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Sample records for maturation plasticity cshl

  1. Developmental plasticity in child growth and maturation.

    PubMed

    Hochberg, Ze'ev

    2011-01-01

    The ability of a given genotype to produce different phenotypes in response to different environments is termed "plasticity," and is part of the organism's "adaptability" to environmental cues. The expressions of suites of genes, particularly during development or life history transitions, probably underlie the fundamental plasticity of an organism. Plasticity in developmental programming has evolved in order to provide the best chances of survival and reproductive success to organisms under changing environments. Environmental conditions that are experienced in early life can profoundly influence human biology, child growth and maturation, and long-term health and longevity. Developmental origins of health and disease and life history transitions are purported to use placental, nutritional, and endocrine cues for setting long-term biological, mental, and behavioral strategies for child growth and maturation in response to local ecological and/or social conditions. The window of developmental plasticity extends from conception to early childhood, and even beyond to the transition from juvenility to adolescence, and could be transmitted transgenerationally. It involves epigenetic responses to environmental changes, which exert their effects during life history phase transitions.

  2. Activity-dependent PSA expression regulates inhibitory maturation and onset of critical period plasticity.

    PubMed

    Di Cristo, Graziella; Chattopadhyaya, Bidisha; Kuhlman, Sandra J; Fu, Yu; Bélanger, Marie-Claude; Wu, Cai Zhi; Rutishauser, Urs; Maffei, Lamberto; Huang, Z Josh

    2007-12-01

    Functional maturation of GABAergic innervation in the developing visual cortex is regulated by neural activity and sensory inputs and in turn influences the critical period of ocular dominance plasticity. Here we show that polysialic acid (PSA), presented by the neural cell adhesion molecule, has a role in the maturation of GABAergic innervation and ocular dominance plasticity. Concentrations of PSA significantly decline shortly after eye opening in the adolescent mouse visual cortex; this decline is hindered by visual deprivation. The developmental and activity-dependent regulation of PSA expression is inversely correlated with the maturation of GABAergic innervation. Premature removal of PSA in visual cortex results in precocious maturation of perisomatic innervation by basket interneurons, enhanced inhibitory synaptic transmission, and earlier onset of ocular dominance plasticity. The developmental and activity-dependent decline of PSA expression therefore regulates the timing of the maturation of GABAergic inhibition and the onset of ocular dominance plasticity.

  3. Plastics: Still young, but having a mature impact

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plastic is used in every aspect of our lives, from the morning toothbrush to the garbage bag that is carried out at the end of the day. Plastics are also used in agriculture (e.g. soil fumigation, produce shipping and storage). This editorial examines the current plastic recycling statistics and exa...

  4. BDNF regulates the maturation of inhibition and the critical period of plasticity in mouse visual cortex.

    PubMed

    Huang, Z J; Kirkwood, A; Pizzorusso, T; Porciatti, V; Morales, B; Bear, M F; Maffei, L; Tonegawa, S

    1999-09-17

    Maturation of the visual cortex is influenced by visual experience during an early postnatal period. The factors that regulate such a critical period remain unclear. We examined the maturation and plasticity of the visual cortex in transgenic mice in which the postnatal rise of brain-derived neurotrophic factor (BDNF) was accelerated. In these mice, the maturation of GABAergic innervation and inhibition was accelerated. Furthermore, the age-dependent decline of cortical long-term potentiation induced by white matter stimulation, a form of synaptic plasticity sensitive to cortical inhibition, occurred earlier. Finally, transgenic mice showed a precocious development of visual acuity and an earlier termination of the critical period for ocular dominance plasticity. We propose that BDNF promotes the maturation of cortical inhibition during early postnatal life, thereby regulating the critical period for visual cortical plasticity.

  5. The between-population genetic architecture of growth, maturation, and plasticity in Atlantic salmon.

    PubMed

    Debes, Paul Vincent; Fraser, Dylan John; Yates, Matthew; Hutchings, Jeffrey A

    2014-04-01

    The between-population genetic architecture for growth and maturation has not been examined in detail for many animal species despite its central importance in understanding hybrid fitness. We studied the genetic architecture of population divergence in: (i) maturation probabilities at the same age; (ii) size at age and growth, while accounting for maturity status and sex; and (iii) growth plasticity in response to environmental factors, using divergent wild and domesticated Atlantic salmon (Salmo salar). Our work examined two populations and their multigenerational hybrids in a common experimental arrangement in which salinity and quantity of suspended sediments were manipulated to mimic naturally occurring environmental variation. Average specific growth rates across environments differed among crosses, maturity groups, and cross-by-maturity groups, but a growth-rate reduction in the presence of suspended sediments was equal for all groups. Our results revealed both additive and nonadditive outbreeding effects for size at age and for growth rates that differed with life stage, as well as the presence of different sex- and size-specific maturation probabilities between populations. The major implication of our work is that estimates of the genetic architecture of growth and maturation can be biased if one does not simultaneously account for temporal changes in growth and for different maturation probabilities between populations. Namely, these correlated traits interact differently within each population and between sexes and among generations, due to nonadditive effects and a level of independence in the genetic control for traits. Our results emphasize the challenges to investigating and predicting phenotypic changes resulting from between-population outbreeding.

  6. Sex-specific plasticity of growth and maturation size in a spider: implications for sexual size dimorphism.

    PubMed

    Fernández-Montraveta, C; Moya-Laraño, J

    2007-09-01

    Sex-specific plasticity in body size has been recently proposed to cause intraspecific patterns of variation in sexual size dimorphism (SSD). We reared juvenile male and female Mediterranean tarantulas (Lycosa tarantula) under two feeding regimes and monitored their growth until maturation. Selection gradients calculated across studies show how maturation size is under net stabilizing selection in females and under directional selection in males. This pattern was used to predict that body size should be more canalized in females than in males. As expected, feeding affected male but not female maturation size. The sex-specific response of maturation size was related to a dramatic divergence between subadult male and female growth pathways. These results demonstrate the existence of sex-specific canalization and resource allocation to maturation size in this species, which causes variation in SSD depending on developmental conditions consistent with the differential-plasticity hypothesis explaining Rensch's Rule.

  7. Alternative functions of core cell cycle regulators in neuronal migration, neuronal maturation, and synaptic plasticity

    PubMed Central

    Frank, Christopher L.; Tsai, Li-Huei

    2009-01-01

    Recent studies have demonstrated that boundaries separating a cycling cell from a post-mitotic neuron are not as concrete as expected. Novel and unique physiological functions in neurons have been ascribed for proteins fundamentally required for cell cycle progression and control. These “core” cell cycle regulators serve diverse post-mitotic functions that span various developmental stages of a neuron, including neuronal migration, axonal elongation, axon pruning, dendrite morphogenesis, and synaptic maturation and plasticity. In this review, we detail the non-proliferative post-mitotic roles that these cell cycle proteins have recently been reported to play, the significance of their expression in neurons, mechanistic insight when available, and future prospects. PMID:19447088

  8. Transcriptional and translational plasticity in rodent urinary bladder TRP channels with urinary bladder inflammation, bladder dysfunction, or postnatal maturation.

    PubMed

    Merrill, Liana; Girard, Beatrice M; May, Victor; Vizzard, Margaret A

    2012-11-01

    These studies examined the transcriptional and translational plasticity of three transient receptor potential (TRP) channels (TRPA1, TRPV1, TRPV4) with established neuronal and non-neuronal expression and functional roles in the lower urinary tract. Mechanosensor and nociceptor roles in either physiological or pathological lower urinary tract states have been suggested for TRPA1, TRPV1, and TRPV4. We have previously demonstrated the neurochemical, organizational, and functional plasticity in micturition reflex pathways following induction of urinary bladder inflammation using the antineoplastic agent, cyclophosphamide. More recently, we have characterized similar plasticity in micturition reflex pathways in a transgenic mouse model with chronic urothelial overexpression (OE) of nerve growth factor (NGF) and in a transgenic mouse model with deletion of vasoactive intestinal polypeptide (VIP). In addition, the micturition reflex undergoes postnatal maturation that may also reflect plasticity in urinary bladder TRP channel expression. Thus, we examined plasticity in urinary bladder TRP channel expression in diverse contexts using a combination of quantitative, real-time PCR and western blotting approaches. We demonstrate transcriptional and translational plasticity of urinary bladder TRPA1, TRPV1, and TRVP4 expression. Although the functional significance of urinary bladder TRP channel plasticity awaits further investigation, these studies demonstrate context- (inflammation, postnatal development, NGF-OE, VIP deletion) and tissue-dependent (urothelium + suburothelium, detrusor) plasticity.

  9. Omega-3 fatty acid deficiency during brain maturation reduces neuronal and behavioral plasticity in adulthood.

    PubMed

    Bhatia, Harsharan Singh; Agrawal, Rahul; Sharma, Sandeep; Huo, Yi-Xin; Ying, Zhe; Gomez-Pinilla, Fernando

    2011-01-01

    Omega-3-fatty acid DHA is a structural component of brain plasma membranes, thereby crucial for neuronal signaling; however, the brain is inefficient at synthesizing DHA. We have asked how levels of dietary n-3 fatty acids during brain growth would affect brain function and plasticity during adult life. Pregnant rats and their male offspring were fed an n-3 adequate diet or n-3 deficient diets for 15 weeks. Results showed that the n-3 deficiency increased parameters of anxiety-like behavior using open field and elevated plus maze tests in the male offspring. Behavioral changes were accompanied by a level reduction in the anxiolytic-related neuropeptide Y-1 receptor, and an increase in the anxiogenic-related glucocorticoid receptor in the cognitive related frontal cortex, hypothalamus and hippocampus. The n-3 deficiency reduced brain levels of docosahexaenoic acid (DHA) and increased the ratio n-6/n-3 assessed by gas chromatography. The n-3 deficiency reduced the levels of BDNF and signaling through the BDNF receptor TrkB, in proportion to brain DHA levels, and reduced the activation of the BDNF-related signaling molecule CREB in selected brain regions. The n-3 deficiency also disrupted the insulin signaling pathways as evidenced by changes in insulin receptor (IR) and insulin receptor substrate (IRS). DHA deficiency during brain maturation reduces plasticity and compromises brain function in adulthood. Adequate levels of dietary DHA seem crucial for building long-term neuronal resilience for optimal brain performance and aiding in the battle against neurological disorders.

  10. Dissecting the proteome of pea mature seeds reveals the phenotypic plasticity of seed protein composition.

    PubMed

    Bourgeois, Michael; Jacquin, Françoise; Savois, Vincent; Sommerer, Nicolas; Labas, Valérie; Henry, Céline; Burstin, Judith

    2009-01-01

    Pea (Pisum sativum L.) is the most cultivated European pulse crop and the pea seeds mainly serve as a protein source for monogastric animals. Because the seed protein composition impacts on seed nutritional value, we aimed at identifying the determinants of its variability. This paper presents the first pea mature seed proteome reference map, which includes 156 identified proteins (http://www.inra.fr/legumbase/peaseedmap/). This map provides a fine dissection of the pea seed storage protein composition revealing a large diversity of storage proteins resulting both from gene diversity and post-translational processing. It gives new insights into the pea storage protein processing (especially 7S globulins) as a possible adaptation towards progressive mobilization of the proteins during germination. The nonstorage seed proteome revealed the presence of proteins involved in seed defense together with proteins preparing germination. The plasticity of the seed proteome was revealed for seeds produced in three successive years of cultivation, and 30% of the spots were affected by environmental variations. This work pinpoints seed proteins most affected by environment, highlighting new targets to stabilize storage protein composition that should be further analyzed.

  11. Chronic fluoxetine treatment suppresses plasticity (long-term potentiation) in the mature rodent primary auditory cortex in vivo.

    PubMed

    Dringenberg, Hans C; Branfield Day, Leora R; Choi, Deanna H

    2014-01-01

    Several recent studies have provided evidence that chronic treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine can facilitate synaptic plasticity (e.g., ocular dominance shifts) in the adult central nervous system. Here, we assessed whether fluoxetine enhances long-term potentiation (LTP) in the thalamocortical auditory system of mature rats, a developmentally regulated form of plasticity that shows a characteristic decline during postnatal life. Adult rats were chronically treated with fluoxetine (administered in the drinking water, 0.2 mg/mL, four weeks of treatment). Electrophysiological assessments were conducted using an anesthetized (urethane) in vivo preparation, with LTP of field potentials in the primary auditory cortex (A1) induced by theta-burst stimulation of the medial geniculate nucleus. We find that, compared to water-treated control animals, fluoxetine-treated rats did not express higher levels of LTP and, in fact, exhibited reduced levels of potentiation at presumed intracortical A1 synapses. Bioactivity of fluoxetine was confirmed by a reduction of weight gain and fluid intake during the four-week treatment period. We conclude that chronic fluoxetine treatment fails to enhance LTP in the mature rodent thalamocortical auditory system, results that bring into question the notion that SSRIs act as general facilitators of synaptic plasticity in the mammalian forebrain.

  12. Plastic downregulation of the transcriptional repressor BCL6 during maturation of human dendritic cells

    SciTech Connect

    Pantano, Serafino . E-mail: serafino.pantano@unil.ch; Jarrossay, David; Saccani, Simona; Bosisio, Daniela; Natoli, Gioacchino

    2006-05-01

    Dendritic cell (DC) maturation links peripheral events initiated by the encounter with pathogens to the activation and expansion of antigen-specific T lymphocytes in secondary lymphoid organs. Here, we describe an as yet unrecognized modulator of human DC maturation, the transcriptional repressor BCL6. We found that both myeloid and plasmacytoid DCs constitutively express BCL6, which is rapidly downregulated following maturation triggered by selected stimuli. Both in unstimulated and maturing DCs, control of BCL6 protein levels reflects the convergence of several mechanisms regulating BCL6 stability, mRNA transcription and nuclear export. By regulating the induction of several genes implicated in the immune response, including inflammatory cytokines, chemokines and survival genes, BCL6 may represent a pivotal modulator of the afferent branch of the immune response.

  13. MFRP project: plastic-wrap preserved mature orchardgrass round-baled hay up to 34% moisture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of harvest moisture and bale wrapping on forage quality and mold formation in orchardgrass hay intended for equine feeding have not been investigated. The objectives of this study were to determine the effects of initial bale moisture and plastic wrapping on temperature, forage quality, and ...

  14. Disruption of Coordinated Presynaptic and Postsynaptic Maturation Underlies the Defects in Hippocampal Synapse Stability and Plasticity in Abl2/Arg-Deficient Mice

    PubMed Central

    Xiao, Xiao; Levy, Aaron D.; Rosenberg, Brian J.; Higley, Michael J.

    2016-01-01

    Immature glutamatergic synapses in cultured neurons contain high-release probability (Pr) presynaptic sites coupled to postsynaptic sites bearing GluN2B-containing NMDA receptors (NMDARs), which mature into low-Pr, GluN2B-deficient synapses. Whether this coordinated maturation of high-Pr, GluN2B+ synapses to low-Pr, GluN2B-deficient synapses actually occurs in vivo, and if so, what factors regulate it and what role it might play in long-term synapse function and plasticity are unknown. We report that loss of the integrin-regulated Abl2/Arg kinase in vivo yields a subpopulation of “immature” high-Pr, GluN2B+ hippocampal synapses that are maintained throughout late postnatal development and early adulthood. These high-Pr, GluN2B+ synapses are evident in arg−/− animals as early as postnatal day 21 (P21), a time that precedes any observable defects in synapse or dendritic spine number or structure in arg−/− mice. Using focal glutamate uncaging at individual synapses, we find only a subpopulation of arg−/− spines exhibits increased GluN2B-mediated responses at P21. As arg−/− mice age, these synapses increase in proportion, and their associated spines enlarge. These changes coincide with an overall loss of spines and synapses in the Arg-deficient mice. We also demonstrate that, although LTP and LTD are normal in P21 arg−/− slices, both forms of plasticity are significantly altered by P42. These data demonstrate that the integrin-regulated Arg kinase coordinates the maturation of presynaptic and postsynaptic compartments in a subset of hippocampal synapses in vivo, and this coordination is critical for NMDAR-dependent long-term synaptic stability and plasticity. SIGNIFICANCE STATEMENT Synapses mature in vitro from high-release probability (Pr) GluN2B+ to low-Pr, GluN2B−, but it is unknown why this happens or whether it occurs in vivo. High-Pr, GluN2B+ synapses persist into early adulthood in Arg-deficient mice in vivo and have elevated NMDA

  15. Neural stem cells and neuro/gliogenesis in the central nervous system: understanding the structural and functional plasticity of the developing, mature, and diseased brain.

    PubMed

    Yamaguchi, Masahiro; Seki, Tatsunori; Imayoshi, Itaru; Tamamaki, Nobuaki; Hayashi, Yoshitaka; Tatebayashi, Yoshitaka; Hitoshi, Seiji

    2016-05-01

    Neurons and glia in the central nervous system (CNS) originate from neural stem cells (NSCs). Knowledge of the mechanisms of neuro/gliogenesis from NSCs is fundamental to our understanding of how complex brain architecture and function develop. NSCs are present not only in the developing brain but also in the mature brain in adults. Adult neurogenesis likely provides remarkable plasticity to the mature brain. In addition, recent progress in basic research in mental disorders suggests an etiological link with impaired neuro/gliogenesis in particular brain regions. Here, we review the recent progress and discuss future directions in stem cell and neuro/gliogenesis biology by introducing several topics presented at a joint meeting of the Japanese Association of Anatomists and the Physiological Society of Japan in 2015. Collectively, these topics indicated that neuro/gliogenesis from NSCs is a common event occurring in many brain regions at various ages in animals. Given that significant structural and functional changes in cells and neural networks are accompanied by neuro/gliogenesis from NSCs and the integration of newly generated cells into the network, stem cell and neuro/gliogenesis biology provides a good platform from which to develop an integrated understanding of the structural and functional plasticity that underlies the development of the CNS, its remodeling in adulthood, and the recovery from diseases that affect it.

  16. Neuronal plasticity in the mushroom body calyx during adult maturation in the honeybee and possible pheromonal influences.

    PubMed

    Muenz, Thomas S; Groh, Claudia; Maisonnasse, Alban; Le Conte, Yves; Plettner, Erika; Rössler, Wolfgang

    2015-12-01

    Honeybee workers express a pronounced age-dependent polyethism switching from various indoor duties to foraging outside the hive. This transition is accompanied by tremendous changes in the sensory environment that sensory systems and higher brain centers have to cope with. Foraging and age have earlier been shown to be associated with volume changes in the mushroom bodies (MBs). Using age- and task-controlled bees this study provides a detailed framework of neuronal maturation processes in the MB calyx during the course of natural behavioral maturation. We show that the MB calyx volume already increases during the first week of adult life. This process is mainly driven by broadening of the Kenyon cell dendritic branching pattern and then followed by pruning of projection neuron axonal boutons during the actual transition from indoor to outdoor duties. To further investigate the flexible regulation of division of labor and its neuronal correlates in a honeybee colony, we studied the modulation of the nurse-forager transition via a chemical communication system, the primer pheromone ethyl oleate (EO). EO is found at high concentrations on foragers in contrast to nurse bees and was shown to delay the onset of foraging. In this study, EO effects on colony behavior were not as robust as expected, and we found no direct correlation between EO treatment and synaptic maturation in the MB calyx. In general, we assume that the primer pheromone EO rather acts in concert with other factors influencing the onset of foraging with its effect being highly adaptive.

  17. Measurement invariance of big-five factors over the life span: ESEM tests of gender, age, plasticity, maturity, and la dolce vita effects.

    PubMed

    Marsh, Herbert W; Nagengast, Benjamin; Morin, Alexandre J S

    2013-06-01

    This substantive-methodological synergy applies evolving approaches to factor analysis to substantively important developmental issues of how five-factor-approach (FFA) personality measures vary with gender, age, and their interaction. Confirmatory factor analyses (CFAs) conducted at the item level often do not support a priori FFA structures, due in part to the overly restrictive assumptions of CFA models. Here we demonstrate that exploratory structural equation modeling (ESEM), an integration of CFA and exploratory factor analysis, overcomes these problems with the 15-item Big Five Inventory administered as part of the nationally representative British Household Panel Study (N = 14,021; age: 15-99 years, Mage = 47.1). ESEM fitted the data substantially better and resulted in much more differentiated (less correlated) factors than did CFA. Methodologically, we extended ESEM (introducing ESEM-within-CFA models and a hybrid of multiple groups and multiple indicators multiple causes models), evaluating full measurement invariance and latent mean differences over age, gender, and their interaction. Substantively the results showed that women had higher latent scores for all Big Five factors except for Openness and that these gender differences were consistent over the entire life span. Substantial nonlinear age effects led to the rejection of the plaster hypothesis and the maturity principle but did support a newly proposed la dolce vita effect in old age. In later years, individuals become happier (more agreeable and less neurotic), more self-content and self-centered (less extroverted and open), more laid back and satisfied with what they have (less conscientious, open, outgoing and extroverted), and less preoccupied with productivity.

  18. Adult myelination: wrapping up neuronal plasticity

    PubMed Central

    O’Rourke, Megan; Gasperini, Robert; Young, Kaylene M.

    2014-01-01

    In this review, we outline the major neural plasticity mechanisms that have been identified in the adult central nervous system (CNS), and offer a perspective on how they regulate CNS function. In particular we examine how myelin plasticity can operate alongside neurogenesis and synaptic plasticity to influence information processing and transfer in the mature CNS. PMID:25221576

  19. Plastic Surgery

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A ... her forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word " ...

  20. White matter plasticity in adulthood.

    PubMed

    Wang, S; Young, K M

    2014-09-12

    CNS white matter is subject to a novel form of neural plasticity which has been termed "myelin plasticity". It is well established that oligodendrocyte generation and the addition of new myelin internodes continue throughout normal adulthood. These new myelin internodes maybe required for the de novo myelination of previously unmyelinated axons, myelin sheath replacement, or even myelin remodeling. Each process could alter axonal conduction velocity, but to what end? We review the changes that occur within the white matter over the lifetime, the known regulators and mediators of white matter plasticity in the mature CNS, and the physiological role this plasticity may play in CNS function.

  1. Plastic Jellyfish.

    ERIC Educational Resources Information Center

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  2. Plastics Technology.

    ERIC Educational Resources Information Center

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  3. Neuronal plasticity: beyond the critical period.

    PubMed

    Hübener, Mark; Bonhoeffer, Tobias

    2014-11-06

    Neuronal plasticity in the brain is greatly enhanced during critical periods early in life and was long thought to be rather limited thereafter. Studies in primary sensory areas of the neocortex have revealed a substantial degree of plasticity in the mature brain, too. Often, plasticity in the adult neocortex lies dormant but can be reactivated by modifications of sensory input or sensory-motor interactions, which alter the level and pattern of activity in cortical circuits. Such interventions, potentially in combination with drugs targeting molecular brakes on plasticity present in the adult brain, might help recovery of function in the injured or diseased brain.

  4. Plastic Surgery Statistics

    MedlinePlus

    ... PRS GO PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the ... Plastic Surgery Statistics 2005 Plastic Surgery Statistics 2016 Plastic Surgery Statistics Stats Report 2016 National Clearinghouse of ...

  5. Mature Teachers Matter

    ERIC Educational Resources Information Center

    Berl, Patricia Scallan

    2005-01-01

    In this article, the author discusses the consequences of losing mature teachers due to voluntary separation or retirement and the mindset of a mature teacher that is different from younger teachers in a number of ways. Mature teachers are colleagues over 45 years of age possessing significant experience in the field. Future trends in teacher…

  6. Maturation of the adolescent brain

    PubMed Central

    Arain, Mariam; Haque, Maliha; Johal, Lina; Mathur, Puja; Nel, Wynand; Rais, Afsha; Sandhu, Ranbir; Sharma, Sushil

    2013-01-01

    Adolescence is the developmental epoch during which children become adults – intellectually, physically, hormonally, and socially. Adolescence is a tumultuous time, full of changes and transformations. The pubertal transition to adulthood involves both gonadal and behavioral maturation. Magnetic resonance imaging studies have discovered that myelinogenesis, required for proper insulation and efficient neurocybernetics, continues from childhood and the brain’s region-specific neurocircuitry remains structurally and functionally vulnerable to impulsive sex, food, and sleep habits. The maturation of the adolescent brain is also influenced by heredity, environment, and sex hormones (estrogen, progesterone, and testosterone), which play a crucial role in myelination. Furthermore, glutamatergic neurotransmission predominates, whereas gamma-aminobutyric acid neurotransmission remains under construction, and this might be responsible for immature and impulsive behavior and neurobehavioral excitement during adolescent life. The adolescent population is highly vulnerable to driving under the influence of alcohol and social maladjustments due to an immature limbic system and prefrontal cortex. Synaptic plasticity and the release of neurotransmitters may also be influenced by environmental neurotoxins and drugs of abuse including cigarettes, caffeine, and alcohol during adolescence. Adolescents may become involved with offensive crimes, irresponsible behavior, unprotected sex, juvenile courts, or even prison. According to a report by the Centers for Disease Control and Prevention, the major cause of death among the teenage population is due to injury and violence related to sex and substance abuse. Prenatal neglect, cigarette smoking, and alcohol consumption may also significantly impact maturation of the adolescent brain. Pharmacological interventions to regulate adolescent behavior have been attempted with limited success. Since several factors, including age, sex

  7. Plastic Bronchitis.

    PubMed

    Rubin, Bruce K

    2016-09-01

    Plastic bronchitis is an uncommon and probably underrecognized disorder, diagnosed by the expectoration or bronchoscopic removal of firm, cohesive, branching casts. It should not be confused with purulent mucous plugging of the airway as seen in patients with cystic fibrosis or bronchiectasis. Few medications have been shown to be effective and some are now recognized as potentially harmful. Current research directions in plastic bronchitis research include understanding the genetics of lymphatic development and maldevelopment, determining how abnormal lymphatic malformations contribute to cast formation, and developing new treatments.

  8. Plastics Technician.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document contains 16 units to consider for use in a tech prep competency profile for the occupation of plastics technician. All the units listed will not necessarily apply to every situation or tech prep consortium, nor will all the competencies within each unit be appropriate. Several units appear within each specific occupation and would…

  9. GLASS FIBER REINFORCED PLASTICS,

    DTIC Science & Technology

    Contents: Fibrous glass fillers Binders used in the glass plastic industry Method of manufacturing glass plastics and glass plastic articles Properties of fiberglass Primary areas for use of glass fibre reinforced plastics

  10. Plastic bronchitis

    PubMed Central

    Singhi, Anil Kumar; Vinoth, Bharathi; Kuruvilla, Sarah; Sivakumar, Kothandam

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding. PMID:26556975

  11. [Adolescent brain maturation].

    PubMed

    Holzer, L; Halfon, O; Thoua, V

    2011-05-01

    Recent progress in neuroscience has yielded major findings regarding brain maturation during adolescence. Unlike the body, which reaches adult size and morphology during this period, the adolescent brain is still maturing. The prefrontal cortex appears to be an important locus of maturational change subserving executive functions that may regulate emotional and motivational issues. The recent expansion of the adolescent period has increased the lag between the onset of emotional and motivational changes activated by puberty and the completion of cognitive development-the maturation of self-regulatory capacities and skills that are continuing to develop long after puberty has occurred. This "disconnect" predicts risk for a broad set of behavioral and emotional problems. Adolescence is a critical period for high-level cognitive functions such as socialization that rely on maturation of the prefrontal cortex. Intervention during the period of adolescent brain development provides opportunities and requires an interdisciplinary approach.

  12. Age-Dependent Glutamate Induction of Synaptic Plasticity in Cultured Hippocampal Neurons

    ERIC Educational Resources Information Center

    Ivenshitz, Miriam; Segal, Menahem; Sapoznik, Stav

    2006-01-01

    A common denominator for the induction of morphological and functional plasticity in cultured hippocampal neurons involves the activation of excitatory synapses. We now demonstrate massive morphological plasticity in mature cultured hippocampal neurons caused by a brief exposure to glutamate. This plasticity involves a slow, 70%-80% increase in…

  13. A Semi-Persistent Adult Ocular Dominance Plasticity in Visual Cortex Is Stabilized by Activated CREB

    ERIC Educational Resources Information Center

    Barco, Angel; Kandel, Eric R.; Gordon, Barbara; Lickey, Marvin E.; Suzuki, Seigo; Pham, Tony A.; Graham, Sarah J.

    2004-01-01

    The adult cerebral cortex can adapt to environmental change. Using monocular deprivation as a paradigm, we find that rapid experience-dependent plasticity exists even in the mature primary visual cortex. However, adult cortical plasticity differs from developmental plasticity in two important ways. First, the effect of adult, but not juvenile…

  14. Toward Teacher Maturity.

    ERIC Educational Resources Information Center

    Pickle, Judy

    1985-01-01

    The essence of teacher maturity can be synthesized into personal, professional, and process domains. Although overlapping, these categories add a multidimensional approach to the search for what is good in teaching and provide a model for professional development. (MT)

  15. The role of GABAergic inhibition in ocular dominance plasticity.

    PubMed

    Heimel, J Alexander; van Versendaal, Daniëlle; Levelt, Christiaan N

    2011-01-01

    During the last decade, we have gained much insight into the mechanisms that open and close a sensitive period of plasticity in the visual cortex. This brings the hope that novel treatments can be developed for brain injuries requiring renewed plasticity potential and neurodevelopmental brain disorders caused by defective synaptic plasticity. One of the central mechanisms responsible for opening the sensitive period is the maturation of inhibitory innervation. Many molecular and cellular events have been identified that drive this developmental process, including signaling through BDNF and IGF-1, transcriptional control by OTX2, maturation of the extracellular matrix, and GABA-regulated inhibitory synapse formation. The mechanisms through which the development of inhibitory innervation triggers and potentially closes the sensitive period may involve plasticity of inhibitory inputs or permissive regulation of excitatory synapse plasticity. Here, we discuss the current state of knowledge in the field and open questions to be addressed.

  16. Phagosome maturation: aging gracefully.

    PubMed Central

    Vieira, Otilia V; Botelho, Roberto J; Grinstein, Sergio

    2002-01-01

    Foreign particles and apoptotic bodies are eliminated from the body by phagocytic leucocytes. The initial stage of the elimination process is the internalization of the particles into a plasma membrane-derived vacuole known as the phagosome. Such nascent phagosomes, however, lack the ability to kill pathogens or to degrade the ingested targets. These properties are acquired during the course of phagosomal maturation, a complex sequence of reactions that result in drastic remodelling of the phagosomal membrane and contents. The determinants and consequences of the fusion and fission reactions that underlie phagosomal maturation are the topic of this review. PMID:12061891

  17. A Developmental Switch for Hebbian Plasticity

    PubMed Central

    Martens, Marijn B.; Celikel, Tansu; Tiesinga, Paul H. E.

    2015-01-01

    Hebbian forms of synaptic plasticity are required for the orderly development of sensory circuits in the brain and are powerful modulators of learning and memory in adulthood. During development, emergence of Hebbian plasticity leads to formation of functional circuits. By modeling the dynamics of neurotransmitter release during early postnatal cortical development we show that a developmentally regulated switch in vesicle exocytosis mode triggers associative (i.e. Hebbian) plasticity. Early in development spontaneous vesicle exocytosis (SVE), often considered as 'synaptic noise', is important for homogenization of synaptic weights and maintenance of synaptic weights in the appropriate dynamic range. Our results demonstrate that SVE has a permissive, whereas subsequent evoked vesicle exocytosis (EVE) has an instructive role in the expression of Hebbian plasticity. A timed onset for Hebbian plasticity can be achieved by switching from SVE to EVE and the balance between SVE and EVE can control the effective rate of Hebbian plasticity. We further show that this developmental switch in neurotransmitter release mode enables maturation of spike-timing dependent plasticity. A mis-timed or inadequate SVE to EVE switch may lead to malformation of brain networks thereby contributing to the etiology of neurodevelopmental disorders. PMID:26172394

  18. Brain maturation and epilepsy.

    PubMed

    Dulac, Olivier; Milh, Mathieu; Holmes, Gregory L

    2013-01-01

    At full term, both glutamate and gamma-amino-butyric acid (GABA) are excitatory; cortical synapses are beginning to appear, there is little myelin in the cerebral hemispheres, and long tracts hardly start to develop. Neonatal myoclonic encephalopathy can result from premature activation of N-methyl-D-aspartate (NMDA) transmission. Benign neonatal seizures and migrating partial seizures in infancy could involve excessive or premature excitability of deep cortical layers. Benign rolandic epilepsy and continuous spike waves in slow sleep are consistent with an excess of both excitatory and inhibitory cortical synapses. West and Lennox-Gastaut syndromes express age-related diffuse cortical hyperexcitability, the pattern depending on the age of occurrence; synchronization of spikes is becoming possible with maturation of the myelin. Idiopathic generalized epilepsy is itself modulated by maturation that causes frontal hyperexcitability generating myoclonic-astatic seizures, between the ages of infantile and juvenile myoclonic epilepsies. Physiological delay of hippocampo-neocortical pathways maturation could account for the delayed occurrence of mesial temporal epilepsy following infantile damage, whereas premature maturation could contribute to fronto-temporal damage characteristic of fever-induced epileptic encephalopathy in school-age children, a dramatic school-age epileptic encephalopathy.

  19. Maturation in Larch 1

    PubMed Central

    Greenwood, Michael S.; Hopper, Catherine A.; Hutchison, Keith W.

    1989-01-01

    The time course of maturation in eastern larch (Larix laricina [Du Roi] K. Koch) was examined by grafting scions from trees of different ages onto 2-year-old root stock and following scion development for several years. Height, diameter, foliar chlorophyll content, and rooting ability of scion-derived cuttings all varied linearly as a function of log10 age. Chlorophyll content (milligrams per gram of dry weight) increased while height, diameter, and ability to root decreased with age (P < 0.01). The tendency toward orthotropic growth and branch formation per centimeter of main stem decreased abruptly between age 1 and 5 years (P < 0.01). Total chlorophyll content of both long and short shoot foliage increased by 30 to 50% with increasing age, but the chlorophyll a/b ratio did not change. Also, juvenile long shoot needles were significantly longer than mature (P < 0.01). Surprisingly, the juvenile scions produced more total strobili over two successive years, but the mature scions produced a significantly higher proportion of male strobili (P < 0.001 year 1; P < 0.02 year 2). The age-related changes in foliar traits were not associated with changes in DNA methylation between juvenile and mature scions. Using HPLC, we found that 20% of foliar DNA cytosine residues were methylated in both scion types. Images Figure 1 PMID:16666785

  20. Mature Students Studying Mathematics.

    ERIC Educational Resources Information Center

    Hirst, Keith

    1999-01-01

    Discusses mature students in the single subject area of mathematics in a single institution and makes comparisons with traditional universities. Reviews some features of the age distribution, entry qualifications, degree-class distribution, non-completion rates and gender distribution. (Author/ASK)

  1. Providing plastic zone extrusion

    DOEpatents

    Manchiraju, Venkata Kiran; Feng, Zhili; David, Stan A.; Yu, Zhenzhen

    2017-04-11

    Plastic zone extrusion may be provided. First, a compressor may generate frictional heat in stock to place the stock in a plastic zone of the stock. Then, a conveyer may receive the stock in its plastic zone from the compressor and transport the stock in its plastic zone from the compressor. Next, a die may receive the stock in its plastic zone from the conveyer and extrude the stock to form a wire.

  2. Delayed visual maturation.

    PubMed Central

    Cole, G F; Hungerford, J; Jones, R B

    1984-01-01

    Sixteen blind babies who were considered to be showing the characteristics of delayed visual maturation were studied prospectively. The diagnosis was made on clinical grounds, and the criteria for this are discussed. All of these infants developed visual responses between 4 and 6 months of age and had normal or near normal visual acuities by 1 year of age. Long term follow up, however, has shown neurological abnormalities in some of these children. PMID:6200080

  3. Synapse Maturation by Activity-Dependent Ectodomain Shedding of SIRPα

    PubMed Central

    Toth, Anna B.; Terauchi, Akiko; Zhang, Lily Y.; Johnson-Venkatesh, Erin M.; Larsen, David J.; Sutton, Michael A.; Umemori, Hisashi

    2013-01-01

    Formation of appropriate synaptic connections is critical for proper functioning of the brain. After initial synaptic differentiation, active synapses are stabilized by neural activity-dependent signals to establish functional synaptic connections. However, the molecular mechanisms underlying activity-dependent synapse maturation remain to be elucidated. Here we show that activity-dependent ectodomain shedding of SIRPα mediates presynaptic maturation. Two target-derived molecules, FGF22 and SIRPα, sequentially organize the glutamatergic presynaptic terminals during the initial synaptic differentiation and synapse maturation stages, respectively, in the mouse hippocampus. SIRPα drives presynaptic maturation in an activity-dependent fashion. Remarkably, neural activity cleaves the extracellular domain of SIRPα, and the shed ectodomain, in turn, promotes the maturation of the presynaptic terminal. This process involves CaM kinase, matrix metalloproteinases, and the presynaptic receptor CD47. Finally, SIRPα-dependent synapse maturation has significant impacts on synaptic function and plasticity. Thus, ectodomain shedding of SIRPα is an activity-dependent trans-synaptic mechanism for the maturation of functional synapses. PMID:24036914

  4. Vocational Maturity and Self Concepts.

    ERIC Educational Resources Information Center

    Helbing, Hans

    The relationship between separate dimensions of vocational maturity and different self-concept and identity variables were examined. Subjects were Dutch students, age 14-18 years. The vocational maturity dimensions were measured by Dutch adaptations of American vocational maturity scales. Instruments for self-concept and identity measurement were…

  5. Age, Plasticity, and Homeostasis In Childhood Brain Disorders

    PubMed Central

    Dennis, Maureen; Spiegler, Brenda J.; Juranek, Jenifer J.; Bigler, Erin D.; Snead, O. Carter; Fletcher, Jack M.

    2013-01-01

    It has been widely accepted that the younger the age and/or immaturity of the organism, the greater the brain plasticity, the young age plasticity privilege. This paper examines the relation of a young age to plasticity, reviewing human pediatric brain disorders, as well as selected animal models, human developmental and adult brain disorder studies. As well, we review developmental and childhood acquired disorders that involve a failure of regulatory homeostasis. Our core arguments are: Plasticity is neutral with respect to outcome. Although the effects of plasticity are often beneficial, the outcome of plasticity may be adaptive or maladaptive.The young age plasticity privilege has been overstated.Plastic change operates in concert with homeostatic mechanisms regulating change at every point in the lifespan.The same mechanisms that propel developmental change expose the immature brain to adverse events, making it more difficult for the immature than for the mature brain to sustain equilibrium between plasticity and homeostasis.Poor outcome in many neurodevelopmental disorders and childhood acquired brain insults is related to disequilibrium between plasticity and homeostasis. PMID:24096190

  6. Plastic encapsulated parts

    SciTech Connect

    Castillo, T.

    1994-10-01

    Plastic semiconductor packages were characterized as possible alternatives for canned devices, which are susceptible to internal shorts caused by conductive particles. Highly accelerated stress testing (HAST) as well as electrical and mechanical testing were conducted on plastic technology devices.

  7. Plastic casting resin poisoning

    MedlinePlus

    Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.

  8. Dissociation of motor maturation.

    PubMed

    DiMario, Francis J

    2003-06-01

    We prospectively acquired clinical data regarding the presentation, evaluation, and developmental progress of all patients identified with dissociated motor maturation to define their clinical outcomes. Children (N = 8) referred for evaluation of suspected cerebral palsy because of delayed sitting or walking and identified to have dissociated motor maturation were followed with serial clinical examination. All displayed the characteristic "sitting on air" posture while held in vertical suspension and had otherwise normal developmental assessments. This posture is composed of the hips held in flexion and abduction with the knees extended and feet plantar or dorsiflexed. Three children were initially evaluated at 10 months of age owing to absence of sitting and five other children were evaluated at a mean of 14 months (range 12-19 months) owing to inability to stand. Follow-up evaluations were conducted over a mean of 10.5 months (range 5-34 months). Five children were born prematurely at 34 to 36 weeks gestation. Denver Developmental Screening Test and general and neurologic examinations were normal except to note hypotonia in six children and the "sitting on air" posture in all of the children. Four children have older siblings or parents who "walked late" (after 15 months). On average, the children attained sitting by 8 months (range 7-10 months). One child did not crawl prior to independent walking, two children scooted rather than crawled, and five children crawled at an average of 13.5 months (range 10-16 months). All children cruised by a mean of 18 months (range 16-21.5 months) and attained independent walking by 20.1 months (range 18-25 months). Neuroimaging and serum creatine kinase enzyme testing were normal in two children who were tested. These eight children conform to the syndrome of dissociated motor maturation. The "sitting on air" posture serves as a diagnostic sign and anticipated excellent prognosis, but follow-up is required to ensure a normal

  9. Maturation in Larch 1

    PubMed Central

    Hutchison, Keith W.; Sherman, Christopher D.; Weber, Jill; Smith, Sandra Schiller; Singer, Patricia B.; Greenwood, Michael S.

    1990-01-01

    The effect of maturation on the morphological and photosynthetic characteristics, as well as the expression of two genes involved in photosynthesis in the developing, current year foliage of Eastern larch (Larix laricina [Du Roi]) is described. These effects were observed on foliage during the third growing season after grafting of scions from trees of different ages onto 2 year old rootstock. Specific leaf weight (gram dry weight per square meter), leaf cross-sectional area (per square millimeter), and chlorophyll content (milligram per gram dry weight) all increase with increasing age in long shoot foliage from both indoor- and outdoor-grown trees. Net photosynthesis (NPS) (mole of CO2 per square millimeter per second) increases with age on indoor- but not outdoor-grown trees. NPS also increases with increased chlorophyll content, but outdoor-grown scions of all ages had higher chlorophyll content, and chlorophyll does not appear to be limiting for NPS outdoors. To extend these studies of maturation-related differences in foliar morphology and physiology to the molecular genetic level, sequences were cloned from the cab and rbsS gene families of larch. Both cab and rbcS gene families are expressed in foliage but not in roots, and they are expressed in light-grown seedlings of larch but only at very low levels in dark-grown seedlings (~2% of light-grown seedlings). Steady-state cab mRNA levels are relatively higher (~40%) in newly expanding short shoot foliage from juvenile plants compared to mature plants. Unlike cab, the expression of the rbcS gene family did not seem to vary with age. These data show that the maturation-related changes in morphological and physiological phenotypes are associated with changes in gene expression. No causal relationship has been established, however. Indeed, we conclude that the faster growth of juvenile scions reported previously (MS Greenwood, CA Hopper, KW Hutchison [1989] Plant Physiol 90: 406-412) is not due to increased NPS

  10. Recovering automotive plastics

    SciTech Connect

    Not Available

    1993-10-01

    This article reports on the results of a study on increasing the recycling of plastics in automobiles. Plastics are being used in increasing amounts in vehicles and new methods of retrieving these plastics for recycling are needed to reduce the amount of automotive shredder residue that is currently being sent to residues. The study concentrated on increasing the ease of disassembly and contaminant removal.

  11. Plastics in Building.

    ERIC Educational Resources Information Center

    Skeist, Irving, Ed.

    The evaluation and use of plastics in the construction industry are explained. The contributors offer extensive, timely, and thoroughly researched data on the chemistry, properties, functions, engineering behavior, and specific applications of plastics to building requirements. The major subjects discussed in depth are--(1) the role of plastics in…

  12. Processing of plastics

    PubMed Central

    Spaak, Albert

    1975-01-01

    An overview is given of the processing of plastic materials from the handling of polymers in the pellet and powder form to manufacturing of a plastic fabricated product. Various types of equipment used and melt processing ranges of various polymer formulations to make the myriad of plastic products that are commercially available are discussed. PMID:1175556

  13. Tomorrow's Plastic World

    ERIC Educational Resources Information Center

    Macdonald, Averil

    2005-01-01

    Far from being just cheap packaging materials, plastics may be the materials of tomorrow. Plastic can conduct electricity, and this opens up a host of high-tech possibilities in the home and in energy generation. These possibilities are discussed here along with how plastic can be recycled and perhaps even grown.

  14. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  15. Biodegradability of plastics.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  16. Developmental plasticity and language: A comparative perspective

    PubMed Central

    Griebel, Ulrike; Pepperberg, Irene; Oller, D. Kimbrough

    2016-01-01

    The growing field of evo-devo is increasingly demonstrating the complexity of steps involved in genetic, intracellular regulatory, and extracellular environmental control of the development of phenotypes. A key result of such work is an account for the remarkable plasticity of organismal form in many species based on relatively minor changes in regulation of highly conserved genes and genetic processes. Accounting for behavioral plasticity is of similar potential interest but has received far less attention. Of particular interest is plasticity in communication systems, where human language represents an ultimate target for research. The present paper considers plasticity of language capabilities in a comparative framework, focusing attention on examples of a remarkable fact: Whereas there exist design features of mature human language that have never been observed to occur in nonhumans in the wild, many of these features can be developed to notable extents when nonhumans are enculturated through human training (especially with intensive social interaction). These examples of enculturated developmental plasticity across extremely diverse taxa suggest, consistent with the evo-devo theme of highly conserved processes in evolution, that human language is founded in part on cognitive capabilities that are indeed ancient and that even modern humans show self-organized emergence of many language capabilities in the context of rich enculturation, built on the special social/ecological history of the hominin line. Human culture can thus be seen as a regulatory system encouraging language development in the context of a cognitive background with many highly conserved features. PMID:27003391

  17. Epigenetic Basis of Neuronal and Synaptic Plasticity.

    PubMed

    Karpova, Nina N; Sales, Amanda J; Joca, Samia R

    2017-01-01

    Neuronal network and plasticity change as a function of experience. Altered neural connectivity leads to distinct transcriptional programs of neuronal plasticity-related genes. The environmental challenges throughout life may promote long-lasting reprogramming of gene expression and the development of brain disorders. The modifications in neuronal epigenome mediate gene-environmental interactions and are required for activity-dependent regulation of neuronal differentiation, maturation and plasticity. Here, we highlight the latest advances in understanding the role of the main players of epigenetic machinery (DNA methylation and demethylation, histone modifications, chromatin-remodeling enzymes, transposons, and non-coding RNAs) in activity-dependent and long- term neural and synaptic plasticity. The review focuses on both the transcriptional and post-transcriptional regulation of gene expression levels, including the processes of promoter activation, alternative splicing, regulation of stability of gene transcripts by natural antisense RNAs, and alternative polyadenylation. Further, we discuss the epigenetic aspects of impaired neuronal plasticity and the pathogenesis of neurodevelopmental (Rett syndrome, Fragile X Syndrome, genomic imprinting disorders, schizophrenia, and others), stressrelated (mood disorders) and neurodegenerative Alzheimer's, Parkinson's and Huntington's disorders. The review also highlights the pharmacological compounds that modulate epigenetic programming of gene expression, the potential treatment strategies of discussed brain disorders, and the questions that should be addressed during the development of effective and safe approaches for the treatment of brain disorders.

