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Sample records for maturation plasticity cshl

  1. Experience-dependent plasticity of mature adult-born neurons.

    PubMed

    Livneh, Yoav; Mizrahi, Adi

    2012-01-01

    The adult olfactory bulb and hippocampus are continuously supplied with newborn neurons that are thought to possess a capacity for plasticity only at a young neuronal age, mainly during the early stages of integration into the network. We find that the two main types of adult-born neurons in the mouse olfactory bulb undergo experience-dependent plasticity long after maturation and integration, as evidenced by stabilization of synaptic turnover rates. Thus, the potential time window for plasticity of adult-born neurons extends well into maturity. PMID:22081159

  2. 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...

  3. 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.

  4. The Between-Population Genetic Architecture of Growth, Maturation, and Plasticity in Atlantic Salmon

    PubMed Central

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

    2014-01-01

    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. PMID:24473933

  5. Otx2 binding to perineuronal nets persistently regulates plasticity in the mature visual cortex.

    PubMed

    Beurdeley, Marine; Spatazza, Julien; Lee, Henry H C; Sugiyama, Sayaka; Bernard, Clémence; Di Nardo, Ariel A; Hensch, Takao K; Prochiantz, Alain

    2012-07-01

    Specific transfer of (orthodenticle homeobox 2) Otx2 homeoprotein into GABAergic interneurons expressing parvalbumin (PV) is necessary and sufficient to open, then close, a critical period (CP) of plasticity in the developing mouse visual cortex. The accumulation of endogenous Otx2 in PV cells suggests the presence of specific Otx2 binding sites. Here, we find that perineuronal nets (PNNs) on the surfaces of PV cells permit the specific, constitutive capture of Otx2. We identify a 15 aa domain containing an arginine-lysine doublet (RK peptide) within Otx2, bearing prototypic traits of a glycosaminoglycan (GAG) binding sequence that mediates Otx2 binding to PNNs, and specifically to chondroitin sulfate D and E, with high affinity. Accordingly, PNN hydrolysis by chondroitinase ABC reduces the amount of endogenous Otx2 in PV cells. Direct infusion of RK peptide similarly disrupts endogenous Otx2 localization to PV cells, reduces PV and PNN expression, and reopens plasticity in adult mice. The closure of one eye during this transient window reduces cortical acuity and is specific to the RK motif, as an Alanine-Alanine variant or a scrambled peptide fails to reactivate plasticity. Conversely, this transient reopening of plasticity in the adult restores binocular vision in amblyopic mice. Thus, one function of PNNs is to facilitate the persistent internalization of Otx2 by PV cells to maintain CP closure. The pharmacological use of the Otx2 GAG binding domain offers a novel, potent therapeutic tool with which to restore cortical plasticity in the mature brain. PMID:22764251

  6. Activity-dependent plasticity of spinal circuits in the developing and mature spinal cord.

    PubMed

    Tahayori, Behdad; Koceja, David M

    2012-01-01

    Part of the development and maturation of the central nervous system (CNS) occurs through interactions with the environment. Through physical activities and interactions with the world, an animal receives considerable sensory information from various sources. These sources can be internally (proprioceptive) or externally (such as touch and pressure) generated senses. Ample evidence exists to demonstrate that the sensory information originating from large diameter afferents (Ia fibers) have an important role in inducing essential functional and morphological changes for the maturation of both the brain and the spinal cord. The Ia fibers transmit sensory information generated by muscle activity and movement. Such use or activity-dependent plastic changes occur throughout life and are one reason for the ability to acquire new skills and learn new movements. However, the extent and particularly the mechanisms of activity-dependent changes are markedly different between a developing nervous system and a mature nervous system. Understanding these mechanisms is an important step to develop strategies for regaining motor function after different injuries to the CNS. Plastic changes induced by activity occur both in the brain and spinal cord. This paper reviews the activity-dependent changes in the spinal cord neural circuits during both the developmental stages of the CNS and in adulthood. PMID:22900208

  7. Hebbian plasticity guides maturation of glutamate receptor fields in vivo.

    PubMed

    Ljaschenko, Dmitrij; Ehmann, Nadine; Kittel, Robert J

    2013-05-30

    Synaptic plasticity shapes the development of functional neural circuits and provides a basis for cellular models of learning and memory. Hebbian plasticity describes an activity-dependent change in synaptic strength that is input-specific and depends on correlated pre- and postsynaptic activity. Although it is recognized that synaptic activity and synapse development are intimately linked, our mechanistic understanding of the coupling is far from complete. Using Channelrhodopsin-2 to evoke activity in vivo, we investigated synaptic plasticity at the glutamatergic Drosophila neuromuscular junction. Remarkably, correlated pre- and postsynaptic stimulation increased postsynaptic sensitivity by promoting synapse-specific recruitment of GluR-IIA-type glutamate receptor subunits into postsynaptic receptor fields. Conversely, GluR-IIA was rapidly removed from synapses whose activity failed to evoke substantial postsynaptic depolarization. Uniting these results with developmental GluR-IIA dynamics provides a comprehensive physiological concept of how Hebbian plasticity guides synaptic maturation and sparse transmitter release controls the stabilization of the molecular composition of individual synapses.

  8. Absence of sex differential plasticity to light availability during seed maturation in Geranium sylvaticum.

    PubMed

    Varga, Sandra; Laaksonen, Ester; Siikamäki, Pirkko; Kytöviita, Minna-Maarit

    2015-01-01

    Sex-differential plasticity (SDP) hypothesis suggests that since hermaphrodites gain fitness through both pollen and seed production they may have evolved a higher degree of plasticity in their reproductive strategy compared to females which achieve fitness only through seed production. SDP may explain the difference in seed production observed between sexes in gynodioecious species in response to resource (nutrients or water) availability. In harsh environments, hermaphrodites decrease seed production whereas females keep it relatively similar regardless of the environmental conditions. Light availability can be also a limiting resource and thus could theoretically affect differently female and hermaphrodite seed output even though this ecological factor has been largely overlooked. We tested whether the two sexes in the gynodioecious species Geranium sylvaticum differ in their tolerance to light limitation during seed maturation in the field. We used a fully factorial block experiment exposing female and hermaphrodite plants to two different light environments (control and shade) after their peak flowering period. Specifically, we measured fruit and seed production in response to decreased light availability and compared it between the sexes. Shading reduced the number of fruits and seeds produced, but the decrease was similar between the sexes. Furthermore, shading delayed seed production by three days in both sexes, but did not affect seed mass, seed P content, or the probability of re-flowering the following year. Our results give no evidence for reproductive SDP in response to light during seed maturation.

  9. Presynaptic ultrastructural plasticity along CA3→CA1 axons during LTP in Mature Hippocampus

    PubMed Central

    Bourne, Jennifer N.; Chirillo, Michael A.; Harris, Kristen M.

    2013-01-01

    In area CA1 of the mature hippocampus, synaptogenesis occurs within 30 min after the induction of LTP; however, by 2 hr many small dendritic spines are lost, and those remaining have larger synapses. Little is known, however, about associated changes in presynaptic vesicles and axonal boutons. Axons in CA1 stratum radiatum were evaluated with three-dimensional reconstructions from serial section electron microscopy at 30 min and 2 hr after induction of LTP by theta-burst stimulation (TBS). The frequency of axonal boutons with a single postsynaptic partner was decreased by 33% at 2 hr, corresponding perfectly to the 33% loss specifically of small dendritic spines (head diameters <0.45 μm). Docked vesicles were reduced at 30 min and then returned to control levels by 2 hr following induction of LTP. By 2 hr there were fewer small synaptic vesicles overall in the presynaptic vesicle pool. Clathrin-mediated endocytosis was used as a marker of local activity, and axonal boutons containing clathrin-coated pits showed a more pronounced decrease in presynaptic vesicles at both 30 min and 2 hr after induction of LTP relative to control values. Putative transport packets, identified as a cluster of less than 10 axonal vesicles occurring between synaptic boutons, were stable at 30 min but markedly reduced by 2 hr after the induction of LTP. APV blocked these effects, suggesting that the loss of axonal boutons and presynaptic vesicles was dependent on NMDA receptor activation during LTP. These findings show that specific presynaptic ultrastructural changes complement postsynaptic ultrastructural plasticity during LTP. PMID:23784793

  10. 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.

  11. Sex-specific plasticity and genotype × sex interactions for age and size of maturity in the sheepshead swordtail, Xiphophorus birchmanni.

    PubMed

    Boulton, K; Rosenthal, G G; Grimmer, A J; Walling, C A; Wilson, A J

    2016-03-01

    Responses to sexually antagonistic selection are thought to be constrained by the shared genetic architecture of homologous male and female traits. Accordingly, adaptive sexual dimorphism depends on mechanisms such as genotype-by-sex interaction (G×S) and sex-specific plasticity to alleviate this constraint. We tested these mechanisms in a population of Xiphophorus birchmanni (sheepshead swordtail), where the intensity of male competition is expected to mediate intersexual conflict over age and size at maturity. Combining quantitative genetics with density manipulations and analysis of sex ratio variation, we confirm that maturation traits are dimorphic and heritable, but also subject to large G×S. Although cross-sex genetic correlations are close to zero, suggesting sex-linked genes with important effects on growth and maturation are likely segregating in this population, we found less evidence of sex-specific adaptive plasticity. At high density, there was a weak trend towards later and smaller maturation in both sexes. Effects of sex ratio were stronger and putatively adaptive in males but not in females. Males delay maturation in the presence of mature rivals, resulting in larger adult size with subsequent benefit to competitive ability. However, females also delay maturation in male-biased groups, incurring a loss of reproductive lifespan without apparent benefit. Thus, in highly competitive environments, female fitness may be limited by the lack of sex-specific plasticity. More generally, assuming that selection does act antagonistically on male and female maturation traits in the wild, our results demonstrate that genetic architecture of homologous traits can ease a major constraint on the evolution of adaptive dimorphism.

  12. Plastic and Heritable Variation in Shell Thickness of the Intertidal Gastropod Nucella lapillus Associated with Risks of Crab Predation and Wave Action, and Sexual Maturation

    PubMed Central

    Pascoal, Sonia; Carvalho, Gary; Creer, Simon; Mendo, Sonia; Hughes, Roger

    2012-01-01

    The intertidal snail Nucella lapillus generally has thicker shells at sites sheltered from wave action, where crabs are abundant and pose a high risk of predation, than at exposed sites where crabs are rare. We studied two populations showing the opposite trend. We reciprocally transplanted snails between field sites and measured shell length, width and lip thickness of those recaptured 12 months later. Snails transplanted to the sheltered site grew larger than sheltered-site residents, which in turn grew larger than transplants to the exposed site. Relative shell-lip thickness was greater in residents at the exposed site than at the sheltered site. Transplants from shelter to exposure developed relatively thicker shells than their controls and relatively thinner shells from exposure to shelter. Progeny of the two populations were reared for 12 months in a common garden experiment presenting effluent from crabs feeding on broken conspecifics as the treatment and fresh sea-water as the control. The crab-effluent treatment decreased foraging activity, concomitantly reducing cumulative somatic growth and reproductive output. Juveniles receiving crab-effluent grew slower in shell length while developing relatively thicker shell lips than controls, the level of response being similar between lineages. F2 progeny of the exposed-site lineage showed similar trends to the F1s; sheltered-site F2s were too few for statistical analysis. At sexual maturity, shell-lip thickness was greater in snails receiving crab-effluent than in controls, indicating plasticity, but was also greater in the exposed-site than in the sheltered-site lineage, indicating heritable variation, probably in degree of sexual thickening of the shell lip. Results corroborate hypotheses that ‘defensive’ shell thickening is a passive consequence of starvation and that heritable and plastic control of defensive shell morphology act synergistically. Shell thickening of juveniles was similar between lineages

  13. A Myosin Va Mutant Mouse with Disruptions in Glutamate Synaptic Development and Mature Plasticity in Visual Cortex

    PubMed Central

    Yoshii, Akira; Zhao, Jianping; Pandian, Swarna; van Zundert, Brigitte; Constantine-Paton, Martha

    2013-01-01

    MyosinVa (MyoVa) mediates F-actin-based vesicular transport toward the plasma membrane and is found at neuronal postsynaptic densities (PSDs), but the role of MyoVa in synaptic development and function is largely unknown. Here, in studies using the dominant negative MyoVa neurological mutant mouse Flailer, we find that MyoVa plays an essential role in activity-dependent delivery of PSD-95 and other critical PSD molecules to synapses and in endocytosis of AMPA-type glutamate receptors (AMPAR) in the dendrites of CNS neurons. MyoVa is known to carry a complex containing the major scaffolding proteins of the mature PSD, PSD-95, SAPAP1/GKAP, Shank and Homer, to dendritic spine synapses. In Flailer, neurons show abnormal dendritic shaft localization of PSD-95, stargazin, dynamin3, AMPA glutamate receptors (AMPARs) and abnormal spine morphology. Flailer neurons also have abnormally high AMPAR miniature current frequencies and spontaneous AMPAR currents that are more frequent and larger than in WT while numbers of NMDAR containing synapses remain normal. The AMPAR abnormalities are consistent with a severely disrupted developmental regulation of long-term depression that we find in cortical Flailer neurons. Thus MyoVa plays a fundamentally important role both in localizing mature glutamate synapses to spines and in organizing the synapse for normal function. For this reason Flailer mice will be valuable in further dissecting the role of MyoVa in normal synaptic and circuit refinement and also in studies of neurological and neuropsychiatric diseases where disruptions of normal glutamate synapses are frequently observed. PMID:23658184

  14. Coordination of crown structure, leaf plasticity and carbon gain within the crowns of three winter-deciduous mature trees.

    PubMed

    Uemura, Akira; Harayama, Hisanori; Koike, Nobuya; Ishida, Atsushi

    2006-05-01

    We examined the vertical profiles of leaf characteristics within the crowns of two late-successional (Fagus crenata Blume and Fagus japonica Maxim.) and one early-successional tree species (Betula grossa Sieb. et Zucc.) in a Japanese forest. We also assessed the contributions of the leaves in each crown layer to whole-crown instantaneous carbon gain at midday. Carbon gain was estimated from the relationship between electron transport and photosynthetic rates. We hypothesized that more irradiance can penetrate into the middle of the crown if the upper crown layers have steep leaf inclination angles. We found that such a crown has a high whole-crown carbon gain, even if leaf traits do not change greatly with decreasing crown height. Leaf area indices (LAIs) of the two Fagus trees (5.26-5.52) were higher than the LAI of the B. grossa tree (4.50) and the leaves of the F. crenata tree were more concentrated in the top crown layers than were leaves of the other trees. Whole-crown carbon gain per unit ground area (micromol m(-2) ground s(-1)) at midday on fine days in summer was 16.3 for F. crenata, 11.0 for F. japonica, and 20.4 for B. grossa. In all study trees, leaf dry mass (LMA) and leaf nitrogen content (N) per unit area decreased with decreasing height in the crown, but leaf N per unit mass increased. Variations (plasticity) between the uppermost and lowermost crown layers in LMA, leaf N, the ratio of chlorophyll to N and the ratio of chlorophyll a to b were smaller for F. japonica and B. grossa than for F. crenata. The light extinction coefficients in the crowns were lower for the F. japonica and B. grossa trees than for the F. crenata tree. The leaf carbon isotope ratio (delta(13)C) was higher for F. japonica and B. grossa than for F. crenata, especially in the mid-crown. These results suggest that, in crowns with low leaf plasticity but steep leaf inclination angles, such as those of F. japonica and B. grossa trees, irradiance can penetrate into the middle of

  15. Career Maturity.

    ERIC Educational Resources Information Center

    Crites, John O.

    1973-01-01

    Research in the field of Career Maturity is reviewed and summarized, with particular attention to Super's Career Pattern Study, Gribbons and Lohnes' Career Development Study, and Crites' Vocational Development Project. Crites' organization and revision into a hierarchical structure of the five dimensions of vocational maturity proposed in Supers'…

  16. Virus Maturation

    PubMed Central

    Veesler, David; Johnson, John E.

    2013-01-01

    We examined virus maturation of selected non-enveloped and enveloped ssRNA viruses; retroviruses; bacteriophages and herpes virus. Processes associated with maturation in the RNA viruses range from subtle (noda and picornaviruses) to dramatic (tetraviruses and togaviruses). The elaborate assembly and maturation pathway of HIV is discussed in contrast to the less sophisticated but highly efficient processes associated with togaviruses. Bacteriophage assembly and maturation are discussed in general terms with specific examples chosen for emphasis. Finally the herpes viruses are compared with bacteriophages. The data support divergent evolution of noda, picorna and tetraviruses from a common ancestor and divergent evolution of alpha and flaviviruses from a common ancestor. Likewise, bacteriophages and herpes viruses almost certainly share a common ancestor in their evolution. Comparing all the viruses, we conclude that maturation is a convergent process that is required to solve conflicting requirements in biological dynamics and function. PMID:22404678

  17. Plastic Surgery

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? 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 " ...

  18. Market maturity

    SciTech Connect

    Meade, B.; Bowden, S.; Ellis, M

    1995-02-01

    The power sector in the Philipines provides one of the most mature independent power markets in Asia. Over the past five years, National Power Corp. (NPC), the government owned utility, has actively invited the power sector into power generation. Distribution has remained in the hands of private and rural cooperative utilities. Private utilities have been operating as full requirements customers of NPC while the growth in capacity additions by independent power producers (IPPs) has outpaced NPC`s for the second year in a row. With a recovering economy and regulatory reform proceeding, the outlook for independent power remains strong through the end of the decade. The Philipine Congress is now reviewing draft legislation that will decentralize NPC and begin the process of privatization and market-based reforms throughout the country`s power sector.

  19. 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)

  20. 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,…

  1. The importance of social dimension and maturation stage for the probabilistic maturation reaction norm in Poecilia reticulata.

    PubMed

    Diaz Pauli, B; Pauli, B D; Heino, M

    2013-10-01

    Maturation is an important event in an organism's life history, with important implications on dynamics of both wild and captive populations. The probabilistic maturation reaction norm (PMRN) has emerged as an important method to describe variation in maturation in wild fish. Because most PMRNs are based on age and size only, it is important to understand limitations of these variables in explaining maturation. We experimentally assessed (i) the sensitivity of age- and size-based PMRNs to unaccounted sources of plasticity, (ii) the role of social environment on maturation and (iii) the significance of estimating PMRNs early and late in the maturation process (initiation and completion of maturation, respectively). We reared male guppies (Poecilia reticulata) under laboratory conditions, subjected to two food levels and three different social cues. We found that growth and social environment affected the maturation in a way that could not be accounted for by their effect on age and size. PMRNs estimated for the initiation stage were less plastic (growth differences and social cues influenced the PMRN shape only little) than those for completion. The initiation of maturation is probably closer to the maturation 'decision' and allows determining factors influencing maturation decision most accurately.

  2. Plastic condoms.

    PubMed

    1968-01-01

    Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

  3. 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

  4. Inhibitory interneurons in visual cortical plasticity.

    PubMed

    van Versendaal, Daniëlle; Levelt, Christiaan N

    2016-10-01

    For proper maturation of the neocortex and acquisition of specific functions and skills, exposure to sensory stimuli is vital during critical periods of development when synaptic connectivity is highly malleable. To preserve reliable cortical processing, it is essential that these critical periods end after which learning becomes more conditional and active interaction with the environment becomes more important. How these age-dependent forms of plasticity are regulated has been studied extensively in the primary visual cortex. This has revealed that inhibitory innervation plays a crucial role and that a temporary decrease in inhibition is essential for plasticity to take place. Here, we discuss how different interneuron subsets regulate plasticity during different stages of cortical maturation. We propose a theory in which different interneuron subsets select the sources of neuronal input that undergo plasticity.

  5. Cosmetic Plastic Surgery Statistics

    MedlinePlus

    2014 Cosmetic Plastic Surgery Statistics Cosmetic Procedure Trends 2014 Plastic Surgery Statistics Report Please credit the AMERICAN SOCIETY OF PLASTIC SURGEONS when citing statistical data or using ...

  6. 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…

  7. Plastic bronchitis.

    PubMed

    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

  8. 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…

  9. 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…

  10. Data Product Maturity

    Atmospheric Science Data Center

    2013-03-25

    ... document, maturity levels are provided separately for each scientific data set (SDS) included with the data files. The data product ... indiscriminate use of these data products as the basis for research findings, journal publications, and/or presentations.   ...

  11. Mechanics of bacteriophage maturation.

    PubMed

    Roos, Wouter H; Gertsman, Ilya; May, Eric R; Brooks, Charles L; Johnson, John E; Wuite, Gijs J L

    2012-02-14

    Capsid maturation with large-scale subunit reorganization occurs in virtually all viruses that use a motor to package nucleic acid into preformed particles. A variety of ensemble studies indicate that the particles gain greater stability during this process, however, it is unknown which material properties of the fragile procapsids change. Using Atomic Force Microscopy-based nano-indentation, we study the development of the mechanical properties during maturation of bacteriophage HK97, a λ-like phage of which the maturation-induced morphological changes are well described. We show that mechanical stabilization and strengthening occurs in three independent ways: (i) an increase of the Young's modulus, (ii) a strong rise of the capsid's ultimate strength, and (iii) a growth of the resistance against material fatigue. The Young's modulus of immature and mature capsids, as determined from thin shell theory, fit with the values calculated using a new multiscale simulation approach. This multiscale calculation shows that the increase in Young's modulus isn't dependent on the crosslinking between capsomers. In contrast, the ultimate strength of the capsids does increase even when a limited number of cross-links are formed while full crosslinking appears to protect the shell against material fatigue. Compared to phage λ, the covalent crosslinking at the icosahedral and quasi threefold axes of HK97 yields a mechanically more robust particle than the addition of the gpD protein during maturation of phage λ. These results corroborate the expected increase in capsid stability and strength during maturation, however in an unexpected intricate way, underlining the complex structure of these self-assembling nanocontainers.

  12. 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

  13. 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

  14. Periodontal Plastic Surgery

    MedlinePlus

    ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ...

  15. Plasticity and Geotechnics

    NASA Astrophysics Data System (ADS)

    Yu, Hai-Sui

    Plasticity and Geotechnics is the first attempt to summarize and present, in one volume, the major developments achieved to date in the field of plasticity theory for geotechnical materials and its applications to geotechnical analysis and design.

  16. Plastic Surgery for Teenagers

    MedlinePlus

    ... or severe acne and scarring. Teens frequently gain self-esteem and confidence when their physical problems are corrected. ... art as a helpful index of anxiety and self-esteem with plastic surgery. Plastic and Reconstructive Surgery 2002. ...

  17. 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.

  18. Ear Plastic Surgery

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  19. 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.

  20. A Socioanalytic Model of Maturity

    ERIC Educational Resources Information Center

    Hogan, Robert; Roberts, Brent W.

    2004-01-01

    K0 describes a point of view on maturity that departs from earlier treatments in two ways. First, it rejects the popular assumption from humanistic psychology that maturity is a function of self-actualization and stipulates that maturity is related to certain performance capacities--namely, the ability to form lasting relationships and to achieve…

  1. VARIABLES ASSOCIATED WITH VOCATIONAL MATURITY.

    ERIC Educational Resources Information Center

    REICHMAN, WALTER

    EVIDENCE ABOUT THE CONSTRUCT VALIDITY OF PRESUMED VOCATIONAL MATURITY FACTOR SCORES WAS OBTAINED BY STUDYING THE RELATIONSHIP BETWEEN FACTORS OF VOCATIONAL MATURITY AND A GROUP OF CONCURRENT VARIABLES DEEMED RELEVANT TO VOCATIONAL MATURITY. THESE VARIABLES WERE CLASSIFIED INTO FIVE GROUPS--FAMILY SOCIOECONOMIC STATUS, ABILITY AND ACHIEVEMENT,…

  2. 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

  3. 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.

  4. 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

  5. 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…

  6. Social induction of maturation and sex determination in a coral reef fish.

    PubMed Central

    Hobbs, Jean-Paul A.; Munday, Philip L.; Jones, Geoffrey P.

