Aroclor 1254, a developmental neurotoxicant, alters energy metabolism- and intracellular signaling-associated protein networks in rat cerebellum and hippocampus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodavanti, Prasada Rao S., E-mail: kodavanti.prasada@epa.gov; Osorio, Cristina; Program on Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, North Carolina

2011-11-15

The vast literature on the mode of action of polychlorinated biphenyls (PCBs) indicates that PCBs are a unique model for understanding the mechanisms of toxicity of environmental mixtures of persistent chemicals. PCBs have been shown to adversely affect psychomotor function and learning and memory in humans. Although the molecular mechanisms for PCB effects are unclear, several studies indicate that the disruption of Ca{sup 2+}-mediated signal transduction plays significant roles in PCB-induced developmental neurotoxicity. Culminating events in signal transduction pathways include the regulation of gene and protein expression, which affects the growth and function of the nervous system. Our previous studiesmore » showed changes in gene expression related to signal transduction and neuronal growth. In this study, protein expression following developmental exposure to PCB is examined. Pregnant rats (Long Evans) were dosed with 0.0 or 6.0 mg/kg/day of Aroclor-1254 from gestation day 6 through postnatal day (PND) 21, and the cerebellum and hippocampus from PND14 animals were analyzed to determine Aroclor 1254-induced differential protein expression. Two proteins were found to be differentially expressed in the cerebellum following PCB exposure while 18 proteins were differentially expressed in the hippocampus. These proteins are related to energy metabolism in mitochondria (ATP synthase, sub unit {beta} (ATP5B), creatine kinase, and malate dehydrogenase), calcium signaling (voltage-dependent anion-selective channel protein 1 (VDAC1) and ryanodine receptor type II (RyR2)), and growth of the nervous system (dihydropyrimidinase-related protein 4 (DPYSL4), valosin-containing protein (VCP)). Results suggest that Aroclor 1254-like persistent chemicals may alter energy metabolism and intracellular signaling, which might result in developmental neurotoxicity. -- Highlights: Black-Right-Pointing-Pointer We performed brain proteomic analysis of rats exposed to the

Building a Database of Developmental Neurotoxitants: Evidence from Human and Animal Studies

EPA Science Inventory

EPA’s program for the screening and prioritization of chemicals for developmental neurotoxicity (DNT) necessitates the generation of a list of chemicals that are known mammalian developmental neurotoxicants. This chemical list will be used to evaluate the sensitivity, reliability...

Functional Assays and Alternative Species: Using Larval Zebrafish in Developmental Neurotoxicity Screening

EPA Science Inventory

The U.S. Environmental Protection Agency is developing and evaluating methods to screen and prioritize large numbers of chemicals for developmental toxicity. Towards this goal, we are exploring methods to detect developmental neurotoxicants in very young larval zebrafish. We have...

Evaluating alterations in Zebrafish retino-tectal projections as an indication of developmental neurotoxicity

EPA Science Inventory

The U.S. EPA is developing alternative screening methods to identify putative developmental neurotoxicants and prioritize chemicals for additional testing. One method developmentally exposes zebrafish embryos and assesses nervous system structure at 2 days post-fertilization (dpf...

Developmental Neurotoxicity Testing: A Path Forward

EPA Science Inventory

Great progress has been made over the past 40 years in understanding the hazards of exposure to a small number of developmental neurotoxicants. Lead, PCBs, and methylmercury are all good examples of science-based approaches to characterizing the hazard to the developing nervous s...

Is decabromodiphenyl ether (BDE-209) a developmental neurotoxicant?

PubMed Central

Costa, Lucio G.; Giordano, Gennaro

2011-01-01

Polybrominated diphenyl ether (PBDE) flame retardants have become ubiquitous environmental pollutants. The relatively higher body burden in toddlers and children has reaised concern for their potential developmental neurotoxicity, which has been suggested by animal studies, in vitro experiments, and recent human epidemiological evidence. While lower brominated PBDEs have been banned in several countries, the fully brominated decaBDE (BDE-209) is still utilized, though manufacturers will discontinue production in the U.S.A. in 2013. The recent decision by the U.S. Environmental Protection Agency to base the Reference Dose (RfD) for BDE-209 on a developmental neurotoxicity study has generated some controversy. Because of its bulky configuration, BDE-209 is poorly absorbed and does not easily penetrate the cell wall. Its acute and chronic toxicities are relatively low, with the liver and the thyroid as the primary targets, though there is some evidence of carcinogenicity. A few animal studies have indicated that BDE-209 may cause developmental neurotoxicity, affecting motor and cognitive domains, as seen for other PBDEs. Limited in vivo and in vitro studies have also evidenced effects of BDE-209 on thyroid hormone homeostasis and direct effects on nervous cells, again similar to what found with other lower brominated PBDEs. In contrast, a recent developmental neurotoxicity study, carried out according to international guidelines, has provided no evidence of adverse effects on neurodevelopment, and this should be considered in a future re-evaluation of BDE-209. While estimated exposure to BDE-209 in children is believed to be several orders of magnitude below the most conservative RfD proposed by the USEPA, questions remain on the extent and relevance of BDE-209 metabolism to lower brominated PBDEs in the environment and in humans. PMID:21182867

DEVELOPMENTAL NEUROTOXICITY FOLLOWING NEONATAL EXPOSURE TO 3,3'-IMINODIPROPIONITRILE IN THE RAT

EPA Science Inventory

Adult exposure to the neurotoxicant 3,3'-iminodipropionitrile (IDPN) induces a hyperkinetic syndrome consisting of spontaneous head movements, abnormal circling, backwards locomotion, and sensory disruption. e report here the behavioral effects of developmental exposure to IDPN i...

EXTRAPOLATION FROM IN VITRO MECHANISMS TO IN VIVO EFFECTS FOR DEVELOPMENTAL NEUROTOXICOLOGY.

EPA Science Inventory

Processes that are critical to development of the nervous system can be altered by both genetic and epigenetic factors. Developmental exposure to neurotoxicants can alter these processes and lead to perturbation of normal neural development. As numerous processes occur in tande...

Increasing Diversity in Cognitive Developmental Research: Issues and Solutions

ERIC Educational Resources Information Center

Rowley, Stephanie J.; Camacho, Tissyana C.

2015-01-01

The current article discusses the importance of increasing racial-ethnic and socioeconomic diversity in cognitive developmental research. It begins with discussion of the implications of the underrepresentation of ethnic minority children in cognitive developmental research. It goes on to suggest reasons underlying these omissions, such as the…

The significance of developmental robustness for species diversity.

PubMed

Melzer, Rainer; Theißen, Günter

2016-04-01

The origin of new species and of new forms is one of the fundamental characteristics of evolution. However, the mechanisms that govern the diversity and disparity of lineages remain poorly understood. Particularly unclear are the reasons why some taxa are vastly more species-rich than others and the manner in which species diversity and morphological disparity are interrelated. Evolutionary innovations and ecological opportunities are usually cited as among the major factors promoting the evolution of species diversity. In many cases it is likely that these factors are positively reinforcing, with evolutionary innovations creating ecological opportunities that in turn foster the origin of new innovations. However, we propose that a third factor, developmental robustness, is very often essential for this reinforcement to be effective. Evolutionary innovations need to be stably and robustly integrated into the developmental genetic programme of an organism to be a suitable substrate for selection to 'explore' ecological opportunities and morphological 'design' space (morphospace). In particular, we propose that developmental robustness of the bauplan is often a prerequisite for the exploration of morphospace and to enable the evolution of further novelties built upon this bauplan Thus, while robustness may reduce the morphological disparity at one level, it may be the basis for increased morphological disparity and for evolutionary innovations at another level, thus fostering species diversity. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Developmental origin of lung macrophage diversity

PubMed Central

Tan, Serena Y. S.; Krasnow, Mark A.

2016-01-01

Macrophages are specialized phagocytic cells, present in all tissues, which engulf and digest pathogens, infected and dying cells, and debris, and can recruit and regulate other immune cells and the inflammatory response and aid in tissue repair. Macrophage subpopulations play distinct roles in these processes and in disease, and are typically recognized by differences in marker expression, immune function, or tissue of residency. Although macrophage subpopulations in the brain have been found to have distinct developmental origins, the extent to which development contributes to macrophage diversity between tissues and within tissues is not well understood. Here, we investigate the development and maintenance of mouse lung macrophages by marker expression patterns, genetic lineage tracing and parabiosis. We show that macrophages populate the lung in three developmental waves, each giving rise to a distinct lineage. These lineages express different markers, reside in different locations, renew in different ways, and show little or no interconversion. Thus, development contributes significantly to lung macrophage diversity and targets each lineage to a different anatomical domain. PMID:26952982

The Role of Astrocyte Mitochondria in Differential Regional Susceptibility to Environmental Neurotoxicants: Tools for Understanding Neurodegeneration

PubMed Central

Kubik, Laura L.; Philbert, Martin A.

2015-01-01

In recent decades, there has been a significant expansion in our understanding of the role of astrocytes in neuroprotection, including spatial buffering of extracellular ions, secretion of metabolic coenzymes, and synaptic regulation. Astrocytic neuroprotective functions require energy, and therefore require a network of functional mitochondria. Disturbances to astrocytic mitochondrial homeostasis and their ability to produce ATP can negatively impact neural function. Perturbations in astrocyte mitochondrial function may accrue as the result of physiological aging processes or as a consequence of neurotoxicant exposure. Hydrophobic environmental neurotoxicants, such as 1,3-dinitrobenzene and α-chlorohydrin, cause regionally specific spongiform lesions mimicking energy deprivation syndromes. Astrocyte involvement includes mitochondrial damage that either precedes or is accompanied by neuronal damage. Similarly, environmental neurotoxicants that are implicated in the etiology of age-related neurodegenerative conditions cause regionally specific damage in the brain. Based on the regioselective nature of age-related neurodegenerative lesions, chemically induced models of regioselective lesions targeting astrocyte mitochondria can provide insight into age-related susceptibilities in astrocyte mitochondria. Most of the available research to date focuses on neuronal damage in cases of age-related neurodegeneration; however, there is a body of evidence that supports a central mechanistic role for astrocyte mitochondria in the expression of neural injury. Regional susceptibility to neuronal damage induced by aging by exposure to neurotoxicants may be a reflection of highly variable regional energy requirements. This review identifies region-specific vulnerabilities in astrocyte mitochondria in examples of exposure to neurotoxicants and in age-related neurodegeneration. PMID:25740792

MicroRNA Profiling as Tool for In Vitro Developmental Neurotoxicity Testing: The Case of Sodium Valproate

PubMed Central

Smirnova, Lena; Block, Katharina; Sittka, Alexandra; Oelgeschläger, Michael; Seiler, Andrea E. M.; Luch, Andreas

2014-01-01

Studying chemical disturbances during neural differentiation of murine embryonic stem cells (mESCs) has been established as an alternative in vitro testing approach for the identification of developmental neurotoxicants. miRNAs represent a class of small non-coding RNA molecules involved in the regulation of neural development and ESC differentiation and specification. Thus, neural differentiation of mESCs in vitro allows investigating the role of miRNAs in chemical-mediated developmental toxicity. We analyzed changes in miRNome and transcriptome during neural differentiation of mESCs exposed to the developmental neurotoxicant sodium valproate (VPA). A total of 110 miRNAs and 377 mRNAs were identified differently expressed in neurally differentiating mESCs upon VPA treatment. Based on miRNA profiling we observed that VPA shifts the lineage specification from neural to myogenic differentiation (upregulation of muscle-abundant miRNAs, mir-206, mir-133a and mir-10a, and downregulation of neural-specific mir-124a, mir-128 and mir-137). These findings were confirmed on the mRNA level and via immunochemistry. Particularly, the expression of myogenic regulatory factors (MRFs) as well as muscle-specific genes (Actc1, calponin, myosin light chain, asporin, decorin) were found elevated, while genes involved in neurogenesis (e.g. Otx1, 2, and Zic3, 4, 5) were repressed. These results were specific for valproate treatment and―based on the following two observations―most likely due to the inhibition of histone deacetylase (HDAC) activity: (i) we did not observe any induction of muscle-specific miRNAs in neurally differentiating mESCs exposed to the unrelated developmental neurotoxicant sodium arsenite; and (ii) the expression of muscle-abundant mir-206 and mir-10a was similarly increased in cells exposed to the structurally different HDAC inhibitor trichostatin A (TSA). Based on our results we conclude that miRNA expression profiling is a suitable molecular endpoint for

Diversity & Developmentally Appropriate Practices: Challenges for Early Childhood Education.

ERIC Educational Resources Information Center

Mallory, Bruce L., Ed.; New, Rebecca S., Ed.

The current conceptualization of what is appropriate in early childhood education is overly narrow in its interpretation of the role of the teacher, and with respect to variations in cultural and developmental diversity. Based on this observation, this book discusses various issues surrounding diversity, inclusion, and appropriate early…

TRIMETHYLTIN, A SELECTIVE LIMBIC SYSTEM NEUROTOXICANT, IMPAIRS RADIAL-ARM MAZE PERFORMANCE

EPA Science Inventory

Rats were trained for fifteen sessions in an automated eight arm radial maze prior to treatment with 6 mg/kg trimethyltin chloride. This compound is a neurotoxicant which primarily damages the limbic system, in particular pyramidal cells in the CA3 region of the hippocampus. Foll...

Using Neural Progenitor Cells in High-Throughput Screens for Developmental Neurotoxicants: Triumphs and Tragedies

EPA Science Inventory

Current protocols for developmental neurotoxicity testing are insufficient to test thousands of commercial chemicals. Thus, development of highthroughput screens (HTS) to detect and prioritize chemicals that may cause developmental neurotoxicity is needed to improve protection of...

Assessing the Developmental Neurotoxicity of 27 ...

EPA Pesticide Factsheets

Assessing the Developmental Neurotoxicity of 27 Organophosphorus Pesticides Using a Zebrafish Behavioral Assay, Waalkes, M., Hunter, D.L., Jarema, K., Mundy, W., and S. Padilla. The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize organophosphorus pesticides for developmental neurotoxicity. As such, we are exploring a behavioral testing paradigm that can assess the effects of sublethal and subteratogenic concentrations of developmental neurotoxicants on zebrafish (Danio rerio). This in vivo assay quantifies the locomotor response to light stimuli under tandem light and dark conditions in a 96-well plate using a video tracking system on 6 day post fertilization zebrafish larvae. Each of twenty-seven organophosphorus pesticides was tested for their developmental neurotoxic potential by exposing zebrafish embryos/larvae to the pesticide at several concentrations (≤ 100 μM nominal concentration) during the first five days of development, followed by 24 hours of depuration and then behavioral testing. Approximately 22% of the chemicals (Acephate, Dichlorvos, Diazoxon, Bensulide,Tribufos, Tebupirimfos) did not produce any behavioral changes after developmental exposure, while many (Malaoxon Fosthiazate, Dimethoate, Dicrotophos, Ethoprop, Malathion, Naled, Diazinon, Methamidophos, Terbufos, Trichlorfon, Phorate, Pirimiphos-methyl, Profenofos, Z-Tetrachlorvinphos, Chlorpyrifos, Coumaphos, Phosmet, Omethoate) produced changes in swi

Gender and Cultural Diversity Bias in Developmental Textbooks.

ERIC Educational Resources Information Center

Conti, Nancy E.; Kimmel, Ellen B.

This paper reports the results of a content-analysis for the treatment of gender and diversity in the 11 top-selling lifespan developmental textbooks. The purposes were to measure the amount of information provided on aspects of development specific to Caucasian females and females of Color and to evaluate qualitatively the incorporation of the…

Screening for Developmental Neurotoxicants using In Vitro "Brain on a Chip" Cultures

EPA Science Inventory

Currently there are thousands of chemicals in the environment that have not been screened for their potential to cause developmental neurotoxicity (DNT). The use of microelectrode array (MEA) technology allows for simultaneous extracellular measurement of action potential (spike)...

Ultraviolet Photolysis of Chlorpyrifos: Developmental Neurotoxicity Modeled in PC12 Cells

PubMed Central

Slotkin, Theodore A.; Seidler, Frederic J.; Wu, Changlong; MacKillop, Emiko A.; Linden, Karl G.

2009-01-01

Background Ultraviolet photodegradation products from pesticides form both in the field and during water treatment. Objectives We evaluated the photolytic breakdown of the organophosphate pesticide chlorpyrifos (CPF) in terms of both the chemical entities generated by low-pressure ultraviolet C irradiation and their potential as developmental neurotoxicants. Methods We separated by-products using high-performance liquid chromatography and characterized them by gas chromatography/mass spectrometry. We assessed neurotoxicity in neuronotypic PC12 cells, both in the undifferentiated state and during differentiation. Results Photodegradation of CPF in methanol solution generated CPF oxon and trichloropyridinol, products known to retain developmental neurotoxicant actions, as well as a series of related organophosphate and phosphorothionate derivatives. Exposure conditions that led to 50% degradation of CPF thus did not reduce developmental neurotoxicity. The degradation mixture inhibited DNA synthesis in undifferentiated cells to the same extent as native CPF. In differentiating cells, the products likewise retained the full ability to elicit shortfalls in cell number and corresponding effects on cell growth and neurite formation. When the exposure was prolonged to the point where 70% of the CPF was degraded, the adverse effects on PC12 cells were no longer evident; however, these conditions were sufficiently severe to generate toxic products from the methanol vehicle. Conclusions Our results indicate that field conditions or remediation treatments that degrade a significant proportion of the CPF do not necessarily produce inactive products and, indeed, may elicit formation of even more toxic chemicals that are more water soluble and thus have greater field mobility than CPF itself. PMID:19337505

Species diversity vs. morphological disparity in the light of evolutionary developmental biology

PubMed Central

Minelli, Alessandro

2016-01-01

Background Two indicators of a clade’s success are its diversity (number of included species) and its disparity (extent of morphospace occupied by its members). Many large genera show high diversity with low disparity, while others such as Euphorbia and Drosophila are highly diverse but also exhibit high disparity. The largest genera are often characterized by key innovations that often, but not necessarily, coincide with their diagnostic apomorphies. In terms of their contribution to speciation, apomorphies are either permissive (e.g. flightlessness) or generative (e.g. nectariferous spurs). Scope Except for Drosophila, virtually no genus among those with the highest diversity or disparity includes species currently studied as model species in developmental genetics or evolutionary developmental biology (evo-devo). An evo-devo approach is, however, potentially important to understand how diversity and disparity could rapidly increase in the largest genera currently accepted by taxonomists. The most promising directions for future research and a set of key questions to be addressed are presented in this review. Conclusions From an evo-devo perspective, the evolution of clades with high diversity and/or disparity can be addressed from three main perspectives: (1) evolvability, in terms of release from previous constraints and of the presence of genetic or developmental conditions favouring multiple parallel occurrences of a given evolutionary transition and its reversal; (2) phenotypic plasticity as a facilitator of speciation; and (3) modularity, heterochrony and a coupling between the complexity of the life cycle and the evolution of diversity and disparity in a clade. This simple preliminary analysis suggests a set of topics that deserve priority for scrutiny, including the possible role of saltational evolution in the origination of high diversity and/or disparity, the predictability of morphological evolution following release from a former constraint, and

Species diversity vs. morphological disparity in the light of evolutionary developmental biology.

PubMed

Minelli, Alessandro

2016-04-01

Two indicators of a clade's success are its diversity (number of included species) and its disparity (extent of morphospace occupied by its members). Many large genera show high diversity with low disparity, while others such as Euphorbia and Drosophila are highly diverse but also exhibit high disparity. The largest genera are often characterized by key innovations that often, but not necessarily, coincide with their diagnostic apomorphies. In terms of their contribution to speciation, apomorphies are either permissive (e.g. flightlessness) or generative (e.g. nectariferous spurs). Except for Drosophila, virtually no genus among those with the highest diversity or disparity includes species currently studied as model species in developmental genetics or evolutionary developmental biology (evo-devo). An evo-devo approach is, however, potentially important to understand how diversity and disparity could rapidly increase in the largest genera currently accepted by taxonomists. The most promising directions for future research and a set of key questions to be addressed are presented in this review. From an evo-devo perspective, the evolution of clades with high diversity and/or disparity can be addressed from three main perspectives: (1) evolvability, in terms of release from previous constraints and of the presence of genetic or developmental conditions favouring multiple parallel occurrences of a given evolutionary transition and its reversal; (2) phenotypic plasticity as a facilitator of speciation; and (3) modularity, heterochrony and a coupling between the complexity of the life cycle and the evolution of diversity and disparity in a clade. This simple preliminary analysis suggests a set of topics that deserve priority for scrutiny, including the possible role of saltational evolution in the origination of high diversity and/or disparity, the predictability of morphological evolution following release from a former constraint, and the extent and the possible

Prologue: Toward Accurate Identification of Developmental Language Disorder Within Linguistically Diverse Schools.

PubMed

Oetting, Janna B

2018-04-05

Although the 5 studies presented within this clinical forum include children who differ widely in locality, language learning profile, and age, all were motivated by a desire to improve the accuracy at which developmental language disorder is identified within linguistically diverse schools. The purpose of this prologue is to introduce the readers to a conceptual framework that unites the studies while also highlighting the approaches and methods each research team is pursuing to improve assessment outcomes within their respective linguistically diverse community. A disorder within diversity framework is presented to replace previous difference vs. disorder approaches. Then, the 5 studies within the forum are reviewed by clinical question, type of tool(s), and analytical approach. Across studies of different linguistically diverse groups, research teams are seeking answers to similar questions about child language screening and diagnostic practices, using similar analytical approaches to answer their questions, and finding promising results with tools focused on morphosyntax. More studies that are modeled after or designed to extend those in this forum are needed to improve the accuracy at which developmental language disorder is identified.

A 3-dimensional human embryonic stem cell (hESC)-derived model to detect developmental neurotoxicity of nanoparticles.

PubMed

Hoelting, Lisa; Scheinhardt, Benjamin; Bondarenko, Olesja; Schildknecht, Stefan; Kapitza, Marion; Tanavde, Vivek; Tan, Betty; Lee, Qian Yi; Mecking, Stefan; Leist, Marcel; Kadereit, Suzanne

2013-04-01

Nanoparticles (NPs) have been shown to accumulate in organs, cross the blood-brain barrier and placenta, and have the potential to elicit developmental neurotoxicity (DNT). Here, we developed a human embryonic stem cell (hESC)-derived 3-dimensional (3-D) in vitro model that allows for testing of potential developmental neurotoxicants. Early central nervous system PAX6(+) precursor cells were generated from hESCs and differentiated further within 3-D structures. The 3-D model was characterized for neural marker expression revealing robust differentiation toward neuronal precursor cells, and gene expression profiling suggested a predominantly forebrain-like development. Altered neural gene expression due to exposure to non-cytotoxic concentrations of the known developmental neurotoxicant, methylmercury, indicated that the 3-D model could detect DNT. To test for specific toxicity of NPs, chemically inert polyethylene NPs (PE-NPs) were chosen. They penetrated deep into the 3-D structures and impacted gene expression at non-cytotoxic concentrations. NOTCH pathway genes such as HES5 and NOTCH1 were reduced in expression, as well as downstream neuronal precursor genes such as NEUROD1 and ASCL1. FOXG1, a patterning marker, was also reduced. As loss of function of these genes results in severe nervous system impairments in mice, our data suggest that the 3-D hESC-derived model could be used to test for Nano-DNT.

TRANSCRIPTIONAL PROFILES FOR GLUTAMATE TRANSPORTERS REVEAL DIFFERENCES BETWEEN ORGANOPHOSPHATES BUT SIMILARITIES WITH UNRELATED NEUROTOXICANTS

PubMed Central

Slotkin, Theodore A.; Lobner, Doug; Seidler, Frederic J.

2010-01-01

The developmental neurotoxicity of organophosphates involves mechanisms other than their shared property as cholinesterase inhibitors, among which are excitotoxicity and oxidative stress. We used PC12 cells as a neurodevelopmental model to compare the effects of chlorpyrifos and diazinon on the expression of genes encoding glutamate transporters. Chlorpyrifos had a greater effect in cells undergoing nerve growth factor-induced neurodifferentiation as compared to undifferentiated PC12 cells, with peak sensitivity at the initiation of differentiation, reflecting a global upregulation of all the glutamate transporter genes expressed in this cell line. In differentiating cells, chlorpyrifos had a significantly greater effect than did diazinon and concordance analysis indicated no resemblance in their expression patterns. At the same time, the smaller effects of diazinon were highly concordant with those of an organochlorine pesticide (dieldrin) and a metal (divalent nickel). We also performed similar evaluations for the cystine/glutamate exchanger, which provides protection against oxidative stress by moving cystine into the cell; again, chlorpyrifos had the greatest effect, in this case reducing expression in undifferentiated and differentiating cells. Our results point to excitotoxicity and oxidative stress as major contributors to the noncholinesterase mechanisms that distinguish the neurodevelopmental outcomes betweem different organophosphates while providing a means whereby apparently unrelated neurotoxicants may produce similar outcomes. PMID:20600679

Zebrafish as a systems toxicology model for developmental neurotoxicity testing.

PubMed

Nishimura, Yuhei; Murakami, Soichiro; Ashikawa, Yoshifumi; Sasagawa, Shota; Umemoto, Noriko; Shimada, Yasuhito; Tanaka, Toshio

2015-02-01

The developing brain is extremely sensitive to many chemicals. Exposure to neurotoxicants during development has been implicated in various neuropsychiatric and neurological disorders, including autism spectrum disorder, attention deficit hyperactive disorder, schizophrenia, Parkinson's disease, and Alzheimer's disease. Although rodents have been widely used for developmental neurotoxicity testing, experiments using large numbers of rodents are time-consuming, expensive, and raise ethical concerns. Using alternative non-mammalian animal models may relieve some of these pressures by allowing testing of large numbers of subjects while reducing expenses and minimizing the use of mammalian subjects. In this review, we discuss some of the advantages of using zebrafish in developmental neurotoxicity testing, focusing on central nervous system development, neurobehavior, toxicokinetics, and toxicodynamics in this species. We also describe some important examples of developmental neurotoxicity testing using zebrafish combined with gene expression profiling, neuroimaging, or neurobehavioral assessment. Zebrafish may be a systems toxicology model that has the potential to reveal the pathways of developmental neurotoxicity and to provide a sound basis for human risk assessments. © 2014 Japanese Teratology Society.

Developmentally Universal Practice: Visioning Innovative Early Childhood Pedagogy for Meeting the Needs of Diverse Learners

ERIC Educational Resources Information Center

Harris, Kathleen I.

2015-01-01

Although developmentally appropriate practice (DAP) has strong merits, there are considerations pertaining to its development and implementation which must be raised. In order for educators to include diverse voices of young children, the time has come for a new conversation to unfold introducing developmentally universal practice (DUP). With this…

Non-invasive fluorescent imaging of gliosis in transgenic mice for profiling developmental neurotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Gideon; Zhang Chunyan; Zhuo Lang

2007-05-15

Gliosis is a universal response of Brain to almost all types of neural insults, including neurotoxicity, neurodegeneration, viral infection, and stroke. A hallmark of gliotic reaction is the up-regulation of the astrocytic biomarker GFAP (glial fibrillary acidic protein), which often precedes the anatomically apparent damages in Brain. In this study, neonatal transgenic mice at postnatal day (PD) 4 expressing GFP (green fluorescent protein) under the control of a widely used 2.2-kb human GFAP promoter in Brain are treated with two model neurotoxicants, 1-methyl-4(2'-methylphenyl)-1,2,3,6-tetrahydropyridine (2'-CH{sub 3}-MPTP), and kainic acid (KA), respectively, to induce gliosis. Here we show that the neurotoxicant-induced acutemore » gliosis can be non-invasively imaged and quantified in Brain of conscious (un-anesthetized) mice in real-time, at 0, 2, 4, 6, and 8 h post-toxicant dosing. Therefore the current methodology could be a useful tool for studying the developmental aspects of neuropathies and neurotoxicity.« less

Sample diversity and premise typicality in inductive reasoning: evidence for developmental change.

PubMed

Rhodes, Marjorie; Brickman, Daniel; Gelman, Susan A

2008-08-01

Evaluating whether a limited sample of evidence provides a good basis for induction is a critical cognitive task. We hypothesized that whereas adults evaluate the inductive strength of samples containing multiple pieces of evidence by attending to the relations among the exemplars (e.g., sample diversity), six-year-olds would attend to the degree to which each individual exemplar in a sample independently appears informative (e.g., premise typicality). To test these hypotheses, participants were asked to select between diverse and non-diverse samples to help them learn about basic-level animal categories. Across various between-subject conditions (N=133), we varied the typicality present in the diverse and non-diverse samples. We found that adults reliably selected to examine diverse over non-diverse samples, regardless of exemplar typicality, six-year-olds preferred to examine samples containing typical exemplars, regardless of sample diversity, and nine-year-olds were somewhat in the midst of this developmental transition.

Brominated flame retardants: a novel class of developmental neurotoxicants in our environment?

PubMed

Eriksson, P; Jakobsson, E; Fredriksson, A

2001-09-01

Brominated flame retardants are a novel group of global environmental contaminants. Within this group the polybrominated diphenyl ethers (PBDE) constitute one class of many that are found in electrical appliances, building materials, and textiles. PBDEs are persistent compounds that appear to have an environmental dispersion similar to that of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT). Levels of PBDEs are increasing in mother's milk while other organohalogens have decreased in concentration. We studied for developmental neurotoxic effects two polybrominated diphenyl ethers, 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47) and 2,2',4,4',5-pentabromodiphenyl ether (PBDE 99)--congeners that dominate in environmental and human samples--together with another frequently used brominated flame retardant, tetrabromo-bis-phenol-A (TBBPA). The compounds were given to 10-day-old NMRI male mice, as follows: PBDE 47, 0.7 mg (1.4 micromol), 10.5 mg (21.1 micromol)/kg body weight (bw); PBDE 99, 0.8 mg (1.4 micromol), 12.0 mg (21.1 micromol)/kg bw; TBBPA, 0.75 mg (1.4 micromol), 11.5 mg (21.1 micromol)/kg bw. Mice serving as controls received 10 mL/kg bw of the 20% fat emulsion vehicle in the same manner. The present study has shown that neonatal exposure to PBDE 99 and PBDE 47 can cause permanent aberrations in spontaneous behavior, evident in 2- and 4-month-old animals. This effect together with the habituation capability was more pronounced with increasing age, and the changes were dose-response related. Furthermore, neonatal exposure to PBDE 99 also affected learning and memory functions in adult animals. These are developmental defects that have been detected previously in connection with PCBs.

Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royland, Joyce E.; Wu, Jinfang; Zawia, Nasser H.

2008-09-01

The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive development, causes psychomotor difficulties, and contributes to attention deficits in children, all of which seem to be associated with altered patterns of neuronal connectivity. In the present study, we examined gene expression profiles in the rat nervous system following PCB developmental exposure. Pregnant rats (Long-Evans) were dosed perinatally with 0 or 6 mg/kg/day of Aroclor 1254 from gestation day 6 through postnatal day (PND)more » 21. Gene expression in cerebellum and hippocampus from PND7 and PND14 animals was analyzed with an emphasis on developmental aspects. Changes in gene expression ({>=} 1.5 fold) in control animals identified normal developmental changes. These basal levels of expression were compared to data from Aroclor 1254-treated animals to determine the impact of gestational PCB exposure on developmental parameters. The results indicate that the expression of a number of developmental genes related to cell cycle, synaptic function, cell maintenance, and neurogenesis is significantly altered from PND7 to PND14. Aroclor 1254 treatment appears to dampen the overall growth-related gene expression levels in both regions with the effect being more pronounced in the cerebellum. Functional analysis suggests that Aroclor 1254 delays maturation of the developing nervous system, with the consequences dependent on the ontological state of the brain area and the functional role of the individual gene. Such changes may underlie learning and memory deficits observed in PCB exposed animals and humans.« less

A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYS

EPA Science Inventory

AbstractTITLE: A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYSABSTRACT BODY: Microelectrode array (MEA) recordings are increasingly being used as an in vitro method to detect and characte...

Cellular manganese content is developmentally regulated in human dopaminergic neurons

NASA Astrophysics Data System (ADS)

Kumar, Kevin K.; Lowe, Edward W., Jr.; Aboud, Asad A.; Neely, M. Diana; Redha, Rey; Bauer, Joshua A.; Odak, Mihir; Weaver, C. David; Meiler, Jens; Aschner, Michael; Bowman, Aaron B.

2014-10-01

Manganese (Mn) is both an essential biological cofactor and neurotoxicant. Disruption of Mn biology in the basal ganglia has been implicated in the pathogenesis of neurodegenerative disorders, such as parkinsonism and Huntington's disease. Handling of other essential metals (e.g. iron and zinc) occurs via complex intracellular signaling networks that link metal detection and transport systems. However, beyond several non-selective transporters, little is known about the intracellular processes regulating neuronal Mn homeostasis. We hypothesized that small molecules that modulate intracellular Mn could provide insight into cell-level Mn regulatory mechanisms. We performed a high throughput screen of 40,167 small molecules for modifiers of cellular Mn content in a mouse striatal neuron cell line. Following stringent validation assays and chemical informatics, we obtained a chemical `toolbox' of 41 small molecules with diverse structure-activity relationships that can alter intracellular Mn levels under biologically relevant Mn exposures. We utilized this toolbox to test for differential regulation of Mn handling in human floor-plate lineage dopaminergic neurons, a lineage especially vulnerable to environmental Mn exposure. We report differential Mn accumulation between developmental stages and stage-specific differences in the Mn-altering activity of individual small molecules. This work demonstrates cell-level regulation of Mn content across neuronal differentiation.

Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vose, Sarah C.; Center for Children's Environmental Health Research, School of Public Health, University of California, Berkeley, CA 94720; Holland, Nina T.

2007-10-01

Brain neuropathy target esterase (NTE), associated with organophosphorus (OP)-induced delayed neuropathy, has the same OP inhibitor sensitivity and specificity profiles assayed in the classical way (paraoxon-resistant, mipafox-sensitive hydrolysis of phenyl valerate) or with lysophosphatidylcholine (LysoPC) as the substrate. Extending our earlier observation with mice, we now examine human erythrocyte, lymphocyte, and brain LysoPC hydrolases as possible sensitive targets for OP delayed neurotoxicants and insecticides. Inhibitor profiling of human erythrocytes and lymphocytes gave the surprising result of essentially the same pattern as with brain. Human erythrocyte LysoPC hydrolases are highly sensitive to OP delayed neurotoxicants, with in vitro IC{sub 50} valuesmore » of 0.13-85 nM for longer alkyl analogs, and poorly sensitive to the current OP insecticides. In agricultural workers, erythrocyte LysoPC hydrolyzing activities are similar for newborn children and their mothers and do not vary with paraoxonase status but have high intersample variation that limits their use as a biomarker. Mouse erythrocyte LysoPC hydrolase activity is also of low sensitivity in vitro and in vivo to the OP insecticides whereas the delayed neurotoxicant ethyl n-octylphosphonyl fluoride inhibits activity in vivo at 1-3 mg/kg. Overall, inhibition of blood LysoPC hydrolases is as good as inhibition of brain NTE as a predictor of OP inducers of delayed neuropathy. NTE and lysophospholipases (LysoPLAs) both hydrolyze LysoPC, yet they are in distinct enzyme families with no sequence homology and very different catalytic sites. The relative contributions of NTE and LysoPLAs to LysoPC hydrolysis and clearance from erythrocytes, lymphocytes, and brain remain to be defined.« less

IN VITRO SCREENING OF DEVELOPMENTAL NEUROTOXICANTS IN RAT PRIMARY CORTICAL NEURONS USING HIGH CONTENT IMAGE

EPA Science Inventory

There is a need for more efficient and cost-effective methods for identifying, characterizing and prioritizing chemicals which may result in developmental neurotoxicity. One approach is to utilize in vitro test systems which recapitulate the critical processes of nervous system d...

Developmental diversity in free-living flatworms

PubMed Central

2012-01-01

Flatworm embryology has attracted attention since the early beginnings of comparative evolutionary biology. Considered for a long time the most basal bilaterians, the Platyhelminthes (excluding Acoelomorpha) are now robustly placed within the Spiralia. Despite having lost their relevance to explain the transition from radially to bilaterally symmetrical animals, the study of flatworm embryology is still of great importance to understand the diversification of bilaterians and of developmental mechanisms. Flatworms are acoelomate organisms generally with a simple centralized nervous system, a blind gut, and lacking a circulatory organ, a skeleton and a respiratory system other than the epidermis. Regeneration and asexual reproduction, based on a totipotent neoblast stem cell system, are broadly present among different groups of flatworms. While some more basally branching groups - such as polyclad flatworms - retain the ancestral quartet spiral cleavage pattern, most flatworms have significantly diverged from this pattern and exhibit unique strategies to specify the common adult body plan. Most free-living flatworms (i.e. Platyhelminthes excluding the parasitic Neodermata) are directly developing, whereas in polyclads, also indirect developers with an intermediate free-living larval stage and subsequent metamorphosis are found. A comparative study of developmental diversity may help understanding major questions in evolutionary biology, such as the evolution of cleavage patterns, gastrulation and axial specification, the evolution of larval types, and the diversification and specialization of organ systems. In this review, we present a thorough overview of the embryonic development of the different groups of free-living (turbellarian) platyhelminths, including the Catenulida, Macrostomorpha, Polycladida, Lecithoepitheliata, Proseriata, Bothrioplanida, Rhabdocoela, Fecampiida, Prolecithophora and Tricladida, and discuss their main features under a consensus phylogeny

Transformation of Developmental Neurotoxicity Data into a Structure-Searchable Relational Database

EPA Science Inventory

A database of neurotoxicants is critical to support the development and validation of animal alternatives for neurotoxicity. Validation of in vitro test methods can only be done using known animal and human neurotoxicants producing defined responses for neurochemical, neuropatho...

The sea urchin embryo as a model for mammalian developmental neurotoxicity: ontogenesis of the high-affinity choline transporter and its role in cholinergic trophic activity.

PubMed Central

Qiao, Dan; Nikitina, Lyudmila A; Buznikov, Gennady A; Lauder, Jean M; Seidler, Frederic J; Slotkin, Theodore A

2003-01-01

Embryonic development in the sea urchin requires trophic actions of the same neurotransmitters that participate in mammalian brain assembly. We evaluated the development of the high-affinity choline transporter, which controls acetylcholine synthesis. A variety of developmental neurotoxicants affect this transporter in mammalian brain. [3H]Hemicholinium-3 binding to the transporter was found in the cell membrane fraction at stages from the unfertilized egg to pluteus, with a binding affinity comparable with that seen in mammalian brain. Over the course of development, the concentration of transporter sites rose more than 3-fold, achieving concentrations comparable with those of cholinergically enriched mammalian brain regions. Dimethylaminoethanol (DMAE), a competitive inhibitor of choline transport, elicited dysmorphology beginning at the mid-blastula stage, with anomalies beginning progressively later as the concentration of DMAE was lowered. Pretreatment, cotreatment, or delayed treatment with acetylcholine or choline prevented the adverse effects of DMAE. Because acetylcholine was protective at a lower threshold, the DMAE-induced defects were most likely mediated by its effects on acetylcholine synthesis. Transient removal of the hyaline layer enabled a charged transport inhibitor, hemicholinium-3, to penetrate sufficiently to elicit similar anomalies, which were again prevented by acetylcholine or choline. These results indicate that the developing sea urchin possesses a high-affinity choline transporter analogous to that found in the mammalian brain, and, as in mammals, the functioning of this transporter plays a key role in the developmental, trophic activity of acetylcholine. The sea urchin model may thus be useful in high-throughput screening of suspected developmental neurotoxicants. PMID:14594623

The sea urchin embryo as a model for mammalian developmental neurotoxicity: ontogenesis of the high-affinity choline transporter and its role in cholinergic trophic activity.

PubMed

Qiao, Dan; Nikitina, Lyudmila A; Buznikov, Gennady A; Lauder, Jean M; Seidler, Frederic J; Slotkin, Theodore A

2003-11-01

Embryonic development in the sea urchin requires trophic actions of the same neurotransmitters that participate in mammalian brain assembly. We evaluated the development of the high-affinity choline transporter, which controls acetylcholine synthesis. A variety of developmental neurotoxicants affect this transporter in mammalian brain. [3H]Hemicholinium-3 binding to the transporter was found in the cell membrane fraction at stages from the unfertilized egg to pluteus, with a binding affinity comparable with that seen in mammalian brain. Over the course of development, the concentration of transporter sites rose more than 3-fold, achieving concentrations comparable with those of cholinergically enriched mammalian brain regions. Dimethylaminoethanol (DMAE), a competitive inhibitor of choline transport, elicited dysmorphology beginning at the mid-blastula stage, with anomalies beginning progressively later as the concentration of DMAE was lowered. Pretreatment, cotreatment, or delayed treatment with acetylcholine or choline prevented the adverse effects of DMAE. Because acetylcholine was protective at a lower threshold, the DMAE-induced defects were most likely mediated by its effects on acetylcholine synthesis. Transient removal of the hyaline layer enabled a charged transport inhibitor, hemicholinium-3, to penetrate sufficiently to elicit similar anomalies, which were again prevented by acetylcholine or choline. These results indicate that the developing sea urchin possesses a high-affinity choline transporter analogous to that found in the mammalian brain, and, as in mammals, the functioning of this transporter plays a key role in the developmental, trophic activity of acetylcholine. The sea urchin model may thus be useful in high-throughput screening of suspected developmental neurotoxicants.

Vowels--Sonic Gems of Emotion for Social Communication: Practical Singing Strategies for Non-Musician Teachers with Developmentally Diverse Young Children

ERIC Educational Resources Information Center

Weeks, Kaja

2015-01-01

Communicative and social capacities are known to be of primary developmental importance to all children and often present a particular difficulty for children with neurodevelopmental disorders. A recurring challenge for teachers is achieving effective communication with children who span developmental diversity (e.g. inclusive settings or those…

Evaluation of microtransplantation of rat brain neurolemma into Xenopus laevis oocytes as a technique to study the effect of neurotoxicants on endogenous voltage-sensitive ion channels.

PubMed

Murenzi, Edwin; Toltin, Abigail C; Symington, Steven B; Morgan, Molly M; Clark, John M

2017-05-01

Microtransplantation of mammalian brain neurolemma into the plasma membrane of Xenopus oocytes is used to study ion channels in their native form as they appear in the central nervous system. Use of microtransplanted neurolemma is advantageous for various reasons: tissue can be obtained from various sources and at different developmental stages; ion channels and receptors are present in their native configuration in their proper lipid environment along with appropriate auxiliary subunits; allowing the evaluation of numerous channelpathies caused by neurotoxicants in an ex vivo state. Here we show that Xenopus oocytes injected with post-natal day 90 (PND90) rat brain neurolemma fragments successfully express functional ion channels. Using a high throughput two electrode voltage clamp (TEVC) electrophysiological system, currents that were sensitive to tetrodotoxin, ω-conotoxin MVIIC, and tetraethylammonium were detected, indicating the presence of multiple voltage-sensitive ion channels (voltage-sensitive sodium (VSSC), calcium and potassium channels, respectively). The protein expression pattern for nine different VSSC isoforms (Na v 1.1-Na v 1.9) was determined in neurolemma using automated western blotting, with the predominant isoforms expressed being Na v 1.2 and Na v 1.6. VSSC were also successfully detected in the plasma membrane of Xenopus oocytes microtransplanted with neurolemma. Using this approach, a "proof-of-principle" experiment was conducted where a well-established structure-activity relationship between the neurotoxicant, 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (DDT) and its non-neurotoxic metabolite, 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (DDE) was examined. A differential sensitivity of DDT and DDE on neurolemma-injected oocytes was determined where DDT elicited a concentration-dependent increase in TTX-sensitive inward sodium current upon pulse-depolarization whereas DDE resulted in no significant effect. Additionally, DDT resulted in

The developmental neurotoxicity of arsenic: cognitive and behavioral consequences of early life exposure.

PubMed

Tolins, Molly; Ruchirawat, Mathuros; Landrigan, Philip

2014-01-01

More than 200 million people worldwide are chronically exposed to arsenic. Arsenic is a known human carcinogen, and its carcinogenic and systemic toxicity have been extensively studied. By contrast, the developmental neurotoxicity of arsenic has been less well described. The aim of this review was to provide a comprehensive review of the developmental neurotoxicity of arsenic. We reviewed the published epidemiological and toxicological literature on the developmental neurotoxicity of arsenic. Arsenic is able to gain access to the developing brain and cause neurotoxic effects. Animal models link prenatal and early postnatal exposure to reduction in brain weight, reductions in numbers of glia and neurons, and alterations in neurotransmitter systems. Animal and in vitro studies both suggest that oxidative stress may be a mechanism of arsenic neurotoxicity. Fifteen epidemiological studies indicate that early life exposure is associated with deficits in intelligence and memory. These effects may occur at levels of exposure below current safety guidelines, and some neurocognitive consequences may become manifest only later in life. Sex, concomitant exposures, and timing of exposure appear to modify the developmental neurotoxicity of arsenic. Four epidemiological studies failed to show behavioral outcomes of arsenic exposure. The published literature indicates that arsenic is a human developmental neurotoxicant. Ongoing and future prospective birth cohort studies will allow more precise definition of the developmental consequences of arsenic exposure in early life. Copyright © 2014. Published by Elsevier Inc.

Gene expression profiles in the cerebellum and hippocampus following exposure to a neurotoxicant, Aroclor 1254: Developmental effects.

EPA Science Inventory

The developmental consequences of exposure to the polychlorinated biphenyls (PCBs) have been widely studied, making PCBs a unique model to understand issues related to environmental mixture of persistent chemicals. PCB exposure in humans adversely affects neurocognitive developm...

A mechanistic view of polybrominated diphenyl ether (PBDE) developmental neurotoxicity

PubMed Central

Costa, Lucio G.; de Laat, Rian; Tagliaferri, Sara; Pellacani, Claudia

2013-01-01

Polybrominated diphenyl ethers (PBDEs), extensively used in the past few decades as flame retardants in a variety of consumer products, have become world-wide persistent environmental pollutants. Levels in North America are usually higher than those in Europe and Asia, and body burden is 3 to 9-fold higher in infants and toddlers than in adults. The latter has raised concern for potential developmental toxicity and neurotoxicity of PBDEs. Experimental studies in animals and epidemiological observations in humans suggest that PBDEs may be developmental neurotoxicants. Pre- and/or post-natal exposure to PBDEs may cause long-lasting behavioral abnormalities, particularly in the domains of motor activity and cognition. The mechanisms underlying the developmental neurotoxic effects of PBDEs are not known, though several hypotheses have been put forward. One general mode of action relates to the ability of PBDEs to impair thyroid hormone homeostasis, thus indirectly affecting the developing brain. An alternative or additional mode of action involves a direct effect of PBDEs on nervous system cells; PBDEs can cause oxidative stress-related damage (DNA damage, mitochondrial dysfunction, apoptosis), and interfere with signal transduction (particularly calcium signaling), and with neurotransmitter systems. Important issues such as bioavailability and metabolism of PBDEs, extrapolation of results to low level of exposures, and the potential effects of interactions among PBDE congeners and between PBDEs and other contaminants also need to be taken into account. PMID:24270005

CHLORPYRIFOS DEVELOPMENTAL NEUROTOXICITY: INTERACTION WITH GLUCOCORTICOIDS IN PC12 CELLS

PubMed Central

Slotkin, Theodore A.; Card, Jennifer; Seidler, Frederic J.

2012-01-01

Prenatal coexposures to glucocorticoids and organophosphate pesticides are widespread. Glucocorticoids are elevated by maternal stress and are commonly given in preterm labor; organophosphate exposures are virtually ubiquitous. We used PC12 cells undergoing neurodifferentiation in order to assess whether dexamethasone enhances the developmental neurotoxicity of chlorpyrifos, focusing on concentrations relevant to human exposures. By themselves, each agent reduced the number of cells and the combined exposure elicited a correspondingly greater effect than with either agent alone. There was no general cytotoxicity, as cell growth was actually enhanced, and again, the combined treatment evoked greater cellular hypertrophy than with the individual compounds. The effects on neurodifferentiation were more complex. Chlorpyrifos alone had a promotional effect on neuri to genesis whereas dexamethasone impaired it; combined treatment showed an overall impairment greater than that seen with dexamethasone alone. The effect of chlorpyrifos on differentiation into specific neurotransmitter phenotypes was shifted by dexamethasone. Either agent alone promoted differentiation into the dopaminergic phenotype at the expense of the cholinergic phenotype. However, in dexamethasone-primed cells, chlorpyrifos actually enhanced cholinergic neurodifferentiation instead of suppressing this phenotype. Our results indicate that developmental exposure to glucocorticoids, either in the context of stress or the therapy of preterm labor, could enhance the developmental neurotoxicity of organophosphates and potentially of other neurotoxicants, as well as producing neurobehavioral outcomes distinct from those seen with either individual agent. PMID:22796634

Language used in interaction during developmental science instruction

NASA Astrophysics Data System (ADS)

Avenia-Tapper, Brianna

The coordination of theory and evidence is an important part of scientific practice. Developmental approaches to instruction, which make the relationship between the abstract and the concrete a central focus of students' learning activity, provide educators with a unique opportunity to strengthen students' coordination of theory and evidence. Therefore, developmental approaches may be a useful instructional response to documented science achievement gaps for linguistically diverse students. However, if we are to leverage the potential of developmental instruction to improve the science achievement of linguistically diverse students, we need more information on the intersection of developmental science instruction and linguistically diverse learning contexts. This manuscript style dissertation uses discourse analysis to investigate the language used in interaction during developmental teaching-learning in three linguistically diverse third grade classrooms. The first manuscript asks how language was used to construct ascension from the abstract to the concrete. The second manuscript asks how students' non-English home languages were useful (or not) for meeting the learning goals of the developmental instructional program. The third manuscript asks how students' interlocutors may influence student choice to use an important discourse practice--justification--during the developmental teaching-learning activity. All three manuscripts report findings relevant to the instructional decisions that teachers need to make when implementing developmental instruction in linguistically diverse contexts.

Efficacy of moclobemide in a rat model of neurotoxicant-induced edema.

PubMed

Girard, Philippe; Verniers, Danielle; Pansart, Yannick; Gillardin, Jean-Marie

2007-05-01

The potent antidepressant effect of moclobemide, a selective and reversible type A monoamine oxidase (MAO) inhibitor, is clinically established. In view of the ongoing debate on the neuroprotective properties of MAO inhibitors, the present study was undertaken to further define the protective effect of moclobemide in a rat model of neurotoxicant-induced edema. In this model, daily oral triethyltin (TET) administration for 5 consecutive days strongly perturbed the rat behaviour and induced a cerebral edema at the 5th day. Oral coadministration of moclobemide (2 x 100 mg.kg-1.day-1) with TET blocked the development of brain edema and the increase in the cerebral chloride content induced by TET. Moreover, moclobemide reduced the increase in the cerebral sodium content and attenuated the neurological deficit. In conclusion, moclobemide possesses potent protective properties in this rat model of cerebral edema, suggesting potential clinical utility as a neuroprotectant.

Oxidative mechanisms contributing to the developmental neurotoxicity of nicotine and chlorpyrifos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiao, Dan; Seidler, Frederic J.; Slotkin, Theodore A.

Nicotine and chlorpyrifos are developmental neurotoxicants that, despite their differences in structure and mechanism of action, share many aspects for damage to the developing brain. Both are thought to generate oxidative radicals; in the current study, we evaluated their ability to produce lipid peroxidation in two in vitro models of neural cell development (PC12 and SH-SY5Y cells) and for nicotine, with treatment of adolescent rats in vivo. Nicotine and chlorpyrifos, in concentrations relevant to human exposures, elicited an increase in thiobarbituric-acid-reactive species (TBARS) in undifferentiated cells, an effect that was prevented by addition of the antioxidant, Vitamin E. Initiating differentiationmore » with nerve growth factor, which enhances nicotinic acetylcholine receptor expression, increased the TBARS response to nicotine but not chlorpyrifos, suggesting that the two agents act by different originating mechanisms to converge on the endpoint of oxidative damage. Furthermore, nicotine protected the cells from oxidative damage evoked by chlorpyrifos and similarly blocked the antimitotic effect of chlorpyrifos. Treatment of adolescent rats with nicotine elicited increases in TBARS in multiple brain regions when given in doses that simulate plasma nicotine concentrations found in smokers or at one-tenth the dose. Our results indicate that nicotine and chlorpyrifos elicit oxidative damage to developing neural cells both in vitro and in vivo, a mechanism that explains some of the neurodevelopmental endpoints that are common to the two agents. The balance between neuroprotectant and neurotoxicant actions of nicotine may be particularly important in situations where exposure to tobacco smoke is combined with other prooxidant insults.« less

Developmental Origins of Adult Diseases and Neurotoxicity: Epidemiological and Experimental Studies

PubMed Central

Fox, Donald A.; Grandjean, Philippe; de Groot, Didima; Paule, Merle

2013-01-01

To date, only a small number of commercial chemicals have been tested and documented as developmental neurotoxicants. Moreover, an increasing number of epidemiological, clinical and experimental studies suggest an association between toxicant or drug exposure during the perinatal period and the development of metabolic-related diseases and neurotoxicity later in life. The four speakers in this symposium presented their research results on different neurotoxic chemicals as they relate to the developmental origins of health and adult disease (DOHaD). Philippe Grandjean presented epidemiological data on children exposed to methylmercury and discussed the behavioral outcome measures as they relate to age and stage of brain development. Donald A. Fox presented data that low-to-moderate dose human equivalent gestational lead exposure produced late-onset obesity, and motor and coordination dysfunction only in male mice. Didima de Groot discussed the role of caloric restriction and/or high fat diets during gestation and/or postnatal development in mediating the metabolic and neurotoxic effects of developmental methylmercury exposure in rats. Merle G. Paule addressed the long-term changes in learning, motivation and short-term memory in aged Rhesus monkeys following 24 hour exposure to ketamine during early development. Overall, these presentations addressed fundamental issues in the emerging areas of lifetime neurotoxicity testing, differential vulnerable periods of exposure, nonmonotonic dose-response effects and neurotoxic risk assessment. PMID:22245043

Recruitment strategies should not be randomly selected: empirically improving recruitment success and diversity in developmental psychology research

PubMed Central

Sugden, Nicole A.; Moulson, Margaret C.

