Early-life stress and reproductive cost: A two-hit developmental model of accelerated aging?
Shalev, Idan; Belsky, Jay
2016-05-01
Two seemingly independent bodies of research suggest a two-hit model of accelerated aging, one highlighting early-life stress and the other reproduction. The first, informed by developmental models of early-life stress, highlights reduced longevity effects of early adversity on telomere erosion, whereas the second, informed by evolutionary theories of aging, highlights such effects with regard to reproductive cost (in females). The fact that both early-life adversity and reproductive effort are associated with shorter telomeres and increased oxidative stress raises the prospect, consistent with life-history theory, that these two theoretical frameworks currently informing much research are tapping into the same evolutionary-developmental process of increased senescence and reduced longevity. Here we propose a mechanistic view of a two-hit model of accelerated aging in human females through (a) early-life adversity and (b) early reproduction, via a process of telomere erosion, while highlighting mediating biological embedding mechanisms that might link these two developmental aging processes. Copyright © 2016 Elsevier Ltd. All rights reserved.
Denver, R J
1997-04-01
Environmentally induced phenotypic plasticity allows developing organisms to respond adaptively to changes in their habitat. Desert amphibians have evolved traits which allow successful development in unpredictable environments. Tadpoles of these species can accelerate metamorphosis as their pond dries, thus escaping mortality in the larval habitat. This developmental response can be replicated in the laboratory, which allows elucidation of the underlying physiological mechanisms. Here I demonstrate a link between a classical neurohormonal stress pathway (involving corticotropin-releasing hormone, CRH) and the developmental response to habitat desiccation. Injections of CRH-like peptides accelerated metamorphosis in western spadefoot toad tadpoles. Conversely, treatment with two CRH antagonists, the CRH receptor antagonist alpha-helical CRH(9-41) and anti-CRH serum, attenuated the developmental acceleration induced by habitat desiccation. Tadpoles subjected to habitat desiccation exhibited elevated hypothalamic CRH content at the time when they responded developmentally to the declining water level. CRH injections elevated whole-body thyroxine, triiodothyronine, and corticosterone content, the primary hormonal regulators of metamorphosis. In contrast, alpha-helical CRH(9-41) reduced thyroid activity. These results support a central role for CRH as a neurohormonal transducer of environmental stimuli into the endocrine response which modulates the rate of metamorphosis. Because in mammals, increased fetal/placental CRH production may initiate parturition, and CRH has been implicated in precipitating preterm birth arising from fetal stress, this neurohormonal pathway may represent a phylogenetically ancient developmental regulatory system that allows the organism to escape an unfavorable larval/fetal habitat.
ERIC Educational Resources Information Center
Belsky, Jay; Ruttle, Paula L.; Boyce, W. Thomas; Armstrong, Jeffrey M.; Essex, Marilyn J.
2015-01-01
Evolutionary-minded developmentalists studying predictive-adaptive-response processes linking childhood adversity with accelerated female reproductive development and health scientists investigating the developmental origins of health and disease (DOoHaD) may be tapping the same process, whereby longer-term health costs are traded off for…
Developmental instability and fitness in Periploca laevigata experiencing grazing disturbance
Alados, C.L.; Giner, M.L.; Dehesa, L.; Escos, J.; Barroso, F.; Emlen, J.M.; Freeman, D.C.
2002-01-01
We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.
ERIC Educational Resources Information Center
Suldo, Shannon M.; Dedrick, Robert F.; Shaunessy-Dedrick, Elizabeth; Roth, Rachel A.; Ferron, John
2015-01-01
High school students in accelerated curricula face stressors beyond typical adolescent developmental challenges. The Student Rating of Environmental Stressors Scale (StRESS) is a self-report measure of environmental stressors appropriate for students in Advanced Placement (AP) and International Baccalaureate (IB) courses. We developed the StRESS…
Berghänel, Andreas; Heistermann, Michael; Schülke, Oliver; Ostner, Julia
2017-01-01
Across mammals, prenatal maternal stress (PREMS) affects many aspects of offspring development, including offspring growth. However, how PREMS translates to offspring growth is inconsistent, even within species. To explain the full range of reported effects of prenatal adversity on offspring growth, we propose an integrative hypothesis: developmental constraints and a counteracting adaptive growth plasticity work in opposition to drive PREMS effects on growth. Mothers experiencing adversity reduce maternal investment leading to stunted growth (developmental constraints). Concomitantly, the pace of offspring life history is recalibrated to partly compensate for these developmental constraints (adaptive growth plasticity). Moreover, the relative importance of each process changes across ontogeny with increasing offspring independence. Thus, offspring exposed to PREMS may grow at the same rate as controls during gestation and lactation, but faster after weaning when direct maternal investment has ceased. We tested these predictions with a comparative analysis on the outcomes of 719 studies across 21 mammal species. First, the observed growth changes in response to PREMS varied across offspring developmental periods as predicted. We argue that the observed growth acceleration after weaning is not “catch-up growth,” because offspring that were small for age grew slower. Second, only PREMS exposure early during gestation produced adaptive growth plasticity. Our results suggest that PREMS effects benefit the mother’s future reproduction and at the same time accelerate offspring growth and possibly maturation and reproductive rate. In this sense, PREMS effects on offspring growth allow mother and offspring to make the best of a bad start. PMID:29180423
Fernandez-Twinn, Denise S.; Chen, Jian Hua; Hargreaves, Iain P.; Neergheen, Viruna; Aiken, Catherine E.; Ozanne, Susan E.
2016-01-01
ABSTRACT ‘Developmental programming’, which occurs as a consequence of suboptimal in utero and early environments, can be associated with metabolic dysfunction in later life, including an increased incidence of cardiovascular disease and type 2 diabetes, and predisposition of older men to sarcopenia. However, the molecular mechanisms underpinning these associations are poorly understood. Many conditions associated with developmental programming are also known to be associated with the aging process. We therefore utilized our well-established rat model of low birth weight and accelerated postnatal catch-up growth (termed ‘recuperated’) in this study to establish the effects of suboptimal maternal nutrition on age-associated factors in skeletal muscle. We demonstrated accelerated telomere shortening (a robust marker of cellular aging) as evidenced by a reduced frequency of long telomeres (48.5-8.6 kb) and an increased frequency of short telomeres (4.2-1.3 kb) in vastus lateralis muscle from aged recuperated offspring compared to controls. This was associated with increased protein expression of the DNA-damage-repair marker 8-oxoguanine-glycosylase (OGG1) in recuperated offspring. Recuperated animals also demonstrated an oxidative stress phenotype, with decreased citrate synthase activity, increased electron-transport-complex activities of complex I, complex II-III and complex IV (all markers of functional mitochondria), and increased xanthine oxidase (XO), p67phox and nuclear-factor kappa-light-chain-enhancer of activated B-cells (NF-κB). Recuperated offspring also demonstrated increased antioxidant defense capacity, with increased protein expression of manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), catalase and heme oxygenase-1 (HO1), all of which are known targets of NF-κB and can be upregulated as a consequence of oxidative stress. Recuperated offspring also had a pro-inflammatory phenotype, as evidenced by increased tumor necrosis factor-α (TNFα) and interleukin-1β (IL1β) protein levels. Taken together, we demonstrate, for the first time to our knowledge, an accelerated aging phenotype in skeletal muscle in the context of developmental programming. These findings may pave the way for suitable interventions in at-risk populations. PMID:27585884
Early life stress accelerates behavioral and neural maturation of the hippocampus in male mice.
Bath, K; Manzano-Nieves, G; Goodwill, H
2016-06-01
Early life stress (ELS) increases the risk for later cognitive and emotional dysfunction. ELS is known to truncate neural development through effects on suppressing cell birth, increasing cell death, and altering neuronal morphology, effects that have been associated with behavioral profiles indicative of precocious maturation. However, how earlier silencing of growth drives accelerated behavioral maturation has remained puzzling. Here, we test the novel hypothesis that, ELS drives a switch from growth to maturation to accelerate neural and behavioral development. To test this, we used a mouse model of ELS, fragmented maternal care, and a cross-sectional dense sampling approach focusing on hippocampus and measured effects of ELS on the ontogeny of behavioral development and biomarkers of neural maturation. Consistent with previous work, ELS was associated with an earlier developmental decline in expression of markers of cell proliferation (Ki-67) and differentiation (doublecortin). However, ELS also led to a precocious arrival of Parvalbumin-positive cells, led to an earlier switch in NMDA receptor subunit expression (marker of synaptic maturity), and was associated with an earlier rise in myelin basic protein expression (key component of the myelin sheath). In addition, in a contextual fear-conditioning task, ELS accelerated the timed developmental suppression of contextual fear. Together, these data provide support for the hypothesis that ELS serves to switch neurodevelopment from processes of growth to maturation and promotes accelerated development of some forms of emotional learning. Copyright © 2016 Elsevier Inc. All rights reserved.
The Stress Acceleration Hypothesis of Nightmares
Nielsen, Tore
2017-01-01
Adverse childhood experiences can deleteriously affect future physical and mental health, increasing risk for many illnesses, including psychiatric problems, sleep disorders, and, according to the present hypothesis, idiopathic nightmares. Much like post-traumatic nightmares, which are triggered by trauma and lead to recurrent emotional dreaming about the trauma, idiopathic nightmares are hypothesized to originate in early adverse experiences that lead in later life to the expression of early memories and emotions in dream content. Accordingly, the objectives of this paper are to (1) review existing literature on sleep, dreaming and nightmares in relation to early adverse experiences, drawing upon both empirical studies of dreaming and nightmares and books and chapters by recognized nightmare experts and (2) propose a new approach to explaining nightmares that is based upon the Stress Acceleration Hypothesis of mental illness. The latter stipulates that susceptibility to mental illness is increased by adversity occurring during a developmentally sensitive window for emotional maturation—the infantile amnesia period—that ends around age 3½. Early adversity accelerates the neural and behavioral maturation of emotional systems governing the expression, learning, and extinction of fear memories and may afford short-term adaptive value. But it also engenders long-term dysfunctional consequences including an increased risk for nightmares. Two mechanisms are proposed: (1) disruption of infantile amnesia allows normally forgotten early childhood memories to influence later emotions, cognitions and behavior, including the common expression of threats in nightmares; (2) alterations of normal emotion regulation processes of both waking and sleep lead to increased fear sensitivity and less effective fear extinction. These changes influence an affect network previously hypothesized to regulate fear extinction during REM sleep, disruption of which leads to nightmares. This network consists of a fear circuit that includes amygdala, hippocampus, and medial prefrontal cortex and whose substantial overlap with the stress acceleration findings allows the latter to be incorporated into a wider, more developmentally coherent framework. PMID:28620339
Kirschman, Lucas J; Crespi, Erica J; Warne, Robin W
2018-01-01
Ubiquitous environmental stressors are often thought to alter animal susceptibility to pathogens and contribute to disease emergence. However, duration of exposure to a stressor is likely critical, because while chronic stress is often immunosuppressive, acute stress can temporarily enhance immune function. Furthermore, host susceptibility to stress and disease often varies with ontogeny; increasing during critical developmental windows. How the duration and timing of exposure to stressors interact to shape critical windows and influence disease processes is not well tested. We used ranavirus and larval amphibians as a model system to investigate how physiological stress and pathogenic infection shape development and disease dynamics in vertebrates. Based on a resource allocation model, we designed experiments to test how exposure to stressors may induce resource trade-offs that shape critical windows and disease processes because the neuroendocrine stress axis coordinates developmental remodelling, immune function and energy allocation in larval amphibians. We used wood frog larvae (Lithobates sylvaticus) to investigate how chronic and acute exposure to corticosterone, the dominant amphibian glucocorticoid hormone, mediates development and immune function via splenocyte immunohistochemistry analysis in association with ranavirus infection. Corticosterone treatments affected immune function, as both chronic and acute exposure suppressed splenocyte proliferation, although viral replication rate increased only in the chronic corticosterone treatment. Time to metamorphosis and survival depended on both corticosterone treatment and infection status. In the control and chronic corticosterone treatments, ranavirus infection decreased survival and delayed metamorphosis, although chronic corticosterone exposure accelerated rate of metamorphosis in uninfected larvae. Acute corticosterone exposure accelerated metamorphosis increased survival in infected larvae. Interactions between stress exposure (via glucocorticoid actions) and infection impose resource trade-offs that shape optimal allocation between development and somatic function. As a result, critical disease windows are likely shaped by stress exposure because any conditions that induce changes in differentiation rates will alter the duration and susceptibility of organisms to stressors or disease. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
Implicit Personality and Leadership in Stressful and Dangerous Situations: A First Step
2012-05-01
psychological interpretation. New York: Holt. Aspelmeier, J . E., & Pierce, T . W. (2009). SPSS: A user friendly approach. New York, NY: Worth...Occupational and Organizational Psychology, 72, 441- 462. Avolio, B. J ., & Hannah, S. T . (2008). Developmental readiness: Accelerating leader development...Nonconscious activation and pursuit of behavioral goals. Journal of Personality and Social Psychology, 81(6), 1014-1027. Bargh, J . A., & Chartrand, T
Three Accelerated Developmental Education Programs: Features, Student Outcomes, and Implications
ERIC Educational Resources Information Center
Jaggars, Shanna Smith; Hodara, Michelle; Cho, Sung-Woo; Xu, Di
2015-01-01
To support the long-term success of underprepared students, many community colleges are experimenting with accelerated developmental education models, which allow students to complete remediation and enroll in college-level math and English within a shorter time frame. This study examines three developmental acceleration programs, including two in…
Hankin, Benjamin L; Young, Jami F; Abela, John R Z; Smolen, Andrew; Jenness, Jessica L; Gulley, Lauren D; Technow, Jessica R; Gottlieb, Andrea Barrocas; Cohen, Joseph R; Oppenheimer, Caroline W
2015-11-01
Depression is a debilitating mental illness with clear developmental patterns from childhood through late adolescence. Here, we present data from the Gene Environment Mood (GEM) study, which used an accelerated longitudinal cohort design with youth (N = 665) starting in 3rd, 6th, and 9th grades, and a caretaker, who were recruited from the general community, and were then assessed repeatedly through semistructured diagnostic interviews every 6 months over 3 years (7 waves of data) to establish and then predict trajectories of depression from age 8 to 18. First, we demonstrated that overall prevalence rates of depression over time, by age, gender, and pubertal status, in the GEM study closely match those trajectories previously obtained in past developmental epidemiological research. Second, we tested whether a genetic vulnerability-stress model involving 5-HTTLPR and chronic peer stress was moderated by developmental factors. Results showed that older aged adolescents with SS/SL genotype, who experienced higher peer chronic stress over 3 years, were the most likely to be diagnosed with a depressive episode over time. Girls experiencing greater peer chronic stress were the most likely to develop depression. This study used repeated assessments of diagnostic interviewing in a moderately large sample of youth over 3 years to show that depression rates increase in middle to late adolescence, or postpubertally, and that the gender difference in depression emerges earlier in adolescence (age 12.5), or postpubertally. Additionally, genetically susceptible older adolescents who experience chronic peer stress were the most likely to become depressed over time. (c) 2015 APA, all rights reserved).
ERIC Educational Resources Information Center
Parks, Paula L.
2014-01-01
Most developmental community college students are not completing the composition sequence successfully. This mixed-methods study examined acceleration as a way to help developmental community college students complete the composition sequence more quickly and more successfully. Acceleration is a curricular redesign that includes challenging…
Walzer, Andreas; Schausberger, Peter
2011-03-01
We studied developmental plasticity under food stress in three female-biased size dimorphic predatory mite species, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni. All three species prey on two-spotted spider mites but differ in the degree of adaptation to this prey. Phytoseiulus persimilis is a specialized spider mite predator, N. californicus is a generalist with a preference for spider mites, and A. andersoni is a broad generalist. Immature predators were offered prey patches of varying density and their survival chances, dispersal tendencies, age and size at maturity measured. Amblyseius andersoni dispersed earlier from and had lower survival chances in low density prey patches than N. californicus and P. persimilis. Age at maturity was not affected by prey density in the generalist A. andersoni, whereas both the specialist P. persimilis and the generalist N. californicus accelerated development at low prey densities. Species-specific plasticity in age at maturity reflects opposite survival strategies when confronted with limited prey: to prematurely leave and search for other food (A. andersoni) or to stay and accelerate development (P. persimilis, N. californicus). In all species, size at maturity was more plastic in females than males, indicating that males incur higher fitness costs from deviations from optimal body size.
Berghänel, Andreas; Heistermann, Michael; Schülke, Oliver; Ostner, Julia
2016-09-28
Prenatal maternal stress affects offspring phenotype in numerous species including humans, but it is debated whether these effects are evolutionarily adaptive. Relating stress to adverse conditions, current explanations invoke either short-term developmental constraints on offspring phenotype resulting in decelerated growth to avoid starvation, or long-term predictive adaptive responses (PARs) resulting in accelerated growth and reproduction in response to reduced life expectancies. Two PAR subtypes were proposed, acting either on predicted internal somatic states or predicted external environmental conditions, but because both affect phenotypes similarly, they are largely indistinguishable. Only external (not internal) PARs rely on high environmental stability particularly in long-lived species. We report on a crucial test case in a wild long-lived mammal, the Assamese macaque (Macaca assamensis), which evolved and lives in an unpredictable environment where external PARs are probably not advantageous. We quantified food availability, growth, motor skills, maternal caretaking style and maternal physiological stress from faecal glucocorticoid measures. Prenatal maternal stress was negatively correlated to prenatal food availability and led to accelerated offspring growth accompanied by decelerated motor skill acquisition and reduced immune function. These results support the 'internal PAR' theory, which stresses the role of stable adverse internal somatic states rather than stable external environments. © 2016 The Author(s).
Walzer, Andreas; Schausberger, Peter
2011-01-01
We studied developmental plasticity under food stress in three female-biased size dimorphic predatory mite species, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni. All three species prey on two-spotted spider mites but differ in the degree of adaptation to this prey. Phytoseiulus persimilis is a specialized spider mite predator, N. californicus is a generalist with a preference for spider mites, and A. andersoni is a broad generalist. Immature predators were offered prey patches of varying density and their survival chances, dispersal tendencies, age and size at maturity measured. Amblyseius andersoni dispersed earlier from and had lower survival chances in low density prey patches than N. californicus and P. persimilis. Age at maturity was not affected by prey density in the generalist A. andersoni, whereas both the specialist P. persimilis and the generalist N. californicus accelerated development at low prey densities. Species-specific plasticity in age at maturity reflects opposite survival strategies when confronted with limited prey: to prematurely leave and search for other food (A. andersoni) or to stay and accelerate development (P. persimilis, N. californicus). In all species, size at maturity was more plastic in females than males, indicating that males incur higher fitness costs from deviations from optimal body size. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 650–660. PMID:22003259
ERIC Educational Resources Information Center
Travers, Steven T.
2017-01-01
Many developmental mathematics programs at community colleges in recent years have undergone a process of redesign in an attempt increase the historical poor rate of student successful completion of required developmental coursework. Various curriculum and instructional design models that incorporate methods of avoiding and accelerating the…
Marasco, Valeria; Spencer, Karen A; Robinson, Jane; Herzyk, Pawel; Costantini, David
2013-09-15
Across diverse vertebrate taxa, stressful environmental conditions during development can shape phenotypic trajectories of developing individuals, which, while adaptive in the short-term, may impair health and survival in adulthood. Regardless, the long-lasting benefits or costs of early life stress are likely to depend on the conditions experienced across differing stages of development. Here, we used the Japanese quail (Coturnix coturnix japonica) to experimentally manipulate exposure to stress hormones in developing individuals. We tested the hypothesis that interactions occurring between pre- and post-natal developmental periods can induce long-term shifts on the adult oxidant phenotype in non-breeding sexually mature individuals. We showed that early life stress can induce long-term alterations in the basal antioxidant defences. The magnitude of these effects depended upon the timing of glucocorticoid exposure and upon interactions between the pre- and post-natal stressful stimuli. We also found differences among tissues with stronger effects in the erythrocytes than in the brain in which the long-term effects of glucocorticoids on antioxidant biomarkers appeared to be region-specific. Recent experimental work has demonstrated that early life exposure to stress hormones can markedly reduce adult survival (Monaghan et al., 2012). Our results suggest that long-term shifts in basal antioxidant defences might be one of the potential mechanisms driving such accelerated ageing processes and that post-natal interventions during development may be a potential tool to shape the effects induced by pre-natally glucococorticoid-exposed phenotypes. Copyright © 2013 Elsevier Inc. All rights reserved.
Tarry-Adkins, Jane L; Fernandez-Twinn, Denise S; Hargreaves, Iain P; Neergheen, Viruna; Aiken, Catherine E; Martin-Gronert, Malgorzata S; McConnell, Josie M; Ozanne, Susan E
2016-01-01
Background: It is well established that low birth weight and accelerated postnatal growth increase the risk of liver dysfunction in later life. However, molecular mechanisms underlying such developmental programming are not well characterized, and potential intervention strategies are poorly defined. Objectives: We tested the hypotheses that poor maternal nutrition and accelerated postnatal growth would lead to increased hepatic fibrosis (a pathological marker of liver dysfunction) and that postnatal supplementation with the antioxidant coenzyme Q10 (CoQ10) would prevent this programmed phenotype. Design: A rat model of maternal protein restriction was used to generate low-birth-weight offspring that underwent accelerated postnatal growth (termed “recuperated”). These were compared with control rats. Offspring were weaned onto standard feed pellets with or without dietary CoQ10 (1 mg/kg body weight per day) supplementation. At 12 mo, hepatic fibrosis, indexes of inflammation, oxidative stress, and insulin signaling were measured by histology, Western blot, ELISA, and reverse transcriptase–polymerase chain reaction. Results: Hepatic collagen deposition (diameter of deposit) was greater in recuperated offspring (mean ± SEM: 12 ± 2 μm) than in controls (5 ± 0.5 μm) (P < 0.001). This was associated with greater inflammation (interleukin 6: 38% ± 24% increase; P < 0.05; tumor necrosis factor α: 64% ± 24% increase; P < 0.05), lipid peroxidation (4-hydroxynonenal, measured by ELISA: 0.30 ± 0.02 compared with 0.19 ± 0.05 μg/mL per μg protein; P < 0.05), and hyperinsulinemia (P < 0.05). CoQ10 supplementation increased (P < 0.01) hepatic CoQ10 concentrations and ameliorated liver fibrosis (P < 0.001), inflammation (P < 0.001), some measures of oxidative stress (P < 0.001), and hyperinsulinemia (P < 0.01). Conclusions: Suboptimal in utero nutrition combined with accelerated postnatal catch-up growth caused more hepatic fibrosis in adulthood, which was associated with higher indexes of oxidative stress and inflammation and hyperinsulinemia. CoQ10 supplementation prevented liver fibrosis accompanied by downregulation of oxidative stress, inflammation, and hyperinsulinemia. PMID:26718412
ERIC Educational Resources Information Center
Floyd, Anika Z.
2017-01-01
The purpose of this study was to examine the effect of the accelerated course learning format on student achievement in developmental English and math courses offered at a rural community college. Due to a rise in the number of underprepared students who enroll in community college, some college officials implemented the accelerated course…
Polε Instability Drives Replication Stress, Abnormal Development, and Tumorigenesis.
Bellelli, Roberto; Borel, Valerie; Logan, Clare; Svendsen, Jennifer; Cox, Danielle E; Nye, Emma; Metcalfe, Kay; O'Connell, Susan M; Stamp, Gordon; Flynn, Helen R; Snijders, Ambrosius P; Lassailly, François; Jackson, Andrew; Boulton, Simon J
2018-05-17
DNA polymerase ε (POLE) is a four-subunit complex and the major leading strand polymerase in eukaryotes. Budding yeast orthologs of POLE3 and POLE4 promote Polε processivity in vitro but are dispensable for viability in vivo. Here, we report that POLE4 deficiency in mice destabilizes the entire Polε complex, leading to embryonic lethality in inbred strains and extensive developmental abnormalities, leukopenia, and tumor predisposition in outbred strains. Comparable phenotypes of growth retardation and immunodeficiency are also observed in human patients harboring destabilizing mutations in POLE1. In both Pole4 -/- mouse and POLE1 mutant human cells, Polε hypomorphy is associated with replication stress and p53 activation, which we attribute to inefficient replication origin firing. Strikingly, removing p53 is sufficient to rescue embryonic lethality and all developmental abnormalities in Pole4 null mice. However, Pole4 -/- p53 +/- mice exhibit accelerated tumorigenesis, revealing an important role for controlled CMG and origin activation in normal development and tumor prevention. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.
Poupin, María Josefina; Timmermann, Tania; Vega, Andrea; Zuñiga, Ana; González, Bernardo
2013-01-01
Plant growth-promoting rhizobacteria (PGPR) induce positive effects in plants, such as increased growth or reduced stress susceptibility. The mechanisms behind PGPR/plant interaction are poorly understood, as most studies have described short-term responses on plants and only a few studies have analyzed plant molecular responses under PGPR colonization. Here, we studied the effects of the PGPR bacterial model Burkholderiaphytofirmans PsJN on the whole life cycle of Arabidopsis thaliana plants. We reported that at different plant developmental points, strain PsJN can be found in the rhizosphere and also colonizing their internal tissues. In early ontogeny, strain PsJN increased several growth parameters and accelerated growth rate of the plants. Also, an Arabidopsis transcriptome analysis revealed that 408 genes showed differential expression in PsJN-inoculated plants; some of these genes are involved in stress response and hormone pathways. Specifically, genes implicated in auxin and gibberellin pathways were induced. Quantitative transcriptional analyses of selected genes in different developmental stages revealed that the beginning of these changes could be evidenced early in development, especially among the down-regulated genes. The inoculation with heat-killed bacteria provoked a more severe transcriptional response in plants, but was not able to induce plant growth-promotion. Later in ontogeny, the growth rates of inoculated plants decreased with respect to the non-inoculated group and, interestingly, the inoculation accelerated the flowering time and the appearance of senescence signs in plants; these modifications correlate with the early up-regulation of flowering control genes. Then, we show that a single inoculation with a PGPR could affect the whole life cycle of a plant, accelerating its growth rate and shortening its vegetative period, both effects relevant for most crops. Thus, these findings provide novel and interesting aspects of these relevant biological interactions.
Contextualizing Arithmetic into Developmental Elementary Algebra Using Guided Problem Solving
ERIC Educational Resources Information Center
Guy, G. Michael; Cornick, Jonathan; Puri, Karan
2016-01-01
Many colleges are finding that the use of acceleration in developmental education is a promising direction for improved student progress toward a degree or certificate. Acceleration has been defined in the literature as the reorganization of curricula and instruction in ways that facilitate the completion of educational requirements in an…
Developmental stress increases reproductive success in male zebra finches.
Crino, Ondi L; Prather, Colin T; Driscoll, Stephanie C; Good, Jeffrey M; Breuner, Creagh W
2014-11-22
There is increasing evidence that exposure to stress during development can have sustained effects on animal phenotype and performance across life-history stages. For example, developmental stress has been shown to decrease the quality of sexually selected traits (e.g. bird song), and therefore is thought to decrease reproductive success. However, animals exposed to developmental stress may compensate for poor quality sexually selected traits by pursuing alternative reproductive tactics. Here, we examine the effects of developmental stress on adult male reproductive investment and success in the zebra finch (Taeniopygia guttata). We tested the hypothesis that males exposed to developmental stress sire fewer offspring through extra-pair copulations (EPCs), but invest more in parental care. To test this hypothesis, we fed nestlings corticosterone (CORT; the dominant avian stress hormone) during the nestling period and measured their adult reproductive success using common garden breeding experiments. We found that nestlings reared by CORT-fed fathers received more parental care compared with nestlings reared by control fathers. Consequently, males fed CORT during development reared nestlings in better condition compared with control males. Contrary to the prediction that developmental stress decreases male reproductive success, we found that CORT-fed males also sired more offspring and were less likely to rear non-genetic offspring compared with control males, and thus had greater overall reproductive success. These data are the first to demonstrate that developmental stress can have a positive effect on fitness via changes in reproductive success and provide support for an adaptive role of developmental stress in shaping animal phenotype. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
The Root Cause of Post-traumatic and Developmental Stress Disorder
2013-03-01
Post - traumatic and Developmental Stress Disorder PRINCIPAL INVESTIGATOR: Keith A...28 Feb 2013 4. TITLE AND SUBTITLE The Root Cause of Post - traumatic and Developmental Stress Disorder 5a. CONTRACT NUMBER W81XWH-‐07-‐1-‐0244...goal of Project 1 is to describe the progression of post -deployment stress disorders ( PTSD , major depression, suicidality) in active duty troops
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…
Parental Stress in Families of Children With Autism and Other Developmental Disabilities.
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.
Rise Time Perception and Detection of Syllable Stress in Adults with Developmental Dyslexia
ERIC Educational Resources Information Center
Leong, Victoria; Hamalainen, Jarmo; Soltesz, Fruzsina; Goswami, Usha
2011-01-01
Introduction: The perception of syllable stress has not been widely studied in developmental dyslexia, despite strong evidence for auditory rhythmic perceptual difficulties. Here we investigate the hypothesis that perception of sound rise time is related to the perception of syllable stress in adults with developmental dyslexia. Methods: A…
Careau, Vincent; Buttemer, William A; Buchanan, Katherine L
2014-10-01
Adaptive developmental plasticity allows individuals experiencing poor environmental conditions in early life to adjust their life-history strategy in order to prioritize short-term fitness benefits and maximize reproductive output in challenging environments. Much research has been conducted to test whether such adoption of a "faster" life-history strategy is accompanied by concordant changes in behavior and physiology, with mixed results. As research in this field has focused on comparison of mean-level responses of treatment groups, few studies include repeated measures of response variables and the effect that developmental stress may have on repeatability per se. We investigated how early-developmental stress affects the mean expression of (and repeatability in) a variety of behavioral and physiological traits in female zebra finches. We predicted that: (1) individuals subjected to nutritional restriction in the nestling phase would have higher feeding and activity rates, with associated increases in hematocrit and basal metabolic rates (BMRs), (2) nutritional restriction in early life would alter adults' stress-induced corticosterone level, and (3) developmental stress would, respectively, influence the amount of among-individual and within-individual variation in behavioral and physiological traits, hence affecting the repeatability of these traits. In comparison to control females, stressed females did not differ in activity rate or stress-induced corticosterone level, but they did have higher levels of feeding, hematocrit, and BMR. Among-individual variance and repeatability were generally higher in stressed females than in controls. Finally, we found that developmental dietary restriction significantly reduced the amount of within-individual variance both in activity rate in the novel environment and in stress-induced corticosterone level. Our results not only confirm previous findings on the effect of early-developmental stress on BMR, but also extend its effect to feeding rate and hematocrit, suggesting that developmental plasticity in these traits is ontogenetically linked. Early-developmental stress may disable particular genetic canalizing processes, which would release cryptic genetic variation and explain why repeatability and among-individual variance were generally higher in the stressed groups than in controls. For activity rate in the novel environment and with stress-induced corticosterone level, however, early-developmental stress significantly reduced within-individual variance, which may be a consequence of increased canalization of these traits at the micro-environmental level. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Webster, Richard I; Majnemer, Annette; Platt, Robert W; Shevell, Michael I
2008-01-01
Chronic disorders are known to have a wide-ranging impact on overall health and family dynamics. The objective of this study was to assess child health and well-being and parental stress in a cohort of school-age children diagnosed before school entry with either global developmental delay or developmental language impairment. In total, 65 children with preschool developmental delay were assessed at school age (mean +/- SD age: 7.3 +/- 0.7 years) with the Child Health Questionnaire and Parenting Stress Index, with a mean interval between assessment of 3.9 years. Almost all children who completed testing (60/62) continued to show developmental impairments across domains. On the Child Health Questionnaire, children showed the greatest impairment on the mental health scale (median z score: -0.9). The median Child Health Questionnaire psychosocial health score (40.7) was almost 1 SD below established normative values ( P < .001). More than 40% of parents had a Parenting Stress Index above the 85th percentile (clinically significant parenting stress). Using multiple linear regression analysis, high levels of parenting stress were best predicted by a child's Child Health Questionnaire psychosocial health score (r2 = 0.49, P < .001). Thus, 4 years after a preschool-age diagnosis of developmental delay, poor psychosocial health was a common comorbidity. Almost half the parents showed clinically significant levels of parenting stress. There is a need to both recognize and provide ongoing social and emotional support for young children diagnosed with developmental disability and their families.
Modeling Reliability Growth in Accelerated Stress Testing
2013-12-01
MODELING RELIABILITY GROWTH IN ACCELERATED STRESS TESTING DISSERTATION Jason K. Freels Major...Defense, or the United States Government. AFIT-ENS-DS-13-D-02 MODELING RELIABILITY GROWTH IN ACCELERATED STRESS TESTING ...DISTRIBUTION UNLIMITED AFIT-ENS-DS-13-D-02 MODELING RELIABILITY GROWTH IN ACCELERATED STRESS TESTING Jason K. Freels
Campbell, W.B.; Emlen, J.M.
1997-01-01
Stress in organisms results in energy dissipation, making developmental pathways less stable. Effects of chronic stress, manifested as small random departures from phenotypic symmetry, reflect developmental instability, are considered to be epigenetic and an effect produced by compromised fitness. Instability is detectable and effectively interpreted among sites or populations if samples are collected randomly, the stressor is present throughout character development, characters are identified accurately and excessive mortality does not erase the existence of developmental instability. Bacterial kidney disease (BKD) is a chronic systemic disease in salmonids that, after vertical transmission from parent to egg, persists and spreads throughout ontogeny, potentially affecting developmental processes. Because levels of progeny infection reflect parental infection levels, groups of offspring from parents with high and low levels of BKD infection can be compared to assess the effects of disease-mediated developmental stress. Analyses of fluctuating asymmetry in five bilateral characters were inconclusive, but significant reductions in the proportion of unusable scales, in the number of circulus errors, and in the directional asymmetry of branchiostegal rays were observed in fish from the high-BKD group. This group also contained individuals of significantly larger size. These results are opposite to those expected from traditional developmental instability theory in suggesting that surviving high-BKD fish have greater developmental stability. This reversal appears to be produced by selective mortality having a greater effect than sublethal stress in altering developmental instability patterns. These results are discussed with respect to size selectivity, heterosis and the assumptions supporting developmental instability as a tool for detecting chronic sublethal stress.
A Developmental Inventory of Sources of Stress.
ERIC Educational Resources Information Center
Higbee, Jeanne L.; Dwinell, Patricia L.
The Developmental Inventory of Sources of Stress (DISS) is an instructional tool designed to assist counselors, advisors, and faculty in reducing stress among college students (specifically, high risk college freshmen, although it can be utilized effectively with any college student population). The instrument focuses on sources of stress over…
Research-Based Integrated Reading and Writing Course Development
ERIC Educational Resources Information Center
Pierce, Calisa A.
2017-01-01
With the continuing national emphases on acceleration and completion, an integrated reading and writing course (a combined developmental reading and developmental writing course, with all levels compressed into a single course) is one way to move students more quickly and efficiently through the developmental sequence while still maintaining…
ERIC Educational Resources Information Center
Nettle, Daniel; Frankenhuis, Willem E.; Rickard, Ian J.
2012-01-01
Four of the articles published in this special section of "Developmental Psychology" build on and refine psychosocial acceleration theory. In this short commentary, we discuss some of the adaptive assumptions of psychosocial acceleration theory that have not received much attention. Psychosocial acceleration theory relies on the behavior of…
Early-Life Stress Triggers Juvenile Zebra Finches to Switch Social Learning Strategies.
Farine, Damien R; Spencer, Karen A; Boogert, Neeltje J
2015-08-17
Stress during early life can cause disease and cognitive impairment in humans and non-humans alike. However, stress and other environmental factors can also program developmental pathways. We investigate whether differential exposure to developmental stress can drive divergent social learning strategies between siblings. In many species, juveniles acquire essential foraging skills by copying others: they can copy peers (horizontal social learning), learn from their parents (vertical social learning), or learn from other adults (oblique social learning). However, whether juveniles' learning strategies are condition dependent largely remains a mystery. We found that juvenile zebra finches living in flocks socially learned novel foraging skills exclusively from adults. By experimentally manipulating developmental stress, we further show that social learning targets are phenotypically plastic. While control juveniles learned foraging skills from their parents, their siblings, exposed as nestlings to experimentally elevated stress hormone levels, learned exclusively from unrelated adults. Thus, early-life conditions triggered individuals to switch strategies from vertical to oblique social learning. This switch could arise from stress-induced differences in developmental rate, cognitive and physical state, or the use of stress as an environmental cue. Acquisition of alternative social learning strategies may impact juveniles' fit to their environment and ultimately change their developmental trajectories. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Logan-Garbisch, Theresa; Bortolazzo, Anthony; Luu, Peter; Ford, Audrey; Do, David; Khodabakhshi, Payam; French, Rachael L.
2014-01-01
Ethanol exposure during development causes an array of developmental abnormalities, both physiological and behavioral. In mammals, these abnormalities are collectively known as fetal alcohol effects (FAE) or fetal alcohol spectrum disorder (FASD). We have established a Drosophila melanogaster model of FASD and have previously shown that developmental ethanol exposure in flies leads to reduced expression of insulin-like peptides (dILPs) and their receptor. In this work, we link that observation to dysregulation of fatty acid metabolism and lipid accumulation. Further, we show that developmental ethanol exposure in Drosophila causes oxidative stress, that this stress is a primary cause of the developmental lethality and delay associated with ethanol exposure, and, finally, that one of the mechanisms by which ethanol increases oxidative stress is through abnormal fatty acid metabolism. These data suggest a previously uncharacterized mechanism by which ethanol causes the symptoms associated with FASD. PMID:25387828
Freeman, D.C.; Brown, M.L.; Duda, J.J.; Graraham, J.H.; Emlen, J.M.; Krzysik, A.J.; Balbach, H.; Kovacic, D.A.; Zak, J.C.
2005-01-01
We studied Cnidoscolus stimulosus and Ipomoea pandurata, two common herbs of the Fall Line Sandhills to assess their potential as ecosystem level stress indicators. We focused on plants because they are among the most persistent organisms in terrestrial ecosystems. We used developmental instability as an indicator of plant population stress. Developmental instability is usually measured as deviations from symmetry, in traits that normally develop symmetrically. Thus, symmetry represents an idealized a priori phenotype. Stress presumably causes perturbations during development that may exceed the capacity of the organism to buffer or correct, resulting in developmental instability, and hence deviations from this ideal. Soil disturbance imposed by different land use patterns at Fort Benning, Georgia provided a gradient of soil disturbance. In 2000-2002 we collected plants from nine different sites representing three levels of disturbance. In addition, in 2002 we collected microhabitat data in 1 m quadrats surrounding each plant whose developmental stability we also assessed. The developmental instability of both species was influenced by land use patterns, whether or not the sites had been previously burned, and microhabitat variables. Developmental instability increased with soil disturbance, burning in the prior year, and as the percentage of bare ground increased around the target individual. To some extent, favorable microhabitat conditions reduced developmental instability in sites with medium and high soil disturbance, whereas unfavorable conditions at low soil disturbance sites increased developmental instability. As an indicator of community level stress, developmental instability is best used in conjunction with other indices of environmental quality. ?? Published by Elsevier Ltd.
ERIC Educational Resources Information Center
Plant, K. M.; Sanders, M. R.
2007-01-01
Background: This study examined the predictors, mediators and moderators of parent stress in families of preschool-aged children with developmental disability. Method: One hundred and five mothers of preschool-aged children with developmental disability completed assessment measures addressing the key variables. Results: Analyses demonstrated that…
ERIC Educational Resources Information Center
Langer, Amie; Lawrence, Erika; Barry, Robin A.
2008-01-01
The authors used a vulnerability-stress-adaptation framework to examine personality traits and chronic stress as predictors of the developmental course of physical aggression in the early years of marriage. Additionally, personality traits and physical aggression were examined as predictors of the developmental course of chronic stress. Data from…
Prenatal stress and development: beyond the single cause and effect paradigm.
Hamlin, Heather J
2012-12-01
Our awareness of the causes of stress-induced developmental dysfunction has increased dramatically over the past decade, and it is becoming increasingly clear that a number of factors can have considerable impacts on the developing fetus. Although there is a tendency in investigations of developmental teratogens to attribute specific causes to adverse fetal outcomes, it is important we recognize that for most developmental dysfunctions it is unlikely a single cause, but yet a series of environmental insults combined with genetic predisposition that ultimately leads to a disease state. Nonetheless, a number of developmental teratogens, such as maternal psychological stress and chemical exposures, have been shown to increase the likelihood of developmental defects. These defects can manifest during development, leading to observable birth defects, or could become evident long after birth, even into adulthood. In addition, epigenetic mutations in the germline can alter the phenotype of successive generations through transgenerational inheritance, and in this way environmental factors can alter the developmental outcomes and disease predispositions of future generations. Understanding this complexity is essential to interpretations of causality in the studies of stress-induced developmental dysfunction and needs to be fully considered to more effectively interpret potential outcomes. Copyright © 2013 Wiley Periodicals, Inc.
Verbruggen, Krijn T; Knijff, Wilma A; Soorani-Lunsing, Roelineke J; Sijens, Paul E; Verhoeven, Nanda M; Salomons, Gajja S; Goorhuis-Brouwer, Siena M; van Spronsen, Francjan J
2007-09-01
Guanidinoacetate N-methyltransferase (GAMT) deficiency is a defect in the biosynthesis of creatine (Cr). So far, reports have not focused on the description of developmental abilities in this disorder. Here, we present the result of formal testing of developmental abilities in a GAMT-deficient patient. Our patient, a 3-year-old boy with GAMT deficiency, presented clinically with a severe language production delay and nearly normal nonverbal development. Treatment with oral Cr supplementation led to partial restoration of the cerebral Cr concentration and a clinically remarkable acceleration of language production development. In contrast to clinical observation, formal testing showed a rather harmonic developmental delay before therapy and a general improvement, but no specific acceleration of language development after therapy. From our case, we conclude that in GAMT deficiency language delay is not always more prominent than delays in other developmental areas. The discrepancy between the clinical impression and formal testing underscores the importance of applying standardized tests in children with developmental delays. Screening for Cr deficiency by metabolite analysis of body fluids or proton magnetic resonance spectroscopy of the brain deficiency should be considered in any child with global developmental delay/mental retardation lacking clues for an alternative etiology.
Crino, Ondi L; Klaassen van Oorschot, Brett; Crandell, Kristen E; Breuner, Creagh W; Tobalske, Bret W
2017-04-01
The environmental conditions animals experience during development can have sustained effects on morphology, physiology, and behavior. Exposure to elevated levels of stress hormones (glucocorticoids, GCs) during development is one such condition that can have long-term effects on animal phenotype. Many of the phenotypic effects of GC exposure during development (developmental stress) appear negative. However, there is increasing evidence that developmental stress can induce adaptive phenotypic changes. This hypothesis can be tested by examining the effect of developmental stress on fitness-related traits. In birds, flight performance is an ideal metric to assess the fitness consequences of developmental stress. As fledglings, mastering takeoff is crucial to avoid bodily damage and escape predation. As adults, takeoff can contribute to mating and foraging success as well as escape and, thus, can affect both reproductive success and survival. We examined the effects of developmental stress on flight performance across life-history stages in zebra finches ( Taeniopygia guttata ). Specifically, we examined the effects of oral administration of corticosterone (CORT, the dominant avian glucocorticoid) during development on ground-reaction forces and velocity during takeoff. Additionally, we tested for associations between flight performance and reproductive success in adult male zebra finches. Developmental stress had no effect on flight performance at all ages. In contrast, brood size (an unmanipulated variable) had sustained, negative effects on takeoff performance across life-history stages with birds from small broods performing better than birds from large broods. Flight performance at 100 days posthatching predicted future reproductive success in males; the best fliers had significantly higher reproductive success. Our results demonstrate that some environmental factors experienced during development (e.g. clutch size) have stronger, more sustained effects than others (e.g. GC exposure). Additionally, our data provide the first link between flight performance and a direct measure of reproductive success.
Womersley, Jacqueline S; Mpeta, Bafokeng; Dimatelis, Jacqueline J; Kellaway, Lauriston A; Stein, Dan J; Russell, Vivienne A
2016-06-17
Developmental stress has been hypothesised to interact with genetic predisposition to increase the risk of developing substance use disorders. Here we have investigated the effects of maternal separation-induced developmental stress using a behavioural proxy of methamphetamine preference in an animal model of attention-deficit/hyperactivity disorder, the spontaneously hypertensive rat, versus Wistar Kyoto and Sprague-Dawley comparator strains. Analysis of results obtained using a conditioned place preference paradigm revealed a significant strain × stress interaction with maternal separation inducing preference for the methamphetamine-associated compartment in spontaneously hypertensive rats. Maternal separation increased behavioural sensitization to the locomotor-stimulatory effects of methamphetamine in both spontaneously hypertensive and Sprague-Dawley strains but not in Wistar Kyoto rats. Our findings indicate that developmental stress in a genetic rat model of attention-deficit/hyperactivity disorder may foster a vulnerability to the development of substance use disorders.
Oxidative Stress, Unfolded Protein Response, and Apoptosis in Developmental Toxicity
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
ERIC Educational Resources Information Center
Hamlyn-Wright, Sarah; Draghi-Lorenz, Riccardo; Ellis, Jason
2007-01-01
Stress, anxiety and depression are raised amongst parents of children with a developmental disorder. However, the processes by which stress leads to depression and anxiety are poorly understood. In a cross-sectional survey, levels of parental stress, depression and anxiety were compared between parents of children with an autistic disorder,…
Stress errors in a case of developmental surface dyslexia in Filipino.
Dulay, Katrina May; Hanley, J Richard
2015-01-01
This paper reports the case of a dyslexic boy (L.A.) whose impaired reading of Filipino is consistent with developmental surface dyslexia. Filipino has a transparent alphabetic orthography with stress typically falling on the penultimate syllable of multisyllabic words. However, exceptions to the typical stress pattern are not marked in the Filipino orthography. L.A. read words with typical stress patterns as accurately as controls, but made many more stress errors than controls when reading Filipino words with atypical stress. He regularized the pronunciation of many of these words by incorrectly placing the stress on the penultimate syllable. Since he also read nonwords as accurately and quickly as controls and performed well on tests of phonological awareness, L.A. appears to present a clear case of developmental surface dyslexia in a transparent orthography.
The Developmental Inventory of Sources of Stress (DISS).
ERIC Educational Resources Information Center
Higbee, Jeanne L.; Dwinell, Patricia L.
1992-01-01
Describes the Developmental Inventory of Sources of Stress, an instructional tool to assist counselors, advisors, and faculty working with high-risk first-year students. The DISS helps students understand the sources of stress they can control. Describes the DISS's Time Management, Physical Lifestyle, Chemical Stressors, Academic and Interactive…
Childhood Stress and Coping: A Review and Cognitive-Developmental Theory.
ERIC Educational Resources Information Center
Hawkins, Raymond C., II
This paper reviews recent empirical and conceptual studies pertaining to stress in childhood and offers an integrative, cognitive-developmental theory for understanding childhood stress and coping. The theory builds upon Hunt's (1979) view of the epigenesis of intrinsic motivation and Block's (1982) formulation of assimilation and accommodation…
Working through Children's Developmental and Existential Stress in Picture Books.
ERIC Educational Resources Information Center
Schwarcz, Joseph H.
The aesthetic quality and psychological subtlety of contemporary picture books give genuine expression to a child's conscious and unconscious thoughts and emotions. Increasingly, themes of existential and developmental stress are appearing in picture books. Typical reactions aroused by such stress factors--and also by themes treated in picture…
Zhang, Wei; Rajendran, Khushmand; Ham, Jacob; Finik, Jackie; Buthmann, Jessica; Davey, Kei; Pehme, Patricia M; Dana, Kathryn; Pritchett, Alexandra; Laws, Holly; Nomura, Yoko
2018-07-01
Little is known about the impact of prenatal maternal stress (PNMS) on the developmental trajectory of temperament and few studies have been able to incorporate a natural disaster as a quasi-experimental stressor. The current study investigated PNMS related to Superstorm Sandy ('Sandy'), a hurricane that struck the New York metropolitan area in October 2012, in terms of objective exposure during pregnancy, subjective stress reaction as assessed by maternal symptoms of post-traumatic stress, and their impact on the developmental changes in temperament during early childhood. A subsample of 318 mother-child dyads was drawn from the Stress in Pregnancy Study. Temperament was measured at 6, 12, 18, and 24 months of age. Objective exposure was associated with greater High-Intensity Pleasure, Approach, Perceptual Sensitivity and Fearfulness, but lower Cuddliness and Duration of Orientation at 6 months. Objective exposure and its interaction with subjective stress reaction predicted developmental changes in temperament. In particular, objective exposure was linked to greater increases in Activity Level but decreases in High-Intensity Pleasure, Approach, and Fearfulness. The combination of objective exposure and subjective stress reaction was also associated with greater increases in Activity Level. Temperament was measured solely via maternal report. Trimester-specific effects of Sandy on temperament were not examined. This is the first study to examine the effects of prenatal maternal exposure to a natural disaster on trajectories of early childhood temperament. Findings suggest that both objective stress exposure and subjective stress reaction in-utero predict developmental trajectories of temperament in early childhood. Copyright © 2018 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Davis, Allyson L.; Neece, Cameron L.
2017-01-01
Introduction: Studies have shown that parents of children with pervasive developmental disorders (PDD) exhibit higher levels of stress than parents of typically developing children or children with other types of developmental delays (DD). This relationship appears to be mediated by elevated levels of behavior problems observed in children with…
ERIC Educational Resources Information Center
Robinson, Merideth; Neece, Cameron L.
2015-01-01
Studies have found that low marital satisfaction, parenting stress, and child behavior problems are linked in families of children with developmental delays (DD). However, previous investigations examining the relationships between parenting stress, child behavior problems, and marital satisfaction rarely examine the interrelationships of these…
Relating Stress of Mothers of Children with Developmental Disabilities to Family-School Partnerships
ERIC Educational Resources Information Center
Burke, Meghan M.; Hodapp, Robert M.
2014-01-01
Although mothers of children with intellectual and developmental disabilities (IDD) experience high levels of stress and schools constitute an important resource, the relation remains unknown between maternal stress and educational services. Responding to a national, web-based survey, 965 mothers of students with disabilities completed a 163-item…
Johnson, Norman A; Porter, Adam H
2007-01-01
Developmental systems are regulated by a web of interacting loci. One common and useful approach in studying the evolution of development is to focus on classes of interacting elements within these systems. Here, we use individual-based simulations to study the evolution of traits controlled by branched developmental pathways involving three loci, where one locus regulates two different traits. We examined the system under a variety of selective regimes. In the case where one branch was under stabilizing selection and the other under directional selection, we observed "developmental system drift": the trait under stabilizing selection showed little phenotypic change even though the loci underlying that trait showed considerable evolutionary divergence. This occurs because the pleiotropic locus responds to directional selection and compensatory mutants are then favored in the pathway under stabilizing selection. Though developmental system drift may be caused by other mechanisms, it seems likely that it is accelerated by the same underlying genetic mechanism as that producing the Dobzhansky-Muller incompatibilities that lead to speciation in both linear and branched pathways. We also discuss predictions of our model for developmental system drift and how different selective regimes affect probabilities of speciation in the branched pathway system.
Baker, B L; McIntyre, L L; Blacher, J; Crnic, K; Edelbrock, C; Low, C
2003-01-01
Children with intellectual disability are at heightened risk for behaviour problems and diagnosed mental disorder. The present authors studied the early manifestation and continuity of problem behaviours in 205 pre-school children with and without developmental delays. Behaviour problems were quite stable over the year from age 36-48 months. Children with developmental delays were rated higher on behaviour problems than their non-delayed peers, and were three times as likely to score in the clinical range. Mothers and fathers showed high agreement in their rating of child problems, especially in the delayed group. Parenting stress was also higher in the delayed group, but was related to the extent of behaviour problems rather than to the child's developmental delay. Over time, a transactional model fit the relationship between parenting stress and behaviour problems: high parenting stress contributed to a worsening in child behaviour problems over time, and high child behaviour problems contributed to a worsening in parenting stress. Findings for mothers and fathers were quite similar.
Compensatory growth following transient intraguild predation risk in predatory mites.
Walzer, Andreas; Lepp, Natalia; Schausberger, Peter
2015-05-01
Compensatory or catch-up growth following growth impairment caused by transient environmental stress, due to adverse abiotic factors or food, is widespread in animals. Such growth strategies commonly balance retarded development and reduced growth. They depend on the type of stressor but are unknown for predation risk, a prime selective force shaping life history. Anti-predator behaviours by immature prey typically come at the cost of reduced growth rates with potential negative consequences on age and size at maturity. Here, we investigated the hypothesis that transient intraguild predation (IGP) risk induces compensatory or catch-up growth in the plant-inhabiting predatory mite Phytoseiulus persimilis . Immature P. persimilis were exposed in the larval stage to no, low or high IGP risk, and kept under benign conditions in the next developmental stage, the protonymph. High but not low IGP risk prolonged development of P. persimilis larvae, which was compensated in the protonymphal stage by increased foraging activity and accelerated development, resulting in optimal age and size at maturity. Our study provides the first experimental evidence that prey may balance developmental costs accruing from anti-predator behaviour by compensatory growth.
Compensatory growth following transient intraguild predation risk in predatory mites
Walzer, Andreas; Lepp, Natalia; Schausberger, Peter
2015-01-01
Compensatory or catch-up growth following growth impairment caused by transient environmental stress, due to adverse abiotic factors or food, is widespread in animals. Such growth strategies commonly balance retarded development and reduced growth. They depend on the type of stressor but are unknown for predation risk, a prime selective force shaping life history. Anti-predator behaviours by immature prey typically come at the cost of reduced growth rates with potential negative consequences on age and size at maturity. Here, we investigated the hypothesis that transient intraguild predation (IGP) risk induces compensatory or catch-up growth in the plant-inhabiting predatory mite Phytoseiulus persimilis. Immature P. persimilis were exposed in the larval stage to no, low or high IGP risk, and kept under benign conditions in the next developmental stage, the protonymph. High but not low IGP risk prolonged development of P. persimilis larvae, which was compensated in the protonymphal stage by increased foraging activity and accelerated development, resulting in optimal age and size at maturity. Our study provides the first experimental evidence that prey may balance developmental costs accruing from anti-predator behaviour by compensatory growth. PMID:26005221
Prenatal Antecedents of Newborn Neurological Maturation
DiPietro, Janet A.; Kivlighan, Katie T.; Costigan, Kathleen A.; Rubin, Suzanne E.; Shiffler, Dorothy E.; Henderson, Janice L.; Pillion, Joseph P.
2009-01-01
Fetal neurobehavioral development was modeled longitudinally using data collected at weekly intervals from 24- to -38 weeks gestation in a sample of 112 healthy pregnancies. Predictive associations between 3 measures of fetal neurobehavioral functioning and their developmental trajectories to neurological maturation in the 1st weeks after birth were examined. Prenatal measures included fetal heart rate variability, fetal movement, and coupling between fetal motor activity and heart rate patterning; neonatal outcomes include a standard neurologic examination (n = 97) and brainstem auditory evoked potential (BAEP; n = 47). Optimality in newborn motor activity and reflexes was predicted by fetal motor activity; fetal heart rate variability and somatic-cardiac coupling predicted BAEP parameters. Maternal pregnancy-specific psychological stress was associated with accelerated neurologic maturation. PMID:20331657
Masuda, Muneyuki; Wakasaki, Takahiro; Toh, Satoshi
2016-01-01
Recent results of the Cancer Genome Atlas on head and neck squamous cell carcinoma (HNSCC) revealed that HNSCC lacked predominant gain-of-function mutations in oncogenes, whereas an essential role for epigenetics in oncogenesis has become apparent. In parallel, it has gained general acceptance that cancer is considered as complex adaptive system, which evolves responding environmental selective pressures. This somatic evolution appears to proceed concurrently with the acquisition of an atavistic pluripotent state (i.e., “stemness”), which is inducible by intrinsic epigenetic reprogramming program as demonstrated by induced pluripotent stem (iPS) cells. This Nobel prize-winning discovery has markedly accelerated and expanded cancer stem cell research from the point of epigenetic reprogramming. Taken together, we hypothesize that stress-triggered atavistic reprogramming (STAR) may be the major driving force of HNSCC evolution. In this perspective, we discuss the possible mechanisms of STAR in HNSCC, focusing on recent topics of epigenetic reprogramming in developmental and cancer cell biology. PMID:27429838
ERIC Educational Resources Information Center
Dukmak, Samir J.; Aburezeq, Ibtehal M.
2012-01-01
A significant number of individuals all over the world experience various types of developmental disabilities. Families of these individuals are likely to be impacted by these disabilities in different ways. This research examines the UAE parents' adaptation and stress to the developmental disabilities that their children have as well as examines…
ERIC Educational Resources Information Center
Benninger, Tara L.; Witwer, Andrea N.