    2004-01-01

    Labile maturation and sex determination should be advantageous where the probability of finding a mating partner is unpredictable. Here we tested the hypothesis that the presence of a potential mating partner induces maturation and sex determination in a coral-dwelling fish, Gobiodon erythrospilus. In natural populations at Lizard Island (Great Barrier Reef), single individuals were less likely to be mature than paired individuals and they matured at a larger size, indicating plasticity in the timing of maturation. By manipulating group structure we demonstrated that both the timing of maturation and the sex of maturing individuals are socially controlled. Single juveniles did not mature, but maturation was rapidly induced by the presence of an adult partner. In addition, sex determination was found to be labile, with juveniles maturing into the opposite sex of the partner encountered. To our knowledge, this is the first experimental demonstration of social induction of maturation in conjunction with labile sex determination at maturation in vertebrates. This flexibility enables individuals to maximize their reproductive success in an environment where the timing of mate acquisition and the sex of their future partner are unpredictable. PMID:15475329

  7. Propolis inhibits osteoclast maturation.

    PubMed

    Pileggi, Roberta; Antony, Kathryn; Johnson, Kristie; Zuo, Jian; Shannon Holliday, L

    2009-12-01

    Propolis, a natural product produced by the honey bee, has been successfully used in medicine as an anti-inflammatory and antimicrobial agent. Traumatic injuries to the teeth, especially avulsion injuries, present a challenging situation for the clinician because of post-treatment complications, such as inflammatory and/or replacement resorption. Agents that reduce osteoclast numbers and activity may be useful in the treatment of traumatic injuries to the teeth. In this study, we evaluated propolis as an anti-resorptive agent. Calcitriol-stimulated mouse marrow cultures, which contain both osteoclasts and osteoblasts, were exposed to the ethanol extracts of propolis or vehicle control and stained for tartrate-resistant acid phosphatase (TRAP)-activity to identify osteoclasts. A significant, dose-dependent reduction in multinuclear TRAP+ cells was demonstrated, although the propolis treatment accommodated cell growth and survival (P < 0.05). Propolis also reduced the formation of actin rings in pure cultures of RAW 264.7 osteoclast-like cells, suggesting that it exerts direct actions on osteoclast maturation. In summary, our data suggest that propolis inhibits late stages of osteoclast maturation including fusion of osteoclasts precursors to form giant cells and formation of actin rings. This supports the hypothesis that it may prove useful as a medicament to reduce resorption associated with traumatic injuries to the teeth. PMID:19843135

  8. 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

  9. 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.

  10. 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.

  11. Optical plasticity in fish lenses.

    PubMed

    Kröger, Ronald H H

    2013-05-01

    In a typical fish eye, the crystalline lens is the only refractive element. It is spherical in shape and has high refractive power. Most fish species have elaborate color vision and spectral sensitivity may range from the near-infrared to the near-ultraviolet. Longitudinal chromatic aberration exceeds depth of focus and chromatic blur is compensated for by species-specific multifocality of the lens. The complex optical properties of fish lenses are subject to accurate regulation, including circadian reversible adjustments and irreversible developmental tuning. The mechanisms optimize the transfer of visual information to the retina in diverse and variable environments, and allow for rapid evolutionary changes in color vision. Active optical tuning of the lens is achieved by changes in the refractive index gradient and involves layers of mature, denucleated lens fiber cells. First steps have been taken toward unraveling the signaling systems controlling lens optical plasticity. Multifocal lenses compensating for chromatic blur are common in all major groups of vertebrates, including birds and mammals. Furthermore, the optical quality of a monofocal lens, such as in the human eye, is equally sensitive to the exact shape of the refractive index profile. Optical plasticity in the crystalline lens may thus be present in vertebrates in general.

  12. 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

  13. Waste plastics liquefaction technology

    SciTech Connect

    Machidori, Hideki; Ikawa, Hironori

    1996-12-31

    Plastics are now indispensable not only in industries but for daily life because of their excellent convenience. Only in Japan, about 12.25 million tons of plastics were produced in 1993. On the other hand, the production of waste plastics in the form of industrial and municipal wastes reached 7.56 million tons in the same year. A greater part of the produced waste plastics are now disposed of by incineration and landfill. The incineration would however generate detrimental substances from burned-up plastics and emit them into the exhaust gas, while the landfill would reduce rapidly the residual capacity of the final repositories. Under the circumstances, the Law for the Promotion of Sorted Collection and Recommercialization of Plastics Containers and Packages is to be enforced in 2000 in Japan. Waste plastics liquefaction technology has become high-lighted and is presupposed to employ for the treatment of waste plastics other than PET bottles in the law for the reason that relatively wide variety of waste plastics can be processed in quantity by this technology. The Kubota Corporation has made R and D efforts relating to the plastics liquefaction technology for more than 4 years, and it is now entering the stage of its commercialization.

  14. 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.

  15. 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.

  16. Our plastic age

    PubMed Central

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

    2009-01-01

    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. PMID:19528049

  17. 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. PMID:19528049

  18. Plasticized phenolphthalein polycarbonate

    NASA Technical Reports Server (NTRS)

    Harrison, E. S.

    1976-01-01

    Phenolphthalein polycarbonate was successfully plasticized with polychlorinated biphenyls (e.g., Aroclor 1231) or tricresyl phosphate and cast from tetrahydrofuran to give clear films without loss of fire resistance. At loadings of 20 to 30 percent plasticizer the Tg was lowered to approximately 100 C which would render phenolphthalein polycarbonate easily moldable. Although these materials had some mechanical integrity as shown by their film forming ability, the room temperature toughness of the plasticized polymer was not significantly improved over unmodified polymer.

  19. Plasticity and Geomechanics

    NASA Astrophysics Data System (ADS)

    Davis, R. O.; Selvadurai, A. P. S.

    2002-11-01

    Plasticity and Geomechanics is a concise introduction to the general subject of plasticity with a particular emphasis on applications in geomechanics. Derived from the authors' lecture notes, this book is written with students firmly in mind. Excessive use of mathematical methods is avoided and, where possible, physical interpretations are given for important concepts. The authors present a clear introduction to the complex ideas and concepts of plasticity and demonstrate how this developing subject is of critical importance to geomechanics and geotechnical engineering.

  20. Plasticity and Geomechanics

    NASA Astrophysics Data System (ADS)

    Davis, R. O.; Selvadurai, A. P. S.

    2005-08-01

    Plasticity and Geomechanics is a concise introduction to the general subject of plasticity with a particular emphasis on applications in geomechanics. Derived from the authors' lecture notes, this book is written with students firmly in mind. Excessive use of mathematical methods is avoided and, where possible, physical interpretations are given for important concepts. The authors present a clear introduction to the complex ideas and concepts of plasticity and demonstrate how this developing subject is of critical importance to geomechanics and geotechnical engineering.

  1. 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.

  2. The plastics waste problem

    SciTech Connect

    Rowatt, R.J.

    1993-01-01

    Post-consumer plastic is a symptom of the municipal solid waste (MSW) problem, not the cause. Yet the U.S. public sees plastic as a major contributor to the waste stream. Two-thirds say the environmental risks of using plastics outweigh the benefits and that they favor mandatory recycling programs in their community; more than four-fifths think recycling can substantially reduce the amount of solid waste and decry the presence of nonbiodegradable plastics in landfills. Given this perception, the author reviews solid waste management issues and examines the contributions that resin producers can make.

  3. Coatings For Plastic Optics

    NASA Astrophysics Data System (ADS)

    Schaffer, Robert W.

    1983-11-01

    Over the past decade there has been a tremendous surge of interest in the use of plastic optical elements to supplement or replace glass optics. While the technology of molding and polishing plastic optics has been the chief interest, there has been increasing need for precision coatings for these elements. In some instances these coatings are as critical as the elements themselves. In this paper we will describe the difficulties incurred in coating plastic and some of the many coatings presently available today despite the difficulties encountered. We will then cover the durability aspects of these coatings and lastly, point out some areas to consider when evaluating using plastic instead of glass.

  4. Work Maturity Skills Instructor Guide.

    ERIC Educational Resources Information Center

    Lankard, Bettina; And Others

    This teaching guide is a part of those materials developed for the Work Maturity Skills Training Program. (The Work Maturity Skills Training Program is a set of individualized competency-based units that are designed to help participants develop the competencies they need to find and retain jobs.) Following a brief description of the purpose and…

  5. 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)

  6. Reinforced plastics durability

    SciTech Connect

    Pritchard, G.

    1999-01-01

    Written especially for first-time users of reinforced plastics. The book offers substantial introductory information with key concepts. Chapters examine the long-term threats to the integrity of reinforced plastics: outdoor weathering, solvent/water attack, high temperatures, and repetitive stress.

  7. Coatings for plastic glazing

    SciTech Connect

    Not Available

    1993-05-01

    This article describes how, as a replacement for glass, coated thermoplastic polymers can reduce cost and weight and increase occupant retention and design flexibility. Advances in transparent protective coatings have increased the potential for successful use of plastics in automotive applications. Originally, plastic materials were considered replacements for metals but, with proven performance, the utility of plastics is expanding beyond metal displacement. Now, transparent plastics are being considered as a potential replacement for glass. Driving this approach are many of the same reasons that plastics were first considered as alternatives to metals--cost, weight, design flexibility, and CAFE requirements. Glass has good optical properties, abrasion and chemical resistance, and outdoor durability, but it is also heavy, breakable, and expensive to form into intricate shapes. Although most clear plastics offer good optical properties, moldability, toughness, and cost benefits, their primary limitation is poor surface resistance to abrasion, scratching, chemicals, and the outdoor environment. In many cases, clear protective coatings can minimize these limitations. The potential advantages and disadvantages of plastic vs glass in automotive applications are given. Transparent plastic materials available for consideration as replacements for automotive glazing are listed.

  8. 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 ...

  9. 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.

  10. 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... determination was published in the Federal Register on Monday, July 23, 2012 (77 FR 43123). ] At the request of... plastic parts. New information shows that Fortis Plastics is now called Carlyle Plastics and Resins....

  11. 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

  12. Sustainable harvest: managing plasticity for resilient crops.

    PubMed

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

    2014-06-01

    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.

  13. Plastic Surgery for Ethnic Patients

    MedlinePlus

    ... Briefing Papers > Plastic Surgery for Ethnic Patients Briefing Paper: Plastic Surgery for Ethnic Patients More than 3. ... 2067-2071. Share Related Links Plastic Surgery Briefing Papers Menu Cosmetic Reconstructive Patient Safety Before & After Find ...

  14. Evolutionary regime shifts in age and size at maturation of exploited fish stocks

    PubMed Central

    de Roos, André M; Boukal, David S; Persson, Lennart

    2006-01-01

    Worldwide declines of fish stocks raise concerns about deleterious consequences of harvesting for stock abundances and individual life histories, and call for appropriate recovery strategies. Fishes in exploited stocks mature earlier at either larger or smaller sizes due to both genetic and plastic responses. The latter occur commonly when reduced competition for food leads to faster growth. Using a size-structured consumer–resource model, which accounts for both genetic and plastic responses, we show that fisheries-induced evolutionary changes in individual life history and stock properties can easily become irreversible. As a result of annual spawning, early maturation at small sizes and late maturation at large sizes can become alternative, evolutionarily and ecologically stable states under otherwise identical environmental conditions. Exploitation of late-maturing populations can then induce an evolutionary regime shift to smaller maturation sizes associated with stepwise, 1-year decreases in age at first reproduction. Complete and early fishing moratoria slowly reverse this process, but belated or partial closure of fisheries may accelerate or even instigate further evolution to smaller sizes at maturation. We suggest that stepwise decreases in maturation age can be used as early warnings of upcoming evolutionary changes, and should inspire timely restrictions of fisheries. PMID:16822746

  15. 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

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  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. 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

  2. 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.)

  3. 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.

  4. Recycle plastics into feedstocks

    SciTech Connect

    Kastner, H.; Kaminsky, W.

    1995-05-01

    Thermal cracking of mixed-plastics wastes with a fluidized-bed reactor can be a viable and cost-effective means to meet mandatory recycling laws. Strict worldwide environmental statutes require the hydrocarbon processing industry (HPI) to develop and implement product applications and technologies that reuse post-consumer mixed-plastics waste. Recycling or reuse of plastics waste has a broad definition. Recycling entails more than mechanical regranulation and remelting of polymers for film and molding applications. A European consortium of academia and refiners have investigated if it is possible and profitable to thermally crack plastics into feedstocks for refining and petrochemical applications. Development and demonstration of pyrolysis methods show promising possibilities of converting landfill garbage into valuable feedstocks such as ethylene, propylene, BTX, etc. Fluidized-bed reactor technologies offer HPI operators a possible avenue to meet recycling laws, conserve raw materials and yield a profit. The paper describes thermal cracking for feedstocks and pyrolysis of polyolefins.

  5. 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.

  6. Cortical plasticity and rehabilitation.

    PubMed

    Moucha, Raluca; Kilgard, Michael P

    2006-01-01

    The brain is constantly adapting to environmental and endogenous changes (including injury) that occur at every stage of life. The mechanisms that regulate neural plasticity have been refined over millions of years. Motivation and sensory experience directly shape the rewiring that makes learning and neurological recovery possible. Guiding neural reorganization in a manner that facilitates recovery of function is a primary goal of neurological rehabilitation. As the rules that govern neural plasticity become better understood, it will be possible to manipulate the sensory and motor experience of patients to induce specific forms of plasticity. This review summarizes our current knowledge regarding factors that regulate cortical plasticity, illustrates specific forms of reorganization induced by control of each factor, and suggests how to exploit these factors for clinical benefit.

  7. 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.

  8. Sensitive periods in affective development: nonlinear maturation of fear learning.

    PubMed

    Hartley, Catherine A; Lee, Francis S

    2015-01-01

    At specific maturational stages, neural circuits enter sensitive periods of heightened plasticity, during which the development of both brain and behavior are highly receptive to particular experiential information. A relatively advanced understanding of the regulatory mechanisms governing the initiation, closure, and reinstatement of sensitive period plasticity has emerged from extensive research examining the development of the visual system. In this article, we discuss a large body of work characterizing the pronounced nonlinear changes in fear learning and extinction that occur from childhood through adulthood, and their underlying neural substrates. We draw upon the model of sensitive period regulation within the visual system, and present burgeoning evidence suggesting that parallel mechanisms may regulate the qualitative changes in fear learning across development.

  9. Developmental Plasticity and Language: A Comparative Perspective.

    PubMed

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

    2016-04-01

    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 non-humans in the wild, many of these features can be developed to notable extents when non-humans 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

  10. 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…

  11. From Crescent to Mature Virion: Vaccinia Virus Assembly and Maturation

    PubMed Central

    Liu, Liang; Cooper, Tamara; Howley, Paul M.; Hayball, John D.

    2014-01-01

    Vaccinia virus (VACV) has achieved unprecedented success as a live viral vaccine for smallpox which mitigated eradication of the disease. Vaccinia virus has a complex virion morphology and recent advances have been made to answer some of the key outstanding questions, in particular, the origin and biogenesis of the virion membrane, the transformation from immature virion (IV) to mature virus (MV), and the role of several novel genes, which were previously uncharacterized, but have now been shown to be essential for VACV virion formation. This new knowledge will undoubtedly contribute to the rational design of safe, immunogenic vaccine candidates, or effective antivirals in the future. This review endeavors to provide an update on our current knowledge of the VACV maturation processes with a specific focus on the initiation of VACV replication through to the formation of mature virions. PMID:25296112

  12. 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

  13. Demonstrating the improvement of predictive maturity of a computational model

    SciTech Connect

    Hemez, Francois M; Unal, Cetin; Atamturktur, Huriye S

    2010-01-01

    We demonstrate an improvement of predictive capability brought to a non-linear material model using a combination of test data, sensitivity analysis, uncertainty quantification, and calibration. A model that captures increasingly complicated phenomena, such as plasticity, temperature and strain rate effects, is analyzed. Predictive maturity is defined, here, as the accuracy of the model to predict multiple Hopkinson bar experiments. A statistical discrepancy quantifies the systematic disagreement (bias) between measurements and predictions. Our hypothesis is that improving the predictive capability of a model should translate into better agreement between measurements and predictions. This agreement, in turn, should lead to a smaller discrepancy. We have recently proposed to use discrepancy and coverage, that is, the extent to which the physical experiments used for calibration populate the regime of applicability of the model, as basis to define a Predictive Maturity Index (PMI). It was shown that predictive maturity could be improved when additional physical tests are made available to increase coverage of the regime of applicability. This contribution illustrates how the PMI changes as 'better' physics are implemented in the model. The application is the non-linear Preston-Tonks-Wallace (PTW) strength model applied to Beryllium metal. We demonstrate that our framework tracks the evolution of maturity of the PTW model. Robustness of the PMI with respect to the selection of coefficients needed in its definition is also studied.

  14. 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.

  15. 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

  16. 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

  17. Plastic condom developed.

    PubMed

    1992-01-01

    A prototype plastic condom that is expected to be at least as strong as latex, less likely to fail, and more comfortable to use has been designed by researchers at North Carolina-based Family Health International (FHI). The National Institutes of Health has granted the nonprofit medical research organization $1.3 million to conduct tests that will include clinical trials involving volunteer couples to examine the condom/s safety, efficacy in preventing pregnancy, and acceptability among users. Researchers hope the tests, expected to take about 4 years, will show that the plastic condom can be stored for years without weakening, whereas latex loses strength with time. In addition, FHI claims the plastic condom can be used with any kind of lubricant, while Latex is limited to water-based or silicone lubricants. Latex condoms lose up to 90% of their strength when used with oil-based lubricants such as hand lotion, according to studies.

  18. 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

  19. Adaptation without Plasticity.

    PubMed

    Del Mar Quiroga, Maria; Morris, Adam P; Krekelberg, Bart

    2016-09-27

    Sensory adaptation is a phenomenon in which neurons are affected not only by their immediate input but also by the sequence of preceding inputs. In visual cortex, for example, neurons shift their preferred orientation after exposure to an oriented stimulus. This adaptation is traditionally attributed to plasticity. We show that a recurrent network generates tuning curve shifts observed in cat and macaque visual cortex, even when all synaptic weights and intrinsic properties in the model are fixed. This demonstrates that, in a recurrent network, adaptation on timescales of hundreds of milliseconds does not require plasticity. Given the ubiquity of recurrent connections, this phenomenon likely contributes to responses observed across cortex and shows that plasticity cannot be inferred solely from changes in tuning on these timescales. More broadly, our findings show that recurrent connections can endow a network with a powerful mechanism to store and integrate recent contextual information. PMID:27681421

  20. Motivational Maturity and Helping Behavior

    ERIC Educational Resources Information Center

    Haymes, Michael; Green, Logan

    1977-01-01

    Maturity in conative development (type of motivation included in Maslow's needs hierarchy) was found to be predictive of helping behavior in middle class white male college students. The effects of safety and esteem needs were compared, and the acceptance of responsibility was also investigated. (GDC)

  1. Steps to Maturity Program. Evaluation.

    ERIC Educational Resources Information Center

    Nanaimo School District #68 (British Columbia).

    In fall 1989, the Nanaimo (British Columbia) School District No. 68 asked five people, selected from the school system and community, to evaluate the "Steps to Maturity" Program (STMP), a district-wide family life education and affective development program that has developed gradually since 1972. The evaluation team interviewed a large number of…

  2. 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…

  3. 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…

  4. College Freshmen: Turmoil or Maturity?

    ERIC Educational Resources Information Center

    Rubin, Stephen

    1988-01-01

    Administered the Personal Orientation Inventory, Tennessee Self-Concept Scale, a group Rorschach, and a biographical questionnaire to 24 randomly selected freshmen from a small Northwest liberal arts college. Results indicated that the young adults responded differently from either children or mature adults. Findings support contention that…

  5. The People Capability Maturity Model

    ERIC Educational Resources Information Center

    Wademan, Mark R.; Spuches, Charles M.; Doughty, Philip L.

    2007-01-01

    The People Capability Maturity Model[R] (People CMM[R]) advocates a staged approach to organizational change. Developed by the Carnegie Mellon University Software Engineering Institute, this model seeks to bring discipline to the people side of management by promoting a structured, repeatable, and predictable approach for improving an…

  6. Rhetorical Maturity: Definition and Development.

    ERIC Educational Resources Information Center

    Miller, Susan

    Lawrence Kohlberg's stages of moral development, when applied to theories of teaching composition, support any method or material that refers to the age and prior experience of the writer and the newness of the task the writer is attempting. Rhetorical development and maturation in the ability to write and argue persuasively are partly conceptual…

  7. 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. PMID:21854965

  8. 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.

  9. Prolonged period of cortical plasticity upon redox dysregulation in fast-spiking interneurons

    PubMed Central

    Morishita, Hirofumi; Cabungcal, Jan-Harry; Chen, Ying; Do, Kim Q.; Hensch, Takao K.

    2015-01-01

    Background Oxidative stress and the specific impairment of peri-somatic GABA circuits are hallmarks of the schizophrenic brain and its animal models. Proper maturation of these fast-spiking inhibitory interneurons normally defines critical periods of experience-dependent cortical plasticity. Method Here, we link these processes by genetically inducing a redox dysregulation restricted to such parvalbumin-positive cells and examined the impact on critical period plasticity using the visual system as a model (3–6mice/group). Results Oxidative stress was accompanied by a significant loss of perineuronal nets, which normally enwrap mature fast-spiking cells to limit adult plasticity. Accordingly, the neocortex remained plastic even beyond the peak of its natural critical period. These effects were not seen when redox dysregulation was targeted in excitatory principal cells. Conclusion A cell-specific regulation of redox state thus balances plasticity and stability of cortical networks. Mis-timed developmental trajectories of brain plasticity may underlie in part the pathophysiology of mental illness. Such prolonged developmental plasticity may in turn offer a therapeutic opportunity for cognitive interventions targeting brain plasticity in schizophrenia. PMID:25758057

  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

    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. Otx2-PNN Interaction to Regulate Cortical Plasticity.

    PubMed

    Bernard, Clémence; Prochiantz, Alain

    2016-01-01

    The ability of the environment to shape cortical function is at its highest during critical periods of postnatal development. In the visual cortex, critical period onset is triggered by the maturation of parvalbumin inhibitory interneurons, which gradually become surrounded by a specialized glycosaminoglycan-rich extracellular matrix: the perineuronal nets. Among the identified factors regulating cortical plasticity in the visual cortex, extracortical homeoprotein Otx2 is transferred specifically into parvalbumin interneurons and this transfer regulates both the onset and the closure of the critical period of plasticity for binocular vision. Here, we review the interaction between the complex sugars of the perineuronal nets and homeoprotein Otx2 and how this interaction regulates cortical plasticity during critical period and in adulthood.

  13. Otx2-PNN Interaction to Regulate Cortical Plasticity

    PubMed Central

    Bernard, Clémence; Prochiantz, Alain

    2016-01-01

    The ability of the environment to shape cortical function is at its highest during critical periods of postnatal development. In the visual cortex, critical period onset is triggered by the maturation of parvalbumin inhibitory interneurons, which gradually become surrounded by a specialized glycosaminoglycan-rich extracellular matrix: the perineuronal nets. Among the identified factors regulating cortical plasticity in the visual cortex, extracortical homeoprotein Otx2 is transferred specifically into parvalbumin interneurons and this transfer regulates both the onset and the closure of the critical period of plasticity for binocular vision. Here, we review the interaction between the complex sugars of the perineuronal nets and homeoprotein Otx2 and how this interaction regulates cortical plasticity during critical period and in adulthood. PMID:26881132

  14. Successfully Integrating Research into Plastic Surgery Training Programs.

    PubMed

    Ballard, Tiffany N S; Sando, Ian C; Kasten, Steven J; Cederna, Paul S

    2015-11-01

    Successful integration of research into the educational mission of a plastic surgery residency program requires the support and dedication of the faculty members to create a culture that promotes innovation, discovery, and advancement of the field of plastic surgery. Dedicated research time during plastic surgery training is beneficial to both the resident and training program. Regardless of whether residents plan to pursue an academic career or enter private practice, participating in research provides an opportunity to develop skills to think critically and mature professionally. In this article, we review the benefits of resident research to both the trainee and training program and discuss strategies to overcome barriers to integrating research into the curriculum. PMID:26517468

  15. 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

  16. 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)

  17. Seabirds and floating plastic debris.

    PubMed

    Cadée, Gerhard C

    2002-11-01

    80% of floating plastic debris freshly washed ashore on a Dutch coast showed peckmarks made by birds at sea. They either mistake these debris for cuttlebones or simply test all floating objects. Ingestion of plastic is deleterious for marine organisms. It is urgent to set measures to plastic litter production.

  18. 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.

  19. 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

  20. 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.

  1. 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

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

    PubMed

    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

  3. Probabilistic maturation reaction norms assessed from mark-recaptures of wild fish in their natural habitat.

    PubMed

    Olsen, Esben M; Serbezov, Dimitar; Vøllestad, Leif A

    2014-05-01

    Reaction norms are a valuable tool in evolutionary biology. Lately, the probabilistic maturation reaction norm approach, describing probabilities of maturing at combinations of age and body size, has been much applied for testing whether phenotypic changes in exploited populations of fish are mainly plastic or involving an evolutionary component. However, due to typical field data limitations, with imperfect knowledge about individual life histories, this demographic method still needs to be assessed. Using 13 years of direct mark-recapture observations on individual growth and maturation in an intensively sampled population of brown trout (Salmo trutta), we show that the probabilistic maturation reaction norm approach may perform well even if the assumption of equal survival of juvenile and maturing fish does not hold. Earlier studies have pointed out that growth effects may confound the interpretation of shifts in maturation reaction norms, because this method in its basic form deals with body size rather than growth. In our case, however, we found that juvenile body size, rather than annual growth, was more strongly associated with maturation. Viewed against earlier studies, our results also underscore the challenges of generalizing life-history patterns among species and populations. PMID:24967078

  4. 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

  5. Breathing: Rhythmicity, Plasticity, Chemosensitivity

    PubMed Central

    Feldman, Jack L.; Mitchell, Gordon S.; Nattie, Eugene E.