  18. A theory of the transition to critical period plasticity: inhibition selectively suppresses spontaneous activity.

    PubMed

    Toyoizumi, Taro; Miyamoto, Hiroyuki; Yazaki-Sugiyama, Yoko; Atapour, Nafiseh; Hensch, Takao K; Miller, Kenneth D

    2013-10-02

    What causes critical periods (CPs) to open? For the best-studied case, ocular dominance plasticity in primary visual cortex in response to monocular deprivation (MD), the maturation of inhibition is necessary and sufficient. How does inhibition open the CP? We present a theory: the transition from pre-CP to CP plasticity arises because inhibition preferentially suppresses responses to spontaneous relative to visually driven input activity, switching learning cues from internal to external sources. This differs from previous proposals in (1) arguing that the CP can open without changes in plasticity mechanisms when activity patterns become more sensitive to sensory experience through circuit development, and (2) explaining not simply a transition from no plasticity to plasticity, but a change in outcome of MD-induced plasticity from pre-CP to CP. More broadly, hierarchical organization of sensory-motor pathways may develop through a cascade of CPs induced as circuit maturation progresses from "lower" to "higher" cortical areas.

  19. CFD - Mature Technology?

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan

    2005-01-01

    Over the past 30 years, numerical methods and simulation tools for fluid dynamic problems have advanced as a new discipline, namely, computational fluid dynamics (CFD). Although a wide spectrum of flow regimes are encountered in many areas of science and engineering, simulation of compressible flow has been the major driver for developing computational algorithms and tools. This is probably due to a large demand for predicting the aerodynamic performance characteristics of flight vehicles, such as commercial, military, and space vehicles. As flow analysis is required to be more accurate and computationally efficient for both commercial and mission-oriented applications (such as those encountered in meteorology, aerospace vehicle development, general fluid engineering and biofluid analysis) CFD tools for engineering become increasingly important for predicting safety, performance and cost. This paper presents the author's perspective on the maturity of CFD, especially from an aerospace engineering point of view.

  20. Time to change: retina sends a messenger to promote plasticity in visual cortex.

    PubMed

    Huang, Z Josh; Di Cristo, Graziella

    2008-08-14

    Maturation of GABA inhibitory circuitry in primary visual cortex activates the critical period of plasticity, but the underlying mechanisms are not well understood. In the August 8th issue of Cell, Sugiyama et al. demonstrate that visual experience promotes the passage of a retina-derived homeoprotein along the visual pathway, which nurtures subclasses of cortical interneurons implicated in regulating critical period plasticity.

  1. Life-history plasticity in female threespine stickleback

    PubMed Central

    Baker, J A; Wund, M A; Heins, D C; King, R W; Reyes, M L; Foster, S A

    2015-01-01

    The postglacial adaptive radiation of the threespine stickleback fish (Gasterosteus aculeatus) has been widely used to investigate the roles of both adaptive evolution and plasticity in behavioral and morphological divergence from the ancestral condition represented by present-day oceanic stickleback. These phenotypes tend to exhibit high levels of ecotypic differentiation. Population divergence in life history has also been well studied, but in contrast to behavior and morphology, the extent and importance of plasticity has been much less well studied. In this review, we summarize what is known about life-history plasticity in female threespine stickleback, considering four traits intimately associated with reproductive output: age/size at maturation, level of reproductive effort, egg size and clutch size. We envision life-history plasticity in an iterative, ontogenetic framework, in which females may express plasticity repeatedly across each of several time frames. We contrast the results of laboratory and field studies because, for most traits, these approaches give somewhat different answers. We provide ideas on what the cues might be for observed plasticity in each trait and, when possible, we inquire about the relative costs and benefits to expressed plasticity. We end with an example of how we think plasticity may play out in stickleback life history given what we know of plasticity in the ancestor. PMID:26286665

  2. How Plastics Work

    NASA Astrophysics Data System (ADS)

    Bloomfield, Louis

    2013-03-01

    We encounter plastics every day, but despite their widespread use, amazing range of properties, and basic scientific underpinnings, most physicists--like most people--know relatively little about plastics. In contrast to hard crystalline and amorphous solids (e.g., metals, salts, ceramics, and glasses), we take plastics for granted, select them carelessly, and examine them more closely only on a need-to-know basis. By ignoring plastics until we need them, however, we risk not knowing what we don't know and using the wrong ones. To repurpose a familiar advertisement, ``there's a plastic for that.'' This talk will review some of the basic physics and science of plastics. It will examine the roles of temperature, order, intermolecular forces, entanglements, and linkages in plastics, and how those issues affect the properties of a given plastic. We'll stop along the way to recognize a few of the more familiar plastics, natural and synthetic, and explain some of their mechanical, chemical, and optical properties. The talk will conclude by explaining the remarkable properties of a plastic that has been largely misunderstood since its discovery 70 years ago: Silly Putty.

  3. Maturational and Non-Maturational Factors in Heritage Language Acquisition

    ERIC Educational Resources Information Center

    Moon, Ji Hye

    2012-01-01

    This dissertation aims to understand the maturational and non-maturational aspects of early bilingualism and language attrition in heritage speakers who have acquired their L1 incompletely in childhood. The study highlights the influential role of age and input dynamics in early L1 development, where the timing of reduction in L1 input and the…

  4. Our plastic age.

    PubMed

    Thompson, Richard C; Swan, Shanna H; Moore, Charles J; vom Saal, Frederick S

    2009-07-27

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation.

  5. CDK5 downregulation enhances synaptic plasticity.

    PubMed

    Posada-Duque, Rafael Andrés; Ramirez, Omar; Härtel, Steffen; Inestrosa, Nibaldo C; Bodaleo, Felipe; González-Billault, Christian; Kirkwood, Alfredo; Cardona-Gómez, Gloria Patricia

    2017-01-01

    CDK5 is a serine/threonine kinase that is involved in the normal function of the adult brain and plays a role in neurotransmission and synaptic plasticity. However, its over-regulation has been associated with Tau hyperphosphorylation and cognitive deficits. Our previous studies have demonstrated that CDK5 targeting using shRNA-miR provides neuroprotection and prevents cognitive deficits. Dendritic spine morphogenesis and forms of long-term synaptic plasticity-such as long-term potentiation (LTP)-have been proposed as essential processes of neuroplasticity. However, whether CDK5 participates in these processes remains controversial and depends on the experimental model. Using wild-type mice that received injections of CDK5 shRNA-miR in CA1 showed an increased LTP and recovered the PPF in deficient LTP of APPswe/PS1Δ9 transgenic mice. On mature hippocampal neurons CDK5, shRNA-miR for 12 days induced increased dendritic protrusion morphogenesis, which was dependent on Rac activity. In addition, silencing of CDK5 increased BDNF expression, temporarily increased phosphorylation of CaMKII, ERK, and CREB; and facilitated calcium signaling in neurites. Together, our data suggest that CDK5 downregulation induces synaptic plasticity in mature neurons involving Ca(2+) signaling and BDNF/CREB activation.

  6. Plastics and health risks.

    PubMed

    Halden, Rolf U

    2010-01-01

    By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics.

  7. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  8. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  9. Career Maturity of Welfare Recipients.

    ERIC Educational Resources Information Center

    Beckman, Carol M.

    To investigate the career maturity of welfare recipients, this thesis examines six independent variables: (1) race; (2) sex; (3) age; (4) level of formal education; (5) general intelligence; and (6) locus of control. Scales taken from the Career Maturity Inventory served as the dependent variables. The sample consisted of 83 welfare recipients who…

  10. Career Education and Career Maturity.

    ERIC Educational Resources Information Center

    Trebilco, Geoffrey R.

    1984-01-01

    Investigated the relationships between career maturity and career curriculum in 38 Melbourne metropolitan secondary schools (N=2280 students) using an Australian adaption of the Career Development Inventory. Results confirmed that schools with career education programs achieved higher gains in student career maturity. (JAC)

  11. Detecting plastics in seedcotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To increase global market share and value the US cotton industry needs to supply cotton lint that is free of contamination. Removing plastic contamination first requires developing a means to detect plastics in seedcotton. This study was conducted to validate a custom Ion Mobility Spectrometer (IM...

  12. Detecting plastics in seedcotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The US cotton industry wants to increase market share and value by supplying pure cotton. Removing contamination requires developing a means to detect plastics in seedcotton. This study was conducted to determine if Ion Mobility Spectrometry (IMS) could be used to find small amounts of plastic in ...

  13. Biodegradation of plastics.

    PubMed

    Shimao, M

    2001-06-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  14. Track recording plastic compositions

    NASA Technical Reports Server (NTRS)

    Tarle, Gregory (Inventor)

    1983-01-01

    Improved nuclear track recording plastic compositions are provided which exhibit greatly decreased surface roughness when etched to produce visible tracks of energetic nuclear particles which have passed into and/or through said plastic. The improved compositions incorporate a small quantity of a phthalic acid ester into the major plastic component which is derived from the polymerization of monomeric di-ethylene glycol bis allyl carbonate. Di-substituted phthalic acid esters are preferred as the added component, with the further perference that the ester substituent has a chain length of 2 or more carbon atoms. The inclusion of the phthalic acid ester to an extent of from about 1-2% by weight of the plastic compositions is sufficient to drastically reduce the surface roughness ordinarily produced when the track recording plastic is contacted by etchants.

  15. Sustainable harvest: managing plasticity for resilient crops

    PubMed Central

    Bloomfield, Justin A; Rose, Terry J; King, Graham J

    2014-01-01

    Maintaining crop production to feed a growing world population is a major challenge for this period of rapid global climate change. No consistent conceptual or experimental framework for crop plants integrates information at the levels of genome regulation, metabolism, physiology and response to growing environment. An important role for plasticity in plants is assisting in homeostasis in response to variable environmental conditions. Here, we outline how plant plasticity is facilitated by epigenetic processes that modulate chromatin through dynamic changes in DNA methylation, histone variants, small RNAs and transposable elements. We present examples of plant plasticity in the context of epigenetic regulation of developmental phases and transitions and map these onto the key stages of crop establishment, growth, floral initiation, pollination, seed set and maturation of harvestable product. In particular, we consider how feedback loops of environmental signals and plant nutrition affect plant ontogeny. Recent advances in understanding epigenetic processes enable us to take a fresh look at the crosstalk between regulatory systems that confer plasticity in the context of crop development. We propose that these insights into genotype × environment (G × E) interaction should underpin development of new crop management strategies, both in terms of information-led agronomy and in recognizing the role of epigenetic variation in crop breeding. PMID:24891039

  16. American Society of Plastic Surgeons

    MedlinePlus

    ... that instill confidence. Do Your Homework Patient Safety Plastic Surgery When you choose a doctor who is ... to procedure selector Why Choose A Board Certified Plastic Surgeon Choose a board-certified plastic surgeon and ...

  17. POLYESTER GLASS PLASTICS FOR SHIPBUILDING,

    DTIC Science & Technology

    POLYESTER PLASTICS , SHIP HULLS), (*SHIP HULLS, POLYESTER PLASTICS ), GLASS TEXTILES, REINFORCING MATERIALS, SHIP STRUCTURAL COMPONENTS, COMPOSITE MATERIALS, PROCESSING, CHEMISTRY, HANDBOOKS, BINDERS, USSR

  18. Subplate Neurons: Crucial Regulators of Cortical Development and Plasticity

    PubMed Central

    Kanold, Patrick O.

    2009-01-01

    The developing cerebral cortex contains a distinct class of cells, subplate neurons, which form one of the first functional cortical circuits. Subplate neurons reside in the cortical white matter, receive thalamic inputs and project into the developing cortical plate, mostly to layer 4. Subplate neurons are present at key time points during development. Removal of subplate neurons profoundly affects cortical development. Subplate removal in visual cortex prevents the maturation of thalamocortical synapse, the maturation of inhibition in layer 4, the development of orientation selective responses in individual cortical neurons, and the formation of ocular dominance columns. In addition, monocular deprivation during development reveals that ocular dominance plasticity is paradoxical in the absence of subplate neurons. Because subplate neurons projecting to layer 4 are glutamatergic, these diverse deficits following subplate removal were hypothesized to be due to lack of feed-forward thalamic driven cortical excitation. A computational model of the developing thalamocortical pathway incorporating feed-forward excitatory subplate projections replicates both normal development and plasticity of ocular dominance as well as the effects of subplate removal. Therefore, we postulate that feed-forward excitatory projections from subplate neurons into the developing cortical plate enhance correlated activity between thalamus and layer 4 and, in concert with Hebbian learning rules in layer 4, allow maturational and plastic processes in layer 4 to commence. Thus subplate neurons are a crucial regulator of cortical development and plasticity, and damage to these neurons might play a role in the pathology of many neurodevelopmental disorders. PMID:19738926

  19. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  20. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  1. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  2. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  3. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  4. Reproductive maturity of cherry fruit fly (Diptera: Tephritidae) in managed and natural habitats.

    PubMed

    Teixeira, Luís A F; Gut, Larry J; Isaacs, Rufus; Alston, Diane G

    2009-08-01

    We studied the timing of reproductive maturity of cherry fruit fly, Rhagoletis cingulata (Loew), a key pest of sweet and tart cherries in the eastern United States. To determine when cherry fruit fly females become reproductively mature in managed and natural habitats, we deployed traps in sweet and tart cherry orchards and nearby stands of the ancestral host tree, black cherry. Flies were removed from the traps and females were dissected to determine the presence of fully developed eggs. We found that capture of reproductively mature female flies occurred earlier in orchards that are not sprayed with insecticides than in sprayed orchards or in black cherry tree sites. In addition, the gap between the flights of immature and mature females in unmanaged sweet or tart cherry orchards was shorter than in managed orchards or black cherry tree sites. We also determined fruit color, size, and skin hardness to characterize the progression of fruit maturity. We found that fruit became mature earlier in sweet and tart cherry orchards than in black cherry tree sites. This study indicates that the timing of female reproductive maturity is plastic and varies among cherry fruit fly populations present in distinct habitats. Variation in the timing of reproductive maturity is related to the fruit maturity period of distinct host plant species and to orchard management.

  5. Mechanical plasticity of cells

    NASA Astrophysics Data System (ADS)

    Bonakdar, Navid; Gerum, Richard; Kuhn, Michael; Spörrer, Marina; Lippert, Anna; Schneider, Werner; Aifantis, Katerina E.; Fabry, Ben

    2016-10-01

    Under mechanical loading, most living cells show a viscoelastic deformation that follows a power law in time. After removal of the mechanical load, the cell shape recovers only incompletely to its original undeformed configuration. Here, we show that incomplete shape recovery is due to an additive plastic deformation that displays the same power-law dynamics as the fully reversible viscoelastic deformation response. Moreover, the plastic deformation is a constant fraction of the total cell deformation and originates from bond ruptures within the cytoskeleton. A simple extension of the prevailing viscoelastic power-law response theory with a plastic element correctly predicts the cell behaviour under cyclic loading. Our findings show that plastic energy dissipation during cell deformation is tightly linked to elastic cytoskeletal stresses, which suggests the existence of an adaptive mechanism that protects the cell against mechanical damage.

  6. Shape-Shifting Plastic

    SciTech Connect

    2015-05-20

    A new plastic developed by ORNL and Washington State University transforms from its original shape through a series of temporary shapes and returns to its initial form. The shape-shifting process is controlled through changes in temperature

  7. A Plastic Menagerie

    ERIC Educational Resources Information Center

    Hadley, Mary Jane

    2010-01-01

    Bobble heads had become quite popular, depicting all sorts of sports figures, animals, and even presidents. In this article, the author describes how her fourth graders made bobble head sculptures out of empty plastic drink bottles. (Contains 1 online resource.)

  8. Strain avalanches in plasticity

    NASA Astrophysics Data System (ADS)

    Argon, A. S.

    2013-09-01

    Plastic deformation at the mechanism level in all solids occurs in the form of discrete thermally activated individual stress relaxation events. While there are clear differences in mechanisms between dislocation mediated events in crystalline solids and by individual shear transformations in amorphous metals and semiconductors, such relaxation events interact strongly to form avalanches of strain bursts. In all cases the attendant distributions of released energy as amplitudes of acoustic emissions, or in serration amplitudes in flow stress, the levels of strain bursts are of fractal character with fractal exponents in the range from -1.5 to -2.0, having the character of phenomena of self-organized criticality, SOC. Here we examine strain avalanches in single crystals of ice, hcp metals, the jerky plastic deformations of nano-pillars of fcc and bcc metals deforming in compression, those in the plastic flow of bulk metallic glasses, all demonstrating the remarkable universality of character of plastic relaxation events.

  9. Dreaming in plastic

    NASA Astrophysics Data System (ADS)

    Korzhov, Marianna; Andelman, David; Shikler, Rafi

    2008-07-01

    Plastic is one of the most versatile materials available. It is cheap, flexible and easy to process, and as a result it is all around us - from our computer keyboards to the soles of our shoes. One of its most common applications is as an insulating coating for electric wires; indeed, plastic is well known for its insulating characteristics. It came as something of a surprise, therefore, when in the late 1970s a new generation of plastics was discovered that displayed exactly the opposite behaviour - the ability to conduct electricity. In fact, plastics can be made with a whole range of conductivities - there are polymer materials that behave like semiconductors and there are those that can conduct as well as metals. This discovery sparked a revolution in the electronics community, and three decades of research effort is now yielding a range of stunning new applications for this ubiquitous material.

  10. Physics in Plastics Technology.

    ERIC Educational Resources Information Center

    Thomas, Ken

    1980-01-01

    Discusses the increasing role of the physicist in plastics technology. Relationships of molecular structure to material behavior, design which is related to the material, and the practical problems of fabricating a material into an article are included. (HM)

  11. Laser cutting plastic materials

    SciTech Connect

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  12. The Need for Plastics Education.

    ERIC Educational Resources Information Center

    Society of Plastics Engineers, Inc., Stamford, CT.

    In view of a lack of trained personnel in the industry, the Plastics Education Foundation proposes that educators (1) add more plastics programs, (2) establish plastics engineering degrees at appropriate 4-year institutions, (3) add plastics processing technology to current engineering curricula, and (4) interest younger students in courses and/or…

  13. Roles of presynaptic NMDA receptors in neurotransmission and plasticity

    PubMed Central

    Banerjee, Abhishek; Larsen, Rylan S.; Philpot, Benjamin D.; Paulsen, Ole

    2015-01-01

    Presynaptic NMDA receptors (preNMDARs) play pivotal roles in excitatory neurotransmission and synaptic plasticity. They facilitate presynaptic neurotransmitter release and modulate mechanisms controlling synaptic maturation and plasticity during formative periods of brain development. There is an increasing understanding of the roles of preNMDARs in experience-dependent synaptic and circuit-specific computation. In this review, we summarize the latest understanding of compartment-specific expression and function of preNMDARs, and how they contribute to synapse-specific and circuit-level information processing. PMID:26726120

  14. Longitudinal maturation of auditory cortical function during adolescence

    PubMed Central

    Fitzroy, Ahren B.; Krizman, Jennifer; Tierney, Adam; Agouridou, Manto; Kraus, Nina

    2015-01-01

    Cross-sectional studies have demonstrated that the cortical auditory evoked potential (CAEP) changes substantially in amplitude and latency from childhood to adulthood, suggesting that these aspects of the CAEP continue to mature through adolescence. However, no study to date has longitudinally followed maturation of these CAEP measures through this developmental period. Additionally, no study has examined the trial-to-trial variability of the CAEP during adolescence. Therefore, we longitudinally tracked changes in the latency, amplitude, and variability of the P1, N1, P2, and N2 components of the CAEP in 68 adolescents from age 14 years to age 17 years. Latency decreased for N1 and N2, and did not change for P1 or P2. Amplitude decreased for P1 and N2, increased for N1, and did not change for P2. Variability decreased with age for all CAEP components. These findings provide longitudinal support for the view that the human auditory system continues to mature through adolescence. Continued auditory system maturation through adolescence suggests that CAEP neural generators remain plastic during this age range and potentially amenable to experience-based enhancement or deprivation. PMID:26539092

  15. WNT signaling in neuronal maturation and synaptogenesis

    PubMed Central

    Rosso, Silvana B.; Inestrosa, Nibaldo C.

    2013-01-01

    The Wnt signaling pathway plays a role in the development of the central nervous system and growing evidence indicates that Wnts also regulates the structure and function of the adult nervous system. Wnt components are key regulators of a variety of developmental processes, including embryonic patterning, cell specification, and cell polarity. In the nervous system, Wnt signaling also regulates the formation and function of neuronal circuits by controlling neuronal differentiation, axon outgrowth and guidance, dendrite development, synaptic function, and neuronal plasticity. Wnt factors can signal through three very well characterized cascades: canonical or β-catenin pathway, planar cell polarity pathway and calcium pathway that control different processes. However, divergent downstream cascades have been identified to control neuronal morphogenesis. In the nervous system, the expression of Wnt proteins is a highly controlled process. In addition, deregulation of Wnt signaling has been associated with neurodegenerative diseases. Here, we will review different aspects of neuronal and dendrite maturation, including spinogenesis and synaptogenesis. Finally, the role of Wnt pathway components on Alzheimer’s disease will be revised. PMID:23847469

  16. Ribosome maturation in E. coli.

    PubMed

    Silengo, L; Altruda, F; Dotto, G P; Lacquaniti, F; Perlo, C; Turco, E; Mangiarotti, G

    1977-01-01

    In vivo and in vitro experiments have shown that processing of ribosomal RNA is a late event in ribosome biogenesis. The precursor form of RNA is probably necessary to speed up the assembly of ribomal proteins. Newly formed ribosomal particles which have already entered polyribosomes differ from mature ribosomes not only in their RNA content but also in their susceptibility to unfolding in low Mg concentration and to RNase attack. Final maturation of new ribosomes is probably dependent on their functioning in protein synthesis. Thus only those ribosomes which have proven to be functional may be converted into stable cellular structures.

  17. The plasticity of clays

    USGS Publications Warehouse

    Group, F.F.

    1905-01-01

    (1) Sand injures plasticity little at first because the grains are suspended in a plastic mass. It is only when grains are abundant enough to come in contact with their neighbors, that the effect becomes serious, and then both strength and amount of possible flow are injured. (2) Certain rare organic colloids increase the plasticity by rendering the water viscous. (3) Fineness also tends to increase plasticity. (4) Plane surfaces (plates) increase the amount of possible flow. They also give a chance for lubrication by thinner films, thus increasing the friction of film, and the strength of the whole mass. The action of plates is thus twofold ; but fineness may be carried to such an extent as to break up plate-like grains into angular fragments. The beneficial effects of plates are also decreased by the fact that each is so closely surrounded by others in the mass. (5) Molecular attraction is twofold in increasing plasticity. As the attraction increases, the coherence and strength of the mass increase, and the amount of possible deformation before crumbling also increases. Fineness increases this action by requiring more water. Colloids and crystalloids in solution may also increase the attraction. It is thus seen to be more active than any other single factor.

  18. Alternative life histories in Xiphophorus multilineatus: evidence for different ages at sexual maturity and growth responses in the wild.

    PubMed

    Bono, L M; Rios-Cardenas, O; Morris, M R

    2011-05-01

    In order to examine potential trade-offs in alternative life histories of the high-backed pygmy swordtail Xiphophorus multilineatus, otoliths were used from wild-caught males to determine if sneaker males had the advantage of maturing earlier in natural environments. The sneakers matured significantly earlier than courters, but there was no difference among the three courter variants. In addition, analyses suggested that the effect of the pituitary locus on size at sexual maturity and growth rates was a consequence of age at sexual maturity. Finally, one of the courter variants had a significantly different relationship between age and size at sexual maturity than the other variants, suggesting that in this variant, age at sexual maturity may be more closely related to size and therefore may be less plastic in its growth responses.

  19. Adult cortical plasticity following injury: Recapitulation of critical period mechanisms?

    PubMed Central

    Nahmani, Marc; Turrigiano, Gina G.

    2014-01-01

    A primary goal of research on developmental critical periods is the recapitulation of a juvenile-like state of malleability in the adult brain that might enable recovery from injury. These ambitions are often framed in terms of the simple reinstatement of enhanced plasticity in the growth-restricted milieu of an injured adult brain. Here, we provide an analysis of the similarities and differences between deprivation-induced and injury-induced cortical plasticity, to provide for a nuanced comparison of these remarkably similar processes. As a first step, we review the factors that drive ocular dominance plasticity in the primary visual cortex of the uninjured brain during the critical period (CP) and in adults, to highlight processes that might confer adaptive advantage. In addition, we directly compare deprivation-induced cortical plasticity during the CP and plasticity following acute injury or ischemia in mature brain. We find that these two processes display a biphasic response profile following deprivation or injury: an initial decrease in GABAergic inhibition and synapse loss transitions into a period of neurite expansion and synaptic gain. This biphasic response profile emphasizes the transition from a period of cortical healing to one of reconnection and recovery of function. Yet while injury-induced plasticity in adult shares several salient characteristics with deprivation-induced plasticity during the CP, the degree to which the adult injured brain is able to functionally rewire, and the time required to do so, present major limitations for recovery. Attempts to recapitulate a measure of CP plasticity in an adult injury context will need to carefully dissect the circuit alterations and plasticity mechanisms involved while measuring functional behavioral output to assess their ultimate success. PMID:24791715

  20. Transient ECM protease activity promotes synaptic plasticity

    PubMed Central

    Magnowska, Marta; Gorkiewicz, Tomasz; Suska, Anna; Wawrzyniak, Marcin; Rutkowska-Wlodarczyk, Izabela; Kaczmarek, Leszek; Wlodarczyk, Jakub

    2016-01-01

    Activity-dependent proteolysis at a synapse has been recognized as a pivotal factor in controlling dynamic changes in dendritic spine shape and function; however, excessive proteolytic activity is detrimental to the cells. The exact mechanism of control of these seemingly contradictory outcomes of protease activity remains unknown. Here, we reveal that dendritic spine maturation is strictly controlled by the proteolytic activity, and its inhibition by the endogenous inhibitor (Tissue inhibitor of matrix metalloproteinases-1 – TIMP-1). Excessive proteolytic activity impairs long-term potentiation of the synaptic efficacy (LTP), and this impairment could be rescued by inhibition of protease activity. Moreover LTP is altered persistently when the ability of TIMP-1 to inhibit protease activity is abrogated, further demonstrating the role of such inhibition in the promotion of synaptic plasticity under well-defined conditions. We also show that dendritic spine maturation involves an intermediate formation of elongated spines, followed by their conversion into mushroom shape. The formation of mushroom-shaped spines is accompanied by increase in AMPA/NMDA ratio of glutamate receptors. Altogether, our results identify inhibition of protease activity as a critical regulatory mechanism for dendritic spines maturation. PMID:27282248

  1. Consumer hazards of plastics.

    PubMed Central

    Wiberg, G S

    1976-01-01

    The modern consumer is exposed to a wide variety of plastic and rubber products in his day to day life: at home, work, school, shopping, recreation and play, and transport. A large variety of toxic sequellae have resulted from untoward exposures by many different routes: oral, dermal, inhalation, and parenteral. Toxic change may result from the plastic itself, migration of unbound components and additives, chemical decomposition or toxic pyrolysis products. The type of damage may involve acute poisoning, chronic organ damage, reproductive disorders, and carcinogenic, mutagenic and teratogenic episodes. Typical examples for all routes are cited along with the activites of Canadian regulatory agencies to reduce both the incidence and severity of plastic-induced disease. PMID:1026409

  2. Adolescent Maturation in Transitioning Cultures.

    ERIC Educational Resources Information Center

    Mulroy, Kevin; Palacios, Anna; Reid, Robert E.

    This is a theoretical study of adolescent maturation within a cultural context. Personality development and disintegration due to the pressure of a dominant culture on a minority culture is considered. An attempt is made to understand how teachers might assist students to work out their psychological growth by story telling. The need for cultural…

  3. Psychosocial Maturity or Social Desirability?

    ERIC Educational Resources Information Center

    Greenberger, Ellen

    The psychosocial maturity scale (PSM) described in several earlier papers is a self-report questionnaire. It is vulnerable, as are other questionnaires of this type, to respondents' wishes to present themselves in a socially desirable light. In this study, scores on two social desirability scales are examined in relation to PSM. Correlations…

  4. Enticing Mature Females into College.

    ERIC Educational Resources Information Center

    Loseth, Lexie; Moreau, Linda

    Following a review of the literature on mature female students, this paper examines enrollment trends in a selection of colleges in Alberta (Canada) and presents the findings of a survey of returning women students at Red Deer College. The literature review highlights factors related to the personal and professional development of women graduates…

  5. Human oocyte maturation in vitro.

    PubMed

    Coticchio, Giovanni; Dal-Canto, Mariabeatrice; Guglielmo, Maria-Cristina; Mignini-Renzini, Mario; Fadini, Rubens

    2012-01-01

    Oocytes from medium-sized antral follicles have already completed their growth phase and, if released from the follicular environment and cultured in vitro, are able to resume the meiotic process and mature. However, in vitro maturation (IVM) does not entirely support all the nuclear and cytoplasmic changes that occur physiologically as an effect of the ovulatory stimulus. Regardless, oocyte IVM is widely applied for the breeding of agriculturally important species. In assisted reproduction technology, IVM has been proposed as an alternative treatment to circumvent the drawbacks of standard ovarian stimulation regimens. Initially introduced to eliminate the risks of ovarian hyperstimulation syndrome afflicting women presenting with polycystic ovaries, subsequently IVM has been suggested to represent an additional approach suitable also for normovulatory patients. So far, in children born from IVM cycles, no doubts of an increased incidence of congenital abnormalities have been raised. Many more births would be achieved if novel IVM systems, currently dominated by empiricism, could be conceived according to more physiological criteria. Recent findings shedding new light on the control of meiotic progression, the support of cumulus cells to the oocyte cellular reorganization occurring during maturation, and the modulation of the stimulus that promotes oocyte maturation downstream the mid-cycle gonadotropin signal are likely to provide crucial hints for the development of more efficient IVM systems.

  6. Sleep and developmental plasticity not just for kids.

    PubMed

    Frank, Marcos Gabriel

    2011-01-01

    In a variety of mammalian species, sleep amounts are highest during developmental periods of rapid brain development and synaptic plasticity than at any other time in life [Frank, M. G. & Heller, H. C. (1997a). Development of REM and slow wave sleep in the rat. American Journal of Physiology, 272, R1792-R1799; Jouvet-Mounier, D., Astic, L., & Lacote, D. (1970). Ontogenesis of the states of sleep in rat, cat and guinea pig during the first postnatal month. Developmental Psychobiology, 2, 216-239; Roffwarg, H. P., Muzio, J. N., & Dement, W. C. (1966). Ontogenetic development of the human sleep-dream cycle. Science, 604-619]. Many of the mechanisms governing developmental plasticity also mediate plasticity in the adult brain. Therefore, studying the role of sleep in developmental plasticity may provide insights more generally into sleep function across the lifespan. In this chapter, I review the evidence that supports a critical role for sleep in developmental brain plasticity. I begin with an overview of past studies that support a role for sleep in general brain maturation. This is followed by more recent findings in the developing visual cortex that more specifically address a possible role for sleep in cortical plasticity.

  7. Depletion of primary cilia from mature dentate granule cells impairs hippocampus-dependent contextual memory

    PubMed Central

    Rhee, Soyoung; Kirschen, Gregory W.; Gu, Yan; Ge, Shaoyu

    2016-01-01

    The primary cilium, a sensory organelle, regulates cell proliferation and neuronal development of dentate granule cells in the hippocampus. However, its role in the function of mature dentate granule cells remains unknown. Here we specifically depleted and disrupted ciliary proteins IFT20 and Kif3A (respectively) in mature dentate granule cells and investigated hippocampus-dependent contextual memory and long-term plasticity at mossy fiber synapses. We found that depletion of IFT20 in these cells significantly impaired context-dependent fear-related memory. Furthermore, we tested synaptic plasticity of mossy fiber synapses in area CA3 and found increased long-term potentiation upon depletion of IFT20 or disruption of Kif3A. Our findings suggest a role of primary cilia in the memory function of mature dentate granule cells, which may result from abnormal mossy fiber synaptic plasticity. A direct link between the primary cilia of mature dentate granule cells and behavior will require further investigation using independent approaches to manipulate primary cilia. PMID:27678193

  8. Corticospinal circuit plasticity in motor rehabilitation from spinal cord injury.

    PubMed

    Serradj, Najet; Agger, Sydney F; Hollis, Edmund R

    2016-12-06

    Restoring corticospinal function after spinal cord injury is a significant challenge as the corticospinal tract elicits no substantive, spontaneous regeneration, and its interruption leaves a permanent deficit. The corticospinal circuit serves multiple motor and sensory functions within the mammalian nervous system as the direct link between isocortex and spinal cord. Maturation of the corticospinal circuit involves the refinement of projections within the spinal cord and a subsequent refinement of motor maps within the cortex. The plasticity of these cortical motor maps mirrors the acquisition of skilled motor learning, and both the maps and motor skills are disrupted following injury to the corticospinal tract. The motor cortex exhibits the capacity to incorporate changes in corticospinal projections induced by both spontaneous and therapeutic-mediated plasticity of corticospinal axons through appropriate rehabilitation. An understanding of the mechanisms of corticospinal plasticity in motor learning will undoubtedly help inform strategies to improve motor rehabilitation after spinal cord injury.

  9. Adaptive variability in the duration of critical windows of plasticity

    PubMed Central

    Wells, Jonathan C. K.

    2014-01-01

    Developmental plasticity underlies widespread associations between early-life exposures and many components of adult phenotype, including the risk of chronic diseases. Humans take almost two decades to reach reproductive maturity, and yet the ‘critical windows’ of physiological sensitivity that confer developmental plasticity tend to close during fetal life or infancy. While several explanations for lengthy human maturation have been offered, the brevity of physiological plasticity has received less attention. I argue that offspring plasticity is only viable within the niche of maternal care, and that as this protection is withdrawn, the offspring is obliged to canalize many developmental traits in order to minimize environmental disruptions. The schedule of maternal care may therefore shape the duration of critical windows, and since the duration of this care is subject to parent–offspring conflict, the resolution of this conflict may shape the duration of critical windows. This perspective may help understand (i) why windows close at different times for different traits, and (ii) why the duration of critical windows may vary across human populations. The issue is explored in relation to population differences in the association between infant weight gain and later body composition. The occupation of more stable environments by western populations may have favoured earlier closure of the critical window during which growth in lean mass is sensitive to nutritional intake. This may paradoxically have elevated the risk of obesity following rapid infant weight gain in such populations. PMID:25095791

  10. Plastics in Perspective.

    ERIC Educational Resources Information Center

    Bergandine, David R.; Holm, D. Andrew

    The materials in this curriculum supplement, developed for middle school or high school science classes, present solid waste problems related to plastics. The set of curriculum materials is divided into two units to be used together or independently. Unit I begins by comparing patterns in solid waste from 1960 to 1990 and introducing methods for…

  11. Hydrodynamic Elastic Magneto Plastic

    SciTech Connect

    Wilkins, M. L.; Levatin, J. A.

    1985-02-01

    The HEMP code solves the conservation equations of two-dimensional elastic-plastic flow, in plane x-y coordinates or in cylindrical symmetry around the x-axis. Provisions for calculation of fixed boundaries, free surfaces, pistons, and boundary slide planes have been included, along with other special conditions.

  12. Preserving in Plastic.

    ERIC Educational Resources Information Center

    Wahla, James

    1985-01-01

    Outlines steps for casting insects in permanent molds prepared from commercially available liquid plastic. Also describes dry mountings in glass, acrylic, and petri dishes. The rationale for specimen use, hints for producing quality results, purchasing information, and safety precautions are considered. (DH)

  13. Plastics (Environmental Health Student Portal)

    MedlinePlus

    ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Plastics The Basics Plastics play a ...

  14. Plastics Pollution Control Technology Research

    DTIC Science & Technology

    1992-01-01

    various machines, the plastics processor, the pulper, and the compactor, being developed to address the plastics problem firsthand. The Dialogue...incinerators themselves may not be a part of the Navy’s solution to the plastics problem , the space that the incinerators occupy will be useful. It is the... plastics problem although they believe that the Navy will not be in compliance by 1993. They suggested that a change in the law which will allow them to keep

  15. Reducing Navy Marine Plastic Pollution

    DTIC Science & Technology

    1988-06-28

    pollution. Plastic debris from ships is littering beaches, and killing and debilitating fish and wildlife because they are ingesting plastic , or because...they are becoming entangled in plastic debris . While no one is purposefully causing these impacts, the effects are becoming more pronounced. In the...generate support for shipboard and service-wide activities. The recommendations in this section call for disseminating information about the plastic debris

  16. Maturation of Oocytes in Vitro.

    PubMed

    Lonergan, Patrick; Fair, Trudee

    2016-01-01

    Only a fraction of oocytes present in the ovaries at birth are ever ovulated during the lifetime of a female mammal. In vitro maturation (IVM) offers the possibility to exploit what is a largely untapped biological resource. Although IVM is used routinely for the in vitro production of embryos in domestic species, especially cattle, its clinical use in human-assisted reproduction is still evolving. The successful recapitulation in vitro of the events associated with successful oocyte maturation is not always achieved, with the majority of immature oocytes typically failing to develop to the blastocyst stage. Evidence suggests that although culture conditions throughout in vitro embryo production may have a modest influence on the developmental potential of the early embryo, the quality of the oocyte at the start of the process is the key factor determining the proportion of oocytes developing to the blastocyst stage.

  17. The Influence of Ouabain on Human Dendritic Cells Maturation

    PubMed Central

    Nascimento, C. R.; Valente, R. C.; Echevarria-Lima, J.; Fontes, C. F. L.; de Araujo-Martins, L.; Araujo, E. G.; Rumjanek, V. M.

    2014-01-01

    Although known as a Na,K-ATPase inhibitor, several other cellular and systemic actions have been ascribed to the steroid Ouabain (Oua). Particularly in the immune system, our group showed that Ouabain acts on decreasing lymphocyte proliferation, synergizing with glucocorticoids in spontaneous thymocyte apoptosis, and also lessening CD14 expression and blocking CD16 upregulation on human monocytes. However, Ouabain effects on dendritic cells (DCs) were not explored so far. Considering the peculiar plasticity and the importance of DCs in immune responses, the aim of our study was to investigate DC maturation under Ouabain influence. To generate immature DCs, human monocytes were cultured with IL-4 and GM-CSF (5 days). To investigate Ouabain role on DC activation, DCs were stimulated with TNF-α for 48 h in the presence or absence of Ouabain. TNF-induced CD83 expression and IL-12 production were abolished in DCs incubated with 100 nM Ouabain, though DC functional capacity concerning lymphocyte activation remained unaltered. Nevertheless, TNF-α-induced antigen capture downregulation, another maturation marker, occurred even in the presence of Ouabain. Besides, Ouabain increased HLA-DR and CD86 expression, whereas CD80 expression was maintained. Collectively, our results suggest that DCs respond to Ouabain maturating into a distinct category, possibly contributing to the balance between immunity and tolerance. PMID:25609892

  18. Plastics for Elementary School Children

    ERIC Educational Resources Information Center

    Hanson, Jack

    1977-01-01

    Describes three plastics projects (which involve making a styrene fishing bobber, an acrylic salad fork and spoon set, and acetate shrink art) designed to provide elementary level students an opportunity to work with plastics and to learn about careers in plastics production and distribution. (TA)

  19. Maturity model for enterprise interoperability

    NASA Astrophysics Data System (ADS)

    Guédria, Wided; Naudet, Yannick; Chen, David

    2015-01-01

    Historically, progress occurs when entities communicate, share information and together create something that no one individually could do alone. Moving beyond people to machines and systems, interoperability is becoming a key factor of success in all domains. In particular, interoperability has become a challenge for enterprises, to exploit market opportunities, to meet their own objectives of cooperation or simply to survive in a growing competitive world where the networked enterprise is becoming a standard. Within this context, many research works have been conducted over the past few years and enterprise interoperability has become an important area of research, ensuring the competitiveness and growth of European enterprises. Among others, enterprises have to control their interoperability strategy and enhance their ability to interoperate. This is the purpose of the interoperability assessment. Assessing interoperability maturity allows a company to know its strengths and weaknesses in terms of interoperability with its current and potential partners, and to prioritise actions for improvement. The objective of this paper is to define a maturity model for enterprise interoperability that takes into account existing maturity models while extending the coverage of the interoperability domain. The assessment methodology is also presented. Both are demonstrated with a real case study.

  20. The Difference of Structural State and Deformation Behavior between Teenage and Mature Human Dentin

    PubMed Central

    Panfilov, Peter; Zaytsev, Dmitry; Antonova, Olga V.; Alpatova, Victoria; Kiselnikova, Larissa P.

    2016-01-01

    Objective. The cause of considerable elasticity and plasticity of human dentin is discussed in the relationship with its microstructure. Methods. Structural state of teenage and mature human dentin is examined by using XRD and TEM techniques, and their deformation behavior under compression is studied as well. Result. XRD study has shown that crystallographic type of calcium hydroxyapatite in human dentin (calcium hydrogen phosphate hydroxide Ca9HPO4(PO4)5OH; Space Group P63/m (176); a = 9,441 A; c = 6,881 A; c/a = 0,729; Crystallite (Scherrer) 200 A) is the same for these age groups. In both cases, dentin matrix is X-ray amorphous. According to TEM examination, there are amorphous and ultrafine grain phases in teenage and mature dentin. Mature dentin is stronger on about 20% than teenage dentin, while teenage dentin is more elastic on about 20% but is less plastic on about 15% than mature dentin. Conclusion. The amorphous phase is dominant in teenage dentin, whereas the ultrafine grain phase becomes dominant in mature dentin. Mechanical properties of human dentin under compression depend on its structural state, too. PMID:26989416

  1. A QSPR for the plasticization efficiency of polyvinylchloride plasticizers.

    PubMed

    Chandola, Mridula; Marathe, Sujata

    2008-01-01

    A simple quantitative structure property relationship (QSPR) for correlating the plasticization efficiency of 25 polyvinylchloride (PVC) plasticizers was obtained using molecular modeling. The plasticizers studied were-aromatic esters (phthalate, terephthalate, benzoate, trimellitate), aliphatic esters (adipate, sebacate, azelate), citrates and a phosphate. The low temperature flex point, Tf, of plasticized polyvinylchloride resins was considered as an indicator of plasticization efficiency. Initially, we attempted to predict plasticization efficiency of PVC plasticizers from physical and structural descriptors derived from the plasticizer molecule alone. However, the correlation of these descriptors with Tf was not very good with R=0.78 and r2=0.613. This implied that the selected descriptors were unable to predict all the interactions between PVC and plasticizer. Hence, to account for these interactions, a model containing two polyvinylchloride (PVC) chain segments along with a plasticizer molecule in a simulation box was constructed, using molecular mechanics. A good QSPR equation correlating physical and structural descriptors derived from the model to Tf of the plasticized resins was obtained with R=0.954 and r2=0.909.

  2. Rapidly shifting maturation schedules following reduced commercial harvest in a freshwater fish

    PubMed Central

    Feiner, Zachary S; Chong, Stephen C; Knight, Carey T; Lauer, Thomas E; Thomas, Michael V; Tyson, Jeffrey T; Höök, Tomas O

    2015-01-01

    Size-selective harvest of fish stocks can lead to maturation at smaller sizes and younger ages, which may depress stock productivity and recovery. Such changes in maturation may be very slow to reverse, even following complete fisheries closures. We evaluated temporal trends in maturation of five Great Lakes stocks of yellow perch (Perca flavescens Mitchill) using indices that attempt to disentangle plastic and evolutionary changes in maturation: age at 50% maturity and probabilistic maturation reaction norms (PMRNs). Four populations were fished commercially throughout the time series, while the Lake Michigan fishery was closed following a stock collapse. We documented rapid increases in PMRNs of the Lake Michigan stock coincident with the commercial fishery closure. Saginaw Bay and Lake Huron PMRNs also increased following reduced harvest, while Lake Erie populations were continuously fished and showed little change. The rapid response of maturation may have been enhanced by the short generation time of yellow perch and potential gene flow between northern and southern Lake Michigan, in addition to potential reverse adaptation following the fishing moratorium. These results suggest that some fish stocks may retain the ability to recover from fisheries-induced life history shifts following fishing moratoria. PMID:26240608

  3. Mapping the electrophysiological marker of sleep depth reveals skill maturation in children and adolescents.

    PubMed

    Kurth, Salome; Ringli, Maya; Lebourgeois, Monique K; Geiger, Anja; Buchmann, Andreas; Jenni, Oskar G; Huber, Reto

    2012-11-01

    Electroencephalographically (EEG) recorded slow wave activity (SWA, 1-4.5Hz), reflecting the depth of sleep, is suggested to play a crucial role in synaptic plasticity. Mapping of SWA by means of high-density EEG reveals that cortical regions showing signs of maturational changes (structural and behavioral) during childhood and adolescence exhibit more SWA. Moreover, the maturation of specific skills is predicted by the topographical distribution of SWA. Thus, SWA topography may serve as a promising neuroimaging tool with prognostic potential. Finally, our data suggest that deep sleep SWA in humans is involved in cortical development that optimizes performance.

