * Correspondence: Dr. Diana S Madeira, University of Aveiro, Biology, Aveiro, Portugal, 3830-565, Portugal, dianabmar@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Diana S Madeira Carolina Madeira Pedro M Costa Catarina Vinagre Hans Poertner Mário S Diniz Google Diana S Madeira Carolina Madeira Pedro M Costa Catarina Vinagre Hans Poertner Mário S Diniz Google Scholar Diana S Madeira Carolina Madeira Pedro M Costa Catarina Vinagre Hans Poertner Mário S Diniz PubMed Diana S Madeira Carolina Madeira Pedro M Costa Catarina Vinagre Hans Poertner Mário S Diniz Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Vessel noise cuts down communication space for vocalizing fish and marine mammals.

Anthropogenic noise across the world's oceans threatens the ability of vocalizing marine species to communicate. Some species vocalize at key life stages or whilst foraging, and disruption to the acoustic habitat at these times could lead to adverse consequences at the population level. To investigate the risk of these impacts, we investigated the effect of vessel noise on the communication space of the Bryde's whale Balaenoptera edeni, an endangered species which vocalizes at low frequencies, and bigeye Pempheris adspersa, a nocturnal fish species which uses contact calls to maintain group cohesion while foraging. By combining long-term acoustic monitoring data with AIS vessel-tracking data and acoustic propagation modelling, the impact of vessel noise on their communication space was determined. Routine vessel passages cut down communication space by up to 61.5% for bigeyes and 87.4% for Bryde's whales. This influence of vessel noise on communication space exceeded natural variability for between 3.9 and 18.9% of the monitoring period. Additionally, during the closest point of approach of a large commercial vessel, <10km from the listening station, the communication space of both species was reduced by a maximum of 99% compared to the ambient soundscape. These results suggest that vessel noise reduces communication space beyond the evolutionary context of these species and may have chronic effects on these populations. To combat this risk, we propose the application or extension of ship speed restrictions in ecologically significant areas, since our results indicate a reduction in sound source levels for vessels transiting at lower speeds.

Flexible careers across the life course: Advancing theory, research and practice

This introductory article sets out a framework for conceptualizing flexible careers. We focus on the conditions, including the institutional arrangements and the organizational policies and practices, that can support individuals to construct flexible and sustainable careers across the life course. We ask: What are flexible careers? Who are the (multiple) actors determining flexible careers? How do institutions and organizational settings impact upon and shape the career decisions and agency of individuals across the life course? We begin our review by providing a critique of career theory, notably the boundaryless and protean career concepts, which are overly agentic. In contrast, we stress the importance of institutions, notably education and training systems, welfare regimes, worker voice, working-time and leave regulations and retirement systems alongside individual agency. We also emphasize the importance of various organizational actors in determining flexible careers, particularly in relation to flexible work policies, organizational practices, culture and managerial agency. Finally we argue for the importance of a life course framing taking into account key transition points and life stages, which vary in sequence and significance, in the analysis of flexible careers. In concluding remarks, we urge researchers to use and refine our model to the concept of flexible careers conceptually and empirically.

Beyond biomass: Soil feedbacks are transient over plant life stages and alter fitness

Abstract Plants influence associated soil biotic communities that in turn can alter the performance of the subsequently growing plants. Although such “plant–soil feedbacks” (PSFs) are considered as important drivers of plant community assembly, past PSF studies have mainly addressed plant biomass production. However, plant performance is not only the production of biomass but comprises a sequence of different life stages: from seed germination over vegetative growth up to the production of a viable progeny. Here, we assessed the effects of soil biotic communities that were previously conditioned for 3 years by a focal plant species monoculture or species mixtures on key plant life stages from germination and vegetative growth to flowering and the production of viable seeds. We used three common grassland herb species that were grown in a sterile substrate and inoculated with a sterile control soil or with living soils. Living soils were conditioned either by the focal species in monoculture or a four‐ or eight‐species mixture that included the focal species to represent a decrease in the target plants’ conspecific influence on the soil communities. We show that the effect of soil biota changed from positive at the plants’ juvenile life stages to neutral or negative at the plants’ adult life stages and ultimately decreased plant fitness. A higher conspecific influence on the soil communities pronounced the positive effects at the juvenile life stage but also the negative effects at adult life stages. Further, we observed direct soil biotic effects on flower production and plant fitness that were not mediated by adult biomass production. This suggests that soil biotic effects may alter plant resource allocation and even may have transgenerational effects on plant fitness. Synthesis. We conclude that there is no overarching effect of soil biota that remains consistent at all the life stages of a plant. Thus, our results highlight the importance to consider plant life stage and ultimately plant fitness especially when plant–soil interactions are used to explain plant community dynamics.