    2010-01-01

    Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

  6. 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

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

    PubMed Central

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

    2015-01-01

    Electroencephalographically (EEG) recorded slow wave activity (SWA, 1–4.5 Hz), 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. PMID:22498654

  8. Shear bands in a bulk metallic glass after large plastic deformation

    SciTech Connect

    Qu, D.D.; Wang, Y.B.; Liao, X.Z.; Shen, J.

    2012-10-23

    A transmission electron microscopy investigation is conducted to trace shear bands in a Zr{sub 53}Cu{sub 18.7}Ni{sub 12}Al{sub 16.3} bulk metallic glass after experiencing 4% plastic deformation. Shear band initiation, secondary shear band interactions, mature shear band broadening and the interactions of shear bands with shear-induced nanocrystals are captured. Results suggest that the plasticity of the bulk metallic glass is enhanced by complex shear bands and their interactions which accommodate large plastic strain and prevent catastrophic shear band propagation.

  9. 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...

  10. Compensatory plasticity: time matters.

    PubMed

    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

  11. Frozen cultural plasticity.

    PubMed

    Houdek, Petr; Novakova, Julie

    2016-01-01

    We discuss cultural group selection under the view of the frozen plasticity theory and the different explanatory power and predictions of this framework. We present evidence that cultural adaptations and their influence on the degree of cooperation may be more complex than presented by Richerson et al., and conclude with the gene-environment-culture relationship and its impacts on cultural group selection. PMID:27561647

  12. Plasticity of amyloid fibrils†

    PubMed Central

    Wetzel, Ronald; Shivaprasad, Shankaramma; Williams, Angela D.

    2008-01-01

    In experiments designed to characterize the basis of amyloid fibril stability through mutational analysis of the Aβ(1-40) molecule, fibrils exhibit consistent, significant structural malleability. In these results, and in other properties, amyloid fibrils appear to more resemble plastic materials generated from synthetic polymers than they do globular proteins. Thus, like synthetic polymers and plastics, amyloid fibrils exhibit both polymorphism, the ability of one polypeptide to form aggregates of different morphologies, and isomorphism, the ability of different polypeptides to grow into a fibrillar amyloid morphology. This view links amyloid with the prehistorical and 20th Century use of proteins as starting materials to make films, fibers, and plastics, and with the classic protein fiber stretching experiments of the Astbury group. Viewing amyloid from the point of view of the polymer chemist may shed new light on issues such as the role of protofibrils in the mechanism of amyloid formation, the biological potency of fibrils, and the prospects for discovering inhibitors of amyloid fibril formation. PMID:17198370

  13. 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. PMID:2319903

  14. 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.

  15. Respiratory Muscle Plasticity

    PubMed Central

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

    2014-01-01

    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. PMID:23798306

  16. 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.

  17. 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.

  18. 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. PMID:26337962

  19. 7 CFR 51.1904 - Maturity classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Maturity classification. 51.1904 Section 51.1904... STANDARDS) United States Consumer Standards for Fresh Tomatoes Size and Maturity Classification § 51.1904 Maturity classification. Tomatoes which are characteristically red when ripe, but are not overripe or...

  20. 7 CFR 51.1904 - Maturity classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Maturity classification. 51.1904 Section 51.1904 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Maturity Classification § 51.1904 Maturity classification. Tomatoes which are characteristically red...

  1. 7 CFR 51.1904 - Maturity classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Maturity classification. 51.1904 Section 51.1904... STANDARDS) United States Consumer Standards for Fresh Tomatoes Size and Maturity Classification § 51.1904 Maturity classification. Tomatoes which are characteristically red when ripe, but are not overripe or...

  2. 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…

  3. Toward a Concept of Psychosocial Maturity.

    ERIC Educational Resources Information Center

    Greenberger, Ellen; Sorensen, Aage B.

    The first in a series of related reports (see TM 000 775), this paper attempts to define a concept of psychosocial maturity which would be appropriate as a comprehensive educational goal. Biological, sociological, psychological and temporal formulations of maturity are discussed and compared. Am interdisciplinary model of maturity is evolved which…

  4. 7 CFR 51.1904 - Maturity classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Maturity classification. 51.1904 Section 51.1904... STANDARDS) United States Consumer Standards for Fresh Tomatoes Size and Maturity Classification § 51.1904 Maturity classification. Tomatoes which are characteristically red when ripe, but are not overripe or...

  5. Brain plasticity in Diptera and Hymenoptera

    PubMed Central

    Groh, Claudia; Meinertzhagen, Ian A.

    2010-01-01

    To mediate different types of behaviour, nervous systems must coordinate the proper operation of their neural circuits as well as short- and long-term alterations that occur within those circuits. The latter ultimately devolve upon specific changes in neuronal structures, membrane properties and synaptic connections that are all examples of plasticity. This reorganization of the adult nervous system is shaped by internal and external influences both during development and adult maturation. In adults, behavioural experience is a major driving force of neuronal plasticity studied particularly in sensory systems. The range of adaptation depends on features that are important to a particular species, so that learning is essential for foraging in honeybees, while regenerative capacities are important in hemimetabolous insects with long appendages. Experience is usually effective during a critical period in early adult life, when neural function becomes tuned to future conditions in an insect's life. Changes occur at all levels, in synaptic circuits, neuropile volumes, and behaviour. There are many examples, and this review incorporates only a select few, mainly those from Diptera and Hymenoptera. PMID:20036946

  6. 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)

  7. 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.

  8. 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. PMID:23777666

  9. 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.

  10. 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…

  11. 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

  12. 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.

  13. 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.

  14. 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. PMID:27622096

  15. 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

  16. 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.

  17. 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.

  18. History of reinforced plastics

    SciTech Connect

    Milewski, J.V.; Rosato, D.V.

    1981-01-01

    This history of reinforced plastics is told by combining the individual histories of each reinforcement and the way in which they added to and changed the direction and rate of growth of the industry. The early history is based on all resins, fillers, and fibers found in nature. Then came the Baekeland revolution with the first synthetic resin which lasted about 25 years, at which time synthetic fiber glass and polyester resin dramatically changed the industry. Now, for the 1980s, the high modulus fibers developed 10 to 20 years ago are reshaping the industry. 32 figures.

  19. Psychotherapy and brain plasticity

    PubMed Central

    Collerton, Daniel

    2013-01-01

    In this paper, I will review why psychotherapy is relevant to the question of how consciousness relates to brain plasticity. A great deal of the research and theorizing on consciousness and the brain, including my own on hallucinations for example (Collerton and Perry, 2011) has focused upon specific changes in conscious content which can be related to temporal changes in restricted brain systems. I will argue that psychotherapy, in contrast, allows only a focus on holistic aspects of consciousness; an emphasis which may usefully complement what can be learnt from more specific methodologies. PMID:24046752

  20. Advances in engineering plastics

    SciTech Connect

    Leonard, L.

    1997-12-01

    New polymers are being commercialized in record numbers, offering the product designer a new realm of possibilities, and promising tough competition to the traditional engineering resins. Most of the growth is in single-site catalyzed resins. Metallocene (and non-metallocene) single-site catalysts enhance polymer architecture to generate highly uniform molecules, and even permit tailoring new categories of polymers. These new materials include the truly unique aliphatic polyketone, syndiotactic polystyrene (SPS); polyethylene naphthalate (PEN) resins; and novel variations of established polymers. This article provides a closer look at these newcomers to the plastics marketplace, with an emphasis on their properties and potential applications.

  1. 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.

  2. 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

  3. 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

  4. Polyolefins as additives in plastics

    SciTech Connect

    Deanin, R.D.

    1993-12-31

    Polyolefins are not only major commodity plastics - they are also very useful as additives, both in other polyolefins and also in other types of plastics. This review covers ethylene, propylene, butylene and isobutylene polymers, in blends with each other, and as additives to natural rubber, styrene/butadiene rubber, polystyrene, polyvinyl chloride, polymethyl methacrylate, polyphenylene oxide, polycarbonate, thermoplastic polyesters, polyurethanes, polyamides, and mixed automotive plastics recycling.

  5. 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.

  6. Optogenetics and synaptic plasticity.

    PubMed

    Xie, Yu-feng; Jackson, Michael F; Macdonald, John F

    2013-11-01

    The intricate and complex interaction between different populations of neurons in the brain has imposed limits on our ability to gain detailed understanding of synaptic transmission and its integration when employing classical electrophysiological approaches. Indeed, electrical field stimulation delivered via traditional microelectrodes does not permit the targeted, precise and selective control of neuronal activity amongst a varied population of neurons and their inputs (eg, cholinergic, dopaminergic or glutamatergic neurons). Recently established optogenetic techniques overcome these limitations allowing precise control of the target neuron populations, which is essential for the elucidation of the neural substrates underlying complex animal behaviors. Indeed, by introducing light-activated channels (ie, microbial opsin genes) into specific neuronal populations, optogenetics enables non-invasive optical control of specific neurons with milliseconds precision. These approaches can readily be applied to freely behaving live animals. Recently there is increased interests in utilizing optogenetics tools to understand synaptic plasticity and learning/memory. Here, we summarize recent progress in applying optogenetics in in the study of synaptic plasticity.

  7. 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. PMID:20042341

  8. 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.

  9. 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

  10. Postradiation atrophy of mature bone

    SciTech Connect

    Ergun, H.; Howland, W.J.

    1980-01-01

    The primary event of radiation damage to bone is atrophy and true necrosis of bone is uncommon. The postradiation atrophic changes of bone are the result of combined cellular and vascular damage, the former being more important. The damage to the osteoblast resulting in decreased matrix production is apparently the primary histopathologic event. Radiation damaged bone is susceptible to superimposed complications of fracture, infection, necrosis, and sarcoma. The primary radiographic evidence of atrophy, localized osteopenia, is late in appearing. Contrary to former views, the mature bone is quite radiosensitive and reacts quickly to even small doses of radiation. The differentiation of postirradiation atrophy and metastasis may be difficult. Biopsy should be the last resort because of the possibility of causing true necrosis in atrophic bone by trauma and infection.

  11. 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

  12. General classification of maturation reaction-norm shape from size-based processes.

    PubMed

    Christensen, Asbjorn; Andersen, Ken Haste

    2011-05-01

    Phenotypic plasticity of size at maturation is commonly described using size-age maturation reaction norms (MRNs). MRNs for age and size at maturation are analyzed and classified into three general categories related to different size scalings of growth and mortality. The underlying model for growth and mortality is based on processes at the level of the individual, and is motivated by the energy budget of fish. MRN shape is a balance between opposing factors and depends on subtle details of size dependence of growth and mortality. MRNs with both positive and negative slopes are predicted, and for certain mortality conditions also a lower critical spawning mass. The model is applied to predict a generic fishery-induced evolutionary response and allows assessment of climate change impact on MRNs. Our work stresses the importance of using realistic size dependence of mortality and growth, since this strongly influences the predicted MRNs and sensitivity to harvest pressure.

  13. 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

  14. 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

  15. 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

  16. Retrovirus maturation-an extraordinary structural transformation.

    PubMed

    Mattei, Simone; Schur, Florian Km; Briggs, John Ag

    2016-06-01

    Retroviruses such as HIV-1 assemble and bud from infected cells in an immature, non-infectious form. Subsequently, a series of proteolytic cleavages catalysed by the viral protease leads to a spectacular structural rearrangement of the viral particle into a mature form that is competent to fuse with and infect a new cell. Maturation involves changes in the structures of protein domains, in the interactions between protein domains, and in the architecture of the viral components that are assembled by the proteins. Tight control of proteolytic cleavages at different sites is required for successful maturation, and the process is a major target of antiretroviral drugs. Here we will describe what is known about the structures of immature and mature retrovirus particles, and about the maturation process by which one transitions into the other. Despite a wealth of available data, fundamental questions about retroviral maturation remain unanswered. PMID:27010119

  17. 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.

  18. Recycle your plastic waste

    SciTech Connect

    Kuhlke, W.C. )

    1990-05-01

    This paper discusses how source reduction and recycling are alternatives to managing waste. This includes the recycling of material before it leaves the manufacturer or reducing the size of the product being made. In-plant reprocessing of plastic materials is one method of source reduction. Included are such applications as where an injection molder collects the spur, regrinds it, and feeds it back to make an injection molded part. When a polystyrene sheet is thermoformed to make cups, after cutting, the remaining sheet is recycled, chopped up and reextruded to make a sheet to again be fed to the thermoformer. The alternative would be to sell the waste or send it to the city dump.

  19. 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...

  20. Plastics & Composites Technology Needs Assessment.

    ERIC Educational Resources Information Center

    Oakland Community Coll., Farmington, MI. Office of Institutional Planning and Analysis.

    In 1991, a study was conducted by Oakland Community College (OCC) to evaluate the need for a proposed plastics and composites technology program for design engineers. General information was obtained through a literature search, from the Society of the Plastics Industry, Inc., the Michigan Employment Security Commission, and interviews with…

  1. Neuroanatomical prerequisites for language functions in the maturing brain.

    PubMed

    Brauer, Jens; Anwander, Alfred; Friederici, Angela D

    2011-02-01

    The 2 major language-relevant cortical regions in the human brain, Broca's area and Wernicke's area, are connected via the fibers of the arcuate fasciculus/superior longitudinal fasciculus (AF/SLF). Here, we compared this pathway in adults and children and its relation to language processing during development. Comparison of fiber properties demonstrated lower anisotropy in children's AF/SLF, arguing for an immature status of this particular pathway with conceivably a lower degree of myelination. Combined diffusion tensor imaging (DTI) data and functional magnetic resonance imaging (fMRI) data indicated that in adults the termination of the AF/SLF fiber projection is compatible with functional activation in Broca's area, that is pars opercularis. In children, activation in Broca's area extended from the pars opercularis into the pars triangularis revealing an alternative connection to the temporal lobe (Wernicke's area) via the ventrally projecting extreme capsule fiber system. fMRI and DTI data converge to indicate that adults make use of a more confined language network than children based on ongoing maturation of the structural network. Our data suggest relations between language development and brain maturation and, moreover, indicate the brain's plasticity to adjust its function to available structural prerequisites. PMID:20566580

  2. 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.

  3. Computational strain gradient crystal plasticity

    NASA Astrophysics Data System (ADS)

    Niordson, Christian F.; Kysar, Jeffrey W.

    2014-01-01

    A numerical method for viscous strain gradient crystal plasticity theory is presented, which incorporates both energetic and dissipative gradient effects. The underlying minimum principles are discussed as well as convergence properties of the proposed finite element procedure. Three problems of plane crystal plasticity are studied: pure shear of a single crystal between rigid platens as well as plastic deformation around cylindrical voids in hexagonal close packed and face centered cubic crystals. Effective in-plane constitutive slip parameters for plane strain deformation of specifically oriented face centered cubic crystals are developed in terms of the crystallographic slip parameters. The effect on geometrically necessary dislocation structures introduced by plastic deformation is investigated as a function of the ratio of void radius to plasticity length scale.

  4. Adipose tissue plasticity from WAT to BAT and in between.

    PubMed

    Lee, Yun-Hee; Mottillo, Emilio P; Granneman, James G

    2014-03-01

    Adipose tissue plays an essential role in regulating energy balance through its metabolic, cellular and endocrine functions. Adipose tissue has been historically classified into anabolic white adipose tissue and catabolic brown adipose tissue. An explosion of new data, however, points to the remarkable heterogeneity among the cells types that can become adipocytes, as well as the inherent metabolic plasticity of mature cells. These data indicate that targeting cellular and metabolic plasticity of adipose tissue might provide new avenues for treatment of obesity-related diseases. This review will discuss the developmental origins of adipose tissue, the cellular complexity of adipose tissues, and the identification of progenitors that contribute to adipogenesis throughout development. We will touch upon the pathological remodeling of adipose tissue and discuss how our understanding of adipose tissue remodeling can uncover new therapeutic targets. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.

  5. Biodegradability of degradable plastic waste.

    PubMed

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  6. Genomics of environmentally induced phenotypes in 2 extremely plastic arthropods.

    PubMed

    Simon, Jean-Christophe; Pfrender, Michael E; Tollrian, Ralph; Tagu, Denis; Colbourne, John K

    2011-01-01

    Understanding how genes and the environment interact to shape phenotypes is of fundamental importance for resolving important issues in adaptive evolution. Yet, for most model species with mature genetics and accessible genomic resources, we know little about the natural environmental factors that shape their evolution. By contrast, animal species with deeply understood ecologies and well characterized responses to environmental cues are rarely subjects of genomic investigations. Here, we preview advances in genomics in aphids and waterfleas that may help transform research on the regulatory mechanisms of phenotypic plasticity. This insect and crustacean duo has the capacity to produce extremely divergent phenotypes in response to environmental stimuli. Sexual fate and reproductive mode are condition-dependent in both groups, which are also capable of altering morphology, physiology and behavior in response to biotic and abiotic cues. Recently, the genome sequences for the pea aphid Acyrthosiphon pisum and the waterflea Daphnia pulex were described by their respective research communities. We propose that an integrative study of genome biology focused on the condition-dependent transcriptional basis of their shared plastic traits and specialized mode of reproduction will provide broad insight into adaptive plasticity and genome by environment interactions. We highlight recent advances in understanding the genome regulation of alternative phenotypes and environmental cue processing, and we propose future research avenues to discover gene networks and epigenetic mechanisms underlying phenotypic plasticity.

  7. Patient Safety: Guide to Safe Plastic Surgery

    MedlinePlus

    ... and Consumer Information > Patient Safety Guide to Safe Plastic Surgery Patient Safety More Resources Choose a surgeon ... Important facts about the safety and risks of plastic surgery Questions to ask my plastic surgeon Choose ...

  8. Mapping homeostatic synaptic plasticity using cable properties of dendrites.

    PubMed

    Queenan, B N; Lee, K J; Tan, H; Huganir, R L; Vicini, S; Pak, D T S

    2016-02-19

    When chronically silenced, cortical and hippocampal neurons homeostatically upregulate excitatory synaptic function. However, the subcellular position of such changes on the dendritic tree is not clear. We exploited the cable-filtering properties of dendrites to derive a parameter, the dendritic filtering index (DFI), to map the spatial distribution of synaptic currents. Our analysis indicates that young rat cortical neurons globally scale AMPA receptor-mediated currents, while mature hippocampal neurons do not, revealing distinct homeostatic strategies between brain regions and developmental stages. The DFI presents a useful tool for mapping the dendritic origin of synaptic currents and the location of synaptic plasticity changes.

  9. 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. PMID:27625596

  10. 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

  11. 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.

  12. 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.

  13. Postradiation atrophy of mature bone

    SciTech Connect

    Erguen, H.; Howland, W.J.

    1980-01-01

    The growing number of oncological patients subjected to radiotherapy require the diagnostic radiologist to be aware of expected bone changes following irradiation and the differentiation of this entity from metastasis. The primary event of radiation damage to bone is atrophy and true necrosis of bone is uncommon. The postradiation atrophic changes of bone are the result of combined cellular and vascular damage, the former being more important. The damage to the osteoblast resulting in decreased matrix production is apparently the primary histopathologic event. Radiation damaged bone is susceptible to superimposed complications of fracture, infection, necrosis, and sarcoma. The primary radiographic evidence of atrophy, localized osteopenia, is late in appearing, mainly because of the relative insensitivity of radiographs in detecting demineralization. Contrary to former views, the mature bone is quite radiosensitive and reacts quickly to even small doses of radiation. In vivo midrodensitometric analysis and radionuclide bone and bone marrow scans can reveal early changes following irradiation. The differentiation of postirradiation atrophy and metastasis may be difficult. Biopsy should be the last resort because of the possibility of causing true necrosis in atrophic bone by trauma and infection.

  14. Postradiation atrophy of mature bone

    SciTech Connect

    Ergun, H.; Howland, W.J.

    1980-01-01

    The growing number of oncological patients subjected to radiotherapy require the diagnostic radiologist to be aware of expected bone changes following irradiation and the differentiation of this entity from metastasis. The primary event of radiation damage to bone is atrophy and true necrosis of bone is uncommon. The postradiation atrophic changes of bone are the result of combined cellular and vascular damage, the former being more important. The damage to the osteoblast resulting in decreased matrix production is apparently the primary histopathologic event. Radiation damaged bone is susceptible to superimposed complications of fracture, infection, necrosis, and sarcoma. The primary radiographic evidence of atrophy, localized osteopenia, is late in appearing, mainly because of the relative insensitivity of radiographs in detecing demineralization. Contrary to former views, the mature bone is quite radiosensitive and reacts quickly to even small doses of radiation. In vivo midrodensitometric analysis and radionuclide bone and bone marrow scans can reveal early changes following irradiation. The differentiation of postirradiation atrophy and metastasis may be difficult. Biopsy should be the last resort because of the possibility of causing true necrosis in atrophic bone by trauma and infection.

  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. Motivational maturity and helping behavior.

    PubMed

    Haymes, M; Green, L

    1977-12-01

    This study was undertaken to examine the independent influences of conative development (the Maslow needs hierarchy) upon behavioral aspects of prosocial orientations. It provides a behavioral demonstration of conative effects in a helping paradigm, among college-age men. A comparison of the conative data across the ages of 15-22 provided a cross-sectional view of conative development itself. Conative maturity was found to be predictive of greater helping among college-age men. Situational demands were demonstrated which tended to mask, but not override, these predispositional influences on helping. The cross-sectional data on conative development point to probable movement to early esteem concerns among high school men who have reached the conative level of love and belonging. On the other hand, the stability across the years of 15-22 of proportion of safety concerns suggests fixation of such concerns in those exhibiting them in high school. Results are discussed in terms of conative growth for development of prosocial orientations.

  17. Decision-Making Style and Vocational Maturity.

    ERIC Educational Resources Information Center

    Phillips, Susan D.; Strohmer, Douglas C.

    1982-01-01

    Examined the relationship between decision-making style, scholastic achievement, and vocational maturity for college students (N=64). Results did not support the hypothesized relationship between rationality and attitudinal and cognitive maturity. Scholastic achievement and lack of dependent decision style were found to be moderately predictive of…

  18. 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…

  19. 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.)...

  20. 13 CFR 120.933 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maturity. 120.933 Section 120.933 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Development Company Loan Program (504) 504 Loans and Debentures § 120.933 Maturity. From time to time, SBA will publish in...

  1. 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...

  2. 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…

  3. 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...

  4. 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...

  5. 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…

  6. Vocational Maturity among Inner-City Youths

    ERIC Educational Resources Information Center

    Maynard, Peter E.; Hansen, James C.

    1970-01-01

    This study investigates the efficacy of the Vocational Development Inventory in measuring the vocational maturity of inner city boys. Intelligence test results were converted to standardized T scores. Mean vocational maturity scores indicate large differences which disappear when intelligence is controlled by analysis of convariance. A variety of…

  7. Career Maturity and College Student Persistence.

    ERIC Educational Resources Information Center

    Perry, Stephen R.; Cabrera, Alberto F.; Vogt, W. Paul

    1999-01-01

    A study examined the role of career maturity in the college persistence of 307 freshmen at a public, residential, four-year college. Results indicate that the My Vocational Situation instrument is reliable and valid, although theoretical formulations should be reexamined. Career maturity was positively associated with several variables important…

  8. 7 CFR 51.1865 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Fresh Tomatoes 1 Definitions § 51.1865 Mature. Mature means that the tomato has reached the stage of development which will insure a proper completion of the ripening process, and that...

  9. 7 CFR 51.1907 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Consumer Standards for Fresh Tomatoes Definitions § 51.1907 Mature. Mature means that the tomato has reached the stage of development which will insure a proper completion of the ripening process....

  10. 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...

  11. 7 CFR 51.1313 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... stage of maturity which will insure the proper completion of the ripening process. (b) Before a mature... process. Therefore, a statement of firmness should be given in order to indicate the stage of the ripening process. A description of the ground color should also be given. (1) The following terms should be...

  12. 7 CFR 51.1313 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... stage of maturity which will insure the proper completion of the ripening process. (b) Before a mature... process. Therefore, a statement of firmness should be given in order to indicate the stage of the ripening process. A description of the ground color should also be given. (1) The following terms should be...

  13. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... § 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...

  14. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus... 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...

  15. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus... 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...

  16. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... 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...

  17. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... § 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...

  18. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... 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...