2017-01-01
Introduction: Parents and their children with Intellectual and Developmental Disabilities (IDD) are under significant amounts of stress (Lecavalier, Leone & Wiltz, 2006). When stress escalates to crisis, some children with IDD are admitted to the emergency department or an inpatient unit. While existing measures evaluate stress over time, we…
ERIC Educational Resources Information Center
Woodman, Ashley C.; Mawdsley, Helena P.; Hauser-Cram, Penny
2015-01-01
Parents of children with developmental disabilities (DD) are at increased risk of experiencing psychological stress compared to other parents. Children's high levels of internalizing and externalizing problems have been found to contribute to this elevated level of stress. Few studies have considered the reverse direction of effects, however, in…
Parkash, Ravi; Singh, Divya; Lambhod, Chanderkala
2014-03-15
Previous studies on two tropical Drosophila species (D. malerkotliana and D. bipectinata) have shown lower resistance to stress-related traits but the rapid colonization of D. malerkotliana in the past few decades is not consistent with its sensitivity to desiccation and cold stress. We tested the hypothesis that developmental acclimation at two growth temperatures (17 and 25°C) can confer adaptations to desiccation and thermal stresses. We found divergence in developmental plastic effects on cuticular traits, i.e. a significant increase of body melanisation (~2-fold) and of cuticular lipid mass (~3-fold) in D. malerkotliana but only 1.5-fold higher cuticular lipid mass in D. bipectinata when grown at 17°C compared with 25°C. A comparison of the water budget of these two species showed significantly higher effects of developmental acclimation on body water content, rate of water loss and dehydration tolerance resulting in higher desiccation resistance in D. malerkotliana than in D. bipectinata. When grown in cooler conditions (17°C), D. malerkotliana had greater resistance to cold as well as desiccation stress. In contrast, heat resistance of D. bipectinata was higher when grown at 25°C. These laboratory observations are supported by data on seasonally varying populations. Furthermore, adult D. malerkotliana acclimated to different stresses showed greater resistance to those stresses than D. bipectinata adults. Thus, significant increase in stress resistance of D. malerkotliana through developmental acclimation may be responsible for its invasion and ecological success on different continents compared with D. bipectinata.
The Louisiana Accelerated Schools Project First Year Evaluation Report.
ERIC Educational Resources Information Center
St. John, Edward P.; And Others
The Louisiana Accelerated Schools Project (LASP) is a statewide network of schools that are changing from the traditional mode of schooling for at-risk students, which stresses remediation, to one of acceleration, which stresses accelerated learning for all students. The accelerated schools process provides a systematic approach to the…
Software Tool for Computing Maximum Von Mises Stress
NASA Technical Reports Server (NTRS)
Chen, Long Y.; Knutson, Kurt; Martin, Eric
2007-01-01
The maximum Van Mises stress and stress direction are of interest far analyzing launch accelerations such as with the Mass Acceleration Curves developed by JPL. Maximum launch stresses can be combined with appropriate load cases at consistent locations with resulting stress tensors. Maximum Van Mises stress is also of interest for understanding maximum operational loading such as traverse events. - For example, planetary traversing simulations may prescribe bounding acceleration values during traverse for a rover such as Mars Science Lab (MSL) in (X,Y,Z) of the rover. - Such accelerations can be really in any directions for many parts such as a mast or head mounted components which can be in numerous configurations and orientations when traversing a planet surface.
ERIC Educational Resources Information Center
Neece, Cameron L.
2014-01-01
Background: Parents of children with developmental delays (DD) typically report elevated levels of parental stress compared with parents of typically developing children. Children with DD are also at high risk for exhibiting significant behaviour problems. Parental stress has been shown to impact the development of these behaviour problems;…
Amos-Kroohs, Robyn M; Davenport, Laurie L; Atanasova, Nina; Abdulla, Zuhair I; Skelton, Matthew R; Vorhees, Charles V; Williams, Michael T
Manganese (Mn) is an essential element but neurotoxic at higher exposure levels. The effects of Mn overexposure (MnOE) on hippocampal and striatal-dependent learning and memory in rats were tested in combination with iron deficiency (FeD) and developmental stress that often co-occur with MnOE. Moderate FeD affects up to 15% of U.S. children and developmental stress is common in lower socio-economic areas where MnOE occurs. Pregnant Sprague-Dawley rats and their litters were housed in cages with or without (barren cage (BAR)) standard bedding from embryonic day (E)7 to postnatal day (P)28. Dams were fed a 90% FeD or iron sufficient (FeS) diet from E15-P28. Within each litter, separate offspring were treated with 100mg/kg Mn (MnOE) or vehicle (VEH) by gavage on alternate days from P4-28. Offspring were tested as adults in the Morris and Cincinnati water mazes. FeD and developmental stress interactively impaired spatial learning in the Morris water maze. Developmental stress and MnOE impaired learning and memory in both mazes. MnOE resulted in reduced CA1 hippocampal long-term potentiation (LTP) and increased levels of α-synuclein. Preweaning MnOE resulted in cognitive deficits on multiple domains of learning and memory accompanied by impaired LTP and α-synuclein changes, effects worsened by developmental stress. Copyright © 2016 Elsevier Inc. All rights reserved.
2011-01-01
Background The current study sought to compare levels of overprotection and parenting stress reported by caregivers of children with disorders of sex development at four different developmental stages. Methods Caregivers (N = 59) of children with disorders of sex development were recruited from specialty clinics and were asked to complete the Parent Protection Scale and Parenting Stress Index/Short Form as measures of overprotective behaviors and parenting stress, respectively. Results Analyses of covariance (ANCOVAs) were conducted to examine differences between caregiver report of overprotection and parenting stress. Results revealed that caregivers of infants and toddlers exhibited more overprotective behaviors than caregivers of children in the other age groups. Further, caregivers of adolescents experienced significantly more parenting stress than caregivers of school-age children, and this effect was driven by personal distress and problematic parent-child interactions, rather than having a difficult child. Conclusions These results suggest that caregivers of children with disorders of sex development may have different psychosocial needs based upon their child's developmental stage and based upon the disorder-related challenges that are most salient at that developmental stage. PMID:22074416
Hashida, Shin-Nosuke; Itami, Taketo; Takahara, Kentaro; Hirabayashi, Takayuki; Uchimiya, Hirofumi; Kawai-Yamada, Maki
2016-11-01
NAD is a well-known co-enzyme that mediates hundreds of redox reactions and is the basis of various processes regulating cell responses to different environmental and developmental cues. The regulatory mechanism that determines the amount of cellular NAD and the rate of NAD metabolism remains unclear. We created Arabidopsis thaliana plants overexpressing the NAD synthase (NADS) gene that participates in the final step of NAD biosynthesis. NADS overexpression enhanced the activity of NAD biosynthesis but not the amounts of NAD + , NADH, NADP + or NADPH. However, the amounts of some intermediates were elevated, suggesting that NAD metabolism increased. The NAD redox state was greatly facilitated by an imbalance between NAD generation and degradation in response to bolting. Metabolite profiling and transcriptional analysis revealed that the drastic modulation of NAD redox homeostasis increased tricarboxylic acid flux, causing the ectopic generation of reactive oxygen species. Vascular bundles suffered from oxidative stress, leading to a malfunction in amino acid and organic acid transportation that caused early wilting of the flower stalk and shortened plant longevity, probably due to malnutrition. We concluded that the mechanism regulating the balance between NAD synthesis and degradation is important in the systemic plant response to developmental cues during the growth-phase transition. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
The fetal programming of telomere biology hypothesis: an update
Entringer, Sonja; Buss, Claudia; Wadhwa, Pathik D.
2018-01-01
Research on mechanisms underlying fetal programming of health and disease risk has focused primarily on processes that are specific to cell types, organs or phenotypes of interest. However, the observation that developmental conditions concomitantly influence a diverse set of phenotypes, the majority of which are implicated in age-related disorders, raises the possibility that such developmental conditions may additionally exert effects via a common underlying mechanism that involves cellular/molecular ageing–related processes. In this context, we submit that telomere biology represents a process of particular interest in humans because, firstly, this system represents among the most salient antecedent cellular phenotypes for common age-related disorders; secondly, its initial (newborn) setting appears to be particularly important for its long-term effects; and thirdly, its initial setting appears to be plastic and under developmental regulation. We propose that the effects of suboptimal intrauterine conditions on the initial setting of telomere length and telomerase expression/activity capacity may be mediated by the programming actions of stress-related maternal–placental–fetal oxidative, immune, endocrine and metabolic pathways in a manner that may ultimately accelerate cellular dysfunction, ageing and disease susceptibility over the lifespan. This perspectives paper provides an overview of each of the elements underlying this hypothesis, with an emphasis on recent developments, findings and future directions. This article is part of the theme issue ‘Understanding diversity in telomere dynamics’. PMID:29335381
The fetal programming of telomere biology hypothesis: an update.
Entringer, Sonja; de Punder, Karin; Buss, Claudia; Wadhwa, Pathik D
2018-03-05
Research on mechanisms underlying fetal programming of health and disease risk has focused primarily on processes that are specific to cell types, organs or phenotypes of interest. However, the observation that developmental conditions concomitantly influence a diverse set of phenotypes, the majority of which are implicated in age-related disorders, raises the possibility that such developmental conditions may additionally exert effects via a common underlying mechanism that involves cellular/molecular ageing-related processes. In this context, we submit that telomere biology represents a process of particular interest in humans because, firstly, this system represents among the most salient antecedent cellular phenotypes for common age-related disorders; secondly, its initial (newborn) setting appears to be particularly important for its long-term effects; and thirdly, its initial setting appears to be plastic and under developmental regulation. We propose that the effects of suboptimal intrauterine conditions on the initial setting of telomere length and telomerase expression/activity capacity may be mediated by the programming actions of stress-related maternal-placental-fetal oxidative, immune, endocrine and metabolic pathways in a manner that may ultimately accelerate cellular dysfunction, ageing and disease susceptibility over the lifespan. This perspectives paper provides an overview of each of the elements underlying this hypothesis, with an emphasis on recent developments, findings and future directions.This article is part of the theme issue 'Understanding diversity in telomere dynamics'. © 2018 The Author(s).
The Root Cause of Post-traumatic and Developmental Stress Disorder
2011-03-01
traumatic and Developmental Stress Disorder Keith A. Young, PhD 1 MAR 2010 - 28 FEB 2011Annual01-03-2011 Our overarching scientific hypothesis holds that...highly susceptible to the effects of severe stress . We are studying this question using both clinical and basic approaches. New findings from our...experience induce a variation of normal brain anatomy that makes the brain highly susceptible to the effects of severe stress . The new goal of Project 1 is
Woolfson, L; Grant, E
2006-03-01
Rearing a child with a developmental disability is associated with increased parental stress. Theories of stress and adjustment and bi-directional theories of child development suggest that parenting could influence these negative outcomes. Relationships between parenting approaches and stress in parents of children with developmental disabilities (DD) (N = 53) were examined across two age groups, 3-5 years and 9-11 years and compared with a contrast group of typically developing children (TD) (N = 60). Measures used were the Parenting Stress Index-Short Form and Rickel and Biasatti's modification of Block's Child Rearing Practices Report, classified into Baumrind's parenting styles using Reitman and Gross's method. Parents in the older DD group used Authoritative parenting less than parents in the younger DD group, while the opposite developmental pattern was seen in the TD group. Multivariate analysis of variance showed a significant group x parenting style interaction for Parental Distress, Parent-Child Dysfunctional Interaction and Difficult Child. Stress measures were higher for the DD group and seemed to be associated with Authoritative parenting approaches, an effect that was not observed in the TD group. Findings suggest that the well-established effect of group on stress may be moderated by parenting style. Authoritative parenting may be highly stressful for parents of children with DD to implement, resulting in a decrease in its use across the two age groups.
Adulthood stress responses in rats are variably altered as a factor of adolescent stress exposure.
Moore, Nicole L T; Altman, Daniel E; Gauchan, Sangeeta; Genovese, Raymond F
2016-05-01
Stress exposure during development may influence adulthood stress response severity. The present study investigates persisting effects of two adolescent stressors upon adulthood response to predator exposure (PE). Rats were exposed to underwater trauma (UWT) or PE during adolescence, then to PE after reaching adulthood. Rats were then exposed to predator odor (PO) to test responses to predator cues alone. Behavioral and neuroendocrine assessments were conducted to determine acute effects of each stress experience. Adolescent stress altered behavioral response to adulthood PE. Acoustic startle response was blunted. Bidirectional changes in plus maze exploration were revealed as a factor of adolescent stress type. Neuroendocrine response magnitude did not predict severity of adolescent or adult stress response, suggesting that different adolescent stress events may differentially alter developmental outcomes regardless of acute behavioral or neuroendocrine response. We report that exposure to two different stressors in adolescence may differentially affect stress response outcomes in adulthood. Acute response to an adolescent stressor may not be consistent across all stressors or all dependent measures, and may not predict alterations in developmental outcomes pertaining to adulthood stress exposure. Further studies are needed to characterize factors underlying long-term effects of a developmental stressor.
Xie, Bin; Palmer, Paula; Li, Yan; Lin, Cindy; Johnson, C Anderson
2013-10-01
We aimed to identify developmental trajectories of cigarette use and risk factors associated with the distinct developmental courses of smoking in Chinese early adolescents from age 12 to 16 years. Analysis was conducted with secondary data from a longitudinal, prospective cohort of 3,521 Chinese adolescents randomly selected from 4 rural and 7 urban middle schools in Wuhan, China. A group-based growth mixture modeling approach was adopted to identify developmental trajectories of cigarette use. Multilayered intrapersonal (e.g., attitudes toward smoking) and interpersonal (e.g., parental smoking and perceived parental disapproval of smoking) risk factors selected from an ecological perspective were prospectively linked to the identified patterns of smoking trajectory. Three trajectory patterns were identified from the whole cohort: nonsmokers (48.7%), stable light/occasional smokers (48.6%), and accelerating smokers (2.7%). After adjustments for gender, urban residence, and family socioeconomic status, adolescents with higher levels of problems in parent-child relationships and family disharmony, higher perceived norms of peer smoking, higher proportion of good friend smoking, having more troubles with teachers, poorer academic performance, and reporting more frequent depressive symptoms were significantly more likely to be in the trajectory group of either stable light/occasional smokers or accelerating smokers than in the group of nonsmokers. The probability of being in the accelerating smoking trajectory group was positively and significantly related to parental smoking and lack of school bonding. Study findings help to advance knowledge of the distinct developmental courses of smoking behavior and their associations with multilayered risk factors among Chinese early adolescents.
ERIC Educational Resources Information Center
Claassen, M.; Naude, H.; Pretorius, E.; Bosman, M. C.
2008-01-01
This paper reports on the contribution of prenatal stress to the pathogenesis of autism as a neurobiological developmental disorder in a dizygotic study. The aim was to explore whether the neurobiological impact of stress prior to week 28 of gestation might be related to the pathogenesis of autism. The following data-generating strategies were…
Distinct developmental genetic mechanisms underlie convergently evolved tooth gain in sticklebacks
Ellis, Nicholas A.; Glazer, Andrew M.; Donde, Nikunj N.; Cleves, Phillip A.; Agoglia, Rachel M.; Miller, Craig T.
2015-01-01
Teeth are a classic model system of organogenesis, as repeated and reciprocal epithelial and mesenchymal interactions pattern placode formation and outgrowth. Less is known about the developmental and genetic bases of tooth formation and replacement in polyphyodonts, which are vertebrates with continual tooth replacement. Here, we leverage natural variation in the threespine stickleback fish Gasterosteus aculeatus to investigate the genetic basis of tooth development and replacement. We find that two derived freshwater stickleback populations have both convergently evolved more ventral pharyngeal teeth through heritable genetic changes. In both populations, evolved tooth gain manifests late in development. Using pulse-chase vital dye labeling to mark newly forming teeth in adult fish, we find that both high-toothed freshwater populations have accelerated tooth replacement rates relative to low-toothed ancestral marine fish. Despite the similar evolved phenotype of more teeth and an accelerated adult replacement rate, the timing of tooth number divergence and the spatial patterns of newly formed adult teeth are different in the two populations, suggesting distinct developmental mechanisms. Using genome-wide linkage mapping in marine-freshwater F2 genetic crosses, we find that the genetic basis of evolved tooth gain in the two freshwater populations is largely distinct. Together, our results support a model whereby increased tooth number and an accelerated tooth replacement rate have evolved convergently in two independently derived freshwater stickleback populations using largely distinct developmental and genetic mechanisms. PMID:26062935
Jensen, Sarah K G; Pangelinan, Melissa; Björnholm, Lassi; Klasnja, Anja; Leemans, Alexander; Drakesmith, Mark; Evans, C J; Barker, Edward D; Paus, Tomáš
2017-10-21
Previous studies have shown that both pre- and post-natal adversities, the latter including exposures to stress during childhood and adolescence, explain variation in structural properties of white matter (WM) in the brain. While previous studies have examined effects of independent stress exposures within one developmental period, such as childhood, we examine effects of stress across development using data from a prospective longitudinal study. More specifically, we ask how stressful events during prenatal development, childhood, and adolescence relate to variation in WM properties in early adulthood in young men recruited from a birth cohort. Using data from 393 mother-son pairs from a community-based birth cohort from England (Avon Longitudinal Study of Parents and Children), we examined how stressful life events relate to variation in different structural properties of WM in the corpus callosum and across the whole brain in early adulthood in men aged 18-21 years. We distinguish between stress occurring during three developmental periods: a) prenatal maternal stress, b) postnatal stress within the first four years of life, c) stress during adolescence (age 12-16 years). To obtain a comprehensive quantification of variation in WM, we assess structural properties of WM using four different measures, namely fractional anisotropy (FA), mean diffusivity (MD), magnetization transfer ratio (MTR) and myelin water fraction (MWF). The developmental model shows that prenatal stress is associated with lower MTR and MWF in the genu and/or splenium of the corpus callosum, and with lower MTR in global (lobar) WM. Stress during early childhood is associated with higher MTR in the splenium, and stress during adolescence is associated with higher MTR in the genu and lower MD in the splenium. We see no associations between postnatal stress and variation in global (lobar) WM. The current study found evidence for independent effects of stress on WM properties during distinct neurodevelopmental periods. We speculate that these independent effects are due to differences in the developmental processes unfolding at different developmental time points. We suggest that associations between prenatal stress and WM properties may relate to abnormalities in neurogenesis, affecting the number and density of axons, while postnatal stress may interfere with processes related to myelination or radial growth of axons. Potential consequences of prenatal glucocorticoid exposure should be considered in obstetric care. Copyright © 2017 Elsevier Inc. All rights reserved.
Estimation of Stresses in a Dry Sand Layer Tested on Shaking Table
NASA Astrophysics Data System (ADS)
Sawicki, Andrzej; Kulczykowski, Marek; Jankowski, Robert
2012-12-01
Theoretical analysis of shaking table experiments, simulating earthquake response of a dry sand layer, is presented. The aim of such experiments is to study seismic-induced compaction of soil and resulting settlements. In order to determine the soil compaction, the cyclic stresses and strains should be calculated first. These stresses are caused by the cyclic horizontal acceleration at the base of soil layer, so it is important to determine the stress field as function of the base acceleration. It is particularly important for a proper interpretation of shaking table tests, where the base acceleration is controlled but the stresses are hard to measure, and they can only be deduced. Preliminary experiments have shown that small accelerations do not lead to essential settlements, whilst large accelerations cause some phenomena typical for limit states, including a visible appearance of slip lines. All these problems should be well understood for rational planning of experiments. The analysis of these problems is presented in this paper. First, some heuristic considerations about the dynamics of experimental system are presented. Then, the analysis of boundary conditions, expressed as resultants of respective stresses is shown. A particular form of boundary conditions has been chosen, which satisfies the macroscopic boundary conditions and the equilibrium equations. Then, some considerations are presented in order to obtain statically admissible stress field, which does not exceed the Coulomb-Mohr yield conditions. Such an approach leads to determination of the limit base accelerations, which do not cause the plastic state in soil. It was shown that larger accelerations lead to increase of the lateral stresses, and the respective method, which may replace complex plasticity analyses, is proposed. It is shown that it is the lateral stress coefficient K0 that controls the statically admissible stress field during the shaking table experiments.
ERIC Educational Resources Information Center
Edwards, Ann R.; Beattie, Rachel L.
2016-01-01
This paper focuses on two research-based frameworks that inform the design of instruction and promote student success in accelerated, developmental mathematics pathways. These are Learning Opportunities--productive struggle on challenging and relevant tasks, deliberate practice, and explicit connections, and Productive Persistence--promoting…
ERIC Educational Resources Information Center
Doherty, Brooks
2016-01-01
Driven by faculty-based action research, redesigned residential and online courses, and changes to placement testing, Rasmussen College increased its developmental education pass rates by double digits while decreasing the number and percentage of students who require remedial coursework. Like many institutions of higher education, Rasmussen…
Developmental Change in Social Responsibility during Adolescence: An Ecological Perspective
ERIC Educational Resources Information Center
Wray-Lake, Laura; Syvertsen, Amy K.; Flanagan, Constance A.
2016-01-01
Social responsibility can be defined as a set of prosocial values representing personal commitments to contribute to community and society. Little is known about developmental change--and predictors of that change--in social responsibility during adolescence. The present study used an accelerated longitudinal research design to investigate the…
Cui, Long-Gang; Shan, Jun-Xiang; Shi, Min; Gao, Ji-Ping; Lin, Hong-Xuan
2014-12-01
Young organisms have relatively strong resistance to diseases and adverse conditions. When confronted with adversity, the process of development is delayed in plants. This phenomenon is thought to result from the rebalancing of energy, which helps plants to coordinate the relationship between development and stress tolerance; however, the molecular mechanism underlying this phenomenon remains mysterious. In this study, we found that miR156 integrates environmental signals to ensure timely flowering, thus enabling the completion of breeding. Under stress conditions, miR156 is induced to maintain the plant in the juvenile state for a relatively long period of time, whereas under favorable conditions, miR156 is suppressed to accelerate the developmental transition. Blocking the miR156 signaling pathway in Arabidopsis thaliana with 35S::MIM156 (via target mimicry) increased the sensitivity of the plant to stress treatment, whereas overexpression of miR156 increased stress tolerance. In fact, this mechanism is also conserved in Oryza sativa (rice). We also identified downstream genes of miR156, i.e. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 9 (SPL9) and DIHYDROFLAVONOL-4-REDUCTASE (DFR), which take part in this process by influencing the metabolism of anthocyanin. Our results uncover a molecular mechanism for plant adaptation to the environment through the miR156-SPLs-DFR pathway, which coordinates development and abiotic stress tolerance. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.
Cabeza de Baca, Tomás; Ellis, Bruce J
2017-06-01
This review focuses on the impact of parental behavior on child development, as interpreted from an evolutionary-developmental perspective. We employ psychosocial acceleration theory to reinterpret the effects of variation in parental investment and involvement on child development, arguing that these effects have been structured by natural selection to match the developing child to current and expected future environments. Over time, an individual's development, physiology, and behavior are organized in a coordinated manner (as instantiated in 'life history strategies') that facilitates survival and reproductive success under different conditions. We review evidence to suggest that parental behavior (1) is strategic and contingent on environmental opportunities and constraints and (2) influences child life history strategies across behavioral, cognitive, and physiological domains. Copyright © 2017 Elsevier Ltd. All rights reserved.
Are GM Crops for Yield and Resilience Possible?
Paul, Matthew J; Nuccio, Michael L; Basu, Shib Sankar
2018-01-01
Crop yield improvements need to accelerate to avoid future food insecurity. Outside Europe, genetically modified (GM) crops for herbicide- and insect-resistance have been transformative in agriculture; other traits have also come to market. However, GM of yield potential and stress resilience has yet to impact on food security. Genes have been identified for yield such as grain number, size, leaf growth, resource allocation, and signaling for drought tolerance, but there is only one commercialized drought-tolerant GM variety. For GM and genome editing to impact on yield and resilience there is a need to understand yield-determining processes in a cell and developmental context combined with evaluation in the grower environment. We highlight a sugar signaling mechanism as a paradigm for this approach. Copyright © 2017 Elsevier Ltd. All rights reserved.
Jung, Hyunwoo; Woo, Eun Jin; Pak, Sunyoung
Cranial fluctuating asymmetry (FA) has been used to examine developmental stress levels in various populations. In bioarchaeological studies, developmental stress can be an important factor for inferring standard of living in a population. However, the crania of a Joseon Dynasty population have only been studied in terms of its morphological characteristics. In this regard, the cranial FA of the two sexes from a Joseon Dynasty population of Korea were compared here for examining their aspects of living conditions in relation to developmental stress and socio-cultural factors. In this study, 77 individuals (39 males and 38 females) who belong to the 15th to the early-20th centuries from Seoul and Gyeonggi province in Korea were investigated. Nineteen three-dimensional landmarks on the vault and basicranium were collected using MicroScribe G2X. The coordinate data were aligned into a common coordinate plane by Procrustes least-squares superimposition. Procrustes ANOVA was adopted to evaluate FA at a population level. The FA of males and females were compared with t-test using SPSS 18. There was statistically insignificant difference in FA between the two sexes in the Joseon Dynasty population. The result was interpreted to reflect both relatively high developmental stress and sex-related discrimination in the population. It was postulated that relatively high developmental stress could increase difference in FA between the two sexes in the prenatal term compared to the postnatal term because sex-related discrimination cannot be practiced before birth and males have lower stress resistance than females. Then, the difference between the two sexes in the cranial FA could be decreased during postnatal development related to sex-related discrimination, resulting in insignificant FA difference of the two sexes in spite of high developmental stress of the Joseon Dynasty population. The results will be useful for comparing and reconstructing living conditions of ancient Korean populations.
Interpersonal Cognitive Distortions and Stress Coping Strategies of Laate Adolescents
ERIC Educational Resources Information Center
Coban, Aysel Esen
2013-01-01
Problem Statement: Adolescence is a stage of major growth and development in terms of significant cognitive, behavioral, psychological, and physiological changes. For adolescents, these developmental changes could be accompanied by stressful situations. Adolescents need to cope with these stressors successfully, yet the developmental period of…
Baroncelli, Laura; Cenni, Maria Cristina; Melani, Riccardo; Deidda, Gabriele; Landi, Silvia; Narducci, Roberta; Cancedda, Laura; Maffei, Lamberto; Berardi, Nicoletta
2017-02-01
Environmental enrichment (EE) has a remarkable impact on brain development. Continuous exposure to EE from birth determines a significant acceleration of visual system maturation both at retinal and cortical levels. A pre-weaning enriched experience is sufficient to trigger the accelerated maturation of the visual system, suggesting that factors affected by EE during the first days of life might prime visual circuits towards a faster development. The search for such factors is crucial not only to gain a better understanding of the molecular hierarchy of brain development but also to identify molecular pathways amenable to be targeted to correct atypical brain developmental trajectories. Here, we showed that IGF-1 levels are increased in the visual cortex of EE rats as early as P6 and this is a crucial event for setting in motion the developmental program induced by EE. Early intracerebroventricular (i.c.v.) infusion of IGF-1 in standard rats was sufficient to mimic the action of EE on visual acuity development, whereas blocking IGF-1 signaling by i.c.v. injections of the IGF-1 receptor antagonist JB1 prevented the deployment of EE effects. Early IGF-1 decreased the ratio between the expression of NKCC1 and KCC2 cation/chloride transporters, and the reversal potential for GABA A R-driven Cl - currents (E Cl ) was shifted toward more negative potentials, indicating that IGF-1 is a crucial factor in accelerating the maturation of GABAergic neurotransmission and promoting the developmental switch of GABA polarity from excitation to inhibition. In addition, early IGF-1 promoted a later occurring increase in its own expression, suggesting a priming effect of early IGF-1 in driving post-weaning cortical maturation. Copyright © 2016 Elsevier Ltd. All rights reserved.
Boschen, K E; Keller, S M; Roth, T L; Klintsova, A Y
The long-term effects of developmental alcohol and stress exposure are well documented in both humans and non-human animal models. Damage to the brain and attendant life-long impairments in cognition and increased risk for psychiatric disorders are debilitating consequences of developmental exposure to alcohol and/or psychological stress. Here we discuss evidence for a role of epigenetic mechanisms in mediating these consequences. While we highlight some of the common ways in which stress or alcohol impact the epigenome, we point out that little is understood of the epigenome's response to experiencing both stress and alcohol exposure, though stress is a contributing factor as to why women drink during pregnancy. Advancing our understanding of this relationship is of critical concern not just for the health and well-being of individuals directly exposed to these teratogens, but for generations to come. Copyright © 2018 Elsevier Inc. All rights reserved.
A developmentally informed adaptation of minority stress for sexual minority adolescents
Goldbach, Jeremy T.; Gibbs, Jeremy J.
2017-01-01
Sexual minority adolescents (lesbian, gay, bisexual) experience disparities in behavioral health outcomes compared to their heterosexual peers, generally attributed to minority stress. Although evidence of the applicability of the minority stress model among adolescents exists, it is based on a primarily adult literature. Developmental and generational differences demand further examination of minority stress to confirm its applicability. Forty-eight life history interviews with sexual minority adolescents in California (age 14–19; M=19.27 SD = 1.38; 39.6% cismale, 35.4% cisfemale, 25% other gender) were completed, recorded, transcribed, and analyzed using thematic analysis in QSR NVivo. Following a consensus model, all transcripts were double coded. Results suggest that minority stress is appropriate for use with adolescents; however, further emphasis should be placed on social context, coping resources, and developmental processes regarding identity development. A conceptual model is provided, as are implications for research and practice. PMID:28033502
Chronic stress from adolescence to aging in the prefrontal cortex: A neuroimmune perspective.
Macht, Victoria A; Reagan, Lawrence P
2018-04-01
The development of the organism is a critical variable which influences the magnitude, duration, and reversibility of the effects of chronic stress. Such factors are relevant to the prefrontal cortex (PFC), as this brain region is the last to mature, the first to decline, and is highly stress-sensitive. Therefore, this review will examine the intersection between the nervous system and immune system at glutamatergic synapses in the PFC across three developmental periods: adolescence, adulthood, and aging. Glutamatergic synapses are tightly juxtaposed with microglia and astrocytes, and each of these cell types exhibits their own developmental trajectory. Not only does chronic stress differentially impact each of these cell types across development, but chronic stress also alters intercellular communication within this quad-partite synapse. These observations suggest that developmental shifts in both neural and immune function across neurons, microglia, and astrocytes mediate shifting effects of chronic stress on glutamatergic transmission. Copyright © 2018 Elsevier Inc. All rights reserved.
Parenting Children with Developmental Delays: The Role of Positive Beliefs
ERIC Educational Resources Information Center
Paczkowski, Emilie; Baker, Bruce L.
2008-01-01
Parents of children with developmental delays consistently report higher levels of child behavior problems and also parenting stress than parents of typically developing children. This study examined how mothers' positive beliefs influence the relation between children's behavior problems and mothers' parenting stress among families of children…
Post-Traumatic Stress Disorder in Young People with Intellectual Disability
ERIC Educational Resources Information Center
Turk, J.; Robbins, I.; Woodhead, M.
2005-01-01
Background: Post-traumatic stress disorder (PTSD) is common and treatable. There is extensive research on people of average intelligence yet little on individuals with developmental disabilities. Methods: We report two people with intellectual disability (ID) who experienced PTSD. The relevance of their developmental difficulties, social and…
Baskar, Venkidasamy; Park, Se Won
2015-07-01
Glucosinolates (GSL) are one of the major secondary metabolites of the Brassicaceae family. In the present study, we aim at characterizing the multiple paralogs of aliphatic GSL regulators, such as BrMYB28 and BrMYB29 genes in Brassica rapa ssp. pekinensis, by quantitative real-time PCR (qRT-PCR) analysis in different tissues and at various developmental stages. An overlapping gene expression pattern between the BrMYBs as well as their downstream genes (DSGs) was found at different developmental stages. Among the BrMYB28 and BrMYB29 paralogous genes, the BrMYB28.3 and BrMYB29.1 genes were dominantly expressed in most of the developmental stages, compared to the other paralogs of the BrMYB genes. Furthermore, the differential expression pattern of the BrMYBs was observed under various stress treatments. Interestingly, BrMYB28.2 showed the least expression in most developmental stages, while its expression was remarkably high in different stress conditions. More specifically, the BrMYB28.2, BrMYB28.3, and BrMYB29.1 genes were highly responsive to various abiotic and biotic stresses, further indicating their possible role in stress tolerance. Moreover, the in silico cis motif analysis in the upstream regulatory regions of BrMYBs showed the presence of various putative stress-specific motifs, which further indicated their responsiveness to biotic and abiotic stresses. These observations suggest that the dominantly expressed BrMYBs, both in different developmental stages and under various stress treatments (BrMYB28.3 and BrMYB29.1), may be potential candidate genes for altering the GSL level through genetic modification studies in B. rapa ssp. pekinensis. Copyright © 2015. Published by Elsevier SAS.
Cantwell, Joanne; Muldoon, Orla T; Gallagher, Stephen
2014-09-01
To date, much of the research linking the stress of caring for children with developmental disabilities (e.g. Autism & Down syndrome) with parental health outcomes have tended to concentrate on mental health with less attention paid to the physical health consequences. Thus, this study sought to explore the psychosocial predictors of poor physical health in these caring parents. One hundred and sixty-seven parents (109 caregivers and 58 control parents) completed measures of stress, child problem behaviours, social support, mastery and physical health. Parents of children with developmental disabilities had poorer physical health compared to control parents. Stress and mastery, but not social support and problem behaviours, were significant predictors of poor physical health within caring parents for children with developmental disabilities. However, the association between mastery and physical health was mediated by perceived stress such that those parents who were higher on mastery reported less stress and better physical health; furthermore, the association between stress and physical health was moderated by social support; those parents high on social support and low in stress had better physical health. These results indicate that the paths between psychosocial factors and poor physical health in the caring parents are working synergistically rather than in isolation. They also underscore the importance of providing multi-component interventions that offer a variety of psychosocial resources to meet the precise needs of the parents. Copyright © 2014 Elsevier Ltd. All rights reserved.
Could head circumference be used to screen for autism in young males with developmental delay?
Gray, Kylie M; Taffe, John; Sweeney, Deborah J; Forster, Sheridan; Tonge, Bruce J
2012-04-01
Research has suggested an abnormal acceleration in head circumference growth in children with autism within the first 12 months of life. This study aimed to examine head circumference at birth and head circumference growth rates in young children with autism and developmental delay, and young children with developmental delay without autism. This study assessed head circumference at birth and rate of change in head circumference in young children with autism (n=86) and children with developmental delay without autism (n=40). For both groups of children, head circumference at birth and head circumference growth were compared with Centers for Disease Control normative data. No differences were found between the group of children with autism and developmental delay compared with the group with developmental delay only. However, when the sample was compared with a range of selected Centers for Disease Control normative medians, the children with autism were found to have significantly smaller head circumferences at birth and significantly larger head circumference at 18.5 months of age. These results are discussed in relation to the potential of accelerated head circumference growth as an early marker for autism. This study failed to find a difference in the head circumferences of children with autism and developmental delay and children with developmental delay only, thus suggesting that head circumference measurement has limited value as an early marker for autism. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
Longitudinal and Integrative Tests of Family Stress Model Effects on Mexican-Origin Adolescents
White, Rebecca M. B.; Liu, Yu; Nair, Rajni L.; Tein, Jenn-Yun
2015-01-01
The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents’ cultural value orientations mitigated the effects of stressors on parenting disruptions and the degree to which environmental adversity qualified the effect of parenting on adolescent adjustment. We tested the hypothesized Integrative Family Stress Model longitudinally in a sample of mother-youth dyads (N = 749) and father-youth dyads (N = 467) from Mexican origin families, across three times points spanning early to middle adolescence. Providing the first longitudinal evidence of family stress mediated effects, mothers’ perceptions of economic pressure were associated with increases in adolescent externalizing symptoms five years later via intermediate increases in harsh parenting. The remaining findings supported the notion that integrative developmental theory can inform family stress model hypothesis testing that is culturally and contextually relevant for wide range of diverse families and youth. For example, fathers’ perceptions of economic pressure and neighborhood danger had important implications for adolescent internalizing, via reductions in paternal warmth, but only at certain levels of neighborhood adversity. Mothers’ familism value orientations mitigated the effects of economic pressure on maternal warmth, protecting their adolescents from experiencing developmental costs associated with environmental stressors. Results are discussed in terms of identifying how integrative developmental theory intersects with the family stress model to set diverse youth on different developmental pathways. PMID:25751100
Longitudinal and integrative tests of family stress model effects on Mexican origin adolescents.
White, Rebecca M B; Liu, Yu; Nair, Rajni L; Tein, Jenn-Yun
2015-05-01
The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents' cultural value orientations mitigated the effects of stressors on parenting disruptions and the degree to which environmental adversity qualified the effect of parenting on adolescent adjustment. We tested the hypothesized integrative family stress model longitudinally in a sample of mother-youth dyads (N = 749) and father-youth dyads (N = 467) from Mexican origin families, across 3 times points spanning early to middle adolescence. Providing the first longitudinal evidence of family stress mediated effects, mothers' perceptions of economic pressure were associated with increases in adolescent externalizing symptoms 5 years later via intermediate increases in harsh parenting. The remaining findings supported the notion that integrative developmental theory can inform family stress model hypothesis testing that is culturally and contextually relevant for a wide range of diverse families and youth. For example, fathers' perceptions of economic pressure and neighborhood danger had important implications for adolescent internalizing, via reductions in paternal warmth, but only at certain levels of neighborhood adversity. Mothers' familism value orientations mitigated the effects of economic pressure on maternal warmth, protecting their adolescents from experiencing developmental costs associated with environmental stressors. Results are discussed in terms of identifying how integrative developmental theory intersects with the family stress model to set diverse youth on different developmental pathways. (c) 2015 APA, all rights reserved).
Acceleration across California: Shorter Pathways in Developmental English and Math
ERIC Educational Resources Information Center
Hern, Katie
2012-01-01
Developmental courses in English, math, and reading have an important purpose in higher education, especially in the open-access world of community colleges. These classes--also referred to as "remedial"--are intended to give less-prepared students a chance to catch up and meet the challenges of college-level coursework. However,…
NASA Astrophysics Data System (ADS)
Waiz, Syma Ashraf; Raies-ul-Haq, Mohammad; Dhanda, Suman; Kumar, Anil; Goud, T. Sridhar; Chauhan, M. S.; Upadhyay, R. C.
2016-09-01
In vitro environments like heat stress usually increase the production of reactive oxygen species in bubaline oocytes which have been implicated as one of the major causes for reduced developmental competence. Oocytes during meiotic maturation are sensitive to oxidative stress, and heat stress accelerates cellular metabolism, resulting in the higher production of free radicals. Therefore, the aim of present work was to assess the impact of heat stress during meiotic maturation on bubaline cumulus-oocyte complexes (COC), denuded oocytes (DO), and cumulus cell mass in terms of their oxidative status. Accordingly, for control group, COC were matured at 38.5 °C for complete 24 h of meiotic maturation and heat stress of 40.5 and 41.5 °C was applied to COC during the first 12 h of maturation and then moved to 38.5 °C for rest of the 12 h. In another group, COC after maturation were denuded from the surrounding cumulus cells by manual pipetting. Results indicated that the production of reactive oxygen species (ROS), lipid peroxides, and nitric oxide (NO) was significantly ( P < 0.05) higher in the oocytes subjected to heat stress (40.5 and 41.5 °C) during meiotic maturation compared to the oocytes matured under standard in vitro culture conditions (38.5 °C). Also, the antioxidant enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were significantly ( P < 0.05) increased in all the treatment groups compared to the control group. Therefore, the present study clearly establishes that heat stress ensues oxidative stress in bubaline oocytes which triggers the induction of antioxidant enzymatic defense system for scavenging the ROS.
Campbell, W.B.; Emlen, J.M.; Hershberger, W.K.
1998-01-01
Developmental stability, or homeostasis, facilitates the production of consistent phenotypes by buffering against stress. Fluctuating asymmetry is produced by developmental instability and is manifested as small random departures from bilateral symmetry. Increased fluctuating asymmetry is thought to parallel compromised fitness, in part, because stress promotes energy dissipation. Compensatory energy expenditures within the organism are required to complete development, thus promoting instability through reductions in homeostasis. Increased heterozygosity may enhance developmental stability by reducing energy dissipation from stress through increased metabolic efficiency, possibly by providing greater flexibility in metabolic pathways. Traditionally, fluctuating asymmetry has been used as a bioindicator of chronic stress, provided that selective mortality of less fit individuals did not reduce stress-mediated increases in fluctuating asymmetry to background levels produced by natural developmental error, or create data inconsistencies such as higher asymmetry in groups exposed to lower stress. Unfortunately, absence of selective mortality and its effects, while often assumed, can be difficult to substantiate. We integrated measures of early growth, mortality, fluctuating asymmetry (mandibular pores, pectoral finrays, pelvic finrays, and gillrakers on the upper and lower arms of the first branchial arch) and directional asymmetry (branchiostegal rays) to assess chronic thermal stress (fluctuating temperatures as opposed to ambient temperatures) in developing eggs from two different coho salmon (Oncorhynchus kisutch) stocks and their reciprocal hybrids. Hybridization provided insight on the capacity of heterozygosity to reduce stress during development. Although egg losses were consistently higher in crosses exposed to fluctuating temperatures, egg mortality was predominantly a function of maternal stock of origin. Post-hatch losses were higher in crosses exposed to ambient temperatures than in crosses exposed to fluctuating temperatures during embryogenesis. Observed patterns of early growth revealed no heterosis, but instead reflected maternal effects, with some crosses slowing growth and yolk utilization when exposed to fluctuating temperatures. Analyses of fluctuating asymmetry also showed no effects from heterosis. While analyses of composite asymmetry scores and branchiostegal rays were inconclusive, analyses of individual characters showed significantly higher fluctuating asymmetry in pelvic finray counts and a marginal change in the numbers of fish asymmetric for this character in crosses exposed to chronic thermal stress. In contrast, the fluctuating asymmetry in lower gillraker counts was significantly higher in crosses exposed to ambient temperatures and there were significantly more fish asymmetric for this character. Data on mortalities and fluctuating asymmetry indicate pelvic finray development was thermally stressed, while the heightened fluctuating asymmetry in lower gillraker counts under ambient temperatures was due to a greater frequency of less fit fish that had not been culled by thermal stress. Changes in early growth patterns in response to developmental stress yielded no parallel responses in meristic characters. We conclude that chronic thermal stress produced both selectively lethal and sublethal effects that directly shaped fluctuating asymmetry and fitness profiles in these crosses. Implicit in this conclusion is that developmental instability analyses can detect more than just chronic sublethal stress, thus providing substantial credence for using instability studies as proactive bioassessment methodologies.
Recent advances in understanding Streptomyces
Chater, Keith F.
2016-01-01
About 2,500 papers dated 2014–2016 were recovered by searching the PubMed database for Streptomyces, which are the richest known source of antibiotics. This review integrates around 100 of these papers in sections dealing with evolution, ecology, pathogenicity, growth and development, stress responses and secondary metabolism, gene expression, and technical advances. Genomic approaches have greatly accelerated progress. For example, it has been definitively shown that interspecies recombination of conserved genes has occurred during evolution, in addition to exchanges of some of the tens of thousands of non-conserved accessory genes. The closeness of the association of Streptomyces with plants, fungi, and insects has become clear and is reflected in the importance of regulators of cellulose and chitin utilisation in overall Streptomyces biology. Interestingly, endogenous cellulose-like glycans are also proving important in hyphal growth and in the clumping that affects industrial fermentations. Nucleotide secondary messengers, including cyclic di-GMP, have been shown to provide key input into developmental processes such as germination and reproductive growth, while late morphological changes during sporulation involve control by phosphorylation. The discovery that nitric oxide is produced endogenously puts a new face on speculative models in which regulatory Wbl proteins (peculiar to actinobacteria) respond to nitric oxide produced in stressful physiological transitions. Some dramatic insights have come from a new model system for Streptomyces developmental biology, Streptomyces venezuelae, including molecular evidence of very close interplay in each of two pairs of regulatory proteins. An extra dimension has been added to the many complexities of the regulation of secondary metabolism by findings of regulatory crosstalk within and between pathways, and even between species, mediated by end products. Among many outcomes from the application of chromosome immunoprecipitation sequencing (ChIP-seq) analysis and other methods based on “next-generation sequencing” has been the finding that 21% of Streptomyces mRNA species lack leader sequences and conventional ribosome binding sites. Further technical advances now emerging should lead to continued acceleration of knowledge, and more effective exploitation, of these astonishing and critically important organisms. PMID:27990276
Maximum von Mises Stress in the Loading Environment of Mass Acceleration Curve
NASA Technical Reports Server (NTRS)
Glaser, Robert J.; Chen, Long Y.
2006-01-01
Method for calculating stress due to acceleration loading: 1) Part has been designed by FEA and hand calculation in one critical loading direction judged by the analyst; 2) Maximum stress can be due to loading in another direction; 3) Analysis procedure to be presented determines: a) The maximum Mises stress at any point; and b) The direction of maximum loading associated with the "stress". Concept of Mass Acceleration Curves (MAC): 1) Developed by JPL to perform preliminary structural sizing (i.e. Mariners, Voyager, Galileo, Pathfinder, MER,...MSL); 2) Acceleration of physical masses are bounded by a curve; 3) G-levels of vibro-acoustic and transient environments; 4) Convergent process before the couple loads cycle; and 5) Semi-empirical method to effectively bound the loads, not a simulation of the actual response.
Accelerated stress testing of terrestrial solar cells
NASA Technical Reports Server (NTRS)
Prince, J. L.; Lathrop, J. W.
1979-01-01
A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.
Long-term moderate exercise accelerates the recovery of stress-evoked cardiovascular responses.
Hsu, Yuan-Chang; Tsai, Sheng-Feng; Yu, Lung; Chuang, Jih-Ing; Wu, Fong-Sen; Jen, Chauying J; Kuo, Yu-Min
2016-01-01
Psychological stress is an important global health problem. It is well documented that stress increases the incidences of various cardiovascular disorders. Regular exercise is known to reduce resting blood pressure (BP) and heart rate (HR). This study was designed to clarify the effects of long-term exercise on stress-evoked cardiovascular responses and to emphasize post-stress recovery effects. Male Wistar rats underwent 8 weeks of moderate treadmill training, with cardiovascular responses, autonomic nervous system activities and local Fos reactivity changes in the cardiovascular regulation center were monitored before, during and after immobilization stress. A spectral analysis of cardiovascular parameters was used to examine autonomic nervous activities. We found that long-term exercise (i) lowered resting BP, HR and sympathetic activity, but increased resting parasympathetic activity and baroreflex sensitivity (BRS); (ii) accelerated post-stress recovery of stress-evoked cardiovascular and sympathetic responses along with increased BRS and (iii) accelerated post-stress recovery of stress-evoked neuron activations in the paraventricular nucleus, but delayed it in the nucleus of the tractus solitarius. We conclude that, in rats, long-term exercise accelerated recovery of stress-evoked cardiovascular responses differentially altering hypothalamic and medullar neuron activities.
Take a Breath: Yoga and Meditation in the Developmental Classroom
ERIC Educational Resources Information Center
Arbeau, Denise Cady
2016-01-01
Teachers of developmental education are familiar with non-traditional students who are balancing innumerate stressors in their lives, in addition to the overwhelming stress of college. Stress relief methods like yoga and meditation are essential life management tools in helping new college students succeed, not only in their education but also in…
ERIC Educational Resources Information Center
Wyman, Peter A.; And Others
1999-01-01
Tested hypotheses from an organizational-developmental model for childhood resilience among 7- to 9-year olds. Found that caregiving factors and early development differentiated children with resilient and stress-affected adaptations. Variables reflecting emotionally responsive, competent parenting were direct, proximal predictors of resilience…
ERIC Educational Resources Information Center
Ó Donnchadha, Seán
2018-01-01
Background: The efficacy of mindfulness-based interventions (MBIs) for stress and psychological distress in professional caregivers supporting individuals with intellectual or developmental disabilities (IDDs) is reviewed. Methods: Eight studies met inclusion criteria and were systematically reviewed, including RCTs and single-group designs.…
ERIC Educational Resources Information Center
Cervantes, Richard C.; Cordova, David
2011-01-01
Hispanic youth currently constitute the largest and fastest growing of all ethnic and racial groups in the United States. In addition to normal developmental life stressors, Hispanic youth also face minority status and acculturation-related stress. This study examined the psychosocial and acculturative stressors of Hispanic youth (n=170) residing…
ERIC Educational Resources Information Center
McDade, Thomas W.; Worthman, Carol M.
2004-01-01
Rapid globalization is forcing youth around the world to confront new developmental challenges, and conceptual models are needed that can capture this experience and its developmental implications. Exposure to nontraditional lifestyles opens up new socialization opportunities and raises the possibility of stress-inducing dissonance between…
NASA Technical Reports Server (NTRS)
Imig, L. A.; Garrett, L. E.
1973-01-01
Possibilities for reducing fatigue-test time for supersonic-transport materials and structures were studied in tests with simulated flight-by-flight loading. In order to determine whether short-time tests were feasible, the results of accelerated tests (2 sec per flight) were compared with the results of real-time tests (96 min per flight). The effects of design mean stress, the stress range for ground-air-ground cycles, simulated thermal stress, the number of stress cycles in each flight, and salt corrosion were studied. The flight-by-flight stress sequences were applied to notched sheet specimens of Ti-8Al-1Mo-1V and Ti-6Al-4V titanium alloys. A linear cumulative-damage analysis accounted for large changes in stress range of the simulated flights but did not account for the differences between real-time and accelerated tests. The fatigue lives from accelerated tests were generally within a factor of two of the lives from real-time tests; thus, within the scope of the investigation, accelerated testing seems feasible.
Wircer, Einav; Blechman, Janna; Borodovsky, Nataliya; Tsoory, Michael; Nunes, Ana Rita; Oliveira, Rui F; Levkowitz, Gil
2017-01-01
Proper response to stress and social stimuli depends on orchestrated development of hypothalamic neuronal circuits. Here we address the effects of the developmental transcription factor orthopedia (Otp) on hypothalamic development and function. We show that developmental mutations in the zebrafish paralogous gene otpa but not otpb affect both stress response and social preference. These behavioral phenotypes were associated with developmental alterations in oxytocinergic (OXT) neurons. Thus, otpa and otpb differentially regulate neuropeptide switching in a newly identified subset of OXT neurons that co-express the corticotropin-releasing hormone (CRH). Single-cell analysis revealed that these neurons project mostly to the hindbrain and spinal cord. Ablation of this neuronal subset specifically reduced adult social preference without affecting stress behavior, thereby uncoupling the contribution of a specific OXT cluster to social behavior from the general otpa−/− deficits. Our findings reveal a new role for Otp in controlling developmental neuropeptide balance in a discrete OXT circuit whose disrupted development affects social behavior. DOI: http://dx.doi.org/10.7554/eLife.22170.001 PMID:28094761
Chan, Priscilla T; Doan, Stacey N; Tompson, Martha C
2014-02-01
The present study examined stress generation in a developmental and family context among 171 mothers and their preadolescent children, ages 8-12 years, at baseline (Time 1) and 1-year follow-up (Time 2). In the current study, we examined the bidirectional relationship between children's depressive symptoms and dependent family stress. Results suggest that children's baseline level of depressive symptoms predicted the generation of dependent family stress 1 year later. However, baseline dependent family stress did not predict an increase in children's depressive symptoms 1 year later. In addition, we examined whether a larger context of both child chronic strain (indicated by academic, behavioral, and peer stress) and family factors, including socioeconomic status and parent-child relationship quality, would influence the stress generation process. Although both chronic strain and socioeconomic status were not associated with dependent family stress at Time 2, poorer parent-child relationship quality significantly predicted greater dependent family stress at Time 2. Child chronic strain, but neither socioeconomic status nor parent-child relationship quality, predicted children's depression symptoms at Time 2. Finally, gender, maternal depression history, and current maternal depressive symptoms did not moderate the relationship between level of dependent family stress and depressive symptoms. Overall, findings provide partial support for a developmental stress generation model operating in the preadolescent period.
Moffitt, Terrie E; Baker, Timothy B; Biddle, Andrea K; Evans, James P; Harrington, HonaLee; Houts, Renate; Meier, Madeline; Sugden, Karen; Williams, Benjamin; Poulton, Richie; Caspi, Avshalom
2013-01-01
OBJECTIVE To test how genomic loci identified in genome-wide association studies (GWAS) influence the developmental progression of smoking behavior. DESIGN A 38-year prospective longitudinal study of a representative birth-cohort. SETTING The Dunedin Multidisciplinary Health and Development Study, New Zealand. PARTICIPANTS N=1037 male and female study members. MAIN EXPOSURES We assessed genetic risk with a multi-locus genetic risk score (GRS). The GRS was composed of single-nucleotide polymorphisms identified in three meta-analyses of GWAS of smoking quantity phenotypes. OUTCOME MEASURES Smoking initiation, conversion to daily smoking, progression to heavy smoking, nicotine dependence (Fagerstrom Test of Nicotine Dependence), and cessation difficulties were evaluated at eight assessments spanning ages 11-38 years. RESULTS Genetic risk score was unrelated to smoking initiation. However, individuals at higher genetic risk were more likely to convert to daily smoking as teenagers, progressed more rapidly from smoking initiation to heavy smoking, persisted longer in smoking heavily, developed nicotine dependence more frequently, were more reliant on smoking to cope with stress, and were more likely to fail in their cessation attempts. Further analysis revealed that two adolescent developmental phenotypes—early conversion to daily smoking and rapid progression to heavy smoking--mediated associations between the genetic risk score and mature phenotypes of persistent heavy smoking, nicotine dependence, and cessation failure. The genetic risk score predicted smoking risk over and above family history. CONCLUSIONS Initiatives that disrupt the developmental progression of smoking behavior among adolescents may mitigate genetic risks for developing adult smoking problems. Future genetic research may maximize discovery potential by focusing on smoking behavior soon after smoking initiation and by studying young smokers. PMID:23536134
Assessing hopping developmental level in childhood using wearable inertial sensor devices.
Masci, Ilaria; Vannozzi, Giuseppe; Getchell, Nancy; Cappozzo, Aurelio
2012-07-01
Assessing movement skills is a fundamental issue in motor development. Current process-oriented assessments, such as developmental sequences, are based on subjective judgments; if paired with quantitative assessments, a better understanding of movement performance and developmental change could be obtained. Our purpose was to examine the use of inertial sensors to evaluate developmental differences in hopping over distance. Forty children executed the task wearing the inertial sensor and relevant time durations and 3D accelerations were obtained. Subjects were also categorized in different developmental levels according to the hopping developmental sequence. Results indicated that some time and kinematic parameters changed with some developmental levels, possibly as a function of anthropometry and previous motor experience. We concluded that, since inertial sensors were suitable in describing hopping performance and sensitive to developmental changes, this technology is promising as an in-field and user-independent motor development assessment tool.
Fluctuating asymmetry and stress in a medieval Nubian population.
Deleon, Valerie B
2007-04-01
Fluctuating asymmetry is commonly used as a bioindicator of developmental stress. This study addresses asymmetry under nutritional/systemic stress in the human craniofacial skeleton and its utility as an indicator of developmental instability. Crania from the diachronic Christian cemeteries at Kulubnarti (Sudanese Nubia) were chosen as a model for nutrition/systemic stress. Previous studies indicate that individuals from the Early Christian cemetery were subjected to greater developmental stress when compared with individuals from the Late Christian cemetery. Therefore, crania from the Early Christian cemetery should display a greater magnitude of fluctuating asymmetry than crania from the Late Christian cemetery. Thirty adult crania of comparable age and sex were selected from each population. Landmark coordinates were digitized in two separate trials and averaged to minimize error. Euclidean distance matrix analysis (EDMA) was used to measure and compare the magnitude of fluctuating asymmetry in each sample. Results indicate that crania from the Early Christian cemetery display greater amounts of fluctuating asymmetry than those from the Late Christian cemetery, as predicted. The degree of fluctuating asymmetry for each linear distance is highly correlated between the cemeteries, suggesting that all humans may share common patterns of fluctuating asymmetry in the skull. In contrast, there is little correlation between magnitude of fluctuating asymmetry and length of linear distance, between-subject variability, or measurement error. These results support the hypothesis that poor nutrition/systemic stress increases developmental instability in the human skull and that increased fluctuating asymmetry constitutes morphological evidence of this stress.
Another Look at Strong Ground Motion Accelerations and Stress Drop
NASA Astrophysics Data System (ADS)
Baltay, A.; Prieto, G.; Ide, S.; Hanks, T. C.; Beroza, G. C.