Science Advancements Key to Increasing Management Value of Life Stage Monitoring Networks for Endangered Sacramento River Winter-Run Chinook Salmon in California

A robust monitoring network that provides quantitative information about the status of imperiled species at key life stages and geographic locations over time is fundamental for sustainable management of fisheries resources. For anadromous species, management actions in one geographic domain can substantially affect abundance of subsequent life stages that span broad geographic regions. Quantitative metrics (e.g., abundance, movement, survival, life history diversity, and condition) at multiple life stages are needed to inform how management actions (e.g., hatcheries, harvest, hydrology, and habitat restoration) influence salmon population dynamics. The existing monitoring network for endangered Sacramento River winter-run Chinook Salmon (SRWRC, Oncorhynchus tshawytscha) in California’s Central Valley was compared to conceptual models developed for each life stage and geographic region of the life cycle to identify relevant SRWRC metrics. We concluded that the current monitoring network was insufficient to diagnose when (life stage) and where (geographic domain) chronic or episodic reductions in SRWRC cohorts occur, precluding within- and among-year comparisons. The strongest quantitative data exist in the Upper Sacramento River, where abundance estimates are generated for adult spawners and emigrating juveniles. However, once SRWRC leave the upper river, our knowledge of their identity, abundance, and condition diminishes, despite the juvenile monitoring enterprise. We identified six system-wide recommended actions to strengthen the value of data generated from the existing monitoring network to assess resource management actions: (1) incorporate genetic run identification; (2) develop juvenile abundance estimates; (3) collect data for life history diversity metrics at multiple life stages; (4) expand and enhance real-time fish survival and movement monitoring; (5) collect fish condition data; and (6) provide timely public access to monitoring data in open data formats. To illustrate how updated technologies can enhance the existing monitoring to provide quantitative data on SRWRC, we provide examples of how each recommendation can address specific management issues

A material lens on socio-technical transitions: The case of steel in Australian buildings

Steel is a critical material for modern-day societies, and more than half of the world’s steel is used in buildings. As the extraction of iron ore and the production and transport of manufactured steel have significant environmental costs, the fate of steel is important for socio-technical transitions towards more sustainable materials use. Using steel in buildings as a case study socio-technical transition, this paper develops a novel application of the multi-level perspective (MLP) that adopts an explicitly material lens. We focus on the circulation of steel between three key life stages for buildings which are treated as socio-technical regimes as described in the MLP. Drawing on concepts from assemblage theory, we consider the role played by the material and expressive qualities of steel within each of these regimes. Our material focus also requires attention to the spatial dimensions of these three regimes and their implications for socio-technical transitions. We describe the nexus of material affordances and inter-scalar relations that influences the use of steel in buildings and consider the potential for change. The main contribution of this paper is to extend the MLP to incorporate a focus on materiality and, in a related way, spatiality. Based on the analysis presented we consider how steel use in Australian buildings may be rendered more sustainable.

Disentangling Genetic and Prenatal Maternal Effects on Offspring Size and Survival.

Organizational processes during prenatal development can have long-term effects on an individual's phenotype. Because these early developmental stages are sensitive to environmental influences, mothers are in a unique position to alter their offspring's phenotype by differentially allocating resources to their developing young. However, such prenatal maternal effects are difficult to disentangle from other forms of parental care, additive genetic effects, and/or other forms of maternal inheritance, hampering our understanding of their evolutionary consequences. Here we used divergent selection lines for high and low prenatal maternal investment and their reciprocal line crosses in a precocial bird-the Japanese quail (Coturnix japonica)-to quantify the relative importance of genes and prenatal maternal effects in shaping offspring phenotype. Maternal but not paternal origin strongly affected offspring body size and survival throughout development. Although the effects of maternal egg investment faded over time, they were large at key life stages. Additionally, there was evidence for other forms of maternal inheritance affecting offspring phenotype at later stages of development. Our study is among the first to successfully disentangle prenatal maternal effects from all other sources of confounding variation and highlights the important role of prenatal maternal provisioning in shaping offspring traits closely linked to fitness.