  19. 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.

  20. Plastic hinge modeling of structures

    NASA Astrophysics Data System (ADS)

    Maruthayappan, Ramakrishnan

    1994-07-01

    The rapid changes taking place in vehicle design has resulted in a great variety of vehicles having different structural configurations. The behavior of such structures under impact or crash conditions demand an efficient modeling of the system. Since a vehicle crash is a dynamic phenomenon exhibiting complex interaction between structural and inertial forces, the model should be able to predict the transient deformations which range from small strain elastic deformations to large strain plastic deformations. Among various formulations and modeling techniques available, the plastic hinge theory offers a simple, realistic and a computationally efficient model. This thesis explores and applies the plastic hinge modeling technique to some simple structures ranging from an elementary cantilever beam to a torque box representing a passenger compartment. The nonlinear static and dynamic behavior of a general aviation seat model for different load cases have been predicted using this theory. A detailed study and application of nonlinear finite element technique has also been performed. A comparative study of the responses yielded by plastic hinge model and finite element model demonstrates the effectiveness and accuracy of the plastic hinge model in predicting the behavior of the structures reliably. This thesis also studies and predicts the dynamics of mechanical systems using plastic hinges modeled with flexible and rigid bodies with contact-impact and plastic deformation.

  1. Translational control of synaptic plasticity.

    PubMed

    Richter, Joel D

    2010-12-01

    Synapses, points of contact between axons and dendrites, are conduits for the flow of information in the circuitry of the central nervous system. The strength of synaptic transmission reflects the interconnectedness of the axons and dendrites at synapses; synaptic strength in turn is modified by the frequency with which the synapses are stimulated. This modulation of synaptic strength, or synaptic plasticity, probably forms the cellular basis for learning and memory. RNA metabolism, particularly translational control at or near the synapse, is one process that controls long-lasting synaptic plasticity and, by extension, memory formation and consolidation. In the present paper, I review some salient features of translational control of synaptic plasticity.

  2. Respiratory supercomplexes: plasticity and implications

    PubMed Central

    Porras, Christina A.; Bai, Yidong

    2015-01-01

    The plasticity model of the electron transport chain has slowly begun to replace both the liquid model of free complexes and the solid model of supercomplexes. The plasticity model predicts that respiratory complexes exist and function both as single complexes and as supercomplexes. The advantages of this system is an electron transport train which is able to adapt to changes in its environment. This review will investigate the current body of work on supercomplexes including their assembly, regulation, and plasticity, and particularly their role in the generation of reactive oxygen species and aging. PMID:25553469

  3. Eusol: the plastic surgeon's choice?

    PubMed

    Humzah, M D; Marshall, J; Breach, N M

    1996-08-01

    Many products are currently promoted for use on wounds. Edinburgh University Solution of Lime (Eusol) has recently received adverse publicity regarding its use in wound management. One hundred and twenty-four consultant plastic surgeons were surveyed regarding their use of Eusol. Ninety-five replies were obtained (77%); of those who replied, 78 (82%) still use Eusol, while nine out of 17 who do not are prevented from using it as they are unable to obtain necessary supplies. In plastic surgery, Eusol is still being used by plastic surgeons in specific situations.

  4. 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

  5. Circadian Regulation of Synaptic Plasticity.

    PubMed

    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

  6. 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.

  7. Dopamine triggers heterosynaptic plasticity.

    PubMed

    Ishikawa, Masago; Otaka, Mami; Huang, Yanhua H; Neumann, Peter A; Winters, Bradley D; Grace, Anthony A; Schlüter, Oliver M; Dong, Yan

    2013-04-17

    As a classic neuromodulator, dopamine has long been thought to modulate, rather than trigger, synaptic plasticity. In contrast, our present results demonstrate that within the parallel projections of dopaminergic and GABAergic terminals from the ventral tegmental area to the nucleus accumbens core (NAcCo), action-potential-activated release of dopamine heterosynaptically triggers LTD at GABAergic synapses, which is likely mediated by activating presynaptically located dopamine D1 class receptors and expressed by inhibiting presynaptic release of GABA. Moreover, this dopamine-mediated heterosynaptic LTD is abolished after withdrawal from cocaine exposure. These results suggest that action-potential-dependent dopamine release triggers very different cellular consequences from those induced by volume release or pharmacological manipulation. Activation of the ventral tegmental area to NAcCo projections is essential for emotional and motivational responses. This dopamine-mediated LTD allows a flexible output of NAcCo neurons, whereas disruption of this LTD may contribute to the rigid emotional and motivational state observed in addicts during cocaine withdrawal.

  8. Timing in neural maturation: arrest, delay, precociousness, and temporal determination of malformations.

    PubMed

    Sarnat, Harvey B; Philippart, Michel; Flores-Sarnat, Laura; Wei, Xing-Chang

    2015-05-01

    Timing is primordial in initiating and synchronizing each developmental process in tissue morphogenesis. Maturational arrest, delay, and precociousness all are conducive to neurological dysfunction and may determine different malformations depending on when in development the faulty timing occurred, regardless of the identification of a specific genetic mutation or an epigenetic teratogenic event. Delay and arrest are distinguished by whether further progressive development over time can be expected or the condition is static. In general, retardation of early developmental processes, such as neurulation, cellular proliferation, and migration, leads to maturational arrest. Retardation of late processes, such as synaptogenesis and myelination, are more likely to result in maturational delay. Faulty timing of neuronal maturation in relation to other developmental processes causes neurological dysfunction and abnormal electroencephalograph maturation in preterm neonates. Precocious synaptogenesis, including pruning to provide plasticity, may facilitate prenatal formation of epileptic circuitry leading to severe postnatal infantile epilepsies. The anterior commissure forms 3 weeks earlier than the corpus callosum; its presence or absence in callosal agenesis is a marker for the onset of the initial insult. An excessively thick corpus callosum may be due to delayed retraction of transitory collateral axons. Malformations that arise at different times can share a common pathogenesis with variations on the extent: timing of mitotic cycles in mosaic somatic mutations may distinguish hemimegalencephaly from focal cortical dysplasia type 2. Timing should always be considered in interpreting cerebral dysgeneses in both imaging and neuropathological diagnoses.

  9. Identification of proliferative and mature β-cells in the islets of Langerhans.

    PubMed

    Bader, Erik; Migliorini, Adriana; Gegg, Moritz; Moruzzi, Noah; Gerdes, Jantje; Roscioni, Sara S; Bakhti, Mostafa; Brandl, Elisabeth; Irmler, Martin; Beckers, Johannes; Aichler, Michaela; Feuchtinger, Annette; Leitzinger, Christin; Zischka, Hans; Wang-Sattler, Rui; Jastroch, Martin; Tschöp, Matthias; Machicao, Fausto; Staiger, Harald; Häring, Hans-Ulrich; Chmelova, Helena; Chouinard, Julie A; Oskolkov, Nikolay; Korsgren, Olle; Speier, Stephan; Lickert, Heiko

    2016-07-21

    Insulin-dependent diabetes is a complex multifactorial disorder characterized by loss or dysfunction of β-cells. Pancreatic β-cells differ in size, glucose responsiveness, insulin secretion and precursor cell potential; understanding the mechanisms that underlie this functional heterogeneity might make it possible to develop new regenerative approaches. Here we show that Fltp (also known as Flattop and Cfap126), a Wnt/planar cell polarity (PCP) effector and reporter gene acts as a marker gene that subdivides endocrine cells into two subpopulations and distinguishes proliferation-competent from mature β-cells with distinct molecular, physiological and ultrastructural features. Genetic lineage tracing revealed that endocrine subpopulations from Fltp-negative and -positive lineages react differently to physiological and pathological changes. The expression of Fltp increases when endocrine cells cluster together to form polarized and mature 3D islet mini-organs. We show that 3D architecture and Wnt/PCP ligands are sufficient to trigger β-cell maturation. By contrast, the Wnt/PCP effector Fltp is not necessary for β-cell development, proliferation or maturation. We conclude that 3D architecture and Wnt/PCP signalling underlie functional β-cell heterogeneity and induce β-cell maturation. The identification of Fltp as a marker for endocrine subpopulations sheds light on the molecular underpinnings of islet cell heterogeneity and plasticity and might enable targeting of endocrine subpopulations for the regeneration of functional β-cell mass in diabetic patients. PMID:27398620

  10. The PPARβ/δ Agonist GW0742 Induces Early Neuronal Maturation of Cortical Post-Mitotic Neurons: Role of PPARβ/δ in Neuronal Maturation.

    PubMed

    Benedetti, Elisabetta; Di Loreto, Silvia; D'Angelo, Barbara; Cristiano, Loredana; d'Angelo, Michele; Antonosante, Andrea; Fidoamore, Alessia; Golini, Raffaella; Cinque, Benedetta; Cifone, Maria Grazia; Ippoliti, Rodolfo; Giordano, Antonio; Cimini, Annamaria

    2016-03-01

    Increasing evidences support that signaling lipids participate in synaptic plasticity and cell survival, and that the lipid signaling is closely associated with neuronal differentiation, learning, and memory and with pathologic events, such as epilepsy and Alzheimer's disease. The Peroxisome Proliferator-Activated Receptors (PPAR) are strongly involved in the fatty acid cell signaling, as many of the natural lypophylic compounds are PPAR ligands. We have previously shown that PPARβ/δ is the main isotype present in cortical neuron primary cultures and that during neuronal maturation, PPARβ/δ is gradually increased and activated. To get more insight into the molecular mechanism by which PPARβ/δ may be involved in neuronal maturation processes, in this work a specific PPARβ/δ agonist, GW0742 was used administered alone or in association with a specific PPARβ/δ antagonist, the GSK0660, and the parameters involved in neuronal differentiation and maturation were assayed. The data obtained demonstrated the strong involvement of PPARβ/δ in neuronal maturation, triggering the agonist an anticipation of neuronal differentiation, and the antagonist abolishing the observed effects. These effects appear to be mediated by the activation of BDNF pathway.

  11. 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...

  12. 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 ...

  13. 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

  14. 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.

  15. Late maturers at a performance disadvantage to their more mature peers in junior Australian football.

    PubMed

    Gastin, Paul B; Bennett, Gary

    2014-01-01

    Children and adolescents mature at different rates such that individuals competing in the same competition may differ in physical and biological maturity despite being of similar chronological age. Whether or not differences translate into on-field performance in competition is relatively unknown. This study investigated the influence of biological maturity on fitness and match running performance in junior Australian football. Eighty-seven under-15 years players were categorised into early (n = 20), average (n = 45) and late (n = 22) maturity groups based on self-reported and anthropometric assessment of biological maturity. Running movements during competition were collected using GPS (5 Hz) technology. Early maturers were heavier and taller than all other boys (P < 0.05), while biological maturity was significantly correlated to 20 m sprint (r = 0.53, P < 0.01). Total distance, high-intensity (>14.4 km · h(-1)) running distance and number of high-intensity efforts were significantly greater (20.8%, 53.6%, 31.7%, respectively; P < 0.01) in early compared to late maturers. Number of sprints and peak speed in competition were not different. Pubertal development and maturity status partially explained the differences between players in physical size, functional running fitness and match running performance. Late maturing players in this Australian football under-15 age group were at a physical and performance disadvantage to their earlier maturing peers.

  16. 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

  17. 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.

  18. 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. PMID:25840687

  19. Mycobacterium avium subspecies impair dendritic cell maturation.

    PubMed

    Basler, Tina; Brumshagen, Christina; Beineke, Andreas; Goethe, Ralph; Bäumer, Wolfgang

    2013-10-01

    Mycobacterium avium ssp. paratuberculosis (MAP) causes Johne's disease, a chronic, granulomatous enteritis of ruminants. Dendritic cells (DC) of the gut are ideally placed to combat invading mycobacteria; however, little is known about their interaction with MAP. Here, we investigated the interaction of MAP and the closely related M. avium ssp. avium (MAA) with murine DC and the effect of infected macrophages on DC maturation. The infection of DC with MAP or MAA induced DC maturation, which differed to that of LPS as maturation was accompanied by higher production of IL-10 and lower production of IL-12. Treatment of maturing DC with supernatants from mycobacteria-infected macrophages resulted in impaired DC maturation, leading to a semi-mature, tolerogenic DC phenotype expressing low levels of MHCII, CD86 and TNF-α after LPS stimulation. Though the cells were not completely differentiated they responded with an increased IL-10 and a decreased IL-12 production. Using recombinant cytokines we provide evidence that the semi-mature DC phenotype results from a combination of secreted cytokines and released antigenic mycobacterial components of the infected macrophage. Our results indicate that MAP and MAA are able to subvert DC function directly by infecting and indirectly via the milieu created by infected macrophages.

  20. Protein syntehsis during soybean seed maturation

    SciTech Connect

    Rosenberg, L.A.; Rinne, R.W.

    1987-04-01

    The authors previous work has demonstrated that physiological and biochemical changes specifically associated with soybean seed maturation can be separated from events associated with seed development. The objective of this study was to determine if soybean seed metabolism is altered during maturation drying at the level of protein synthesis. Seed harvested 35 days after flowering (0% seedling growth) were induced to mature (100% seedling growth) through controlled dehydration. Proteins labeled with (/sup 35/S)-methionine were extracted and analyzed by 1-D PAGE coupled with autoradiography and densitometry. Results show a 31 kD and 128 kD polypeptide synthesized de novo during dehydration and precocious maturation. The same two polypeptides are synthesized during natural dehydration and maturation (>60 days after flowering). Furthermore, these polypeptides persist during rehydration and germination of both precociously and naturally matured seed, but specifically disappear during early seedling growth. The authors are currently investigating the role of protein synthesis during soybean seed maturation and if it is required for establishment of a soybean seedling.

  1. [Plasticity of the cellular phenotype].

    PubMed

    Chneiweiss, Hervé

    2011-01-01

    The tragical consequences of the Hiroshima and Nagasaki atomic bombs in 1945 were to lead to the discovery of hematopoietic stem cells and their phenotypic plasticity, in response to environmental factors. These concepts were much later extended to the founding cells of other tissues. In the following collection of articles, the mechanisms underlying this plasticity, at the frontiers of developmental biology and oncology, are illustrated in the case of various cell types of neural origin and of some tumours. PMID:21501574

  2. [Plasticity of the cellular phenotype].

    PubMed

    Chneiweiss, Hervé

    2011-01-01

    The tragical consequences of the Hiroshima and Nagasaki atomic bombs in 1945 were to lead to the discovery of hematopoietic stem cells and their phenotypic plasticity, in response to environmental factors. These concepts were much later extended to the founding cells of other tissues. In the following collection of articles, the mechanisms underlying this plasticity, at the frontiers of developmental biology and oncology, are illustrated in the case of various cell types of neural origin and of some tumours.

  3. Paraoxonase 1 and HDL maturation.

    PubMed

    Gugliucci, Alejandro; Menini, Teresita

    2015-01-15

    Understanding the kinetics and function of paraoxonase 1 (PON1) is becoming an important issue in atherosclerosis. Low PON1 activity has been consistently linked with an increased risk of major cardiovascular events in the setting of secondary prevention of coronary artery disease. Recent studies have shown that there is a specific interaction of myeloperoxidase (MPO)-apoAI-PON1 on HDL surface that seems to be germane to atherogenesis. MPO specifically inhibits PON1 and PON1 mitigates MPO effects. Surprisingly, very little is known about the routes by which PON1 gets integrated into HDL or its fate during HDL remodeling in the intravascular space. We have developed a method that assesses PON1 activity in the individual HDL subclasses with the aid of which we have shown that PON1 is present across the HDL particle range and preferentially in HDL3, confirming data from ultracentrifugation (UC) studies. Upon HDL maturation ex vivo PON1 is activated and it shows a flux to both smaller and larger HDL particles as well as to VLDL and sdLDL. At the same time apoE, AI and AII are shifted across particle sizes. PON1 activation and flux across HDL particles are blocked by CETP and LCAT inhibitors. In a group of particles with such a complex biology as HDL, knowledge of the interaction between apo-lipoproteins, lipids and enzymes is key for an increased understanding of the yet multiple unknown features of its function. Solving the HDL paradox will necessitate the development of techniques to explore HDL function that are practical and well adapted to clinical studies and eventually become useful in patient monitoring. The confluence of proteomic, functional studies, HDL subclasses, PON1 assays and zymogram will yield data to draw a more elaborate and comprehensive picture of the function of HDL. It must be noted that all these studies are static and conducted in the fasting state. The crucial phase will be achieved when human kinetic studies (both in the fasting and post

  4. 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.

  5. Plasticity effects in hydraulic fracturing

    SciTech Connect

    Medlin, W.L.; Masse, L.

    1986-09-01

    The importance of reservoir rock plasticity in fracturing operations has been investigated by laboratory experiments and field results. A Lagrangian formulation for crack propagation provided the basis for the laboratory experiments. A simple crack propagation experiment showed that plasticity effects can be observed and that the importance of plasticity depends on the relative magnitudes of surface energy and energy dissipated in plastic deformation of a reservoir rock. The latter can be evaluated by laboratory measurements of a plasticity coefficient, ..cap alpha.., which comes out of the Lagrangian analysis. To measure ..cap alpha.., the authors developed a triaxial system for applying tensile stress to rock cores under confining pressure at strain rates characteristic of fracturing operations. Strain gauges mounted on each core were used with a servo-controlled press to apply strain at a linear rate between 10/sup -4/ and 10/sup -6/ seconds /sup -1/ and to obtain stress/strain data to the point of tensile failure. To distinguish between plasticity and nonlinear elastic phenomena, the authors also obtained strain hysteresis data.

  6. Ca2+ signaling differentiation during oocyte maturation.

    PubMed

    Machaca, Khaled

    2007-11-01

    Oocyte maturation is an essential cellular differentiation pathway that prepares the egg for activation at fertilization leading to the initiation of embryogenesis. An integral attribute of oocyte maturation is the remodeling of Ca2+ signaling pathways endowing the egg with the capacity to produce a specialized Ca2+ transient at fertilization that is necessary and sufficient for egg activation. Consequently, mechanistic elucidation of Ca2+ signaling differentiation during oocyte maturation is fundamental to our understanding of egg activation, and offers a glimpse into Ca2+ signaling regulation during the cell cycle.

  7. 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)

  8. 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...

  9. 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...

  10. 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...

  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, 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  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. The Moral Maturity of Repeater Delinquents.

    ERIC Educational Resources Information Center

    Petronio, Richard J.

    1980-01-01

    Differences in moral development (as conceived by Kohlberg) were examined in a sample of delinquent teenagers. The repeater group was not found, as had been hypothesized, to be lower on moral maturity than those who engaged in less delinquency. (GC)

  2. 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.

  3. 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

  4. Effect of hemiplegia on skeletal maturation.

    PubMed

    Roberts, C D; Vogtle, L; Stevenson, R D

    1994-11-01

    Children with cerebral palsy have been reported to have poor growth and delayed skeletal maturation, but it is unclear whether these effects are related to the underlying brain injury or to concomitant malnutrition. This study was designed to evaluate the effects of hemiplegic cerebral palsy on skeletal maturation and growth, with the unaffected side used as each subject's control. Bilateral hand-wrist radiographs were obtained for 19 children with spastic hemiplegia. Skeletal maturation was determined in a blinded fashion with the Fels method. The skeletal age of the affected (hemiplegic) side was less than that of the unaffected (control) side in all 19 subjects; the mean difference in skeletal age was 7.3 months (p < 0.001). The delay in skeletal maturation of the affected side correlated linearly with age and upper extremity function. These findings show that brain injury results in delayed skeletal maturation independent of malnutrition. This effect on skeletal maturation may explain, in part, the reason that some children with cerebral palsy grow poorly. PMID:7965443

  5. Review of Sexual Maturity in the Minipig.

    PubMed

    Howroyd, Paul C; Peter, Birgit; de Rijk, Eveline

    2016-06-01

    It is important to know whether the animals used in toxicology studies are sexually mature. As minipigs are being used increasingly in toxicity studies, we reviewed published data on the age of sexual maturity in the minipig. Maturity in females was assessed on the basis either of normal cycles of progesterone secretion or of the histological presence of corpora lutea and, in males, was assessed on the histological appearance of the seminiferous tubules and epididymides. In female Göttingen minipigs, the first progesterone peak was at 3.7 to 4.2 or 6.1 to 6.5 months of age. These animals were in the presence of a boar. In female Göttingen minipigs in toxicology studies, which were not in the presence of a boar, at least 1 corpus luteum in the ovaries was present in only 50% of the females by 6.5 months of age, while all were mature by 7.7 months of age. Histological maturity in the male Yucatan minipig is reported to be attained at about 4.4 months old, but in male Göttingen minipigs at about 2 months old, although the definition of maturity may have been different in the 2 studies.

  6. 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.

  7. Neurogenomic mechanisms of social plasticity.

    PubMed

    Cardoso, Sara D; Teles, Magda C; Oliveira, Rui F

    2015-01-01

    Group-living animals must adjust the expression of their social behaviour to changes in their social environment and to transitions between life-history stages, and this social plasticity can be seen as an adaptive trait that can be under positive selection when changes in the environment outpace the rate of genetic evolutionary change. Here, we propose a conceptual framework for understanding the neuromolecular mechanisms of social plasticity. According to this framework, social plasticity is achieved by rewiring or by biochemically switching nodes of a neural network underlying social behaviour in response to perceived social information. Therefore, at the molecular level, it depends on the social regulation of gene expression, so that different genomic and epigenetic states of this brain network correspond to different behavioural states, and the switches between states are orchestrated by signalling pathways that interface the social environment and the genotype. Different types of social plasticity can be recognized based on the observed patterns of inter- versus intra-individual occurrence, time scale and reversibility. It is proposed that these different types of social plasticity rely on different proximate mechanisms at the physiological, neural and genomic level. PMID:25568461

  8. 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

  9. Phasic dopamine neuron activity elicits unique mesofrontal plasticity in adolescence.

    PubMed

    Mastwal, Surjeet; Ye, Yizhou; Ren, Ming; Jimenez, Dennisse V; Martinowich, Keri; Gerfen, Charles R; Wang, Kuan Hong

    2014-07-16

    The mesofrontal dopaminergic circuit, which connects the midbrain motivation center to the cortical executive center, is engaged in control of motivated behaviors. In addition, deficiencies in this circuit are associated with adolescent-onset psychiatric disorders in humans. Developmental studies suggest that the mesofrontal circuit exhibits a protracted maturation through adolescence. However, whether the structure and function of this circuit are modifiable by activity in dopaminergic neurons during adolescence remains unknown. Using optogenetic stimulation and in vivo two-photon imaging in adolescent mice, we found that phasic, but not tonic, dopamine neuron activity induces the formation of mesofrontal axonal boutons. In contrast, in adult mice, the effect of phasic activity diminishes. Furthermore, our results showed that dopaminergic and glutamatergic transmission regulate this axonal plasticity in adolescence and inhibition of dopamine D2-type receptors restores this plasticity in adulthood. Finally, we found that phasic activation of dopamine neurons also induces greater changes in mesofrontal circuit activity and psychomotor response in adolescent mice than in adult mice. Together, our findings demonstrate that the structure and function of the mesofrontal circuit are modifiable by phasic activity in dopaminergic neurons during adolescence and suggest that the greater plasticity in adolescence may facilitate activity-dependent strengthening of dopaminergic input and improvement in behavioral control.

  10. Plasticity in the Developing Auditory Cortex: Evidence from Children with Sensorineural Hearing Loss and Auditory Neuropathy Spectrum Disorder

    PubMed Central

    Cardon, Garrett; Campbell, Julia; Sharma, Anu

    2013-01-01

    The developing auditory cortex is highly plastic. As such, the cortex is both primed to mature normally and at risk for re-organizing abnormally, depending upon numerous factors that determine central maturation. From a clinical perspective, at least two major components of development can be manipulated: 1) input to the cortex and 2) the timing of cortical input. Children with sensorineural hearing loss (SNHL) and auditory neuropathy spectrum disorder (ANSD) have provided a model of early deprivation of sensory input to the cortex, and demonstrated the resulting plasticity and development that can occur upon introduction of stimulation. In this article, we review several fundamental principles of cortical development and plasticity and discuss the clinical applications in children with SNHL and ANSD who receive intervention with hearing aids and/or cochlear implants. PMID:22668761

  11. A model of grid cell development through spatial exploration and spike time-dependent plasticity.

    PubMed

    Widloski, John; Fiete, Ila R

    2014-07-16

    Grid cell responses develop gradually after eye opening, but little is known about the rules that govern this process. We present a biologically plausible model for the formation of a grid cell network. An asymmetric spike time-dependent plasticity rule acts upon an initially unstructured network of spiking neurons that receive inputs encoding animal velocity and location. Neurons develop an organized recurrent architecture based on the similarity of their inputs, interacting through inhibitory interneurons. The mature network can convert velocity inputs into estimates of animal location, showing that spatially periodic responses and the capacity of path integration can arise through synaptic plasticity, acting on inputs that display neither. The model provides numerous predictions about the necessity of spatial exploration for grid cell development, network topography, the maturation of velocity tuning and neural correlations, the abrupt transition to stable patterned responses, and possible mechanisms to set grid period across grid modules. PMID:25033187

  12. Maturation and Functional Integration of New Granule Cells into the Adult Hippocampus.

    PubMed

    Toni, Nicolas; Schinder, Alejandro F

    2015-12-04

    The adult hippocampus generates functional dentate granule cells (GCs) that release glutamate onto target cells in the hilus and cornus ammonis (CA)3 region, and receive glutamatergic and γ-aminobutyric acid (GABA)ergic inputs that tightly control their spiking activity. The slow and sequential development of their excitatory and inhibitory inputs makes them particularly relevant for information processing. Although they are still immature, new neurons are recruited by afferent activity and display increased excitability, enhanced activity-dependent plasticity of their input and output connections, and a high rate of synaptogenesis. Once fully mature, new GCs show all the hallmarks of neurons generated during development. In this review, we focus on how developing neurons remodel the adult dentate gyrus and discuss key aspects that illustrate the potential of neurogenesis as a mechanism for circuit plasticity and function.