2010-12-01
The relationship between earthquake stress drop and ground motion acceleration is central to seismic hazard analysis. We revisit measurements of root-mean-square (RMS) acceleration, arms, using KikNet accelerometer data from Japan. We directly measure RMS and peak acceleration, and estimate both apparent stress and corner frequencies using the empirical Green’s function (eGf) coda method of Baltay et al. [2010]. We predict armsfrom corner frequency and stress drop following McGuire and Hanks [1980] to compare with measurements. The theoretical relationship does a good job of predicting observed arms. We use four earthquake sequences in Japan to investigate the source parameters and accelerations: the 2008 Iwate-Miyagi earthquake; the off-Kamaishi repeating sequence; and the 2004 and 2007 Niigata events. In each data set, we choose events that are nearly co-located so that the path term to any station is constant. Small events are used as empirical Green’s functions to correct for propagation effects. For all sequences, we find that the apparent stress averages ~1 MPa for most events. Corner frequencies are consistent with Mo-1/3 scaling. We find the ratio of stress drop and apparent stress to be 5, consistent with the theoretical derivation of Singh and Ordaz [1994], using a Brune [1970] spectra. armsis theoretically proportional to stress drop and the inverse square root of the corner frequency. We show that this calculation can be used as a proxy for armsobservations from strong motion records, using recent data from the four earthquake sequences mentioned above. Even for the Iwate-Miyagi mainshock, which experienced over 4 g’s of acceleration, we find that apparent stress, stress drop and corner frequency follow expected scaling laws and support self-similarity.
Oshri, Assaf; Schwartz, Seth J; Unger, Jennifer B; Kwon, Josephine A; Des Rosiers, Sabrina E; Baezconde-Garbanati, Lourdes; Lorenzo-Blanco, Elma I; Córdova, David; Soto, Daniel W; Lizzi, Karina M; Villamar, Juan A; Szapocznik, José
2014-12-01
Hispanic immigrant youth engage in increased health risk behaviors, such as alcohol misuse, due in part to being confronted with acculturative stress in addition to facing major normative developmental challenges, such as identity consolidation (Berry et al. in Appl Psychol 55:303-332, 2006). Using a developmental psychopathology framework, in the present study we examined the effect of bicultural stress on alcohol misuse among immigrated Hispanic adolescents, indirectly through trajectories of identity formation and alcohol expectancies. Our sample consisted of 302 recently immigrated Hispanic adolescents (53 % male; Mage = 14.5 at baseline) who were interviewed every 6 months for 3 years. Bivariate growth curve modeling was used to examine the influence of initial early bicultural stress on later alcohol misuse via change in identity development (i.e., coherence and confusion) and subsequent growth in cognitive alcohol expectancies. Findings revealed that initial levels and growth of identity coherence were not significantly associated with either bicultural stress or tension reduction (TR) alcohol expectancies. Multiple mediation analyses indicated that the effect of bicultural stress at time 1 on the frequency of being drunk at time 6 was mediated via high initial levels of identity confusion, followed by growth in risky TR expectancies (T4-T6). A developmental approach to the genesis of alcohol use problems in immigrant youth is discussed.
Jiang, Yuanzhong; Duan, Yanjiao; Yin, Jia; Ye, Shenglong; Zhu, Jingru; Zhang, Faqi; Lu, Wanxiang; Fan, Di; Luo, Keming
2014-01-01
WRKY proteins are a large family of regulators involved in various developmental and physiological processes, especially in coping with diverse biotic and abiotic stresses. In this study, 100 putative PtrWRKY genes encoded the proteins contained in the complete WRKY domain in Populus. Phylogenetic analysis revealed that the members of this superfamily among poplar, Arabidopsis, and other species were divided into three groups with several subgroups based on the structures of the WRKY protein sequences. Various cis-acting elements related to stress and defence responses were found in the promoter regions of PtrWRKY genes by promoter analysis. High-throughput transcriptomic analyses identified that 61 of the PtrWRKY genes were induced by biotic and abiotic treatments, such as Marssonina brunnea, salicylic acid (SA), methyl jasmonate (MeJA), wounding, cold, and salinity. Among these PtrWRKY genes, transcripts of 46 selected genes were observed in different tissues, including roots, stems, and leaves. Quantitative RT-PCR analysis further confirmed the induced expression of 18 PtrWRKY genes by one or more stress treatments. The overexpression of an SA-inducible gene, PtrWRKY89, accelerated expression of PR protein genes and improved resistance to pathogens in transgenic poplar, suggesting that PtrWRKY89 is a regulator of an SA-dependent defence-signalling pathway in poplar. Taken together, our results provided significant information for improving the resistance and stress tolerance of woody plants. PMID:25249073
Escos, J.; Alados, C.L.; Pugnaire, F. I.; Puigdefábregas, J.; Emlen, J.
2000-01-01
This paper investigates allocation of energy to mechanisms that generate and preserve architectural forms (i.e. developmental stability, complexity of branching patterns) and productivity (growth and reproduction) in response to environmental disturbances (i.e. grazing and resource availability). The statistical error in translational symmetry was used to detect random intra-individual variability during development. This can be thought of as a measure of developmental instability caused by stress. Additionally, we use changes in fractal complexity and shoot distribution of branch structures as an alternate indicator of stress. These methods were applied to Anthyllis cytisoides L., a semi-arid environment shrub, to ascertain the effect of grazing and slope exposure on developmental traits in a 2×2 factorial design. The results show that A. cytisoidesmaintains developmental stability at the expense of productivity. Anthyllis cytisoides was developmentally more stable when grazed and when on south-facing, as opposed to north-facing slopes. On the contrary, shoot length, leaf area, fractal dimension and reproductive-to-vegetative allocation ratio were larger in north- than in south-facing slopes. As a consequence, under extreme xeric conditions, shrub mortality increased in north-facing slopes, especially when not grazed. The removal of transpiring area and the reduction of plant competition favoured developmental stability and survival in grazed plants. Differences between grazed and ungrazed plants were most evident in more mesic (north-facing) areas.
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.
ERIC Educational Resources Information Center
Weissman, Evan; Butcher, Kristin F.; Schneider, Emily; Teres, Jedediah; Collado, Herbert; Greenberg, David
2011-01-01
Queensborough Community College and Houston Community College are two large, urban institutions that offer learning communities for their developmental math students, with the goals of accelerating students' progress through the math sequence and of helping them to perform better in college and ultimately earn degrees or certificates. They are…
ERIC Educational Resources Information Center
Weissman, Evan; Butcher, Kristin F.; Schneider, Emily; Teres, Jedediah; Collado, Herbert; Greenberg, David
2011-01-01
Queensborough Community College and Houston Community College are two large, urban institutions that offer learning communities for their developmental math students, with the goals of accelerating students' progress through the math sequence and of helping them to perform better in college and ultimately earn degrees or certificates. They are…
ERIC Educational Resources Information Center
de Oliveira, Rita F.; Wann, John P.
2011-01-01
In two experiments, we used an automatic car simulator to examine the steering control, speed regulation and response to hazards of young adults with developmental coordination disorder (DCD) and limited driving experience. In Experiment 1 participants either used the accelerator pedal to regulate their speed, or used the brake pedal when they…
A study on task difficulty and acceleration stress
NASA Technical Reports Server (NTRS)
Repperger, D. W.; Rogers, D. B.
1981-01-01
The results of two experiments which relate to task difficulty and the effects of environmental stress on tracking performance are discussed and compared to subjective evaluations. The first experiment involved five different sum of sine tracking tasks which humans tracked both in a static condition and under a 5 Gz acceleration stress condition. The second experiment involved similar environmental stress conditions but in this case the tasks were constructed from deterministic functions with specially designed velocity and acceleration profiles. Phase Plane performance analysis was conducted to study potential measures of workload or tracking difficulty.
Parental Divorce and Initiation of Alcohol Use in Early Adolescence
Jackson, Kristina M.; Rogers, Michelle L.; Sartor, Carolyn E.
2016-01-01
Parental divorce/separation is among the most commonly endorsed adverse childhood events and has been shown to increase subsequent risk of alcohol dependence and problems across adolescence and early adulthood, but its influence on early stages of alcohol involvement has only recently been explored. The present study examined whether time to first full drink was accelerated among youth who experienced parental divorce/separation. To determine specificity of risk, models controlled for perceived stress as well as family history of alcoholism, current parental drinking, and internalizing and externalizing problems. Developmental specificity in terms of timing of both parental divorce and first drink was also examined. Participants were 931 middle-school students who were enrolled in a prospective study on drinking initiation and progression (52% female; 23% non-White, 11% Hispanic). Students indicated whether and at what age they had consumed a full drink of alcohol. Parental divorce/separation was coded from a parent-reported life events inventory and was grouped based on age experienced (ages 0–5, ages 6–9, age 10+). Cox proportional-hazard models showed increased risk for onset of drinking as a function of divorce/separation, even controlling for stress, parental alcohol involvement, and psychopathology. There was no evidence for developmental specificity of the divorce/separation effect based on when it occurred nor in timing of first drink. However, the effect of parental divorce/separation on initiation was magnified at higher levels of parental drinking. Given the rates of parental divorce/separation and its association with increased risk of early drinking, investigation of the mechanisms underlying this link is clearly warranted. PMID:27322803
Gemmel, Mary; Rayen, Ine; Lotus, Tiffany; van Donkelaar, Eva; Steinbusch, Harry W; De Lacalle, Sonsoles; Kokras, Nikolaos; Dalla, Christina; Pawluski, Jodi L
2016-04-01
Selective serotonin reuptake inhibitor medication exposure during the perinatal period can have a long term impact in adult offspring on neuroplasticity and the serotonergic system, but the impact of these medications during early development is poorly understood. The aim of this study was to determine the effects of developmental exposure to the SSRI, fluoxetine, on the serotonergic system, dopaminergic system, and synaptophysin density in the prefrontal cortex and hippocampus, as well as number of immature neurons in the dentate gyrus, in juvenile rat offspring at weaning. To model aspects of maternal depression, prenatal restraint stress was used. Sprague-Dawley rat offspring were exposed to either prenatal stress and/or fluoxetine. Main findings show that developmental fluoxetine exposure to prenatally stressed offspring decreased 5-HT and 5-HIAA levels and altered the dopaminergic system in the hippocampus. Prenatal stress, regardless of fluoxetine, increased synaptophysin density in the PFC. This work indicates that early exposure to maternal stress and SSRI medication can alter brain monoamine levels and synaptophysin density in offspring at weaning. © 2015 Wiley Periodicals, Inc.
Lee, Who-Seung; Monaghan, Pat; Metcalfe, Neil B
2016-04-01
Fluctuations in early developmental conditions can cause changes in growth trajectories that subsequently affect the adult phenotype. Here, we investigated whether compensatory growth has long-term consequences for patterns of senescence.Using three-spined sticklebacks ( Gasterosteus aculeatus ), we show that a brief period of dietary manipulation in early life affected skeletal growth rate not only during the manipulation itself, but also during a subsequent compensatory phase when fish caught up in size with controls.However, this growth acceleration influenced swimming endurance and its decline over the course of the breeding season, with a faster decline in fish that had undergone faster growth compensation.Similarly, accelerated growth led to a more pronounced reduction in the breeding period (as indicated by the duration of sexual ornamentation) over the following two breeding seasons, suggesting faster reproductive senescence. Parallel experiments showed a heightened effect of accelerated growth on these age-related declines in performance if the fish were under greater time stress to complete their compensation prior to the breeding season.Compensatory growth led to a reduction in median life span of 12% compared to steadily growing controls. While life span was independent of the eventual adult size attained, it was negatively correlated with the age-related decline in swimming endurance and sexual ornamentation.These results, complementary to those found when growth trajectories were altered by temperature rather than dietary manipulations, show that the costs of accelerated growth can last well beyond the time over which growth rates differ and are affected by the time available until an approaching life-history event such as reproduction.
NASA Technical Reports Server (NTRS)
Jiang, L.; Salisbury, F. B.; Campbell, W. F.; Carman, J. G.; Nan, R.
1998-01-01
Super-Dwarf wheat plants were grown in growth chambers under 12 treatments with three photoperiods (18 h, 21 h, 24 h) and four carbon dioxide (CO2) levels (360, 1,200, 3,000 and 7,000 micromoles mol-1). Carbon dioxide concentrations affected flower initiation rates of Super-Dwarf wheat. The optimum CO2 level for flower initiation and development was 1,200 micromoles mol-1. Super-optimum CO2 levels delayed flower initiation, but did not decrease final flower bud number per head. Longer photoperiods not only accelerated flower initiation rates, but also decreased deleterious effects of super-optimum CO2. Flower bud size and head length at the same developmental stage were larger under longer photoperiods, but final flower bud number was not affected by photoperiod.
ERIC Educational Resources Information Center
Blair, Clancy
2010-01-01
The relation of stress hormones and activity in stress response systems to the development of aspects of cognition and behavior important for educational achievement and attainment is examined from the perspective of the developmental psychobiological model. It is proposed that research in neuroendocrinology supports three general conclusions,…
Chen, Kun; Tsutsumi, Yuki; Yoshitake, Shuhei; Qiu, Xuchun; Xu, Hai; Hashiguchi, Yasuyuki; Honda, Masato; Tashiro, Kosuke; Nakayama, Kei; Hano, Takeshi; Suzuki, Nobuo; Hayakawa, Kazuichi; Shimasaki, Yohei; Oshima, Yuji
2017-01-01
Benzo[c]phenanthrene (BcP) is a highly toxic polycyclic aromatic hydrocarbon (PAHs) found throughout the environment. In fish, it is metabolized to 3-hydroxybenzo[c]phenanthrene (3-OHBcP). In the present study, we observed the effects of 1nM 3-OHBcP on the development and gene expression of Japanese medaka (Oryzias latipes) embryos. Embryos were nanoinjected with the chemical after fertilization. Survival, developmental stage, and heart rate of the embryos were observed, and gene expression differences were quantified by messenger RNA sequencing (mRNA-Seq). The exposure to 1nM 3-OHBcP accelerated the development of medaka embryos on the 1st, 4th, and 6th days post fertilization (dpf), and increased heart rates significantly on the 5th dpf. Physical development differences of exposed medaka embryos were consistent with the gene expression profiles of the mRNA-Seq results for the 3rd dpf, which show that the expression of 780 genes differed significantly between the solvent control and 1nM 3-OHBcP exposure groups. The obvious expression changes in the exposure group were found for genes involved in organ formation (eye, muscle, heart), energy supply (ATPase and ATP synthase), and stress-response (heat shock protein genes). The acceleration of development and increased heart rate, which were consistent with the changes in mRNA expression, suggested that 3-OHBcP affects the development of medaka embryos. The observation on the developmental stages and heart beat, in ovo-nanoinjection and mRNA-Seq may be efficient tools to evaluate the effects of chemicals on embryos. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Douglas, Freddie, III
2004-01-01
The accelerated Leadership Option (ALO) combines business management and systems engineering studies at the Massachusetts Institute of Technology (MIT) culminating in a Master of Science degree, with a one year developmental assignment. The program accelerates the development process of exceptionally promising project leaders to positions of increased responsibility. Participants are selected because of technical expertise and proven leadership abilities.
Jensen, Sarah K G; Dumontheil, Iroise; Barker, Edward D
2014-07-01
Maternal depression and contextual risks (e.g. poverty) are known to impact children's cognitive and social functioning. However, few published studies have examined how stress in the social environment (i.e. interpersonal stress) might developmentally inter-relate with maternal depression and contextual risks to negatively affect a child in these domains. This was the purpose of the current study. Mother-child pairs (n = 6979) from the Avon Longitudinal Study of Parents were the study participants. Mothers reported on depression, contextual risks, and interpersonal stress between pregnancy and 33 months child age. At age 8, the children underwent cognitive assessments and the mothers reported on the children's social cognitive skills. Maternal depression, contextual risks, and interpersonal stress showed strong continuity and developmental inter-relatedness. Maternal depression and contextual risks directly predicted a range of child outcomes, including executive functions and social cognitive skills. Interpersonal stress worked indirectly via maternal depression and contextual risks to negatively affect child outcomes. Maternal depression and contextual risks each increased interpersonal stress in the household, which, in turn, contributed to reduced child cognitive and social functioning. © 2013 Wiley Periodicals, Inc.
A Statistical Perspective on Highly Accelerated Testing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thomas, Edward V.
Highly accelerated life testing has been heavily promoted at Sandia (and elsewhere) as a means to rapidly identify product weaknesses caused by flaws in the product's design or manufacturing process. During product development, a small number of units are forced to fail at high stress. The failed units are then examined to determine the root causes of failure. The identification of the root causes of product failures exposed by highly accelerated life testing can instigate changes to the product's design and/or manufacturing process that result in a product with increased reliability. It is widely viewed that this qualitative use ofmore » highly accelerated life testing (often associated with the acronym HALT) can be useful. However, highly accelerated life testing has also been proposed as a quantitative means for "demonstrating" the reliability of a product where unreliability is associated with loss of margin via an identified and dominating failure mechanism. It is assumed that the dominant failure mechanism can be accelerated by changing the level of a stress factor that is assumed to be related to the dominant failure mode. In extreme cases, a minimal number of units (often from a pre-production lot) are subjected to a single highly accelerated stress relative to normal use. If no (or, sufficiently few) units fail at this high stress level, some might claim that a certain level of reliability has been demonstrated (relative to normal use conditions). Underlying this claim are assumptions regarding the level of knowledge associated with the relationship between the stress level and the probability of failure. The primary purpose of this document is to discuss (from a statistical perspective) the efficacy of using accelerated life testing protocols (and, in particular, "highly accelerated" protocols) to make quantitative inferences concerning the performance of a product (e.g., reliability) when in fact there is lack-of-knowledge and uncertainty concerning the assumed relationship between the stress level and performance. In addition, this document contains recommendations for conducting more informative accelerated tests.« less
Prenatal stress and inhibitory neuron systems: implications for neuropsychiatric disorders
Fine, Rebecca; Zhang, Jie; Stevens, Hanna E.
2014-01-01
Prenatal stress is a risk factor for several psychiatric disorders in which inhibitory neuron pathology is implicated. A growing body of research demonstrates that inhibitory circuitry in the brain is directly and persistently affected by prenatal stress. This review synthesizes research that elucidates how this early, developmental risk factor impacts inhibitory neurons and how these findings intersect with research on risk factors and inhibitory neuron pathophysiology in schizophrenia, anxiety, autism and Tourette syndrome. The specific impact of prenatal stress on inhibitory neurons, particularly developmental mechanisms, may elucidate further the pathophysiology of these disorders. PMID:24751963
Mothers of children with developmental disabilities: stress in early and middle childhood.
Azad, Gazi; Blacher, Jan; Marcoulides, George A
2013-10-01
Using a sample of 219 families of children with (n=94) and without (n=125) developmental disabilities, this study examined the longitudinal perspectives of maternal stress in early (ages 3-5) and middle childhood (ages 6-13) and its relationship to mothers' and children's characteristics. Multivariate latent curve models indicated that maternal stress remained high and stable with minimal individual variation in early childhood, but declined with significant individual variation in middle childhood. Maternal stress at the beginning of middle childhood was associated with earlier maternal stress, as well as children's behavioral problems and social skills. The trajectory of maternal stress across middle childhood was related to children's behavioral problems. Implications for interventions are discussed. Copyright © 2013. Published by Elsevier Ltd.
Boulle, Fabien; Pawluski, Jodi L; Homberg, Judith R; Machiels, Barbie; Kroeze, Yvet; Kumar, Neha; Steinbusch, Harry W M; Kenis, Gunter; van den Hove, Daniel L A
2016-04-01
A growing number of infants are exposed to selective serotonin reuptake inhibitor (SSRI) medications during the perinatal period. Perinatal exposure to SSRI medications alter neuroplasticity and increase depressive- and anxiety-related behaviors, particularly in male offspring as little work has been done in female offspring to date. The long-term effects of SSRI on development can also differ with previous exposure to prenatal stress, a model of maternal depression. Because of the limited work done on the role of developmental SSRI exposure on neurobehavioral outcomes in female offspring, the aim of the present study was to investigate how developmental fluoxetine exposure affects anxiety and depression-like behavior, as well as the regulation of hippocampal brain-derived neurotrophic factor (BDNF) signaling in the hippocampus of adult female offspring. To do this female Sprague-Dawley rat offspring were exposed to prenatal stress and fluoxetine via the dam, for a total of four groups of female offspring: 1) No Stress+Vehicle, 2) No Stress+Fluoxetine, 3) Prenatal Stress+Vehicle, and 4) Prenatal Stress+Fluoxetine. Primary results show that, in adult female offspring, developmental SSRI exposure significantly increases behavioral despair measures on the forced swim test, decreases hippocampal BDNF exon IV mRNA levels, and increases levels of the repressive histone 3 lysine 27 tri-methylated mark at the corresponding promoter. There was also a significant negative correlation between hippocampal BDNF exon IV mRNA levels and immobility in the forced swim test. No effects of prenatal stress or developmental fluoxetine exposure were seen on tests of anxiety-like behavior. This research provides important evidence for the long-term programming effects of early-life exposure to SSRIs on female offspring, particularily with regard to affect-related behaviors and their underlying molecular mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.
Wong, Jen D.; Mailick, Marsha R.; Greenberg, Jan S.; Hong, Jinkuk; Coe, Christopher L.
2014-01-01
The effect of daily work stress on the next morning’s awakening cortisol level was determined in a sample of 124 mothers (M age = 49.89, SD= 6.33) of adolescents and adults with developmental disabilities and compared to 115 mothers (M age = 46.19, SD = 7.08) of individuals without disabilities. Mothers participated in 8 days of diary telephone interviews and provided saliva samples. Multilevel models revealed that mothers of individuals with developmental disabilities had lower awakening cortisol levels than comparison mothers. Work stress interacted with parental status to predict the awakening cortisol level on the following morning. When mothers of individuals with developmental disabilities experienced a work stressor, their awakening cortisol level was significantly higher on the subsequent morning, but for comparison mothers, work stressors were not significantly associated with cortisol level. Findings extend understanding of the differential impacts of specific types of stressors on physiological functioning of mothers of individuals with and without developmental disabilities. PMID:25313265
ERIC Educational Resources Information Center
Sladeczek, Ingrid E.; Fontil, Laura; Miodrag, Nancy; Karagiannakis, Anastasia; Amar, Daniel; Amos, Janet
2017-01-01
This study compares two service delivery models (community-based and centre-based), examining them in light of children's adaptive and maladaptive behaviours, and parental perceptions of stress and of care. More specifically, parents of 96 children with developmental delays assessed their children's adaptive and maladaptive behaviours and rated…
Hahn, Mark E.; Timme-Laragy, Alicia R.; Karchner, Sibel I.; Stegeman, John J.
2015-01-01
Oxidative stress is an important mechanism of chemical toxicity, contributing to developmental toxicity and teratogenesis as well as to cardiovascular and neurodegenerative diseases and diabetic embryopathy. Developing animals are especially sensitive to effects of chemicals that disrupt the balance of processes generating reactive species and oxidative stress, and those anti-oxidant defenses that protect against oxidative stress. The expression and inducibility of anti-oxidant defenses through activation of NFE2-related factor 2 (Nrf2) and related proteins is an essential process affecting the susceptibility to oxidants, but the complex interactions of Nrf2 in determining embryonic response to oxidants and oxidative stress are only beginning to be understood. The zebrafish (Danio rerio) is an established model in developmental biology and now also in developmental toxicology and redox signaling. Here we review the regulation of genes involved in protection against oxidative stress in developing vertebrates, with a focus on Nrf2 and related cap’n’collar (CNC)-basic-leucine zipper (bZIP) transcription factors. Vertebrate animals including zebrafish share Nfe2, Nrf1, Nrf2, and Nrf3 as well as a core set of genes that respond to oxidative stress, contributing to the value of zebrafish as a model system with which to investigate the mechanisms involved in regulation of redox signaling and the response to oxidative stress during embryolarval development. Moreover, studies in zebrafish have revealed nrf and keap1 gene duplications that provide an opportunity to dissect multiple functions of vertebrate NRF genes, including multiple sensing mechanisms involved in chemical-specific effects. PMID:26130508
Developmental Context Effects on Bicultural Posttrauma Self Repair in Chimpanzees
ERIC Educational Resources Information Center
Bradshaw, G. A.; Capaldo, Theodora; Lindner, Lorin; Grow, Gloria
2009-01-01
Longitudinal studies have shown how early developmental contexts contribute significantly to self-development; their influence extends through adulthood, informs sociality, and affects resilience under severe stress. While the importance of sociality in trauma recovery is recognized, the relationship between developmental and posttrauma contexts…
Growing Up Or Growing Old? Cellular Aging Linked With Testosterone Reactivity To Stress In Youth
Drury, Stacy S.; Shirtcliff, Elizabeth A.; Shachet, Andrew; Phan, Jenny; Mabile, Emily; Brett, Zoë H.; Wren, Michael; Esteves, Kyle; Theall, Katherine P.
2014-01-01
Background Given the established relation between testosterone and aging in older adults, we tested whether buccal telomere length (TL), an established cellular biomarker of aging, was associated with testosterone levels in youth. Methods Children, mean age 10.2 years, were recruited from the greater New Orleans area and salivary testosterone was measured during both an acute stressor and diurnally. Buccal TL was measured using monochrome multiplex quantitative real-time PCR (MMQ-PCR). Testosterone and telomere length data was available on 77 individuals. The association between buccal TL and testosterone was tested using multivariate Generalized Estimating Equations (GEE) to account for clustering of children within families. Results Greater peak testosterone levels (β=-0.87, p < 0.01) and slower recovery (β=-0.56, p < 0.01) and reactivity (β = -1.22, p < 0.01) following a social stressor were significantly associated with shorter buccal TL after controlling for parental age at conception, child age, sex, sociodemographic factors and puberty. No association was initially present between diurnal measurements of testosterone or morning basal testosterone levels and buccal TL. Sex significantly moderated the relation between testosterone reactivity and buccal TL. Conclusions The association between testosterone and buccal TL supports gonadal maturation as a developmentally sensitive biomarker of aging within youth. As stress levels of testosterone were significantly associated with buccal TL, these findings are consistent with the growing literature linking stress exposure and accelerated maturation. The lack of association of diurnal testosterone or morning basal levels with buccal TL bolsters the notion of a shared stress-related maturational mechanism between cellular stress and the hypothalamic pituitary gonadal (HPG) axis. These data provide novel evidence supporting the interaction of aging, physiologic stress and cellular processes as an underlying mechanism linking negative health outcomes and early life stress. PMID:25010187
Maxwell, Seth D; Fineberg, Anna M; Drabick, Deborah A; Murphy, Shannon K; Ellman, Lauren M
2018-02-01
Maternal stress during pregnancy has been linked to premorbid abnormalities associated with depression (e.g., difficult temperament, cognitive deficits) in offspring. However, few studies have looked across developmental periods to examine maternal stress during pregnancy and offspring depression during adolescence and whether these associations differ by sex. The current study used data from 1711 mother-offspring dyads (offspring sex: 49.8% male) in a longitudinal birth cohort study. Maternal narratives collected during pregnancy were qualitatively coded for stress-related themes by independent raters. Latent class analysis (LCA) identified distinct subgroups of offspring based on exposure to maternal prenatal stress and other developmental factors from the prenatal, childhood, and adolescent periods that have been associated with depression and/or maternal prenatal stress. LCA identified subgroups that were compared to determine whether and to what extent they differed on adolescent depressive symptoms. LCA revealed a subgroup of "high-risk" individuals, characterized by maternal factors during pregnancy (higher ambivalence/negativity and lower positivity towards the pregnancy, higher levels of hassles, lower maternal education and higher maternal age at birth, higher pre-pregnancy BMI) and offspring developmental factors (decreased cognitive functioning during childhood and adolescence, lower perceived parental support during adolescence, and higher levels of maternal depression during adolescence). High-risk females exhibited elevated conduct symptoms and higher birth order, while high-risk males exhibited decreased internalizing symptoms and lower birth order. Both high-risk males and females reported elevated depressive symptoms during adolescence relative to their "low-risk" counterparts.
Kaneko, M; Okui, H; Hirakawa, G; Ishinishi, H; Katayama, Y; Iramina, K
2012-01-01
We have developed an evaluation system for pronation and supination of forearms. The motion of pronation and supination of the forearm is used as a diagnosis method of developmental disability, etc. However, this diagnosis method has a demerit in which diagnosis results between doctors are not consistent. It is hoped that a more quantitative and simple evaluation method is established. Moreover it is hoped a diagnostic criteria obtained from healthy subjects can be established to diagnose developmental disorder patients. We developed a simple and portable evaluation system for pronation and supination of forearms. Three-dimensional wireless acceleration and angular velocity sensors are used for this system. In this study, pronation and supination of forearms of 570 subjects (subjects aged 6-12, 21-100) were examined. We could obtain aging curves in the neuromotor function of pronation and supination. These aging curves obtained by our developed system, has the potential to become diagnostic criteria for a developmental disability, etc.
Fink, Howard A.; Kuskowski, Michael A.; Cauley, Jane A.; Taylor, Brent C.; Schousboe, John T.; Cawthon, Peggy M.; Ensrud, Kristine E.
2015-01-01
Purpose/Introduction Prior studies suggest that stressful life events may increase adverse health outcomes, including falls and possibly fractures. The current study builds on these findings and examines whether stressful life events are associated with increased bone loss. Methods 4388 men aged ≥65 years in the Osteoporotic Fractures in Men study completed total hip bone mineral density (BMD) measures at baseline and visit 2, approximately 4.6 years later, and self-reported stressful life events data mid-way between baseline and visit 2, and at visit 2. We used linear regression to model the association of stressful life events with concurrent annualized total hip BMD loss, and log binomial regression or Poisson regression to model risk of concurrent accelerated BMD loss (>1 SD more than mean annualized change). Results 75.3% of men reported ≥1 type of stressful life event, including 43.3% with ≥2 types of stressful life events. Mean annualized BMD loss was −0.36% (SD 0.88) and 13.9% of men were categorized with accelerated BMD loss (about 5.7% or more total loss). Rate of annualized BMD loss increased with the number of types of stressful life events after adjustment for age (p<0.001), but not after multivariable adjustment (p=0.07). Multivariable-adjusted risk of accelerated BMD loss increased with the number of types of stressful life events (RR, 1.10 [95% CI, 1.04–1.16]) per increase of 1 type of stressful life event). Fracture risk was not significantly different between stressful life event-accelerated bone loss subgroups (p=0.08). Conclusions In these older men, stressful life events were associated with a small, dose-related increase in risk of concurrent accelerated hip bone loss. Low frequency of fractures limited assessment of whether rapid bone loss mediates any association of stressful life events with incident fractures. Future studies are needed to confirm these findings and to investigate the mechanism that may underlie this association. PMID:25169421
Liu, Yu-Xiang; Cheng, Ya-Nan; Miao, Yi-Long; Wei, De-Li; Zhao, Li-Hua; Luo, Ming-Jiu; Tan, Jing-He
2012-01-01
Although the predatory stress experimental protocol is considered more psychological than the restraint protocol, it has rarely been used to study the effect of psychological stress on reproduction. Few studies exist on the direct effect of psychological stress to a female on developmental competence of her oocytes, and the direct effect of predatory maternal stress on oocytes has not been reported. In this study, a predatory stress system was first established for mice with cats as predators. Beginning 24 h after injection of equine chorionic gonadotropin, female mice were subjected to predatory stress for 24 h. Evaluation of mouse responses showed that the predatory stress system that we established increased anxiety-like behaviors and plasma cortisol concentrations significantly and continuously while not affecting food and water intake of the mice. In vitro experiments showed that whereas oocyte maturation and Sr2+ activation or fertilization were unaffected by maternal predatory stress, rate of blastocyst formation and number of cells per blastocyst decreased significantly in stressed mice compared to non-stressed controls. In vivo embryo development indicated that both the number of blastocysts recovered per donor mouse and the average number of young per recipient after embryo transfer of blastocysts with similar cell counts were significantly lower in stressed than in unstressed donor mice. It is concluded that the predatory stress system we established was both effective and durative to induce mouse stress responses. Furthermore, predatory stress applied during the oocyte pre-maturation stage significantly impaired oocyte developmental potential while exerting no measurable impact on nuclear maturation, suggesting that cytoplasmic maturation of mouse oocytes was more vulnerable to maternal stress than nuclear maturation. PMID:23118931
Behavioral family intervention for children with developmental disabilities and behavioral problems.
Roberts, Clare; Mazzucchelli, Trevor; Studman, Lisa; Sanders, Matthew R
2006-06-01
The outcomes of a randomized clinical trial of a new behavioral family intervention, Stepping Stones Triple P, for preschoolers with developmental and behavior problems are presented. Forty-eight children with developmental disabilities participated, 27 randomly allocated to an intervention group and 20 to a wait-list control group. Parents completed measures of parenting style and stress, and independent observers assessed parent-child interactions. The intervention was associated with fewer child behavior problems reported by mothers and independent observers, improved maternal and paternal parenting style, and decreased maternal stress. All effects were maintained at 6-month follow-up.
Lexical Stress Assignment in Italian Developmental Dyslexia
ERIC Educational Resources Information Center
Paizi, Despina; Zoccolotti, Pierluigi; Burani, Cristina
2011-01-01
Stress assignment to Italian polysyllabic words is unpredictable, because stress is neither marked nor predicted by rule. Stress assignment, especially to low frequency words, has been reported to be a function of stress dominance and stress neighbourhood. Two experiments investigate stress assignment in sixth-grade, skilled and dyslexic, readers.…
2012-01-01
Particulate matter (PM) pollution is responsible for hundreds of thousands of deaths worldwide, the majority due to cardiovascular disease (CVD). While many potential pathophysiological mechanisms have been proposed, there is not yet a consensus as to which are most important in causing pollution-related morbidity/mortality. Nor is there consensus regarding which specific types of PM are most likely to affect public health in this regard. One toxicological mechanism linking exposure to airborne PM with CVD outcomes is oxidative stress, a contributor to the development of CVD risk factors including atherosclerosis. Recent work suggests that accelerated shortening of telomeres and, thus, early senescence of cells may be an important pathway by which oxidative stress may accelerate biological aging and the resultant development of age-related morbidity. This pathway may explain a significant proportion of PM-related adverse health outcomes, since shortened telomeres accelerate the progression of many diseases. There is limited but consistent evidence that vehicular emissions produce oxidative stress in humans. Given that oxidative stress is associated with accelerated erosion of telomeres, and that shortened telomeres are linked with acceleration of biological ageing and greater incidence of various age-related pathology, including CVD, it is hypothesized that associations noted between certain pollution types and sources and oxidative stress may reflect a mechanism by which these pollutants result in CVD-related morbidity and mortality, namely accelerated aging via enhanced erosion of telomeres. This paper reviews the literature providing links among oxidative stress, accelerated erosion of telomeres, CVD, and specific sources and types of air pollutants. If certain PM species/sources might be responsible for adverse health outcomes via the proposed mechanism, perhaps the pathway to reducing mortality/morbidity from PM would become clearer. Not only would pollution reduction imperatives be more focused, but interventions which could reduce oxidative stress would become all the more important. PMID:22713210
Fired up or burned out? How developmental challenge differentially impacts leader behavior.
Courtright, Stephen H; Colbert, Amy E; Choi, Daejeong
2014-07-01
Leadership development research has largely drawn on experiential and enactive learning theories to explore the positive effects of developmental challenge on leaders. In contrast, we examined potential positive and negative effects of developmental challenge (i.e., challenging job assignments) on leader behavior through an alternative theoretical lens--transactional stress theory. We predicted, on one hand, that developmental challenge may be associated with higher leader engagement and transformational leadership behavior; however, developmental challenge also has the potential to be associated with higher leader emotional exhaustion and laissez-faire leadership behavior. We further proposed that leadership self-efficacy (LSE) moderates these potential effects of developmental challenge and helps explain why leaders react either positively or negatively to developmental challenge. We tested our hypotheses in a sample of 153 leaders and 631 direct reports at a Fortune 500 company. Findings supported positive relationships among developmental challenge, leader engagement, and transformational leadership. However, we also found support for significant relationships among developmental challenge, emotional exhaustion, and laissez-faire leadership. Additionally, leaders lower in LSE were more likely to encounter the negative effects of developmental challenge by experiencing increased emotional exhaustion and displaying laissez-faire leadership behaviors. Our study contributes to theory and practice by elucidating a "dark side" of developmental challenge, identifying LSE as a moderator of the negative effects of developmental challenge, identifying antecedents of transformational and laissez-faire leadership behaviors, and investigating demands and stress in leadership roles.
Garg, Rohini; Shankar, Rama; Thakkar, Bijal; Kudapa, Himabindu; Krishnamurthy, Lakshmanan; Mantri, Nitin; Varshney, Rajeev K.; Bhatia, Sabhyata; Jain, Mukesh
2016-01-01
Drought and salinity are the major factors that limit chickpea production worldwide. We performed whole transcriptome analyses of chickpea genotypes to investigate the molecular basis of drought and salinity stress response/adaptation. Phenotypic analyses confirmed the contrasting responses of the chickpea genotypes to drought or salinity stress. RNA-seq of the roots of drought and salinity related genotypes was carried out under control and stress conditions at vegetative and/or reproductive stages. Comparative analysis of the transcriptomes revealed divergent gene expression in the chickpea genotypes at different developmental stages. We identified a total of 4954 and 5545 genes exclusively regulated in drought-tolerant and salinity-tolerant genotypes, respectively. A significant fraction (~47%) of the transcription factor encoding genes showed differential expression under stress. The key enzymes involved in metabolic pathways, such as carbohydrate metabolism, photosynthesis, lipid metabolism, generation of precursor metabolites/energy, protein modification, redox homeostasis and cell wall component biogenesis, were affected by drought and/or salinity stresses. Interestingly, transcript isoforms showed expression specificity across the chickpea genotypes and/or developmental stages as illustrated by the AP2-EREBP family members. Our findings provide insights into the transcriptome dynamics and components of regulatory network associated with drought and salinity stress responses in chickpea. PMID:26759178
Parenting Stress and Depression in Children with Mental Retardation and Developmental Disabilities.
ERIC Educational Resources Information Center
Kobe, Frank H.
1994-01-01
This study of 29 children with developmental delays found that parent ratings of children's depression were significantly associated with maternal depression, negative self-image, anxiety, and conduct problems. Data suggest that children with developmental delays exhibit a similar pattern of symptoms and associated characteristics to those found…
Simčič, Tatjana; Jesenšek, Dušan; Brancelj, Anton
2015-08-01
Climate change may result in future alterations in thermal regime which could markedly affect the early developmental stages of cold water fish due to their expected high sensitivity to increasing temperature. In the present study, the effect of temperature increase of 2, 4 and 6°C on the oxygen consumption rate (R), the activity of respiratory electron transport system (ETS) and oxidative stress have been studied in four developmental stages of the marble trout (Salmo marmoratus)-eyed eggs, yolk-sac larvae and juveniles of 1 and 3 months. Oxygen consumption rate and ETS activity increased with level of development and with temperature in all four stages. ETS/R ratios decreased during development and correlated with temperature in eyed eggs, larvae and juveniles of 1 month, but not in juveniles of 3 months. Low ETS/R ratios at higher temperatures indicate stress response in eyed eggs, the most temperature sensitive developmental stage. Catalase (CAT) and glutathione reductase (GR) activities increased during development, but responded differently to elevated temperature in the different developmental stages. Stress in eyed eggs, caused by higher temperatures, resulted in increased oxygen consumption rate and increased activities of CAT and GR. Larvae were sensitive to increased temperature only at the highest experimental temperature of 16°C. Increased temperature did not stress the metabolism of the juveniles, since they were able to compensate their metabolic activity. The earlier developmental stages of marble trout are thus more sensitive to temperature increase than juveniles and therefore more endangered by higher water temperatures. This is the first report connecting oxygen consumption, ETS activity and ETS/R ratio with the activities of antioxidant enzymes in relation to increased temperature in salmonids.
Growing Pains: A Theory of Stress and Moral Conflict.
ERIC Educational Resources Information Center
Blakeney, Ronnie Ann; Blakeney, Charles David
1992-01-01
Outlines relationship between crises that create stress in one's life and periods of instability in moral development. Suggests that stressful issues are more difficult to resolve during periods of developmental instability and that, when problems are most stressful, people often experience impact of stress physiologically. Reconstructs stress and…
A Petunia Homeodomain-Leucine Zipper Protein, PhHD-Zip, Plays an Important Role in Flower Senescence
Chang, Xiaoxiao; Donnelly, Linda; Sun, Daoyang; Rao, Jingping; Reid, Michael S.; Jiang, Cai-Zhong
2014-01-01
Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO), and ABA (NCED) biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA) and abiotic stresses (dehydration, NaCl and cold). Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence. PMID:24551088
Chang, Xiaoxiao; Donnelly, Linda; Sun, Daoyang; Rao, Jingping; Reid, Michael S; Jiang, Cai-Zhong
2014-01-01
Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO), and ABA (NCED) biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA) and abiotic stresses (dehydration, NaCl and cold). Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence.
Knowledge on Accelerated Motion as Measured by Implicit and Explicit Tasks in 5 to 16 Year Olds
ERIC Educational Resources Information Center
Ebersbach, Mirjam; Van Dooren, Wim; Verschaffel, Lieven
2011-01-01
The present study aimed at investigating children's and adolescents' understanding of constant and accelerated motions. The main objectives were (1) to investigate whether different task formats would affect the performance and (2) to track developmental changes in this domain. Five to 16 year olds (N = 157) predicted the distances of a moving…
Hahn, Mark E; Timme-Laragy, Alicia R; Karchner, Sibel I; Stegeman, John J
2015-11-01
Oxidative stress is an important mechanism of chemical toxicity, contributing to developmental toxicity and teratogenesis as well as to cardiovascular and neurodegenerative diseases and diabetic embryopathy. Developing animals are especially sensitive to effects of chemicals that disrupt the balance of processes generating reactive species and oxidative stress, and those anti-oxidant defenses that protect against oxidative stress. The expression and inducibility of anti-oxidant defenses through activation of NFE2-related factor 2 (Nrf2) and related proteins is an essential process affecting the susceptibility to oxidants, but the complex interactions of Nrf2 in determining embryonic response to oxidants and oxidative stress are only beginning to be understood. The zebrafish (Danio rerio) is an established model in developmental biology and now also in developmental toxicology and redox signaling. Here we review the regulation of genes involved in protection against oxidative stress in developing vertebrates, with a focus on Nrf2 and related cap'n'collar (CNC)-basic-leucine zipper (bZIP) transcription factors. Vertebrate animals including zebrafish share Nfe2, Nrf1, Nrf2, and Nrf3 as well as a core set of genes that respond to oxidative stress, contributing to the value of zebrafish as a model system with which to investigate the mechanisms involved in regulation of redox signaling and the response to oxidative stress during embryolarval development. Moreover, studies in zebrafish have revealed nrf and keap1 gene duplications that provide an opportunity to dissect multiple functions of vertebrate NRF genes, including multiple sensing mechanisms involved in chemical-specific effects. Copyright © 2015. Published by Elsevier Inc.
Cell identity regulators link development and stress responses in the Arabidopsis root.
Iyer-Pascuzzi, Anjali S; Jackson, Terry; Cui, Hongchang; Petricka, Jalean J; Busch, Wolfgang; Tsukagoshi, Hironaka; Benfey, Philip N
2011-10-18
Stress responses in plants are tightly coordinated with developmental processes, but interaction of these pathways is poorly understood. We used genome-wide assays at high spatiotemporal resolution to understand the processes that link development and stress in the Arabidopsis root. Our meta-analysis finds little evidence for a universal stress response. However, common stress responses appear to exist with many showing cell type specificity. Common stress responses may be mediated by cell identity regulators because mutations in these genes resulted in altered responses to stress. Evidence for a direct role for cell identity regulators came from genome-wide binding profiling of the key regulator SCARECROW, which showed binding to regulatory regions of stress-responsive genes. Coexpression in response to stress was used to identify genes involved in specific developmental processes. These results reveal surprising linkages between stress and development at cellular resolution, and show the power of multiple genome-wide data sets to elucidate biological processes. Copyright © 2011 Elsevier Inc. All rights reserved.
Jiang, Yuanzhong; Duan, Yanjiao; Yin, Jia; Ye, Shenglong; Zhu, Jingru; Zhang, Faqi; Lu, Wanxiang; Fan, Di; Luo, Keming
2014-12-01
WRKY proteins are a large family of regulators involved in various developmental and physiological processes, especially in coping with diverse biotic and abiotic stresses. In this study, 100 putative PtrWRKY genes encoded the proteins contained in the complete WRKY domain in Populus. Phylogenetic analysis revealed that the members of this superfamily among poplar, Arabidopsis, and other species were divided into three groups with several subgroups based on the structures of the WRKY protein sequences. Various cis-acting elements related to stress and defence responses were found in the promoter regions of PtrWRKY genes by promoter analysis. High-throughput transcriptomic analyses identified that 61 of the PtrWRKY genes were induced by biotic and abiotic treatments, such as Marssonina brunnea, salicylic acid (SA), methyl jasmonate (MeJA), wounding, cold, and salinity. Among these PtrWRKY genes, transcripts of 46 selected genes were observed in different tissues, including roots, stems, and leaves. Quantitative RT-PCR analysis further confirmed the induced expression of 18 PtrWRKY genes by one or more stress treatments. The overexpression of an SA-inducible gene, PtrWRKY89, accelerated expression of PR protein genes and improved resistance to pathogens in transgenic poplar, suggesting that PtrWRKY89 is a regulator of an SA-dependent defence-signalling pathway in poplar. Taken together, our results provided significant information for improving the resistance and stress tolerance of woody plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Social Origins of Developmental Risk for Mental and Physical Illness.
Cameron, Judy L; Eagleson, Kathie L; Fox, Nathan A; Hensch, Takao K; Levitt, Pat
2017-11-08
Adversity in early childhood exerts an enduring impact on mental and physical health, academic achievement, lifetime productivity, and the probability of interfacing with the criminal justice system. More science is needed to understand how the brain is affected by early life stress (ELS), which produces excessive activation of stress response systems broadly throughout the child's body (toxic stress). Our research examines the importance of sex, timing and type of stress exposure, and critical periods for intervention in various brain systems across species. Neglect (the absence of sensitive and responsive caregiving) or disrupted interaction with offspring induces robust, lasting consequences in mice, monkeys, and humans. Complementary assessment of internalizing disorders and brain imaging in children suggests that early adversity can interfere with white matter development in key brain regions, which may increase risk for emotional difficulties in the long term. Neural circuits that are most plastic during ELS exposure in monkeys sustain the greatest change in gene expression, offering a mechanism whereby stress timing might lead to markedly different long-term behaviors. Rodent models reveal that disrupted maternal-infant interactions yield metabolic and behavioral outcomes often differing by sex. Moreover, ELS may further accelerate or delay critical periods of development, which reflect GABA circuit maturation, BDNF, and circadian Clock genes. Such factors are associated with several mental disorders and may contribute to a premature closure of plastic windows for intervention following ELS. Together, complementary cross-species studies are elucidating principles of adaptation to adversity in early childhood with molecular, cellular, and whole organism resolution. Copyright © 2017 the authors 0270-6474/17/3710783-09$15.00/0.
Deak, Terrence; Quinn, Matt; Cidlowski, John A.; Victoria, Nicole C.; Murphy, Anne Z.; Sheridan, John F.
2016-01-01
The last decade has witnessed profound growth in studies examining the role of fundamental neuroimmune processes as key mechanisms that might form a natural bridge between normal physiology and pathological outcomes. Rooted in core concepts from psychoneuroimmunology, this review utilizes a succinct, exemplar-driven approach of several model systems that contribute significantly to our knowledge of the mechanisms by which neuroimmune processes interact with stress physiology. Specifically, we review recent evidence showing that (i) stress challenges produce time-dependent and stressor-specific patterns of cytokine/chemokine expression in the CNS; (ii) inflammation-related genes exhibit unique expression profiles in males and females depending upon individual, cooperative, or antagonistic interactions between steroid hormone receptors (Estrogen and Glucocorticoid receptors); (iii) adverse social experiences incurred through repeated social defeat engage a dynamic process of immune cell migration from the bone marrow to brain and prime neuroimmune function; and (iv) early developmental exposure to an inflammatory stimulus (carageenin injection into the hindpaw) has a lasting influence on stress reactivity across the lifespan. As such, the present review provides a theoretical framework for understanding the role that neuroimmune mechanisms might play in stress plasticity and pathological outcomes, while at the same time pointing toward features of the individual (sex, developmental experience, stress history) that might ultimately be used for the development of personalized strategies for therapeutic intervention in stress-related pathologies. PMID:26176590
Deak, Terrence; Quinn, Matt; Cidlowski, John A; Victoria, Nicole C; Murphy, Anne Z; Sheridan, John F
2015-01-01
The last decade has witnessed profound growth in studies examining the role of fundamental neuroimmune processes as key mechanisms that might form a natural bridge between normal physiology and pathological outcomes. Rooted in core concepts from psychoneuroimmunology, this review utilizes a succinct, exemplar-driven approach of several model systems that contribute significantly to our knowledge of the mechanisms by which neuroimmune processes interact with stress physiology. Specifically, we review recent evidence showing that (i) stress challenges produce time-dependent and stressor-specific patterns of cytokine/chemokine expression in the CNS; (ii) inflammation-related genes exhibit unique expression profiles in males and females depending upon individual, cooperative or antagonistic interactions between steroid hormone receptors (estrogen and glucocorticoid receptors); (iii) adverse social experiences incurred through repeated social defeat engage a dynamic process of immune cell migration from the bone marrow to brain and prime neuroimmune function and (iv) early developmental exposure to an inflammatory stimulus (carageenin injection into the hindpaw) has a lasting influence on stress reactivity across the lifespan. As such, the present review provides a theoretical framework for understanding the role that neuroimmune mechanisms might play in stress plasticity and pathological outcomes, while at the same time pointing toward features of the individual (sex, developmental experience, stress history) that might ultimately be used for the development of personalized strategies for therapeutic intervention in stress-related pathologies.
NASA Technical Reports Server (NTRS)
Gaines, G. B.; Thomas, R. E.; Noel, G. T.; Shilliday, T. S.; Wood, V. E.; Carmichael, D. C.
1979-01-01
An accelerated life test is described which was developed to predict the life of the 25 kW photovoltaic array installed near Mead, Nebraska. A quantitative model for accelerating testing using multiple environmental stresses was used to develop the test design. The model accounts for the effects of thermal stress by a relation of the Arrhenius form. This relation was then corrected for the effects of nonthermal environmental stresses, such as relative humidity, atmospheric pollutants, and ultraviolet radiation. The correction factors for the nonthermal stresses included temperature-dependent exponents to account for the effects of interactions between thermal and nonthermal stresses on the rate of degradation of power output. The test conditions, measurements, and data analyses for the accelerated tests are presented. Constant-temperature, cyclic-temperature, and UV types of tests are specified, incorporating selected levels of relative humidity and chemical contamination and an imposed forward-bias current and static electric field.
Azmat, Rafia
2013-01-01
The effect of mixed inoculums of VAM (Vesicular Arbuscular Mycorrhizas) fungi on seed growth and photosynthetic apparatus in green house was monitored. The plants were watered daily with tap water. Plants were cultivated in natural environment in mid of March (2011). A direct relation between root length and water contents suggests a defense mechanism of MP (microrihzal plants) against the fungal stress. It was also supported by the fact that the leaf area of MP was much greater as compared to the NMP (non microrihzal plants) with elevated concentration of all chlorophyllus pigments in 30 days. An increase in the surface area of the leaf and concentration of the pigments, may be for an acceleration in absorption of CO₂ for reduction of it into glucose through oxidation of water molecule. The non-significant decline in glucose contents support the above hypothesis of rapid redox reaction mechanism which was established to overcome the stress. The positive effects of mycorrhizal which were already mentioned in the literature were reported in this article in relations of survival strategies of the plant, adapted in stress conditions. An increase in the chlorophyll contents (30 d) and leaf area of plants possibly attributed with absorption of solar radiation for the protection of plants. It was also supported by the higher concentration of carotenoids (30 d) that may have an additional function of regulation of certain developmental responses and screening of light to save the plants from stress conditions.
Ortega-Amaro, María A.; Rodríguez-Hernández, Aída A.; Rodríguez-Kessler, Margarita; Hernández-Lucero, Eloísa; Rosales-Mendoza, Sergio; Ibáñez-Salazar, Alejandro; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F.
2015-01-01
Proteins with glycine-rich signatures have been reported in a wide variety of organisms including plants, mammalians, fungi, and bacteria. Plant glycine-rich protein genes exhibit developmental and tissue-specific expression patterns. Herein, we present the characterization of the AtGRDP2 gene using Arabidopsis null and knockdown mutants and, Arabidopsis and lettuce over-expression lines. AtGRDP2 encodes a short glycine-rich domain protein, containing a DUF1399 domain and a putative RNA recognition motif (RRM). AtGRDP2 transcript is mainly expressed in Arabidopsis floral organs, and its deregulation in Arabidopsis Atgrdp2 mutants and 35S::AtGRDP2 over-expression lines produces alterations in development. The 35S::AtGRDP2 over-expression lines grow faster than the WT, while the Atgrdp2 mutants have a delay in growth and development. The over-expression lines accumulate higher levels of indole-3-acetic acid and, have alterations in the expression pattern of ARF6, ARF8, and miR167 regulators of floral development and auxin signaling. Under salt stress conditions, 35S::AtGRDP2 over-expression lines displayed higher tolerance and increased expression of stress marker genes. Likewise, transgenic lettuce plants over-expressing the AtGRDP2 gene manifest increased growth rate and early flowering time. Our data reveal an important role for AtGRDP2 in Arabidopsis development and stress response, and suggest a connection between AtGRDP2 and auxin signaling. PMID:25653657
Quantum corrections to the stress-energy tensor in thermodynamic equilibrium with acceleration
NASA Astrophysics Data System (ADS)
Becattini, F.; Grossi, E.
2015-08-01
We show that the stress-energy tensor has additional terms with respect to the ideal form in states of global thermodynamic equilibrium in flat spacetime with nonvanishing acceleration and vorticity. These corrections are of quantum origin and their leading terms are second order in the gradients of the thermodynamic fields. Their relevant coefficients can be expressed in terms of correlators of the stress-energy tensor operator and the generators of the Lorentz group. With respect to previous assessments, we find that there are more second-order coefficients and that all thermodynamic functions including energy density receive acceleration and vorticity dependent corrections. Notably, also the relation between ρ and p , that is, the equation of state, is affected by acceleration and vorticity. We have calculated the corrections for a free real scalar field—both massive and massless—and we have found that they increase, particularly for a massive field, at very high acceleration and vorticity and very low temperature. Finally, these nonideal terms depend on the explicit form of the stress-energy operator, implying that different stress-energy tensors of the scalar field—canonical or improved—are thermodynamically inequivalent.
Developmental competence of bovine embryos from heat-stressed ova.
Edwards, J L; Bogart, A N; Rispoli, L A; Saxton, A M; Schrick, F N
2009-02-01
Because multiple ovulation embryo transfer procedures are occasionally performed in cows experiencing heat stress, the goal of this study was to assess the developmental competence of otherwise morphologically normal embryos from heat-stressed ova. To this end, the ability of compact morulae from heat-stressed and non-heat-stressed bovine ova to undergo blastocyst development after culture at 38.5 or 41.0 degrees C was examined. It was hypothesized that heat-induced perturbations in the ooplasm carry over to increase the susceptibility of the preattachment embryo to heat stress. Initially, ova were matured at 38.5 or 41.0 degrees C. The consequences of heat stress did not include altered cleavage, but did reduce the proportion of 8- to 16-cell-stage embryos (55.3 vs. 50.6%; SEM +/- 1.9). Although proportionately fewer, compact morulae from heat-stressed ova were equivalent in quality to those from non-heat-stressed ova (2.1 and 2.1; SEM = 0.04). Culture of compact morulae from non-heat-stressed ova at 41.0 degrees C did not affect blastocyst development (71.9 and 71.5%; SEM = 3.0). Furthermore, the development of compact morulae from heat-stressed ova was similar to that of non-heat-stressed ova after culture at 38.5 degrees C (68.2 vs. 71.9 and 71.5%; SEM = 3.0). However, blastocyst development was reduced when compact morulae from heat-stressed ova were cultured at 41.0 degrees C (62.3 vs. 71.9, 71.5 and 68.2; SEM = 3.1). In summary, reduced compaction rates of heat-stressed ova explained in part why fewer develop to the blastocyst stage after fertilization. The thermolability of the few embryos that develop from otherwise developmentally challenged ova emphasizes the importance of minimizing exposure to stressor(s) during oocyte maturation.
The Root Cause of Post-traumatic and Developmental Stress Disorder, Phase 2
2013-10-01
have tested and validated. Project 2 will investigate post -mortem anatomy in subjects with major depression and/or PTSD. Both molecular and...Award Number: W81XWH-11-2-0166 TITLE: The Root Cause of Post -traumatic and Developmental Stress Disorder, Phase II PRINCIPAL INVESTIGATOR: Keith...construed as an official Department of the Army position, policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE
Parental divorce and initiation of alcohol use in early adolescence.