2015-01-01

Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: (1) recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy), (2) recruiters of particular races were more successful than recruiters of other races, and (3) differences in success were related to what the recruiter said to engage the potential participant (i.e., the script). The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: (1) some scripts were more successful than others and (2) we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families. PMID:25972829

A review of developmental and reproductive toxicity of CS2 and H2 S generated by the pesticide sodium tetrathiocarbonate.

PubMed

Silva, Marilyn

2013-04-01

Sodium tetrathiocarbonate (STTC) is an example of a pesticide that when prepared for use in aqueous solution releases two toxic products carbon disulfide (CS2 ) (active ingredient) and hydrogen sulfide (H2 S) in ambient air in equimolar concentrations resulting in potential exposure to workers and bystanders. CS2 and H2 S are pollutants that are generated from several pesticides as well as in industrial settings. Registrant submitted reports and open literature studies for STTC, CS2 and H2 S were reviewed. Previous reports suggest that CS2 was a concern as a developmental and reproductive toxicant. H2 S was also examined since it is a neurotoxicant and potentially harmful to developing fetuses. STTC did not induce developmental or reproductive effects in animal studies. CS2 was a developmental neurobehavioral toxin in rat pups (inhalation no observed effect level [NOEL]=0.01 ppm). Reproductive effects occurred in male and female factory workers after CS2 exposure (NOEL=1 ppm). H2 S had developmental effects in rats at doses at or above those observed for nasal pathology (NOEL=10 ppm) but was not a reproductive or developmental toxin in humans. The database for CS2 indicates a strong potential for developmental neurotoxicity in animals at low doses but it is lacking in acceptable, well-performed studies. There is also a lack of studies performed with CS2 and H2 S as a mixture. © 2013 Wiley Periodicals, Inc.

Testing for developmental neurotoxicity using a battery of in vitro assays for key cellular events in neurodevelopment.

PubMed

Harrill, Joshua A; Freudenrich, Theresa; Wallace, Kathleen; Ball, Kenneth; Shafer, Timothy J; Mundy, William R

2018-04-05

Medium- to high-throughput in vitro assays that recapitulate the critical processes of nervous system development have been proposed as a means to facilitate rapid testing and identification of chemicals which may affect brain development. In vivo neurodevelopment is a complex progression of distinct cellular processes. Therefore, batteries of in vitro assays that model and quantify effects on a variety of neurodevelopmental processes have the potential to identify chemicals which may affect brain development at different developmental stages. In the present study, the results of concentration-response screening of 67 reference chemicals in a battery of high content imaging and microplate reader-based assays that evaluate neural progenitor cell proliferation, neural proginitor cell apoptosis, neurite initiation/outgrowth, neurite maturation and synaptogenesis are summarized and compared. The assay battery had a high degree of combined sensitivity (87%) for categorizing chemicals known to affect neurodevelopment as active and a moderate degree of combined specificity (71%) for categorizing chemicals not associated with affects on neurodevelopment as inactive. The combined sensitivity of the assay battery was higher compared to any individual assay while the combined specificity of the assay battery was lower compared to any individual assay. When selectivity of effects for a neurodevelopmental endpoint as compared to general cytotoxicity was taken into account, the combined sensitivity of the assay battery decreased (68%) while the combined specificity increased (93%). The identity and potency of chemicals identified as active varied across the assay battery, underscoring the need for use of a combination of diverse in vitro models to comprehensively screen chemicals and identify those which potentially affect neurodevelopment. Overall, these data indicate that a battery of assays which address many different processes in nervous system development may be used to

Mechanistic insight into neurotoxicity induced by developmental insults

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamm, Christoffer; Ceccatelli, Sandra

Epidemiological and/or experimental studies have shown that unfavorable prenatal environmental factors, such as stress or exposure to certain neurotoxic environmental contaminants, may have adverse consequences for neurodevelopment. Alterations in neurogenesis can have harmful effects not only for the developing nervous system, but also for the adult brain where neurogenesis is believed to play a role in learning, memory, and even in depression. Many recent advances in the understanding of the complex process of nervous system development can be integrated into the field of neurotoxicology. In the past 15 years we have been using cultured neural stem or progenitor cells tomore » investigate the effects of neurotoxic stimuli on cell survival, proliferation and differentiation, with special focus on heritable effects. This is an overview of the work performed by our group in the attempt to elucidate the mechanisms of developmental neurotoxicity and possibly provide relevant information for the understanding of the etiopathogenesis of complex brain disorders. - Highlights: • The developing nervous system is highly sensitive to toxic insults. • Neural stem cells are relevant models for mechanistic studies as well as for identifying heritable effects due to epigenetic changes. • Depending on the dose, the outcome of exposure to neurotoxicants ranges from altered proliferation and differentiation to cell death. • The elucidation of neurotoxicity mechanisms is relevant for understanding the etiopathogenesis of developmental and adult nervous system disorders.« less

Assessment of attention and inhibitory control in rodent developmental neurotoxicity studies.

PubMed

Driscoll, Lori L; Strupp, Barbara J

2015-01-01

In designing screens to assess potential neurotoxicants, the paramount goal is that the selected assessment tools detect dysfunction if it exists. This goal is particularly challenging in the case of cognitive assessments. Cognition is not a unitary phenomenon, and indeed there is growing evidence that different aspects of cognitive functioning are subserved by distinct neural systems. As a result, if a particular neurotoxicant selectively damages certain neural systems but not others, it can impair some cognitive, sensory, or affective functions, but leave many others intact. Accordingly, studies with human subjects use batteries of cognitive tests, cognizant of the fact that no one test is capable of detecting all forms of cognitive dysfunction. In contrast, assessment of cognitive functioning in non-human animal developmental neurotoxicity (DNT) studies typically consists of a single, presumably representative, "learning and memory" task that is expected to detect all potential effects on cognitive functioning. Streamlining the cognitive assessment in these studies saves time and money, but these shortcuts can have serious consequences if the aspect of cognitive functioning that is impaired is not tapped by the single selected task. In particular, executive functioning - a constellation of cognitive functions which enables the organism to focus on multiple streams of information simultaneously, and revise plans as necessary - is poorly assessed in most animal DNT studies. The failure to adequately assess these functions - which include attention, working memory, inhibitory control, and planning - is particularly worrisome in light of evidence that the neural systems that subserve these functions may be uniquely vulnerable to early developmental insults. We illustrate the importance of tapping these areas of functioning in DNT studies by describing the pattern of effects produced by early developmental Pb exposure. Rats exposed to lead (Pb) early in development

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish

PubMed Central

Kung, Tiffany S.; Richardson, Jason R.; Cooper, Keith R.; White, Lori A.

2015-01-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25–0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3–72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. PMID:25912032

Annual research review: Rare genotypes and childhood psychopathology--uncovering diverse developmental mechanisms of ADHD risk.

PubMed

Scerif, Gaia; Baker, Kate

2015-03-01

Through the increased availability and sophistication of genetic testing, it is now possible to identify causal diagnoses in a growing proportion of children with neurodevelopmental disorders. In addition to developmental delay and intellectual disability, many genetic disorders are associated with high risks of psychopathology, which curtail the wellbeing of affected individuals and their families. Beyond the identification of significant clinical needs, understanding the diverse pathways from rare genetic mutations to cognitive dysfunction and emotional-behavioural disturbance has theoretical and practical utility. We overview (based on a strategic search of the literature) the state-of-the-art on causal mechanisms leading to one of the most common childhood behavioural diagnoses - attention deficit hyperactivity disorder (ADHD) - in the context of specific genetic disorders. We focus on new insights emerging from the mapping of causal pathways from identified genetic differences to neuronal biology, brain abnormalities, cognitive processing differences and ultimately behavioural symptoms of ADHD. First, ADHD research in the context of rare genotypes highlights the complexity of multilevel mechanisms contributing to psychopathology risk. Second, comparisons between genetic disorders associated with similar psychopathology risks can elucidate convergent or distinct mechanisms at each level of analysis, which may inform therapeutic interventions and prognosis. Third, genetic disorders provide an unparalleled opportunity to observe dynamic developmental interactions between neurocognitive risk and behavioural symptoms. Fourth, variation in expression of psychopathology risk within each genetic disorder points to putative moderating and protective factors within the genome and the environment. A common imperative emerging within psychopathology research is the need to investigate mechanistically how developmental trajectories converge or diverge between and within

Developmental Neurotoxicity Study of Dietary Bisphenol A in Sprague-Dawley Rats

PubMed Central

Stump, Donald G.; Beck, Melissa J.; Radovsky, Ann; Garman, Robert H.; Freshwater, Lester L.; Sheets, Larry P.; Marty, M. Sue; Waechter, John M.; Dimond, Stephen S.; Van Miller, John P.; Shiotsuka, Ronald N.; Beyer, Dieter; Chappelle, Anne H.; Hentges, Steven G.

2010-01-01

This study was conducted to determine the potential of bisphenol A (BPA) to induce functional and/or morphological effects to the nervous system of F1 offspring from dietary exposure during gestation and lactation according to the Organization for Economic Cooperation and Development and U.S. Environmental Protection Agency guidelines for the study of developmental neurotoxicity. BPA was offered to female Sprague-Dawley Crl:CD (SD) rats (24 per dose group) and their litters at dietary concentrations of 0 (control), 0.15, 1.5, 75, 750, and 2250 ppm daily from gestation day 0 through lactation day 21. F1 offspring were evaluated using the following tests: detailed clinical observations (postnatal days [PNDs] 4, 11, 21, 35, 45, and 60), auditory startle (PNDs 20 and 60), motor activity (PNDs 13, 17, 21, and 61), learning and memory using the Biel water maze (PNDs 22 and 62), and brain and nervous system neuropathology and brain morphometry (PNDs 21 and 72). For F1 offspring, there were no treatment-related neurobehavioral effects, nor was there evidence of neuropathology or effects on brain morphometry. Based on maternal and offspring body weight reductions, the no-observed-adverse-effect level (NOAEL) for systemic toxicity was 75 ppm (5.85 and 13.1 mg/kg/day during gestation and lactation, respectively), with no treatment-related effects at lower doses or nonmonotonic dose responses observed for any parameter. There was no evidence that BPA is a developmental neurotoxicant in rats, and the NOAEL for developmental neurotoxicity was 2250 ppm, the highest dose tested (164 and 410 mg/kg/day during gestation and lactation, respectively). PMID:20164145

The protective role of nitric oxide in a neurotoxicant-induced demyelinating model.

PubMed

Arnett, Heather A; Hellendall, Ron P; Matsushima, Glenn K; Suzuki, Kinuko; Laubach, Victor E; Sherman, Paula; Ting, Jenny P-Y

2002-01-01

Demyelination is often associated with acute inflammatory events involving the recruitment-activation of microglia/macrophage, astrocytes, and leukocytes. The ultimate role of inflammatory products in demyelinating disease and in the survival of oligodendrocytes, the myelin forming cells, is unresolved. The current study examines the role of inducible NO synthase (iNOS)-derived NO in a neurotoxicant-induced model of demyelination. NO levels were greatly elevated in the midline corpus callosum during demyelination in genetically intact C57BL/6 mice, and this NO was due solely to the induction of iNOS, as the correlates of NO were not found in mice lacking iNOS. C57BL/6 mice lacking iNOS exhibited more demyelination, but did not display an increased overall cellularity in the corpus callosum, attributable to an unimpeded microglia/macrophage presence. An enhanced course of pathology was noted in mice lacking iNOS. This was associated with a greater depletion of mature oligodendrocytes, most likely due to apoptosis of oligodendrocytes. Microglia and astrocytes did not undergo apoptosis during treatment. Our results suggest a moderately protective role for NO during acute inflammation-association demyelination.

Paddling with Individuals with Developmental Disabilities

ERIC Educational Resources Information Center

Todd, Teri; Medina, Jacquie

2013-01-01

Although there is a variety of literature that offers adaptations and teaching suggestions for paddling with individuals who have physical disabilities, only a few address the needs of individuals with developmental disabilities (Gullion, 2009; Zeller, 2009). Developmental disabilities refer to a diverse group of severe chronic conditions that are…

Diversity of developmental patterns in achelate lobsters-today and in the Mesozoic.

PubMed

Haug, Joachim T; Audo, Denis; Charbonnier, Sylvain; Haug, Carolin

2013-11-01

Modern achelate lobsters, slipper and spiny lobsters, have a specific post-embryonic developmental pattern with the following phases: phyllosoma, nisto (slipper lobsters) or puerulus (spiny lobsters), juvenile and adult. The phyllosoma is a peculiar larva, which transforms through a metamorphic moult into another larval form, the nisto or puerulus which largely resembles the juvenile. Unlike the nisto and puerulus, the phyllosoma is characterised by numerous morphological differences to the adult, e.g. a thin head shield, elongate appendages, exopods on these appendages and a special claw. Our reinvestigation of the 85 million years old fossil "Eryoneicus sahelalmae" demonstrates that it represents an unusual type of achelatan lobster larva, characterised by a mixture of phyllosoma and post-phyllosoma characters. We ascribe it to its own genus: Polzicaris nov. gen. We study its significance by comparisons with other cases of Mesozoic fossil larvae also characterised by a mixture of characters. Accordingly, all these larvae are interpreted as ontogenetic intermediates between phyllosoma and post-phyllosoma morphology. Remarkably, most of the larvae show a unique mixture of retained larval and already developed post-larval features. Considering the different-and incompatible-mixture of characters of each of these larvae and their wide geographical and temporal distribution, we interpret all these larvae as belonging to distinct species. The particular character combinations in the different larvae make it currently difficult to reconstruct an evolutionary scenario with a stepwise character acquisition. Yet, it can be concluded that a larger diversity of larval forms and developmental patterns occurred in Mesozoic than in modern faunas.

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

PubMed

Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

2015-08-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

RISK ASSESSMENT OF THYROID HORMONE DISRUPTION AND MIXTURES IN MARINE BIOTA

EPA Science Inventory

Varieties of chemicals alter thyroid hormones (THs) in vertabrates. The importance of THs during neurodevelopment, suggest that these chemicals would likely be developmental neurotoxicants. A number of epidemiological studies have demonstrated associations between exposure to p...

Development and Example Application of a Pilot Model for the Biogeochemical Cycling of Mercury in Watersheds: SERAFM-NPS

EPA Science Inventory

Mercury is a developmental neurotoxicant, ubiquitous in the environment, existing both naturally and through anthropogenic additions, resulting in human and ecological exposure risks primarily via consumption of mercury contaminated fish tissue. To better understand the risk ass...

Diversity of activity participation determines bone mineral content in the lower limbs of pre-pubertal children with developmental coordination disorder.

PubMed

Fong, S S M; Vackova, D; Choi, A W M; Cheng, Y T Y; Yam, T T T; Guo, X

2018-04-01

This study examined the relationships between activity participation and bone mineralization in children with developmental coordination disorder. Limited participation in physical, recreational, social, and skill-based and self-improvement activities contributed to lower bone mineral content. For improved bone health, these children should participate in a variety of activities, not only physical activities. Limited activity participation in children with developmental coordination disorder (DCD) may have a negative impact on bone mineral accrual. The objectives of this study were to compare bone mineralization and activity participation patterns of pre-pubertal children with DCD and those with typical development, and to determine the association between activity participation patterns and bone mineralization in children with DCD. Fifty-two children with DCD (mean age = 7.51 years) and 61 children with typical development (mean age = 7.22 years) participated in the study. Appendicular and total body (less head) bone mineral content (BMC) and bone mineral density (BMD) were evaluated by a whole-body dual-energy X-ray absorptiometry scan. Activity participation patterns were assessed using the Children's Assessment of Participation and Enjoyment (CAPE) questionnaire. Children with DCD had lower appendicular and total body BMCs and BMDs than children with typical development overall (p < 0.05). They also had lower CAPE total activity and physical activity diversity scores (p < 0.05). After accounting for the effects of age, sex, height, lean mass, and fat mass, the total activity diversity score remained independently associated with leg BMC in children with DCD, explaining 5.1% of the variance (p = 0.030). However, the physical activity diversity score was no longer associated with leg BMC (p = 0.090). Diversity of activity participation and bone mineralization were lower in pre-pubertal children with DCD. Decreased total activity

A developmental psychopathology perspective on adolescence.

PubMed

Cicchetti, Dante; Rogosch, Fred A

2002-02-01

Developmental psychopathology offers an integrative framework for conceptualizing the course of development during adolescence, with particular relevance for understanding continuity and the emergence of psychopathology during this and subsequent developmental periods. In this article, the utility of a developmental psychopathology perspective for informing the design of research, prevention, and intervention is highlighted. Interdisciplinary, organizational models of development, emphasizing the dynamic relations between the developing individual and internal and external contexts, are discussed. Examination of boundaries between abnormal and normal development during adolescence offers important vantage points for articulating diversity in the developmental course during this period. Conceptualizing divergence and convergence in developmental pathways, continuity and discontinuity in development, and the transactions of risk and protective processes leading to maladaptation, psychopathology, and resilience are highlighted.

Plants: Novel Developmental Processes.

ERIC Educational Resources Information Center

Goldberg, Robert B.

1988-01-01

Describes the diversity of plants. Outlines novel developmental and complex genetic processes that are specific to plants. Identifies approaches that can be used to solve problems in plant biology. Cites the advantages of using higher plants for experimental systems. (RT)

EFFECT OF AROCLOR 1254 ON THE TRANSCRIPTION FACTOR CREB AND CELL VIABILITY IN A PRIMARY CULTURE OF IMMATURE CORTICAL CELLS.

EPA Science Inventory

Considerable work indicates that elevations in Ca2+ levels and kinase activity are sensitive responses to polychlorinated biphenyls (PCBs), which are developmental neurotoxicants. In cortical cells in vitro the PCB mixture Aroclor 1254 (A1254) induces temporally and mechanistica...

Quantitative Assessment of Neurite Outgrowth in PC12 Cells

EPA Science Inventory

In vitro test methods can provide a rapid approach for the screening of large numbers of chemicals for their potential to produce toxicity. In order to identify potential developmental neurotoxicants, assessment of critical neurodevelopmental processes such as neuronal differenti...

ASSESSMENT OF CHEMICAL EFFECTS ON NEURITE OUTGROWTH, NEURONAL POLARIZATION AND SYNAPTOGENESIS IN RAT CORTICAL NEURONS USING HIGH CONTENT IMAGE ANALYSIS

EPA Science Inventory

There is a need for efficient, cost-effective methods for screening and prioritization of potential developmental neurotoxicants. One approach uses in vitro cell culture models that can recapitulate the critical processes of nervous system development. In vitro, primary cultures ...

Neuronal models for evaluation of proliferation in vitro using high content screening

EPA Science Inventory

In vitro test methods can provide a rapid approach for the screening of large numbers of chemicals for their potential to produce toxicity (hazard identification). In order to identify potential developmental neurotoxicants, a battery of in vitro tests for neurodevelopmental proc...

ONTOGENY OF PROTEINS ASSOCIATED WITH NEURITE GROWTH AND SYNAPTOGENESIS IN CEREBELLAR GRANULE CELLS IN VITRO.

EPA Science Inventory

In vitro techniques may be useful in screening for effects of developmental neurotoxicants. Previously, we characterized changes in biochemical markers associated with neuronal development in a PC12 cell model of differentiation and growth. The current research extended these stu...

RODENT AND HUMAN NEUROPROGENITOR CELLS FOR HIGH-CONTENT SCREENS OF CHEMICAL EFFECTS ON PROLIFERATION AND APOPTOSIS

EPA Science Inventory

The objective of these experiments is to develop high-throughput screens for proliferation and apoptosis in order to compare rodent and human neuroprogenitor cell responses to potential developmental neurotoxicants. Effects of 4 chemicals on proliferation and apoptosis in mouse c...

Handbook of Developmental Disabilities

ERIC Educational Resources Information Center

Odom, Samuel L., Ed.; Horner, Robert H., Ed.; Snell, Martha E., Ed.; Blacher, Jan, Ed.

2007-01-01

This authoritative handbook reviews the breadth of current knowledge about developmental disabilities: neuroscientific and genetic foundations; the impact on health, learning, and behavior; and effective educational and clinical practices. Leading authorities analyze what works in intervening with diverse children and families, from infancy…

Assessment of chemical effects on neurite outgrowth in PC12 cells using high content screening

EPA Science Inventory

Identification of chemicals that pose a hazard to the developing nervous system is the first step in reducing human exposure and preventing health risks to infants and children. In response to the need for more efficient methods to identify potential developmental neurotoxicants,...

Disposition of the brominated flame retardant HBCD alpha and gamma in developing mice over time

EPA Science Inventory

Hexabromocyclododecane (HBCD) is a developmental neurotoxicant in mice following a single exposure on postnatal day 10 (PND 10). HBCD is a mixture of 3 stereoisomers, alpha (a), beta (~) and gamma (y). Evidence oftoxicity and lack of stereoisomer studies drives the importance of ...

Developmental Change and Intraindividual Variability: Relating Cognitive Aging to Cognitive Plasticity, Cardiovascular Lability, and Emotional Diversity

PubMed Central

Ram, Nilam; Gerstorf, Denis; Lindenberger, Ulman; Smith, Jacqui

2010-01-01

Repeated assessments obtained over years can be used to measure individuals’ developmental change, whereas repeated assessments obtained over a few weeks can be used to measure individuals’ dynamic characteristics. Using data from a burst of measurement embedded in the Berlin Aging Study (BASE: Baltes & Mayer, 1999), we illustrate and examine how long-term changes in cognitive ability are related to short-term changes in cognitive performance, cardiovascular function, and emotional experience. Our findings suggest that “better” cognitive aging over approximately13 years was associated with greater cognitive plasticity, less cardiovascular lability, and less emotional diversity over approximately 2 weeks at age 90 years. The study highlights the potential benefits of multi-time scale longitudinal designs for the study of individual function and development. PMID:21443355

Macroevolutionary developmental biology: Embryos, fossils, and phylogenies.

PubMed

Organ, Chris L; Cooper, Lisa Noelle; Hieronymus, Tobin L

2015-10-01

The field of evolutionary developmental biology is broadly focused on identifying the genetic and developmental mechanisms underlying morphological diversity. Connecting the genotype with the phenotype means that evo-devo research often considers a wide range of evidence, from genetics and morphology to fossils. In this commentary, we provide an overview and framework for integrating fossil ontogenetic data with developmental data using phylogenetic comparative methods to test macroevolutionary hypotheses. We survey the vertebrate fossil record of preserved embryos and discuss how phylogenetic comparative methods can integrate data from developmental genetics and paleontology. Fossil embryos provide limited, yet critical, developmental data from deep time. They help constrain when developmental innovations first appeared during the history of life and also reveal the order in which related morphologies evolved. Phylogenetic comparative methods provide a powerful statistical approach that allows evo-devo researchers to infer the presence of nonpreserved developmental traits in fossil species and to detect discordant evolutionary patterns and processes across levels of biological organization. © 2015 Wiley Periodicals, Inc.

Gene expression profiles following exposure to a developmental neurotoxicant, Aroclor 1254: Pathway analysis for possible mode(s) of action

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royland, Joyce E.; Kodavanti, Prasada Rao S.

2008-09-01

Epidemiological studies indicate that low levels of polychlorinated biphenyl (PCB) exposure can adversely affect neurocognitive development. In animal models, perturbations in calcium signaling, neurotransmitters, and thyroid hormones have been postulated as potential mechanisms for PCB-induced developmental neurotoxicity. In order to understand the role of these proposed mechanisms and to identify other mechanisms in PCB-induced neurotoxicity, we have chosen a global approach utilizing oligonucleotide microarrays to examine gene expression profiles in the brain following developmental exposure to Aroclor 1254 (0 or 6 mg/kg/day from gestation day 6 through postnatal day (PND) 21) in Long-Evans rats. Gene expression levels in the cerebellummore » and hippocampus from PNDs 7 and 14 animals were determined on Affymetrix rat 230A{sub 2}.0 chips. In the cerebellum, 87 transcripts were altered at PND7 compared to 27 transcripts at PND14 by Aroclor 1254 exposure, with only one transcript affected at both ages. In hippocampus, 175 transcripts and 50 transcripts were altered at PND7 and PND14, respectively, by Aroclor 1254 exposure with five genes commonly affected. Functional analysis suggests that pathways related to calcium homeostasis (Gng3, Ryr2, Trdn, Cacna1a), intracellular signaling (Camk2d, Stk17b, Pacsin2, Ryr2, Trio, Fert2, Ptk2b), axonal guidance (Lum, Mxd3, Akap11, Gucy1b3), aryl hydrocarbon receptor signaling (Nfia, Col1a2), and transcripts involved in cell proliferation (Gspt2, Cdkn1c, Ptk2b) and differentiation (Ifitm31, Hpca, Zfp260, Igsf4a, Hes5) leading to the development of nervous system were significantly altered by Aroclor 1254 exposure. Of the two brain regions examined, Aroclor 1254-induced genomic changes were greater in the hippocampus than the cerebellum. The genomic data suggests that PCB-induced neurotoxic effects were due to disruption of normal ontogenetic pattern of nervous system growth and development by altering intracellular signaling

Changes in mitogen-activated protein kinase in cerebeller granule neurons by polybrominated diphenyl ethers and polychlorinated biphenyls

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) are used as additive flame retardants and have been detected in human blood, adipose tissue, and breast milk. Both in vitro and in vivo studies have shown that the effects of PBDEs are similar to the known human developmental neurotoxicants ...

Prenatal Dexamethasone Augments the Sex-Selective Developmental Neurotoxicity of Chlorpyrifos: Implications for Vulnerability after Pharmacotherapy for Preterm Labor

PubMed Central

Slotkin, Theodore A.; Card, Jennifer; Infante, Alice; Seidler, Frederic J.

2013-01-01

Glucocorticoids are routinely given in preterm labor and are also elevated by maternal stress; organophosphate exposures are virtually ubiquitous, so coexposures to these two agents are pervasive. We administered dexamethasone to pregnant rats on gestational days 17–19 at a standard therapeutic dose (0.2 mg/kg); offspring were then given chlorpyrifos on postnatal days 1–4, at a dose (1 mg/kg) that produces barely-detectable (<10%) inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of dexamethasone and chlorpyrifos given individually. Dexamethasone did not enhance the systemic toxicity of chlorpyrifos, as evidenced by weight gain and measurements of cholinesterase inhibition during chlorpyrifos treatment. Nevertheless, it enhanced the loss of presynaptic ACh function selectively in females, who ordinarily show sparing of organophosphate developmental neurotoxicity relative to males. Females receiving the combined treatment showed decrements in choline transporter binding and choline acetyltransferase activity that were unique (not found with either treatment alone), as well as additive decrements in nicotinic receptor binding. On the other hand, males given dexamethasone showed no augmentation of the effects of chlorpyrifos. Our findings indicate that prior dexamethasone exposure could create a subpopulation that is especially vulnerable to the adverse effects of organophosphates or other developmental neurotoxicants. PMID:23416428

Issue Brief on Diversity

ERIC Educational Resources Information Center

Division on Developmental Disabilities, Council for Exceptional Children (NJ1), 2013

2013-01-01

During the past year, the Diversity Committee of the Division of Developmental Disabilities (DDD) Board worked with the Board and the Issues Committee Chair to develop an issue brief addressing diversity, its impact on the membership and the wider community that is served by the work of DDD, resulting in recommendations that will influence policy…

Predictors of Developmental Outcome in Very Low Birth Weight Infants.

ERIC Educational Resources Information Center

Macias, Michelle M.; Saylor, Conway F.; Younginer, Erik; Katikaneni, Lakshmi D.

2000-01-01

Examined predictors of development in very low birth weight infants from diverse backgrounds. Found that low income and greater frequency of medical problems predicted developmental risk on the Bayley Scales. In two-parent households, paternal education predicted developmental scores. Several individual biomedical factors predicted…

Natural variation in stomatal abundance of Arabidopsis thaliana includes cryptic diversity for different developmental processes

PubMed Central

Delgado, Dolores; Alonso-Blanco, Carlos; Fenoll, Carmen; Mena, Montaña

2011-01-01

Background and Aims Current understanding of stomatal development in Arabidopsis thaliana is based on mutations producing aberrant, often lethal phenotypes. The aim was to discover if naturally occurring viable phenotypes would be useful for studying stomatal development in a species that enables further molecular analysis. Methods Natural variation in stomatal abundance of A. thaliana was explored in two collections comprising 62 wild accessions by surveying adaxial epidermal cell-type proportion (stomatal index) and density (stomatal and pavement cell density) traits in cotyledons and first leaves. Organ size variation was studied in a subset of accessions. For all traits, maternal effects derived from different laboratory environments were evaluated. In four selected accessions, distinct stomatal initiation processes were quantitatively analysed. Key Results and Conclusions Substantial genetic variation was found for all six stomatal abundance-related traits, which were weakly or not affected by laboratory maternal environments. Correlation analyses revealed overall relationships among all traits. Within each organ, stomatal density highly correlated with the other traits, suggesting common genetic bases. Each trait correlated between organs, supporting supra-organ control of stomatal abundance. Clustering analyses identified accessions with uncommon phenotypic patterns, suggesting differences among genetic programmes controlling the various traits. Variation was also found in organ size, which negatively correlated with cell densities in both organs and with stomatal index in the cotyledon. Relative proportions of primary and satellite lineages varied among the accessions analysed, indicating that distinct developmental components contribute to natural diversity in stomatal abundance. Accessions with similar stomatal indices showed different lineage class ratios, revealing hidden developmental phenotypes and showing that genetic determinants of primary and

STRUCTURE-ACTIVITY RELATIONSHIP AMONG ORGANOTINS IN AN IN VITRO MODEL OF NEURONAL DIFFERENTIATION AND PROGRAMMED CELL DEATH.

EPA Science Inventory

The organotins are used as heat stabilizers in PVC pipes and as marine biocides. Human exposure to monomethyltin (MMT) and dimethyltin (DMT) can occur in the water supply as a result of leaching from PVC pipes. Developmental exposure of rats to MMT and the known neurotoxicant t...

Early Childhood Household Smoke Exposure Predicts Less Task-Oriented Classroom Behavior at Age 10

ERIC Educational Resources Information Center

Pagani, Linda S.; Fitzpatrick, Caroline

2016-01-01

Secondhand tobacco smoke is considered a developmental neurotoxicant especially given underdeveloped vital systems in young children. An ecological test of its negative influence on brain development can be made by examining the prospective association between early childhood household smoke exposure and later classroom behavior. Using a…

Behavioral toxicology, risk assessment, and chlorinated hydrocarbons.

PubMed Central

Evangelista de Duffard, A M; Duffard, R

1996-01-01

Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a wide variety of chemicals including polychlorinated biphenyls, clioquinol, trichloroethylene, hexachlorophene, organochlorine insecticides (DDT, dicofol, chlordecone,dieldrin, and lindane), and phenoxyherbicides. Each of these chemicals has effects on motor, sensory, or cognitive function that are detectable using functional measures such as behavior. Furthermore, there is evidence that if exposure occurs during critical periods of development, many of the chlorinated hydrocarbons are developmental neurotoxicants. Developmental neurotoxicity is frequently expressed as alterations in motor function or cognitive abilities or changes in the ontogeny of sensorimotor reflexes. Neurotoxicity risk assessment should include assessments of the full range of possible neurotoxicological effects, including both structural and functional indicators of neurotoxicity. PMID:9182042

Developmental Stability Covaries with Genome-Wide and Single-Locus Heterozygosity in House Sparrows

PubMed Central

Vangestel, Carl; Mergeay, Joachim; Dawson, Deborah A.; Vandomme, Viki; Lens, Luc

2011-01-01

Fluctuating asymmetry (FA), a measure of developmental instability, has been hypothesized to increase with genetic stress. Despite numerous studies providing empirical evidence for associations between FA and genome-wide properties such as multi-locus heterozygosity, support for single-locus effects remains scant. Here we test if, and to what extent, FA co-varies with single- and multilocus markers of genetic diversity in house sparrow (Passer domesticus) populations along an urban gradient. In line with theoretical expectations, FA was inversely correlated with genetic diversity estimated at genome level. However, this relationship was largely driven by variation at a single key locus. Contrary to our expectations, relationships between FA and genetic diversity were not stronger in individuals from urban populations that experience higher nutritional stress. We conclude that loss of genetic diversity adversely affects developmental stability in P. domesticus, and more generally, that the molecular basis of developmental stability may involve complex interactions between local and genome-wide effects. Further study on the relative effects of single-locus and genome-wide effects on the developmental stability of populations with different genetic properties is therefore needed. PMID:21747940

Developmental neurotoxicity elicited by prenatal or postnatal chlorpyrifos exposure: effects on neurospecific proteins indicate changing vulnerabilities.

PubMed

Garcia, Stephanie J; Seidler, Frederic J; Slotkin, Theodore A

2003-03-01

The developmental neurotoxicity of the organophosphate pesticide chlorpyrifos (CPF) is thought to involve both neurons and glia, thus producing a prolonged window of vulnerability. To characterize the cell types and brain regions involved in these effects, we administered CPF to developing rats and examined neuroprotein markers for oligodendrocytes (myelin basic protein, MBP), for neuronal cell bodies (neurofilament 68 kDa, NF68), and for developing axons (neurofilament 200 kDa, NF200). Prenatal CPF administration on gestational days (GDs) 17-20 elicited an immediate (GD21) enhancement of MBP and NF68; by postnatal day (PN) 30, however, there were deficits in all three biomarkers, with the effect restricted to females. Exposure in the early postnatal period, PN1-4, did not evoke significant short-term or long-term changes in the neuroproteins. However, with treatment on PN11-14, we found reductions in MBP in the immediate posttreatment period (PN15, PN20) throughout the brain, and deficiencies across all three proteins emerged by PN30. With this regimen, males were targeted preferentially. The sex-selective effects seen here for the GD17-20 and PN11-14 regimens match those reported earlier for subsequent behavioral performance. These results indicate a shift in the populations of neural cells targeted by CPF, dependent upon the period of exposure. Similarly, developmental differences in the sex selectivity of the biochemical mechanisms underlying neurotoxicant actions are likely to contribute to discrete behavioral outcomes.

The Developmental Model of Intercultural Sensitivity: A Tool for Understanding Principals' Cultural Competence

ERIC Educational Resources Information Center

Hernandez, Frank; Kose, Brad W.

2012-01-01

Principals' understanding and skills pertaining to diversity are important in leading diverse schools and preparing all students for a democratic and multicultural society. Although educational leadership scholars have theorized about exemplary leadership of and for diversity, a developmental perspective on principals' diversity or cultural…

Supplemental Instruction in Developmental Mathematics

ERIC Educational Resources Information Center

Phelps, Julie M.; Evans, Ruby

2006-01-01

Mirroring the changing demographics of the nation, the community college student population continues to grow in size and diversity. Almost half of all students who enter these institutions need at least one remedial course--which is often developmental mathematics. Developed in 1973, Supplemental Instruction (SI) has quickly gained recognition as…

Developmental Principles: Fact or Fiction

PubMed Central

Durston, A. J.

2012-01-01

While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, “whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm”. We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level?) adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them. PMID:22489210

Developmental principles: fact or fiction.

PubMed

Durston, A J

2012-01-01

While still at school, most of us are deeply impressed by the underlying principles that so beautifully explain why the chemical elements are ordered as they are in the periodic table, and may wonder, with the theoretician Brian Goodwin, "whether there might be equally powerful principles that account for the awe-inspiring diversity of body forms in the living realm". We have considered the arguments for developmental principles, conclude that they do exist and have specifically identified features that may generate principles associated with Hox patterning of the main body axis in bilaterian metazoa in general and in the vertebrates in particular. We wonder whether this exercise serves any purpose. The features we discuss were already known to us as parts of developmental mechanisms and defining developmental principles (how, and at which level?) adds no insight. We also see little profit in the proposal by Goodwin that there are principles outside the emerging genetic mechanisms that need to be taken into account. The emerging developmental genetic hierarchies already reveal a wealth of interesting phenomena, whatever we choose to call them.

Functional Dysregulation of CDC42 Causes Diverse Developmental Phenotypes.

PubMed

Martinelli, Simone; Krumbach, Oliver H F; Pantaleoni, Francesca; Coppola, Simona; Amin, Ehsan; Pannone, Luca; Nouri, Kazem; Farina, Luciapia; Dvorsky, Radovan; Lepri, Francesca; Buchholzer, Marcel; Konopatzki, Raphael; Walsh, Laurence; Payne, Katelyn; Pierpont, Mary Ella; Vergano, Samantha Schrier; Langley, Katherine G; Larsen, Douglas; Farwell, Kelly D; Tang, Sha; Mroske, Cameron; Gallotta, Ivan; Di Schiavi, Elia; Della Monica, Matteo; Lugli, Licia; Rossi, Cesare; Seri, Marco; Cocchi, Guido; Henderson, Lindsay; Baskin, Berivan; Alders, Mariëlle; Mendoza-Londono, Roberto; Dupuis, Lucie; Nickerson, Deborah A; Chong, Jessica X; Meeks, Naomi; Brown, Kathleen; Causey, Tahnee; Cho, Megan T; Demuth, Stephanie; Digilio, Maria Cristina; Gelb, Bruce D; Bamshad, Michael J; Zenker, Martin; Ahmadian, Mohammad Reza; Hennekam, Raoul C; Tartaglia, Marco; Mirzaa, Ghayda M

2018-01-17

Exome sequencing has markedly enhanced the discovery of genes implicated in Mendelian disorders, particularly for individuals in whom a known clinical entity could not be assigned. This has led to the recognition that phenotypic heterogeneity resulting from allelic mutations occurs more commonly than previously appreciated. Here, we report that missense variants in CDC42, a gene encoding a small GTPase functioning as an intracellular signaling node, underlie a clinically heterogeneous group of phenotypes characterized by variable growth dysregulation, facial dysmorphism, and neurodevelopmental, immunological, and hematological anomalies, including a phenotype resembling Noonan syndrome, a developmental disorder caused by dysregulated RAS signaling. In silico, in vitro, and in vivo analyses demonstrate that mutations variably perturb CDC42 function by altering the switch between the active and inactive states of the GTPase and/or affecting CDC42 interaction with effectors, and differentially disturb cellular and developmental processes. These findings reveal the remarkably variable impact that dominantly acting CDC42 mutations have on cell function and development, creating challenges in syndrome definition, and exemplify the importance of functional profiling for syndrome recognition and delineation. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

The classification of motor neuron defects in the zebrafish embryo toxicity test (ZFET) as an animal alternative approach to assess developmental neurotoxicity.

PubMed

Muth-Köhne, Elke; Wichmann, Arne; Delov, Vera; Fenske, Martina

2012-07-01

Rodents are widely used to test the developmental neurotoxicity potential of chemical substances. The regulatory test procedures are elaborate and the requirement of numerous animals is ethically disputable. Therefore, non-animal alternatives are highly desirable, but appropriate test systems that meet regulatory demands are not yet available. Hence, we have developed a new developmental neurotoxicity assay based on specific whole-mount immunostainings of primary and secondary motor neurons (using the monoclonal antibodies znp1 and zn8) in zebrafish embryos. By classifying the motor neuron defects, we evaluated the severity of the neurotoxic damage to individual primary and secondary motor neurons caused by chemical exposure and determined the corresponding effect concentration values (EC₅₀). In a proof-of-principle study, we investigated the effects of three model compounds thiocyclam, cartap and disulfiram, which show some neurotoxicity-indicating effects in vertebrates, and the positive controls ethanol and nicotine and the negative controls 3,4-dichloroaniline (3,4-DCA) and triclosan. As a quantitative measure of the neurotoxic potential of the test compounds, we calculated the ratios of the EC₅₀ values for motor neuron defects and the cumulative malformations, as determined in a zebrafish embryo toxicity test (zFET). Based on this index, disulfiram was classified as the most potent and thiocyclam as the least potent developmental neurotoxin. The index also confirmed the control compounds as positive and negative neurotoxicants. Our findings demonstrate that this index can be used to reliably distinguish between neurotoxic and non-neurotoxic chemicals and provide a sound estimate for the neurodevelopmental hazard potential of a chemical. The demonstrated method can be a feasible approach to reduce the number of animals used in developmental neurotoxicity evaluation procedures. Copyright © 2012 Elsevier Inc. All rights reserved.

Parental Stress in Families of Children With Autism and Other Developmental Disabilities.

PubMed

Valicenti-McDermott, Maria; Lawson, Katharine; Hottinger, Kathryn; Seijo, Rosa; Schechtman, Merryl; Shulman, Lisa; Shinnar, Shlomo

2015-11-01

The level of parental stress in families of children with autism and other developmental disabilities and its association with child comorbid symptoms was studied in an ethnically diverse population, in a cross-sectional study with structured interview. The sample included 50 families of children with autism and 50 families of children with other developmental disabilities, matched by age/gender. Interview included Parenting Stress Index-Short Form, Gastrointestinal Questionnaire, Child Sleep Habits Questionnaire, and Aberrant Behavior Checklist. In this ethnically diverse sample, parental stress was significantly higher for the autism group and for non-Hispanic and US-born mothers. In both study groups, parental stress was related to child irritability. Parental stress was also related to gastrointestinal problems in the autism group and to sleep difficulties in the developmental disabilities group. Targeting child irritability may be particularly important in reducing parental stress for families of children with autism and other developmental disabilities. © The Author(s) 2015.

Angiosperm ovules: diversity, development, evolution

PubMed Central

Endress, Peter K.

2011-01-01

Background Ovules as developmental precursors of seeds are organs of central importance in angiosperm flowers and can be traced back in evolution to the earliest seed plants. Angiosperm ovules are diverse in their position in the ovary, nucellus thickness, number and thickness of integuments, degree and direction of curvature, and histological differentiations. There is a large body of literature on this diversity, and various views on its evolution have been proposed over the course of time. Most recently evo–devo studies have been concentrated on molecular developmental genetics in ovules of model plants. Scope The present review provides a synthetic treatment of several aspects of the sporophytic part of ovule diversity, development and evolution, based on extensive research on the vast original literature and on experience from my own comparative studies in a broad range of angiosperm clades. Conclusions In angiosperms the presence of an outer integument appears to be instrumental for ovule curvature, as indicated from studies on ovule diversity through the major clades of angiosperms, molecular developmental genetics in model species, abnormal ovules in a broad range of angiosperms, and comparison with gymnosperms with curved ovules. Lobation of integuments is not an atavism indicating evolution from telomes, but simply a morphogenetic constraint from the necessity of closure of the micropyle. Ovule shape is partly dependent on locule architecture, which is especially indicated by the occurrence of orthotropous ovules. Some ovule features are even more conservative than earlier assumed and thus of special interest in angiosperm macrosystematics. PMID:21606056

Developmental Diversity in the Academic Language-Learning Experiences of Adult English as a Second or Other Language Learners: A Constructive-Developmental Study

ERIC Educational Resources Information Center

Ouellette-Schramm, Jennifer R.

2016-01-01

Academic language is a challenging yet increasingly important skill for Adult Basic Education/English as a Second or Other Language learners. Related to academic language learning is an adult's developmental perspective. Developmental perspectives have been shown to vary in adulthood and shape qualitatively distinct ways of reasoning and learning…

Insect Gut Bacterial Diversity Determined by Environmental Habitat, Diet, Developmental Stage, and Phylogeny of Host

PubMed Central

Yun, Ji-Hyun; Roh, Seong Woon; Whon, Tae Woong; Jung, Mi-Ja; Kim, Min-Soo; Park, Doo-Sang; Yoon, Changmann; Nam, Young-Do; Kim, Yun-Ji; Choi, Jung-Hye; Kim, Joon-Yong; Shin, Na-Ri; Kim, Sung-Hee; Lee, Won-Jae

2014-01-01

Insects are the most abundant animals on Earth, and the microbiota within their guts play important roles by engaging in beneficial and pathological interactions with these hosts. In this study, we comprehensively characterized insect-associated gut bacteria of 305 individuals belonging to 218 species in 21 taxonomic orders, using 454 pyrosequencing of 16S rRNA genes. In total, 174,374 sequence reads were obtained, identifying 9,301 bacterial operational taxonomic units (OTUs) at the 3% distance level from all samples, with an average of 84.3 (±97.7) OTUs per sample. The insect gut microbiota were dominated by Proteobacteria (62.1% of the total reads, including 14.1% Wolbachia sequences) and Firmicutes (20.7%). Significant differences were found in the relative abundances of anaerobes in insects and were classified according to the criteria of host environmental habitat, diet, developmental stage, and phylogeny. Gut bacterial diversity was significantly higher in omnivorous insects than in stenophagous (carnivorous and herbivorous) insects. This insect-order-spanning investigation of the gut microbiota provides insights into the relationships between insects and their gut bacterial communities. PMID:24928884

Screening for Developmental Neurotoxicity Using PC12 Cells: Comparisons of Organophosphates with a Carbamate, an Organochlorine, and Divalent Nickel

PubMed Central

Slotkin, Theodore A.; MacKillop, Emiko A.; Ryde, Ian T.; Tate, Charlotte A.; Seidler, Frederic J.

2007-01-01

Background In light of the large number of chemicals that are potential developmental neurotoxicants, there is a need to develop rapid screening techniques. Objectives We exposed undifferentiated and differentiating neuronotypic PC12 cells to different organophosphates (chlorpyrifos, diazinon, parathion), a carbamate (physostigmine), an organochlorine (dieldrin), and a metal (divalent nickel; Ni2+) and examined indices of cell replication and differentiation for both short- and long-term exposures. Results In undifferentiated cells, all the agents inhibited DNA synthesis, with the greatest effect for diazinon, but physostigmine eventually produced the largest deficits in the total number of cells after prolonged exposure. The onset of differentiation intensified the adverse effects on DNA synthesis and changed the rank order in keeping with a shift away from noncholinergic mechanisms and toward cholinergic mechanisms. Differentiation also worsened the effects of each agent on cell number after prolonged exposure, whereas cell growth was not suppressed, nor were there any effects on viability as assessed with trypan blue. Nevertheless, differentiating cells displayed signs of oxidative stress from all of the test compounds except Ni2+, as evidenced by measurements of lipid peroxidation. Finally, all of the toxicants shifted the transmitter fate of the cells away from the cholinergic phenotype and toward the catecholaminergic phenotype. Conclusions These studies point out the feasibility of developing cell-based screening methods that enable the detection of multiple end points that may relate to mechanisms associated with developmental neurotoxicity, revealing some common targets for disparate agents. PMID:17366826

Defining the developmental parameters of temper loss in early childhood: implications for developmental psychopathology

PubMed Central

Wakschlag, Lauren S.; Choi, Seung W.; Carter, Alice S.; Hullsiek, Heide; Burns, James; McCarthy, Kimberly; Leibenluft, Ellen; Briggs-Gowan, Margaret J.

2013-01-01

Background Temper modulation problems are both a hallmark of early childhood and a common mental health concern. Thus, characterizing specific behavioral manifestations of temper loss along a dimension from normative misbehaviors to clinically significant problems is an important step toward identifying clinical thresholds. Methods Parent-reported patterns of temper loss were delineated in a diverse community sample of preschoolers (n = 1,490). A developmentally sensitive questionnaire, the Multidimensional Assessment of Preschool Disruptive Behavior (MAP-DB), was used to assess temper loss in terms of tantrum features and anger regulation. Specific aims were: (a) document the normative distribution of temper loss in preschoolers from normative misbehaviors to clinically concerning temper loss behaviors, and test for sociodemographic differences; (b) use Item Response Theory (IRT) to model a Temper Loss dimension; and (c) examine associations of temper loss and concurrent emotional and behavioral problems. Results Across sociodemographic subgroups, a unidimensional Temper Loss model fit the data well. Nearly all (83.7%) preschoolers had tantrums sometimes but only 8.6% had daily tantrums. Normative misbehaviors occurred more frequently than clinically concerning temper loss behaviors. Milder behaviors tended to reflect frustration in expectable contexts, whereas clinically concerning problem indicators were unpredictable, prolonged, and/or destructive. In multivariate models, Temper Loss was associated with emotional and behavioral problems. Conclusions Parent reports on a developmentally informed questionnaire, administered to a large and diverse sample, distinguished normative and problematic manifestations of preschool temper loss. A developmental, dimensional approach shows promise for elucidating the boundaries between normative early childhood temper loss and emergent psychopathology. PMID:22928674

The Sea Urchin Embryo, an Invertebrate Model for Mammalian Developmental Neurotoxicity, Reveals Multiple Neurotransmitter Mechanisms for Effects of Chlorpyrifos: Therapeutic Interventions and a Comparison with the Monoamine Depleter, Reserpine

PubMed Central

Buznikov, Gennady A.; Nikitina, Lyudmila A.; Rakić, Ljubiša M.; Miloševi, Ivan; Bezuglov, Vladimir V.; Lauder, Jean M.; Slotkin, Theodore A.

2007-01-01

Lower organisms show promise for the screening of neurotoxicants that might target mammalian brain development. Sea urchins use neurotransmitters as embryonic growth regulatory signals, so that adverse effects on neural substrates for mammalian brain development can be studied in this simple organism. We compared the effects of the organophosphate insecticide, chlorpyrifos in sea urchin embryos with those of the monoamine depleter, reserpine, so as to investigate multiple neurotransmitter mechanisms involved in developmental toxicity and to evaluate different therapeutic interventions corresponding to each neurotransmitter system. Whereas reserpine interfered with all stages of embryonic development, the effects of chlorpyrifos did not emerge until the mid-blastula stage. After that point, the effects of the two agents were similar. Treatment with membrane permeable analogs of the monoamine neurotransmitters, serotonin and dopamine, prevented the adverse effects of either chlorpyrifos or reserpine, despite the fact that chlorpyrifos works simultaneously through actions on acetylcholine, monoamines and other neurotransmitter pathways. This suggests that different neurotransmitters, converging on the same downstream signaling events, could work together or in parallel to offset the developmental disruption caused by exposure to disparate agents. We tested this hypothesis by evaluating membrane permeable analogs of acetylcholine and cannabinoids, both of which proved effective against chlorpyrifos- or reserpine-induced teratogenesis. Invertebrate test systems can provide both a screening procedure for mammalian neuroteratogenesis and may uncover novel mechanisms underlying developmental vulnerability as well as possible therapeutic approaches to prevent teratogenesis. PMID:17720543

Developmental lead exposure induces opposite effects on ethanol intake and locomotion in response to central vs. systemic cyanamide administration.

PubMed

Mattalloni, Mara Soledad; Deza-Ponzio, Romina; Albrecht, Paula Alejandra; Cancela, Liliana Marina; Virgolini, Miriam Beatriz

2017-02-01

Lead (Pb) is a developmental neurotoxicant that elicits differential responses to drugs of abuse. Particularly, ethanol consumption has been demonstrated to be increased as a consequence of environmental Pb exposure, with catalase (CAT) and brain acetaldehyde (ACD, the first metabolite of ethanol) playing a role. The present study sought to interfere with ethanol metabolism by inhibiting ALDH2 (mitochondrial aldehyde dehydrogenase) activity in both liver and brain from control and Pb-exposed rats as a strategy to accumulate ACD, a substance that plays a major role in the drug's reinforcing and/or aversive effects. To evaluate the impact on a 2-h chronic voluntary ethanol intake test, developmentally Pb-exposed and control rats were administered with cyanamide (CY, an ALDH inhibitor) either systemically or intracerebroventricularly (i.c.v.) on the last 4 sessions of the experiment. Furthermore, on the last session and after locomotor activity was assessed, all animals were sacrificed to obtain brain and liver samples for ALDH2 and CAT activity determination. Systemic CY administration reduced the elevated ethanol intake already reported in the Pb-exposed animals (but not in the controls) accompanied by liver (but not brain) ALDH2 inactivation. On the other hand, a 0.3 mg i.c.v. CY administration enhanced both ethanol intake and locomotor activity accompanied by brain ALDH2 inactivation in control animals, while an increase in ethanol consumption was also observed in the Pb-exposed group, although in the absence of brain ALDH2 blockade. No changes were observed in CAT activity as a consequence of CY administration. These results support the participation of liver and brain ACD in ethanol intake and locomotor activity, responses that are modulated by developmental Pb exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Lead alters the developmental profile of the galactolipid metabolic enzymes in cultured oligodendrocyte lineage cells.