  13. 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.

  14. Surface properties of beached plastics.

    PubMed

    Fotopoulou, Kalliopi N; Karapanagioti, Hrissi K

    2015-07-01

    Studying plastic characteristics in the marine environment is important to better understand interaction between plastics and the environment. In the present study, high-density polyethylene (HDPE), polyethylene terephalate (PET), and polyvinyl chloride (PVC) samples were collected from the coastal environment in order to study their surface properties. Surface properties such as surface functional groups, surface topography, point of zero charge, and color change are important factors that change during degradation. Eroded HDPE demonstrated an altered surface topography and color and new functional groups. Eroded PET surface was uneven, yellow, and occasionally, colonized by microbes. A decrease in Fourier transform infrared (FTIR) peaks was observed for eroded PET suggesting that degradation had occurred. For eroded PVC, its surface became more lamellar and a new FTIR peak was observed. These surface properties were obtained due to degradation and could be used to explain the interaction between plastics, microbes, and pollutants. PMID:25787219

  15. Disposable plasmonic plastic SERS sensor.

    PubMed

    Oo, S Z; Chen, R Y; Siitonen, S; Kontturi, V; Eustace, D A; Tuominen, J; Aikio, S; Charlton, M D B

    2013-07-29

    The 'Klarite™' SERS sensor platform consisting of an array of gold coated inverted square pyramids patterned onto a silicon substrate has become the industry standard over the last decade, providing highly reproducible SERS signals. In this paper, we report successful transfer from silicon to plastic base platform of an optimized SERS substrate design which provides 8 times improvement in sensitivity for a Benzenethiol test molecule compared to standard production Klarite. Transfer is achieved using roll-to-roll and sheet-level nanoimprint fabrication techniques. The new generation plastic SERS sensors provide the added benefit of cheap low cost mass-manufacture, and easy disposal. The plastic replicated SERS sensors are shown to provide ~10(7) enhancement factor with good reproducibility (5%).

  16. 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.

  17. Surface properties of beached plastics.

    PubMed

    Fotopoulou, Kalliopi N; Karapanagioti, Hrissi K

    2015-07-01

    Studying plastic characteristics in the marine environment is important to better understand interaction between plastics and the environment. In the present study, high-density polyethylene (HDPE), polyethylene terephalate (PET), and polyvinyl chloride (PVC) samples were collected from the coastal environment in order to study their surface properties. Surface properties such as surface functional groups, surface topography, point of zero charge, and color change are important factors that change during degradation. Eroded HDPE demonstrated an altered surface topography and color and new functional groups. Eroded PET surface was uneven, yellow, and occasionally, colonized by microbes. A decrease in Fourier transform infrared (FTIR) peaks was observed for eroded PET suggesting that degradation had occurred. For eroded PVC, its surface became more lamellar and a new FTIR peak was observed. These surface properties were obtained due to degradation and could be used to explain the interaction between plastics, microbes, and pollutants.

  18. Recycled plastics for food packaging

    SciTech Connect

    Thorsheim, H.R.; Armstrong, D.J.

    1993-08-01

    There is a strong movement in this country to decrease the amount of waste produced and to use resources more efficiently. The Food and Drug Administration (FDA) is interested in helping to resolve the solid waste problem. The FDA supports recycling and the broader societal goal of diverting material from the solid waste stream, when it is consistent with the statutory responsibilities to protect the public health. The National Environmental Policy Act of 1969 (NEPA) mandates that the FDA review the impact of new food-packaging materials on the environment. Currently, no regulations have been issued for the use of recycled polymers in contact with food. Plastics are permeable, and the possibility that a contaminant such as a pesticide or motor oil might be absorbed by a plastic container and remain in the resin after recycling is very real. The paper discusses FDA policy and research to ensure that recycled plastics are safe for food-contact use.

  19. Plasticity in glutamatergic NTS neurotransmission.

    PubMed

    Kline, David D

    2008-12-10

    Changes in the physiological state of an animal or human can result in alterations in the cardiovascular and respiratory system in order to maintain homeostasis. Accordingly, the cardiovascular and respiratory systems are not static but readily adapt under a variety of circumstances. The same can be said for the brainstem circuits that control these systems. The nucleus tractus solitarius (NTS) is the central integration site of baroreceptor and chemoreceptor sensory afferent fibers. This central nucleus, and in particular the synapse between the sensory afferent and second-order NTS cell, possesses a remarkable degree of plasticity in response to a variety of stimuli, both acute and chronic. This brief review is intended to describe the plasticity observed in the NTS as well as the locus and mechanisms as they are currently understood. The functional consequence of NTS plasticity is also discussed.

  20. Oxytocin and Maternal Brain Plasticity.

    PubMed

    Kim, Sohye; Strathearn, Lane

    2016-09-01

    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 emphasis on the oxytocin system. We examine plasticity observed within the oxytocin system and discuss how these changes mediate an array of other adaptations observed within the maternal brain. We outline factors that affect the oxytocin-mediated plasticity of the maternal brain and review evidence linking disruptions in oxytocin functions to challenges in maternal adaptation. We conclude by suggesting a strategy for intervention with mothers who may be at risk for maladjustment during this transition to motherhood, while highlighting areas where further research is needed. PMID:27589498

  1. [Ocular prosthesis following plastic surgery].

    PubMed

    Morozova, O D; Druianova, Iu S

    1989-01-01

    The shape of the eye prostheses depends on the plastic surgery type. Standard prostheses with thin but not sharp edges are used to recreate the conjunctival cavity, prostheses with a deep retraction or flat ones are employed for a delayed introduction into the stump, prostheses with a 'swelling' at the upper edge are of use in surgery to correct the upper eyelid falling in, prostheses with a flattened lower edge and a 'shelf' at the upper edge are used to fortify the lower eyelid. Individual prostheses are recommended after plastic surgery. The prostheses should not prevent free closing and blinking of the eyelids, retaining the identical opening of the eyes. An inadequately chosen prosthesis brings to nothing the tremendous work made by the surgeon. Ocular prosthetics may be regarded as the final stage stabilizing the results of plastic surgery.

  2. Selective Maturation of Temporal Dynamics of Intracortical Excitatory Transmission at the Critical Period Onset.

    PubMed

    Miao, Qinglong; Yao, Li; Rasch, Malte J; Ye, Qian; Li, Xiang; Zhang, Xiaohui

    2016-08-01

    Although the developmental maturation of cortical inhibitory synapses is known to be a critical factor in gating the onset of critical period (CP) for experience-dependent cortical plasticity, how synaptic transmission dynamics of other cortical synapses are regulated during the transition to CP remains unknown. Here, by systematically examining various intracortical synapses within layer 4 of the mouse visual cortex, we demonstrate that synaptic temporal dynamics of intracortical excitatory synapses on principal cells (PCs) and inhibitory parvalbumin- or somatostatin-expressing cells are selectively regulated before the CP onset, whereas those of intracortical inhibitory synapses and long-range thalamocortical excitatory synapses remain unchanged. This selective maturation of synaptic dynamics results from a ubiquitous reduction of presynaptic release and is dependent on visual experience. These findings provide an additional essential circuit mechanism for regulating CP timing in the developing visual cortex.

  3. 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.

  4. Developmental aspects of sleep slow waves: linking sleep, brain maturation and behavior.

    PubMed

    Ringli, Maya; Huber, Reto

    2011-01-01

    Sleep slow waves are the major electrophysiological features of non-rapid eye movement (NREM) sleep. Although there is growing understanding of where slow waves originate and how they are generated during sleep, the function of slow waves is still largely unclear. A recently proposed hypothesis relates slow waves to the homeostatic regulation of synaptic plasticity. While several studies confirm a correlation between experimentally triggered synaptic changes and slow-wave activity (SWA), little is known about its association to synaptic changes occurring during cortical maturation. Interestingly, slow waves undergo remarkable changes during development that parallel the time course of cortical maturation. In a recent cross-sectional study including children and adolescents, the topographical distribution of SWA was analyzed with high-density electroencephalography. The results showed age-dependent differences in SWA topography: SWA was highest over posterior regions during early childhood and then shifted over central derivations to the frontal cortex in late adolescence. This trajectory of SWA topography matches the course of cortical gray maturation. In this chapter, the major changes in slow waves during development are highlighted and linked to cortical maturation and behavior. Interestingly, synaptic density and slow-wave amplitude increase during childhood are highest shortly before puberty, decline thereafter during adolescence, reaching overall stable levels during adulthood. The question arises whether SWA is merely reflecting cortical changes or if it plays an active role in brain maturation. We thereby propose a model, by which sleep slow waves may contribute to cortical maturation. We hypothesize that while there is a balance between synaptic strengthening and synaptic downscaling in adults, the balance of strengthening/formation and weakening/elimination is tilted during development. PMID:21854956

  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. Coating processes for plastic optics

    NASA Astrophysics Data System (ADS)

    Schulz, Ulrike

    2014-02-01

    Transparent plastics have been used for optical applications with growing demand. This development is accompanied by a desire for extended surface functionalities. Most important optical surface function is antireflection (AR), which is performed mainly by applying plasma-assisted processes. Critical considerations for coating polymers include interaction with emission from plasma and thermal stress. State-of-the-art vacuum processes for coating on plastic, as well as new results of research and development in the fields of AR design and AR structures will be introduced and discussed.

  7. Plasticity: Resource justification and development

    NASA Astrophysics Data System (ADS)

    Sayre, Eleanor C.

    Physics education research is fundamentally concerned with understanding the processes of student learning and facilitating the development of student understanding. A better understanding of learning processes and outcomes is integral to improving said learning. In this thesis, I detail and expand upon Resource Theory, allowing it to account for the development of resources and connecting the activation and use of resources to experimental data. Resource Theory is a general knowledge-in-pieces schema theory. It bridges cognitive science and education research to describe the phenomenology of problem solving. Resources are small, reusable pieces of thought that make up concepts and arguments. The physical context and cognitive state of the user determine which resources are available to be activated; different people have different resources about different things. Over time, resources may develop, acquiring new meanings as they activate in different situations. In this thesis, I introduce "plasticity," a continuum for describing the development of resources. The plasticity continuum blends elements of Process/Object and Cognitive Science with Resource Theory. The name evokes brain plasticity and myelination (markers of learning power and reasoning speed, respectively) and materials plasticity and solidity (with their attendant properties, deformability and stability). In the plasticity continuum, the two directions are more plastic and more solid. More solid resources are more durable and more connected to other resources. Users tend to be more committed to them because reasoning with them has been fruitful in the past. Similarly, users tend not to perform consistency checks on them any more. In contrast, more plastic resources need to be tested against the existing network more often, as users forge links between them and other resources. To explore these expansions and their application, I present several extended examples drawn from an Intermediate Mechanics

  8. 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.

  9. 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.

  10. [Prophylactic antibiotics in plastic surgery].

    PubMed

    Sabovcík, R; Kyslan, K

    2006-06-01

    There is no consensus on the use of prophylactic antibiotics in plastic surgery to prevent postoperative infection. This study was performed to investigate whether the use of prophylactic antibiotics has an effect on postoperative infection rate. A total of 500 patients were classified into 3 groups based on their diagnosis. Approximately half of the cases received amoxicilin/clavulanate combination the other half had no antibiotics. Wound infection was observed in the post operative period. According to our clinical findings, antibiotic prophylaxis is not necessary in plastic surgery in all patients. We did not find significant difference between the antibiotic prophylaxis and placebo group.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. Intracellular Na+ regulates epithelial Na+ channel maturation.

    PubMed

    Heidrich, Elisa; Carattino, Marcelo D; Hughey, Rebecca P; Pilewski, Joseph M; Kleyman, Thomas R; Myerburg, Mike M

    2015-05-01

    Epithelial Na(+) channel (ENaC) function is regulated by the intracellular Na(+) concentration ([Na(+)]i) through a process known as Na(+) feedback inhibition. Although this process is known to decrease the expression of proteolytically processed active channels on the cell surface, it is unknown how [Na(+)]i alters ENaC cleavage. We show here that [Na(+)]i regulates the posttranslational processing of ENaC subunits during channel biogenesis. At times when [Na(+)]i is low, ENaC subunits develop mature N-glycans and are processed by proteases. Conversely, glycan maturation and sensitivity to proteolysis are reduced when [Na(+)]i is relatively high. Surface channels with immature N-glycans were not processed by endogenous channel activating proteases, nor were they sensitive to cleavage by exogenous trypsin. Biotin chase experiments revealed that the immature surface channels were not converted into mature cleaved channels following a reduction in [Na(+)]i. The hypothesis that [Na(+)]i regulates ENaC maturation within the biosynthetic pathways is further supported by the finding that Brefeldin A prevented the accumulation of processed surface channels following a reduction in [Na(+)]i. Therefore, increased [Na(+)]i interferes with ENaC N-glycan maturation and prevents the channel from entering a state that allows proteolytic processing. PMID:25767115

  16. Calcium signaling differentiation during Xenopus oocyte maturation.

    PubMed

    El-Jouni, Wassim; Jang, Byungwoo; Haun, Shirley; Machaca, Khaled

    2005-12-15

    Ca(2+) is the universal signal for egg activation at fertilization in all sexually reproducing species. The Ca(2+) signal at fertilization is necessary for egg activation and exhibits specialized spatial and temporal dynamics. Eggs acquire the ability to produce the fertilization-specific Ca(2+) signal during oocyte maturation. However, the mechanisms regulating Ca(2+) signaling differentiation during oocyte maturation remain largely unknown. At fertilization, Xenopus eggs produce a cytoplasmic Ca(2+) (Ca(2+)(cyt)) rise that lasts for several minutes, and is required for egg activation. Here, we show that during oocyte maturation Ca(2+) transport effectors are tightly modulated. The plasma membrane Ca(2+) ATPase (PMCA) is completely internalized during maturation, and is therefore unable to extrude Ca(2+) out of the cell. Furthermore, IP(3)-dependent Ca(2+) release is required for the sustained Ca(2+)(cyt) rise in eggs, showing that Ca(2+) that is pumped into the ER leaks back out through IP(3) receptors. This apparent futile cycle allows eggs to maintain elevated cytoplasmic Ca(2+) despite the limited available Ca(2+) in intracellular stores. Therefore, Ca(2+) signaling differentiates in a highly orchestrated fashion during Xenopus oocyte maturation endowing the egg with the capacity to produce a sustained Ca(2+)(cyt) transient at fertilization, which defines the egg's competence to activate and initiate embryonic development.

  17. Novel aspects of striatal plasticity associated with long-term levo-dopa administration.

    PubMed

    Busceti, Carla Letizia; Biagioni, Francesca; Calierno, Maria Teresa; Nicoletti, Ferdinando; Ruggieri, Stefano; Fornai, Francesco

    2013-12-01

    "Striatal plasticity" is a term describing a variety of morphological and functional changes occurring both at pre- and post-synaptic level within the basal ganglia. In most cases striatal plasticity occurs when a loss of dopamine (DA) fibers in the striatum, in the course of Parkinsonism takes place. Plastic events include early pre-synaptic and long-term post-synaptic changes. In the context of long-term changes associated with striatal plasticity the role of intrinsic striatal catecholamine cells is emerging. This neuronal population expresses both tyrosine hydroxylase (TH) and DA transporter (DAT). These TH-positive cells are normally resident within the human caudate putamen but they dramatically increase during parkinsonism reaching an amount roughly corresponding to 50% of nigrostriatal neurons counted in control brains. This evidence led to hypothesize fascinating mechanisms bridging these neurons either with compensatory changes or the onset of aberrant behavioral activity. Very recently  the occurrence of these neurons was described during DA replacement therapy in parkinsonism, thus suggesting that these cells may represent the anatomical basis for plastic phenomena.  Thus, the present article, in the attempt to describe novel mechanisms generating striatal plasticity, details these cells in development and adult life and their potential role in maturation phenomena occurring in parkinsonism. PMID:24873927

  18. 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. PMID:26119105

  19. Stacking the odds for Golgi cisternal maturation.

    PubMed

    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.

  20. 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

  1. [Relationship between sexual maturation and subcutaneous fat].

    PubMed

    García Llop, L A; Ramada Benedito, A; Rodríguez-Estecha, P

    1990-10-01

    Due to the great variability at the beginnings and the period of the puberty, authors have studied the modifications of the subcutaneous-fat and their relation with the sexual maturating. They have measured the skinfold thickness of biceps, triceps, subscapular and suprailiac in 358 boys from 10 to 15 years old and 424 girls from 8 to 14 years old inrelation to sexual maturating through the stages described by Tanner. It has been found more subcutaneous fat in girls than in boys (p less than 0.05). The boys increase their subcutaneous fat until the stage 3 (except the skinfold triceps) and decrease later (except the skinfold subscapular). In boys, the analysis of varianza, show that the variations are related with the sexual maturating and not with chronologic age. PMID:2278437

  2. Macrophage-induced thymic lymphocyte maturation.

    PubMed Central

    Van den Tweel, J G; Walker, W S

    1977-01-01

    Guinea-pig peritoneal macrophages were found to influence the functional maturation of thymic lymphocytes. Autologous thymic lymphocytes obtained from macrophage co-cultures responded to three different mitogens and were reduced in their ability to reassociate spontaneously with macrophages. Neither of these properties were found in thymic lymphocytes that had not been cultured with macrophages. These functional changes appeared to be specific for macrophages since thymic lymphocytes incubated with skin fibroblasts failed to respond to the test mitogens. Furthermore, they were not the result of either the inactivation, by macrophages, of a putative suppressor thymocyte or a soluble macrophage product. In addition to influencing the functional maturation of thymic lymphocytes, macrophages also appeared to play a direct role in inducing the mitogen response of functionally mature cells. PMID:304037

  3. Stacking the odds for Golgi cisternal maturation.

    PubMed

    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. PMID:27542195

  4. Micromechanics of nonlinear plastic modes.

    PubMed

    Lerner, Edan

    2016-05-01

    Nonlinear plastic modes (NPMs) are collective displacements that are indicative of imminent plastic instabilities in elastic solids. In this work we formulate the atomistic theory that describes the reversible evolution of NPMs and their associated stiffnesses under external deformations. The deformation dynamics of NPMs is compared to those of the analogous observables derived from atomistic linear elastic theory, namely, destabilizing eigenmodes of the dynamical matrix and their associated eigenvalues. The key result we present and explain is that the dynamics of NPMs and of destabilizing eigenmodes under external deformations follow different scaling laws with respect to the proximity to imminent instabilities. In particular, destabilizing modes vary with a singular rate, whereas NPMs exhibit no such singularity. As a result, NPMs converge much earlier than destabilizing eigenmodes to their common final form at plastic instabilities. This dynamical difference between NPMs and linear destabilizing eigenmodes underlines the usefulness of NPMs for predicting the locus and geometry of plastic instabilities, compared to their linear-elastic counterparts. PMID:27300970

  5. 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.

  6. Boron trifluoride coatings for plastics

    NASA Technical Reports Server (NTRS)

    Kubacki, R. M.

    1978-01-01

    Tough, durable coatings of boron triflouride can be deposited on plastic optical components to protect them from destructive effects of abrasion, scratching, and environment. Coating material can be applied simultaneously with organic polymers, using plasma glow-discharge methods, or it can be used as base material for other coatings to increase adhesion.

  7. 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…

  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. 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)

  10. Genetic influences on neural plasticity.

    PubMed

    Pearson-Fuhrhop, Kristin M; Cramer, Steven C

    2010-12-01

    Neural plasticity refers to the capability of the brain to alter function or structure in response to a range of events and is a crucial component of both functional recovery after injury and skill learning in healthy individuals. A number of factors influence neural plasticity and recovery of function after brain injury. The current review considers the impact of genetic factors. Polymorphisms in the human genes coding for brain-derived neurotrophic factor and apolipoprotein E have been studied in the context of plasticity and stroke recovery and are discussed here in detail. Several processes involved in plasticity and stroke recovery, such as depression or pharmacotherapy effects, are modulated by other genetic polymorphisms and are also discussed. Finally, new genetic polymorphisms that have not been studied in the context of stroke are proposed as new directions for study. A better understanding of genetic influences on recovery and response to therapy might allow improved treatment after a number of forms of central nervous system injury.

  11. 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…

  12. Micromechanics of nonlinear plastic modes

    NASA Astrophysics Data System (ADS)

    Lerner, Edan

    2016-05-01

    Nonlinear plastic modes (NPMs) are collective displacements that are indicative of imminent plastic instabilities in elastic solids. In this work we formulate the atomistic theory that describes the reversible evolution of NPMs and their associated stiffnesses under external deformations. The deformation dynamics of NPMs is compared to those of the analogous observables derived from atomistic linear elastic theory, namely, destabilizing eigenmodes of the dynamical matrix and their associated eigenvalues. The key result we present and explain is that the dynamics of NPMs and of destabilizing eigenmodes under external deformations follow different scaling laws with respect to the proximity to imminent instabilities. In particular, destabilizing modes vary with a singular rate, whereas NPMs exhibit no such singularity. As a result, NPMs converge much earlier than destabilizing eigenmodes to their common final form at plastic instabilities. This dynamical difference between NPMs and linear destabilizing eigenmodes underlines the usefulness of NPMs for predicting the locus and geometry of plastic instabilities, compared to their linear-elastic counterparts.

  13. American Society of Plastic Surgeons

    MedlinePlus

    ... know the risks and trust a board-certified plastic surgeon to perform your cosmetic or reconstructive surgery. ASPS member surgeons have the training and experience that ... 1300 Chain Bridge Road McLean, VA 22101 (703) 790-5454 Timothy Germain ...

  14. 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.

  15. Recycling of plastics in Germany

    SciTech Connect

    Thienen, N. von; Patel, M.

    1999-07-01

    This article deals with the waste management of post-consumer plastics in Germany and its potential to save fossil fuels and reduce CO{sub 2} emissions. Since most experience is available for packaging, the paper first gives an overview of the legislative background and the material flows for this sector. Then recycling and recovery processes for plastics waste from all sectors are assessed in terms of their contribution to energy saving and CO{sub 2} abatement. Practically all the options studied show a better performance than waste treatment in an average incinerator which has been chosen as the reference case. High ecological benefits can be achieved by mechanical recycling if virgin polymers are substituted. The paper then presents different scenarios for managing plastic waste in Germany in 1995: considerable savings can be made by strongly enhancing the efficiency of waste incinerators. Under these conditions the distribution of plastics waste among mechanical recycling, feedstock recycling and energy recovery has a comparatively mall impact on the overall results. The maximum savings amount to 74 PJ of energy, i.e, 9% of the chemical sector energy demand in 1995 and 7.0 Mt CO{sub 2}, representing 13% of the sector's emissions. The assessment does not support a general recommendation of energy recovery due to the large difference between the German average and the best available municipal waste-to-energy facilities and also due to new technological developments in the field of mechanical recycling.

  16. Body dysmorphia and plastic surgery.

    PubMed

    Kyle, Allison

    2012-01-01

    Body dysmorphic disorder is a mental disorder characterized by a preoccupation with some aspect of one's appearance. In cosmetic surgery, this preoccupation can be overlooked by practitioners resulting in a discrepancy between expected and realistic outcome. Identifying the characteristics of this disorder may be crucial to the practitioner-patient relationship in the plastic surgery setting. PMID:22929194

  17. Farm surpluses: sources for plastics

    SciTech Connect

    Hardin, B.