Jackson, Kristina M; Rogers, Michelle L; Sartor, Carolyn E
2016-06-01
Parental divorce/separation is among the most commonly endorsed adverse childhood events. It has been shown to increase subsequent risk of alcohol dependence and problems across adolescence and early adulthood, but its influence on early stages of alcohol involvement has only recently been explored. In the present study, we examined whether time to first full drink was accelerated among youth who experienced parental divorce/separation. To determine specificity of risk, models controlled for perceived stress as well as family history of alcoholism, current parental drinking, and internalizing and externalizing problems. Developmental specificity in terms of timing of both parental divorce and first drink was also examined. Participants were 931 middle-school students (488 girls, 443 boys) who were enrolled in a prospective study on drinking initiation and progression (52% female; 23% non-White, 11% Hispanic). Students indicated whether and at what age they had consumed a full drink of alcohol. Parental divorce/separation was coded from a parent-reported life-events inventory and was grouped based on age experienced (ages 0-5, ages 6-9, age 10+). Cox proportional hazard models showed increased risk for onset of drinking as a function of divorce/separation, even controlling for stress, parental alcohol involvement, and psychopathology. There was no evidence for developmental specificity of the divorce/separation effect based on when it occurred nor in timing of first drink. However, the effect of parental divorce/separation on initiation was magnified at higher levels of parental drinking. Given the rates of parental divorce/separation and its association with increased risk of early drinking, investigation of the mechanisms underlying this link is clearly warranted. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
NASA Astrophysics Data System (ADS)
Wirth, D.; Rohleder, N.; Welsch, H.
2005-08-01
Prediction of student pilots' +Gz tolerance by stress hormone levels would be a useful tool in aviation medicine. The aim of the present study was to analyze the relationship between neuroendocrine parameters with performance during acceleration training on the human centrifuge (HC).We investigated 21 student pilots during self-controlled acceleration training on the HC. Adrenocorticotropic hormone (ACTH), cortisol, epinephrine, and norepinephrine were measured after individual training sessions and at rest. Performance was defined by several characteristics including maximum tolerated acceleration. ACTH and cortisol, were significantly higher 20 minutes after acceleration training compared to the resting condition. Subjects tolerated a maximal acceleration of +6.69 Gz. HPA hormone levels and responses were associated with maximum tolerated acceleration +Gz. These findings support the expectation that acceleration- induced increases in stress hormones may enable the organism to tolerate a higher acceleration and could therefore be used as predictors for acceleration tolerance.
ERIC Educational Resources Information Center
Arnekrans, Allison K.; Calmes, Stephanie A.; Laux, John M.; Roseman, Christopher P.; Piazza, Nick J.; Reynolds, Jennifer L.; Harmening, Debra; Scott, Holly L.
2018-01-01
Developmental trauma--distressing childhood experiences that include mistreatment, interpersonal violence, abuse, assault, and neglect--is associated with substance use and poor academic performance. The authors investigated the links between developmental trauma, grade point average, substance use, and resilience among first-year college students…
Beyond allostatic load: rethinking the role of stress in regulating human development.
Ellis, Bruce J; Del Giudice, Marco
2014-02-01
How do exposures to stress affect biobehavioral development and, through it, psychiatric and biomedical disorder? In the health sciences, the allostatic load model provides a widely accepted answer to this question: stress responses, while essential for survival, have negative long-term effects that promote illness. Thus, the benefits of mounting repeated biological responses to threat are traded off against costs to mental and physical health. The adaptive calibration model, an evolutionary-developmental theory of stress-health relations, extends this logic by conceptualizing these trade-offs as decision nodes in allocation of resources. Each decision node influences the next in a chain of resource allocations that become instantiated in the regulatory parameters of stress response systems. Over development, these parameters filter and embed information about key dimensions of environmental stress and support, mediating the organism's openness to environmental inputs, and function to regulate life history strategies to match those dimensions. Drawing on the adaptive calibration model, we propose that consideration of biological fitness trade-offs, as delineated by life history theory, is needed to more fully explain the complex relations between developmental exposures to stress, stress responsivity, behavioral strategies, and health. We conclude that the adaptive calibration model and allostatic load model are only partially complementary and, in some cases, support different approaches to intervention. In the long run, the field may be better served by a model informed by life history theory that addresses the adaptive role of stress response systems in regulating alternative developmental pathways.
Davis, Jordan P; Dumas, Tara M; Berey, Benjamin L; Merrin, Gabriel J; Cimpian, Joseph R; Roberts, Brent W
2017-07-01
A vast literature has found longitudinal effects of early life stress on substance use and self-regulatory processes. These associations may vary by period-specific development among youth involved in the juvenile justice system. The current study used an accelerated longitudinal design and auto-regressive latent trajectory with structure residuals (ALT-SR) model to examine the within-person cross-lagged associations between binge drinking, impulse control, and victimization from 15 to 25 years of age. A large sample (N = 1100) of justice-involved youth were followed longitudinally for 7 years (M age baseline = 15.8, M age conclusion = 22.8). In general, the sample was ethnically diverse (41% Black, 34% Hispanic, 21% White, 4.3% Other) and primarily male (87.2%). Participants reported on their frequency of binge drinking, impulse control, and frequency of victimization at each time point. The results indicated that, during adolescence, victimization and binge drinking attenuated impulse control, which resulted in more binge drinking and victimization during young adulthood. The current study highlights the importance of assessing developmental processes and period-specific transitions among at risk youth, especially for youth experiencing early life stress.
Accelerated testing of space batteries
NASA Technical Reports Server (NTRS)
Mccallum, J.; Thomas, R. E.; Waite, J. H.
1973-01-01
An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.
Parent Perspectives of Applying Mindfulness-Based Stress Reduction Strategies to Special Education.
Burke, Meghan M; Chan, Neilson; Neece, Cameron L
2017-06-01
Parents of children with (versus without) intellectual and developmental disabilities report greater stress; such stress may be exacerbated by dissatisfaction with school services, poor parent-school partnerships, and the need for parent advocacy. Increasingly, mindfulness interventions have been used to reduce parent stress. However, it is unclear whether parents apply mindfulness strategies during the special education process to reduce school-related stress. To investigate whether mindfulness may reduce school-related stress, interviews were conducted with 26 parents of children with intellectual and developmental disabilities who completed a mindfulness-based stress reduction intervention. Participants were asked about their stress during meetings with the school, use of mindfulness strategies in communicating with the school, and the impact of such strategies. The majority of parent participants reported: special education meetings were stressful; they used mindfulness strategies during IEP meetings; and such strategies affected parents' perceptions of improvements in personal well-being, advocacy, family-school relationships, and access to services for their children. Implications for future research, policy, and practice are discussed.
Asanov, E O; Os'mak, Ie D; Kuz'mins'ka, L A
2013-01-01
The peculiarities of the response of the sympathoadrenal system to psychoemotional and hypoxic stress in healthy young people and in aged people with physiological and accelerated aging of respiratory system were studied. It was shown that in aging a more pronounced response of the sympathoadrenal system to psychoemotional stress. At the same time, elderly people with different types of aging of the respiratory system did not demonstrate a difference in the response of the sympathoadrenal system to psychoemotional stress. Unlike in young people, in aged people, combination of psychoemotional and hypoxic stresses resulted in further activation of the sympathoadrenal system. The reaction of the sympathoadrenal system was more expressed in elderly people with accelerated ageing of the respiratory system.
Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells
NASA Technical Reports Server (NTRS)
Prince, J. L.; Lathrop, J. W.
1979-01-01
The results of accelerated stress testing of four different types of silicon terrestrial solar cells are discussed. The accelerated stress tests used included bias-temperature tests, bias-temperature-humidity tests, thermal cycle and thermal shock tests, and power cycle tests. Characterization of the cells was performed before stress testing and at periodic down-times, using electrical measurement, visual inspection, and metal adherence pull tests. Electrical parameters measured included short-circuit current, open circuit voltage, and output power, voltage, and current at the maximum power point. Incorporated in the report are the distributions of the prestress electrical data for all cell types. Data were also obtained on cell series and shunt resistance.
ERIC Educational Resources Information Center
Scrivener, Susan; Weiss, Michael J.
2013-01-01
This policy brief presents results from a random assignment evaluation of the City University of New York's Accelerated Study in Associate Programs (ASAP). An ambitious and promising endeavor, ASAP provides a comprehensive array of services and supports to help community college students graduate and to help them graduate sooner. The evaluation…
Davis, Elysia Poggi; Pfaff, Donald
2014-01-01
During gestation, development proceeds at a pace that is unmatched by any other stage of the lifecycle. For these reason the human fetus is particularly susceptible not only to organizing influences, but also to pathogenic disorganizing influences. Growing evidence suggests that exposure to prenatal adversity leads to neurological changes that underlie lifetime risks for mental illness. Beginning early in gestation, males and females show differential developmental trajectories and responses to stress. It is likely that sex-dependent organization of neural circuits during the fetal period influences differential vulnerability to mental health problems. We consider in this review evidence that sexually dimorphic responses to early life stress are linked to two developmental disorders: affective problems (greater female prevalence) and autism spectrum disorder (greater male prevalence). Recent prospective studies illustrating the neurodevelopmental consequences of fetal exposure to stress and stress hormones for males and females are considered here. Plausible biological mechanisms including the role of the sexually differentiated placenta are discussed. We consider in this review evidence that sexually dimorphic responses to early life stress are linked to two sets of developmental disorders: affective problems (greater female prevalence) and autism spectrum disorders (greater male prevalence). PMID:25038479
Hoover, Kara C; Matsumura, Hirofumi
2008-12-01
We examined nutritional and developmental instability in prehistoric Japan, using data from 49 individuals across 13 archaeological sites. Hypoplasia incidence was used as a measure of nutritional stress, and fluctuating asymmetry (of upper facial breath, orbital breadth, and orbital height) as an indirect assessment of developmental instability. Abundant resources due to a stable climate during the Middle Jomon (5,000-3,000 BP) encouraged population growth, which led to regional cultural homogeneity and complexity. A population crash on Honshu in the Late/Final Jomon (roughly 4,000-2,000 BP) led to regionally divergent subsistence economies and settlement patterns. We find that the nutritional stress was consistent between periods, but developmental instability (DI) decreased in the Late/Final Jomon. While the DI values were not statistically significant, the higher values for Middle Jomon may result from sedentism, social stratification, and differential access to resources. On Hokkaido, Jomon culture persisted until the Okhotsk period (1,000-600 BP), marked by the arrival of immigrants from Sakhalin. Nutritional stress was consistent between Middle and Late/Final Jomon, but DI increased in the Late/Final. Nutritional and developmental instability decreased from Late/Final to Okhotsk, suggesting a positive immigrant effect. We expected to find an association between stress markers due to the synergistic relationship between nutrition and pathology. The data support this hypothesis, but only one finding was statistically significant. While high critical values from small sample sizes place limits on the significance of our results, we find that the impact of environmental and cultural change to prehistoric Japanese populations was minimal. (c) 2008 Wiley-Liss, Inc.
Effects of heat stress on bovine preimplantation embryos produced in vitro
SAKATANI, Miki
2017-01-01
Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress. PMID:28496018
Effects of heat stress on bovine preimplantation embryos produced in vitro.
Sakatani, Miki
2017-08-19
Summer heat stress decreases the pregnancy rate in cattle and has been thought to be associated with the early embryonic death caused by the elevation of maternal body temperature. In vitro cultures have been widely used for the evaluation of effects of heat stress on oocytes, fertilization, preimplantation, and embryonic development. Susceptibility to heat stress is present in developmental stages from oocytes to cleavage-stage (before embryonic gene activation, EGA) embryos, leading to a consequent decrease in developmental competence. On the other hand, advanced-stage embryos such as morula or blastocysts have acquired thermotolerance. The mechanism for the developmental stage-dependent change in thermotolerance is considered to be the accumulation of antioxidants in embryos in response to heat-inducible production of reactive oxygen species. The supplementation of antioxidants to the culture media has been known to neutralize the detrimental effects of heat stress. Besides, EGA could be involved in acquisition of thermotolerance in later stages of embryos. Morulae or blastocysts can repair heat-induced unfolded proteins or prevent DNA damage occurring in processes such as apoptosis. Therefore, embryo transfer (ET) that can bypass the heat-sensitive stage could be a good solution to improve the pregnancy rate under heat stress. However, frozen-thawed ET could not improve the pregnancy rate as expected. Frozen-thawed blastocysts were more sensitive to heat stress and showed less proliferation upon heat exposure, compared to fresh blastocysts. Therefore, further research is required to improve the reduction in pregnancy rates due to summer heat stress.
Smith, Ashlyn L.; Romski, MaryAnn; Sevcik, Rose A.; Adamson, Lauren B.; Barker, R. Michael
2013-01-01
This study extended research on the Down syndrome advantage by examining differences in parent stress and parent perceptions of language development between 29 parents of young children with Down syndrome and 82 parents of children with other developmental disabilities. Parents of children with Down syndrome reported lower levels of total stress, child-related stress, and stress surrounding the parent-child interaction. Parents of children in both groups reported that they felt successful in their ability to impact their children’s communication development but did differ on perceptions of difficulty such that parents of children with Down syndrome perceived their children’s communication difficulties as less severe despite the children exhibiting similar language skills. Finally, after accounting for potential explanatory confounding variables, child diagnosis remained a significant predictor of parent stress and perceptions of language development. Results highlight the importance of considering etiology when assisting families raising a child with a disability. PMID:24753637
Social Buffering of Stress in Development: A Career Perspective
Gunnar, Megan R.
2016-01-01
This review provides a broad overview of my research group's work on social buffering in human development in the context of the field. Much of the focus is on social buffering of the hypothalamic-pituitary-adrenocortical (HPA) system, one of the two major arms of the mammalian stress system. This focus reflects the centrality of the HPA system in research on social buffering in the fields of developmental psychobiology and developmental science. However, buffering of the cardiovascular and autonomic nervous system is also discussed. The central developmental question in this area derives from attachment theory which argues that the infant's experience of stress and arousal regulation in the context of her early attachment relationships is not an immature form of social buffering experienced in adulthood, but rather the foundation out of which individual differences in the capacity to gain stress relief from social partners emerge. The emergence of social buffering in infancy, changes in social buffering throughout childhood and adolescence, the influence of early experience on later individual differences in social buffering, and critical gaps in our knowledge are described. PMID:28544861
Childhood Stress: The Teacher's Role.
ERIC Educational Resources Information Center
Chandler, Louis A.
The paper examines the effects of stress on children and considers ways in which teachers can help them cope. Three major sources of stress are identified: (1) normal developmental stress, such as pressure for academic success; (2) endemic social stress, resulting from such social trends as rising divorce rates and the general erosion of the…
ERIC Educational Resources Information Center
Seiffge-Krenke, Inge; Aunola, Kaisa; Nurmi, Jari-Erik
2009-01-01
The present study investigated the interplay between developmental changes in stress and coping during early and late adolescence. Using a longitudinal design, stress perception and coping styles of 200 adolescents in 7 different stressful situations were investigated. Multilevel piecewise latent growth curve models showed that stress perception…
USDA-ARS?s Scientific Manuscript database
Adolescents experience stressful situations at a high rate during school. Indeed, school is the most common source of stress for teens. This high rate of stress may promote increases in adiposity during a developmental period important for establishing the adult physique. Adiposity gains may be th...
Developmental and Evolutionary History Affect Survival in Stressful Environments
Hopkins, Gareth R.; Brodie, Edmund D.; French, Susannah S.
2014-01-01
The world is increasingly impacted by a variety of stressors that have the potential to differentially influence life history stages of organisms. Organisms have evolved to cope with some stressors, while with others they have little capacity. It is thus important to understand the effects of both developmental and evolutionary history on survival in stressful environments. We present evidence of the effects of both developmental and evolutionary history on survival of a freshwater vertebrate, the rough-skinned newt (Taricha granulosa) in an osmotically stressful environment. We compared the survival of larvae in either NaCl or MgCl2 that were exposed to salinity either as larvae only or as embryos as well. Embryonic exposure to salinity led to greater mortality of newt larvae than larval exposure alone, and this reduced survival probability was strongly linked to the carry-over effect of stunted embryonic growth in salts. Larval survival was also dependent on the type of salt (NaCl or MgCl2) the larvae were exposed to, and was lowest in MgCl2, a widely-used chemical deicer that, unlike NaCl, amphibian larvae do not have an evolutionary history of regulating at high levels. Both developmental and evolutionary history are critical factors in determining survival in this stressful environment, a pattern that may have widespread implications for the survival of animals increasingly impacted by substances with which they have little evolutionary history. PMID:24748021
Allison, Beth J.; Kaandorp, Joepe J.; Kane, Andrew D.; Camm, Emily J.; Lusby, Ciara; Cross, Christine M.; Nevin-Dolan, Rhianon; Thakor, Avnesh S.; Derks, Jan B.; Tarry-Adkins, Jane L.; Ozanne, Susan E.; Giussani, Dino A.
2016-01-01
Aging and developmental programming are both associated with oxidative stress and endothelial dysfunction, suggesting common mechanistic origins. However, their interrelationship has been little explored. In a rodent model of programmed cardiovascular dysfunction we determined endothelial function and vascular telomere length in young (4 mo) and aged (15 mo) adult offspring of normoxic or hypoxic pregnancy with or without maternal antioxidant treatment. We show loss of endothelial function [maximal arterial relaxation to acetylcholine (71 ± 3 vs. 55 ± 3%) and increased vascular short telomere abundance (4.2–1.3 kb) 43.0 ± 1.5 vs. 55.1 ± 3.8%) in aged vs. young offspring of normoxic pregnancy (P < 0.05). Hypoxic pregnancy in young offspring accelerated endothelial dysfunction (maximal arterial relaxation to acetylcholine: 42 ± 1%, P < 0.05) but this was dissociated from increased vascular short telomere length abundance. Maternal allopurinol rescued maximal arterial relaxation to acetylcholine in aged offspring of normoxic or hypoxic pregnancy but not in young offspring of hypoxic pregnancy. Aged offspring of hypoxic allopurinol pregnancy compared with aged offspring of untreated hypoxic pregnancy had lower levels of short telomeres (vascular short telomere length abundance 35.1 ± 2.5 vs. 48.2 ± 2.6%) and of plasma proinflammatory chemokine (24.6 ± 2.8 vs. 36.8 ± 5.5 pg/ml, P < 0.05). These data provide evidence for divergence of mechanistic pathways mediating cardiovascular aging and developmental programming of cardiovascular disease, and aging being decelerated by antioxidants even prior to birth.—Allison, B. J., Kaandorp, J. J., Kane, A. D., Camm, E. J., Lusby, C., Cross, C. M., Nevin-Dolan, R., Thakor, A. S., Derks, J. B., Tarry-Adkins, J. L., Ozanne, S. E., Giussani, D. A. Divergence of mechanistic pathways mediating cardiovascular aging and developmental programming of cardiovascular disease. PMID:26932929
Allison, Beth J; Kaandorp, Joepe J; Kane, Andrew D; Camm, Emily J; Lusby, Ciara; Cross, Christine M; Nevin-Dolan, Rhianon; Thakor, Avnesh S; Derks, Jan B; Tarry-Adkins, Jane L; Ozanne, Susan E; Giussani, Dino A
2016-05-01
Aging and developmental programming are both associated with oxidative stress and endothelial dysfunction, suggesting common mechanistic origins. However, their interrelationship has been little explored. In a rodent model of programmed cardiovascular dysfunction we determined endothelial function and vascular telomere length in young (4 mo) and aged (15 mo) adult offspring of normoxic or hypoxic pregnancy with or without maternal antioxidant treatment. We show loss of endothelial function [maximal arterial relaxation to acetylcholine (71 ± 3 vs. 55 ± 3%) and increased vascular short telomere abundance (4.2-1.3 kb) 43.0 ± 1.5 vs. 55.1 ± 3.8%) in aged vs. young offspring of normoxic pregnancy (P < 0.05). Hypoxic pregnancy in young offspring accelerated endothelial dysfunction (maximal arterial relaxation to acetylcholine: 42 ± 1%, P < 0.05) but this was dissociated from increased vascular short telomere length abundance. Maternal allopurinol rescued maximal arterial relaxation to acetylcholine in aged offspring of normoxic or hypoxic pregnancy but not in young offspring of hypoxic pregnancy. Aged offspring of hypoxic allopurinol pregnancy compared with aged offspring of untreated hypoxic pregnancy had lower levels of short telomeres (vascular short telomere length abundance 35.1 ± 2.5 vs. 48.2 ± 2.6%) and of plasma proinflammatory chemokine (24.6 ± 2.8 vs. 36.8 ± 5.5 pg/ml, P < 0.05). These data provide evidence for divergence of mechanistic pathways mediating cardiovascular aging and developmental programming of cardiovascular disease, and aging being decelerated by antioxidants even prior to birth.-Allison, B. J., Kaandorp, J. J., Kane, A. D., Camm, E. J., Lusby, C., Cross, C. M., Nevin-Dolan, R., Thakor, A. S., Derks, J. B., Tarry-Adkins, J. L., Ozanne, S. E., Giussani, D. A. Divergence of mechanistic pathways mediating cardiovascular aging and developmental programming of cardiovascular disease. © FASEB.
Reduction in plasma vasopressin levels of dehydrated rats following acute stress
NASA Technical Reports Server (NTRS)
Keil, L. C.; Severs, W. B.
1977-01-01
Results are presented for an investigation directed to substantiate and extend preliminary findings of stress-induced reduction in plasma arginine vasopressin (pAVP). Since normally hydrated rats have very low levels of pAVP, it is difficult to measure reliably any decrease in pAVP that may result from stress. To overcome this problem, the pAVP levels of the tested rats were raised by dehydration prior to application of stress. A radioimmunoassay for pAVP is described and used to determine the levels of vasopressin in the plasma of nondehydrated and dehydrated rats after exposure to ether or acceleration stress. Plasma pAVP is also determined in rats following nicotine administration. It is shown that exposure of nondehydrated rats to ether or acceleration stress does not elicit any significant alterations in circulating pAVP levels while nicotine injections stimulate a marked increase. In particular, ether and acceleration stress produce a rapid reduction in the pAVP level of dehydrated rats, the decrease being observed in both large and small animals. The mechanism for this reduction in pAVP level following stress is yet unknown.
ERIC Educational Resources Information Center
Gupta, Himani
2017-01-01
The Accelerated Study in Associate Programs (ASAP), developed by the City University of New York (CUNY), is an uncommonly comprehensive and long-term program designed to address low graduation rates among community college students. MDRC has been studying the effects of ASAP on low-income students with developmental (remedial) education needs at…
Réus, Gislaine Z; Fernandes, Gabrielly C; de Moura, Airam B; Silva, Ritele H; Darabas, Ana Caroline; de Souza, Thays G; Abelaira, Helena M; Carneiro, Celso; Wendhausen, Diogo; Michels, Monique; Pescador, Bruna; Dal-Pizzol, Felipe; Macêdo, Danielle S; Quevedo, João
2017-12-01
This study used an animal model of depression induced by maternal care deprivation (MCD) to investigate whether depressive behaviour, neuroinflammation and oxidative stress were underlying factors in developmental programming after early life stress. At postnatal days (PND) 20, 30, 40, and 60, individual subsets of animals were evaluated in behavioural tests and then euthanized to assess cytokine levels and oxidative stress parameters in the prefrontal cortex (PFC), hippocampus and serum. The results showed that MCD did not induce behavioural changes at PND 30 and 40. However, at PND 20 and 60, the rats displayed a depressive-like behaviour in the forced swimming test, without changes in locomotor spontaneous activity. In the brain and serum, the levels of pro-inflammatory cytokines (interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)) were increased, and the anti-inflammatory cytokine (interleukin-10) level was reduced throughout developmental programming (PND 20, 30, 40 and 60). Protein carbonyl levels increased in the brain at PND 30, 40 and 60. Superoxide dismutase (SOD) activity was decreased during all developmental programming phases evaluated in the brain. Catalase (CAT) activity was decreased at PND 20, 40 and 60 in the brain. Our results revealed that "critical episodes" in early life stressful events are able to induce behavioural alterations that persist into adulthood and can stimulate inflammation and oxidative damage in both central and peripheral systems, which are required for distinct patterns of resilience against psychiatric disorders later in life. Copyright © 2017 Elsevier Ltd. All rights reserved.
Reynolds, L P; Borowicz, P P; Caton, J S; Vonnahme, K A; Luther, J S; Hammer, C J; Maddock Carlin, K R; Grazul-Bilska, A T; Redmer, D A
2010-04-01
Developmental programming refers to the programming of various bodily systems and processes by a stressor of the maternal system during pregnancy or during the neonatal period. Such stressors include nutritional stress, multiple pregnancy (i.e., increased numbers of fetuses in the gravid uterus), environmental stress (e.g., high environmental temperature, high altitude, prenatal steroid exposure), gynecological immaturity, and maternal or fetal genotype. Programming refers to impaired function of numerous bodily systems or processes, leading to poor growth, altered body composition, metabolic dysfunction, and poor productivity (e.g., poor growth, reproductive dysfunction) of the offspring throughout their lifespan and even across generations. A key component of developmental programming seems to be placental dysfunction, leading to altered fetal growth and development. We discuss various large animal models of developmental programming and how they have and will continue to contribute to our understanding of the mechanisms underlying altered placental function and developmental programming, and, further, how large animal models also will be critical to the identification and application of therapeutic strategies that will alleviate the negative consequences of developmental programming to improve offspring performance in livestock production and human medicine.
Newland, Rebecca P; Crnic, Keith A
2017-01-01
Despite the compelling nature of goodness of fit, empirical support has lagged for this construct. The present study examined an interactional approach to measuring goodness of fit and prospectively explored associations with mother-child relationship quality, child behavior problems, and parenting stress across the preschool period. In addition, as goodness of fit might be particularly important for children at developmental risk, the presence of early developmental delay was considered as a moderator of goodness of fit processes. Children with ( n = 110) and without ( n = 137) developmental delays and their mothers were coded while interacting in the lab at child age 36 months and during naturalistic home observations at child ages 36 and 48 months. Mothers also completed questionnaires at child age 60 months. Results highlight the effects of child developmental risk as a moderator of mother-child goodness of fit processes across the preschool period. There was also evidence that the goodness of fit between maternal scaffolding and child activity level at 36 months influenced both mother and child functioning at 60 months. Findings call for more precise models and expanded developmental perspectives to fully capture the transactional and dynamic nature of goodness of fit.
Parent Perspectives of Applying Mindfulness-Based Stress Reduction Strategies to Special Education
ERIC Educational Resources Information Center
Burke, Meghan M.; Chan, Neilson; Neece, Cameron L.
2017-01-01
Parents of children with (versus without) intellectual and developmental disabilities report greater stress; such stress may be exacerbated by dissatisfaction with school services, poor parent-school partnerships, and the need for parent advocacy. Increasingly, mindfulness interventions have been used to reduce parent stress. However, it is…
In utero exposure to mild variable stress has been reported to influence learning and memory formation in offspring. Our research aims to examine whether nonchemical environmental stressors will exacerbate effects to chemical exposure. This study utilized a varying stress parad...
Parker, Karen J.; Maestripieri, Dario
2010-01-01
This article examines the complex role of early stressful experiences in producing both vulnerability and resilience to later stress-related psychopathology in a variety of primate models of human development. Two types of models are reviewed: Parental Separation Models (e.g., isolate-rearing, peer-rearing, parental separations, and stress inoculation) and Maternal Behavior Models (e.g., foraging demands, variation in maternal style, and maternal abuse). Based on empirical evidence, it is argued that early life stress exposure does not increase adult vulnerability to stress-related psychopathology as a linear function, as is generally believed, but instead reflects a quadratic function. Features of early stress exposure including the type, duration, frequency, ecological validity, sensory modality, and developmental timing, within and between species, are identified to better understand how early stressful experiences alter neurobiological systems to produce such diverse developmental outcomes. This article concludes by identifying gaps in our current knowledge, providing directions for future research, and discussing the translational implications of these primate models for human development and psychopathology. PMID:20851145
Burke, Meghan M; Hodapp, Robert M
2014-02-01
Although mothers of children with intellectual and developmental disabilities (IDD) experience high levels of stress and schools constitute an important resource, the relation remains unknown between maternal stress and educational services. Responding to a national, web-based survey, 965 mothers of students with disabilities completed a 163-item questionnaire about parent stress. We examined which child, parent, and parent-school characteristics correlated with maternal stress. Mothers with lower stress levels reported better parent-school relationships and low levels of parent advocacy. However, lower stress levels were predominantly shown by mothers with good-to-excellent parent-school relationships (vs. poor-to-fair partnerships) and who engaged in virtually no (vs. any) advocacy activities. Lower maternal stress levels were also noted when children had fewer behavior problems, Down syndrome, and did not have autism. Less stress was also reported by mothers who had not enacted procedural safeguards, were minorities, and rated themselves lower on neuroticism and were more extroverted, dependable, and open to new experiences. This study has important implications for practitioners and researchers.
Martha Muchow and Organismic-Developmental Theory.
ERIC Educational Resources Information Center
Wapner, Seymour
1985-01-01
Examines Martha Muchow's work from the perspective of Heinz Werner's organismic-developmental theory, in terms of its stress on the environment as perceived and experienced by the child and its relevance to Werner's concept of differing "spheres of reality." (Author/SO)
NASA Technical Reports Server (NTRS)
Lathrop, J. W.
1985-01-01
If thin film cells are to be considered a viable option for terrestrial power generation their reliability attributes will need to be explored and confidence in their stability obtained through accelerated testing. Development of a thin film accelerated test program will be more difficult than was the case for crystalline cells because of the monolithic construction nature of the cells. Specially constructed test samples will need to be fabricated, requiring committment to the concept of accelerated testing by the manufacturers. A new test schedule appropriate to thin film cells will need to be developed which will be different from that used in connection with crystalline cells. Preliminary work has been started to seek thin film schedule variations to two of the simplest tests: unbiased temperature and unbiased temperature humidity. Still to be examined are tests which involve the passage of current during temperature and/or humidity stress, either by biasing in the forward (or reverse) directions or by the application of light during stress. Investigation of these current (voltage) accelerated tests will involve development of methods of reliably contacting the thin conductive films during stress.
Yamada, Atsurou; Suzuki, Miyoshi; Kato, Misuzu; Suzuki, Mie; Tanaka, Sayumi; Shindo, Takuo; Taketani, Kazuo; Akechi, Tatsuo; Furukawa, Toshi A
2007-12-01
A number of studies have reported that parents of autistic children face higher levels of stress, but few studies examined the stress associated with the home care of children with pervasive developmental disorders (PDD) other than autistic disorder. The aims of the present study were therefore to (i) evaluate the emotional stress level of parents caring for their children with PDD; and (ii) explore the correlates of their emotional stress. Participants were 147 families (147 mothers and 122 fathers) of 158 children with PDD (42 with autistic disorder, 35 with Asperger's disorder and 81 with PDD not otherwise specified). K6 was used to measure the stress level of the parents. Marital relationships and personality were assessed with the Intimate Bond Measure and the NEO Five-Factor Inventory, respectively. The parents also rated the characteristics of their children with PDD through the Pervasive Developmental Disorder-Autism Society Japan Rating Scale (PARS). The mean K6 score of the mothers was significantly higher than that of the women in the general population in Japan. Stepwise multiple regression indicated that the emotional stress of the mothers was correlated with the personality traits of Neuroticism and Agreeableness, perceived Control by the husband, and the children's PARS score. Clinicians can deliver better service by paying appropriate attention to the emotional distress of mothers of children with not only autistic disorder but also other PDD.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ciborowski, J.J.H.; Cervi, L.; Sinasac, D.
1995-12-31
Sublethal environmental stresses produce effects ranging from subtle biochemical changes that protect an organism from damage, through developmental effects that interfere with growth and compromise fitness. Benthic chironomids live in intimate contact with the sediments to which most persistent chemicals are bound. Their short life cycle and unique developmental and genetic structure make them excellent candidates as biological indicators of stress. The authors evaluated the short and long-term responses of Chironomus riparius larvae to contaminants. To determine short-term stress responses, third and fourth instar Chironomus larvae were exposed to up to 1.5 {micro}L/g creosote or up to 100 {micro}g/g Cdmore » for 12 h. Creosote-exposed larvae exhibited proteins of a molecular weight consistent with production of heat shock proteins of the HSP 70 family. Exposure to Cd induced significant enlargement of Balbiani Rings of the 4th chromosome in chironomid salivary glands, indicative of increased transcription of RNA precursors to salivary mucoproteins. Chironomus larvae individually reared from second instar larvae at [Cd] up to 40 {micro}g/g sediment exhibited increased incidence of mentum deformities, and delayed development that resulted in larger size at pupation. Thus deformities are biologically relevant indicators of stress. Overall, the results confirm the potential of chironomids as relevant bioindicators of contaminant stress.« less
ERIC Educational Resources Information Center
La Fountain, Rebecca; Geoffroy, Kevin
This study was conducted to investigate the effect that a parent support group and a counseling group had on the stress levels, self-esteem, and degree of coping of parents (N=48) of developmentally delayed or handicapped infants enrolled in an infant intervention program. It was hypothesized that, compared to parents in the control group, parents…
Decreased head circumference velocity as related to developmental deficit in infancy.
Tal, Galit; Cohen, Ayala; Habib, Sonia; Tirosh, Emanuel
2012-11-01
We evaluated the significance of head circumference growth velocity as related to developmental deficits during infancy. Head circumferences, lengths, and developmental diagnoses were retrieved in a standard manner at ≥ 2 time points from 437 infants with developmental deficits, and 3909 normally developing infants. Infants' ages ranged from 1-24 months, with final diagnoses ascertained at age 24 months. Increased velocity during the first 2 months in typical infants was evident in the study group during the period 2-4 months. A differential head circumference growth velocity was observed, and infants diagnosed with motor delay presented decreased velocity between ages 2-4 months, compared with infants receiving other nonmotor developmental diagnoses. These differences remained after controlling for birth weight and length. No significant sex effect was evident. Infants with developmental deficits demonstrate delayed acceleration of head circumference velocity, compared with typical infants in the first 2 months. Infants with motor delay manifest decreased velocity, compared with infants presenting other developmental deficits. These differences may be related to delayed white matter maturation. Copyright © 2012 Elsevier Inc. All rights reserved.
McGlashan, Jessica K; Thompson, Michael B; Van Dyke, James U; Spencer, Ricky-John
Metabolic processes are affected by both temperature and thyroid hormones in ectothermic vertebrates. Temperature is the major determinant of incubation length in oviparous vertebrates, but turtles can also alter developmental rate independent of temperature. Temperature gradients within natural nests cause different developmental rates of turtle embryos within nests. Despite temperature-induced reductions in developmental rate, cooler-incubated neonates often hatch synchronously with warmer siblings via metabolic compensation. The physiological mechanisms underlying metabolic compensation are unknown, but thyroid hormones may play a critical role. We applied excess triiodothyronine (T 3 ) to developing eggs of Murray River short-necked turtle (Emydura macquarii)-a species that exhibits metabolic compensation and synchronous hatching-to determine whether T 3 influences developmental rate and whether changes to incubation period incur metabolic costs. We measured heart rate, oxygen consumption and incubation period of eggs, and morphology and performance of hatchlings. Embryos that were exposed to T 3 pipped up to 3.5 d earlier than untreated controls, despite no change in total metabolic expenditure, and there were no treatment differences in hatchling morphology. Hatchlings treated with T 3 demonstrated similar righting ability to hatchlings from the control groups. Exposure to T 3 shortens incubation length by accelerating embryonic development but without statistically increasing embryonic metabolism. Thus, T 3 is a mechanism that cooler-incubated reptiles could use to accelerate their development to allow synchronous hatching with their warmer clutch mates but at little or no metabolic cost. Thus, metabolic compensation for synchronous hatching may not be metabolically expensive if T 3 is the underlying mechanism.
Pandey, Jitendra Kumar; Dash, Sidhartha Kumar; Biswal, Basanti
2017-07-01
The precise nature of the developmental modulation of the activity of cell wall hydrolases that breakdown the wall polysaccharides to maintain cellular sugar homeostasis under sugar starvation environment still remains unclear. In this work, the activity of β-galactosidase (EC 3.2.1.23), a cell-wall-bound enzyme known to degrade the wall polysaccharides, has been demonstrated to remarkably enhance during senescence-induced loss in photosynthesis in Arabidopsis thaliana. The enhancement in the enzyme activity reaches a peak at the terminal phase of senescence when the rate of photosynthesis is at its minimum. Although the precise nature of chemistry of the interface between the decline in photosynthesis and enhancement in the activity of the enzyme could not be fully resolved, the enhancement in its activity in dark and its suppression in light or with exogenous sugars may indicate the involvement of loss of photosynthetic production of sugars as a key factor that initiates and stimulates the activity of the enzyme. The hydrolase possibly participates in the catabolic network of cell wall polysaccharides to produce sugars for execution of energy-dependant senescence program in the background of loss of photosynthesis. Drought stress experienced by the senescing leaves accelerates the decline in photosynthesis with further stimulation in the activity of the enzyme. The stress recovery of photosynthesis and suppression of the enzyme activity on withdrawal of stress support the proposition of photosynthetic modulation of the cell-wall-bound enzyme activity.
Alados, C.L.; Emlen, J.M.; Wachocki, B.; Freeman, D.C.
1998-01-01
Developmental instability has been used to monitor the well-being of natural populations exposed to physical, chemical and biological stressors. Here, we use developmental instability to assess the impact of grazing on Chrysothamnus greenii and Seriphidium novumshrubs, and Oryzopsis hymenoidesgrass, common in the arid intermountain west of the U.S.A. Statistical noise in allometric relations was used as an indicator of developmental instability arising from grazing-induced stress. Unpalatable species that are not grazed (Chrysothamnus greenii) or species that are dormant during the winter–spring grazing period (Oryzopsis hymenoides) show lower allometric variability under high grazing pressure. Palatable species (Seriphidium novum) exhibit high developmental instability under low and high grazing pressure. Grazing pressure imposed by presumably co-adapted wild herbivores enhances developmental stability in species habituated to moderate grazing, likeOryzopsis hymenoides, but stresses plants such as Chrysothamnus greenii that prefer disturbed environments. These grazing effects are probably due to the impact grazing has on competitive relationships and not to the direct action of the herbivore on the plants.
Developmental Stability Covaries with Genome-Wide and Single-Locus Heterozygosity in House Sparrows
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
Nonlinear interaction of strong S-waves with the rupture front in the shallow subsurface
NASA Astrophysics Data System (ADS)
Sleep, N. H.
2017-12-01
Shallow deformation in moderate to large earthquakes is sometimes distributed rather than being concentrated on a single fault plane. Strong high-frequency S-waves interact with the rupture front to produce this effect. For strike-slip faults, the rupture propagation velocity is a fraction of the S-wave velocity. The rupture propagation vector refracts essentially vertically in the low (S-wave) velocity shallow subsurface. So does the propagation direction of S-waves. The shallow rupture front is essentially mode 3 near the surface. Strong S-waves arrive before the rupture front. They continue to arrive for several seconds in a large event. There are simple scaling relationships. The dynamic Coulomb stress ratio of horizontal stress on horizontal planes from S-waves is the normalized acceleration in g's. For fractured rock and gravel, frictional failure occurs when the normalized acceleration exceeds the effective coefficient of friction. Acceleration tends to saturate at that level as the anelastic strain rate increases rapidly with stress. For muddy materials, failure begins at a low normalized acceleration but increases slowly with dynamic stress. Dynamic accelerations sometimes exceed 1 g. In both cases, the rupture tip finds the shallow subsurface already in nonlinear failure down to a few to tens of meters depth. The material does not distinguish between S-wave and rupture tip stresses. Both stresses add to the stress invariant and hence to the anelastic strain rate tensor. Surface anelastic strain from fault slip is thus distributed laterally over a distance scaling to the depth of nonlinearity from S-waves. The environs of the fault anelastically accommodate the fault slip at depth. This process differs from blind faults where the shallow coseismic strain is mostly elastic and interseismic anelastic processes accommodate the long-term shallow deformation.
ERIC Educational Resources Information Center
Scrivener, Susan; Weiss, Michael J.; Sommo, Colleen
2012-01-01
In recent years, there has been unprecedented national focus on the importance of increasing the stubbornly low graduation rates of community college students. Most reforms that have been tried are short-term and address one or only a few barriers to student success. The City University of New York's (CUNY's) Accelerated Study in Associate…
Fortuna, Keren; Roisman, Glenn I
2008-03-01
This report was designed to clarify links among self-reports of psychiatric symptomatology, stress, and adult attachment insecurity, as operationalized using measures drawn from both the developmental and social psychological literatures. Based on a sample of 160 college students, this study demonstrated that insecurity reflected in the Adult Attachment Interview (AAI) was associated with self-reports of psychiatric symptomatology principally for individuals experiencing high levels of life stress (consistent with a diathesis-stress model) whereas self-reports of attachment-related avoidance and anxiety correlated robustly with psychopathology under conditions of both relatively high and low life stress (consistent with a risk model). Results provide further evidence that social psychological and developmental approaches to the assessment of adult attachment-related variation are associated with domains of adaptation central to Bowlby's account of human development in empirically distinct ways.
photovoltaic (PV) modules, inspections for root cause of module failures in the field, and accelerated lifetime delamination. His research interests are in modeling of degradation processes of PV modules, module integrated analysis of PV degradation data. He also explores accelerated multi-stress and combined stress testing to
NASA Technical Reports Server (NTRS)
Greenleaf, J. E.; Gundo, D. P.; Watenpaugh, D. E.; Mulenburg, G. M.; Mckenzie, M. A.; Looft-Wilson, R.; Hargens, A. R.
1997-01-01
In addition to extensive use of lower extremity physical exercise training as a countermeasure for the work capacity component of spaceflight deconditioning, some form of additional head-to-foot (+Gz) gravitational (orthostatic) stress may be required to further attenuate or prevent the signs and symptoms (nausea, vertigo, instability, fatigue) of the general reentry syndrome (GRS) that can reduce astronaut performance during landing. Orthostatic (head-to-foot) stress can be induced by standing, by lower body negative pressure, and by +Gz acceleration. One important question is whether acceleration training alone or with concurrent leg exercise would provide sufficient additive stimulation to attenuate the GRS. Use of a new human-powered centrifuge may be the answer. Thus, the purpose for this study was to compare heart rate (HR), i.e., a stress response during human-powered acceleration, in four men (35-62 yr) and two women (30-31 yr) during exercise acceleration versus passive acceleration (by an off-board operator) at 100% (maximal acceleration = A(max)), and at 25%, 50%, and 75% of A(max). Mean (+/-SE) A(max) was 43.7 +/- 1.3 rpm (+3.9 +/- 0.2Gz). Mean HR at exercise A(max) was 189 +/- 13 b/min (50-70 sec run time), and 142 +/- 22 b/min at passive A(max) (40-70 sec run time). Regression of mean HR on the various +Gz levels indicated explained variance (correlations squared) of r(exp 2) = 0.88 (exercise) and r(exp 2) = 0.96 (passive): exercise HR of 107 +/- 4 (25%) to 189 +/- 13 (100%) b/min were 43-50 b/min higher (p less than 0.05) than comparable passive HR of 64 +/- 2 to 142 +/- 22 b/min. Thus, exercise adds significant physiological stress during +Gz acceleration. Inflight use of this combined exercise and acceleration countermeasure may maintain work capacity as well as normalize acceleration and orthostatic tolerances which could attenuate or perhaps eliminate the GRS.
Govindaraj, Sakthivel; Shanmuganathan, Annadurai; Rajan, Ravindran
2017-01-01
Background Stress is an inevitable part of life, and maternal stress during the gestational period has dramatic effects in the early programming of the physiology and behavior of offspring. The developmental period is crucial for the well-being of the offspring. Prenatal stress influences the developmental outcomes of the fetus, in part because the developing brain is particularly vulnerable to stress. The etiology of birth defects of the offspring is reported to be 30–40% genetic and 7–10% multifactorial, with the remaining 50% still unknown and also there is no clear cause for neonatal mortality and still-birth. Objective The present study explores the association of maternal psychological stress on mother and the offspring’s incidence of birth defects, stillbirth, and neonatal mortality. Study design Pregnant animals were restrained to induce psychological stress (3 times per day, 45 minutes per session). Except control group, other animals were exposed to restraint stress during the gestational period: early gestational stress (EGS, stress exposure during 1st day to 10th days of gestational period), late gestational stress (LGS, stress exposure during 11th day to till parturition), and full term gestational stress (FGS, stress exposure to the whole gestational period). The effects of maternal stress on the mother and their offspring were analyzed. Results Expectant female rats exposed to stress by physical restraint showed decreased body weight gain, food intake, and fecal pellet levels. Specifically, the offspring of female rats subjected to late gestational and full term gestational restraint stress showed more deleterious effects, such as physical impairment (LGS 24.44%, FGS 10%), neonatal mortality (EGS 2.56%, LGS 24.44%, FGS 17.5%), stillbirths (FGS 27.5%), low birth weight (EGS 5.42g, LGS 4.40g, FGS 4.12g), preterm births (EGS 539 Hrs, LGS 514 Hrs, FGS 520.6 Hrs), and delayed eyelid opening (EGS 15.16 Days, LGS 17 Days, FGS 17.67 Days). Conclusion The results of this study reveal that maternal stress may be associated with the offspring’s abnormal structural phenotyping, preterm birth, stillbirth and neonatal mortality. PMID:28222133
Evolution and Ontogeny of Stress Response to Social Challenges in the Human Child
ERIC Educational Resources Information Center
Flinn, Mark V.
2006-01-01
The stress response systems of the human child are highly sensitive to social challenges. Because stress hormones can have negative developmental and health consequences, this presents an evolutionary paradox: Why would natural selection have favored mechanisms that elevate stress hormone levels in response to psychosocial stimuli? Two…
Zimmer, Cédric; Larriva, Maria; Boogert, Neeltje J.; Spencer, Karen A.
2017-01-01
An interesting aspect of developmental programming is the existence of transgenerational effects that influence offspring characteristics and performance later in life. These transgenerational effects have been hypothesized to allow individuals to cope better with predictable environmental fluctuations and thus facilitate adaptation to changing environments. Here, we test for the first time how early-life stress drives developmental programming and transgenerational effects of maternal exposure to early-life stress on several phenotypic traits in their offspring in a functionally relevant context using a fully factorial design. We manipulated pre- and/or post-natal stress in both Japanese quail mothers and offspring and examined the consequences for several stress-related traits in the offspring generation. We show that pre-natal stress experienced by the mother did not simply affect offspring phenotype but resulted in the inheritance of the same stress-coping traits in the offspring across all phenotypic levels that we investigated, shaping neuroendocrine, physiological and behavioural traits. This may serve mothers to better prepare their offspring to cope with later environments where the same stressors are experienced. PMID:28387355
Effects of free-air CO2 and temperature enrichment on soybean growth and development
NASA Astrophysics Data System (ADS)
Ruiz Vera, U. M.; Bernacchi, C. J.
2012-12-01
According to the growing degree days approach, the progression of plant developmental stages requires certain accumulation of heat; therefore greenhouse gas-induced warming of the atmosphere could contribute to more rapid plant development. However, the influence of rising carbon dioxide concentration ([CO2]) on development of crops is uncertain, accelerating and other times delaying certain developmental stages. In soybean, the increase of [CO2] is shown to delay reproductive development, which is attributed to a higher investment of resources into extra nodes. The combined effects of elevated temperature and [CO2] can have significant changes in the progression through development that can influence on total grain production, carbon uptake, and susceptibility to early end-of-season frosts. We designed the Temperature by Free Air CO2 Enrichment (T-FACE) experiment to test over two growing seasons (2009 and 2011) and under field conditions the impact of increased temperature and/or [CO2] on soybean. The heated T-FACE subplots were situated in the larger FACE plots at 385 or 585 ppm of [CO2] and subjected to either ambient or heated (+~3.5°C) temperatures. The experiment is full factorial with ambient temperature and [CO2] (control), elevated temperature (eT), elevated [CO2] (eC) and combined (eT+eC) treatments. We hypothesized that soybean grown (1) under elevated [CO2] will produce more nodes than control, (2) under high temperature will produce nodes faster than control and (3) under both elevated temperature and [CO2] will produce more nodes in less time than control. For reproductive development, we hypothesized that (1) reproductive development will initiate simultaneously regardless of increased [CO2] or temperature because soybean reproduction is triggered by day length, (2) elevated temperature will accelerate the progression through key reproductive stages and (3) the delay in soybean reproductive development by elevated [CO2] will be ameliorated by the raise in temperature. Soybean developmental stages were recorded on six plants per subplot three times per week from emergence to senescence. In 2009, no temperature effect was detected on the vegetative development, but in 2011 temperature accelerates node formation. Elevated [CO2] was not significant on vegetative development, however plants under this effect produced more nodes than control. Reproductive development was delayed by elevated [CO2]. High temperature accelerated reproductive stages only in 2009, ameliorating the effect of elevated [CO2] in eT+eC. In 2011 elevated temperature delayed reproductive stages, a response that could be related with stress imposed by the weather conditions of that season. In the Midwest, the soybean cultivars generally mature before the first frost of the year avoiding seed damage. The delayed in soybean maturation by the increasing of [CO2] could potentially reduce yield; however the increase of temperature could diminish this risk by mitigating this delay. Alternatively, the more rapid progression through the reproductive stages could decrease the translocation of resources to pods, thereby negatively impacting yields. Using soybean as a model for leguminous C3 species suggested implications could arise for yield in crop plants and reproductive fitness in native vegetation.
Saha, Anusree; Das, Shubhajit; Moin, Mazahar; Dutta, Mouboni; Bakshi, Achala; Madhav, M. S.; Kirti, P. B.
2017-01-01
Ribosomal proteins (RPs) are indispensable in ribosome biogenesis and protein synthesis, and play a crucial role in diverse developmental processes. Our previous studies on Ribosomal Protein Large subunit (RPL) genes provided insights into their stress responsive roles in rice. In the present study, we have explored the developmental and stress regulated expression patterns of Ribosomal Protein Small (RPS) subunit genes for their differential expression in a spatiotemporal and stress dependent manner. We have also performed an in silico analysis of gene structure, cis-elements in upstream regulatory regions, protein properties and phylogeny. Expression studies of the 34 RPS genes in 13 different tissues of rice covering major growth and developmental stages revealed that their expression was substantially elevated, mostly in shoots and leaves indicating their possible involvement in the development of vegetative organs. The majority of the RPS genes have manifested significant expression under all abiotic stress treatments with ABA, PEG, NaCl, and H2O2. Infection with important rice pathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Rhizoctonia solani also induced the up-regulation of several of the RPS genes. RPS4, 13a, 18a, and 4a have shown higher transcript levels under all the abiotic stresses, whereas, RPS4 is up-regulated in both the biotic stress treatments. The information obtained from the present investigation would be useful in appreciating the possible stress-regulatory attributes of the genes coding for rice ribosomal small subunit proteins apart from their functions as house-keeping proteins. A detailed functional analysis of independent genes is required to study their roles in stress tolerance and generating stress- tolerant crops. PMID:28966624
Al-Gubory, Kaïs H
2014-07-01
Developmental toxicity caused by exposure to a mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviours, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase susceptibility of offspring to diseases. There is evidence to suggest that the developmental toxicological mechanisms of chemicals and lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased ROS generation overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Data on the involvement of oxidative stress in the mechanism of developmental toxicity following exposure to environmental pollutants are reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on post-natal development and health outcomes. Developmental toxicity caused by exposure to mixture of environmental pollutants has become a major health concern. Human-made chemicals, including xenoestrogens, pesticides and heavy metals, as well as unhealthy lifestyle behaviors, mainly tobacco smoking, alcohol consumption and medical drug abuse, are major factors that adversely influence prenatal development and increase the susceptibility of offspring to development complications and diseases. There is evidence to suggest that the developmental toxicological mechanisms of human-made chemicals and unhealthy lifestyle factors involve the generation of reactive oxygen species (ROS) and cellular oxidative damage. Overproduction of ROS induces oxidative stress, a state where increased generation of ROS overwhelms antioxidant protection and subsequently leads to oxidative damage of cellular macromolecules. Exposure to various environmental pollutants induces synergic and cumulative dose-additive adverse effects on prenatal development, pregnancy outcomes and neonate health. Data from the literature on the involvement of oxidative stress in the mechanism of developmental toxicity following in vivo exposure to environmental pollutants will be reviewed in an attempt to provide an updated basis for future studies on the toxic effect of such pollutants, particularly the notion of increased risk for developmental toxicity due to combined and cumulative exposure to various environmental pollutants. The aims of such studies are to better understand the mechanisms by which environmental pollutants adversely affect conceptus development and to elucidate the impact of cumulative exposures to multiple pollutants on postnatal development and health outcomes. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
Zannas, Anthony S; Arloth, Janine; Carrillo-Roa, Tania; Iurato, Stella; Röh, Simone; Ressler, Kerry J; Nemeroff, Charles B; Smith, Alicia K; Bradley, Bekh; Heim, Christine; Menke, Andreas; Lange, Jennifer F; Brückl, Tanja; Ising, Marcus; Wray, Naomi R; Erhardt, Angelika; Binder, Elisabeth B; Mehta, Divya
2015-12-17
Chronic psychological stress is associated with accelerated aging and increased risk for aging-related diseases, but the underlying molecular mechanisms are unclear. We examined the effect of lifetime stressors on a DNA methylation-based age predictor, epigenetic clock. After controlling for blood cell-type composition and lifestyle parameters, cumulative lifetime stress, but not childhood maltreatment or current stress alone, predicted accelerated epigenetic aging in an urban, African American cohort (n = 392). This effect was primarily driven by personal life stressors, was more pronounced with advancing age, and was blunted in individuals with higher childhood abuse exposure. Hypothesizing that these epigenetic effects could be mediated by glucocorticoid signaling, we found that a high number (n = 85) of epigenetic clock CpG sites were located within glucocorticoid response elements. We further examined the functional effects of glucocorticoids on epigenetic clock CpGs in an independent sample with genome-wide DNA methylation (n = 124) and gene expression data (n = 297) before and after exposure to the glucocorticoid receptor agonist dexamethasone. Dexamethasone induced dynamic changes in methylation in 31.2 % (110/353) of these CpGs and transcription in 81.7 % (139/170) of genes neighboring epigenetic clock CpGs. Disease enrichment analysis of these dexamethasone-regulated genes showed enriched association for aging-related diseases, including coronary artery disease, arteriosclerosis, and leukemias. Cumulative lifetime stress may accelerate epigenetic aging, an effect that could be driven by glucocorticoid-induced epigenetic changes. These findings contribute to our understanding of mechanisms linking chronic stress with accelerated aging and heightened disease risk.
ERIC Educational Resources Information Center
McStay, Rebecca L.; Dissanayake, Cheryl; Scheeren, Anke; Koot, Hans M.; Begeer, Sander
2014-01-01
While stress is a common experience for parents caring for a child with a developmental disability, current measures fail to distinguish between general stress in parents and the demands of parenting and perceptions of parenting skills (parenting stress). This study examined differences in "parenting stress" reported by parents of…
Accelerated Stress-Corrosion Testing
NASA Technical Reports Server (NTRS)
1986-01-01
Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.
Huang, Yu-Ping; Chang, Ming-yuh; Chi, Yu-Lin; Lai, Fei-Chen
2014-02-01
The aims of this study were to compare parental stress and health-related quality of life (HRQOL) between Taiwanese fathers of children with and without developmental disabilities (DDs) and to examine the mediating effect of parental stress on the association between having a child with DD and paternal HRQOL within Chinese culture. This cross-sectional, prospective, unmatched case-control study included 206 fathers of children with DDs and 207 fathers of healthy children. HRQOL was assessed by the SF-36 short-form questionnaire, and parental stress was assessed by the Chinese version Parental Stress Scale. Fathers of children with DDs experienced poorer mental and physical HRQOL and higher parental stress than fathers of healthy children. Parental stress acted as a complete mediator for paternal physical HRQOL, while parental stress had a partial mediating effect on the relationship between having a child with DD and paternal mental HRQOL. Having a child with DD also directly affected paternal mental HRQOL. Fathers of children with DDs should be monitored for parental stress and HRQOL, and interventions should be provided to empower them with the knowledge and skills to reduce their stress and to enhance their HRQOL.
Ros, Rosmary; Hernandez, Jennifer; Graziano, Paulo A.; Bagner, Daniel M.