Maintaining the Japan Connection: The Impact of Study Abroad on Japanese Language Learners’ Life Trajectories and Ongoing Interaction with Japanese Speakers

This article explores the post-study abroad life trajectories of learners of Japanese. Drawing upon data collected from eight interviewees, it presents the experiences of study abroad returnees’ ongoing engagement with Japan and Japanese speakers once they were removed from the study abroad environment. In particular, it focuses on the impact of study abroad on ongoing studies and career trajectory, and examines ongoing interaction with Japanese speakers throughout these key life stages. Through the lens of possible selves theory (Markus &amp; Nurius, 1986), this study also examines how the informants’ ongoing engagement with the target language is reflected in their post-study abroad L2 self-concepts. It was found that although the experience of studying abroad in Japan presented a critical incident in each of the informants’ future life trajectories, and each of them remain connected to Japan in various ways, their patterns of engagement with Japanese speakers after returning home differed significantly.

Joint effects of habitat, zooplankton, host stage structure and diversity on amphibian chytrid.

Why does the severity of parasite infection differ dramatically across habitats? This question remains challenging to answer because multiple correlated pathways drive disease. Here, we examined habitat-disease links through direct effects on parasites and indirect effects on parasite predators (zooplankton), host diversity and key life stages of hosts. We used a case study of amphibian hosts and the chytrid fungus, Batrachochytrium dendrobatidis, in a set of permanent and ephemeral alpine ponds. A field experiment showed that ultraviolet radiation (UVR) killed the free-living infectious stage of the parasite. Yet, permanent ponds with more UVR exposure had higher infection prevalence. Two habitat-related indirect effects worked together to counteract parasite losses from UVR: (i) UVR reduced the density of parasite predators and (ii) permanent sites fostered multi-season host larvae that fuelled parasite production. Host diversity was unlinked to hydroperiod or UVR but counteracted parasite gains; sites with higher diversity of host species had lower prevalence of infection. Thus, while habitat structure explained considerable variation in infection prevalence through two indirect pathways, it could not account for everything. This study demonstrates the importance of creating mechanistic, food web-based links between multiple habitat dimensions and disease.

Quantitative proteomics links metabolic pathways to specific developmental stages of the plant-pathogenic oomycete Phytophthora capsici.

The oomycete Phytophthora capsici is a plant pathogen responsible for important losses to vegetable production worldwide. Its asexual reproduction plays an important role in the rapid propagation and spread of the disease in the field. A global proteomics study was conducted to compare two key asexual life stages of P. capsici, i.e. the mycelium and cysts, to identify stage-specific biochemical processes. A total of 1200 proteins was identified using qualitative and quantitative proteomics. The transcript abundance of some of the enriched proteins was also analysed by quantitative real-time polymerase chain reaction. Seventy-three proteins exhibited different levels of abundance between the mycelium and cysts. The proteins enriched in the mycelium are mainly associated with glycolysis, the tricarboxylic acid (or citric acid) cycle and the pentose phosphate pathway, providing the energy required for the biosynthesis of cellular building blocks and hyphal growth. In contrast, the proteins that are predominant in cysts are essentially involved in fatty acid degradation, suggesting that the early infection stage of the pathogen relies primarily on fatty acid degradation for energy production. The data provide a better understanding of P. capsici biology and suggest potential metabolic targets at the two different developmental stages for disease control.

Coupling Developmental Physiology, Photoperiod, and Temperature to Model Phenology and Dynamics of an Invasive Heteropteran, Halyomorpha halys.

We developed an agent-based stochastic model expressing stage-specific phenology and population dynamics for an insect species across geographic regions. We used the invasive pentatomid, Halyomorpha halys, as the model organism because gaps in knowledge exist regarding its developmental physiology, it is expanding its global distribution, and it is of significant economic importance. Model predictions were compared against field observations over 3 years, and the parameter set that enables the largest population growth was applied to eight locations over 10 years, capturing the variation in temperature and photoperiod profiles of significant horticultural crop production that could be affected by H. halys in the US. As a species that overwinters as adults, critical photoperiod significantly impacted H. halys seasonality and population size through its influence on diapause termination and induction, and this may impact other insects with similar life-histories. Photoperiod and temperature interactions influenced life stage synchrony among years, resulting in an order of magnitude difference, for occurrence of key life stages. At all locations, there was a high degree of overlap among life stages and generation. Although all populations produced F2 adults and thus could be characterized as bivoltine, the size and relative contribution of each generation to the total, or overwintering, adult population also varied dramatically. In about half of the years in two locations (Geneva, NY and Salem, OR), F1 adults comprised half or more of the adult population at the end of the year. Yearly degree-day accumulation was a significant covariate influencing variation in population growth, and average maximum adult population size varied by 10-fold among locations. Average final population growth was positive (Asheville, NC, Homestead, FL, Davis, CA) or marginal (Geneva, NY, Bridgeton, NJ, Salem, OR, Riverside, CA), but was negative in one location (Wenatchee WA) due to cooler temperatures coupled with timing of vitellogenesis of F2 adults. Years of the highest population growth in the mid-Atlantic site coincided with years of highest crop damage reports. We discuss these results with respect to assumptions and critical knowledge gaps, the ability to realistically model phenology of species with strongly overlapping life stage and which diapause as adults.