PubMed

Deng, W; Poretz, R D

2001-08-01

Lead is a neurotoxicant that can cause myelin deficits. Galactolipids are expressed during differentiation of oligodendrocyte lineage cells and accumulate in myelin. To examine the impact of lead on oligodendroglial differentiation, galactolipid metabolism in cultured oligodendrocyte lineage cells exposed to the metal was studied. Oligodendrocyte progenitor cells obtained from newborn rat pups were exposed to 1 microM lead acetate for 24 h prior to maintenance of the cells in medium containing the metal salt for 0, 2, or 6 days of differentiation. Lead caused approximately 50% reduction in levels of the galactolipid biosynthetic transferases, UDP-galactose:ceramide galactosyltransferase and 3'-phosphoadenosine-5'-phosphosulfate:galactocerebroside sulfotransferase, as compared to sodium-treated controls, in cultures of oligodendrocyte lineage cells following 2 days of differentiation. The activities of the galactolipid catabolic hydrolases, galactocerebroside-beta-galactosidase and arylsulfatase A, were reduced by 20%. Following 6 days of differentiation, lead-exposed cells exhibited levels of all the enzymes, except for arylsulfatase A, similar to those of the control cells. These results are consistent with the lead-induced delay of oligodendrocyte differentiation, as evidenced by the emergence of stage-specific immunochemical markers and the observed change in the developmental activity profile of 2',3'-cyclic nucleotide 3'-phosphohydrolase. The activity of arylsulfatase A in lead-treated 6-day oligodendrocytes was significantly less than that found in control cultures. This effect is consistent with the lead-induced reduction of arylsulfatase A in human fibroblasts caused by mis-sorting the newly-synthesized enzyme. The perturbation of galactolipid metabolism by lead during developmental maturation of oligodendrocytes may represent a contributing mechanism for lead-induced neurotoxicity.

Developmental Education: The Recognition of Individual Differences

ERIC Educational Resources Information Center

Blimline, Carol; Klimek, Richard

1977-01-01

This article describes the historical, empirical, and theoretical aspects of a series of one-credit student development courses offered at a multicampus community college. The courses, ranging from "The Emerging Woman" to "Study Skills," were specifically designed to meet a variety of developmental needs for a diverse student…

Brominated and organophosphate flame retardants target different neurodevelopmental stages, characterized with embryonic neural stem cells and neuronotypic PC12 cells.

PubMed

Slotkin, Theodore A; Skavicus, Samantha; Stapleton, Heather M; Seidler, Frederic J

2017-09-01

In addition to their activity as endocrine disruptors, brominated and organophosphate flame retardants are suspected to be developmental neurotoxicants, although identifying their specific mechanisms for that activity has been elusive. In the current study, we evaluated the effects of several flame retardants on neurodifferentiation using two in vitro models that assess distinct "decision nodes" in neural cell development: embryonic rat neural stem cells (NSCs), which evaluate the origination of neurons and glia from precursors, and rat neuronotypic PC12 cells, which characterize a later stage where cells committed to a neuronal phenotype undergo neurite outgrowth and neurotransmitter specification. In NSCs, both brominated and organophosphate flame retardants diverted the phenotype in favor of glia and away from formation of neurons, leading to an increased glia/neuron ratio, a common hallmark of the in vivo effects of neurotoxicants. For this early decision node, the brominated flame retardants were far more potent than the organophosphates. In PC12 cells, the brominated flame retardants were far less effective, whereas tris (1,3-dichloro-2-propyl) phosphate, an organophosphate, was more effective. Thus, the two classes of flame retardants differentially impact the two distinct vulnerable periods of neurodifferentiation. Furthermore, the effects on neurodifferentiation were separable from outright cytotoxicity, an important requirement in establishing a specific effect of these agents on neural cell development. These results reinforce the likelihood that flame retardants act as developmental neurotoxicants via direct effects on neural cell differentiation, over and above other activities that can impact nervous system development, such as endocrine disruption. Copyright © 2017 Elsevier B.V. All rights reserved.

Oxidative Stress, Unfolded Protein Response, and Apoptosis in Developmental Toxicity

PubMed Central

Kupsco, Allison; Schlenk, Daniel

2016-01-01

Physiological development requires precise spatiotemporal regulation of cellular and molecular processes. Disruption of these key events can generate developmental toxicity in the form of teratogenesis or mortality. The mechanism behind many developmental toxicants remains unknown. While recent work has focused on the unfolded protein response (UPR), oxidative stress, and apoptosis in the pathogenesis of disease, few studies have addressed their relationship in developmental toxicity. Redox regulation, UPR, and apoptosis are essential for physiological development and can be disturbed by a variety of endogenous and exogenous toxicants to generate lethality and diverse malformations. This review examines the current knowledge of the role of oxidative stress, UPR, and apoptosis in physiological development as well as in developmental toxicity, focusing on studies and advances in vertebrates model systems. PMID:26008783

Epigenetics and Developmental Plasticity Across Species

PubMed Central

Champagne, Frances A.

2012-01-01

Plasticity is a typical feature of development and can lead to divergent phenotypes. There is increasing evidence that epigenetic mechanisms, such as DNA methylation, are present across species, are modifiable by the environment, and are involved in developmental plasticity. Thus, in the context of the concept of developmental homology, epigenetic mechanisms may serve to create a process homology between species by providing a common molecular pathway through which environmental experiences shape development, ultimately leading to phenotypic diversity. This article will highlight evidence derived from across-species investigations of epigenetics, development, and plasticity which may contribute to our understanding of the homology that exists between species and between ancestors and descendants. PMID:22711291

Epigenetics and developmental plasticity across species.

PubMed

Champagne, Frances A

2013-01-01

Plasticity is a typical feature of development and can lead to divergent phenotypes. There is increasing evidence that epigenetic mechanisms, such as DNA methylation, are present across species, are modifiable by the environment, and are involved in developmental plasticity. Thus, in the context of the concept of developmental homology, epigenetic mechanisms may serve to create a process homology between species by providing a common molecular pathway through which environmental experiences shape development, ultimately leading to phenotypic diversity. This article will highlight evidence derived from across-species investigations of epigenetics, development, and plasticity which may contribute to our understanding of the homology that exists between species and between ancestors and descendants. Copyright © 2012 Wiley Periodicals, Inc.

Biomarkers of adult and developmental neurotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slikker, William; Bowyer, John F.

2005-08-07

Neurotoxicity may be defined as any adverse effect on the structure or function of the central and/or peripheral nervous system by a biological, chemical, or physical agent. A multidisciplinary approach is necessary to assess adult and developmental neurotoxicity due to the complex and diverse functions of the nervous system. The overall strategy for understanding developmental neurotoxicity is based on two assumptions: (1) significant differences in the adult versus the developing nervous system susceptibility to neurotoxicity exist and they are often developmental stage dependent; (2) a multidisciplinary approach using neurobiological, including gene expression assays, neurophysiological, neuropathological, and behavioral function is necessarymore » for a precise assessment of neurotoxicity. Application of genomic approaches to developmental studies must use the same criteria for evaluating microarray studies as those in adults including consideration of reproducibility, statistical analysis, homogenous cell populations, and confirmation with non-array methods. A study using amphetamine to induce neurotoxicity supports the following: (1) gene expression data can help define neurotoxic mechanism(s) (2) gene expression changes can be useful biomarkers of effect, and (3) the site-selective nature of gene expression in the nervous system may mandate assessment of selective cell populations.« less

Diversity Matters: Parent Input Predicts Toddler Verb Production

ERIC Educational Resources Information Center

Hsu, Ning; Hadley, Pamela A.; Rispoli, Matthew

2017-01-01

The contribution of parent input to children's subsequent expressive verb diversity was explored in twenty typically developing toddlers with small verb lexicons. Child developmental factors and parent input measures (i.e. verb quantity, verb diversity, and verb-related structural cues) at age 1;9 were examined as potential predictors of…

Discriminative stimulus effects of cocaine and amphetamine in rats following developmental exposure to polychlorinated biphenyls (PCBs)

PubMed Central

Sable, Helen J. K.; Monaikul, Supida; Poon, Emily; Eubig, Paul A.; Schantz, Susan L.

2010-01-01

Polychlorinated biphenyls (PCBs) are environmental neurotoxicants known to affect the brain dopaminergic (DA) system. This project investigated whether developmental exposure to PCBs would alter the discriminative stimulus effects of psychostimulant drugs known to act on the DA system. Female Long-Evans rats were orally exposed to 0, 3, or 6 mg/kg/day of an environmentally relevant PCB mixture from four weeks prior to breeding through weaning of their litters on PND 21. When they reached adulthood one male and female/litter were trained to discriminate cocaine (10.0 mg/kg, IP) from saline by repeatedly pairing cocaine injections with reinforcement on one operant response lever, and saline injections with reinforcement on the other lever. After response training, generalization tests to four lower doses of cocaine (7.5, 5.0, 2.5, and 1.25 mg/kg, IP) and to amphetamine (1.0, 0.5, 0.25, and 0.125 mg/kg, IP) were given two days/week, with additional training dose days in-between. Percent responding of the PCB-exposed rats on the cocaine-paired lever was significantly higher than that of controls for the highest generalization dose of cocaine, and lower than that of controls for the highest dose of amphetamine. Response rate and percent responding on the cocaine lever did not differ among the exposure groups on the days when the training dose of cocaine was given, suggesting the generalization test results were not due to pre-existing differences in discrimination ability or rate of responding. These findings suggest developmental PCB exposure can alter the interoceptive cues of psychostimulants. PMID:20933596

Developmental Changes in the Consideration of Sample Diversity in Inductive Reasoning

ERIC Educational Resources Information Center

Rhodes, Marjorie; Gelman, Susan A.; Brickman, Daniel

2008-01-01

Determining whether a sample provides a good basis for broader generalizations is a basic challenge of inductive reasoning. Adults apply a diversity-based strategy to this challenge, expecting diverse samples to be a better basis for generalization than homogeneous samples. For example, adults expect that a property shared by two diverse mammals…

Developmental Surveillance and Screening Practices by Pediatric Primary Care Providers: Implications for Early Intervention Professionals

ERIC Educational Resources Information Center

Porter, Sallie; Qureshi, Rubab; Caldwell, Barbara Ann; Echevarria, Mercedes; Dubbs, William B.; Sullivan, Margaret W.

2016-01-01

This study used a survey approach to investigate current developmental surveillance and developmental screening practices by pediatric primary care providers in a diverse New Jersey county. A total of 217 providers were contacted with a final sample size of 57 pediatric primary care respondents from 13 different municipalities. Most providers…

Developmental outcomes after early prefrontal cortex damage.

PubMed

Eslinger, Paul J; Flaherty-Craig, Claire V; Benton, Arthur L

2004-06-01

The neuropsychological bases of cognitive, social, and moral development are minimally understood, with a seemingly wide chasm between developmental theories and brain maturation models. As one approach to bridging ideas in these areas, we review 10 cases of early prefrontal cortex damage from the clinical literature, highlighting overall clinical profiles and real life developmental outcomes. Based on these cases, there is preliminary evidence to support distinctive developmental differences after: (1) dorsolateral, (2) mesial, and (3) orbital-polar prefrontal lesions, for more profound impairments after bilateral damage, and possibly for recovery differences after very early vs. later childhood lesion onset. Further case and group studies are needed to confirm reliable effects of specific lesion locations, the influence of age of lesion onset, and related experiential and treatment variables in determining adult outcomes. Rather than a single underlying deficit associated with early prefrontal cortex damage, we interpret the findings to suggest that it is the altered integration and interplay of cognitive, emotional, self-regulatory, and executive/metacognitive deficits that contribute to diverse developmental frontal lobe syndromes. The findings support the fundamental importance of prefrontal cortex maturation in protracted cognitive, social-emotional, and moral development.

Manganese Exposure and Cognition Across the Lifespan: Contemporary Review and Argument for Biphasic Dose-Response Health Effects

PubMed Central

Vollet, Kaitlin; Dietrich, Kim N.

2016-01-01

Manganese (Mn) is both an essential micronutrient and potential neurotoxicant. This dual role underlies a growing body of literature demonstrating that Mn exhibits a biphasic dose-response relationship with neurocognitive outcomes. We reviewed recent epidemiologic studies from 2007–2016 that investigated the relationship between Mn exposure and cognitive outcomes across the lifespan: early life, school-aged children, and adulthood. In total, 27 research articles were included in this review: 12 pediatric and 15 adult studies (10 occupational and five environmental exposures). The majority of these studies provided evidence of the negative effects of Mn exposure on cognition. The pediatric literature provides evidence that both high and low levels of Mn are negatively associated with intellectual development. Future Mn research should include examination of non-linear relationships and multiple neurotoxicants across the lifespan, and particularly during critical developmental windows. PMID:27722879

Temporal variations in early developmental decisions: an engine of forebrain evolution.

PubMed

Bielen, H; Pal, S; Tole, S; Houart, C

2017-02-01

Tight control of developmental timing is pivotal to many major processes in developmental biology, such as patterning, fate specification, cell cycle dynamics, cell migration and connectivity. Temporal change in these ontogenetic sequences is known as heterochrony, a major force in the evolution of body plans and organogenesis. In the last 5 years, studies in fish and rodents indicate that heterochrony in signaling during early development generates diversity in forebrain size and complexity. Here, we summarize these findings and propose that, additionally to spatio-temporal tuning of neurogenesis, temporal and quantitative modulation of signaling events drive pivotal changes in shape, size and complexity of the forebrain across evolution, participating to the generation of diversity in animal behavior and emergence of cognition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Examining Developmental Readiness in an International Service-Learning Context

ERIC Educational Resources Information Center

Taylor, Kari B.; Jones, Susan R.; Massey, Rachel; Mickey, Jasmine; Reynolds, Danyelle J.; Jackson, Torrie

2017-01-01

The authors examined students' developmental readiness for productively negotiating the disorienting dilemmas and dissonance they experienced during an international service-learning experience. Using a case study methodology, researchers collected data from a diverse group composed of 7 graduate students and 5 undergraduates who participated in a…

Some Cognitive Developmental Characteristics of Social Diversity Education.

ERIC Educational Resources Information Center

Adams, Maurianne; Zhou, Yu-hui A.

This paper, on a 1988-89 study of 219 undergraduates, addresses issues of cognitive development, learning style, and attitudes toward social diversity and social justice. A parallel study was conducted in spring/fall 1989 with subsequent changes noted. The table of contents presents the following sections: (1) "Background and Educational Context";…

Developmental constraints shape the evolution of the nematode mid-developmental transition.

PubMed

Zalts, Harel; Yanai, Itai

2017-03-27

Evolutionary theory assumes that genetic variation is uniform and gradual in nature, yet morphological and gene expression studies have revealed that different life-stages exhibit distinct levels of cross-species conservation. In particular, a stage in mid-embryogenesis is highly conserved across species of the same phylum, suggesting that this stage is subject to developmental constraints, either by increased purifying selection or by a strong mutational bias. An alternative explanation, however, holds that the same 'hourglass' pattern of variation may result from increased positive selection at the earlier and later stages of development. To distinguish between these scenarios, we examined gene expression variation in a population of the nematode Caenorhabditis elegans using an experimental design that eliminated the influence of positive selection. By measuring gene expression for all genes throughout development in 20 strains, we found that variations were highly uneven throughout development, with a significant depletion during mid-embryogenesis. In particular, the family of homeodomain transcription factors, whose expression generally coincides with mid-embryogenesis, evolved under high constraint. Our data further show that genes responsible for the integration of germ layers during morphogenesis are the most constrained class of genes. Together, these results provide strong evidence for developmental constraints as the mechanism underlying the hourglass model of animal evolution. Understanding the pattern and mechanism of developmental constraints provides a framework to understand how evolutionary processes have interacted with embryogenesis and led to the diversity of animal life on Earth.

A developmental-psychobiological approach to developmental neuropsychology.

PubMed

Michel, G F

2001-01-01

Although both developmental psychobiology and developmental neuropsychology examine the interface between biological and psychological processes, they differ in conceptual framework. This article argues for the incorporation into developmental neuropsychology of certain aspects of the conceptual framework of developmental psychobiology. Three principles of dynamic psychobiological interaction are described and applied to four issues in neuropsychology (handedness, sex differences in behavior, critical periods, and modularity of structure-function relations). Then, it is proposed that developmental psychobiology can make four direct contributions to developmental neuropsychology. Finally, it is argued that the value of the conceptual framework provided by developmental psychobiology depends, in part, on how well it translates into procedures that can be applied in the clinical settings of the developmental neuropsychologist.

Diversity-based reasoning in children.

PubMed

Heit, E; Hahn, U

2001-12-01

One of the hallmarks of inductive reasoning by adults is the diversity effect, namely that people draw stronger inferences from a diverse set of evidence than from a more homogenous set of evidence. However, past developmental work has not found consistent diversity effects with children age 9 and younger. We report robust sensitivity to diversity in children as young as 5, using everyday stimuli such as pictures of objects with people. Experiment 1 showed the basic diversity effect in 5- to 9-year-olds. Experiment 2 showed that, like adults, children restrict their use of diversity information when making inferences about remote categories. Experiment 3 used other stimulus sets to overcome an alternate explanation in terms of sample size rather than diversity effects. Finally, Experiment 4 showed that children more readily draw on diversity when reasoning about objects and their relations with people than when reasoning about objects' internal, hidden properties, thus partially explaining the negative findings of previous work. Relations to cross-cultural work and models of induction are discussed. Copyright 2001 Academic Press.

Diverse Developmental Disorders from The One Ring: Distinct Molecular Pathways Underlie the Cohesinopathies

PubMed Central

Horsfield, Julia A.; Print, Cristin G.; Mönnich, Maren

2012-01-01

The multi-subunit protein complex, cohesin, is responsible for sister chromatid cohesion during cell division. The interaction of cohesin with DNA is controlled by a number of additional regulatory proteins. Mutations in cohesin, or its regulators, cause a spectrum of human developmental syndromes known as the “cohesinopathies.” Cohesinopathy disorders include Cornelia de Lange Syndrome and Roberts Syndrome. The discovery of novel roles for chromatid cohesion proteins in regulating gene expression led to the idea that cohesinopathies are caused by dysregulation of multiple genes downstream of mutations in cohesion proteins. Consistent with this idea, Drosophila, mouse, and zebrafish cohesinopathy models all show altered expression of developmental genes. However, there appears to be incomplete overlap among dysregulated genes downstream of mutations in different components of the cohesion apparatus. This is surprising because mutations in all cohesion proteins would be predicted to affect cohesin’s roles in cell division and gene expression in similar ways. Here we review the differences and similarities between genetic pathways downstream of components of the cohesion apparatus, and discuss how such differences might arise, and contribute to the spectrum of cohesinopathy disorders. We propose that mutations in different elements of the cohesion apparatus have distinct developmental outcomes that can be explained by sometimes subtly different molecular effects. PMID:22988450

Genetic Diversity Influences the Response of the Brain to Developmental Lead Exposure

PubMed Central

Schneider, Jay S.; Talsania, Keyur; Mettil, William; Anderson, David W.

2014-01-01

Although extrinsic factors, such as nutritional status, and some intrinsic genetic factors may modify susceptibility to developmental lead (Pb) poisoning, no studies have specifically examined the influence of genetic background on outcomes from Pb exposure. In this study, we used gene microarray profiling to identify Pb-responsive genes in rats of different genetic backgrounds, including inbred (Fischer 344 (F344)) and outbred (Long Evans (LE), Sprague Dawley (SD)) strains, to investigate the role that genetic variation may play in influencing outcomes from developmental Pb exposure. Male and female animals received either perinatal (gestation through lactation) or postnatal (birth through weaning) exposure to Pb in food (0, 250, or 750 ppm). RNA was extracted from the hippocampus at day 55 and hybridized to Affymetrix Rat Gene 1.0 ST Arrays. There were significant strain-specific effects of Pb on the hippocampal transcriptome with 978 transcripts differentially expressed in LE rats across all experimental groups, 269 transcripts differentially expressed in F344 rats, and only 179 transcripts differentially expressed in SD rats. These results were not due to strain-related differences in brain accumulation of Pb. Further, no genes were consistently differentially regulated in all experimental conditions. There was no set of “Pb toxicity” genes that are a molecular signature for Pb neurotoxicity that transcended sex, exposure condition, and strain. These results demonstrate the influence that strain and genetic background play in modifying the brain's response to developmental Pb exposure and may have relevance for better understanding the molecular underpinnings of the lack of a neurobehavioral signature in childhood Pb poisoning. PMID:24913800

Prevalence and architecture of de novo mutations in developmental disorders.

PubMed

2017-02-23

The genomes of individuals with severe, undiagnosed developmental disorders are enriched in damaging de novo mutations (DNMs) in developmentally important genes. Here we have sequenced the exomes of 4,293 families containing individuals with developmental disorders, and meta-analysed these data with data from another 3,287 individuals with similar disorders. We show that the most important factors influencing the diagnostic yield of DNMs are the sex of the affected individual, the relatedness of their parents, whether close relatives are affected and the parental ages. We identified 94 genes enriched in damaging DNMs, including 14 that previously lacked compelling evidence of involvement in developmental disorders. We have also characterized the phenotypic diversity among these disorders. We estimate that 42% of our cohort carry pathogenic DNMs in coding sequences; approximately half of these DNMs disrupt gene function and the remainder result in altered protein function. We estimate that developmental disorders caused by DNMs have an average prevalence of 1 in 213 to 1 in 448 births, depending on parental age. Given current global demographics, this equates to almost 400,000 children born per year.

Evolutionary developmental genetics of fruit morphological variation within the Solanaceae

PubMed Central

Wang, Li; Li, Jing; Zhao, Jing; He, Chaoying

2015-01-01

Morphological variations of fruits such as shape and size, and color are a result of adaptive evolution. The evolution of morphological novelties is particularly intriguing. An understanding of these evolutionary processes calls for the elucidation of the developmental and genetic mechanisms that result in particular fruit morphological characteristics, which determine seed dispersal. The genetic and developmental basis for fruit morphological variation was established at a microevolutionary time scale. Here, we summarize the progress on the evolutionary developmental genetics of fruit size, shape and color in the Solanaceae. Studies suggest that the recruitment of a pre-existing gene and subsequent modification of its interaction and regulatory networks are frequently involved in the evolution of morphological diversity. The basic mechanisms underlying changes in plant morphology are alterations in gene expression and/or gene function. We also deliberate on the future direction in evolutionary developmental genetics of fruit morphological variation such as fruit type. These studies will provide insights into plant developmental processes and will help to improve the productivity and fruit quality of crops. PMID:25918515

Developmental Screening of Refugees: A Qualitative Study

PubMed Central

Moore, Jessica A.; Welch, Therese R.; Halterman, Jill S.; Hyman, Susan L.

2016-01-01

BACKGROUND AND OBJECTIVES: Refugee children are at high developmental risk due to dislocation and deprivation. Standardized developmental screening in this diverse population is challenging. We used the Health Belief Model to guide key-informant interviews and focus groups with medical interpreters, health care providers, community collaborators, and refugee parents to explore key elements needed for developmental screening. Cultural and community-specific values and practices related to child development and barriers and facilitators to screening were examined. METHODS: We conducted 19 interviews and 2 focus groups involving 16 Bhutanese-Nepali, Burmese, Iraqi, and Somali participants, 7 community collaborators, and 6 providers from the Center for Refugee Health in Rochester, New York. Subjects were identified through purposive sampling until data saturation. Interviews were recorded, coded, and analyzed using a qualitative framework technique. RESULTS: Twenty-one themes in 4 domains were identified: values/beliefs about development/disability, practices around development/disability, the refugee experience, and feedback specific to the Parents’ Evaluation of Developmental Status screen. Most participants denied a word for “development” in their primary language and reported limited awareness of developmental milestones. Concern was unlikely unless speech or behavior problems were present. Physical disabilities were recognized but not seen as problematic. Perceived barriers to identification of delays included limited education, poor healthcare knowledge, language, and traditional healing practices. Facilitators included community navigators, trust in health care providers, in-person interpretation, visual supports, and education about child development. CONCLUSIONS: Refugee perspectives on child development may influence a parent’s recognition of and response to developmental concerns. Despite challenges, standardized screening was supported. PMID

Developmental Screening of Refugees: A Qualitative Study.

PubMed

Kroening, Abigail L H; Moore, Jessica A; Welch, Therese R; Halterman, Jill S; Hyman, Susan L

2016-09-01

Refugee children are at high developmental risk due to dislocation and deprivation. Standardized developmental screening in this diverse population is challenging. We used the Health Belief Model to guide key-informant interviews and focus groups with medical interpreters, health care providers, community collaborators, and refugee parents to explore key elements needed for developmental screening. Cultural and community-specific values and practices related to child development and barriers and facilitators to screening were examined. We conducted 19 interviews and 2 focus groups involving 16 Bhutanese-Nepali, Burmese, Iraqi, and Somali participants, 7 community collaborators, and 6 providers from the Center for Refugee Health in Rochester, New York. Subjects were identified through purposive sampling until data saturation. Interviews were recorded, coded, and analyzed using a qualitative framework technique. Twenty-one themes in 4 domains were identified: values/beliefs about development/disability, practices around development/disability, the refugee experience, and feedback specific to the Parents' Evaluation of Developmental Status screen. Most participants denied a word for "development" in their primary language and reported limited awareness of developmental milestones. Concern was unlikely unless speech or behavior problems were present. Physical disabilities were recognized but not seen as problematic. Perceived barriers to identification of delays included limited education, poor healthcare knowledge, language, and traditional healing practices. Facilitators included community navigators, trust in health care providers, in-person interpretation, visual supports, and education about child development. Refugee perspectives on child development may influence a parent's recognition of and response to developmental concerns. Despite challenges, standardized screening was supported. Copyright © 2016 by the American Academy of Pediatrics.

Developmental plasticity of mating calls enables acoustic communication in diverse environments

PubMed Central

Beckers, Oliver M; Schul, Johannes

2008-01-01

Male calls of the katydid Neoconocephalus triops exhibit substantial developmental plasticity in two parameters: (i) calls of winter males are continuous and lack the verse structure of summer calls and (ii) at equal temperatures, summer males produce calls with a substantially higher pulse rate than winter males. We raised female N. triops under conditions that reliably induced either summer or winter phenotype and tested their preferences for the call parameters that differ between summer and winter males. Neither generation was selective for the presence of verses, but females had strong preferences for pulse rates: only a narrow range of pulse rates was attractive. The attractive ranges did not differ between summer and winter females. Both male pulse rate and female preference for pulse rate changed with ambient temperature, but female preference changed more than the male calls. As a result, the summer call was attractive only at 25°C, whereas the slower winter call was attractive only at 20°C. Thus, developmental plasticity of male calls compensates for differences in temperature dependency between calls and preferences and enables the communication system to function in heterogeneous environments. The potential role of call plasticity during the invasion of new habitats is discussed. PMID:18302998

Screening and Assessment of Young Children at Developmental Risk.

ERIC Educational Resources Information Center

Meier, John

Presented in the monograph are current or proposed methods for screening and assessing children, from birth to 5 years of age, who have diverse developmental disorders or who are at risk, and whose mental and physical development will benefit from early identification and intervention. Considered in relation to general screening are a screening…

INCREASED SUSCEPTIBILITY OF ADULTS FOLLOWING DEVELOPMENT EXPOSURE TO NEUROTOXICANTS: ANOTHER SUSCEPTIBLE POPULATION?

EPA Science Inventory

There is considerable public and regulatory interest in the adverse outcomes of developmental exposure to toxicants. The 1996 Food Quality Protection Act spurred research on understanding potential neurotoxic, immunotoxic, and endocrine outcomes in susceptible populations, parti...

Diversity and the Postsecondary Experience

ERIC Educational Resources Information Center

Higbee, Jeanne L., Ed.; Lundell, Dana B., Ed.; Duranczyk, Irene M., Ed

2007-01-01

During the past year the Center for Research on Developmental Education and Urban Literacy (CRDEUL) has moved from the former General College (GC), which after 74 years of service to a diverse student body closed its doors on June 30, 2006, to the University of Minnesota's new College of Education and Human Development (CEHD). The new mission…

Developmental Pathways Are Blueprints for Designing Successful Crops

PubMed Central

Trevaskis, Ben

2018-01-01

Genes controlling plant development have been studied in multiple plant systems. This has provided deep insights into conserved genetic pathways controlling core developmental processes including meristem identity, phase transitions, determinacy, stem elongation, and branching. These pathways control plant growth patterns and are fundamentally important to crop biology and agriculture. This review describes the conserved pathways that control plant development, using Arabidopsis as a model. Historical examples of how plant development has been altered through selection to improve crop performance are then presented. These examples, drawn from diverse crops, show how the genetic pathways controlling development have been modified to increase yield or tailor growth patterns to suit local growing environments or specialized crop management practices. Strategies to apply current progress in genomics and developmental biology to future crop improvement are then discussed within the broader context of emerging trends in plant breeding. The ways that knowledge of developmental processes and understanding of gene function can contribute to crop improvement, beyond what can be achieved by selection alone, are emphasized. These include using genome re-sequencing, mutagenesis, and gene editing to identify or generate novel variation in developmental genes. The expanding scope for comparative genomics, the possibility to engineer new developmental traits and new approaches to resolve gene–gene or gene–environment interactions are also discussed. Finally, opportunities to integrate fundamental research and crop breeding are highlighted. PMID:29922318

Developmental Pathways Are Blueprints for Designing Successful Crops.

PubMed

Trevaskis, Ben

2018-01-01

Genes controlling plant development have been studied in multiple plant systems. This has provided deep insights into conserved genetic pathways controlling core developmental processes including meristem identity, phase transitions, determinacy, stem elongation, and branching. These pathways control plant growth patterns and are fundamentally important to crop biology and agriculture. This review describes the conserved pathways that control plant development, using Arabidopsis as a model. Historical examples of how plant development has been altered through selection to improve crop performance are then presented. These examples, drawn from diverse crops, show how the genetic pathways controlling development have been modified to increase yield or tailor growth patterns to suit local growing environments or specialized crop management practices. Strategies to apply current progress in genomics and developmental biology to future crop improvement are then discussed within the broader context of emerging trends in plant breeding. The ways that knowledge of developmental processes and understanding of gene function can contribute to crop improvement, beyond what can be achieved by selection alone, are emphasized. These include using genome re-sequencing, mutagenesis, and gene editing to identify or generate novel variation in developmental genes. The expanding scope for comparative genomics, the possibility to engineer new developmental traits and new approaches to resolve gene-gene or gene-environment interactions are also discussed. Finally, opportunities to integrate fundamental research and crop breeding are highlighted.

Maternal dietary free or bound fructose diversely influence developmental programming of lipogenesis.

PubMed

Yuruk, Armagan Aytug; Nergiz-Unal, Reyhan

2017-12-01

Maternal dietary choices throughout preconception, pregnancy, and lactation irreversibly affect the development of fetal tissues and organs, known as fetal programming. Recommendations tend to emphasize reducing added sugars. However, the impact of maternal dietary free or bound fructose in added sugars on developmental programming of lipogenesis is unknown. Virgin Sprague-Dawley rats were randomly divided into five groups. Rats were given feed and plain water (control) or water containing maltodextrin (vehicle), fructose, high-fructose corn syrup (HFCS) containing 55% fructose, sucrose (20% w/v) for 12 weeks before mating and throughout the pregnancy and lactation periods. Body weight, water, and feed intake were measured throughout the study. At the end of the lactation period, blood was drawn to determine the fasting levels of glucose, insulin, triglycerides, and non-esterified fatty acids (NEFA) in blood. Triglycerides and acetyl Co-A Carboxylase-1 (ACC1) levels in livers were analyzed, and insulin resistance was calculated. The energy intake of dams in the HFCS group was higher than in the fructose group, while weight gain was less in the HFCS group than in the fructose group. HFCS resulted in greater insulin resistance in dams, whereas free fructose had a robust effect on the fetal programming of insulin resistance. Free fructose and HFCS in the maternal diet increased blood and liver triglycerides and NEFA content in pups. Furthermore, fructose and HFCS exposure increased phosphorylated ACC1 as compared to maltodextrin and control, indicating greater fatty acid synthesis in pups and dams. Different types of added sugar in the maternal diet have different metabolic effects on the developmental programming of lipogenesis. Consequently, high fructose intake via processed foods may increase the risk for chronic diseases, and free fructose might contribute to developmental programming of chronic diseases more than bound fructose.

Engaging a Developmentally Disabled Community through Arts-Based Service-Learning

ERIC Educational Resources Information Center

Alexander, Amanda

2015-01-01

This study examined whether teaching in a community arts organization that provides services for people with developmental disabilities enabled preservice art teachers to better understand diverse contexts of art programs and the benefits of teaching the arts to others. Through this activity, the author also examined whether preservice art…

Developmental mechanisms facilitating the evolution of bills and quills

PubMed Central

Schneider, Richard A

2005-01-01

Beaks and feathers epitomize inimitable avian traits. Within individuals and across species there exists astounding diversity in the size, shape, arrangement, and colour of beaks and feathers in association with various functional adaptations. What has enabled the concomitantly divergent evolution of beaks and feathers? The common denominator may lie in their developmental programmes. As revealed through recent transplant experiments using quail and duck embryos, the developmental programme for each structure utilizes mesenchyme as a dominant source of species-specific patterning information, acts as a module of closely coupled molecular and histogenic events, and operates with a high degree of spatial and temporal plasticity. By synergizing these three features, the developmental programmes underlying beaks and feathers likely have the essential potential to react spontaneously to novel conditions and new gene functions, and as a consequence are well equipped to generate and accommodate innovative phenotypes during the course of evolution. PMID:16313392

Integration of a Faculty's Ongoing Research into an Undergraduate Laboratory Teaching Class in Developmental Biology

ERIC Educational Resources Information Center

Nam, Sang-Chul

2018-01-01

Traditional developmental biology laboratory classes have utilized a number of different model organisms to allow students to be exposed to diverse biological phenomena in developing organisms. This traditional approach has mainly focused on the diverse morphological and anatomical descriptions of the developing organisms. However, modern…

Current and future needs for developmental toxicity testing.

PubMed

Makris, Susan L; Kim, James H; Ellis, Amy; Faber, Willem; Harrouk, Wafa; Lewis, Joseph M; Paule, Merle G; Seed, Jennifer; Tassinari, Melissa; Tyl, Rochelle

2011-10-01

A review is presented of the use of developmental toxicity testing in the United States and international regulatory assessment of human health risks associated with exposures to pharmaceuticals (human and veterinary), chemicals (agricultural, industrial, and environmental), food additives, cosmetics, and consumer products. Developmental toxicology data are used for prioritization and screening of pharmaceuticals and chemicals, for evaluating and labeling of pharmaceuticals, and for characterizing hazards and risk of exposures to industrial and environmental chemicals. The in vivo study designs utilized in hazard characterization and dose-response assessment for developmental outcomes have not changed substantially over the past 30 years and have served the process well. Now there are opportunities to incorporate new technologies and approaches to testing into the existing assessment paradigm, or to apply innovative approaches to various aspects of risk assessment. Developmental toxicology testing can be enhanced by the refinement or replacement of traditional in vivo protocols, including through the use of in vitro assays, studies conducted in alternative nonmammalian species, the application of new technologies, and the use of in silico models. Potential benefits to the current regulatory process include the ability to screen large numbers of chemicals quickly, with the commitment of fewer resources than traditional toxicology studies, and to refine the risk assessment process through an enhanced understanding of the mechanisms of developmental toxicity and their relevance to potential human risk. As the testing paradigm evolves, the ability to use developmental toxicology data to meet diverse critical regulatory needs must be retained. © 2011 Wiley Periodicals, Inc.

How Evolution May Work Through Curiosity-Driven Developmental Process.

PubMed

Oudeyer, Pierre-Yves; Smith, Linda B

2016-04-01

Infants' own activities create and actively select their learning experiences. Here we review recent models of embodied information seeking and curiosity-driven learning and show that these mechanisms have deep implications for development and evolution. We discuss how these mechanisms yield self-organized epigenesis with emergent ordered behavioral and cognitive developmental stages. We describe a robotic experiment that explored the hypothesis that progress in learning, in and for itself, generates intrinsic rewards: The robot learners probabilistically selected experiences according to their potential for reducing uncertainty. In these experiments, curiosity-driven learning led the robot learner to successively discover object affordances and vocal interaction with its peers. We explain how a learning curriculum adapted to the current constraints of the learning system automatically formed, constraining learning and shaping the developmental trajectory. The observed trajectories in the robot experiment share many properties with those in infant development, including a mixture of regularities and diversities in the developmental patterns. Finally, we argue that such emergent developmental structures can guide and constrain evolution, in particular with regard to the origins of language. Copyright © 2016 Cognitive Science Society, Inc.

Computational Modeling and Simulation of Developmental ...

EPA Pesticide Factsheets

Standard practice for assessing developmental toxicity is the observation of apical endpoints (intrauterine death, fetal growth retardation, structural malformations) in pregnant rats/rabbits following exposure during organogenesis. EPA’s computational toxicology research program (ToxCast) generated vast in vitro cellular and molecular effects data on >1858 chemicals in >600 high-throughput screening (HTS) assays. The diversity of assays has been increased for developmental toxicity with several HTS platforms, including the devTOX-quickPredict assay from Stemina Biomarker Discovery utilizing the human embryonic stem cell line (H9). Translating these HTS data into higher order-predictions of developmental toxicity is a significant challenge. Here, we address the application of computational systems models that recapitulate the kinematics of dynamical cell signaling networks (e.g., SHH, FGF, BMP, retinoids) in a CompuCell3D.org modeling environment. Examples include angiogenesis (angiodysplasia) and dysmorphogenesis. Being numerically responsive to perturbation, these models are amenable to data integration for systems Toxicology and Adverse Outcome Pathways (AOPs). The AOP simulation outputs predict potential phenotypes based on the in vitro HTS data ToxCast. A heuristic computational intelligence framework that recapitulates the kinematics of dynamical cell signaling networks in the embryo, together with the in vitro profiling data, produce quantitative predic

Sensory Organization of Balance Control in Children with Developmental Coordination Disorder

ERIC Educational Resources Information Center

Fong, Shirley S. M.; Lee, Velma Y. L.; Pang, Marco Y. C.

2011-01-01

This study aimed to (1) compare functional balance performance and sensory organization of postural control between children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control and participation diversity among children with DCD. We recruited 81 children with DCD and 67 typically…

What underlies the diversity of brain tumors?

PubMed Central

Swartling, Fredrik J.; Hede, Sanna-Maria; Weiss, William A.

2012-01-01

Glioma and medulloblastoma represent the most commonly occurring malignant brain tumors in adults and in children respectively. Recent genomic and transcriptional approaches present a complex group of diseases, and delineate a number of molecular subgroups within tumors that share a common histopathology. Differences in cells of origin, regional niches, developmental timing and genetic events all contribute to this heterogeneity. In an attempt to recapitulate the diversity of brain tumors, an increasing array of genetically engineered mouse models (GEMMs) has been developed. These models often utilize promoters and genetic drivers from normal brain development, and can provide insight into specific cells from which these tumors originate. GEMMs show promise in both developmental biology and developmental therapeutics. This review describes numerous murine brain tumor models in the context of normal brain development, and the potential for these animals to impact brain tumor research. PMID:23085857

Continuity and change in the development of category-based induction: The test case of diversity-based reasoning.

PubMed

Rhodes, Marjorie; Liebenson, Peter

2015-11-01

The present research examined the extent to which the cognitive mechanisms available to support inductive inference stay constant across development or undergo fundamental change. Four studies tested how children (ages 5-10) incorporate information about sample composition into their category-based generalizations. Children's use of sample composition varied across age and type of category. For familiar natural kinds, children ages 5-8 generalized similarly from diverse and non-diverse samples of evidence, whereas older children generalized more broadly from more diverse sets. In contrast, for novel categories, children of each age made broader generalizations from diverse than non-diverse samples. These studies provide the first clear evidence that young children are able to incorporate sample diversity into their inductive reasoning. These findings suggest developmental continuity in the cognitive mechanisms available for inductive inference, but developmental changes in the role that prior knowledge plays in shaping these processes. Copyright © 2015 Elsevier Inc. All rights reserved.

A Conserved Core of Programmed Cell Death Indicator Genes Discriminates Developmentally and Environmentally Induced Programmed Cell Death in Plants.

PubMed

Olvera-Carrillo, Yadira; Van Bel, Michiel; Van Hautegem, Tom; Fendrych, Matyáš; Huysmans, Marlies; Simaskova, Maria; van Durme, Matthias; Buscaill, Pierre; Rivas, Susana; Coll, Nuria S.; Coppens, Frederik; Maere, Steven; Nowack, Moritz K.

2015-12-01

A plethora of diverse programmed cell death (PCD) processes has been described in living organisms. In animals and plants, different forms of PCD play crucial roles in development, immunity, and responses to the environment. While the molecular control of some animal PCD forms such as apoptosis is known in great detail, we still know comparatively little about the regulation of the diverse types of plant PCD. In part, this deficiency in molecular understanding is caused by the lack of reliable reporters to detect PCD processes. Here, we addressed this issue by using a combination of bioinformatics approaches to identify commonly regulated genes during diverse plant PCD processes in Arabidopsis (Arabidopsis thaliana). Our results indicate that the transcriptional signatures of developmentally controlled cell death are largely distinct from the ones associated with environmentally induced cell death. Moreover, different cases of developmental PCD share a set of cell death-associated genes. Most of these genes are evolutionary conserved within the green plant lineage, arguing for an evolutionary conserved core machinery of developmental PCD. Based on this information, we established an array of specific promoter-reporter lines for developmental PCD in Arabidopsis. These PCD indicators represent a powerful resource that can be used in addition to established morphological and biochemical methods to detect and analyze PCD processes in vivo and in planta. © 2015 American Society of Plant Biologists. All Rights Reserved.

Educational and Developmental Belief Systems among African-American Parents of Kindergarten Children.

ERIC Educational Resources Information Center

Hyson, Marion C.; DeCsipkes, Candace

By describing the characteristics of the educational and developmental belief systems of low-income African-American parents of kindergarten children, this study extended previous research on parents' beliefs about early education and development to more ethnically and socioeconomically diverse subject groups. A sample of 115 African-American…

Mapping developmental precursors of cyber-aggression: trajectories of risk predict perpetration and victimization.

PubMed

Modecki, Kathryn L; Barber, Bonnie L; Vernon, Lynette; Vernon, Lynnette

2013-05-01

Technologically mediated contexts are social arenas in which adolescents can be both perpetrators and victims of aggression. Yet, there remains little understanding of the developmental etiology of cyber aggression, itself, as experienced by either perpetrators or victims. The current study examines 3-year latent within-person trajectories of known correlates of cyber-aggression: problem behavior, (low) self-esteem, and depressed mood, in a large and diverse sample of youth (N = 1,364; 54.6% female; 12-14 years old at T1). Findings demonstrate that developmental increases in problem behavior across grades 8-10 predict both cyber-perpetration and victimization in grade 11. Developmental decreases in self-esteem also predicted both grade 11 perpetration and victimization. Finally, early depressed mood predicted both perpetration and victimization later on, regardless of developmental change in depressed mood in the interim. Our results reveal a clear link between risky developmental trajectories across the early high school years and later cyber-aggression and imply that mitigating trajectories of risk early on may lead to decreases in cyber-aggression at a later date.

Knowledge and Beliefs about National Development and Developmental Hierarchies: the Viewpoints of Ordinary People in Thirteen Countries

PubMed Central

Thornton, Arland; Binstock, Georgina; Abbasi-Shavazi, Mohammad Jalal; Ghimire, Dirgha; Gjonca, Arjan; Melegh, Attila; Mitchell, Colter; Moaddel, Mansoor; Xie, Yu; Yang, Li-shou; Young-DeMarco, Linda; Yount, Kathryn M.

2012-01-01

Scholars and policy makers have for centuries constructed and used developmental hierarchies to characterize different countries. The hypotheses motivating this paper are that such social constructions have been circulated internationally, are constructed similarly in various countries, and follow the social constructions of elite international organizations, such as the United Nations. This paper uses data from fifteen surveys in thirteen diverse countries to study how developmental hierarchies are understood in everyday life. Our research shows that most people have constructions of developmental hierarchies that are similar across countries and are similar to the developmental hierarchies constructed by the United Nations. These findings suggest that developmental hierarchies are widely understood around the world and are widely available to ordinary people as they make decisions about many aspects of life. PMID:23017917

Functional Anthology of Intrinsic Disorder. II. Cellular Components, Domains, Technical Terms, Developmental Processes and Coding Sequence Diversities Correlated with Long Disordered Regions

PubMed Central

Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

2008-01-01

Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes ~90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes and coding sequence diversities possessing strong positive and negative correlation with long disordered regions. PMID:17391015

Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions.

PubMed

Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

2007-05-01

Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes approximately 90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions.

Developmental Toxicology##

EPA Science Inventory

Developmental toxicology encompasses the study of developmental exposures, pharmacokinetics, mechanisms, pathogenesis, and outcomes potentially leading to adverse health effects. Manifestations of developmental toxicity include structural malformations, growth retardation, functi...

Neurobehavioral Teratogenicity of Perfluorinated Alkyls in an Avian Model

PubMed Central

Pinkas, Adi; Slotkin, Theodore A.; Brick-Turin, Yael; Van der Zee, Eddy A.; Yanai, Joseph

2010-01-01

Perfluorinated alkyls are widely-used agents that accumulate in ecosystems and organisms because of their slow rate of degradation. There is increasing concern that these agents may be developmental neurotoxicants and the present study was designed to develop an avian model for the neurobehavioral teratogenicity of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Fertilized chicken eggs were injected with 5 or 10 mg/kg of either compound on incubation day 0. On the day of hatching, imprinting behavior was impaired by both compounds. We then explored underlying mechanisms involving the targeting of protein kinase C (PKC) isoforms (α, β, γ) in the intermedial part of the hyperstriatum ventrale, the region most closely associated with imprinting. With PFOA exposure, cytosolic PKC concentrations were significantly elevated for all three isoforms; despite the overall increase in PKC expression, membrane-associated PKC was unaffected, indicating a defect in PKC translocation. In contrast, PFOS exposure evoked a significant decrease in cytosolic PKC, primarily for the β and γ isoforms, but again without a corresponding change in membrane-associated enzyme; this likely partial, compensatory increases in translocation to offset the net PKC deficiency. Our studies indicate that perfluorinated alkyls are indeed developmental neurotoxicants that affect posthatch cognitive performance but that the underlying synaptic mechanisms may differ substantially among the various members of this class of compounds, setting the stage for disparate outcomes later in life. PMID:19945530

Neurotoxicity of lead, methylmercury, and PCBs in relation to the Great Lakes.

PubMed Central

Rice, D C

1995-01-01

There is ample evidence identifying lead, methylmercury, and polychlorinated biphenyls (PCBs) as neurotoxic agents. A large body of data on the neurotoxicity of lead, based on both epidemiologic studies in children and animal models of developmental exposure, reveals that body burdens of lead typical of people in industrialized environments produce behavioral impairment. Methylmercury was identified as a neurotoxicant in both adults and the developing organism based on episodes of human poisoning: these effects have been replicated and extended in animals. High-dose PCB exposure was recognized as a developmental toxicant as a result of several episodes of contamination of cooking oil. The threshold for PCB neurotoxicity in humans is less clear, although research in animals suggests that relatively low-level exposure produces behavioral impairment and other toxic effects. Tissue levels in fish below which human health would not be adversely affected were estimated for methylmercury and PCBs based on calculated reference doses (RfDs) and estimated fish intake. Present levels in fish tissue in the Great Lakes exceed these levels for both neurotoxicants. Great Lakes fish and water do not pose a particular hazard for increased lead intake. However, the fact that the present human body burden is in a range at which functional deficits are probable suggests that efforts should be made to eliminate point sources of lead contamination in the Great Lakes basin. PMID:8635443

Constructivist developmental theory is needed in developmental neuroscience

NASA Astrophysics Data System (ADS)

Arsalidou, Marie; Pascual-Leone, Juan

2016-12-01

Neuroscience techniques provide an open window previously unavailable to the origin of thoughts and actions in children. Developmental cognitive neuroscience is booming, and knowledge from human brain mapping is finding its way into education and pediatric practice. Promises of application in developmental cognitive neuroscience rests however on better theory-guided data interpretation. Massive amounts of neuroimaging data from children are being processed, yet published studies often do not frame their work within developmental models—in detriment, we believe, to progress in this field. Here we describe some core challenges in interpreting the data from developmental cognitive neuroscience, and advocate the use of constructivist developmental theories of human cognition with a neuroscience interpretation.

Convergent occurrence of the developmental hourglass in plant and animal embryogenesis?

PubMed

Cridge, Andrew G; Dearden, Peter K; Brownfield, Lynette R

2016-04-01

The remarkable similarity of animal embryos at particular stages of development led to the proposal of a developmental hourglass. In this model, early events in development are less conserved across species but lead to a highly conserved 'phylotypic period'. Beyond this stage, the model suggests that development once again becomes less conserved, leading to the diversity of forms. Recent comparative studies of gene expression in animal groups have provided strong support for the hourglass model. How and why might such an hourglass pattern be generated? More importantly, how might early acting events in development evolve while still maintaining a later conserved stage? The discovery that an hourglass pattern may also exist in the embryogenesis of plants provides comparative data that may help us explain this phenomenon. Whether the developmental hourglass occurs in plants, and what this means for our understanding of embryogenesis in plants and animals is discussed. Models by which conserved early-acting genes might change their functional role in the evolution of gene networks, how networks buffer these changes, and how that might constrain, or confer diversity, of the body plan are also discused. Evidence of a morphological and molecular hourglass in plant and animal embryogenesis suggests convergent evolution. This convergence is likely due to developmental constraints imposed upon embryogenesis by the need to produce a viable embryo with an established body plan, controlled by the architecture of the underlying gene regulatory networks. As the body plan is largely laid down during the middle phases of embryo development in plants and animals, then it is perhaps not surprising this stage represents the narrow waist of the hourglass where the gene regulatory networks are the oldest and most robust and integrated, limiting species diversity and constraining morphological space. © The Author 2016. Published by Oxford University Press on behalf of the Annals of

Conserved Gene Expression Programs in Developing Roots from Diverse Plants.

PubMed

Huang, Ling; Schiefelbein, John

2015-08-01

The molecular basis for the origin and diversification of morphological adaptations is a central issue in evolutionary developmental biology. Here, we defined temporal transcript accumulation in developing roots from seven vascular plants, permitting a genome-wide comparative analysis of the molecular programs used by a single organ across diverse species. The resulting gene expression maps uncover significant similarity in the genes employed in roots and their developmental expression profiles. The detailed analysis of a subset of 133 genes known to be associated with root development in Arabidopsis thaliana indicates that most of these are used in all plant species. Strikingly, this was also true for root development in a lycophyte (Selaginella moellendorffii), which forms morphologically different roots and is thought to have evolved roots independently. Thus, despite vast differences in size and anatomy of roots from diverse plants, the basic molecular mechanisms employed during root formation appear to be conserved. This suggests that roots evolved in the two major vascular plant lineages either by parallel recruitment of largely the same developmental program or by elaboration of an existing root program in the common ancestor of vascular plants. © 2015 American Society of Plant Biologists. All rights reserved.

Diversity and function of bacterial microbiota in the mosquito holobiont

PubMed Central

2013-01-01

Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

Diversity of immunoglobulin lambda light chain gene usage over developmental stages in the horse.

PubMed

Tallmadge, Rebecca L; Tseng, Chia T; Felippe, M Julia B

2014-10-01

To further studies of neonatal immune responses to pathogens and vaccination, we investigated the dynamics of B lymphocyte development and immunoglobulin (Ig) gene diversity. Previously we demonstrated that equine fetal Ig VDJ sequences exhibit combinatorial and junctional diversity levels comparable to those of adult Ig VDJ sequences. Herein, RACE clones from fetal, neonatal, foal, and adult lymphoid tissue were assessed for Ig lambda light chain combinatorial, junctional, and sequence diversity. Remarkably, more lambda variable genes (IGLV) were used during fetal life than later stages and IGLV gene usage differed significantly with time, in contrast to the Ig heavy chain. Junctional diversity measured by CDR3L length was constant over time. Comparison of Ig lambda transcripts to germline revealed significant increases in nucleotide diversity over time, even during fetal life. These results suggest that the Ig lambda light chain provides an additional dimension of diversity to the equine Ig repertoire. Copyright © 2014 Elsevier Ltd. All rights reserved.