2015-01-01
This study investigated the extent to which parental homework completion during behavioral parent training (BPT) for children with or at risk for developmental delay contributed to parenting and child outcomes. Parents of 48 children (Mage = 44.17 months, SD = 14.29; 73% male; 72% White) with developmental delay (IQ < 75) or at risk for developmental delay (due to premature birth) with co-occurring clinically elevated externalizing behavior problems received Parent-Child Interaction Therapy (PCIT) as part of two previously completed randomized controlled trials. Parental homework completion was measured using parental report of home practice of treatment skills collected weekly by therapists. Parents also reported on child externalizing behavior problems and levels of parenting stress, while parenting skills were observed during a 5-min child directed play and child compliance was observed during a 5-min cleanup situation. Results indicated that higher rates of parental homework completion predicted parenting outcomes (i.e., increased positive parenting skills and decreased levels of parenting stress) and child outcomes (i.e., lower levels of externalizing behavior problems). Additionally, although limited by temporal precedence, there was an indirect effect of reductions in parenting stress on the negative association between parental homework completion and child externalizing behavior problems. These findings highlight the importance of parents practicing skills learned during BPT for optimizing treatment outcome. Parenting stress was also identified as a potential mechanism by which high levels of parental homework completion contributed to reductions in child externalizing behavior problems. PMID:26763493
Integrating the role of stressors through carbohydrate dynamics
Phillip M. Wargo
1999-01-01
Biological stress is defined as any environmental factor (stressors) capable of inducing a potentially injurious strain in living organisms (Levitt 1972). Organisms respond to these stresses physiologically or developmentally, and depending on the duration and severity of the stress, may or may not be injured.
Hamlyn-Wright, Sarah; Draghi-Lorenz, Riccardo; Ellis, Jason
2007-11-01
Stress, anxiety and depression are raised amongst parents of children with a developmental disorder. However, the processes by which stress leads to depression and anxiety are poorly understood. In a cross-sectional survey, levels of parental stress, depression and anxiety were compared between parents of children with an autistic disorder, children with Down's syndrome and children with no disorder (N = 619) and the mediational role of locus of control was examined. Anxiety and depression were higher in parents of children with a disorder, and highest in parents of children with autism. Locus of control was more external in parents of children with autism. Locus of control failed to mediate the relationship between stress and both anxiety and depression in parents of children with a disorder. This suggests that help for parents of a child with a disorder may be effective if focused on the sources of stress rather than perceived control over events.
Hydroxylated PBDEs induce developmental arrest in zebrafish
DOE Office of Scientific and Technical Information (OSTI.GOV)
Usenko, Crystal Y., E-mail: Crystal_usenko@baylor.edu; Hopkins, David C.; Trumble, Stephen J., E-mail: Stephen_trumble@baylor.edu
The ubiquitous spread of polybrominated diphenyl ethers (PBDEs) has led to concerns regarding the metabolites of these congeners, in particular hydroxylated PBDEs. There are limited studies regarding the biological interactions of these chemicals, yet there is some concern they may be more toxic than their parent compounds. In this study three hydroxylated PBDEs were assessed for toxicity in embryonic zebrafish: 3-OH-BDE 47, 5-OH-BDE 47, and 6-OH-BDE 47. All three congeners induced developmental arrest in a concentration-dependent manner; however, 6-OH-BDE 47 induced adverse effects at lower concentrations than the other congeners. Furthermore, all three induced cell death; however apoptosis was notmore » observed. In short-term exposures (24–28 hours post fertilization), all hydroxylated PBDEs generated oxidative stress in the region corresponding to the cell death at 5 and 10 ppm. To further investigate the short-term effects that may be responsible for the developmental arrest observed in this study, gene regulation was assessed for embryos exposed to 0.625 ppm 6-OH-BDE 47 from 24 to 28 hpf. Genes involved in stress response, thyroid hormone regulation, and neurodevelopment were significantly upregulated compared to controls; however, genes related to oxidative stress were either unaffected or downregulated. This study suggests that hydroxylated PBDEs disrupt development, and may induce oxidative stress and potentially disrupt the cholinergic system and thyroid hormone homeostasis. -- Highlights: ► OH-PBDEs induce developmental arrest in a concentration-dependent manner. ► Hydroxyl group location influences biological interaction. ► OH-PBDEs induce oxidative stress. ► Thyroid hormone gene regulation was disrupted following exposure. ► To our knowledge, this is the first whole organism study of OH-PBDE toxicity.« less
Hsu, Hung-Yao
2016-01-01
Bone cells are deformed according to mechanical stimulation they receive and their mechanical characteristics. However, how osteoblasts are affected by mechanical vibration frequency and acceleration amplitude remains unclear. By developing 3D osteoblast finite element (FE) models, this study investigated the effect of cell shapes on vibration characteristics and effect of acceleration (vibration intensity) on vibrational responses of cultured osteoblasts. Firstly, the developed FE models predicted natural frequencies of osteoblasts within 6.85–48.69 Hz. Then, three different levels of acceleration of base excitation were selected (0.5, 1, and 2 g) to simulate vibrational responses, and acceleration of base excitation was found to have no influence on natural frequencies of osteoblasts. However, vibration response values of displacement, stress, and strain increased with the increase of acceleration. Finally, stress and stress distributions of osteoblast models under 0.5 g acceleration in Z-direction were investigated further. It was revealed that resonance frequencies can be a monotonic function of cell height or bottom area when cell volumes and material properties were assumed as constants. These findings will be useful in understanding how forces are transferred and influence osteoblast mechanical responses during vibrations and in providing guidance for cell culture and external vibration loading in experimental and clinical osteogenesis studies. PMID:28074178
Traumatic stress and accelerated DNA methylation age: A meta-analysis.
Wolf, Erika J; Maniates, Hannah; Nugent, Nicole; Maihofer, Adam X; Armstrong, Don; Ratanatharathorn, Andrew; Ashley-Koch, Allison E; Garrett, Melanie; Kimbrel, Nathan A; Lori, Adriana; Va Mid-Atlantic Mirecc Workgroup; Aiello, Allison E; Baker, Dewleen G; Beckham, Jean C; Boks, Marco P; Galea, Sandro; Geuze, Elbert; Hauser, Michael A; Kessler, Ronald C; Koenen, Karestan C; Miller, Mark W; Ressler, Kerry J; Risbrough, Victoria; Rutten, Bart P F; Stein, Murray B; Ursano, Robert J; Vermetten, Eric; Vinkers, Christiaan H; Uddin, Monica; Smith, Alicia K; Nievergelt, Caroline M; Logue, Mark W
2018-06-01
Recent studies examining the association between posttraumatic stress disorder (PTSD) and accelerated aging, as defined by DNA methylation-based estimates of cellular age that exceed chronological age, have yielded mixed results. We conducted a meta-analysis of trauma exposure and PTSD diagnosis and symptom severity in association with accelerated DNA methylation age using data from 9 cohorts contributing to the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup (combined N = 2186). Associations between demographic and cellular variables and accelerated DNA methylation age were also examined, as was the moderating influence of demographic variables. Meta-analysis of regression coefficients from contributing cohorts revealed that childhood trauma exposure (when measured with the Childhood Trauma Questionnaire) and lifetime PTSD severity evidenced significant, albeit small, meta-analytic associations with accelerated DNA methylation age (ps = 0.028 and 0.016, respectively). Sex, CD4T cell proportions, and natural killer cell proportions were also significantly associated with accelerated DNA methylation age (all ps < 0.02). PTSD diagnosis and lifetime trauma exposure were not associated with advanced DNA methylation age. There was no evidence of moderation of the trauma or PTSD variables by demographic factors. Results suggest that traumatic stress is associated with advanced epigenetic age and raise the possibility that cells integral to immune system maintenance and responsivity play a role in this. This study highlights the need for additional research into the biological mechanisms linking traumatic stress to accelerated DNA methylation age and the importance of furthering our understanding of the neurobiological and health consequences of PTSD. Published by Elsevier Ltd.
Development of the brine shrimp Artemia is accelerated during spaceflight
NASA Technical Reports Server (NTRS)
Spooner, B. S.; Metcalf, J.; DeBell, L.; Paulsen, A.; Noren, W.; Guikema, J. A.
1994-01-01
Developmentally arrested brine shrimp cysts have been reactivated during orbital spaceflight on two different Space Shuttle missions (STS-50 and STS-54), and their subsequent development has been compared with that of simultaneously reactivated ground controls. Flight and control brine shrimp do not significantly differ with respect to hatching rates or larval morphology at the scanning and transmission EM levels. A small percentage of the flight larvae had defective nauplier eye development, but the observation was not statistically significant. However, in three different experiments on two different flights, involving a total of 232 larvae that developed in space, a highly significant difference in degree of flight to control development was found. By as early as 2.25 days after reactivation of development, spaceflight brine shrimp were accelerated, by a full instar, over ground control brine shrimp. Although developing more rapidly, flight shrimp grew as long as control shrimp at each developmental instar or stage.
Accelerated stress testing of terrestrial solar cells
NASA Technical Reports Server (NTRS)
Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.
1982-01-01
The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.
Newland, Rebecca P.; Crnic, Keith A.
2016-01-01
Despite the compelling nature of goodness of fit, empirical support has lagged for this construct. The present study examined an interactional approach to measuring goodness of fit and prospectively explored associations with mother-child relationship quality, child behavior problems, and parenting stress across the preschool period. In addition, as goodness of fit might be particularly important for children at developmental risk, the presence of early developmental delay was considered as a moderator of goodness of fit processes. Children with (n = 110) and without (n = 137) developmental delays and their mothers were coded while interacting in the lab at child age 36 months and during naturalistic home observations at child ages 36 and 48 months. Mothers also completed questionnaires at child age 60 months. Results highlight the effects of child developmental risk as a moderator of mother-child goodness of fit processes across the preschool period. There was also evidence that the goodness of fit between maternal scaffolding and child activity level at 36 months influenced both mother and child functioning at 60 months. Findings call for more precise models and expanded developmental perspectives to fully capture the transactional and dynamic nature of goodness of fit. PMID:28943806
QI, Xiaonan; LI, Huatao; CONG, Xia; WANG, Xin; JIANG, Zhongling; CAO, Rongfeng; TIAN, Wenru
2016-01-01
Scutellaria baicalensis has been effectively used in Chinese traditional medicine to prevent miscarriages. However, little information is available on its mechanism of action. This study is designed specifically to reveal how baicalin, the main effective ingredient of S. baicalensis, improves developmental competence of embryos in vitro, using the mouse as a model. Mouse pronuclear embryos were cultured in KSOM medium supplemented with (0, 2, 4 and 8 μg/ml) baicalin. The results demonstrated that in vitro culture conditions significantly decreased the blastocyst developmental rate and blastocyst quality, possibly due to increased cellular stress and apoptosis. Baicalin (4 µg/ml) significantly increased 2- and 4-cell cleavage rates, morula developmental rate, and blastocyst developmental rate and cell number of in vitro-cultured mouse embryos. Moreover, baicalin increased the expression of Gja1, Cdh1, Bcl-2, and Dnmt3a genes, decreased the expression of Dnmt1 gene, and decreased cellular stress and apoptosis as it decreased the expression of HSP70, CASP3, and BAX and increased BCL-2 expression in blastocysts cultured in vitro. In conclusion, baicalin improves developmental competence of in vitro-cultured mouse embryos through inhibition of cellular apoptosis and HSP70 expression, and improvement of DNA methylation. PMID:27478062
Hazel, Nicholas A; Oppenheimer, Caroline W; Technow, Jessica R; Young, Jami F; Hankin, Benjamin L
2014-08-01
During the transition to adolescence, several developmental trends converge to increase the importance of peer relationships, the likelihood of peer-related stressors, and the experience of depressive symptoms. Simultaneously, there are significant changes in parent-child relationships. The current study sought to evaluate whether positive relationship quality with parents continued to serve a protective effect by buffering the relationship between stressful life events, especially peer stress, and increases in depressive symptoms throughout the transition to adolescence. Participants in a large (N = 692) 2-site accelerated longitudinal study were recruited in 3rd, 6th, and 9th grade and followed every 3 months for 1 year. At baseline, parents and youth reported on parent-child relationship quality, and every 3 months thereafter reported on their levels of stressors and depressive symptoms. Parent relationship quality moderated the relationship of person-level fluctuations in peer stressors, such that there was a stronger association between peer stressors and increases in depressive symptoms in youth with lower levels of positive parental relationship quality. This effect was specific to peer stressors. These results suggest that low levels of parent relationship quality leave youth particularly vulnerable to the depressogenic effects of peer stressors from childhood through adolescence. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Corticosteroid signaling in frog metamorphosis.
Kulkarni, Saurabh S; Buchholz, Daniel R
2014-07-01
Stress in fetal and larval life can impact later health and fitness in humans and wildlife. Long-term effects of early life stress are mediated by altered stress physiology induced during the process of relaying environmental effects on development. Amphibian metamorphosis has been an important model system to study the role of hormones in development in an environmental context. Thyroid hormone (TH) is necessary and sufficient to initiate the dramatic morphological and physiological changes of metamorphosis, but TH alone is insufficient to complete metamorphosis. Other hormones, importantly corticosteroid hormones (CSs), influence the timing and nature of post-embryonic development. Stressors or treatments with CSs delay or accelerate metamorphic change, depending on the developmental stage of treatment. Also, TH and CSs have synergistic, antagonistic, and independent effects on gene regulation. Importantly, the identity of the endogenous corticosteroid hormone or receptor underlying any gene induction or remodeling event has not been determined. Levels of both CSs, corticosterone and aldosterone, peak at metamorphic climax, and the corticosteroid receptors, glucocorticoid and mineralocorticoid receptors, have wide expression distribution among tadpole tissues. Conclusive experiments to identify the endogenous players have been elusive due to difficulties in experimental control of corticosteroid production and signaling. Current data are consistent with the hypothesis that the two CSs and their receptors serve largely overlapping functions in regulating metamorphosis and synergy with TH. Knowledge of the endogenous players is critical to understanding the basic mechanisms and significance of corticosteroid action in regulating post-embryonic development in environmental contexts. Copyright © 2014 Elsevier Inc. All rights reserved.
Optimism and positive and negative feelings in parents of young children with developmental delay.
Kurtz-Nelson, E; McIntyre, L L
2017-07-01
Parents' positive and negative feelings about their young children influence both parenting behaviour and child problem behaviour. Research has not previously examined factors that contribute to positive and negative feelings in parents of young children with developmental delay (DD). The present study sought to examine whether optimism, a known protective factor for parents of children with DD, was predictive of positive and negative feelings for these parents. Data were collected from 119 parents of preschool-aged children with developmental delay. Two separate hierarchical linear regression analyses were conducted to determine if optimism significantly predicted positive feelings and negative feelings and whether optimism moderated relations between parenting stress and parent feelings. Increased optimism was found to predict increased positive feelings and decreased negative feelings after controlling for child problem behaviour and parenting stress. In addition, optimism was found to moderate the relation between parenting stress and positive feelings. Results suggest that optimism may impact how parents perceive their children with DD. Future research should examine how positive and negative feelings impact positive parenting behaviour and the trajectory of problem behaviour specifically for children with DD. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.
Fluctuating asymmetry as risk marker for stress and structural defects in a toxicologic experiment.
Breno, Matteo; Bots, Jessica; De Schaepdrijver, Luc; Van Dongen, Stefan
2013-08-01
Fluctuating asymmetry (the directionally random asymmetry of bilateral structures, FA) is commonly used as a measure of developmental instability, and may increase with stress. As several studies reported a relation between FA and developmental abnormalities, we investigate whether FA could be an additional perhaps more sensitive marker of developmental toxicity. The aim of this work is analyzing patterns of FA in multiple traits in a large dataset of rabbit fetuses, which were prenatally exposed to a toxic compound and sacrificed just before natural delivery. Gravid females were exposed to three doses of this compound, inducing abnormalities in the fetuses at the high dose only. The average FA, however, was already higher than control in rabbit fetuses of the low-dose group but did not further increase with higher concentrations. Moreover, the increase in FA differed between traits, with the hindlimbs showing the strongest response. In addition, we did not find any association between FA and the presence of fetal abnormalities at the individual level. Although these results suggest that FA may act as "an early warning system," we did not find a dose-response relationship with increasing stress and effects were trait-specific. Further testing is needed before FA may be considered as a sensitive marker in developmental toxicity studies. © 2013 Wiley Periodicals, Inc.
Children & Stress: Helping Children Cope.
ERIC Educational Resources Information Center
McNamee, Abigail Stahl, Ed.; And Others
Written by professional psychologists, the 10 articles collected in this bulletin focus on stressful experiences that, when inappropriately responded to, can result in developmental problems for children. Stress factors are conceptualized as being either direct or indirect, or internal or external. Articles are organized in terms of these four…
ERIC Educational Resources Information Center
Provenzi, Livio; Olson, Karen L.; Montirosso, Rosario; Tronick, Ed
2016-01-01
The study of infants' interactive style and social stress response to repeated stress exposures is of great interest for developmental and clinical psychologists. Stable maternal and dyadic behavior is critical to sustain infants' development of an adaptive social stress response, but the association between infants' interactive style and social…
Crnic, Keith; Arbona, Anita Pedersen y; Baker, Bruce; Blacher, Jan
2009-01-01
Much of our understanding of families and parenting of children with intellectual disabilities (ID) reflects the thoughts, beliefs, attitudes, and behaviors of mothers with relatively little focus on the ways in which fathers contribute to and are affected by this unique context. In this chapter, we address the importance of fathers as a source of critical developmental influence, and contrast fathers and mothers of children with ID along three important dimensions of parent functioning (stress, well-being, and interactive behavior). The contrasts explore the developmental trajectories of these parenting constructs over time from the perspective of an emerging new complexity in conceptual models of family and parent adaptation. Data from the Collaborative Family Study are used to explore paternal and maternal stress, well-being, and behavior across the preschool through transition to school-age developmental period, and findings are discussed within the context of the broader literature in each area. PMID:20224748
Rates and patterns of plankton response to stress exposure under natural conditions
NASA Astrophysics Data System (ADS)
Kucera, M.; Weinkauf, M.
2016-02-01
The effects of long-term exposure to natural levels of stress are often difficult to assess directly, because the resulting physiological changes and adaptations occur over times scales that cannot be covered by observations and where the outcome of the exposure cannot be predicted. Biometric studies on fossils provide a unique opportunity bridge this time scale and provide information on the reaction of populations to different levels of stress, including stress leading to extinction. In this respect, planktonic foraminifera represent a suitable model organism. This is because their shells, which are well preserved in marine sediments, record their entire ontogeny and allow assessment of developmental stability. Here we studied fossil populations of planktonic foraminifera transitioning into a high-stress environment during the onset of the deposition of Sapropel S5 in the Eastern Mediterranean, which culminated in local extinctions of several species. We show that calcification intensity (i.e. the amount of calcite secreted for a given body size) showed a strong and rapid reaction to surface water perturbation, with the same direction of change all species but no change prior to extinction, indicating that this parameters is primarily under environmental control. In contrast, shell morphology was not strictly tied to environmental change, but we observed large and rapid deviations in developmental stability immediately preceding local extinctions. It seems that developmental stability throughout ontogeny can be disrupted by enhanced stress levels leading to increased variation. This mechanism seems to operate on very short (decadal) time scales. It can potentially play a role in microevolution, and may be useful as an environmental stress proxy in plankton communities.
Woodman, Ashley C.; Mawdsley, Helena P.; Hauser-Cram, Penny
2014-01-01
Parents of children with developmental disabilities (DD) are at increased risk of experiencing psychological stress compared to other parents. Children’s high levels of internalizing and externalizing problems have been found to contribute to this elevated level of stress. Few studies have considered the reverse direction of effects, however, in families where a child has a DD. The present study investigated transactional relations between child behavior problems and maternal stress within 176 families raising a child with early diagnosed DD. There was evidence of both child-driven and parent-driven effects over the 15-year study period, spanning from early childhood (age 3) to adolescence (age 18), consistent with transactional models of development. Parent-child transactions were found to vary across different life phases and with different domains of behavior problems. PMID:25462487
Alados, C.L.; Escos, J.; Emlen, J.M.
1994-01-01
Developmental lnstability (DI) has been proposed as an inexpensive, quickly applied, and sensitive indicator of stress that can be utilized in early warning and in monitoring anthropogenic impacts on fish and other animals and plants. A problem arises, however, to the extent that natural stressors confound the effects of human-induced disturbances. Our objective in this work was to investigate whether a natural stressor, in the form of EI Nino conditions, contributed to DI in the Pacific hake. Right-left (fluctuating> asymmetry of otolith length, width, growth rate, and weight, as well as right-left otolith shape differences, were used as measures of DI. Results show that indeed EI Nino disrupts development, indicating stress. This outcome suggests that DI, as an early warning and monitoring tool for stress, must be used with caution.
Slabaugh, Erin
2011-01-01
Membrane-tethered transcription factors (MTTFs) are proteins that are targeted to membranes and are capable of regulating gene expression. In this way, they are physically restrained from entering the nucleus and are innately dormant. Upon specific signal recognition cues, MTTFs are activated through cleavage by a protease that releases the transcription factor domain into the cytosol thus allowing it to translocate to the nucleus where it can regulate gene expression. MTTFs are classically thought to provide an advantage to an organism by allowing for rapid signal transduction in response to cellular and environmental stresses. However, recent findings suggest that MTTFs may not only act as a means to respond quickly to stress but also are able to regulate developmental pathways, illustrating a point of interaction between stress and development. PMID:21758012
Albihlal, Waleed S; Obomighie, Irabonosi; Blein, Thomas; Persad, Ramona; Chernukhin, Igor; Crespi, Martin; Bechtold, Ulrike; Mullineaux, Philip M
2018-05-19
In Arabidopsis thaliana, HEAT SHOCK TRANSCRIPTION FACTORA1b (HSFA1b) controls resistance to environmental stress and is a determinant of reproductive fitness by influencing seed yield. To understand how HSFA1b achieves this, we surveyed its genome-wide targets (ChIP-seq) and its impact on the transcriptome (RNA-seq) under non-stress (NS), heat stress (HS) in the wild type, and in HSFA1b-overexpressing plants under NS. A total of 952 differentially expressed HSFA1b-targeted genes were identified, of which at least 85 are development associated and were bound predominantly under NS. A further 1780 genes were differentially expressed but not bound by HSFA1b, of which 281 were classified as having development-associated functions. These genes are indirectly regulated through a hierarchical network of 27 transcription factors (TFs). Furthermore, we identified 480 natural antisense non-coding RNA (cisNAT) genes bound by HSFA1b, defining a further mode of indirect regulation. Finally, HSFA1b-targeted genomic features not only harboured heat shock elements, but also MADS box, LEAFY, and G-Box promoter motifs. This revealed that HSFA1b is one of eight TFs that target a common group of stress defence and developmental genes. We propose that HSFA1b transduces environmental cues to many stress tolerance and developmental genes to allow plants to adjust their growth and development continually in a varying environment.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prince, J.L.; Lathrop, J.W.
1979-05-01
The results of accelerated stress testing of four different types of silicon terrestrial solar cells are discussed. The accelerated stress tests used included bias-temperature tests, bias-temperature-humidity tests, thermal cycle and thermal shock tests, and power cycle tests. Characterization of the cells was performed before stress testing and at periodic down-times, using electrical measurement, visual inspection, and metal adherence pull tests. Electrical parameters measured included short-circuit current, I/sub sc/, open circuit voltage, V/sub oc/, and output power, voltage, and current at the maximum power point, P/sub m/, V/sub m/, and I/sub m/ respectively. Incorporated in the report are the distributions ofmore » the prestress electrical data for all cell types. Data was also obtained on cell series and shunt resistance. Significant differences in the response to the various stress tests was observed between cell types. On the basis of the experience gained in this research work, a suggested Reliability Qualification Test Schedule was developed.« less
Adolescence and the Ontogeny of the Hormonal Stress Response in Male and Female Rats and Mice
Romeo, Russell D.; Patel, Ravenna; Pham, Laurie; So, Veronica M.
2016-01-01
Adolescent development is marked by many changes in neuroendocrine function, resulting in both immediate and long-term influences on an individual’s physiology and behavior. Stress-induced hormonal responses are one such change, with adolescent animals often showing different patterns of hormonal reactivity following a stressor compared with adults. This review will describe the unique ways in which adolescent animals respond to a variety of stressors and how these adolescent-related changes in hormonal responsiveness can be further modified by the sex and previous experience of the individual. Potential central and peripheral mechanisms that contribute to these developmental shifts in stress reactivity are also discussed. Finally, the short- and long-term programming effects of chronic stress exposure during adolescence on later adult hormonal responsiveness are also examined. Though far from a clear understanding of the neurobehavioral consequences of these adolescent-related shifts in stress reactivity, continued study of developmental changes in stress-induced hormonal responses may shed light on the increased vulnerability to physical and psychological dysfunctions that often accompany a stressful adolescence. PMID:27235079
Nitric Oxide Regulates Protein Methylation during Stress Responses in Plants.
Hu, Jiliang; Yang, Huanjie; Mu, Jinye; Lu, Tiancong; Peng, Juli; Deng, Xian; Kong, Zhaosheng; Bao, Shilai; Cao, Xiaofeng; Zuo, Jianru
2017-08-17
Methylation and nitric oxide (NO)-based S-nitrosylation are highly conserved protein posttranslational modifications that regulate diverse biological processes. In higher eukaryotes, PRMT5 catalyzes Arg symmetric dimethylation, including key components of the spliceosome. The Arabidopsis prmt5 mutant shows severe developmental defects and impaired stress responses. However, little is known about the mechanisms regulating the PRMT5 activity. Here, we report that NO positively regulates the PRMT5 activity through S-nitrosylation at Cys-125 during stress responses. In prmt5-1 plants, a PRMT5 C125S transgene, carrying a non-nitrosylatable mutation at Cys-125, fully rescues the developmental defects, but not the stress hypersensitive phenotype and the responsiveness to NO during stress responses. Moreover, the salt-induced Arg symmetric dimethylation is abolished in PRMT5 C125S /prmt5-1 plants, correlated to aberrant splicing of pre-mRNA derived from a stress-related gene. These findings define a mechanism by which plants transduce stress-triggered NO signal to protein methylation machinery through S-nitrosylation of PRMT5 in response to environmental alterations. Copyright © 2017 Elsevier Inc. All rights reserved.
Nakamura, Hidetoshi; Kikuma, Takashi; Jin, Feng Jie; Maruyama, Jun-ichi; Kitamoto, Katsuhiko
2016-04-01
The serine-threonine kinase Rim15p is a master regulator of stress signaling and is required for stress tolerance and sexual sporulation in the yeast Saccharomyces cerevisiae. However, in filamentous fungi that reproduce asexually via conidiation, the physiological function of Rim15p homologs has not been extensively analyzed. Here, we functionally characterized the protein homolog of Rim15p in the filamentous fungus Aspergillus oryzae, by deleting and overexpressing the corresponding Aorim15 gene and examining the role of this protein in stress tolerance and development. Deletion of Aorim15 resulted in an increase in the sensitivity of conidia to oxidative and heat stresses, whereas conidia of the Aorim15 overexpressing strain were more resistant to these stresses. These results indicated that AoRim15 functions in stress tolerance, similar to S. cerevisiae Rim15p. Phenotypic analysis revealed that conidiation was markedly reduced by overexpression of Aorim15 in A. oryzae, and was completely abolished in the deletion strain. In addition, the formation of sclerotia, which is another type of developmental structure in filamentous fungi, was decreased by the deletion of Aorim15, whereas Aorim15 overexpression increased the number of sclerotia. These results indicated that AoRim15 is a positive regulator of sclerotia formation and that overexpression of AoRim15 shifts the developmental balance from conidiation towards sclerotia formation. Collectively, we demonstrated that AoRim15 is involved in the stress tolerance of conidia and differentially regulates between the two developmental fates of conidiation and sclerotia formation. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
Hiss, Manuel; Laule, Oliver; Meskauskiene, Rasa M; Arif, Muhammad A; Decker, Eva L; Erxleben, Anika; Frank, Wolfgang; Hanke, Sebastian T; Lang, Daniel; Martin, Anja; Neu, Christina; Reski, Ralf; Richardt, Sandra; Schallenberg-Rüdinger, Mareike; Szövényi, Peter; Tiko, Theodhor; Wiedemann, Gertrud; Wolf, Luise; Zimmermann, Philip; Rensing, Stefan A
2014-08-01
The moss Physcomitrella patens is an important model organism for studying plant evolution, development, physiology and biotechnology. Here we have generated microarray gene expression data covering the principal developmental stages, culture forms and some environmental/stress conditions. Example analyses of developmental stages and growth conditions as well as abiotic stress treatments demonstrate that (i) growth stage is dominant over culture conditions, (ii) liquid culture is not stressful for the plant, (iii) low pH might aid protoplastation by reduced expression of cell wall structure genes, (iv) largely the same gene pool mediates response to dehydration and rehydration, and (v) AP2/EREBP transcription factors play important roles in stress response reactions. With regard to the AP2 gene family, phylogenetic analysis and comparison with Arabidopsis thaliana shows commonalities as well as uniquely expressed family members under drought, light perturbations and protoplastation. Gene expression profiles for P. patens are available for the scientific community via the easy-to-use tool at https://www.genevestigator.com. By providing large-scale expression profiles, the usability of this model organism is further enhanced, for example by enabling selection of control genes for quantitative real-time PCR. Now, gene expression levels across a broad range of conditions can be accessed online for P. patens. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.
ERIC Educational Resources Information Center
Thomas-Tate, Shurita; Daugherty, Timothy K.
2017-01-01
Employing an existing database of African American and biracial children entering metropolitan Detroit schools, we examined children of caregivers with and without reported stressful police contact. As anticipated, young children of caregivers with recent stressful police contact appear to suffer cognitive performance decrements on a nonverbal…
Carotenoid profiling of leaves of selected eggplant accessions subjected to drought stress
USDA-ARS?s Scientific Manuscript database
This study focused on the quantification of carotenoids of the leaves of African eggplants commonly consumed as leafy and fruit vegetables. The results gave comparative profiles of carotenoids at different growth and developmental stages and under drought stress. Stress was achieved by limiting irri...
Child Abuse and Developmental Disabilities.
ERIC Educational Resources Information Center
Grayson, Joann, Ed.; Bartlette, Don
1992-01-01
Literature indicating high rates of abuse in this population is reviewed, as is literature indicating high rates of developmental disabilities in child victims of abuse. Problems in data collecting practices are noted. Reasons for these children's greater risk for abuse are identified, including child attributes, stress, parent vulnerabilities,…
Developmentally Appropriate Practice: What Does Research Tell Us?
ERIC Educational Resources Information Center
Dunn, Loraine; Kontos, Susan
1998-01-01
Examines recent research on developmentally appropriate practice (DAP) and social-emotional and cognitive development and what has been learned about DAP in early childhood classrooms. Finds that, in general, child-initiated environments are associated with higher levels of cognitive functioning, which, coupled with findings on stress and…
Americans with Developmental Disabilities: Policy Directions for the States.
ERIC Educational Resources Information Center
Wright, Barbara; King, Martha P.
This Task Force report offers recommendations to state legislatures in the following policy areas: early intervention, family support, transition services, community living, supported employment, and funding for persons with developmental disabilities. Stressed is a consumer orientation which focuses on individual and family strengths and needs.…
Creating Profiles of High Risk Students.
ERIC Educational Resources Information Center
Higbee, Jeanne L.; Dwinell, Patricia L.
Measures used at the Division of Developmental Studies at the University of Georgia in constructing a student profile (specifically, of high-risk college freshmen) are discussed. The areas measured concern: goals; learning styles; career exploration; stress and academic anxiety; developmental tasks; and locus of control. The goals checklist…
NASA Technical Reports Server (NTRS)
Sprowls, D. O.
1984-01-01
A review of the literature is presented with the objectives of identifying relationships between various accelerated stress corrosion testing techniques, and for determining the combination of test methods best suited to selection and design of high strength aluminum alloys. The following areas are reviewed: status of stress-corrosion test standards, the influence of mechanical and environmental factors on stress corrosion testing, correlation of accelerated test data with in-service experience, and procedures used to avoid stress corrosion problems in service. Promising areas for further work are identified.
ERIC Educational Resources Information Center
Suldo, Shannon M.; Shaunessy-Dedrick, Elizabeth
2013-01-01
This study determined whether participation in an accelerated curriculum (specifically, the International Baccalaureate [IB] program) upon entry to high school is associated with increases in stress and/or associated with psychological problems. Data from self-report questionnaires were collected at two time points (summer after eighth grade, fall…
Os'mak, E D; Asanov, É O
2014-01-01
The effect of hypoxic training on autonomic regulation in psycho-emotional stress conditions in hypoxic conditions in older people with physiological (25 people) and accelerated (28 people) aging respiratory system. It is shown that hypoxic training leads to an increase in vagal activity indicators (HF) and reduced simpatovagal index (LF/HF), have a normalizing effect on the autonomic balance during stress loads in older people with different types of aging respiratory system.
McFadden, Joseph
2017-11-01
The schism between psychiatry, psychology and analysis, while long present, has widened even more in the past half-century with the advances in psychopharmacology. With the advances in electronic brain imaging, particularly in developmental and post-traumatic stress disorders, there has emerged both an understanding of brain changes resulting from severe, chronic stress and an ability to target brain chemistry in ways that can relieve clinical symptomatology. The use of alpha-1 adrenergic brain receptor antagonists decreases many of the manifestations of PTSD. Additionally, this paper discusses the ways in which dreaming, thinking and the analytic process are facilitated with this concomitant treatment and hypervigilence and hyper-arousal states are signficiantly decreased. © 2017, The Society of Analytical Psychology.
Parent stress across molecular subtypes of children with Angelman syndrome.
Miodrag, N; Peters, S
2015-09-01
Parenting stress has been consistently reported among parents of children with developmental disabilities. However, to date, no studies have investigated the impact of a molecular subtype of Angelman syndrome (AS) on parent stress, despite distinct phenotypic differences among subtypes. Data for 124 families of children with three subtypes of AS: class I and II deletions (n = 99), imprinting centre defects (IC defects; n = 11) and paternal uniparental disomy (UPD; n = 14) were drawn from the AS Rare Diseases Clinical Research Network (RDCRN) database and collected from five research sites across the Unites States. The AS study at the RDCRN gathered health information to understand how the syndrome develops and how to treat it. Parents completed questionnaires on their perceived psychological stress, the severity of children's aberrant behaviour and children's sleep patterns. Children's adaptive functioning and developmental levels were clinically evaluated. Child-related stress reached clinical levels for 40% of parents of children with deletions, 100% for IC defects and 64.3% for UPD. Sleep difficulties were similar and elevated across subtypes. There were no differences between molecular subtypes for overall child and parent-related stress. However, results showed greater isolation and lack of perceived parenting skills for parents of children with UPD compared with deletions. Better overall cognition for children with deletions was significantly related to more child-related stress while their poorer adaptive functioning was associated with more child-related stress. For all three groups, the severity of children's inappropriate behaviour was positively related to different aspects of stress. How parents react to stress depends, in part, on children's AS molecular subtype. Despite falling under the larger umbrella term of AS, it is important to acknowledge the unique aspects associated with children's molecular subtype. Identifying these factors can lead to tailored interventions that fit the particular needs of families of children with different AS subtypes. © 2015 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.
Ros, Rosmary; Hernandez, Jennifer; Graziano, Paulo A; Bagner, Daniel M
2016-01-01
This study investigated the extent to which parental homework completion during behavioral parent training (BPT) for children with or at risk for developmental delay contributed to parenting and child outcomes. Parents of 48 children (Mage=44.17 months, SD=14.29; 73% male; 72% White) with developmental delay (IQ<75) or at risk for developmental delay (due to premature birth) with co-occurring clinically elevated externalizing behavior problems received Parent-Child Interaction Therapy (PCIT) as part of two previously completed randomized controlled trials. Parental homework completion was measured using parental report of home practice of treatment skills collected weekly by therapists. Parents also reported on child externalizing behavior problems and levels of parenting stress, while parenting skills were observed during a 5-min child directed play and child compliance was observed during a 5-min cleanup situation. Results indicated that higher rates of parental homework completion predicted parenting outcomes (i.e., increased positive parenting skills and decreased levels of parenting stress) and child outcomes (i.e., lower levels of externalizing behavior problems). Additionally, although limited by temporal precedence, there was an indirect effect of reductions in parenting stress on the negative association between parental homework completion and child externalizing behavior problems. These findings highlight the importance of parents practicing skills learned during BPT for optimizing treatment outcome. Parenting stress was also identified as a potential mechanism by which high levels of parental homework completion contributed to reductions in child externalizing behavior problems. Copyright © 2015. Published by Elsevier Ltd.
Chen, Juan; Fan, Lei; Du, Ya; Zhu, Weining; Tang, Ziqin; Li, Na; Zhang, Dapeng; Zhang, Linsheng
2016-11-01
Drought stress is a major factor limiting wheat growth and productivity. Late embryogenesis abundant (LEA) proteins are tolerant to water-related stress. To reveal the regulatory mechanisms of LEA proteins under drought stress, we cloned a novel group 3 LEA gene, namely, TaDlea3, from wheat (Triticum aestivum L.) Shaanhe 6. Subcellular localization assay showed that TaDlea3 protein accumulated in the cytoplasm. Quantitative real-time polymerase chain reaction results revealed that TaDlea3 expression was induced by drought stress. Western blot results indicated that TaDlea3 protein expression gradually increased with drought stress during four different developmental stages. Under normal conditions, no obvious phenotype difference was observed between the transgenic and wild-type seedlings. Meanwhile, the overexpression of TaDlea3 in Arabidopsis resulted in enhanced tolerance to drought stress, as determined by the assessment of antioxidant enzyme activities. Our results provide a basis for highly detailed functional analyses of LEA proteins and offer a promising approach for improving the tolerances of wheat cultivars to drought stress through genetic engineering. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Evans, Brittany E; Greaves-Lord, Kirstin; Euser, Anja S; Tulen, Joke H M; Franken, Ingmar H A; Huizink, Anja C
2013-01-01
Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. In a stratified sample of 363 children (7-12 years) and 344 adolescents (13-20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.
Rith-Najarian, Leslie R.; McLaughlin, Katie A.; Sheridan, Margaret A.; Nock, Matthew K.
2014-01-01
Extensive research among adults supports the biopsychosocial (BPS) model of challenge and threat, which describes relationships among stress appraisals, physiological stress reactivity, and performance; however, no previous studies have examined these relationships in adolescents. Perceptions of stressors as well as physiological reactivity to stress increase during adolescence, highlighting the importance of understanding the relationships among stress appraisals, physiological reactivity, and performance during this developmental period. In this study, 79 adolescent participants reported on stress appraisals before and after a Trier Social Stress Test in which they performed a speech task. Physiological stress reactivity was defined by changes in cardiac output and total peripheral resistance from a baseline rest period to the speech task, and performance on the speech was coded using an objective rating system. We observed in adolescents only two relationships found in past adult research on the BPS model variables: (1) pre-task stress appraisal predicted post-task stress appraisal and (2) performance predicted post-task stress appraisal. Physiological reactivity during the speech was unrelated to pre- and post-task stress appraisals and to performance. We conclude that the lack of association between post-task stress appraisal and physiological stress reactivity suggests that adolescents might have low self-awareness of physiological emotional arousal. Our findings further suggest that adolescent stress appraisals are based largely on their performance during stressful situations. Developmental implications of this potential lack of awareness of one’s physiological and emotional state during adolescence are discussed. PMID:24491123
Rith-Najarian, Leslie R; McLaughlin, Katie A; Sheridan, Margaret A; Nock, Matthew K
2014-03-01
Extensive research among adults supports the biopsychosocial (BPS) model of challenge and threat, which describes relationships among stress appraisals, physiological stress reactivity, and performance; however, no previous studies have examined these relationships in adolescents. Perceptions of stressors as well as physiological reactivity to stress increase during adolescence, highlighting the importance of understanding the relationships among stress appraisals, physiological reactivity, and performance during this developmental period. In this study, 79 adolescent participants reported on stress appraisals before and after a Trier Social Stress Test in which they performed a speech task. Physiological stress reactivity was defined by changes in cardiac output and total peripheral resistance from a baseline rest period to the speech task, and performance on the speech was coded using an objective rating system. We observed in adolescents only two relationships found in past adult research on the BPS model variables: (1) pre-task stress appraisal predicted post-task stress appraisal and (2) performance predicted post-task stress appraisal. Physiological reactivity during the speech was unrelated to pre- and post-task stress appraisals and to performance. We conclude that the lack of association between post-task stress appraisal and physiological stress reactivity suggests that adolescents might have low self-awareness of physiological emotional arousal. Our findings further suggest that adolescent stress appraisals are based largely on their performance during stressful situations. Developmental implications of this potential lack of awareness of one's physiological and emotional state during adolescence are discussed.
Developmental Aspects of Composition (or Think Young).
ERIC Educational Resources Information Center
Lundsteen, Sara W.
Stressing the importance of understanding child development, this paper first describes the writing of several children in a kindergarten class who represent various levels of emerging literacy. Based on the descriptions of classroom activities, the paper argues that with a developmental perspective the teacher can build instruction on what the…
ERIC Educational Resources Information Center
Del Giudice, Marco
2016-01-01
According to models of differential susceptibility, the same neurobiological and temperamental traits that determine increased sensitivity to stress and adversity also confer enhanced responsivity to the positive aspects of the environment. Differential susceptibility models have expanded to include complex developmental processes in which genetic…
ERIC Educational Resources Information Center
Tobing, Lauren E.; Glenwick, David S.
2006-01-01
This study explored potential predictors of psychological distress and moderators of the relation between parenting stress and psychological distress in mothers of children with pervasive developmental disorders (PDDs). Ninety-seven mothers of children diagnosed with autism spectrum disorders completed measures assessing children's functional…
Auditory and Motor Rhythm Awareness in Adults with Dyslexia
ERIC Educational Resources Information Center
Thomson, Jennifer M.; Fryer, Ben; Maltby, James; Goswami, Usha
2006-01-01
Children with developmental dyslexia appear to be insensitive to basic auditory cues to speech rhythm and stress. For example, they experience difficulties in processing duration and amplitude envelope onset cues. Here we explored the sensitivity of adults with developmental dyslexia to the same cues. In addition, relations with expressive and…
Feeding Disorders in Children with Developmental Disabilities.
ERIC Educational Resources Information Center
Schwarz, Steven M.
2003-01-01
This article describes an approach to evaluating and managing feeding disorders in children with developmental disabilities and examines effects of these management strategies on growth and clinical outcomes. A structured approach is stressed and a diagnostic and treatment algorithm is presented. Use with 79 children found that diagnostic-specific…
Planning for School Transition: An Ecological-Developmental Approach.
ERIC Educational Resources Information Center
Diamond, Karen E.; And Others
1988-01-01
The paper describes an ecological-developmental model for planning a child's transition from a preschool special education program to a public school classroom. The model stresses interactions between the various environments in which the child functions. A description of a preschool transition program based on the model is also included.…
Age Differences in Coping with Chronic Illness.
ERIC Educational Resources Information Center
Felton, Barbara J.; Revenson, Tracey A.
While most lifespan developmental theories of personality predict age-related changes in coping, little direct evidence exists for determining whether age differences in coping style are due to intrinsic developmental processes or to age differences in the kinds of stresses encountered. To evaluate age differences in coping strategies and whether…
ERIC Educational Resources Information Center
Malo, Eve; Bullard, Julie
This handbook was developed to assist educators and parents in fostering children's self-concept through developmentally appropriate kindergarten experiences. Guidelines for parental involvement, classroom volunteers, and families under stress are included. The handbook describes basic characteristics of children from ages 3-8 in terms of…
Epigenetic stress responses induce muscle stem-cell ageing by Hoxa9 developmental signals.
Schwörer, Simon; Becker, Friedrich; Feller, Christian; Baig, Ali H; Köber, Ute; Henze, Henriette; Kraus, Johann M; Xin, Beibei; Lechel, André; Lipka, Daniel B; Varghese, Christy S; Schmidt, Manuel; Rohs, Remo; Aebersold, Ruedi; Medina, Kay L; Kestler, Hans A; Neri, Francesco; von Maltzahn, Julia; Tümpel, Stefan; Rudolph, K Lenhard
2016-12-15
The functionality of stem cells declines during ageing, and this decline contributes to ageing-associated impairments in tissue regeneration and function. Alterations in developmental pathways have been associated with declines in stem-cell function during ageing, but the nature of this process remains poorly understood. Hox genes are key regulators of stem cells and tissue patterning during embryogenesis with an unknown role in ageing. Here we show that the epigenetic stress response in muscle stem cells (also known as satellite cells) differs between aged and young mice. The alteration includes aberrant global and site-specific induction of active chromatin marks in activated satellite cells from aged mice, resulting in the specific induction of Hoxa9 but not other Hox genes. Hoxa9 in turn activates several developmental pathways and represents a decisive factor that separates satellite cell gene expression in aged mice from that in young mice. The activated pathways include most of the currently known inhibitors of satellite cell function in ageing muscle, including Wnt, TGFβ, JAK/STAT and senescence signalling. Inhibition of aberrant chromatin activation or deletion of Hoxa9 improves satellite cell function and muscle regeneration in aged mice, whereas overexpression of Hoxa9 mimics ageing-associated defects in satellite cells from young mice, which can be rescued by the inhibition of Hoxa9-targeted developmental pathways. Together, these data delineate an altered epigenetic stress response in activated satellite cells from aged mice, which limits satellite cell function and muscle regeneration by Hoxa9-dependent activation of developmental pathways.
77 FR 4550 - Promising and Practical Strategies to Increase Postsecondary Success
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-30
... Education. Appendix A: Standard Keywords and Tags Accelerated Learning Achievement Gap Closure Adult Education Affordability Assessment Technology Badges Basic Skills Blended Learning Block Scheduling [[Page... Collection/Use Degree Attainment Developmental/Remedial Education Digital Materials Dual Degrees Earn and...
Developmental programming modulates olfactory behavior in C. elegans via endogenous RNAi pathways
Sims, Jennie R; Ow, Maria C; Nishiguchi, Mailyn A; Kim, Kyuhyung; Sengupta, Piali; Hall, Sarah E
2016-01-01
Environmental stress during early development can impact adult phenotypes via programmed changes in gene expression. C. elegans larvae respond to environmental stress by entering the stress-resistant dauer diapause pathway and resume development once conditions improve (postdauers). Here we show that the osm-9 TRPV channel gene is a target of developmental programming and is down-regulated specifically in the ADL chemosensory neurons of postdauer adults, resulting in a corresponding altered olfactory behavior that is mediated by ADL in an OSM-9-dependent manner. We identify a cis-acting motif bound by the DAF-3 SMAD and ZFP-1 (AF10) proteins that is necessary for the differential regulation of osm-9, and demonstrate that both chromatin remodeling and endo-siRNA pathways are major contributors to the transcriptional silencing of the osm-9 locus. This work describes an elegant mechanism by which developmental experience influences adult phenotypes by establishing and maintaining transcriptional changes via RNAi and chromatin remodeling pathways. DOI: http://dx.doi.org/10.7554/eLife.11642.001 PMID:27351255
Mueller-Pfeiffer, Christoph; Moergeli, Hanspeter; Schumacher, Sonja; Martin-Soelch, Chantal; Wirtz, Gustav; Fuhrhans, Christoph; Hindermann, Esther; Rufer, Michael
2013-06-01
Little is known about the influence of particular characteristics of childhood maltreatment, such as developmental stage, relationship to the perpetrator, and nature of the trauma, on adult psychopathology. The effects of childhood maltreatment were assessed in adult psychiatric patients (N = 287) using self-rating scales and diagnostic checklists. Maltreatment was strongly associated with dissociation. This relationship was observed for all childhood developmental stages and was strongest when the perpetrator was outside the family. Dissociation was more strongly correlated with childhood emotional abuse and sexual harassment than with sexual or physical abuse. Childhood sexual abuse was found to be associated with symptoms of posttraumatic stress. The findings suggest that dissociation is a relatively specific consequence of childhood maltreatment that is largely independent of the familial relationship to the perpetrator or the child's developmental stage.
Zhang, Xiaoyu; Sun, Ling; Shen, Yang; Tian, Mi; Zhao, Jing; Zhao, Yu; Li, Meiyan; Zhou, Xingtao
2017-07-01
This study aimed to compare the biomechanical and histopathologic effects of transepithelial and accelerated epithelium-off pulsed-light accelerated corneal collagen cross-linking (CXL). A total of 24 New Zealand rabbits were analyzed after sham operation (control) or transepithelial or epithelium-off operation (45 mW/cm for both). The transepithelial group was treated with pulsed-light ultraviolet A for 5 minutes 20 seconds, and the epithelium-off group was treated for 90 seconds. Biomechanical testing, including ultimate stress, Young modulus, and the physiological modulus, was analyzed. Histological changes were evaluated by light microscopy and transmission electron microscopy. The stress-strain curve was nonlinear in both accelerated transepithelial and epithelium-off CXL groups. The stress and elastic moduli were all significantly higher in both experimental groups compared with the control group (P < 0.05), whereas there were no significant differences between the 2 treatment groups (P > 0.05). Six months after the operation, hematoxylin and eosin staining and transmission electron microscopy showed that the subcutaneous collagen fibers were arranged in a regular pattern, and the fiber density was higher in the experimental groups. Both transepithelial and accelerated epithelium-off CXL produced biomechanical and histopathologic improvements, which were not significantly different between the 2 pulsed-light accelerated CXL treatments.
NASA Astrophysics Data System (ADS)
Jia, Mei-Hui; Wang, Cheng-Lin; Ren, Bin
2017-07-01
Stress, strain and vibration characteristics of rotor parts should be changed significantly under high acceleration, manufacturing error is one of the most important reason. However, current research on this problem has not been carried out. A rotor with an acceleration of 150,000 g is considered as the objective, the effects of manufacturing errors on rotor mechanical properties and dynamic characteristics are executed by the selection of the key affecting factors. Through the force balance equation of the rotor infinitesimal unit establishment, a theoretical model of stress calculation based on slice method is proposed and established, a formula for the rotor stress at any point derives. A finite element model (FEM) of rotor with holes is established with manufacturing errors. The changes of the stresses and strains of a rotor in parallelism and symmetry errors are analyzed, which verify the validity of the theoretical model. The pre-stressing modal analysis is performed based on the aforementioned static analysis. The key dynamic characteristics are analyzed. The results demonstrated that, as the parallelism and symmetry errors increase, the equivalent stresses and strains of the rotor slowly increase linearly, the highest growth rate does not exceed 4%, the maximum change rate of natural frequency is 0.1%. The rotor vibration mode is not significantly affected. The FEM construction method of the rotor with manufacturing errors can be utilized for the quantitative research on rotor characteristics, which will assist in the active control of rotor component reliability under high acceleration.
An Exploratory Investigation of the Role of Parenting Stress in Relationship Focused Intervention
ERIC Educational Resources Information Center
Alquraini, Turki; Mahoney, Gerald
2015-01-01
Background: Mothers of young children with Pervasive Developmental Disorders (PDD) and other disabilities (DD) have been reported to experience high levels of stress. This investigation examined the effects of parental stress on mother's participation in a Relationship Focused intervention (RFI). Methods: Mothers and young children who had either…
Measuring Physiological Stress Responses in Children: Lessons from a Novice
ERIC Educational Resources Information Center
Quas, Jodi A.
2011-01-01
In this article the author describes challenges associated with integrating physiological measures of stress into developmental research, especially in the domains of memory and cognition. An initial critical challenge concerns how to define stress, which can refer to one or a series of events, a response, the consequence of that response, an…
ERIC Educational Resources Information Center
Franks, Bridget A.
2014-01-01
Posttraumatic stress disorder (PTSD) was first included in the American Psychiatric Association's "Diagnostic and statistical manual of mental disorders" in 1980. Long used to describe the reactions of soldiers affected by stress in combat situations, PTSD is now recognised as a disorder affecting abused and neglected infants and…
USDA-ARS?s Scientific Manuscript database
For real-time reverse transcription-PCR (qRT-PCR) in soybean, reference genes in different tissues, developmental stages, various cultivars, and under stress conditions have been suggested but their usefulness for research on soybean under various biotic stresses occurring in North-Central U.S. is n...
LaGasse, Linda L.; Conradt, Elisabeth; Karalunas, Sarah L.; Dansereau, Lynne M.; Butner, Jonathan E.; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles R.; Whitaker, Toni M.; Lester, Barry M.
2016-01-01
Developmental psychopathologists face the difficult task of identifying the environmental conditions that may contribute to early childhood behavior problems. Highly stressed caregivers can exacerbate behavior problems, while children with behavior problems may make parenting more difficult and increase caregiver stress. Unknown is: (1) how these transactions originate, (2) whether they persist over time to contribute to the development of problem behavior and (3) what role resilience factors, such as child executive functioning, may play in mitigating the development of problem behavior. In the present study, transactional relations between caregiving stress, executive functioning, and behavior problems were examined in a sample of 1,388 children with prenatal drug exposures at three developmental time points: early childhood (birth-age 5), middle childhood (ages 6 to 9), and early adolescence (ages 10 to 13). Transactional relations differed between caregiving stress and internalizing versus externalizing behavior. Targeting executive functioning in evidence-based interventions for children with prenatal substance exposure who present with internalizing problems and treating caregiving psychopathology, depression, and parenting stress in early childhood may be particularly important for children presenting with internalizing behavior. PMID:27427803
Stress and adolescent well-being: the need for an interdisciplinary framework
Sigfusdottir, Inga Dora; Kristjansson, Alfgeir Logi; Thorlindsson, Thorolfur; Allegrante, John P
2017-01-01
Abstract Stress and strain among adolescents have been investigated and discussed largely within three separate disciplines: mental health, where the focus has been on the negative effects of stress on emotional health; criminology, where the emphasis has been on the effects of strain on delinquency; and biology, where the focus has been to understand the effects of stress on physiology. Recently, scholars have called for increased multilevel developmental analyses of the bio-psychosocial nature of risk and protection for behaviors of individuals. This paper draws on several different but converging theoretical perspectives in an attempt to provide an overview of research relevant to stress in adolescence and puts forth a new framework that aims to provide both a common language and consilience by which future research can analyze the effects of multiple biological, social and environmental factors experienced during specific developmental periods, and cumulatively over time, on harmful behavior during adolescence. We present a framework to examine the effects of stress on diverse behavioral outcomes among adolescents, including substance use, suicidal behavior, self-inflicted harm, and delinquency. PMID:27153917
Jaye Capretto, Jessica
2017-04-01
Child physical and sexual maltreatment have emerged as documented risk factors for a wide range of health problems in adulthood, including depression and post-traumatic stress symptoms. Prior research focuses on generalized childhood adversities without accounting for how different critical details about the maltreatment may affect outcomes in adulthood. The present study examines the impact of two critical details, timing and type of child maltreatment, on depression and post-traumatic stress symptoms in adulthood. Participants ( N = 104) completed the Maltreatment and Abuse Chronology of Exposure scale (MACE) and the Inventory of Depression and Anxiety Scale-Second Version (IDAS-II). Hierarchical multiple regressions compared three different models of child maltreatment predictors and their differential utility for predicting depression and post-traumatic stress symptoms in adulthood: (a) number of child maltreatment experiences, (b) severity of child maltreatment, and (c) timing of child maltreatment. Results indicate that severity of child maltreatment and timing of child maltreatment are greater predictors for adult depression and post-traumatic stress symptoms than number of child maltreatment experiences. Compared with other developmental periods, early childhood sexual maltreatment experiences (5 years of age and below) and late childhood physical maltreatment experiences (13 years of age and above) were stronger predictors of adult depression and post-traumatic stress symptoms. Children maltreated during these age groups may be prioritized for prevention and intervention efforts, particularly when there are limited resources. Clinical interviews with maltreated children should also be expanded to include information about developmental timing and severity of maltreatment, which have ramifications for later health problems. Implications for assessment of maltreated children, prevention of adult depression and post-traumatic stress symptoms, and future research directions are discussed.
NASA Technical Reports Server (NTRS)
Klein, M.; Reynolds, J.; Ricks, E.
1989-01-01
Load and stress recovery from transient dynamic studies are improved upon using an extended acceleration vector in the modal acceleration technique applied to structural analysis. Extension of the normal LTM (load transformation matrices) stress recovery to automatically compute margins of safety is presented with an application to the Hubble space telescope.
Remodeling a tissue: subtraction adds insight.
Axelrod, Jeffrey D
2012-11-27
Sculpting a body plan requires both patterning of gene expression and translating that pattern into morphogenesis. Developmental biologists have made remarkable strides in understanding gene expression patterning, but despite a long history of fascination with the mechanics of morphogenesis, knowledge of how patterned gene expression drives the emergence of even simple shapes and forms has grown at a slower pace. The successful merging of approaches from cell biology, developmental biology, imaging, engineering, and mathematical and computational sciences is now accelerating progress toward a fuller and better integrated understanding of the forces shaping morphogenesis.
ERIC Educational Resources Information Center
Erbe, Ryan; Lohrmann, David
2015-01-01
Stress poses one of the biggest threats to the health and well-being of young people. Adolescents are especially vulnerable to the negative effects of stress due to developmental factors. Recently, Mindfulness Meditation (MM) programs have been implemented into both clinical and school-based settings to reduce stress and promote the health of…
Moon, Seong Min; Kim, Y D; Oh, S K; Park, M J; Kwak, Joon Seop
2012-05-01
We have investigated the high-temperature degradation of optical power as well as electrical properties of InGaN/GaN light-emitting diodes (LEDs) fabricated with ITO transparent p-electrode during accelerated electro-thermal stress. As the thermal stress increased from 150 degrees C to 250 degrees C at a electrical stress of 200 mA, the optical power of the LEDs was significantly reduced. Degradation of the optical power was thermally activated, with the activation of 0.9 eV. In addition, the activation energy of the degradation of optical power was fairly similar to that of the degradation of series resistance of the LEDs, 1.0 eV, which implies that the increase in the series resistance may result in the severe degradation of optical power. We also showed that the increase in the series resistance of the LEDs during the accelerated electro-thermal stress can be attributed to reduction of the active acceptor concentration in the p-type semiconductor layers and local joule heating due to the current crowding.
Wang, Guo-Kun; Zhang, Meng; Gong, Jiang-Feng; Guo, Qi-Fang; Feng, Ya-Nan; Wang, Wei
2012-12-01
Overexpressing TaUb2 promoted stem growth and resulted in early flowering in transgenic tobacco plants. Ubiquitin are involved in the production, metabolism and proper function of gibberellin. The ubiquitin-26S proteasome system (UPS), in which ubiquitin (Ub) functions as a marker, is a post-translational regulatory system that plays a prominent role in various biological processes. To investigate the impact of different Ub levels on plant growth and development, transgenic tobacco (Nicotiana tabacum L.) plants were engineered to express an Ub gene (TaUb2) from wheat (Triticum aestivum L.) under the control of cauliflower mosaic virus 35S promoter. Transgenic tobacco plants overexpressing TaUb2 demonstrated an accelerated growth rate at early stage and an early flowering phenotype in development. The preceding expression of MADS-box genes also corresponded to the accelerated developmental phenotypes of the transgenic tobacco plants compared to that of wild-type (WT). Total gibberellin (GA) and active GA contents in transgenic tobacco plants were higher than those in WT at the corresponding developmental stages, and some GA metabolism genes were upregulated. Treatment with GA(3) conferred a similarly accelerated grown rate in WT plants to that of transgenic tobacco plants, while growth was inhibited when transgenic tobacco plants were treated with a GA biosynthesis inhibitor. Thus, the results suggest that Ub are involved in the production, metabolism and proper function of GA, which is important in the regulation of plant growth and development.
Brown, Alan S.; Gyllenberg, David; Hinkka-Yli-Salomäki, Susanna; Sourander, Andre; McKeague, Ian W.
2016-01-01
Identification of abnormalities in the developmental trajectory during infancy of future schizophrenia cases offers the potential to reveal pathogenic mechanisms of this disorder. Previous studies of head circumference in pre-schizophrenia were limited to measures at birth. The use of growth acceleration of head circumference (defined as the rate of change in head circumference) provides a more informative representation of the maturational landscape of this measure compared to studies based on static head circumference measures. To date, however, no study has examined whether HC growth acceleration differs between pre-schizophrenia cases and controls. In the present study, we employed a nested case control design of a national birth cohort in Finland. Cases with schizophrenia or schizoaffective disorder (N=375) and controls (N=375) drawn from the birth cohort were matched 1:1 on date of birth (within 1 month), sex, and residence in Finland at case diagnosis. Longitudinal data were obtained on head circumference from birth through age 1. Data were analyzed using a new nonparametric Bayesian inversion method which allows for a detailed understanding of growth dynamics. Adjusting for growth velocity of height and weight, and gestational age, there was significantly accelerated growth of head circumference in females with schizophrenia from birth to 2 months; the findings remained significant following Bonferroni correction (p < 0.0125). This is the first study to report abnormal HC growth acceleration, a more sensitive measure of somatic developmental deviation of this measure, in schizophrenia. PMID:27818077
ERIC Educational Resources Information Center
Mitchell, D. B.; Hauser-Cram, P.
2010-01-01
Background: The importance of positive parent-adolescent relationships is stressed in research on adolescents, although very little is known about this relationship when a teen has developmental disabilities (DD). We investigated the relationships of adolescents with disabilities with their mothers and their fathers in order to answer a number of…
ERIC Educational Resources Information Center
Kim, Eunha; Hwang, Jowon; Park, Sukyoung
2018-01-01
This study examined how child problem behaviour could be related to maternal Hwa-Byung (HB; Korean culture syndrome, meaning "anger illness") among Korean mothers of children with developmental disabilities. Acceptance of disabilities and parenting stress were tested as mediators for the relationship between child problem behaviour and…
Developmental Tasks of Women Entering Higher Education at Mid-Life. Final Report.
ERIC Educational Resources Information Center
Richardson, Virginia; Sands, Roberta G.
Women who enrolled in college during their middle-aged years (between ages 30 and 49) were studied. Attention was directed to: the relationship between returning to school and critical developmental issues; the influence of educational experience on understanding such issues; and the stress factors experienced by mid-life university women.…
Coping and Psychological Health of Aging Parents of Adult Children with Developmental Disabilities
ERIC Educational Resources Information Center
Piazza, Vivian E.; Floyd, Frank J.; Mailick, Marsha R.; Greenberg, Jan S.
2014-01-01
Among aging parents (mean age = 65, "N" = 139) of adults with developmental disabilities, we examined the effectiveness of multiple forms of coping with caregiver burden. As expected, accommodative strategies of adapting to stress (secondary engagement), used frequently in later life, buffered the impact of caregiver burden, whereas…
ERIC Educational Resources Information Center
Kirby, Anne V.; White, Tamira J.; Baranek, Grace T.
2015-01-01
Caring for children with disabilities contributes to increased levels of parent stress or caregiver strain. However, the potential relationship of sensory features to strain among caregivers of children with autism spectrum disorder (ASD) and other developmental disabilities (DD) is unknown. Sensory features include overreactions, underreactions,…
ERIC Educational Resources Information Center
Delta Coll., University Center, MI. Allied Health-Community Affairs.
Developed as part of Delta College's Parent Awareness Program, this manual provides information related to the special concerns of parents and families of developmentally disabled children, adolescents, and adults. The first section stresses the importance of planning and preparing for the future and establishing adequate financial and personal…
ERIC Educational Resources Information Center
Scotti, Joseph R.; Stevens, Sarah B.; Jacoby, Vanessa M.; Bracken, Magdalene R.; Freed, Rachel; Schmidt, Elizabeth
2012-01-01
Generally, studies have revealed that only a minority of people are bothered by participation in research on traumatic stress. Severity of traumatic events and subsequent responses are typically unrelated to negative reactions. We included 386 family members and caregivers (respondents) of people with intellectual and developmental disabilities…
ERIC Educational Resources Information Center
Ho, Tzu-Hua
2013-01-01
This study investigated the influences of children's adaptive skills, problem behaviors, and parent support systems (informal support and formal professional support) on maternal well-being (health and stress) in Taiwanese mothers of young children with developmental disabilities. The study examined the moderating effects of formal support and…
Duda, J.J.; Freeman, D.C.; Brown, M.L.; Graham, J.H.; Krzysik, A.J.; Emlen, J.M.; Zak, J.C.; Kovacic, D.A.
2004-01-01
We used developmental instability, water potential, and variable fluorescence to determine if populations of winged sumac (Rhus copallinum) were being negatively effected by military training disturbance. We established nine sites that represented a land-use disturbance gradient with three impact levels (low, medium, and high), the effects mostly due to mechanized infantry training maneuvers. Although mean values of developmental instability, water potential, and variable fluorescence differed significantly among sites, the patterns did not consistently differentiate sites relative to the disturbance gradient. At the population level, some measures of developmental instability and variable fluorescence were positively correlated. All nine sites consisted of habitat mosaics, with the abundance of higher quality habitat patches and canopy gaps closely related to habitat impacts. It may be that R. copallinum is selecting similar micro-environments at all sites and therefore minimizing inter-site variation in stress measures, despite large differences in overall habitat condition. Our results call for caution in developing ecological indicators using the response of physiological and morphological measures from a single plant species. ?? 2003 Elsevier Ltd. All rights reserved.
Fluctuating asymmetry and psychometric intelligence.
Furlow, F B; Armijo-Prewitt, T; Gangestad, S W; Thornhill, R
1997-01-01
Little is known about the genetic nature of human psychometric intelligence (IQ), but it is widely assumed that IQ's heritability is at loci for intelligence per se. We present evidence consistent with a hypothesis that interindividual IQ differences are partly due to heritable vulnerabilities to environmental sources of developmental stress, an indirect genetic mechanism for the heritability of IQ. Using fluctuating asymmetry (FA) of the body (the asymmetry resulting from errors in the development of normally symmetrical bilateral traits under stressful conditions), we estimated the relative developmental instability of 112 undergraduates and administered to them Cattell's culture fair intelligence test (CFIT). A subsequent replication on 128 students was performed. In both samples, FA correlated negatively and significantly with CFIT scores. We propose two non-mutually exclusive physiological explanations for this correlation. First, external body FA may correlate negatively with the developmental integrity of the brain. Second, individual energy budget allocations and/or low metabolic efficiency in high-FA individuals may lower IQ scores. We review the data on IQ in light of our findings and conclude that improving developmental quality may increase average IQ in future generations. PMID:9265189
Brodeur, Julie C; Sassone, Alina; Hermida, Gladys N; Codugnello, Nadia
2013-06-01
Despite of the various studies reporting on the subject, anticipating the impacts of the widely-used herbicide atrazine on anuran tadpoles metamorphosis remains complex as increases or decreases of larval period duration are almost as frequently reported as an absence of effect. The aim of the present study was to examine the effects of environmentally-relevant concentrations of atrazine (0.1, 1, 10, 100, and 1000μg/L) on the timings of metamorphosis and body size at metamorphosis in the common South American toad, Rhinella arenarum (Anura: bufonidae). None of the atrazine concentrations tested significantly altered survival. Low atrazine concentrations in the range of 1-100μg/L were found to accelerate developmental rate in a non-monotonic U-shaped concentration-response relationship. This observed acceleration of the metamorphic process occurred entirely between stages 25 and 39; treated tadpoles proceeding through metamorphosis as control animals beyond this point. Together with proceeding through metamorphosis at a faster rate, tadpoles exposed to atrazine concentrations in the range of 1-100μg/L furthermore transformed into significantly larger metamorphs than controls, the concentration-response curve taking the form of an inverted U in this case. The no observed effect concentration (NOEC) was 0.1μg atrazine/L for both size at metamorphosis and timings of metamorphosis. Tadpoles exposed to 100μg/L 17β-estradiol presented the exact same alterations of developmental rate and body size as those treated with 1, 10 and 100μg/L of atrazine. Elements of the experimental design that facilitated the detection of alterations of metamorphosis at low concentrations of atrazine are discussed, together with the ecological significance of those findings. Copyright © 2013 Elsevier Inc. All rights reserved.
Ghasem, Saki; Majid, Jasemi; Shiva, Razi
2013-07-01
To assess developmental capacity of fertilised oocytes by sperm of mouse exposed to forced swimming stress. The experimental study was conducted at the Physiology Research Center of Ahvaz Jundishapur University of Medical Sciences, from August 2011 to January 2012. It comprised 20 adult male and 10 female mice. The male mice were randomly divided into two equal groups (n=10): control and experimental. Animals of the experimental group were submitted to forced swimming stress. All male mice were euthanised and the cauda epididymis removed before contents were squeezed out. A pre-incubated capacitated sperm was gently added to the freshly collected ova of the two groups of study. The combined sperm-oocyte suspension was incubated for 4-6 hours under a condition of 5% Carbon dioxide and 37 degreeC temperature. The ova were then washed through several changes of medium and finally incubated. Fertilisation was assessed by recording the number of 1-cell embryos 4-6 hours after insemination. The 1-cell embryos were allowed to further develop in vitro for about 120 hours. Development of embryos everyday and during 5 days of culture was observed by using inverted microscope. SPSS 13.0.1 was used for statistical analysis. The percentage of oocytes fertilised was 75:96 (78.12+/-4.8%) and 50:10 (49.5+/-3.9%) in the control and experimental groups, respectively. The difference was significant (p <0.001). At 24 hours after insemination, 70:75 (93.33+/-2.7%) and 39:50 (78+/-3.5%)of fertilized oocytes developed to two=cell embryos in control and experimental groups respectively.The difference was significant (p <0.02).There were not significant differences (p>0.05) between the two groups in terms of speed and developmental capacity of blastocysts. Fertilisation capacity of male mice affected by forced swimming stress and also the developmental capacity of oocyte fertilised by sperm of mouse exposed to forced swimming stress decreased.
Evans, Brittany E.; Greaves-Lord, Kirstin; Euser, Anja S.; Tulen, Joke H. M.; Franken, Ingmar H. A.; Huizink, Anja C.
2013-01-01
Aims Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related) of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. Method In a stratified sample of 363 children (7–12 years) and 344 adolescents (13–20 years) from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. Results Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. Conclusions As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness. PMID:23620785
Predictors of Parenting Stress among Mothers of Children with Autism in South Korea
ERIC Educational Resources Information Center
Lee, Ji Kyung
2011-01-01
Parenting stress may be inevitable for any parent. However, stress can be even greater for parents with children who have disabilities. Among parents of children with disabilities, parents of children with autism are particularly at risk of feeling overwhelmed due to the specific developmental condition and characteristics of children who have…
ERIC Educational Resources Information Center
Guralnick, M. J.; Hammond, M. A.; Neville, B.; Connor, R. T.
2008-01-01
Background: In this longitudinal study, we examined the relationship between the sources and functions of social support and dimensions of child- and parent-related stress for mothers of young children with mild developmental delays. Methods: Sixty-three mothers completed assessments of stress and support at two time points. Results: Multiple…
Stress and Stress Management in Families with Adopted Children Who Have Severe Disabilities.
ERIC Educational Resources Information Center
Todis, Bonnie; Singer, George
Qualitative research methods were used to investigate the sources and methods of dealing with stress in eight families with adopted children who have severe developmental or multiple disabilities. The families, who had each adopted from two to 30 children, included "birth children" and, in some cases, foster children as well. The research methods…
Gyrokinetic theory of turbulent acceleration and momentum conservation in tokamak plasmas
NASA Astrophysics Data System (ADS)
Lu, WANG; Shuitao, PENG; P, H. DIAMOND
2018-07-01
Understanding the generation of intrinsic rotation in tokamak plasmas is crucial for future fusion reactors such as ITER. We proposed a new mechanism named turbulent acceleration for the origin of the intrinsic parallel rotation based on gyrokinetic theory. The turbulent acceleration acts as a local source or sink of parallel rotation, i.e., volume force, which is different from the divergence of residual stress, i.e., surface force. However, the order of magnitude of turbulent acceleration can be comparable to that of the divergence of residual stress for electrostatic ion temperature gradient (ITG) turbulence. A possible theoretical explanation for the experimental observation of electron cyclotron heating induced decrease of co-current rotation was also proposed via comparison between the turbulent acceleration driven by ITG turbulence and that driven by collisionless trapped electron mode turbulence. We also extended this theory to electromagnetic ITG turbulence and investigated the electromagnetic effects on intrinsic parallel rotation drive. Finally, we demonstrated that the presence of turbulent acceleration does not conflict with momentum conservation.
NASA Astrophysics Data System (ADS)
Guardiera, Simon; Schneider, Stefan
2008-06-01
Several studies reported that human motor performance is impaired during acceleration to hypergravity. While physiological explanations (e.g. vestibular activity) are widely discussed, psycho-physiological reasons (e.g. stress) are less considered. The present study therefore evaluates the interaction between psycho-physiological effects and motor performance in hypergravity. Eleven subjects performed a manual tracking task. Additionally, stress hormone concentration, EEG and subjective mood were evaluated. All measurements were performed in normal (+1Gz), and in (or directly after) three times gravitational acceleration (+3Gz). Motor performance decreased, while all determined stress hormone concentrations increased in +3Gz. EEG analysis revealed an increase of brain cortical activity in right frontal lobe in +3Gz. Subjective mood decreased due to +3Gz. Our data confirm, that motor performance is decreased in hypergravity, whereas an increase in psychophysiological stress markers could be obtained. We conclude that psycho-physiological changes have to be regarded as a possible explanation for deficits in motor performance in hypergravity.
Leung, Cynthia; Chan, Stanley; Lam, Tiney; Yau, Sharon; Tsang, Sandra
2016-09-01
This study aimed to evaluate the efficacy of a parent education program, the Happy Parenting program, for Chinese preschool children with developmental disabilities. This study adopted randomized controlled trial design without blinding. Participants were randomized into intervention group (n=62) who were offered the Happy Parenting program delivered by educational psychologists and trainee educational psychologists, and a control group (n=57) who were offered a parent talk after the intervention group had completed treatment. Parent participants were requested to complete questionnaires on their children's behavior, their parenting stress, and discipline strategies. Analysis was by intention-to-treat. The results indicated significant decrease in child problem behaviors, parenting stress and dysfunctional discipline strategies in the intervention group at post-intervention. This study provided promising evidence on the effectiveness of a parent education program, the Happy Parenting program, for Chinese preschool children with developmental disabilities. Copyright © 2016 Elsevier Ltd. All rights reserved.
Children in Foster Care and the Development of Favorable Outcomes
Fisher, Philip A.
2011-01-01
Young foster children have invariably faced a variety of risks that are strongly linked to long-term deficits in functioning across multiple developmental domains. Despite these risks, however, some children demonstrate more favorable outcomes and exhibit adaptation and the development of assets. In the present study, the relationship of early childhood factors (e.g., maltreatment history, placement history, parenting practices, environmental stress, developmental status, and attachment behavior) to the development of favorable outcomes in middle childhood were examined in a sample of foster children who had been in foster care in preschool (N = 35). Favorable outcomes were defined as demonstrations of emotion regulation and school adjustment in during middle childhood. Developmental status (particularly attention and executive functioning) and a lack of environmental stress during early childhood foster care experiences had a significant positive relationship with the development of emotion regulation and school adjustment in middle childhood. PMID:21987598
Braking and Accelerating of the Adolescent Brain
ERIC Educational Resources Information Center
Casey, B. J.; Jones, Rebecca M.; Somerville, Leah H.
2011-01-01
Adolescence is a developmental period often characterized as a time of impulsive and risky choices leading to increased incidence of unintentional injuries and violence, alcohol and drug abuse, unintended pregnancy, and sexually transmitted diseases. Traditional neurobiological and cognitive explanations for such suboptimal choices and actions…
Stress corrosion cracking evaluation of precipitation-hardening stainless steel
NASA Technical Reports Server (NTRS)
Humphries, T. S.; Nelson, E. E.
1970-01-01
Accelerated test program results show which precipitation hardening stainless steels are resistant to stress corrosion cracking. In certain cases stress corrosion susceptibility was found to be associated with the process procedure.
ERIC Educational Resources Information Center
Bugental, Daphne Blunt
2012-01-01
Children's physiological reactions to stress are presented from the broader theoretical perspective of adaptive calibration to the environment, as rooted in life history theory. Del Giudice, Hinnant, Ellis, and El-Sheikh (2012) focus on children's physiological responses to a stressful task as a consequence of their history of family stress.…
Entringer, Sonja; Buss, Claudia; Swanson, James M.; Cooper, Dan M.; Wing, Deborah A.; Waffarn, Feizal; Wadhwa, Pathik D.
2012-01-01
Epidemiological, clinical, physiological, cellular, and molecular evidence suggests that the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. In this perspectives paper we propose that in addition to maternal nutrition-related processes it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition), on brain and peripheral targets of programming of body composition, energy balance homeostasis, and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate mechanisms that may underlie the long-term effects of intrauterine stress. We conclude with a commentary of the implications for future research and clinical practice. PMID:22655178
NASA Technical Reports Server (NTRS)
Smedal, Harald A.; Havill, C. Dewey
1962-01-01
A TIME-HONORED system of recording medical histories and the data obtained on physical and laboratory examination has been that of writing the information on record sheets that go into a folder for each patient. In order to have information which would be more readily retrieved, 'a program was initiated in 1952 by the U. S. Naval School of Aviation Medicine in connection with their "Care of the Flyer" study to place this information on machine record cards. In 1958, a machine record card method was developed for recording medical data in connection with the astronaut selection program. Machine record cards were also developed by the Aero Medical Laboratory, Wright-Patterson AFB, Ohio, and the Aviation Medical Acceleration Laboratory, Naval Air Development Center, Johnsville, Pennsylvania, for use in connection with a variety of tests including acceleration stress.1 Therefore, a variety of systems resulted in which data of a medical nature could easily be recalled. During the NASA, Ames Research Center centrifuge studies/'S the pilot subjects were interviewed after each centrifuge run, or series of runs, and subjective information was recorded in a log book by the usual history taking methods referred to above. After the methods Were reviewed, it' was recognized that a card system would be very useful in recording data from our pilots after they had been exposed to acceleration stress. Since the acceleration stress cards already developed did not meet our requirements, it was decided a different card was needed.
NASA Astrophysics Data System (ADS)
Nagai, Yukie; Asada, Minoru; Hosoda, Koh
This paper presents a developmental learning model for joint attention between a robot and a human caregiver. The basic idea of the proposed model comes from the insight of the cognitive developmental science that the development can help the task learning. The model consists of a learning mechanism based on evaluation and two kinds of developmental mechanisms: a robot's development and a caregiver's one. The former means that the sensing and the actuating capabilities of the robot change from immaturity to maturity. On the other hand, the latter is defined as a process that the caregiver changes the task from easy situation to difficult one. These two developments are triggered by the learning progress. The experimental results show that the proposed model can accelerate the learning of joint attention owing to the caregiver's development. Furthermore, it is observed that the robot's development can improve the final task performance by reducing the internal representation in the learned neural network. The mechanisms that bring these effects to the learning are analyzed in line with the cognitive developmental science.
NASA Technical Reports Server (NTRS)
Kohl, Randall L.
1987-01-01
The concentrations of adrenocorticotropic hormone (ACTH), vasopressin (AVP), epinephrine (EPI), and norepinephrine (NE) in 22 subjects administered 10 to 20 mg of metoclopramide prior to parabolic flight are measured. The effect of metoclopramide on motion sickness is examined. It is observed that metoclopramide is ineffective in the modulation of motion sickness due to stressful linear and angular acceleration and orbital flight, and it does not affect serum hormones prior to parabolic flight. It is detected that the serum level of AVP declines following emesis induced by parabolic flight and stressful angular acceleration; the serum levels of ACTH and EPI are elevated by parabolic flight and stressful angular acceleration; and serum NE is significantly elevated immediately following emesis. The possible roles of these hormones in the etiology of space motion sickness are discussed.
Rienth, Markus; Torregrosa, Laurent; Luchaire, Nathalie; Chatbanyong, Ratthaphon; Lecourieux, David; Kelly, Mary T; Romieu, Charles
2014-04-28
Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. This first day - night study on heat stress adaption of the grapevine berry shows that the transcriptome of fleshy fruits is differentially affected by abiotic stress at night. The present results emphasize the necessity of including different developmental stages and especially several daytime points in transcriptomic studies.
Coping of Siblings of Children with Developmental Disabilities in the Bedouin Community
ERIC Educational Resources Information Center
Manor-Binyamini, Iris; Abu-Ajaj, Othman
2012-01-01
This is the first study that examines the coping of siblings of children with developmental disabilities in comparison with siblings of children without disabilities in the Bedouin community in Israel. For this purpose, the study examines the components of self-esteem, stress, and growth. Data were collected from 200 adolescents. The findings of…
ERIC Educational Resources Information Center
Richdale, Amanda; Wiggs, Luci
2005-01-01
This paper reviews behavioral treatments for sleep problems in children with a developmental disorder (DD). Sleep problems are common in children with a DD and children's sleep problems may be associated with adverse consequences including behaviour problems, compromised daytime functioning and family stress. However, the sleep intervention…
ERIC Educational Resources Information Center
Congdon, David M.; And Others
This program manual was developed by the Grant-Blackford Development Center in order to help other professionals and organizations working with developmentally disabled persons to improve their recreation and leisure programs. The manual's philosophy is to structure recreation programs for fun, not just for skill teaching: stressing abilities, not…
ERIC Educational Resources Information Center
Yorke, Jan
2010-01-01
Emotional stress and trauma impacts the neurobiology of children. They are especially vulnerable given the developmental plasticity of the brain. The neural synaptic circular processes between the anterior cingulated cortex, prefrontal cortex, amygdala and the hypothalamus are altered. Trauma results in the release of the peptide glucocortisoid,…
Validating the Stress Survey Schedule for Persons with Autism and Other Developmental Disabilities
ERIC Educational Resources Information Center
Goodwin, Matthew S.; Groden, June; Velicer, Wayne F.; Diller, Amy
2007-01-01
It has been suggested that individuals with autism are more vulnerable to, and less able to cope with, the effects of stressors than the general population. However, very little work has been done to develop tools such as surveys or questionnaires that assess reactions to stressors in individuals with developmental disabilities. In the present…
Developmental Assets and Ethnic Identity as Predictors of Thriving in Hispanic Adolescents
ERIC Educational Resources Information Center
Alvarado, Melissa; Ricard, Richard J.
2013-01-01
This study examined the confluence of developmental assets, ethnic identity, and acculturative stress in the prediction of thriving among Hispanic adolescents. Thriving is used to encompass youth who are not only doing well now but who are also on the trajectory toward overall success. Study participants included 130 self-reported Hispanic middle…
ERIC Educational Resources Information Center
Kersh, J.; Hedvat, T. T.; Hauser-Cram, P.; Warfield, M. E.
2006-01-01
Background: This study examines the contribution of the marital relationship to the well-being of both mothers and fathers of children with developmental disabilities. Parent well-being is conceptualized in terms of mental health, parenting stress and parenting efficacy. Methods: These analyses are based on data from 67 families participating in…
ERIC Educational Resources Information Center
Gettings, Robert M.
This report examines possible steps the State of Illinois might take to expand the availability of Medicaid support for services to persons with developmental disabilties. Stressed throughout are the importance of: (1) evaluating whether any given application of Medicaid funding is consistent with the State's goals for persons with developmental…
Encopresis, Soiling and Constipation in Children and Adults with Developmental Disability
ERIC Educational Resources Information Center
Matson, Johnny L.; LoVullo, Santino V.
2009-01-01
Children and adults with developmental disabilities are more likely to evince encopresis, soiling and constipation than the general population. This set of related behaviors can produce a great deal of stress and can be a major restriction in independent living. This paper provides a review of the current state of knowledge on the prevalence,…
ERIC Educational Resources Information Center
Barr, William; DelFava, Christine
The paper describes combined public education and community mental health in a preschool educational day treatment program for seriously emotionally disturbed children. The Developmental Therapy model on which the Tacoma, Washington, program is based is described as using five normal developmental stages to facilitate treatment which stresses the…
Zhang, Yiqiang; Fischer, Kathleen E; Soto, Vanessa; Liu, Yuhong; Sosnowska, Danuta; Richardson, Arlan; Salmon, Adam B
2015-06-15
Obesity is a serious chronic disease that increases the risk of numerous co-morbidities including metabolic syndrome, cardiovascular disease and cancer as well as increases risk of mortality, leading some to suggest this condition represents accelerated aging. Obesity is associated with significant increases in oxidative stress in vivo and, despite the well-explored relationship between oxidative stress and aging, the role this plays in the increased mortality of obese subjects remains an unanswered question. Here, we addressed this by undertaking a comprehensive, longitudinal study of a group of high fat-fed obese mice and assessed both their changes in oxidative stress and in their performance in physiological assays known to decline with aging. In female C57BL/6J mice fed a high-fat diet starting in adulthood, mortality was significantly increased as was oxidative damage in vivo. High fat-feeding significantly accelerated the decline in performance in several assays, including activity, gait, and rotarod. However, we also found that obesity had little effect on other markers of function and actually improved performance in grip strength, a marker of muscular function. Together, this first comprehensive assessment of longitudinal, functional changes in high fat-fed mice suggests that obesity may induce segmental acceleration of some of the aging process. Published by Elsevier Inc.
Zhang, Yiqiang; Fischer, Kathleen E.; Soto, Vanessa; Liu, Yuhong; Sosnowska, Danuta; Richardson, Arlan; Salmon, Adam B.
2015-01-01
Obesity is a serious chronic disease that increases the risk of numerous co-morbidities including metabolic syndrome, cardiovascular disease and cancer as well as increases risk of mortality leading some to suggest this represents accelerated aging. Obesity is associated with significant increases in oxidative stress in vivo and, despite the well-explored relationship between oxidative stress and aging, the role this plays in the increased mortality of obese subjects remains an unanswered question. Here, we addressed this by undertaking a comprehensive, longitudinal study of a group of high fat-fed obese mice and assessed both their changes in oxidative stress and in their performance in physiological assays known to decline with aging. In female C57BL/6J mice fed a high-fat diet starting in adulthood, mortality was significantly increased in high fat-fed mice as was oxidative damage in vivo. High fat-feeding significantly accelerated the decline in performance in several assays, including activity, gait, and rotarod. However, we also found that obesity had little effect on other markers and actually improved performance in grip strength, a marker of muscular function. Together, this first comprehensive assessment of longitudinal functional changes in high fat-fed mice suggests that obesity may induce segmental acceleration of some of the aging process. PMID:25558793
Community College Pathways: 2013-2014 Descriptive Report
ERIC Educational Resources Information Center
Sowers, Nicole; Yamada, Hiroyuki
2015-01-01
The Community College Pathways initiative consists of two pathways, Statway® and Quantway®, that accelerate post-secondary students' progress through their developmental mathematics sequence and a college-level course for credit. Launched in 2011, the Pathways have been remarkably successful, helping thousands of students achieve success in…
Plants under Stress: Involvement of Auxin and Cytokinin
Bielach, Agnieszka; Hrtyan, Monika; Tognetti, Vanesa B.
2017-01-01
Plant growth and development are critically influenced by unpredictable abiotic factors. To survive fluctuating changes in their environments, plants have had to develop robust adaptive mechanisms. The dynamic and complementary actions of the auxin and cytokinin pathways regulate a plethora of developmental processes, and their ability to crosstalk makes them ideal candidates for mediating stress-adaptation responses. Other crucial signaling molecules responsible for the tremendous plasticity observed in plant morphology and in response to abiotic stress are reactive oxygen species (ROS). Proper temporal and spatial distribution of ROS and hormone gradients is crucial for plant survival in response to unfavorable environments. In this regard, the convergence of ROS with phytohormone pathways acts as an integrator of external and developmental signals into systemic responses organized to adapt plants to their environments. Auxin and cytokinin signaling pathways have been studied extensively. Nevertheless, we do not yet understand the impact on plant stress tolerance of the sophisticated crosstalk between the two hormones. Here, we review current knowledge on the function of auxin and cytokinin in redirecting growth induced by abiotic stress in order to deduce their potential points of crosstalk. PMID:28677656
Plants under Stress: Involvement of Auxin and Cytokinin.
Bielach, Agnieszka; Hrtyan, Monika; Tognetti, Vanesa B
2017-07-04
Plant growth and development are critically influenced by unpredictable abiotic factors. To survive fluctuating changes in their environments, plants have had to develop robust adaptive mechanisms. The dynamic and complementary actions of the auxin and cytokinin pathways regulate a plethora of developmental processes, and their ability to crosstalk makes them ideal candidates for mediating stress-adaptation responses. Other crucial signaling molecules responsible for the tremendous plasticity observed in plant morphology and in response to abiotic stress are reactive oxygen species (ROS). Proper temporal and spatial distribution of ROS and hormone gradients is crucial for plant survival in response to unfavorable environments. In this regard, the convergence of ROS with phytohormone pathways acts as an integrator of external and developmental signals into systemic responses organized to adapt plants to their environments. Auxin and cytokinin signaling pathways have been studied extensively. Nevertheless, we do not yet understand the impact on plant stress tolerance of the sophisticated crosstalk between the two hormones. Here, we review current knowledge on the function of auxin and cytokinin in redirecting growth induced by abiotic stress in order to deduce their potential points of crosstalk.
Zhang, Fan; Yuan, Sanna; Shao, Feng; Wang, Weiwen
2016-01-01
Negative social experiences during adolescence increase the risk of psychiatric disorders in adulthood. Using “resident-intruder” stress, the present study aimed to investigate the effects of adolescent social defeat on emotional and cognitive symptoms associated with psychiatric disorders during adulthood and the effects of the developmental stage and social condition on this process. In Experiment 1, animals were exposed to social defeat or manipulation for 10 days during early adolescence (EA, postnatal days [PND] 28–37), late adolescence (LA, PND 38–47), and adulthood (ADULT, PND 70–79) and then singly housed until the behavioral tests. Behaviors, including social avoidance of the defeat context and cortically mediated cognitive flexibility in an attentional set-shifting task (AST), were assessed during the week following stress or after 6 weeks during adulthood. We determined that social defeat induced significant and continuous social avoidance across age groups at both time points. The mice that experienced social defeat during adulthood exhibited short-term impairments in reversal learning (RL) on the AST that dissipated after 6 weeks. In contrast, social defeat during EA but not LA induced a delayed deficit in extra-dimensional set-shifting (EDS) in adulthood but not during adolescence. In Experiment 2, we further examined the effects of social condition (isolation or social housing after stress) on the alterations induced by social defeat during EA in adult mice. The adult mice that had experienced stress during EA exhibited social avoidance similar to the avoidance identified in Experiment 1 regardless of the isolation or social housing after the stress. However, social housing after the stress ameliorated the cognitive flexibility deficits induced by early adolescent social defeat in the adult mice, and the social condition had no effect on cognitive function. These findings suggest that the effects of social defeat on emotion and cognitive function are differentially affected by the developmental stage and social condition. EA may comprise a particularly sensitive developmental period in which social defeat may produce a delayed impairment in cognitive flexibility during adulthood, and the social condition following stress appears to play an important intermediary role in the development of these cognitive deficits. PMID:27489540
ERIC Educational Resources Information Center
Ricker, Ashley A.; Corley, Robin; DeFries, John C.; Wadsworth, Sally J.; Reynolds, Chandra A.
2018-01-01
The present study prospectively evaluated cumulative early life perceived stress in relation to differential change in memory and perceptual speed from middle childhood to early adulthood. We aimed to identify periods of cognitive development susceptible to the effects of perceived stress among both adopted and nonadopted individuals. The sample…
ERIC Educational Resources Information Center
Gunnar, Megan R.
2006-01-01
A growing body of science shows the critical effects of an extreme and sustained stressful environment for children on their developing brain architecture and the expression of genes in later life. Toxic stress can shift the brain into surviving in a way that's more rigid and less adaptive. For example, as a result of biologically altered brain…
Accelerated aging in schizophrenia patients: the potential role of oxidative stress.
Okusaga, Olaoluwa O
2014-08-01
Several lines of evidence suggest that schizophrenia, a severe mental illness characterized by delusions, hallucinations and thought disorder is associated with accelerated aging. The free radical (oxidative stress) theory of aging assumes that aging occurs as a result of damage to cell constituents and connective tissues by free radicals arising from oxygen-associated reactions. Schizophrenia has been associated with oxidative stress and chronic inflammation, both of which also appear to reciprocally induce each other in a positive feedback manner. The buildup of damaged macromolecules due to increased oxidative stress and failure of protein repair and maintenance systems is an indicator of aging both at the cellular and organismal level. When compared with age-matched healthy controls, schizophrenia patients have higher levels of markers of oxidative cellular damage such as protein carbonyls, products of lipid peroxidation and DNA hydroxylation. Potential confounders such as antipsychotic medication, smoking, socio-economic status and unhealthy lifestyle make it impossible to solely attribute the earlier onset of aging-related changes or oxidative stress to having a diagnosis of schizophrenia. Regardless of whether oxidative stress can be attributed solely to a diagnosis of schizophrenia or whether it is due to other factors associated with schizophrenia, the available evidence is in support of increased oxidative stress-induced cellular damage of macromolecules which may play a role in the phenomenon of accelerated aging presumed to be associated with schizophrenia.
OsMADS26 Negatively Regulates Resistance to Pathogens and Drought Tolerance in Rice1[OPEN
Khong, Giang Ngan; Richaud, Frédérique; Parizot, Boris; Mai, Chung Duc; Bès, Martine; Bourrié, Isabelle; Meynard, Donaldo; Beeckman, Tom; Selvaraj, Michael Gomez; Manabu, Ishitani; Brugidou, Christophe; Nang Do, Vinh; Guiderdoni, Emmanuel; Morel, Jean-Benoit; Gantet, Pascal
2015-01-01
Functional analyses of MADS-box transcription factors in plants have unraveled their role in major developmental programs (e.g. flowering and floral organ identity) as well as stress-related developmental processes, such as abscission, fruit ripening, and senescence. Overexpression of the rice (Oryza sativa) MADS26 gene in rice has revealed a possible function related to stress response. Here, we show that OsMADS26-down-regulated plants exhibit enhanced resistance against two major rice pathogens: Magnaporthe oryzae and Xanthomonas oryzae. Despite this enhanced resistance to biotic stresses, OsMADS26-down-regulated plants also displayed enhanced tolerance to water deficit. These phenotypes were observed in both controlled and field conditions. Interestingly, alteration of OsMADS26 expression does not have a strong impact on plant development. Gene expression profiling revealed that a majority of genes misregulated in overexpresser and down-regulated OsMADS26 lines compared with control plants are associated to biotic or abiotic stress response. Altogether, our data indicate that OsMADS26 acts as an upstream regulator of stress-associated genes and thereby, a hub to modulate the response to various stresses in the rice plant. PMID:26424158
Gunnar, Megan R; Fisher, Philip A
2006-01-01
A major focus in developmental psychopathology is on understanding developmental mechanisms and, armed with this information, intervening to improve children's outcomes. Translational research attempts to bridge the distance between understanding and intervention. In the collaborations that have formed the core of our research network on early experience, stress, and prevention science, we have focused on translating basic research on early experiences and stress neurobiology into preventive interventions for neglected and abused children. Our experiences in attempting to move from bench to bedside have led us to recognize the many challenges that face translational researchers. This review provides a brief synopsis of the animal model literature on early experience and stress neurobiology from which we glean several key bridging issues. We then review what is currently known about the impact of childhood neglect and abuse on stress neurobiology in human adults and children. Next, we describe how this work has informed the evaluation of our preventive interventions with maltreated children. Finally, we discuss several considerations that should facilitate a more complete integration of basic research on early experience and stress neurobiology into preventive intervention strategies.
Diagnosis of Posttraumatic Stress Disorder in Preschool Children
ERIC Educational Resources Information Center
De Young, Alexandra C.; Kenardy, Justin A.; Cobham, Vanessa E.
2011-01-01
This study investigated the existing diagnostic algorithms for posttraumatic stress disorder (PTSD) to determine the most developmentally sensitive and valid approach for diagnosing this disorder in preschoolers. Participants were 130 parents of unintentionally burned children (1-6 years). Diagnostic interviews were conducted with parents to…
Food availability determines the response to pond desiccation in anuran tadpoles.
Enriquez-Urzelai, Urtzi; San Sebastián, Olatz; Garriga, Núria; Llorente, Gustavo A
2013-09-01
Food availability and pond desiccation are two of the most studied factors that condition amphibian metamorphosis. It is well known that, when food is abundant, organisms undergo metamorphosis early and when they are relatively large. The capability of anurans to accelerate their developmental rate in response to desiccation is also common knowledge. These two variables must act together in nature, since we know that, as a pond dries, the per capita resources decrease. We conduct an experiment to evaluate the effects of desiccation and food availability separately and in combination in tadpoles of the painted frog (Discoglossus pictus). We demonstrate that food deprivation leads to slow growth rates, which delay metamorphosis and produce smaller size and weight. The capability to accelerate metamorphosis when facing a drying pond is also confirmed, but, nevertheless, with factor interaction (when the pool is drying and resources are scarce) the capacity to respond to desiccation is lost. In addition, slow drying rates are shown to be stressful situations, but not enough to provoke a shortening of the larval period; in fact, the larval period becomes longer. We also demonstrate that the interaction of these factors changes the allometric relationship of different parts of the hind limb, which has implications for the biomechanics of jumping. Due to low mortality rates and an adequate response to both environmental factors, we expect D. pictus to have a great invasive potential in its new Mediterranean distribution area, where lots of temporary and ephemeral ponds are present.
Jablonski, Sarah A.; Graham, Devon L.; Vorhees, Charles V.; Williams, Michael T.
2017-01-01
Neonatal exposure to methamphetamine (MA) and developmental chronic stress significantly alter neurodevelopmental profiles that show a variety of long-term physiological and behavioral effects. In the current experiment, Sprague-Dawley rats were exposed to one of two housing conditions along with MA. Rats were given 0 (saline), 5, or 7.5 mg/kg MA, four times per day from postnatal day (P)11 to 15 or P11 to 20. Half of the litters were reared in cages with standard bedding and half with no bedding. Separate litters were assessed at P15 or P20 for organ weights (adrenals, spleen, thymus); corticosterone; and monoamine assessments (dopamine, serotonin, norepinephrine) and their metabolites within the neostriatum, hippocampus, and prefrontal cortex. Findings show neonatal MA altered mono-amines, corticosterone, and organ characteristics alone, and as a function of developmental age and stress compared with controls. These alterations may in part be responsible for MA and early life stress-induced long-term learning and memory deficits. PMID:27817108
Elephants born in the high stress season have faster reproductive ageing.
Mumby, Hannah S; Mar, Khyne U; Hayward, Adam D; Htut, Win; Htut-Aung, Ye; Lummaa, Virpi
2015-09-14
Senescent declines in reproduction and survival are found across the tree of life, but little is known of the factors causing individual variation in reproductive ageing rates. One contributor may be variation in early developmental conditions, but only a few studies quantify the effects of early environment on reproductive ageing and none concern comparably long-lived species to humans. We determine the effects of 'stressful' birth conditions on lifetime reproduction in a large semi-captive population of Asian elephants (Elephas maximus). We categorise birth month into stressful vs. not-stressful periods based on longitudinal measures of glucocorticoid metabolites in reproductive-aged females, which peak during heavy workload and the start of the monsoon in June-August. Females born in these months exhibit faster reproductive senescence in adulthood and have significantly reduced lifetime reproductive success than their counterparts born at other times of year. Improving developmental conditions could therefore delay reproductive ageing in species as long-lived as humans.
Stressful Life Events and Predictors of Post-traumatic Growth among High-Risk Early Emerging Adults.
Arpawong, Thalida E; Rohrbach, Louise A; Milam, Joel E; Unger, Jennifer B; Land, Helen; Sun, Ping; Spruijt-Metz, Donna; Sussman, Steve
2016-01-01
Stressful life events (SLEs) may elicit positive psychosocial change among youth, referred to as Post-traumatic Growth (PTG). We assessed types of SLEs experienced, degree to which participants reported PTG, and variables predicting PTG across 24 months among a sample of high risk, ethnically diverse early emerging adults. Participants were recruited from alternative high schools ( n = 564; mean age=16.8; 65% Hispanic). Multi-level regression models were constructed to examine the impact of environmental (SLE quantity, severity) and personal factors (hedonic ability, perceived stress, developmental stage, future time orientation) on a composite score of PTG. The majority of participants reported positive changes resulted from their most life-altering SLE of the past two years. Predictors of PTG included fewer SLEs, less general stress, having a future time perspective, and greater identification with the developmental stage of Emerging Adulthood. Findings suggest intervention targets to foster positive adaptation among early emerging adults who experience frequent SLEs.
Developmental trajectories of brain maturation and behavior: Relevance to major mental illnesses.
Lockhart, Sedona; Sawa, Akira; Niwa, Minae
2018-05-01
Adverse events in childhood and adolescence, such as social neglect or drug abuse, are known to lead to behavioral changes in young adulthood. This is particularly true for the subset of people who are intrinsically more vulnerable to stressful conditions. Yet the underlying mechanisms for such developmental trajectory from early life insult to aberrant adult behavior remains elusive. Adolescence is a period of dynamic physiological, psychological, and behavioral changes, encompassing a distinct neurodevelopmental stage called the 'critical period'. During adolescence, the brain is uniquely susceptible to stress. Stress mediators may lead to disturbances to biological processes that can cause permanent alterations in the adult stage, even as severe as the onset of mental illness when paired with genetic risk and environmental factors. Understanding the molecular factors governing the critical period and how stress can disturb the maturation processes will allow for better treatment and prevention of late adolescent/young adult onset psychiatric disorders. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.
Mazurais, David; Servili, Arianna; Zambonino-Infante, Jose-Luis; Miest, Joanna J.; Sørensen, Sune R.; Tomkiewicz, Jonna; Butts, Ian A. E.
2017-01-01
Temperature is important for optimization of rearing conditions in aquaculture, especially during the critical early life history stages of fish. Here, we experimentally investigated the impact of temperature (16, 18, 20, 22 and 24°C) on thermally induced phenotypic variability, from larval hatch to first-feeding, and the linked expression of targeted genes [heat shock proteins (hsp), growth hormone (gh) and insulin-like growth factors (igf)] associated to larval performance of European eel, Anguilla anguilla. Temperature effects on larval morphology and gene expression were investigated throughout early larval development (in real time from 0 to 18 days post hatch) and at specific developmental stages (hatch, jaw/teeth formation, and first-feeding). Results showed that hatch success, yolk utilization efficiency, survival, deformities, yolk utilization, and growth rates were all significantly affected by temperature. In real time, increasing temperature from 16 to 22°C accelerated larval development, while larval gene expression patterns (hsp70, hsp90, gh and igf-1) were delayed at cold temperatures (16°C) or accelerated at warm temperatures (20–22°C). All targeted genes (hsp70, hsp90, gh, igf-1, igf-2a, igf-2b) were differentially expressed during larval development. Moreover, expression of gh was highest at 16°C during the jaw/teeth formation, and the first-feeding developmental stages, while expression of hsp90 was highest at 22°C, suggesting thermal stress. Furthermore, 24°C was shown to be deleterious (resulting in 100% mortality), while 16°C and 22°C (~50 and 90% deformities respectively) represent the lower and upper thermal tolerance limits. In conclusion, the high survival, lowest incidence of deformities at hatch, high yolk utilization efficiency, high gh and low hsp expression, suggest 18°C as the optimal temperature for offspring of European eel. Furthermore, our results suggest that the still enigmatic early life history stages of European eel may inhabit the deeper layer of the Sargasso Sea and indicate vulnerability of this critically endangered species to increasing ocean temperature. PMID:28806748
Guo, Rui; Shi, LianXuan; Yang, ChunWu; Yan, ChangRong; Zhong, XiuLi; Liu, Qi; Xia, Xu; Li, HaoRu
2016-01-01
Soil salinization is an important agriculture-related environmental problem. Alkali stress and salt stress strongly influence the metabolic balance in plants. Salt and alkali stresses exert varied effects on old and young tissues, which display different adaptive strategies. In this study, we used cotton (Gossypium hirsutum L.) plants as experimental material to investigate whether alkali stress induces ionic and metabolism changes in old and young leaves of cotton plants exposed to alkali stress. Results showed that alkali stress exerted a considerably stronger growth inhibition on old leaves than on young leaves. Under alkali stress, young leaves can maintain low Na and high K contents and retain relatively stable tricarboxylic acid cycle, resulting in greater accumulation of photosynthetic metabolites. In terms of metabolic response, the young and old leaves clearly displayed different mechanisms of osmotic regulation. The amounts of inositol and mannose significantly increased in both old and young leaves of cotton exposed to alkali stress, and the extent of increase was higher in young leaves than in old leaves. In old leaves, synthesis of amino acids, such as GABA, valine, and serine, was dramatically enhanced, and this phenomenon is favorable for osmotic adjustment and membrane stability. Organs at different developmental stages possibly display different mechanisms of metabolic regulation under stress condition. Thus, we propose that future investigations on alkali stress should use more organs obtained at different developmental stages. PMID:27933088
Nolte, Tobias; Guiney, Jo; Fonagy, Peter; Mayes, Linda C.; Luyten, Patrick
2011-01-01
Anxiety disorders represent a common but often debilitating form of psychopathology in both children and adults. While there is a growing understanding of the etiology and maintenance of these disorders across various research domains, only recently have integrative accounts been proposed. While classical attachment history has been a traditional core construct in psychological models of anxiety, contemporary attachment theory has the potential to integrate neurobiological and behavioral findings within a multidisciplinary developmental framework. The current paper proposes a modern attachment theory-based developmental model grounded in relevant literature from multiple disciplines including social neuroscience, genetics, neuroendocrinology, and the study of family factors involved in the development of anxiety disorders. Recent accounts of stress regulation have highlighted the interplay between stress, anxiety, and activation of the attachment system. This interplay directly affects the development of social–cognitive and mentalizing capacities that are acquired in the interpersonal context of early attachment relationships. Early attachment experiences are conceptualized as the key organizer of a complex interplay between genetic, environmental, and epigenetic contributions to the development of anxiety disorders – a multifactorial etiology resulting from dysfunctional co-regulation of fear and stress states. These risk-conferring processes are characterized by hyperactivation strategies in the face of anxiety. The cumulative allostatic load and subsequent “wear and tear” effects associated with hyperactivation strategies converge on the neural pathways of anxiety and stress. Attachment experiences further influence the development of anxiety as potential moderators of risk factors, differentially impacting on genetic vulnerability and relevant neurobiological pathways. Implications for further research and potential treatments are outlined. PMID:21960962
Kelly, Sean D.; Harrell, Constance S.; Neigh, Gretchen N.
2014-01-01
Facilitative glucose transporters (GLUT) mediate glucose uptake across the blood-brain-barrier into neurons and glia. Deficits in specific cerebral GLUT isoforms are linked to developmental and neurological dysfunction, but less is known about the range of variation in cerebral GLUT expression in normal conditions and the effects of environmental influences on cerebral GLUT expression. Knowing that puberty is a time of increased cerebral plasticity, metabolic demand, and shifts in hormonal balance for males and females, we first assessed gene expression of five GLUT subtypes in four brain regions in male and female adolescent and adult Wistar rats. The data indicated that sex differences in GLUT expression were most profound in the hypothalamus, and the transition from adolescence to adulthood had the most profound effect on GLUT expression in the hippocampus. Next, given the substantial energetic demands during adolescence and prior demonstrations of the adverse effects of adolescent stress, we determined the extent to which chronic stress altered GLUT expression in males and females in both adolescence and adulthood. Chronic stress significantly altered cerebral GLUT expression in males and females throughout both developmental stages but in a sexually dimorphic and brain region-specific manner. Collectively, our data demonstrate that cerebral GLUTs are expressed differentially based on brain region, sex, age, and stress exposure. These results suggest that developmental and environmental factors influence GLUT expression in multiple brain regions. Given the importance of appropriate metabolic balance within the brain, further assessment of the functional implications of life stage and environmentally-induced changes in GLUTs are warranted. PMID:24382486
NASA Technical Reports Server (NTRS)
Polzin, Kurt A.; Sivak, Amy D.; Balla, Joseph V.
2011-01-01
Pulsed inductive plasma accelerators are electrodeless space propulsion devices where a capacitor is charged to an initial voltage and then discharged through a coil as a high-current pulse that inductively couples energy into the propellant. The field produced by this pulse ionizes the propellant, producing a plasma near the face of the coil. Once a plasma is formed if can be accelerated and expelled at a high exhaust velocity by the Lorentz force arising from the interaction of an induced plasma current and the magnetic field. While there are many coil geometries that can be employed to inductively accelerate a plasma, in this paper the discussion is limit to planar geometries where the coil take the shape of a flat spiral. A recent review of the developmental history of planar-geometry pulsed inductive thrusters can be found in Ref. [1]. Two concepts that have employed this geometry are the Pulsed Inductive Thruster (PIT) and the Faraday Accelerator with Radio-frequency Assisted Discharge (FARAD).
Jeddi, Zahra; Jafari, Zahra; Motasaddi Zarandy, Masoud; Kassani, Aziz
2014-03-01
The purpose of this study was to investigate the benefits of aural rehabilitation on the development of cognition, social communication, and motor skills in children with cochlear implants. The study examined the development of cognition, social communication, and motor skills in 15 deaf children (7 males, 8 females; mean age 45 months 27 days) using the Newsha Developmental Scale before they received the cochlear implants, and then again 2, 4, 6, and 8 months after the implantation. The developmental age, Pretest Developmental Rate, Intervention Efficiency Index, and Proportional Change Index were calculated for each skill. There were significant differences between the preintervention and four follow-up Developmental Rate assessments for cognition, social communication, and motor skills (P < 0.0001). Significant differences were also observed between the four follow-up Proportional Change Index assessments for cognition, social communication, and motor skills (P ≤ 0.005). Cochlear implantation and aural rehabilitation may result in accelerated rates of cognition, social communication, and motor skill development in deaf children.
Medina, Rubén G; Paxton, Robert J; De Luna, Efraín; Fleites-Ayil, Fernando A; Medina Medina, Luis A; Quezada-Euán, José Javier G
2018-05-01
Beekeeping with the western honey bee (Apis mellifera) is important in tropical regions but scant information is available on the possible consequences of global warming for tropical beekeeping. We evaluated the effect of heat stress on developmental stability, the age at onset of foraging (AOF) and longevity in Africanized honey bees (AHBs) in the Yucatan Peninsula of Mexico, one of the main honey producing areas in the Neotropics, where high temperatures occur in spring and summer. To do so, we reared worker AHB pupae under a fluctuating temperature regime, simulating current tropical heatwaves, with a high temperature peak of 40.0 °C for 1 h daily across six days, and compared them to control pupae reared at stable temperatures of 34.0-35.5 °C. Heat stress did not markedly affect overall body size, though the forewing of heat-stressed bees was slightly shorter than controls. However, bees reared under heat stress showed significantly greater fluctuating asymmetry (FA) in forewing shape. Heat stress also decreased AOF and reduced longevity. Our results show that changes occur in the phenotype and behavior of honey bees under heat stress, with potential consequences for colony fitness. Copyright © 2018 Elsevier Ltd. All rights reserved.
Impacts of Early Life Stress on the Methylome and Transcriptome of Atlantic Salmon.
Moghadam, Hooman K; Johnsen, Hanne; Robinson, Nicholas; Andersen, Øivind; H Jørgensen, Even; Johnsen, Helge K; Bæhr, Vegar J; Tveiten, Helge
2017-07-10
Exposure to environmental stressors during early-life stages can change the rate and timing of various developmental processes. Epigenetic marks affecting transcriptional regulation can be altered by such environmental stimuli. To assess how stress might affect the methylome and transcriptome in salmon, fish were treated using cold-shock and air-exposure from the eye-stage until start-feeding. The fish were either stressed prior to hatching (E), post-hatching (PH), pre- and post-hatching (EPH) or not stressed (CO). Assessing transcriptional abundances just prior to start feeding, E and PH individuals were found to have modified the expression of thousands of genes, many with important functions in developmental processes. The EPH individuals however, showed expression similar to those of CO, suggesting an adaptive response to extended periods of stress. The methylome of stressed individuals differed from that of the CO, suggesting the importance of environment in shaping methylation signatures. Through integration of methylation with transcription, we identified bases with potential regulatory functions, some 10s of kb away from the targeted genes. We then followed fish growth for an additional year. Individuals in EPH showed superior growth compared to other treatment groups, highlighting how stress can potentially have long-lasting effects on an organism's ability to adapt to environmental perturbations.
Lipner, Hildy S; Huron, Randye F
2018-02-01
Practices in the neonatal intensive care unit (NICU) that reduce infant stress and respond to behavioral cues positively influence developmental outcomes. Proactive developmental surveillance and timely introduction of early intervention services improve outcomes for premature infants. A model that emphasizes infant development and a continuum of care beginning in the NICU with transition to outpatient monitoring and provision of early intervention services is hypothesized to support the most optimal outcomes for premature infants. Copyright © 2017 Elsevier Inc. All rights reserved.
Wright, Hannah F.; Mills, Daniel S.
2017-01-01
There is growing scientific and societal recognition of the role that pet dogs can play in healthy development of children; both those who are neuro-typically developing and those who live with a neuro-developmental disorder, such as autism or attention deficit hyperactivity disorder. However, little attention has been paid to how living with children positively and negatively affects quality of life of a pet dog. In this exploratory study we conducted semi-structured interviews with parents of neuro-typically developing children (n = 18) and those with a neuro-developmental disorder (n = 18) who owned a pet dog, until no new factors were identified. Living with children brought potentially positive benefits to the dog’s life including: imposition of a routine, participation in recreational activities and the development of a strong bond between the child and the dog. The importance of maintaining a routine was particularly prevalent in families with children with neuro-developmental disorders. Potential negative factors included having to cope with child meltdowns and tantrums, over stimulation from child visitors, harsh contact and rough and tumble play with the child. The regularity and intensity of meltdowns and tantrums was particularly evident in responses from parents with children with a neuro-developmental disorder. However, child visitors and rough play and contact were mentioned similarly across the groups. Protective factors included having a safe haven for the dog to escape to, parent’s awareness of stress signs and child education in dog-interaction. Parents were also asked to complete a stress response scale to provide an initial quantitative comparison of stress responses between dogs living with the two family-types. Parents with neuro-typically developing children more frequently observed their dog rapidly running away from a situation and less frequently observed their dog widening their eyes, than parents with children with a neuro-developmental disorder. We propose the development of a stress audit based on the findings reported here, to prevent potential dangerous situations, which may lead to dog bites and dog relinquishment and allow owners to maximise the benefits of dog ownership. PMID:28953961
Hall, Sophie S; Wright, Hannah F; Mills, Daniel S
2017-01-01
There is growing scientific and societal recognition of the role that pet dogs can play in healthy development of children; both those who are neuro-typically developing and those who live with a neuro-developmental disorder, such as autism or attention deficit hyperactivity disorder. However, little attention has been paid to how living with children positively and negatively affects quality of life of a pet dog. In this exploratory study we conducted semi-structured interviews with parents of neuro-typically developing children (n = 18) and those with a neuro-developmental disorder (n = 18) who owned a pet dog, until no new factors were identified. Living with children brought potentially positive benefits to the dog's life including: imposition of a routine, participation in recreational activities and the development of a strong bond between the child and the dog. The importance of maintaining a routine was particularly prevalent in families with children with neuro-developmental disorders. Potential negative factors included having to cope with child meltdowns and tantrums, over stimulation from child visitors, harsh contact and rough and tumble play with the child. The regularity and intensity of meltdowns and tantrums was particularly evident in responses from parents with children with a neuro-developmental disorder. However, child visitors and rough play and contact were mentioned similarly across the groups. Protective factors included having a safe haven for the dog to escape to, parent's awareness of stress signs and child education in dog-interaction. Parents were also asked to complete a stress response scale to provide an initial quantitative comparison of stress responses between dogs living with the two family-types. Parents with neuro-typically developing children more frequently observed their dog rapidly running away from a situation and less frequently observed their dog widening their eyes, than parents with children with a neuro-developmental disorder. We propose the development of a stress audit based on the findings reported here, to prevent potential dangerous situations, which may lead to dog bites and dog relinquishment and allow owners to maximise the benefits of dog ownership.
The Scope and Design of Structured Group Learning Experiences at Community Colleges
ERIC Educational Resources Information Center
Hatch, Deryl K.; Bohlig, E. Michael
2015-01-01
This study explores through descriptive analysis the similarities of structured group learning experiences such as first-year seminars, learning communities, orientation, success courses, and accelerated developmental education programs, in terms of their design features and implementation at community colleges. The study takes as its conceptual…
"Imitatio" Revisited: Its Theoretical and Practical Implications into the Twenty-First Century.
ERIC Educational Resources Information Center
Walborn, Eric D.
The instructional practice of imitation works most effectively as a developmental and remedial instrument within a writing-centered, student-centered pedagogy. In this context, imitation can accelerate natural language acquisition and encourage language competence and control, thus enabling student writers to focus their attention on particular…
Guidelines for Developing a Preschool Level Gifted Program in the Private Sector.
ERIC Educational Resources Information Center
McMurtry, Doyleen
This practicum addresses the creation of an economically viable school in the private sector to meet the educational and social needs of cognitively developmentally accelerated preschool-age children. Anticipated outcomes of the practicum included development of a well-documented philosophical approach to preschool gifted education, curriculum…
Teaching Creativity: Current Findings, Trends, and Controversies in the Psychology of Creativity
ERIC Educational Resources Information Center
Simonton, Dean Keith
2012-01-01
In the past decade, the psychological study of creativity has accelerated greatly. To facilitate the teaching of creativity, I provide an overview of the recent literature. The overview begins by discussing recent empirical results and research trends. This discussion specifically treats creativity's cognitive, differential, developmental, and…
The Journal of the Society for Accelerative Learning and Teaching. Volume 15, 1990.
ERIC Educational Resources Information Center
Journal of the Society for Accelerative Learning and Teaching, 1990
1990-01-01
Articles in this volume of the Journal of the Society for Accelerative Learning and Teaching (SALT) include the following: "Accelerated Learning Components in Elementary Classrooms"; "Ball-Stick Bird: Teaching with the Story Engram"; "A SALT Pilot Study in College Developmental Mathematics"; "Black Education in…
Brown, Alan S; Gyllenberg, David; Hinkka-Yli-Salomäki, Susanna; Sourander, Andre; McKeague, Ian W
2017-04-01
Identification of abnormalities in the developmental trajectory during infancy of future schizophrenia cases offers the potential to reveal pathogenic mechanisms of this disorder. Previous studies of head circumference in pre-schizophrenia were limited to measures at birth. The use of growth acceleration of head circumference (defined as the rate of change in head circumference) provides a more informative representation of the maturational landscape of this measure compared to studies based on static head circumference measures. To date, however, no study has examined whether HC growth acceleration differs between pre-schizophrenia cases and controls. In the present study, we employed a nested case control design of a national birth cohort in Finland. Cases with schizophrenia or schizoaffective disorder (N=375) and controls (N=375) drawn from the birth cohort were matched 1:1 on date of birth (within 1month), sex, and residence in Finland at case diagnosis. Longitudinal data were obtained on head circumference from birth through age 1. Data were analyzed using a new nonparametric Bayesian inversion method which allows for a detailed understanding of growth dynamics. Adjusting for growth velocity of height and weight, and gestational age, there was significantly accelerated growth of head circumference in females with schizophrenia from birth to 2months; the findings remained significant following Bonferroni correction (p<0.0125). This is the first study to report abnormal HC growth acceleration, a more sensitive measure of somatic developmental deviation of this measure, in schizophrenia. Copyright © 2016 Elsevier B.V. All rights reserved.
Winter, Klaus; Holtum, Joseph A.M.
2007-01-01
The relative influence of plant age and environmental stress signals in triggering a shift from C3 photosynthesis to Crassulacean acid metabolism (CAM) in the annual halophytic C3-CAM species Mesembryanthemum crystallinum was explored by continuously monitoring net CO2 exchange of whole shoots from the seedling stage until seed set. Plants exposed to high salinity (400 mm NaCl) in hydroponic culture solution or grown in saline-droughted soil acquired between 11% and 24% of their carbon via net dark CO2 uptake involving CAM. In contrast, plants grown under nonsaline, well-watered conditions were capable of completing their life cycle by operating in the C3 mode without ever exhibiting net CO2 uptake at night. These observations are not consistent with the widely expressed view that the induction of CAM by high salinity in M. crystallinum represents an acceleration of preprogrammed developmental processes. Rather, our study demonstrates that the induction of the CAM pathway for carbon acquisition in M. crystallinum is under environmental control. PMID:17056756
Winter, Klaus; Holtum, Joseph A M
2007-01-01
The relative influence of plant age and environmental stress signals in triggering a shift from C(3) photosynthesis to Crassulacean acid metabolism (CAM) in the annual halophytic C(3)-CAM species Mesembryanthemum crystallinum was explored by continuously monitoring net CO(2) exchange of whole shoots from the seedling stage until seed set. Plants exposed to high salinity (400 mm NaCl) in hydroponic culture solution or grown in saline-droughted soil acquired between 11% and 24% of their carbon via net dark CO(2) uptake involving CAM. In contrast, plants grown under nonsaline, well-watered conditions were capable of completing their life cycle by operating in the C(3) mode without ever exhibiting net CO(2) uptake at night. These observations are not consistent with the widely expressed view that the induction of CAM by high salinity in M. crystallinum represents an acceleration of preprogrammed developmental processes. Rather, our study demonstrates that the induction of the CAM pathway for carbon acquisition in M. crystallinum is under environmental control.
Kim, Ju Young; Liu, Cindy Y; Zhang, Fengyu; Duan, Xin; Wen, Zhexing; Song, Juan; Feighery, Emer; Lu, Bai; Rujescu, Dan; St Clair, David; Christian, Kimberly; Callicott, Joseph H; Weinberger, Daniel R; Song, Hongjun; Ming, Guo-li
2012-03-02
How extrinsic stimuli and intrinsic factors interact to regulate continuous neurogenesis in the postnatal mammalian brain is unknown. Here we show that regulation of dendritic development of newborn neurons by Disrupted-in-Schizophrenia 1 (DISC1) during adult hippocampal neurogenesis requires neurotransmitter GABA-induced, NKCC1-dependent depolarization through a convergence onto the AKT-mTOR pathway. In contrast, DISC1 fails to modulate early-postnatal hippocampal neurogenesis when conversion of GABA-induced depolarization to hyperpolarization is accelerated. Extending the period of GABA-induced depolarization or maternal deprivation stress restores DISC1-dependent dendritic regulation through mTOR pathway during early-postnatal hippocampal neurogenesis. Furthermore, DISC1 and NKCC1 interact epistatically to affect risk for schizophrenia in two independent case control studies. Our study uncovers an interplay between intrinsic DISC1 and extrinsic GABA signaling, two schizophrenia susceptibility pathways, in controlling neurogenesis and suggests critical roles of developmental tempo and experience in manifesting the impact of susceptibility genes on neuronal development and risk for mental disorders. Copyright © 2012 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Bourke-Taylor, Helen; Pallant, Julie F.; Law, Mary; Howie, Linsey
2012-01-01
Aim: Many mothers of children with developmental disabilities are known to experience high levels of stress, and compromised mental health. Research is crucial to better understand and assist mothers with compromised mental health, and ultimately better service families raising and supporting a child with a disability. Method: Data were collected…
ERIC Educational Resources Information Center
Dinehart, Laura H.; Katz, Lynne F.; Manfra, Louis; Ullery, Mary Anne
2013-01-01
The current paper highlights the few studies that examine the role of early care and education on the developmental and early academic outcomes of children who experience maltreatment. First, we argue that children who experience maltreatment are at significant risk for poor developmental outcomes as a result of the chronic exposure to stress that…
ERIC Educational Resources Information Center
Ogle, Christin M.; Rubin, David C.; Siegler, Ilene C.
2013-01-01
The present study examined the impact of the developmental timing of trauma exposure on posttraumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (N = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas…
Lee, Meonghun; Yoe, Hyun
2015-01-01
The environment promotes evolution. Evolutionary processes represent environmental adaptations over long time scales; evolution of crop genomes is not inducible within the relatively short time span of a human generation. Extreme environmental conditions can accelerate evolution, but such conditions are often stress inducing and disruptive. Artificial growth systems can be used to induce and select genomic variation by changing external environmental conditions, thus, accelerating evolution. By using cloud computing and big-data analysis, we analyzed environmental stress factors for Pleurotus ostreatus by assessing, evaluating, and predicting information of the growth environment. Through the indexing of environmental stress, the growth environment can be precisely controlled and developed into a technology for improving crop quality and production. PMID:25874206
Mészáros, István; Tóth, Renáta; Olasz, Ferenc; Tijssen, Peter; Zádori, Zoltán
2017-08-15
The SAT protein (SATp) of porcine parvovirus (PPV) accumulates in the endoplasmic reticulum (ER), and SAT deletion induces the slow-spreading phenotype. The in vitro comparison of the wild-type Kresse strain and its SAT knockout (SAT - ) mutant revealed that prolonged cell integrity and late viral release are responsible for the slower spreading of the SAT - virus. During PPV infection, regardless of the presence or absence of SATp, the expression of downstream ER stress response proteins (Xbp1 and CHOP) was induced. However, in the absence of SATp, significant differences in the quantity and the localization of CHOP were detected, suggesting a role of SATp in the induction of irreversible ER stress in infected cells. The involvement of the induction of irreversible ER stress in porcine testis (PT) cell necrosis and viral egress was confirmed by treatment of infected cells by ER stress-inducing chemicals (MG132, dithiothreitol, and thapsigargin), which accelerated the egress and spreading of both the wild-type and the SAT - viruses. UV stress induction had no beneficial effect on PPV infection, underscoring the specificity of ER stress pathways in the process. However, induction of CHOP and its nuclear translocation cannot alone be responsible for the biological effect of SAT, since nuclear CHOP could not complement the lack of SAT in a coexpression experiment. IMPORTANCE SATp is encoded by an alternative open reading frame of the PPV genome. Earlier we showed that SATp of the attenuated PPV NADL-2 strain accumulates in the ER and accelerates virus release and spreading. Our present work revealed that slow spreading is a general feature of SAT - PPVs and is the consequence of prolonged cell integrity. PPV infection induced ER stress in infected cells regardless of the presence of SATp, as demonstrated by the morphological changes of the ER and expression of the stress response proteins Xbp1 and CHOP. However, the presence of SATp made the ER stress more severe and accelerated cell death during infection, as shown by the higher rate of expression of CHOP and alteration of the localization of CHOP. The beneficial effect of irreversible ER stress on PPV spread was confirmed by treatment of infected cells with ER stress-inducing chemicals. Copyright © 2017 American Society for Microbiology.
Tóth, Renáta; Olasz, Ferenc; Tijssen, Peter; Zádori, Zoltán
2017-01-01
ABSTRACT The SAT protein (SATp) of porcine parvovirus (PPV) accumulates in the endoplasmic reticulum (ER), and SAT deletion induces the slow-spreading phenotype. The in vitro comparison of the wild-type Kresse strain and its SAT knockout (SAT−) mutant revealed that prolonged cell integrity and late viral release are responsible for the slower spreading of the SAT− virus. During PPV infection, regardless of the presence or absence of SATp, the expression of downstream ER stress response proteins (Xbp1 and CHOP) was induced. However, in the absence of SATp, significant differences in the quantity and the localization of CHOP were detected, suggesting a role of SATp in the induction of irreversible ER stress in infected cells. The involvement of the induction of irreversible ER stress in porcine testis (PT) cell necrosis and viral egress was confirmed by treatment of infected cells by ER stress-inducing chemicals (MG132, dithiothreitol, and thapsigargin), which accelerated the egress and spreading of both the wild-type and the SAT− viruses. UV stress induction had no beneficial effect on PPV infection, underscoring the specificity of ER stress pathways in the process. However, induction of CHOP and its nuclear translocation cannot alone be responsible for the biological effect of SAT, since nuclear CHOP could not complement the lack of SAT in a coexpression experiment. IMPORTANCE SATp is encoded by an alternative open reading frame of the PPV genome. Earlier we showed that SATp of the attenuated PPV NADL-2 strain accumulates in the ER and accelerates virus release and spreading. Our present work revealed that slow spreading is a general feature of SAT− PPVs and is the consequence of prolonged cell integrity. PPV infection induced ER stress in infected cells regardless of the presence of SATp, as demonstrated by the morphological changes of the ER and expression of the stress response proteins Xbp1 and CHOP. However, the presence of SATp made the ER stress more severe and accelerated cell death during infection, as shown by the higher rate of expression of CHOP and alteration of the localization of CHOP. The beneficial effect of irreversible ER stress on PPV spread was confirmed by treatment of infected cells with ER stress-inducing chemicals. PMID:28566374
Morag, Iris; Rotem, Ifat; Frisch, Mor; Hendler, Israel; Simchen, Michal J; Leibovitz, Leah; Maayan-Metzger, Ayala; Strauss, Tzipora
2017-06-01
Extensive exposure of preterm infants to pain-related stress (PRS) at a time of physiological immaturity and rapid brain development may contribute to altered neurodevelopment. To examine the relationship between early PRS and neurodevelopmental outcomes among low-risk very preterm infants at the age of one year corrected age (CA). Participants included 107 infants born <32weeks gestational age (GA) and monitored prospectively at 12.5months CA. Excluded were infants with severe neonatal morbidities associated with impaired neurodevelopment. PRS documentation was performed via the number of skin-breaking procedures (SBP) and by the use of the neonatal infant stressor scale (NISS). Adjustment was made for early neonatal morbidities. Developmental outcomes among the study infants were within the norm (mean 100±11.03). Infants who underwent invasive mechanical ventilation (IMV) (n=31) were exposed to significantly more PRS than non-IMV infants (n=76) (p<0.000). Developmental outcomes were similar in both groups (99.7±11.1 vs. 100.8±11 p=0.63). Among IMV infants, increased exposure to PRS was associated with lower developmental scores independent of GA, gender or other sociodemographic factors. Increased exposure to PRS among low-risk preterm infants who underwent IMV is associated with lower developmental scores at 12.5month CA. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Lathrop, J. W.; Prince, J. L.
1979-01-01
Results obtained include the definition of a simplified stress test schedule for terrestrial solar cells based on the work performed during the first program year, and the design and fabrication of improved jigs and fixtures for electrical measurement and stress testing. Implementation of these advanced techniques for accelerated stress testing is underway on three solar cell types. In addition, review of the literature on second quadrant phenomena was begun and some preliminary second-quadrant electrical measurements were performed. Results obtained at the first down time for 75 C B-T testing and biased and unbiased T-H pressure cooker testing of type F cells showed little or no degradation in electrical parameters. Significant physical effects (large solder bubbles) were noted for type F cells subjected to the pressure cooker stress test.
Wu, Li-Min; Hu, Mei-Hong; Tong, Xian-Hong; Han, Hui; Shen, Ni; Jin, Ren-Tao; Wang, Wei; Zhou, Gui-Xiang; He, Guo-Ping; Liu, Yu-Sheng
2012-01-01
Brain-derived neurotropic factor (BDNF) was originally described in the nervous system but has been shown to be expressed in ovary tissues recently, acting as a paracrine/autocrine regulator required for developments of follicles and oocytes. Although it is generally accepted that chronic stress impairs female reproduction and decreases the expression of BDNF in limbic structures of central nervous system, which contributes to mood disorder. However, it is not known whether chronic stress affects oocytes developments, nor whether it affects expression of BDNF in ovary. Mice were randomly assigned into control group, stressed group, BDNF-treated group and BDNF-treated stressed group. The chronic unpredictable mild stress model was used to produce psychosocial stress in mice, and the model was verified by open field test and hypothalamic-pituitary-adrenal (HPA) axis activity. The methods of immunohistochemistry and western blotting were used to detect BDNF protein level and distribution. The number of retrieved oocytes, oocyte maturation, embryo cleavage and the rates of blastocyst formation after parthenogenetic activation were evaluated. Chronic unpredictable stress decreased the BDNF expression in antral follicles, but didn't affect the BDNF expression in primordial, primary and secondary follicles. Chronic unpredictable stress also decreased the number of retrieved oocytes and the rate of blastocyst formation, which was rescued by exogenous BDNF treatment. BDNF in mouse ovaries may be related to the decreased number of retrieved oocytes and impaired oocytes developmental potential induced by chronic unpredictable stress.
Tong, Xian-Hong; Han, Hui; Shen, Ni; Jin, Ren-Tao; Wang, Wei; Zhou, Gui-Xiang; He, Guo-Ping; Liu, Yu-Sheng
2012-01-01
Background Brain-derived neurotropic factor (BDNF) was originally described in the nervous system but has been shown to be expressed in ovary tissues recently, acting as a paracrine/autocrine regulator required for developments of follicles and oocytes. Although it is generally accepted that chronic stress impairs female reproduction and decreases the expression of BDNF in limbic structures of central nervous system, which contributes to mood disorder. However, it is not known whether chronic stress affects oocytes developments, nor whether it affects expression of BDNF in ovary. Methods Mice were randomly assigned into control group, stressed group, BDNF-treated group and BDNF-treated stressed group. The chronic unpredictable mild stress model was used to produce psychosocial stress in mice, and the model was verified by open field test and hypothalamic-pituitary-adrenal (HPA) axis activity. The methods of immunohistochemistry and western blotting were used to detect BDNF protein level and distribution. The number of retrieved oocytes, oocyte maturation, embryo cleavage and the rates of blastocyst formation after parthenogenetic activation were evaluated. Results Chronic unpredictable stress decreased the BDNF expression in antral follicles, but didn’t affect the BDNF expression in primordial, primary and secondary follicles. Chronic unpredictable stress also decreased the number of retrieved oocytes and the rate of blastocyst formation, which was rescued by exogenous BDNF treatment. Conclusion BDNF in mouse ovaries may be related to the decreased number of retrieved oocytes and impaired oocytes developmental potential induced by chronic unpredictable stress. PMID:23284991
Developmental toxicology: adequacy of current methods.
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 applicable in developmental and especially prenatal toxicology; to describe the different agents that might act as developmental toxicants or teratogens; to show the broad scope of different effects caused by developmental toxic agents; and to indicate methods to detect and to recognise causes of developmental defects with the primary objective of preventing these disorders.
Van Camp, Gilles; Cigalotti, Jenny; Bouwalerh, Hammou; Mairesse, Jérôme; Gatta, Eleonora; Palanza, Paola; Maccari, Stefania; Morley-Fletcher, Sara
2018-07-01
The interplay between experiences during critical developmental periods and later adult life is crucial in shaping individual variability in stress coping strategies. Exposure to stressful events in early life has strongly programs an individual's phenotype and adaptive capabilities. Until now, studies on programming and reversal strategies in early life stress animal models have been essentially limited to males. By using the perinatal stress (PRS) rat model (a model more sensitive to aging changes) in middle-aged females, we investigated the behavioral and endocrine responses following exposure in later life to an unpredictable chronic mild stress (uCMS) condition for six weeks. PRS by itself accelerated the ageing-related-disruption in the estrous cycle and led to reductions in the levels of estradiol. It also reduced motivational and risk-taking behavior in later life, with PRS females being characterized by a reduction in self-grooming in the splash test, in the exploration of the light compartment in the light/dark box test and in the time spent eating a palatable food in the novelty-induced suppression feeding test. PRS females showed impaired regulation of plasma glucose and insulin levels following a glucose challenge, with a hyperglycemic phenotype, and disrupted feedback of the HPA axis after acute stress with respect to controls. Remarkably, all PRS-induced alterations were modified by exposure to the uCMS procedure, thus resulting in a disease-dependent intervention; controls were not affected by uCMS, except for a slight and transient reduction in body weight, while PRS females displayed a reduced body weight gain for the entire duration of the uCMS procedure. Interestingly, the effects of uCMS on PRS females were still observed up to two months after its termination and the females displayed heightened rhythms of locomotor activity and enhanced sensitivity to reward with respect to controls exposed to uCMS. Our findings indicate that many parameters of the PRS female adult phenotype are shaped by both early and later life experiences in a non-additive way. As a consequence, early stressed individuals may be programmed with a more dynamic phenotype than non-stressed individuals. Copyright © 2018 Elsevier Ltd. All rights reserved.
The three-dimensional simulation analysis of dynamic response on perforated strings
NASA Astrophysics Data System (ADS)
Li, M. F.; Liu, H. F.; Dou, Y. H.; Cao, L. H.; Liu, Y. X.
2018-06-01
It analyzes the dynamic response and stresses of perforating tubular string to detonating impact load in oil-gas well in ANSYS, obtains the response of vibration displacement, velocity and acceleration of perforating tubularstring caused by detonating impact load, finds the influence of the length and wall thickness of perforating tubular string to working stresses. The result shows that:when the detonating impact load exerts the perforating tubular string with compressive and tensile axial force alternatively;the vibration displacement, velocity and acceleration of perfora-ting tubular string change periodically at same cycle;the closer to the perforating gun, the larger the amplitude of vi-bration velocity and acceleration;the closer to the packer the smaller the vibration displacement, the larger the work-ing equivalent stress of perforating tubular string;the longer or the thicker the perforating tubular string, the smaller the working equivalent stress and the higher the strength safety. Therefore, it uses the damping tube between packer and perforating gun as well as thick walled tubing to increase the strength safety of perforating tubular string.
Colors Of Liquid Crystals Used To Measure Surface Shear Stresses
NASA Technical Reports Server (NTRS)
Reda, D. C.; Muratore, J. J., Jr.
1996-01-01
Developmental method of mapping shear stresses on aerodynamic surfaces involves observation, at multiple viewing angles, of colors of liquid-crystal surface coats illuminated by white light. Report describing method referenced in "Liquid Crystals Indicate Directions Of Surface Shear Stresses" (ARC-13379). Resulting maps of surface shear stresses contain valuable data on magnitudes and directions of skin friction forces associated with surface flows; data used to refine mathematical models of aerodynamics for research and design purposes.
García-Sanz, Patricia; Mirasierra, Mercedes; Moratalla, Rosario; Vallejo, Mario
2017-03-24
Oxidative stress constitutes a major cause for increased risk of congenital malformations associated to severe hyperglycaemia during pregnancy. Mutations in the gene encoding the transcription factor ALX3 cause congenital craniofacial and neural tube defects. Since oxidative stress and lack of ALX3 favour excessive embryonic apoptosis, we investigated whether ALX3-deficiency further increases the risk of embryonic damage during gestational hyperglycaemia in mice. We found that congenital malformations associated to ALX3-deficiency are enhanced in diabetic pregnancies. Increased expression of genes encoding oxidative stress-scavenging enzymes in embryos from diabetic mothers was blunted in the absence of ALX3, leading to increased oxidative stress. Levels of ALX3 increased in response to glucose, but ALX3 did not activate oxidative stress defence genes directly. Instead, ALX3 stimulated the transcription of Foxo1, a master regulator of oxidative stress-scavenging genes, by binding to a newly identified binding site located in the Foxo1 promoter. Our data identify ALX3 as an important component of the defence mechanisms against the occurrence of developmental malformations during diabetic gestations, stimulating the expression of oxidative stress-scavenging genes in a glucose-dependent manner via Foxo1 activation. Thus, ALX3 deficiency provides a novel molecular mechanism for developmental defects arising from maternal hyperglycaemia.
Adaptive Patterns of Stress Responsivity: A Preliminary Investigation
ERIC Educational Resources Information Center
Del Giudice, Marco; Hinnant, J. Benjamin; Ellis, Bruce J.; El-Sheikh, Mona
2012-01-01
The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern…
Social Stress in Young People with Specific Language Impairment
ERIC Educational Resources Information Center
Wadman, Ruth; Durkin, Kevin; Conti-Ramsden, Gina
2011-01-01
Social interactions can be a source of social stress for adolescents. Little is known about how adolescents with developmental difficulties, such as specific language impairment (SLI), feel when interacting socially. Participants included 28 adolescents with SLI and 28 adolescents with typical language abilities (TL). Self-report measures of…
Academic Stress in Kindergarten Children.
ERIC Educational Resources Information Center
Wiedey, Linda Brenckman; Lichtenstein, James M.
This research examined stress in the kindergarten in the public school system of North Carolina. A questionnaire was designed to collect information from public school kindergarten teachers concerning seven stressors: (1) academic tasks that students were developmentally unable to handle; (2) death of a close family member or friend; (3) the move…
Relationship Satisfaction, Parenting Stress, and Depression in Mothers of Children with Autism
ERIC Educational Resources Information Center
Weitlauf, Amy S.; Vehorn, Alison C.; Taylor, Julie L.; Warren, Zachary E.
2014-01-01
Mothers of children with autism report higher levels of depression than mothers of children with other developmental disabilities. We explored the relations between child characteristics of diagnostic severity and problem behaviors, parenting stress, relationship quality, and depressive symptoms in 70 mothers of young children with autism. We…
School-Aged Children's Phonological Production of Derived English Words
ERIC Educational Resources Information Center
Jarmulowicz, Linda
2006-01-01
Purpose: Little is known about the phonological aspects of derivational processes. Neutral suffixes (e.g., "-ness") that do not change stress and rhythmic or nonneutral suffixes (e.g., "-ity") that alter stem stress were used in a production task that explored developmental changes in phonological accuracy of derived English…
The Decision-Filled Years of Adolescence.
ERIC Educational Resources Information Center
Baugher, Shirley L.; Martin, Betty B.
1981-01-01
After a discussion of the causes and results of adolescent stress, the authors suggest possible topics which home economics teachers could address in their curricula. These include developmental and transitional life stages, stress reactions, recovery from loss and grief, death, divorce, teen pregnancy and abortion, child abuse, rape, and others.…
Rodriguez, Christina M
2010-02-01
According to Social Information Processing theory, parents' cognitive processes influence their decisions to engage in physical maltreatment, although cognitions occur in the context of other aspects of the parents' life. The present study investigated whether cognitive processes (external locus of control, inappropriate developmental expectations) predicted child abuse potential and overreactive disciplinary style beyond personal contextual factors characteristic of the parent (hostility, stress, and coping). 363 parents were recruited online. Results highlight the relative importance of the contextual characteristics (particularly stress, avoidant coping, and irritability) relative to cognitive processes in predicting abuse potential and overreactive discipline strategies, although an external locus of control also significantly contributed. Findings do not support that parents' developmental expectations uniquely predict elevated abuse risk. Results indicate stressed parents who utilize avoidance coping strategies are more likely to use overreactive discipline and report increased abuse potential. Findings are discussed with regard to implications for prevention/intervention efforts.
Jasmonate action in plant growth and development.
Huang, Huang; Liu, Bei; Liu, Liangyu; Song, Susheng
2017-03-01
Phytohormones, including jasmonates (JAs), gibberellin, ethylene, abscisic acid, and auxin, integrate endogenous developmental cues with environmental signals to regulate plant growth, development, and defense. JAs are well- recognized lipid-derived stress hormones that regulate plant adaptations to biotic stresses, including herbivore attack and pathogen infection, as well as abiotic stresses, including wounding, ozone, and ultraviolet radiation. An increasing number of studies have shown that JAs also have functions in a remarkable number of plant developmental events, including primary root growth, reproductive development, and leaf senescence. Since the 1980s, details of the JA biosynthesis pathway, signaling pathway, and crosstalk during plant growth and development have been elucidated. Here, we summarize recent advances and give an updated overview of JA action and crosstalk in plant growth and development. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Yoon, Susan; Kobulsky, Julia M.; Yoon, Dalhee; Kim, Wonhee
2018-01-01
While many studies have identified a significant relation between child maltreatment and adolescent substance use, the developmental pathways linking this relation remain sparsely explored. The current study examines posttraumatic stress (PTS) symptoms, mother-child relationships, and internalizing and externalizing problems as potential longitudinal pathways through which child maltreatment influences adolescent substance use. Structural equation modeling was conducted on 883 adolescents drawn from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN). The pathways of PTS symptoms linked physical and sexual abuse to substance use, and the pathways of mother-child relationships linked emotional abuse and neglect to substance use. None of the four types of maltreatment affected substance use via internalizing or externalizing problems. The findings suggest that intervention efforts aimed at addressing posttraumatic stress symptoms and improving mother-child relationship quality may be beneficial in reducing substance use among adolescents with child maltreatment histories. PMID:29503490
Acceleration effects in solid propellant rocket motors
NASA Technical Reports Server (NTRS)
Langhenry, M. T.
1986-01-01
The performance variations due to acceleration loads imposed on spinning solid propellant rocket motors are investigated. The four potentially most significant modes of acceleration-induced phenomena are identified from a study of the literature and modeled. The four modes are a mechanical mode which deals with deformations of the propellant and case: a thermodynamic mode which covers acceleration-induced combustion phenomena; a stress mode which covers the stressed propellant's effect on burn rate; and a gas dynamic mode which deals with changes in gas flow in the chamber and through the nozzle. Simplified models of each mode are developed or taken from the literature and are added to an internal ballistics evaluation computer program. The resulting analysis is the first to include all of the modes. In order to do this an original analysis of the mechanical and stress modes was necessary. However, the analysis shows that the stress mode is not important for the circular perforated grains studied. The other effects are shown to have a significant influence on solid rocket motor performance. The magnitude of the different mode effects are such that one may not be ignored over the others as has been done in the past. The results of the analysis are compared to published rocket motor data. The comparisons indicate an erosive burning effect that is a function of spin rate. A qualitative explanation of the erosive effect is presented.
Contact integrity testing of stress-tested silicon terrestrial solar cells
NASA Technical Reports Server (NTRS)
Prince, J. L.; Lathrop, J. W.; Witter, G. W.
1980-01-01
A test procedure was developed and applied to terrestrial silicon solar cells in order to determine the effect of accelerated environmental and time-temperature aging on metal contact integrity. Quantities of cells of four different manufacturers were given the contact integrity test after being subjected to accelerated stress tests that included forward bias-temperature, thermal cycle and thermal shock, power cycle, and bias-temperature humidity tests at two temperature-humidity levels. Significant effects due to certain stress tests were found for some cell types. It is concluded that cells fabricated using plated nickel/solder metallization showed significantly more serious contact integrity degradation than silver-metallized cells.
Leung, Cynthia; Fan, Angel; Sanders, Matthew R
2013-03-01
The study examined the effectiveness of Group Triple P, a Level 4 variant of the Triple P multilevel system of parenting support, with Chinese parents who had a preschool aged child with a developmental disability, using randomized controlled trial design. Participants (Intervention group: 42; Waitlist Control group: 39) completed measures on child behaviour, parental stress, dysfunctional discipline styles and parental conflict before and after program completion by the Intervention group. Intervention group participants also completed these same measures six months after program completion. Compared to the Waitlist Control group, parents receiving Group Triple P reported significantly lower levels of child behaviour problems, parental stress, dysfunctional discipline style and parental conflict scores. The Intervention group participants maintained their gains six months after program completion. The results provided promising evidence for the Level 4 Group Triple P as an effective intervention program for Chinese parents who have preschool aged children with developmental disabilities. Copyright © 2012 Elsevier Ltd. All rights reserved.
Sheehy, Eamon J; Vinardell, Tatiana; Toner, Mary E; Buckley, Conor T; Kelly, Daniel J
2014-01-01
Cartilaginous tissues engineered using mesenchymal stem cells (MSCs) can be leveraged to generate bone in vivo by executing an endochondral program, leading to increased interest in the use of such hypertrophic grafts for the regeneration of osseous defects. During normal skeletogenesis, canals within the developing hypertrophic cartilage play a key role in facilitating endochondral ossification. Inspired by this developmental feature, the objective of this study was to promote endochondral ossification of an engineered cartilaginous construct through modification of scaffold architecture. Our hypothesis was that the introduction of channels into MSC-seeded hydrogels would firstly facilitate the in vitro development of scaled-up hypertrophic cartilaginous tissues, and secondly would accelerate vascularisation and mineralisation of the graft in vivo. MSCs were encapsulated into hydrogels containing either an array of micro-channels, or into non-channelled 'solid' controls, and maintained in culture conditions known to promote a hypertrophic cartilaginous phenotype. Solid constructs accumulated significantly more sGAG and collagen in vitro, while channelled constructs accumulated significantly more calcium. In vivo, the channels acted as conduits for vascularisation and accelerated mineralisation of the engineered graft. Cartilaginous tissue within the channels underwent endochondral ossification, producing lamellar bone surrounding a hematopoietic marrow component. This study highlights the potential of utilising engineering methodologies, inspired by developmental skeletal processes, in order to enhance endochondral bone regeneration strategies.
Sheehy, Eamon J.; Vinardell, Tatiana; Toner, Mary E.; Buckley, Conor T.; Kelly, Daniel J.
2014-01-01
Cartilaginous tissues engineered using mesenchymal stem cells (MSCs) can be leveraged to generate bone in vivo by executing an endochondral program, leading to increased interest in the use of such hypertrophic grafts for the regeneration of osseous defects. During normal skeletogenesis, canals within the developing hypertrophic cartilage play a key role in facilitating endochondral ossification. Inspired by this developmental feature, the objective of this study was to promote endochondral ossification of an engineered cartilaginous construct through modification of scaffold architecture. Our hypothesis was that the introduction of channels into MSC-seeded hydrogels would firstly facilitate the in vitro development of scaled-up hypertrophic cartilaginous tissues, and secondly would accelerate vascularisation and mineralisation of the graft in vivo. MSCs were encapsulated into hydrogels containing either an array of micro-channels, or into non-channelled ‘solid’ controls, and maintained in culture conditions known to promote a hypertrophic cartilaginous phenotype. Solid constructs accumulated significantly more sGAG and collagen in vitro, while channelled constructs accumulated significantly more calcium. In vivo, the channels acted as conduits for vascularisation and accelerated mineralisation of the engineered graft. Cartilaginous tissue within the channels underwent endochondral ossification, producing lamellar bone surrounding a hematopoietic marrow component. This study highlights the potential of utilising engineering methodologies, inspired by developmental skeletal processes, in order to enhance endochondral bone regeneration strategies. PMID:24595316
A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept.
Dong, R G; Welcome, D E; Wu, J Z
2007-11-01
This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is th e biodynamic stressdistributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.
Taylor, Jessica J; Wilson, Samantha M; Sopinka, Natalie M; Hinch, Scott G; Patterson, David A; Cooke, Steven J; Willmore, William G
2015-06-01
Intergenerational effects of stress have been reported in a wide range of taxa; however, few researchers have examined the intergenerational consequences of oxidative stress. Oxidative stress occurs in living organisms when reactive oxygen species remain unquenched by antioxidant defense systems and become detrimental to cells. In fish, it is unknown how maternal oxidative stress and antioxidant capacity influence offspring quality. The semelparous, migratory life history of Pacific salmon (Oncorhynchus spp.) provides a unique opportunity to explore intergenerational effects of oxidative stress. This study examined the effects of population origin on maternal and developing offspring oxidative stress and antioxidant capacity, and elucidated intergenerational relationships among populations of sockeye salmon (Oncorhynchus nerka) with varying migration effort. For three geographically distinct populations of Fraser River sockeye salmon (British Columbia, Canada), antioxidant capacity and oxidative stress were measured in adult female plasma, heart, brain, and liver, as well as in developing offspring until time of emergence. Maternal and offspring oxidative stress and antioxidant capacity varied among populations but patterns were not consistent across tissue/developmental stage. Furthermore, maternal oxidative stress and antioxidant capacity did not affect offspring oxidative stress and antioxidant capacity across any of the developmental stages or populations sampled. Our results revealed that offspring develop their endogenous antioxidant systems at varying rates across populations; however, this variability is overcome by the time of emergence. While offspring may be relying on maternally derived antioxidants in the initial stages of development, they rapidly develop their own antioxidant systems (mainly glutathione) during later stages of development. Copyright © 2015 Elsevier Inc. All rights reserved.
Abnormal stress responsivity in a rodent developmental disruption model of schizophrenia.
Zimmerman, Eric C; Bellaire, Mark; Ewing, Samuel G; Grace, Anthony A
2013-10-01
Although numerous studies have implicated stress in the pathophysiology of schizophrenia, less is known about how the effects of stress interact with genetic, developmental, and/or environmental determinants to promote disease progression. In particular, it has been proposed that in humans, stress exposure in adolescence could combine with a predisposition towards increased stress sensitivity, leading to prodromal symptoms and eventually psychosis. However, the neurobiological substrates for this interaction are not fully characterized. Previous work in our lab has demonstrated that rats born to dams administered with the DNA-methylating agent methylazoxymethanol acetate (MAM) at gestational day 17 exhibit as adults behavioral and anatomical abnormalities consistent with those observed in patients with schizophrenia. Here, we examined behavioral and neuroendocrine responses to stress in the MAM model of schizophrenia. MAM-treated male rats were exposed to acute and repeated footshock stress at prepubertal, peripubteral, and adult ages. Ultrasonic vocalizations (USVs), freezing, and corticosterone responses were quantified. We found that juvenile MAM-treated rats emitted significantly more calls, spent more time vocalizing, emitted calls at a higher rate, and showed more freezing in response to acute footshock stress when compared with their saline (SAL) treated counterparts, and that this difference is not present in older animals. In addition, adolescent MAM-treated animals displayed a blunted HPA axis corticosterone response to acute footshock that did not adapt after 10 days of stress exposure. These data demonstrate abnormal stress responsivity in the MAM model of schizophrenia and suggest that these animals are more sensitive to the effects of stress in youth.
Golenberg, Edward M; West, Nicholas W
2013-06-01
Most models for dioecy in flowering plants assume that dioecy arises directly from hermaphroditism through a series of independent feminizing and masculinizing mutations that become chromosomally linked. However, dioecy appears to evolve most frequently through monoecious grades. The major genetic models do not explain the evolution of unisexual flowers in monoecious and submonoecious populations, nor do they account for environmentally induced sexual plasticity. In this review, we explore the roles of environmental stress and hormones on sex determination, and propose a model that can explain the evolution of dioecy through monoecy, and the mechanisms of environmental sex determination. Environmental stresses elicit hormones that allow plants to mediate the negative effects of the stresses. Many of these same hormones are involved in the regulation of floral developmental genes. Recent studies have elucidated the mechanisms whereby these hormones interact and can act as switchpoints in regulatory pathways. Consequently, differential concentrations of plant hormones can regulate whole developmental pathways, providing a mechanism for differential development within isogenic individuals such as seen in monoecious plants. Sex-determining genes in such systems will evolve to generate clusters of coexpressed suites. Coexpression rather than coinheritance of gender-specific genes will define the sexual developmental fate. Therefore, selection for gender type will drive evolution of the regulatory sequences of such genes rather than their synteny. Subsequent mutations to hyper- or hyposensitive alleles within the hormone response pathway can result in segregating dioecious populations. Simultaneously, such developmental systems will remain sensitive to external stimuli that modify hormone responses.
Impacts of stress and sex hormones on dopamine neurotransmission in the adolescent brain.
Sinclair, Duncan; Purves-Tyson, Tertia D; Allen, Katherine M; Weickert, Cynthia Shannon
2014-04-01
Adolescence is a developmental period of complex neurobiological change and heightened vulnerability to psychiatric illness. As a result, understanding factors such as sex and stress hormones which drive brain changes in adolescence, and how these factors may influence key neurotransmitter systems implicated in psychiatric illness, is paramount. In this review, we outline the impact of sex and stress hormones at adolescence on dopamine neurotransmission, a signaling pathway which is critical to healthy brain function and has been implicated in psychiatric illness. We review normative developmental changes in dopamine, sex hormone, and stress hormone signaling during adolescence and throughout postnatal life, then highlight the interaction of sex and stress hormones and review their impacts on dopamine neurotransmission in the adolescent brain. Adolescence is a time of increased responsiveness to sex and stress hormones, during which the maturing dopaminergic neural circuitry is profoundly influenced by these factors. Testosterone, estrogen, and glucocorticoids interact with each other and have distinct, brain region-specific impacts on dopamine neurotransmission in the adolescent brain, shaping brain maturation and cognitive function in adolescence and adulthood. Some effects of stress/sex hormones on cortical and subcortical dopamine parameters bear similarities with dopaminergic abnormalities seen in schizophrenia, suggesting a possible role for sex/stress hormones at adolescence in influencing risk for psychiatric illness via modulation of dopamine neurotransmission. Stress and sex hormones may prove useful targets in future strategies for modifying risk for psychiatric illness.
ERIC Educational Resources Information Center
Fey, Marc E.; Warren, Steven F.; Brady, Nancy; Finestack, Lizbeth H.; Bredin-Oja, Shelley L.; Fairchild, Martha; Sokol, Shari; Yoder, Paul J.
2006-01-01
Purpose: To evaluate the efficacy of a 6-month course of responsivity education/prelinguistic milieu teaching (RE/PMT) for children with developmental delay and RE/PMT's effects on parenting stress in a randomized clinical trial. Method: Fifty-one children, age 24-33 months, with no more than 10 expressive words or signs, were randomly assigned to…
ERIC Educational Resources Information Center
Robert, Marie; Leblanc, Line; Boyer, Thierry
2015-01-01
Parents of children with developmental disabilities (autism or intellectual disabilities) are more susceptible to stress and have a greater burden of adversity than other parents. Their well-being and satisfaction greatly depend on the system's response of finding them formal support and the help they need. This study proposes an interpretive…
ERIC Educational Resources Information Center
Thackeray, Lisa A.; Eatough, Virginia
2015-01-01
Background: The predominant focus of extant literature exploring maternal experience of developmental disability has been stress, adaptation, efficacy of interventions and the burden of care. Most studies involve mothers of children, with scant attention given to what life is like later. This study qualitatively explores the experience of mothers…
Xiong, Xiaoqin; Luo, Si; Wu, Benli; Wang, Jianwei
2017-02-01
Dimethyl sulfoxide (DMSO), a widely used carrier solvent, can be toxic to test organisms and has species-specific sensitivity. In this study, the developmental toxicity and stress protein responses of DMSO to rare minnow (Gobiocypris rarus) and zebrafish (Danio rerio) with two tests were compared in the early life stage. In the first test, fertilized eggs were exposed to 0%, 0.0001%, 0.001%, 0.01%, 0.1%, 1.0%, 1.5%, and 2.0% v/v of DMSO until 3 days post hatching. In the second test, larvae from 0 to 8 d were exposed to 2% DMSO until 4 days. Our results showed that DMSO was toxic to rare minnow and zebrafish on multiple indexes, and the no-observed-effect concentrations of DMSO in both species were 1.0% and 0.001% for developmental toxicity analysis and stress protein analysis, respectively. Furthermore, rare minnow larvae were more sensitive than zebrafish to DMSO for spinal malformation. The sensitive period for induction of spinal malformation by DMSO was 0-7 d after hatch (dah) for rare minnow and 0-4 dah for zebrafish. Together, these results will provide support to the use of DMSO in ecotoxicological studies using rare minnow and will contribute to a better understanding of the toxicity of DMSO.
Adult Education and National Development: Concepts and Practices in India.
ERIC Educational Resources Information Center
Ministry of Education and Social Welfare, New Delhi (India).
The importance of eradicating adult illiteracy in developing countries as a part of promoting community participation in democracy and in accelerating the rate of national development is treated in the study of adult education in India. Attempts have been made to: link adult education to major developmental and productive activities through…
ERIC Educational Resources Information Center
McGee, Daniel; Vasquez, Pedro; Cajigas, Jesus
2014-01-01
The University of Puerto Rico in Mayaguez (UPRM) has found that there are disadvantages to a semester long remedial mathematics course that is administered during the freshmen year to students with mathematics deficiencies in STEM (Science, Technology, Engineering and Math) programs. Correspondingly, the UPRM designed and implemented an…
Transforming Education Research through Open Video Data Sharing
ERIC Educational Resources Information Center
Gilmore, Rick O.; Adolph, Karen E.; Millman, David S.; Gordon, Andrew
2016-01-01
Open data sharing promises to accelerate the pace of discovery in the developmental and learning sciences, but significant technical, policy, and cultural barriers have limited its adoption. As a result, most research on learning and development remains shrouded in a culture of isolation. Data sharing is the rare exception (Gilmore, 2016). Many…
ERIC Educational Resources Information Center
Neuburger, Jane
2018-01-01
The "NADE Self-Evaluation Guides" are a compendium of best practices in four areas: (1) Tutoring Services; (2) Course-based Learning Assistance; (3) the Teaching & Learning Process; and (4) Developmental Coursework, also recently known as transitional, co-requisite, accelerated, or bridge programs, all of which are…
ERIC Educational Resources Information Center
Golding, Alison; Boes, Claudia; Nordin-Bates, Sanna M.
2016-01-01
The understanding of the significance of movement to learning benefits from advances in neuroscience. This study considered a neurophysiological perspective in relation to the educational theory of Accelerated Learning (AL) for which little empirical evidence exists. Childhood development themes and learning strategies from a…
ERIC Educational Resources Information Center
Fielding, Rob
1989-01-01
Explicates the socio-cultural developmental theories of Vygotsky and Feuerstein which advocate teacher mediated learning in order to stimulate and accelerate development. Implications for art education include the need for the teacher to become involved in the enculturation of the child into the thinking processes and conceptual organization of…
ERIC Educational Resources Information Center
Lam, Chun Bun; Greene, Kaylin M.; McHale, Susan M.
2016-01-01
The developmental course, family correlates, and adjustment implications of youth housework participation from age 8-18 were examined. Mothers, fathers, and 2 siblings from 201 European American families provided questionnaire and/or daily diary data on 6 occasions across 7 years. Multilevel modeling within an accelerated longitudinal design…
Environmental stress increases variability in the expression of dental cusps.
Riga, Alessandro; Belcastro, Maria Giovanna; Moggi-Cecchi, Jacopo
2014-03-01
Teeth are an important model for developmental studies but, despite an extensive literature on the genetics of dental development, little is known about the environmental influences on dental morphology. Here we test whether and to what extent the environment plays a role in producing morphological variation in human teeth. We selected a sample of modern human skulls and used dental enamel hypoplasia as an environmental stress marker to identify two groups with different stress levels, referred to as SG ("stressed" group) and NSG ("nonstressed" group). We collected data on the occurrence and the relative development of 15 morphological traits on upper molars using a standard methodology (ASU-DAS system) and then we compared the frequencies of the traits in the two groups. Overall, the results suggest that (a) stressors like malnutrition and/or systemic diseases have a significant effect on upper molar morphology; (b) stress generates a developmental response which increases the morphological variability of the SG; and (c) the increase in variability is directional, since individuals belonging to the SG have more developed and extra cusps. These results are consistent with the expectations of the current model of dental development. Copyright © 2013 Wiley Periodicals, Inc.
Maternal Prenatal Stress and Infant Regulatory Capacity in Mexican Americans
Lin, Betty; Crnic, Keith A.; Luecken, Linda J.; Gonzales, Nancy A.
2014-01-01
The early postpartum period lays important groundwork for later self-regulation as infants' dispositional traits interact with caregivers' co-regulatory behaviors to produce the earliest forms of self-regulation. Although emerging literature suggests that fetal exposure to maternal stress may be integral in determining child self-regulatory capacity, the complex pathways that characterize these early developmental processes remain unclear. The current study considers these complex, transactional processes in a low income, Mexican American sample. Data were collected from 295 Mexican American infants and their mothers during prenatal, 6- and 12-week postpartum home interviews. Mother reports of stress were obtained prenatally, and mother reports of infant temperament were obtained at 6 weeks. Observer ratings of maternal sensitivity and infant regulatory behaviors were obtained at the 6- and 12-week time points. Study results indicate that prenatal stress predicts higher levels of infant negativity and surgency, both of which directly or interactively predict later engagement in regulatory behaviors. Unexpectedly, prenatal stress also predicted more engagement in orienting, but not self-comforting behaviors. Advancing understandings about the nature of these developmental pathways may have significant implications for targets of early intervention in this high risk population. PMID:25113917
Fisher, Philip A; Gunnar, Megan R; Dozier, Mary; Bruce, Jacqueline; Pears, Katherine C
2006-12-01
Young children in foster care are exposed to high levels of stress. These experiences place foster children at risk for poor social, academic, and mental heath outcomes. The role of adverse events in stimulating neurobiological stress responses presumably plays a role in shaping neural systems that contribute to these problems. Systematic and developmentally well-timed interventions might have the potential to change developmental trajectories and promote resilience. Moreover, understanding how specific dimensions of early adversity affect underlying stress response systems and how alterations in these systems are related to later psychosocial outcomes might facilitate more precise and targeted interventions. Data are drawn from two ongoing randomized trials involving foster infants/toddlers and preschoolers. Consistent with prior animal models of early adversity, these studies have shown that early adversity-particularly neglect, younger age at first foster placement, and higher number of placements-is associated with altered hypothalamic-pituitary-adrenal (HPA) axis function. The interventions under investigation have produced evidence that it is possible to impact many areas that have been negatively affected by early stress, including HPA axis activity, behavior, and attachment to caregivers.
Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs.
Erickson, Gregory M; Makovicky, Peter J; Currie, Philip J; Norell, Mark A; Yerby, Scott A; Brochu, Christopher A
2004-08-12
How evolutionary changes in body size are brought about by variance in developmental timing and/or growth rates (also known as heterochrony) is a topic of considerable interest in evolutionary biology. In particular, extreme size change leading to gigantism occurred within the dinosaurs on multiple occasions. Whether this change was brought about by accelerated growth, delayed maturity or a combination of both processes is unknown. A better understanding of relationships between non-avian dinosaur groups and the newfound capacity to reconstruct their growth curves make it possible to address these questions quantitatively. Here we study growth patterns within the Tyrannosauridae, the best known group of large carnivorous dinosaurs, and determine the developmental means by which Tyrannosaurus rex, weighing 5,000 kg and more, grew to be one of the most enormous terrestrial carnivorous animals ever. T. rex had a maximal growth rate of 2.1 kg d(-1), reached skeletal maturity in two decades and lived for up to 28 years. T. rex's great stature was primarily attained by accelerating growth rates beyond that of its closest relatives.
Chen, Jingchao; Huang, Zhaofeng; Huang, Hongjuan; Wei, Shouhui; Liu, Yan; Jiang, Cuilan; Zhang, Jie; Zhang, Chaoxian
2017-04-21
Goosegrass (Eleusine indica) is one of the most serious annual grassy weeds worldwide, and its evolved herbicide-resistant populations are more difficult to control. Quantitative real-time PCR (qPCR) is a common technique for investigating the resistance mechanism; however, there is as yet no report on the systematic selection of stable reference genes for goosegrass. This study proposed to test the expression stability of 9 candidate reference genes in goosegrass in different tissues and developmental stages and under stress from three types of herbicide. The results show that for different developmental stages and organs (control), eukaryotic initiation factor 4 A (eIF-4) is the most stable reference gene. Chloroplast acetolactate synthase (ALS) is the most stable reference gene under glyphosate stress. Under glufosinate stress, eIF-4 is the best reference gene. Ubiquitin-conjugating enzyme (UCE) is the most stable reference gene under quizalofop-p-ethyl stress. The gene eIF-4 is the recommended reference gene for goosegrass under the stress of all three herbicides. Moreover, pairwise analysis showed that seven reference genes were sufficient to normalize the gene expression data under three herbicides treatment. This study provides a list of reliable reference genes for transcript normalization in goosegrass, which will facilitate resistance mechanism studies in this weed species.
NASA Technical Reports Server (NTRS)
Lathrop, J. W.
1983-01-01
Results of an ongoing research program into the reliability of terrestrial solar cells are presented. Laboratory accelerated testing procedures are used to identify failure/degradation modes which are then related to basic physical, chemical, and metallurgical phenomena. In the most recent tests, ten different types of production cells, both with and without encapsulation, from eight different manufacturers were subjected to a variety of accelerated tests. Results indicated the presence of a number of hitherto undetected failure mechanisms, including Schottky barrier formation at back contacts and loss of adhesion of grid metallization. The mechanism of Schottky barrier formation is explained by hydrogen, formed by the dissociation of water molecules at the contact surface, diffusing to the metal semiconductor interface. This same mechanism accounts for the surprising increase in sensitivity to accelerated stress conditions that was observed in some cells when encapsulated.
Zhang, Qun-Fang; Li, Ying-Wen; Liu, Zhi-Hao; Chen, Qi-Liang
2016-12-01
Mercury (Hg) is a widespread environmental pollutant that can produce severe negative effects on fish even at very low concentrations. However, the mechanisms underlying inorganic Hg-induced oxidative stress and immunotoxicity in the early development stage of fish still need to be clarified. In the present study, zebrafish (Danio rerio) embryos were exposed to different concentrations of Hg 2+ (0, 1, 4 and 16μg/L; added as mercuric chloride, HgCl 2 ) from 2h post-fertilization (hpf) to 168hpf. Developmental parameters and total Hg accumulation were monitored during the exposure period, and antioxidant status and the mRNA expression of genes related to the innate immune system were examined at 168hpf. The results showed that increasing Hg 2+ concentration and time significantly increased total Hg accumulation in zebrafish embryos-larvae. Exposure to 16μg/L Hg 2+ caused developmental damage, including increased mortality and malformation, decreased body length, and delayed hatching period. Meanwhile, HgCl 2 exposure (especially in the 16μg/L Hg 2+ group) induced oxidative stress affecting antioxidant enzyme (CAT, GST and GPX) activities, endogenous GSH and MDA contents, as well as the mRNA levels of genes (cat1, sod1, gstr, gpx1a, nrf2, keap1, hsp70 and mt) encoding antioxidant proteins. Moreover, the transcription levels of several representative genes (il-1β, il-8, il-10, tnfα2, lyz and c3) involved in innate immunity were up-regulated by HgCl 2 exposure, suggesting that inorganic Hg had the potential to induce immunotoxicity. Taken together, the present study provides evidence that waterborne HgCl 2 exposure can induce developmental impairment, oxidative stress and immunotoxicity in the early development stage of fish, which brings insights into the toxicity mechanisms of inorganic Hg in fish. Copyright © 2016 Elsevier B.V. All rights reserved.
Accelerated deflation promotes homogeneous airspace liquid distribution in the edematous lung.
Wu, You; Nguyen, Tam L; Perlman, Carrie E
2017-04-01
Edematous lungs contain regions with heterogeneous alveolar flooding. Liquid is trapped in flooded alveoli by a pressure barrier-higher liquid pressure at the border than in the center of flooded alveoli-that is proportional to surface tension, T Stress is concentrated between aerated and flooded alveoli, to a degree proportional to T Mechanical ventilation, by cyclically increasing T , injuriously exacerbates stress concentrations. Overcoming the pressure barrier to redistribute liquid more homogeneously between alveoli should reduce stress concentration prevalence and ventilation injury. In isolated rat lungs, we test whether accelerated deflation can overcome the pressure barrier and catapult liquid out of flooded alveoli. We generate a local edema model with normal T by microinfusing liquid into surface alveoli. We generate a global edema model with high T by establishing hydrostatic edema, which does not alter T , and then gently ventilating the edematous lungs, which increases T at 15 cmH 2 O transpulmonary pressure by 52%. Thus ventilation of globally edematous lungs increases T , which should increase stress concentrations and, with positive feedback, cause escalating ventilation injury. In the local model, when the pressure barrier is moderate, accelerated deflation causes liquid to escape from flooded alveoli and redistribute more equitably. Flooding heterogeneity tends to decrease. In the global model, accelerated deflation causes liquid escape, but-because of elevated T -the liquid jumps to nearby, aerated alveoli. Flooding heterogeneity is unaltered. In pulmonary edema with normal T , early ventilation with accelerated deflation might reduce the positive feedback mechanism through which ventilation injury increases over time. NEW & NOTEWORTHY We introduce, in the isolated rat lung, a new model of pulmonary edema with elevated surface tension. We first generate hydrostatic edema and then ventilate gently to increase surface tension. We investigate the mechanical mechanisms through which 1 ) ventilation injures edematous lungs and 2 ) ventilation with accelerated deflation might lessen ventilation injury. Copyright © 2017 the American Physiological Society.
Accelerated deflation promotes homogeneous airspace liquid distribution in the edematous lung
Wu, You; Nguyen, Tam L.
2017-01-01
Edematous lungs contain regions with heterogeneous alveolar flooding. Liquid is trapped in flooded alveoli by a pressure barrier—higher liquid pressure at the border than in the center of flooded alveoli—that is proportional to surface tension, T. Stress is concentrated between aerated and flooded alveoli, to a degree proportional to T. Mechanical ventilation, by cyclically increasing T, injuriously exacerbates stress concentrations. Overcoming the pressure barrier to redistribute liquid more homogeneously between alveoli should reduce stress concentration prevalence and ventilation injury. In isolated rat lungs, we test whether accelerated deflation can overcome the pressure barrier and catapult liquid out of flooded alveoli. We generate a local edema model with normal T by microinfusing liquid into surface alveoli. We generate a global edema model with high T by establishing hydrostatic edema, which does not alter T, and then gently ventilating the edematous lungs, which increases T at 15 cmH2O transpulmonary pressure by 52%. Thus ventilation of globally edematous lungs increases T, which should increase stress concentrations and, with positive feedback, cause escalating ventilation injury. In the local model, when the pressure barrier is moderate, accelerated deflation causes liquid to escape from flooded alveoli and redistribute more equitably. Flooding heterogeneity tends to decrease. In the global model, accelerated deflation causes liquid escape, but—because of elevated T—the liquid jumps to nearby, aerated alveoli. Flooding heterogeneity is unaltered. In pulmonary edema with normal T, early ventilation with accelerated deflation might reduce the positive feedback mechanism through which ventilation injury increases over time. NEW & NOTEWORTHY We introduce, in the isolated rat lung, a new model of pulmonary edema with elevated surface tension. We first generate hydrostatic edema and then ventilate gently to increase surface tension. We investigate the mechanical mechanisms through which 1) ventilation injures edematous lungs and 2) ventilation with accelerated deflation might lessen ventilation injury. PMID:27979983
2014-01-01
Background Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Results Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. Conclusions This first day - night study on heat stress adaption of the grapevine berry shows that the transcriptome of fleshy fruits is differentially affected by abiotic stress at night. The present results emphasize the necessity of including different developmental stages and especially several daytime points in transcriptomic studies. PMID:24774299
On Everyday Stress and Coping Strategies among Elementary School Children
ERIC Educational Resources Information Center
Sotardi, Valerie A.
2013-01-01
Elementary school students are confronted with a variety of everyday challenges ranging from comprehension obstacles to interpersonal conflict. Learning to cope effectively with moments of tension is an important part of a child's education because adaptation to stress is likely to influence academic and developmental success. However,…
International Adoption in the U. S: Traumatic Stress and Normal Developmental Responses
ERIC Educational Resources Information Center
Wolfgang, Jeff Drayton
2011-01-01
The purpose of this paper is to present a review of literature on internationally adopted children in the U.S. that provides context, references for normal development, and describes traumatic stress with children. This gives counselors and other professionals who work with young children and families of international adoption a conceptual…
ERIC Educational Resources Information Center
Fox, Jeremy K.; Halpern, Leslie F.; Ryan, Julie L.; Lowe, Kelly A.
2010-01-01
Although the tripartite model reliably distinguishes anxiety and depression in adolescents, it remains unclear how negative affectivity (NA) and positive affectivity (PA) influence developmental pathways to internalizing problems. Based on models which propose that affectivity shapes how youth react to stress, the present study attempted to…
USDA-ARS?s Scientific Manuscript database
Calcium has been shown to increase stress tolerance, enhance fruit firmness and reduce decay. Previously we reported that seven tomato SlSRs encode calcium/calmodulin-regulated proteins, and that their expressions are developmentally regulated during fruit development and ripening, and are also resp...
Posttraumatic Stress Disorder in Individuals with Diagnosis of Autistic Spectrum Disorders
ERIC Educational Resources Information Center
Mehtar, Mohamad; Mukaddes, Nahit Motavalli
2011-01-01
Although children and adolescents with developmental disabilities are said to have higher risks of abuse than those without, trauma and Posttraumatic Stress Disorder (PTSD) are little examined in those diagnosed with Autistic Spectrum Disorders (ASDs). Our study aims to assess trauma types, prevalence, risk factors and symptoms; and PTSD in…
Impaired Perception of Syllable Stress in Children with Dyslexia: A Longitudinal Study
ERIC Educational Resources Information Center
Goswami, Usha; Mead, Natasha; Fosker, Tim; Huss, Martina; Barnes, Lisa; Leong, Victoria
2013-01-01
Prosodic patterning is a key structural element of spoken language. However, the potential role of prosodic awareness in the phonological difficulties that characterise children with developmental dyslexia has been little studied. Here we report the first longitudinal study of sensitivity to syllable stress in children with dyslexia, enabling the…
USDA-ARS?s Scientific Manuscript database
Developmental changes in response to prenatal stressors (PNS) may represent an adaptive strategy to enhance survival traits in the offspring. Yet, PNS could be maladaptive for captive animals, causing anxiety and abnormal social development. Oxytocin (OT) reduces anxiety, whereas OT deficiencies are...
ERIC Educational Resources Information Center
Weichold, Karina; Buttig, Sabine; Silbereisen, Rainer K.
2008-01-01
Individuation, a process whereby adolescents gain autonomy from their parents while maintaining emotional relatedness, is displayed by characteristic styles of verbal exchanges. Negotiating this developmental transition is often stressful for adolescents and their parents. This study deals with the association between pubertal timing,…
Assessing Cardiovascular Responses to Stressors in Individuals with Autism Spectrum Disorders
ERIC Educational Resources Information Center
Groden, June; Goodwin, Matthew S.; Baron, M. Grace; Groden, Gerald; Velicer, Wayne F.; Lipsitt, Lewis P.; Hofmann, Stefan G.; Plummer, Brett
2005-01-01
Characteristics of persons with autism and other developmental disabilities may make this population especially vulnerable to the effects of stress. Prior research on stress and its measurement in this population is reviewed. Using a single-case multi-element design, this study explores the feasibility of measuring cardiovascular responses to four…
Longitudinal and Integrative Tests of Family Stress Model Effects on Mexican Origin Adolescents
ERIC Educational Resources Information Center
White, Rebecca M. B.; Liu, Yu; Nair, Rajni L.; Tein, Jenn-Yun
2015-01-01
The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents'…
ERIC Educational Resources Information Center
Benner, Aprile D.; Kim, Su Yeong
2010-01-01
In this brief report, we investigated whether the Family Stress Model could be replicated with a sample of Chinese American families. Path analyses with 444 adolescents and their parents provided support for the model's generalizability. Specifically, mothers' and fathers' reports of economic status (i.e., income, financial, and job instability)…
Stress Can Be a Good Thing for Blood Formation.
Speck, Nancy A
2016-09-01
Like politics, most developmental signals are local. However, in this issue of Cell Stem Cell, Kwan et al. (2016) and colleagues describe how a stress-induced signal that originates in the zebrafish brain promotes the formation of blood at a distant site, the dorsal aorta. Copyright © 2016 Elsevier Inc. All rights reserved.
Mothers' Stress, Resilience and Early Intervention
ERIC Educational Resources Information Center
Margalit, M.; Kleitman, T.
2006-01-01
The aim of the study was to examine factors that predict maternal stress, reported by mothers whose infants were diagnosed as having developmental disabilities at the beginning of participating in an early intervention programme "Me and My Mommy" and after one year. A second goal was to identify and to portray a subgroup of resilient…
Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents.
Murphy, M O; Cohn, D M; Loria, A S
2017-03-01
The Developmental Origins of Health and Disease (DOHaD) hypothesizes that environmental insults during childhood programs the individual to develop chronic disease in adulthood. Emerging epidemiological data strongly supports that early life stress (ELS) given by the exposure to adverse childhood experiences is regarded as an independent risk factor capable of predicting future risk of cardiovascular disease. Experimental animal models utilizing chronic behavioral stress during postnatal life, specifically maternal separation (MatSep) provides a suitable tool to elucidate molecular mechanisms by which ELS increases the risk to develop cardiovascular disease, including hypertension. The purpose of this review is to highlight current epidemiological studies linking ELS to the development of cardiovascular disease and to discuss the potential molecular mechanisms identified from animal studies. Overall, this review reveals the need for future investigations to further clarify the molecular mechanisms of ELS in order to develop more personalized therapeutics to mitigate the long-term consequences of chronic behavioral stress including cardiovascular and heart disease in adulthood. Copyright © 2016 Elsevier Ltd. All rights reserved.
Batth, Rituraj; Singh, Kapil; Kumari, Sumita; Mustafiz, Ananda
2017-01-01
Abiotic stress and climate change is the major concern for plant growth and crop yield. Abiotic stresses lead to enhanced accumulation of reactive oxygen species (ROS) consequently resulting in cellular damage and major losses in crop yield. One of the major scavengers of ROS is ascorbate (AA) which acts as first line of defense against external oxidants. An enzyme named ascorbate oxidase (AAO) is known to oxidize AA and deleteriously affect the plant system in response to stress. Genome-wide analysis of AAO gene family has led to the identification of five, three, seven, four, and six AAO genes in Oryza sativa, Arabidopsis, Glycine max, Zea mays, and Sorghum bicolor genomes, respectively. Expression profiling of these genes was carried out in response to various abiotic stresses and during various stages of vegetative and reproductive development using publicly available microarray database. Expression analysis in Oryza sativa revealed tissue specific expression of AAO genes wherein few members were exclusively expressed in either root or shoot. These genes were found to be regulated by both developmental cues as well as diverse stress conditions. The qRT-PCR analysis in response to salinity and drought stress in rice shoots revealed OsAAO2 to be the most stress responsive gene. On the other hand, OsAAO3 and OsAAO4 genes showed enhanced expression in roots under salinity/drought stresses. This study provides lead about important stress responsive AAO genes in various crop plants, which could be used to engineer climate resilient crop plants. PMID:28261251
Gerber, Markus; Pühse, Uwe
2008-10-01
Stressful experiences occupy a central role in most etiological models of developmental psychopathology. Stress alone, however, insufficiently explains negative health outcomes. This raises the question why some children and adolescents are more vulnerable to the development of psychopathological symptoms than others. The primary purpose of this research was to demonstrate whether leisure time physical activity and self-esteem protect against stress-induced health problems. The findings are based on a cross-sectional study of 407 Swiss boys and girls (M=14.01 years). All variables are self-reported. Analyses of covariance were applied to test for main and moderator effects. The findings suggest that school-based stress and psychosomatic complaints are important issues during adolescence. The results show that a higher level of psychosomatic complaints accompanies stress. Surprisingly, psychosomatic complaints and physical activity were unrelated. Likewise, no association was found between physical activity and stress. In contrast, students with high self-esteem reported significantly less complaints and a lower extent of perceived stress. Finally, the results do not support the stress-moderation hypothesis. Neither physical activity nor self-esteem buffered against the detrimental effects of school-based stress on psychosomatic health. The findings lend support to previous research with German-speaking samples but are in marked contrast to Anglo-Saxon studies, which generally support the role of physical activity as a moderator of the health-illness relationship. In this investigation, developmental features and methodological limitations may have accounted for the insignificant results.
The ecological origins of snakes as revealed by skull evolution.
Da Silva, Filipe O; Fabre, Anne-Claire; Savriama, Yoland; Ollonen, Joni; Mahlow, Kristin; Herrel, Anthony; Müller, Johannes; Di-Poï, Nicolas
2018-01-25
The ecological origin of snakes remains amongst the most controversial topics in evolution, with three competing hypotheses: fossorial; marine; or terrestrial. Here we use a geometric morphometric approach integrating ecological, phylogenetic, paleontological, and developmental data for building models of skull shape and size evolution and developmental rate changes in squamates. Our large-scale data reveal that whereas the most recent common ancestor of crown snakes had a small skull with a shape undeniably adapted for fossoriality, all snakes plus their sister group derive from a surface-terrestrial form with non-fossorial behavior, thus redirecting the debate toward an underexplored evolutionary scenario. Our comprehensive heterochrony analyses further indicate that snakes later evolved novel craniofacial specializations through global acceleration of skull development. These results highlight the importance of the interplay between natural selection and developmental processes in snake origin and diversification, leading first to invasion of a new habitat and then to subsequent ecological radiations.
Cortisol and DHEA in development and psychopathology.
Kamin, Hayley S; Kertes, Darlene A
2017-03-01
Dehydroepiandrosterone (DHEA) and cortisol are the most abundant hormones of the human fetal and adult adrenals released as end products of a tightly coordinated endocrine response to stress. Together, they mediate short- and long-term stress responses and enable physiological and behavioral adjustments necessary for maintaining homeostasis. Detrimental effects of chronic or repeated elevations in cortisol on behavioral and emotional health are well documented. Evidence for actions of DHEA that offset or oppose those of cortisol has stimulated interest in examining their levels as a ratio, as an alternate index of adrenocortical activity and the net effects of cortisol. Such research necessitates a thorough understanding of the co-actions of these hormones on physiological functioning and in association with developmental outcomes. This review addresses the state of the science in understanding the role of DHEA, cortisol, and their ratio in typical development and developmental psychopathology. A rationale for studying DHEA and cortisol in concert is supported by physiological data on the coordinated synthesis and release of these hormones in the adrenal and by their opposing physiological actions. We then present evidence that researching cortisol and DHEA necessitates a developmental perspective. Age-related changes in DHEA and cortisol are described from the perinatal period through adolescence, along with observed associations of these hormones with developmental psychopathology. Along the way, we identify several major knowledge gaps in the role of DHEA in modulating cortisol in typical development and developmental psychopathology with implications for future research. Copyright © 2016 Elsevier Inc. All rights reserved.
Perinatal Complications and Aging Indicators by Midlife
Caspi, Avshalom; Ambler, Antony; Belsky, Daniel W.; Chapple, Simon; Cohen, Harvey Jay; Israel, Salomon; Poulton, Richie; Ramrakha, Sandhya; Rivera, Christine D.; Sugden, Karen; Williams, Benjamin; Wolke, Dieter; Moffitt, Terrie E.
2014-01-01
BACKGROUND: Perinatal complications predict increased risk for morbidity and early mortality. Evidence of perinatal programming of adult mortality raises the question of what mechanisms embed this long-term effect. We tested a hypothesis related to the theory of developmental origins of health and disease: that perinatal complications assessed at birth predict indicators of accelerated aging by midlife. METHODS: Perinatal complications, including both maternal and neonatal complications, were assessed in the Dunedin Multidisciplinary Health and Development Study cohort (N = 1037), a 38-year, prospective longitudinal study of a representative birth cohort. Two aging indicators were assessed at age 38 years, objectively by leukocyte telomere length (TL) and subjectively by perceived facial age. RESULTS: Perinatal complications predicted both leukocyte TL (β = −0.101; 95% confidence interval, −0.169 to −0.033; P = .004) and perceived age (β = 0.097; 95% confidence interval, 0.029 to 0.165; P = .005) by midlife. We repeated analyses with controls for measures of family history and social risk that could predispose to perinatal complications and accelerated aging, and for measures of poor health taken in between birth and the age-38 follow-up. These covariates attenuated, but did not fully explain the associations observed between perinatal complications and aging indicators. CONCLUSIONS: Our findings provide support for early-life developmental programming by linking newborns’ perinatal complications to accelerated aging at midlife. We observed indications of accelerated aging “inside,” as measured by leukocyte TL, an indicator of cellular aging, and “outside,” as measured by perceived age, an indicator of declining tissue integrity. A better understanding of mechanisms underlying perinatal programming of adult aging is needed. PMID:25349321
Covariant Formulation of Hooke's Law.
ERIC Educational Resources Information Center
Gron, O.
1981-01-01
Introducing a four-vector strain and a four-force stress, Hooke's law is written as a four-vector equation. This formulation is shown to clarify seemingly paradoxical results in connection with uniformly accelerated motion, and rotational motion with angular acceleration. (Author/JN)
Wallingford, Anna K; Loeb, Gregory M
2016-08-01
We investigated the influence of developmental conditions on adult morphology, reproductive arrest, and winter stress tolerance of the invasive pest of small fruit, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Cooler rearing temperatures (15 °C) resulted in larger, darker "winter morph" (WM) adults than "summer morph" flies reared at optimal temperatures (25 °C). Abdominal pigmentation scores and body size measurements of laboratory-reared WMs were similar to those of D. suzukii females captured in late autumn in Geneva, NY. We evaluated reproductive diapause and cold hardiness in live-captured D. suzukii WMs as well as WMs reared in the laboratory from egg to adult under four developmental conditions: static cool temperatures (SWM; 15 °C, 12:12 h L:D), fluctuating temperatures (FWM; 20 °C L: 10 °C D, 12:12 h L:D), and static cool temperatures (15 °C, 12:12 h L:D) followed by posteclosion chilling (CWM; 10 °C) under short-day (SD; 12:12 h L:D) or long-day photoperiods (LD; 16:8 h L:D). Live-captured D. suzukii WMs and CWMs had longer preoviposition times than newly eclosed summer morph adults, indicating a reproductive diapause that was not observed in SWMs or FWMs. Additionally, recovery after acute freeze stress was not different between CWM-SD females and live captured WM females. More 7-d-old CWMs survived 0, -1, or - 3 °C freeze stress than summer morph adults, and more CWM-SD adults survived -3 °C freeze stress than CWM-LD adults. Survival after -3 °C freeze stress was significantly higher in diapausing, CWMs than nondiapausing SWMs and FWMs. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Freeman, D. Carl; Brown, Michelle L.; Duda, Jeffrey J.; Graham, John H.; Emlen, John M.; Krzysik, Anthony J.; Balbach, Harold E.; Kovacic, David A.; Zak, John C.
2004-01-01
We examined net photosynthesis, transpiration, stomatal conductance, and leaf fluctuating asymmetry on two species (Rhus copallinum and Ipomoea pandurata) as indicators of stress at nine sites across a gradient of soil disturbance at Fort Benning, Georgia. There were three sites for each of three disturbance levels. Physical habitat disturbance was caused by activities associated with infantry training, including mechanized elements (tanks and personnel carriers) and foot soldiers. In addition, we examined the influence of prescribed burns and microhabitat effects (within meter‐square quadrats centered about the plant) on these measures of plant stress. Net photosynthesis declined with increasing disturbance in the absence of burning for both species. However, when sites were burned the previous year, net photosynthesis increased with increasing disturbance. Developmental instability in Rhus, as measured by fluctuating asymmetry, also declined with increasing disturbance in the absence of burning but increased with disturbance if sites were burned the previous year. Developmental instability was much less sensitive to burning in Ipomoea and in general was lowest at intermediate disturbance sites. Microenvironmental and microhabitat effects were weakly correlated with measures of plant stress when all sites were combined. However, higher correlations were obtained within site categories, especially when the recent history of prescribed burning was used as a category. Finally, using all of the combined data in a discriminant function analysis allowed us to correctly predict the disturbance level of more than 80% of the plants. Plant stress is responsive to both large‐scale perturbations, such as burning, and microhabitat parameters. Because of this, it is important to include macro‐ and microhabitat parameters when assessing stress. Similarly, we found a combination of developmental and physiological indicators of stress was superior to using them separately.
Perceived Stress at Work Is Associated with Lower Levels of DHEA-S
Lennartsson, Anna-Karin; Theorell, Töres; Rockwood, Alan L.; Kushnir, Mark M.; Jonsdottir, Ingibjörg H.
2013-01-01
Background It is known that long-term psychosocial stress may cause or contribute to different diseases and symptoms and accelerate aging. One of the consequences of prolonged psychosocial stress may be a negative effect on the levels of dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEA-S). The aim of this study is to investigate whether levels of DHEA and DHEA-S differ in individuals who report perceived stress at work compared to individuals who report no perceived stress at work. Methods Morning fasting DHEA-S and DHEA levels were measured in serum in a non-stressed group (n = 40) and a stressed group (n = 41). DHEA and DHEA-S levels were compared between the groups using ANCOVA, controlling for age. Results The mean DHEA-S levels were 23% lower in the subjects who reported stress at work compared to the non-stressed group. Statistical analysis (ANCOVA) showed a significant difference in DHEA-S levels between the groups (p = 0.010). There was no difference in DHEA level between the groups. Conclusions This study indicates that stressed individual have markedly lower levels of DHEA-S. Given the important and beneficial functions of DHEA and DHEA-S, lower levels of DHEA-S may constitute one link between psychosocial stress, ill health and accelerated ageing. PMID:24015247
Perceived stress at work is associated with lower levels of DHEA-S.
Lennartsson, Anna-Karin; Theorell, Töres; Rockwood, Alan L; Kushnir, Mark M; Jonsdottir, Ingibjörg H
2013-01-01
It is known that long-term psychosocial stress may cause or contribute to different diseases and symptoms and accelerate aging. One of the consequences of prolonged psychosocial stress may be a negative effect on the levels of dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEA-S). The aim of this study is to investigate whether levels of DHEA and DHEA-S differ in individuals who report perceived stress at work compared to individuals who report no perceived stress at work. Morning fasting DHEA-S and DHEA levels were measured in serum in a non-stressed group (n = 40) and a stressed group (n = 41). DHEA and DHEA-S levels were compared between the groups using ANCOVA, controlling for age. The mean DHEA-S levels were 23% lower in the subjects who reported stress at work compared to the non-stressed group. Statistical analysis (ANCOVA) showed a significant difference in DHEA-S levels between the groups (p = 0.010). There was no difference in DHEA level between the groups. This study indicates that stressed individual have markedly lower levels of DHEA-S. Given the important and beneficial functions of DHEA and DHEA-S, lower levels of DHEA-S may constitute one link between psychosocial stress, ill health and accelerated ageing.
Rapid effects of humidity acclimation on stress resistance in Drosophila melanogaster.
Aggarwal, Dau Dayal; Ranga, Poonam; Kalra, Bhawna; Parkash, Ravi; Rashkovetsky, Eugenia; Bantis, Leonidas E
2013-09-01
We tested the hypothesis whether developmental acclimation at ecologically relevant humidity regimes (40% and 75% RH) affects desiccation resistance of pre-adults (3rd instar larvae) and adults of Drosophila melanogaster Meigen (Diptera: Drosophilidae). Additionally, we untangled whether drought (40% RH) acclimation affects cold-tolerance in the adults of D. melanogaster. We observed that low humidity (40% RH) acclimated individuals survived significantly longer (1.6-fold) under lethal levels of desiccation stress (0-5% RH) than their counter-replicates acclimated at 75% RH. In contrast to a faster duration of development of 1st and 2nd instar larvae, 3rd instar larvae showed a delayed development at 40% RH as compared to their counterparts grown at 75% RH. Rearing to low humidity conferred an increase in bulk water, hemolymph content and dehydration tolerance, consistent with increase in desiccation resistance for replicates grown at 40% as compared to their counterparts at 75% RH. Further, we found a trade-off between the levels of carbohydrates and body lipid reserves at 40% and 75% RH. Higher levels of carbohydrates sustained longer survival under desiccation stress for individuals developed at 40% RH than their congeners at 75% RH. However, the rate of carbohydrate utilization did not differ between the individuals reared at these contrasting humidity regimes. Interestingly, our results of accelerated failure time (AFT) models showed substantial decreased death rates at a series of low temperatures (0, -2, or -4°C) for replicates acclimated at 40% RH as compared to their counter-parts at 75% RH. Therefore, our findings indicate that development to low humidity conditions constrained on multiple physiological mechanisms of water-balance, and conferred cross-tolerance towards desiccation and cold stress in D. melanogaster. Finally, we suggest that the ability of generalist Drosophila species to tolerate fluctuations in humidity might aid in their existence and abundance under expected changes in moisture level in course of global climate change. Copyright © 2013 Elsevier Inc. All rights reserved.
Coping and Psychological Health of Aging Parents of Adult Children With Developmental Disabilities
Piazza, Vivian E.; Floyd, Frank J.; Mailick, Marsha R.; Greenberg, Jan S.
2015-01-01
Among aging parents (mean age = 65, N = 139) of adults with developmental disabilities, we examined the effectiveness of multiple forms of coping with caregiver burden. As expected, accommodative strategies of adapting to stress (secondary engagement), used frequently in later life, buffered the impact of caregiver burden, whereas disengagement and distraction strategies exacerbated the effects of burden on depression symptoms. Most effects were similar for mothers and fathers, and all coping strategies, including active strategies to reduce stress (primary engagement), had greater effects for the parents with co-resident children. Vulnerability to caregiver burden was greatest when the aging parents with co-resident children used disengagement and distraction coping, but those who used engagement coping were resilient. PMID:24679353
Many human accelerated regions are developmental enhancers
Capra, John A.; Erwin, Genevieve D.; McKinsey, Gabriel; Rubenstein, John L. R.; Pollard, Katherine S.
2013-01-01
The genetic changes underlying the dramatic differences in form and function between humans and other primates are largely unknown, although it is clear that gene regulatory changes play an important role. To identify regulatory sequences with potentially human-specific functions, we and others used comparative genomics to find non-coding regions conserved across mammals that have acquired many sequence changes in humans since divergence from chimpanzees. These regions are good candidates for performing human-specific regulatory functions. Here, we analysed the DNA sequence, evolutionary history, histone modifications, chromatin state and transcription factor (TF) binding sites of a combined set of 2649 non-coding human accelerated regions (ncHARs) and predicted that at least 30% of them function as developmental enhancers. We prioritized the predicted ncHAR enhancers using analysis of TF binding site gain and loss, along with the functional annotations and expression patterns of nearby genes. We then tested both the human and chimpanzee sequence for 29 ncHARs in transgenic mice, and found 24 novel developmental enhancers active in both species, 17 of which had very consistent patterns of activity in specific embryonic tissues. Of these ncHAR enhancers, five drove expression patterns suggestive of different activity for the human and chimpanzee sequence at embryonic day 11.5. The changes to human non-coding DNA in these ncHAR enhancers may modify the complex patterns of gene expression necessary for proper development in a human-specific manner and are thus promising candidates for understanding the genetic basis of human-specific biology. PMID:24218637
Preloading To Accelerate Slow-Crack-Growth Testing
NASA Technical Reports Server (NTRS)
Gyekenyesi, John P.; Choi, Sung R.; Pawlik, Ralph J.
2004-01-01
An accelerated-testing methodology has been developed for measuring the slow-crack-growth (SCG) behavior of brittle materials. Like the prior methodology, the accelerated-testing methodology involves dynamic fatigue ( constant stress-rate) testing, in which a load or a displacement is applied to a specimen at a constant rate. SCG parameters or life prediction parameters needed for designing components made of the same material as that of the specimen are calculated from the relationship between (1) the strength of the material as measured in the test and (2) the applied stress rate used in the test. Despite its simplicity and convenience, dynamic fatigue testing as practiced heretofore has one major drawback: it is extremely time-consuming, especially at low stress rates. The present accelerated methodology reduces the time needed to test a specimen at a given rate of applied load, stress, or displacement. Instead of starting the test from zero applied load or displacement as in the prior methodology, one preloads the specimen and increases the applied load at the specified rate (see Figure 1). One might expect the preload to alter the results of the test and indeed it does, but fortunately, it is possible to account for the effect of the preload in interpreting the results. The accounting is done by calculating the normalized strength (defined as the strength in the presence of preload the strength in the absence of preload) as a function of (1) the preloading factor (defined as the preload stress the strength in the absence of preload) and (2) a SCG parameter, denoted n, that is used in a power-law crack-speed formulation. Figure 2 presents numerical results from this theoretical calculation.
Parenting Stress and Child Behavior Problems: A Transactional Relationship Across Time
Neece, Cameron L.; Green, Shulamite A.; Baker, Bruce L.
2016-01-01
Parenting stress and child behavior problems have been posited to have a transactional effect on each other across development. However, few studies have tested this model empirically. The authors investigated the relationship between parenting stress and child behavior problems from ages 3 to 9 years old among 237 children, 144 of whom were typically developing and 93 who were identified as developmentally delayed. Behavior problems and parenting stress covaried significantly across time for both groups of children. Cross-lagged panel analyses generally supported a bidirectional relationship between parenting stress and child behavior problems for mothers and fathers. PMID:22264112
Longevity factor klotho and chronic psychological stress
Prather, A A; Epel, E S; Arenander, J; Broestl, L; Garay, B I; Wang, D; Dubal, D B
2015-01-01
Chronic psychological stress is associated with accelerated aging and premature morbidity and mortality; however, the biology linking chronic psychological stress and its maladaptive effects remains largely unknown. Klotho is a pleiotropic hormone that regulates the aging process and promotes better brain and body health. Whether klotho is linked to psychosocial stress or its negative impact in humans has not been investigated. To address this gap, we recruited 178 healthy women who were either chronically high-stress maternal caregivers for a child with autism spectrum disorder (n=90) or low-stress control mothers of a typically developing child (n=88). We found that women under high chronic stress displayed significantly lower levels of the longevity hormone klotho compared with low-stress controls (t(176)=2.92, P=0.004; d=0.44), and the decrease among those under high stress was age-dependent. In addition, high-stress caregivers who reported more depressive symptoms displayed even lower klotho levels compared with low-stress participants. These findings provide the first evidence that klotho levels are sensitive to psychosocial stressors and raise the possibility that klotho may serve as a novel biological link connecting stress, depression and risk for accelerated disease development. Furthermore, these findings have important implications for understanding the plasticity of the aging process and may represent a therapeutic target for mitigating the deleterious effects of chronic psychological stress on health and well-being. PMID:26080320
ERIC Educational Resources Information Center
Edgecombe, Nikki; Jaggars, Shanna Smith; Baker, Elaine DeLott; Bailey, Thomas
2013-01-01
Originally designed for students who test into at least two levels of developmental education in a particular subject area, FastStart is a compressed course program model launched in 2005 at the Community College of Denver (CCD). The program combines multiple semester-length courses into a single intensive semester, while providing case…
Gender in Adolescent Autonomy: Distinction between Boys and Girls Accelerates at 16 Years of Age
ERIC Educational Resources Information Center
Fleming, Manuela
2005-01-01
Introduction: Autonomy is a major developmental feature of adolescents. Its success mediates transition into adulthood. It involves a number of psychological parameters, including desire, conflict with parents and actual achievement. Method: How male and female adolescents view autonomy was investigated in a large sample of 12-17 year-old…
Transforming Community College Education at The City University of New York
ERIC Educational Resources Information Center
Schmidt, Benno
2013-01-01
The City University of New York (CUNY) developed and implemented two evidence-based, educational initiatives at its community colleges. Accelerated Study in Associate Programs (ASAP), on six campuses, helped 55 percent of students who enter with one or two developmental needs earn an associate degree within three years. This compares with 20…
The Effects of an Intensive Postsecondary Transition Program on College Readiness for Adult Learners
ERIC Educational Resources Information Center
Kallison, James M., Jr.
2017-01-01
Postsecondary transition programs have emerged to prepare adult learners to enter college with either limited or no remediation work needed in developmental education. This article examines the results of a pilot study, in which participants (ages 20 years and older who held GED® credentials or high school degrees) received accelerated instruction…
ERIC Educational Resources Information Center
Smith, Regina O.
2014-01-01
Research into the best practices for basic skills education, national bridge programs, the new GED® assessment, and accelerated developmental education indicated that contextualized instruction was most effective when preparing adult literacy students for college and work. Nevertheless, "remedial pedagogy" with a sole focus on the…
Sleep EEG Fingerprints Reveal Accelerated Thalamocortical Oscillatory Dynamics in Williams Syndrome
ERIC Educational Resources Information Center
Bodizs, Robert; Gombos, Ferenc; Kovacs, Ilona
2012-01-01
Sleep EEG alterations are emerging features of several developmental disabilities, but detailed quantitative EEG data on the sleep phenotype of patients with Williams syndrome (WS, 7q11.23 microdeletion) is still lacking. Based on laboratory (Study I) and home sleep records (Study II) here we report WS-related features of the patterns of…
5 CFR 9901.345 - Accelerated Compensation for Developmental Positions (ACDP).
Code of Federal Regulations, 2011 CFR
2011-01-01
... applicable control point, unless the criteria for exceeding the control point are met. (f) To qualify for an ACDP, an employee must have a rating of record of Level 3 (or equivalent non-NSPS rating of record) or... performing at the equivalent of Level 3 or higher. This performance assessment does not constitute a rating...
5 CFR 9901.345 - Accelerated Compensation for Developmental Positions (ACDP).
Code of Federal Regulations, 2010 CFR
2010-01-01
... applicable control point, unless the criteria for exceeding the control point are met. (f) To qualify for an ACDP, an employee must have a rating of record of Level 3 (or equivalent non-NSPS rating of record) or... performing at the equivalent of Level 3 or higher. This performance assessment does not constitute a rating...
DeWitte, Sharon N
2018-01-01
Previous research revealed declines in survivorship in London before the Black Death (c. 1346-1353), and improvements in survivorship following the epidemic. These trends indicate that there were declines in general levels of health before the Black Death and improvements thereof afterwards. This study expands on previous research by examining whether changes in survivorship were consistent between the sexes, and how patterns of developmental stress markers changed before and after the Black Death. This study uses samples from London cemeteries dated to one of three periods: Early Pre-Black Death (1000-1200 AD, n = 255), Late Pre-Black Death (1200-1250 AD, n = 247), or Post-Black Death (1350-1540 AD n = 329). Temporal trends in survivorship are assessed via Kaplan-Meier survival analysis, and trends in tibial length (as a proxy for stature) and linear enamel hypoplasia (LEH) are assessed using t-tests and Chi-square tests, respectively. Survivorship for both sexes decreased before the Black Death and increased afterwards. For males, LEH frequencies increased and stature decreased before the epidemic, and LEH declined and stature increased after the Black Death. For females, the only significant change with respect to developmental stress markers was a decrease in stature after the Black Death. These results might reflect variation between the sexes in sensitivity to stressors, the effects of nutrition on pubertal timing, disproportionate access to dietary resources for males in the aftermath of the Black Death, the disproportionate deaths of frail individuals during the epidemic, or some combination of these factors. © 2017 Wiley Periodicals, Inc.
Neece, Cameron L
2014-03-01
Parents of children with developmental delays (DD) typically report elevated levels of parental stress compared with parents of typically developing children. Children with DD are also at high risk for exhibiting significant behaviour problems. Parental stress has been shown to impact the development of these behaviour problems; however, it is rarely addressed in interventions aimed at reducing child behaviour problems. The current study examined the efficacy of mindfulness-based stress reduction (MBSR) for parents of children with DD by investigating whether this intervention is effective in reducing parenting stress and whether decreases in parenting stress lead to reductions in behaviour problems among children with DD. Forty six parents of children with DD were randomly assigned to an immediate treatment or wait list-control group. Participants completed questionnaires assessing parental stress and child behaviour problems at intake and at a second assessment, which took place after only the immediate treatment group had received the MBSR. Parents who participated in MBSR reported significantly less stress and depression as well as greater life satisfaction compared with wait list-control parents. Regarding child outcomes, children whose parents participated in MBSR were reported to have fewer behaviour problems following the intervention, specifically in the areas of attention problems and ADHD symptomatology. Results indicated that MBSR may be an effective intervention for ameliorating parental stress and mental health problems among parents of children with DD. Additionally, these benefits may 'spill over' and improve behaviour challenges among these children. © 2013 John Wiley & Sons Ltd.
Hetz, Jennifer A; Menzies, Brandon R; Shaw, Geoffrey; Stefanidis, Aneta; Cowley, Michael A; Renfree, Marilyn B
2016-06-15
When 60-day-old tammar wallaby pouch young (Macropus eugenii) are fostered to mothers at 120 days of lactation, their growth, developmental rate and maturation of their GH/IGF axes are markedly accelerated. To determine the effect of fostering on energy intake, body composition and fat accretion, we first measured total body fat and lean mass in these young. Next, we mimicked the triglyceride oleic and palmitic acid composition of 120-day milk by supplementing 60 day young with these fatty acids and comparing their growth with that of growth accelerated young. There was no difference in the weight or growth axis maturation of supplemented young but there was significantly more body fat in these and in the growth-accelerated fostered young than in controls. We conclude that the accelerated growth and GH/IGF axis maturation observed previously in fostered young is most likely due to increased milk consumption and earlier access to specific nutrients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Medical Standards for Experimental Human Use in Acceleration Stress Research
1983-01-01
or re- teroposterior and lateral X-rays of the cervical , thoracic, sources, we consider a positive treadmill test to be dis- and lumbar spine. These...Gz stress. The requirement for a complete cervical , thoracic and dividuals who developed significant stress dysrhythmias lumbar spine X-ray series...hematoma h. Hernia Ill. Cardiac Stress: a. Dywrhythmla (Tachyarrhythmias and Bradyarrhythmim) b. Heart blocks c. Stress caadlomyopmt U244 Awono. spme
Ground Motion Prediction Equations Empowered by Stress Drop Measurement
NASA Astrophysics Data System (ADS)
Miyake, H.; Oth, A.
2015-12-01
Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.
Phonological Skills, Visual Attention Span, and Visual Stress in Developmental Dyslexia
ERIC Educational Resources Information Center
Saksida, Amanda; Iannuzzi, Stéphanie; Bogliotti, Caroline; Chaix, Yves; Démonet, Jean-François; Bricout, Laure; Billard, Catherine; Nguyen-Morel, Marie-Ange; Le Heuzey, Marie-France; Soares-Boucaud, Isabelle; George, Florence; Ziegler, Johannes C.; Ramus, Franck
2016-01-01
In this study, we concurrently investigated 3 possible causes of dyslexia--a phonological deficit, visual stress, and a reduced visual attention span--in a large population of 164 dyslexic and 118 control French children, aged between 8 and 13 years old. We found that most dyslexic children showed a phonological deficit, either in terms of…
Work Stress, Burnout, and Social and Personal Resources among Direct Care Workers
ERIC Educational Resources Information Center
Gray-Stanley, Jennifer A.; Muramatsu, Naoko
2011-01-01
Work stress is endemic among direct care workers (DCWs) who serve people with intellectual and developmental disabilities. Social resources, such as work social support, and personal resources, such as an internal locus of control, may help DCWs perceive work overload and other work-related stressors as less threatening and galvanize them to cope…
Seedling growth characteristics relates to the staygreen trait and dhurrin levels in sorghum
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...
ERIC Educational Resources Information Center
Maheau, Marissa E.; Ressler, Kerry J.
2017-01-01
The manipulation of neural plasticity as a means of intervening in the onset and progression of stress-related disorders retains its appeal for many researchers, despite our limited success in translating such interventions from the laboratory to the clinic. Given the challenges of identifying individual genetic variants that confer increased risk…
Exploring the Dynamics of Development and Evolution: Comment on Blair and Raver (2012)
ERIC Educational Resources Information Center
Lickliter, Robert
2012-01-01
Blair and Raver (2012) have provided an organism-in-environment conceptualization of the development of stress response physiology and its relation to the development of self-regulation. They argue that we must consider the context in which self-regulation and stress reactivity occur to understand their implications for developmental outcome. More…
When the Job Has Lost Its Appeal: Intentions to Quit among Direct Care Workers
ERIC Educational Resources Information Center
Gray, Jennifer A.; Muramatsu, Naoko
2013-01-01
Background: Previous research indicates that work stress contributes to intentions to quit among direct care workers (DCWs) who provide services to people with intellectual and developmental disability (IDD). Though resources can help DCWs cope and remain in a job, little is known about how various dimensions of work stress and resources (social…
ERIC Educational Resources Information Center
Marcovitch, Sharon; And Others
Parental stress and supports, child temperament and mother-child interaction in free play were assessed in three groups of families of delayed preschoolers: 40 children with Down's Syndrome, 29 children with neurological impairments, and 40 children with delayed development of unknown etiology. In addition to a number of instruments completed by…
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...
ERIC Educational Resources Information Center
Richards, Susan; Goswami, Usha
2015-01-01
Purpose: We investigated whether impaired acoustic processing is a factor in developmental language disorders. The amplitude envelope of the speech signal is known to be important in language processing. We examined whether impaired perception of amplitude envelope rise time is related to impaired perception of lexical and phrasal stress in…
Self-Esteem and Hopelessness, and Resiliency: An Exploratory Study of Adolescents in Turkey
ERIC Educational Resources Information Center
Karatas, Zeynep; Cakar, Firdevs Savi
2011-01-01
Adolescence is a time of rapid development and change. In this developmental period, adolescents have to struggle with a large number of stress factors. In this process resilience is important to have as an adaptive, stress-resistant personal quality. The recent research considers that numerous factors contribute to resilience in adolescents; the…
Incorporating Children's Lives into a Life Course Perspective on Stress and Mental Health
ERIC Educational Resources Information Center
Avison, William R.
2010-01-01
Emerging themes in demography, developmental medicine, and psychiatry suggest that a comprehensive understanding of mental health across the life course requires that we incorporate the lives of children into our research. If we can learn more about the ways in which the stress process unfolds for children, we will gain important insights into the…
Parasite Prevalence and the Distribution of Intelligence among the States of the USA
ERIC Educational Resources Information Center
Eppig, Christopher; Fincher, Corey L.; Thornhill, Randy
2011-01-01
In this study, we tested the parasite-stress hypothesis for the distribution of intelligence among the USA states: the hypothesis proposes that intelligence emerges from a developmental trade-off between maximizing brain vs. immune function. From this we predicted that among the USA states where infectious disease stress was high, average…
ERIC Educational Resources Information Center
Schneider, Mary L.; Moore, Colleen F.; Gajewski, Lisa L.; Larson, Julie A.; Roberts, Andrew D.; Converse, Alexander K.; DeJesus, Onofre T.
2008-01-01
Disrupted sensory processing, characterized by over- or underresponsiveness to environmental stimuli, has been reported in children with a variety of developmental disabilities. This study examined the effects of prenatal stress and moderate-level prenatal alcohol exposure on tactile sensitivity and its relationship to striatal dopamine system…
Stress and Deep Structure: A Measure of Language Acquisition, Grades K-6.
ERIC Educational Resources Information Center
Milner, Joseph O.
A study was undertaken to see whether developmental patterns of language acquisition could be discovered in children beyond age five. Specifically, the study attempted to uncover a pattern in the development of the skill of stress interpretation, or the understanding of the effect of emphasis of a particular word on the deep structure of the…
Roles of Position, Stress, and Proficiency in L2 Children's Spelling: A Developmental Perspective
ERIC Educational Resources Information Center
Hong, Su Chin; Chen, Shu Hui
2011-01-01
This study investigated the roles of phoneme position, stress, and proficiency in L2 spelling development by Taiwanese students learning English as a Foreign Language (EFL), an alphabetic writing system typologically different from the learners' L1 logographic system. Structured nonword spelling tests were administered to EFL sixth-graders with…
Parental Perceptions of Family Adjustment in Childhood Developmental Disabilities
ERIC Educational Resources Information Center
Thompson, Sandra; Hiebert-Murphy, Diane; Trute, Barry
2013-01-01
Based on the adjustment phase of the double ABC-X model of family stress (McCubbin and Patterson, 1983) this study examined the impact of parenting stress, positive appraisal of the impact of child disability on the family, and parental self-esteem on parental perceptions of family adjustment in families of children with disabilities. For mothers,…
Seizures and pain uncertainty associated with parenting stress and Rett syndrome.
Byiers, Breanne J; Tervo, Raymond C; Feyma, Timothy J; Symons, Frank J
2014-04-01
Data were collected parenting stress, adaptive behavior, pain, and health issues from the caregivers of 35 girls and women with Rett syndrome (mean age = 20.3). A majority (60%) of parents reported stress in the clinical range on at least 1 subscale of the Parenting Stress Index-Short Form. Seizures and uncertainty about their daughter's gastrointestinal pain experience were significantly associated with higher levels of parenting stress. No other child factors (adaptive behavior, age, residential status) were significantly related to parenting stress. Factors related to chronic health concerns (seizures, ambiguous pain presentation) may be important when considering family stress issues in relation to general outcomes for girls with Rett syndrome and related developmental disorders.
BrainAGE score indicates accelerated brain aging in schizophrenia, but not bipolar disorder.
Nenadić, Igor; Dietzek, Maren; Langbein, Kerstin; Sauer, Heinrich; Gaser, Christian
2017-08-30
BrainAGE (brain age gap estimation) is a novel morphometric parameter providing a univariate score derived from multivariate voxel-wise analyses. It uses a machine learning approach and can be used to analyse deviation from physiological developmental or aging-related trajectories. Using structural MRI data and BrainAGE quantification of acceleration or deceleration of in individual aging, we analysed data from 45 schizophrenia patients, 22 bipolar I disorder patients (mostly with previous psychotic symptoms / episodes), and 70 healthy controls. We found significantly higher BrainAGE scores in schizophrenia, but not bipolar disorder patients. Our findings indicate significantly accelerated brain structural aging in schizophrenia. This suggests, that despite the conceptualisation of schizophrenia as a neurodevelopmental disorder, there might be an additional progressive pathogenic component. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.
Protective actions of melatonin and growth hormone on the aged cardiovascular system.
Paredes, Sergio D; Forman, Katherine A; García, Cruz; Vara, Elena; Escames, Germaine; Tresguerres, Jesús A F
2014-05-01
Epidemiological studies indicate that certain aspects of lifestyle and genetics act as risk factors for a variety of cardiovascular disorders, including coronary disease, hypertension, heart failure and stroke. Aging, however, appears to be the major contributor for morbidity and mortality of the impaired cardiovascular system. Growth hormone (GH) and melatonin seem to prevent cardiac aging, as they contribute to the recovery of several physiological parameters affected by age. These hormones exhibit antioxidant properties and decrease oxidative stress and apoptosis. This paper summarizes a set of studies related to the potential role that therapy with GH and melatonin may play in the protection of the altered cardiac function due to aging, with a focus on experiments performed in our laboratory using the senescence-accelerated mouse as an aging model. In general, we observed significantly increased inflammation, oxidative stress and apoptosis markers in hearts from senescence-accelerated prone 10-month-old animals compared to 2-month-old controls, while anti-inflammatory and antiapoptotic markers as well as endothelial nitric oxide synthase were decreased. Senescence-accelerated resistant animals showed no significant changes with age. GH or melatonin treatment prevented the age-dependent cardiac alterations observed in the senescence-accelerated prone group. Combined administration of GH plus melatonin reduced the age-related changes in senescence-accelerated prone hearts in an additive fashion that was different to that displayed when administered alone. GH and melatonin may be potential agents for counteracting oxidative stress, apoptosis and inflammation in the aging heart.
Learning To Breathe: Developmental Phase Transitions in Oxygen Status.
Considine, Michael J; Diaz-Vivancos, Pedro; Kerchev, Pavel; Signorelli, Santiago; Agudelo-Romero, Patricia; Gibbs, Daniel J; Foyer, Christine H
2017-02-01
Plants are developmentally disposed to significant changes in oxygen availability, but our understanding of the importance of hypoxia is almost entirely limited to stress biology. Differential patterns of the abundance of oxygen, nitric oxide ( • NO), and reactive oxygen species (ROS), as well as of redox potential, occur in organs and meristems, and examples are emerging in the literature of mechanistic relationships of these to development. We describe here the convergence of these cues in meristematic and reproductive tissues, and discuss the evidence for regulated hypoxic niches within which oxygen-, ROS-, • NO-, and redox-dependent signalling curate developmental transitions in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.
Developmental Programming, a Pathway to Disease
Cardoso, Rodolfo C.; Puttabyatappa, Muraly
2016-01-01
Accumulating evidence suggests that insults occurring during the perinatal period alter the developmental trajectory of the fetus/offspring leading to long-term detrimental outcomes that often culminate in adult pathologies. These perinatal insults include maternal/fetal disease states, nutritional deficits/excess, stress, lifestyle choices, exposure to environmental chemicals, and medical interventions. In addition to reviewing the various insults that contribute to developmental programming and the benefits of animal models in addressing underlying mechanisms, this review focuses on the commonalities in disease outcomes stemming from various insults, the convergence of mechanistic pathways via which various insults can lead to common outcomes, and identifies the knowledge gaps in the field and future directions. PMID:26859334
BBU design of linear induction accelerator cells for radiography application
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shang, C.C.; Chen, Y.J.; Gaporaso, G.J.
1997-05-06
There is an ongoing effort to develop accelerating modules for high-current electron accelerators for advanced radiography application. Accelerating modules with low beam-cavity coupling impedances along with gap designs with acceptable field stresses comprise a set of fundamental design criteria. We examine improved cell designs which have been developed for accelerator application in several radiographic operating regimes. We evaluate interaction impedances, analyze the effects of beam structure coupling on beam dynamics (beam break-up instability and corkscrew motion). We also provide estimates of coupling through interesting new high-gradient insulators and evaluate their potential future application in induction cells.
NASA Technical Reports Server (NTRS)
Davis, C. W.; Lathrop, J. W.
1985-01-01
Attention is given to the construction, calibration, and performance of a repeatable measurement system for use in conjunction with the accelerated stress testing of a-Si:H cells. A filtered diode array is utilized to approximate the spectral response of any type of solar cell in discrete portions of the spectrum. It is noted that in order to achieve the necessary degree of overall repeatability, it is necessary to pay particular attention to methods of contacting and positioning the cells.
NASA Technical Reports Server (NTRS)
Kohl, Randall Lee
1987-01-01
Orally administered metoclopramide (REGLAN) at doses of 10 or 20 mg, 75 min prior to either stressful linear acceleration (parabolic flight) or cross-coupled accelerative semicircular canal stimulation in a rotating chair was evaluated for its ability to prevent emesis or nausea II, respectively. Although metoclopramide is an effective antiemetic agent that enhances gastric emptying and prevents cancer chemotherapy-induced emesis, it was not possible to demonstrate any significant (p less than 0.05) effects of this drug on motion sickness.
Yoshimoto, Sazu; Babygirija, Reji; Dobner, Anthony; Ludwig, Kirk; Takahashi, Toku
2012-05-01
Disorders of colonic motility may contribute to symptoms in patients with irritable bowel syndrome (IBS), and stress is widely believed to play a major role in developing IBS. Stress increases corticotropin releasing factor (CRF) of the hypothalamus, resulting in acceleration of colonic transit in rodents. In contrast, hypothalamic oxytocin (OXT) has an anti-stress effect via inhibiting CRF expression and hypothalamic-pituitary-adrenal axis activity. Although transcutaneous electrical nerve stimulation (TENS) and acupuncture have been shown to have anti-stress effects, the mechanism of the beneficial effects remains unknown. We tested the hypothesis that TENS upregulates hypothalamic OXT expression resulting in reduced CRF expression and restoration of colonic dysmotility in response to chronic stress. Male SD rats received different types of stressors for seven consecutive days (chronic heterotypic stress). TENS was applied to the bilateral hind limbs every other day before stress loading. Another group of rats did not receive TENS treatment. TENS significantly attenuated accelerated colonic transit induced by chronic heterotypic stress, which was antagonized by a central injection of an OXT antagonist. Immunohistochemical study showed that TENS increased OXT expression and decreased CRF expression at the paraventricular nucleus (PVN) following chronic heterotypic stress. It is suggested that TENS upregulates hypothalamic OXT expression which acts as an anti-stressor agent and mediates restored colonic dysmotility following chronic stress. TENS may be useful to treat gastrointestinal symptoms associated with stress.
Rodriguez, Christina M; Richardson, Michael J
2007-11-01
Progress in the child maltreatment field depends on refinements in leading models. This study examines aspects of social information processing theory (Milner, 2000) in predicting physical maltreatment risk in a community sample. Consistent with this theory, selected preexisting schema (external locus-of-control orientation, inappropriate developmental expectations, low empathic perspective-taking ability, and low perceived attachment relationship to child) were expected to predict child abuse risk beyond contextual factors (parenting stress and anger expression). Based on 115 parents' self-report, results from this study support cognitive factors that predict abuse risk (with locus of control, perceived attachment, or empathy predicting different abuse risk measures, but not developmental expectations), although the broad contextual factors involving negative affectivity and stress were consistent predictors across abuse risk markers. Findings are discussed with regard to implications for future model evaluations, with indications the model may apply to other forms of maltreatment, such as psychological maltreatment or neglect.
Gaur, Himanshu; Purushothaman, Srinithi; Pullaguri, Narasimha; Bhargava, Yogesh; Bhargava, Anamika
2018-07-20
Sodium benzoate (SB) is a common food preservative. Its FDA described safety limit is 1000 ppm. Lately, increased use of SB has prompted investigations regarding its effects on biological systems. Data regarding toxicity of SB is divergent and controversial with studies reporting both harmful and beneficial effects. Therefore, we did a systematic dose dependent toxicity study of SB using zebrafish vertebrate animal model. We also investigated oxidative stress and anxiety-like behaviour in zebrafish larva treated with SB. Our results indicate that SB induced developmental (delayed hatching), morphological (pericardial edema, yolk sac edema and tail bending), biochemical (oxidative stress) and behavioural (anxiety-like behaviour) abnormalities in developing zebrafish larva. LC 50 of SB induced toxicity was approximately 400 ppm after 48 h of SB exposure. Our study strongly supports its harmful effects on vertebrates at increasing doses. Thus, we suggest caution in the excessive use of this preservative in processed and convenience foods. Copyright © 2018 Elsevier Inc. All rights reserved.
Mechanical analysis of a heat-shock induced developmental defect
NASA Astrophysics Data System (ADS)
Crews, Sarah M.; McCleery, W. Tyler; Hutson, M. Shane
2014-03-01
Embryonic development in Drosophila is a complex process involving coordinated movements of mechanically interacting tissues. Perturbing this system with a transient heat shock can result in a number of developmental defects. In particular, a heat shock applied during the earliest morphogenetic movements of gastrulation can lead to apparent recovery, but then subsequent morphogenetic failure 5-6 hours later during germ band retraction. The process of germ band retraction requires an intact amnioserosa - a single layered extra-embryonic epithelial tissue - and heat shock at gastrulation can induce the later opening of holes in the amnioserosa. These holes are highly correlated with failures of germ band retraction. These holes could be caused by a combination of mechanical weakness in the amnioserosa or local increases in mechanical stress. Here, we assess the role of mechanical stress using confocal imaging to compare cell and tissue morphology in the amnioserosa of normal and heat-shocked embryos and laser hole drilling to map the stress field around the times and locations at which heat-shock induced holes open.
Pasch, Bret; Abbasi, Mustafa Z; Wilson, Macey; Zhao, Daniel; Searle, Jeremy B; Webster, Michael S; Rice, Aaron N
2016-04-01
Nutritional stress can have lasting impacts on the development of traits involved in vocal production. Cross-fostering experiments are often used to examine the propensity for vocal learning in a variety of taxa, but few studies assess the influence of malnourishment that can occur as a byproduct of this technique. In this study, we reciprocally cross-fostered sister taxa of voluble grasshopper mice (genus Onychomys) to explore their propensity for vocal learning. Vocalizations of Onychomys leucogaster did not differ between control and cross-fostered animals, but cross-fostered Onychomys arenicola produced vocalizations that were higher in frequency in a direction away from tutors. These same animals exhibited a transient reduction in body mass early in development, indicative of malnutrition. Our findings simultaneously refute vocal learning and support the developmental stress hypothesis to highlight the importance of early ontogeny on the production of vocalizations later in life. Copyright © 2016 Elsevier Inc. All rights reserved.
Elephants born in the high stress season have faster reproductive ageing
Mumby, Hannah S.; Mar, Khyne U.; Hayward, Adam D.; Htut, Win; Htut-Aung, Ye; Lummaa, Virpi
2015-01-01
Senescent declines in reproduction and survival are found across the tree of life, but little is known of the factors causing individual variation in reproductive ageing rates. One contributor may be variation in early developmental conditions, but only a few studies quantify the effects of early environment on reproductive ageing and none concern comparably long-lived species to humans. We determine the effects of ‘stressful’ birth conditions on lifetime reproduction in a large semi-captive population of Asian elephants (Elephas maximus). We categorise birth month into stressful vs. not-stressful periods based on longitudinal measures of glucocorticoid metabolites in reproductive-aged females, which peak during heavy workload and the start of the monsoon in June-August. Females born in these months exhibit faster reproductive senescence in adulthood and have significantly reduced lifetime reproductive success than their counterparts born at other times of year. Improving developmental conditions could therefore delay reproductive ageing in species as long-lived as humans. PMID:26365592