  4. 7 CFR 51.2651 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2651 Mature. Mature means that the cherries have reached the stage of growth which will insure the...

  5. 7 CFR 51.3058 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Florida Avocados Definitions § 51.3058 Mature. Mature means that the avocado has reached a stage of growth which will insure a proper completion of...

  6. 7 CFR 51.2651 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2651 Mature. Mature means that the cherries have reached the stage of growth which will insure the...

  7. Career Maturity: The Construct and its Measurement.

    ERIC Educational Resources Information Center

    Savickas, Mark L.

    1984-01-01

    Describes vocational maturity and assists counselors in identifying what the various career maturity instruments measure. Discusses task variable measures, intervening variable measures, response variable measures, and methods of choosing an instrument. (JAC)

  8. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics Acquisitions Inc., Including On-Site Leased Workers From Kelly Services and Shelley... Adjustment Assistance on July 3, 2012, applicable to workers and former workers of workers of Fortis...

  9. Energy metabolism plasticity enables stemness programs.

    PubMed

    Folmes, Clifford D L; Nelson, Timothy J; Dzeja, Petras P; Terzic, Andre

    2012-04-01

    Engineering pluripotency through nuclear reprogramming and directing stem cells into defined lineages underscores cell fate plasticity. Acquisition of and departure from stemness are governed by genetic and epigenetic controllers, with modulation of energy metabolism and associated signaling increasingly implicated in cell identity determination. Transition from oxidative metabolism, typical of somatic tissues, into glycolysis is a prerequisite to fuel-proficient reprogramming, directing a differentiated cytotype back to the pluripotent state. The glycolytic metabotype supports the anabolic and catabolic requirements of pluripotent cell homeostasis. Conversely, redirection of pluripotency into defined lineages requires mitochondrial biogenesis and maturation of efficient oxidative energy generation and distribution networks to match demands. The vital function of bioenergetics in regulating stemness and lineage specification implicates a broader role for metabolic reprogramming in cell fate decisions and determinations of tissue regenerative potential.

  10. Brain plasticity in the developing brain.

    PubMed

    Kolb, Bryan; Mychasiuk, Richelle; Muhammad, Arif; Gibb, Robbin

    2013-01-01

    The developing normal brain shows a remarkable capacity for plastic change in response to a wide range of experiences including sensory and motor experience, psychoactive drugs, parent-child relationships, peer relationships, stress, gonadal hormones, intestinal flora, diet, and injury. The effects of injury vary with the precise age-at-injury, with the general result being that injury during cell migration and neuronal maturation has a poor functional outcome, whereas similar injury during synaptogenesis has a far better outcome. A variety of factors influence functional outcome including the nature of the behavior in question and the age at behavioral assessment as well as pre- and postinjury experiences. Here, we review the phases of brain development, how factors influence brain, and behavioral development in both the normal and perturbed brain, and propose mechanisms that may underlie these effects.

  11. Respiratory muscle plasticity.

    PubMed

    Rowley, Katharine L; Mantilla, Carlos B; Sieck, Gary C

    2005-07-28

    Plasticity of respiratory muscles must be considered in the context of their unique physiological demands. The continuous rhythmic activation of respiratory muscles makes them among the most active in the body. Respiratory muscles, especially the diaphragm, are non-weight-bearing, and thus, in contrast to limb muscles, are not exposed to gravitational effects. Perturbations in normal activation and load known to induce plasticity in limb muscles may not cause similar adaptations in respiratory muscles. In this review, we explore the structural and functional properties of the diaphragm muscle and their response to alterations in load and activity. Overall, relatively modest changes in diaphragm structural and functional properties occur in response to perturbations in load or activity. However, disruptions in the normal influence of phrenic innervation by frank denervation, tetrodotoxin nerve block and spinal hemisection, induce profound changes in the diaphragm, indicating the substantial trophic influence of phrenic motoneurons on diaphragm muscle.

  12. Stress-gradient plasticity

    PubMed Central

    Chakravarthy, Srinath S.; Curtin, W. A.

    2011-01-01

    A new model, stress-gradient plasticity, is presented that provides unique mechanistic insight into size-dependent phenomena in plasticity. This dislocation-based model predicts strengthening of materials when a gradient in stress acts over dislocation source–obstacle configurations. The model has a physical length scale, the spacing of dislocation obstacles, and is validated by several levels of discrete-dislocation simulations. When incorporated into a continuum viscoplastic model, predictions for bending and torsion in polycrystalline metals show excellent agreement with experiments in the initial strengthening and subsequent hardening as a function of both sample-size dependence and grain size, when the operative obstacle spacing is proportional to the grain size. PMID:21911403

  13. Compensatory plasticity: time matters

    PubMed Central

    Lazzouni, Latifa; Lepore, Franco

    2014-01-01

    Plasticity in the human and animal brain is the rule, the base for development, and the way to deal effectively with the environment for making the most efficient use of all the senses. When the brain is deprived of one sensory modality, plasticity becomes compensatory: the exception that invalidates the general loss hypothesis giving the opportunity of effective change. Sensory deprivation comes with massive alterations in brain structure and function, behavioral outcomes, and neural interactions. Blind individuals do as good as the sighted and even more, show superior abilities in auditory, tactile and olfactory processing. This behavioral enhancement is accompanied with changes in occipital cortex function, where visual areas at different levels become responsive to non-visual information. The intact senses are in general used more efficiently in the blind but are also used more exclusively. New findings are disentangling these two aspects of compensatory plasticity. What is due to visual deprivation and what is dependent on the extended use of spared modalities? The latter seems to contribute highly to compensatory changes in the congenitally blind. Short-term deprivation through the use of blindfolds shows that cortical excitability of the visual cortex is likely to show rapid modulatory changes after few minutes of light deprivation and therefore changes are possible in adulthood. However, reorganization remains more pronounced in the congenitally blind. Cortico-cortical pathways between visual areas and the areas of preserved sensory modalities are inhibited in the presence of vision, but are unmasked after loss of vision or blindfolding as a mechanism likely to drive cross-modal information to the deafferented visual cortex. The development of specialized higher order visual pathways independently from early sensory experience is likely to preserve their function and switch to the intact modalities. Plasticity in the blind is also accompanied with

  14. New perspectives in plastic biodegradation.

    PubMed

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution.

  15. Plastic footwear for leprosy.

    PubMed

    Antia, N H

    1990-03-01

    The anaesthetic foot in leprosy poses the most major problem in the rehabilitation of its patients. Various attempts have been made to produce protective footwear such as the microcellular rubber-car-tyre sandals. Unfortunately these attempts have had little success on a large scale because of the inability to produce them in large numbers and the stigma attached to such unusual footwear. While such footwear may be superior to the 'tennis' shoe in protecting the foot from injury by the penetration of sharp objects, it fails to distribute the weight-bearing forces which is the major cause of plantar damage and ulceration in the anaesthetic foot. This can be achieved by providing rigidity to the sole, as demonstrated by the healing of ulcers in plaster of paris casts or the rigid wooden clog. A new type of moulded plastic footwear has been evolved in conjunction with the plastic footwear industry which provides footwear that can be mass produced at a low price and which overcomes the stigma of leprosy. Controlled rigidity is provided by the incorporation of a spring steel shank between the sponge insole and the hard wearing plastic sole. Trials have demonstrated both the acceptability of the footwear and its protective effects as well as its hard wearing properties.

  16. Respiratory muscle plasticity.

    PubMed

    Gransee, Heather M; Mantilla, Carlos B; Sieck, Gary C

    2012-04-01

    Muscle plasticity is defined as the ability of a given muscle to alter its structural and functional properties in accordance with the environmental conditions imposed on it. As such, respiratory muscle is in a constant state of remodeling, and the basis of muscle's plasticity is its ability to change protein expression and resultant protein balance in response to varying environmental conditions. Here, we will describe the changes of respiratory muscle imposed by extrinsic changes in mechanical load, activity, and innervation. Although there is a large body of literature on the structural and functional plasticity of respiratory muscles, we are only beginning to understand the molecular-scale protein changes that contribute to protein balance. We will give an overview of key mechanisms regulating protein synthesis and protein degradation, as well as the complex interactions between them. We suggest future application of a systems biology approach that would develop a mathematical model of protein balance and greatly improve treatments in a variety of clinical settings related to maintaining both muscle mass and optimal contractile function of respiratory muscles.

  17. Microelectronics plastic molded packaging

    SciTech Connect

    Johnson, D.R.; Palmer, D.W.; Peterson, D.W.

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  18. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter...

  19. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter...

  20. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter...

  1. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter...

  2. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter...

  3. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter...

  4. Career Maturity in High School Age Females.

    ERIC Educational Resources Information Center

    Pedro, Joan Daniels

    1982-01-01

    Examined career maturity in high school females by using a set of general career-maturity and gender-specific, career-related measures, and an alternate career-maturity criterion measure, career-planning involvement. Results indicated significant relationships between achievement orientation and occupational information and knowledge of women's…

  5. 7 CFR 906.11 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Maturity. 906.11 Section 906.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Definitions § 906.11 Maturity. Maturity...

  6. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.

  7. [Arrest of maturation in spermatogenesis].

    PubMed

    Francavilla, S; Bellocci, M; Martini, M; Bruno, B; Moscardelli, S; Fabbrini, A; Properzi, G

    1982-07-30

    The ultrastructural aspects of the germinal epithelium of 10 infertile men affected by maturative arrest of spermatogenesis were studied. We noted an increased number of malformed germinal cells. Marginal nuclear vescicles were present in spermatogonia of patients affected by spermatogonial arrest. The few spermatid present in the germinal epithelium of the patients affected by a spermatidic arrest presented changes of the nuclear condensation, the acrosome, and the tail. The Sertoli cells presented an immature aspect of the nucleus and changes of the "mantle". A possible correlation between the Sertoli cells changes and the altered spermatogenesis was proposed.

  8. Phenotype of normal hairline maturation.

    PubMed

    Rassman, William R; Pak, Jae P; Kim, Jino

    2013-08-01

    Hairlines change shape with age, starting at birth. A good head of hair is frequently present some time after ages 3 to 5 years. The look of childhood has its corresponding hairline, and, as the child grows and develops into adulthood, facial morphology migrate changes from a childlike look to a more mature look. This article discusses the dynamics of hairline evolution and the phenotypic variations of the front and side hairlines in men and women. A modeling system is introduced that provides a common language to define the various anatomic points of the full range of hairlines.

  9. Independent genetic control of maize (Zea mays L.) kernel weight determination and its phenotypic plasticity.

    PubMed

    Alvarez Prado, Santiago; Sadras, Víctor O; Borrás, Lucas

    2014-08-01

    Maize kernel weight (KW) is associated with the duration of the grain-filling period (GFD) and the rate of kernel biomass accumulation (KGR). It is also related to the dynamics of water and hence is physiologically linked to the maximum kernel water content (MWC), kernel desiccation rate (KDR), and moisture concentration at physiological maturity (MCPM). This work proposed that principles of phenotypic plasticity can help to consolidated the understanding of the environmental modulation and genetic control of these traits. For that purpose, a maize population of 245 recombinant inbred lines (RILs) was grown under different environmental conditions. Trait plasticity was calculated as the ratio of the variance of each RIL to the overall phenotypic variance of the population of RILs. This work found a hierarchy of plasticities: KDR ≈ GFD > MCPM > KGR > KW > MWC. There was no phenotypic and genetic correlation between traits per se and trait plasticities. MWC, the trait with the lowest plasticity, was the exception because common quantitative trait loci were found for the trait and its plasticity. Independent genetic control of a trait per se and genetic control of its plasticity is a condition for the independent evolution of traits and their plasticities. This allows breeders potentially to select for high or low plasticity in combination with high or low values of economically relevant traits.

  10. The Evolution of Photography and Three-Dimensional Imaging in Plastic Surgery.

    PubMed

    Weissler, Jason M; Stern, Carrie S; Schreiber, Jillian; Amirlak, Bardia; Tepper, Oren M

    2016-11-21

    Throughout history, the technological advancements of conventional clinical photography in plastic surgery have refined not only the plastic surgeon's armamentarium, but have invigorated the profession through technology. The technology of the once traditional two-dimensional photograph has since been revolutionized and refashioned to incorporate novel applications, which have since become the standard in clinical photography.Contrary to traditional standardized two-dimensional photographs, three-dimensional photography provides the surgeon with an invaluable volumetric and morphological analysis by demonstrating true surface dimensions both pre and postoperatively. Clinical photography has served as one of the fundamental objective means by which plastic surgeons review outcomes, however the newer three-dimensional technology has been primarily used to enhance the preoperative consultation with surgical simulations.We intend to familiarize readers with the notion that 3D photography extends well beyond its marketing application during surgical consultation. For the cosmetic surgeon, as the application of three-dimensional photography continues to mature in facial plastic surgery, it will continue to bypass the dated conventional photographic methods plastic surgeons once relied upon.This paper reviews a paradigm shift and provides a historical review of the fascinating evolution of photography in plastic surgery by highlighting the clinical utility of three-dimensional photography as an adjunct to plastic and reconstructive surgery practices. As three-dimensional photographic technology continues to evolve, its application in facial plastic surgery will provide an opportunity for a new objective standard in plastic surgery.

  11. The Evolution of Photography and Three-Dimensional Imaging in Plastic Surgery.

    PubMed

    Weissler, Jason M; Stern, Carrie S; Schreiber, Jillian E; Amirlak, Bardia; Tepper, Oren M

    2017-03-01

    Throughout history, the technological advancements of conventional clinical photography in plastic surgery have not only refined the methods available to the plastic surgeon, but have invigorated the profession through technology. The technology of the once traditional two-dimensional photograph has since been revolutionized and refashioned to incorporate novel applications, which have since become the standard in clinical photography. Contrary to traditional standardized two-dimensional photographs, three-dimensional photography provides the surgeon with an invaluable volumetric and morphologic analysis by demonstrating true surface dimensions both preoperatively and postoperatively. Clinical photography has served as one of the fundamental objective means by which plastic surgeons review outcomes; however, the newer three-dimensional technology has been primarily used to enhance the preoperative consultation with surgical simulations. The authors intend to familiarize readers with the notion that three-dimensional photography extends well beyond its marketing application during surgical consultation. For the cosmetic surgeon, as the application of three-dimensional photography continues to mature in facial plastic surgery, it will continue to bypass the dated conventional photographic methods plastic surgeons once relied on. This article reviews a paradigm shift and provides a historical review of the fascinating evolution of photography in plastic surgery by highlighting the clinical utility of three-dimensional photography as an adjunct to plastic and reconstructive surgery practices. As three-dimensional photographic technology continues to evolve, its application in facial plastic surgery will provide an opportunity for a new objective standard in plastic surgery.

  12. Academic Achievement of High School Students in Relation to Their Anxiety, Emotional Maturity and Social Maturity

    ERIC Educational Resources Information Center

    Puar, Surjit Singh

    2013-01-01

    The present study has been designed to investigate the non-cognitive variables like anxiety, emotional maturity and social maturity and their relationship with academic achievement and also to see the locale-wise differences on the basis of their anxiety, emotional maturity and social maturity. The study was conducted over a sample of 400 (200…

  13. The Relationship Between Cognitive Career Maturity and Self-Reported Career Maturity of High School Students.

    ERIC Educational Resources Information Center

    Westbrook, Bert W.; And Others

    1987-01-01

    Investigated relationship between scores on measures of cognitive career maturity and self-reported career maturity in high school sophomores (N=391) and juniors (N=283). Results suggest that there is no relationship between measured career maturity competencies and self-reported career maturity competencies of high school students. (Author/NB)

  14. Plastics in the Marine Environment.

    PubMed

    Law, Kara Lavender

    2017-01-03

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence-albeit limited-of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  15. Abiotic degradation of plastic films

    NASA Astrophysics Data System (ADS)

    Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.

    2017-01-01

    Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

  16. Plastics in the Marine Environment

    NASA Astrophysics Data System (ADS)

    Law, Kara Lavender

    2017-01-01

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence—albeit limited—of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  17. Sexual maturation of female Saguinus oedipus oedipus

    SciTech Connect

    Tardif, S.D.

    1982-01-01

    This study is an examination of the process of female sexual maturation in the cotton-top tamarin, Saguinus oedipus oedipus, a South-American primate of the family, Callitrichidae. Two types of questions are addressed. The first question is whether the type of social grouping in which a young female lives affects the rate of her sexual maturation. Specifically, is there a difference between the maturation rate of a female housed with a strange adult male and a female housed with her natal group (i.e., her parents and various siblings). Second, the effect of sexual maturation on various social interactions is examined. Specifically are male-female interactions in mated pairs and mother-daughter interactions in natal groups changed by the sexual maturation of the young females. The mother's presence was not related to the daughter's maturation age. However, whether the natal group, as a whole, inhibited maturation, or unrelated males accelerated maturation, or both, remains unknown. Most of the behavioral interactions involving maturing females were unchanged by maturation. There was some indication that certain behaviors were affected by maturation, but only if a strange unrelated male was present.

  18. Neural networks predict tomato maturity stage

    NASA Astrophysics Data System (ADS)

    Hahn, Federico

    1999-03-01

    Almost 40% of the total horticultural produce exported from Mexico the USA is tomato, and quality is fundamental for maintaining the market. Many fruits packed at the green-mature stage do not mature towards a red color as they were harvested before achieving its physiological maturity. Tomato gassed for advancing maturation does not respond on those fruits, and repacking is necessary at terminal markets, causing losses to the producer. Tomato spectral signatures are different on each maturity stage and tomato size was poorly correlated against peak wavelengths. A back-propagation neural network was used to predict tomato maturity using reflectance ratios as inputs. Higher success rates were achieved on tomato maturity stage recognition with neural networks than with discriminant analysis.

  19. Physiological thermoregulation of mature alligators.

    PubMed

    Smith, E N; Standora, E A; Robertson, S L

    1984-01-01

    A 67.1 kg alligator (Alligator mississippiensis), tested in air, heated twice as fast as it cooled. The cooling thermal time constant was 425 min while alive. Warming and cooling thermal time constants were 421 min after death. The thermal time constant was not appropriate in describing warming in air of mature alligators. Surface and subdermal heat flow measurements of the 67.1 kg animal indicate greater blood flow in the skin during warming compared to cooling. Two mature alligators, 49.9 and 103 kg, were heated and cooled in water. Warming time constants were 67 and 110 min respectively. Cooling time constants were 180 and 246 min. Data from this study were combined with previously published thermal time constants for alligators providing regression equations for alligators ranging from 37 g to 103 kg. Regression equations for alligators tested in water are: tau w = 8.81 M050 tau c = 12.6 M0.62. Time constants (tau) are in minutes (w = warming, c = cooling) with all measurements in stirred water; mass, M, is in kg. Thermal conductance and metabolism data are combined to provide an estimate of the amount the body temperature of theoretical alligators ranging from 50 g to 1000 kg would be elevated by metabolism. A body temperature of 34.2 degrees C is predicted for a 1000 kg theoretical alligator in 30 degrees C water.

  20. Membrane remodeling during reticulocyte maturation

    PubMed Central

    Liu, Jing; Guo, Xinhua; Mohandas, Narla; Chasis, Joel A.

    2010-01-01

    The transition of reticulocytes into erythrocytes is accompanied by extensive changes in the structure and properties of the plasma membrane. These changes include an increase in shear resistance, loss of surface area, and acquisition of a biconcave shape. The processes by which these changes are effected have remained largely undefined. Here we examine how the expression of 30 distinct membrane proteins and their interactions change during murine reticulocyte maturation. We show that tubulin and cytosolic actin are lost, whereas the membrane content of myosin, tropomyosin, intercellular adhesion molecule-4, glucose transporter-4, Na-K-ATPase, sodium/hydrogen exchanger 1, glycophorin A, CD47, Duffy, and Kell is reduced. The degradation of tubulin and actin is, at least in part, through the ubiquitin-proteasome degradation pathway. In regard to the protein-protein interactions, the formation of membrane-associated spectrin tetramers from dimers is unperturbed, whereas the interactions responsible for the formation of the membrane-skeletal junctions are weaker in reticulocytes, as is the attachment of transmembrane proteins to these structures. This weakness, in part, results from the elevated phosphorylation of 4.1R in reticulocytes, which leads to a decrease in shear resistance by reducing its interaction with spectrin and actin. These observations begin to unravel the mechanistic basis of crucial changes accompanying reticulocyte maturation. PMID:20038785

  1. Hippocampal Structural Plasticity Accompanies the Resulting Contextual Fear Memory Following Stress and Fear Conditioning

    ERIC Educational Resources Information Center

    Giachero, Marcelo; Calfa, Gaston D.; Molina, Victor A.

    2013-01-01

    The present research investigated the resulting contextual fear memory and structural plasticity changes in the dorsal hippocampus (DH) following stress and fear conditioning. This combination enhanced fear retention and increased the number of total and mature dendritic spines in DH. Intra-basolateral amygdala (BLA) infusion of midazolam prior to…

  2. Use of recycled plastics in wood plastic composites - a review.

    PubMed

    Kazemi Najafi, Saeed

    2013-09-01

    The use of recycled and waste thermoplastics has been recently considered for producing wood plastic composites (WPCs). They have great potential for WPCs manufacturing according to results of some limited researches. This paper presents a detailed review about some essential properties of waste and recycled plastics, important for WPCs production, and of research published on the effect of recycled plastics on the physical and mechanical properties of WPCs.

  3. Sexual maturation in kokanee Oncorhynchus nerka

    USGS Publications Warehouse

    Patterson, S.D.; Scarnecchia, D.L.; Congleton, J.L.

    2008-01-01

    We used observational and experimental approaches to obtain information on factors affecting the timing of maturation of kokanee Oncorhynchus nerka, a semelparous, landlocked salmon. Gonadal staging criteria were developed and applied to three kokanee populations in Idaho lakes and reservoirs. Testes were classified into three stages: immature (stage one, S1), maturing (S2), and mature (S3). Ovaries were classified into eight stages: immature (S1-S3), transitional (stage S4), maturing (S5-S7), and mature (S8). Males entered the maturing stage (S2) in February through April of the spawning year. Females entered maturing stage (S5) as early as July of the year before the spawning year, and as late as March of the spawning year. Three hatchery experiments demonstrated that attainment of a larger body size 10 to 16 months before spawning increased the likelihood of initiation of maturation in both sexes. No gonads in a state of regression were observed. A gonadosomatic index above 0.1 by early July was a good indicator of a maturing male, and a gonadosomatic index above 1.0 by early July was a good indicator of a maturing female. Instantaneous growth rates were not good predictors of maturation, but attaining a size threshold of 18 to 19 cm in the fall was a good predictor of maturation the following year. This improved knowledge of kokanee maturation will permit more effectively management of the species for age, growth and size at maturity as well as for contributions to fisheries. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  4. One plasticity model for problems of plastic metal working

    NASA Astrophysics Data System (ADS)

    Greshnov, V. M.

    2008-11-01

    Scalar and tensor models of plastic flow of metals extending plasticity theory are considered over a wide range of temperatures and strain rates. Equations are derived using the physico-phenomenological approach based on modern concepts and methods of the physics and mechanics of plastic deformation. For hardening and viscoplastic solids, a new mathematical formulation of the boundary-value plasticity problem taking into account loading history is obtained. Results of testing of the model are given. A numerical finite-element algorithm for the solution of applied problems is described.

  5. Plastic Surgery and Suicide: A Clinical Guide for Plastic Surgeons.

    PubMed

    Reddy, Vikram; Coffey, M Justin

    2016-08-01

    Several studies have identified an increased risk of suicide among patient populations which a plastic surgeon may have a high risk of encountering: women undergoing breast augmentation, cosmetic surgery patients, and breast cancer patients. No formal guidelines exist to assist a plastic surgeon when faced with such a patient, and not every plastic surgery team has mental health clinicians that are readily accessible for consultation or referral. The goal of this clinical guide is to offer plastic surgeons a set of practical approaches to manage potentially suicidal patients. In addition, the authors review a screening tool, which can assist surgeons when encountering high-risk patients.

  6. Plastic Surgery and Suicide: A Clinical Guide for Plastic Surgeons

    PubMed Central

    Coffey, M. Justin

    2016-01-01

    Summary: Several studies have identified an increased risk of suicide among patient populations which a plastic surgeon may have a high risk of encountering: women undergoing breast augmentation, cosmetic surgery patients, and breast cancer patients. No formal guidelines exist to assist a plastic surgeon when faced with such a patient, and not every plastic surgery team has mental health clinicians that are readily accessible for consultation or referral. The goal of this clinical guide is to offer plastic surgeons a set of practical approaches to manage potentially suicidal patients. In addition, the authors review a screening tool, which can assist surgeons when encountering high-risk patients. PMID:27622096

  7. Direct liquefaction of plastics and coprocessing of coal with plastics

    SciTech Connect

    Huffman, G.P.; Feng, Z.; Mahajan, V.

    1995-12-31

    The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In the coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.

  8. Processing plastics in Packerland

    SciTech Connect

    Ridgley, H.

    1998-04-01

    Located in Green Bay, Wisconsin, Catenation, Inc. is a privately held recycling company dedicated to the recovery of post-consumer plastic containers. What makes the company stand out is its ability to separate and sort material from a commingled bale. Catenation uses custom-made, high-speed, computer-driven vision equipment to scan and sort every bottle by category. The computer even can be programmed to distinguish soiled jugs from clean containers. This is a selling point for buyers of resin who are insistent on receiving high-grade material.

  9. Fabrication of plastic biochips

    SciTech Connect

    Saaem, Ishtiaq; Ma, Kuo-Sheng; Alam, S. Munir; Tian Jingdong

    2010-07-15

    A versatile surface functionalization procedure based on rf magnetron sputtering of silica was performed on poly(methylmethacrylate), polycarbonate, polypropylene, and cyclic olefin copolymers (Topas 6015). The hybrid thermoplastic surfaces were characterized by x-ray photoelectron spectrometer analysis and contact angle measurements. The authors then used these hybrid materials to perform a sandwich assay targeting an HIV-1 antibody using fluorescent detection and biotinylated peptides immobilized using the bioaffinity of biotin-neutravidin. They found a limit of detection similar to arrays on glass surfaces and believed that this plastic biochip platform may be used for the development of disposable immunosensing and diagnostic applications.

  10. Presynaptic long-term plasticity

    PubMed Central

    Yang, Ying; Calakos, Nicole

    2013-01-01

    Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity. PMID:24146648

  11. Spindle Activity Orchestrates Plasticity during Development and Sleep

    PubMed Central

    Lindemann, Christoph; Ahlbeck, Joachim; Bitzenhofer, Sebastian H.; Hanganu-Opatz, Ileana L.

    2016-01-01

    Spindle oscillations have been described during early brain development and in the adult brain. Besides similarities in temporal patterns and involved brain areas, neonatal spindle bursts (NSBs) and adult sleep spindles (ASSs) show differences in their occurrence, spatial distribution, and underlying mechanisms. While NSBs have been proposed to coordinate the refinement of the maturating neuronal network, ASSs are associated with the implementation of acquired information within existing networks. Along with these functional differences, separate synaptic plasticity mechanisms seem to be recruited. Here, we review the generation of spindle oscillations in the developing and adult brain and discuss possible implications of their differences for synaptic plasticity. The first part of the review is dedicated to the generation and function of ASSs with a particular focus on their role in healthy and impaired neuronal networks. The second part overviews the present knowledge of spindle activity during development and the ability of NSBs to organize immature circuits. Studies linking abnormal maturation of brain wiring with neurological and neuropsychiatric disorders highlight the importance to better elucidate neonatal plasticity rules in future research. PMID:27293903

  12. Rapid and continuous activity-dependent plasticity of olfactory sensory input

    PubMed Central

    Cheetham, Claire E. J.; Park, Una; Belluscio, Leonardo

    2016-01-01

    Incorporation of new neurons enables plasticity and repair of circuits in the adult brain. Adult neurogenesis is a key feature of the mammalian olfactory system, with new olfactory sensory neurons (OSNs) wiring into highly organized olfactory bulb (OB) circuits throughout life. However, neither when new postnatally generated OSNs first form synapses nor whether OSNs retain the capacity for synaptogenesis once mature, is known. Therefore, how integration of adult-born OSNs may contribute to lifelong OB plasticity is unclear. Here, we use a combination of electron microscopy, optogenetic activation and in vivo time-lapse imaging to show that newly generated OSNs form highly dynamic synapses and are capable of eliciting robust stimulus-locked firing of neurons in the mouse OB. Furthermore, we demonstrate that mature OSN axons undergo continuous activity-dependent synaptic remodelling that persists into adulthood. OSN synaptogenesis, therefore, provides a sustained potential for OB plasticity and repair that is much faster than OSN replacement alone. PMID:26898529

  13. A Conservative Formulation for Plasticity

    DTIC Science & Technology

    1992-01-01

    diverse. For instance, the microphysical pictures of metal plasticity and of the flow of granular materials are quite different. Furthermore, passage from...of inhomogeneous materials can be adapted to model plasticity by allowing- the local reference frames of Noll to be dynramic [6]. In this approach...gradient and the entropy. Choosing a plasticity model amounts to specifying thle evolu- tion and constitutive e-vations. 472 PLOHIR AND SHARP A general

  14. The commercialization of plastic surgery.

    PubMed

    Swanson, Eric

    2013-09-01

    The last decade has brought a major challenge to the traditional practice of plastic surgery from corporations that treat plastic surgery as a commercial product and market directly to the public. This corporate medicine model may include promotion of a trademarked procedure or device, national advertising that promises stunning results, sales consultants, and claims of innovation, superiority, and improved safety. This article explores the ethics of this business practice and whether corporate medicine is a desirable model for patients and plastic surgeons.

  15. Developmental Synaptic Plasticity at the Thalamocortical Input to Barrel Cortex: Mechanisms and Roles

    PubMed Central

    Daw, Michael I.; Scott, Helen L.; Isaac, John T.R.

    2007-01-01

    The thalamocortical (TC) input to layer IV provides the major pathway for ascending sensory information to the mammalian sensory cortex. During development there is a dramatic refinement of this input that underlies the maturation of the topographical map in layer IV. Over the last ten years our understanding of the mechanisms of the developmental and experience-driven changes in synaptic function at TC synapses has been greatly advanced. Here we describe these studies that point to a key role for NMDA receptor-dependent synaptic plasticity, a role for kainate receptors and for a rapid maturation in GABAergic inhibition. The expression mechanisms of some of the forms of neonatal synaptic plasticity are novel and, in combination with other mechanisms, produce a layer IV circuit that exhibits functional properties necessary for mature sensory processing. PMID:17329121

  16. Americium behaviour in plastic vessels.

    PubMed

    Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

    2010-01-01

    The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  17. THERMAL STABILITY OF GLASS PLASTICS.

    DTIC Science & Technology

    COMPOSITE MATERIALS, THERMAL STABILITY), (* GLASS TEXTILES, THERMAL STABILITY), (*LAMINATED PLASTICS , THERMAL STABILITY), HEATING, COOLING, MECHANICAL PROPERTIES, FATIGUE(MECHANICS), FLEXURAL STRENGTH, THERMAL STRESSES, USSR

  18. Maturation of the MOUTh Intervention

    PubMed Central

    Jablonski-Jaudon, Rita A.; Kolanowski, Ann M.; Winstead, Vicki; Jones-Townsend, Corteza; Azuero, Andres

    2016-01-01

    The purpose of the current article is to describe a personalized practice originally conceived as a way to prevent and minimize care-resistant behavior to provide mouth care to older adult with dementia. The original intervention, Managing Oral Hygiene Using Threat Reduction Strategies (MOUTh), matured during the clinical trial study into a relationship-centered intervention with emphasis on developing strategies that support residents behavioral health and staff involved in care. Relationships that were initially pragmatic (i.e., focused on the task of completing mouth care) developed into more personal and responsive relationships that involved deeper engagement between mouth care providers and nursing home (NH) residents. Mouth care was accomplished and completed in a manner enjoyable to NH residents and mouth care providers. The MOUTh intervention may also concurrently affirm the dignity and personhood of the care recipient because of its emphasis on connecting with older adults. PMID:26934969

  19. [Erythropoietin in plastic surgery].

    PubMed

    Günter, C I; Rezaeian, F; Harder, Y; Lohmeyer, J A; Egert, S; Bader, A; Schilling, A F; Machens, H-G

    2013-04-01

    EPO is an autologous hormone, which is known to regulate erythropoiesis. For 30 years it has been used for the therapy of diverse forms of anaemia, such as renal anaemia, tumour-related anaemias, etc. Meanwhile, a multitude of scientific publications were able to demonstrate its pro-regenerative effects after trauma. These include short-term effects such as the inhibition of the "primary injury response" or apoptosis, and mid- and long-term effects for example the stimulation of stem cell recruitment, growth factor production, angiogenesis and re-epithelialisation. Known adverse reactions are increases of thromboembolic events and blood pressure, as well as a higher mortality in patients with tumour anaemias treated with EPO. Scientific investigations of EPO in the field of plastic surgery included: free and local flaps, nerve regeneration, wound healing enhancement after dermal thermal injuries and in chronic wounds.Acute evidence for the clinical use of EPO in the field of plastic surgery is still not satisfactory, due to the insufficient number of Good Clinical Practice (GCP)-conform clinical trials. Thus, the initiation of more scientifically sound trials is indicated.

  20. Optimizing IV and V for Mature Organizations

    NASA Technical Reports Server (NTRS)

    Fuhman, Christopher

    2003-01-01

    NASA is intending for its future software development agencies to have at least a Level 3 rating in the Carnegie Mellon University Capability Maturity Model (CMM). The CMM has built-in Verification and Validation (V&V) processes that support higher software quality. Independent Verification and Validation (IV&V) of software developed by mature agencies can be therefore more effective than for software developed by less mature organizations. How is Independent V&V different with respect to the maturity of an organization? Knowing a priori the maturity of an organization's processes, how can IV&V planners better identify areas of need choose IV&V activities, etc? The objective of this research is to provide a complementary set of guidelines and criteria to assist the planning of IV&V activities on a project using a priori knowledge of the measurable levels of maturity of the organization developing the software.

  1. Plastics recycling: challenges and opportunities.

    PubMed

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-07-27

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3-4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  2. Plastics recycling: challenges and opportunities

    PubMed Central

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  3. [Postoperative complications in plastic surgery].

    PubMed

    Vogt, P M

    2009-09-01

    Plastic surgery covers a broad spectrum of diseases and conditions in the areas of reconstructive surgery, hand, burn and aesthetic surgery. Besides acquired defects or malformations an increasing number of patients are being treated for surgical or multimodal complications. In a considerable number of patients plastic and reconstructive surgery remains the only therapeutic alternative after other therapy has failed. Therefore complication management in plastic surgery is of utmost importance for a successful outcome. In addition patient expectations in the results of plastic surgery as a discipline of invention and problem solving are steadily increasing. This challenge is reflected in clinical patient management by intensive research in tissue engineering and regenerative medicine. Patients in plastic surgery are recruited from all age groups of either gender, involving traumatic and oncologic as well as congenital and aesthetic disorders. The demographics of aging, multimorbidity and obesity pose new challenges to plastic surgery. Although age over 70 years is not an independent risk factor per se for complications in plastic surgery, e.g. for complex free flap transfer, medical problems are present at a higher rate, which is to be expected in this age group. Risk factors such as alcoholism and coronary heart diseases seem to be independent predictors of perioperative complications. Therefore older patients can also benefit from plastic surgery and recurrent operations by the corresponding risk and complication management. Complication management necessitates careful patient selection, estimation of operative risks and patient-adapted selection of procedures. In addition to expertise in plastic surgery a thorough knowledge of non-surgical and surgical back-up procedures for technical incidents as well as vascular circulatory and wound healing disorders is required to deal successfully with complications in plastic surgery. This article presents these specific

  4. Cassava root membrane proteome reveals activities during storage root maturation.

    PubMed

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava.

  5. Mechanisms of eukaryotic transcription: a meeting report August 27–31, 2013, CSHL, Cold Spring Harbor, New York.

    PubMed

    D'Orso, Iván

    2013-01-01

    The "Mechanisms of Eukaryotic Transcription" meeting at Cold Spring Harbor Laboratory, organized by Stephen Buratowski (Harvard Medical School), Katherine Jones (The Salk Institute for Biological Studies) and John Lis (Cornell University), counted with 364 registered attendees, 64 speakers and 215 posters. Top-notch researchers in a very dynamic and collegial atmosphere chaired eight sessions. Here, I discuss selected presentations of each session from an impressive list of speakers. I apologize in advance to speakers whose work I did not discuss due to space constraints.

  6. Physical and Mechanical Properties of Glass--Reinforced Plastics,

    DTIC Science & Technology

    REINFORCED PLASTICS , REVIEWS), GLASS TEXTILES, MECHANICAL PROPERTIES, ELECTRICAL PROPERTIES, SILICONE PLASTICS , POLYESTER PLASTICS , PHENOLIC... PLASTICS , EPOXY RESINS, TEST METHODS, NONDESTRUCTIVE TESTING, FIRE RESISTANT MATERIALS, POLYVINYL CHLORIDE, USSR

  7. Skeletal maturation determined by cervical vertebrae development.

    PubMed

    San Román, Paloma; Palma, Juan Carlos; Oteo, M Dolores; Nevado, Esther

    2002-06-01

    The aim of this study was to determine the validity of cervical vertebrae radiographic assessment to predict skeletal maturation. Left hand-wrist and lateral cephalometric radiographs of 958 Spanish children from 5 to 18 years of age were measured. On the left hand-wrist radiographs the classification of Grave and Brown was used to assess skeletal maturation. Cervical vertebrae maturation was evaluated with lateral cephalometric radiographs using the stages described by Lamparski and by Hassel and Farman. A new method to evaluate the cervical maturation by studying the changes in the concavity of the lower border, height, and shape of the vertebral body was created. Correlation coefficients were calculated to establish the relationship between skeletal maturation values obtained by the three classifications of vertebral and skeletal maturation measured at the wrist. All correlation values obtained were statistically significant (P < 0.001). The results suggest that this new method to determine skeletal maturation is very reliable. A simple method based on morphological characteristics of the cervical vertebral bodies to evaluate the maturation stage has been designed. In the population investigated, this method is as accurate as the Hassel and Farman classification and superior to the Lamparski classification. The morphological vertebral parameter best able to estimate the maturation is the concavity of the lower border of the body.

  8. Plastics to fuel: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reviews recent developments in catalytic and non-catalytic degradation of waste plastics into fuels. Thermal degradation decomposes plastic into three fractions: gas, crude oil, and solid residue. Crude oil from non-catalytic pyrolysis is usually composed of higher boiling point hydrocarb...

  9. Splicing plastic optical fibers

    NASA Astrophysics Data System (ADS)

    Carson, Susan D.; Salazar, Roberto A.

    1991-12-01

    Polymethylmethacrylate (PMMA) plastic optical fiber (500 micrometers diameter, fluoropolymer cladding) has been spliced using a fused silica sleeve and a variety of solvent/PMMA solutions as adhesives. Mechanical splicing using index matching fluid has also been investigated. To ensure good bonding and minimize scattering, fiber ends are polished prior to application of adhesive. Using an LED ((lambda) max approximately 640 nm), losses are routinely less than 1.0 dB/splice, and some adhesive formulations have exhibited losses as low as 0.2 dB/splice. Five-meter fibers with as many as ten splices/fiber have been monitored over a period of several months. No fiber has exhibited an increase in optical loss with time.

  10. Neuropsin--a possible modulator of synaptic plasticity.

    PubMed

    Shiosaka, Sadao; Ishikawa, Yasuyuki

    2011-09-01

    Accumulating evidence has suggested pivotal roles for neural proteases in development, maturation, aging, and cognitive functions. Among such proteases, neuropsin, a kallikrein gene-related (KLK) endoprotease, appears to have a significant plasticity function that has been analyzed primarily in the hippocampal Schaffer-collateral pathway. In this article, after reviewing the general features of neuropsin, its role in Schaffer-collateral synaptic plasticity is discussed in some detail. Enzymatically active neuropsin is necessary to establish the early phase of long-term potentiation (LTP). This type of LTP, which can be elicited by rather weak tetanic stimulation, is significant in synaptic late association between two independent hippocampal synapses. Neuropsin deficiency completely impaired the early phase of LTP, leading to the absence of late associativity. Associations between early and persistent-LTP synapses may be related to mammalian working memory and consequently integration in learning and memory.

  11. Injection molding of engineering plastics

    NASA Astrophysics Data System (ADS)

    Kalyon, Dilhan M.

    1991-03-01

    This final report summarizes the findings of a study in injection molding of engineering plastics. Two engineering plastic resins, i.e., unmodified grades of a polyetherimide and a poly (2,6-dimethyl-1,4-phenylene ether) were thoroughly characterized. The characterization included rheology, thermal properties and P-V-T behavior. The data were employed to predict various microstructural distributions including density, residual stress and birefringence distributions in compression and injection molded specimens of these two engineering plastics. The detailed microstructural distributions were also studied experimentally upon processing the two engineering plastics, employing instrumented machines and industrial practices. The experimental findings were elucidated under the light of the numerical simulation results. Overall, this study should furnish a first order understanding of the microstructure development in articles injection molded from amorphous engineering plastic resins.

  12. Influence of Plastic Deformation on Bimaterial Fault Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Templeton-Barrett, E. L.; Dedontney, N.; Rice, J. R.; Dmowska, R.

    2011-12-01

    Material juxtapositions across mature faults are a common occurrence. Previous work has found that this elastic mismatch results in a rupture that will preferentially propagate in the direction of slip displacement on the more compliant side of the fault, with more off-fault damage in the stiffer material. This result has implications for inferring preferred rupture directions based on observations of damage zone asymmetry. We perform a complete numerical investigation of the role of the stress state on the distribution of plastic deformation and the direction of preferred rupture propagation. We show that there are important factors, in addition to the elastic mismatch, which control the preferred direction of propagation as well as the side of the fault in which damage predominately accumulates. The orientation of the most compressive principal stress is the controlling factor in determining the location of plastic deformation. For different orientations, plastic deformation can accumulate in either the stiffer or the more compliant material. For high angles of most compressive stress, the aforementioned preferred rupture direction prediction holds true. However, the off-fault plastic response can reverse that direction for low angles of most compressive stress so that rupture will preferentially propagate in the direction of slip displacement in the stiffer material. Also, as already established in the case of purely elastic materials, when pre-stress is close to static friction (low seismic S ratio) a transition to supershear may take place in the direction opposite to what was the preferred direction.

  13. Cortical Plasticity and Olfactory Function in Early Blindness.

    PubMed

    Araneda, Rodrigo; Renier, Laurent A; Rombaux, Philippe; Cuevas, Isabel; De Volder, Anne G

    2016-01-01

    Over the last decade, functional brain imaging has provided insight to the maturation processes and has helped elucidate the pathophysiological mechanisms involved in brain plasticity in the absence of vision. In case of congenital blindness, drastic changes occur within the deafferented "visual" cortex that starts receiving and processing non visual inputs, including olfactory stimuli. This functional reorganization of the occipital cortex gives rise to compensatory perceptual and cognitive mechanisms that help blind persons achieve perceptual tasks, leading to superior olfactory abilities in these subjects. This view receives support from psychophysical testing, volumetric measurements and functional brain imaging studies in humans, which are presented here.

  14. Cortical Plasticity and Olfactory Function in Early Blindness

    PubMed Central

    Araneda, Rodrigo; Renier, Laurent A.; Rombaux, Philippe; Cuevas, Isabel; De Volder, Anne G.

    2016-01-01

    Over the last decade, functional brain imaging has provided insight to the maturation processes and has helped elucidate the pathophysiological mechanisms involved in brain plasticity in the absence of vision. In case of congenital blindness, drastic changes occur within the deafferented “visual” cortex that starts receiving and processing non visual inputs, including olfactory stimuli. This functional reorganization of the occipital cortex gives rise to compensatory perceptual and cognitive mechanisms that help blind persons achieve perceptual tasks, leading to superior olfactory abilities in these subjects. This view receives support from psychophysical testing, volumetric measurements and functional brain imaging studies in humans, which are presented here. PMID:27625596

  15. Smart Grid Interoperability Maturity Model

    SciTech Connect

    Widergren, Steven E.; Levinson, Alex; Mater, J.; Drummond, R.

    2010-04-28

    The integration of automation associated with electricity resources (including transmission and distribution automation and demand-side resources operated by end-users) is key to supporting greater efficiencies and incorporating variable renewable resources and electric vehicles into the power system. The integration problems faced by this community are analogous to those faced in the health industry, emergency services, and other complex communities with many stakeholders. To highlight this issue and encourage communication and the development of a smart grid interoperability community, the GridWise Architecture Council (GWAC) created an Interoperability Context-Setting Framework. This "conceptual model" has been helpful to explain the importance of organizational alignment in addition to technical and informational interface specifications for "smart grid" devices and systems. As a next step to building a community sensitive to interoperability, the GWAC is investigating an interoperability maturity model (IMM) based on work done by others to address similar circumstances. The objective is to create a tool or set of tools that encourages a culture of interoperability in this emerging community. The tools would measure status and progress, analyze gaps, and prioritize efforts to improve the situation.

  16. Removing brakes on adult brain plasticity: from molecular to behavioral interventions

    PubMed Central

    Bavelier, D.; Levi, D.M.; Li, R.W.; Dan, Y.; Hensch, T.K.

    2010-01-01

    Adult brain plasticity, although possible, remains more restricted in scope than during development. Here, we address conditions under which circuit rewiring may be facilitated in the mature brain. At a cellular and molecular level, adult plasticity is actively limited. Some of these “brakes” are structural, such as peri-neuronal nets or myelin, which inhibit neurite outgrowth. Others are functional, acting directly upon excitatory-inhibitory balance within local circuits. Plasticity in adulthood can be induced either by lifting these brakes through invasive interventions or by exploiting endogenous permissive factors, such as neuromodulators. Using the amblyopic visual system as a model, we discuss genetic, pharmacological, and environmental removal of brakes to enable recovery of vision in adult rodents. Although these mechanisms remain largely uncharted in the human, we consider how they may provide a biological foundation for the remarkable increase in plasticity after action video game play by amblyopic subjects. PMID:21068299

  17. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  18. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  19. The Mature Woman and the Community College

    ERIC Educational Resources Information Center

    Elliot, Jeffrey M.; Mantz, Concetta M.

    1976-01-01

    The factors and motivations contributing to the presence of increasing numbers of mature women in college are examined, and seven proposals are offered, representing an attempt to develop a total community college program which will meet the needs of mature women students. (NHM)

  20. Quantifying Semantic Linguistic Maturity in Children

    ERIC Educational Resources Information Center

    Hansson, Kristina; Bååth, Rasmus; Löhndorf, Simone; Sahlén, Birgitta; Sikström, Sverker

    2016-01-01

    We propose a method to quantify "semantic linguistic maturity" (SELMA) based on a high dimensional semantic representation of words created from the co-occurrence of words in a large text corpus. The method was applied to oral narratives from 108 children aged 4;0-12;10. By comparing the SELMA measure with maturity ratings made by human…

  1. 7 CFR 29.6026 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Maturity. 29.6026 Section 29.6026 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6026 Maturity. The degree of ripeness. (See chart.)...

  2. New definitions for cotton fiber maturity ratio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fiber maturity affects fiber physical, mechanical, and chemical properties, as well as the processability and qualities of yarn and fabrics. New definitions of cotton fiber maturity ratio are introduced. The influences of sampling, sample preparation, measurement method, and correlations am...

  3. Thinned Mature Deciduous Forest Silvopastures for Appalachia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available on effective management and utilization of silvopastures developed from the ubiquitous mature woodlots which comprise 40-50% of small Appalachian farm acreage. We thinned a white oak dominated mature second growth forested area establishing two 0.5 ha, eight-paddock,...

  4. Canopy temperature and maturity in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat units are a widely used indicator of maturity in cotton. It is generally assumed that it takes approximately 2200°F (1222°C) heat units for a cotton plant on the South High Plains of Texas to mature. This value is based on a typical planting date of May 15 with ample irrigation. As water for c...

  5. Motivation and Maturity Patterns in Marital Success.

    ERIC Educational Resources Information Center

    McClelland, David C.; And Others

    1978-01-01

    Married couples rated their marital satisfaction and played interpersonal competitive games which revealed the success with which they interacted. Younger husbands who scored more maturely on the Stewart measure of psychosocial maturity belonged to more successful marriages, as did college-educated wives who showed less immaturity and more phallic…

  6. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for Application, Commitment, and Endorsement Generally... Requirements for Existing Projects Mortgage Provisions § 200.82 Maturity. The mortgage shall have a maturity... included under the applicable section of the Act. (2) Thirty-five years for existing projects, except...

  7. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for Application, Commitment, and Endorsement Generally... Requirements for Existing Projects Mortgage Provisions § 200.82 Maturity. The mortgage shall have a maturity... included under the applicable section of the Act. (2) Thirty-five years for existing projects, except...

  8. Toward the Measurement of Psychosocial Maturity.

    ERIC Educational Resources Information Center

    Greenberger, Ellen; And Others

    The concept of psychosocial maturity is reviewed in preparation for the exploration of the feasibility of constructing a scale that measures maturity. Investigation produced a preliminary 54-item scale with high reliability and moderate validity, which is appended. A factor analysis of the scale supports the a priori structure by the theoretical…

  9. The FMI: Dimensions of Follower Maturity

    ERIC Educational Resources Information Center

    Moore, Loren I.

    1976-01-01

    The Follower Maturity Index (FMI) is an instrument derived from leadership theory and based on observations of verbal and nonverbal behavior of followers in task groups. Dimensions of follower maturity--achievement, responsibility, experience, activity, dependence, variety, interests, perspective, position, and awareness--are discussed. For…

  10. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  11. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  12. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  13. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  14. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  15. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  16. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  17. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  18. 7 CFR 51.1238 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Cleaned Virginia Type Peanuts in the Shell Definitions § 51.1238 Mature. Mature means that...

  19. International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): A review.

    PubMed

    Xanthos, Dirk; Walker, Tony R

    2017-02-18

    Marine plastic pollution has been a growing concern for decades. Single-use plastics (plastic bags and microbeads) are a significant source of this pollution. Although research outlining environmental, social, and economic impacts of marine plastic pollution is growing, few studies have examined policy and legislative tools to reduce plastic pollution, particularly single-use plastics (plastic bags and microbeads). This paper reviews current international market-based strategies and policies to reduce plastic bags and microbeads. While policies to reduce microbeads began in 2014, interventions for plastic bags began much earlier in 1991. However, few studies have documented or measured the effectiveness of these reduction strategies. Recommendations to further reduce single-use plastic marine pollution include: (i) research to evaluate effectiveness of bans and levies to ensure policies are having positive impacts on marine environments; and (ii) education and outreach to reduce consumption of plastic bags and microbeads at source.

  20. Extruding plastic scintillator at Fermilab

    SciTech Connect

    Anna Pla-Dalmau; Alan D. Bross; Victor V. Rykalin

    2003-10-31

    An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab.

  1. White matter maturation profiles through early childhood predict general cognitive ability.

    PubMed

    Deoni, Sean C L; O'Muircheartaigh, Jonathan; Elison, Jed T; Walker, Lindsay; Doernberg, Ellen; Waskiewicz, Nicole; Dirks, Holly; Piryatinsky, Irene; Dean, Doug C; Jumbe, N L

    2016-03-01

    Infancy and early childhood are periods of rapid brain development, during which brain structure and function mature alongside evolving cognitive ability. An important neurodevelopmental process during this postnatal period is the maturation of the myelinated white matter, which facilitates rapid communication across neural systems and networks. Though prior brain imaging studies in children (4 years of age and above), adolescents, and adults have consistently linked white matter development with cognitive maturation and intelligence, few studies have examined how these processes are related throughout early development (birth to 4 years of age). Here, we show that the profile of white matter myelination across the first 5 years of life is strongly and specifically related to cognitive ability. Using a longitudinal design, coupled with advanced magnetic resonance imaging, we demonstrate that children with above-average ability show differential trajectories of myelin development compared to average and below average ability children, even when controlling for socioeconomic status, gestation, and birth weight. Specifically, higher ability children exhibit slower but more prolonged early development, resulting in overall increased myelin measures by ~3 years of age. These results provide new insight into the early neuroanatomical correlates of cognitive ability, and suggest an early period of prolonged maturation with associated protracted white matter plasticity may result in strengthened neural networks that can better support later development. Further, these results reinforce the necessity of a longitudinal perspective in investigating typical or suspected atypical cognitive maturation.

  2. A role for synaptic plasticity in the adolescent development of executive function

    PubMed Central

    Selemon, L D

    2013-01-01

    Adolescent brain maturation is characterized by the emergence of executive function mediated by the prefrontal cortex, e.g., goal planning, inhibition of impulsive behavior and set shifting. Synaptic pruning of excitatory contacts is the signature morphologic event of late brain maturation during adolescence. Mounting evidence suggests that glutamate receptor-mediated synaptic plasticity, in particular long term depression (LTD), is important for elimination of synaptic contacts in brain development. This review examines the possibility (1) that LTD mechanisms are enhanced in the prefrontal cortex during adolescence due to ongoing synaptic pruning in this late developing cortex and (2) that enhanced synaptic plasticity in the prefrontal cortex represents a key molecular substrate underlying the critical period for maturation of executive function. Molecular sites of interaction between environmental factors, such as alcohol and stress, and glutamate receptor mediated plasticity are considered. The accentuated negative impact of these factors during adolescence may be due in part to interference with LTD mechanisms that refine prefrontal cortical circuitry and when disrupted derail normal maturation of executive function. Diminished prefrontal cortical control over risk-taking behavior could further exacerbate negative outcomes associated with these behaviors, as for example addiction and depression. Greater insight into the neurobiology of the adolescent brain is needed to fully understand the molecular basis for heightened vulnerability during adolescence to the injurious effects of substance abuse and stress. PMID:23462989

  3. Circadian Regulation of Synaptic Plasticity.

    PubMed

    Frank, Marcos G

    2016-07-13

    Circadian rhythms refer to oscillations in biological processes with a period of approximately 24 h. In addition to the sleep/wake cycle, there are circadian rhythms in metabolism, body temperature, hormone output, organ function and gene expression. There is also evidence of circadian rhythms in synaptic plasticity, in some cases driven by a master central clock and in other cases by peripheral clocks. In this article, I review the evidence for circadian influences on synaptic plasticity. I also discuss ways to disentangle the effects of brain state and rhythms on synaptic plasticity.

  4. [Neuronal plasticity and gene expression].

    PubMed

    Sokolova, O O; Shtark, M B; Lisachev, P D

    2010-01-01

    Neuronal plasticity--a fundamental feature of brain--provides adequate interactions with dynamic environment. One of the most deeply investigated forms of the neuronal plasticity is a long-term potentiation (LTP)--a phenomenon underlying learning and memory. Signal paths activated during LTP converge into the nuclear of the neuron, giving rise to launch of the molecular-genetic programs, which mediate structural and functional remodeling of synapses. In the review data concerning involvement of multilevel gene expression into plastic change under neuronal activation are summarized.

  5. Biodegradable plastics from renewable sources.

    PubMed

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  6. Circadian Regulation of Synaptic Plasticity

    PubMed Central

    Frank, Marcos G.

    2016-01-01

    Circadian rhythms refer to oscillations in biological processes with a period of approximately 24 h. In addition to the sleep/wake cycle, there are circadian rhythms in metabolism, body temperature, hormone output, organ function and gene expression. There is also evidence of circadian rhythms in synaptic plasticity, in some cases driven by a master central clock and in other cases by peripheral clocks. In this article, I review the evidence for circadian influences on synaptic plasticity. I also discuss ways to disentangle the effects of brain state and rhythms on synaptic plasticity. PMID:27420105

  7. Musical experience, plasticity, and maturation: issues in measuring developmental change using EEG and MEG.

    PubMed

    Trainor, Laurel J

    2012-04-01

    The neuroscientific study of musical behavior has become a significant field of research during the last decade, and reports of this research in the popular press have caught the imagination of the public. This enterprise has also made it evident that studying the development of musical behavior can make a significant contribution to important questions in the field, such as the evolutionary origins of music, cross-cultural similarity and diversity, the effects of experience on musical processing, and relations between music and other domains. Studying musical development brings a unique set of methodological issues. We discuss a select set of these related to measurement of the electroencephalogram (EEG) and magnetoencephalogram (MEG). We use specific examples from our laboratory to illustrate the types of questions that can be answered with different data analysis techniques.

  8. Recycling of Reinforced Plastics

    NASA Astrophysics Data System (ADS)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  9. [Memory and synaptic plasticity].

    PubMed

    Maitre, M

    1996-01-01

    Short term memory traces are probably induced by a sustained and specific functional activation of some sensory and/or motor circuits in brain. These modifications, which could concern a large proportion of the brain but especially the limbic areas, are constituted primarily by ionic mechanisms and second messengers cascades induced by the activation of glutamatergic receptors (namely NMDA). In the invertebrate (Drosophilia melanogaster, aplysia), the role of serotonergic receptors seems to be more important. The activated cAMP-dependent and calcium dependent protein kinases target several proteins which are reversibly phosphorylated modifying the synaptic functions which in turn induce potentiated (PLT) or depressed (DLT) post-synaptic responses. These phenomena are at the basis of specific protein neosynthesis which is initiated by several early genes or trancription factor (cfos, zif 268, jun, CREB). Specific mRNA migrate to the potentiated synapse or dendritic spine where activated polyribosomes synthesize trophic factor, adhesion molecules and synaptic constituents. The building of new synaptic contacts and/or the plastic evolution of existing synapses could explain long-term LTP and long-term memory traces.

  10. Autonomic cardiac innervation: development and adult plasticity.

    PubMed

    Hasan, Wohaib

    2013-01-01

    Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targets, upon which target-derived trophic factors take over final maturation, synaptic strength and postnatal survival. Although target-derived neurotrophins have a central role to play in development, alternative sources of neurotrophins may also modulate innervation. Both developing and adult sympathetic neurons express proNGF, and adult parasympathetic cardiac ganglion neurons also synthesize and release NGF. The physiological function of these "non-classical" cardiac sources of neurotrophins remains to be determined, especially in relation to autocrine/paracrine sustenance during development.   Cardiac autonomic nerves are closely spatially associated in cardiac plexuses, ganglia and pacemaker regions and so are sensitive to release of neurotransmitter, neuropeptides and trophic factors from adjacent nerves. As such, in many cardiac pathologies, it is an imbalance within the two arms of the autonomic system that is critical for disease progression. Although this crosstalk between sympathetic and parasympathetic nerves has been well established for adult nerves, it is unclear whether a degree of paracrine regulation occurs across the autonomic limbs during development. Aberrant nerve remodeling is a common occurrence in many adult cardiovascular pathologies, and the mechanisms regulating outgrowth or denervation are disparate. However, autonomic neurons display considerable plasticity in this regard with neurotrophins and inflammatory cytokines having a central regulatory

  11. Neurophysiological mechanisms underlying sex- and maturation-related variation in pheromone responses in honey bees (Apis mellifera).

    PubMed

    Villar, Gabriel; Baker, Thomas C; Patch, Harland M; Grozinger, Christina M

    2015-07-01

    In the honey bee (Apis mellifera), social organization is primarily mediated by pheromones. Queen-produced 9-oxo-2-decenoic acid (9-ODA) functions as both a social and sex pheromone, eliciting attraction in both female workers and male drones, but also affecting other critical aspects of worker physiology and behavior. These effects are also maturation related, as younger workers and sexually mature drones are most receptive to 9-ODA. While changes in the peripheral nervous system drive sex-related differences in sensitivity to 9-ODA, the mechanisms driving maturation-related shifts in receptivity to 9-ODA remain unknown. Here, we investigate the hypothesis that changes at the peripheral nervous system may be mediating plastic responses to 9-ODA by characterizing expression levels of AmOR11 (the olfactory receptor tuned to 9-ODA) and electrophysiological responses to 9-ODA. We find that receptor expression correlates significantly with behavioral receptivity to 9-ODA, with nurses and sexually mature drones exhibiting higher levels of expression than foragers and immature drones, respectively. Electrophysiological responses to 9-ODA were not found to correlate with behavioral receptivity or receptor expression, however. Thus, while receptor expression at the periphery exhibits a level of plasticity that correlates with behavior, the mechanisms driving maturation-dependent responsiveness to 9-ODA appear to function primarily in the central nervous system.

  12. Extracellular Matrix Mediated Maturation of Human Pluripotent Stem Cell Derived Cardiac Monolayer Structure and Electrophysiological Function

    PubMed Central

    Herron, Todd J.; Rocha, Andre Monteiro Da; Campbell, Katherine; Ponce-Balbuena, Daniela; Willis, B. Cicero; Guerrero-Serna, Guadalupe; Liu, Qinghua; Klos, Matt; Musa, Hassan; Zarzoso, Manuel; Bizy, Alexandra; Furness, Jamie; Anumonwo, Justus; Mironov, Sergey; Jalife, José

    2016-01-01

    Background Human pluripotent stem cell-derived cardiomyocyte (hPSC-CMs) monolayers generated to date display an immature embryonic-like functional and structural phenotype that limits their utility for research and cardiac regeneration. In particular, the electrophysiological function of hPSC-CM monolayers and bioengineered constructs used to date are characterized by slow electrical impulse propagation velocity and immature action potential profiles. Methods and Results Here we have identified an optimal extracellular matrix (ECM) for significant electrophysiological and structural maturation of hPSC-CM monolayers. hPSC-CM plated in the optimal ECM combination have impulse propagation velocities ~2X faster than previously reported (43.6±7.0 cm·s−1 n=9) and have mature cardiomyocyte action potential profiles including hyperpolarized diastolic potential and rapid action potential upstroke velocity (146.5±17.7 V/s, N=5 monolayers). In addition the optimal ECM promoted hypertrophic growth of cardiomyocytes and the expression of key mature sarcolemmal (SCN5A, Kir2.1 and Connexin43) and myofilament markers (cTroponin I). The maturation process reported here relies on activation of integrin signaling pathways: neutralization of β1 integrin receptors via blocking antibodies and pharmacological blockade of focal adhesion kinase (FAK) activation prevented structural maturation. Conclusions Maturation of human stem cell derived cardiomyocyte monolayers is achieved in a one week period by plating cardiomyocytes on PDMS coverslips rather than on conventional 2D cell culture formats such as glass coverslips or plastic dishes. Activation of integrin signaling and FAK are essential for significant maturation of human cardiac monolayers. PMID:27069088

  13. Activation-Dependent Rapid Postsynaptic Clustering of Glycine Receptors in Mature Spinal Cord Neurons

    PubMed Central

    Eto, Kei; Murakoshi, Hideji; Watanabe, Miho; Hirata, Hiromi; Moorhouse, Andrew J.; Ishibashi, Hitoshi

    2017-01-01

    Abstract Inhibitory synapses are established during development but continue to be generated and modulated in strength in the mature nervous system. In the spinal cord and brainstem, presynaptically released inhibitory neurotransmitter dominantly switches from GABA to glycine during normal development in vivo. While presynaptic mechanisms of the shift of inhibitory neurotransmission are well investigated, the contribution of postsynaptic neurotransmitter receptors to this shift is not fully elucidated. Synaptic clustering of glycine receptors (GlyRs) is regulated by activation-dependent depolarization in early development. However, GlyR activation induces hyperpolarization after the first postnatal week, and little is known whether and how presynaptically released glycine regulates postsynaptic receptors in a depolarization-independent manner in mature developmental stage. Here we developed spinal cord neuronal culture of rodents using chronic strychnine application to investigate whether initial activation of GlyRs in mature stage could change postsynaptic localization of GlyRs. Immunocytochemical analyses demonstrate that chronic blockade of GlyR activation until mature developmental stage resulted in smaller clusters of postsynaptic GlyRs that could be enlarged upon receptor activation for 1 h in the mature stage. Furthermore, live cell-imaging techniques show that GlyR activation decreases its lateral diffusion at synapses, and this phenomenon is dependent on PKC, but neither Ca2+ nor CaMKII activity. These results suggest that the GlyR activation can regulate receptor diffusion and cluster size at inhibitory synapses in mature stage, providing not only new insights into the postsynaptic mechanism of shifting inhibitory neurotransmission but also the inhibitory synaptic plasticity in mature nervous system. PMID:28197549

  14. The stress of maternal separation causes misprogramming in the postnatal maturation of rat resistance arteries.

    PubMed

    Reho, John J; Fisher, Steven A

    2015-11-01

    We examined the effect of stress in the first 2 wk of life induced by brief periods of daily maternal separation on developmental programming of rat small resistance mesenteric arteries (MAs). In MAs of littermate controls, mRNAs encoding mediators of vasoconstriction, including the α1a-adrenergic receptor, smooth muscle myosin heavy chain, and CPI-17, the inhibitory subunit of myosin phosphatase, increased from after birth through sexual [postnatal day (PND) 35] and full maturity, up to ∼80-fold, as measured by quantitative PCR. This was commensurate with two- to fivefold increases in maximum force production to KCl depolarization, calcium, and the α-adrenergic agonist phenylephrine, and increasing systolic blood pressure. Rats exposed to maternal separation stress as neonates had markedly accelerated trajectories of maturation of arterial contractile gene expression and function measured at PND14 or PND21 (weaning), 1 wk after the end of the stress protocol. This was suppressed by the α-adrenergic receptor blocker terazosin (0.5 mg·kg ip(-1)·day(-1)), indicating dependence on stress activation of sympathetic signaling. Due to the continued maturation of MAs in control rats, by sexual maturity (PND35) and into adulthood, no differences were observed in arterial function or response to a second stressor in rats stressed as neonates. Thus early life stress misprograms resistance artery smooth muscle, increasing vasoconstrictor function and blood pressure. This effect wanes in later stages, suggesting plasticity during arterial maturation. Further studies are indicated to determine whether stress in different periods of arterial maturation may cause misprogramming persisting through maturity and the potential salutary effect of α-adrenergic blockade in suppression of this response.

  15. WEATHERABILITY OF ENHANCED DEGRADABLE PLASTICS

    EPA Science Inventory

    The main objective of this study was to assess the performance and the asociated variability of several selected enhanced degradable plastic materials under a variety of different exposure conditions. Other objectives were to identify the major products formed during degradation ...

  16. Network Plasticity as Bayesian Inference

    PubMed Central

    Legenstein, Robert; Maass, Wolfgang

    2015-01-01

    General results from statistical learning theory suggest to understand not only brain computations, but also brain plasticity as probabilistic inference. But a model for that has been missing. We propose that inherently stochastic features of synaptic plasticity and spine motility enable cortical networks of neurons to carry out probabilistic inference by sampling from a posterior distribution of network configurations. This model provides a viable alternative to existing models that propose convergence of parameters to maximum likelihood values. It explains how priors on weight distributions and connection probabilities can be merged optimally with learned experience, how cortical networks can generalize learned information so well to novel experiences, and how they can compensate continuously for unforeseen disturbances of the network. The resulting new theory of network plasticity explains from a functional perspective a number of experimental data on stochastic aspects of synaptic plasticity that previously appeared to be quite puzzling. PMID:26545099

  17. Smartphones and the plastic surgeon.

    PubMed

    Al-Hadithy, Nada; Ghosh, Sudip

    2013-06-01

    Surgical trainees are facing limited training opportunities since the introduction of the European Working Time Directive. Smartphone sales are increasing and have usurped computer sales for the first time. In this context, smartphones are an important portable reference and educational tool, already in the possession of the majority of surgeons in training. Technology in the palm of our hands has led to a revolution of accessible information for the plastic surgery trainee and surgeon. This article reviews the uses of smartphones and applications for plastic surgeons in education, telemedicine and global health. A comprehensive guide to existing and upcoming learning materials and clinical tools for the plastic surgeon is included. E-books, podcasts, educational videos, guidelines, work-based assessment tools and online logbooks are presented. In the limited resource setting of modern clinical practice, savvy plastic surgeons can select technological tools to democratise access to education and best clinical care.

  18. THERMAL DEPOLYMERIZATION OF POSTCONSUMER PLASTICS

    EPA Science Inventory

    The University of North Dakota Energy & Environmental Research Center (EERC) performed two series of tests to evaluate process conditions for thermal depolymerization of postconsumer plastics. The objective of the first test series was to provide data for optimization of reactio...

  19. Nano-Ceramic Coated Plastics

    NASA Technical Reports Server (NTRS)

    Cho, Junghyun

    2013-01-01

    Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (<100 C) is also a key to generating these ceramic coatings on the plastics. One possible way of processing nanoceramic coatings at low temperatures (< 90 C) is to take advantage of in-situ precipitated nanoparticles and nanostructures grown from aqueous solution. These nanostructures can be tailored to ceramic film formation and the subsequent microstructure development. In addition, the process provides environment- friendly processing because of the

  20. Plastic Deformation of Granular Materials

    DTIC Science & Technology

    1993-01-25

    discontinuities. These result will be important in our granular flow work, when considering viscoplastic constitutive relations (i.e. relaxation systems...5 CUNDN( NUMRES Plastic Deformation of Granular Materials (U) 61102F 6. AUTHOR(S) 2304/A4 Dr. E. Bruce Pitman 7 PERFORMING ORGANIZATION NA .h • 8...lose hyperbolicity. 98 3 81 061! SUBJECT TERMS 15. NUMBER OF PAGES granular material ; plastic deformation; hyperbolic 12 equations 16. PRICE CODE 17

  1. Plastic bronchitis: a management challenge.

    PubMed

    Eberlein, Michael H; Drummond, Michael B; Haponik, Edward F

    2008-02-01

    Plastic bronchitis is an uncommon and underdiagnosed entity, characterized by recurrent expectoration of large, branching bronchial casts. We describe a 39-year-woman with no prior lung disease who had episodic wheezing, severe dyspnea with expectoration of large and thick secretions, branching in appearance, which she described as resembling squid. A comprehensive evaluation revealed no specific cause and a diagnosis of idiopathic plastic bronchitis was made. In plastic bronchitis the bronchial casts may vary in size from small segmental casts of a bronchus to casts filling the airways of an entire lung. Plastic bronchitis can therefore present as an acute life-threatening emergency if mechanical obstruction of major airways occurs. The casts are differentiated into type I, inflammatory casts, or type II, acellular casts. The type I inflammatory casts are often associated with bronchial disease and often have an acute presentation. The acellular type of cast production is often chronic or recurrent. Numerous systemic illnesses are associated with plastic bronchitis, but often, as in our patient, no underlying cause can be identified. The treatment of plastic bronchitis includes acute therapy to aid the removal and expectoration of casts, and specific short- or long-term treatments attempting to address the underlying hypersecretory process. The therapeutic options are supported only by anecdotal evidence based on case reports as the rarity and heterogeneity of plastic bronchitis confounds systematic investigations of its treatment. Improved understanding of the regulation of mucus production may allow for new treatment options in plastic bronchitis and other chronic lung diseases characterized by hypersecretion of mucus.

  2. Sexual maturity in western Atlantic bluefin tuna

    PubMed Central

    Heinisch, Gilad; Rosenfeld, Hanna; Knapp, Jessica M.; Gordin, Hillel; Lutcavage, Molly E.

    2014-01-01

    We introduce a novel endocrine approach for assessing the unresolved matter of the timing of sexual maturation in western Atlantic bluefin tuna (ABFT), a highly migratory population whose status remains uncertain. Ratios of follicle stimulating hormone to luteinizing hormone, a sexual maturity indicator, in all ABFT ≥134 cm curved fork length (CFL) were <0.4, similar to Mediterranean spawners, indicating that western ABFT mature at considerably smaller sizes and at a much younger age than currently assumed (≥185 cm CFL). PMID:25431301

  3. Helene: A Plastic Model

    NASA Astrophysics Data System (ADS)

    Umurhan, O. M.; Moore, J. M.; Howard, A. D.; Schenk, P.; White, O. L.

    2014-12-01

    Helene, the Saturnian L4 Trojan satellite co-orbiting Dionne and sitting within the E-ring, possesses an unusual morphology characteristic of broad km-scale basins and depressions and a generally smooth surface patterned with streaks and grooves which are indicative of non-typical mass transport. Elevation angles do not appear to exceed 10o at most. The nature and origin of the surface materials forming these grooved patterns is unknown. Given the low surface gravity (<5mm/s2), it hard to imagine how such transport features can come about with such low grades and surface gravities. Preliminary examinations of classical linear and nonlinear mass wasting mechanisms do not appear to reproduce these curious features. A suite of hypothesis that we examine is the possibility that the fine grain material on the surface has been either (i) accreted or (ii) generated as refractory detritus resulting from sublimation of the icy bedrock, and that these materials subsequently mass-waste like a non-Newtonian highly non-linear creeping flow. Modifying the landform evolution model MARSSIM to handle two new mass-wasting mechanism, the first due to glacial-like flow via Glen's Law and the second due to plastic-like flow like a Bingham fluid, we setup and test a number of likely scenarios to explain the observations. The numerical results qualitatively indicate that treating the mass-wasting materials as a Bingham material reproduces many of the qualitative features observed. We also find that in those simulations in which accretion is concomitant with Bingham mass-wasting, the long time-evolution of the surface flow shows intermittency in the total surface activity (defined as total surface integral of the absolute magnitude of the mass-flux). Detailed analyses identify the locations where this activity is most pronounced and we will discuss these and its implications in further detail.

  4. 49 CFR 192.281 - Plastic pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  5. 49 CFR 192.281 - Plastic pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  6. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  7. 49 CFR 192.281 - Plastic pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  8. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  9. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  10. 49 CFR 192.281 - Plastic pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  11. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  12. 49 CFR 192.281 - Plastic pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Plastic pipe. 192.281 Section 192.281... Plastic pipe. (a) General. A plastic pipe joint that is joined by solvent cement, adhesive, or heat fusion may not be disturbed until it has properly set. Plastic pipe may not be joined by a threaded joint...

  13. 49 CFR 192.59 - Plastic pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Plastic pipe. 192.59 Section 192.59 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.59 Plastic pipe. (a) New plastic pipe... specification; and (2) It is resistant to chemicals with which contact may be anticipated. (b) Used plastic...

  14. The Story of the Plastics Industry.

    ERIC Educational Resources Information Center

    Masson, Don, Ed.

    This is an illustrated informative booklet, designed to serve members of the Society of the Plastics Industry, Inc., and the plastics industry as a whole. It provides basic information about the industry's history and growth, plastics raw materials, typical uses of plastics, properties, and methods of processing and fabricating. (Author/DS)

  15. Stress as a fundamental theme in cell plasticity.

    PubMed

    Shoshani, Ofer; Zipori, Dov

    2015-04-01

    Over a decade of intensive investigation of the possible plasticity of mammalian cells has eventually substantiated that mammalian species are endowed with a remarkable capacity to change mature cell fates. We review below the evidence for the occurrence of processes such as dedifferentiation and transdifferentiation within mammalian tissues in vivo, and in cells removed from their protective microenvironment and seeded in culture under conditions poorly resembling their physiological state in situ. Overall, these studies point to one major conclusion: stressful conditions, whether due to in vivo tissue damage or otherwise to isolation of cells from their in vivo restrictive niches, lead to extreme fate changes. Some examples of dedifferentiation are discussed in detail showing that rare cells within the population tend to turn back into less mature ones due to severe cell damage. It is proposed that cell stress, mechanistically sensed by isolation from neighboring cells, leads to dedifferentiation, in an attempt to build a new stem cell reservoir for subsequent regeneration of the damaged tissue. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity.

  16. Training-Induced Plasticity of Auditory Localization in Adult Mammals

    PubMed Central

    Kacelnik, Oliver; Nodal, Fernando R; Parsons, Carl H

    2006-01-01

    Accurate auditory localization relies on neural computations based on spatial cues present in the sound waves at each ear. The values of these cues depend on the size, shape, and separation of the two ears and can therefore vary from one individual to another. As with other perceptual skills, the neural circuits involved in spatial hearing are shaped by experience during development and retain some capacity for plasticity in later life. However, the factors that enable and promote plasticity of auditory localization in the adult brain are unknown. Here we show that mature ferrets can rapidly relearn to localize sounds after having their spatial cues altered by reversibly occluding one ear, but only if they are trained to use these cues in a behaviorally relevant task, with greater and more rapid improvement occurring with more frequent training. We also found that auditory adaptation is possible in the absence of vision or error feedback. Finally, we show that this process involves a shift in sensitivity away from the abnormal auditory spatial cues to other cues that are less affected by the earplug. The mature auditory system is therefore capable of adapting to abnormal spatial information by reweighting different localization cues. These results suggest that training should facilitate acclimatization to hearing aids in the hearing impaired. PMID:16509769

  17. Deformation mechanisms of plasticized starch materials.

    PubMed

    Mikus, P-Y; Alix, S; Soulestin, J; Lacrampe, M F; Krawczak, P; Coqueret, X; Dole, P

    2014-12-19

    The aim of this paper is to understand the influence of plasticizer and plasticizer amount on the mechanical and deformation behaviors of plasticized starch. Glycerol, sorbitol and mannitol have been used as plasticizers. After extrusion of the various samples, dynamic mechanical analyses and video-controlled tensile tests have been performed. It was found that the nature of plasticizer, its amount as well as the aging of the material has an impact on the involved deformation mechanism. The variations of volume deformation could be explained by an antiplasticization effect (low plasticizer amount), a phase-separation phenomenon (excess of plasticizer) and/or by the retrogradation of starch.

  18. Evolution of phenotypic plasticity in colonizing species.

    PubMed

    Lande, Russell

    2015-05-01

    I elaborate an hypothesis to explain inconsistent empirical findings comparing phenotypic plasticity in colonizing populations or species with plasticity from their native or ancestral range. Quantitative genetic theory on the evolution of plasticity reveals that colonization of a novel environment can cause a transient increase in plasticity: a rapid initial increase in plasticity accelerates evolution of a new optimal phenotype, followed by slow genetic assimilation of the new phenotype and reduction of plasticity. An association of colonization with increased plasticity depends on the difference in the optimal phenotype between ancestral and colonized environments, the difference in mean, variance and predictability of the environment, the cost of plasticity, and the time elapsed since colonization. The relative importance of these parameters depends on whether a phenotypic character develops by one-shot plasticity to a constant adult phenotype or by labile plasticity involving continuous and reversible development throughout adult life.

  19. 7 CFR 51.1218 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1218 Mature. “Mature” means that the peach has reached the stage of growth which will ensure a proper completion of...

  20. 7 CFR 51.1218 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1218 Mature. “Mature” means that the peach has reached the stage of growth which will ensure a proper completion of...

  1. 38 CFR 7.7 - Maturity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... policy as a death claim or otherwise (SSCRA, as amended) will not include a termination or maturity of a... approval by the Department of Veterans Affairs. The statement of account will include the rate of...

  2. 38 CFR 7.7 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... policy as a death claim or otherwise (SSCRA, as amended) will not include a termination or maturity of a... approval by the Department of Veterans Affairs. The statement of account will include the rate of...

  3. 38 CFR 7.7 - Maturity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... policy as a death claim or otherwise (SSCRA, as amended) will not include a termination or maturity of a... approval by the Department of Veterans Affairs. The statement of account will include the rate of...

  4. 7 CFR 1710.115 - Final maturity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... maturities for loans for the implementation of programs for demand side management and energy resource conservation and on and off grid renewable energy sources not owned by the borrower will be determined by...

  5. Structure, function and dynamics in adenovirus maturation.

    PubMed

    Mangel, Walter F; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a "molecular sled" to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. Finally, possible roles for maturation of the terminal protein are discussed.

  6. Structure, function and dynamics in adenovirus maturation

    DOE PAGES

    Mangel, Walter F.; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core ismore » more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. In conclusion, possible roles for maturation of the terminal protein are discussed.« less

  7. Structure, Function and Dynamics in Adenovirus Maturation

    PubMed Central

    Mangel, Walter F.; San Martín, Carmen

    2014-01-01

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. Finally, possible roles for maturation of the terminal protein are discussed. PMID:25421887

  8. Structure, function and dynamics in adenovirus maturation

    SciTech Connect

    Mangel, Walter F.; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. In conclusion, possible roles for maturation of the terminal protein are discussed.

  9. Color back projection for fruit maturity evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    In general, fruits and vegetables such as tomatoes and dates are harvested before they fully ripen. After harvesting, they continue to ripen and their color changes. Color is a good indicator of fruit maturity. For example, tomatoes change color from dark green to light green and then pink, light red, and dark red. Assessing tomato maturity helps maximize its shelf life. Color is used to determine the length of time the tomatoes can be transported. Medjool dates change color from green to yellow, and the orange, light red and dark red. Assessing date maturity helps determine the length of drying process to help ripen the dates. Color evaluation is an important step in the processing and inventory control of fruits and vegetables that directly affects profitability. This paper presents an efficient color back projection and image processing technique that is designed specifically for real-time maturity evaluation of fruits. This color processing method requires very simple training procedure to obtain the frequencies of colors that appear in each maturity stage. This color statistics is used to back project colors to predefined color indexes. Fruit maturity is then evaluated by analyzing the reprojected color indexes. This method has been implemented and used for commercial production.

  10. Plastic reproductive strategies in a clonal marine invertebrate.

    PubMed Central

    McGovern, Tamara M

    2003-01-01

    Plastic reproductive allocation may allow individuals to maximize their fitness when conditions vary. Mate availability is one condition that may determine the fitness of an individual's allocation strategy. Using a variety of methods, I detected evidence of plastic allocation to asexual (clonal) reproduction in response to mate availability in the brittle star Ophiactis savignyi. There were more mature individuals in populations in which both sexes were present, and clones from these populations had fewer clone-mates than clones from single-sex populations. Animals placed with mates in a field experiment divided less frequently than animals without a mate. These findings demonstrate that animals reduce their allocation to asexual reproduction when mates are present and when a loss of fecundity associated with cloning would decrease offspring production. This plasticity is probably adaptive because it maximizes sexual-reproductive potential when fertilization is more likely, but maximizes survival of the clone when mates are absent and gametes are unlikely to be converted to offspring. PMID:14667344

  11. Mitochondria, synaptic plasticity, and schizophrenia.

    PubMed

    Ben-Shachar, Dorit; Laifenfeld, Daphna

    2004-01-01

    The conceptualization of schizophrenia as a disorder of connectivity, i.e., of neuronal?synaptic plasticity, suggests abnormal synaptic modeling and neuronal signaling, possibly as a consequence of flawed interactions with the environment, as at least a secondary mechanism underlying the pathophysiology of this disorder. Indeed, deficits in episodic memory and malfunction of hippocampal circuitry, as well as anomalies of axonal sprouting and synapse formation, are all suggestive of diminished neuronal plasticity in schizophrenia. Evidence supports a dysfunction of mitochondria in schizophrenia, including mitochondrial hypoplasia, and a dysfunction of the oxidative phosphorylation system, as well as altered mitochondrial-related gene expression. Mitochondrial dysfunction leads to alterations in ATP production and cytoplasmatic calcium concentrations, as well as reactive oxygen species and nitric oxide production. All of the latter processes have been well established as leading to altered synaptic strength or plasticity. Moreover, mitochondria have been shown to play a role in plasticity of neuronal polarity, and studies in the visual cortex show an association between mitochondria and synaptogenesis. Finally, mitochondrial gene upregulation has been observed following synaptic and neuronal activity. This review proposes that mitochondrial dysfunction in schizophrenia could cause, or arise from, anomalies in processes of plasticity in this disorder.

  12. Comparison of maturity based on steroid and vanadyl porphyrin parameters: A new vanadyl porphyrin maturity parameter for higher maturities

    NASA Astrophysics Data System (ADS)

    Sundararaman, Padmanabhan; Moldowan, J. Michael

    1993-03-01

    Correlations are demonstrated between steroid maturity parameters and the porphyrin maturity parameter (PMP) which is based on the ratio of specific vanadyl porphyrins C 28E /(C 28E + C 32D) measured by HPLC. Measurements from a global selection of > 100 rock extracts and oils show that PMP parallels changes in the C 29-sterane 20S/(20S + 20R) and tri/(tri + mono) aromatic steroid ratios, and that all three parameters appear to attain their maximum values at similar maturity levels. The triaromatic steroid side chain cracking parameter, TA I/(I + II), reaches approximately 20% of its maximum value when PMP has reached 100%. These results suggest that PMP is effective in the early to peak portion of the oil window. A new parameter, PMP-2, based on changes in the relative concentrations of two peaks in the HPLC fingerprint (vanadyl "etio" porphyrins), appears effective in assessing the maturity of source rocks beyond peak oil generation. In combination with PMP this parameter extends the effective range of vanadyl porphyrins parameters to higher maturities as demonstrated by a suite of oils from the Oriente Basin, Ecuador, South America.

  13. Encoding of High Frequencies Improves with Maturation of Action Potential Generation in Cultured Neocortical Neurons

    PubMed Central

    Nikitin, Evgeny S.; Bal, Natalia V.; Malyshev, Aleksey; Ierusalimsky, Victor N.; Spivak, Yulia; Balaban, Pavel M.; Volgushev, Maxim

    2017-01-01

    The ability of neocortical neurons to detect and encode rapid changes at their inputs is crucial for basic neuronal computations, such as coincidence detection, precise synchronization of activity and spike-timing dependent plasticity. Indeed, populations of cortical neurons can respond to subtle changes of the input very fast, on a millisecond time scale. Theoretical studies and model simulations linked the encoding abilities of neuronal populations to the fast onset dynamics of action potentials (APs). Experimental results support this idea, however mechanisms of fast onset of APs in cortical neurons remain elusive. Studies in neuronal cultures, that are allowing for accurate control over conditions of growth and microenvironment during the development of neurons and provide better access to the spike initiation zone, may help to shed light on mechanisms of AP generation and encoding. Here we characterize properties of AP encoding in neocortical neurons grown for 11–25 days in culture. We show that encoding of high frequencies improves upon culture maturation, which is accompanied by the development of passive electrophysiological properties and AP generation. The onset of APs becomes faster with culture maturation. Statistical analysis using correlations and linear model approaches identified the onset dynamics of APs as a major predictor of age-dependent changes of encoding. Encoding of high frequencies strongly correlated also with the input resistance of neurons. Finally, we show that maturation of encoding properties of neurons in cultures is similar to the maturation of encoding in neurons studied in slices. These results show that maturation of AP generators and encoding is, to a large extent, determined genetically and takes place even without normal micro-environment and activity of the whole brain in vivo. This establishes neuronal cultures as a valid experimental model for studying mechanisms of AP generation and encoding, and their maturation. PMID

  14. Source rock maturation, San Juan sag

    SciTech Connect

    Gries, R.R.; Clayton, J.L.

    1989-09-01

    Kinetic modeling for thermal histories was simulated for seven wells in the San Juan sag honoring measured geochemical data. Wells in the area of Del Norte field (Sec. 9, T40N, R5E), where minor production has been established from an igneous sill reservoir, show that the Mancos Shale source rocks are in the mature oil generation window as a combined result of high regional heat flow and burial by approximately 2,700 m of Oligocene volcanic rocks. Maturation was relatively recent for this area and insignificant during Laramide subsidence. In the vicinity of Gramps field (Sec. 24, T33N, R2E) on the southwest flank of the San Juan sag, these same source rocks are exposed due to erosion of the volcanic cover but appear to have undergone a similar maturation history. At the north and south margins of the sag, two wells (Champlin 34A-13, Sec. 13, T35N, R4.5E; and Champlin 24A-1, Sec. 1, T44N, R5E) were analyzed and revealed that although the regional heat flow was probably similar to other wells, the depth of burial was insufficient to cause maturation (except where intruded by thick igneous sills that caused localized maturation). The Meridian Oil 23-17 South Fork well (Sec. 17, T39N, R4E) was drilled in a deeper part of the San Juan sag, and source rocks were intruded by numerous igneous sills creating a complex maturation history that includes overmature rocks in the lowermost Mancos Shale, possible CO{sub 2} generation from the calcareous Niobrara Member of the Mancos Shale, and mature source rocks in the upper Mancos Shale.

  15. Extruded plastic scintillator including inorganic powders

    DOEpatents

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2006-06-27

    A method for producing a plastic scintillator is disclosed. A plurality of nano-sized particles and one or more dopants can be combined with a plastic material for the formation of a plastic scintillator thereof. The nano-sized particles, the dopant and the plastic material can be combined within the dry inert atmosphere of an extruder to produce a reaction that results in the formation of a plastic scintillator thereof and the deposition of energy within the plastic scintillator, such that the plastic scintillator produces light signifying the detection of a radiative element. The nano-sized particles can be treated with an inert gas prior to processing the nano-sized particles, the dopant and the plastic material utilizing the extruder. The plastic scintillator can be a neutron-sensitive scintillator, x-ray sensitive scintillator and/or a scintillator for the detection of minimum ionizing particles.