    1986-10-01

    Starch from corn may soon replace petrochemicals in plastic films. And glycerol - a byproduct from processing of animal fats, soybeans, and other vegetable oil crops - may one day compete with petrochemicals in acrylic plastic manufacturing. These are two examples of how research may help convert the nation's surplus farm commodities into needed industrial products. Studies at the USDA Agricultural Research Service center in Peoria, IL, show that starch can be blended into plastic films that may serve as biodegradable mulches for tomatoes and other high-value crops. We are working on new formulas for mulches that micro-organisms can break down after a crop is harvested, says chemist Felix Otey. This feature preserves the environment and saves the expense of having to remove and burn or bury the mulches. Home gardeners and farmers use plastic mulches to protect crops from weeds and drought and extend the growing season by warming the soil sooner in the spring. And farmers use them to produce an earlier crop that commands a good price.

  18. 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

  19. Local adaptation and the evolution of phenotypic plasticity in Trinidadian guppies (Poecilia reticulata).

    PubMed

    Torres-Dowdall, Julián; Handelsman, Corey A; Reznick, David N; Ghalambor, Cameron K

    2012-11-01

    Divergent selection pressures across environments can result in phenotypic differentiation that is due to local adaptation, phenotypic plasticity, or both. Trinidadian guppies exhibit local adaptation to the presence or absence of predators, but the degree to which predator-induced plasticity contributes to population differentiation is less clear. We conducted common garden experiments on guppies obtained from two drainages containing populations adapted to high- and low-predation environments. We reared full-siblings from all populations in treatments simulating the presumed ancestral (predator cues present) and derived (predator cues absent) conditions and measured water column use, head morphology, and size at maturity. When reared in presence of predator cues, all populations had phenotypes that were typical of a high-predation ecotype. However, when reared in the absence of predator cues, guppies from high- and low-predation regimes differed in head morphology and size at maturity; the qualitative nature of these differences corresponded to those that characterize adaptive phenotypes in high- versus low-predation environments. Thus, divergence in plasticity is due to phenotypic differences between high- and low-predation populations when reared in the absence of predator cues. These results suggest that plasticity might initially play an important role during colonization of novel environments, and then evolve as a by-product of adaptation to the derived environment.

  20. ProBDNF negatively regulates neuronal remodeling, synaptic transmission and synaptic plasticity in hippocampus

    PubMed Central

    Yang, Jianmin; Harte-Hargrove, Lauren C.; Siao, Chia-Jen; Marinic, Tina; Clarke, Roshelle; Ma, Qian; Jing, Deqiang; LaFrancois, John J.; Bath, Kevin G.; Mark, Willie; Ballon, Douglas; Lee, Francis S.; Scharfman, Helen E.; Hempstead, Barbara L.

    2014-01-01

    Summary Experience-dependent plasticity shapes postnatal development of neural circuits, but the mechanisms that refine dendritic arbors, remodel spines, and impair synaptic activity are poorly understood. Mature brain-derived neurotrophic factor (BDNF) modulates neuronal morphology and synaptic plasticity, including long-term potentiation (LTP) via TrkB activation. BDNF is initially translated as proBDNF which binds p75NTR. In vitro, recombinant proBDNF modulates neuronal structure and alters hippocampal long-term plasticity, but the actions of endogenously expressed proBDNF are unclear. Therefore, we generated a cleavage-resistant probdnf knock-in mouse. Our results demonstrate that proBDNF negatively regulates hippocampal dendritic complexity and spine density through p75NTR. Hippocampal slices from probdnf mice exhibit depressed synaptic transmission, impaired LTP and enhanced long-term depression (LTD) in area CA1. These results suggest that proBDNF acts in vivo as a biologically active factor that regulates hippocampal structure, synaptic transmission and plasticity, effects that are distinct from mature BDNF. PMID:24746813

  1. Local adaptation and the evolution of phenotypic plasticity in Trinidadian guppies (Poecilia reticulata).

    PubMed

    Torres-Dowdall, Julián; Handelsman, Corey A; Reznick, David N; Ghalambor, Cameron K

    2012-11-01

    Divergent selection pressures across environments can result in phenotypic differentiation that is due to local adaptation, phenotypic plasticity, or both. Trinidadian guppies exhibit local adaptation to the presence or absence of predators, but the degree to which predator-induced plasticity contributes to population differentiation is less clear. We conducted common garden experiments on guppies obtained from two drainages containing populations adapted to high- and low-predation environments. We reared full-siblings from all populations in treatments simulating the presumed ancestral (predator cues present) and derived (predator cues absent) conditions and measured water column use, head morphology, and size at maturity. When reared in presence of predator cues, all populations had phenotypes that were typical of a high-predation ecotype. However, when reared in the absence of predator cues, guppies from high- and low-predation regimes differed in head morphology and size at maturity; the qualitative nature of these differences corresponded to those that characterize adaptive phenotypes in high- versus low-predation environments. Thus, divergence in plasticity is due to phenotypic differences between high- and low-predation populations when reared in the absence of predator cues. These results suggest that plasticity might initially play an important role during colonization of novel environments, and then evolve as a by-product of adaptation to the derived environment. PMID:23106708

  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. The maturation of ovulatory potential in man.

    PubMed

    Kulin, H E

    1980-01-01

    The maturation of the potential for ovulation in man is reviewed in the light of recent data quantitating gonadotropins and gonadal steroids in the prepubertal child. The primary limitations of the hypothalamic-pituitary-gonadal axis are seen as related to feedback control mechanisms. Based on preliminary data obtained in patients with gonadal dysgenesis, a hypothesis which links positive and negative feedback maturation is proposed. The development of full reproductive potential in man is clearly a process which extends over a decade or more.

  5. The Maturely, Immature Orientale Impact Basin

    NASA Astrophysics Data System (ADS)

    Cahill, J. T.; Lawrence, D. J.; Stickle, A. M.; Delen, O.; Patterson, G.; Greenhagen, B. T.

    2015-12-01

    Lunar surface maturity is consistently examined using the NIR optical maturity parameter (OMAT) [1]. However, the NIR only provides a perspective of the upper microns of the lunar surface. Recent studies of Lunar Prospector (LP) and Lunar Reconnaissance Orbiter data sets are now demonstrating additional measures of maturity with sensitivities to greater depths (~2 m) in the regolith. These include thermal infrared, S-band radar, and epithermal neutron data sets [2-4]. Interestingly, each of these parameters is directly comparable to OMAT despite each measuring slightly different aspects of the regolith. This is demonstrated by Lawrence et al. [3] where LP-measured non-polar highlands epithermal neutrons trend well with albedo, OMAT, and the Christensen Feature (CF). Lawrence et al. [3] used these data to derive and map highlands hydrogen (H) which is dominantly a function of H-implantation. With this in mind, areas of enriched-H are mature, while areas of depleted H are immature. Surface roughness as measured by S-band radar [4], also provides a measure of maturity. In this case, the circular polarization ratio (CPR) is high when rough and immature, and low when smooth and mature. Knowing this, one can recognize areas in the non-polar lunar highlands that show contradictory measures of maturity. For example, while many lunar localities show consistently immature albedo, OMAT, CF, CPR, and H concentrations (e.g., Tycho), others do not. Orientale basin is the most prominent example, shown to have immature CPR, CF, and H concentrations despite a relatively mature albedo and OMAT values as well as an old age determination (~3.8 Ga). To better understand how the lunar regolith is weathering in the upper 1-2 m of regolith with time we examine the Orientale basin relative to other highlands regions. [1] Lucey et al. (2000) JGR, 105, 20377; [2] Lucey et al. (2013) LPSC, 44, 2890; [3] Lawrence et al. (2015) Icarus, j.icarus.2015.01.005; [4] Neish et al. (2013) JGR, 118

  6. Maturation of rat proximal tubule chloride permeability.

    PubMed

    Baum, Michel; Quigley, Raymond

    2005-12-01

    We have previously shown that neonate rabbit tubules have a lower chloride permeability but comparable mannitol permeability compared with adult proximal tubules. The surprising finding of lower chloride permeability in neonate proximals compared with adults impacts net chloride transport in this segment, which reabsorbs 60% of the filtered chloride in adults. However, this maturational difference in chloride permeability may not be applicable to other species. The present in vitro microperfusion study directly examined the chloride and mannitol permeability using in vitro perfused rat proximal tubules during postnatal maturation. Whereas there was no maturational change in mannitol permeability, chloride permeability was 6.3 +/- 1.3 x 10(-5) cm/s in neonate rat proximal convoluted tubule and 16.1 +/- 2.3 x 10(-5) cm/s in adult rat proximal convoluted tubule (P < 0.01). There was also a maturational increase in chloride permeability in the rat proximal straight tubule (5.1 +/- 0.6 x 10(-5) cm/s vs. 9.3 +/- 0.6 x 10(-5) cm/s, P < 0.01). There was no maturational change in bicarbonate-to-chloride permeabilities (P(HCO3)/P(Cl)) in the rat proximal straight tubules (PST) and proximal convoluted tubules (PCT) or in the sodium-to-chloride permeability (P(Na)/P(Cl)) in the proximal straight tubule; however, there was a significant maturational decrease in proximal convoluted tubule P(Na)/P(Cl) with postnatal development (1.31 +/- 0.12 in neonates vs. 0.75 +/- 0.06 in adults, P < 0.001). There was no difference in the transepithelial resistance measured by current injection and cable analysis in the PCT, but there was a maturational decrease in the PST (7.2 +/- 0.8 vs. 4.6 +/- 0.1 ohms x cm2, P < 0.05). These studies demonstrate there are maturational changes in the rat paracellular pathway that impact net NaCl transport during development. PMID:16051720

  7. Comparison of Career Maturity among Graduate Students and Undergraduates.

    ERIC Educational Resources Information Center

    McCaffrey, Sue Saunders; And Others

    1984-01-01

    Compared the career maturity of graduate and undergraduate students (N=249) and investigated the relationship of gender to career maturity. Results indicated that achievement of career maturity tasks was similar for seniors and graduate students and that similar levels of career maturity were found between males and females. (LLL)

  8. Career Maturity in College Students with Learning Disabilities.

    ERIC Educational Resources Information Center

    Ohler, Denise L.; And Others

    1996-01-01

    Compared levels of career maturity between college students (n=76) with and without learning disabilities and investigated factors associated with career maturity. Few differences in career maturity were found. However, different predictors of career maturity for the two groups emerged. Students with learning disabilities who received more…

  9. 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.

  10. 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.

  11. 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)

  12. 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. PMID:18834997

  13. 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.

  14. 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.

  15. 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…

  16. 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 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. Caudal Ganglionic Eminence Precursor Transplants Disperse and Integrate as Lineage-Specific Interneurons but Do Not Induce Cortical Plasticity.

    PubMed

    Larimer, Phillip; Spatazza, Julien; Espinosa, Juan Sebastian; Tang, Yunshuo; Kaneko, Megumi; Hasenstaub, Andrea R; Stryker, Michael P; Alvarez-Buylla, Arturo

    2016-08-01

    The maturation of inhibitory GABAergic cortical circuits regulates experience-dependent plasticity. We recently showed that the heterochronic transplantation of parvalbumin (PV) or somatostatin (SST) interneurons from the medial ganglionic eminence (MGE) reactivates ocular dominance plasticity (ODP) in the postnatal mouse visual cortex. Might other types of interneurons similarly induce cortical plasticity? Here, we establish that caudal ganglionic eminence (CGE)-derived interneurons, when transplanted into the visual cortex of neonatal mice, migrate extensively in the host brain and acquire laminar distribution, marker expression, electrophysiological properties, and visual response properties like those of host CGE interneurons. Although transplants from the anatomical CGE do induce ODP, we found that this plasticity reactivation is mediated by a small fraction of MGE-derived cells contained in the transplant. These findings demonstrate that transplanted CGE cells can successfully engraft into the postnatal mouse brain and confirm the unique role of MGE lineage neurons in the induction of ODP. PMID:27425623

  2. Preadipocyte conversion to macrophage. Evidence of plasticity.

    PubMed

    Charrière, Guillaume; Cousin, Béatrice; Arnaud, Emmanuelle; André, Mireille; Bacou, Francis; Penicaud, Luc; Casteilla, Louis

    2003-03-14

    Preadipocytes are present throughout adult life in adipose tissues and can proliferate and differentiate into mature adipocytes according to the energy balance. An increasing number of reports demonstrate that cells from adipose lineages (preadipocytes and adipocytes) and macrophages share numerous functional or antigenic properties. No large scale comparison reflecting the phenotype complexity has been performed between these different cell types until now. We used profiling analysis to define the common features shared by preadipocyte, adipocyte, and macrophage populations. Our analysis showed that the preadipocyte profile is surprisingly closer to the macrophage than to the adipocyte profile. From these data, we hypothesized that in a macrophage environment preadipocytes could effectively be converted into macrophages. We injected labeled stroma-vascular cells isolated from mouse white adipose tissue or 3T3-L1 preadipocyte cell line into the peritoneal cavity of nude mice and investigated changes in their phenotype. Preadipocytes rapidly and massively acquired high phagocytic activity and index. 60-70% of preadipocytes also expressed five macrophage-specific antigens: F4/80, Mac-1, CD80, CD86, and CD45. These values were similar to those observed for peritoneal macrophages. In vitro experiments showed that cell-to-cell contact between preadipocytes and peritoneal macrophages partially induced this preadipocyte phenotype conversion. Overall, these results suggest that preadipocyte and macrophage phenotypes are very similar and that preadipocytes have the potential to be very efficiently and rapidly converted into macrophages. This work emphasizes the great cellular plasticity of adipose precursors and reinforces the link between adipose tissue and innate immunity processes. PMID:12519759

  3. The cerebellum on cocaine: plasticity and metaplasticity.

    PubMed

    Vazquez-Sanroman, Dolores; Leto, Ketty; Cerezo-Garcia, Miguel; Carbo-Gas, María; Sanchis-Segura, Carla; Carulli, Daniela; Rossi, Ferdinando; Miquel, Marta

    2015-09-01

    Despite the fact that several data have supported the involvement of the cerebellum in the functional alterations observed after prolonged cocaine use, this brain structure has been traditionally ignored and excluded from the circuitry affected by addictive drugs. In the present study, we investigated the effects of a chronic cocaine treatment on molecular and structural plasticity in the cerebellum, including BDNF, D3 dopamine receptors, ΔFosB, the Glu2 AMPA receptor subunit, structural modifications in Purkinje neurons and, finally, the evaluation of perineuronal nets (PNNs) in the projection neurons of the medial nucleus, the output of the cerebellar vermis. In the current experimental conditions in which repeated cocaine treatment was followed by a 1-week withdrawal period and a new cocaine challenge, our results showed that cocaine induced a large increase in cerebellar proBDNF levels and its expression in Purkinje neurons, with the mature BDNF expression remaining unchanged. Together with this, cocaine-treated mice exhibited a substantial enhancement of D3 receptor levels. Both ΔFosB and AMPA receptor Glu2 subunit expressions were enhanced in cocaine-treated animals. Significant pruning in Purkinje dendrite arborization and reduction in the size and density of Purkinje boutons contacting deep cerebellar projection neurons accompanied cocaine-dependent increase in proBDNF. Cocaine-associated effects point to the inhibitory Purkinje function impairment, as was evidenced by lower activity in these cells. Moreover, the probability of any remodelling in Purkinje synapses appears to be decreased due to an upregulation of extracellular matrix components in the PNNs surrounding the medial nuclear neurons.

  4. Influence of maturation and aging on mechanical and biochemical properties of connective tissue in rats.

    PubMed

    Vogel, H G

    1980-01-01

    maturation may be explained by an increase of cross-linking of collagen. Other phenomena such as changes at low extension degrees or parameters of plasticity cannot be explained on this basis. Further studies are needed for a better understanding of the true aging process in connective tissue.

  5. Two Noninvasive Methods to Measure Female Maturation.

    ERIC Educational Resources Information Center

    Kozinetz, Claudia A.

    1986-01-01

    Data from a sample of 278 females, aged 7 to 13, were used to compare two methods of measuring maturation. The methods were self-assessment of secondary sex characteristics and prediction of adult height. Results are presented. (Author/MT)

  6. 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,…

  7. 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…

  8. Sperm Proteome Maturation in the Mouse Epididymis

    PubMed Central

    Skerget, Sheri; Rosenow, Matthew A.; Petritis, Konstantinos; Karr, Timothy L.

    2015-01-01

    In mammals, transit through the epididymis, which involves the acquisition, loss and modification of proteins, is required to confer motility and fertilization competency to sperm. The overall dynamics of maturation is poorly understood, and a systems level understanding of the complex maturation process will provide valuable new information about changes occurring during epididymal transport. We report the proteomes of sperm collected from the caput, corpus and cauda segments of the mouse epididymis, identifying 1536, 1720 and 1234 proteins respectively. This study identified 765 proteins that are present in sperm obtained from all three segments. We identified 1766 proteins that are potentially added (732) or removed (1034) from sperm during epididymal transit. Phenotypic analyses of the caput, corpus and cauda sperm proteomes identified 60 proteins that have known sperm phenotypes when mutated, or absent from sperm. Our analysis indicates that as much as one-third of proteins with known sperm phenotypes are added to sperm during epididymal transit. GO analyses revealed that cauda sperm are enriched for specific functions including sperm-egg recognition and motility, consistent with the observation that sperm acquire motility and fertilization competency during transit through the epididymis. In addition, GO analyses revealed that the immunity protein profile of sperm changes during sperm maturation. Finally, we identified components of the 26S proteasome, the immunoproteasome, and a proteasome activator in mature sperm. PMID:26556802

  9. Bluetongue virus capsid assembly and maturation.

    PubMed

    Mohl, Bjorn-Patrick; Roy, Polly

    2014-08-01

    Maturation is an intrinsic phase of the viral life cycle and is often intertwined with egress. In this review we focus on orbivirus maturation by using Bluetongue virus (BTV) as a representative. BTV, a member of the genus Orbivirus within the family Reoviridae, has over the last three decades been subjected to intense molecular study and is thus one of the best understood viruses. BTV is a non-enveloped virus comprised of two concentric protein shells that encapsidate 10 double-stranded RNA genome segments. Upon cell entry, the outer capsid is shed, releasing the core which does not disassemble into the cytoplasm. The polymerase complex within the core then synthesizes transcripts from each genome segment and extrudes these into the cytoplasm where they act as templates for protein synthesis. Newly synthesized ssRNA then associates with the replicase complex prior to encapsidation by inner and outer protein layers of core within virus-triggered inclusion bodies. Maturation of core occurs outside these inclusion bodies (IBs) via the addition of the outer capsid proteins, which appears to be coupled to a non-lytic, exocytic pathway during early infection. Similar to the enveloped viruses, BTV hijacks the exocytosis and endosomal sorting complex required for trafficking (ESCRT) pathway via a non-structural glycoprotein. This exquisitely detailed understanding is assembled from a broad array of assays, spanning numerous and diverse in vitro and in vivo studies. Presented here are the detailed insights of BTV maturation and egress. PMID:25196482

  10. 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.

  11. Job Search Manual for Mature Workers.

    ERIC Educational Resources Information Center

    Merrill, Fred L.

    This document is designed to help mature persons find the "right" professional, managerial, or technical jobs. Section 1 introduces the materials. Section 2 shows job seekers how to write a general statement that defines the nature of the position desired and how to assess their skills, abilities, interests, work values, and personal qualities…

  12. Evaluating Hass Avocado Maturity Using Hyperspectral Imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maturity of avocado fruit is usually assessed by measuring its dry matter content(DM), which is a destructive and time consuming process. The aim of this study is tointroduce a non-destructive and quick technique that can estimate the DM content of an avocado fruit. 'Hass' avocado fruits at diff...

  13. 24 CFR 242.27 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Maturity. 242.27 Section 242.27 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN......

  14. 24 CFR 242.27 - Maturity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Maturity. 242.27 Section 242.27 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN......

  15. 24 CFR 242.27 - Maturity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Maturity. 242.27 Section 242.27 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN......

  16. 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:...

  17. 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:...

  18. 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:...

  19. 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…

  20. 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…

  1. 7 CFR 51.1313 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Winter Pears 1 Definitions § 51.1313 Mature. (a... also be given. (1) The following terms should be used for describing the ground color: Green, Light Green, Yellowish Green, and Yellow. (2) The following terms should be used for describing the...

  2. 7 CFR 51.1272 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Summer and Fall Pears 1 Definitions § 51.1272 Mature... also be given. (1) The following terms should be used for describing the ground color: Green, Light Green, Yellowish Green, and Yellow. (2) The following terms should be used for describing the...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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…

  9. 7 CFR 51.2841 - 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... considered mature when harvested in accordance with good commercial practice at a stage which will not...

  10. 7 CFR 51.888 - Maturity requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, in the case of Arizona maturity..., Standardization Section, Room 2065-S, 14th and Independence Avenue, Washington, DC 20250 or at the National....5 Cardinal, Emperor, Perlette, Ribier, Olivette Blanche, Rish Baba, Red Malaga, and...

  11. 7 CFR 51.888 - Maturity requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, in the case of Arizona maturity..., Standardization Section, Room 2065-S, 14th and Independence Avenue, Washington, DC 20250 or at the National....5 Cardinal, Emperor, Perlette, Ribier, Olivette Blanche, Rish Baba, Red Malaga, and...

  12. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maturity. 200.82 Section 200.82 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN...

  13. Neuropsychological and Early Maturational Correlates of Intelligence.

    ERIC Educational Resources Information Center

    Denno, Deborah J.

    A study designed to examine biological, sociological, and early maturational correlates of intelligence collected data prospectively, from birth to 15 years of age, on a sample of 987 black children. Multiple indicators of eight independent and three dependent variables were tested in a structural equation model. Altogether, clear sex differences…

  14. 7 CFR 51.1272 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... reached the stage of maturity which will insure the proper completion of the ripening process. (b) Before... the ripening process. Therefore, a statement of firmness should be given in order to indicate the stage of the ripening process. A description of the ground color should also be given. (1) The...

  15. 7 CFR 51.1272 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... reached the stage of maturity which will insure the proper completion of the ripening process. (b) Before... the ripening process. Therefore, a statement of firmness should be given in order to indicate the stage of the ripening process. A description of the ground color should also be given. (1) The...

  16. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be... 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...

  17. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be... 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...

  18. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 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...

  19. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be... 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...

  20. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... 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...

  1. Relative dental maturity and associated skeletal maturity in prehistoric native Americans of the Ohio valley area.

    PubMed

    Sciulli, Paul W

    2007-04-01

    Estimation of age-at-death of subadults in prehistoric skeletal samples based on modern reference standards rests on a number of assumptions of which many are untestable. If these assumptions are not met error of unknown magnitude and direction will be introduced to the subadult age estimates. This situation suggests that an independent estimate or estimates of age-related features, free of most of the assumptions made when using modern reference standards may be useful supplements in evaluating the age of subadults in prehistoric samples. The present study provides an internally consistent, population-specific measure of maturity for prehistoric Ohio valley Native Americans based on the seriation of dental development that may be used as a supplement to age-estimation. The developing dentition of 581 subadults from eight Ohio valley prehistoric-protohistoric groups was seriated within and among individuals resulting in a sequence of tooth development and a sequence of individuals from least to most mature. Dental maturity stages or sorting categories were then defined based on exclusive, easily observable, and highly repeatable tooth-formation stages. Tooth eruption (into occlusion), bone lengths, and fusion of skeletal elements are summarized by dental maturity stage. This procedure provides maturity estimates for skeletal features ordered by dental maturity stages derived from the same sample thus making explicit the relationship between dental and skeletal maturity.

  2. A Drosophila model to image phagosome maturation.

    PubMed

    Shandala, Tetyana; Lim, Chiaoxin; Sorvina, Alexandra; Brooks, Douglas A

    2013-01-01

    Phagocytosis involves the internalization of extracellular material by invagination of the plasma membrane to form intracellular vesicles called phagosomes, which have functions that include pathogen degradation. The degradative properties of phagosomes are thought to be conferred by sequential fusion with endosomes and lysosomes; however, this maturation process has not been studied in vivo. We employed Drosophila hemocytes, which are similar to mammalian professional macrophages, to establish a model of phagosome maturation. Adult Drosophila females, carrying transgenic Rab7-GFP endosome and Lamp1-GFP lysosome markers, were injected with E. coli DH5α and the hemocytes were collected at 15, 30, 45 and 60 minutes after infection. In wild-type females, E. coli were detected within enlarged Rab7-GFP positive phagosomes at 15 to 45 minutes after infection; and were also observed in enlarged Lamp1-GFP positive phagolysosomes at 45 minutes. Two-photon imaging of hemocytes in vivo confirmed this vesicle morphology, including enlargement of Rab7-GFP and Lamp1-GFP structures that often appeared to protrude from hemocytes. The interaction of endosomes and lysosomes with E. coli phagosomes observed in Drosophila hemocytes was consistent with that previously described for phagosome maturation in human ex vivo macrophages. We also tested our model as a tool for genetic analysis using 14-3-3e mutants, and demonstrated altered phagosome maturation with delayed E. coli internalization, trafficking and/or degradation. These findings demonstrate that Drosophila hemocytes provide an appropriate, genetically amenable, model for analyzing phagosome maturation ex vivo and in vivo. PMID:24709696

  3. 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.