TRIENNIAL LACTATION SYMPOSIUM: Nutrigenomics in livestock: Systems biology meets nutrition.

The advent of high-throughput technologies to study an animal's genome, proteome, and metabolome (i.e., "omics" tools) constituted a setback to the use of reductionism in livestock research. More recent development of "next-generation sequencing" tools was instrumental in allowing in-depth studies of the microbiome in the rumen and other sections of the gastrointestinal tract. Omics, along with bioinformatics, constitutes the foundation of modern systems biology, a field of study widely used in model organisms (e.g., rodents, yeast, humans) to enhance understanding of the complex biological interactions occurring within cells and tissues at the gene, protein, and metabolite level. Application of systems biology concepts is ideal for the study of interactions between nutrition and physiological state with tissue and cell metabolism and function during key life stages of livestock species, including the transition from pregnancy to lactation, in utero development, or postnatal growth. Modern bioinformatic tools capable of discerning functional outcomes and biologically meaningful networks complement the ever-increasing ability to generate large molecular, microbial, and metabolite data sets. Simultaneous visualization of the complex intertissue adaptations to physiological state and nutrition can now be discerned. Studies to understand the linkages between the microbiome and the absorptive epithelium using the integrative approach are emerging. We present examples of new knowledge generated through the application of functional analyses of transcriptomic, proteomic, and metabolomic data sets encompassing nutritional management of dairy cows, pigs, and poultry. Published work to date underscores that the integrative approach across and within tissues may prove useful for fine-tuning nutritional management of livestock. An important goal during this process is to uncover key molecular players involved in the organismal adaptations to nutrition.

Implementing a framework for integrating toxicokinetics into human health risk assessment for agrochemicals

A strategic and comprehensive program in which toxicokinetic (TK) measurements are made for all agrochemicals undergoing toxicity testing (both new compounds and compounds already registered for use) is described. This approach provides the data to more accurately assess the toxicokinetics of agrochemicals and their metabolites in laboratory animals and humans. Having this knowledge provides the ability to conduct more insightful toxicity studies, refine and interpret exposure assessments and reduce uncertainty in risk assessments. By developing a better understanding of TK across species, including humans via in vitro metabolism studies, any differences across species in TK can be identified early and the most relevant species can be selected for toxicity tests. It also provides the ability to identify any non-linearities in TK as a function of dose, which in turn can be used to identify a kinetically derived maximum dose (KMD) and avoid dosing inappropriately outside of the kinetic linear range. Measuring TK in key life stages also helps to identify changes in ADME parameters from in utero to adults. A robust TK database can also be used to set internal concentration based “Reference Concentrations” and Biomonitoring Equivalents (BE), and support selection of Chemical Specific Adjustment Factors (CSAF). All of these factors support the reduction of uncertainty throughout the entire risk assessment process. This paper outlines how a TK research strategy can be integrated into new agrochemical toxicity testing programs, together with a proposed Framework for future use.

Comparative population genetics of two invading ticks: Evidence of the ecological mechanisms underlying tick range expansions

Two species of ixodid tick, Ixodes affinis Neumann and Amblyomma maculatum Koch, are simultaneously expanding their ranges throughout the mid-Atlantic region of the US. Although we have some understanding of the ecology and life history of these species, the ecological mechanisms governing where and how new populations establish and persist are unclear. To assess population connectivity and ancestry, we sequenced a fragment of the 16S mitochondrial rRNA gene from a representative sample of individuals of both species from populations throughout the eastern US. We found that despite overlapping host preferences throughout ontogeny, each species exhibited very different genetic and geographic patterns of population establishment and connectivity. I. affinis was of two distinct mitochondrial clades, with a clear geographic break separating northern and southern populations. Both I. affinis populations showed evidence of recent expansion, although the southern population was more genetically diverse, indicating a longer history of establishment. A. maculatum exhibited diverse haplotypes that showed no significant relationship with geographic patterns and little apparent connectivity between sites. Heteroplasmy was also observed in the 16S mitochondrial rRNA gene in 3.5% of A. maculatum individuals. Genetic evidence suggests that these species rely on different key life stages to successfully disperse into novel environments, and that host vagility, habitat stability and habitat connectivity all play critical roles in the establishment of new tick populations.