  16. Scale Invariant Disordered Nanotopography Promotes Hippocampal Neuron Development and Maturation with Involvement of Mechanotransductive Pathways

    PubMed Central

    Schulte, Carsten; Ripamonti, Maddalena; Maffioli, Elisa; Cappelluti, Martino A.; Nonnis, Simona; Puricelli, Luca; Lamanna, Jacopo; Piazzoni, Claudio; Podestà, Alessandro; Lenardi, Cristina; Tedeschi, Gabriella; Malgaroli, Antonio; Milani, Paolo

    2016-01-01

    The identification of biomaterials which promote neuronal maturation up to the generation of integrated neural circuits is fundamental for modern neuroscience. The development of neural circuits arises from complex maturative processes regulated by poorly understood signaling events, often guided by the extracellular matrix (ECM). Here we report that nanostructured zirconia surfaces, produced by supersonic cluster beam deposition of zirconia nanoparticles and characterized by ECM-like nanotopographical features, can direct the maturation of neural networks. Hippocampal neurons cultured on such cluster-assembled surfaces displayed enhanced differentiation paralleled by functional changes. The latter was demonstrated by single-cell electrophysiology showing earlier action potential generation and increased spontaneous postsynaptic currents compared to the neurons grown on the featureless unnaturally flat standard control surfaces. Label-free shotgun proteomics broadly confirmed the functional changes and suggests furthermore a vast impact of the neuron/nanotopography interaction on mechanotransductive machinery components, known to control physiological in vivo ECM-regulated axon guidance and synaptic plasticity. Our results indicate a potential of cluster-assembled zirconia nanotopography exploitable for the creation of efficient neural tissue interfaces and cell culture devices promoting neurogenic events, but also for unveiling mechanotransductive aspects of neuronal development and maturation. PMID:27917111

  17. The toxic effects and possible mechanisms of Bisphenol A on oocyte maturation of porcine in vitro

    PubMed Central

    Wang, Teng; Han, Jun; Duan, Xing; Xiong, Bo; Cui, Xiang-Shun; Kim, Nam-Hyung; Liu, Hong-Lin; Sun, Shao-Chen

    2016-01-01

    Bisphenol A (BPA) and Di-(2-ethylhexyl) phthalate (DEHP) are widely used in the plastic industry such as water bottles, containers, packaging and toys. BPA and DEHP are shown to be the endocrine disruptors which disturb the endocrine system and are linked to several diseases including infertility. In this study, we investigated the effects of BPA exposure on porcine oocyte maturation and its possible reasons. Our results showed that: (i) the rates of oocyte maturation significantly decreased with 250 μM BPA treatment in vitro, but not DEHP. This might be due to the delayed cell cycle progression of oocyte maturation. (ii) BPA treatment resulted in abnormal cytoskeletons on porcine oocytes, showing with aberrant actin distribution, spindle morphology and chromosome alignment, which was further confirmed by the reduced p-MAPK level. (iii) The fluorescence intensity of histone methylation (H3K4me2) and DNA methylation (5 mC) levels were altered after BPA treatment, indicating that epigenetic modification was disturbed. (iv) BPA-exposed oocytes had higher rates of early stage apoptosis/autophagy, and this may be resulted from the increased level of oxidative stress. Collectively, our results indicated that porcine oocytes maturation was disrupted after BPA treatment through disrupting cytoskeletal dynamics, epigenetic modifications and inducing apoptosis/autophagy. PMID:27086915

  18. Scale Invariant Disordered Nanotopography Promotes Hippocampal Neuron Development and Maturation with Involvement of Mechanotransductive Pathways.

    PubMed

    Schulte, Carsten; Ripamonti, Maddalena; Maffioli, Elisa; Cappelluti, Martino A; Nonnis, Simona; Puricelli, Luca; Lamanna, Jacopo; Piazzoni, Claudio; Podestà, Alessandro; Lenardi, Cristina; Tedeschi, Gabriella; Malgaroli, Antonio; Milani, Paolo

    2016-01-01

    The identification of biomaterials which promote neuronal maturation up to the generation of integrated neural circuits is fundamental for modern neuroscience. The development of neural circuits arises from complex maturative processes regulated by poorly understood signaling events, often guided by the extracellular matrix (ECM). Here we report that nanostructured zirconia surfaces, produced by supersonic cluster beam deposition of zirconia nanoparticles and characterized by ECM-like nanotopographical features, can direct the maturation of neural networks. Hippocampal neurons cultured on such cluster-assembled surfaces displayed enhanced differentiation paralleled by functional changes. The latter was demonstrated by single-cell electrophysiology showing earlier action potential generation and increased spontaneous postsynaptic currents compared to the neurons grown on the featureless unnaturally flat standard control surfaces. Label-free shotgun proteomics broadly confirmed the functional changes and suggests furthermore a vast impact of the neuron/nanotopography interaction on mechanotransductive machinery components, known to control physiological in vivo ECM-regulated axon guidance and synaptic plasticity. Our results indicate a potential of cluster-assembled zirconia nanotopography exploitable for the creation of efficient neural tissue interfaces and cell culture devices promoting neurogenic events, but also for unveiling mechanotransductive aspects of neuronal development and maturation.

  19. MIPP Plastic Ball electronics upgrade

    SciTech Connect

    Baldin, Boris; /Fermilab

    2009-01-01

    An upgrade electronics design for Plastic Ball detector is described. The Plastic Ball detector was a part of several experiments in the past and its back portion (proposed to be used in MIPP) consists of 340 photomultipliers equipped with a sandwich scintillator. The scintillator sandwich has fast and slow signal component with decay times 10 ns and 1 {micro}s respectively. The upgraded MIPP experiment will collect up to 12,000 events during each 4 second spill and read them out in {approx}50 seconds between spills. The MIPP data acquisition system will employ deadtime-less concept successfully implemented in Muon Electronics of Dzero experiment at Fermilab. An 8-channel prototype design of the Plastic Ball Front End (PBFE) implementing these requirements is discussed. Details of the schematic design, simulation and prototype test results are discussed.

  20. Ocular Dominance Plasticity after Stroke Was Preserved in PSD-95 Knockout Mice.

    PubMed

    Greifzu, Franziska; Parthier, Daniel; Goetze, Bianka; Schlüter, Oliver M; Löwel, Siegrid

    2016-01-01

    Neuronal plasticity is essential to enable rehabilitation when the brain suffers from injury, such as following a stroke. One of the most established models to study cortical plasticity is ocular dominance (OD) plasticity in the primary visual cortex (V1) of the mammalian brain induced by monocular deprivation (MD). We have previously shown that OD-plasticity in adult mouse V1 is absent after a photothrombotic (PT) stroke lesion in the adjacent primary somatosensory cortex (S1). Exposing lesioned mice to conditions which reduce the inhibitory tone in V1, such as raising animals in an enriched environment or short-term dark exposure, preserved OD-plasticity after an S1-lesion. Here we tested whether modification of excitatory circuits can also be beneficial for preserving V1-plasticity after stroke. Mice lacking postsynaptic density protein-95 (PSD-95), a signaling scaffold present at mature excitatory synapses, have lifelong juvenile-like OD-plasticity caused by an increased number of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) -silent synapses in V1 but unaltered inhibitory tone. In fact, using intrinsic signal optical imaging, we show here that OD-plasticity was preserved in V1 of adult PSD-95 KO mice after an S1-lesion but not in PSD-95 wildtype (WT)-mice. In addition, experience-enabled enhancement of the optomotor reflex of the open eye after MD was compromised in both lesioned PSD-95 KO and PSD-95 WT mice. Basic V1-activation and retinotopic map quality were, however, not different between lesioned PSD-95 KO mice and their WT littermates. The preserved OD-plasticity in the PSD-95 KO mice indicates that V1-plasticity after a distant stroke can be promoted by either changes in excitatory circuitry or by lowering the inhibitory tone in V1 as previously shown. Furthermore, the present data indicate that an increased number of AMPA-silent synapses preserves OD-plasticity not only in the healthy brain, but also in another experimental paradigm of

  1. Ocular Dominance Plasticity after Stroke Was Preserved in PSD-95 Knockout Mice

    PubMed Central

    Greifzu, Franziska; Parthier, Daniel; Goetze, Bianka; Schlüter, Oliver M.; Löwel, Siegrid

    2016-01-01

    Neuronal plasticity is essential to enable rehabilitation when the brain suffers from injury, such as following a stroke. One of the most established models to study cortical plasticity is ocular dominance (OD) plasticity in the primary visual cortex (V1) of the mammalian brain induced by monocular deprivation (MD). We have previously shown that OD-plasticity in adult mouse V1 is absent after a photothrombotic (PT) stroke lesion in the adjacent primary somatosensory cortex (S1). Exposing lesioned mice to conditions which reduce the inhibitory tone in V1, such as raising animals in an enriched environment or short-term dark exposure, preserved OD-plasticity after an S1-lesion. Here we tested whether modification of excitatory circuits can also be beneficial for preserving V1-plasticity after stroke. Mice lacking postsynaptic density protein-95 (PSD-95), a signaling scaffold present at mature excitatory synapses, have lifelong juvenile-like OD-plasticity caused by an increased number of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) -silent synapses in V1 but unaltered inhibitory tone. In fact, using intrinsic signal optical imaging, we show here that OD-plasticity was preserved in V1 of adult PSD-95 KO mice after an S1-lesion but not in PSD-95 wildtype (WT)-mice. In addition, experience-enabled enhancement of the optomotor reflex of the open eye after MD was compromised in both lesioned PSD-95 KO and PSD-95 WT mice. Basic V1-activation and retinotopic map quality were, however, not different between lesioned PSD-95 KO mice and their WT littermates. The preserved OD-plasticity in the PSD-95 KO mice indicates that V1-plasticity after a distant stroke can be promoted by either changes in excitatory circuitry or by lowering the inhibitory tone in V1 as previously shown. Furthermore, the present data indicate that an increased number of AMPA-silent synapses preserves OD-plasticity not only in the healthy brain, but also in another experimental paradigm of

  2. Mature BDNF, but not proBDNF, reduces excitability of fast-spiking interneurons in mouse dentate gyrus.

    PubMed

    Holm, Mai Marie; Nieto-Gonzalez, Jose Luis; Vardya, Irina; Vaegter, Christian Bjerggaard; Nykjaer, Anders; Jensen, Kimmo

    2009-10-07

    Mature BDNF and its precursor proBDNF may both be secreted to exert opposite effects on synaptic plasticity in the hippocampus. However, it is unknown how proBDNF and mature BDNF affect the excitability of GABAergic interneurons and thereby regulate GABAergic inhibition. We made recordings of GABAergic spontaneous IPSCs (sIPSCs) in mouse dentate gyrus granule cells and found that chronic or acute BDNF reductions led to large increases in the sIPSC frequencies, which were TTX (tetrodotoxin) sensitive and therefore action-potential driven. Conversely, addition of mature BDNF, but not proBDNF, within minutes led to a decrease in the sIPSC frequency to 44%. Direct recordings from fast-spiking GABAergic interneurons revealed that mature BDNF reduced their excitability and depressed their action potential firing, whereas proBDNF had no effect. Using the TrkB inhibitor K-252a, or mice deficient for the common neurotrophin receptor p75(NTR), the regulation of GABAergic activity was shown specifically to be mediated by BDNF binding to the neurotrophin receptor TrkB. In agreement, immunohistochemistry demonstrated that TrkB, but not p75(NTR), was expressed in parvalbumin-positive interneurons. Our results suggest that mature BDNF decreases the excitability of GABAergic interneurons via activation of TrkB, while proBDNF does not impact on GABAergic activity. Thus, by affecting the firing of GABAergic interneurons, mature BDNF may play an important role in regulating network oscillations in the hippocampus.

  3. High energy resolution plastic scintillator

    NASA Astrophysics Data System (ADS)

    van Loef, Edgar V.; Feng, Patrick; Markosyan, Gary; Shirwadkar, Urmila; Doty, Patrick; Shah, Kanai S.

    2016-09-01

    In this paper we present results on a novel tin-loaded plastic scintillator. We will show that this particular plastic scintillator has a light output similar to that of BGO, a fast scintillation decay (< 10 ns), exhibits good neutron/gamma PSD with a Figure-of-Merit of 1.3 at 2.5 MeVee cut-off energy, and excellent energy resolution of about 12% (FWHM) at 662 keV. Under X-ray excitation, the radioluminescence spectrum exhibits a broad band between 350 and 500 nm peaking at 420 nm which is well-matched to bialkali photomultiplier tubes and UV-enhanced photodiodes.

  4. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, M.S.

    1995-08-22

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired. 5 figs.

  5. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, M.S.

    1993-01-01

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains colloidal silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{sup TM}, LEXAN{sup TM}, LUCITE{sup TM}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  6. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, Michael S.

    1995-01-01

    A polishing compound for plastic surfaces. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS.TM., LEXAN.TM., LUCITE.TM., polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  7. Lysosomal protease expression in mature enamel.

    PubMed

    Tye, Coralee E; Lorenz, Rachel L; Bartlett, John D

    2009-01-01

    The enamel matrix proteins (amelogenin, enamelin and ameloblastin) are degraded by matrix metalloproteinase-20 and kallikrein-4 during enamel development and mature enamel is virtually protein free. The precise mechanism of removal and degradation of the enamel protein cleavage products from the matrix, however, remains poorly understood. It has been proposed that receptor-mediated endocytosis allows for the cleaved proteins to be removed from the matrix during enamel formation and then transported to the lysosome for further degradation. This study aims to identify lysosomal proteases that are present in maturation-stage enamel organ. RNA from first molars of 11-day-old mice was collected and expression was initially assessed by RT-PCR and then quantified by qPCR. The pattern of expression of selected proteases was assessed by immunohistochemical staining of demineralized mouse incisors. With the exception of cathepsin G, all lysosomal proteases assessed were expressed in maturation-stage enamel organ. Identified proteases included cathepsins B, D, F, H, K, L, O, S and Z. Tripeptidyl peptidases I and II as well as dipeptidyl peptidases I, II, III and IV were also found to be expressed. Immunohistochemical staining confirmed that the maturation-stage ameloblasts express cathepsins L and S and tripeptidyl peptidase II. Our results suggest that the ameloblasts are enriched by a large number of lysosomal proteases at maturation that are likely involved in the degradation of the organic matrix.

  8. Maturity Model for Advancing Smart Grid Interoperability

    SciTech Connect

    Knight, Mark; Widergren, Steven E.; Mater, J.; Montgomery, Austin

    2013-10-28

    Abstract—Interoperability is about the properties of devices and systems to connect and work properly. Advancing interoperability eases integration and maintenance of the resulting interconnection. This leads to faster integration, lower labor and component costs, predictability of projects and the resulting performance, and evolutionary paths for upgrade. When specifications are shared and standardized, competition and novel solutions can bring new value streams to the community of stakeholders involved. Advancing interoperability involves reaching agreement for how things join at their interfaces. The quality of the agreements and the alignment of parties involved in the agreement present challenges that are best met with process improvement techniques. The GridWise® Architecture Council (GWAC) sponsored by the United States Department of Energy is supporting an effort to use concepts from capability maturity models used in the software industry to advance interoperability of smart grid technology. An interoperability maturity model has been drafted and experience is being gained through trials on various types of projects and community efforts. This paper describes the value and objectives of maturity models, the nature of the interoperability maturity model and how it compares with other maturity models, and experiences gained with its use.

  9. Cellular and Molecular Implications of Mature Adipocyte Dedifferentiation

    PubMed Central

    Wei, Shengjuan; Duarte, Marcio S.; Zan, Linsen; Du, Min; Jiang, Zhihua; Guan, LeLuo; Chen, Jie; Hausman, Gary J.; Dodson, Michael V.

    2013-01-01

    There is a voluminous amount of scientific literature dealing with the involvement of adipocytes in molecular regulation of carcass composition, obesity, metabolic syndrome, or diabetes. To form adipocytes (process termed adipogenesis) nearly all scientific papers refer to the use of preadipocytes, adipofibroblasts, stromal vascular cells or adipogenic cell lines, and their differentiation to form lipid-assimilating cells containing storage triacylglyceride. However, mature adipocytes, themselves, possess ability to undergo dedifferentiation, form proliferative-competent progeny cells (the exact plasticity is unknown) and reinitiate formation of cells capable of lipid metabolism and storage. The progeny cells would make a viable (and alternative) cell system for the evaluation of cell ability to reestablish lipid assimilation, ability to differentially express genes (as compared to other adipogenic cells), and to form other types of cells (multi-lineage potential). Understanding the dedifferentiation process itself and/or dedifferentiated fat cells could contribute to our knowledge of normal growth processes, or to disease function. Indeed, the ability of progeny cells to form other cell types could turn-out to be important for processes of tissue reconstruction/engineering and may have implications in clinical, biochemical or molecular processes. PMID:25031650

  10. Genome-wide association mapping of flowering time and maturity dates in early mature soybean germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max L. Merr.) is a photoperiod-sensitive and short-day major crop grown worldwide. Days to flowering (DTF) and maturity (DTM) are two traits affecting soybean adaptability and yield. Some genes conditioning soybean flowering and maturity have been recently characterized. However, ...

  11. Need for speed: Sexual maturation precedes social maturation in gray mouse lemurs.

    PubMed

    Hohenbrink, Sarah; Zimmermann, Elke; Radespiel, Ute

    2015-10-01

    The life history of mammals underlies a fast-slow continuum, ranging from "slow" species with large body size, delayed sexual maturation, low fertility, and long lifespan, to "fast" species showing the opposite traits. Primates fall into the "slow" category, considering their relatively low offspring numbers and delayed juvenile development. However, social and sexual maturation processes do not necessarily have to be completed simultaneously. The comparison of the timeframes for sexual and social maturation is largely lacking for primates, with the prominent exception of humans. Here, we compare both maturation processes in a basal primate, the gray mouse lemur, which ranges in many aspects at the fast end of the slow-fast life history continuum among primates. We compared the patterns and frequencies of various social and solitary behaviors in young adults (YA, 12-13 months old) and older individuals (A, ≥2 years) of both sexes outside estrus. Observations were conducted during mix-sexed dyadic encounter experiments under controlled captive conditions (eight dyads per age class). Results indicate that although all young adults were sexually mature, social maturation was not yet completed in all behavioral domains: Age-dependent differences were found in the number of playing dyads, female marking behavior, female aggression, and social tolerance. Thus, this study provides a first indication that social maturation lags behind sexual maturation in an ancestral nocturnal primate model, indicating that these two developmental schemes may have been decoupled early and throughout the primate lineage.

  12. Genetic transformation of mature citrus plants.

    PubMed

    Cervera, Magdalena; Juárez, José; Navarro, Luis; Peña, Leandro

    2005-01-01

    Most woody fruit species have long juvenile periods that drastically prolong the time required to analyze mature traits. Evaluation of characteristics related to fruits is a requisite to release any new variety into the market. Because of a decline in regenerative and transformation potential, genetic transformation procedures usually employ juvenile material as the source of plant tissue, therefore resulting in the production of juvenile plants. Direct transformation of mature material could ensure the production of adult transgenic plants, bypassing in this way the juvenile phase. Invigoration of the source adult material, establishment of adequate transformation and regeneration conditions, and acceleration of plant development through grafting allowed us to produce transgenic mature sweet orange trees flowering and bearing fruits in a short time period.

  13. Elevated Social Anxiety among Early Maturing Girls

    PubMed Central

    Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Babson, Kimberly A.; Gahr, Jessica L.; Trainor, Casey D.; Frala, Jamie L.

    2012-01-01

    Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to further elucidate the relation between pubertal timing and social anxiety, with a focus on clarifying the role of gender. Participants were 138 adolescents (ages 12-17 years) recruited from the general community. Level of social anxiety was examined as a function of gender and within-sample pubertal timing. As expected, early-maturing girls evidenced significantly higher social anxiety as compared to on-time girls and early-maturing boys, and no other differences were found as a function of gender or developmental timing. Findings and future directions are discussed in terms of forwarding developmentally-sensitive models of social anxiety etiology and prevention. PMID:21604866

  14. Strength, flexibility, and maturity in adolescent athletes.

    PubMed

    Pratt, M

    1989-05-01

    The relationship between lower-extremity strength and flexibility and maturational status as measured by Tanner staging (TS) was assessed in 84 male high school athletes. The sum of one-repetition maximum lifts for knee extension and flexion was determined and flexibility was measured with the American Alliance of Health, Physical Education, Recreation, and Dance sit-and-reach test. Chronologic age, body weight, and percent fat were also recorded. Strength and flexibility were compared for each maturational and chronologic age category. Maturational age was better correlated with strength and flexibility than was chronologic age. All correlations were significant. Multiple regression analysis demonstrated significant correlations of TS and age with strength and flexibility. Tanner staging had greater predictive value than age for strength and flexibility. After adjusting for age, the relationship between TS and strength remained significant.

  15. Stacking the odds for Golgi cisternal maturation

    PubMed Central

    Mani, Somya; Thattai, Mukund

    2016-01-01

    What is the minimal set of cell-biological ingredients needed to generate a Golgi apparatus? The compositions of eukaryotic organelles arise through a process of molecular exchange via vesicle traffic. Here we statistically sample tens of thousands of homeostatic vesicle traffic networks generated by realistic molecular rules governing vesicle budding and fusion. Remarkably, the plurality of these networks contain chains of compartments that undergo creation, compositional maturation, and dissipation, coupled by molecular recycling along retrograde vesicles. This motif precisely matches the cisternal maturation model of the Golgi, which was developed to explain many observed aspects of the eukaryotic secretory pathway. In our analysis cisternal maturation is a robust consequence of vesicle traffic homeostasis, independent of the underlying details of molecular interactions or spatial stacking. This architecture may have been exapted rather than selected for its role in the secretion of large cargo. DOI: http://dx.doi.org/10.7554/eLife.16231.001 PMID:27542195

  16. Calcium ion currents mediating oocyte maturation events

    PubMed Central

    Tosti, Elisabetta

    2006-01-01

    During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed. PMID:16684344

  17. An unexpected twist in viral capsid maturation

    SciTech Connect

    Gertsman, Ilya; Gan, Lu; Guttman, Miklos; Lee, Kelly; Speir, Jeffrey A.; Duda, Robert L.; Hendrix, Roger W.; Komives, Elizabeth A.; Johnson, John E.

    2009-04-14

    Lambda-like double-stranded (ds) DNA bacteriophage undergo massive conformational changes in their capsid shell during the packaging of their viral genomes. Capsid shells are complex organizations of hundreds of protein subunits that assemble into intricate quaternary complexes that ultimately are able to withstand over 50 atm of pressure during genome packaging. The extensive integration between subunits in capsids requires the formation of an intermediate complex, termed a procapsid, from which individual subunits can undergo the necessary refolding and structural rearrangements needed to transition to the more stable capsid. Although various mature capsids have been characterized at atomic resolution, no such procapsid structure is available for a dsDNA virus or bacteriophage. Here we present a procapsid X-ray structure at 3.65 {angstrom} resolution, termed prohead II, of the lambda-like bacteriophage HK97, the mature capsid structure of which was previously solved to 3.44 {angstrom}. A comparison of the two largely different capsid forms has unveiled an unprecedented expansion mechanism that describes the transition. Crystallographic and hydrogen/deuterium exchange data presented here demonstrate that the subunit tertiary structures are significantly different between the two states, with twisting and bending motions occurring in both helical and -sheet regions. We also identified subunit interactions at each three-fold axis of the capsid that are maintained throughout maturation. The interactions sustain capsid integrity during subunit refolding and provide a fixed hinge from which subunits undergo rotational and translational motions during maturation. Previously published calorimetric data of a closely related bacteriophage, P22, showed that capsid maturation was an exothermic process that resulted in a release of 90 kJ mol{sup -1} of energy. We propose that the major tertiary changes presented in this study reveal a structural basis for an exothermic

  18. On the maturation rate of the neutrophil.

    PubMed

    Zajicek, G; Shohat, M; Polliack, A

    1984-05-01

    Fifty-three maturing bone marrow cells of the granulocyte cell series stained with Giemsa stain and magnified 1,000 times were scanned by a "computerized microscope" consisting of a LSI-11/23 microprocessor and a black-and-white video camera attached to a "frame grabber ." Each sampled cell was digitized into 70 X 70 pixels, each pixel representing 0.04 micron of the real image. The pixel gray values ranged between 0 and 255. Zero stood for white, 255 represented black, while the numbers in between stood for the various shades of gray. The cells represented six different stages of granulocytic maturation: myeloblast, promyelocyte, myelocyte, metamyelocyte , band form, and polymorphonuclear granulocyte. A discriminant analysis program selected 19 features best distinguishing between the six different cell types and computed five canonical discriminant functions defining a Space in which maturation was studied. In the Space, distance between two cells serves as a measure of similarity. The closer two cells are, the more similar they are and vice versa. This measure was applied here to express the degree of similarity between the neutrophil maturation classes, and since they represent states in the neutrophil life history, it is applicable also as a yardstick for the quantitation of differentiation. In the Space, the life history of a cell is represented by a trajectory originating in the myeloblast and terminating in the granulocyte state. Displacement along the trajectory represents cell maturation that is expressed relatively to the least differentiated state of the myeloblast. The further a cell from this state the more mature it is. The same yardstick also serves for differentiation rate estimates represented in the Space by displacement velocities that are derived from the known "transit times" of a cell in each state. The methodology is also applied for cell production estimates. Unlike other "computerized microscopes" serving for cell classification, the

  19. Adaptive variability in the duration of critical windows of plasticity: Implications for the programming of obesity.

    PubMed

    Wells, Jonathan C K

    2014-08-05

    Developmental plasticity underlies widespread associations between early-life exposures and many components of adult phenotype, including the risk of chronic diseases. Humans take almost two decades to reach reproductive maturity, and yet the 'critical windows' of physiological sensitivity that confer developmental plasticity tend to close during fetal life or infancy. While several explanations for lengthy human maturation have been offered, the brevity of physiological plasticity has received less attention. I argue that offspring plasticity is only viable within the niche of maternal care, and that as this protection is withdrawn, the offspring is obliged to canalize many developmental traits in order to minimize environmental disruptions. The schedule of maternal care may therefore shape the duration of critical windows, and since the duration of this care is subject to parent-offspring conflict, the resolution of this conflict may shape the duration of critical windows. This perspective may help understand (i) why windows close at different times for different traits, and (ii) why the duration of critical windows may vary across human populations. The issue is explored in relation to population differences in the association between infant weight gain and later body composition. The occupation of more stable environments by western populations may have favoured earlier closure of the critical window during which growth in lean mass is sensitive to nutritional intake. This may paradoxically have elevated the risk of obesity following rapid infant weight gain in such populations.

  20. The Corpus Callosum and the Visual Cortex: Plasticity Is a Game for Two

    PubMed Central

    Pietrasanta, Marta; Restani, Laura; Caleo, Matteo

    2012-01-01

    Throughout life, experience shapes and selects the most appropriate brain functional connectivity to adapt to a changing environment. An ideal system to study experience-dependent plasticity is the visual cortex, because visual experience can be easily manipulated. In this paper, we focus on the role of interhemispheric, transcallosal projections in experience-dependent plasticity of the visual cortex. We review data showing that deprivation of sensory experience can modify the morphology of callosal fibres, thus altering the communication between the two hemispheres. More importantly, manipulation of callosal input activity during an early critical period alters developmental maturation of functional properties in visual cortex and modifies its ability to remodel in response to experience. We also discuss recent data in rat visual cortex, demonstrating that the corpus callosum plays a role in binocularity of cortical neurons and is involved in the plastic shift of eye preference that follows a period of monocular eyelid suture (monocular deprivation) in early age. Thus, experience can modify the fine connectivity of the corpus callosum, and callosal connections represent a major pathway through which experience can mediate functional maturation and plastic rearrangements in the visual cortex. PMID:22792494

  1. Presynaptic Protein Synthesis Is Required for Long-Term Plasticity of GABA Release.

    PubMed

    Younts, Thomas J; Monday, Hannah R; Dudok, Barna; Klein, Matthew E; Jordan, Bryen A; Katona, István; Castillo, Pablo E

    2016-10-19

    Long-term changes of neurotransmitter release are critical for proper brain function. However, the molecular mechanisms underlying these changes are poorly understood. While protein synthesis is crucial for the consolidation of postsynaptic plasticity, whether and how protein synthesis regulates presynaptic plasticity in the mature mammalian brain remain unclear. Here, using paired whole-cell recordings in rodent hippocampal slices, we report that presynaptic protein synthesis is required for long-term, but not short-term, plasticity of GABA release from type 1 cannabinoid receptor (CB1)-expressing axons. This long-term depression of inhibitory transmission (iLTD) involves cap-dependent protein synthesis in presynaptic interneuron axons, but not somata. Translation is required during the induction, but not maintenance, of iLTD. Mechanistically, CB1 activation enhances protein synthesis via the mTOR pathway. Furthermore, using super-resolution STORM microscopy, we revealed eukaryotic ribosomes in CB1-expressing axon terminals. These findings suggest that presynaptic local protein synthesis controls neurotransmitter release during long-term plasticity in the mature mammalian brain.

  2. Management and Breeding Soundness of Mature Bulls.

    PubMed

    Palmer, Colin W

    2016-07-01

    Mature bulls must be fed a balanced ration, vaccinated appropriately, and undergo a breeding soundness evaluation to ensure they meet what is required of a short, but intense breeding season. To be classified as a satisfactory potential breeder, minimum standards for physical soundness, scrotal circumference, sperm motility, and sperm morphology must be achieved using an accepted bull-breeding soundness evaluation format. Sperm production requires approximately 70 days. Heat and stress are the most common insults to spermatogenesis, causing an increase in morphologic abnormalities with obesity-associated scrotal fat accumulation being the most frequent cause of elevated testicular temperature in mature bulls.

  3. Posttesticular sperm maturation, infertility, and hypercholesterolemia

    PubMed Central

    Whitfield, Marjorie; Pollet-Villard, Xavier; Levy, Rachel; Drevet, Joël R; Saez, Fabrice

    2015-01-01

    Cholesterol is a key molecule in the mammalian physiology of especial particular importance for the reproductive system as it is the common precursor for steroid hormone synthesis. Cholesterol is also a recognized modulator of sperm functions, not only at the level of gametogenesis. Cholesterol homeostasis regulation is crucial for posttesticular sperm maturation, and imbalanced cholesterol levels may particularly affect these posttesticular events. Metabolic lipid disorders (dyslipidemia) affect male fertility but are most of the time studied from the angle of endocrine/testicular consequences. This review will focus on the deleterious effects of a particular dyslipidemia, i.e., hypercholesterolemia, on posttesticular maturation of mammalian spermatozoa. PMID:26067871

  4. Sexual maturation in East German girls.

    PubMed

    Engelhardt, L; Willers, B; Pelz, L

    1995-12-01

    According to the internationally accepted classification (Tanner, 1962; van Wieringen, 1971), sexual maturation was investigated in 8703 healthy East German girls by means of the status quo method and probit regression analysis. The third, 50th and 97th centiles were calculated for the development of breasts, axillary and pubic hair, and the shape of the hips. The findings were compared with those of recent studies from different European countries. Special attention was paid to the stages at the beginning and at the end of sexual maturation, e.g. B2/B5, AH2/AH3, etc.

  5. Sexual maturation in East German boys.

    PubMed

    Willers, B; Engelhardt, L; Pelz, L

    1996-07-01

    According to the internationally accepted classification, sexual maturation was investigated in 8685 healthy East German boys by means of the status quo method and the probit regression analysis. The 3rd, 50th and 97th centiles were calculated for the development of both the male external genitalia and pubic and axillary hairs. The findings are in line with those of recent studies from different European countries. Special attention was paid to the stages at the beginning and at the end of sexual maturation, e.g. B 2, B 5; AH2, AH3; PH 2, PH5/6, etc.

  6. Oxytocin and Maternal Brain Plasticity

    ERIC Educational Resources Information Center

    Kim, Sohye; Strathearn, Lane

    2016-01-01

    Although dramatic postnatal changes in maternal behavior have long been noted, we are only now beginning to understand the neurobiological mechanisms that support this transition. The present paper synthesizes growing insights from both animal and human research to provide an overview of the plasticity of the mother's brain, with a particular…

  7. Synaptic Plasticity and Translation Initiation

    ERIC Educational Resources Information Center

    Klann, Eric; Antion, Marcia D.; Banko, Jessica L.; Hou, Lingfei

    2004-01-01

    It is widely accepted that protein synthesis, including local protein synthesis at synapses, is required for several forms of synaptic plasticity. Local protein synthesis enables synapses to control synaptic strength independent of the cell body via rapid protein production from pre-existing mRNA. Therefore, regulation of translation initiation is…

  8. Biobased plastics in a bioeconomy.

    PubMed

    Philp, J C; Ritchie, R J; Guy, K

    2013-02-01

    Bioeconomy plans include a biobased industries sector in which some oil-derived plastics and chemicals are replaced by new or equivalent products derived, at least partially, from biomass. Some of these biobased products are here today, but to fulfil their societal potential, greater attention is required to promote awareness, and to improve their market share while making valuable contributions to climate change mitigation.

  9. Plastic Clamp Retains Clevis Pin

    NASA Technical Reports Server (NTRS)

    Cortes, R. G.

    1983-01-01

    Plastic clamp requires no special installation or removal tools. Clamp slips easily over end of pin. Once engaged in groove, holds pin securely. Installed and removed easily without special tools - screwdriver or putty knife adequate for prying out of groove. Used to retain bearings, rollers pulleys, other parts that rotate. Applications include slowly and intermittently rotating parts in appliances.

  10. HEMP. Hydrodynamic Elastic Magneto Plastic

    SciTech Connect

    Wilkins, M.L.; Levatin, J.A.

    1985-02-01

    The HEMP code solves the conservation equations of two-dimensional elastic-plastic flow, in plane x-y coordinates or in cylindrical symmetry around the x-axis. Provisions for calculation of fixed boundaries, free surfaces, pistons, and boundary slide planes have been included, along with other special conditions.

  11. Scribable coating for plastic films

    NASA Technical Reports Server (NTRS)

    Clark, R. T.

    1967-01-01

    Scribable opaque coating for transparent plastic film tape is not affected by aging, vacuum, and moderate temperature extremes. It consists of titanium dioxide, a water-compatible acrylic polymer emulsion, and a detergent. The coating mixture is readily dispersed in water before it is dried.

  12. For the Classroom: "Plastic" Jellyfish.

    ERIC Educational Resources Information Center

    Current: The Journal of Marine Education, 1989

    1989-01-01

    Describes an activity in which students monitor the plastic waste production in their households, research its effects on freshwater and marine life, and propose ways to lessen the problem. Provides objectives, background information, materials, procedures, extension activities, and an evaluation for students. (Author/RT)

  13. Chemistry technology: Adhesives and plastics: A compilation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Technical information on chemical formulations for improving and/or producing adhesives is presented. Data are also reported on polymeric plastics with special characteristics or those plastics that were produced by innovative means.

  14. Interpretation on Recycling Plastics from Shredder Residue

    EPA Pesticide Factsheets

    EPA is considering an interpretation of its regulations that would generally allow for recycling of plastic separated from shredder residue under the conditions described in the Voluntary Procedures for Recycling Plastics from Shredder Residue.

  15. Gas Experiments with Plastic Soda Bottles.

    ERIC Educational Resources Information Center

    Kavanah, Patrick; Zipp, Arden P.

    1998-01-01

    Describes the use of an inexpensive device consisting of a plastic soda bottle and a modified plastic cap in a range of demonstrations and experimental activities having to do with the behavior of gases. (Author/WRM)

  16. Plastic Surgeons Often Miss Patients' Mental Disorders

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_163120.html Plastic Surgeons Often Miss Patients' Mental Disorders 10 percent ... News) -- Nearly one in 10 patients seeking facial plastic surgery suffers from a mental illness that distorts ...

  17. Plastics and beaches: a degrading relationship.

    PubMed

    Corcoran, Patricia L; Biesinger, Mark C; Grifi, Meriem

    2009-01-01

    Plastic debris in Earth's oceans presents a serious environmental issue because breakdown by chemical weathering and mechanical erosion is minimal at sea. Following deposition on beaches, plastic materials are exposed to UV radiation and physical processes controlled by wind, current, wave and tide action. Plastic particles from Kauai's beaches were sampled to determine relationships between composition, surface textures, and plastics degradation. SEM images indicated that beach plastics feature both mechanically eroded and chemically weathered surface textures. Granular oxidation textures were concentrated along mechanically weakened fractures and along the margins of the more rounded plastic particles. Particles with oxidation textures also produced the most intense peaks in the lower wavenumber region of FTIR spectra. The textural results suggest that plastic debris is particularly conducive to both chemical and mechanical breakdown in beach environments, which cannot be said for plastics in other natural settings on Earth.

  18. ANTEC '86: Plastic-value through technology

    SciTech Connect

    Not Available

    1986-01-01

    This book contains 23 sections, each containing several papers. There are also papers under a general category and a student category. The section titles are: Plastics in Automotive Division; Thermoplastic Materials and Foams Division; Injection Molding Division; Mold Making and Mold Design Division; Electrical and Electronic Division; Plastics Analysis Division and Electrical and Electronic Division Joint Sessions; Plastics Analysis Division and Engineering Properties and Structure Division; Plastics Analysis Division; Engineering Properties and Structure Division and Plastics Analysis Division Joint Session; Engineering Properties and Structure Division; Blow Molding Division; Extrusion Division and Thermoforming Division Joint Session; Extrusion Division; Thermoforming Division; Plastics Education and Training; Marketing Division; Medical Plastics Division; Decorating Division; Polymer Modifiers and Additives Division; Color and Appearance Division; Vinyl Division; Thermoset Division; and Computers and the Plastics Industry.

  19. [The history of plastic surgery in Israel].

    PubMed

    Wiser, Itay; Scheflan, Michael; Heller, Lior

    2014-09-01

    The medical institutions in the country have advanced together with the development of the state of Israel. Plastic surgery, which has progressed significantly during the 20th century, has also grown rapidly in the new state. The arrival of Jewish plastic surgeons from all over the world with the knowledge and experience gained in their countries of origin, as well as the need for reconstructive surgical treatment for many combat injured soldiers, also contributed to the development of plastic surgery. This review tells the story of plastic surgery in Israel, since its foundation until nowadays. This article reviews the work of the founders of plastic surgery in Israel, indicating significant milestones in its development, and clinical and scientific contribution to the international plastic surgery profession. Moreover, the article describes the current condition of the field of plastic surgery in Israel and presents the trends and the future challenges facing the next generation of plastic surgery in Israel.

  20. Plasma levels of mature brain-derived neurotrophic factor (BDNF) and matrix metalloproteinase-9 (MMP-9) in treatment-resistant schizophrenia treated with clozapine.

    PubMed

    Yamamori, Hidenaga; Hashimoto, Ryota; Ishima, Tamaki; Kishi, Fukuko; Yasuda, Yuka; Ohi, Kazutaka; Fujimoto, Michiko; Umeda-Yano, Satomi; Ito, Akira; Hashimoto, Kenji; Takeda, Masatoshi

    2013-11-27

    Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. Peripheral BDNF levels in patients with schizophrenia have been widely reported in the literature. However, it is still controversial whether peripheral levels of BDNF are altered in patients with schizophrenia. The peripheral BDNF levels previously reported in patients with schizophrenia were total BDNF (proBDNF and mature BDNF) as it was unable to specifically measure mature BDNF due to limited BDNF antibody specificity. In this study, we examined whether peripheral levels of mature BDNF were altered in patients with treatment-resistant schizophrenia. Matrix metalloproteinase-9 (MMP-9) levels were also measured, as MMP-9 plays a role in the conversion of proBDNF to mature BDNF. Twenty-two patients with treatment-resistant schizophrenia treated with clozapine and 22 age- and sex-matched healthy controls were enrolled. The plasma levels of mature BDNF and MMP-9 were measured using ELISA kits. No significant difference was observed for mature BDNF however, MMP-9 was significantly increased in patients with schizophrenia. The significant correlation was observed between mature BDNF and MMP-9 plasma levels. Neither mature BDNF nor MMP-9 plasma levels were associated clinical variables. Our results do not support the view that peripheral BDNF levels are associated with schizophrenia. MMP-9 may play a role in the pathophysiology of schizophrenia and serve as a biomarker for schizophrenia.

  1. Think small: nanotechnology for plastic surgeons.

    PubMed

    Nasir, Amir R; Brenner, Sara A

    2012-11-01

    The purpose of this article is to introduce the topic of nanotechnology to plastic surgeons and to discuss its relevance to medicine in general and plastic surgery in particular. Nanotechnology will be defined, and some important historical milestones discussed. Common applications of nanotechnology in various medical and surgical subspecialties will be reviewed. Future applications of nanotechnology to plastic surgery will be examined. Finally, the critical field of nanotoxicology and the safe use of nanotechnology in medicine and plastic surgery will be addressed.

  2. The advent of the restorative plastic surgeon.

    PubMed

    Carty, Matthew J; Pribaz, Julian J; Talbot, Simon G; Caterson, Edward J; Pomahac, Bohdan

    2014-01-01

    Plastic surgery is presently typified by the existence of discrete clinical identities, namely that of the cosmetic plastic surgeon and the reconstructive plastic surgeon. The emergence of vascularized composite allotransplantation has been accompanied by the development of a third distinct clinical identity, that of the restorative plastic surgeon. The authors describe the core competencies that characterize this new identity, and discuss the implications of the advent of this new professional paradigm.

  3. Plastic biliary stents for malignant biliary diseases.

    PubMed

    Huibregtse, Inge; Fockens, Paul

    2011-07-01

    Plastic biliary endoprostheses have not changed much since their introduction more than 3 decades ago. Although their use has been challenged by the introduction of metal stents, plastic stents still remain commonly used. Much work has been done to improve the problem of stent obstruction but without substantial clinical success. In this review, the authors discuss the history of plastic biliary stent development and the current use of plastic stents for malignant biliary diseases.

  4. Phsyical and Mechanical Properties of Fiber-Glass Reinforced Plastics (A Collection of Articles),

    DTIC Science & Technology

    REINFORCED PLASTICS , MECHANICAL PROPERTIES), LAMINATED PLASTICS , GLASS TEXTILES, TEST METHODS, SILICONE PLASTICS , POLYESTER PLASTICS , PHENOLIC... PLASTICS , EPOXY RESINS, POLYVINYL CHLORIDE, STYRENE PLASTICS , POLYAMIDE PLASTICS , TENSILE PROPERTIES, COMPRESSIVE PROPERTIES, SHEAR STRESSES, NONDESTRUCTIVE TESTING, ULTRANSONIC RADIATION, FIRE RESISTANT MATERIALS, USSR

  5. Plastic flow around rigid spherical inclusions

    NASA Technical Reports Server (NTRS)

    Ruoff, A. L.; Nelson, D. A., Jr.

    1974-01-01

    The extent of plastic flow in a spherical solid (assumed to be homogeneous and elastically and plastically isotropic), surrounding a concentric rigid sphere was calculated as a function of applied external pressure. The applied pressure necessary to cause plastic deformation throughout the solid was obtained.

  6. 7 CFR 58.326 - Plastic cream.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the...

  7. 7 CFR 58.326 - Plastic cream.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the...

  8. 7 CFR 58.326 - Plastic cream.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the...

  9. 7 CFR 58.326 - Plastic cream.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the...

  10. The Rhetorical Limits of the "Plastic Body"

    ERIC Educational Resources Information Center

    Jordan, John W.

    2004-01-01

    This essay analyzes the "plastic body" as it is produced in the discourse of plastic surgery. The contemporary industry has constructed a popular image of plastic surgery as a readily available and personally empowering means to resolve body image issues, on the presumption that any body can become a "better" body. The ideology underlying the…

  11. 7 CFR 58.326 - Plastic cream.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Plastic cream. 58.326 Section 58.326 Agriculture... Material § 58.326 Plastic cream. To produce plastic cream eligible for official certification, the quality of the cream used shall meet the requirements of cream acceptable for the manufacture of U.S....

  12. Plastics. A Handbook for Workplace Educators.

    ERIC Educational Resources Information Center

    Curry, Donna; Smith, Mikki

    This handbook was designed to help adult literacy education teachers to understand the plastics industry, develop a curriculum, and teach basic skills classes in a plastics company. The book contains four main sections. The first section, on the basics of plastics, contains a brief history of the industry, an elementary description of the…

  13. 75 FR 34170 - Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-16

    ... Employment and Training Administration Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium... Assistance on March 18, 2010, applicable to workers of Plastic Omnium Automotive Exteriors, LLC, Anderson... have occurred involving workers in support of the Anderson, South Carolina location of Plastic...

  14. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  15. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  16. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  17. Thermal maturity of carboniferous strata, Ouachita Mountains

    SciTech Connect

    Houseknecht, D.W.; Matthews, S.M.

    1985-03-01

    The Ouachita Mountains, a relatively untested, potential hydrocarbon province, contain a thick Paleozoic section of apparently favorable source beds, reservoir beds, and trap configurations. To estimate the thermal maturity of these strata, vitrinite reflectance was measured on 89 samples collected mostly from Carboniferous rocks from throughout the Ouachita outcrop area.

  18. Skeletal maturation evaluation using cervical vertebrae.

    PubMed

    Hassel, B; Farman, A G

    1995-01-01

    Lateral cephalometric and left hand-wrist radiographs from the Bolton-Brush Growth Center at Case Western Reserve University were reviewed a posteriori to develop a cervical vertebrae maturation index (CVMI). By using the lateral profiles of the second, third and fourth cervical vertebrae, it was possible to develop a reliable ranking of patients according to the potential for future adolescent growth potential.

  19. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  20. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  1. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  2. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  3. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  4. Career Maturity: A Priority for Secondary Education

    ERIC Educational Resources Information Center

    Gonzalez, Manuel Alvarez

    2008-01-01

    This study reviews the current state of career maturity in secondary education--a period of education which is critical for development of this construct, when students are faced with ongoing academic and occupational decisions over the course of their studies. This paper is organized in three parts: first we focus on the concept, models,…

  5. Prenatal Antecedents of Newborn Neurological Maturation

    ERIC Educational Resources Information Center

    DiPietro, Janet A.; Kivlighan, Katie T.; Costigan, Kathleen A.; Rubin, Suzanne E.; Shiffler, Dorothy E.; Henderson, Janice L.; Pillion, Joseph P.

    2010-01-01

    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 first weeks after birth…

  6. Late Maturation of Auditory Perceptual Learning

    ERIC Educational Resources Information Center

    Huyck, Julia Jones; Wright, Beverly A.

    2011-01-01

    Adults can improve their performance on many perceptual tasks with training, but when does the response to training become mature? To investigate this question, we trained 11-year-olds, 14-year-olds and adults on a basic auditory task (temporal-interval discrimination) using a multiple-session training regimen known to be effective for adults. The…

  7. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.19, and...

  8. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.21, and...

  9. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.21, and...

  10. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.16, 601.17,...

  11. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.19, and...

  12. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.19, and...

  13. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.16, 601.17,...

  14. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.16, 601.17,...

  15. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter 601, Florida Statutes, Sections 601.21, and...

  16. Manual for the Employability Maturity Interview.

    ERIC Educational Resources Information Center

    Roessler, Richard; Bolton, Brian

    The Employability Maturity Interview (EMI) is a 10-item structured interview developed to assess readiness for the vocational rehabilitation planning process and the need for additional vocational exploration and employability services. The items deal with occupational choice, self-appraisal of abilities, self-appraisal of personality…

  17. Young Carers: Mature before Their Time

    ERIC Educational Resources Information Center

    Charles, Grant; Stainton, Tim; Marshall, Sheila

    2009-01-01

    There is a population of remarkable young people who may go unnoticed due to the absence of overt acting out behaviors. Often mature beyond their age, they are forced by family situations to assume care-giving roles which are usually the responsibility of parents and elders. Being placed prematurely in adult caring roles potentially may have both…

  18. Role of adenosine in oligodendrocyte precursor maturation

    PubMed Central

    Coppi, Elisabetta; Cellai, Lucrezia; Maraula, Giovanna; Dettori, Ilaria; Melani, Alessia; Pugliese, Anna Maria; Pedata, Felicita

    2015-01-01

    Differentiation and maturation of oligodendroglial cells are postnatal processes that involve specific morphological changes correlated with the expression of stage-specific surface antigens and functional voltage-gated ion channels. A small fraction of oligodendrocyte progenitor cells (OPCs) generated during development are maintained in an immature and slowly proliferative or quiescent state in the adult central nervous system (CNS) representing an endogenous reservoir of immature cells. Adenosine receptors are expressed by OPCs and a key role of adenosine in oligodendrocyte maturation has been recently recognized. As evaluated on OPC cultures, adenosine, by stimulating A1 receptors, promotes oligodendrocyte maturation and inhibits their proliferation; on the contrary, by stimulating A2A receptors, it inhibits oligodendrocyte maturation. A1 and A2A receptor-mediated effects are related to opposite modifications of outward delayed rectifying membrane K+ currents (IK) that are involved in the regulation of oligodendrocyte differentiation. Brain A1 and A2A receptors might represent new molecular targets for drugs useful in demyelinating pathologies, such as multiple sclerosis (MS), stroke and brain trauma. PMID:25964740

  19. Gene expression associated with tuber periderm maturation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato periderm maturation and associated resistance to tuber excoriation, i.e. skinning injury, is of scientific and agricultural importance because of the losses created by shrinkage, tuber market quality defects and infections. The cells and cellular changes responsible for the development of re...

  20. Teaching Copywriting Students about the Mature Market.

    ERIC Educational Resources Information Center

    Drewniany, Bonnie

    Advertising educators have a responsibility to make students aware of the importance of the mature market (older people) and to teach them methods to reach this group. An assignment in a copywriting class asked students to write and design ads to promote blue jeans to adults over 50. The assignment accomplished three things: (1) helped students…

  1. Black-White Differences in Psychosocial Maturity.

    ERIC Educational Resources Information Center

    Starr, B. James; And Others

    The present investigation reviews the racial comparison literature in order to make specific predictions about racial differences on the psychosocial maturity scale developed by Greenberger, Campbell, Sorensen, and O'Connor (1971). On the basis of this review, it was predicted that blacks would score lower than whites on the scale, and that this…

  2. Growth Goals, Maturity, and Well-Being

    ERIC Educational Resources Information Center

    Bauer, Jack J.; McAdams, Dan P.

    2004-01-01

    In 2 studies (125 college students and 51 adults), 2 forms of growth goals (exploratory and intrinsic) were compared with 2 forms of personality development (social-cognitive maturity and social-emotional well-being). Participants whose narratives of major life goals emphasized conceptual exploration were especially likely to have high levels of…

  3. Elevated Social Anxiety among Early Maturing Girls

    ERIC Educational Resources Information Center

    Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Babson, Kimberly A.; Gahr, Jessica L.; Trainor, Casey D.; Frala, Jamie L.

    2011-01-01

    Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to…

  4. Strain rate dependence in plasticized and un-plasticized PVC

    NASA Astrophysics Data System (ADS)

    Kendall, M. J.; Siviour, C. R.

    2012-08-01

    An experimental and analytical investigation has been made into the mechanical behaviour of two poly (vinyl chloride) (PVC) polymers - an un-plasticized PVC and a diisononyl phthalate (DINP)-plasticized PVC. Measurements of the compressive stress-strain behaviour of the PVCs at strain rates ranging from 10-3 to 103s-1 and temperatures from - 60 to 100∘C are presented. Dynamic Mechanical Analysis was also performed in order to understand the material transitions observed in compression testing as the strain rate is increased. This investigation develops a better understanding of the interplay between the temperature dependence and rate dependence of polymers, with a focus on locating the temperature and rate-dependent material transitions that occur during high rate testing.

  5. Phenotypic plasticity and experimental evolution.

    PubMed

    Garland, Theodore; Kelly, Scott A

    2006-06-01

    Natural or artificial selection that favors higher values of a particular trait within a given population should engender an evolutionary response that increases the mean value of the trait. For this prediction to hold, the phenotypic variance of the trait must be caused in part by additive effects of alleles segregating in the population, and also the trait must not be too strongly genetically correlated with other traits that are under selection. Another prediction, rarely discussed in the literature, is that directional selection should favor alleles that increase phenotypic plasticity in the direction of selection, where phenotypic plasticity is defined as the ability of one genotype to produce more than one phenotype when exposed to different environments. This prediction has received relatively little empirical attention. Nonetheless, many laboratory experiments impose selection regimes that could allow for the evolution of enhanced plasticity (e.g. desiccation trials with Drosophila that last for several hours or days). We review one example that involved culturing of Drosophila on lemon for multiple generations and then tested for enhanced plasticity of detoxifying enzymes. We also review an example with vertebrates that involves selective breeding for high voluntary activity levels in house mice, targeting wheel-running behavior on days 5+6 of a 6-day wheel exposure. This selection regime allows for the possibility of wheel running itself or subordinate traits that support such running to increase in plasticity over days 1-4 of wheel access. Indeed, some traits, such as the concentration of the glucose transporter GLUT4 in gastrocnemius muscle, do show enhanced plasticity in the selected lines over a 5-6 day period. In several experiments we have housed mice from both the Selected (S) and Control (C) lines with or without wheel access for several weeks to test for differences in plasticity (training effects). A variety of patterns were observed, including

  6. American Academy of Facial Plastic and Reconstructive Surgery

    MedlinePlus

    ... is the world's largest specialty association for facial plastic surgery. It represents more than 2,700 facial plastic ... the American Board of Otolaryngology , which includes facial plastic surgery. Others are certified in plastic surgery, ophthalmology, and ...

  7. Interface controlled plastic flow modelled by strain gradient plasticity theory

    NASA Astrophysics Data System (ADS)

    Pardoen, Thomas; Massart, Thierry J.

    The resistance to plastic flow in metals is often dominated by the presence of interfaces which interfere with dislocation nucleation and motion. Interfaces can be static such as grain and phase boundaries or dynamic such as new boundaries resulting from a phase transformation. The interface can be hard and fully impenetrable to dislocations, or soft and partly or fully transparent. The interactions between dislocations and interfaces constitute the main mechanism controlling the strength and strain hardening capacity of many metallic systems especially in very fine microstructures with a high density of interfaces. A phenomenological strain gradient plasticity theory is used to introduce, within a continuum framework, higher order boundary conditions which empirically represent the effect of interfaces on plastic flow. The strength of the interfaces can evolve during the loading in order to enrich the description of their response. The behaviour of single and dual phase steels, with possible TRIP effect, accounting for the interactions with static and dynamic boundaries, is addressed, with a specific focus on the size dependent strength and ductility balance. The size dependent response of weak precipitate free zones surrounding grain boundaries is treated as an example involving more than one microstructural length scale.

  8. Relative Age, Maturation and Physical Biases on Position Allocation in Elite-Youth Soccer.

    PubMed

    Towlson, Chris; Cobley, Stephen; Midgley, Adrian Wayne; Garrett, Andrew; Parkin, Guy; Lovell, Ric

    2017-03-01

    This study assessed the contribution of relative age, anthropometry, maturation, and physical fitness characteristics on soccer playing position (goalkeeper [GK], central-defender [CD], lateral-defender [LD], central-midfield [CM], lateral-midfielder [LM], and forward [FWD]) for 465 elite-youth players (U13-U18's). U13-14 CD were relatively older than LD and CM (likely small effects). CD and GK were generally taller and heavier (likely small to very-likely moderate effects) than other players at each developmental stage and were advanced maturers at U13-14 (very-likely small to likely moderate effects). GK had inferior agility (very-likely small to likely moderate effects), endurance (very-likely small to likely moderate effects), and sprint capacities (likely small-moderate effects) vs. outfield positions at U13-14, but deficits in anaerobic phenotypes were diminished in U15-16 and U17-18. Position specific fitness characteristics were distinguished at U15-16 (likely small) and U17-18 (likely moderate), where LM were faster than their central counterparts. In summary, relative age, maturation and anthropometric characteristics appear to bias the allocation of players into key defensive roles from an early development stage, whereas position-specific physical attributes do not become apparent until the latter stages of talent development in outfield players. Given the inter-individual trajectories of physical development according to biological maturation, playing position allocation might be considered 'plastic' by selectors, until complete-maturity is achieved.

  9. From metamorphosis to maturity in complex life cycles: equal performance of different juvenile life history pathways.

    PubMed

    Schmidt, Benedikt R; Hödl, Walter; Schaub, Michael

    2012-03-01

    Performance in one stage of a complex life cycle may affect performance in the subsequent stage. Animals that start a new stage at a smaller size than conspecifics may either always remain smaller or they may be able to "catch up" through plasticity, usually elevated growth rates. We study how size at and date of metamorphosis affected subsequent performance in the terrestrial juvenile stage and lifetime fitness of spadefoot toads (Pelobates fuscus). We analyzed capture-recapture data of > 3000 individuals sampled during nine years with mark-recapture models to estimate first-year juvenile survival probabilities and age-specific first-time breeding probabilities of toads, followed by model selection to assess whether these probabilities were correlated with size at and date of metamorphosis. Males attained maturity after two years, whereas females reached maturity 2-4 years after metamorphosis. Age at maturity was weakly correlated with metamorphic traits. In both sexes, first-year juvenile survival depended positively on date of metamorphosis and, in males, also negatively on size at metamorphosis. In males, toads that metamorphosed early at a small size had the highest probability to reach maturity. However, because very few toadlets metamorphosed early, the vast majority of male metamorphs had a very similar probability to reach maturity. A matrix projection model constructed for females showed that different juvenile life history pathways resulted in similar lifetime fitness. We found that the effects of date of and size at metamorphosis on different juvenile traits cancelled each other out such that toads that were small or large at metamorphosis had equal performance. Because the costs and benefits of juvenile life history pathways may also depend on population fluctuations, ample phenotypic variation in life history traits may be maintained.

  10. Comparative effect of treadmill exercise on mature BDNF production in control versus stroke rats.

    PubMed

    Quirié, Aurore; Hervieu, Marie; Garnier, Philippe; Demougeot, Céline; Mossiat, Claude; Bertrand, Nathalie; Martin, Alain; Marie, Christine; Prigent-Tessier, Anne

    2012-01-01

    Physical exercise constitutes an innovative strategy to treat deficits associated with stroke through the promotion of BDNF-dependent neuroplasticity. However, there is no consensus on the optimal intensity/duration of exercise. In addition, whether previous stroke changes the effect of exercise on the brain is not known. Therefore, the present study compared the effects of a clinically-relevant form of exercise on cerebral BDNF levels and localization in control versus stroke rats. For this purpose, treadmill exercise (0.3 m/s, 30 min/day, for 7 consecutive days) was started in rats with a cortical ischemic stroke after complete maturation of the lesion or in control rats. Sedentary rats were run in parallel. Mature and proBDNF levels were measured on the day following the last boot of exercise using Western blotting analysis. Total BDNF levels were simultaneously measured using ELISA tests. As compared to the striatum and the hippocampus, the cortex was the most responsive region to exercise. In this region, exercise resulted in a comparable increase in the production of mature BDNF in intact and stroke rats but increased proBDNF levels only in intact rats. Importantly, levels of mature BDNF and synaptophysin were strongly correlated. These changes in BDNF metabolism coincided with the appearance of intense BDNF labeling in the endothelium of cortical vessels. Notably, ELISA tests failed to detect changes in BDNF forms. Our results suggest that control beings can be used to find conditions of exercise that will result in increased mBDNF levels in stroke beings. They also suggest cerebral endothelium as a potential source of BDNF after exercise and highlight the importance to specifically measure the mature form of BDNF to assess BDNF-dependent plasticity in relation with exercise.

  11. Sex-specific developmental plasticity of generalist and specialist predatory mites (Acari: Phytoseiidae) in response to food stress.

    PubMed

    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.

  12. Public health impact of plastics: An overview

    PubMed Central

    Rustagi, Neeti; Pradhan, S. K.; Singh, Ritesh

    2011-01-01

    Plastic, one of the most preferred materials in today's industrial world is posing serious threat to environment and consumer's health in many direct and indirect ways. Exposure to harmful chemicals during manufacturing, leaching in the stored food items while using plastic packages or chewing of plastic teethers and toys by children are linked with severe adverse health outcomes such as cancers, birth defects, impaired immunity, endocrine disruption, developmental and reproductive effects etc. Promotion of plastics substitutes and safe disposal of plastic waste requires urgent and definitive action to take care of this potential health hazard in future. PMID:22412286

  13. On the Evolution of Plasticity and Incompatibility

    SciTech Connect

    Gupta, A; Steigmann, D J; St?lken, J S

    2005-11-23

    The phenomenological theory of elastic-plastic deformations is reconsidered in the light of recent opinion regarding the constitutive character of their constituent elastic and plastic components. The primary role of dissipation in the physics of plastic evolution is emphasized and shown to lead to the clarification of a number of open questions. Particular attention is given to the invariance properties of the elastic and plastic deformations, to the kinematics of discontinuities, and to the role of material symmetry in restricting constitutive equations for elastic response, yield and plastic evolution.

  14. Process for remediation of plastic waste

    DOEpatents

    Pol, Vilas G [Westmont, IL; Thiyagarajan, Pappannan [Germantown, MD

    2012-04-10

    A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically egg-shaped and spherical-shaped solid carbons. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

  15. Process for remediation of plastic waste

    DOEpatents

    Pol, Vilas G; Thiyagarajan, Pappannan

    2013-11-12

    A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of about 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically carbon nanotubes having a partially filled core (encapsulated) adjacent to one end of the nanotube. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

  16. Sleep and Plasticity in Schizophrenia

    PubMed Central

    Sprecher, Kate E.; Ferrarelli, Fabio

    2016-01-01

    Schizophrenia is a devastating mental illness with a worldwide prevalence of approximately 1 %. Although the clinical features of the disorder were described over one hundred years ago, its neurobiology is still largely elusive despite several decades of research. Schizophrenia is associated with marked sleep disturbances and memory impairment. Above and beyond altered sleep architecture, sleep rhythms including slow waves and spindles are disrupted in schizophrenia. In the healthy brain, these rhythms reflect and participate in plastic processes during sleep. This chapter discusses evidence that schizophrenia patients exhibit dysfunction of sleep-mediated plasticity on a behavioral, cellular, and molecular level and offers suggestions on how the study of sleeping brain activity can shed light on the pathophysiological mechanisms of the disorder. PMID:25608723

  17. Plastic buckling of cylindrical shells

    SciTech Connect

    Bandyopadhyay, K.; Xu, J.; Shteyngart, S.; Eckert, H.

    1994-05-01

    Cylindrical shells exhibit buckling under axial loads at stresses much less than the respective theoretical critical stresses. This is due primarily to the presence of geometrical imperfections even through such imperfections could be very small (e.g., comparable to thickness). Under internal pressure, the shell regains some of its buckling strength. For a relatively large radius-to-tickness ratio and low internal pressure, the effect can be reasonably estimated by an elastic analysis. However, for low radius-to-thickness ratios and greater pressures, the elastic-plastic collapse controls the failure load. In order to quantify the elastic-plastic buckling capacity of cylindrical shells, an analysis program was carried out by use of the computer code BOSOR5 developed by Bushnell of Lockheed Missiles and Space company. The analysis was performed for various radius-to- thickness ratios and imperfection amplitudes. The analysis results are presented in this paper.

  18. Transformation plasticity in ductile solids

    SciTech Connect

    Olson, G.B.

    1993-02-01

    Research has addressed the role of martensitic transformation plasticity in the enhancement of toughness in high-strength austenitic steels, and the enhancement of formability in multiphase low-alloy sheet steels. In the austenitic steels, optimal processing conditions have been established to achieve a significant increase in strength level, in order to investigate the interaction of strain-induced transformation with the microvoid nucleation and shear localization mechanisms operating at ultrahigh strength levels. The stress-state dependence of transformation and fracture mechanisms has been investigated in model alloys, comparing behavior in uniaxial tension and blunt-notch tension specimens. A numerical constitutive model for transformation plasticity has been reformulated to allow a more thorough analysis of transformation/fracture interactions. Processing of a new low alloy steel composition has been optimized to stabilize retained austenite by isothermal bainitic transformation after intercritical annealing. Preliminary results show a good correlation of uniform ductility with the austenite amount and stability.

  19. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, M.S.

    1991-01-01

    This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

  20. Postsynaptic Signaling and Plasticity Mechanisms

    NASA Astrophysics Data System (ADS)

    Sheng, Morgan; Jong Kim, Myung

    2002-10-01

    In excitatory synapses of the brain, specific receptors in the postsynaptic membrane lie ready to respond to the release of the neurotransmitter glutamate from the presynaptic terminal. Upon stimulation, these glutamate receptors activate multiple biochemical pathways that transduce signals into the postsynaptic neuron. Different kinds of synaptic activity elicit different patterns of postsynaptic signals that lead to short- or long-lasting strengthening or weakening of synaptic transmission. The complex molecular mechanisms that underlie postsynaptic signaling and plasticity are beginning to emerge.

  1. The rise of plastic bioelectronics

    NASA Astrophysics Data System (ADS)

    Someya, Takao; Bao, Zhenan; Malliaras, George G.

    2016-12-01

    Plastic bioelectronics is a research field that takes advantage of the inherent properties of polymers and soft organic electronics for applications at the interface of biology and electronics. The resulting electronic materials and devices are soft, stretchable and mechanically conformable, which are important qualities for interacting with biological systems in both wearable and implantable devices. Work is currently aimed at improving these devices with a view to making the electronic-biological interface as seamless as possible.

  2. The Future of Plastic Surgery: Surgeon's Perspective.

    PubMed

    Ozturk, Sinan; Karagoz, Huseyin; Zor, Fatih

    2015-11-01

    Since the days of Sushruta, innovation has shaped the history of plastic surgery. Plastic surgeons have always been known as innovators or close followers of innovations. With this descriptive international survey study, the authors aimed to evaluate the future of plastic surgeons by analyzing how plastic surgery and plastic surgeons will be affected by new trends in medicine. Aesthetic surgery is the main subclass of plastic surgery thought to be the one that will change the most in the future. Stem cell therapy is considered by plastic surgeons to be the most likely "game changer." Along with changes in surgery, plastic surgeons also expect changes in plastic surgery education. The most approved assumption for the future of plastic surgery is, "The number of cosmetic nonsurgical procedures will increase in the future." If surgeons want to have better outcomes in their practice, they must at least be open minded for innovations if they do not become innovators themselves. Besides the individual effort of each surgeon, international and local plastic surgery associations should develop new strategies to adopt these innovations in surgical practice and education.

  3. Leveraging People-Related Maturity Issues for Achieving Higher Maturity and Capability Levels

    NASA Astrophysics Data System (ADS)

    Buglione, Luigi

    During the past 20 years Maturity Models (MM) become a buzzword in the ICT world. Since the initial Crosby's idea in 1979, plenty of models have been created in the Software & Systems Engineering domains, addressing various perspectives. By analyzing the content of the Process Reference Models (PRM) in many of them, it can be noticed that people-related issues have little weight in the appraisals of the capabilities of organizations while in practice they are considered as significant contributors in traditional process and organizational performance appraisals, as stressed instead in well-known Performance Management models such as MBQA, EFQM and BSC. This paper proposes some ways for leveraging people-related maturity issues merging HR practices from several types of maturity models into the organizational Business Process Model (BPM) in order to achieve higher organizational maturity and capability levels.

  4. Distinctive features of adult ocular dominance plasticity.

    PubMed

    Sato, Masaaki; Stryker, Michael P

    2008-10-08

    Sensory experience profoundly shapes neural circuitry of juvenile brain. Although the visual cortex of adult rodents retains a capacity for plasticity in response to monocular visual deprivation, the nature of this plasticity and the neural circuit changes that accompany it remain enigmatic. Here, we investigate differences between adult and juvenile ocular dominance plasticity using Fourier optical imaging of intrinsic signals in mouse visual cortex. This comparison reveals that adult plasticity takes longer than in the juvenile mouse, is of smaller magnitude, has a greater contribution from the increase in response to the open eye, and has less effect on the hemisphere ipsilateral to the deprived eye. Binocular deprivation also causes different changes in the adult. Adult plasticity is similar to juvenile plasticity in its dependence on signaling through NMDA receptors. We propose that adult ocular dominance plasticity arises from compensatory mechanisms that counterbalance the loss of afferent activity caused by visual deprivation.

  5. Applications and societal benefits of plastics.

    PubMed

    Andrady, Anthony L; Neal, Mike A

    2009-07-27

    This article explains the history, from 1600 BC to 2008, of materials that are today termed 'plastics'. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years.

  6. Regulatory mechanisms link phenotypic plasticity to evolvability.

    PubMed

    van Gestel, Jordi; Weissing, Franz J

    2016-04-18

    Organisms have a remarkable capacity to respond to environmental change. They can either respond directly, by means of phenotypic plasticity, or they can slowly adapt through evolution. Yet, how phenotypic plasticity links to evolutionary adaptability is largely unknown. Current studies of plasticity tend to adopt a phenomenological reaction norm (RN) approach, which neglects the mechanisms underlying plasticity. Focusing on a concrete question - the optimal timing of bacterial sporulation - we here also consider a mechanistic approach, the evolution of a gene regulatory network (GRN) underlying plasticity. Using individual-based simulations, we compare the RN and GRN approach and find a number of striking differences. Most importantly, the GRN model results in a much higher diversity of responsive strategies than the RN model. We show that each of the evolved strategies is pre-adapted to a unique set of unseen environmental conditions. The regulatory mechanisms that control plasticity therefore critically link phenotypic plasticity to the adaptive potential of biological populations.

  7. Anaesthetic complications in plastic surgery.

    PubMed

    Nath, Soumya Sankar; Roy, Debashis; Ansari, Farrukh; Pawar, Sundeep T

    2013-05-01

    Anaesthesia related complications in plastic surgeries are fortunately rare, but potentially catastrophic. Maintaining patient safety in the operating room is a major concern of anaesthesiologists, surgeons, hospitals and surgical facilities. Circumventing preventable complications is essential and pressure to avoid these complications in cosmetic surgery is increasing. Key aspects of patient safety in the operating room are outlined, including patient positioning, airway management and issues related to some specific conditions, essential for minimizing post-operative morbidity. Risks associated with extremes of age in the plastic surgery population, may be minimised by a better understanding of the physiologic changes as well as the pre-operative and post-operative considerations in caring for this special group of patients. An understanding of the anaesthesiologist's concerns during paediatric plastic surgical procedures can facilitate the coordination of efforts between the multiple services involved in the care of these children. Finally, the reader will have a better understanding of the perioperative care of unique populations including the morbidly obese and the elderly. Attention to detail in these aspects of patient safety can help avoid unnecessary complication and significantly improve the patients' experience and surgical outcome.

  8. Anaesthetic complications in plastic surgery

    PubMed Central

    Nath, Soumya Sankar; Roy, Debashis; Ansari, Farrukh; Pawar, Sundeep T.

    2013-01-01

    Anaesthesia related complications in plastic surgeries are fortunately rare, but potentially catastrophic. Maintaining patient safety in the operating room is a major concern of anaesthesiologists, surgeons, hospitals and surgical facilities. Circumventing preventable complications is essential and pressure to avoid these complications in cosmetic surgery is increasing. Key aspects of patient safety in the operating room are outlined, including patient positioning, airway management and issues related to some specific conditions, essential for minimizing post-operative morbidity. Risks associated with extremes of age in the plastic surgery population, may be minimised by a better understanding of the physiologic changes as well as the pre-operative and post-operative considerations in caring for this special group of patients. An understanding of the anaesthesiologist's concerns during paediatric plastic surgical procedures can facilitate the coordination of efforts between the multiple services involved in the care of these children. Finally, the reader will have a better understanding of the perioperative care of unique populations including the morbidly obese and the elderly. Attention to detail in these aspects of patient safety can help avoid unnecessary complication and significantly improve the patients’ experience and surgical outcome. PMID:24501480

  9. Corticosterone facilitates fluoxetine-induced neuronal plasticity in the hippocampus.

    PubMed

    Kobayashi, Katsunori; Ikeda, Yumiko; Asada, Minoru; Inagaki, Hirofumi; Kawada, Tomoyuki; Suzuki, Hidenori

    2013-01-01

    The hippocampal dentate gyrus has been implicated in a neuronal basis of antidepressant action. We have recently shown a distinct form of neuronal plasticity induced by the serotonergic antidepressant fluoxetine, that is, a reversal of maturation of the dentate granule cells in adult mice. This "dematuration" is induced in a large population of dentate neurons and maintained for at least one month after withdrawal of fluoxetine, suggesting long-lasting strong influence of dematuration on brain functioning. However, reliable induction of dematuration required doses of fluoxetine higher than suggested optimal doses for mice (10 to 18 mg/kg/day), which casts doubt on the clinical relevance of this effect. Since our previous studies were performed in naive mice, in the present study, we reexamined effects of fluoxetine using mice treated with chronic corticosterone that model neuroendocrine pathophysiology associated with depression. In corticosterone-treated mice, fluoxetine at 10 mg/kg/day downregulated expression of mature granule cell markers and attenuated strong frequency facilitation at the synapse formed by the granule cell axon mossy fiber, suggesting the induction of granule cell dematuration. In addition, fluoxetine caused marked enhancement of dopaminergic modulation at the mossy fiber synapse. In vehicle-treated mice, however, fluoxetine at this dose had no significant effects. The plasma level of fluoxetine was comparable to that in patients taking chronic fluoxetine, and corticosterone did not affect it. These results indicate that corticosterone facilitates fluoxetine-induced plastic changes in the dentate granule cells. Our finding may provide insight into neuronal mechanisms underlying enhanced responsiveness to antidepressant medication in certain pathological conditions.

  10. Diagnostic performance of dental maturity for identification of skeletal maturation phase.

    PubMed

    Perinetti, G; Contardo, L; Gabrieli, P; Baccetti, T; Di Lenarda, R

    2012-08-01

    The objective of this study is to analyse the diagnostic performance of the circumpubertal dental maturation phases for the identification of individual-specific skeletal maturation phases. A total of 354 healthy subjects, 208 females and 146 males (mean age, 11.1 ± 2.4 years; range, 6.8-17.1 years), were enrolled in the study. Dental maturity was assessed through the calcification stages from panoramic radiographs of the mandibular canine, the first and second premolars, and the second molar. Determination of skeletal maturity was according to the cervical vertebra maturation (CVM) method on lateral cephalograms. Diagnostic performances were evaluated according to the dental maturation stages for each tooth for the identification of the CVM stages and growth phases (as pre-pubertal, pubertal, and post-pubertal) using positive likelihood ratios (LHRs). A positive LHR threshold of 10 or more was considered for satisfactory reliability of any dental maturation stage for the identification of any of the CVM stages or growth phases. The positive LHRs were generally less than 2.0, with a few exceptions. These four teeth showed positive LHRs greater than 10 only for the identification of the pre-pubertal growth phase, with values from 10.8 for the second molar (stage E) to 39.3 for the first premolar (stage E). Dental maturation assessment is only useful for diagnosis of the pre-pubertal growth phase, and thus, precise information in relation to the timing of the onset of the growth spurt is not provided by these indices.

  11. Differential dendritic Ca2+ signalling in young and mature hippocampal granule cells

    PubMed Central

    Stocca, Gabriella; Schmidt-Hieber, Christoph; Bischofberger, Josef

    2008-01-01

    Neuronal activity is critically important for development and plasticity of dendrites, axons and synaptic connections. Although Ca2+ is an important signal molecule for these processes, not much is known about the regulation of the dendritic Ca2+ concentration in developing neurons. Here we used confocal Ca2+ imaging to investigate dendritic Ca2+ signalling in young and mature hippocampal granule cells, identified by the expression of the immature neuronal marker polysialated neural cell adhesion molecule (PSA-NCAM). Using the Ca2+-sensitive fluorescent dye OGB-5N, we found that both young and mature granule cells showed large action-potential evoked dendritic Ca2+ transients with similar amplitude of ∼200 nm, indicating active backpropagation of action potentials. However, the decay of the dendritic Ca2+ concentration back to baseline values was substantially different with a decay time constant of 550 ms in young versus 130 ms in mature cells, leading to a more efficient temporal summation of Ca2+ signals during theta-frequency stimulation in the young neurons. Comparison of the peak Ca2+ concentration and the decay measured with different Ca2+ indicators (OGB-5N, OGB-1) in the two populations of neurons revealed that the young cells had an ∼3 times smaller endogenous Ca2+-binding ratio (∼75 versus∼220) and an ∼10 times slower Ca2+ extrusion rate (∼170 s−1versus∼1800 s−1). These data suggest that the large dendritic Ca2+ signals due to low buffer capacity and slow extrusion rates in young granule cells may contribute to the activity-dependent growth and plasticity of dendrites and new synaptic connections. This will finally support differentiation and integration of young neurons into the hippocampal network. PMID:18591186

  12. Unravelling the development of the visual cortex: implications for plasticity and repair

    PubMed Central

    Bourne, James A

    2010-01-01

    The visual cortex comprises over 50 areas in the human, each with a specified role and distinct physiology, connectivity and cellular morphology. How these individual areas emerge during development still remains something of a mystery and, although much attention has been paid to the initial stages of the development of the visual cortex, especially its lamination, very little is known about the mechanisms responsible for the arealization and functional organization of this region of the brain. In recent years we have started to discover that it is the interplay of intrinsic (molecular) and extrinsic (afferent connections) cues that are responsible for the maturation of individual areas, and that there is a spatiotemporal sequence in the maturation of the primary visual cortex (striate cortex, V1) and the multiple extrastriate/association areas. Studies in both humans and non-human primates have started to highlight the specific neural underpinnings responsible for the maturation of the visual cortex, and how experience-dependent plasticity and perturbations to the visual system can impact upon its normal development. Furthermore, damage to specific nuclei of the visual cortex, such as the primary visual cortex (V1), is a common occurrence as a result of a stroke, neurotrauma, disease or hypoxia in both neonates and adults alike. However, the consequences of a focal injury differ between the immature and adult brain, with the immature brain demonstrating a higher level of functional resilience. With better techniques for examining specific molecular and connectional changes, we are now starting to uncover the mechanisms responsible for the increased neural plasticity that leads to significant recovery following injury during this early phase of life. Further advances in our understanding of postnatal development/maturation and plasticity observed during early life could offer new strategies to improve outcomes by recapitulating aspects of the developmental program

  13. Developmental plasticity in Protea as an evolutionary response to environmental clines in the Cape Floristic Region.

    PubMed

    Carlson, Jane E; Holsinger, Kent E

    2012-01-01

    Local adaptation along steep environmental gradients likely contributes to plant diversity in the Cape Region of South Africa, yet existing analyses of trait divergence are limited to static measurements of functional traits rather than trajectories of individual development. We explore whether five taxa of evergreen shrubs (Protea section Exsertae) differ in their developmental trajectories and capacity for plasticity using two environmentally-distinct common gardens in South Africa. We measured seedlings in the summer-dry season and winter-wet season of each of two consecutive years to characterize ontogeny and plasticity within years, as same-age leaf cohorts mature, and between years, i.e., from leaf one cohort to the next. We compared patterns of development between gardens to assess whether trait trajectories are programmed versus plastic and examined whether developmental differences covaried with characteristics of a seedling's home environment. We detected plasticity in developmental trajectories for leaf area, stomatal size, stomatal pore index, and to a limited extent specific leaf area, but not for stomatal density. We showed that the species growing in the harshest environments exhibits both the smallest increase in leaf area between years and the least change in SLA and photosynthetic rates as leaves age within years. These results show that within this clade, species have diverged in developmental trajectories and plasticity as well as in mean trait values. Some of these differences may be associated with adaptation to cold and drought stress within an environmentally-complex region.

  14. Developmental Plasticity in Protea as an Evolutionary Response to Environmental Clines in the Cape Floristic Region

    PubMed Central

    Carlson, Jane E.; Holsinger, Kent E.

    2012-01-01

    Local adaptation along steep environmental gradients likely contributes to plant diversity in the Cape Region of South Africa, yet existing analyses of trait divergence are limited to static measurements of functional traits rather than trajectories of individual development. We explore whether five taxa of evergreen shrubs (Protea section Exsertae) differ in their developmental trajectories and capacity for plasticity using two environmentally-distinct common gardens in South Africa. We measured seedlings in the summer-dry season and winter-wet season of each of two consecutive years to characterize ontogeny and plasticity within years, as same-age leaf cohorts mature, and between years, i.e., from leaf one cohort to the next. We compared patterns of development between gardens to assess whether trait trajectories are programmed versus plastic and examined whether developmental differences covaried with characteristics of a seedling’s home environment. We detected plasticity in developmental trajectories for leaf area, stomatal size, stomatal pore index, and to a limited extent specific leaf area, but not for stomatal density. We showed that the species growing in the harshest environments exhibits both the smallest increase in leaf area between years and the least change in SLA and photosynthetic rates as leaves age within years. These results show that within this clade, species have diverged in developmental trajectories and plasticity as well as in mean trait values. Some of these differences may be associated with adaptation to cold and drought stress within an environmentally-complex region. PMID:23272203

  15. Predator-induced phenotypic plasticity within- and across-generations: a challenge for theory?

    PubMed Central

    Walsh, Matthew R.; Cooley, Frank; Biles, Kelsey; Munch, Stephan B.

    2015-01-01

    Much work has shown that the environment can induce non-genetic changes in phenotype that span multiple generations. Theory predicts that predictable environmental variation selects for both increased within- and across-generation responses. Yet, to the best of our knowledge, there are no empirical tests of this prediction. We explored the relationship between within- versus across-generation plasticity by evaluating the influence of predator cues on the life-history traits of Daphnia ambigua. We measured the duration of predator-induced transgenerational effects, determined when transgenerational responses are induced, and quantified the cues that activate transgenerational plasticity. We show that predator exposure during embryonic development causes earlier maturation and increased reproductive output. Such effects are detectable two generations removed from predator exposure and are similar in magnitude in response to exposure to cues emitted by injured conspecifics. Moreover, all experimental contexts and traits yielded a negative correlation between within- versus across-generation responses. That is, responses to predator cues within- and across-generations were opposite in sign and magnitude. Although many models address transgenerational plasticity, none of them explain this apparent negative relationship between within- and across-generation plasticities. Our results highlight the need to refine the theory of transgenerational plasticity. PMID:25392477

  16. Development and validation of the Eating Maturity Questionnaire: Preliminary findings.

    PubMed

    Potocka, Adrianna; Najder, Anna

    2016-10-01

    This article describes the development of the Eating Maturity Questionnaire, a self-reported measurement of eating maturity that initiates and gives direction to human eating behaviors. The Eating Maturity Questionnaire was designed to study individuals' biological and psychosocial motives for eating. The Eating Maturity Questionnaire is a 21-item tool with satisfactory psychometric values (Cronbach's α coefficients between 0.83 and 0.88) consisting of two subscales: Rational Eating and Psychosocial Maturity Eating Maturity Questionnaire results may be used to design programs that target eating behaviors and body mass modification.

  17. Competition with Primary Sensory Afferents Drives Remodeling of Corticospinal Axons in Mature Spinal Motor Circuits

    PubMed Central

    Jiang, Yu-Qiu; Zaaimi, Boubker

    2016-01-01

    Injury to the mature motor system drives significant spontaneous axonal sprouting instead of axon regeneration. Knowing the circuit-level determinants of axonal sprouting is important for repairing motor circuits after injury to achieve functional rehabilitation. Competitive interactions are known to shape corticospinal tract axon outgrowth and withdrawal during development. Whether and how competition contributes to reorganization of mature spinal motor circuits is unclear. To study this question, we examined plastic changes in corticospinal axons in response to two complementary proprioceptive afferent manipulations: (1) enhancing proprioceptive afferents activity by electrical stimulation; or (2) diminishing their input by dorsal rootlet rhizotomy. Experiments were conducted in adult rats. Electrical stimulation produced proprioceptive afferent sprouting that was accompanied by significant corticospinal axon withdrawal and a decrease in corticospinal connections on cholinergic interneurons in the medial intermediate zone and C boutons on motoneurons. In contrast, dorsal rootlet rhizotomy led to a significant increase in corticospinal connections, including those on cholinergic interneurons; C bouton density increased correspondingly. Motor cortex-evoked muscle potentials showed parallel changes to those of corticospinal axons, suggesting that reciprocal corticospinal axon changes are functional. Using the two complementary models, we showed that competitive interactions between proprioceptive and corticospinal axons are an important determinant in the organization of mature corticospinal axons and spinal motor circuits. The activity- and synaptic space-dependent properties of the competition enables prediction of the remodeling of spared corticospinal connection and spinal motor circuits after injury and informs the target-specific control of corticospinal connections to promote functional recovery. SIGNIFICANCE STATEMENT Neuroplasticity is limited in maturity

  18. Visualizing Antibody Affinity Maturation in Germinal Centers

    PubMed Central

    Tas, Jeroen M.J.; Mesin, Luka; Pasqual, Giulia; Targ, Sasha; Jacobsen, Johanne T.; Mano, Yasuko M.; Chen, Casie S.; Weill, Jean-Claude; Reynaud, Claude-Agnès; Browne, Edward P.; Meyer-Hermann, Michael; Victora, Gabriel D.

    2016-01-01

    Antibodies somatically mutate to attain high affinity in germinal centers (GCs). There, competition between B cell clones and among somatic mutants of each clone drives an increase in average affinity across the population. The extent to which higher-affinity cells eliminating competitors restricts clonal diversity is unknown. By combining multiphoton microscopy and sequencing, we show that tens to hundreds of distinct B cell clones seed each GC, and that GCs lose clonal diversity at widely disparate rates. Furthermore, efficient affinity maturation can occur in the absence of homogenizing selection, ensuring that many clones can mature in parallel within the same GC. Our findings have implications for development of vaccines in which antibodies with non-immunodominant specificities must be elicited, as is the case for HIV-1 and influenza. PMID:26912368

  19. Remotely sensing wheat maturation with radar

    NASA Technical Reports Server (NTRS)

    Bush, T. F.; Ulaby, F. T.

    1975-01-01

    The scattering properties of wheat were studied in the 8-18 GHz band as a function of frequency, polarization, incidence angle, and crop maturity. Supporting ground truth was collected at the time of measurement. The data indicate that the radar backscattering coefficient is sensitive to both radar system parameters and crop characteristics particularly at incidence angles near nadir. Linear regression analyses of the radar backscattering coefficient on both time and plant moisture content result in rather good correlation. Furthermore, by calculating the average time rate of change of the radar backscattering coefficient it is found that it undergoes rapid variations shortly before and after the wheat is harvested. Both of these analyses suggest methods for estimating wheat maturity and for monitoring the progress of harvest.

  20. Mature osteoblasts dedifferentiate in response to traumatic bone injury in the zebrafish fin and skull.

    PubMed

    Geurtzen, Karina; Knopf, Franziska; Wehner, Daniel; Huitema, Leonie F A; Schulte-Merker, Stefan; Weidinger, Gilbert

    2014-06-01

    Zebrafish have an unlimited capacity to regenerate bone after fin amputation. In this process, mature osteoblasts dedifferentiate to osteogenic precursor cells and thus represent an important source of newly forming bone. By contrast, differentiated osteoblasts do not appear to contribute to repair of bone injuries in mammals; rather, osteoblasts form anew from mesenchymal stem cells. This raises the question whether osteoblast dedifferentiation is specific to appendage regeneration, a special feature of the lepidotrichia bone of the fish fin, or a process found more generally in fish bone. Here, we show that dedifferentiation of mature osteoblasts is not restricted to fin regeneration after amputation, but also occurs during repair of zebrafish fin fractures and skull injuries. In both models, mature osteoblasts surrounding the injury downregulate the expression of differentiation markers, upregulate markers of the pre-osteoblast state and become proliferative. Making use of photoconvertible Kaede protein as well as Cre-driven genetic fate mapping, we show that osteoblasts migrate to the site of injury to replace damaged tissue. Our findings suggest a fundamental role for osteoblast dedifferentiation in reparative bone formation in fish and indicate that adult fish osteoblasts display elevated cellular plasticity compared with mammalian bone-forming cells.

  1. Amyloid Oligomers and Mature Fibrils Prepared from an Innocuous Protein Cause Diverging Cellular Death Mechanisms*

    PubMed Central

    Harte, Níal P.; Klyubin, Igor; McCarthy, Eoin K.; Min, Soyoung; Garrahy, Sarah Ann; Xie, Yongjing; Davey, Gavin P.; Boland, John J.; Rowan, Michael J.; Mok, K. Hun

    2015-01-01

    Despite significant advances, the molecular identity of the cytotoxic species populated during in vivo amyloid formation crucial for the understanding of neurodegenerative disorders is yet to be revealed. In this study lysozyme prefibrillar oligomers and fibrils in both mature and sonicated states have been isolated through an optimized ultrafiltration/ultracentrifugation method and characterized with various optical spectroscopic techniques, atomic force microscopy, and transmission electron microscopy. We examined their level and mode of toxicity on rat pheochromocytoma (PC12) cells in both differentiated and undifferentiated states. We find that oligomers and fibrils display cytotoxic capabilities toward cultured cells in vitro, with oligomers producing elevated levels of cellular injury toward undifferentiated PC12 cells (PC12undiff). Furthermore, dual flow cytometry staining experiments demonstrate that the oligomers and mature fibrils induce divergent cellular death pathways (apoptosis and secondary necrosis, respectively) in these PC12 cells. We have also shown that oligomers but not sonicated mature fibrils inhibit hippocampal long term potentiation, a form of synaptic plasticity implicated in learning and memory, in vivo. We conclude that our in vitro and in vivo findings confer a level of resistance toward amyloid fibrils, and that the PC 12-based comparative cytotoxicity assay can provide insights into toxicity differences between differently aggregated protein species. PMID:26221033

  2. Self-synthesized extracellular matrix contributes to mature adipose tissue regeneration in a tissue engineering chamber.

    PubMed

    Zhan, Weiqing; Chang, Qiang; Xiao, Xiaolian; Dong, Ziqing; Zeng, Zhaowei; Gao, Jianhua; Lu, Feng

    2015-01-01

    The development of an engineered adipose tissue substitute capable of supporting reliable, predictable, and complete fat tissue regeneration would be of value in plastic and reconstructive surgery. For adipogenesis, a tissue engineering chamber provides an optimized microenvironment that is both efficacious and reproducible; however, for reasons that remain unclear, tissues regenerated in a tissue engineering chamber consist mostly of connective rather than adipose tissue. Here, we describe a chamber-based system for improving the yield of mature adipose tissue and discuss the potential mechanism of adipogenesis in tissue-chamber models. Adipose tissue flaps with independent vascular pedicles placed in chambers were implanted into rabbits. Adipose volume increased significantly during the observation period (week 1, 2, 3, 4, 16). Histomorphometry revealed mature adipose tissue with signs of adipose tissue remolding. The induced engineered constructs showed high-level expression of adipogenic (peroxisome proliferator-activated receptor γ), chemotactic (stromal cell-derived factor 1a), and inflammatory (interleukin 1 and 6) genes. In our system, the extracellular matrix may have served as a scaffold for cell migration and proliferation, allowing mature adipose tissue to be obtained in a chamber microenvironment without the need for an exogenous scaffold. Our results provide new insights into key elements involved in the early development of adipose tissue regeneration.

  3. Predicting skeletal maturation using cervical vertebrae.

    PubMed

    Minars, Michael; Burch, James; Masella, Richard; Meister, Malcolm

    2003-10-01

    This study's objective was to familiarize the profession with determining skeletal maturation and skeletal age, and predicting growth potential by using cervical vertebrae images of lateral cephalograms. The investigation was done through repeated evaluations of 30 randomly selected, pretreatment lateral cepaholometric radiographs. The accuracy of determining skeletal age and growth potential with lateral cephalograms was found to be R=0.98 (highly accurate) by statistical analysis.

  4. Maturation of Fetal Responses to Music

    ERIC Educational Resources Information Center

    Kisilevsky, B. S.; Hains, S. M. J.; Jacquet, A.-Y.; Granier-Deferre, C.; Lecanuet, J. P.

    2004-01-01

    Maturation of fetal response to music was characterized over the last trimester of pregnancy using a 5-minute piano recording of Brahms' Lullaby, played at an average of 95, 100, 105 or 110 dB (A). Within 30 seconds of the onset of the music, the youngest fetuses (28-32 weeks GA) showed a heart rate increase limited to the two highest dB levels;…

  5. Mature brain tissue in the sacrococcygeal region

    PubMed Central

    Shrestha, Binod Bade; Ghimire, Pradeep; Ghartimagar, Dilasma; Jwarchan, Bishnu; Lalchan, Subita; Karmacharya, Mikesh

    2016-01-01

    Complete mature brain tissue in sacrococcygeal region is a rare congenital anomaly in a newborn, which usually is misdiagnosed for sacrococcygeal teratoma. Glial tumor-like ependymoma is also common in sacrococcygeal area but mostly appears later in life. We present a case of complete heterotopic brain tissue in the sacrococcygeal region. The patient underwent total excision of mass with coccygectomy. To our knowledge it is the second case being reported. PMID:27194682

  6. NATO NEC C2 Maturity Model

    DTIC Science & Technology

    2010-02-01

    This broader construct demands greater agility on the part of both military and non-military leadership and organisations. Therefore, agility must be...the situation; • infrastructure (availability, quality); • clarity, unity of intent (purpose), and strategy ; • nature of effects space (PMESII...in time, energy , and resources needed for higher levels of C2 maturity is clear from the analysis in these experiences. From the perspective of the

  7. Mature monocytic cells enter tissues and engraft

    PubMed Central

    Kennedy, David W.; Abkowitz, Janis L.

    1998-01-01

    The goal of this study was to identify the circulating cell that is the immediate precursor of tissue macrophages. ROSA 26 marrow mononuclear cells (containing the β-geo transgene that encodes β-galactosidase and neomycin resistance activities) were cultured in the presence of macrophage colony-stimulating factor and flt3 Ligand for 6 days to generate monocytic cells at all stages of maturation. Expanded monocyte cells (EMC), the immature (ER-MP12+) and more mature (ER-MP20+) subpopulations, were transplanted into irradiated B6/129 F2 mice. β-gal staining of tissue sections from animals 15 min after transplantation demonstrated that the donor cells landed randomly. By 3 h, donor cells in lung and liver were more frequent in animals transplanted with ER-MP20+ (more mature) EMC than in animals transplanted with unseparated EMC or fresh marrow mononuclear cells, a pattern that persisted at 3 and 7 days. At 3 days, donor cells were found in spleen, liver, lung, and brain (rarely) as clusters as well as individual cells. By 7 and 14 days, the clusters had increased in size, and the cells expressed the macrophage antigen F4/80, suggesting that further replication and differentiation had occurred. PCR for the neogene was used to quantitate the amount of donor DNA in tissues from transplanted animals and confirmed that ER-MP20+ EMC preferentially engrafted. These data demonstrate that a mature monocytic cell gives rise to tissue macrophages. Because these cells can be expanded and manipulated in vitro, they may be a suitable target population for gene therapy of lysosomal storage diseases. PMID:9843995

  8. Recycling of plastic waste: Presence of phthalates in plastics from households and industry.

    PubMed

    Pivnenko, K; Eriksen, M K; Martín-Fernández, J A; Eriksson, E; Astrup, T F

    2016-08-01

    Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large volumes and are commonly used as plasticisers in plastics manufacturing. Potential impacts on human health require restricted use in selected applications and a need for the closer monitoring of potential sources of human exposure. Although the presence of phthalates in a variety of plastics has been recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP had the highest frequency of detection in the samples analysed, with 360μg/g, 460μg/g and 2700μg/g as the maximum measured concentrations, respectively. Among other, statistical analysis of the analytical results suggested that phthalates were potentially added in the later stages of plastic product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications is recommended if recycled plastics are to be used as raw material in production.

  9. Localization of mature neprilysin in lipid rafts.

    PubMed

    Sato, Kimihiko; Tanabe, Chiaki; Yonemura, Yoji; Watahiki, Haruhiko; Zhao, Yimeng; Yagishita, Sosuke; Ebina, Maiko; Suo, Satoshi; Futai, Eugene; Murata, Masayuki; Ishiura, Shoichi

    2012-04-01

    Alzheimer's disease (AD) is characterized by senile plaques caused by amyloid-β peptide (Aβ) accumulation. It has been reported that Aβ generation and accumulation occur in membrane microdomains, called lipid rafts, which are enriched in cholesterol and glycosphingolipids. Moreover, the ablation of cholesterol metabolism has been implicated in AD. Neprilysin (NEP), a neutral endopeptidase, is one of the major Aβ-degrading enzymes in the brain. Activation of NEP is a possible therapeutic target. However, it remains unknown whether the activity of NEP is regulated by its association with lipid rafts. Here we show that only the mature form of NEP, which has been glycosylated in the Golgi, exists in lipid rafts, where it is directly associated with phosphatidylserine. Moreover, the localization of NEP in lipid rafts is enhanced by its dimerization, as shown using the NEP E403C homodimerization mutant. However, the protease activities of the mature form of NEP, as assessed by in vitro peptide hydrolysis, did not differ between lipid rafts and nonlipid rafts. We conclude that cholesterol and other lipids regulate the localization of mature NEP to lipid rafts, where the substrate Aβ accumulates but does not modulate the protease activity of NEP.

  10. DNA damage response during mouse oocyte maturation

    PubMed Central

    Mayer, Alexandra; Baran, Vladimir; Sakakibara, Yogo; Brzakova, Adela; Ferencova, Ivana; Motlik, Jan; Kitajima, Tomoya S.; Schultz, Richard M.; Solc, Petr

    2016-01-01

    ABSTRACT Because low levels of DNA double strand breaks (DSBs) appear not to activate the ATM-mediated prophase I checkpoint in full-grown oocytes, there may exist mechanisms to protect chromosome integrity during meiotic maturation. Using live imaging we demonstrate that low levels of DSBs induced by the radiomimetic drug Neocarzinostatin (NCS) increase the incidence of chromosome fragments and lagging chromosomes but do not lead to APC/C activation and anaphase onset delay. The number of DSBs, represented by γH2AX foci, significantly decreases between prophase I and metaphase II in both control and NCS-treated oocytes. Transient treatment with NCS increases >2-fold the number of DSBs in prophase I oocytes, but less than 30% of these oocytes enter anaphase with segregation errors. MRE11, but not ATM, is essential to detect DSBs in prophase I and is involved in H2AX phosphorylation during metaphase I. Inhibiting MRE11 by mirin during meiotic maturation results in anaphase bridges and also increases the number of γH2AX foci in metaphase II.  Compromised DNA integrity in mirin-treated oocytes indicates a role for MRE11 in chromosome integrity during meiotic maturation. PMID:26745237

  11. Maturation modeling in Otway Basin, Australia

    SciTech Connect

    Middleton, M.F.; Falvey, D.A.

    1983-02-01

    The Otway basin is a Jurassic to Pliocene sedimentary basin formed on the southern Australian continental margin. Its formation is associated with rifting and breakup of the Australian and Antarctic plates. Lithospheric cooling and contraction have probably produced post-breakup subsidence. Either lithospheric stretching or deep crustal metamorphism may have produced pre-breakup subsidence. These mechanisms have identifiable thermal histories. Organic diagenesis (specifically the reflectance of vitrinite in oil) is empirically determined by the thermal and depositional history of an organic sediment. Thus, the stages of hydrocarbon maturity of Otway basin sediments can be modeled. Depositional history is determined from ''geohistory analysis'' and thermal history depends on the subsidence mechanism applied to the basin. A paleo-heat-flow history derived from the deep crustal metamorphism model of subsidence produces a maturation profile with depth that is consistent with observed vitrinite reflectance data, although organic diagenesis modeling is relatively insensitive to precise details of thermal history. Depositional and maturation history modeling for the present day, 20 Ma ago, 40 Ma ago, and 60 Ma ago is applied to a seismic profile across the southern Australian continental shelf in the Otway basin as a demonstration of the projection backward in time of sedimentation and organic diagenesis.

  12. Proteolysis regulates cardiomyocyte maturation and tissue integration

    PubMed Central

    Fukuda, Ryuichi; Gunawan, Felix; Beisaw, Arica; Jimenez-Amilburu, Vanesa; Maischein, Hans-Martin; Kostin, Sawa; Kawakami, Koichi; Stainier, Didier Y. R.

    2017-01-01

    Tissue integrity is critical for organ formation and function. During heart development, cardiomyocytes differentiate and integrate to form a coherent tissue that contracts synchronously. However, the molecular mechanisms regulating cardiac tissue integrity are poorly understood. Here we show that proteolysis, via the E3 ubiquitin ligase ASB2, regulates cardiomyocyte maturation and tissue integrity. Cardiomyocytes in asb2b zebrafish mutants fail to terminally differentiate, resulting in reduced cardiac contractility and output. Mosaic analyses reveal a cell-autonomous requirement for Asb2b in cardiomyocytes for their integration as asb2b mutant cardiomyocytes are unable to meld into wild-type myocardial tissue. In vitro and in vivo data indicate that ASB2 negatively regulates TCF3, a bHLH transcription factor. TCF3 must be degraded for cardiomyocyte maturation, as TCF3 gain-of-function causes a number of phenotypes associated with cardiomyocyte dedifferentiation. Overall, our results show that proteolysis has an important role in cardiomyocyte maturation and the formation of a coherent myocardial tissue. PMID:28211472

  13. The AGU Data Management Maturity Model Initiative

    NASA Astrophysics Data System (ADS)

    Bates, J. J.

    2015-12-01

    In September 2014, the AGU Board of Directors approved two initiatives to help the Earth and space sciences community address the growing challenges accompanying the increasing size and complexity of data. These initiatives are: 1) Data Science Credentialing: development of a continuing education and professional certification program to help scientists in their careers and to meet growing responsibilities and requirements around data science; and 2) Data Management Maturity (DMM) Model: development and implementation of a data management maturity model to assess process maturity against best practices, and to identify opportunities in organizational data management processes. Each of these has been organized within AGU as an Editorial Board and both Boards have held kick off meetings. The DMM model Editorial Board will recommend strategies for adapting and deploying a DMM model to the Earth and space sciences create guidance documents to assist in its implementation, and provide input on a pilot appraisal process. This presentation will provide an overview of progress to date in the DMM model Editorial Board and plans for work to be done over the upcoming year.

  14. Epigenetic mechanisms in pubertal brain maturation

    PubMed Central

    Morrison, Kathleen E.; Rodgers, Ali B.; Morgan, Christopher P.; Bale, Tracy L.

    2014-01-01

    Puberty is a critical period of development during which the reemergence of gonadotropin releasing hormone secretion from the hypothalamus triggers a cascade of hormone-dependent processes. Maturation of specific brain regions including the prefrontal cortex occurs during this window, but the complex mechanisms underlying these dynamic changes are not well understood. Particularly, the potential involvement of epigenetics in this programming has been under-examined. The epigenome is known to guide earlier stages of development, and it is similarly poised to regulate vital pubertal-driven brain maturation. Further, as epigenetic machinery is highly environmentally responsive, its involvement may also lend this period of growth to greater vulnerability to external insults, resulting in reprogramming and increased disease risk. Importantly, neuropsychiatric diseases commonly present in individuals during or immediately following puberty, and environmental perturbations including stress may precipitate disease onset by disrupting the normal trajectory of pubertal brain development via epigenetic mechanisms. In this review, we discuss epigenetic processes involved in pubertal brain maturation, the potential points of derailment, and the importance of future studies for understanding this dynamic developmental window and gaining a better understanding of neuropsychiatric disease risk. PMID:24239720

  15. The Mature Athlete’s Shoulder

    PubMed Central

    Tokish, John M.

    2014-01-01

    Context: The mature athlete’s shoulder remains a challenging clinical condition to manage. A normal natural history of the shoulder includes stiffness, rotator cuff tears, and osteoarthritis, all of which can become increasingly more symptomatic as an athlete ages. Evidence Acquisition: PubMed (1978-2013). Study Design: Clinical review. Level of Evidence: Level 3-4. Results: Rotator cuff pathology increases with age and activity level. Partial tears rarely heal, and debridement of significant partial tears results in poorer outcomes than those of repair. Repair of partial-thickness tears can be accomplished with completion and subsequent repair or in situ repair. The most successful result for treatment of osteoarthritis in the shoulder remains total shoulder arthroplasty, with more than 80% survival at 20 years and high rates of return to sport. Caution should be taken in patients younger than 60 years, as they show much worse results with this treatment. Adhesive capsulitis of the shoulder can be successfully treated with nonoperative management in 90% of cases. Conclusion: Mature athletes tend to have rotator cuff pathology, osteoarthritis, and stiffness, which may limit their participation in athletic events. Age is a significant consideration, even within the “mature athlete” population, as patients younger than 50 years should be approached differently than those older than 65 years with regard to treatment regimens and postoperative restriction. PMID:24427439

  16. Technology Maturation of Integrated System Health Management

    NASA Astrophysics Data System (ADS)

    Feather, Martin S.; Uckun, Serdar; Hicks, Kenneth A.

    2008-01-01

    Despite two decades of significant investments in R&D of Integrated System Health Management (ISHM), mission-critical applications of it in aerospace are few and far between. ISHM is subject to the general difficulty of transitioning technologies out of R&D labs and into practical applications. New and unproven methods such as ISHM introduce multiple mission risks (technology, schedule, cost), and may require a transition to unconventional and as-yet-unproven operations concepts in order to be effective. Laboratory and flight demonstrations are necessary but insufficient to adequately reduce those risks. What is needed is a solid business case before a new technology can be considered for fleetwide deployment. To address these problems, we recently applied a technology maturation assessment process developed at NASA's Jet Propulsion Laboratory to study the challenges of ISHM technology maturation. This application resulted in identification of the technologies (and technology maturation activities) that would result in the greatest risk reduction per investment dollar. Our approach and its results are described herein.

  17. Stem cells and somatic cells: reprogramming and plasticity.

    PubMed

    Estrov, Zeev

    2009-01-01

    Recent seminal discoveries have significantly advanced the field of stem cell research and received worldwide attention. Improvements in somatic cell nuclear transfer (SCNT) technology, enabling the cloning of Dolly the sheep, and the derivation and differentiation of human embryonic stem cells raised hopes that normal cells could be generated to replace diseased or injured tissue. At the same time, in vitro and in vivo studies demonstrated that somatic cells of one tissue are capable of generating cells of another tissue. It was theorized that any cell might be reprogrammed, by exposure to a new environment, to become another cell type. This concept contradicts two established hypotheses: (1) that only specific tissues are generated from the endoderm, mesoderm, and ectoderm and (2) that tissue cells arise from a rare population of tissue-specific stem cells in a hierarchical fashion. SCNT, cell fusion experiments, and most recent gene transfer studies also contradict these hypotheses, as they demonstrate that mature somatic cells can be reprogrammed to regain pluripotent (or even totipotent) stem cell capacity. On the basis of the stem cell theory, hierarchical cancer stem cell differentiation models have been proposed. Cancer cell plasticity is an established phenomenon that supports the notion that cellular phenotype and function might be altered. Therefore, mechanisms of cellular plasticity should be exploited and the clinical significance of the cancer stem cell theory cautiously assessed.

  18. Plastic and evolutionary responses to climate change in fish

    PubMed Central

    Crozier, Lisa G; Hutchings, Jeffrey A

    2014-01-01

    The physical and ecological ‘fingerprints’ of anthropogenic climate change over the past century are now well documented in many environments and taxa. We reviewed the evidence for phenotypic responses to recent climate change in fish. Changes in the timing of migration and reproduction, age at maturity, age at juvenile migration, growth, survival and fecundity were associated primarily with changes in temperature. Although these traits can evolve rapidly, only two studies attributed phenotypic changes formally to evolutionary mechanisms. The correlation-based methods most frequently employed point largely to ‘fine-grained’ population responses to environmental variability (i.e. rapid phenotypic changes relative to generation time), consistent with plastic mechanisms. Ultimately, many species will likely adapt to long-term warming trends overlaid on natural climate oscillations. Considering the strong plasticity in all traits studied, we recommend development and expanded use of methods capable of detecting evolutionary change, such as the long term study of selection coefficients and temporal shifts in reaction norms, and increased attention to forecasting adaptive change in response to the synergistic interactions of the multiple selection pressures likely to be associated with climate change. PMID:24454549

  19. Early Versus Late Maturation Arrest: Reproductive Outcomes of Testicular Failure

    PubMed Central

    Weedin, John W.; Bennett, Richard C.; Fenig, David M.; Lamb, Dolores J.; Lipshultz, Larry I.

    2013-01-01

    Purpose There is a paucity of data characterizing infertile men with maturation arrest. We hypothesized that men with early stage maturation arrest could be clinically distinguished from men with late maturation arrest and would have worse reproductive outcomes. Materials and Methods We retrospectively reviewed the records of all patients with nonobstructive azoospermia and cryptozoospermia who underwent testis mapping and sperm extraction from 2002 to 2009 and for whom histopathological findings were available. Patients had uniform maturation arrest if multiple biopsies revealed maturation arrest at the spermatogonia/spermatocyte (early maturation arrest) or the spermatid (late maturation arrest) stage. Clinical parameters and pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection were examined. Statistical analysis consisted of univariate and multivariate analysis. Results Uniform maturation arrest was identified in 49 of 219 men (22.3%) undergoing testicular sperm extraction. On multivariate analysis men with maturation arrest had significantly larger testes (p = 0.01), decreased follicle-stimulating hormone (p = 0.05) and more detectable genetic abnormalities (p = 0.01) than men with other histopathological conditions. Men with late maturation arrest had decreased follicle-stimulating hormone (p = 0.02), increased testosterone (p = 0.03) and a higher sperm retrieval rate at testicular sperm extraction (p = 0.01) than men with early maturation arrest. Predictors of successful sperm retrieval were larger testes, cryptozoospermia, late maturation arrest and hypospermatogenesis (each p ≤0.05). Pregnancy outcomes for men with maturation arrest were not significantly different from those for men with other histopathological conditions. Conclusions Maturation arrest is a common, diverse histopathological subtype of severe male infertility. Compared to men with late maturation arrest those with early maturation arrest have increased follicle

  20. Nutritional tryptophan restriction impairs plasticity of retinotectal axons during the critical period.

    PubMed

    Penedo, Letícia Abel; Oliveira-Silva, Priscilla; Gonzalez, Ericka M C; Maciel, Rafaela; Jurgilas, Patricia B; Melibeu, Adriana da Cunha Faria; Campello-Costa, Paula; Serfaty, Claudio Alberto

    2009-05-01

    The use-dependent specification of neural circuits occurs during post-natal development with a conspicuous influence of environmental factors, such as malnutrition that interferes with the major steps of brain maturation. Serotonin (5-HT), derived exclusively from the essential aminoacid tryptophan, is involved in mechanisms of development and use-dependent plasticity of the central nervous system. We studied the effects of the nutritional restriction of tryptophan in the plasticity of uncrossed retinotectal axons following a retinal lesion to the contralateral retina during the critical period in pigmented rats. Litters were fed through their mothers with a low tryptophan content diet, based on corn and gelatin, a complemented diet with standard tryptophan requirements for rodents or standard laboratory diet. The results suggest a marked reduction in the plasticity of intact axons into denervated territories in the tryptophan restricted group in comparison to control groups. Tryptophan complementation between PND10-21 completely restored retinotectal plasticity. However, the re-introduction of tryptophan after the end of the critical period (between PND28-P41) did not restore the sprouting ability of uncrossed axons suggesting a time-dependent effect to the reversion of plasticity deficits. Tryptophan-restricted animals showed a reduced activity of matrix metalloproteinase-9 and altered expressions of phosphorylated forms of ERK1/2 and AKT. Our results demonstrate the influence of this essential aminoacid as a modulator of neural plasticity during the critical period through the reduction of serotonin content which alters plasticity-related signaling pathways and matrix degradation.

  1. A review of plastic waste biodegradation.

    PubMed

    Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

    2005-01-01

    With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

  2. Adaptive plasticity and niche expansion in an invasive thistle.

    PubMed

    Turner, Kathryn G; Fréville, Hélène; Rieseberg, Loren H

    2015-08-01

    Phenotypic differentiation in size and fecundity between native and invasive populations of a species has been suggested as a causal driver of invasion in plants. Local adaptation to novel environmental conditions through a micro-evolutionary response to natural selection may lead to phenotypic differentiation and fitness advantages in the invaded range. Local adaptation may occur along a stress tolerance trade-off, favoring individuals that, in benign conditions, shift resource allocation from stress tolerance to increased vigor and fecundity and, therefore, invasiveness. Alternately, the typically disturbed invaded range may select for a plastic, generalist strategy, making phenotypic plasticity the main driver of invasion success. To distinguish between these hypotheses, we performed a field common garden and tested for genetically based phenotypic differentiation, resource allocation shifts in response to water limitation, and local adaptation to the environmental gradient which describes the source locations for native and invasive populations of diffuse knapweed (Centaurea diffusa). Plants were grown in an experimental field in France (naturalized range) under water addition and limitation conditions. After accounting for phenotypic variation arising from environmental differences among collection locations, we found evidence of genetic variation between the invasive and native populations for most morphological and life-history traits under study. Invasive C. diffusa populations produced larger, later maturing, and therefore potentially fitter individuals than native populations. Evidence for local adaptation along a resource allocation trade-off for water limitation tolerance is equivocal. However, native populations do show evidence of local adaptation to an environmental gradient, a relationship which is typically not observed in the invaded range. Broader analysis of the climatic niche inhabited by the species in both ranges suggests that the

  3. Maturation and demise of human primary monocytes by carbon nanotubes

    NASA Astrophysics Data System (ADS)

    De Nicola, Milena; Mirabile Gattia, Daniele; Traversa, Enrico; Ghibelli, Lina

    2013-06-01

    The possibility of exploiting carbon nanotubes (CNT) in biomedical practices requires thorough analysis of the chemical or bulk effects they may exert on the immune system, the complex network that recognizes and eliminates foreign particles. In particular, the phagocytosing ability of cells belonging to the monocyte/macrophage lineage may render these immune cells an ideal toxicological target of pristine CNT, which may form aggregates of size exceeding monocyte/macrophage phagocytosing plasticity. To shed light on this issue, we analyzed the effects that pristine multi-walled CNT (MWCNT) without metal or biological impurities exert on survival and activation of freshly explanted human peripheral blood monocytes, analyzing in parallel the non-phagocytosing lymphocytes, and using graphite as control carbon material. MWCNT (diameter 10-50 nm, length up to 10 μm) exert two different toxic effects on mononuclear leukocytes: a minor apoptogenic effect (on lymphocytes > monocytes), and a major, apoptosis-independent effect that exclusively and deeply affect monocyte homeostasis. Analysis of monocyte number, adhesion, redox equilibrium, and the differentiation markers CD14 and CD11b reveals that MWCNT cause the selective disappearance of phagocytosis-competent monocytes by mechanisms related to the presence of large nanoparticle aggregates, suggesting phenomena of bulk toxicity possibly consisting of frustrated phagocytosis. At the same time, MWCNT stimulate adhesion of the phagocytosis-incompetent monocytes, and their differentiation toward a peculiar maturation asset. These observations point out novel mechanisms of CNT toxicity, renewing concerns that they may impair the innate immune system deranging the inflammatory responses.

  4. Characterization of plastic blends made from mixed plastics waste of different sources.

    PubMed

    Turku, Irina; Kärki, Timo; Rinne, Kimmo; Puurtinen, Ari

    2017-02-01

    This paper studies the recyclability of construction and household plastic waste collected from local landfills. Samples were processed from mixed plastic waste by injection moulding. In addition, blends of pure plastics, polypropylene and polyethylene were processed as a reference set. Reference samples with known plastic ratio were used as the calibration set for quantitative analysis of plastic fractions in recycled blends. The samples were tested for the tensile properties; scanning electron microscope-energy-dispersive X-ray spectroscopy was used for elemental analysis of the blend surfaces and Fourier transform infrared (FTIR) analysis was used for the quantification of plastics contents.

  5. 7 CFR 51.1555 - Fairly well matured.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ....1555 Fairly well matured. Fairly well matured means that the skins of the potatoes are generally fairly firmly set and not more than 10 percent of the potatoes in the lot have more than one-fourth of the...

  6. 7 CFR 51.1555 - Fairly well matured.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....1555 Fairly well matured. Fairly well matured means that the skins of the potatoes are generally fairly firmly set and not more than 10 percent of the potatoes in the lot have more than one-fourth of the...

  7. Moral Judgment Maturity of Process and Reactive Schizophrenics.

    ERIC Educational Resources Information Center

    Herron, William G.; And Others

    1983-01-01

    Premorbid adjustment, paranoid symptomatology, and orientation were examined as major predictors of moral judgment maturity in 40 schizophrenics. Results suggest the importance of cognitive and social skills in the development of schizophrenics' moral judgment maturity. (Author/RH)

  8. Hormone-induced cortical maturation ensures the slow block to polyspermy and does not couple with meiotic maturation in starfish.

    PubMed

    Hirohashi, Noritaka; Harada, Kaori; Chiba, Kazuyoshi

    2008-06-01

    Meiotic progression in starfish oocytes is reinitiated by a maturation-inducing hormone called 1-methyladenine (1-MeAde). In addition to meiotic maturation, 1-MeAde induces cortical maturation in which cortical granules become competent to discharge in response to fusion of a single sperm, which results in the formation of the fertilization envelope. We found that subthreshold concentrations of 1-MeAde induce cortical maturation without germinal vesicle breakdown (GVBD). During cortical maturation, the IP3 sensitivity of calcium stores was increased as well as during meiotic maturation. When oocytes were exposed with 1-MeAde only on a hemisphere of oocytes, the IP3 sensitivity of the cortical region was increased only in the exposed hemisphere, suggesting that signals and components involved in cortical maturation do not readily spread in the cytoplasm. Although a specific inhibitor of phosphatidylinositol-3 kinase, LY294002 blocked both GVBD and cortical maturation, a Cdc2 kinase inhibitor, roscovitine did not block cortical maturation. Inhibition of Akt activation by injecting the competitors for Akt phosphorylation and membrane recruitment also blocked cortical maturation. These results suggest that the signaling pathway leading to Akt activation is common in cortical maturation and meiotic maturation, and Cdc2 activation was not required for cortical maturation.

  9. Epigenetics of memory and plasticity.

    PubMed

    Woldemichael, Bisrat T; Bohacek, Johannes; Gapp, Katharina; Mansuy, Isabelle M

    2014-01-01

    Although all neurons carry the same genetic information, they vary considerably in morphology and functions and respond differently to environmental conditions. Such variability results mostly from differences in gene expression. Among the processes that regulate gene activity, epigenetic mechanisms play a key role and provide an additional layer of complexity to the genome. They allow the dynamic modulation of gene expression in a locus- and cell-specific manner. These mechanisms primarily involve DNA methylation, posttranslational modifications (PTMs) of histones and noncoding RNAs that together remodel chromatin and facilitate or suppress gene expression. Through these mechanisms, the brain gains high plasticity in response to experience and can integrate and store new information to shape future neuronal and behavioral responses. Dynamic epigenetic footprints underlying the plasticity of brain cells and circuits contribute to the persistent impact of life experiences on an individual's behavior and physiology ranging from the formation of long-term memory to the sequelae of traumatic events or of drug addiction. They also contribute to the way lifestyle, life events, or exposure to environmental toxins can predispose an individual to disease. This chapter describes the most prominent examples of epigenetic marks associated with long-lasting changes in the brain induced by experience. It discusses the role of epigenetic processes in behavioral plasticity triggered by environmental experiences. A particular focus is placed on learning and memory where the importance of epigenetic modifications in brain circuits is best understood. The relevance of epigenetics in memory disorders such as dementia and Alzheimer's disease is also addressed, and promising perspectives for potential epigenetic drug treatment discussed.

  10. On the plastic buckling paradox

    SciTech Connect

    Blachut, J.; Galletly, G.D.; James, S.

    1995-12-31

    Previous investigations, at various laboratories, have raised doubts about the accuracy of flow theory predictions in some plastic plate and shell buckling problems. The present series of buckling experiments on near-perfect, machined, mild steel, cylindrical shell models under biaxial loading (axial tension plus external pressure) was designed to provide additional data for the evaluation of (the J{sub 2}) plasticity theories. Numerical calculations were carried out with the Bosor5 shell buckling program, using the J{sub 2} deformation and flow theories, and these were compared with the test results. Thirty-one cylinders, about 0.05 m in diameter with length to diameter ratio (L/D) of 1.0, 1.5 and 2.0 and diameter to thickness ratio (D/t) of 50 were tested in the programme. The steel was BS 970 grade 070 M20 and came in the form of a 3 m long x 0.070 m dia bar. Each cylinder had an integral flange of 0.013m. A rotating probe was employed to monitor the pre-buckling and buckling deformations. The tests were similar to that of Giezen, Babcock and Singer (1991). However, the current tests were on machined models and the axial tension was applied in a different manner. The tests, by Giezen et al, were on drawn aluminum alloy tubes from stock One of our objectives was to see if reducing the initial geometric imperfections had any significant effect on results. All tests have been carried out by now and computations are near completion. The main conclusion appears to be that for this combined loading plastic buckling problem, the deformation theory predictions are confirmed by the experiment.

  11. Plastic Deformation of Accreted Planetesimals

    NASA Astrophysics Data System (ADS)

    Kadish, J.

    2005-08-01

    The early stages of planetesimal growth follow an accretion model (Weidenschilling, Icarus 2000), which influences the intrinsic strength of a body and may control how its shape evolves after growth. In previous work we have determined the stress field of an accreted planetesimal accounting for possible variation in the object's spin as it accretes (Kadish et al., IJSS In Press) At the end of growth, these objects are subject to transport mechanisms that can distribute them throughout the solar system. As they are transported these objects can be spun-up by tidal forces (Scheeres et al, Icarus 2000), YORP (Bottke et al., Asteroids III 2002), and collisions (Binzel et al., Asteroids II 1989). Such an increase of spin will cause perturbations to the initial stress field and may lead to failure. We are able to show analytically that failure is initiated on the object's surface and a plastic zone propagates inward as the object's spin is increased. If we model an accreted body as a conglomeration of rocks similar to a gravel or sand, the deformation in the region of failure is characterized using a Mohr-Coulomb failure criterion with negligible cohesion and zero hardening(e.g. Holsapple, Icarus 2001). Such a response is highly non-linear and must be solved using finite elements and iterative methods (Simo and Hughes, Computational Inelasticity 1998). Using the commercial finite element code ABAQUS, we present the shape deformation resulting from an elasto-plastic analysis of a spinning, self-gravitating accreted sphere that is spun-up after growth is complete. The methodology can be extended to model plastic deformation due to local failure for more complex planetesimal shapes, such as for the asteroid Kleopatra. This work has implications for the evolution of planetesimal shapes, the creation of binary and contact binary asteroids, and for the maximum spin rate of small planetary bodies.

  12. How to Be a Better Consumer of Security Maturity Models

    DTIC Science & Technology

    2014-10-21

    cybersecurity and resilience domains • Be aware of caution flags when dealing with maturity models • Determine how to choose the right model for your... cybersecurity program? Maturity Models Member Query 17 Maturity Models Member Query – Q1 Have you or your organization ever used any type of maturity...networked systems CERT – Anticipating and solving our nation’s cybersecurity challenges • Largest technical program at SEI • Focused on internet

  13. Everything You Always Wanted to Know About Maturity Models

    DTIC Science & Technology

    2014-01-23

    Types of Maturity Models • Examples of Maturity Models 11 © 2014 Carnegie Mellon University Maturity Model Defined An organized way to convey a...path of experience, wisdom, perfection, or acculturation . Depicts an evolutionary progression of an attribute, characteristic, pattern, or...practice. The subject of a maturity model can be objects or things, ways of doing something, characteristics of something, practices, controls, or

  14. Glassy features of crystal plasticity

    NASA Astrophysics Data System (ADS)

    Lehtinen, Arttu; Costantini, Giulio; Alava, Mikko J.; Zapperi, Stefano; Laurson, Lasse

    2016-08-01

    Crystal plasticity occurs by deformation bursts due to the avalanchelike motion of dislocations. Here we perform extensive numerical simulations of a three-dimensional dislocation dynamics model under quasistatic stress-controlled loading. Our results show that avalanches are power-law distributed and display peculiar stress and sample size dependence: The average avalanche size grows exponentially with the applied stress, and the amount of slip increases with the system size. These results suggest that intermittent deformation processes in crystalline materials exhibit an extended critical-like phase in analogy to glassy systems instead of originating from a nonequilibrium phase transition critical point.

  15. Plasticity of hematopoietic stem cells.

    PubMed

    Ogawa, Makio; LaRue, Amanda C; Mehrotra, Meenal

    2015-01-01

    Almost two decades ago, a number of cell culture and preclinical transplantation studies suggested the striking concept of the tissue-reconstituting ability of hematopoietic stem cells (HSCs). While this heralded an exciting time of radically new therapies for disorders of many organs and tissues, the concept was soon mired by controversy and remained dormant. This chapter provides a brief review of evidence for HSC plasticity including our findings based on single HSC transplantation in mouse. These studies strongly support the concept that HSCs are pluripotent and may be the source for the majority, if not all, of the cell types in our body.

  16. Constraints on the evolution of phenotypic plasticity: limits and costs of phenotype and plasticity.

    PubMed

    Murren, C J; Auld, J R; Callahan, H; Ghalambor, C K; Handelsman, C A; Heskel, M A; Kingsolver, J G; Maclean, H J; Masel, J; Maughan, H; Pfennig, D W; Relyea, R A; Seiter, S; Snell-Rood, E; Steiner, U K; Schlichting, C D

    2015-10-01

    Phenotypic plasticity is ubiquitous and generally regarded as a key mechanism for enabling organisms to survive in the face of environmental change. Because no organism is infinitely or ideally plastic, theory suggests that there must be limits (for example, the lack of ability to produce an optimal trait) to the evolution of phenotypic plasticity, or that plasticity may have inherent significant costs. Yet numerous experimental studies have not detected widespread costs. Explicitly differentiating plasticity costs from phenotype costs, we re-evaluate fundamental questions of the limits to the evolution of plasticity and of generalists vs specialists. We advocate for the view that relaxed selection and variable selection intensities are likely more important constraints to the evolution of plasticity than the costs of plasticity. Some forms of plasticity, such as learning, may be inherently costly. In addition, we examine opportunities to offset costs of phenotypes through ontogeny, amelioration of phenotypic costs across environments, and the condition-dependent hypothesis. We propose avenues of further inquiry in the limits of plasticity using new and classic methods of ecological parameterization, phylogenetics and omics in the context of answering questions on the constraints of plasticity. Given plasticity's key role in coping with environmental change, approaches spanning the spectrum from applied to basic will greatly enrich our understanding of the evolution of plasticity and resolve our understanding of limits.

  17. Tunable plasticity in amorphous silicon carbide films.

    PubMed

    Matsuda, Yusuke; Kim, Namjun; King, Sean W; Bielefeld, Jeff; Stebbins, Jonathan F; Dauskardt, Reinhold H

    2013-08-28

    Plasticity plays a crucial role in the mechanical behavior of engineering materials. For instance, energy dissipation during plastic deformation is vital to the sufficient fracture resistance of engineering materials. Thus, the lack of plasticity in brittle hybrid organic-inorganic glasses (hybrid glasses) often results in a low fracture resistance and has been a significant challenge for their integration and applications. Here, we demonstrate that hydrogenated amorphous silicon carbide films, a class of hybrid glasses, can exhibit a plasticity that is even tunable by controlling their molecular structure and thereby leads to an increased and adjustable fracture resistance in the films. We decouple the plasticity contribution from the fracture resistance of the films by estimating the "work-of-fracture" using a mean-field approach, which provides some insight into a potential connection between the onset of plasticity in the films and the well-known rigidity percolation threshold.

  18. Evolution of environmental cues for phenotypic plasticity.

    PubMed

    Chevin, Luis-Miguel; Lande, Russell

    2015-10-01

    Phenotypically plastic characters may respond to multiple variables in their environment, but the evolutionary consequences of this phenomenon have rarely been addressed theoretically. We model the evolution of linear reaction norms in response to several correlated environmental variables, in a population undergoing stationary environmental fluctuations. At evolutionary equilibrium, the linear combination of environmental variables that acts as a developmental cue for the plastic trait is the multivariate best linear predictor of changes in the optimum. However, the reaction norm with respect to any single environmental variable may exhibit nonintuitive patterns. Apparently maladaptive, or hyperadaptive plasticity can evolve with respect to single environmental variables, and costs of plasticity may increase, rather than reduce, plasticity in response to some variables. We also find conditions for the evolution of an indirect environmental indicator that affects expression of a plastic phenotype, despite not influencing natural selection on it.

  19. Applications and societal benefits of plastics

    PubMed Central

    Andrady, Anthony L.; Neal, Mike A.

    2009-01-01

    This article explains the history, from 1600 BC to 2008, of materials that are today termed ‘plastics’. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years. PMID:19528050

  20. Drug information systems: evolution of benefits with system maturity.

    PubMed

    Leung, Valerie; Hagens, Simon; Zelmer, Jennifer

    2013-01-01

    Benefits from information and communication technology tend to grow over time as system use matures. This study examines pharmacists' experiences with provincial drug information systems (DIS) across Canada. At the time of survey, two provinces had more mature DIS (more than five years) and three provinces had less mature DIS (five years or less).

  1. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  2. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  3. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  4. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  5. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  6. The Relationship between Attitudinal and Behavioral Aspects of Career Maturity.

    ERIC Educational Resources Information Center

    Fouad, Nadya A.; Keeley, Timothy J.

    1992-01-01

    Investigated whether a meaningful relationship existed between an attitudinal measure of career maturity and a measure of career maturity reflecting job performance-related behavioral competencies in African-American high school students (n=74). Only modest relationships were found between several career maturity attitudes and behavioral measures.…

  7. Sex Differences in a Causal Model of Career Maturity.

    ERIC Educational Resources Information Center

    King, Suzanne

    1989-01-01

    Studied sex differences among high school students (N=318) in career development process to determine whether sex differences exist in way six independent variables interact in career maturity causal model of career maturity and to compare each variable's effect on career maturity. Results suggest significant sex differences consistent with…

  8. Career Maturity of Emotionally Maladjusted High School Students.

    ERIC Educational Resources Information Center

    Karayanni, Mousa

    1981-01-01

    The Career Maturity Inventory Scale was used to investigate the vocational maturity of emotionally maladjusted and well-adjusted high school students. Results indicated a significant difference in career maturity between the two groups. Sex, class, and race differences were also examined. (RC)

  9. Damage Diagnosis for Elasto-Plastic Structures.

    DTIC Science & Technology

    1986-12-01

    nonsta- tionary. The stiffness matrix is nonlinear to simulate the elasto-plastic behavior of a damaged structure. The stiffness matrix is also random...23 3.2 Small length cut from a beam .... ............... . 24 3.3 Stress-strain curve of elasto-plastic material ...... . 26...excitation. The stiffness matrix is nonlinear to simulate the elasto-plastic behavior of a damaged structure. The stiffness matrix is also random to

  10. Plastic Recycling Experiments in Materials Education

    NASA Technical Reports Server (NTRS)

    Liu, Ping; Waskom, Tommy L.

    1996-01-01

    The objective of this project was to introduce a series of plastic recycling experiments to students in materials-related courses such as materials science, material technology and materials testing. With the plastic recycling experiments, students not only can learn the fundamentals of plastic processing and properties as in conventional materials courses, but also can be exposed to the issue of materials life cycle and the impact on society and environment.

  11. Altered postnatal maturation of striatal GABAergic interneurons in a phenotypic animal model of dystonia.

    PubMed

    Bode, Christoph; Richter, Franziska; Spröte, Christine; Brigadski, Tanja; Bauer, Anne; Fietz, Simone; Fritschy, Jean-Marc; Richter, Angelika

    2017-01-01

    GABAergic disinhibition has been suggested to play a critical role in the pathophysiology of several basal ganglia disorders, including dystonia, a common movement disorder. Previous studies have shown a deficit of striatal GABAergic interneurons (IN) in the dt(sz) mutant hamster, one of the few phenotypic animal models of dystonia. However, mechanisms underlying this deficit are largely unknown. In the present study, we investigated the migration and maturation of striatal IN during postnatal development (18days of age) and at age of highest severity of dystonia (33days of age) in this hamster model. In line with previous findings, the density of GAD67-positive IN and the level of parvalbumin mRNA, a marker for fast spiking GABAergic IN, were lower in the dt(sz) mutant than in control hamsters. However, an unaltered density of Nkx2.1 labeled cells and Nkx2.1 mRNA level suggested that the migration of GABAergic IN into the striatum was not retarded. Therefore, different factors that indicate maturation of GABAergic IN were determined. While mRNA of the KCC2 cation/chloride transporters and the cytosolic carboanhydrase VII, used as markers for the so called GABA switch, as well as BDNF were unaltered, we found a reduced number of IN expressing the alpha1 subunit of the GABAA-receptor (37.5%) in dt(sz) hamsters at an age of 33days, but not after spontaneous remission of dystonia at an age of 90days. Since IN shift expression from alpha2 to alpha1 subunits during postnatal maturation, this result together with a decreased parvalbumin mRNA expression suggest a delayed maturation of striatal GABAergic IN in this animal model, which might underlie abnormal neuronal activity and striatal plasticity.

  12. Exogenous t-PA Administration Increases Hippocampal Mature BDNF Levels. Plasmin- or NMDA-Dependent Mechanism?

    PubMed Central

    Rodier, Marion; Prigent-Tessier, Anne; Béjot, Yannick; Jacquin, Agnès; Mossiat, Claude; Marie, Christine; Garnier, Philippe

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA)/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA) receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (r)t-PA administration on brain BDNF metabolism in rats. In the hippocampus, we found that rt-PA (10 mg/kg) administration induced a progressive increase in mature BDNF levels associated with TrkB activation. In order to delineate the mechanistic involved, plasmin activity was assessed and its inhibition was attempted using tranexamic acid (30 or 300 mg/kg, i.v.) while NMDA receptors were antagonized with MK801 (0.3 or 3 mg/kg, i.p.) in combination with rt-PA treatment. Our results showed that despite a rise in rt-PA activity, rt-PA administration failed to increase hippocampal plasmin activity suggesting that the plasminogen/plasmin system is not involved whereas MK801 abrogated the augmentation in mature BDNF levels observed after rt-PA administration. All together, our results show that rt-PA administration induces increase in hippocampal mature BDNF expression and suggests that rt-PA contributes to the control of brain BDNF synthesis through a plasmin-independent potentiation of NMDA receptors signaling. PMID:24670989

  13. Maturation of 6S regulatory RNA to a highly elongated structure.

    PubMed

    Fadouloglou, Vasiliki E; Lin, Hong-Tin V; Tria, Giancarlo; Hernández, Helena; Robinson, Carol V; Svergun, Dmitri I; Luisi, Ben F

    2015-12-01

    As bacterial populations leave the exponential growth phase and enter the stationary phase, their patterns of gene expression undergo marked changes. A key effector of this change is 6S RNA, which is a highly conserved regulatory RNA that impedes the transcription of genes associated with exponential growth by forming an inactivating ternary complex with RNA polymerase and sigma factor σ(70) (σ(70)-RNAP). In Escherichia coli, the endoribonuclease RNase E generates 6S RNA by specific cleavage of a precursor that is nearly twice the size of the 58 kDa mature form. We have explored recognition of the precursor by RNase E, and observed that processing is inhibited under conditions of excess substrate. This finding supports a largely distributive mechanism, meaning that each round of catalysis results in enzyme dissociation and re-binding to the substrate. We show that the precursor molecule and the mature 6S share a structural core dominated by an A-type helix, indicating that processing is not accompanied by extensive refolding. Both precursor and mature forms of 6S have a highly stable secondary structure, adopt an elongated shape, and show the potential to form dimers under specific conditions; nonetheless, 6S has a high structural plasticity that probably enables it to be structurally adapted upon binding to its cognate protein partners. Analysis of the 6S-σ(70)-RNAP complex by native mass spectrometry reveals a stable association with a stoichiometry of 1:1:1. A theoretical 3D model of mature 6S is presented, which is consistent with the experimental data and supports a previously proposed structure with a small stem-loop inside the central bubble.

  14. Input-specific regulation of hippocampal circuit maturation by non-muscle Myosin IIB

    PubMed Central

    Ozkan, Emin D.; Aceti, Massimiliano; Creson, Thomas K.; Rojas, Camilo S.; Hubbs, Cristopher; McGuire, Megan N.; Kakad, Priyanka P.; Miller, Courtney A.; Rumbaugh, Gavin

    2015-01-01

    Myh9 and Myh10, which encode two major isoforms of non-muscle myosin II expressed in the brain, have emerged as risk factors for developmental brain disorders. Myosin II motors regulate neuronal cytoskeletal dynamics leading to optimization of synaptic plasticity and memory formation. However, the role of these motor complexes in brain development remains poorly understood. Here, we disrupted the in vivo expression of Myh9 and/or Myh10 in developing hippocampal neurons to determine how these motors contribute to circuit maturation in this brain area important for cognition. We found that Myh10 ablation in early postnatal, but not mature, CA1 pyramidal neurons reduced excitatory synaptic function in the Schaffer collateral pathway, while more distal inputs to CA1 neurons were relatively unaffected. Myh10 ablation in young neurons also selectively impaired the elongation of oblique dendrites that receive Schaffer collateral inputs, while the structure of distal dendrites was normal. We observed normal spine density and spontaneous excitatory currents in these neurons, indicating that Myh10 KO impaired proximal pathway synaptic maturation through disruptions to dendritic development rather than postsynaptic strength or spine morphogenesis. To address possible redundancy and/or compensation by other Myosin II motors expressed in neurons, we performed similar experiments in Myh9 null neurons. In contrast to findings in Myh10 mutants, evoked synaptic function in young Myh9 KO hippocampal neurons was normal. Data obtained from double Myh9/Myh10 KO neurons largely resembled the MyH10 KO synaptic phenotype. These data indicate that Myosin IIB is a key molecular factor that guides input-specific circuit maturation in the developing hippocampus. PMID:25931194

  15. Exogenous t-PA administration increases hippocampal mature BDNF levels. plasmin- or NMDA-dependent mechanism?

    PubMed

    Rodier, Marion; Prigent-Tessier, Anne; Béjot, Yannick; Jacquin, Agnès; Mossiat, Claude; Marie, Christine; Garnier, Philippe

    2014-01-01

    Brain-derived neurotrophic factor (BDNF) through TrkB activation is central for brain functioning. Since the demonstration that plasmin is able to process pro-BDNF to mature BDNF and that these two forms have opposite effects on neuronal survival and plasticity, a particular attention has been paid to the link between tissue plasminogen activator (tPA)/plasmin system and BDNF metabolism. However, t-PA via its action on different N-methyl-D-aspartate (NMDA) receptor subunits is also considered as a neuromodulator of glutamatergic transmission. In this context, the aim of our study was to investigate the effect of recombinant (r)t-PA administration on brain BDNF metabolism in rats. In the hippocampus, we found that rt-PA (10 mg/kg) administration induced a progressive increase in mature BDNF levels associated with TrkB activation. In order to delineate the mechanistic involved, plasmin activity was assessed and its inhibition was attempted using tranexamic acid (30 or 300 mg/kg, i.v.) while NMDA receptors were antagonized with MK801 (0.3 or 3 mg/kg, i.p.) in combination with rt-PA treatment. Our results showed that despite a rise in rt-PA activity, rt-PA administration failed to increase hippocampal plasmin activity suggesting that the plasminogen/plasmin system is not involved whereas MK801 abrogated the augmentation in mature BDNF levels observed after rt-PA administration. All together, our results show that rt-PA administration induces increase in hippocampal mature BDNF expression and suggests that rt-PA contributes to the control of brain BDNF synthesis through a plasmin-independent potentiation of NMDA receptors signaling.

  16. Potential for plastics to transport hydrophobic contaminants.

    PubMed

    Teuten, Emma L; Rowland, Steven J; Galloway, Tamara S; Thompson, Richard C

    2007-11-15

    Plastic debris litters marine and terrestrial habitats worldwide. It is ingested by numerous species of animals, causing deleterious physical effects. High concentrations of hydrophobic organic contaminants have also been measured on plastic debris collected from the environment, but the fate of these contaminants is poorly understood. Here, we examine the uptake and subsequent release of phenanthrene by three plastics. Equilibrium distribution coefficients for sorption of phenanthrene from seawater onto the plastics varied by more than an order of magnitude (polyethylene > polypropylene > polyvinyl chloride (PVC)). In all cases, sorption to plastics greatly exceeded sorption to two natural sediments. Desorption rates of phenanthrene from the plastics or sediments back into solution spanned several orders of magnitude. As expected, desorption occurred more rapidly from the sediments than from the plastics. Using the equilibrium partitioning method, the effects of adding very small quantities of plastic with sorbed phenanthrene to sediment inhabited by the lugworm (Arenicola marina) were evaluated. We estimate that the addition of as little as 1 microg of contaminated polyethylene to a gram of sediment would give a significant increase in phenanthrene accumulation by A. marina. Thus, plastics may be important agents in the transport of hydrophobic contaminants to sediment-dwelling organisms.

  17. Extruded plastic scintillator for MINERvA

    SciTech Connect

    Pla-Dalmau, Anna; Bross, Alan D.; Rykalin, Victor V.; Wood, Brian M.; /NICADD, DeKalb

    2005-11-01

    An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here.

  18. Plastics on the Sargasso sea surface.

    PubMed

    Carpenter, E J; Smith, K L

    1972-03-17

    Plastic particles, in concentrations averaging 3500 pieces and 290 grams per square kilometer, are widespread in the western Sargasso Sea. Pieces are brittle, apparently due to the weathering of the plasticizers, and many are in a pellet shape about 0.25 to 0.5 centimeters in diameter. The particles are surfaces for the attachment of diatoms and hydroids. Increasing production of plastics, combined with present waste-disposal practices, will undoubtedly lead to increases in the concentration of these particles. Plastics could be a source of some of the polychlorinated biphenyls recently observed in oceanic organisms.

  19. Phenotypic plasticity: molecular mechanisms and adaptive significance.

    PubMed

    Kelly, Scott A; Panhuis, Tami M; Stoehr, Andrew M

    2012-04-01

    Phenotypic plasticity can be broadly defined as the ability of one genotype to produce more than one phenotype when exposed to different environments, as the modification of developmental events by the environment, or as the ability of an individual organism to alter its phenotype in response to changes in environmental conditions. Not surprisingly, the study of phenotypic plasticity is innately interdisciplinary and encompasses aspects of behavior, development, ecology, evolution, genetics, genomics, and multiple physiological systems at various levels of biological organization. From an ecological and evolutionary perspective, phenotypic plasticity may be a powerful means of adaptation and dramatic examples of phenotypic plasticity include predator avoidance, insect wing polymorphisms, the timing of metamorphosis in amphibians, osmoregulation in fishes, and alternative reproductive tactics in male vertebrates. From a human health perspective, documented examples of plasticity most commonly include the results of exercise, training, and/or dieting on human morphology and physiology. Regardless of the discipline, phenotypic plasticity has increasingly become the target of a plethora of investigations with the methodological approaches utilized ranging from the molecular to whole organsimal. In this article, we provide a brief historical outlook on phenotypic plasticity; examine its potential adaptive significance; emphasize recent molecular approaches that provide novel insight into underlying mechanisms, and highlight examples in fishes and insects. Finally, we highlight examples of phenotypic plasticity from a human health perspective and underscore the use of mouse models as a powerful tool in understanding the genetic architecture of phenotypic plasticity.

  20. Interaction between vegetable oil based plasticizer molecules and polyvinyl chloride, and their plasticization effect

    NASA Astrophysics Data System (ADS)

    Haryono, Agus; Triwulandari, Evi; Jiang, Pingping

    2017-01-01

    Plasticizer molecules are low molecular weight compounds that are widely used in polymer industries especially in polyvinyl chloride (PVC) resin. As an additive in PVC resin, the important role of plasticizer molecules is to improve the flexibility and processability of PVC by lowering the glass transition temperature (Tg). However, the commercial plasticizer like di(2-ethylhexyl)phthalate (DEHP) is known to cause liver cancer, at least in laboratory rats. DEHP can leach out from PVC into blood, certain drug solutions and fatty foods, which has been detected in the bloodstream of patients undergoing transfusion. Vegetable oil based plasticizers have some attractive properties such as non-toxic, bio-degradable, good heat and light stability, renewable resources, and environmentally friendly. Here we discussed the main results and development of vegetable oil based plasticizer, and especially palm oil based plasticizer. The interaction between plasticizer and polymer was discussed from the properties of the plasticized polymeric material.

  1. Megakaryopoiesis: transcriptional insights into megakaryocyte maturation.

    PubMed

    Kostyak, John Creigh; Naik, Ulhas Pandurang

    2007-01-01

    Platelets are small anucleate cells that travel near the vessel wall during laminar flow. In response to vascular injury, platelets undergo alterations in morphology which allow them to aggregate and cover the injured site. Platelets are produced by megakaryocytes in a process that involves the formation of platelet precursors called proplatelets and subsequent release of these proplatelets into the circulation. By forming a demarcation membrane system within the cytosol, megakaryocytes contain a membrane reservoir which allows for the production of thousands of platelets per mature megakaryocyte. Interestingly, the above process known as megakaryopoiesis is not yet fully understood. However, several groups have contributed evidence to unveil the role of thrombopoietin (TPO), the principal regulator of megakaryopoiesis in vivo. TPO is necessary for megakaryocyte maturation in that TPO deficient mice display greatly reduced megakaryocyte production as well as reduced numbers of mature megakaryocytes. Several transcription factors have also been implicated in megakaryopoiesis including, GATA-1, friend of GATA-1 (FOG-1), nuclear factor-erythroid 2 (NF-E2), and Fli-1. In fact, interactions among some of the transcription factors have been reported to produce synergistic effects. GATA-1 and Fli-1 interactions result in heightened GPIX and GPIb (2 components of von Willebrand Factor (vWF) receptor) expression, while GATA-1, RUNX1 and core-binding factor beta interactions result in improved alphaIIb promoter activity. Mutations in the vWF complex and alphaIIb beta3 have been linked to disorders such as Bernard-Soulier syndrome and Glazmann thrombasthenia respectively. Therefore, a more comprehensive understanding of the transcriptional control of megakaryopoiesis may lead to more effective treatments of platelet-related disorders.

  2. Maturing Technologies for Stirling Space Power Generation

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Nowlin, Brentley C.; Dobbs, Michael W.; Schmitz, Paul C.; Huth, James

    2016-01-01

    Stirling Radioisotope Power Systems (RPS) are being developed as an option to provide power on future space science missions where robotic spacecraft will orbit, flyby, land or rove. A Stirling Radioisotope Generator (SRG) could offer space missions a more efficient power system that uses one fourth of the nuclear fuel and decreases the thermal footprint of the current state of the art. The RPS Program Office, working in collaboration with the U.S. Department of Energy (DOE), manages projects to develop thermoelectric and dynamic power systems, including Stirling Radioisotope Generators (SRGs). The Stirling Cycle Technology Development (SCTD) Project, located at Glenn Research Center (GRC), is developing Stirling-based subsystems, including convertors and controllers. The SCTD Project also performs research that focuses on a wide variety of objectives, including increasing convertor temperature capability to enable new environments, improving system reliability or fault tolerance, reducing mass or size, and developing advanced concepts that are mission enabling. Research activity includes maturing subsystems, assemblies, and components to prepare them for infusion into future convertor and generator designs. The status of several technology development efforts are described here. As part of the maturation process, technologies are assessed for readiness in higher-level subsystems. To assess the readiness level of the Dual Convertor Controller (DCC), a Technology Readiness Assessment (TRA) was performed and the process and results are shown. Stirling technology research is being performed by the SCTD Project for NASA's RPS Program Office, where tasks focus on maturation of Stirling-based systems and subsystems for future space science missions.

  3. A regulatory network for coordinated flower maturation.

    PubMed

    Reeves, Paul H; Ellis, Christine M; Ploense, Sara E; Wu, Miin-Feng; Yadav, Vandana; Tholl, Dorothea; Chételat, Aurore; Haupt, Ina; Kennerley, Brian J; Hodgens, Charles; Farmer, Edward E; Nagpal, Punita; Reed, Jason W

    2012-02-01

    For self-pollinating plants to reproduce, male and female organ development must be coordinated as flowers mature. The Arabidopsis transcription factors AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8 regulate this complex process by promoting petal expansion, stamen filament elongation, anther dehiscence, and gynoecium maturation, thereby ensuring that pollen released from the anthers is deposited on the stigma of a receptive gynoecium. ARF6 and ARF8 induce jasmonate production, which in turn triggers expression of MYB21 and MYB24, encoding R2R3 MYB transcription factors that promote petal and stamen growth. To understand the dynamics of this flower maturation regulatory network, we have characterized morphological, chemical, and global gene expression phenotypes of arf, myb, and jasmonate pathway mutant flowers. We found that MYB21 and MYB24 promoted not only petal and stamen development but also gynoecium growth. As well as regulating reproductive competence, both the ARF and MYB factors promoted nectary development or function and volatile sesquiterpene production, which may attract insect pollinators and/or repel pathogens. Mutants lacking jasmonate synthesis or response had decreased MYB21 expression and stamen and petal growth at the stage when flowers normally open, but had increased MYB21 expression in petals of older flowers, resulting in renewed and persistent petal expansion at later stages. Both auxin response and jasmonate synthesis promoted positive feedbacks that may ensure rapid petal and stamen growth as flowers open. MYB21 also fed back negatively on expression of jasmonate biosynthesis pathway genes to decrease flower jasmonate level, which correlated with termination of growth after flowers have opened. These dynamic feedbacks may promote timely, coordinated, and transient growth of flower organs.

  4. Neural Prostheses and Brain Plasticity

    PubMed Central

    Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

    2010-01-01

    The success of modern neural prostheses is dependent on a complex interplay between the devices’ hardware and software and the dynamic environment in which the devices operate: the patient’s body or ‘wetware’. Over 110,000 severe/profoundly deaf individuals presently receive information enabling auditory awareness and speech perception from cochlear implants. The cochlear implant therefore provides a useful case study for a review of the complex interactions between hardware, software and wetware, and of the important role of the dynamic nature of wetware. This review will examine the evidence of changes in the wetware contributing to changes in speech perception and discuss how these changes relate to electrophysiological and functional imaging studies in humans. The relationship between the human data and evidence from animals of the remarkable capacity for plastic change of the central auditory system, even into adulthood, will then be examined. Finally, we will discuss the role of brain plasticity in neural prostheses in general. PMID:19850976

  5. Phenotypic plasticity in bacterial plasmids.

    PubMed Central

    Turner, Paul E

    2004-01-01

    Plasmid pB15 was previously shown to evolve increased horizontal (infectious) transfer at the expense of reduced vertical (intergenerational) transfer and vice versa, a key trade-off assumed in theories of parasite virulence. Whereas the models predict that susceptible host abundance should determine which mode of transfer is selectively favored, host density failed to mediate the trade-off in pB15. One possibility is that the plasmid's transfer deviates from the assumption that horizontal spread (conjugation) occurs in direct proportion to cell density. I tested this hypothesis using Escherichia coli/pB15 associations in laboratory serial culture. Contrary to most models of plasmid transfer kinetics, my data show that pB15 invades static (nonshaking) bacterial cultures only at intermediate densities. The results can be explained by phenotypic plasticity in traits governing plasmid transfer. As cells become more numerous, the plasmid's conjugative transfer unexpectedly declines, while the trade-off between transmission routes causes vertical transfer to increase. Thus, at intermediate densities the plasmid's horizontal transfer can offset selection against plasmid-bearing cells, but at high densities pB15 conjugates so poorly that it cannot invade. I discuss adaptive vs. nonadaptive causes for the phenotypic plasticity, as well as potential mechanisms that may lead to complex transfer dynamics of plasmids in liquid environments. PMID:15166133

  6. The plasticity of social emotions.

    PubMed

    Klimecki, Olga M

    2015-01-01

    Social emotions such as empathy or compassion greatly facilitate our interactions with others. Despite the importance of social emotions, scientific studies have only recently revealed functional neural plasticity associated with the training of such emotions. Using the framework of two antagonistic neural systems, the threat and social disconnection system on the one hand, and the reward and social connection system on the other, this article describes how training compassion and empathy can change the functioning of these systems in a targeted manner. Whereas excessive empathic sharing of suffering can increase negative feelings and activations in the insula and anterior cingulate cortex (corresponding to the threat and social disconnection system), compassion training can strengthen positive affect and neural activations in the medial orbitofrontal cortex and striatum (corresponding to the reward and social connection system). These neuroimaging findings are complemented by results from behavioral studies showing that compassion is linked to helping and forgiveness behavior, whereas empathic distress not only decreases helping behavior, but is even associated with increased aggressive behavior. Taken together, these data provide encouraging evidence for the plasticity of adaptive social emotions with wide-ranging implications for basic science and applied settings.

  7. Fabrication of plastic microfluidic components

    NASA Astrophysics Data System (ADS)

    Martin, Peter M.; Matson, Dean W.; Bennett, Wendy D.; Hammerstrom, D. J.

    1998-09-01

    Plastic components have many advantages, including ease of fabrication, low cost, chemical inertness, lightweight, and disposability. We report on the fabrication of three plastics-based microfluidic components: a motherboard, a dialysis unit, and a metal sensor. Microchannels, headers, and interconnects were produced in thin sheets (>=50 microns) of polyimide, PMMA, polyethylene, and polycarbonate using a direct-write excimer laser micromachining system. Machined sheets were laminated by thermal and adhesive bonding to form leak-tight microfluidic components. The microfluidic motherboard borrowed the `functionality on a chip' concept from the electronics industry and was the heart of a complex microfluidic analytical device. The motherboard platform was designed to be tightly integrated and self-contained (i.e., liquid flows are all confined within machined microchannels), reducing the need for tubing with fluid distribution and connectivity. This concept greatly facilitated system integration and miniaturization. As fabricated, the motherboard consisted of three fluid reservoirs connected to micropumps by microchannels. The fluids could either be pumped independently or mixed in microchannels prior to being directed to exterior analytical components via outlet ports. The microdialysis device was intended to separate electrolytic solutes from low volume samples prior to mass spectrometric analysis. The device consisted of a dialysis membrane laminated between opposed serpentine microchannels containing the sample fluid and a buffer solution. The laminated metal sensor consisted of fluid reservoirs, micro-flow channels, micropumps, mixing channels, reaction channels, and detector circuitry.

  8. Neural prostheses and brain plasticity

    NASA Astrophysics Data System (ADS)

    Fallon, James B.; Irvine, Dexter R. F.; Shepherd, Robert K.

    2009-12-01

    The success of modern neural prostheses is dependent on a complex interplay between the devices' hardware and software and the dynamic environment in which the devices operate: the patient's body or 'wetware'. Over 120 000 severe/profoundly deaf individuals presently receive information enabling auditory awareness and speech perception from cochlear implants. The cochlear implant therefore provides a useful case study for a review of the complex interactions between hardware, software and wetware, and of the important role of the dynamic nature of wetware. In the case of neural prostheses, the most critical component of that wetware is the central nervous system. This paper will examine the evidence of changes in the central auditory system that contribute to changes in performance with a cochlear implant, and discuss how these changes relate to electrophysiological and functional imaging studies in humans. The relationship between the human data and evidence from animals of the remarkable capacity for plastic change of the central auditory system, even into adulthood, will then be examined. Finally, we will discuss the role of brain plasticity in neural prostheses in general.

  9. Network-timing-dependent plasticity.

    PubMed

    Delattre, Vincent; Keller, Daniel; Perich, Matthew; Markram, Henry; Muller, Eilif B

    2015-01-01

    Bursts of activity in networks of neurons are thought to convey salient information and drive synaptic plasticity. Here we report that network bursts also exert a profound effect on Spike-Timing-Dependent Plasticity (STDP). In acute slices of juvenile rat somatosensory cortex we paired a network burst, which alone induced long-term depression (LTD), with STDP-induced long-term potentiation (LTP) and LTD. We observed that STDP-induced LTP was either unaffected, blocked or flipped into LTD by the network burst, and that STDP-induced LTD was either saturated or flipped into LTP, depending on the relative timing of the network burst with respect to spike coincidences of the STDP event. We hypothesized that network bursts flip STDP-induced LTP to LTD by depleting resources needed for LTP and therefore developed a resource-dependent STDP learning rule. In a model neural network under the influence of the proposed resource-dependent STDP rule, we found that excitatory synaptic coupling was homeostatically regulated to produce power law distributed burst amplitudes reflecting self-organized criticality, a state that ensures optimal information coding.

  10. Network-timing-dependent plasticity

    PubMed Central

    Delattre, Vincent; Keller, Daniel; Perich, Matthew; Markram, Henry; Muller, Eilif B.

    2015-01-01

    Bursts of activity in networks of neurons are thought to convey salient information and drive synaptic plasticity. Here we report that network bursts also exert a profound effect on Spike-Timing-Dependent Plasticity (STDP). In acute slices of juvenile rat somatosensory cortex we paired a network burst, which alone induced long-term depression (LTD), with STDP-induced long-term potentiation (LTP) and LTD. We observed that STDP-induced LTP was either unaffected, blocked or flipped into LTD by the network burst, and that STDP-induced LTD was either saturated or flipped into LTP, depending on the relative timing of the network burst with respect to spike coincidences of the STDP event. We hypothesized that network bursts flip STDP-induced LTP to LTD by depleting resources needed for LTP and therefore developed a resource-dependent STDP learning rule. In a model neural network under the influence of the proposed resource-dependent STDP rule, we found that excitatory synaptic coupling was homeostatically regulated to produce power law distributed burst amplitudes reflecting self-organized criticality, a state that ensures optimal information coding. PMID:26106298

  11. GTPases involved in bacterial ribosome maturation.

    PubMed

    Goto, Simon; Muto, Akira; Himeno, Hyouta

    2013-05-01

    The ribosome is an RNA- and protein-based macromolecule having multiple functional domains to facilitate protein synthesis, and it is synthesized through multiple steps including transcription, stepwise cleavages of the primary transcript, modifications of ribosomal proteins and RNAs and assemblies of ribosomal proteins with rRNAs. This process requires dozens of trans-acting factors including GTP- and ATP-binding proteins to overcome several energy-consuming steps. Despite accumulation of genetic, biochemical and structural data, the entire process of bacterial ribosome synthesis remains elusive. Here, we review GTPases involved in bacterial ribosome maturation.

  12. Micropropagation of Elaeagnus angustifolia from mature trees.

    PubMed

    Iriondo, J M; De La Iglesia, M; Pérez, C

    1995-10-01

    Multiple shoots were obtained from nodal segments of mature trees of Elaeagnus angustifolia L. cultured on MS medium (Murashige and Skoog 1962) supplemented with 0, 0.88 or 2.22 micro M N(6)-benzyladenine. When nodal segments taken from the in vitro proliferated shoots were cultured under the same conditions, additional multiple shoots were obtained. Rooting of the in vitro propagated shoots was achieved on full strength MS medium or on MS supplemented with 2.46 micro M indole-3-butyric acid. Regenerated plantlets were acclimatized and successfully transplanted to soil.

  13. Performance, growth, and maturity of Nellore bulls.

    PubMed

    Costa e Silva, Luiz Fernando; Valadares Filho, Sebastião de Campos; Detmann, Edenio; Rotta, Polyana Pizzi; Zanetti, Diego; Villadiego, Faider Alberto Castaño; Pellizzoni, Samantha Gusmão; Pereira, Rafael Moura Guimarães

    2013-03-01

    The objectives of this study were to evaluate the dry matter intake (DMI), digestibility, average daily gain (ADG), microbial efficiency, empty body weight (EBW) gain, and body composition of Nellore bulls. Additionally, Nellore bull maturity was estimated, and the prediction equation for DMI, suggested by the Brazilian nutrient requirements system (BR CORTE; Azevêdo et al. 2010), was evaluated. Thirty-three Nellore bulls, with a mean initial weight of 259 ± 25 kg and age of 14 ± 1 months, were used in this study. Five animals were slaughtered at the beginning of the experiment (control group), and the remaining 28 were divided into 4 groups, each slaughtered at 42-day intervals. Their diet was composed of corn silage and concentrate (55:45). The power model was used to estimate muscle tissue, bone tissue, crude protein (CP), mineral matter (MM), and water present in the empty body, while the exponential model was used to estimate adipose tissue and ether extract (EE) present in the empty body. When expressed in kilograms per day, differences were observed (P < 0.05) only for the intake of EE and neutral detergent fiber as a function of feedlot time periods. Although there was a difference in relation to nutrient intake, it did not affect (P > 0.05) digestibility, with the exception of EE digestibility. The equation suggested by BR CORTE correctly estimates the DMI of Nellore bulls. ADG was not affected (P > 0.05) by time spent in the feedlot. No differences were observed (P > 0.05) for microbial efficiency; a mean value of 142 g microbial crude protein/kg total digestible nutrients was achieved. The muscle and bone tissues, CP, MM, and water present in the empty body increased as the animal grew, although at a lower rate. The adipose tissue and EE present in the empty body increased their deposition rate when the animal reached its mature weight. Maturity is defined as when an animal reaches 22 % EE in the empty body, which

  14. 141 BOVINE EMBRYO DEVELOPMENT RATES ARE AFFECTED WHEN OOCYTES ARE MATURED IN DIFFERENT VIALS CONTAINING HEPES/BICARBONATE BUFFERED MEDIUM.

    PubMed

    Hashem, N; Secher, J O; Pryor, J H; Long, C R; Looney, C R; Avery, B; Hyttel, P; Stroebech, L

    2016-01-01

    Laboratory ware for the in vitro-produced embryos is generally made from embryo-tested plastic instead of glass. The quality of the plastic is crucial for the outcome because plastic is often toxic to gametes (Nijs et al. 2009 Fertil. Steril. 92, 527-535). In addition, gas molecules permeate through the plastic at a rate that depends on a variety of factors, such as diffusion coefficient and thickness of the plastic. In an incubator with appropriate concentration of CO2 and vented culture vessels, the gas permeability of the plastic is not important. When oocytes are transported outside a controlled atmosphere, gas permeability, toxicity, and oocyte cumulus cell CO2 metabolism could perturb the outcome. Medium containing bicarbonate buffer increases pH outside of a controlled atmosphere within minutes, whereas medium buffered with HEPES maintains suitable pH for hours. Previously, we tested that gas permeability differs among plastic vials and glass vials with no cumulus-oocyte complexes (COC) by measuring pH after 2, 5, and 24h at the same temperature. The objective of this study was to compare pH post-maturation, blastocyst development rates on Day 8 post-IVF (Day 0=IVF) between 2 different 1.2-mL polypropylene cryovials (A: VWR DK, 479-1219; B: Sigma-Aldrich, St. Louis, MO, USA, CLS430289), glass vial (VWR DK, NSCAC4015-96), and 4-well plate (4WP) as control (Thermo Fisher Scientific, Waltham, MA, USA, 144444). A total of 1135 abattoir-derived COC in Exp. 1 and 133 in Exp. 2 were divided equally between the treatments (20-25 COC per vessel). Vials/4WP contained 0.8/0.5mL of BO-IVM HEPES, a HEPES/bicarbonate medium (IVF Bioscience; BO-HEPES-IVM, UK). Maturation lasted 22 to 24h at 38.8°C in an incubator with either a humidified atmosphere of 5.5% CO2 in air (Exp. 1) or with no CO2 contact (Exp. 2). In Exp. 1, oocyte vials were matured without a vial lid while in Exp. 2 vial lids were closed. Statistical analysis was performed with chi-square and mean±SD. In Exp

  15. Method to separate and recover oil and plastic from plastic contaminated with oil

    DOEpatents

    Smith, Henry M.; Bohnert, George W.; Olson, Ronald B.; Hand, Thomas E.

    1998-01-27

    The present invention provides a method to separate and recover oils and recyclable plastic from plastic contaminated with oil. The invention utilizes the different solubility of oil in as liquid or supercritical fluid as compared to a gas to effect separation of the oil from the plastic.

  16. Method to separate and recover oil and plastic from plastic contaminated with oil

    DOEpatents

    Smith, H.M.; Bohnert, G.W.; Olson, R.B.; Hand, T.E.

    1998-01-27

    The present invention provides a method to separate and recover oils and recyclable plastic from plastic contaminated with oil. The invention utilizes the different solubility of oil in a liquid or supercritical fluid as compared to a gas to effect separation of the oil from the plastic. 3 figs.

  17. Chronic pregabalin treatment decreases excitability of dentate gyrus and accelerates maturation of adult-born granule cells.

    PubMed

    Lempel, Augusto Abel; Coll, Lucia; Schinder, Alejandro F; Uchitel, Osvaldo Daniel; Piriz, Joaquin

    2017-01-01

    Pregabalin (PGB) is extensively prescribed to treat neurological and neuropsychiatrical conditions such as neuropathic pain, anxiety disorders, and epilepsy. Although PGB is known to bind selectively to the α2δ subunit of voltage-gated calcium channels, there is little understanding about how it exerts its therapeutic effects. In this article, we analyzed the effects of an in vivo chronic treatment with PGB over the physiology of dentate gyrus granule cells (DGGCs) using ex vivo electrophysiological and morphological analysis in adult mice. We found that PGB decreases neuronal excitability of DGGCs. In addition, PGB accelerates maturation of adult-born DGGCs, an effect that would modify dentate gyrus plasticity. Together, these findings suggest that PGB reduces activity in the dentate gyrus and modulates overall network plasticity, which might contribute to its therapeutic effects. Cover Image for this issue: doi: 10.1111/jnc.13783.

  18. Effects of PSA Removal from NCAM on the Critical Period Plasticity Triggered by the Antidepressant Fluoxetine in the Visual Cortex

    PubMed Central

    Guirado, Ramon; La Terra, Danilo; Bourguignon, Mathieu; Carceller, Hector; Umemori, Juzoh; Sipilä, Pia; Nacher, Juan; Castrén, Eero

    2016-01-01

    Neuronal plasticity peaks during critical periods of postnatal development and is reduced towards adulthood. Recent data suggests that windows of juvenile-like plasticity can be triggered in the adult brain by antidepressant drugs such as Fluoxetine. Although the exact mechanisms of how Fluoxetine promotes such plasticity remains unknown, several studies indicate that inhibitory circuits play an important role. The polysialylated form of the neural cell adhesion molecules (PSA-NCAM) has been suggested to mediate the effects of Fluoxetine and it is expressed in the adult brain by mature interneurons. Moreover, the enzymatic removal of PSA by neuroaminidase-N not only affects the structure of interneurons but also has been shown to play a role in the onset of critical periods during development. We have here used ocular dominance plasticity in the mouse visual cortex as a model to investigate whether removal of PSA might influence the Fluoxetine-induced plasticity. We demonstrate that PSA removal in the adult visual cortex alters neither the baseline ocular dominance, nor the fluoxetine-induced shift in the ocular dominance. We also show that both chronic Fluoxetine treatment and PSA removal independently increase the basal FosB expression in parvalbumin (PV) interneurons in the primary visual cortex. Therefore, our data suggest that although PSA-NCAM regulates inhibitory circuitry, it is not required for the reactivation of juvenile-like plasticity triggered by Fluoxetine. PMID:26903807

  19. Evolutionary plasticity determination by orthologous groups distribution

    PubMed Central

    2011-01-01

    Background Genetic plasticity may be understood as the ability of a functional gene network to tolerate alterations in its components or structure. Usually, the studies involving gene modifications in the course of the evolution are concerned to nucleotide sequence alterations in closely related species. However, the analysis of large scale data about the distribution of gene families in non-exclusively closely related species can provide insights on how plastic or how conserved a given gene family is. Here, we analyze the abundance and diversity of all Eukaryotic Clusters of Orthologous Groups (KOG) present in STRING database, resulting in a total of 4,850 KOGs. This dataset comprises 481,421 proteins distributed among 55 eukaryotes. Results We propose an index to evaluate the evolutionary plasticity and conservation of an orthologous group based on its abundance and diversity across eukaryotes. To further KOG plasticity analysis, we estimate the evolutionary distance average among all proteins which take part in the same orthologous group. As a result, we found a strong correlation between the evolutionary distance average and the proposed evolutionary plasticity index. Additionally, we found low evolutionary plasticity in Saccharomyces cerevisiae genes associated with inviability and Mus musculus genes associated with early lethality. At last, we plot the evolutionary plasticity value in different gene networks from yeast and humans. As a result, it was possible to discriminate among higher and lower plastic areas of the gene networks analyzed. Conclusions The distribution of gene families brings valuable information on evolutionary plasticity which might be related with genetic plasticity. Accordingly, it is possible to discriminate among conserved and plastic orthologous groups by evaluating their abundance and diversity across eukaryotes. Reviewers This article was reviewed by Prof Manyuan Long, Hiroyuki Toh, and Sebastien Halary. PMID:21586164

  20. Validation of the Psychological Work Maturity Scale in Chinese employees.

    PubMed

    Tong, Jiajin; Wang, Lei

    2010-12-01

    Psychological work maturity is an important concept in situational leadership theory. The present research revised the Psychological Work Maturity Scale for use in Chinese organizations. Three samples of full-time employees (Ns = 205, 266, and 283) from different companies and industries participated in the present study. Confirmatory factor analysis showed that a single-factor structure fit the data. The scale had acceptable reliabilities, convergent and criterion-related validities, and was shown to be an appropriate measure of psychological work maturity in Chinese employees. Maturity differences in several demographic variables were not found, but employees with longer tenure in Sample 2 scored higher on maturity, which shows that psychological work maturity may be dependent on personal development in the interaction with the varying situational factors, especially in the work domain. Implications for research and practice on psychological work maturity in China are discussed.

  1. The insemination of goldfish ( Carassium auratus) oocyte matured in vitro

    NASA Astrophysics Data System (ADS)

    Wang, Renxue; Wu, Xianhan; Zhou, Jing; Zhang, Shicui; Ma, Yingjie; Wu, Shangqin; Shi, Yingxian

    1991-03-01

    Full maturation of goldfish oocyte was induced in vitro by 17 α-hydroxy-20β-dihydroprogesterone. The oocyte maturation involves GV migration to the periphery of the oocyte and germinal vesicle breakdown (GVBD). In the experiment, incubation duration for GVBD varied in different broods of oocytes. Generally, if the duration for GVBD was shorter than 6 h, oocytes would have a better chance to survive after maturation and insemination. The maturation of nucleus (GV) and cytoplasm are not synchronous. Cytoplasm maturation occurs several hs after GVBD. Oocytes inseminated 8 9 h after GVBD have the highest fertilizing and hatching rate. Fertilized ova matured in vitro can develop to sexually mature adults capable of reproduction.

  2. Pitch perception prior to cortical maturation

    NASA Astrophysics Data System (ADS)

    Lau, Bonnie K.

    Pitch perception plays an important role in many complex auditory tasks including speech perception, music perception, and sound source segregation. Because of the protracted and extensive development of the human auditory cortex, pitch perception might be expected to mature, at least over the first few months of life. This dissertation investigates complex pitch perception in 3-month-olds, 7-month-olds and adults -- time points when the organization of the auditory pathway is distinctly different. Using an observer-based psychophysical procedure, a series of four studies were conducted to determine whether infants (1) discriminate the pitch of harmonic complex tones, (2) discriminate the pitch of unresolved harmonics, (3) discriminate the pitch of missing fundamental melodies, and (4) have comparable sensitivity to pitch and spectral changes as adult listeners. The stimuli used in these studies were harmonic complex tones, with energy missing at the fundamental frequency. Infants at both three and seven months of age discriminated the pitch of missing fundamental complexes composed of resolved and unresolved harmonics as well as missing fundamental melodies, demonstrating perception of complex pitch by three months of age. More surprisingly, infants in both age groups had lower pitch and spectral discrimination thresholds than adult listeners. Furthermore, no differences in performance on any of the tasks presented were observed between infants at three and seven months of age. These results suggest that subcortical processing is not only sufficient to support pitch perception prior to cortical maturation, but provides adult-like sensitivity to pitch by three months.

  3. Schlafen 3 changes during rat intestinal maturation

    PubMed Central

    Walsh, Mary F.; Hermann, Rebecca; Sun, Kelian; Basson, Marc D.

    2015-01-01

    BACKGROUND Understanding gut development may illuminate the adaptive response to massive small-bowel resection and facilitate enteral nutrition. We reported that Schlafen-3 (Slfn3) mediates differentiation in vitro in rat intestinal epithelial. We hypothesized that Slfn3 is involved in intestinal development in vivo. METHODS We removed fetal intestines, liver, and lungs on day 20 of gestation, at birth, and on postnatal days 1 and 5. Expression of Slfn3, markers of intestinal differentiation, and Slfn5, to address specificity, were determined by quantitative reverse-transcription polymerase chain reaction. RESULTS Villin expression increased on days 1 and 5 (8.7 ± .6 and 5.4 ± .4, respectively; P < .01). Intestinal Slfn3 expression was increased substantially after birth (2.1- ± .5-fold) and on days 1 and 5 (P < .02). Slfn3 was higher after birth in liver and lung but decreased sharply thereafter. Slfn5 expression was mostly unchanged. CONCLUSIONS The data suggest that the developmental/maturation effects we observed correlate with Slfn3 but not Slfn5 and are more relevant to the intestines. A better understanding of how Slfn3 promotes intestinal differentiation could help promote intestinal maturation, improving outcomes in children or adults with short-gut syndrome. PMID:22906252

  4. Molecular Signaling in Muscle Plasticity

    NASA Technical Reports Server (NTRS)

    Epstein, Henry F.

    1999-01-01

    Extended spaceflight under microgravity conditions leads to significant atrophy of weight-bearing muscles. Atrophy and hypertrophy are the extreme outcomes of the high degree of plasticity exhibited by skeletal muscle. Stimuli which control muscle plasticity include neuronal, hormonal, nutritional, and mechanical inputs. The mechanical stimulus for muscle is directly related to the work or exercise against a load performed. Little or no work is performed by weight-bearing muscles under microgravity conditions. A major hypothesis is that focal adhesion kinase (FAK) which is associated with integrin at the adherens junctions and costa meres of all skeletal muscles is an integral part of the major mechanism for molecular signaling upon mechanical stimulation in all muscle fibers. Additionally, we propose that myotonic protein kinase (DMPK) and dystrophin (DYSTR) also participate in distinct mechanically stimulated molecular signaling pathways that are most critical in type I and type II muscle fibers, respectively. To test these hypotheses, we will use the paradigms of hindlimb unloading and overloading in mice as models for microgravity conditions and a potential exercise countermeasure, respectively, in mice. We expect that FAK loss-of-function will impair hypertrophy and enhance atrophy in all skeletal muscle fibers whereas DYSTR and DMPK loss-of-function will have similar but more selective effects on Type IT and Type I fibers, respectively. Gene expression will be monitored by muscle-specific creatine kinase M promoter-reporter construct activity and specific MRNA and protein accumulation in the soleus (type I primarily) and plantaris (type 11 primarily) muscles. With these paradigms and assays, the following Specific Project Aims will be tested in genetically altered mice: 1) identify the roles of DYSTR and its pathway; 2) evaluate the roles of the DMPK and its pathway; 3) characterize the roles of FAK and its pathway and 4) genetically analyze the mechanisms

  5. Central plasticity and dysfunction elicited by aural deprivation in the critical period.

    PubMed

    Chen, Zhiji; Yuan, Wei

    2015-01-01

    The acoustic signal is crucial for animals to obtain information from the surrounding environment. Like other sensory modalities, the central auditory system undergoes adaptive changes (i.e., plasticity) during the developmental stage as well as other stages of life. Owing to its plasticity, auditory centers may be susceptible to various factors, such as medical intervention, variation in ambient acoustic signals and lesion of the peripheral hearing organ. There are critical periods during which auditory centers are vulnerable to abnormal experiences. Particularly in the early postnatal development period, aural inputs are essential for functional maturity of auditory centers. An aural deprivation model, which can be achieved by attenuating or blocking the peripheral acoustic afferent input to the auditory center, is ideal for investigating plastic changes of auditory centers. Generally, auditory plasticity includes structural and functional changes, some of which can be irreversible. Aural deprivation can distort tonotopic maps, disrupt the binaural integration, reorganize the neural network and change the synaptic transmission in the primary auditory cortex or at lower levels of the auditory system. The regulation of specific gene expression and the modified signal pathway may be the deep molecular mechanism of these plastic changes. By studying this model, researchers may explore the pathogenesis of hearing loss and reveal plastic changes of the auditory cortex, facilitating the therapeutic advancement in patients with severe hearing loss. After summarizing developmental features of auditory centers in auditory deprived animals and discussing changes of central auditory remodeling in hearing loss patients, we aim at stressing the significant of an early and well-designed auditory training program for the hearing rehabilitation.

  6. Industrial plastics waste: Identification and segregation

    NASA Technical Reports Server (NTRS)

    Widener, Edward L.

    1990-01-01

    Throwaway plastic products, mainly packaging, are inundating our landfills and incinerators. Most are ethenic thermoplastics, which can be recycled as new products or fossil-fuels. Lab experiments are described, involving destructive and non-destructive tests for identifying and using plastics. The burn-test, with simple apparatus and familiar samples, is recommended as quick, cheap and effective.

  7. Plastic accumulation in the Mediterranean sea.

    PubMed

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  8. Plastic properties of matrix composites in bending

    NASA Astrophysics Data System (ADS)

    Novikov, V. V.; Papkovskaya, O. B.

    1997-11-01

    Using the methods of integrated cross-sections and elastic solutions, we solve an elastico-plastic problem of bending of a Kirchhoff inhomogeneous square plate. The elastico-plastic properties and the effective yield stress of the inhomogeneous plate are calculated on an electronic computer. The computational results form the basis for a qualitative analysis and for the conclusions made.

  9. Integrating Hebbian and homeostatic plasticity: introduction.

    PubMed

    Fox, Kevin; Stryker, Michael

    2017-03-05

    Hebbian plasticity is widely considered to be the mechanism by which information can be coded and retained in neurons in the brain. Homeostatic plasticity moves the neuron back towards its original state following a perturbation, including perturbations produced by Hebbian plasticity. How then does homeostatic plasticity avoid erasing the Hebbian coded information? To understand how plasticity works in the brain, and therefore to understand learning, memory, sensory adaptation, development and recovery from injury, requires development of a theory of plasticity that integrates both forms of plasticity into a whole. In April 2016, a group of computational and experimental neuroscientists met in London at a discussion meeting hosted by the Royal Society to identify the critical questions in the field and to frame the research agenda for the next steps. Here, we provide a brief introduction to the papers arising from the meeting and highlight some of the themes to have emerged from the discussions.This article is part of the themed issue 'Integrating Hebbian and homeostatic plasticity'.

  10. Biological degradation of plastics: a comprehensive review.

    PubMed

    Shah, Aamer Ali; Hasan, Fariha; Hameed, Abdul; Ahmed, Safia

    2008-01-01

    Lack of degradability and the closing of landfill sites as well as growing water and land pollution problems have led to concern about plastics. With the excessive use of plastics and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. The interest in environmental issues is growing and there are increasing demands to develop material which do not burden the environment significantly. Biodegradation is necessary for water-soluble or water-immiscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires understanding of the interactions between materials and microorganisms and the biochemical changes involved. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. This paper reviews the current research on the biodegradation of biodegradable and also the conventional synthetic plastics and also use of various techniques for the analysis of degradation in vitro.

  11. Starch plastics packaging and agriculture applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The environmental impact of petroleum-based plastics is a growing concern throughout the world. Containers and packaging comprise the largest sector of municipal solid waste and are a major component of pollution on both land and sea. Although the benefits of plastics in many consumer and industrial...

  12. Plastic and Failure Analysis of Composites

    NASA Technical Reports Server (NTRS)

    Bigelow, C. A.; Johnson, W. S.

    1985-01-01

    Three-dimensional finite-element computer program called PAFAC (Plastic and Failure Analysis of Composites) developed for elastic/plastic analysis of fiber-reinforced composite materials and structures. PAFAC written in FORTRAN IV for batch execution. Particularly suited for analyzing laminated metal-matrix composites.

  13. Plastic Accumulation in the Mediterranean Sea

    PubMed Central

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  14. The impact of inflammation on respiratory plasticity.

    PubMed

    Hocker, Austin D; Stokes, Jennifer A; Powell, Frank L; Huxtable, Adrianne G

    2017-01-01

    Breathing is a vital homeostatic behavior and must be precisely regulated throughout life. Clinical conditions commonly associated with inflammation, undermine respiratory function may involve plasticity in respiratory control circuits to compensate and maintain adequate ventilation. Alternatively, other clinical conditions may evoke maladaptive plasticity. Yet, we have only recently begun to understand the effects of inflammation on respiratory plasticity. Here, we review some of common models used to investigate the effects of inflammation and discuss the impact of inflammation on nociception, chemosensory plasticity, medullary respiratory centers, motor plasticity in motor neurons and respiratory frequency, and adaptation to high altitude. We provide new data suggesting glial cells contribute to CNS inflammatory gene expression after 24h of sustained hypoxia and inflammation induced by 8h of intermittent hypoxia inhibits long-term facilitation of respiratory frequency. We also discuss how inflammation can have opposite effects on the capacity for plasticity, whereby it is necessary for increases in the hypoxic ventilatory response with sustained hypoxia, but inhibits phrenic long term facilitation after intermittent hypoxia. This review highlights gaps in our knowledge about the effects of inflammation on respiratory control (development, age, and sex differences). In summary, data to date suggest plasticity can be either adaptive or maladaptive and understanding how inflammation alters the respiratory system is crucial for development of better therapeutic interventions to promote breathing and for utilization of plasticity as a clinical treatment.

  15. Improved hardening theory for cyclic plasticity.

    NASA Technical Reports Server (NTRS)

    Vos, R. G.; Armstrong, W. H.

    1973-01-01

    A temperature-dependent version of a combined hardening theory, including isotropic and kinematic hardening, is presented within the framework of recent plasticity formulations. This theory has been found to be especially useful in finite-element analysis of aerospace vehicle engines under conditions of large plastic strain and low-cycle fatigue.

  16. Demonstrating Fluorescence with Neon Paper and Plastic

    ERIC Educational Resources Information Center

    Birriel, Jennifer J.; Roe, Clarissa

    2015-01-01

    Several papers in this journal have dealt with the fluorescence in orange neon plastic, olive oil, and soda. In each case, the fluorescent emission was excited by either green or violet-blue laser light. In this paper, we examine the fluorescent emission spectra of so-called neon colored papers and plastic clipboards available in department and…

  17. Microwave interferometer controls cutting depth of plastics

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Iceland, W. F.

    1969-01-01

    Microwave interferometer system controls the cutting of plastic materials to a prescribed depth. The interferometer is mounted on a carriage with a spindle and cutting tool. A cross slide, mounted on the carriage, allows the interferometer and cutter to move toward or away from the plastic workpiece.

  18. Nano-plastics in the aquatic environment.

    PubMed

    Mattsson, K; Hansson, L-A; Cedervall, T

    2015-10-01

    The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data.

  19. 7 CFR 58.348 - Plastic cream.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Plastic cream. 58.348 Section 58.348 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Products Bearing Usda Official Identification § 58.348 Plastic cream. The flavor shall be sweet,...

  20. 7 CFR 58.348 - Plastic cream.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Plastic cream. 58.348 Section 58.348 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Products Bearing Usda Official Identification § 58.348 Plastic cream. The flavor shall be sweet,...