  4. Background to plastic media blasting

    NASA Astrophysics Data System (ADS)

    Foster, Terry

    1995-04-01

    Chemical strippers based on active phenolic components in a chlorinated solvent have been the traditional method for removing of paints and coatings from aircraft. With the recent recognition of the environmental and health concerns of chlorinated solvents and the problem disposing of phenols there have been some major developments in paint removal technology. One of the first techniques developed to replace chemical strippers and now one of the most widely used techniques for paint removal from aircraft was plastic media blasting (PMB). The PMB technique is similar to traditional grit blasting (slag, sand alumina or carborundum) techniques used on steel and other metals (based on grits) but using polymer based media that are softer and less aggressive. Plastic media are ranked by hardness and density as well as chemical composition.

  5. 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.

  6. PPARs and Adipose Cell Plasticity

    PubMed Central

    Casteilla, Louis; Cousin, Béatrice; Carmona, Mamen

    2007-01-01

    Due to the importance of fat tissues in both energy balance and in the associated disorders arising when such balance is not maintained, adipocyte differentiation has been extensively investigated in order to control and inhibit the enlargement of white adipose tissue. The ability of a cell to undergo adipocyte differentiation is one particular feature of all mesenchymal cells. Up until now, the peroxysome proliferator-activated receptor (PPAR) subtypes appear to be the keys and essential players capable of inducing and controlling adipocyte differentiation. In addition, it is now accepted that adipose cells present a broad plasticity that allows them to differentiate towards various mesodermal phenotypes. The role of PPARs in such plasticity is reviewed here, although no definite conclusion can yet be drawn. Many questions thus remain open concerning the definition of preadipocytes and the relative importance of PPARs in comparison to other master factors involved in the other mesodermal phenotypes. PMID:17710234

  7. 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

  8. Process for remediation of plastic waste

    SciTech Connect

    Pol, Vilas G.; Thiyagarajan, Pappannan

    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.

  9. 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.

  10. Public health impact of plastics: An overview.

    PubMed

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

    2011-09-01

    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.

  11. Leatherback turtles: the menace of plastic.

    PubMed

    Mrosovsky, N; Ryan, Geraldine D; James, Michael C

    2009-02-01

    The leatherback, Dermochelyscoriacea, is a large sea turtle that feeds primarily on jellyfish. Floating plastic garbage could be mistaken for such prey. Autopsy records of 408 leatherback turtles, spanning 123 years (1885-2007), were studied for the presence or absence of plastic in the GI tract. Plastic was reported in 34% of these cases. If only cases from our first report (1968) of plastic were considered, the figure was 37%. Blockage of the gut by plastic was mentioned in some accounts. These findings are discussed in the context of removal of top predators from poorly understood food chains. PMID:19135688

  12. Public health impact of plastics: An overview.

    PubMed

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

    2011-09-01

    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. Plasticity in Gray and White

    PubMed Central

    Zatorre, R.J.; Fields, R.D.; Johansen-Berg, H.

    2013-01-01

    Human brain imaging has identified structural changes in gray and white matter that occur with learning. However, ascribing imaging measures to underlying cellular and molecular events is challenging. Here, we review human neuroimaging findings of structural plasticity and then discuss cellular and molecular level changes that could underlie observed imaging effects. We propose that greater dialogue between researchers in these different fields will help to facilitate cross talk between cellular and systems level explanations of how learning sculpts brain structure. PMID:22426254

  14. Neural plasticity: changes with age.

    PubMed

    Nieto-Sampedro, M; Nieto-Díaz, M

    2005-01-01

    Changes in the number, type and function of nervous system connections, in the morphology and function of glia and in neuron-glia interactions, are at the basis of vertebrate adjustment to changing environmental and physiological conditions. Collected under "neural plasticity", these age-dependent changes underlie adaptations apparently as different as the physiological response to dehydration or learning, and its electrophysiological and morphological correlates.

  15. Homegrown lubricants and plastics. [Brassica

    SciTech Connect

    Senft, D.

    1988-10-01

    A small bushy lesquerella plant of the mustard family growing wild in Arizona, New Mexico, Oklahoma and Texas produces seeds that may be used to make lubricants, plastics, protective coatings, surfactants, and pharmaceuticals. The plant thrives on poor soils that receive as little as 10 inches of rain a year. Studies to date indicate that target yields can be reached with a reasonable breeding effort coupled with agronomic research.

  16. Plastic Deformations in Complex Plasmas

    SciTech Connect

    Durniak, C.; Samsonov, D.

    2011-04-29

    Complex plasmas are macroscopic model systems of real solids and liquids, used to study underdamped dynamics and wave phenomena. Plastic deformations of complex plasma crystals under slow uniaxial compression have been studied experimentally and numerically. It is shown that the lattice becomes locally sheared and that this strain is relaxed by shear slips resulting in global uniform compression and heat generation. Shear slips generate pairs of dislocations which move in opposite directions at subsonic speeds.

  17. 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. PMID:23333433

  18. 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. PMID:24501480

  19. 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.

  20. 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.

  1. Ratio between mature and immature enzymatic cross-links correlates with post-yield cortical bone behavior: An insight into greenstick fractures of the child fibula.

    PubMed

    Berteau, Jean-Philippe; Gineyts, Evelyne; Pithioux, Martine; Baron, Cécile; Boivin, Georges; Lasaygues, Philippe; Chabrand, Patrick; Follet, Hélène

    2015-10-01

    As a determinant of skeletal fragility, the organic matrix is responsible for the post-yield and creep behavior of bone and for its toughness, while the mineral apatite acts on stiffness. Specific to the fibula and ulna in children, greenstick fractures show a plastic in vivo mechanical behavior before bone fracture. During growth, the immature form of collagen enzymatic cross-links gradually decreases, to be replaced by the mature form until adolescence, subsequently remaining constant throughout adult life. However, the link between the cortical bone organic matrix and greenstick fractures in children remains to be explored. Here, we sought to determine: 1) whether plastic bending fractures can occur in vitro, by testing cortical bone samples from children's fibula and 2) whether the post-yield behavior (ωp plastic energy) of cortical bone before fracture is related to total quantity of the collagen matrix, or to the quantity of mature and immature enzymatic cross-links and the quantity of non-enzymatic cross-links. We used a two-step approach; first, a 3-point microbending device tested 22 fibula machined bone samples from 7 children and 3 elderly adults until fracture. Second, biochemical analysis by HPLC was performed on the sample fragments. When pooling two groups of donors, children and elderly adults, results show a rank correlation between total energy dissipated before fracture and age and a linear correlation between plastic energy dissipated before fracture and ratio of immature/mature cross-links. A collagen matrix with more immature cross-links (i.e. a higher immature/mature cross-link ratio) is more likely to plastically deform before fracture. We conclude that this ratio in the sub-nanostructure of the organic matrix in cortical bone from the fibula may go some way towards explaining the variance in post-yield behavior. From a clinical point of view, therefore, our results provide a potential explanation of the presence of greenstick fractures in

  2. 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.

  3. Assessment of banana fruit maturity by image processing technique.

    PubMed

    Surya Prabha, D; Satheesh Kumar, J

    2015-03-01

    Maturity stage of fresh banana fruit is an important factor that affects the fruit quality during ripening and marketability after ripening. The ability to identify maturity of fresh banana fruit will be a great support for farmers to optimize harvesting phase which helps to avoid harvesting either under-matured or over-matured banana. This study attempted to use image processing technique to detect the maturity stage of fresh banana fruit by its color and size value of their images precisely. A total of 120 images comprising 40 images from each stage such as under-mature, mature and over-mature were used for developing algorithm and accuracy prediction. The mean color intensity from histogram; area, perimeter, major axis length and minor axis length from the size values, were extracted from the calibration images. Analysis of variance between each maturity stage on these features indicated that the mean color intensity and area features were more significant in predicting the maturity of banana fruit. Hence, two classifier algorithms namely, mean color intensity algorithm and area algorithm were developed and their accuracy on maturity detection was assessed. The mean color intensity algorithm showed 99.1 % accuracy in classifying the banana fruit maturity. The area algorithm classified the under-mature fruit at 85 % accuracy. Hence the maturity assessment technique proposed in this paper could be used commercially to develop a field based complete automatic detection system to take decision on the right time of harvest by the banana growers. PMID:25745200

  4. 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

  5. Digestive capacity in weanling and mature horses.

    PubMed

    Earing, J E; Lawrence, L M; Hayes, S H; Brummer, M; Vanzant, E

    2013-05-01

    The ability of young and mature horses to digest DM, OM, and NDF was compared using 6 weanling colts and 6 mature (13.2 ± 3.0 yr) geldings. Each colt was paired with a gelding, and the pair was adapted to a diet containing 67% alfalfa cubes and 33% concentrate for 21 d. During the adaptation period, horses were accustomed to housing and all handling procedures. The adaptation period was also used to adjust the amount of feed offered to minimize orts and to maintain similar rates of intake within a pair. After the adaptation period, a 5-d fecal collection period using fecal collection harnesses ensued. The average age of the weanling colts at the start of the 5-d collection period was 181.8 ± 2.9 d. On the morning of the first collection day, Co-EDTA (9 mg Co/kg BW(0.75)) and ytterbium-labeled hay fiber (9 mg Yb/kg BW(0.75)) were added to the concentrate portion of the diet, and horses were closely observed for complete consumption of the markers before additional feed was offered. The fecal collection bags were emptied every 1 to 2 h, and each collection was weighed and subsampled for later measurement of Co and Yb concentrations, which were used to determine the mean retention time (MRT) of the fluid and particulate phases of digesta, respectively. The remaining feces for each horse were composited each day and then subsampled for measurement of DM digestibility (DMD), NDF digestibility (NDFD), and OM digestibility (OMD). During the fecal collection period, DMI was similar between colts and geldings (91.4 and 91.2 g/kg BW(0.75), respectively). There were no differences between colts and mature geldings for DMD, OMD, or NDFD. Across both ages, the MRT of the particulate phase was 24.9 h compared with 21.8 h for the fluid phase (P = 0.002). However, MRT for the particulate phase was not different between colts and mature geldings (24.7 and 25.2 h, respectively). There was no difference in the MRT for the fluid phase between colts and mature geldings (21.5 and 22

  6. 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

  7. The role of sound in adult and developmental auditory cortical plasticity.

    PubMed

    Eggermont, Jos J

    2008-12-01

    The purpose of the current review is to highlight the role of the acoustic environment in auditory cortical plasticity. In order do this we have reviewed our past studies on auditory cortical plasticity based on long-latency evoked potential recordings in humans following cochlear implantation, and multiple single-unit recordings from cat auditory cortex following noise trauma and exposure to a non-deafening acoustic environment. The results of these studies, and those of other investigators highlighted here, show that the auditory cortex shows plastic changes throughout life. Those that occur during maturation are typically considered the most profound and long lasting. In that case plasticity is beneficial as it allows adaptation to behaviorally important sound and adapts easily to changes induced by deafness and subsequent application of hearing aids or cochlear implants. In children as well as adults, changes in cortical representation of frequency can occur following hearing loss, but may be accompanied by unpleasant side effects such as tinnitus. Long exposure to a spectrally enhanced acoustic environment of moderate sound level that does not cause hearing loss paradoxically also results in pronounced changes in the cortical tonotopic maps. These changes are very similar to those following noise trauma. This review provides evidence that in adults, long-lasting plastic changes in auditory cortex occur even in the absence of behaviorally relevant acoustic stimulation. However, in children, the long lasting absence of auditory stimulation arrests cortical development.

  8. 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

  9. Stepwise maturation of apicobasal polarity of the neuroepithelium is essential for vertebrate neurulation.

    PubMed

    Yang, Xiaojun; Zou, Jian; Hyde, David R; Davidson, Lance A; Wei, Xiangyun

    2009-09-16

    During vertebrate neurulation, extensive cell movements transform the flat neural plate into the neural tube. This dynamic morphogenesis requires the tissue to bear a certain amount of plasticity to accommodate shape and position changes of individual cells as well as intercellular cohesiveness to maintain tissue integrity and architecture. For most of the neural plate-neural tube transition, cells are polarized along the apicobasal axis. The establishment and maintenance of this polarity requires many polarity proteins that mediate cell-cell adhesion either directly or indirectly. Intercellular adhesion reduces tissue plasticity and enhances tissue integrity. However, it remains unclear how apicobasal polarity is regulated to meet the opposing needs for tissue plasticity and tissue integrity during neurulation. Here, we show that N-Cad/ZO-1 complex-initiated apicobasal polarity is stabilized by the late-onsetting Lin7c/Nok complex after the extensive morphogenetic cell movements in neurulation. Loss of either N-Cad or Lin7c disrupts neural tube formation. Furthermore, precocious overexpression of Lin7c induces multiaxial mirror symmetry in zebrafish neurulation. Our data suggest that stepwise maturation of apicobasal polarity plays an essential role in vertebrate neurulation.

  10. Stepwise maturation of apicobasal polarity of the neuroepithelium is essential for vertebrate neurulation

    PubMed Central

    Yang, Xiaojun; Zou, Jian; Hyde, David R.; Davidson, Lance A.; Wei, Xiangyun

    2009-01-01

    During vertebrate neurulation, extensive cell movements transform the flat neural plate into the neural tube. This dynamic morphogenesis requires the tissue to bear a certain amount of plasticity to accommodate shape and position changes of individual cells as well as intercellular cohesiveness to maintain tissue integrity and architecture. For most of the neural plate - neural tube transition, cells are polarized along the apicobasal axis. The establishment and maintenance of this polarity requires many polarity proteins that mediate cell-cell adhesion either directly or indirectly. Intercellular adhesion reduces tissue plasticity and enhances tissue integrity. However, it remains unclear how apicobasal polarity is regulated to meet the opposing needs for tissue plasticity and tissue integrity during neurulation. Here, we show that N-Cad/ZO-1 complex-initiated apicobasal polarity is stabilized by the late-onsetting Lin7c/Nok complex after the extensive morphogenetic cell movements in neurulation. Loss of either N-Cad or Lin7c disrupts neural tube formation. Furthermore, precocious overexpression of Lin7c induces multiaxial mirror symmetry in zebrafish neurulation. Our data suggest that stepwise maturation of apicobasal polarity plays an essential role in vertebrate neurulation. PMID:19759292

  11. 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.

  12. Miniature Neurotransmission Regulates Drosophila Synaptic Structural Maturation

    PubMed Central

    Choi, Ben Jiwon; Imlach, Wendy L.; Jiao, Wei; Wolfram, Verena; Wu, Ying; Grbic, Mark; Cela, Carolina; Baines, Richard A.; Nitabach, Michael N.; McCabe, Brian D.

    2014-01-01

    Summary Miniature neurotransmission is the transsynaptic process where single synaptic vesicles spontaneously released from presynaptic neurons induce miniature postsynaptic potentials. Since their discovery over 60 years ago, miniature events have been found at every chemical synapse studied. However, the in vivo necessity for these small-amplitude events has remained enigmatic. Here, we show that miniature neurotransmission is required for the normal structural maturation of Drosophila glutamatergic synapses in a developmental role that is not shared by evoked neurotransmission. Conversely, we find that increasing miniature events is sufficient to induce synaptic terminal growth. We show that miniature neurotransmission acts locally at terminals to regulate synapse maturation via a Trio guanine nucleotide exchange factor (GEF) and Rac1 GTPase molecular signaling pathway. Our results establish that miniature neurotransmission, a universal but often-overlooked feature of synapses, has unique and essential functions in vivo. PMID:24811381

  13. 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

  14. Termination of plastic-clad fiber. [Plastic-clad silica

    SciTech Connect

    Nance, W.R.

    1982-03-01

    Optical waveguides are ideal in a nuclear weapon environment because of their resistance to electromagnetic interference. Of the fibers on today's market, plastic-clad silica (PCS) is the most radiation resistant and therfore the best choice. Because terminating PCS is complex, this paper attemps to address the major problems associated with these terminations including selecting the proper connector and optimizing the terminating procedures. The sources of losses in the connectors are summarized and typical loss values are given for four connectors which were tested.

  15. 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

  16. 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.

  17. 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. PMID:27211312

  18. Maturation of the Human Papillomavirus 16 Capsid

    PubMed Central

    Cardone, Giovanni; Moyer, Adam L.; Cheng, Naiqian; Thompson, Cynthia D.; Dvoretzky, Israel; Lowy, Douglas R.; Schiller, John T.; Steven, Alasdair C.; Buck, Christopher B.

    2014-01-01

    ABSTRACT Papillomaviruses are a family of nonenveloped DNA viruses that infect the skin or mucosa of their vertebrate hosts. The viral life cycle is closely tied to the differentiation of infected keratinocytes. Papillomavirus virions are released into the environment through a process known as desquamation, in which keratinocytes lose structural integrity prior to being shed from the surface of the skin. During this process, virions are exposed to an increasingly oxidative environment, leading to their stabilization through the formation of disulfide cross-links between neighboring molecules of the major capsid protein, L1. We used time-lapse cryo-electron microscopy and image analysis to study the maturation of HPV16 capsids assembled in mammalian cells and exposed to an oxidizing environment after cell lysis. Initially, the virion is a loosely connected procapsid that, under in vitro conditions, condenses over several hours into the more familiar 60-nm-diameter papillomavirus capsid. In this process, the procapsid shrinks by ~5% in diameter, its pentameric capsomers change in structure (most markedly in the axial region), and the interaction surfaces between adjacent capsomers are consolidated. A C175S mutant that cannot achieve normal inter-L1 disulfide cross-links shows maturation-related shrinkage but does not achieve the fully condensed 60-nm form. Pseudoatomic modeling based on a 9-Å resolution reconstruction of fully mature capsids revealed C-terminal disulfide-stabilized “suspended bridges” that form intercapsomeric cross-links. The data suggest a model in which procapsids exist in a range of dynamic intermediates that can be locked into increasingly mature configurations by disulfide cross-linking, possibly through a Brownian ratchet mechanism. PMID:25096873

  19. 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

  20. 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;…

  1. Mature brain tissue in the sacrococcygeal region.

    PubMed

    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

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

    PubMed

    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

    2015-11-20

    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 (PC12(undiff)). 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.

  4. 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

  5. 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. PMID:19778860

  6. 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

  7. 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.

  8. 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.

  9. DNA damage response during mouse oocyte maturation.

    PubMed

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

    2016-01-01

    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

  10. Decelerating Mature Adipocyte Dedifferentiation by Media Composition.

    PubMed

    Huber, Birgit; Kluger, Petra J

    2015-12-01

    The establishment of adipose tissue test systems is still a major challenge in the investigation of cellular and molecular interactions responsible for the pathogenesis of inflammatory diseases involving adipose tissue. Mature adipocytes are mainly involved in these pathologies, but rarely used in vitro, due to the lack of an appropriate culture medium which inhibits dedifferentiation and maintains adipocyte functionality. In our study, we showed that Dulbecco's Modified Eagle's Medium/Ham's F-12 with 10% fetal calf serum (FCS) reported for the culture of mature adipocytes favors dedifferentiation, which was accompanied by a high glycerol release, a decreasing release of leptin, and a low expression of the adipocyte marker perilipin A, but high expression of CD73 after 21 days. Optimized media containing FCS, biotin, pantothenate, insulin, and dexamethasone decelerated the dedifferentiation process. These cells showed a lower lipolysis rate, a high level of leptin release, as well as a high expression of perilipin A. CD73-positive dedifferentiated fat cells were only found in low quantity. In this work, we showed that mature adipocytes when cultured under optimized conditions could be highly valuable for adipose tissue engineering in vitro. PMID:26228997

  11. Conformational maturation of measles virus nucleocapsid protein.

    PubMed Central

    Gombart, A F; Hirano, A; Wong, T C

    1993-01-01

    We have obtained a polyclonal antiserum, N-BE, against the denatured, amino-terminal half of the measles virus (MV) nucleocapsid (N) protein and a monoclonal antibody (MAb), N46, which recognizes a conformation-dependent epitope in the same region. Amino acid residues 23 to 239 were required and sufficient for the formation of the conformational epitope. Using these antibodies, we show that the N protein of MV is synthesized as a relatively unfolded protein which first appears in the free-protein pool. This nascent N protein undergoes a conformational change into a more folded mature form. This change does not require the participation of other viral proteins or genomic RNA. The mature N protein does not accumulate in the free-protein pool but is quickly and selectively incorporated into the viral nucleocapsids. The mature N protein is a target for interaction with the phosphoprotein (P protein) of MV. This interaction interferes with the recognition of the N protein by the N46 MAb. This suggests that the association with the P protein may mask the binding site for the N46 MAb or that it induces a conformational change in the N protein. Images PMID:7685410

  12. 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.

  13. 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.

  14. Adaptive plasticity and niche expansion in an invasive thistle

    PubMed Central

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

    2015-01-01

    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

  15. Down-regulation of NR3A-containing NMDARs is required for synapse maturation and memory consolidation

    PubMed Central

    Roberts, Adam C.; Díez-García, Javier; Rodriguiz, Ramona M.; López, Iciar Paula; Luján, Rafael; Martínez-Turrillas, Rebeca; Picó, Esther; Henson, Maile A.; Bernardo, Danilo R.; Jarrett, Thomas M.; Clendeninn, Dallis J.; López-Mascaraque, Laura; Feng, Guoping; Lo, Donald C.; Wesseling, John F.; Wetsel, William C.; Philpot, Benjamin D.; Pérez-Otaño, Isabel

    2012-01-01

    SUMMARY NR3A is the only NMDA receptor (NMDAR) subunit that down-regulates sharply prior to the onset of sensitive periods for plasticity, yet the functional importance of this transient expression remains largely unknown. To investigate the possibility that removal/replacement of juvenile NR3A-containing NMDARs is involved in experience-driven synapse maturation, we used a reversible transgenic system that allowed persistent NR3A expression in the postnatal forebrain. We found that removal of NR3A is required to develop strong NMDAR currents, full expression of long-term synaptic plasticity, a mature synaptic organization characterized by more synapses and larger postsynaptic densities, and the ability to form long-term memories. Deficits associated with prolonged NR3A were reversible, as late-onset suppression of transgene expression rescued both the synaptic and memory impairments. Our results suggest that NR3A behaves as a molecular brake to prevent the premature strengthening and stabilization of excitatory synapses, and that NR3A removal might thereby initiate critical stages of synapse maturation during early postnatal neural development. PMID:19679074

  16. Syntaxin 1A modulates the sexual maturity rate and progeny egg size related to phase changes in locusts.

    PubMed

    Chen, Qianquan; He, Jing; Ma, Chuan; Yu, Dan; Kang, Le

    2015-01-01

    The migratory locust (Locusta migratoria) exhibits clear phenotypic plasticity depending on its population density. Previous studies have explored the molecular mechanisms of body colour, behavior, immunity, and metabolism between high population density gregarious (G) and low population density solitarious (S) locusts. However, the molecular mechanisms underlying differences in reproductive traits remain unknown. G locusts reach sexual maturation much faster and lay larger eggs compared with S locusts. The traits of G locusts decreased significantly with isolation, whereas those of S locusts increased with crowding. Analysis of gene expression in female adults indicated that syntaxin 1A (Syx1A) was expressed significantly higher in G locusts than in S locusts. After silencing Syx1A expression in G locusts by RNA interference (RNAi), their sexual maturity rate and progeny egg size changed towards those of S locusts. Similarly, increment in the traits of S locusts with crowding was blocked by Syx1A interference. Changes in the traits were also confirmed by decrease in the level of vitellogenin, which is regulated by Syx1A. In conclusion, plasticity of the sexual maturity rate and progeny egg size of G and S locusts, which is beneficial for locusts to adapt to environmental changes, is regulated by Syx1A.

  17. 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...

  18. 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...

  19. Cognitive Complexity and Career Maturity among College Students.

    ERIC Educational Resources Information Center

    Winer, Jane L.; And Others

    1979-01-01

    Investigated the role of cognitive complexity in the career maturity of college students. Results generally supported the prediction that career maturity would be positively associated with cognitive complexity. (Author)

  20. Morphology of preovulatory bovine follicles as related to oocyte maturation.

    PubMed

    de Loos, F A; Bevers, M M; Dieleman, S J; Kruip, T A

    1991-03-01

    Thirty-three preovulatory bovine oocytes and their follicles were collected during the period of final maturation in normally cyclic cows. Cell density of the membrana granulosa, mitotic index of the membrana granulosa, and the occurrence of eosinophilic granulocytes around the basal membrane as well as the maturational stage of the oocyte were determined. Cell density decreased during the period of final maturation. Mitotic indices also decreased after an initial high level in the first hours of the final maturation. Eosinophilic granulocytes were only seen during the last hours of final maturation. The maturational stages of the oocytes were related to distinct maturational stages of the follicular wall as determined by morphological characteristics. We propose a scoring system for the maturity of the follicular wall based on cell density, presence of mitotic figures and the presence of eosinophilic granulocytes outside the vascular compartment. PMID:16726922

  1. Homogenization in micro-plasticity

    NASA Astrophysics Data System (ADS)

    Berdichevsky, Victor L.