Towards an ontogenetic understanding of inflorescence diversity

PubMed Central

Claßen-Bockhoff, Regine; Bull-Hereñu, Kester

2013-01-01

Backgrounds and Aims Conceptual and terminological conflicts in inflorescence morphology indicate a lack of understanding of the phenotypic diversity of inflorescences. In this study, an ontogeny-based inflorescence concept is presented considering different meristem types and developmental pathways. By going back to the ontogenetic origin, diversity is reduced to a limited number of types and terms. Methods Species from 105 genera in 52 angiosperm families are investigated to identify their specific reproductive meristems and developmental pathways. Based on these studies, long-term experience with inflorescences and literature research, a conceptual framework for the understanding of inflorescences is presented. Key Results Ontogeny reveals that reproductive systems traditionally called inflorescences fall into three groups, i.e. ‘flowering shoot systems’ (FSS), ‘inflorescences’ sensu stricto and ‘floral units’ (FUs). Our concept is, first, based on the identification of reproductive meristem position and developmental potential. The FSS, defined as a seasonal growth unit, is used as a reference framework. As the FSS is a leafy shoot system bearing reproductive units, foliage and flowering sequence play an important role. Second, the identification of two different flower-producing meristems is essential. While ‘inflorescence meristems’ (IMs) share acropetal primordia production with vegetative meristems, ‘floral unit meristems’ (FUMs) resemble flower meristems in being indeterminate. IMs produce the basic inflorescence types, i.e. compound and simple racemes, panicles and botryoids. FUMs give rise to dense, often flower-like units (e.g. heads). They occur solitarily at the FSS or occupy flower positions in inflorescences, rendering the latter thyrses in the case of cymose branching. Conclusions The ontogenetic concept differs from all existing inflorescence concepts in being based on meristems and developmental processes. It includes clear

Size and species diversity of zooplankton communities in fluctuating Mediterranean salt marshes

NASA Astrophysics Data System (ADS)

Brucet, Sandra; Boix, Dani; López-Flores, Rocío; Badosa, Anna; Quintana, Xavier D.

2006-04-01

Differences in size and species diversity were analysed in a zooplankton community of a Mediterranean salt marsh (Empordà wetlands, NE Iberian Peninsula), where the dominance of a single species was frequent. In the permanent salt marsh, species diversity and size diversity had similar patterns along zooplankton succession. In the temporary salt marsh species diversity was high after flooding and diminished once water inputs ceased. As species diversity declined size diversity increased. Eventually, one species of calanoid dominated the zooplankton community. The high size diversity in situations of calanoid dominance was possibly due to the co-occurrence of different developmental stages, each of which have different diets. Size diversity would thus indicate trophic niche segregation among different sizes. The combined use of species and size diversity values allows the identification of the successional phases.

Pre-Service Teachers' Dispositions towards Diversity: Arguing for a Developmental Hierarchy of Change

ERIC Educational Resources Information Center

Mills, Carmen; Ballantyne, Julie

2010-01-01

This article explores Australian pre-service teachers' beliefs about and attitudes towards diversity. Building on Garmon's [Garmon, M. A. (2004). "Changing preservice teachers' attitudes/beliefs about diversity: what are the critical factors?" "Journal of Teacher Education, 55"(3), 201-213] argument that there are three…

Between and within Ethnic Differences in Strategic Learning: A Study of Developmental Mathematics Students

ERIC Educational Resources Information Center

Fong, Carlton J.; Zientek, Linda Reichwein; Yetkiner Ozel, Zeynep Ebrar; Phelps, Julie M.

2015-01-01

The present study investigated developmental mathematics students' efficacy beliefs for motivational, self-regulated learning, resource management, and cognitive strategies and which of these beliefs most differentiated European American, African American and Hispanic students in terms of their mathematics achievement. The diverse sample consisted…

Developmental Localization and Methylesterification of Pectin Epitopes during Somatic Embryogenesis of Banana (Musa spp. AAA)

PubMed Central

Xu, Chunxiang; Zhao, Lu; Pan, Xiao; Šamaj, Jozef

2011-01-01

Background The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development. Methodology/Principal Findings Developmental localization of pectic homogalacturonan (HG) epitopes and the (1→4)-β-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment. Conclusions/Significance These data suggest that both low

Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents.

PubMed

Gilbert, Scott F; Bosch, Thomas C G; Ledón-Rettig, Cristina

2015-10-01

The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.

Patterns of threshold evolution in polyphenic insects under different developmental models.

PubMed

Tomkins, Joseph L; Moczek, Armin P

2009-02-01

Two hypotheses address the evolution of polyphenic traits in insects. Under the developmental reprogramming model, individuals exceeding a threshold follow a different developmental pathway from individuals below the threshold. This decoupling is thought to free selection to independently hone alternative morphologies, increasing phenotypic plasticity and morphological diversity. Under the alternative model, extreme positive allometry explains the existence of alternative phenotypes and divergent phenotypes are developmentally coupled by a continuous reaction norm, such that selection on either morph acts on both. We test the hypothesis that continuous reaction norm polyphenisms, evolve through changes in the allometric parameters of even the smallest males with minimal trait expression, whereas threshold polyphenisms evolve independent of the allometric parameters of individuals below the threshold. We compare two polyphenic species; the dung beetle Onthophagus taurus, whose allometry has been modeled both as a threshold polyphenism and a continuous reaction norm and the earwig Forficula auricularia, whose allometry is best modeled with a discontinuous threshold. We find that across populations of both species, variation in forceps or horn allometry in minor males are correlated to the population's threshold. These findings suggest that regardless of developmental mode, alternative morphs do not evolve independently of one another.

Developmental pathways in infants from 4 to 24 months.

PubMed

Valla, L; Birkeland, M S; Hofoss, D; Slinning, K

2017-07-01

There has been limited epidemiological research describing population-based samples regarding developmental pathways throughout infancy, and the research that exists has revealed substantial diversity. Identifying predictors for developmental pathways can inform early intervention services. The Ages and Stages Questionnaire was used to measure communication, gross motor, fine motor, problem-solving and personal-social skills longitudinally in a large, population-based sample of 1555 infants recruited from well-baby clinics in five municipalities in southeast Norway. We conducted latent class analyses to identify common pathways within the five developmental areas. Our results indicated that most classes of infants showed generally positive and stable normative developmental pathways. However, for communication and gross motor areas, more heterogeneity was found. For gross motor development, a class of 10% followed a U-shaped curve. A class of 8% had a declining communication pathway and did not reach the level of the high stable communication class at 24 months. Low gestational age, low Apgar score, male sex, maternal depression symptoms, non-Scandinavian maternal ethnicity and high maternal education significantly predict less beneficial communication pathways. The results suggest that infants with low gestational age, low Apgar score, male sex and a mother with depression symptoms or non-Scandinavian ethnicity may be at risk of developing less beneficial developmental pathways, especially within the communication area. Targeting these infants for surveillance and support might be protective against delayed development in several areas during a critical window of development. © 2017 John Wiley & Sons Ltd.

Psychosocial development in racially and ethnically diverse youth: conceptual and methodological challenges in the 21st century.

PubMed

Swanson, Dena Phillips; Spencer, Margaret Beale; Harpalani, Vinay; Dupree, Davido; Noll, Elizabeth; Ginzburg, Sofia; Seaton, Gregory

2003-01-01

As the US population becomes more diverse in the 21st century, researchers face many conceptual and methodological challenges in working with diverse populations. We discuss these issues for racially and ethnically diverse youth, using Spencer's phenomenological variant of ecological systems theory (PVEST) as a guiding framework. We present a brief historical background and discuss recurring conceptual flaws in research on diverse youth, presenting PVEST as a corrective to these flaws. We highlight the interaction of race, culture, socioeconomic status, and various contexts of development with identity formation and other salient developmental processes. Challenges in research design and interpretation of data are also covered with regard to both assessment of contexts and developmental processes. We draw upon examples from neighborhood assessments, ethnic identity development, and attachment research to illustrate conceptual and methodological challenges, and we discuss strategies to address these challenges. The policy implications of our analysis are also considered.

Using Developmental Evaluation as a Design Thinking Tool for Curriculum Innovation in Professional Higher Education

ERIC Educational Resources Information Center

Leonard, Simon N.; Fitzgerald, Robert N.; Riordan, Geoffrey

2016-01-01

This paper argues for the use of "developmental" evaluation as a design-based research tool for sustainable curriculum innovation in professional higher education. Professional education is multi-faceted and complex with diverse views from researchers, professional practitioners, employers and the world of politics leaving little…

Larval adaptations and patterns of brachiopod diversity in space and time

NASA Technical Reports Server (NTRS)

Valentine, J. W.; Jablonski, D.

1983-01-01

Modern biodistributional patterns suggest that modes of larval development are a factor in determining the patterns of diversity in benthic invertebrates. Paleozoic brachiopods had diversity patterns suggesting that they possessed both planktotrophic and nonplanktotrophic modes. It is presently hypothesized that the planktotrophic lineages were lost to extinction, largely or entirely during the Permian-Triassic event, and that the failure of the articulate brachiopods to regain their former importance is substantially due to their nonplanktotrophic developmental mode.

A View of Developmental Education and the "Disadvantaged" in a National Perspective: Implications for International Education

ERIC Educational Resources Information Center

Wilson, Thomasyne Lightfoote

1972-01-01

After defining developmental education as referring to processes that expand the physical, emotional, educational, artistic, scientific, and political spheres of diverse ethnic and cultural communities within a nation, the author discusses the case of the Loma people of Liberia. (JM)

Developmental evaluation and the 'Stronger Economies Together' initiative in the United States.

PubMed

Honadle, Beth Walter; Zapata, Marisa A; Auffrey, Christopher; vom Hofe, Rainer; Looye, Johanna

2014-04-01

This article describes a developmental evaluation and explains its impact on the Stronger Economies Together (SET) initiative of the U.S. Department of Agriculture in collaboration with the Nation's four Regional Rural Development Centers and Land-Grant universities. Through a dynamic process, this evaluation of the early phases of an initiative led to continuous program alterations based on feedback. The relationship of the evaluation team to the initiative's coordinating team enabled seamless transfer of observations, suggestions, and recommendations to decision makers. The multidisciplinary character of the evaluation team provided a diverse set of perspectives with a depth of subject matter and knowledge from relevant fields. One lesson is that developmental evaluators must be flexible, nimble, creative, and adaptive. When expected data are imperfect or nonexistent, the team must collect alternate information and make recommendations to improve data collection. As the initiative proceeded and modifications came about, the evaluation team had to recognize the changes in the program and focus on different questions. This experience with developmental evaluation provides insights into how interdisciplinary teams may need to change course and conduct a developmental evaluation when a formative evaluation was originally envisioned. Published by Elsevier Ltd.

Participation Patterns of Preschool Children With Intellectual Developmental Disabilities.

PubMed

Gilboa, Yafit; Fuchs, Reut

2018-04-01

We aim to examine the pattern of participation of children with intellectual developmental disabilities (IDD) or global developmental delay (GDD) in comparison with typically developing preschoolers. In addition, to identify environmental and personal factors associated with their participation, 20 children with mild to moderate GDD or IDD, and 24 age- and gender-matched controls, aged 3 to 6 years, were assessed using the Assessment of Preschool Children's Participation and the Environmental Restriction Questionnaire. Significant differences were found between the groups, both for general scales of participation and for each activity area. For the IDD/GDD group, participation was significantly negatively correlated with environmental restrictions at home. For the control group, participation was correlated with demographic variables. Typically developing children participate at a higher frequency and in a more diverse range of activities compared with children with IDD/GDD. Associations between participation and contextual factors varied depending on the child's health condition.

Latent Class Analysis of Early Developmental Trajectory in Baby Siblings of Children with Autism

ERIC Educational Resources Information Center

Landa, Rebecca J.; Gross, Alden L.; Stuart, Elizabeth A.; Bauman, Margaret

2012-01-01

Background: Siblings of children with autism (sibs-A) are at increased genetic risk for autism spectrum disorders (ASD) and milder impairments. To elucidate diversity and contour of early developmental trajectories exhibited by sibs-A, regardless of diagnostic classification, latent class modeling was used. Methods: Sibs-A (N = 204) were assessed…

THE NEUROTOXICANT TRIMETHYLTIN STIMULATES APOPTOSIS VIA OXIDATIVE STRESS, CASPASE ACTIVATION AND P38 PROTEIN KINASE.

EPA Science Inventory

Acute exposure to the tri-substituted organotin trimethyltin (TMT) causes neuronal degeneration in the hippocampus, amygdala, pyriform cortex, and neocortex. Developmental exposure to TMT impairs later learning and memory. Despite extensive efforts elucidating neuropathological...

A Functionally Conserved Gene Regulatory Network Module Governing Olfactory Neuron Diversity.

PubMed

Li, Qingyun; Barish, Scott; Okuwa, Sumie; Maciejewski, Abigail; Brandt, Alicia T; Reinhold, Dominik; Jones, Corbin D; Volkan, Pelin Cayirlioglu

2016-01-01

Sensory neuron diversity is required for organisms to decipher complex environmental cues. In Drosophila, the olfactory environment is detected by 50 different olfactory receptor neuron (ORN) classes that are clustered in combinations within distinct sensilla subtypes. Each sensilla subtype houses stereotypically clustered 1-4 ORN identities that arise through asymmetric divisions from a single multipotent sensory organ precursor (SOP). How each class of SOPs acquires a unique differentiation potential that accounts for ORN diversity is unknown. Previously, we reported a critical component of SOP diversification program, Rotund (Rn), increases ORN diversity by generating novel developmental trajectories from existing precursors within each independent sensilla type lineages. Here, we show that Rn, along with BarH1/H2 (Bar), Bric-à-brac (Bab), Apterous (Ap) and Dachshund (Dac), constitutes a transcription factor (TF) network that patterns the developing olfactory tissue. This network was previously shown to pattern the segmentation of the leg, which suggests that this network is functionally conserved. In antennal imaginal discs, precursors with diverse ORN differentiation potentials are selected from concentric rings defined by unique combinations of these TFs along the proximodistal axis of the developing antennal disc. The combinatorial code that demarcates each precursor field is set up by cross-regulatory interactions among different factors within the network. Modifications of this network lead to predictable changes in the diversity of sensilla subtypes and ORN pools. In light of our data, we propose a molecular map that defines each unique SOP fate. Our results highlight the importance of the early prepatterning gene regulatory network as a modulator of SOP and terminally differentiated ORN diversity. Finally, our model illustrates how conserved developmental strategies are used to generate neuronal diversity.

Deconstructing Pancreas Developmental Biology

PubMed Central

Benitez, Cecil M.; Goodyer, William R.

2012-01-01

The relentless nature and increasing prevalence of human pancreatic diseases, in particular, diabetes mellitus and adenocarcinoma, has motivated further understanding of pancreas organogenesis. The pancreas is a multifunctional organ whose epithelial cells govern a diversity of physiologically vital endocrine and exocrine functions. The mechanisms governing the birth, differentiation, morphogenesis, growth, maturation, and maintenance of the endocrine and exocrine components in the pancreas have been discovered recently with increasing tempo. This includes recent studies unveiling mechanisms permitting unexpected flexibility in the developmental potential of immature and mature pancreatic cell subsets, including the ability to interconvert fates. In this article, we describe how classical cell biology, genetic analysis, lineage tracing, and embryological investigations are being complemented by powerful modern methods including epigenetic analysis, time-lapse imaging, and flow cytometry-based cell purification to dissect fundamental processes of pancreas development. PMID:22587935

Intragroup Contact and Anxiety Among Ethnic Minority Adolescents: Considering Ethnic Identity and School Diversity Transitions

PubMed Central

Yip, Tiffany; Shelton, J. Nicole

2015-01-01

Everyday interactions with same-racial/ethnic others may confer positive benefits for adolescents, but the meaning of these interactions are likely influenced by individual differences and larger structural contexts. This study examined the situation-level association between contact with same-ethnic others and anxiety symptoms among a diverse sample of 306 racial/ethnic minority adolescents (Mage = 14 years; 66 % female), based on (1) individual differences in ethnic identity centrality and (2) developmental histories of transitions in diversity between elementary, middle, and high school. The results indicated that at the level of the situation, when adolescents interacted with more same-ethnic others, they reported fewer anxiety symptoms. Further, for adolescents who had experienced a transition in school diversity, the positive benefits of contact with same-ethnic others was only conferred for those who felt that their ethnicity was very important to them. The importance of examining individual differences within larger developmental histories to understand the everyday experiences of ethnic minority adolescents are discussed. PMID:24951944

Developmental Screening

MedlinePlus

Learn More about Your Child’s Development: Developmental Monitoring and Screening Taking a first step, waving “bye-bye,” and pointing to something interesting are all developmental milestones, ...

Meeting report: alternatives for developmental neurotoxicity testing.

PubMed

Lein, Pamela; Locke, Paul; Goldberg, Alan

2007-05-01

Developmental neurotoxicity testing (DNT) is perceived by many stakeholders to be an area in critical need of alternatives to current animal testing protocols and guidelines. To address this need, the Johns Hopkins Center for Alternatives to Animal Testing (CAAT), the U.S. Environmental Protection Agency, and the National Toxicology Program are collaborating in a program called TestSmart DNT, the goals of which are to: (a) develop alternative methodologies for identifying and prioritizing chemicals and exposures that may cause developmental neurotoxicity in humans; (b) develop the policies for incorporating DNT alternatives into regulatory decision making; and (c) identify opportunities for reducing, refining, or replacing the use of animals in DNT. The first TestSmart DNT workshop was an open registration meeting held 13-15 March 2006 in Reston, Virginia. The primary objective was to bring together stakeholders (test developers, test users, regulators, and advocates for children's health, animal welfare, and environmental health) and individuals representing diverse disciplines (developmental neurobiology, toxicology, policy, and regulatory science) from around the world to share information and concerns relating to the science and policy of DNT. Individual presentations are available at the CAAT TestSmart website. This report provides a synthesis of workgroup discussions and recommendations for future directions and priorities, which include initiating a systematic evaluation of alternative models and technologies, developing a framework for the creation of an open database to catalog DNT data, and devising a strategy for harmonizing the validation process across international jurisdictional borders.

I. DEVELOPMENTAL METHODOLOGY AS A CENTRAL SUBDISCIPLINE OF DEVELOPMENTAL SCIENCE.

PubMed

Card, Noel A

2017-06-01

This first chapter introduces the main goals of the monograph and previews the remaining chapters. The goals of this monograph are to provide summaries of our current understanding of advanced developmental methodologies, provide information that can advance our understanding of human development, identify shortcomings in our understanding of developmental methodology, and serve as a flagpost for organizing developmental methodology as a subdiscipline within the broader field of developmental science. The remaining chapters in this monograph address issues in design (sampling and big data), longitudinal data analysis, and issues of replication and research accumulation. The final chapter describes the history of developmental methodology, considers how the previous chapters in this monograph fit within this subdiscipline, and offers recommendations for further advancement. © 2017 The Society for Research in Child Development, Inc.

Teaching, Learning and Leading in Today's Complex World: Reaching New Heights with a Developmental Approach

ERIC Educational Resources Information Center

Drago-Severson, Eleanor

2016-01-01

"What is happening in education today?" and "What is most needed for the future of teaching, learning and leading?" This article presents a developmental approach to learning, leadership and advancing professional learning--one that takes into account adults' diverse meaning making processes--that can help educators build the…

Promoting positive human development and social justice: Integrating theory, research and application in contemporary developmental science.

PubMed

Lerner, Richard M

2015-06-01

The bold claim that developmental science can contribute to both enhancing positive development among diverse individuals across the life span and promoting social justice in their communities, nations and regions is supported by decades of theoretical, methodological and research contributions. To explain the basis of this claim, I describe the relational developmental systems (RDS) metamodel that frames contemporary developmental science, and I present an example of a programme of research within the adolescent portion of the life span that is associated with this metamodel and is pertinent to promoting positive human development. I then discuss methodological issues associated with using RDS-based models as frames for research and application. Finally, I explain how the theoretical and methodological ideas associated with RDS thinking may provide the scholarly tools needed by developmental scientists seeking to contribute to human thriving and to advance social justice in the Global South. © 2015 International Union of Psychological Science.

Communication-based assessment of developmental age for young children with developmental disabilities.

PubMed

DeVeney, Shari L; Hoffman, Lesa; Cress, Cynthia J

2012-06-01

In this study, the authors compared a multiple-domain strategy for assessing developmental age of young children with developmental disabilities who were at risk for long-term reliance on augmentative and alternative communication (AAC) with a communication-based strategy composed of receptive language and communication indices that may be less affected by physically challenging tasks than traditional developmental age scores. Participants were 42 children (age 9-27 months) with developmental disabilities and who were at risk for long-term reliance on AAC. Children were assessed longitudinally in their homes at 3 occasions over 18 months using multiple-domain and communication-based measures. Confirmatory factor analysis examined dimensionality across the measures, and age-equivalence scores under each strategy were compared, where possible. The communication-based latent factor of developmental age demonstrated good reliability and was almost perfectly correlated with the multiple-domain latent factor. However, the mean age-equivalence score of the communication-based assessment significantly exceeded that of the multiple-domain assessment by 5.3 months across ages. Clinicians working with young children with developmental disabilities should consider a communication-based approach as an alternative developmental age assessment strategy for characterizing children's capabilities, identifying challenges, and developing interventions. A communication-based developmental age estimation is sufficiently reliable and may result in more valid inferences about developmental age for children whose developmental or cognitive age scores may otherwise be limited by their physical capabilities.

Comparative Developmental Toxicity of Flavonoids Using an Integrative Zebrafish System

PubMed Central

Bugel, Sean M.; Bonventre, Josephine A.; Tanguay, Robert L.

2016-01-01

Flavonoids are a large, structurally diverse class of bioactive naturally occurring chemicals commonly detected in breast milk, soy based infant formulas, amniotic fluid, and fetal cord blood. The potential for pervasive early life stage exposures raises concerns for perturbation of embryogenesis, though developmental toxicity and bioactivity information is limited for many flavonoids. Therefore, we evaluated a suite of 24 flavonoid and flavonoid-like chemicals using a zebrafish embryo-larval toxicity bioassay—an alternative model for investigating developmental toxicity of environmentally relevant chemicals. Embryos were exposed to 1–50 µM of each chemical from 6 to 120 h postfertilization (hpf), and assessed for 26 adverse developmental endpoints at 24, 72, and 120 hpf. Behavioral changes were evaluated in morphologically normal animals at 24 and 72 hpf, at 120 hpf using a larval photomotor response (LPR) assay. Gene expression was comparatively evaluated for all compounds for effects on biomarker transcripts indicative of AHR (cyp1a) and ER (cyp19a1b, esr1, lhb, vtg) pathway bioactivity. Overall, 15 of 24 flavonoids elicited adverse effects on one or more of the developmental or behavioral endpoints. Hierarchical clustering and principle component analyses compared toxicity profiles and identified 3 distinct groups of bioactive flavonoids. Despite robust induction of multiple estrogen-responsive biomarkers, co-exposure with ER and GPER antagonists did not ameliorate toxicity, suggesting ER-independence and alternative modes of action. Taken together, these studies demonstrate that development is sensitive to perturbation by bioactive flavonoids in zebrafish that are not related to traditional estrogen receptor mode of action pathways. This integrative zebrafish platform provides a useful framework for evaluating flavonoid developmental toxicity and hazard prioritization. PMID:27492224

Evaluation of 1066 ToxCast Chemicals in a human stem cell assay for developmental toxicity (SOT)

EPA Science Inventory

To increase the diversity of assays used to assess potential developmental toxicity, the ToxCast chemical library was screened in the Stemina devTOX quickPREDICT assay using human embryonic stem (hES) cells. A model for predicting teratogenicity was based on a training set of 23 ...

Discovery of four recessive developmental disorders using probabilistic genotype and phenotype matching among 4,125 families

PubMed Central

Ansari, Morad; Balasubramanian, Meena; Blyth, Moira; Brady, Angela F.; Clayton, Stephen; Cole, Trevor; Deshpande, Charu; Fitzgerald, Tomas W.; Foulds, Nicola; Francis, Richard; Gabriel, George; Gerety, Sebastian S.; Goodship, Judith; Hobson, Emma; Jones, Wendy D.; Joss, Shelagh; King, Daniel; Klena, Nikolai; Kumar, Ajith; Lees, Melissa; Lelliott, Chris; Lord, Jenny; McMullan, Dominic; O'Regan, Mary; Osio, Deborah; Piombo, Virginia; Prigmore, Elena; Rajan, Diana; Rosser, Elisabeth; Sifrim, Alejandro; Smith, Audrey; Swaminathan, Ganesh J.; Turnpenny, Peter; Whitworth, James; Wright, Caroline F.; Firth, Helen V.; Barrett, Jeffrey C.; Lo, Cecilia W.; FitzPatrick, David R.; Hurles, Matthew E.

2018-01-01

Discovery of most autosomal recessive disease genes has involved analysis of large, often consanguineous, multiplex families or small cohorts of unrelated individuals with a well-defined clinical condition. Discovery of novel dominant causes of rare, genetically heterogenous developmental disorders has been revolutionized by exome analysis of large cohorts of phenotypically diverse parent-offspring trios 1,2. Here we analysed 4,125 families with diverse, rare, genetically heterogeneous developmental disorders and identified four novel autosomal recessive disorders. These four disorders were identified by integrating Mendelian filtering (identifying probands with rare biallelic putatively damaging variants in the same gene) with statistical assessments of (i) the likelihood of sampling the observed genotypes from the general population, and (ii) the phenotypic similarity of patients with the same recessive candidate gene. This new paradigm promises to catalyse discovery of novel recessive disorders, especially those with less consistent or nonspecific clinical presentations, and those caused predominantly by compound heterozygous genotypes. PMID:26437029

Discovery of four recessive developmental disorders using probabilistic genotype and phenotype matching among 4,125 families.

PubMed

Akawi, Nadia; McRae, Jeremy; Ansari, Morad; Balasubramanian, Meena; Blyth, Moira; Brady, Angela F; Clayton, Stephen; Cole, Trevor; Deshpande, Charu; Fitzgerald, Tomas W; Foulds, Nicola; Francis, Richard; Gabriel, George; Gerety, Sebastian S; Goodship, Judith; Hobson, Emma; Jones, Wendy D; Joss, Shelagh; King, Daniel; Klena, Nikolai; Kumar, Ajith; Lees, Melissa; Lelliott, Chris; Lord, Jenny; McMullan, Dominic; O'Regan, Mary; Osio, Deborah; Piombo, Virginia; Prigmore, Elena; Rajan, Diana; Rosser, Elisabeth; Sifrim, Alejandro; Smith, Audrey; Swaminathan, Ganesh J; Turnpenny, Peter; Whitworth, James; Wright, Caroline F; Firth, Helen V; Barrett, Jeffrey C; Lo, Cecilia W; FitzPatrick, David R; Hurles, Matthew E

2015-11-01

Discovery of most autosomal recessive disease-associated genes has involved analysis of large, often consanguineous multiplex families or small cohorts of unrelated individuals with a well-defined clinical condition. Discovery of new dominant causes of rare, genetically heterogeneous developmental disorders has been revolutionized by exome analysis of large cohorts of phenotypically diverse parent-offspring trios. Here we analyzed 4,125 families with diverse, rare and genetically heterogeneous developmental disorders and identified four new autosomal recessive disorders. These four disorders were identified by integrating Mendelian filtering (selecting probands with rare, biallelic and putatively damaging variants in the same gene) with statistical assessments of (i) the likelihood of sampling the observed genotypes from the general population and (ii) the phenotypic similarity of patients with recessive variants in the same candidate gene. This new paradigm promises to catalyze the discovery of novel recessive disorders, especially those with less consistent or nonspecific clinical presentations and those caused predominantly by compound heterozygous genotypes.

Why developmental niche construction is not selective niche construction: and why it matters

PubMed Central

2017-01-01

In the last decade, niche construction has been heralded as the neglected process in evolution. But niche construction is just one way in which the organism's interaction with and construction of the environment can have potential evolutionary significance. The constructed environment does not just select for, it also produces new variation. Nearly 3 decades ago, and in parallel with Odling-Smee's article ‘Niche-constructing phenotypes', West and King introduced the ‘ontogenetic niche’ to give the phenomena of exogenetic inheritance a formal name. Since then, a range of fields in the life sciences and medicine has amassed evidence that parents influence their offspring by means other than DNA (parental effects), and proposed mechanisms for how heritable variation can be environmentally induced and developmentally regulated. The concept of ‘developmental niche construction’ (DNC) elucidates how a diverse range of mechanisms contributes to the transgenerational transfer of developmental resources. My most central of claims is that whereas the selective niche of niche construction theory is primarily used to explain the active role of the organism in its selective environment, DNC is meant to indicate the active role of the organism in its developmental environment. The paper highlights the differences between the construction of the selective and the developmental niche, and explores the overall significance of DNC for evolutionary theory. PMID:28839923

Why developmental niche construction is not selective niche construction: and why it matters.

PubMed

Stotz, Karola

2017-10-06

In the last decade, niche construction has been heralded as the neglected process in evolution. But niche construction is just one way in which the organism's interaction with and construction of the environment can have potential evolutionary significance. The constructed environment does not just select for , it also produces new variation. Nearly 3 decades ago, and in parallel with Odling-Smee's article 'Niche-constructing phenotypes', West and King introduced the 'ontogenetic niche' to give the phenomena of exo genetic inheritance a formal name. Since then, a range of fields in the life sciences and medicine has amassed evidence that parents influence their offspring by means other than DNA (parental effects), and proposed mechanisms for how heritable variation can be environmentally induced and developmentally regulated. The concept of 'developmental niche construction' (DNC) elucidates how a diverse range of mechanisms contributes to the transgenerational transfer of developmental resources. My most central of claims is that whereas the selective niche of niche construction theory is primarily used to explain the active role of the organism in its selective environment, DNC is meant to indicate the active role of the organism in its developmental environment. The paper highlights the differences between the construction of the selective and the developmental niche, and explores the overall significance of DNC for evolutionary theory.

Developmental Toxicity

EPA Science Inventory

This chapter provides an overview the developmental toxicity resulting from exposure to perfluorinated alkyl acids (PFAAs). The majority of studies of PFAA-induced developmental toxicity have examined effects of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA) a...

Executive Functions in Girls with and without Childhood ADHD: Developmental Trajectories and Associations with Symptom Change

ERIC Educational Resources Information Center

Miller, Meghan; Loya, Fred; Hinshaw, Stephen P.

2013-01-01

Background: We prospectively followed an ethnically and socioeconomically diverse sample of girls with attention-deficit/hyperactivity disorder (ADHD) (n = 140) and a matched comparison sample (n = 88) from childhood through young adulthood to evaluate developmental trajectories of executive functions (EF) and associations between EF trajectories…

Micro-computed tomography imaging and analysis in developmental biology and toxicology.

PubMed

Wise, L David; Winkelmann, Christopher T; Dogdas, Belma; Bagchi, Ansuman

2013-06-01

Micro-computed tomography (micro-CT) is a high resolution imaging technique that has expanded and strengthened in use since it was last reviewed in this journal in 2004. The technology has expanded to include more detailed analysis of bone, as well as soft tissues, by use of various contrast agents. It is increasingly applied to questions in developmental biology and developmental toxicology. Relatively high-throughput protocols now provide a powerful and efficient means to evaluate embryos and fetuses subjected to genetic manipulations or chemical exposures. This review provides an overview of the technology, including scanning, reconstruction, visualization, segmentation, and analysis of micro-CT generated images. This is followed by a review of more recent applications of the technology in some common laboratory species that highlight the diverse issues that can be addressed. Copyright © 2013 Wiley Periodicals, Inc.

Developmental experiences during extracurricular activities and Australian adolescents' self-concept: particularly important for youth from disadvantaged schools.

PubMed

Blomfield, Corey J; Barber, Bonnie L

2011-05-01

Extracurricular activities provide adolescents with a number of positive personal and interpersonal developmental experiences. This study investigated whether developmental experiences that occurred during extracurricular activities were linked to a more positive self-concept for Australian adolescents, and whether this link was particularly salient for youth from disadvantaged schools. Adolescents (N = 1,504, 56% Female) from 26 diverse high schools across Western Australia were surveyed. The findings revealed that adolescents from low socio-economic status schools who participated in extracurricular activities had a more positive general self-worth and social self-concept than adolescents from similar socio-economic schools who did not participate in any extracurricular activities. Furthermore, the positive developmental experiences that occurred during extracurricular activities predicted a more positive general self-worth and social and academic self-concept, and this link was stronger for youth from low SES schools. These findings suggest that the developmental experiences afforded by extracurricular activities may foster positive adolescent development.

Meeting Report: Alternatives for Developmental Neurotoxicity Testing

PubMed Central

Lein, Pamela; Locke, Paul; Goldberg, Alan

2007-01-01

Developmental neurotoxicity testing (DNT) is perceived by many stakeholders to be an area in critical need of alternatives to current animal testing protocols and guidelines. To address this need, the Johns Hopkins Center for Alternatives to Animal Testing (CAAT), the U.S. Environmental Protection Agency, and the National Toxicology Program are collaborating in a program called TestSmart DNT, the goals of which are to: (a) develop alternative methodologies for identifying and prioritizing chemicals and exposures that may cause developmental neurotoxicity in humans; (b) develop the policies for incorporating DNT alternatives into regulatory decision making; and (c) identify opportunities for reducing, refining, or replacing the use of animals in DNT. The first TestSmart DNT workshop was an open registration meeting held 13–15 March 2006 in Reston, Virginia. The primary objective was to bring together stakeholders (test developers, test users, regulators, and advocates for children’s health, animal welfare, and environmental health) and individuals representing diverse disciplines (developmental neurobiology, toxicology, policy, and regulatory science) from around the world to share information and concerns relating to the science and policy of DNT. Individual presentations are available at the CAAT TestSmart website. This report provides a synthesis of workgroup discussions and recommendations for future directions and priorities, which include initiating a systematic evaluation of alternative models and technologies, developing a framework for the creation of an open database to catalog DNT data, and devising a strategy for harmonizing the validation process across international jurisdictional borders. PMID:17520065

Turtle Carapace Anomalies: The Roles of Genetic Diversity and Environment

PubMed Central

Velo-Antón, Guillermo; Becker, C. Guilherme; Cordero-Rivera, Adolfo

2011-01-01

Background Phenotypic anomalies are common in wild populations and multiple genetic, biotic and abiotic factors might contribute to their formation. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. Methodology/Principal Findings In this study, we integrated field observations, manipulative experiments, and climatic and genetic approaches to investigate the origin of carapace scute anomalies across Iberian populations of the European pond turtle, Emys orbicularis. The proportion of anomalous individuals varied from 3% to 69% in local populations, with increasing frequency of anomalies in northern regions. We found no significant effect of climatic and soil moisture, or climatic temperature on the occurrence of anomalies. However, lower genetic diversity and inbreeding were good predictors of the prevalence of scute anomalies among populations. Both decreasing genetic diversity and increasing proportion of anomalous individuals in northern parts of the Iberian distribution may be linked to recolonization events from the Southern Pleistocene refugium. Conclusions/Significance Overall, our results suggest that developmental instability in turtle carapace formation might be caused, at least in part, by genetic factors, although the influence of environmental factors affecting the developmental stability of turtle carapace cannot be ruled out. Further studies of the effects of environmental factors, pollutants and heritability of anomalies would be useful to better understand the complex origin of anomalies in natural populations. PMID:21533278

The Generation of Variation and The Developmental Basis for Evolutionary Novelty

PubMed Central

Hallgrímsson, Benedikt; Jamniczky, Heather A.; Young, Nathan M.; Rolian, Campbell; Schmidt-Ott, Urs; Marcucio, Ralph S.

2013-01-01

Organisms exhibit an incredible diversity of form, a fact that makes the evolution of novelty seemingly self-evident. However, despite the “obvious” case for novelty, defining this concept in evolutionary terms is highly problematic, so much so that some have suggested discarding it altogether. Approaches to this problem tend to take either an adaptation or development-based perspective, but we argue here that an exclusive focus on either of these misses the original intent of the novelty concept and undermines its practical utility. We instead propose that for a feature to be novel it must have evolved both by a transition between adaptive peaks on the fitness landscape and that this transition must have overcome a previous developmental constraint. This definition focuses novelty on the explanation of apparently difficult or low probability evolutionary transitions and highlights how the integration of developmental and functional considerations is necessary to evolutionary explanation. It further reinforces that novelty is a central concern not just of evolutionary developmental biology (i.e., “evo-devo”) but of evolutionary biology more generally. We explore this definition of novelty in light of four examples that range from the obvious to subtle. PMID:22649039

Developmental Specificity in Targeting and Teaching Play Activities to Children with Pervasive Developmental Disorders

ERIC Educational Resources Information Center

Lifter, Karin; Ellis, James; Cannon, Barbara; Anderson, Stephen R.

2005-01-01

Developmentally specific play programs were designed for three children with pervasive developmental disorders being served in a home-based program. Using the Developmental Play Assessment, six activities for each of three adjacent developmentally sequenced play categories were targeted for direct instruction using different toy sets. A modified…

The never-ending story: from pluripotency to plant developmental plasticity

PubMed Central

Gaillochet, Christophe; Lohmann, Jan U.

2015-01-01

Plants are sessile organisms, some of which can live for over a thousand years. Unlike most animals, plants employ a post-embryonic mode of development driven by the continuous activity of pluripotent stem cells. Consequently, plants are able to initiate new organs over extended periods of time, and many species can readily replace lost body structures by de novo organogenesis. Classical studies have also shown that plant tissues have a remarkable capacity to undergo de-differentiation and proliferation in vitro, highlighting the fact that plant cell fate is highly plastic. This suggests that the mechanisms regulating fate transitions must be continuously active in most plant cells and that the control of cellular pluripotency lies at the core of diverse developmental programs. Here, we review how pluripotency is established in plant stem cell systems, how it is maintained during development and growth and re-initiated during regeneration, and how these mechanisms eventually contribute to the amazing developmental plasticity of plants. PMID:26130755

The Domain of Developmental Psychopathology.

ERIC Educational Resources Information Center

Sroufe, L. Alan; Rutter, Michael

1984-01-01

Describes how developmental psychopathology differs from related disciplines, including abnormal psychology, psychiatry, clinical child psychology, and developmental psychology. Points out propositions underlying a developmental perspective and discusses implications for research in developmental psychopathology. (Author/RH)

Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development

PubMed Central

Schaeffer, Scott M.; Christian, Ryan; Castro-Velasquez, Nohely; Hyden, Brennan; Lynch-Holm, Valerie

2017-01-01

Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids—chromoplasts—are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant ‘Granny Smith’, carotenoid-predominant ‘Golden Delicious’, and anthocyanin-predominant ‘Top Red Delicious’. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex biochemistry of plastids in perennial non-model systems. PMID:28698906

Using systematic reviews and meta-analyses to support regulatory decision making for neurotoxicants: lessons learned from a case study of PCBs.

PubMed

Goodman, Michael; Squibb, Katherine; Youngstrom, Eric; Anthony, Laura Gutermuth; Kenworthy, Lauren; Lipkin, Paul H; Mattison, Donald R; Lakind, Judy S

2010-06-01

Epidemiologic weight-of-evidence reviews to support regulatory decision making regarding the association between environmental chemical exposures and neurodevelopmental outcomes in children are often complicated by lack of consistency across studies. We examined prospective cohort studies evaluating the relation between prenatal and neonatal exposure to polychlorinated biphenyls (PCBs) and neurodevelopment in children to assess the feasibility of conducting a meta-analysis to support decision making. We described studies in terms of exposure and end point categorization, statistical analysis, and reporting of results. We used this evaluation to assess the feasibility of grouping studies into reasonably uniform categories. The current literature includes 11 cohorts of children for whom effects from prenatal or neonatal PCB exposures were assessed. The most consistently used tests included Brazelton's Neonatal Behavioral Assessment Scale, the neurologic optimality score in the neonatal period, the Bayley Scales of Infant Development at 5-8 months of age, and the McCarthy Scales of Children's Abilities in 5-year-olds. Despite administering the same tests at similar ages, the studies were too dissimilar to allow a meaningful quantitative examination of outcomes across cohorts. These analyses indicate that our ability to conduct weight-of-evidence assessments of the epidemiologic literature on neurotoxicants may be limited, even in the presence of multiple studies, if the available study methods, data analysis, and reporting lack comparability. Our findings add support to previous calls for establishing consensus standards for the conduct, analysis, and reporting of epidemiologic studies in general, and for those evaluating the effects of potential neurotoxic exposures in particular.

Developmental and functional outcomes in children with global developmental delay or developmental language impairment.

PubMed

Shevell, Michael; Majnemer, Annette; Platt, Robert W; Webster, Richard; Birnbaum, Rena

2005-10-01

Preschool children diagnosed with either global developmental delay (GDD) or developmental language impairment (DLI) were reassessed during their early school years with standardized developmental (Battelle Developmental Inventory [BDI]) and functional (Vineland Adaptive Behavior Scale [VABS]) outcome measures. Of an original cohort of 99 children with GDD and 70 children with DLI assessed and diagnosed at a mean age of 3 years 5 months (SD 1.1) and 3 years 7 months (SD 0.7) respectively, 48 children (34 [71%] males) with GDD and 43 children (36 [84%] males) with DLI were reassessed at a mean age of 7 years 4 months (SD 0.9) and 7 years 5 months (SD 0.7) respectively. The overall total mean BDI score for children with GDD was 66.4 (SD 4.3) versus 71.9 (SD 8.2) for children with DLI (p=0.002). On each subdomain of the BDI, except communication, mean scores for the GDD group were significantly lower than for the DLI group (p<0.05). Similarly, the VABS total score for the GDD group was significantly lower than for the DLI group (p<0.001). For each subdomain of the VABS, the GDD group scored significantly lower than the DLI group (p<0.001). The proportion of children falling below meaningful cut-offs on the outcome measures selected was significantly higher for those initially diagnosed with GDD. Preschool diagnosis of either GDD or DLI has later prognostic validity with regard to persisting developmental and functional deficits.

Understanding African American Adolescents’ Identity Development: A Relational Developmental Systems Perspective

PubMed Central

Brittian, Aerika S.

2012-01-01

This article examines the development of African American adolescents’ identity using a relational developmental systems theory framework, which led to the expectation that identity development is linked to both the reduction of risk behaviors and the promotion of African American adolescents’ healthy development. Different personological theories of identity development were discussed, including Erikson’s theory of psychosocial development and Marcia’s theory of identity statuses. Developmental systems theory was used to further the literature on African American adolescents’ identity development, by integrating various views of identity development as they pertain to these youth. Furthermore, the formation of many aspects of identity may be an important coping and resilience process for such youth. In addition, directions for future research are discussed, including a consideration of the complexity of diversity that exists within the African American adolescent population, and a call for more longitudinal assessments of identity development is presented. PMID:23243325

Developmental Neurotoxicology: History and Outline of Developmental Neurotoxicity Study Guidelines.

EPA Science Inventory

The present work provides a brief review of basic concepts in developmental neurotoxicology, as well as current representative testing guidelines for evaluating developmental neurotoxicity (DNT) of xenobiotics. Historically, DNT was initially recognized as a “functional” teratoge...

Comparison of the validity of direct pediatric developmental evaluation versus developmental screening by parent report

USDA-ARS?s Scientific Manuscript database

To compare the validity of direct pediatric developmental evaluation with developmental screening by parent report, parents completed a developmental screen (the Child Development Review), a pediatrician performed a direct developmental evaluation (Capute Scales), and a psychologist administered the...

The significance and scope of evolutionary developmental biology: a vision for the 21st century.

PubMed

Moczek, Armin P; Sears, Karen E; Stollewerk, Angelika; Wittkopp, Patricia J; Diggle, Pamela; Dworkin, Ian; Ledon-Rettig, Cristina; Matus, David Q; Roth, Siegfried; Abouheif, Ehab; Brown, Federico D; Chiu, Chi-Hua; Cohen, C Sarah; Tomaso, Anthony W De; Gilbert, Scott F; Hall, Brian; Love, Alan C; Lyons, Deirdre C; Sanger, Thomas J; Smith, Joel; Specht, Chelsea; Vallejo-Marin, Mario; Extavour, Cassandra G

2015-01-01

Evolutionary developmental biology (evo-devo) has undergone dramatic transformations since its emergence as a distinct discipline. This paper aims to highlight the scope, power, and future promise of evo-devo to transform and unify diverse aspects of biology. We articulate key questions at the core of eleven biological disciplines-from Evolution, Development, Paleontology, and Neurobiology to Cellular and Molecular Biology, Quantitative Genetics, Human Diseases, Ecology, Agriculture and Science Education, and lastly, Evolutionary Developmental Biology itself-and discuss why evo-devo is uniquely situated to substantially improve our ability to find meaningful answers to these fundamental questions. We posit that the tools, concepts, and ways of thinking developed by evo-devo have profound potential to advance, integrate, and unify biological sciences as well as inform policy decisions and illuminate science education. We look to the next generation of evolutionary developmental biologists to help shape this process as we confront the scientific challenges of the 21st century. © 2015 Wiley Periodicals, Inc.

Working with Practicing Teachers in a High-Stakes Teaching Context to Rethink Their Pedagogical Practices with Children of Diverse Backgrounds

ERIC Educational Resources Information Center

Brown, Christopher P.; Weber, Natalie Babiak

2016-01-01

The public education system in the United States continues to struggle in educating children of diverse backgrounds. Many have addressed this issue by documenting how certain practices teach children particular types of knowledge and skills. This developmental focus on what should be happening to children of diverse backgrounds tends to ignore the…

III. FROM SMALL TO BIG: METHODS FOR INCORPORATING LARGE SCALE DATA INTO DEVELOPMENTAL SCIENCE.

PubMed

Davis-Kean, Pamela E; Jager, Justin

2017-06-01

For decades, developmental science has been based primarily on relatively small-scale data collections with children and families. Part of the reason for the dominance of this type of data collection is the complexity of collecting cognitive and social data on infants and small children. These small data sets are limited in both power to detect differences and the demographic diversity to generalize clearly and broadly. Thus, in this chapter we will discuss the value of using existing large-scale data sets to tests the complex questions of child development and how to develop future large-scale data sets that are both representative and can answer the important questions of developmental scientists. © 2017 The Society for Research in Child Development, Inc.

CHANGES IN PROTEOMIC PROFILES OF CEREBELLUM AND HIPPOCAMPUS FOLLOWING EXPOSURE TO A DEVELOPMENTAL NEUROTOXICANT.

EPA Science Inventory

The vast literature on the group of chemicals known as polychlorinated biphenyls (PCBs) makes it a unique model to understand major issues related to environmental mixtures of persistent chemicals. At background levels of exposure, PCBs have been shown to adversely affect human h...

Antagonism of LIN-17/Frizzled and LIN-18/Ryk in nematode vulva induction reveals evolutionary alterations in core developmental pathways.

PubMed

Wang, Xiaoyue; Sommer, Ralf J

2011-07-01

Most diversity in animals and plants results from the modification of already existing structures. Many organ systems, for example, are permanently modified during evolution to create developmental and morphological diversity, but little is known about the evolution of the underlying developmental mechanisms. The theory of developmental systems drift proposes that the development of conserved morphological structures can involve large-scale modifications in their regulatory mechanisms. We test this hypothesis by comparing vulva induction in two genetically tractable nematodes, Caenorhabditis elegans and Pristionchus pacificus. Previous work indicated that the vulva is induced by epidermal growth factor (EGF)/RAS and WNT signaling in Caenorhabditis and Pristionchus, respectively. Here, we show that the evolution of vulva induction involves major molecular alterations and that this shift of signaling pathways involves a novel wiring of WNT signaling and the acquisition of novel domains in otherwise conserved receptors in Pristionchus vulva induction. First, Ppa-LIN-17/Frizzled acts as an antagonist of WNT signaling and suppresses the ligand Ppa-EGL-20 by ligand sequestration. Second, Ppa-LIN-18/Ryk transmits WNT signaling and requires inhibitory SH3 domain binding motifs, unknown from Cel-LIN-18/Ryk. Third, Ppa-LIN-18/Ryk signaling involves Axin and β-catenin and Ppa-axl-1/Axin is epistatic to Ppa-lin-18/Ryk. These results confirm developmental system drift as an important theory for the evolution of organ systems and they highlight the significance of protein modularity in signal transduction and the dynamics of signaling networks.

[Models and Foundations of Developmental Education.

ERIC Educational Resources Information Center

Boylan, Hunter R., Ed.; Kerstiens, Gene, Ed.

1988-01-01

These five issues of "Research in Developmental Education," examine the theoretical models and foundations of developmental education. Included are the following: (1) "Theoretical Foundations of Developmental Education," by Hunter R. Boylan, which examines the behaviorist, humanist, and developmental theories underpinning developmental education;…

Comparative ultrastructure of fruit plastids in three genetically diverse genotypes of apple (Malus × domestica Borkh.) during development.

PubMed

Schaeffer, Scott M; Christian, Ryan; Castro-Velasquez, Nohely; Hyden, Brennan; Lynch-Holm, Valerie; Dhingra, Amit

2017-10-01

Comparative ultrastructural developmental time-course analysis has identified discrete stages at which the fruit plastids undergo structural and consequently functional transitions to facilitate subsequent development-guided understanding of the complex plastid biology. Plastids are the defining organelle for a plant cell and are critical for myriad metabolic functions. The role of leaf plastid, chloroplast, is extensively documented; however, fruit plastids-chromoplasts-are poorly understood, especially in the context of the diverse metabolic processes operating in these diverse plant organs. Recently, in a comparative study of the predicted plastid-targeted proteomes across seven plant species, we reported that each plant species is predicted to harbor a unique set of plastid-targeted proteins. However, the temporal and developmental context of these processes remains unknown. In this study, an ultrastructural analysis approach was used to characterize fruit plastids in the epidermal and collenchymal cell layers at 11 developmental timepoints in three genotypes of apple (Malus × domestica Borkh.): chlorophyll-predominant 'Granny Smith', carotenoid-predominant 'Golden Delicious', and anthocyanin-predominant 'Top Red Delicious'. Plastids transitioned from a proplastid-like plastid to a chromoplast-like plastid in epidermis cells, while in the collenchyma cells, they transitioned from a chloroplast-like plastid to a chloro-chromo-amyloplast plastid. Plastids in the collenchyma cells of the three genotypes demonstrated a diverse array of structures and features. This study enabled the identification of discrete developmental stages during which specific functions are most likely being performed by the plastids as indicated by accumulation of plastoglobuli, starch granules, and other sub-organeller structures. Information regarding the metabolically active developmental stages is expected to facilitate biologically relevant omics studies to unravel the complex

Practice parameters and financial factors impacting developmental-behavioral pediatrics.

PubMed

Adair, Robin; Perrin, Ellen; Hubbard, Carol; Savageau, Judith A

2010-01-01

Little has been published about the professional activities of developmental-behavioral (DB) pediatricians. To better understand the settings in which DB pediatricians work, allocation of their professional time, and how financial considerations impact their practice, the Society for Developmental and Behavioral Pediatrics surveyed its membership. An extensive on-line three-part survey was conducted in 2006-2007 assessing sociodemographic characteristics, practice descriptors, coding and billing practices, productivity goals and perceived pressures among Society for Developmental and Behavioral Pediatric's 438 physician members. Of the pediatricians responding, representing all regions of the United States, 93% were DB pediatrics subspecialty board certified or eligible. The majority was practicing DB pediatrics full-time (73%); and 67% were exclusively in academic settings. All reported seeing patients, 84% reported teaching, 76% reported having administrative responsibilities, and 46% reported conducting research. Despite having non-clinical responsibilities, full-time equivalent positions included an average of 25 hours per week in direct patient care and 14.5 hours per week (37% of clinical time) in indirect patient care. Only 42% reported working with multidisciplinary teams. Salaries varied widely within and across regions. Deficits in billing/coding practices, awareness of personal clinical productivity, and familiarity with national productivity benchmarks were identified. DB pediatricians work in diverse settings nationwide. They provide considerable time in indirect patient care, which is poorly reimbursed in general and relative to direct patient care. The results of this survey offer opportunities for provider, institutional and payer education.

Evidence for a conserved microbiota across the different developmental stages of Plodia interpunctella.

PubMed

Mereghetti, Valeria; Chouaia, Bessem; Limonta, Lidia; Locatelli, Daria Patrizia; Montagna, Matteo

2017-11-01

Diversity and composition of lepidopteran microbiotas are poorly investigated, especially across the different developmental stages. To improve this knowledge, we characterize the microbiota among different developmental stages of the Indian meal moth, Plodia interpunctella, which is considered one of the major pest of commodities worldwide. Using culture-independent approach based on Illumina 16S rRNA gene sequencing we characterized the microbiota of four developmental stages: eggs, first-, and last-instar larvae, and adult. A total of 1022 bacterial OTUs were obtained, showing a quite diversified microbiota associated to all the analyzed stages. The microbiotas associated with P. interpunctella resulted almost constant throughout the developmental stages, with approximately 77% of bacterial OTUs belonging to the phylum of Proteobacteria. The dominant bacterial genus is represented by Burkholderia (∼64%), followed by Propionibacterium, Delftia, Pseudomonas, and Stenotrophomonas. A core bacterial community, composed of 139 OTUs, was detected in all the developmental stages, among which 112 OTUs were assigned to the genus Burkholderia. A phylogenetic reconstruction, based on the 16S rRNA, revealed that our Burkholderia OTUs clustered with Burkholderia cepacia complex, in the same group of those isolated from the hemipterans Gossyparia spuria and Acanthococcus aceris. The functional profiling, predicted on the base of the bacterial 16S rRNA, indicates differences in the metabolic pathways related to metabolism of amino acids between preimaginal and adult stages. We can hypothesize that bacteria may support the insect host during preimaginal stages. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Building a developmental toxicity ontology.

PubMed

Baker, Nancy; Boobis, Alan; Burgoon, Lyle; Carney, Edward; Currie, Richard; Fritsche, Ellen; Knudsen, Thomas; Laffont, Madeleine; Piersma, Aldert H; Poole, Alan; Schneider, Steffen; Daston, George

2018-04-03

As more information is generated about modes of action for developmental toxicity and more data are generated using high-throughput and high-content technologies, it is becoming necessary to organize that information. This report discussed the need for a systematic representation of knowledge about developmental toxicity (i.e., an ontology) and proposes a method to build one based on knowledge of developmental biology and mode of action/ adverse outcome pathways in developmental toxicity. This report is the result of a consensus working group developing a plan to create an ontology for developmental toxicity that spans multiple levels of biological organization. This report provide a description of some of the challenges in building a developmental toxicity ontology and outlines a proposed methodology to meet those challenges. As the ontology is built on currently available web-based resources, a review of these resources is provided. Case studies on one of the most well-understood morphogens and developmental toxicants, retinoic acid, are presented as examples of how such an ontology might be developed. This report outlines an approach to construct a developmental toxicity ontology. Such an ontology will facilitate computer-based prediction of substances likely to induce human developmental toxicity. © 2018 Wiley Periodicals, Inc.

Developmental dyscalculia.

PubMed

Shalev, Ruth S

2004-10-01

Developmental dyscalculia is a specific learning disability affecting the normal acquisition of arithmetic skills. Genetic, neurobiologic, and epidemiologic evidence indicates that dyscalculia, like other learning disabilities, is a brain-based disorder. However, poor teaching and environmental deprivation have also been implicated in its etiology. Because the neural network of both hemispheres comprises the substrate of normal arithmetic skills, dyscalculia can result from dysfunction of either hemisphere, although the left parietotemporal area is of particular significance. The prevalence of developmental dyscalculia is 5 to 6% in the school-aged population and is as common in girls as in boys. Dyscalculia can occur as a consequence of prematurity and low birthweight and is frequently encountered in a variety of neurologic disorders, such as attention-deficit hyperactivity disorder (ADHD), developmental language disorder, epilepsy, and fragile X syndrome. Developmental dyscalculia has proven to be a persisting learning disability, at least for the short term, in about half of affected preteen pupils. Educational interventions for dyscalculia range from rote learning of arithmetic facts to developing strategies for solving arithmetic exercises. The long-term prognosis of dyscalculia and the role of remediation in its outcome are yet to be determined.

Genome-wide chromatin state transitions associated with developmental and environmental cues.

PubMed

Zhu, Jiang; Adli, Mazhar; Zou, James Y; Verstappen, Griet; Coyne, Michael; Zhang, Xiaolan; Durham, Timothy; Miri, Mohammad; Deshpande, Vikram; De Jager, Philip L; Bennett, David A; Houmard, Joseph A; Muoio, Deborah M; Onder, Tamer T; Camahort, Ray; Cowan, Chad A; Meissner, Alexander; Epstein, Charles B; Shoresh, Noam; Bernstein, Bradley E

2013-01-31

Differences in chromatin organization are key to the multiplicity of cell states that arise from a single genetic background, yet the landscapes of in vivo tissues remain largely uncharted. Here, we mapped chromatin genome-wide in a large and diverse collection of human tissues and stem cells. The maps yield unprecedented annotations of functional genomic elements and their regulation across developmental stages, lineages, and cellular environments. They also reveal global features of the epigenome, related to nuclear architecture, that also vary across cellular phenotypes. Specifically, developmental specification is accompanied by progressive chromatin restriction as the default state transitions from dynamic remodeling to generalized compaction. Exposure to serum in vitro triggers a distinct transition that involves de novo establishment of domains with features of constitutive heterochromatin. We describe how these global chromatin state transitions relate to chromosome and nuclear architecture, and discuss their implications for lineage fidelity, cellular senescence, and reprogramming. Copyright © 2013 Elsevier Inc. All rights reserved.

Transgenerational developmental programming.

PubMed

Aiken, Catherine E; Ozanne, Susan E

2014-01-01

The concept of developmental programming suggests that the early life environment influences offspring characteristics in later life, including the propensity to develop diseases such as the metabolic syndrome. There is now growing evidence that the effects of developmental programming may also manifest in further generations without further suboptimal exposure. This review considers the evidence, primarily from rodent models, for effects persisting to subsequent generations, and evaluates the mechanisms by which developmental programming may be transmitted to further generations. In particular, we focus on the potential role of the intrauterine environment in contributing to a developmentally programmed phenotype in subsequent generations. The literature was systematically searched at http://pubmed.org and http://scholar.google.com to identify published findings regarding transgenerational (F2 and beyond) developmental programming effects in human populations and animal models. Transmission of programming effects is often viewed as a form of epigenetic inheritance, either via the maternal or paternal line. Evidence exists for both germline and somatic inheritance of epigenetic modifications which may be responsible for phenotypic changes in further generations. However, there is increasing evidence for the role of both extra-genomic components of the zygote and the interaction of the developing conceptus with the intrauterine environment in propagating programming effects. The contribution of a suboptimal reproductive tract environment or maternal adaptations to pregnancy may be critical to inheritance of programming effects via the maternal line. As the effects of age exacerbate the programmed metabolic phenotype, advancing maternal age may increase the likelihood of developmental programming effects being transmitted to further generations. We suggest that developmental programming effects could be propagated through the maternal line de novo in generations

Agro-morphological characterization of diverse sorghum lines for pre-and postflowering drought tolerance

USDA-ARS?s Scientific Manuscript database

The impact of drought stress on sorghum yield does not only depend on the intensity and timing of drought, but as well on the developmental stage of the crop. One of the limitations in breeding for pre-and/or postflowering drought stress resistance in sorghum is the fewer availability of diverse gen...

Developmental control of transcriptional and proliferative potency during the evolutionary emergence of animals

PubMed Central

Arenas-Mena, Cesar; Coffman, James A.

2016-01-01

Summary It is proposed that the evolution of complex animals required repressive genetic mechanisms for controlling the transcriptional and proliferative potency of cells. Unicellular organisms are transcriptionally potent, able to express their full genetic complement as the need arises through their life cycle, whereas differentiated cells of multicellular organisms can only express a fraction of their genomic potential. Likewise, whereas cell proliferation in unicellular organisms is primarily limited by nutrient availability, cell proliferation in multicellular organisms is developmentally regulated. Repressive genetic controls limiting the potency of cells at the end of ontogeny would have stabilized the gene expression states of differentiated cells and prevented disruptive proliferation, allowing the emergence of diverse cell types and functional shapes. We propose that distal cis-regulatory elements represent the primary innovations that set the stage for the evolution of developmental gene regulatory networks and the repressive control of key multipotency and cell-cycle control genes. The testable prediction of this model is that the genomes of extant animals, unlike those of our unicellular relatives, encode gene regulatory circuits dedicated to the developmental control of transcriptional and proliferative potency. PMID:26173445

Evolutionary Developmental Robotics: Improving Morphology and Control of Physical Robots.

PubMed

Vujovic, Vuk; Rosendo, Andre; Brodbeck, Luzius; Iida, Fumiya

2017-01-01

Evolutionary algorithms have previously been applied to the design of morphology and control of robots. The design space for such tasks can be very complex, which can prevent evolution from efficiently discovering fit solutions. In this article we introduce an evolutionary-developmental (evo-devo) experiment with real-world robots. It allows robots to grow their leg size to simulate ontogenetic morphological changes, and this is the first time that such an experiment has been performed in the physical world. To test diverse robot morphologies, robot legs of variable shapes were generated during the evolutionary process and autonomously built using additive fabrication. We present two cases with evo-devo experiments and one with evolution, and we hypothesize that the addition of a developmental stage can be used within robotics to improve performance. Moreover, our results show that a nonlinear system-environment interaction exists, which explains the nontrivial locomotion patterns observed. In the future, robots will be present in our daily lives, and this work introduces for the first time physical robots that evolve and grow while interacting with the environment.

X chromosome regulation: diverse patterns in development, tissues and disease

PubMed Central

Deng, Xinxian; Berletch, Joel B.; Nguyen, Di K.; Disteche, Christine M.

2014-01-01

Genes on the mammalian X chromosome are present in one copy in males and two copies in females. The complex mechanisms that regulate the X chromosome lead to evolutionary and physiological variability in gene expression between species, the sexes, individuals, developmental stages, tissues and cell types. In early development, delayed and incomplete X chromosome inactivation (XCI) in some species causes variability in gene expression. Additional diversity stems from escape from XCI and from mosaicism or XCI skewing in females. This causes sex-specific differences that manifest as differential gene expression and associated phenotypes. Furthermore, the complexity and diversity of X dosage regulation affect the severity of diseases caused by X-linked mutations. PMID:24733023

CDC Kerala 15: Developmental Evaluation Clinic (2-10 y)--developmental diagnosis and use of home intervention package.

PubMed

Nair, M K C; Lakshmi, M A; Latha, S; Lakshmi, Geetha; Harikumaran Nair, G S; Bhaskaran, Deepa; George, Babu; Leena, M L; Russell, Paul Swamidhas Sudhakar

2014-12-01

To describe the last 5 years' experience of Child Development Centre (CDC), Kerala Developmental Evaluation Clinic II for children between 2 and 10 y, referred for suspicion of developmental lag in the preschool years and scholastic difficulty in the primary classes with specific focus on developmental profile and the experience of the home based intervention package taught to the mothers. A team of evaluators including developmental therapist, preschool teacher with special training in clinical child development, speech therapist, special educator, clinical psychologist and developmental pediatrician assessed all the children referred to CDC Kerala. Denver Developmental Screening Test (DDST-II), Vineland Social Maturity Scale (VSMS) and Intelligent Quotient (IQ) tests were administered to all children below 6 y and those above 6 with apparent developmental delay. Speech/delay (35.9%), behavior problem (15.4%), global delay/ intellectual disability (15.4%), learning problem (10.9%), pervasive developmental disorders (7.7%), seizure disorder (1.7%), hearing impairment (0.7%), and visual impairment (0.7%) were the clinical diagnosis by a developmental pediatrician. Each child with developmental problem was offered a home based intervention package consisting of developmental therapy and special education items, appropriate to the clinical diagnosis of the individual child and the same was taught to the mother. The experience of conducting the developmental evaluation clinic for children between 2 and 10 y has shown that a team consisting of developmental therapist, speech therapist, preschool teacher, special educator, clinical child psychologist and developmental pediatrician, using appropriate test results of the child could make a clinical diagnosis good enough for providing early intervention therapy using a home based intervention package.

Diversity Beliefs and Postformal Thinking in Late Adolescence: A Cognitive Basis of Multicultural Literacy

ERIC Educational Resources Information Center

Chang, Yevvon Yi-Chi; Chiou, Wen-Bin

2014-01-01

The present study investigated the developmental relationship between cognitive thinking and diversity beliefs among late adolescents from a postPiagetian perspective. The participants were 762 Taiwanese undergraduates aging from 19 to 25 years. The Social Paradigm Belief Scale was used to assess three modes of cognitive development of late…

Developmental biology of Streptomyces from the perspective of 100 actinobacterial genome sequences

PubMed Central

Chandra, Govind; Chater, Keith F

2014-01-01

To illuminate the evolution and mechanisms of actinobacterial complexity, we evaluate the distribution and origins of known Streptomyces developmental genes and the developmental significance of actinobacteria-specific genes. As an aid, we developed the Actinoblast database of reciprocal blastp best hits between the Streptomyces coelicolor genome and more than 100 other actinobacterial genomes (http://streptomyces.org.uk/actinoblast/). We suggest that the emergence of morphological complexity was underpinned by special features of early actinobacteria, such as polar growth and the coupled participation of regulatory Wbl proteins and the redox-protecting thiol mycothiol in transducing a transient nitric oxide signal generated during physiologically stressful growth transitions. It seems that some cell growth and division proteins of early actinobacteria have acquired greater importance for sporulation of complex actinobacteria than for mycelial growth, in which septa are infrequent and not associated with complete cell separation. The acquisition of extracellular proteins with structural roles, a highly regulated extracellular protease cascade, and additional regulatory genes allowed early actinobacterial stationary phase processes to be redeployed in the emergence of aerial hyphae from mycelial mats and in the formation of spore chains. These extracellular proteins may have contributed to speciation. Simpler members of morphologically diverse clades have lost some developmental genes. PMID:24164321

Antagonism of LIN-17/Frizzled and LIN-18/Ryk in Nematode Vulva Induction Reveals Evolutionary Alterations in Core Developmental Pathways

PubMed Central

Wang, Xiaoyue; Sommer, Ralf J.

2011-01-01

Most diversity in animals and plants results from the modification of already existing structures. Many organ systems, for example, are permanently modified during evolution to create developmental and morphological diversity, but little is known about the evolution of the underlying developmental mechanisms. The theory of developmental systems drift proposes that the development of conserved morphological structures can involve large-scale modifications in their regulatory mechanisms. We test this hypothesis by comparing vulva induction in two genetically tractable nematodes, Caenorhabditis elegans and Pristionchus pacificus. Previous work indicated that the vulva is induced by epidermal growth factor (EGF)/RAS and WNT signaling in Caenorhabditis and Pristionchus, respectively. Here, we show that the evolution of vulva induction involves major molecular alterations and that this shift of signaling pathways involves a novel wiring of WNT signaling and the acquisition of novel domains in otherwise conserved receptors in Pristionchus vulva induction. First, Ppa-LIN-17/Frizzled acts as an antagonist of WNT signaling and suppresses the ligand Ppa-EGL-20 by ligand sequestration. Second, Ppa-LIN-18/Ryk transmits WNT signaling and requires inhibitory SH3 domain binding motifs, unknown from Cel-LIN-18/Ryk. Third, Ppa-LIN-18/Ryk signaling involves Axin and β-catenin and Ppa-axl-1/Axin is epistatic to Ppa-lin-18/Ryk. These results confirm developmental system drift as an important theory for the evolution of organ systems and they highlight the significance of protein modularity in signal transduction and the dynamics of signaling networks. PMID:21814488

Contextual diversity is a main determinant of word identification times in young readers.

PubMed

Perea, Manuel; Soares, Ana Paula; Comesaña, Montserrat

2013-09-01

Recent research with college-aged skilled readers by Adelman and colleagues revealed that contextual diversity (i.e., the number of contexts in which a word appears) is a more critical determinant of visual word recognition than mere repeated exposure (i.e., word frequency) (Psychological Science, 2006, Vol. 17, pp. 814-823). Given that contextual diversity has been claimed to be a relevant factor to word acquisition in developing readers, the effects of contextual diversity should also be a main determinant of word identification times in developing readers. A lexical decision experiment was conducted to examine the effects of contextual diversity and word frequency in young readers (children in fourth grade). Results revealed a sizable effect of contextual diversity, but not of word frequency, thereby generalizing Adelman and colleagues' data to a child population. These findings call for the implementation of dynamic developmental models of visual word recognition that go beyond a learning rule by mere exposure. Copyright © 2012 Elsevier Inc. All rights reserved.

Developmental Idealism in China

PubMed Central

Thornton, Arland; Xie, Yu

2016-01-01

This paper examines the intersection of developmental idealism with China. It discusses how developmental idealism has been widely disseminated within China and has had enormous effects on public policy and programs, on social institutions, and on the lives of individuals and their families. This dissemination of developmental idealism to China began in the 19th century, when China met with several military defeats that led many in the country to question the place of China in the world. By the beginning of the 20th century, substantial numbers of Chinese had reacted to the country’s defeats by exploring developmental idealism as a route to independence, international respect, and prosperity. Then, with important but brief aberrations, the country began to implement many of the elements of developmental idealism, a movement that became especially important following the assumption of power by the Communist Party of China in 1949. This movement has played a substantial role in politics, in the economy, and in family life. The beliefs and values of developmental idealism have also been directly disseminated to the grassroots in China, where substantial majorities of Chinese citizens have assimilated them. These ideas are both known and endorsed by very large numbers in China today. PMID:28316833

Developmental Idealism in China.

PubMed

Thornton, Arland; Xie, Yu

2016-10-01

This paper examines the intersection of developmental idealism with China. It discusses how developmental idealism has been widely disseminated within China and has had enormous effects on public policy and programs, on social institutions, and on the lives of individuals and their families. This dissemination of developmental idealism to China began in the 19 th century, when China met with several military defeats that led many in the country to question the place of China in the world. By the beginning of the 20 th century, substantial numbers of Chinese had reacted to the country's defeats by exploring developmental idealism as a route to independence, international respect, and prosperity. Then, with important but brief aberrations, the country began to implement many of the elements of developmental idealism, a movement that became especially important following the assumption of power by the Communist Party of China in 1949. This movement has played a substantial role in politics, in the economy, and in family life. The beliefs and values of developmental idealism have also been directly disseminated to the grassroots in China, where substantial majorities of Chinese citizens have assimilated them. These ideas are both known and endorsed by very large numbers in China today.

Early Influences and Later Outcomes Associated With Developmental Trajectories of Eriksonian Fidelity

PubMed Central

Brittian, Aerika S.; Lerner, Richard M.

2014-01-01

Although Eriksonian theory suggests that adolescents’ sense of fidelity is a key component of healthy development, research on this psychosocial construct has been limited. The current study developed an index of youth fidelity, examined the developmental course of this construct, explored the influence of contextual factors on different fidelity trajectories, and tested if trajectories were associated with later indicators of adolescents’ positive development. Participants included 1,941 ethnically diverse youth (61% female) participants in the 4-H Study of Positive Youth Development who were recruited from schools and youth development programs across the United States. Results suggested that three types of developmental trajectories existed among youth: high and increasing, moderate and increasing, and low and decreasing. Fidelity group membership varied in relation to social relationships and psychosocial and behavioral characteristics (i.e., contribution, substance use, and delinquency). Girls were more likely than boys to be in the highest fidelity trajectories. Directions for future research and implications for enhancing the thriving of adolescents are discussed. PMID:22545838

Understanding the Diversity: A Taxonomy for Postsecondary Education Programs and Services for Students with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

McEathron, Mary A.; Beuhring, Trisha; Maynard, Amelia; Mavis, Ann

2013-01-01

The number of postsecondary education (PSE) programs for individuals with intellectual and developmental disabilities (IDD) has been steadily growing over the last few decades. There has been little public information regarding these programs and schools. Consequently, students, families, and researchers alike lack details about the various…

The interplay between inflorescence development and function as the crucible of architectural diversity

PubMed Central

Harder, Lawrence D.; Prusinkiewicz, Przemyslaw

2013-01-01

Background Most angiosperms present flowers in inflorescences, which play roles in reproduction, primarily related to pollination, beyond those served by individual flowers alone. An inflorescence's overall reproductive contribution depends primarily on the three-dimensional arrangement of the floral canopy and its dynamics during its flowering period. These features depend in turn on characteristics of the underlying branching structure (scaffold) that supports and supplies water and nutrients to the floral canopy. This scaffold is produced by developmental algorithms that are genetically specified and hormonally mediated. Thus, the extensive inflorescence diversity evident among angiosperms evolves through changes in the developmental programmes that specify scaffold characteristics, which in turn modify canopy features that promote reproductive performance in a particular pollination and mating environment. Nevertheless, developmental and ecological aspects of inflorescences have typically been studied independently, limiting comprehensive understanding of the relations between inflorescence form, reproductive function, and evolution. Scope This review fosters an integrated perspective on inflorescences by summarizing aspects of their development and pollination function that enable and guide inflorescence evolution and diversification. Conclusions The architecture of flowering inflorescences comprises three related components: topology (branching patterns, flower number), geometry (phyllotaxis, internode and pedicel lengths, three-dimensional flower arrangement) and phenology (flower opening rate and longevity, dichogamy). Genetic and developmental evidence reveals that these components are largely subject to quantitative control. Consequently, inflorescence evolution proceeds along a multidimensional continuum. Nevertheless, some combinations of topology, geometry and phenology are represented more commonly than others, because they serve reproductive function

Determining Developmental Education Effectiveness in Math

ERIC Educational Resources Information Center

May, Joseph E.

2017-01-01

One of the most problematic issues facing community colleges is developmental education. In the last decade, more research has been conducted examining developmental education. The purpose of this study was to evaluate the effectiveness of developmental math in a rural community college setting. Is developmental math an effective intervention?…

An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics

ERIC Educational Resources Information Center

Molenaar, Peter C. M.

2015-01-01

The main theme of this paper concerns the persistent critique of Gilbert Gottlieb on developmental behavior genetics and my reactions to this critique, the latter changing from rejection to complete acceptation. Concise characterizations of developmental behavior genetics, developmental systems theory (to which Gottlieb made essential…

Caribbean Families: Diversity among Ethnic Groups. Advances in Applied Developmental Psychology, Volume 14.

ERIC Educational Resources Information Center

Roopnarine, Jaipaul L., Ed.; Brown, Janet, Ed.

Little is known about the development and function of families in major Caribbean communities, an area composed of diverse ethnic and political groups, the majority of whom live on the edge of poverty. This edited book provides an interdisciplinary examination of Caribbean families, each chapter detailing studies dealing with family structures and…

Evo-devo models of tooth development and the origin of hominoid molar diversity

PubMed Central

Bailey, Shara E.; Schwartz, Gary T.; Skinner, Matthew M.

2018-01-01

The detailed anatomical features that characterize fossil hominin molars figure prominently in the reconstruction of their taxonomy, phylogeny, and paleobiology. Despite the prominence of molar form in human origins research, the underlying developmental mechanisms generating the diversity of tooth crown features remain poorly understood. A model of tooth morphogenesis—the patterning cascade model (PCM)—provides a developmental framework to explore how and why the varying molar morphologies arose throughout human evolution. We generated virtual maps of the inner enamel epithelium—an indelibly preserved record of enamel knot arrangement—in 17 living and fossil hominoid species to investigate whether the PCM explains the expression of all major accessory cusps. We found that most of the variation and evolutionary changes in hominoid molar morphology followed the general developmental rule shared by all mammals, outlined by the PCM. Our results have implications for the accurate interpretation of molar crown configuration in hominoid systematics. PMID:29651459

Unique pattern of dietary adaptation in the dentition of Carnivora: its advantage and developmental origin

PubMed Central

Saito, Kazuyuki; Kishida, Takushi; Takahashi, Katsu; Bessho, Kazuhisa

2016-01-01

Carnivora is a successful taxon in terms of dietary diversity. We investigated the dietary adaptations of carnivoran dentition and the developmental background of their dental diversity, which may have contributed to the success of the lineage. A developmental model was tested and extended to explain the unique variability and exceptional phenotypes observed in carnivoran dentition. Carnivorous mammalian orders exhibited two distinct patterns of dietary adaptation in molars and only Carnivora evolved novel variability, exhibiting a high correlation between relative molar size and the shape of the first molar. Studies of Bmp7-hetero-deficient mice, which may exhibit lower Bmp7 expression, suggested that Bmp7 has pleiotropic effects on these two dental traits. Its effects are consistent with the pattern of dietary adaptation observed in Carnivora, but not that observed in other carnivorous mammals. A molecular evolutionary analysis revealed that Bmp7 sequence evolved by natural selection during ursid evolution, suggesting that it plays an evolutionary role in the variation of carnivoran dentition. Using mouse experiments and a molecular evolutionary analysis, we extrapolated the causal mechanism of the hitherto enigmatic ursid dentition (larger M2 than M1 and M3). Our results demonstrate how carnivorans acquired novel dental variability that benefits their dietary divergence.

Response diversity of wild bees to overwintering temperatures.

PubMed

Fründ, Jochen; Zieger, Sarah L; Tscharntke, Teja

2013-12-01

Biodiversity can provide insurance against environmental change, but only if species differ in their response to environmental conditions (response diversity). Wild bees provide pollination services to wild and crop plants, and response diversity might insure this function against changing climate. To experimentally test the hypothesis that bee species differ in their response to increasing winter temperature, we stored cocoons of nine bee species at different temperatures during the winter (1.5-9.5 °C). Bee species differed significantly in their responses (weight loss, weight at emergence and emergence date). The developmental stage during the winter explained some of these differences. Bee species overwintering as adults generally showed decreased weight and earlier emergence with increasing temperature, whereas bee species overwintering in pre-imaginal stages showed weaker or even opposite responses. This means that winter warming will likely affect some bee species negatively by increasing energy expenditure, while others are less sensitive presumably due to different physiology. Likewise, species phenologies will respond differently to winter warming, potentially affecting plant-pollinator interactions. Responses are not independent of current flight periods: bees active in spring will likely show the strongest phenological advances. Taken together, wild bee diversity provides response diversity to climate change, which may be the basis for an insurance effect.

Attentional networks in developmental dyscalculia

PubMed Central

2010-01-01

Background Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Methods Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test - interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. Results The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. Conclusions These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing. PMID:20157427

Attentional networks in developmental dyscalculia.

PubMed

Askenazi, Sarit; Henik, Avishai

2010-01-07

Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test-interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

Eating disorders and the serotonin connection: state, trait and developmental effects

PubMed Central

Steiger, Howard

2004-01-01

Alterations in brain serotonin (5-hydroxytryptamine [5-HT]) function are thought to contribute to diverse aspects of eating disorders, including binge eating, perfectionism, impulsivity and mood-regulation problems. In addition, 5-HT anomalies in individuals with eating disorders are believed to have multiple determinants associated with secondary (state-related) effects of their nutritional status, hereditary effects (related to such trait variations as impulsivity or perfectionism) and, possibly, long-term neurobiologic sequelae of developmental stressors (such as childhood abuse). On the strength of the available neurobiologic and genetic data, this paper presents the idea that 5-HT variations in those with eating disorders represent (1) a structured coaggregation of biologic, psychologic and social influences and (2) converging state, trait and developmental effects. Data are taken to support a multidimensional model of 5-HT function in eating disorders that, it is argued, can serve as a prototype for etiologic modelling, diagnostic classification and clinical decision-making bearing not only upon eating disorders but also upon other psychiatric disturbances. PMID:14719047

Developmental instability of gynodioecious Teucrium lusitanicum

USGS Publications Warehouse

Alados, C.L.; Navarro, T.; Cabezudo, B.; Emlen, J.M.; Freeman, C.

1998-01-01

Developmental instability was assessed in two geographical races of Teucrium lusitanicum using morphometric measures of vegetative and reproductive structures. T. lusitanicum is a gynodioecious species. Male sterile (female) individuals showed greater developmental instability at all sites. Plants located inland had higher developmental instability of vegetative characters and lower developmental instability of reproductive characters than coastal plants. These results support the contentions that (1) developmental instability is affected more by the disruption of co-adapted gene complexes than by lower heterozygosity, and (2) different habitat characteristics result in the differential response of vegetative and reproductive structures.

Participation by women in developmental, social, cognitive, and general psychology: A context for interpreting trends in behavior analysis.

PubMed

McSweeney, Frances K; Parks, Craig D

2002-01-01

We examined participation by women in journals devoted to social, developmental, cognitive, and general psychology. Authorship and first authorship by women increased from 1978 to 1997 for most journals. Participation by women on the editorial staff did not keep pace with their increased authorship for social and developmental psychology. Based on these trends, women's participation decreased with increases in the selectivity of the position for social and developmental psychology (a glass ceiling). The development of a glass ceiling suggests that the contributions of men and women are not always treated equally (gender inequity). Because a similar glass ceiling was reported for journals in behavior analysis (McSweeney, Donahoe, & Swindell, 2000; McSweeney & Swindell, 1998), the causes of this inequity appear to be relatively widespread. The failure to find a glass ceiling for general and cognitive psychology suggests that the inequity might be reduced by subtle pressure for diversity in editorial positions and by adopting actions that encourage women to pursue research positions.

Participation by women in developmental, social, cognitive, and general psychology: A context for interpreting trends in behavior analysis

PubMed Central

McSweeney, Frances K.; Parks, Craig D.

2002-01-01

We examined participation by women in journals devoted to social, developmental, cognitive, and general psychology. Authorship and first authorship by women increased from 1978 to 1997 for most journals. Participation by women on the editorial staff did not keep pace with their increased authorship for social and developmental psychology. Based on these trends, women's participation decreased with increases in the selectivity of the position for social and developmental psychology (a glass ceiling). The development of a glass ceiling suggests that the contributions of men and women are not always treated equally (gender inequity). Because a similar glass ceiling was reported for journals in behavior analysis (McSweeney, Donahoe, & Swindell, 2000; McSweeney & Swindell, 1998), the causes of this inequity appear to be relatively widespread. The failure to find a glass ceiling for general and cognitive psychology suggests that the inequity might be reduced by subtle pressure for diversity in editorial positions and by adopting actions that encourage women to pursue research positions. PMID:22478376

What is the role of culture, diversity, and community engagement in transdisciplinary translational science?

PubMed

Graham, Phillip W; Kim, Mimi M; Clinton-Sherrod, A Monique; Yaros, Anna; Richmond, Alan N; Jackson, Melvin; Corbie-Smith, Giselle

2016-03-01

Concepts of culture and diversity are necessary considerations in the scientific application of theory generation and developmental processes of preventive interventions; yet, culture and/or diversity are often overlooked until later stages (e.g., adaptation [T3] and dissemination [T4]) of the translational science process. Here, we present a conceptual framework focused on the seamless incorporation of culture and diversity throughout the various stages of the translational science process (T1-T5). Informed by a community-engaged research approach, this framework guides integration of cultural and diversity considerations at each phase with emphasis on the importance and value of "citizen scientists" being research partners to promote ecological validity. The integrated partnership covers the first phase of intervention development through final phases that ultimately facilitate more global, universal translation of changes in attitudes, norms, and systems. Our comprehensive model for incorporating culture and diversity into translational research provides a basis for further discussion and translational science development.

The fossil record of phenotypic integration and modularity: A deep-time perspective on developmental and evolutionary dynamics.

PubMed

Goswami, Anjali; Binder, Wendy J; Meachen, Julie; O'Keefe, F Robin

2015-04-21

Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because they provide the only information on deep-time developmental and evolutionary dynamics, including trends in trait relationships and their role in shaping organismal diversity. Here, we demonstrate the important perspective on phenotypic integration provided by the fossil record with a study of Smilodon fatalis (saber-toothed cats) and Canis dirus (dire wolves). We quantified temporal trends in size, variance, phenotypic integration, and direct developmental integration (fluctuating asymmetry) through 27,000 y of Late Pleistocene climate change. Both S. fatalis and C. dirus showed a gradual decrease in magnitude of phenotypic integration and an increase in variance and the correlation between fluctuating asymmetry and overall integration through time, suggesting that developmental integration mediated morphological response to environmental change in the later populations of these species. These results are consistent with experimental studies and represent, to our knowledge, the first deep-time validation of the importance of developmental integration in stabilizing morphological evolution through periods of environmental change.

The fossil record of phenotypic integration and modularity: A deep-time perspective on developmental and evolutionary dynamics

PubMed Central

Goswami, Anjali; Binder, Wendy J.; Meachen, Julie; O’Keefe, F. Robin

2015-01-01

Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because they provide the only information on deep-time developmental and evolutionary dynamics, including trends in trait relationships and their role in shaping organismal diversity. Here, we demonstrate the important perspective on phenotypic integration provided by the fossil record with a study of Smilodon fatalis (saber-toothed cats) and Canis dirus (dire wolves). We quantified temporal trends in size, variance, phenotypic integration, and direct developmental integration (fluctuating asymmetry) through 27,000 y of Late Pleistocene climate change. Both S. fatalis and C. dirus showed a gradual decrease in magnitude of phenotypic integration and an increase in variance and the correlation between fluctuating asymmetry and overall integration through time, suggesting that developmental integration mediated morphological response to environmental change in the later populations of these species. These results are consistent with experimental studies and represent, to our knowledge, the first deep-time validation of the importance of developmental integration in stabilizing morphological evolution through periods of environmental change. PMID:25901310

29 CFR 1952.101 - Developmental schedule.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Oregon § 1952.101 Developmental schedule. The Oregon plan is developmental. The schedule of developmental steps as described in the plan is...

29 CFR 1952.101 - Developmental schedule.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Oregon § 1952.101 Developmental schedule. The Oregon plan is developmental. The schedule of developmental steps as described in the plan is...

The Residency as a Developmental Process.

ERIC Educational Resources Information Center

Brent, David A.

1981-01-01

The residency is examined from the standpoint of adult developmental theory, and significant developmental tasks facing residents are described. Recommendations for management of common developmental conflicts occurring in residency are discussed. (Author/MLW)

The persistent sampling bias in developmental psychology: A call to action.

PubMed

Nielsen, Mark; Haun, Daniel; Kärtner, Joscha; Legare, Cristine H

2017-10-01

Psychology must confront the bias in its broad literature toward the study of participants developing in environments unrepresentative of the vast majority of the world's population. Here, we focus on the implications of addressing this challenge, highlight the need to address overreliance on a narrow participant pool, and emphasize the value and necessity of conducting research with diverse populations. We show that high-impact-factor developmental journals are heavily skewed toward publishing articles with data from WEIRD (Western, educated, industrialized, rich, and democratic) populations. Most critically, despite calls for change and supposed widespread awareness of this problem, there is a habitual dependence on convenience sampling and little evidence that the discipline is making any meaningful movement toward drawing from diverse samples. Failure to confront the possibility that culturally specific findings are being misattributed as universal traits has broad implications for the construction of scientifically defensible theories and for the reliable public dissemination of study findings. Copyright © 2017 Elsevier Inc. All rights reserved.

Congenital hypoplasia of the cerebellum: developmental causes and behavioral consequences

PubMed Central

Basson, M. Albert; Wingate, Richard J.

2013-01-01

Over the last 60 years, the spotlight of research has periodically returned to the cerebellum as new techniques and insights have emerged. Because of its simple homogeneous structure, limited diversity of cell types and characteristic behavioral pathologies, the cerebellum is a natural home for studies of cell specification, patterning, and neuronal migration. However, recent evidence has extended the traditional range of perceived cerebellar function to include modulation of cognitive processes and implicated cerebellar hypoplasia and Purkinje neuron hypo-cellularity with autistic spectrum disorder. In the light of this emerging frontier, we review the key stages and genetic mechanisms behind cerebellum development. In particular, we discuss the role of the midbrain hindbrain isthmic organizer in the development of the cerebellar vermis and the specification and differentiation of Purkinje cells and granule neurons. These developmental processes are then considered in relation to recent insights into selected human developmental cerebellar defects: Joubert syndrome, Dandy–Walker malformation, and pontocerebellar hypoplasia. Finally, we review current research that opens up the possibility of using the mouse as a genetic model to study the role of the cerebellum in cognitive function. PMID:24027500

Teaching Diversity in the Graduate Classroom: The Instructor, the Students, the Classroom, or All of the Above?

ERIC Educational Resources Information Center

Morgan Consoli, Melissa L.; Marin, Patricia

2016-01-01

Diversity courses in higher education have been associated with many positive educational and developmental outcomes as well as challenges. Studies have examined these types of undergraduate courses within education, psychology, and other disciplines (e.g., Hurtado, 2001; Hurtado, Mayhew, & Engberg, 2012; Larke & Larke, 2009); however,…

A developmental analysis of elementary school-aged children's concepts of pride and embarrassment.

PubMed

Seidner, L B; Stipek, D J; Feshbach, N D

1988-04-01

Developmental changes in conditions engendering pride and embarrassment were explored. Subjects included 41 adults and 189 5-, 7-, 9-, and 11-year-old children from diverse ethnic backgrounds. Subjects were asked to report events that had made them feel proud, embarrassed, happy, and sad. Content analyses of responses concerning pride and embarrassment indicated that references to noncontingent, uncontrollable events decreased with age, but most 5-year-olds understood that feelings of pride and, to a lesser extent, embarrassment result primarily from outcomes controlled by and contingent on one's own behavior or characteristics. Responses of children in all 4 age groups and adults suggest that an audience is important for both pride and embarrassment, but particularly for embarrassment. An audience and external reinforcement were more important in children's than in adults' reports of pride. Developmental change was found in the standards used to evaluate emotional experiences; references to social comparison increased with age and references to mastery decreased.

MOLECULAR AND MORPHOLOGICAL CHANGES IN ZEBRAFISH FOLLOWING TRANSIENT ETHANOL EXPOSURE DURING DEFINED DEVELOPMENTAL STAGES

PubMed Central

Zhang, Chengjin; Frazier, Jared M.; Chen, Hao; Liu, Yao; Lee, Ju-Ahng; Cole, Gregory J.

2014-01-01

Alcohol is a teratogen that has diverse effects on brain and craniofacial development, leading to a constellation of developmental disorders referred to as fetal alcohol spectrum disorder (FASD). The molecular basis of ethanol insult remains poorly understood, as does the relationship between molecular and behavioral changes as a consequence of prenatal ethanol exposure. Zebrafish embryos were exposed to a range of ethanol concentrations (0.5–5.0%) during defined developmental stages, and examined for morphological phenotypes characteristic of FASD. Embryos were also analyzed by in situ hybridization for changes in expression of defined cell markers for neural cell types that are sonic hedgehog-dependent. We show that transient binge-like ethanol exposures during defined developmental stages, such as early gastrulation and early neurulation, result in a range of phenotypes and changes in expression of Shh-dependent genes. The severity of fetal alcohol syndrome (FAS) morphological phenotypes, such as microphthalmia, depends on the embryonic stage and concentration of alcohol exposure, as does diminution of retinal Pax6a or forebrain and hindbrain GAD1 gene expression. We also show that changes in eye and brain morphology correlate with changes in Pax6a and GAD1 gene expression. Our results therefore show that transient binge-like ethanol exposures in zebrafish embryos produce the stereotypical morphological phenotypes of FAS, with the severity of phenotypes depending on the developmental stage and alcohol concentration of exposure. PMID:24929233

Selective pathologies of the head and neck in children: a developmental perspective.

PubMed

Ozolek, John A

2009-09-01

The range of pathology seen in the head and neck region is truly amazing and to a large extent probably mirrors the complex signaling pathways and careful orchestration of events that occurs between the primordial germ layers during the development of this region. As is true in general for the entire discipline of pediatric pathology, the head and neck pathology within this age group is as diverse and different as its adult counterpart. Cases that come across the pediatric head and neck surgical pathology bench are more heavily weighted toward developmental and congenital lesions such as branchial cleft anomalies, thyroglossal duct cysts, ectopias, heterotopias, choristomas, and primitive tumors. Many congenital "benign" lesions can cause significant morbidity and even mortality if they compress the airway or other vital structures. Exciting investigations into the molecular embryology of craniofacial development have begun to shed light on the pathogenesis of craniofacial developmental lesions and syndromes. Much more investigation is needed, however, to intertwine aberrations in the molecular ontogeny and development of the head and neck regions to the represented pathology. This review will integrate traditional morphologic embryology with some of the recent advances in the molecular pathways of head and neck development followed by a discussion of a variety of developmental lesions finishing with tumors presumed to be derived from pluripotent/progenitor cells and tumors that show anomalous or aborted development.

Communication-Based Assessment of Developmental Age for Young Children with Developmental Disabilities

ERIC Educational Resources Information Center

DeVeney, Shari L.; Hoffman, Lesa; Cress, Cynthia J.

2012-01-01

Purpose: In this study, the authors compared a multiple-domain strategy for assessing developmental age of young children with developmental disabilities who were at risk for long-term reliance on augmentative and alternative communication (AAC) with a communication-based strategy composed of receptive language and communication indices that may…

Developmental Care Rounds: An Interdisciplinary Approach to Support Developmentally Appropriate Care of Infants Born with Complex Congenital Heart Disease.

PubMed

Lisanti, Amy Jo; Cribben, Jeanne; Connock, Erin McManus; Lessen, Rachelle; Medoff-Cooper, Barbara

2016-03-01

Newborn infants with complex congenital heart disease are at risk for developmental delay. Developmental care practices benefit prematurely born infants in neonatal intensive care units. Cardiac intensive care units until recently had not integrated developmental care practices into their care framework. Interdisciplinary developmental care rounds in our center have helped in the promotion of developmentally supportive care for infants before and after cardiac surgery. This article discusses basic principles of developmental care, the role of each member of the interdisciplinary team on rounds, common developmental care practices integrated into care from rounds, and impacts to patients, families, and staff. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic and developmental basis for parallel evolution and its significance for hominoid evolution.

PubMed

Reno, Philip L

2014-01-01

Greater understanding of ape comparative anatomy and evolutionary history has brought a general appreciation that the hominoid radiation is characterized by substantial homoplasy.(1-4) However, little consensus has been reached regarding which features result from repeated evolution. This has important implications for reconstructing ancestral states throughout hominoid evolution, including the nature of the Pan-Homo last common ancestor (LCA). Advances from evolutionary developmental biology (evo-devo) have expanded the diversity of model organisms available for uncovering the morphogenetic mechanisms underlying instances of repeated phenotypic change. Of particular relevance to hominoids are data from adaptive radiations of birds, fish, and even flies demonstrating that parallel phenotypic changes often use similar genetic and developmental mechanisms. The frequent reuse of a limited set of genes and pathways underlying phenotypic homoplasy suggests that the conserved nature of the genetic and developmental architecture of animals can influence evolutionary outcomes. Such biases are particularly likely to be shared by closely related taxa that reside in similar ecological niches and face common selective pressures. Consideration of these developmental and ecological factors provides a strong theoretical justification for the substantial homoplasy observed in the evolution of complex characters and the remarkable parallel similarities that can occur in closely related taxa. Thus, as in other branches of the hominoid radiation, repeated phenotypic evolution within African apes is also a distinct possibility. If so, the availability of complete genomes for each of the hominoid genera makes them another model to explore the genetic basis of repeated evolution. © 2014 Wiley Periodicals, Inc.

Development of a Preschool Developmental Assessment Scale for Assessment of Developmental Disabilities

ERIC Educational Resources Information Center

Leung, Cynthia; Mak, Rose; Lau, Vanessa; Cheung, Jasmine; Lam, Catherine

2010-01-01

The aim of this paper was to describe the development of the cognitive domain of the Preschool Developmental Assessment Scale (PDAS) for assessment of preschool children with developmental disabilities. The initial version of the cognitive domain consisted of 87 items. They were administered to 324 preschool children, including 240 children from…

Studies of threespine stickleback developmental evolution: progress and promise.

PubMed

Cresko, William A; McGuigan, Katrina L; Phillips, Patrick C; Postlethwait, John H

2007-01-01

A promising route for understanding the origin and diversification of organismal form is through studies at the intersection of evolution and development (evo-devo). While much has been learned over the last two decades concerning macroevolutionary patterns of developmental change, a fundamental gap in the evo-devo synthesis is the integration of mathematical population and quantitative genetics with studies of how genetic variation in natural populations affects developmental processes. This micro-evo-devo synthesis requires model organisms with which to ask empirical questions. Threespine stickleback fish (Gasterosteus aculeatus), long a model for studying behavior, ecology and evolution, is emerging as a prominent model micro-evo-devo system. Research on stickleback over the last decade has begun to address the genetic basis of morphological variation and sex determination, and much of this work has important implications for understanding the genetics of speciation. In this paper we review recent threespine stickleback micro-evo-devo results, and outline the resources that have been developed to make this synthesis possible. The prospects for stickleback research to speed the micro-(and macro-) evo-devo syntheses are great, and this workhorse model system is well situated to continue contributing to our understanding of the generation of diversity in organismal form for many more decades.

Ascidians and the plasticity of the chordate developmental program.

PubMed

Lemaire, Patrick; Smith, William C; Nishida, Hiroki

2008-07-22

Little is known about the ancient chordates that gave rise to the first vertebrates, but the descendants of other invertebrate chordates extant at the time still flourish in the ocean. These invertebrates include the cephalochordates and tunicates, whose larvae share with vertebrate embryos a common body plan with a central notochord and a dorsal nerve cord. Tunicates are now thought to be the sister group of vertebrates. However, research based on several species of ascidians, a diverse and wide-spread class of tunicates, revealed that the molecular strategies underlying their development appear to diverge greatly from those found in vertebrates. Furthermore, the adult body plan of most tunicates, which arises following an extensive post-larval metamorphosis, shows little resemblance to the body plan of any other chordate. In this review, we compare the developmental strategies of ascidians and vertebrates and argue that the very divergence of these strategies reveals the surprising level of plasticity of the chordate developmental program and is a rich resource to identify core regulatory mechanisms that are evolutionarily conserved in chordates. Further, we propose that the comparative analysis of the architecture of ascidian and vertebrate gene regulatory networks may provide critical insight into the origin of the chordate body plan.

Developmental plasticity: Friend or foe?

PubMed

Michels, Karin B

2017-01-01

Developmental plasticity - the concept that adaptation to changing and unfavorable environmental conditions are possible but may come at the price of compromised health potentials - has evolutionary grounding as it facilitates survival but dissents with fundamental evolutionary principles in that it may advance the lesser fit. It is an important cornerstone of the Developmental Origins of Health and Disease (DOHaD). Unlike evolutionary adaptation developmental plasticity may be short-lived and restricted to one or few generations and inheritance is uncertain. Potential mechanisms include epigenetic modifications adopted in utero which may not transmit to the next generation; future insights may allow adjustments of the outcomes of developmental plasticity.

Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection.

PubMed

Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan; Bae, Chang-Joon; Hwang, Dae-Youn

2016-06-01

To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75(NTR) expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis.

Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection

PubMed Central

Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan

2016-01-01

To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75NTR expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis. PMID:27382379

Use of complementary and alternative medicine in children with autism and other developmental disabilities: associations with ethnicity, child comorbid symptoms, and parental stress.

PubMed

Valicenti-McDermott, Maria; Burrows, Bethany; Bernstein, Leora; Hottinger, Kathryn; Lawson, Katharine; Seijo, Rosa; Schechtman, Merryl; Shulman, Lisa; Shinnar, Shlomo

2014-03-01

The use of complementary and alternative medicine by children with autism and the association of its use with child comorbid symptoms and parental stress was studied in an ethnically diverse population, in a cross-sectional study with structured interviews. The sample included 50 families of children with autism and 50 families of children with other developmental disabilities, matched by age/gender. Interview included the Complementary and Alternative Medicine Questionnaire, Gastrointestinal Questionnaire, Children's Sleep Habits Questionnaire, Aberrant Behavior Checklist, and Parenting Stress Index. In this ethnically diverse sample, the use of complementary and alternative medicine was significantly higher for the autism group. In the autism group, use was significantly related to child's irritability, hyperactivity, food allergies, and parental stress; in the developmental disabilities group, there was no association with child comorbid symptoms or parental stress. The results contribute information to health care providers about families of children with autism who are more likely to use complementary and alternative medicine.

Developmentally Programmed 3′ CpG Island Methylation Confers Tissue- and Cell-Type-Specific Transcriptional Activation

PubMed Central

Yu, Da-Hai; Ware, Carol; Waterland, Robert A.; Zhang, Jiexin; Chen, Miao-Hsueh; Gadkari, Manasi; Kunde-Ramamoorthy, Govindarajan; Nosavanh, Lagina M.

2013-01-01

During development, a small but significant number of CpG islands (CGIs) become methylated. The timing of developmentally programmed CGI methylation and associated mechanisms of transcriptional regulation during cellular differentiation, however, remain poorly characterized. Here, we used genome-wide DNA methylation microarrays to identify epigenetic changes during human embryonic stem cell (hESC) differentiation. We discovered a group of CGIs associated with developmental genes that gain methylation after hESCs differentiate. Conversely, erasure of methylation was observed at the identified CGIs during subsequent reprogramming to induced pluripotent stem cells (iPSCs), further supporting a functional role for the CGI methylation. Both global gene expression profiling and quantitative reverse transcription-PCR (RT-PCR) validation indicated opposing effects of CGI methylation in transcriptional regulation during differentiation, with promoter CGI methylation repressing and 3′ CGI methylation activating transcription. By studying diverse human tissues and mouse models, we further confirmed that developmentally programmed 3′ CGI methylation confers tissue- and cell-type-specific gene activation in vivo. Importantly, luciferase reporter assays provided evidence that 3′ CGI methylation regulates transcriptional activation via a CTCF-dependent enhancer-blocking mechanism. These findings expand the classic view of mammalian CGI methylation as a mechanism for transcriptional silencing and indicate a functional role for 3′ CGI methylation in developmental gene regulation. PMID:23459939

Werner's Relevance for Contemporary Developmental Psychology.

ERIC Educational Resources Information Center

Glick, Joseph A.

1992-01-01

Considers the contributions of Heinz Werner to developmental psychology and identifies the tensions between Werner's theory and the practices of contemporary developmental psychology. Core issues of Werner's psychology concern: (1) development as heuristic, rather than phenomenon; (2) developmental process analysis; and (3) conceptions of the…

Positive Youth Development among Diverse Racial-Ethnic Children: Quality Afterschool Contexts as Developmental Assets

ERIC Educational Resources Information Center

Smith, Emilie Phillips; Witherspoon, Dawn P.; Osgood, D. Wayne

2017-01-01

Positive youth development (PYD) deserves more empirical attention, particularly among children of diverse racial-ethnic backgrounds. Given the need among families for monitoring and supervision during out-of-school time, community-based afterschool is a potentially promotive ecological setting. This study explores the quality of afterschool…

A developmental perspective on the link between parents' employment and children's obesity.

PubMed

Crosnoe, Robert; Dunifon, Rachel

2017-01-01

Despite public concerns about the negative implications of the increased labor force participation of mothers for child development, decades of research have revealed few risks and some benefits. One potential risk-a consistently observed association between maternal employment and childhood obesity-offers a window into how some dimensions of family health may be undermined by work in an economic and policy context that is not family friendly. The purpose of this article is to identify ways that a developmental perspective can enrich the literature on how children's weight may be related to the work experiences of both mothers and fathers across diverse populations, a literature that heretofore has been dominated by economic and demographic perspectives, focused almost solely on women, and largely ignored racial/ethnic variation. After reviewing the extant literature, we put forward a conceptual model that uses ecological and developmental insights to identify the mechanisms by which parents' employment might matter to children's weight and discuss this model in the context of the contemporary landscape of family policy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

THE NEUROTOXICANT TRIMETHYLTIN INDUCES APOPTOSIS VIA CASPASE ACTIVATION, P38 PROTEIN KINASE, AND OXIDATIVE STRESS IN PC12 CELLS.

EPA Science Inventory

This manuscript describes in vitro cell signaling mechanisms involved in trimethyltin-induced neurotoxicity. The signaling pathways and effects presage effects on developmental process including neural differentiation and apoptosis. These mechanisms may be pertinent to other orga...

29 CFR 1952.241 - Developmental schedule.

Code of Federal Regulations, 2010 CFR

2010-07-01

... extended training plan of substantially permanent form will be developed and adopted by October 1, 1976. (e... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Alaska § 1952.241 Developmental schedule. The Alaska plan is developmental. The Schedule of developmental steps (described in the plan as...

29 CFR 1952.371 - Developmental schedule.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Virginia § 1952.371 Developmental schedule. The Virginia plan is developmental. Following is a schedule of major developmental steps: (a) Standards identical to the Federal standards will be completely adopted by January 1, 1978. (b) A plan for...

29 CFR 1952.371 - Developmental schedule.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Virginia § 1952.371 Developmental schedule. The Virginia plan is developmental. Following is a schedule of major developmental steps: (a) Standards identical to the Federal standards will be completely adopted by January 1, 1978. (b) A plan for...

29 CFR 1952.371 - Developmental schedule.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Virginia § 1952.371 Developmental schedule. The Virginia plan is developmental. Following is a schedule of major developmental steps: (a) Standards identical to the Federal standards will be completely adopted by January 1, 1978. (b) A plan for...

29 CFR 1952.371 - Developmental schedule.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Virginia § 1952.371 Developmental schedule. The Virginia plan is developmental. Following is a schedule of major developmental steps: (a) Standards identical to the Federal standards will be completely adopted by January 1, 1978. (b) A plan for...

Heterogeneity and Developmental Connections between Cell Types Inhabiting Teeth

PubMed Central

Krivanek, Jan; Adameyko, Igor; Fried, Kaj

2017-01-01

Every tissue is composed of multiple cell types that are developmentally, evolutionary and functionally integrated into the unit we call an organ. Teeth, our organs for biting and mastication, are complex and made of many different cell types connected or disconnected in terms of their ontogeny. In general, epithelial and mesenchymal compartments represent the major framework of tooth formation. Thus, they give rise to the two most important matrix–producing populations: ameloblasts generating enamel and odontoblasts producing dentin. However, the real picture is far from this quite simplified view. Diverse pulp cells, the immune system, the vascular system, the innervation and cells organizing the dental follicle all interact, and jointly participate in transforming lifeless matrix into a functional organ that can sense and protect itself. Here we outline the heterogeneity of cell types that inhabit the tooth, and also provide a life history of the major populations. The mouse model system has been indispensable not only for the studies of cell lineages and heterogeneity, but also for the investigation of dental stem cells and tooth patterning during development. Finally, we briefly discuss the evolutionary aspects of cell type diversity and dental tissue integration. PMID:28638345

Designing Meaningful Developmental Reform. Research Overview

ERIC Educational Resources Information Center

Jaggars, Shanna Smith; Hodara, Michelle; Stacey, Georgia West

2013-01-01

This practitioner packet is designed to help community college administrators implement reforms to developmental education at their colleges. It reviews common impediments to developmental reform and presents data that supports directions colleges can take to create a system of developmental education that might serve students more effectively.…

Developmental Rainbow: Early Childhood Development Profile.

ERIC Educational Resources Information Center

Mahoney, Gerald; Mahoney, Frida

One of the most important skills of professionals who work with young children is the ability to assess developmental functioning through informal observation. This skill serves as the foundation for screening or identifying children in need of developmental services, conducting play-based developmental assessments, and helping parents to…

Comparison of MeHg-induced toxicogenomic responses across in vivo and in vitro models used in developmental toxicology.

PubMed

Robinson, Joshua F; Theunissen, Peter T; van Dartel, Dorien A M; Pennings, Jeroen L; Faustman, Elaine M; Piersma, Aldert H

2011-09-01

Toxicogenomic evaluations may improve toxicity prediction of in vitro-based developmental models, such as whole embryo culture (WEC) and embryonic stem cells (ESC), by providing a robust mechanistic marker which can be linked with responses associated with developmental toxicity in vivo. While promising in theory, toxicogenomic comparisons between in vivo and in vitro models are complex due to inherent differences in model characteristics and experimental design. Determining factors which influence these global comparisons are critical in the identification of reliable mechanistic-based markers of developmental toxicity. In this study, we compared available toxicogenomic data assessing the impact of the known teratogen, methylmercury (MeHg) across a diverse set of in vitro and in vivo models to investigate the impact of experimental variables (i.e. model, dose, time) on our comparative assessments. We evaluated common and unique aspects at both the functional (Gene Ontology) and gene level of MeHg-induced response. At the functional level, we observed stronger similarity in MeHg-response between mouse embryos exposed in utero (2 studies), ESC, and WEC as compared to liver, brain and mouse embryonic fibroblast MeHg studies. These findings were strongly correlated to the presence of a MeHg-induced developmentally related gene signature. In addition, we identified specific MeHg-induced gene expression alterations associated with developmental signaling and heart development across WEC, ESC and in vivo systems. However, the significance of overlap between studies was highly dependent on traditional experimental variables (i.e. dose, time). In summary, we identify promising examples of unique gene expression responses which show in vitro-in vivo similarities supporting the relevance of in vitro developmental models for predicting in vivo developmental toxicity. Copyright © 2011 Elsevier Inc. All rights reserved.

Cerebellum cholinergic muscarinic receptor (subtype-2 and -3) and cytoarchitecture after developmental exposure to methylmercury: an immunohistochemical study in rat.

PubMed

Roda, Elisa; Coccini, Teresa; Acerbi, Davide; Castoldi, Anna; Bernocchi, Graziella; Manzo, Luigi

2008-05-01

The developing central nervous system (CNS) is a target of the environmental toxicant methylmercury (MeHg), and the cerebellum seems the most susceptible tissue in response to this neurotoxicant. The cholinergic system is essential for brain development, acting as a modulator of neuronal proliferation, migration and differentiation processes; its muscarinic receptors (MRs) play pivotal roles in regulating important basic physiologic functions. By immunohistochemistry, we investigated the effects of perinatal (GD7-PD21) MeHg (0.5 mg/kg bw/day in drinking water) administration on cerebellum of mature (PD36) and immature (PD21) rats, evaluating the: (i) M2- and M3-MR expression; (ii) presence of gliosis; (iii) cytoarchitecture alterations. Regarding to M2-MRs, we showed that: at PD21, MeHg-treated animals did not display any differences compared to controls, while, at PD36 there was a significant increase of M2-immunopositive Bergmann cells in the molecular layer (ML), suggesting a MeHg-related cytotoxic effect. Similarly to M2-MRs, at PD21 the M3-MRs were not affected by MeHg, while, at PD36 a lacking immunoreactivity of the granular layer (IGL) was observed after MeHg treatment. In MeHg-treated rats, at both developmental points, we showed reactive gliosis, e.g. a significant increase in Bergmann glia of the ML and astrocytes of the IGL, identified by their expression of glial fibrillar acidic protein. No MeHg-related effects on Purkinje cells were detected neither at weaning nor at puberty. These findings suggest: (i) a delayed MeHg exposure-related effect on M2- and M3-MRs, (ii) an overt MeHg-related cytotoxic effect on cerebellar oligodendroglia, e.g. reactive gliosis, (iii) a selective vulnerability of granule cells and Purkinje neurons to MeHg, with the latter that remain unharmed.

CHEMICAL PRIORITIZATION FOR DEVELOPMENTAL ...

EPA Pesticide Factsheets

Defining a predictive model of developmental toxicity from in vitro and high-throughput screening (HTS) assays can be limited by the availability of developmental defects data. ToxRefDB (www.epa.gov/ncct/todrefdb) was built from animal studies on data-rich environmental chemicals, and has been used as an anchor for predictive modeling of ToxCast™ data. Scaling to thousands of untested chemicals requires another approach. ToxPlorer™ was developed as a tool to query and extract specific facts about defined biological entities from the open scientific literature and to coherently synthesize relevant knowledge about relationships, pathways and processes in toxicity. Here, we investigated the specific application of ToxPlorer to weighting HTS assay targets for relevance to developmental defects as defined in the literature. First, we systemically analyzed 88,193 Pubmed abstracts selected by bulk query using harmonized terminology for 862 developmental endpoints (www.devtox.net) and 364,334 dictionary term entities in our VT-KB (virtual tissues knowledgebase). We specifically focused on entities corresponding to genes/proteins mapped across of >500 ToxCast HTS assays. The 88,193 devtox abstracts mentioned 244 gene/protein entities in an aggregated total of ~8,000 occurrences. Each of the 244 assays was scored and weighted by the number of devtox articles and relevance to developmental processes. This score was used as a feature for chemical prioritization by Toxic

Developmental Education Repeaters: Stories about Repetition

ERIC Educational Resources Information Center

O'Dell, Jade J.

2012-01-01

Developmental education students make up almost half of the community college population in the United States (Bettinger & Long, 2005). Approximately 42% of first-time freshmen at community colleges must enroll in at least one developmental education course in English, reading and/or math (NCES, 2010). Many developmental education students are…

OS082. CHIPS-Child: Testing the developmental origins hypothesis.

PubMed

Magee, L A; Synnes, A

2012-07-01

.05, SD 1). Recruitment has begun. The primary outcome will be the between-group difference in early postnatal weight gain ('change in z score for weight') between birth and 12m (p<0.05). Secondary:outcomes are (i) hypothalamic pituitary adrenal axis function (hair cortisol for overall cortisol production); and (ii) between-groups differences in DNA methylation, using targeted (genes associated with growth, obesity, cardiovascular disease, and/or a developmental programming effect) and global (genome-wide microarray) methods. CHIPS-Child offers a unique opportunity to both clarify whether differential dBP control in pregnancy has developmental programming effects and contribute to our understanding of human biology and diversity in a way that a cross-sectional or other observational studies cannot. Copyright © 2012. Published by Elsevier B.V.

Applied Developmental Science: An Advanced Textbook. The SAGE Program on Applied Developmental Science

ERIC Educational Resources Information Center

Lerner, Richard M., Ed.; Jacobs, Fraincine, Ed.; Wertlieb, Donald, Ed.

2005-01-01

This course textbook has been adapted from the four-volume "Handbook of Applied Developmental Science" (SAGE 2003), a work that offers a detailed roadmap for action and research in ensuring positive child, youth, and family development. In 20 chapters, "Applied Developmental Science: An Advanced Textbook" brings together theory and application…

The taming of the neural crest: a developmental perspective on the origins of morphological covariation in domesticated mammals

NASA Astrophysics Data System (ADS)

Sánchez-Villagra, Marcelo R.; Geiger, Madeleine; Schneider, Richard A.

2016-06-01

Studies on domestication are blooming, but the developmental bases for the generation of domestication traits and breed diversity remain largely unexplored. Some phenotypic patterns of human neurocristopathies are suggestive of those reported for domesticated mammals and disrupting neural crest developmental programmes have been argued to be the source of traits deemed the `domestication syndrome'. These character changes span multiple organ systems and morphological structures. But an in-depth examination within the phylogenetic framework of mammals including domesticated forms reveals that the distribution of such traits is not universal, with canids being the only group showing a large set of predicted features. Modularity of traits tied to phylogeny characterizes domesticated mammals: through selective breeding, individual behavioural and morphological traits can be reordered, truncated, augmented or deleted. Similarly, mammalian evolution on islands has resulted in suites of phenotypic changes like those of some domesticated forms. Many domesticated mammals can serve as valuable models for conducting comparative studies on the evolutionary developmental biology of the neural crest, given that series of their embryos are readily available and that their phylogenetic histories and genomes are well characterized.

The developmental genetics of biological robustness

PubMed Central

Mestek Boukhibar, Lamia; Barkoulas, Michalis

2016-01-01

Background Living organisms are continuously confronted with perturbations, such as environmental changes that include fluctuations in temperature and nutrient availability, or genetic changes such as mutations. While some developmental systems are affected by such challenges and display variation in phenotypic traits, others continue consistently to produce invariable phenotypes despite perturbation. This ability of a living system to maintain an invariable phenotype in the face of perturbations is termed developmental robustness. Biological robustness is a phenomenon observed across phyla, and studying its mechanisms is central to deciphering the genotype–phenotype relationship. Recent work in yeast, animals and plants has shown that robustness is genetically controlled and has started to reveal the underlying mechinisms behind it. Scope and Conclusions Studying biological robustness involves focusing on an important property of developmental traits, which is the phenotypic distribution within a population. This is often neglected because the vast majority of developmental biology studies instead focus on population aggregates, such as trait averages. By drawing on findings in animals and yeast, this Viewpoint considers how studies on plant developmental robustness may benefit from strict definitions of what is the developmental system of choice and what is the relevant perturbation, and also from clear distinctions between gene effects on the trait mean and the trait variance. Recent advances in quantitative developmental biology and high-throughput phenotyping now allow the design of targeted genetic screens to identify genes that amplify or restrict developmental trait variance and to study how variation propagates across different phenotypic levels in biological systems. The molecular characterization of more quantitative trait loci affecting trait variance will provide further insights into the evolution of genes modulating developmental robustness. The

Age cohort differences in the developmental milestones of gay men.

PubMed

Drasin, Harry; Beals, Kristin P; Elliott, Marc N; Lever, Janet; Klein, David J; Schuster, Mark A

2008-01-01

As the social context in which gay men live changes due to greater visibility, greater acceptance, and easier access to gay subculture, gay males may self-identify and take part in gay social activities at earlier ages than in the past. This study examined whether developmental milestones associated with sexual orientation for gay men have changed over the past several decades. A large and diverse sample of 2,402 gay men who responded to a 1994 survey published in a national magazine provided retrospective information on the age at which they reached individual psychological, social, and sexual behavior developmental milestones. We found evidence that individual psychological and sexual behavior milestones (e.g., awareness of attraction to males, having an orgasm with other male) are slowly moving toward earlier chronological ages (by 1 year of age every 8-25 years, p < 0.05), whereas social milestones (e.g., coming out) are moving more rapidly in a similar direction (by 1 year of age every 2-5 years, p < 0.001). The authors perform an innovative sensitivity test to demonstrate the persistence of the finding after correcting for the bias attributable to underrepresentation of those who have not yet self-identified as gay in such samples.

Identifying gene coexpression networks underlying the dynamic regulation of wood-forming tissues in Populus under diverse environmental conditions.

PubMed

Zinkgraf, Matthew; Liu, Lijun; Groover, Andrew; Filkov, Vladimir

2017-06-01

Trees modify wood formation through integration of environmental and developmental signals in complex but poorly defined transcriptional networks, allowing trees to produce woody tissues appropriate to diverse environmental conditions. In order to identify relationships among genes expressed during wood formation, we integrated data from new and publically available datasets in Populus. These datasets were generated from woody tissue and include transcriptome profiling, transcription factor binding, DNA accessibility and genome-wide association mapping experiments. Coexpression modules were calculated, each of which contains genes showing similar expression patterns across experimental conditions, genotypes and treatments. Conserved gene coexpression modules (four modules totaling 8398 genes) were identified that were highly preserved across diverse environmental conditions and genetic backgrounds. Functional annotations as well as correlations with specific experimental treatments associated individual conserved modules with distinct biological processes underlying wood formation, such as cell-wall biosynthesis, meristem development and epigenetic pathways. Module genes were also enriched for DNase I hypersensitivity footprints and binding from four transcription factors associated with wood formation. The conserved modules are excellent candidates for modeling core developmental pathways common to wood formation in diverse environments and genotypes, and serve as testbeds for hypothesis generation and testing for future studies. No claim to original US government works. New Phytologist © 2017 New Phytologist Trust.

Piaget's Structural Developmental Psychology. v. Ideology-Critique and the Possibility of a Critical Developmental Theory.

ERIC Educational Resources Information Center

Broughton, John M.

1981-01-01

This final essay in a five-part series examining Piaget's structural developmental psychology suggests that a psychological theory which integrates aspects of developmental structuralism within a critical social framework can be developed. (Author/RH)

The forkhead domain gene unc-130 generates chemosensory neuron diversity in C. elegans

PubMed Central

Sarafi-Reinach, Trina R.; Sengupta, Piali

2000-01-01

Caenorhabditis elegans responds to its complex chemical environment using a small number of chemosensory neurons. Each of these neurons exhibits a unique sensory response repertoire. The developmental mechanisms that generate this diversity of function are largely unknown. Many C. elegans chemosensory neurons, including the AWA and ASG neurons, arise as lineal sisters of an asymmetric division. Here we describe the gene unc-130, which plays a role in the generation of the AWA and ASG neurons. In unc-130 mutants, the ASG neurons adopt the fate of the AWA neurons. unc-130 encodes a member of the forkhead domain family of transcription factors, and is expressed in the precursors to AWA and ASG neurons. Misexpression of unc-130 in the AWA neurons is partly sufficient to repress the AWA fate, but not to promote ASG fate. unc-130 also plays a role in the development of additional chemosensory neurons. Our experiments show that the ASG neurons share a developmental default state in common with three types of olfactory neurons. We propose that distinct cell fates and hence diversity of function in the chemosensory neurons of C. elegans are generated in a hierarchical manner, utilizing both lineage-dependent and independent mechanisms. PMID:11018015

47 CFR 80.391 - Frequencies for developmental stations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... developmental stations. (a) Ship and shore stations engaged in developmental operations may be assigned any... following frequency bands are also assignable to ships and coast stations for developmental operations: Ship... are assignable for developmental operations at ship and shore radiolocation stations if their...

47 CFR 80.391 - Frequencies for developmental stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... developmental stations. (a) Ship and shore stations engaged in developmental operations may be assigned any... following frequency bands are also assignable to ships and coast stations for developmental operations: Ship... are assignable for developmental operations at ship and shore radiolocation stations if their...

47 CFR 80.391 - Frequencies for developmental stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... developmental stations. (a) Ship and shore stations engaged in developmental operations may be assigned any... following frequency bands are also assignable to ships and coast stations for developmental operations: Ship... are assignable for developmental operations at ship and shore radiolocation stations if their...

47 CFR 101.413 - Developmental report required.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Developmental report required. 101.413 Section 101.413 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Developmental Authorizations § 101.413 Developmental report required. (a...

47 CFR 101.413 - Developmental report required.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Developmental report required. 101.413 Section 101.413 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Developmental Authorizations § 101.413 Developmental report required. (a...

47 CFR 101.413 - Developmental report required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Developmental report required. 101.413 Section 101.413 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Developmental Authorizations § 101.413 Developmental report required. (a...

Why are orchid flowers so diverse? Reduction of evolutionary constraints by paralogues of class B floral homeotic genes

PubMed Central

Mondragón-Palomino, Mariana; Theißen, Günter

2009-01-01

Background The nearly 30 000 species of orchids produce flowers of unprecedented diversity. However, whether specific genetic mechanisms contributed to this diversity is a neglected topic and remains speculative. We recently published a theory, the ‘orchid code’, maintaining that the identity of the different perianth organs is specified by the combinatorial interaction of four DEF-like MADS-box genes with other floral homeotic genes. Scope Here the developmental and evolutionary implications of our theory are explored. Specifically, it is shown that all frequent floral terata, including all peloric types, can be explained by monogenic gain- or-loss-of-function mutants, changing either expression of a DEF-like or CYC-like gene. Supposed dominance or recessiveness of mutant alleles is correlated with the frequency of terata in both cultivation and nature. Our findings suggest that changes in DEF- and CYC-like genes not only underlie terata but also the natural diversity of orchid species. We argue, however, that true changes in organ identity are rare events in the evolution of orchid flowers, even though we review some likely cases. Conclusions The four DEF paralogues shaped floral diversity in orchids in a dramatic way by modularizing the floral perianth based on a complex series of sub- and neo-functionalization events. These genes may have eliminated constraints, so that different kinds of perianth organs could then evolve individually and thus often in dramatically different ways in response to selection by pollinators or by genetic drift. We therefore argue that floral diversity in orchids may be the result of an unprecedented developmental genetic predisposition that originated early in orchid evolution. PMID:19141602

Neuropeptides and epitheliopeptides: structural and functional diversity in an ancestral metazoan Hydra.

PubMed

Takahashi, Toshio

2013-06-01

Peptides are known to play important developmental and physiological roles in signaling. The rich diversity of peptides, with functions as diverse as intercellular communication, neurotransmission and signaling that spatially and temporally controls axis formation and cell differentiation, hints at the wealth of information passed between interacting cells. Little is known about peptides that control developmental processes such as cell differentiation and pattern formation in metazoans. The cnidarian Hydra is one of the most basic metazoans and is a key model system for study of the peptides involved in these processes. We developed a novel peptidomic approach for the isolation and identification of functional peptide signaling molecules from Hydra (the Hydra Peptide Project). Over the course of this project, a wide variety of novel neuropeptides were identified. Most of these peptides act directly on muscle cells and their functions include induction of contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. Moreover, epitheliopeptides that are produced by epithelial cells were originally identified in Hydra. Some of these epitheliopeptides exhibit morphogen-like activities, whereas others are involved in regulating neuron differentiation, possibly through neuron-epithelial cell interactions. We also describe below our high-throughput reverse-phase nano-flow LCMALDI- TOF-MS/MS approach, which has proved a powerful tool for the discovery of novel peptide signaling molecules in Hydra.

The Broad Spectrum of Human Natural Killer Cell Diversity.

PubMed

Freud, Aharon G; Mundy-Bosse, Bethany L; Yu, Jianhua; Caligiuri, Michael A

2017-11-21

Natural killer (NK) cells provide protection against infectious pathogens and cancer. For decades it has been appreciated that two major NK cell subsets (CD56 bright and CD56 dim ) exist in humans and have distinct anatomical localization patterns, phenotypes, and functions in immunity. In light of this traditional NK cell dichotomy, it is now clear that the spectrum of human NK cell diversity is much broader than originally appreciated as a result of variegated surface receptor, intracellular signaling molecule, and transcription factor expression; tissue-specific imprinting; and foreign antigen exposure. The recent discoveries of tissue-resident NK cell developmental intermediates, non-NK innate lymphoid cells, and the capacity for NK cells to adapt and differentiate into long-lived memory cells has added further complexity to this field. Here we review our current understanding of the breadth and generation of human NK cell diversity. Copyright © 2017 Elsevier Inc. All rights reserved.

Lampreys as Diverse Model Organisms in the Genomics Era.

PubMed

McCauley, David W; Docker, Margaret F; Whyard, Steve; Li, Weiming

2015-11-01

Lampreys, one of the two surviving groups of ancient vertebrates, have become important models for study in diverse fields of biology. Lampreys (of which there are approximately 40 species) are being studied, for example, (a) to control pest sea lamprey in the North American Great Lakes and to restore declining populations of native species elsewhere; (b) in biomedical research, focusing particularly on the regenerative capability of lampreys; and (c) by developmental biologists studying the evolution of key vertebrate characters. Although a lack of genetic resources has hindered research on the mechanisms regulating many aspects of lamprey life history and development, formerly intractable questions are now amenable to investigation following the recent publication of the sea lamprey genome. Here, we provide an overview of the ways in which genomic tools are currently being deployed to tackle diverse research questions and suggest several areas that may benefit from the availability of the sea lamprey genome.

Lampreys as Diverse Model Organisms in the Genomics Era

PubMed Central

McCauley, David W.; Docker, Margaret F.; Whyard, Steve; Li, Weiming

2015-01-01

Lampreys, one of the two surviving groups of ancient vertebrates, have become important models for study in diverse fields of biology. Lampreys (of which there are approximately 40 species) are being studied, for example, (a) to control pest sea lamprey in the North American Great Lakes and to restore declining populations of native species elsewhere; (b) in biomedical research, focusing particularly on the regenerative capability of lampreys; and (c) by developmental biologists studying the evolution of key vertebrate characters. Although a lack of genetic resources has hindered research on the mechanisms regulating many aspects of lamprey life history and development, formerly intractable questions are now amenable to investigation following the recent publication of the sea lamprey genome. Here, we provide an overview of the ways in which genomic tools are currently being deployed to tackle diverse research questions and suggest several areas that may benefit from the availability of the sea lamprey genome. PMID:26951616

NEUROTOXICITY OF CARBARYL IN THE AGING BROWN NORWAY RAT: EFFECTS ON CORE TEMPERATURE AND MOTOR ACTIVITY.

EPA Science Inventory

The US EPA is pursuing a variety of research efforts to assess the susceptibility of the aged to neurotoxicants. The BN strain is a popular animal model for aging studies but there is a need for improved methods of monitoring their physiological responses to neurotoxicants over t...

Somatic stem cell heterogeneity: diversity in the blood, skin and intestinal stem cell compartments

PubMed Central

Goodell, Margaret A.; Nguyen, Hoang; Shroyer, Noah

2017-01-01

Somatic stem cells replenish many tissues throughout life to repair damage and to maintain tissue homeostasis. Stem cell function is frequently described as following a hierarchical model in which a single master cell undergoes self-renewal and differentiation into multiple cell types and is responsible for most regenerative activity. However, recent data from studies on blood, skin and intestinal epithelium all point to the concomitant action of multiple types of stem cells with distinct everyday roles. Under stress conditions such as acute injury, the surprising developmental flexibility of these stem cells enables them to adapt to diverse roles and to acquire different regeneration capabilities. This paradigm shift raises many new questions about the developmental origins, inter-relationships and molecular regulation of these multiple stem cell types. PMID:25907613

Comparative developmental toxicity of environmentally relevant oxygenated PAHs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knecht, Andrea L., E-mail: andrea.knecht@tanguaylab.com; Goodale, Britton C., E-mail: goodaleb@onid.orst.edu; Truong, Lisa, E-mail: lisa.truong.888@gmail.com

2013-09-01

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are byproducts of combustion and photo-oxidation of parent PAHs. OPAHs are widely present in the environment and pose an unknown hazard to human health. The developing zebrafish was used to evaluate a structurally diverse set of 38 OPAHs for malformation induction, gene expression changes and mitochondrial function. Zebrafish embryos were exposed from 6 to 120 h post fertilization (hpf) to a dilution series of 38 different OPAHs and evaluated for 22 developmental endpoints. AHR activation was determined via CYP1A immunohistochemistry. Phenanthrenequinone (9,10-PHEQ), 1,9-benz-10-anthrone (BEZO), xanthone (XAN), benz(a)anthracene-7,12-dione (7,12-B[a]AQ), and 9,10-anthraquinone (9,10-ANTQ) were evaluated for transcriptionalmore » responses at 48 hpf, prior to the onset of malformations. qRT-PCR was conducted for a number of oxidative stress genes, including the glutathione transferase(gst), glutathione peroxidase(gpx), and superoxide dismutase(sod) families. Bioenergetics was assayed to measure in vivo oxidative stress and mitochondrial function in 26 hpf embryos exposed to OPAHs. Hierarchical clustering of the structure-activity outcomes indicated that the most toxic of the OPAHs contained adjacent diones on 6-carbon moieties or terminal, para-diones on multi-ring structures. 5-carbon moieties with adjacent diones were among the least toxic OPAHs while the toxicity of multi-ring structures with more centralized para-diones varied considerably. 9,10-PHEQ, BEZO, 7,12-B[a]AQ, and XAN exposures increased expression of several oxidative stress related genes and decreased oxygen consumption rate (OCR), a measurement of mitochondrial respiration. Comprehensive in vivo characterization of 38 structurally diverse OPAHs indicated differential AHR dependency and a prominent role for oxidative stress in the toxicity mechanisms. - Highlights: • OPAHs are byproducts of combustion present in the environment. • OPAHs pose a

Young Children with Developmental Delays as Young Adults: Predicting Developmental and Personal-Social Outcomes

ERIC Educational Resources Information Center

Bernheimer, Lucinda P.; Keogh, Barbara K.; Guthrie, Donald

2006-01-01

We report on a 20-year follow-up of 30 children with developmental delays identified at age 3. Our purpose was to assess the relationship of early indicators of delay to cognitive and personal-social status in young adulthood. Predictors were Developmental and Personal-Social factors derived from standardized tests and parent questionnaires…

Developmental origins of epigenetic transgenerational inheritance

PubMed Central

Hanson, Mark A.; Skinner, Michael K.

2016-01-01

Abstract Environmental factors can induce epigenetic alterations in the germ cells that can potentially be transmitted transgenerationally. This non-genetic form of inheritance is termed epigenetic transgenerational inheritance and has been shown in a variety of species including plants, flies, worms, fish, rodents, pigs, and humans. This phenomenon operates during specific critical windows of exposure, linked to the developmental biology of the germ cells (sperm and eggs). Therefore, concepts of the developmental origins of transgenerational inheritance of phenotypic variation and subsequent disease risk need to include epigenetic processes affecting the developmental biology of the germ cell. These developmental impacts on epigenetic transgenerational inheritance, in contrast to multigenerational exposures, are the focus of this Perspective. PMID:27390622

A stratified myeloid system, the challenge of understanding macrophage diversity.

PubMed

Geissmann, F; Mass, E

2015-12-01

The present issue of 'Seminars in Immunology' addresses the topic of macrophage biology, 100 years after the death of Elie Metchnikoff (May 1845-July 1916). As foreseen by Metchnikoff, the roles of macrophages in the maintenance of homeostasis and immunity against pathogens have become a broad and active area of investigation. We now start to realize that the myeloid system includes a multiplicity of cell types with diverse developmental origins and functions. Therefore, the textbook picture of a plastic and multifunctional macrophage does not meet the requirements of our current knowledge anymore. Further development toward a quantitative and molecular understanding of myeloid cell biology in vivo and their roles in tissue homeostasis and remodeling will benefit from taking this complexity into account. A tentative model to help in this pursuit and account for myeloid cell and macrophage diversity is discussed below. Copyright © 2016. Published by Elsevier Ltd.

[Contemporary cognitive theories about developmental dyscalculia].

PubMed

Castro-Cañizares, D; Estévez-Pérez, N; Reigosa-Crespo, V

To analyze the current theories describing the cognitive mechanisms underlying developmental dyscalculia. The four most researched hypotheses concerning the cognitive deficits related to developmental dyscalculia, as well as experimental evidences supporting or refusing them are presented. The first hypothesis states that developmental dyscalculia is consequence of domain general cognitive deficits. The second hypothesis suggests that it is due to a failure in the development of specialized brain systems dedicated to numerosity processing. The third hypothesis asserts the disorder is caused by a deficit in accessing quantity representation through numerical symbols. The last hypothesis states developmental dyscalculia appears as a consequence of impairments in a generalized magnitude system dedicated to the processing of continuous and discrete magnitudes. None of the hypotheses has been proven more plausible than the rest. Relevant issues rose by them need to be revisited and answered in the light of new experimental designs. In the last years the understanding of cognitive disorders involved in developmental dyscalculia has remarkably increased, but it is nonetheless insufficient. Additional research is required in order to achieve a comprehensive cognitive model of numerical processing development and its disorders. This will improve the diagnostic precision and the effectiveness of developmental dyscalculia intervention strategies.

Increasingly diverse brain dynamics in the developmental arc: using Pareto-optimization to infer a mechanism

NASA Astrophysics Data System (ADS)

Tang, Evelyn; Giusti, Chad; Baum, Graham; Gu, Shi; Pollock, Eli; Kahn, Ari; Roalf, David; Moore, Tyler; Ruparel, Kosha; Gur, Ruben; Gur, Raquel; Satterthwaite, Theodore; Bassett, Danielle

Motivated by a recent demonstration that the network architecture of white matter supports emerging control of diverse neural dynamics as children mature into adults, we seek to investigate structural mechanisms that support these changes. Beginning from a network representation of diffusion imaging data, we simulate network evolution with a set of simple growth rules built on principles of network control. Notably, the optimal evolutionary trajectory displays a striking correspondence to the progression of child to adult brain, suggesting that network control is a driver of development. More generally, and in comparison to the complete set of available models, we demonstrate that all brain networks from child to adult are structured in a manner highly optimized for the control of diverse neural dynamics. Within this near-optimality, we observe differences in the predicted control mechanisms of the child and adult brains, suggesting that the white matter architecture in children has a greater potential to increasingly support brain state transitions, potentially underlying cognitive switching.

STRUCTURE-ACTIVITY COMPARISON OF ORGANOTIN SPECIES: DIBUTYLTIN IS A DEVELOPMENTAL NEUROTOXICANT IN VITRO AND IN VIVO.

EPA Science Inventory

This manuscript compares the toxicity of a number of organotin species present in drinking water using a set of in vitro assays that model neuronal differentiation, and viability and apoptosis. Dibutyltin (DBT), dimethyltin (DMT), monomethyltin (MMT), and the positive control tri...

Trisomy 21 and Facial Developmental Instability

PubMed Central

Starbuck, John M.; Cole, Theodore M.; Reeves, Roger H.; Richtsmeier, Joan T.

2013-01-01

The most common live-born human aneuploidy is trisomy 21, which causes Down syndrome (DS). Dosage imbalance of genes on chromosome 21 (Hsa21) affects complex gene-regulatory interactions and alters development to produce a wide range of phenotypes, including characteristic facial dysmorphology. Little is known about how trisomy 21 alters craniofacial morphogenesis to create this characteristic appearance. Proponents of the “amplified developmental instability” hypothesis argue that trisomy 21 causes a generalized genetic imbalance that disrupts evolutionarily conserved developmental pathways by decreasing developmental homeostasis and precision throughout development. Based on this model, we test the hypothesis that DS faces exhibit increased developmental instability relative to euploid individuals. Developmental instability was assessed by a statistical analysis of fluctuating asymmetry. We compared the magnitude and patterns of fluctuating asymmetry among siblings using three-dimensional coordinate locations of 20 anatomic landmarks collected from facial surface reconstructions in four age-matched samples ranging from 4 to 12 years: 1) DS individuals (n=55); 2) biological siblings of DS individuals (n=55); 3) and 4) two samples of typically developing individuals (n=55 for each sample), who are euploid siblings and age-matched to the DS individuals and their euploid siblings (samples 1 and 2). Identification in the DS sample of facial prominences exhibiting increased fluctuating asymmetry during facial morphogenesis provides evidence for increased developmental instability in DS faces. We found the highest developmental instability in facial structures derived from the mandibular prominence and lowest in facial regions derived from the frontal prominence. PMID:23505010

Trisomy 21 and facial developmental instability.

PubMed

Starbuck, John M; Cole, Theodore M; Reeves, Roger H; Richtsmeier, Joan T

2013-05-01

The most common live-born human aneuploidy is trisomy 21, which causes Down syndrome (DS). Dosage imbalance of genes on chromosome 21 (Hsa21) affects complex gene-regulatory interactions and alters development to produce a wide range of phenotypes, including characteristic facial dysmorphology. Little is known about how trisomy 21 alters craniofacial morphogenesis to create this characteristic appearance. Proponents of the "amplified developmental instability" hypothesis argue that trisomy 21 causes a generalized genetic imbalance that disrupts evolutionarily conserved developmental pathways by decreasing developmental homeostasis and precision throughout development. Based on this model, we test the hypothesis that DS faces exhibit increased developmental instability relative to euploid individuals. Developmental instability was assessed by a statistical analysis of fluctuating asymmetry. We compared the magnitude and patterns of fluctuating asymmetry among siblings using three-dimensional coordinate locations of 20 anatomic landmarks collected from facial surface reconstructions in four age-matched samples ranging from 4 to 12 years: (1) DS individuals (n = 55); (2) biological siblings of DS individuals (n = 55); 3) and 4) two samples of typically developing individuals (n = 55 for each sample), who are euploid siblings and age-matched to the DS individuals and their euploid siblings (samples 1 and 2). Identification in the DS sample of facial prominences exhibiting increased fluctuating asymmetry during facial morphogenesis provides evidence for increased developmental instability in DS faces. We found the highest developmental instability in facial structures derived from the mandibular prominence and lowest in facial regions derived from the frontal prominence. Copyright © 2013 Wiley Periodicals, Inc.

The Role of Gender in Violence Experienced by Adults With Developmental Disabilities.

PubMed

Platt, Laura; Powers, Laurie; Leotti, Sandra; Hughes, Rosemary B; Robinson-Whelen, Susan; Osburn, Sherri; Ashkenazy, Elesia; Beers, Leanne; Lund, Emily M; Nicolaidis, Christina

2017-01-01

Violence against people with developmental disabilities is a highly prevalent yet understudied phenomenon. In particular, there is a paucity of literature surrounding the role of gender and the experiences of men. Using a cross-sectional study design, we surveyed 350 people with diverse developmental disabilities about experiences of abuse, perpetrators of abuse, and their physical and mental health status. These data were analyzed to determine whether gender influenced these domains. Statistical methods included chi-square, independent t tests, logistic regression, and hierarchical multiple regressions. Male and female participants reported abuse at high rates, with 61.9% of men and 58.2% of women reporting abuse as children and 63.7% of men and 68.2% of women reporting abuse as adults. More women than men reported adult sexual abuse, but there was no gender difference in the prevalence of any other form of abuse. Women were more likely than men to identify an intimate partner as their abuser, although intimate partners represented the minority of abusers for both men and women. Violence was associated with worse health status regardless of participant gender. These findings confirm that violence is an important issue for both men and women with developmental disabilities. Although some expected gender differences arose, such as higher rates of adult sexual abuse and intimate partner violence against women, these differences were less pronounced than they are in the general population, and the overall picture of abuse was one of gender similarities rather than differences. © The Author(s) 2015.

The evolution of plasticity of dauer larva developmental arrest in the nematode Caenorhabditis elegans.

PubMed

Diaz, S Anaid; Viney, Mark

2015-03-01

Organisms can end up in unfavourable conditions and to survive this they have evolved various strategies. Some organisms, including nematodes, survive unfavourable conditions by undergoing developmental arrest. The model nematode Caenorhabditis elegans has a developmental choice between two larval forms, and it chooses to develop into the arrested dauer larva form in unfavourable conditions (specifically, a lack of food and high population density, indicated by the concentration of a pheromone). Wild C. elegans isolates vary extensively in their dauer larva arrest phenotypes, and this prompts the question of what selective pressures maintain such phenotypic diversity? To investigate this we grew C. elegans in four different environments, consisting of different combinations of cues that can induce dauer larva development: two combinations of food concentration (high and low) in the presence or absence of a dauer larva-inducing pheromone. Five generations of artificial selection of dauer larvae resulted in an overall increase in dauer larva formation in most selection regimes. The presence of pheromone in the environment selected for twice the number of dauer larvae, compared with environments not containing pheromone. Further, only a high food concentration environment containing pheromone increased the plasticity of dauer larva formation. These evolutionary responses also affected the timing of the worms' reproduction. Overall, these results give an insight into the environments that can select for different plasticities of C. elegans dauer larva arrest phenotypes, suggesting that different combinations of environmental cues can select for the diversity of phenotypically plastic responses seen in C. elegans.

Developmental Stage of Parasites Influences the Structure of Fish-Parasite Networks

PubMed Central

Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

2013-01-01

Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries. PMID:24124506

Developmental stage of parasites influences the structure of fish-parasite networks.

PubMed

Bellay, Sybelle; de Oliveira, Edson Fontes; Almeida-Neto, Mário; Lima Junior, Dilermando Pereira; Takemoto, Ricardo Massato; Luque, José Luis

2013-01-01

Specialized interactions tend to be more common in systems that require strong reciprocal adaptation between species, such as those observed between parasites and hosts. Parasites exhibit a high diversity of species and life history strategies, presenting host specificity which increases the complexity of these antagonistic systems. However, most studies are limited to the description of interactions between a few parasite and host species, which restricts our understanding of these systems as a whole. We investigated the effect of the developmental stage of the parasite on the structure of 30 metazoan fish-parasite networks, with an emphasis on the specificity of the interactions, connectance and modularity. We assessed the functional role of each species in modular networks and its interactions within and among the modules according to the developmental stage (larval and adult) and taxonomic group of the parasites. We observed that most parasite and host species perform a few interactions but that parasites at the larval stage tended to be generalists, increasing the network connectivity within and among modules. The parasite groups did not differ among each other in the number of interactions within and among the modules when considering only species at the larval stage. However, the same groups of adult individuals differed from each other in their interaction patterns, which were related to variations in the degree of host specificity at this stage. Our results show that the interaction pattern of fishes with parasites, such as acanthocephalans, cestodes, digeneans and nematodes, is more closely associated with their developmental stage than their phylogenetic history. This finding corroborates the hypothesis that the life history of parasites results in adaptations that cross phylogenetic boundaries.

Developmentally Appropriate Peace Education Curricula

ERIC Educational Resources Information Center

Lewsader, Joellen; Myers-Walls, Judith A.

2017-01-01

Peace education has been offered to children for decades, but those curricula have been only minimally guided by children's developmental stages and needs. In this article, the authors apply their research on children's developmental understanding of peace along with peace education principles and Vygotsky's sociocultural theory to present…

Developmental Kindergarten Program Evaluation Report.

ERIC Educational Resources Information Center

Blois, George T.; Cushing, Katherine S.

The evaluation of the Developmental Kindergarten (DK) Program at the Harrison School District #2, Colorado Springs, Colorado, involved pre- and post-testing of student academic gains and interviewing of principals and teachers. The program aimed to provide developmentally appropriate activities for students believed to be "at risk" of…

Developmental Assets and the Middle School Counselor

ERIC Educational Resources Information Center

Scales, Peter C.

2005-01-01

Search Institute has identified 40 Developmental Assets[TM] that are building blocks of healthy development and success for children and adolescents. Young people's experience of most of these developmental assets declines over the middle school years. In this article, research is described showing the prevalence and impact of developmental assets…

Developmental Milestones in Toddlers with Atypical Development

ERIC Educational Resources Information Center

Horovitz, Max; Matson, Johnny L.

2011-01-01

The attainment of developmental milestones was examined and compared in 162 infants and toddlers with developmental disabilities, including Down Syndrome (n = 26), Cerebral Palsy (n = 19), Global Developmental Delay (n = 22), Premature birth (n = 66), and Seizure Disorder (n = 29). Toddlers in the Seizures Disorder group began crawling at a…

Developmental biology, the stem cell of biological disciplines.

PubMed

Gilbert, Scott F

2017-12-01

Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines." Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, developmental biology remains vigorous, pluripotent, and relatively undifferentiated. In many disciplines, especially in evolutionary biology and oncology, the developmental perspective is being reasserted as an important research program.

Developmental Dyspraxia

MedlinePlus

... disorder may be of average or above average intelligence, they may behave immaturely. × Definition Developmental dyspraxia is ... disorder may be of average or above average intelligence, they may behave immaturely. View Full Definition Treatment ...

Developmental toxicology: adequacy of current methods.

PubMed

Peters, P W

1998-01-01

Toxicology embraces several disciplines such as carcinogenicity, mutagenicity and reproductive toxicity. Reproductive toxicology is concerned with possible effects of substances on the reproductive process, i.e. on sexual organs and their functions, endocrine regulation, fertilization, transport of the fertilized ovum, implantation, and embryonic, fetal and postnatal development, until the end-differentiation of the organs is achieved. Reproductive toxicology is divided into areas related to male and female fertility, and developmental toxicology. Developmental toxicology can be further broken down into prenatal and postnatal toxicology. Today, much new information is available about the origins of developmental disorders resulting from chemical exposure. While these findings seem to promise important new developments in methodology and research, there is a danger of losing sight of the precepts and principles established in the light of existing knowledge. There is also a danger that we may fail to correct shortcomings in our existing procedures and practice. The aim of this presentation is to emphasize the importance of testing substances for their impact in advance of their use and to underline that we must use the best existing tools for carrying out risk assessments. Moreover, it needs to be stressed that there are many substances that are never assessed with respect to reproductive and developmental toxicity. Similarly, our programmes for post-marketing surveillance with respect to developmental toxicology are grossly inadequate. Our ability to identify risks to normal development and reproduction would be much improved, first if a number of straightforward precepts were always followed and second, if we had a clearer understanding of what we mean by risk and acceptable levels of risk in the context of development. Other aims of this paper are: to stress the complexity of the different stages of normal prenatal development; to note the principles that are

Developmental Math: What's the Answer?

ERIC Educational Resources Information Center

Cafarella, Brian

2016-01-01

Developmental mathematics has been under the radar within higher education for some time. The reality is that there are many proven best practices in developmental math. Unfortunately, there are many obstacles that prevent student success. Moreover, the high rates of attrition and failure have led state legislators and college administrators to…

Character: A Multifaceted Developmental System

ERIC Educational Resources Information Center

Nucci, Larry

2017-01-01

Character is a developmental system embedded within the self-system. This Relational Developmental Systems (RDS) view is in juxtaposition with virtue theory and accounts of character in terms of moral identity. The character system includes 4 components 3 of which: basic moral cognition (as described within domain theory); other regarding; and…

Developmental milestones among Aboriginal children in Canada

PubMed Central

Findlay, Leanne; Kohen, Dafna; Miller, Anton

2014-01-01

BACKGROUND: Windows of achievement provide age ranges for the attainment of early developmental skills. Group-specific research is warranted given that development may be influenced by social or cultural factors. OBJECTIVES: To examine developmental milestones for Inuit, Métis and off-reserve First Nation children in Canada, based on developmental domains collected from the 2006 Aboriginal Children’s Survey. Sociodemographic and health predictors of risk for developmental delay were also examined. RESULTS: The ranges in which children achieve certain developmental milestones are presented. Gross motor and self-help skills were found to be achieved earlier (across the three Aboriginal groups), whereas language skills were achieved slightly later than in Canadian children in general. Furthermore, health factors (eg, low birth weight, chronic health conditions) were associated with late achievement of developmental outcomes even when sociodemographic characteristics were considered. CONCLUSIONS: Findings suggest that the timing of milestone achievement may differ for Aboriginal children, highlighting the importance of establishing culturally specific norms and standards rather than relying on those derived from general populations. This information may be useful for practitioners and parents interested in identifying the age ranges for development, as well as age ranges indicating potential for developmental risk and opportunities for early intervention among Aboriginal children. PMID:24855426

Developmental Dyslexia: An Evaluation of a Theory.

ERIC Educational Resources Information Center

Satz, Paul; Van Nostrand, Gary K.

The paper reviews a theory advanced by Satz and Sparrow (1970) which purports to explain the nature and cause of specific developmental dyslexia, and evaluates several developmental hypotheses which are generated bythe theory. The theory postulates that developmental dyslexia is not a unitary syndrome but rather reflects a lag in the maturation of…

29 CFR 1952.222 - Completed developmental steps.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Completed developmental steps. 1952.222 Section 1952.222... Completed developmental steps. (a) In accordance with § 1952.223(b), the Tennessee Occupational Safety and..., as having completed all developmental steps specified in its plan as approved on June 28, 1973, on or...

29 CFR 1952.242 - Completed developmental steps.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Completed developmental steps. 1952.242 Section 1952.242... Completed developmental steps. (a) In accordance with § 1952.243(d) Alaska completed its interim training... completed on or before October 1, 1976, all developmental steps specified in the plan as approved on July 31...

Challenges and opportunities in developmental integrative physiology☆

PubMed Central

Mueller, C.A.; Eme, J.; Burggren, W.W.; Roghair, R.D.; Rundle, S.D.

2015-01-01

This review explores challenges and opportunities in developmental physiology outlined by a symposium at the 2014 American Physiological Society Intersociety Meeting: Comparative Approaches to Grand Challenges in Physiology. Across animal taxa, adverse embryonic/fetal environmental conditions can alter morphological and physiological phenotypes in juveniles or adults, and capacities for developmental plasticity are common phenomena. Human neonates with body sizes at the extremes of perinatal growth are at an increased risk of adult disease, particularly hypertension and cardiovascular disease. There are many rewarding areas of current and future research in comparative developmental physiology. We present key mechanisms, models, and experimental designs that can be used across taxa to investigate patterns in, and implications of, the development of animal phenotypes. Intraspecific variation in the timing of developmental events can be increased through developmental plasticity (heterokairy), and could provide the raw material for selection to produce heterochrony — an evolutionary change in the timing of developmental events. Epigenetics and critical windows research recognizes that in ovo or fetal development represent a vulnerable period in the life history of an animal, when the developing organism may be unable to actively mitigate environmental perturbations. ‘Critical windows’ are periods of susceptibility or vulnerability to environmental or maternal challenges, periods when recovery from challenge is possible, and periods when the phenotype or epigenome has been altered. Developmental plasticity may allow survival in an altered environment, but it also has possible long-term consequences for the animal. “Catch-up growth” in humans after the critical perinatal window has closed elicits adult obesity and exacerbates a programmed hypertensive phenotype (one of many examples of “fetal programing”). Grand challenges for developmental physiology

A comparative review of developmental screening tests.

PubMed

Glascoe, F P; Martin, E D; Humphrey, S

1990-10-01

Public Law 99-457 amends the Education of the Handicapped Act to include services for children from birth through 3 years. Inasmuch as detection and referral of children with developmental delays continues to reside largely with pediatricians and other health care professionals, developmental screening, using standardized tests, is increasingly important. To help physicians select from the array of instruments, 19 different screening tests were administered by a pediatrician and rated by a panel of pediatricians and a special educator. While the panel found few tests that fit within the time constraints of pediatric practice, several tests approached standards for educational and psychologic tests. These included the Battelle Developmental Inventory Screening Test, Infant Monitoring System, Developmental Indicators for Assessment of Learning-Revised, Screening Children for Related Early Educational Needs, and the Developmental Profile II.

Dopaminergic neurotoxicant 6-OHDA induces oxidative damage through proteolytic activation of PKC{delta} in cell culture and animal models of Parkinson's disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latchoumycandane, Calivarathan; Anantharam, Vellareddy; Jin, Huajun

2011-11-15

The neurotoxicant 6-hydroxydopamine (6-OHDA) is used to investigate the cellular and molecular mechanisms underlying selective degeneration of dopaminergic neurons in Parkinson's disease (PD). Oxidative stress and caspase activation contribute to the 6-OHDA-induced apoptotic cell death of dopaminergic neurons. In the present study, we sought to systematically characterize the key downstream signaling molecule involved in 6-OHDA-induced dopaminergic degeneration in cell culture and animal models of PD. Treatment of mesencephalic dopaminergic neuronal N27 cells with 6-OHDA (100 {mu}M) for 24 h significantly reduced mitochondrial activity and increased cytosolic cytochrome c, followed by sequential activation of caspase-9 and caspase-3. Co-treatment with the freemore » radical scavenger MnTBAP (10 {mu}M) significantly attenuated 6-OHDA-induced caspase activities. Interestingly, 6-OHDA induced proteolytic cleavage and activation of protein kinase C delta (PKC{delta}) was completely suppressed by treatment with a caspase-3-specific inhibitor, Z-DEVD-FMK (50 {mu}M). Furthermore, expression of caspase-3 cleavage site-resistant mutant PKC{delta}{sup D327A} and kinase dead PKC{delta}{sup K376R} or siRNA-mediated knockdown of PKC{delta} protected against 6-OHDA-induced neuronal cell death, suggesting that caspase-3-dependent PKC{delta} promotes oxidative stress-induced dopaminergic degeneration. Suppression of PKC{delta} expression by siRNA also effectively protected N27 cells from 6-OHDA-induced apoptotic cell death. PKC{delta} cleavage was also observed in the substantia nigra of 6-OHDA-injected C57 black mice but not in control animals. Viral-mediated delivery of PKC{delta}{sup D327A} protein protected against 6-OHDA-induced PKC{delta} activation in mouse substantia nigra. Collectively, these results strongly suggest that proteolytic activation of PKC{delta} is a key downstream event in dopaminergic degeneration, and these results may have important translational value

Developmental Systems Theory and the Person-Oriented Approach. Commentary on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

ERIC Educational Resources Information Center

Bergman, Lars R.

2015-01-01

Molenaar's (2015) article concerns Developmental Systems Theory (DST) in relation to behavior genetics and he presents implications of DST for empirical research, especially the need for subject-specific studies. In this commentary, the article is discussed from a broader developmental science perspective, particularly regarded through the lens of…

Early developmental trajectories of preterm infants.

PubMed

Yaari, Maya; Mankuta, David; Harel-Gadassi, Ayelet; Friedlander, Edwa; Bar-Oz, Benjamin; Eventov-Friedman, Smadar; Maniv, Nimrod; Zucker, David; Yirmiya, Nurit

2017-11-04

Preterm infants are at risk for neuro-developmental impairments and atypical developmental trajectories. The aims of this study were to delineate early developmental trajectories of preterm and full-term infants. The cognitive, language, and motor development of 149 infants - 19 extremely preterm (EPT), 34 very preterm (VPT), 57 moderately preterm (MPT), and 39 full-term (FT) - was evaluated using Mullen Scales at 1, 4, 8, 12, and 18 months. Mixed models were applied to examine group differences. Gender, maternal education, and neurobehavior were included as predictors of developmental trajectories. The EPT and VPT infants achieved significantly lower scores than the FT infants in all domains, with a significantly increasing gap over time. The MPT infants' trajectories were more favorable than those of the EPT and VPT infants yet lower than the FT infants on the Visual Reception, Gross, and Fine Motor subscales. Male gender and lower maternal education were associated with lower scores that declined over time. Abnormal neonatal neurobehavior was associated lower Mullen scores and with less stability in scores over time. The EPT and VPT infants were found to have disadvantages across all domains. The MPT infants revealed more favorable developmental trajectories yet displayed vulnerability compared to the FT infants. Gender, maternal education, and neonatal neurobehavior are important in predicting the developmental outcomes of preterm infants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toward developmental models of psychiatric disorders in zebrafish

PubMed Central

Norton, William H. J.

2013-01-01

Psychiatric disorders are a diverse set of diseases that affect all aspects of mental function including social interaction, thinking, feeling, and mood. Although psychiatric disorders place a large economic burden on society, the drugs available to treat them are often palliative with variable efficacy and intolerable side-effects. The development of novel drugs has been hindered by a lack of knowledge about the etiology of these diseases. It is thus necessary to further investigate psychiatric disorders using a combination of human molecular genetics, gene-by-environment studies, in vitro pharmacological and biochemistry experiments, animal models, and investigation of the non-biological basis of these diseases, such as environmental effects. Many psychiatric disorders, including autism spectrum disorder, attention-deficit/hyperactivity disorder, mental retardation, and schizophrenia can be triggered by alterations to neural development. The zebrafish is a popular model for developmental biology that is increasingly used to study human disease. Recent work has extended this approach to examine psychiatric disorders as well. However, since psychiatric disorders affect complex mental functions that might be human specific, it is not possible to fully model them in fish. In this review, I will propose that the suitability of zebrafish for developmental studies, and the genetic tools available to manipulate them, provide a powerful model to study the roles of genes that are linked to psychiatric disorders during neural development. The relative speed and ease of conducting experiments in zebrafish can be used to address two areas of future research: the contribution of environmental factors to disease onset, and screening for novel therapeutic compounds. PMID:23637652

Developmental constraints and convergent evolution in Drosophila sex comb formation.

PubMed

Atallah, Joel; Liu, Nana Hou; Dennis, Peter; Hon, Andy; Larsen, Ellen W

2009-01-01

The most complex and diverse secondary sexual character in Drosophila is the sex comb (SC), an arrangement of modified bristles on the forelegs of a subclade of male fruit flies. We examined SC formation in six representative nonmodel fruit fly species, in an effort to understand how the variation in comb patterning arises. We first compared SC development in two species with relatively small combs, Drosophila takahashii, where the SCs remain approximately transverse, and Drosophila biarmipes, where two rows of SC teeth rotate and move in an anterior direction relative to other bristle landmarks. We then analyzed comb ontogeny in species with prominent extended SCs parallel to the proximodistal axis, including Drosophila ficusphila and species of the montium subgroup. Our study allowed us to identify two general methods of generating longitudinal combs on the tarsus, and we showed that a montium subgroup species (Drosophila nikananu) with a comb convergently similar in size, orientation and position to the model organism Drosophila melanogaster, forms its SC through a different developmental mechanism. We also found that the protein product of the leg patterning gene, dachshund (dac), is strongly reduced in the SC in all species, but not in other bristles. Our results suggest that an apparent constraint on SC position in the adult may be attributable to at least two different lineage-specific developmental processes, although external forces could also play a role.

Family Life and Developmental Idealism in Yazd, Iran

PubMed Central

Abbasi-Shavazi, Mohammad Jalal; Askari-Nodoushan, Abbas

2012-01-01

BACKGROUND This paper is motivated by the theory that developmental idealism has been disseminated globally and has become an international force for family and demographic change. Developmental idealism is a set of cultural beliefs and values about development and how development relates to family and demographic behavior. It holds that modern societies are causal forces producing modern families, that modern families help to produce modern societies, and that modern family change is to be expected. OBJECTIVE We examine the extent to which developmental idealism has been disseminated in Iran. We also investigate predictors of the dissemination of developmental idealism. METHODS We use survey data collected in 2007 from a sample of women in Yazd, a city in Iran. We examine the distribution of developmental idealism in the sample and the multivariate predictors of developmental idealism. RESULTS We find considerable support for the expectation that many elements of developmental idealism have been widely disseminated. Statistically significant majorities associate development with particular family attributes, believe that development causes change in families, believe that fertility reductions and age-at-marriage increases help foster development, and perceive family trends in Iran headed toward modernity. As predicted, parental education, respondent education, and income affect adherence to developmental idealism. CONCLUSIONS Developmental idealism has been widely disseminated in Yazd, Iran and is related to social and demographic factors in predicted ways. COMMENTS Although our data come from only one city, we expect that developmental idealism has been widely distributed in Iran, with important implications for family and demographic behavior. PMID:22942772

Developmental Audits with Challenging Youth

ERIC Educational Resources Information Center

Brendtro, Larry K.; du Toit, Lesley; Bath, Howard; Van Bockern, Steve

2006-01-01

The Developmental Audit[R] is a new strength-based assessment model for youth who are in conflict in home, school, or community. Developmental Audits involve collaboration with young persons who are seen as experts on themselves. Discussing challenging life events provides a window to the young person's private logic and goals. The audit scans…

Developmental Sentence Scoring for Japanese

ERIC Educational Resources Information Center

Miyata, Susanne; MacWhinney, Brian; Otomo, Kiyoshi; Sirai, Hidetosi; Oshima-Takane, Yuriko; Hirakawa, Makiko; Shirai, Yasuhiro; Sugiura, Masatoshi; Itoh, Keiko

2013-01-01

This article reports on the development and use of the Developmental Sentence Scoring for Japanese (DSSJ), a new morpho-syntactical measure for Japanese constructed after the model of Lee's English Developmental Sentence Scoring model. Using this measure, the authors calculated DSSJ scores for 84 children divided into six age groups between 2;8…

Toward a Practice-Oriented Approach to Developmental Education Theory: Instructor Worldviews and Beliefs about Developmental Mathematics

ERIC Educational Resources Information Center

Rosen, Karen M.

2010-01-01

The purpose of this exploratory, phenomenological study was to understand developmental mathematics in community college by examining the beliefs and worldviews of developmental mathematics instructors. This study interviewed 11 instructors in 4 demographically different community colleges within a single state with decentralized developmental…

Future Directions in Sleep and Developmental Psychopathology.

PubMed

Meltzer, Lisa J

2017-01-01

It is critical for psychologists to gain a better understanding about the intersection between sleep and developmental psychopathology. However, while many strive to answer the question of whether sleep causes developmental psychopathology, or vice versa, ultimately the relationship between sleep and developmental psychopathology is complex and dynamic. This article considers future directions in the field of clinical child and adolescent psychology that go beyond this mechanistic question, highlighting areas important to address for clinicians and researchers who strive to better understand how best to serve children and adolescents with developmental psychopathology. Questions are presented about what is normal in terms of sleep across development, the role of individual variability in terms of sleep needs and vulnerability to sleep loss, and how sleep may serve as a risk or resilience factor for developmental psychopathology, concluding with considerations for interventions.

Author's Response to Commentaries on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

ERIC Educational Resources Information Center

Molenaar, Peter C. M.

2015-01-01

In this article, Peter Molenaar responds to three commentaries (this issue) on his article, "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics." He addresses aspects of relational developmental systems (RDS) mentioned and questions raised in each of the…

The Role of Protein Radicals in Chronic Neuroimmune Dysfunction and Neuropathology in Response to a Multiple-Hit Model of Gulf War Exposure

DTIC Science & Technology

2014-10-01

potential neurotoxicants and triggers of inflammation, such as persistent peripheral inflammation and the organophosphate pesticide chlorpyrifos (CPF...War Illness Mouse Model, Chlorpyrifos , LPS, NF-KB p50, microglia, chronic neuroinflammation, serum markers, neuropathology 16. SECURITY...neurotoxicants and triggers of inflammation, such as persistent infections, and the organophosphate pesticide chlorpyrifos (CPF) may interact to

Developmental Immunotoxicity

EPA Science Inventory

Animal models suggest that the immature immune system is more susceptible to xenobiotics than the fully mature system, and sequelae of developmental immunotoxicant exposure may be persistent well into adulthood. Immune maturation may be delayed by xenobiotic exposure and recover...

48 CFR 819.7110 - Developmental assistance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS VA Mentor-Protégé Program 819.7110 Developmental assistance. The forms of developmental assistance a mentor can provide to a protégé include, but are not limited...

Adolescent Romantic Relationships: A Developmental Perspective.

ERIC Educational Resources Information Center

Furman, Wyndol; Wehner, Elizabeth A.

1997-01-01

Presents a conceptual and empirical framework for examining the developmental changes that romantic relationships undergo over the course of adolescence. Describes several empirical studies that have examined age differences and delineates an agenda for subsequent developmental work. (JPB)

Multi-scale computational modeling of developmental biology.

PubMed

Setty, Yaki

2012-08-01

Normal development of multicellular organisms is regulated by a highly complex process in which a set of precursor cells proliferate, differentiate and move, forming over time a functioning tissue. To handle their complexity, developmental systems can be studied over distinct scales. The dynamics of each scale is determined by the collective activity of entities at the scale below it. I describe a multi-scale computational approach for modeling developmental systems and detail the methodology through a synthetic example of a developmental system that retains key features of real developmental systems. I discuss the simulation of the system as it emerges from cross-scale and intra-scale interactions and describe how an in silico study can be carried out by modifying these interactions in a way that mimics in vivo experiments. I highlight biological features of the results through a comparison with findings in Caenorhabditis elegans germline development and finally discuss about the applications of the approach in real developmental systems and propose future extensions. The source code of the model of the synthetic developmental system can be found in www.wisdom.weizmann.ac.il/~yaki/MultiScaleModel. yaki.setty@gmail.com Supplementary data are available at Bioinformatics online.

Critical periods of vulnerability for the developing nervous system: evidence from humans and animal models.

PubMed Central

Rice, D; Barone, S

2000-01-01

Vulnerable periods during the development of the nervous system are sensitive to environmental insults because they are dependent on the temporal and regional emergence of critical developmental processes (i.e., proliferation, migration, differentiation, synaptogenesis, myelination, and apoptosis). Evidence from numerous sources demonstrates that neural development extends from the embryonic period through adolescence. In general, the sequence of events is comparable among species, although the time scales are considerably different. Developmental exposure of animals or humans to numerous agents (e.g., X-ray irradiation, methylazoxymethanol, ethanol, lead, methyl mercury, or chlorpyrifos) demonstrates that interference with one or more of these developmental processes can lead to developmental neurotoxicity. Different behavioral domains (e.g., sensory, motor, and various cognitive functions) are subserved by different brain areas. Although there are important differences between the rodent and human brain, analogous structures can be identified. Moreover, the ontogeny of specific behaviors can be used to draw inferences regarding the maturation of specific brain structures or neural circuits in rodents and primates, including humans. Furthermore, various clinical disorders in humans (e.g., schizophrenia, dyslexia, epilepsy, and autism) may also be the result of interference with normal ontogeny of developmental processes in the nervous system. Of critical concern is the possibility that developmental exposure to neurotoxicants may result in an acceleration of age-related decline in function. This concern is compounded by the fact that developmental neurotoxicity that results in small effects can have a profound societal impact when amortized across the entire population and across the life span of humans. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 9 Figure 12 Figure 14 Figure 16 Figure 17 PMID:10852851

Community Report from the Autism and Developmental Disabilities Monitoring (ADDM) Network: Prevalence of Autism Spectrum Disorders (ASDs) among Multiple Areas of the United States in 2008

ERIC Educational Resources Information Center

Centers for Disease Control and Prevention, 2012

2012-01-01

The Centers for Disease Control and Prevention (CDC) estimates that about 1 in 88 children has been identified with an autism spectrum disorder (ASD). CDC's estimate comes from the Autism and Developmental Disabilities Monitoring (ADDM) Network, which monitors the number of 8-year-old children with ASDs living in diverse communities throughout the…

Evolutionary and Developmental Modules

PubMed Central

Lacquaniti, Francesco; Ivanenko, Yuri P.; d’Avella, Andrea; Zelik, Karl E.; Zago, Myrka

2013-01-01

The identification of biological modules at the systems level often follows top-down decomposition of a task goal, or bottom-up decomposition of multidimensional data arrays into basic elements or patterns representing shared features. These approaches traditionally have been applied to mature, fully developed systems. Here we review some results from two other perspectives on modularity, namely the developmental and evolutionary perspective. There is growing evidence that modular units of development were highly preserved and recombined during evolution. We first consider a few examples of modules well identifiable from morphology. Next we consider the more difficult issue of identifying functional developmental modules. We dwell especially on modular control of locomotion to argue that the building blocks used to construct different locomotor behaviors are similar across several animal species, presumably related to ancestral neural networks of command. A recurrent theme from comparative studies is that the developmental addition of new premotor modules underlies the postnatal acquisition and refinement of several different motor behaviors in vertebrates. PMID:23730285

Evolutionary and developmental modules.

PubMed

Lacquaniti, Francesco; Ivanenko, Yuri P; d'Avella, Andrea; Zelik, Karl E; Zago, Myrka

2013-01-01

The identification of biological modules at the systems level often follows top-down decomposition of a task goal, or bottom-up decomposition of multidimensional data arrays into basic elements or patterns representing shared features. These approaches traditionally have been applied to mature, fully developed systems. Here we review some results from two other perspectives on modularity, namely the developmental and evolutionary perspective. There is growing evidence that modular units of development were highly preserved and recombined during evolution. We first consider a few examples of modules well identifiable from morphology. Next we consider the more difficult issue of identifying functional developmental modules. We dwell especially on modular control of locomotion to argue that the building blocks used to construct different locomotor behaviors are similar across several animal species, presumably related to ancestral neural networks of command. A recurrent theme from comparative studies is that the developmental addition of new premotor modules underlies the postnatal acquisition and refinement of several different motor behaviors in vertebrates.

Sexual dysfunction within an adult developmental perspective.

PubMed

Fagan, P J; Meyer, J K; Schmidt, C W

1986-01-01

The focus of this paper is on the adult who has adequately mastered the oedipal stage of psychosexual development and who presents with a sexual dysfunction. Drawing on the developmental sequence of Erik Erikson, the authors suggest that failure to address adequately an adult psychosocial crisis may result in sexual dysfunction. There may be both adult developmental deficits and regression to adolescent and adult stages previously negotiated. Both may be symptomatically represented by sexual dysfunction. The authors urge that the sexual and marital problems be evaluated within an adult developmental framework and that the therapy address the psychosocial issues which are appropriate to the developmental stage of the patient.

Lead exposure delays the differentiation of oligodendroglial progenitors in vitro.

PubMed

Deng, W; McKinnon, R D; Poretz, R D

2001-08-01

Lead (Pb) is an environmental neurotoxicant that can cause hypo- and demyelination. Oligodendrocytes (OLs), the myelin-forming cells in the central nervous system, may be a possible target for Pb toxicity. The present study describes the effect of Pb on the maturation of rat OL progenitor (OP) cells and the developmental expression of myelin-specific galactolipids. Dose-response studies showed that OP cultures were more sensitive to Pb than mature OLs. Pb delayed the differentiation of OL progenitors, as demonstrated by cell morphology and immunostaining with a panel of stage-specific differentiation markers. Pb given prior to and during differentiation caused a decrease in the biosynthesis of galactolipids in both undifferentiated and differentiated OLs, as detected by metabolic radiolabeling with 3H-D-galactose. While the ratios of galacto/gluco-cerebrosides, hydroxy fatty acid/nonhydroxy fatty acid galactolipids, and galactocerebrosides/sulfatides increased in control cultures during cell differentiation, Pb treatment prevented these changes. The results suggest that chronic Pb exposure may impact brain development by interfering with the timely developmental maturation of OL progenitors. Copyright 2001 Academic Press.

METROPOLITAN ATLANTA DEVELOPMENTAL DISABILITIES PROGRAM (MADDSP)

EPA Science Inventory

To address the problem of developmental disabilities among children, CDC, the former Division of Birth Defects and Developmental Disabilities, which was funded by the Agency for Toxic Substances and Disease Registry (ATSDR), and the Georgia Department of Human Resources, initiate...

The Role of Protein Radicals in Chronic Neuroimmune Dysfunction and Neuropathology in Response to a Multiple-Hit Model of Gulf War Exposures

DTIC Science & Technology

2015-10-01

neurotoxicants and triggers of inflammation, such as persistent peripheral inflammation and the organophosphate pesticide chlorpyrifos (CPF) may interact to...Model, Chlorpyrifos , LPS, NF-KB p50, microglia, chronic neuroinflammation, serum markers, neuropathology 16. SECURITY CLASSIFICATION OF: 17...potential neurotoxicants and triggers of inflammation, such as persistent infections, and the organophosphate pesticide chlorpyrifos (CPF) may

Use of drawings in children with pervasive developmental disorder during hospitalization: a developmental perspective.

PubMed

Stefanatou, Athena

2008-12-01

The level and nature of emotional upheaval and relationship to developmental stage was studied in children with pervasive developmental disorder (PDD) hospitalized for head injury. The sample consisted of 25 hospitalized children aged 5-12 years. Children were asked to make the drawing of a ;person in hospital'. The drawings were evaluated by Koppitz's emotional indicators. Punishment and persecution were the main cognitive constructs of children in order to explain hospitalization.

The Zebrafish Models to Explore Genetic and Epigenetic Impacts on Evolutionary Developmental Origins of Aging

PubMed Central

Kishi, Shuji

2014-01-01

Can we reset, reprogram, rejuvenate or reverse the organismal aging process? Certain genetic manipulations could at least reset and reprogram epigenetic dynamics beyond phenotypic plasticity and elasticity in cells, which can be further manipulated into organisms. However, in a whole complex aging organism, how can we rejuvenate intrinsic resources and infrastructures in an intact/noninvasive manner? The incidence of diseases increases exponentially with age, accompanied by progressive deteriorations of physiological functions in organisms. Aging-associated diseases are sporadic but essentially inevitable complications arising from senescence. Senescence is often considered the antithesis of early development, but yet there may be factors and mechanisms in common between these two phenomena to rejuvenate over the dynamic process of aging. The association between early development and late-onset disease with advancing age is thought to come from a consequence of developmental plasticity, the phenomenon by which one genotype can give rise to a range of physiologically and/or morphologically adaptive states based on diverse epigenotypes, in response to intrinsic or extrinsic environmental cues and genetic perturbations. We hypothesized that the future aging process can be predictive based on adaptivity during the early developmental period. Modulating the thresholds and windows of plasticity and its robustness by molecular genetic and chemical epigenetic approaches, we have successfully conducted experiments to isolate zebrafish mutants expressing apparently altered senescence phenotypes during their embryonic and/or larval stages (“embryonic/larval senescence”). Subsequently, at least some of these mutant animals were found to show shortened lifespan, while some others would be expected to live longer in adulthoods. We anticipate that previously uncharacterized developmental genes may mediate the aging process and play a pivotal role in senescence. On the other

Motor Performance and Rhythmic Perception of Children with Intellectual and Developmental Disability and Developmental Coordination Disorder

ERIC Educational Resources Information Center

Kartasidou, Lefkothea; Varsamis, Panagiotis; Sampsonidou, Anna

2012-01-01

Professionals who work with children presenting intellectual and developmental disability (IDD) and developmental coordination disorder (DCD) are concerned with their motor development and their rhythmic perception. The aim of this study is to investigate the correlation between a motor performance test and a music rhythmic test that measures…

48 CFR 519.7012 - Developmental assistance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS GSA Mentor-Protégé Program 519.7012 Developmental assistance. The forms of developmental assistance a mentor can provide to a protégé include: (a) Management... Mentor-Protégé Program Manager. ...

Histories of Developmental Education. CRDEUL Monograph.

ERIC Educational Resources Information Center

Lundell, Dana Britt, Ed.; Higbee, Jeanne L., Ed.

This collection of papers on the history of developmental education includes: "Historical Perspectives: With Hindsight We Gain Foresight" (Normal Stahl); "Supporting the Research Mission" (David V. Taylor); "A Brief History of the American Council of Developmental Education Associations" (Hunter R. Boylan);…

Clumsiness in Children: Developmental Coordination Disorder.

ERIC Educational Resources Information Center

Fox, Mervyn A.

1998-01-01

Explores the diagnostic criteria of developmental coordination disorder, a condition that is characterized by motor awkwardness and has a strong association with psychiatric disorders and learning disabilities. Delineates the nature of developmental coordination disorder and discusses its treatment through occupational therapy and cognitive…

Post-natal myogenic and adipogenic developmental

PubMed Central

Konings, Gonda; van Weeghel, Michel; van den Hoogenhof, Maarten MG; Gijbels, Marion; van Erk, Arie; Schoonderwoerd, Kees; van den Bosch, Bianca; Dahlmans, Vivian; Calis, Chantal; Houten, Sander M; Misteli, Tom

2011-01-01

A-type lamins are a major component of the nuclear lamina. Mutations in the LMNA gene, which encodes the A-type lamins A and C, cause a set of phenotypically diverse diseases collectively called laminopathies. While adult LMNA null mice show various symptoms typically associated with laminopathies, the effect of loss of lamin A/C on early post-natal development is poorly understood. Here we developed a novel LMNA null mouse (LMNAGT−/−) based on genetrap technology and analyzed its early post-natal development. We detect LMNA transcripts in heart, the outflow tract, dorsal aorta, liver and somites during early embryonic development. Loss of A-type lamins results in severe growth retardation and developmental defects of the heart, including impaired myocyte hypertrophy, skeletal muscle hypotrophy, decreased amounts of subcutaneous adipose tissue and impaired ex vivo adipogenic differentiation. These defects cause death at 2 to 3 weeks post partum associated with muscle weakness and metabolic complications, but without the occurrence of dilated cardiomyopathy or an obvious progeroid phenotype. Our results indicate that defective early post-natal development critically contributes to the disease phenotypes in adult laminopathies. PMID:21818413

Mathematical modelling in developmental biology.

PubMed

Vasieva, Olga; Rasolonjanahary, Manan'Iarivo; Vasiev, Bakhtier

2013-06-01

In recent decades, molecular and cellular biology has benefited from numerous fascinating developments in experimental technique, generating an overwhelming amount of data on various biological objects and processes. This, in turn, has led biologists to look for appropriate tools to facilitate systematic analysis of data. Thus, the need for mathematical techniques, which can be used to aid the classification and understanding of this ever-growing body of experimental data, is more profound now than ever before. Mathematical modelling is becoming increasingly integrated into biological studies in general and into developmental biology particularly. This review outlines some achievements of mathematics as applied to developmental biology and demonstrates the mathematical formulation of basic principles driving morphogenesis. We begin by describing a mathematical formalism used to analyse the formation and scaling of morphogen gradients. Then we address a problem of interplay between the dynamics of morphogen gradients and movement of cells, referring to mathematical models of gastrulation in the chick embryo. In the last section, we give an overview of various mathematical models used in the study of the developmental cycle of Dictyostelium discoideum, which is probably the best example of successful mathematical modelling in developmental biology.

Developmental delay

USDA-ARS?s Scientific Manuscript database

Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

DEVELOPMENTAL PALEOBIOLOGY OF THE VERTEBRATE SKELETON.

PubMed

Rücklin, Martin; Donoghue, Philip C J; Cunningham, John A; Marone, Federica; Stampanoni, Marco

2014-07-01

Studies of the development of organisms can reveal crucial information on homology of structures. Developmental data are not peculiar to living organisms, and they are routinely preserved in the mineralized tissues that comprise the vertebrate skeleton, allowing us to obtain direct insight into the developmental evolution of this most formative of vertebrate innovations. The pattern of developmental processes is recorded in fossils as successive stages inferred from the gross morphology of multiple specimens and, more reliably and routinely, through the ontogenetic stages of development seen in the skeletal histology of individuals. Traditional techniques are destructive and restricted to a 2-D plane with the third dimension inferred. Effective non-invasive methods of visualizing paleohistology to reconstruct developmental stages of the skeleton are necessary. In a brief survey of paleohistological techniques we discuss the pros and cons of these methods. The use of tomographic methods to reconstruct development of organs is exemplified by the study of the placoderm dentition. Testing evidence for the presence of teeth in placoderms, the first jawed vertebrates, we compare the methods that have been used. These include inferring the development from morphology, and using serial sectioning, microCT or synchrotron X-ray tomographic microscopy (SRXTM) to reconstruct growth stages and directions of growth. The ensuing developmental interpretations are biased by the methods and degree of inference. The most direct and reliable method is using SRXTM data to trace sclerochronology. The resulting developmental data can be used to resolve homology and test hypotheses on the origin of evolutionary novelties.

Arguments from Developmental Order.

PubMed

Stöckle-Schobel, Richard

2016-01-01

In this article, I investigate a special type of argument regarding the role of development in theorizing about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind - getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories. Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasizing the importance of the early cognitive processes and arguments emphasizing the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive) development, and I will present some topics that also pertain to a full-fledged 'philosophy of development.'

Manganese inhibits the ability of astrocytes to promote neuronal differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giordano, Gennaro; Pizzurro, Daniella; VanDeMark, Kathryn

Manganese (Mn) is a known neurotoxicant and developmental neurotoxicant. As Mn has been shown to accumulate in astrocytes, we sought to investigate whether Mn would alter astrocyte-neuronal interactions, specifically the ability of astrocytes to promote differentiation of neurons. We found that exposure of rat cortical astrocytes to Mn (50-500 {mu}M) impaired their ability to promote axonal and neurite outgrowth in hippocampal neurons. This effect of Mn appeared to be mediated by oxidative stress, as it was reversed by antioxidants (melatonin and PBN) and by increasing glutathione levels, while it was potentiated by glutathione depletion in astrocytes. As the extracellular matrixmore » protein fibronectin plays an important role in astrocyte-mediated neuronal neurite outgrowth, we also investigated the effect of Mn on fibronectin. Mn caused a concentration-dependent decrease of fibronectin protein and mRNA in astrocytes lysate and of fibronectin protein in astrocyte medium; these effects were also antagonized by antioxidants. Exposure of astrocytes to two oxidants, H{sub 2}O{sub 2} and DMNQ, similarly impaired their neuritogenic action, and led to a decreased expression of fibronectin. Mn had no inhibitory effect on neurite outgrowth when applied directly onto hippocampal neurons, where it actually caused a small increase in neuritogenesis. These results indicate that Mn, by targeting astrocytes, affects their ability to promote neuronal differentiation by a mechanism which is likely to involve oxidative stress.« less

47 CFR 87.37 - Developmental license.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Developmental license. 87.37 Section 87.37 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AVIATION SERVICES Applications and Licenses § 87.37 Developmental license. This section contains rules about the licensing of...

Student Success in Developmental Mathematics Courses

ERIC Educational Resources Information Center

Zientek, Linda Reichwein; Yetkiner Ozel, Z. Ebrar; Fong, Carlton J.; Griffin, Mel

2013-01-01

Mathematics is a particular stumbling block for community college students in developmental course work. The present study empirically investigated student-level and teacher-level factors that influence the success of community college students enrolled in developmental mathematics courses. Specifically, numerous variables in one statistical model…

47 CFR 87.37 - Developmental license.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Developmental license. 87.37 Section 87.37 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AVIATION SERVICES Applications and Licenses § 87.37 Developmental license. This section contains rules about the licensing of...

47 CFR 87.37 - Developmental license.

Code of Federal Regulations, 2012 CFR

2012-10-01

... understanding. The showing must be signed by the applicant. (c) Assignable frequencies. Developmental stations may be authorized to use frequencies available for the service and class of station proposed. The number of frequencies assigned will depend upon the specific requirements of the developmental program...

The Comet Cometh: Evolving Developmental Systems.

PubMed

Jaeger, Johannes; Laubichler, Manfred; Callebaut, Werner

In a recent opinion piece, Denis Duboule has claimed that the increasing shift towards systems biology is driving evolutionary and developmental biology apart, and that a true reunification of these two disciplines within the framework of evolutionary developmental biology (EvoDevo) may easily take another 100 years. He identifies methodological, epistemological, and social differences as causes for this supposed separation. Our article provides a contrasting view. We argue that Duboule's prediction is based on a one-sided understanding of systems biology as a science that is only interested in functional, not evolutionary, aspects of biological processes. Instead, we propose a research program for an evolutionary systems biology, which is based on local exploration of the configuration space in evolving developmental systems. We call this approach-which is based on reverse engineering, simulation, and mathematical analysis-the natural history of configuration space. We discuss a number of illustrative examples that demonstrate the past success of local exploration, as opposed to global mapping, in different biological contexts. We argue that this pragmatic mode of inquiry can be extended and applied to the mathematical analysis of the developmental repertoire and evolutionary potential of evolving developmental mechanisms and that evolutionary systems biology so conceived provides a pragmatic epistemological framework for the EvoDevo synthesis.

Replication and robustness in developmental research.

PubMed

Duncan, Greg J; Engel, Mimi; Claessens, Amy; Dowsett, Chantelle J

2014-11-01

Replications and robustness checks are key elements of the scientific method and a staple in many disciplines. However, leading journals in developmental psychology rarely include explicit replications of prior research conducted by different investigators, and few require authors to establish in their articles or online appendices that their key results are robust across estimation methods, data sets, and demographic subgroups. This article makes the case for prioritizing both explicit replications and, especially, within-study robustness checks in developmental psychology. It provides evidence on variation in effect sizes in developmental studies and documents strikingly different replication and robustness-checking practices in a sample of journals in developmental psychology and a sister behavioral science-applied economics. Our goal is not to show that any one behavioral science has a monopoly on best practices, but rather to show how journals from a related discipline address vital concerns of replication and generalizability shared by all social and behavioral sciences. We provide recommendations for promoting graduate training in replication and robustness-checking methods and for editorial policies that encourage these practices. Although some of our recommendations may shift the form and substance of developmental research articles, we argue that they would generate considerable scientific benefits for the field. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Cross-Modal Binding in Developmental Dyslexia

ERIC Educational Resources Information Center

Jones, Manon W.; Branigan, Holly P.; Parra, Mario A.; Logie, Robert H.

2013-01-01

The ability to learn visual-phonological associations is a unique predictor of word reading, and individuals with developmental dyslexia show impaired ability in learning these associations. In this study, we compared developmentally dyslexic and nondyslexic adults on their ability to form cross-modal associations (or "bindings") based…

Introducing Newspapers in Developmental Reading Classes

ERIC Educational Resources Information Center

Karstadt, Roberta; Rey, Victoria M.

2009-01-01

Newspapers are an effective educational and motivational tool in developmental reading classes. However, many students are unfamiliar with newspapers and read them infrequently. In order to foster newspaper reading and familiarize the college freshmen enrolled in their developmental reading classes with newspapers, the writers of this article…

Evaluation Theory for Developmental Mathematics Practitioners

ERIC Educational Resources Information Center

Duranczyk, Irene Mary

2007-01-01

This article is designed to present an overview of critical theory, research, and evaluation for the developmental mathematics educator. Students caught in the gap between high school mathematics preparation and entry-level college mathematics expectations--developmental mathematics education students--need to have their personal narratives told…

29 CFR 1902.33 - Developmental period.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... consideration of developmental changes by OSHA. Generally, whenever a State completes a developmental step, it must submit the resulting plan change as a supplement to its plan to OSHA for approval. OSHA's approval...

29 CFR 1902.33 - Developmental period.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... consideration of developmental changes by OSHA. Generally, whenever a State completes a developmental step, it must submit the resulting plan change as a supplement to its plan to OSHA for approval. OSHA's approval...

Developmental analysis of the dopamine-containing neurons of the Drosophila brain

PubMed Central

Hartenstein, Volker; Cruz, Louie; Lovick, Jennifer K.; Guo, Ming

2016-01-01

The Drosophila dopaminergic (DA) system consists of a relatively small number of neurons clustered throughout the brain and ventral nerve cord. Previous work shows that clusters of DA neurons innervate different brain compartments, which in part accounts for functional diversity of the DA system. In this paper, we analyzed the association between DA neuron clusters and specific brain lineages, developmental and structural units of the Drosophila brain which provide a framework of connections that can be followed throughout development. The hatching larval brain contains six groups of primary DA neurons (born in the embryo), which we assign to six distinct lineages. We can show that all larval DA clusters persist into the adult brain. Some clusters increase in cell number during late larval stages while others do not become DA-positive until early pupa. Ablating neuroblasts with hydroxyurea (HU) prior to onset of larval proliferation (generates secondary neurons) confirms these added DA clusters are primary neurons born in the embryo, rather than secondary neurons. A single cluster that becomes DA-positive in the late pupa, PAM1/lineage DALcm1/2, forms part of a secondary lineage which can be ablated by larval HU application. By supplying lineage information for each DA cluster, our analysis promotes further developmental and functional analyses of this important system of neurons. PMID:27350102

Developmental Neurotoxicology: History and Outline of ...

EPA Pesticide Factsheets

The present work provides a brief review of basic concepts in developmental neurotoxicology, as well as current representative testing guidelines for evaluating developmental neurotoxicity (DNT) of xenobiotics. Historically, DNT was initially recognized as a “functional” teratogenicity: the main concern was that prenatal and/or early postnatal exposures to chemicals during critical periods of central nervous system (CNS) development would cause later functional abnormalities of the brain. Current internationally harmonized DNT study guidelines are thus intended to predict adverse effects of test compounds on the developing CNS by observing such postnatal parameters as motor activity, startle response, and learning and memory, as well as neropathological alterations. The reliability of current DNT study guidelines and sensitivity of testing methodologies recommended in these guidelines have been confirmed by retrospective evaluations of the many international and domestic collaborative validation studies in developed nations including Japan. Invited review with brief review of basic concepts in developmental neurotoxicology, as well as current representative testing guidelines for evaluating developmental neurotoxicity (DNT) of xenobiotics.

Demographic history, selection and functional diversity of the canine genome.

PubMed

Ostrander, Elaine A; Wayne, Robert K; Freedman, Adam H; Davis, Brian W

2017-12-01

The domestic dog represents one of the most dramatic long-term evolutionary experiments undertaken by humans. From a large wolf-like progenitor, unparalleled diversity in phenotype and behaviour has developed in dogs, providing a model for understanding the developmental and genomic mechanisms of diversification. We discuss pattern and process in domestication, beginning with general findings about early domestication and problems in documenting selection at the genomic level. Furthermore, we summarize genotype-phenotype studies based first on single nucleotide polymorphism (SNP) genotyping and then with whole-genome data and show how an understanding of evolution informs topics as different as human history, adaptive and deleterious variation, morphological development, ageing, cancer and behaviour.

Diversity of Entomopathogenic Fungi: Which Groups Conquered the Insect Body?

PubMed

Araújo, J P M; Hughes, D P

2016-01-01

The entomopathogenic fungi are organisms that evolved to exploit insects. They comprise a wide range of morphologically, phylogenetically, and ecologically diverse fungal species. Entomopathogenic fungi can be found distributed among five of the eight fungal phyla. Entomopathogens are also present among the ecologically similar but phylogenetically distinct Oomycota or water molds, which belong to a different kingdom, the Stramenopila. As a group of parasites, the entomopathogenic fungi and water molds infect a wide range of insect hosts, from aquatic larvae to adult insects from high canopies in tropical forests or even deserts. Their hosts are spread among 20 of the 31 orders of insects, in all developmental stages: eggs, larvae, pupae, nymphs, and adults. Such assortment of niches has resulted in these parasites evolving a considerable morphological diversity, resulting in enormous biodiversity, the majority of which remains unknown. Here we undertake a comprehensive survey of records of these entomopathogens in order to compare and contrast both their morphologies and their ecological traits. Our findings highlight a wide range of adaptations that evolved following the evolutionary transition by the fungi and water molds to infect the most diverse and widespread animals on Earth, the insects. Copyright © 2016 Elsevier Inc. All rights reserved.

[Theoretical Development and Research Trends in Developmental Care].

PubMed

Wang, Yu-Wen; Chang, Ying-Ju

2015-10-01

The Newborn Individualized Developmental Care and Assessment Program (NIDCAP), based on the Synactive Theory, is applied to improve brain development in premature and illness infants within a supportive environment. The NIDCAP has been used widely in the clinical setting. The aim of this article was to systematically review research published between 2000 and 2013 that relates to the evidence and application of developmental care. Most studies support the effectiveness of developmental care in terms of facilitating the healthy growth of premature infants, reducing oxygen dependence, reducing hospitalization times, and improving neurodevelopmental outcomes at two years of age. However, research results related to the effects of developmental care on neurodevelopmental outcomes from 2 years old to school age are not consistent. The heterogeneity of interventions, outcome indicators, and measurements in studies may contribute to these mixed results. In addition, as developmental care has been applied for many years, the contamination of participants in the supportive environment should be considered. Based on current evidence, neonatal healthcare professionals must recognize the core value of developmental care in dealing with premature infants and their families. In order to provide effective interventions for infants, further research is needed to assess the comparative effects of the single intervention and the holistic approach in developmental care.

Unraveling the Miswired Connectome: A Developmental Perspective

PubMed Central

Di Martino, Adriana; Fair, Damien A.; Kelly, Clare; Satterthwaite, Theodore D.; Castellanos, F. Xavier; Thomason, Moriah E.; Craddock, R. Cameron; Luna, Beatriz; Leventhal, Bennett L.; Zuo, Xi-Nian; Milham, Michael P.

2014-01-01

Summary The vast majority of mental illnesses can be conceptualized as developmental disorders of neural interactions within the connectome, or developmental miswiring. The recent maturation of pediatric in vivo brain imaging is bringing within reach the identification of clinically meaningful brain-based biomarkers of developmental disorders. Even more auspicious, is the ability to study the evolving connectome throughout life, beginning in utero, which promises to move the field from topological phenomenology to etiological nosology. Here, we scope advances in pediatric imaging of the brain connectome as the field faces the challenge of unraveling developmental miswiring. We highlight promises while also providing a pragmatic review of the many obstacles ahead that must be overcome to significantly impact public health. PMID:25233316

Predicting Success of Developmental Math Students

ERIC Educational Resources Information Center

Martinez, Isaac

2017-01-01

Addressing the needs of developmental math students has been one of the most challenging problems in higher education. Administrators at a private university were concerned about poor academic performance of math-deficient students and sought to identify factors that influenced students' successful progression from developmental to college-level…

Using Popular Culture in Developmental Writing

ERIC Educational Resources Information Center

Barnes, Sharon L.

2006-01-01

Using popular culture in my developmental writing course has prompted me to reconsider what it means to create successful developmental writing assignments. Having slipped into the questionable habit of assuming that removing complexity makes an assignment appropriate for developing writers, I pared down a fairly open-ended "media…

Developmental Regression in Autism Spectrum Disorders

ERIC Educational Resources Information Center

Rogers, Sally J.

2004-01-01

The occurrence of developmental regression in autism is one of the more puzzling features of this disorder. Although several studies have documented the validity of parental reports of regression using home videos, accumulating data suggest that most children who demonstrate regression also demonstrated previous, subtle, developmental differences.…

Multiculturalism in Developmental Education. CRDEUL Monograph.

ERIC Educational Resources Information Center

Higbee, Jeanne L., Ed.; Lundell, Dana Britt, Ed.; Duranczyk, Irene M., Ed.

This collection of papers is intended to help make connections between multicultural education and developmental education. The papers include an introduction by Jeanne L. Higbee and: "The Centrality of Multiculturalism in Developmental Education" (Karen L. Miksch, Patrick L. Bruch, Jeanne L. Higbee, Rashne R. Jehangir, and Data Britt…

Neonicotinoid pesticides can reduce honeybee colony genetic diversity

PubMed Central

Troxler, Aline; Retschnig, Gina; Gauthier, Laurent; Straub, Lars; Moritz, Robin F. A.; Neumann, Peter; Williams, Geoffrey R.

2017-01-01

Neonicotinoid insecticides can cause a variety of adverse sub-lethal effects in bees. In social species such as the honeybee, Apis mellifera, queens are essential for reproduction and colony functioning. Therefore, any negative effect of these agricultural chemicals on the mating success of queens may have serious consequences for the fitness of the entire colony. Queens were exposed to the common neonicotinoid pesticides thiamethoxam and clothianidin during their developmental stage. After mating, their spermathecae were dissected to count the number of stored spermatozoa. Furthermore, their worker offspring were genotyped with DNA microsatellites to determine the number of matings and the genotypic composition of the colony. Colonies providing the male mating partners were also inferred. Both neonicotinoid and control queens mated with drones originating from the same drone source colonies, and stored similar number of spermatozoa. However, queens reared in colonies exposed to both neonicotinoids experienced fewer matings. This resulted in a reduction of the genetic diversity in their colonies (i.e. higher intracolonial relatedness). As decreased genetic diversity among worker bees is known to negatively affect colony vitality, neonicotinoids may have a cryptic effect on colony health by reducing the mating frequency of queens. PMID:29059234

Where Do Epigenetics and Developmental Origins Take the Field of Developmental Psychopathology?

PubMed

Nigg, Joel T

2016-04-01

The time is ripe for upgrading or rethinking the assumed paradigms for how we study developmental psychopathology. The classic transactional models appear robust but need specification in terms of biological and psychosocial processes. That specification is increasingly tractable due to developments in genetics, epigenetics, the measurement of psychosocial processes, and theory and data on developmental origins of health and disease. This essay offers a high-level view of where the field has been and where it may be going in regard to nosology and conceptions of etiology. Remarks seek to consider rapidly evolving contexts not only for children, but also for the science itself due to progress in our field and in neighboring fields. Illustrations are provided as to how syndromal nosology can be enriched and advanced by careful integration with biologically relevant behavioral dimensions and application of quantitative methods. It is concluded that a revised, forward-looking, transactional model of abnormal child psychology will incorporate prenatal and postnatal developmental programming, epigenetic mechanisms and their associated genotype x environment interactions, and inflammatory processes as a potential common mediator influencing numerous health and mental health conditions.

Value of parents' estimates of children's developmental ages.

PubMed

Glascoe, F P; Sandler, H

1995-11-01

To determine whether parents' estimates of children's developmental ages can function as a prescreening technique. Parents of 234 children from birth to 77 months of age seeking well-child care in pediatric offices were queried in two separate studies. In the first study, parents were asked to give an estimate of their child's overall developmental age and, in the second study, to estimate ages in each of six developmental domains. Children were administered a range of screening measures of intelligence, speech-language, and adoptive behavior. The overall age-estimate, if less than chronologic age, was 75% sensitive to likely developmental problems and, if equal to or greater than chronologic age, was 90% specific in identifying children likely to have typical development. Age estimates for each developmental domain were 81% sensitive to likely developmental problems if less than chronologic age in the domains of fine motor, language, grass motor, or behavior, and 62% specific if equal to or greater than chronologic age. Estimates at or below chronologic age in receptive language or personal-social domains were 90% sensitive and 43% specific in identifying likely behavior problems. There were no differences in the accuracy of parents estimates on the basis of children's age, gender, race, parents' level of education, or parenting experience. Parents' overall age-estimates provided a sensitive and specific indicator of global developmental status, but insufficient information about strengths and weaknesses to enable focused referrals for services. In contrast, discrete patterns of age estimates in each developmental domain sensitively discriminated children with developmental versus behavioral problems, although specificity was limited. Age estimates appear to be a potentially helpful method for identifying a subset of children in need of thorough screening, although further research is needed on a larger sample given diagnostic rather than screening tests.

A Comparison of Motor Delays in Young Children: Autism Spectrum Disorder, Developmental Delay, and Developmental Concerns

ERIC Educational Resources Information Center

Provost, Beth; Lopez, Brian R.; Heimerl, Sandra

2007-01-01

This study assessed motor delay in young children 21-41 months of age with autism spectrum disorder (ASD), and compared motor scores in children with ASD to those of children without ASD. Fifty-six children (42 boys, 14 girls) were in three groups: children with ASD, children with developmental delay (DD), and children with developmental concerns…

Sequential evolution of bacterial morphology by co-option of a developmental regulator.

PubMed

Jiang, Chao; Brown, Pamela J B; Ducret, Adrien; Brun, Yves V

2014-02-27

What mechanisms underlie the transitions responsible for the diverse shapes observed in the living world? Although bacteria exhibit a myriad of morphologies, the mechanisms responsible for the evolution of bacterial cell shape are not understood. We investigated morphological diversity in a group of bacteria that synthesize an appendage-like extension of the cell envelope called the stalk. The location and number of stalks varies among species, as exemplified by three distinct subcellular positions of stalks within a rod-shaped cell body: polar in the genus Caulobacter and subpolar or bilateral in the genus Asticcacaulis. Here we show that a developmental regulator of Caulobacter crescentus, SpmX, is co-opted in the genus Asticcacaulis to specify stalk synthesis either at the subpolar or bilateral positions. We also show that stepwise evolution of a specific region of SpmX led to the gain of a new function and localization of this protein, which drove the sequential transition in stalk positioning. Our results indicate that changes in protein function, co-option and modularity are key elements in the evolution of bacterial morphology. Therefore, similar evolutionary principles of morphological transitions apply to both single-celled prokaryotes and multicellular eukaryotes.

Project Developmental Continuity: Field Procedures Manual.

ERIC Educational Resources Information Center

Morris, Mary

This operations manual for field staff (site monitors, site coordinators, and testers) involved in the observation and testing of children is part of a series of documents on the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's…

Developmental Perspectives on the Social Studies.

ERIC Educational Resources Information Center

Rosenzweig, Linda W., Ed.

This bulletin provides an overview of developmental theory and practice in relation to social studies instruction in K-12 curriculum. In the first of eight chapters developmental theories pertaining to teaching and learning social studies are presented. The theories of Erik Erikson, Jane Loevinger, Jean Piaget, Lawrence Kohlberg, and Robert Selman…

Developmental Planning: An Introduction for Parents

ERIC Educational Resources Information Center

Noland, Jim

2009-01-01

"Developmental Planning" is the thinking process of using developmental milestones as a general basis for planning and predicting needs for the child within the early years. It considers the time frames associated with normal development across all facets of the child's development. The areas include bone and joint development, movement, sensory…

Games and Simulations in Developmental Education.

ERIC Educational Resources Information Center

Clavner, Jerry B.

Developmental education activities should attempt to provide experiences which do not hold the student back from the normal flow of learning and which utilize processes already in the student's repertoire. Virtually all areas of developmental instruction can be supplemented with games and simulations, that is, activities designed to show the…

Developmental dyscalculia: a dysconnection syndrome?

PubMed

Kucian, Karin; Ashkenazi, Simone Schwizer; Hänggi, Jürgen; Rotzer, Stephanie; Jäncke, Lutz; Martin, Ernst; von Aster, Michael

2014-09-01

Numerical understanding is important for everyday life. For children with developmental dyscalculia (DD), numbers and magnitudes present profound problems which are thought to be based upon neuronal impairments of key regions for numerical understanding. The aim of the present study was to investigate possible differences in white matter fibre integrity between children with DD and controls using diffusion tensor imaging. White matter integrity and behavioural measures were evaluated in 15 children with developmental dyscalculia aged around 10 years and 15 matched controls. The main finding, obtained by a whole brain group comparison, revealed reduced fractional anisotropy in the superior longitudinal fasciculus in children with developmental dyscalculia. In addition, a region of interest analysis exhibited prominent deficits in fibres of the superior longitudinal fasciculus adjacent to the intraparietal sulcus, which is thought to be the core region for number processing. To conclude, our results outline deficient fibre projection between parietal, temporal and frontal regions in children with developmental dyscalculia, and therefore raise the question of whether dyscalculia can be seen as a dysconnection syndrome. Since the superior longitudinal fasciculus is involved in the integration and control of distributed brain processes, the present results highlight the importance of considering broader domain-general mechanisms in the diagnosis and therapy of dyscalculia.

Developmental trends in adaptive memory.

PubMed

Otgaar, Henry; Howe, Mark L; Smeets, Tom; Garner, Sarah R

2014-01-01

Recent studies have revealed that memory is enhanced when information is processed for fitness-related purposes. The main objective of the current experiments was to test developmental trends in the evolutionary foundation of memory using different types of stimuli and paradigms. In Experiment 1, 11-year-olds and adults were presented with neutral, negative, and survival-related DRM word lists. We found a memory benefit for the survival-related words and showed that false memories were more likely to be elicited for the survival-related word lists than for the other lists. Experiment 2 examined developmental trends in the survival processing paradigm using neutral, negative, and survival-related pictures. A survival processing advantage was found for survival-related pictures in adults, for negative pictures in 11/12-year-olds, and for neutral pictures in 7/8-year-olds. In Experiment 3, 11/12-year-olds and adults had to imagine the standard survival scenario or an adapted survival condition (or pleasantness condition) that was designed to reduce the possibilities for elaborative processing. We found superior memory retention for both survival scenarios in children and adults. Collectively, our results evidently show that the survival processing advantage is developmentally invariant and that certain proximate mechanisms (elaboration and distinctiveness) underlie these developmental trends.

Children with developmental and behavioural concerns in Singapore.

PubMed

Lian, Wee Bin; Ho, Selina Kah Ying; Choo, Sylvia Hean Tean; Shah, Varsha Atul; Chan, Daisy Kwai Lin; Yeo, Cheo Lian; Ho, Lai Yun

2012-07-01

Childhood developmental and behavioural disorders (CDABD) have been increasingly recognised in recent years. This study evaluated the profiles and outcomes of children referred for developmental and behavioural concerns to a tertiary child developmental centre in Singapore. This is the first such regional database. Baseline information, obtained through a questionnaire, together with history at first consultation, provided information for referral, demographic and presentation profiles. Clinical formulations were then made. Definitive developmental and medical diagnoses, as well as outcomes based on clinical assessment and standardised testing, were recorded at one year post first consultation. Out of 1,304 referrals between January 1, 2003 and December 1, 2004, 45% were 2-4 years old and 74% were boys. The waiting time from referral to first consultation exceeded four months in 52% of children. Following clinical evaluation, 7% were found to be developmentally appropriate. The single most common presenting concern was speech and language (S&L) delay (29%). The most common clinical developmental diagnosis was autism spectrum disorder (ASD) (30%), followed by isolated S&L disorder, global developmental delay (GDD) and cognitive impairment (CI). Recommendations included S&L therapy (57%), occupational therapy (50%) and psychological/behavioural services (40%). At one year, ASD remained the most common definitive developmental diagnosis (31%), followed by S&L disorder, CI and GDD. Most were children with high-prevalence, low-moderate severity disorders who could potentially achieve fair-good prognosis with early intervention. Better appreciation of the profile and outcome of children with CDABD in Singapore could enable better resource planning for diagnosis and intervention.

Developmental trend of children with Down's syndrome - How do sex and neonatal conditions influence their developmental patterns?

PubMed

Aoki, Sayaka; Yamauchi, Yuko; Hashimoto, Keiji

2018-03-01

This study investigated factors that would influence developmental trend of children with Down's syndrome (DS) in three different domains (motor, cognitive, language), specifically focusing on the effect of sex and neonatal conditions, including preterm birth, low birth weight, and congenital heart disease (CHD). The participants were 158 children with DS (mean age at the initial test = 25.5 months) receiving clinical service at a rehabilitation center in Yokohama, Japan. Kyoto Scale of Psychological Development was used to measure developmental level, which derive total developmental age (DA), Posture-motor DA, Cognitive-adaptive DA, and Language-social DA. For the analyses, a multilevel model for change was adopted, as the model allowed us to investigate intrapersonal growth and the between-personal factors that are associated with individual differences in the pattern of growth. The developmental speed of children with DS was found to be slower than that of typical children in all the three developmental domains assessed (i.e., the estimated coefficient of the slope for chronological age on DA was less than 1). DS Girls developed significantly faster than boys in non-verbal cognitive and language abilities. Low birth weight and CHD had a significant negative impact on development of non-verbal cognitive abilities for boys, but had a somewhat positive effect for girls. As was shown in previous studies, the result of this study indicated that the children with DS develop slower than non-disabled children. Low birth weight and CHD were found to influence developmental trend of children with DS, differently for boys and girls. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Virtual Tissue Models in Developmental Toxicity Research

EPA Science Inventory

Prenatal exposure to drugs and chemicals may perturb, directly or indirectly, core developmental processes in the embryo (patterning, morphogenesis, proliferation and apoptosis, and cell differentiation), leading to adverse developmental outcomes. Because embryogenesis entails a...

Common features in diverse insect clocks.

PubMed

Numata, Hideharu; Miyazaki, Yosuke; Ikeno, Tomoko

2015-01-01

This review describes common features among diverse biological clocks in insects, including circadian, circatidal, circalunar/circasemilunar, and circannual clocks. These clocks control various behaviors, physiological functions, and developmental events, enabling adaptation to periodic environmental changes. Circadian clocks also function in time-compensation for celestial navigation and in the measurement of day or night length for photoperiodism. Phase response curves for such clocks reported thus far exhibit close similarities; specifically, the circannual clock in Anthrenus verbasci shows striking similarity to circadian clocks in its phase response. It is suggested that diverse biological clocks share physiological properties in their phase responses irrespective of period length. Molecular and physiological mechanisms are best understood for the optic-lobe and mid-brain circadian clocks, although there is no direct evidence that these clocks are involved in rhythmic phenomena other than circadian rhythms in daily events. Circadian clocks have also been localized in peripheral tissues, and research on their role in various rhythmic phenomena has been started. Although clock genes have been identified as controllers of circadian rhythms in daily events, some of these genes have also been shown to be involved in photoperiodism and possibly in time-compensated celestial navigation. In contrast, there is no experimental evidence indicating that any known clock gene is involved in biological clocks other than circadian clocks.

Developmentally Appropriate Gardening for Young Children.

ERIC Educational Resources Information Center

Stoecklin, Vicki L.

Noting that the recent interest in gardening with young children has resulted in a variety of programs but little support to teachers or horticulturists on how to understand the developmental needs of children and how to adapt gardening activities to those needs, this paper presents principles and goals of developmentally appropriate gardening.…

Developmental plasticity in schistosomes and other helminths

PubMed Central

Davies, Stephen J.; McKerrow, James H.

2010-01-01

Developmental plasticity in helminth life cycles serves, in most cases, to increase the probability of transmission between hosts, suggesting that the necessity to achieve transmission is a prominent selective pressure in the evolution of this phenomenon. Some evidence suggests that digenean trematodes from the genus Schistosoma are also capable of limited developmental responses to host factors. Here we review the currently available data on this phenomenon and attempt to draw comparisons with similar processes in the life cycles of other helminths. At present the biological significance of developmental responses by schistosomes under laboratory conditions remains unclear. Further work is needed to determine whether developmental plasticity plays any role in increasing the probability of schistosome transmission and life cycle propagation under adverse conditions, as it does in other helminth life cycles. PMID:13678642

Psychosocially influenced cancer: diverse early-life stress experiences and links to breast cancer.

PubMed

Schuler, Linda A; Auger, Anthony P

2010-11-01

This perspective on Boyd et al. (beginning on page 1398 in this issue of the journal) discusses recent published research examining the interplay between social stress and breast cancer. Cross-disciplinary studies using genetically defined mouse models and established neonatal and peripubertal paradigms of social stress are illuminating biological programming by diverse early-life experiences for the risk of breast cancer. Understanding the mechanisms underlying this programming can lead to the identification of risk factors and sensitive developmental windows, enabling improved prevention and treatment strategies for this devastating disease. ©2010 AACR.

Sniffing on microbes: diverse roles of microbial volatile organic compounds in plant health.

PubMed

Bitas, Vasileios; Kim, Hye-Seon; Bennett, Joan W; Kang, Seogchan

2013-08-01

Secreted proteins and metabolites play diverse and critical roles in organismal and organism-environment interactions. Volatile organic compounds (VOC) can travel far from the point of production through the atmosphere, porous soils, and liquid, making them ideal info-chemicals for mediating both short- and long-distance intercellular and organismal interactions. Critical ecological roles for animal- and plant-derived VOC in directing animal behaviors and for VOC as a language for plant-to-plant communication and regulators of various physiological processes have been well documented. Similarly, microbial VOC appear to be involved in antagonism, mutualism, intra- and interspecies regulation of cellular and developmental processes, and modification of their surrounding environments. However, the available knowledge of how microbial VOC affect other organisms is very limited. Evidence supporting diverse roles of microbial VOC with the focus on their impact on plant health is reviewed here. Given the vast diversity of microbes in nature and the critical importance of microbial communities associated with plants for their ecology and fitness, systematic exploration of microbial VOC and characterization of their biological functions and ecological roles will likely uncover novel mechanisms for controlling diverse biological processes critical to plant health and will also offer tangible practical benefits in addressing agricultural and environmental problems.

[Developmental disorders in adulthood: concept, differential diagnosis, and treatment].

PubMed

Honda, Hideo

2014-01-01

The number of cases diagnosed with developmental disorders is rapidly increasing among those consulting psychiatry clinics for the first time in their adulthood. The author presents the concept of developmental disorders, discusses how they can be differentiated from other psychiatric disorders, and proposes some treatments. From now on, all psychiatrists should know the difference between developmental disorders and other psychiatric disorders, and diagnose them multi-axially, including the dimension of development. They should always keep in mind how developmental disorders lead to difficulties in everyday life, and treat developmental disorders in conjunction with adequate environmental modifications along with the treatment of other comorbid psychiatric disorders.

Toward an Intersectional Approach in Developmental Science: The Role of Race, Gender, Sexual Orientation, and Immigrant Status.

PubMed

Ghavami, Negin; Katsiaficas, Dalal; Rogers, Leoandra Onnie

2016-01-01

Developmental theory and research have often focused on a single social identity category, for example, race or sexual orientation, and examined the consequences of that category on life outcomes. Yet intersectional models of social disadvantage (eg, Cole, 2009; Crenshaw, 1995; King, 1988) suggest that social categories combine to shape the experiences and life outcomes of individuals across life domains. In this chapter, we review empirical research that offers insight into the intersectionality of social identities across three critical developmental periods, namely, middle childhood, adolescence, and emerging adulthood. We also consider the consequences of intersecting identities across several life domains, including intergroup relations and political and civic engagement. Recognizing that the body of work on social identities is expansive, we focus our review on race/ethnicity, gender, sexual orientation, and immigrant status. In each developmental stage, we discuss what we know, drawing from the limited empirical literature, and offer suggestions on where we need to go moving forward. We conclude that research that focuses on as a single category and ignores the specific domain of development provides an incomplete and inaccurate picture that will hinder efforts to develop culturally appropriate and clinically effective prevention and intervention programs to meet the needs of our diverse children and youth living in the United States. © 2016 Elsevier Inc. All rights reserved.

Development of Mentalizing and Communication: From Viewpoint of Developmental Cybernetics and Developmental Cognitive Neuroscience

NASA Astrophysics Data System (ADS)

Itakura, Shoji

The ability to mentalize is essential for human socialization. Such ability is strongly related to communication. In this paper, I discuss the development of mentalizing and communication from the perspectives of a new idea, Developmental Cybernetics, and developmental cognitive neuroscience. Children only attributed intention to a robot when they saw it behaving as a human and displaying social signals such as eye gaze. The emergence of powerful new methods and tools, such as neuroimaging, now allows questions about mentalizing to resolved more directly than before.

CHANGES IN GENE EXPRESSION PROFILE IN THE CEREBELLUM AND THE HIPPOCAMPUS FOLLOWING DEVELOPMENTAL EXPOSURE TO A NEUROTOXICANT.

EPA Science Inventory

The vast literature on the group of chemicals known as polychlorinated biphenyls (PCBs) makes it a unique model to understand major issues related to environmental mixtures of persistent chemicals. At background levels of exposure, PCBs have been shown to affect human health incl...

The dynamic lift of developmental process.

PubMed

Smith, Linda B; Breazeal, Cynthia

2007-01-01

What are the essential properties of human intelligence, currently unparalleled in its power relative to other biological forms and relative to artificial forms of intelligence? We suggest that answering this question depends critically on understanding developmental process. This paper considers three principles potentially essential to building human-like intelligence: the heterogeneity of the component processes, the embedding of development in a social world, and developmental processes that change the cognitive system as a function of the history of soft-assemblies of these heterogeneous processes in specific tasks. The paper uses examples from human development and from developmental robotics to show how these processes also may underlie biological intelligence and enable us to generate more advanced forms of artificial intelligence.

Proteome labelling and protein identification in specific tissues and at specific developmental stages in an animal

PubMed Central

Elliott, Thomas S.; Townsley, Fiona M.; Bianco, Ambra; Ernst, Russell J.; Sachdeva, Amit; Elsässer, Simon J.; Davis, Lloyd; Lang, Kathrin; Pisa, Rudolf; Greiss, Sebastian.; Lilley, Kathryn S.; Chin, Jason W.

2014-01-01

Identifying the proteins synthesized in defined cells at specific times in an animal will facilitate the study of cellular functions and dynamic processes. Here we introduce stochastic orthogonal recoding of translation with chemoselective modification (SORT-M) to address this challenge. SORT-M involves modifying cells to express an orthogonal aminoacyl-tRNA synthetase/tRNA pair to enable the incorporation of chemically modifiable analogs of amino acids at diverse sense codons in cells in rich media. We apply SORT-M to Drosophila melanogaster fed standard food to label and image proteins in specific tissues at precise developmental stages with diverse chemistries, including cyclopropene-tetrazine inverse electron demand Diels-Alder cycloaddition reactions. We also use SORT-M to identify proteins synthesized in germ cells of the fly ovary without dissection. SORT-M will facilitate the definition of proteins synthesized in specific sets of cells to study development, and learning and memory in flies, and may be extended to other animals. PMID:24727715

Cell migration analysis: A low-cost laboratory experiment for cell and developmental biology courses using keratocytes from fish scales.

PubMed

Prieto, Daniel; Aparicio, Gonzalo; Sotelo-Silveira, Jose R

2017-11-01

Cell and developmental processes are complex, and profoundly dependent on spatial relationships that change over time. Innovative educational or teaching strategies are always needed to foster deep comprehension of these processes and their dynamic features. However, laboratory exercises in cell and developmental biology at the undergraduate level do not often take into account the time dimension. In this article, we provide a laboratory exercise focused in cell migration, aiming to stimulate thinking in time and space dimensions through a simplification of more complex processes occurring in cell or developmental biology. The use of open-source tools for the analysis, as well as the whole package of raw results (available at http://github.com/danielprieto/keratocyte) make it suitable for its implementation in courses with very diverse budgets. Aiming to facilitate the student's transition from science-students to science-practitioners we propose an exercise of scientific thinking, and an evaluation method. This in turn is communicated here to facilitate the finding of common caveats and weaknesses in the process of producing simple scientific communications describing the results achieved. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):475-482, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

The origin and diversification of the developmental mechanisms that pattern the vertebrate head skeleton.

PubMed

Square, Tyler; Jandzik, David; Romášek, Marek; Cerny, Robert; Medeiros, Daniel Meulemans

2017-07-15

The apparent evolvability of the vertebrate head skeleton has allowed a diverse array of shapes, sizes, and compositions of the head in order to better adapt species to their environments. This encompasses feeding, breathing, sensing, and communicating: the head skeleton somehow participated in the evolution of all these critical processes for the last 500 million years. Through evolution, present head diversity was made possible via developmental modifications to the first head skeletal genetic program. Understanding the development of the vertebrate common ancestor's head skeleton is thus an important step in identifying how different lineages have respectively achieved their many innovations in the head. To this end, cyclostomes (jawless vertebrates) are extremely useful, having diverged from jawed vertebrates approximately 400 million years ago, at the deepest node within living vertebrates. From this ancestral vantage point (that is, the node connecting cyclostomes and gnathostomes) we can best identify the earliest major differences in development between vertebrate classes, and start to address how these might translate onto morphology. In this review we survey what is currently known about the cell biology and gene expression during head development in modern vertebrates, allowing us to better characterize the developmental genetics driving head skeleton formation in the most recent common ancestor of all living vertebrates. By pairing this vertebrate composite with information from fossil chordates, we can also deduce how gene regulatory modules might have been arranged in the ancestral vertebrate head. Together, we can immediately begin to understand which aspects of head skeletal development are the most conserved, and which are divergent, informing us as to when the first differences appear during development, and thus which pathways or cell types might be involved in generating lineage specific shape and structure. Copyright © 2017 Elsevier Inc. All

Developmental milestones record

MedlinePlus

... in the early years is to follow your child's development. Most parents also watch for different milestones. Talk ... child's provider if you have concerns about your child's development. Closely watching a "checklist" or calendar of developmental ...

Developmental coordination disorder

MedlinePlus

Physical causes and other types of learning disabilities must be ruled out before the diagnosis can be confirmed. ... Elsevier; 2016:chap 90. Szklut SE, Philibert DB. Learning disabilities and developmental coordination disorder. In: Umphred DA, Burton ...

A rich diversity of opercle bone shape among teleost fishes

PubMed Central

Small, Clayton M.; Knope, Matthew L.

2017-01-01

The opercle is a prominent craniofacial bone supporting the gill cover in all bony fish and has been the subject of morphological, developmental, and genetic investigation. We surveyed the shapes of this bone among 110 families spanning the teleost tree and examined its pattern of occupancy in a principal component-based morphospace. Contrasting with expectations from the literature that suggest the local morphospace would be only sparsely occupied, we find primarily dense, broad filling of the morphological landscape, indicating rich diversity. Phylomorphospace plots suggest that dynamic evolution underlies the observed spatial patterning. Evolutionary transits through the morphospaces are sometimes long, and occur in a variety of directions. The trajectories seem to represent both evolutionary divergences and convergences, the latter supported by convevol analysis. We suggest that that this pattern of occupancy reflects the various adaptations of different groups of fishes, seemingly paralleling their diverse marine and freshwater ecologies and life histories. Opercle shape evolution within the acanthomorphs, spiny ray-finned fishes, appears to have been especially dynamic. PMID:29281662

48 CFR 719.273-8 - Developmental assistance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (USAID) Mentor-Protégé Program 719.273-8 Developmental assistance. The forms of developmental assistance a Mentor can provide to a Protégé include and are not limited to the following: (a) Guidance...

Childrearing practices and developmental expectations for Mexican-American mothers and the developmental status of their infants.

PubMed

Kolobe, Thubi H A

2004-05-01

The impact of parent education programs on early intervention programs is not thought to be uniform among children from majority and minority populations. This study examined the relationship between maternal childrearing practices and behaviors and the developmental status of Mexican-American infants. Participants were 62 Mexican-American mother-infant pairs. The infants' mean adjusted age was 12 months (SD=1.7, range=9-14). A third of the children were diagnosed with developmental delays and referred for early intervention by physicians or therapists when the children received their medical follow-up. The group was stratified according to socioeconomic status and acculturation using the Bidimensional Acculturation Scale for Hispanics. This scale uses cutoff points to classify individuals into 3 levels of acculturation. Information on childrearing practices and behaviors was gathered using the Parent Behavior Checklist (PBC), the Home Observation for Measurement of the Environment (HOME) Inventory, and the Nursing Child Assessment Teaching Scale (NCATS). Infants' developmental status was assessed by use of the Bayley Scales of Infant Development II (BSID II). The Pearson product moment correlation, partial correlations, Fisher z transformation, and multiple regression analyses were used to examine the relationship between childrearing practices and parenting behaviors, demographic factors, and infants' developmental status. Maternal nurturing behaviors, parent-child interaction, and quality of the home environment were positively correlated with the infants' cognitive development. Maternal years of education modified the observed relationship between PBC and BSID II scores but not the observed relationship between HOME Inventory and NCATS scores. The childrearing practices, maternal socioeconomic status (SES) and age, and infants' gestational age at birth (GA) explained 45% of the variance in infants' cognitive scores. The infants' GA, maternal SES and age, and

Lead exposure and fear-potentiated startle in the VA Normative Aging Study: a pilot study of a novel physiological approach to investigating neurotoxicant effects.

PubMed

Grashow, Rachel; Miller, Mark W; McKinney, Ann; Nie, Linda H; Sparrow, David; Hu, Howard; Weisskopf, Marc G

2013-01-01

Physiologically-based indicators of neural plasticity in humans could provide mechanistic insights into toxicant actions on learning in the brain, and perhaps prove more objective and sensitive measures of such effects than other methods. We explored the association between lead exposure and classical conditioning of the acoustic startle reflex (ASR)-a simple form of associative learning in the brain-in a population of elderly men. Fifty-one men from the VA Normative Aging Study with cumulative bone lead exposure measurements made with K-X-Ray-Fluorescence participated in a fear-conditioning protocol. The mean age of the men was 75.5years (standard deviation [sd]=5.9) and mean patella lead concentration was 22.7μg/g bone (sd=15.9). Baseline ASR eyeblink response decreased with age, but was not associated with subsequent conditioning. Among 37 men with valid responses at the end of the protocol, higher patella lead was associated with decreased awareness of the conditioning contingency (declarative learning; adjusted odds ratio [OR] per 20μg/g patella lead=0.91, 95% confidence interval [CI]: 0.84, 0.99, p=0.03). Eyeblink conditioning (non-declarative learning) was 0.44sd less (95% CI: -0.91, 0.02; p=0.06) per 20μg/g patella lead after adjustment. Each result was stronger when correcting for the interval between lead measurement and startle testing (awareness: OR=0.88, 95% CI: 0.78, 0.99, p=0.04; conditioning: -0.79sd less, 95% CI: -1.56, 0.03, p=0.04). This initial exploration suggests that lead exposure interferes with specific neural mechanisms of learning and offers the possibility that the ASR may provide a new approach to physiologically explore the effects of neurotoxicant exposures on neural mechanisms of learning in humans with a paradigm that is directly comparable to animal models. Copyright © 2013 Elsevier Inc. All rights reserved.

The diversification of developmental biology.

PubMed

Crowe, Nathan; Dietrich, Michael R; Alomepe, Beverly S; Antrim, Amelia F; ByrneSim, Bay Lauris; He, Yi

2015-10-01

In the 1960s, "developmental biology" became the dominant term to describe some of the research that had previously been included under the rubrics of embryology, growth, morphology, and physiology. As scientific societies formed under this new label, a new discipline took shape. Historians, however, have a number of different perspectives on what changes led to this new field of developmental biology and how the field itself was constituted during this period. Using the General Embryological Information Service, a global index of post-World War II development-related research, we have documented and visualized significant changes in the kinds of research that occurred as this new field formed. In particular, our analysis supports the claim that the transition toward developmental biology was marked by a growth in new topics and forms of research. Although many historians privilege the role of molecular biology and/or the molecularization of biology in general during this formative period, we have found that the influence of molecular biology is not sufficient to account for the wide range of new research that constituted developmental biology at the time. Overall, our work creates a robust characterization of the changes that occurred with regard to research on growth and development in the decades following World War II and provides a context for future work on the specific drivers of those changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

BRAIN DEVELOPMENT AND METHYLMERCURY: UNDERESTIMATION OF NEUROTOXICITY

PubMed Central

Grandjean, Philippe; Herz, Katherine T.

2011-01-01

Methylmercury is now recognized as an important developmental neurotoxicant, though this insight developed slowly over many decades. Developmental neurotoxicity was first reported in a Swedish case report in 1952, and from a serious outbreak in Minamata, Japan a few years later. While the infant suffered congenital poisoning, the mother was barely harmed, thus reflecting a unique vulnerability of the developing nervous system. Nonetheless, exposure limits for this environmental chemical were based solely on adult toxicity until 50 years after the first report on developmental neurotoxicity. Even current evidence is affected by uncertainty, most importantly by imprecision of the exposure assessment in epidemiological studies. Detailed calculations suggest that the relative imprecision may be as much as 50%, or greater, thereby substantially biasing the results toward the null. In addition, as methylmercury exposure usually originates from fish and seafood that also contains essential nutrients, so-called negative confounding may occur. Thus, the beneficial effects of the nutrients may appear to dampen the toxicity, unless proper adjustment is included in the analysis to reveal the true extent of adverse effects. These problems delayed the recognition of low-level methylmercury neurotoxicity. However, such problems are not unique, and many other industrial compounds are thought to cause developmental neurotoxicity, mostly with less epidemiological support than methylmercury. The experience obtained with methylmercury should therefore be taken into account when evaluating the evidence for other substances suspected of being neurotoxic. PMID:21259267

At Issue: Developmental Education, an Annotated Bibliography

ERIC Educational Resources Information Center

Pricer, Wayne

2012-01-01

In this feature, the author has compiled a collection of links to developmental education best practices, literature reviews, publications, research reports, teaching strategies, and related tutorials. The author hopes that one will find this collection of developmental education resources useful.

Sleep Is Overrated: The Developmental Education Innovative Research Imperative

ERIC Educational Resources Information Center

Burley, Hansel

2008-01-01

Developmental education sits at the nexus of all things educational, yet developmental education research seems asleep, unaware of the valuable and critical perspectives the field can provide. In that light, this article addresses the developmental education identity crisis addressed by Arendale (2005) in "Terms of Endearment,"…

Offending outcomes of a mental health youth diversion pilot scheme in England.

PubMed

Haines, Alina; Lane, Steven; McGuire, James; Perkins, Elizabeth; Whittington, Richard

2015-04-01

A youth justice diversion scheme designed to enhance health provision for young people with mental health and developmental problems as soon as they enter the youth justice system has been piloted in six areas of England. As part of a wider evaluation of the first youth justice diversion scheme outside the USA, our aim here was to examine re-offending. We sought to test the hypothesis that a specialised service for young people with mental health difficulties would be associated with reductions in re-offending. In addition, we examined factors associated with the re-offending that occurred. Two hundred and eight young offenders with access to the diversion scheme and 200 without were compared in four geographical area pairings to allow for socio-demographic contextual differences. Officially recorded re-offending was ascertained for 15-30 months after study entry. We also tested characteristics associated with re-offending among everyone entering the diversion scheme (n = 870). There was no statistically significant difference in re-offending rates between the diversion and comparison samples, but those with access to diversion had significantly longer periods of desistance from offending than those who did not. In multivariate analysis, the only significant characteristic associated with re-offending was history of previous offending. Prevention of re-offending is only one of the potentially beneficial outcomes of diversion of young people who are vulnerable because of mental health problems, but it is an important one. The advantage of longer survival without prevention of re-offending suggests that future research should explore critical timings for these young people. The equivocal nature of the findings suggests that a randomised controlled trial would be justified. Copyright © 2014 John Wiley & Sons, Ltd.

Tretinoin: a review of the nonclinical developmental toxicology experience.

PubMed

Kochhar, D M; Christian, M S

1997-03-01

Tretinoin has been thoroughly evaluated for its potential as an embryofetal developmental toxicant. Oral tretinoin produces developmental anomalies in animal models; the minimal teratogenic dose is consistently 2.5 to 10 mg/kg. In contrast, topical application does not induce developmental malformations in laboratory animals. A structurally related compound, isotretinoin, is a potent toxicant in humans and animals; the lowest systemic dose that induces fetal anomalies varies more than 100-fold depending on the model. Oral isotretinoin is a more potent developmental toxicant than oral tretinoin in monkeys. Between-drug differences in the metabolism and transplacental transfer of the two retinoids account for the differences in toxicant potency. Pharmacokinetic studies reveal that absorption of tretinoin from the skin is poor and yields maternal plasma concentrations below the developmentally toxic threshold established after oral administration. Analysis of outcomes of developmental toxicology and pharmacokinetic studies suggests that the human risk of fetal anomalies is negligible after therapeutic application of topical tretinoin.

Transcriptional signatures of ancient floral developmental genetics in avocado (Persea americana; Lauraceae).

PubMed

Chanderbali, André S; Albert, Victor A; Leebens-Mack, Jim; Altman, Naomi S; Soltis, Douglas E; Soltis, Pamela S

2009-06-02

The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, male and female reproductive organs surrounded by a sterile perianth of sepals and petals constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure of floral organs, whereas the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. Here we show that broadly overlapping transcriptional programs characterize the floral transcriptome of the basal angiosperm Persea americana (avocado), whereas floral gene expression domains are considerably more organ specific in the model eudicot Arabidopsis thaliana. Our findings therefore support the "fading borders" model for organ identity determination in basal angiosperm flowers and extend it from the action of regulatory genes to downstream transcriptional programs. Furthermore, the declining expression of components of the staminal transcriptome in central and peripheral regions of Persea flowers concurs with elements of a previous hypothesis for developmental regulation in a gymnosperm "floral progenitor." Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis, floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs.

Why are the seed cones of conifers so diverse at pollination?

PubMed

Losada, Juan M; Leslie, Andrew B

2018-06-08

Form and function relationships in plant reproductive structures have long fascinated biologists. Although the intricate associations between specific pollinators and reproductive morphology have been widely explored among animal-pollinated plants, the evolutionary processes underlying the diverse morphologies of wind-pollinated plants remain less well understood. Here we study how this diversity may have arisen by focusing on two conifer species in the pine family that have divergent reproductive cone morphologies at pollination. Standard histology methods, artificial wind pollination assays and phylogenetic analyses were used in this study. A detailed study of cone ontogeny in these species reveals that variation in the rate at which their cone scales mature means that pollination occurs at different stages in their development, and thus in association with different specific morphologies. Pollination experiments nevertheless indicate that both species effectively capture pollen. In wind-pollinated plants, morphological diversity may result from simple variation in development among lineages rather than selective pressures for any major differences in function or performance. This work also illustrates the broader importance of developmental context in understanding plant form and function relationships; because plant reproductive structures perform many different functions over their lifetime, subtle differences in development may dramatically alter the specific morphologies that they use to meet these demands.

Basal tissue structure in the earliest euconodonts: Testing hypotheses of developmental plasticity in euconodont phylogeny

USGS Publications Warehouse

Dong, X.-P.; Donoghue, P.C.J.; Repetski, J.E.

2005-01-01

The hypothesis that conodonts are vertebrates rests solely on evidence of soft tissue anatomy. This has been corroborated by microstructural, topological and developmental evidence of homology between conodont and vertebrate hard tissues. However, these conclusions have been reached on the basis of evidence from highly derived euconodont taxa and the degree to which they are representative of plesiomorphic euconodonts remains an open question. Furthermore, the range of variation in tissue types comprising the euconodont basal body has been used to establish a hypothesis of developmental plasticity early in the phylogeny of the clade, and a model of diminishing potentiality in the evolution of development systems. The microstructural fabrics of the basal tissues of the earliest euconodonts (presumed to be the most plesiomorphic) are examined to test these two hypotheses. It is found that the range of microstructural variation observed hitherto was already apparent among plesiomorphic euconodonts. Thus, established histological data are representative of the most plesiomorphic euconodonts. However, although there is evidence of a range in microstructural fabrics, these are compatible with the dentine tissue system alone, and the degree of variation is compatible with that seen in clades of comparable diversity. ?? The Palaeontological Association.

MADS-Box gene diversity in seed plants 300 million years ago.

PubMed

Becker, A; Winter, K U; Meyer, B; Saedler, H; Theissen, G

2000-10-01

MADS-box genes encode a family of transcription factors which control diverse developmental processes in flowering plants ranging from root development to flower and fruit development. Through phylogeny reconstructions, most of these genes can be subdivided into defined monophyletic gene clades whose members share similar expression patterns and functions. Therefore, the establishment of the diversity of gene clades was probably an important event in land plant evolution. In order to determine when these clades originated, we isolated cDNAs of 19 different MADS-box genes from Gnetum gnemon, a gymnosperm model species and thus a representative of the sister group of the angiosperms. Phylogeny reconstructions involving all published MADS-box genes were then used to identify gene clades containing putative orthologs from both angiosperm and gymnosperm lineages. Thus, the minimal number of MADS-box genes that were already present in the last common ancestor of extant gymnosperms and angiosperms was determined. Comparative expression studies involving pairs of putatively orthologous genes revealed a diversity of patterns that has been largely conserved since the time when the angiosperm and gymnosperm lineages separated. Taken together, our data suggest that there were already at least seven different MADS-box genes present at the base of extant seed plants about 300 MYA. These genes were probably already quite diverse in terms of both sequence and function. In addition, our data demonstrate that the MADS-box gene families of extant gymnosperms and angiosperms are of similar complexities.

Are Students with Developmental Dyslexia Neurologically Different?

ERIC Educational Resources Information Center

Goldsmith-Phillips, Josephine

1994-01-01

Reviews the controversy over a biological basis for developmental dyslexia and illustrates it with two case studies of junior high school students. Reviews neurological evidence for developmental dyslexia, and proposes seven signs characteristic of reading disability that may qualify as dyslexia. (SR)

Anchorage Kindergarten Profile: Implementing the Alaska Kindergarten Developmental Profile.

ERIC Educational Resources Information Center

Fenton, Ray

This paper discusses the development of the Anchorage Kindergarten Developmental Profile in the context of the Alaska Kindergarten Developmental Profile and presents some evaluation results from studies of the Anchorage measure. Alaska mandated the completion of an Alaska Developmental Profile (ADP) on each kindergarten student and each student…

29 CFR 1956.52 - Completed developmental steps and certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Completed developmental steps and certification. 1956.52... PLANS New York § 1956.52 Completed developmental steps and certification. (a) In accordance with 29 CFR..., 2006 as having successfully completed all developmental steps specified in the plan as initially...

RNAi screening of developmental toolkit genes: a search for novel wing genes in the red flour beetle, Tribolium castaneum.

PubMed

Linz, David M; Tomoyasu, Yoshinori

2015-01-01

The amazing array of diversity among insect wings offers a powerful opportunity to study the mechanisms guiding morphological evolution. Studies in Drosophila (the fruit fly) have identified dozens of genes important for wing development. These genes are often called candidate genes, serving as an ideal starting point to study wing development in other insects. However, we also need to explore beyond the candidate genes to gain a more comprehensive view of insect wing evolution. As a first step away from the traditional candidate genes, we utilized Tribolium (the red flour beetle) as a model and assessed the potential involvement of a group of developmental toolkit genes (embryonic patterning genes) in beetle wing development. We hypothesized that the highly pleiotropic nature of these developmental genes would increase the likelihood of finding novel wing genes in Tribolium. Through the RNA interference screening, we found that Tc-cactus has a less characterized (but potentially evolutionarily conserved) role in wing development. We also found that the odd-skipped family genes are essential for the formation of the thoracic pleural plates, including the recently discovered wing serial homologs in Tribolium. In addition, we obtained several novel insights into the function of these developmental genes, such as the involvement of mille-pattes and Tc-odd-paired in metamorphosis. Despite these findings, no gene we examined was found to have novel wing-related roles unique in Tribolium. These results suggest a relatively conserved nature of developmental toolkit genes and highlight the limited degree to which these genes are co-opted during insect wing evolution.

The International Society for Developmental Psychobiology Annual Meeting Symposium: Impact of Early Life Experiences on Brain and Behavioral Development

PubMed Central

Sullivan, Regina; Wilson, Donald A.; Feldon, Joram; Yee, Benjamin K.; Meyer, Urs; Richter-Levin, Gal; Avi, Avital; Michael, Tsoory; Gruss, Michael; Bock, Jörg; Helmeke, Carina; Braun, Katharina

2007-01-01

Decades of research in the area of developmental psychobiology have shown that early life experience alters behavioral and brain development, which canalizes development to suit different environments. Recent methodological advances have begun to identify the mechanisms by which early life experiences cause these diverse adult outcomes. Here we present four different research programs that demonstrate the intricacies of early environmental influences on behavioral and brain development in both pathological and normal development. First, an animal model of schizophrenia is presented that suggests prenatal immune stimulation influences the postpubertal emergence of psychosis-related behavior in mice. Second, we describe a research program on infant rats that demonstrates how early odor learning has unique characteristics due to the unique functioning of the infant limbic system. Third, we present work on the rodent Octodon degus, which shows that early paternal and/or maternal deprivation alters development of limbic system synaptic density that corresponds to heightened emotionality. Fourth, ajuvenile model of stress is presented that suggests this developmental period is important in determining adulthood emotional well being. The approach of each research program is strikingly different, yet all succeed in delineating a specific aspect of early development and its effects on infant and adult outcome that expands our understanding of the developmental impact of infant experiences on emotional and limbic system development. Together, these research programs suggest that the developing organism’s developmental trajectory is influenced by environmental factors beginning in the fetus and extending through adolescence, although the specific timing and nature of the environmental influence has unique impact on adult mental health. PMID:17016842

Young Children’s Developmental Ecologies and Kindergarten Readiness

PubMed Central

Mollborn, Stefanie

2016-01-01

Children enter the crucial transition to school with sociodemographic disparities firmly established. Domain-specific research (e.g., on poverty and family structure) has shed light on these disparities, but we need broader operationalizations of children’s environments to explain them. Building on existing theory, this study articulates the concept of developmental ecology—those interrelated features of a child’s proximal environment that shape development and health. Developmental ecology links structural and demographic factors with interactional, psychological, and genetic factors. Using the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), this study conducts latent class analyses to identify how 41 factors from three domains—namely, household resources, health risks, and ecological changes—cluster within children as four overarching developmental ecologies. Because it documents how numerous factors co-occur within children, this method allows an approximation of their lived environments. Findings illuminate powerful relationships between race/ethnicity, parental age, socioeconomic background, and nativity and a child’s developmental ecology, as well as associations between developmental ecology and kindergarten cognition, behavior, and health. Developmental ecology represents a major pathway through which demographic characteristics shape school readiness. Because specific factors have different implications depending on the ecologies in which they are embedded, findings support the usefulness of a broad ecological approach. PMID:27873222

Co-Occurrence of Developmental Disorders: The Case of Developmental Dyscalculia

ERIC Educational Resources Information Center

Rubinsten, Orly

2009-01-01

Five to seven percent of children experience severe difficulties in learning mathematics and/or reading. Current trials that are focused on identifying biological markers suggest that these learning disabilities, known as Developmental Dyscalculia (DD) and Dyslexia (for reading), are due to underlying brain dysfunctions. One ongoing controversy…

Distinguishing between Development and Change: Reviving Organismic-Developmental Theory

ERIC Educational Resources Information Center

Raeff, Catherine

2011-01-01

The goal of this paper is to contribute to the revival of Heinz Werner's organismic-developmental theory by considering some of its key claims in relation to contemporary developmental theory and research. The organismic-developmental definition of development in terms of differentiation and integration is first discussed in relation to…

Developmental Summer Bridge Programs. What Works Clearinghouse™ Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2015

2015-01-01

Developmental summer bridge programs are designed to reduce the need for developmental education in college by providing students with accelerated instruction in areas where additional knowledge and skills are needed to help them succeed in higher education. The WWC identified one study of developmental summer bridge programs that meets WWC…

Community College Library Practices in Developmental Education

ERIC Educational Resources Information Center

Roselle, Ann

2008-01-01

This qualitative study examines current community college library practices in developmental education. Based on semistructured telephone interviews with 27 librarians across the United States, analysis of the results shows that there are librarians who proactively integrate basic library skills into developmental education and academic success…

29 CFR 1952.384 - Completed developmental steps.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Completed developmental steps. 1952.384 Section 1952.384 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION....384 Completed developmental steps. (a) In accordance with the requirements of § 1952.10, Puerto Rico's...

Developmental Cognitive Neuroscience: Origins, Issues, and Prospects

ERIC Educational Resources Information Center

Pennington, Bruce F.; Snyder, Kelly A.; Roberts, Ralph J., Jr.

2007-01-01

This commentary explains how the field of developmental cognitive neuroscience (DCN) holds the promise of a much wider interdisciplinary integration across sciences concerned with development: psychology, molecular genetics, neurobiology, and evolutionary developmental biology. First we present a brief history of DCN, including the key theoretical…

Case study: child with global developmental delay.

PubMed

Okumakpeyi, Pearline; Lunney, Margaret

2010-01-01

This case study focused on the care of a child with global developmental delay. Data were obtained through the author's clinical practice in long-term care pediatric rehabilitation and literature sources. NANDA-International Classifications, the Nursing Interventions Classification (NIC), and Nursing Outcomes Classification (NOC) were used to identify the appropriate nursing diagnosis, nursing interventions, and patient outcomes. This case study provides the pertinent nursing diagnoses, interventions, and outcomes for a child with global developmental delay. The interdisciplinary team approach and family involvement is addressed. Use of NANDA, NIC, and NOC outcomes constructs for enhancing the care of a child with global developmental delay.

Diverse Classrooms, Diverse Curriculum, Diverse Complications: Three Teacher Perspectives

ERIC Educational Resources Information Center

Ungemah, Lori D.

2015-01-01

Racial, ethnic, linguistic, and religious diversity continues to increase in classrooms. Many call for a more diverse curriculum, but curricular diversity brings its own challenges to both teachers and students. These three vignettes are drawn from my ethnographic data at Atlantic High School in Brooklyn, New York, where I worked for ten years as…

Systems theory and cascades in developmental psychopathology.

PubMed

Cox, Martha J; Mills-Koonce, Roger; Propper, Cathi; Gariépy, Jean-Louis

2010-08-01

In the wake of prominent theoreticians in developmental science, whose contributions we review in this article, many developmental psychologists came to endorse a systems approach to understanding how the individual, as it develops, establishes functional relationships to social ecological contexts that from birth to school entry rapidly increase in complexity. The concept of developmental cascade has been introduced in this context to describe lawful processes by which antecedent conditions may be related with varying probabilities to specified outcomes. These are understood as processes by which function at one level or in one domain of behavior affect the organization of competency in later developing domains of general adaptation. Here we propose a developmental sequence by which the developing child acquires regulative capacities that are key to adjustment to a society that demands considerable control of emotional and cognitive functions early in life. We report empirical evidence showing that the acquisition of regulative capacities may be understood as a cascade of shifts in control parameters induced by the progressive integration of biological, transactional, and socioaffective systems over development. We conclude by suggesting how the developmental process may be accessed for effective intervention in populations deemed "at risk" for later problems of psychosocial adjustment.

Understanding the Interplay of Individual and Social-Developmental Factors in the Progression of Substance Use and Mental Health from Childhood to Adulthood

PubMed Central

Jones, Tiffany M.; Hill, Karl G.; Epstein, Marina; Lee, Jungeun Olivia; Hawkins, J. David; Catalano, Richard F.

2016-01-01

This study examines the interplay between individual and social-developmental factors in the development of positive functioning, substance use problems, and mental health problems. This interplay is nested within positive and negative developmental cascades that span childhood, adolescence, the transition to adulthood, and adulthood. Data are drawn from the Seattle Social Development Project, a gender-balanced, ethnically diverse community sample of 808 participants interviewed 12 times from ages 10 to 33. Path modeling showed short- and long-term cascading effects of positive social environments, family history of depression, and substance using social environments throughout development. Positive family social environments set a template for future partner social environment interaction and had positive influences on proximal individual functioning, both in the next developmental period and long term. Family history of depression adversely affected mental health functioning throughout adulthood. Family substance use began a cascade of substance-specific social environments across development, which was the pathway through which increasing severity of substance use problems flowed. The model also indicated that adolescent, but not adult, individual functioning influenced selection into positive social environments, and significant cross-domain effects were found in which substance using social environments affected subsequent mental health. PMID:27427802

Understanding the interplay of individual and social-developmental factors in the progression of substance use and mental health from childhood to adulthood.

PubMed

Jones, Tiffany M; Hill, Karl G; Epstein, Marina; Lee, Jungeun Olivia; Hawkins, J David; Catalano, Richard F

2016-08-01

This study examines the interplay between individual and social-developmental factors in the development of positive functioning, substance use problems, and mental health problems. This interplay is nested within positive and negative developmental cascades that span childhood, adolescence, the transition to adulthood, and adulthood. Data are drawn from the Seattle Social Development Project, a gender-balanced, ethnically diverse community sample of 808 participants interviewed 12 times from ages 10 to 33. Path modeling showed short- and long-term cascading effects of positive social environments, family history of depression, and substance-using social environments throughout development. Positive family social environments set a template for future partner social environment interaction and had positive influences on proximal individual functioning, both in the next developmental period and long term. Family history of depression adversely affected mental health functioning throughout adulthood. Family substance use began a cascade of substance-specific social environments across development, which was the pathway through which increasing severity of substance use problems flowed. The model also indicated that adolescent, but not adult, individual functioning influenced selection into positive social environments, and significant cross-domain effects were found in which substance-using social environments affected subsequent mental health.

Developmental spinal canal stenosis and somatotype.

PubMed Central

Nightingale, S

1989-01-01

The hypothesis that somatotype and cervical spine developmental canal stenosis may be associated has been investigated by anthropometry and measurement of lateral projection cervical spine radiographs. A significant association of canal size with somatotype has been found such that those with developmentally narrow canals are more likely to have relatively shorter long-bones, particularly in the upper arm, and longer trunks. Images PMID:2769282

Psychological Resources of Adults with Developmental Dyslexia

ERIC Educational Resources Information Center

Lockiewicz, Marta; Bogdanowicz, Katarzyna M.; Bogdanowicz, Marta

2014-01-01

The aim of our study was to describe specific psychological resources of adults with developmental dyslexia and compare them with psychological resources of adults without developmental dyslexia. Potential differences were analyzed in visual-spatial, creative, and motivational abilities. No evidence was found for either creative, or visuospatial…

Project Developmental Continuity: PDC Classroom Observation Manual.

ERIC Educational Resources Information Center

Meece, Judy; And Others

This classroom observation manual (Fall 1976) was developed for use in the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's Head Start and primary school experiences. The manual provides detailed instructions for the observer on…

Exploring Urban Literacy & Developmental Education. CRDEUL Monograph.

ERIC Educational Resources Information Center

Lundell, Dana Britt, Ed.; Higbee, Jeanne L., Ed.

This collection of papers includes: "Introduction: Why Should We Discuss 'Urban Literacy' in Developmental Education?" (Dana Britt Lundell and Jeanne L. Higbee); "History of the Center for Research on Developmental Education and Urban Literacy: 1996-2002" (Dana Britt Lundell); "The Traveling City: The Hudson's Store, Urban…

Modeling Developmental Transitions in Adaptive Resonance Theory

ERIC Educational Resources Information Center

Raijmakers, Maartje E. J.; Molenaar, Peter C. M.

2004-01-01

Neural networks are applied to a theoretical subject in developmental psychology: modeling developmental transitions. Two issues that are involved will be discussed: discontinuities and acquiring qualitatively new knowledge. We will argue that by the appearance of a bifurcation, a neural network can show discontinuities and may acquire…

A Framework for Assessing Developmental Education Programs

ERIC Educational Resources Information Center

Goldwasser, Molly; Martin, Kimberly; Harris, Eugenia

2017-01-01

This paper presents a framework for educators, administrators, and researchers to assess distinct facets of developmental education programs. The researchers review the literature on best practices in developmental education with regards to program cost, program structure, and student placement procedures. This paper also identifies seven model…

Social Inclusion of Adults with Developmental Disabilities.

ERIC Educational Resources Information Center

Gaylord, Vicki, Ed.

1997-01-01

This feature issue presents articles on the social inclusion of people with developmental disabilities into the community and also some related news items. This issue provides profiles of organizations, workplaces, and schools that are successfully integrating people with developmental disabilities into community activities. The articles are:…

Spreading the Good News: The Far-Reaching Benefits of Developmental Education.

ERIC Educational Resources Information Center

Beckett, Gene

1996-01-01

Asserts that as developmental education is being attacked by cost-minded legislators, developmental educators must do a better job of advertising its benefits. Outlines the benefits of developmental education for both underprepared and prepared individuals, society, faculty, and administrators. Claims that developmental education enhances student…

Global Developmental Delay and Its Relationship to Cognitive Skills

ERIC Educational Resources Information Center

Riou, Emilie M.; Ghosh, Shuvo; Francoeur, Emmett; Shevell, Michael I.

2009-01-01

Global developmental delay (GDD) is defined as evidence of significant delays in two or more developmental domains. Our study determined the cognitive skills of a cohort of young children with GDD. A retrospective chart review of all children diagnosed with GDD within a single developmental clinic was carried out. Scores on fine motor (Peabody…

Fluoxetine for persistent developmental stuttering.

PubMed

Kumar, Amardeep; Balan, Sabish

2007-01-01

Stuttering is a disturbance in the normal fluency and time patterning of speech. Developmental stuttering (DS), with or without associated psychiatric illness, is the most common form and includes all cases with gradual onset in childhood that are not the result of acquired brain damage. Persistent developmental stuttering (PDS) is DS that has not undergone spontaneous or speech therapy-induced remission. Adults in speech therapy behavioral programs will often show regression and even total relapse if they stop practicing. This case report deals with a patient of PDS who responded significantly to treatment with fluoxetine.

Flower structure and developmental stages of the capitulum of Smallanthus sonchifolius (Asteraceae): reproductive implications.

PubMed

Ibañez, M S; Mercado, M I; Coll Aráoz, M V; Zannier, M L; Grau, A; Ponessa, G I

2017-03-01

Yacon (Smallanthus sonchifolius, Asteraceae) is an ancient andean crop that has numerous dietary and medicinal properties. Morphological and anatomical features and developmental changes of the capitulum were studied. A ray floret is a pistillate, female flower, while a disc floret is a staminate male flower, and the former opens before the latter, being pseudanthium protogynous. The capitulum presents interesting attributes for pollinators such as flower structure, nectaries and pollenkitt. Gynoecial nectaries were found on undeveloped ovary in the disc floret, but not in the ray floret. Glandular trichomes were observed on the abaxial epidermis of corolla in the ray floret, but not in the disc floret. Capitulum development was divided into eight stages. Stigma receptivity varied with these stages. Pollen viability was low (15%). In accordance with low viability, pollen grains exhibit diverse sizes and shapes, reduction in length of spines, and abnormal protoplasm. Examination of ovary development in the ray floret showed that a mature ovule was formed, but fertilization did not occur. In advanced developmental stages, the capitulum showed proliferation of the endothelium, degeneration of the embryo sac, and all harvested cypselae had aborted seeds. Problems found in pollen viability and aborted cypselae could be the result of a history of vegetative propagation in the domestication process.

Project Developmental Continuity Evaluation: Site Visitors' Manual.

ERIC Educational Resources Information Center

Morris, Mary; Smith, Allen

This site visitors' manual is part of a series of documents on the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's Head Start and primary school experiences. The PDC evaluation documents and analyzes the process of program…

Project Developmental Continuity Evaluation: Implementation Rating Instrument.

ERIC Educational Resources Information Center

High/Scope Educational Research Foundation, Ypsilanti, MI.

This instrument is part of a series of documents on the evaluation of Project Developmental Continuity (PDC), a Head Start demonstration program aimed at providing educational and developmental continuity between children's Head Start and primary school experiences. The Implementation Rating Instrument (IRI) was developed to provide a quantitative…

Techtalk: How Technology Has Changed Developmental Education.

ERIC Educational Resources Information Center

Caverly, David C.; MacDonald, Lucy

2003-01-01

Discusses how technology has changed higher education and how it is important to teach developmental students to effectively use technology to become better students and more effective workers. Describes a variety of portable devices and learning strategy applications. Recommends that developmental educators seriously consider the use of Personal…

Variations in Developmental Patterns across Pragmatic Features

ERIC Educational Resources Information Center

Li, Qiong

2016-01-01

Drawing on the findings of longitudinal studies in uninstructed contexts over the last two decades, this synthesis explores variations in developmental patterns across second language (L2) pragmatic features. Two synthesis questions were addressed: (a) What are the variations in developmental patterns across pragmatic features?, and (b) What are…

Essential Role of Culture in Developmental Psychology

ERIC Educational Resources Information Center

Miller, Joan G.

2005-01-01

This chapter argues for the essential role of culture in forming the basic constructs and theories of developmental psychology. The case is made for the need to overcome the cultural insularity of core developmental concepts and methods in order to create a psychology that is more truly universal.

Delaying Developmental Mathematics: The Characteristics and Costs

ERIC Educational Resources Information Center

Johnson, Marianne; Kuennen, Eric

2004-01-01

This paper investigates which students delay taking a required developmental mathematics course and the impact of delay on student performance in introductory microeconomics. Analysis of a sample of 1462 students at a large Midwestern university revealed that, although developmental-level mathematics students did not reach the same level of…

Working Memory in Children with Developmental Disorders

ERIC Educational Resources Information Center

Alloway, Tracy Packiam; Rajendran, Gnanathusharan; Archibald, Lisa M. D.

2009-01-01

The aim of the present study was to directly compare working memory skills across students with different developmental disorders to investigate whether the uniqueness of their diagnosis would impact memory skills. The authors report findings confirming differential memory profiles on the basis of the following developmental disorders: Specific…

Viromes of one year old infants reveal the impact of birth mode on microbiome diversity.

PubMed

McCann, Angela; Ryan, Feargal J; Stockdale, Stephen R; Dalmasso, Marion; Blake, Tony; Ryan, C Anthony; Stanton, Catherine; Mills, Susan; Ross, Paul R; Hill, Colin

2018-01-01

Establishing a diverse gut microbiota after birth is being increasingly recognised as important for preventing illnesses later in life. It is well established that bacterial diversity rapidly increases post-partum; however, few studies have examined the infant gut virome/phageome during this developmental period. We performed a metagenomic analysis of 20 infant faecal viromes at one year of age to determine whether spontaneous vaginal delivery (SVD) or caesarean section (CS) influenced viral composition. We find that birth mode results in distinctly different viral communities, with SVD infants having greater viral and bacteriophage diversity. We demonstrate that CrAssphage is acquired early in life, both in this cohort and two others, although no difference in birth mode is detected. A previous study has shown that bacterial OTU's (operational taxonomic units) identified in the same infants could not discriminate between birth mode at 12 months of age. Therefore, our results indicate that vertical transmission of viral communities from mother to child may play a role in shaping the early life microbiome, and that birth mode should be considered when studying the early life gut virome.

Developmental variation, homology, and the pharyngula stage.

PubMed

Collazo, A

2000-03-01

Understanding how development varies both inter- and intraspecifically can be important for systematic and evolutionary studies. This review will explore three different ways such understanding can be applied to evolutionary analyses. First, developmental data can be useful for homology determination. Interspecific variation in development has been thought to make developmental data poor candidates for determining homology. However, an updated developmental criterion that is more broadly comparative and mechanistic augments the available criteria used in homology determination. Second, modern cell and molecular biology are providing a better understanding of the many developmental processes involved in a structure's formation and will augment the number of characters available for phylogenetic analyses. Recent work has revealed that what had been thought to be a highly conserved developmental stage, the pharyngula (the phylotypic and zootypic stage of craniates) is highly variable. This variation can be seen in the development of such tissues as neural crest and placodes. These tissues are particularly interesting from a phylogenetic standpoint because they and the structures they form contribute to key synapomorphies of craniates. Finally, understanding developmental processes and how they form the variety of morphologies seen in nature will help in constructing the transformations that occurred during evolution. One such example involves descriptions of how lateral line development is affected in different mutant lines of zebrafish. The many species of teleost fishes express great variation in the patterns of their lateral lines, and this is often an important systematic character. Understanding the genetic basis of lateral line development would help not only in hypothesizing possible transformational series but also in determining how many genes may have been required for these transformations.

The interplay of diversity training and diversity beliefs on team creativity in nationality diverse teams.

PubMed

Homan, Astrid C; Buengeler, Claudia; Eckhoff, Robert A; van Ginkel, Wendy P; Voelpel, Sven C

2015-09-01

Attaining value from nationality diversity requires active diversity management, which organizations often employ in the form of diversity training programs. Interestingly, however, the previously reported effects of diversity training are often weak and, sometimes, even negative. This situation calls for research on the conditions under which diversity training helps or harms teams. We propose that diversity training can increase team creativity, but only for teams with less positive pretraining diversity beliefs (i.e., teams with a greater need for such training) and that are sufficiently diverse in nationality. Comparing the creativity of teams that attended nationality diversity training versus control training, we found that for teams with less positive diversity beliefs, diversity training increased creative performance when the team's nationality diversity was high, but undermined creativity when the team's nationality diversity was low. Diversity training had less impact on teams with more positive diversity beliefs, and training effects were not contingent upon these teams' diversity. Speaking to the underlying process, we showed that these interactive effects were driven by the experienced team efficacy of the team members. We discuss theoretical and practical implications for nationality diversity management. (c) 2015 APA, all rights reserved).

The diversity, ecology and evolution of extrafloral nectaries: current perspectives and future challenges

PubMed Central

Marazzi, Brigitte; Bronstein, Judith L.; Koptur, Suzanne

2013-01-01

Background Plants in over one hundred families in habitats worldwide bear extrafloral nectaries (EFNs). EFNs display a remarkable diversity of evolutionary origins, as well as diverse morphology and location on the plant. They secrete extrafloral nectar, a carbohydrate-rich food that attracts ants and other arthropods, many of which protect the plant in return. By fostering ecologically important protective mutualisms, EFNs play a significant role in structuring both plant and animal communities. And yet researchers are only now beginning to appreciate their importance and the range of ecological, evolutionary and morphological diversity that EFNs exhibit. Scope This Highlight features a series of papers that illustrate some of the newest directions in the study of EFNs. Here, we introduce this set of papers by providing an overview of current understanding and new insights on EFN diversity, ecology and evolution. We highlight major gaps in our current knowledge, and outline future research directions. Conclusions Our understanding of the roles EFNs play in plant biology is being revolutionized with the use of new tools from developmental biology and genomics, new modes of analysis allowing hypothesis-testing in large-scale phylogenetic frameworks, and new levels of inquiry extending to community-scale interaction networks. But many central questions remain unanswered; indeed, many have not yet been asked. Thus, the EFN puzzle remains an intriguing challenge for the future. PMID:23704115

Sexism in Developmental Education: Tackling the Demon.

ERIC Educational Resources Information Center

Green, Sharon

1994-01-01

Discusses the effects of sexism in education and the means by which educators can reduce it. Indicates that developmental educators are in a unique position to counteract sexism. Contains suggestions for overcoming sexism in five areas of developmental education (math, reading, writing, counseling, and administration) and in the classroom. (35…

The Ultimate Developmental Task in Adolescent Literature.

ERIC Educational Resources Information Center

Abrahamson, Richard F.

The significance of adolescent literature has been judged on the basis of the developmental tasks encountered by the main character. One writer has identified eight developmental tasks that teenagers must undertake as they move toward adulthood: discovering one's sex role in our culture, developing relationships with peers, achieving an easy…

State of the States in Developmental Disabilities

ERIC Educational Resources Information Center

Braddock, David; Hemp, Richard; Rizzolo, Mary Kay

2008-01-01

This is the latest edition of the "State of the States in Developmental Disabilities" study--a thorough and the only one of its kind investigation on public spending, revenues, and programmatic trends of intellectual and developmental programs and services within the United States since 1977. Directed by leading researcher, Dr. David…

40 CFR 798.4900 - Developmental toxicity study.

Code of Federal Regulations, 2011 CFR

2011-07-01

... study is designed to provide information on the potential hazard to the unborn which may arise from... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Developmental toxicity study. 798.4900... Developmental toxicity study. (a) Purpose. In the assessment and evaluation of the toxic characteristics of a...

40 CFR 798.4900 - Developmental toxicity study.

Code of Federal Regulations, 2012 CFR

2012-07-01

... study is designed to provide information on the potential hazard to the unborn which may arise from... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Developmental toxicity study. 798.4900... Developmental toxicity study. (a) Purpose. In the assessment and evaluation of the toxic characteristics of a...

40 CFR 798.4900 - Developmental toxicity study.

Code of Federal Regulations, 2013 CFR

2013-07-01

... study is designed to provide information on the potential hazard to the unborn which may arise from... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Developmental toxicity study. 798.4900... Developmental toxicity study. (a) Purpose. In the assessment and evaluation of the toxic characteristics of a...

40 CFR 798.4900 - Developmental toxicity study.

Code of Federal Regulations, 2014 CFR

2014-07-01

... study is designed to provide information on the potential hazard to the unborn which may arise from... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Developmental toxicity study. 798.4900... Developmental toxicity study. (a) Purpose. In the assessment and evaluation of the toxic characteristics of a...

Who Places into Developmental Education and Why

ERIC Educational Resources Information Center

Pretlow, Joshua, III; Wathington, Heather D.

2013-01-01

Having garnered national attention, high failure rates in developmental education present a significant barrier to state and national policymakers' goals of increasing the percentage of adults who earn a college credential. However, a majority of the research fails to consider why students place into developmental education. This piece examines a…

Innovative Developmental Education Programs: A Texas Model

ERIC Educational Resources Information Center

Booth, Eric A.; Capraro, Mary Margaret; Capraro, Robert M.; Chaudhuri, Nandita; Dyer, James; Marchbanks, Miner P., III

2014-01-01

This article provides insights from a 2-year, cross-site evaluation of state funded developmental education sites and serves as a focus article for response by those sites. Receiving grants from the Texas Higher Education Coordinating Board (THECB), nine sites (5 community colleges and 4 universities) implemented innovative developmental education…

Compound-specific effects of diverse neurodevelopmental toxicants on global gene expression in the neural embryonic stem cell test (ESTn)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Theunissen, P.T., E-mail: Peter.Theunissen@rivm.nl; Department of Toxicogenomics, Maastricht University, Maastricht; Robinson, J.F.

Alternative assays for developmental toxicity testing are needed to reduce animal use in regulatory toxicology. The in vitro murine neural embryonic stem cell test (ESTn) was designed as an alternative for neurodevelopmental toxicity testing. The integration of toxicogenomic-based approaches may further increase predictivity as well as provide insight into underlying mechanisms of developmental toxicity. In the present study, we investigated concentration-dependent effects of six mechanistically diverse compounds, acetaldehyde (ACE), carbamazepine (CBZ), flusilazole (FLU), monoethylhexyl phthalate (MEHP), penicillin G (PENG) and phenytoin (PHE), on the transcriptome and neural differentiation in the ESTn. All compounds with the exception of PENG altered ESTnmore » morphology (cytotoxicity and neural differentiation) in a concentration-dependent manner. Compound induced gene expression changes and corresponding enriched gene ontology biological processes (GO–BP) were identified after 24 h exposure at equipotent differentiation-inhibiting concentrations of the compounds. Both compound-specific and common gene expression changes were observed between subsets of tested compounds, in terms of significance, magnitude of regulation and functionality. For example, ACE, CBZ and FLU induced robust changes in number of significantly altered genes (≥ 687 genes) as well as a variety of GO–BP, as compared to MEHP, PHE and PENG (≤ 55 genes with no significant changes in GO–BP observed). Genes associated with developmentally related processes (embryonic morphogenesis, neuron differentiation, and Wnt signaling) showed diverse regulation after exposure to ACE, CBZ and FLU. In addition, gene expression and GO–BP enrichment showed concentration dependence, allowing discrimination of non-toxic versus toxic concentrations on the basis of transcriptomics. This information may be used to define adaptive versus toxic responses at the transcriptome level.« less