    2005-11-01

    Homogenized descriptions of plasticity on micro- and macro-scale are essentially different. A key distinction is that the energy of micron-size specimens, in contrast to that of macro-specimens, is not a functional of integral characteristics of the dislocation networks. Thus, energy must be considered as an independent characteristic of the body which is additional to all other characteristics. In this paper, a homogenized description of dislocation motion on the micro-scale is proposed. The theory is considered for the case of anti-plane constrained shear which admits an analytical treatment.

  2. 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.

  3. 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. PMID:26590762

  4. On the plasticity event in metallic glass

    NASA Astrophysics Data System (ADS)

    Liu, Weidong; Ruan, Haihui; Zhang, Liangchi

    2013-03-01

    Based on a systematic molecular dynamics analysis, this study reveals that plastic deformation of metallic glass is not through a uniform configuration change but via many localized plasticity events. These events are manifested by the atomic clusters of high kinetic energy and high strain rate, emerging even in the elastic deformation regime. The life of such a plasticity event is on the order of 10-12 s, during which the distribution of kinetic energy follows a power law. The study shows that yielding in metallic glass occurs at the sudden surge point of the number of plasticity events. In the steady plastic deformation regime, the continuous nucleation and annihilation of the plastic events lead to a steady flow stress and stabilized total potential energy.

  5. 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

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

    PubMed Central

    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

    2015-01-01

    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. PMID:25690179

  7. 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.

  8. Sugar-dependent modulation of neuronal development, regeneration, and plasticity by chondroitin sulfate proteoglycans.

    PubMed

    Miller, Gregory M; Hsieh-Wilson, Linda C

    2015-12-01

    Chondroitin sulfate proteoglycans (CSPGs) play important roles in the developing and mature nervous system, where they guide axons, maintain stable connections, restrict synaptic plasticity, and prevent axon regeneration following CNS injury. The chondroitin sulfate glycosaminoglycan (CS GAG) chains that decorate CSPGs are essential for their functions. Through these sugar chains, CSPGs are able to bind and regulate the activity of a diverse range of proteins. CSPGs have been found both to promote and inhibit neuronal growth. They can promote neurite outgrowth by binding to various growth factors such as midkine (MK), pleiotrophin (PTN), brain-derived neurotrophic factor (BDNF) and other neurotrophin family members. CSPGs can also inhibit neuronal growth and limit plasticity by interacting with transmembrane receptors such as protein tyrosine phosphatase σ (PTPσ), leukocyte common antigen-related (LAR) receptor protein tyrosine phosphatase, and the Nogo receptors 1 and 3 (NgR1 and NgR3). These CS-protein interactions depend on specific sulfation patterns within the CS GAG chains, and accordingly, particular CS sulfation motifs are upregulated during development, in the mature nervous system, and in response to CNS injury. Thus, spatiotemporal regulation of CS GAG biosynthesis may provide an important mechanism to control the functions of CSPGs and to modulate intracellular signaling pathways. Here, we will discuss these sulfation-dependent processes and highlight how the CS sugars on CSPGs contribute to neuronal growth, axon guidance, and plasticity in the nervous system.

  9. Sugar-dependent modulation of neuronal development, regeneration, and plasticity by chondroitin sulfate proteoglycans.

    PubMed

    Miller, Gregory M; Hsieh-Wilson, Linda C

    2015-12-01

    Chondroitin sulfate proteoglycans (CSPGs) play important roles in the developing and mature nervous system, where they guide axons, maintain stable connections, restrict synaptic plasticity, and prevent axon regeneration following CNS injury. The chondroitin sulfate glycosaminoglycan (CS GAG) chains that decorate CSPGs are essential for their functions. Through these sugar chains, CSPGs are able to bind and regulate the activity of a diverse range of proteins. CSPGs have been found both to promote and inhibit neuronal growth. They can promote neurite outgrowth by binding to various growth factors such as midkine (MK), pleiotrophin (PTN), brain-derived neurotrophic factor (BDNF) and other neurotrophin family members. CSPGs can also inhibit neuronal growth and limit plasticity by interacting with transmembrane receptors such as protein tyrosine phosphatase σ (PTPσ), leukocyte common antigen-related (LAR) receptor protein tyrosine phosphatase, and the Nogo receptors 1 and 3 (NgR1 and NgR3). These CS-protein interactions depend on specific sulfation patterns within the CS GAG chains, and accordingly, particular CS sulfation motifs are upregulated during development, in the mature nervous system, and in response to CNS injury. Thus, spatiotemporal regulation of CS GAG biosynthesis may provide an important mechanism to control the functions of CSPGs and to modulate intracellular signaling pathways. Here, we will discuss these sulfation-dependent processes and highlight how the CS sugars on CSPGs contribute to neuronal growth, axon guidance, and plasticity in the nervous system. PMID:26315937

  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. 48 CFR 32.304-4 - Guarantee amount and maturity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Guarantee amount and... Guarantee amount and maturity. The agency may change the guarantee amount or maturity date, within the... guarantee amount or maturity date to meet any significant increase in financing need. (b) If the...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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…

  18. Career Maturity Determinants: Individual Development, Social Context, and Historical Time.

    ERIC Educational Resources Information Center

    Schmitt-Rodermund, Eva; Silbereisen, Rainer K.

    1998-01-01

    Compares adolescents from East Germany who experienced an educational system offering little choice with adolescents from West Germany who experienced more leeway to investigate career maturity. East German adolescents reported more career maturity. Person-related variables predicted career maturity in both groups; family and peer context were…

  19. Career Maturity Aspects of the Kuder Occupational Interest Survey.

    ERIC Educational Resources Information Center

    Wigington, John H.

    1982-01-01

    Determined if selected scores from the Kuder Occupational Interest Survey (KOIS) could be indicative of client career maturity. The data for each subject included three scores from the KOIS and one measure of career maturity. Significant correlations were found between the KOIS scores and career maturity. (Author)

  20. The Effect of Career Education on Career Maturity

    ERIC Educational Resources Information Center

    Omvig, Clayton P.; And Others

    1975-01-01

    This study was designed to assess the effects of a career education program on students' career maturity as measured by the Career Maturity Inventory (CMI). Results indicate that the career education program had a positive effect in increasing students' levels of career maturity. (Author)

  1. Testing Crites' Model of Career Maturity: A Hierarchical Strategy.

    ERIC Educational Resources Information Center

    Wallbrown, Fred H.; And Others

    1986-01-01

    Investigated the construct validity of Crites' model of career maturity and the Career Maturity Inventory (CMI). Results from a nationwide sample of adolescents, using hierarchical factor analytic methodology, indicated confirmatory support for the multidimensionality of Crites' model of career maturity, and the construct validity of the CMI as a…

  2. 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.…

  3. Career Maturity and Commitment to Work in University Students.

    ERIC Educational Resources Information Center

    Nevill, Dorothy D.; Super, Donald E.

    1988-01-01

    Examined relationship between career maturity and commitment to work, sex, socioeconomic status, and college level among 372 undergraduates. Found commitment to work related to both attitudinal and cognitive factors of career maturity. Sex and socioeconomic status were not related to career maturity. (Author/NB)

  4. Neuroimaging and plasticity in schizophrenia.

    PubMed

    Meyer-Lindenberg, Andreas; Tost, Heike

    2014-01-01

    Schizophrenia is a frequent and highly heritable brain disorder that typically manifests around or after puberty and has a fluctuating course. Multiple lines of evidence point to a neurodevelopmental origin of the illness and suggest that its (post) pubertal manifestation is related to genetic and environmental risk factors that interfere with the structural and functional reorganization of neural networks at this time. Longitudinal structural neuroimaging studies point to a progressive reduction in gray matter volume in many brain regions in schizophrenia. It has been proposed that these neuroimaging observations reflect an enduring disturbance of experience-dependent synaptic plasticity arising from developmental abnormalities in key neural circuits implicated in schizophrenia, including dorsolateral prefrontal cortex and hippocampal formation. Recent work has identified genetic variants linked to neural plasticity that are associated with changes in these circuits. Furthermore, non-invasive interventions such as transcranial magnetic stimulation have been shown to impact some of these systems-level intermediate phenotypes, suggesting a modifiability of these core pathophysiological processes of schizophrenia that may be exploited by therapy. PMID:23902983

  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. Crossmodal plasticity in sensory loss.

    PubMed

    Frasnelli, Johannes; Collignon, Olivier; Voss, Patrice; Lepore, Franco

    2011-01-01

    In this review, we describe crossmodal plasticity following sensory loss in three parts, with each section focusing on one sensory system. We summarize a wide range of studies showing that sensory loss may lead, depending of the affected sensory system, to functional changes in other, primarily not affected senses, which range from heightened to lowered abilities. In the first part, the effects of blindness on mainly audition and touch are described. The latest findings on brain reorganization in blindness are reported, with a particular emphasis on imaging studies illustrating how nonvisual inputs recruit the visually deafferented occipital cortex. The second part covers crossmodal processing in deafness, with a special focus on the effects of deafness on visual processing. In the last portion of this review, we present the effects that the loss of a chemical sense have on the sensitivity of the other chemical senses, that is, smell, taste, and trigeminal chemosensation. We outline how the convergence of the chemical senses to the same central processing areas may lead to the observed reduction in sensitivity of the primarily not affected senses. Altogether, the studies reviewed herein illustrate the fascinating plasticity of the brain when coping with sensory deprivation. PMID:21741555

  7. Neuroimaging and plasticity in schizophrenia.

    PubMed

    Meyer-Lindenberg, Andreas; Tost, Heike

    2014-01-01

    Schizophrenia is a frequent and highly heritable brain disorder that typically manifests around or after puberty and has a fluctuating course. Multiple lines of evidence point to a neurodevelopmental origin of the illness and suggest that its (post) pubertal manifestation is related to genetic and environmental risk factors that interfere with the structural and functional reorganization of neural networks at this time. Longitudinal structural neuroimaging studies point to a progressive reduction in gray matter volume in many brain regions in schizophrenia. It has been proposed that these neuroimaging observations reflect an enduring disturbance of experience-dependent synaptic plasticity arising from developmental abnormalities in key neural circuits implicated in schizophrenia, including dorsolateral prefrontal cortex and hippocampal formation. Recent work has identified genetic variants linked to neural plasticity that are associated with changes in these circuits. Furthermore, non-invasive interventions such as transcranial magnetic stimulation have been shown to impact some of these systems-level intermediate phenotypes, suggesting a modifiability of these core pathophysiological processes of schizophrenia that may be exploited by therapy.

  8. 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

  9. 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. PMID:26369728

  10. 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.

  11. 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.

  12. 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.

  13. Waste product profile: Plastic film and bags

    SciTech Connect

    Miller, C.

    1996-10-01

    Plastic film is recycled by being pelletized following a granulation or densifying process. Manufacturing and converting plants are the major sources of plastic film for recycling because they can supply sufficient amounts of clean raw material of a known resin type. Post-consumer collection programs are more recent. They tend to focus on businesses such as grocery stores that are large generators of plastic bags. In this case, the recycling process is more complex, requiring sorting, washing, and removal of contaminants as a first step. Curbside collection of plastic bags is rare.

  14. 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.

  15. Plastics processing: statistics, current practices, and evaluation.

    PubMed

    Cooke, F

    1993-11-01

    The health care industry uses a huge quantity of plastic materials each year. Much of the machinery currently used, or supplied, for plastics processing is unsuitable for use in a clean environment. In this article, the author outlines the reasons for the current situation and urges companies to re-examine their plastic-processing methods, whether performed in-house or subcontracted out. Some of the factors that should be considered when evaluating plastics-processing equipment are outlined to assist companies in remaining competitive and complying with impending EC regulations on clean room standards for manufacturing areas.

  16. For lighter cars, a heavier plastics diet

    SciTech Connect

    Not Available

    1980-09-17

    The competition between plastics and aluminum for use in automobile components will intensify after 1985, since up to that time the automobile industry will rely primarily on size reduction to reduce automobile weights. If 1985 automobiles are to achieve 50 mpg, the average weight will have to be cut from the current 2120 lb to 1300 lb, which will require the use of 1000 lb of lightweight material. The cost of plastics in the lightweight car would be less than the cost of aluminum, and the equipment for working plastics is cheaper than metalworking equipment. The equipment for working plastics operates more slowly , however, and plastics cannot withstand the 400/sup 0/F heat of paint ovens, or acquire as good a finish as aluminum. According to the Society of the Plastics Industry Inc., the 1979 uses of plastics in U.S. transportation equipment amounted to (in millions of lb): all thermosets, 569; polyesters, 362; urea and melamine, 24; phenolics, 171; polyurethane foam, 418; all thermoplastics, 1365; low-density polyethylene, 56; high-density polyethylene, 90; polypropylene, 260; ABS and SAN, 317; polystyrene, 23; nylon, 96; PVC, 270; all other thermoplastics, 187; and all plastics (excluding polyurethane foam), 1934. Uses of plastics in specific automobile models are discussed.

  17. Heterosynaptic Plasticity: Multiple Mechanisms and Multiple Roles

    PubMed Central

    Chistiakova, Marina; Bannon, Nicholas M.; Bazhenov, Maxim; Volgushev, Maxim

    2016-01-01

    Plasticity is a universal property of synapses. It is expressed in a variety of forms mediated by a multitude of mechanisms. Here we consider two broad kinds of plasticity that differ in their requirement for presynaptic activity during the induction. Homosynaptic plasticity occurs at synapses that were active during the induction. It is also called input specific or associative, and it is governed by Hebbian-type learning rules. Heterosynaptic plasticity can be induced by episodes of strong postsynaptic activity also at synapses that were not active during the induction, thus making any synapse at a cell a target to heterosynaptic changes. Both forms can be induced by typical protocols used for plasticity induction and operate on the same time scales but have differential computational properties and play different roles in learning systems. Homosynaptic plasticity mediates associative modifications of synaptic weights. Heterosynaptic plasticity counteracts runaway dynamics introduced by Hebbian-type rules and balances synaptic changes. It provides learning systems with stability and enhances synaptic competition. We conclude that homosynaptic and heterosynaptic plasticity represent complementary properties of modifiable synapses, and both are necessary for normal operation of neural systems with plastic synapses. PMID:24727248

  18. National Plastics Corporation: Energy Assessment Helps Automotive Plastic Parts Maker Save $34,000 Per Year

    SciTech Connect

    Not Available

    2005-09-01

    Industrial Technologies Program's BestPractices case study based on a comprehensive plant assessment conducted at National Plastics Corporation by ITP's Industrial Assessment Center in conjunction with The Society of the Plastics Industry, Inc.

  19. 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

    ... Automotive Exteriors, LLC, working out of Troy, Michigan. The workers provided office, engineering and sales... Employment and Training Administration Plastic Omnium Automotive Exteriors, LLC, Anderson, SC; Plastic Omnium Automotive Exteriors, LLC, Troy, MI; Amended Certification Regarding Eligibility To Apply for...

  20. 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

  1. 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.

  2. 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

  3. Melting the Plastic Ceiling: Overcoming Obstacles to Foster Leadership in Women Plastic Surgeons.

    PubMed

    Silva, Amanda K; Preminger, Aviva; Slezak, Sheri; Phillips, Linda G; Johnson, Debra J

    2016-09-01

    The underrepresentation of women leaders in plastic surgery echoes a phenomenon throughout society. The importance of female leadership is presented, and barriers to gender equality in plastic surgery, both intrinsic and extrinsic, are discussed. Strategies for fostering women in leadership on an individual level and for the specialty of plastic surgery are presented. PMID:27556609

  4. Melting the Plastic Ceiling: Overcoming Obstacles to Foster Leadership in Women Plastic Surgeons.

    PubMed

    Silva, Amanda K; Preminger, Aviva; Slezak, Sheri; Phillips, Linda G; Johnson, Debra J

    2016-09-01

    The underrepresentation of women leaders in plastic surgery echoes a phenomenon throughout society. The importance of female leadership is presented, and barriers to gender equality in plastic surgery, both intrinsic and extrinsic, are discussed. Strategies for fostering women in leadership on an individual level and for the specialty of plastic surgery are presented.

  5. 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.

  6. 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.

  7. Motor cortical plasticity in Parkinson's disease.

    PubMed

    Udupa, Kaviraja; Chen, Robert

    2013-09-04

    In Parkinson's disease (PD), there are alterations of the basal ganglia (BG) thalamocortical networks, primarily due to degeneration of nigrostriatal dopaminergic neurons. These changes in subcortical networks lead to plastic changes in primary motor cortex (M1), which mediates cortical motor output and is a potential target for treatment of PD. Studies investigating the motor cortical plasticity using non-invasive transcranial magnetic stimulation (TMS) have found altered plasticity in PD, but there are inconsistencies among these studies. This is likely because plasticity depends on many factors such as the extent of dopaminergic loss and disease severity, response to dopaminergic replacement therapies, development of l-DOPA-induced dyskinesias (LID), the plasticity protocol used, medication, and stimulation status in patients treated with deep brain stimulation (DBS). The influences of LID and DBS on BG and M1 plasticity have been explored in animal models and in PD patients. In addition, many other factors such age, genetic factors (e.g., brain derived neurotropic factor and other neurotransmitters or receptors polymorphism), emotional state, time of the day, physical fitness have been documented to play role in the extent of plasticity induced by TMS in human studies. In this review, we summarize the studies that investigated M1 plasticity in PD and demonstrate how these afore-mentioned factors affect motor cortical plasticity in PD. We conclude that it is important to consider the clinical, demographic, and technical factors that influence various plasticity protocols while developing these protocols as diagnostic or prognostic tools in PD. We also discuss how the modulation of cortical excitability and the plasticity with these non-invasive brain stimulation techniques facilitate the understanding of the pathophysiology of PD and help design potential therapeutic possibilities in this disorder.

  8. 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

  9. 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.

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

    PubMed

    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

  11. 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

  12. 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.

  13. Microstructure in plasticity without nonconvexity

    NASA Astrophysics Data System (ADS)

    Das, Amit; Acharya, Amit; Suquet, Pierre

    2016-03-01

    A simplified one dimensional rate dependent model for the evolution of plastic distortion is obtained from a three dimensional mechanically rigorous model of mesoscale field dislocation mechanics. Computational solutions of variants of this minimal model are investigated to explore the ingredients necessary for the development of microstructure. In contrast to prevalent notions, it is shown that microstructure can be obtained even in the absence of non-monotone equations of state. In this model, incorporation of wave propagative dislocation transport is vital for the modeling of spatial patterning. One variant gives an impression of producing stochastic behavior, despite being a completely deterministic model. The computations focus primarily on demanding macroscopic limit situations, where a convergence study reveals that the model-variant including non-monotone equations of state cannot serve as effective equations in the macroscopic limit; the variant without non-monotone ingredients, in all likelihood, can.

  14. Plastic flow of polycrystalline materials

    NASA Astrophysics Data System (ADS)

    Langer, James

    Leo Kadanoff had a long interest in fluid flows, especially fingering instabilities. This interest was one example of his insatiable curiosity about simple, fundamentally important, and often multidisciplinary phenomena. Here is an example of another class of such phenomena that I had hoped to show him this year. The experts in polycrystalline solid mechanics have insisted for decades that their central problem - dislocation-mediated strain hardening - is intrinsically unsolvable. I think they're wrong. My colleagues and I have made progress recently in theories of both amorphous and polycrystalline plasticity by introducing an effective disorder temperature as a dynamical variable in our equations of motion. In this way, we have been able to describe how the densities of flow defects or dislocations evolve in response to external forcing, and thus to develop theories that promise to become as predictive, and full of surprises, as the laws of fluid flow. For Kadanoff session.

  15. Plastic litter in the sea.

    PubMed

    Depledge, M H; Galgani, F; Panti, C; Caliani, I; Casini, S; Fossi, M C

    2013-12-01

    On June 2013 a workshop at the University of Siena (Italy) was organized to review current knowledge and to clarify what is known, and what remains to be investigated, concerning plastic litter in the sea. The content of the workshop was designed to contribute further to the European Marine Strategy Framework Directive (MSFD) following an inaugural workshop in 2012. Here we report a number of statements relevant to policymakers and scientists that was overwhelming agreement from the participants. Many might view this as already providing sufficient grounds for policy action. At the very least, this early warning of the problems that lie ahead should be taken seriously, and serve as a stimulus for further research.

  16. Vulnerability genes or plasticity genes?

    PubMed Central

    Belsky, J; Jonassaint, C; Pluess, M; Stanton, M; Brummett, B; Williams, R

    2009-01-01

    The classic diathesis–stress framework, which views some individuals as particularly vulnerable to adversity, informs virtually all psychiatric research on behavior–gene–environment (G × E) interaction. An alternative framework of ‘differential susceptibility' is proposed, one which regards those most susceptible to adversity because of their genetic make up as simultaneously most likely to benefit from supportive or enriching experiences—or even just the absence of adversity. Recent G × E findings consistent with this perspective and involving monoamine oxidase-A, 5-HTTLPR (5-hydroxytryptamine-linked polymorphic region polymorphism) and dopamine receptor D4 (DRD4) are reviewed for illustrative purposes. Results considered suggest that putative ‘vulnerability genes' or ‘risk alleles' might, at times, be more appropriately conceptualized as ‘plasticity genes', because they seem to make individuals more susceptible to environmental influences—for better and for worse. PMID:19455150

  17. Brain plasticity-based therapeutics

    PubMed Central

    Merzenich, Michael M.; Van Vleet, Thomas M.; Nahum, Mor

    2014-01-01

    The primary objective of this review article is to summarize how the neuroscience of brain plasticity, exploiting new findings in fundamental, integrative and cognitive neuroscience, is changing the therapeutic landscape for professional communities addressing brain-based disorders and disease. After considering the neurological bases of training-driven neuroplasticity, we shall describe how this neuroscience-guided perspective distinguishes this new approach from (a) the more-behavioral, traditional clinical strategies of professional therapy practitioners, and (b) an even more widely applied pharmaceutical treatment model for neurological and psychiatric treatment domains. With that background, we shall argue that neuroplasticity-based treatments will be an important part of future best-treatment practices in neurological and psychiatric medicine. PMID:25018719

  18. Plastic cars for developing nations

    SciTech Connect

    Ashley, S.

    1997-11-01

    Plastic automobiles may have passed a milestone on the long road to commercial reality with the development of Composite Concept Vehicle (CCV) from Chrysler Corp. in Auburn Hills, Mich. This basic compact car--so basic it could be called bare bones--is built by attaching an injection-molded thermoplastic polyester body onto a tubular steel chassis. The 1,200-pound CCV, which is expected to require one-third the labor and investment needed to build a conventional small car, was designed for new buyers in the emerging economies of China, India, and Southeast Asia. If commercialized, the car would likely cost about $6,000--halfway between a motorcycle and an entry-level auto. The small car was unveiled in September 1996 at the Frankfurt Auto Show in Germany.

  19. lncRNA maturation to initiate heterochromatin formation in the nucleolus is required for exit from pluripotency in ESCs.

    PubMed

    Savić, Nataša; Bär, Dominik; Leone, Sergio; Frommel, Sandra C; Weber, Fabienne A; Vollenweider, Eva; Ferrari, Elena; Ziegler, Urs; Kaech, Andres; Shakhova, Olga; Cinelli, Paolo; Santoro, Raffaella

    2014-12-01

    The open chromatin of embryonic stem cells (ESCs) condenses into repressive heterochromatin as cells exit the pluripotent state. How the 3D genome organization is orchestrated and implicated in pluripotency and lineage specification is not understood. Here, we find that maturation of the long noncoding RNA (lncRNA) pRNA is required for establishment of heterochromatin at ribosomal RNA genes, the genetic component of nucleoli, and this process is inactivated in pluripotent ESCs. By using mature pRNA to tether heterochromatin at nucleoli of ESCs, we find that localized heterochromatin condensation of ribosomal RNA genes initiates establishment of highly condensed chromatin structures outside of the nucleolus. Moreover, we reveal that formation of such highly condensed, transcriptionally repressed heterochromatin promotes transcriptional activation of differentiation genes and loss of pluripotency. Our findings unravel the nucleolus as an active regulator of chromatin plasticity and pluripotency and challenge current views on heterochromatin regulation and function in ESCs.

  20. COMPOSITES FROM RECYCLED WOOD AND PLASTICS

    EPA Science Inventory

    The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt...