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Sample records for dynamics underlie early

  1. Gravitational and Dynamic Components of Muscle Torque Underlie Tonic and Phasic Muscle Activity during Goal-Directed Reaching

    Directory of Open Access Journals (Sweden)

    Erienne V. Olesh

    2017-09-01

    Full Text Available Human reaching movements require complex muscle activations to produce the forces necessary to move the limb in a controlled manner. How gravity and the complex kinetic properties of the limb contribute to the generation of the muscle activation pattern by the central nervous system (CNS is a long-standing and controversial question in neuroscience. To tackle this issue, muscle activity is often subdivided into static and phasic components. The former corresponds to posture maintenance and transitions between postures. The latter corresponds to active movement production and the compensation for the kinetic properties of the limb. In the present study, we improved the methodology for this subdivision of muscle activity into static and phasic components by relating them to joint torques. Ten healthy subjects pointed in virtual reality to visual targets arranged to create a standard center-out reaching task in three dimensions. Muscle activity and motion capture data were synchronously collected during the movements. The motion capture data were used to calculate postural and dynamic components of active muscle torques using a dynamic model of the arm with 5 degrees of freedom. Principal Component Analysis (PCA was then applied to muscle activity and the torque components, separately, to reduce the dimensionality of the data. Muscle activity was also reconstructed from gravitational and dynamic torque components. Results show that the postural and dynamic components of muscle torque represent a significant amount of variance in muscle activity. This method could be used to define static and phasic components of muscle activity using muscle torques.

  2. Interlinked nonlinear subnetworks underlie the formation of robust cellular patterns in Arabidopsis epidermis: a dynamic spatial model

    Directory of Open Access Journals (Sweden)

    Padilla-Longoria Pablo

    2008-11-01

    Full Text Available Abstract Background Dynamical models are instrumental for exploring the way information required to generate robust developmental patterns arises from complex interactions among genetic and non-genetic factors. We address this fundamental issue of developmental biology studying the leaf and root epidermis of Arabidopsis. We propose an experimentally-grounded model of gene regulatory networks (GRNs that are coupled by protein diffusion and comprise a meta-GRN implemented on cellularised domains. Results Steady states of the meta-GRN model correspond to gene expression profiles typical of hair and non-hair epidermal cells. The simulations also render spatial patterns that match the cellular arrangements observed in root and leaf epidermis. As in actual plants, such patterns are robust in the face of diverse perturbations. We validated the model by checking that it also reproduced the patterns of reported mutants. The meta-GRN model shows that interlinked sub-networks contribute redundantly to the formation of robust hair patterns and permits to advance novel and testable predictions regarding the effect of cell shape, signalling pathways and additional gene interactions affecting spatial cell-patterning. Conclusion The spatial meta-GRN model integrates available experimental data and contributes to further understanding of the Arabidopsis epidermal system. It also provides a systems biology framework to explore the interplay among sub-networks of a GRN, cell-to-cell communication, cell shape and domain traits, which could help understanding of general aspects of patterning processes. For instance, our model suggests that the information needed for cell fate determination emerges from dynamic processes that depend upon molecular components inside and outside differentiating cells, suggesting that the classical distinction of lineage versus positional cell differentiation may be instrumental but rather artificial. It also suggests that interlinkage

  3. Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia

    Science.gov (United States)

    Sharma, Koustubh; Bayrakcismith, Rana; Tumursukh, Lkhagvasumberel; Johansson, Orjan; Sevger, Purevsuren; McCarthy, Tom; Mishra, Charudutt

    2014-01-01

    Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation. PMID:25006879

  4. Blood flow patterns underlie developmental heart defects.

    Science.gov (United States)

    Midgett, Madeline; Thornburg, Kent; Rugonyi, Sandra

    2017-03-01

    Although cardiac malformations at birth are typically associated with genetic anomalies, blood flow dynamics also play a crucial role in heart formation. However, the relationship between blood flow patterns in the early embryo and later cardiovascular malformation has not been determined. We used the chicken embryo model to quantify the extent to which anomalous blood flow patterns predict cardiac defects that resemble those in humans and found that restricting either the inflow to the heart or the outflow led to reproducible abnormalities with a dose-response type relationship between blood flow stimuli and the expression of cardiac phenotypes. Constricting the outflow tract by 10-35% led predominantly to ventricular septal defects, whereas constricting by 35-60% most often led to double outlet right ventricle. Ligation of the vitelline vein caused mostly pharyngeal arch artery malformations. We show that both cardiac inflow reduction and graded outflow constriction strongly influence the development of specific and persistent abnormal cardiac structure and function. Moreover, the hemodynamic-associated cardiac defects recapitulate those caused by genetic disorders. Thus our data demonstrate the importance of investigating embryonic blood flow conditions to understand the root causes of congenital heart disease as a prerequisite to future prevention and treatment. NEW & NOTEWORTHY Congenital heart defects result from genetic anomalies, teratogen exposure, and altered blood flow during embryonic development. We show here a novel "dose-response" type relationship between the level of blood flow alteration and manifestation of specific cardiac phenotypes. We speculate that abnormal blood flow may frequently underlie congenital heart defects. Copyright © 2017 the American Physiological Society.

  5. Early dynamics of the semantic priming shift

    Science.gov (United States)

    Lavigne, Frédéric; Chanquoy, Lucile; Dumercy, Laurent; Vitu, Françoise

    2013-01-01

    Semantic processing of sequences of words requires the cognitive system to keep several word meanings simultaneously activated in working memory with limited capacity. The real- time updating of the sequence of word meanings relies on dynamic changes in the associates to the words that are activated. Protocols involving two sequential primes report a semantic priming shift from larger priming of associates to the first prime to larger priming of associates to the second prime, in a range of long SOAs (stimulus-onset asynchronies) between the second prime and the target. However, the possibility for an early semantic priming shift is still to be tested, and its dynamics as a function of association strength remain unknown. Three multiple priming experiments are proposed that cross-manipulate association strength between each of two successive primes and a target, for different values of short SOAs and prime durations. Results show an early priming shift ranging from priming of associates to the first prime only to priming of strong associates to the first prime and all of the associates to the second prime. We investigated the neural basis of the early priming shift by using a network model of spike frequency adaptive cortical neurons (e.g., Deco & Rolls, 2005), able to code different association strengths between the primes and the target. The cortical network model provides a description of the early dynamics of the priming shift in terms of pro-active and retro-active interferences within populations of excitatory neurons regulated by fast and unselective inhibitory feedback. PMID:23717346

  6. Early dynamics of the semantic priming shift.

    Science.gov (United States)

    Lavigne, Frédéric; Chanquoy, Lucile; Dumercy, Laurent; Vitu, Françoise

    2013-01-01

    Semantic processing of sequences of words requires the cognitive system to keep several word meanings simultaneously activated in working memory with limited capacity. The real- time updating of the sequence of word meanings relies on dynamic changes in the associates to the words that are activated. Protocols involving two sequential primes report a semantic priming shift from larger priming of associates to the first prime to larger priming of associates to the second prime, in a range of long SOAs (stimulus-onset asynchronies) between the second prime and the target. However, the possibility for an early semantic priming shift is still to be tested, and its dynamics as a function of association strength remain unknown. Three multiple priming experiments are proposed that cross-manipulate association strength between each of two successive primes and a target, for different values of short SOAs and prime durations. Results show an early priming shift ranging from priming of associates to the first prime only to priming of strong associates to the first prime and all of the associates to the second prime. We investigated the neural basis of the early priming shift by using a network model of spike frequency adaptive cortical neurons (e.g., Deco & Rolls, 2005), able to code different association strengths between the primes and the target. The cortical network model provides a description of the early dynamics of the priming shift in terms of pro-active and retro-active interferences within populations of excitatory neurons regulated by fast and unselective inhibitory feedback.

  7. HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals.

    Science.gov (United States)

    Večeřa, Josef; Bártová, Eva; Krejčí, Jana; Legartová, Soňa; Komůrková, Denisa; Rudá-Kučerová, Jana; Štark, Tibor; Dražanová, Eva; Kašpárek, Tomáš; Šulcová, Alexandra; Dekker, Frank J; Szymanski, Wiktor; Seiser, Christian; Weitzer, Georg; Mechoulam, Raphael; Micale, Vincenzo; Kozubek, Stanislav

    2018-01-01

    Although histone acetylation is one of the most widely studied epigenetic modifications, there is still a lack of information regarding how the acetylome is regulated during brain development and pathophysiological processes. We demonstrate that the embryonic brain (E15) is characterized by an increase in H3K9 acetylation as well as decreases in the levels of HDAC1 and HDAC3. Moreover, experimental induction of H3K9 hyperacetylation led to the overexpression of NCAM in the embryonic cortex and depletion of Sox2 in the subventricular ependyma, which mimicked the differentiation processes. Inducing differentiation in HDAC1-deficient mouse ESCs resulted in early H3K9 deacetylation, Sox2 downregulation, and enhanced astrogliogenesis, whereas neuro-differentiation was almost suppressed. Neuro-differentiation of (wt) ESCs was characterized by H3K9 hyperacetylation that was associated with HDAC1 and HDAC3 depletion. Conversely, the hippocampi of schizophrenia-like animals showed H3K9 deacetylation that was regulated by an increase in both HDAC1 and HDAC3. The hippocampi of schizophrenia-like brains that were treated with the cannabinoid receptor-1 inverse antagonist AM251 expressed H3K9ac at the level observed in normal brains. Together, the results indicate that co-regulation of H3K9ac by HDAC1 and HDAC3 is important to both embryonic brain development and neuro-differentiation as well as the pathophysiology of a schizophrenia-like phenotype. © 2017 Wiley Periodicals, Inc.

  8. Does heterogeneity of intracellular Ca[Formula: see text] dynamics underlie speed tuning of direction-selective responses in starburst amacrine cells?

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    Koizumi, Amane; Poznanski, Roman R

    2016-01-14

    The starburst amacrine cell (SAC) plays a fundamental role in retinal motion perception. In the vertebrate retina, SAC dendrites have been shown to be directionally selective in terms of their Ca[Formula: see text] responses for stimuli that move centrifugally from the soma. The mechanism by which SACs show Ca[Formula: see text] bias for centrifugal motion is yet to be determined with precision. Recent morphological studies support a presynaptic delay in glutamate receptor activation induced Ca[Formula: see text] release from bipolar cells preferentially contacting SACs. However, bipolar cells are known to be electrotonically coupled so time delays between the bipolar cells that provide input to SACs seem unlikely. Using fluorescent microscopy and imunnostaining, we found that the endoplasmic reticulum (ER) is omnipresent in the soma extending to the distal processes of SACs. Consequently, a working hypothesis on heterogeneity of intracellular Ca[Formula: see text] dynamics from ER is proposed as a possible explanation for the cause of speed tuning of direction-selective Ca[Formula: see text] responses in dendrites of SACs.

  9. Dynamic DNA binding, junction recognition and G4 melting activity underlie the telomeric and genome-wide roles of human CST.

    Science.gov (United States)

    Bhattacharjee, Anukana; Wang, Yongyao; Diao, Jiajie; Price, Carolyn M

    2017-12-01

    Human CST (CTC1-STN1-TEN1) is a ssDNA-binding complex that helps resolve replication problems both at telomeres and genome-wide. CST resembles Replication Protein A (RPA) in that the two complexes harbor comparable arrays of OB-folds and have structurally similar small subunits. However, the overall architecture and functions of CST and RPA are distinct. Currently, the mechanism underlying CST action at diverse replication issues remains unclear. To clarify CST mechanism, we examined the capacity of CST to bind and resolve DNA structures found at sites of CST activity. We show that CST binds preferentially to ss-dsDNA junctions, an activity that can explain the incremental nature of telomeric C-strand synthesis following telomerase action. We also show that CST unfolds G-quadruplex structures, thus providing a mechanism for CST to facilitate replication through telomeres and other GC-rich regions. Finally, smFRET analysis indicates that CST binding to ssDNA is dynamic with CST complexes undergoing concentration-dependent self-displacement. These findings support an RPA-based model where dissociation and re-association of individual OB-folds allow CST to mediate loading and unloading of partner proteins to facilitate various aspects of telomere replication and genome-wide resolution of replication stress. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Early Dynamics of the Moon's Core

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    Cuk, Matija; Hamilton, Douglas; Stewart, Sarah T.

    2018-04-01

    The Moon has a small molten iron core (Williams et al. 2006). Remanent magnetization in lunar rocks likely derives from a past lunar dynamo (Wieczorek 2018 and references therein), which may have been powered by differential precession between the mantle and the core. The rotations of the lunar mantle and core were largely decoupled for much of lunar history, with a large mutual offset during the Cassini State Transition (Meyer and Wisdom, 2011). It is likely that the past work underestimated lunar obliquities, and therefore core offsets, during early lunar history (Cuk et al. 2016). Here we investigate the dynamics of the lunar core and mantle using a Lie-Poisson numerical integrator (Touma and Wisdom 2001) which includes interactions between triaxial core and mantle, as well as all gravitational and tidal effects included in the model of Cuk et al. (2016). Since we assume a rigid triaxial mantle, this model is applicable to the Moon only once it has acquired its current shape, which probably happened before the Moon reached 25 Earth radii. While some details of the core dynamics depend on our assumptions about the shape of the lunar core-mantle boundary, we can report some robust preliminary findings. The presence of the core does not change significantly the evolutionary scenario of Cuk et al. (2016). The core and mantle are indeed decoupled, with the core having a much smaller obliquity to the ecliptic than the mantle for almost all of the lunar history. The core was largely in an equivalent of Cassini State 2, with the vernal equinoxes (wrt the ecliptic) of the core and the mantle being anti-aligned. The core-mantle spin axis offset has been very large during the Moon's first billion years (this is true both in canonical and high-inclination tidal evolution), causing the lunar core to be sub-synchronous. If the ancient lunar magnetic dipole was rotating around the core axis that was inclined to the Moon's spin axis, then the magnetic poles would move across

  11. Family Income Dynamics, Early Childhood Education and Care, and Early Child Behavior Problems in Norway

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    Zachrisson, Henrik D.; Dearing, Eric

    2015-01-01

    The sociopolitical context of Norway includes low poverty rates and universal access to subsidized and regulated Early Childhood Education and Care (ECEC). In this context, the association between family income dynamics and changes in early child behavior problems was investigated, as well as whether high-quality ECEC buffers children from the…

  12. Phosphorylation site dynamics of early T-cell receptor signaling

    DEFF Research Database (Denmark)

    Chylek, Lily A; Akimov, Vyacheslav; Dengjel, Jörn

    2014-01-01

    a systems-level understanding of how these components cooperate to control signaling dynamics, especially during the crucial first seconds of stimulation. Here, we used quantitative proteomics to characterize reshaping of the T-cell phosphoproteome in response to TCR/CD28 co-stimulation, and found...... that diverse dynamic patterns emerge within seconds. We detected phosphorylation dynamics as early as 5 s and observed widespread regulation of key TCR signaling proteins by 30 s. Development of a computational model pointed to the presence of novel regulatory mechanisms controlling phosphorylation of sites...

  13. Early signatures of regime shifts in complex dynamical systems

    Indian Academy of Sciences (India)

    2015-02-05

    Feb 5, 2015 ... A large number of studies have recently been carried out on the early signatures of regime shifts in a number of dynamical systems, e.g., ecosystems, the climate, fish and wildlife populations, ... Noise-induced regime shifts are also possible for which the vicinity of the bifurcation point is not essential. In this ...

  14. Early signatures of regime shifts in complex dynamical systems

    Indian Academy of Sciences (India)

    2015-02-05

    Feb 5, 2015 ... Abstract. A large number of studies have recently been carried out on the early signatures of regime shifts in a number of dynamical systems, e.g., ecosystems, the climate, fish and wildlife populations, financial markets, complex diseases and gene circuits. The underlying model in most cases is that of the ...

  15. Systemic banking crisis early warning systems using dynamic bayesian networks

    CSIR Research Space (South Africa)

    Dabrowski, JJ

    2016-11-01

    Full Text Available For decades, the literature on banking crisis early-warning systems has been dominated by two methods, namely, the signal extraction and the logit model methods. However, these methods, do not model the dynamics of the systemic banking system...

  16. Dynamics of Learning Motivation in Early School Age Children

    OpenAIRE

    Arkhireyeva T.V.

    2015-01-01

    The paper presents outcomes of a longitudinal study on learning motivation in children of early school age. The aim was to reveal the leading motives in first, second, third and fourth grades and to explore the dynamics of some learning motives in children over the whole period of elementary school. As it was found, the learning activity in the children was mostly motivated by social motives, among which the leading ones were the motives of selfdetermination and wellbeing. As for learning mot...

  17. Dynamics of learner affective development in early FLL

    Directory of Open Access Journals (Sweden)

    Jelena Mihaljević Djigunović

    2012-10-01

    Full Text Available Affective learner factors were first considered as a cause of success in language learning. This was followed by a change in approach and recently authors (e.g., Edelenbos, Johnstone, & Kubanek, 2006 have considered them an important outcome, especially in early foreign language learning (FLL. Current research into affective learner factors in early FLL tries to catch the developmental aspects too, and studies are emerging that take a contextual view as well. This paper describes a study on affective characteristics of young FL learners that combines the developmental and contextual perspectives. Using the case study methodology the author analyses the affective profiles of three young learners of English as a foreign language who were followed for 4 years. The analyses are done taking into account their immediate language learning environment, home support, out-of-school exposure to English and language achievement. The findings suggest that affective learner factors contribute to the dynamic complexity of early FLL.

  18. Population Dynamics of Early Human Migration in Britain

    Science.gov (United States)

    Vahia, Mayank N.; Ladiwala, Uma; Mahathe, Pavan; Mathur, Deepak

    2016-01-01

    Background Early human migration is largely determined by geography and human needs. These are both deterministic parameters when small populations move into unoccupied areas where conflicts and large group dynamics are not important. The early period of human migration into the British Isles provides such a laboratory which, because of its relative geographical isolation, may allow some insights into the complex dynamics of early human migration and interaction. Method and Results We developed a simulation code based on human affinity to habitable land, as defined by availability of water sources, altitude, and flatness of land, in choosing the path of migration. Movement of people on the British island over the prehistoric period from their initial entry points was simulated on the basis of data from the megalithic period. Topographical and hydro-shed data from satellite databases was used to define habitability, based on distance from water bodies, flatness of the terrain, and altitude above sea level. We simulated population movement based on assumptions of affinity for more habitable places, with the rate of movement tempered by existing populations. We compared results of our computer simulations with genetic data and show that our simulation can predict fairly accurately the points of contacts between different migratory paths. Such comparison also provides more detailed information about the path of peoples’ movement over ~2000 years before the present era. Conclusions We demonstrate an accurate method to simulate prehistoric movements of people based upon current topographical satellite data. Our findings are validated by recently-available genetic data. Our method may prove useful in determining early human population dynamics even when no genetic information is available. PMID:27148959

  19. Early signatures of regime shifts in gene expression dynamics

    International Nuclear Information System (INIS)

    Pal, Mainak; Pal, Amit Kumar; Ghosh, Sayantari; Bose, Indrani

    2013-01-01

    Recently, a large number of studies have been carried out on the early signatures of sudden regime shifts in systems as diverse as ecosystems, financial markets, population biology and complex diseases. The signatures of regime shifts in gene expression dynamics are less systematically investigated. In this paper, we consider sudden regime shifts in the gene expression dynamics described by a fold-bifurcation model involving bistability and hysteresis. We consider two alternative models, models 1 and 2, of competence development in the bacterial population B. subtilis and determine some early signatures of the regime shifts between competence and noncompetence. We use both deterministic and stochastic formalisms for the purpose of our study. The early signatures studied include the critical slowing down as a transition point is approached, rising variance and the lag-1 autocorrelation function, skewness and a ratio of two mean first passage times. Some of the signatures could provide the experimental basis for distinguishing between bistability and excitability as the correct mechanism for the development of competence. (paper)

  20. A dynamic learning concept in early years’ education

    DEFF Research Database (Denmark)

    Broström, Stig

    2017-01-01

    In early childhood education and care, Nordic social pedagogy approach is challenged by a learning orientation that often results in unproductive ‘either/or’ thinking. Therefore, based on the two approaches and by analysing several dimensions of Froebel’s ideas and prevailing social-historical ac......In early childhood education and care, Nordic social pedagogy approach is challenged by a learning orientation that often results in unproductive ‘either/or’ thinking. Therefore, based on the two approaches and by analysing several dimensions of Froebel’s ideas and prevailing social......-historical activity (play) theory, the author deduces four generally accepted play criteria that form the basis for the construction of a dynamic and play-based learning concept that has the three following cornerstones as focal points: (1) learning happens in activities where the child is an active participant...

  1. Dynamical systems modeling of early childhood self-regulation.

    Science.gov (United States)

    Cole, Pamela M; Bendezú, Jason J; Ram, Nilam; Chow, Sy-Miin

    2017-06-01

    Self-regulation can be conceptualized in terms of dynamic tension between highly probable reactions (prepotent responses) and use of strategies that can modulate those reactions (executive processes). This study investigated the value of a dynamical systems approach to the study of early childhood self-regulation. Specifically, ordinary differential equations (ODEs) were used to model the interactive influences of 115 36-month-olds' executive processes (strategy use) and prepotent responses to waiting to open a gift (desire for the gift and frustration about waiting to open it). Using a pair of coupled second-order ODEs in a nonlinear mixed effects framework, the study tested predictions for specific within- and between-child patterns of prepotent response-executive process coupling. Dynamic modeling results articulated the limits of 36-month olds' strategic efforts. They engaged executive processes when their prepotent responding levels were high, which delayed the resurgence of prepotent responses, but ultimately did not damp prepotent responding over the course of the wait. There was, however, preliminary evidence that the effectiveness of 36-month-olds' self-regulation depended upon child characteristics. Externalizing behavior problems were associated with more regulatory interference. Temperamental negative affectivity was marginally associated with more regulatory inefficiency. Compared with conventional methods of studying self-regulation, dynamic modeling yielded complementary and unique findings, suggesting its potential. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Dynamics of Learning Motivation in Early School Age Children

    Directory of Open Access Journals (Sweden)

    Arkhireyeva T.V.

    2015-08-01

    Full Text Available The paper presents outcomes of a longitudinal study on learning motivation in children of early school age. The aim was to reveal the leading motives in first, second, third and fourth grades and to explore the dynamics of some learning motives in children over the whole period of elementary school. As it was found, the learning activity in the children was mostly motivated by social motives, among which the leading ones were the motives of selfdetermination and wellbeing. As for learning motives, over the course of all four years the children were for the most part motivated by the content of the learning activity, and not by its process. The dynamics of certain social motives of the learning activity varied across the sample, with some going through the periods of increase and decrease and others having a oneway dynamics. The study also revealed a decrease in the motivation rooted in the learning activity itself between the second and third year; at the same time, in the second, third and fourth years the children were more motivated by the content of the learning activity than by its process

  3. Simple Mathematical Models Do Not Accurately Predict Early SIV Dynamics

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    Cecilia Noecker

    2015-03-01

    Full Text Available Upon infection of a new host, human immunodeficiency virus (HIV replicates in the mucosal tissues and is generally undetectable in circulation for 1–2 weeks post-infection. Several interventions against HIV including vaccines and antiretroviral prophylaxis target virus replication at this earliest stage of infection. Mathematical models have been used to understand how HIV spreads from mucosal tissues systemically and what impact vaccination and/or antiretroviral prophylaxis has on viral eradication. Because predictions of such models have been rarely compared to experimental data, it remains unclear which processes included in these models are critical for predicting early HIV dynamics. Here we modified the “standard” mathematical model of HIV infection to include two populations of infected cells: cells that are actively producing the virus and cells that are transitioning into virus production mode. We evaluated the effects of several poorly known parameters on infection outcomes in this model and compared model predictions to experimental data on infection of non-human primates with variable doses of simian immunodifficiency virus (SIV. First, we found that the mode of virus production by infected cells (budding vs. bursting has a minimal impact on the early virus dynamics for a wide range of model parameters, as long as the parameters are constrained to provide the observed rate of SIV load increase in the blood of infected animals. Interestingly and in contrast with previous results, we found that the bursting mode of virus production generally results in a higher probability of viral extinction than the budding mode of virus production. Second, this mathematical model was not able to accurately describe the change in experimentally determined probability of host infection with increasing viral doses. Third and finally, the model was also unable to accurately explain the decline in the time to virus detection with increasing viral

  4. Genome sequencing highlights the dynamic early history of dogs.

    Directory of Open Access Journals (Sweden)

    Adam H Freedman

    2014-01-01

    Full Text Available To identify genetic changes underlying dog domestication and reconstruct their early evolutionary history, we generated high-quality genome sequences from three gray wolves, one from each of the three putative centers of dog domestication, two basal dog lineages (Basenji and Dingo and a golden jackal as an outgroup. Analysis of these sequences supports a demographic model in which dogs and wolves diverged through a dynamic process involving population bottlenecks in both lineages and post-divergence gene flow. In dogs, the domestication bottleneck involved at least a 16-fold reduction in population size, a much more severe bottleneck than estimated previously. A sharp bottleneck in wolves occurred soon after their divergence from dogs, implying that the pool of diversity from which dogs arose was substantially larger than represented by modern wolf populations. We narrow the plausible range for the date of initial dog domestication to an interval spanning 11-16 thousand years ago, predating the rise of agriculture. In light of this finding, we expand upon previous work regarding the increase in copy number of the amylase gene (AMY2B in dogs, which is believed to have aided digestion of starch in agricultural refuse. We find standing variation for amylase copy number variation in wolves and little or no copy number increase in the Dingo and Husky lineages. In conjunction with the estimated timing of dog origins, these results provide additional support to archaeological finds, suggesting the earliest dogs arose alongside hunter-gathers rather than agriculturists. Regarding the geographic origin of dogs, we find that, surprisingly, none of the extant wolf lineages from putative domestication centers is more closely related to dogs, and, instead, the sampled wolves form a sister monophyletic clade. This result, in combination with dog-wolf admixture during the process of domestication, suggests that a re-evaluation of past hypotheses regarding dog

  5. Genome sequencing highlights the dynamic early history of dogs.

    Science.gov (United States)

    Freedman, Adam H; Gronau, Ilan; Schweizer, Rena M; Ortega-Del Vecchyo, Diego; Han, Eunjung; Silva, Pedro M; Galaverni, Marco; Fan, Zhenxin; Marx, Peter; Lorente-Galdos, Belen; Beale, Holly; Ramirez, Oscar; Hormozdiari, Farhad; Alkan, Can; Vilà, Carles; Squire, Kevin; Geffen, Eli; Kusak, Josip; Boyko, Adam R; Parker, Heidi G; Lee, Clarence; Tadigotla, Vasisht; Wilton, Alan; Siepel, Adam; Bustamante, Carlos D; Harkins, Timothy T; Nelson, Stanley F; Ostrander, Elaine A; Marques-Bonet, Tomas; Wayne, Robert K; Novembre, John

    2014-01-01

    To identify genetic changes underlying dog domestication and reconstruct their early evolutionary history, we generated high-quality genome sequences from three gray wolves, one from each of the three putative centers of dog domestication, two basal dog lineages (Basenji and Dingo) and a golden jackal as an outgroup. Analysis of these sequences supports a demographic model in which dogs and wolves diverged through a dynamic process involving population bottlenecks in both lineages and post-divergence gene flow. In dogs, the domestication bottleneck involved at least a 16-fold reduction in population size, a much more severe bottleneck than estimated previously. A sharp bottleneck in wolves occurred soon after their divergence from dogs, implying that the pool of diversity from which dogs arose was substantially larger than represented by modern wolf populations. We narrow the plausible range for the date of initial dog domestication to an interval spanning 11-16 thousand years ago, predating the rise of agriculture. In light of this finding, we expand upon previous work regarding the increase in copy number of the amylase gene (AMY2B) in dogs, which is believed to have aided digestion of starch in agricultural refuse. We find standing variation for amylase copy number variation in wolves and little or no copy number increase in the Dingo and Husky lineages. In conjunction with the estimated timing of dog origins, these results provide additional support to archaeological finds, suggesting the earliest dogs arose alongside hunter-gathers rather than agriculturists. Regarding the geographic origin of dogs, we find that, surprisingly, none of the extant wolf lineages from putative domestication centers is more closely related to dogs, and, instead, the sampled wolves form a sister monophyletic clade. This result, in combination with dog-wolf admixture during the process of domestication, suggests that a re-evaluation of past hypotheses regarding dog origins is

  6. Genome Sequencing Highlights the Dynamic Early History of Dogs

    Science.gov (United States)

    Freedman, Adam H.; Gronau, Ilan; Schweizer, Rena M.; Ortega-Del Vecchyo, Diego; Han, Eunjung; Silva, Pedro M.; Galaverni, Marco; Fan, Zhenxin; Marx, Peter; Lorente-Galdos, Belen; Beale, Holly; Ramirez, Oscar; Hormozdiari, Farhad; Alkan, Can; Vilà, Carles; Squire, Kevin; Geffen, Eli; Kusak, Josip; Boyko, Adam R.; Parker, Heidi G.; Lee, Clarence; Tadigotla, Vasisht; Siepel, Adam; Bustamante, Carlos D.; Harkins, Timothy T.; Nelson, Stanley F.; Ostrander, Elaine A.; Marques-Bonet, Tomas; Wayne, Robert K.; Novembre, John

    2014-01-01

    To identify genetic changes underlying dog domestication and reconstruct their early evolutionary history, we generated high-quality genome sequences from three gray wolves, one from each of the three putative centers of dog domestication, two basal dog lineages (Basenji and Dingo) and a golden jackal as an outgroup. Analysis of these sequences supports a demographic model in which dogs and wolves diverged through a dynamic process involving population bottlenecks in both lineages and post-divergence gene flow. In dogs, the domestication bottleneck involved at least a 16-fold reduction in population size, a much more severe bottleneck than estimated previously. A sharp bottleneck in wolves occurred soon after their divergence from dogs, implying that the pool of diversity from which dogs arose was substantially larger than represented by modern wolf populations. We narrow the plausible range for the date of initial dog domestication to an interval spanning 11–16 thousand years ago, predating the rise of agriculture. In light of this finding, we expand upon previous work regarding the increase in copy number of the amylase gene (AMY2B) in dogs, which is believed to have aided digestion of starch in agricultural refuse. We find standing variation for amylase copy number variation in wolves and little or no copy number increase in the Dingo and Husky lineages. In conjunction with the estimated timing of dog origins, these results provide additional support to archaeological finds, suggesting the earliest dogs arose alongside hunter-gathers rather than agriculturists. Regarding the geographic origin of dogs, we find that, surprisingly, none of the extant wolf lineages from putative domestication centers is more closely related to dogs, and, instead, the sampled wolves form a sister monophyletic clade. This result, in combination with dog-wolf admixture during the process of domestication, suggests that a re-evaluation of past hypotheses regarding dog origins is

  7. Dynamic oxygenation of the early atmosphere and oceans

    Science.gov (United States)

    Lyons, Timothy W.; Planavsky, Noah J.; Reinhard, Christopher T.

    2014-05-01

    The traditional view of the oxygenation of the early atmosphere and oceans depicts irreversibly rising abundances in two large steps: one at the Great Oxidation Event (GOE) ca. 2.3-2.4 billion years ago (Ga) and another near the end of the Neoproterozoic. This talk will explore how the latest data challenge this paradigm. Recent results reveal a far more dynamic history of early oxygenation, one with both rising and falling levels, long periods of sustained low concentrations even after the GOE, complex feedback relationships that likely coupled nutrients and ocean redox, and dramatic changes tied through still-emerging cause-and-effect relationships to first-order tectonic, climatic, and evolutionary events. In the face of increasing doubt about the robustness of organic biomarker records from the Archean, researchers are increasingly reliant on inorganic geochemical proxies for the earliest records of oxygenic photosynthesis. Proxy data now suggest oxygenesis at ca. 3.0 Ga with a likelihood of local oxygen build up in the surface ocean long before the GOE, as well as low (and perhaps transient) accumulation in the atmosphere against a backdrop of mostly less than ca. 0.001% of the present atmospheric concentration. By the GOE, the balance between oxygen sources and sinks shifted in favor of persistent accumulation, although sedimentary recycling of non-mass-dependent sulfur isotope signatures allows for the possibility of rising and falling atmospheric oxygen before the GOE as traditionally defined by the sulfur isotope record. Recycling may also hinder our ability to precisely date the transition to permanent oxygen accumulation beyond trace levels. Diverse data point to a dramatic increase in biospheric oxygen following the GOE, coincident with the largest positive carbon isotope excursion in Earth history, followed by an equally dramatic drop. This decline in Earth surface redox potential ushered in more than a billion years of dominantly low oxygen levels in

  8. Carcinoma of the cervix. Value of dynamic magnetic resonance imaging in assessing early stromal invasion

    International Nuclear Information System (INIS)

    Kojima, Yumi; Aoki, Yoichi; Kase, Hiroaki; Kodama, Shoji; Tanaka, Kenichi

    1998-01-01

    The purpose of this study was to assess the accuracy of contrast-enhanced magnetic resonance imaging (dynamic MR imaging) in the evaluation of preinvasive and early invasive cancer of the cervix. Twenty-nine women with untreated squamous cell carcinoma of the cervix with either no stromal invasion or early stromal invasion underwent pretreatment MR imaging and dynamic MR imaging within 4 weeks of surgical evaluation. The images were evaluated for tumor detection and compared with results of histologic examination of the surgical specimens. The lesions in 17 cases with histologically proven stromal invasion of 4 mm or greater were detected with dynamic MR imaging, whereas lesions in only 8 of these cases were detected with T2 imaging. In 9 cases with stromal invasion between 4.0 mm and 5.0 mm, lesions were represented as early phase focal enhancement on dynamic MR images, but not detected on T2-weighted images. In the 12 cases with less than 4 mm stromal invasion, no lesions were visualized on either T2-weighted images or dynamic MR images, except in 1 case of glandular involvement without stromal invasion that appeared as enhancement on early-phase dynamic MR imaging. Dynamic MR imaging detected more lesions of early stromal invasion in pretreatment imaging for cervical cancer than nonenhanced MR imaging. (author)

  9. Landscape and Early Farming Settlement Dynamics in Central Greece

    DEFF Research Database (Denmark)

    Sarri, Kalliopi; Bintliff, John; Farinetti, Emeri

    2006-01-01

    also small, short-lived farms; both were associated withwetland hand cultivation. In later Neolithic and Early Bronze Age times, these locationsremained, but vestigial traces discovered by hyperintensive survey methods have identified anexplosion of small, short-lived, and horizontally migrating farms......Current hyperintensive surface survey in the Tanagra district of Boeotia, central Greece (J. L.Bintliff et al., 2002), together with a recent reanalysis of survey results from the Thespiae dis-trict (J. L. Bintliff et al., 1999), have led to a radical rethinking of how and where early farm...

  10. Dynamics of Learner Affective Development in Early FLL

    Science.gov (United States)

    Mihaljevic Djigunovic, Jelena

    2012-01-01

    Affective learner factors were first considered as a cause of success in language learning. This was followed by a change in approach and recently authors (e.g., Edelenbos, Johnstone, & Kubanek, 2006) have considered them an important outcome, especially in early foreign language learning (FLL). Current research into affective learner factors…

  11. Nitrogen alters carbon dynamics during early succession in boreal forest

    Science.gov (United States)

    Steven D. Allison; Tracy B. Gartner; Michelle C. Mack; Krista McGuire; Kathleen. Treseder

    2010-01-01

    Boreal forests are an important source of wood products, and fertilizers could be used to improve forest yields, especially in nutrient poor regions of the boreal zone. With climate change, fire frequencies may increase, resulting in a larger fraction of the boreal landscape present in early successional stages. Since most fertilization studies have focused on mature...

  12. Dynamics of ~100-kyr glacial cycles during the early Miocene

    NARCIS (Netherlands)

    Liebrand, D.; Lourens, L.J.; Boer, B. de; Wal, R.S.W. van de

    2010-01-01

    Here, we present high-resolution stable isotope records from ODP Site 1264 in the South-Eastern Atlantic Ocean, which resolve the latest Oligocene to early Miocene (23.7–18.9 Ma) climate changes. Using an inverse modelling technique, we decom- posed the oxygen isotope record into temperature and

  13. Dynamic expression patterns of differential proteins during early invasion of hepatocellular carcinoma.

    Science.gov (United States)

    Chen, Rong-Xin; Song, Hai-Yan; Dong, Yin-Ying; Hu, Chao; Zheng, Qiong-Dan; Xue, Tong-Chun; Liu, Xiao-Hui; Zhang, Yang; Chen, Jie; Ren, Zheng-Gang; Liu, Yin-Kun; Cui, Jie-Feng

    2014-01-01

    Tumor cell invasion into the surrounding matrix has been well documented as an early event of metastasis occurrence. However, the dynamic expression patterns of proteins during early invasion of hepatocellular carcinoma (HCC) are largely unknown. Using a three-dimensional HCC invasion culture model established previously, we investigated the dynamic expression patterns of identified proteins during early invasion of HCC. Highly metastatic MHCC97H cells and a liver tissue fragment were long-term co-cultured in a rotating wall vessel (RWV) bioreactor to simulate different pathological states of HCC invasion. The established spherical co-cultures were collected on days 0, 5, 10, and 15 for dynamic expression pattern analysis. Significantly different proteins among spheroids at different time points were screened and identified using quantitative proteomics of iTRAQ labeling coupled with LC-MS/MS. Dynamic expression patterns of differential proteins were further categorized by K-means clustering. The expression modes of several differentially expressed proteins were confirmed by Western blot and qRT-PCR. Time course analysis of invasion/metastasis gene expressions (MMP2, MMP7, MMP9, CD44, SPP1, CXCR4, CXCL12, and CDH1) showed remarkable, dynamic alterations during the invasion process of HCC. A total of 1,028 proteins were identified in spherical co-cultures collected at different time points by quantitative proteomics. Among these proteins, 529 common differential proteins related to HCC invasion were clustered into 25 types of expression patterns. Some proteins displayed significant dynamic alterations during the early invasion process of HCC, such as upregulation at the early invasion stage and downregulation at the late invasion stage (e.g., MAPRE1, PHB2, cathepsin D, etc.) or continuous upregulation during the entire invasion process (e.g., vitronectin, Met, clusterin, ICAM1, GSN, etc.). Dynamic expression patterns of candidate proteins during the early invasion

  14. Dynamic changes in the interchromosomal interaction of early histone gene loci during development of sea urchin.

    Science.gov (United States)

    Matsushita, Masaya; Ochiai, Hiroshi; Suzuki, Ken-Ichi T; Hayashi, Sayaka; Yamamoto, Takashi; Awazu, Akinori; Sakamoto, Naoaki

    2017-12-15

    The nuclear positioning and chromatin dynamics of eukaryotic genes are closely related to the regulation of gene expression, but they have not been well examined during early development, which is accompanied by rapid cell cycle progression and dynamic changes in nuclear organization, such as nuclear size and chromatin constitution. In this study, we focused on the early development of the sea urchin Hemicentrotus pulcherrimus and performed three-dimensional fluorescence in situ hybridization of gene loci encoding early histones (one of the types of histone in sea urchin). There are two non-allelic early histone gene loci per sea urchin genome. We found that during the morula stage, when the early histone gene expression levels are at their maximum, interchromosomal interactions were often formed between the early histone gene loci on separate chromosomes and that the gene loci were directed to locate to more interior positions. Furthermore, these interactions were associated with the active transcription of the early histone genes. Thus, such dynamic interchromosomal interactions may contribute to the efficient synthesis of early histone mRNA during the morula stage of sea urchin development. © 2017. Published by The Company of Biologists Ltd.

  15. Early Disk dynamics Inferred from Isotope Systematics of Individual Chrondules

    DEFF Research Database (Denmark)

    Bollard, Jean Francois André

    can provide direct insights into the environment and dynamics that prevailed at that time. In particular, chondrules are mm-sized igneous silicate spherules that formed throughout the protoplanetary disk by transient heating events in the first few million years. Their sheer abundance in chondrites...... of chondrules has suggested that their formation began approximately 1-2 Myr after the condensation of Calcium-Aluminum-rich Inclusions (CAIs), the oldest known solids, recent absolute dating of individual chondrules by the 207Pb-206Pb chronometer has refuted this supposed age gap. Instead, this chronometer...

  16. Early dynamics of white matter deficits in children developing dyslexia.

    Science.gov (United States)

    Vanderauwera, Jolijn; Wouters, Jan; Vandermosten, Maaike; Ghesquière, Pol

    2017-10-01

    Neural anomalies have been demonstrated in dyslexia. Recent studies in pre-readers at risk for dyslexia and in pre-readers developing poor reading suggest that these anomalies might be a cause of their reading impairment. Our study goes one step further by exploring the neurodevelopmental trajectory of white matter anomalies in pre-readers with and without a familial risk for dyslexia (n=61) of whom a strictly selected sample develops dyslexia later on (n=15). We collected longitudinal diffusion MRI and behavioural data until grade 3. The results provide evidence that children with dyslexia exhibit pre-reading white matter anomalies in left and right long segment of the arcuate fasciculus (AF), with predictive power of the left segment above traditional cognitive measures and familial risk. Whereas white matter differences in the left AF seem most strongly related to the development of dyslexia, differences in the left IFOF and in the right AF seem driven by both familial risk and later reading ability. Moreover, differences in the left AF appeared to be dynamic. This study supports and expands recent insights into the neural basis of dyslexia, pointing towards pre-reading anomalies related to dyslexia, as well as underpinning the dynamic character of white matter. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Early dynamics of white matter deficits in children developing dyslexia

    Directory of Open Access Journals (Sweden)

    Jolijn Vanderauwera

    2017-10-01

    Full Text Available Neural anomalies have been demonstrated in dyslexia. Recent studies in pre-readers at risk for dyslexia and in pre-readers developing poor reading suggest that these anomalies might be a cause of their reading impairment. Our study goes one step further by exploring the neurodevelopmental trajectory of white matter anomalies in pre-readers with and without a familial risk for dyslexia (n = 61 of whom a strictly selected sample develops dyslexia later on (n = 15. We collected longitudinal diffusion MRI and behavioural data until grade 3. The results provide evidence that children with dyslexia exhibit pre-reading white matter anomalies in left and right long segment of the arcuate fasciculus (AF, with predictive power of the left segment above traditional cognitive measures and familial risk. Whereas white matter differences in the left AF seem most strongly related to the development of dyslexia, differences in the left IFOF and in the right AF seem driven by both familial risk and later reading ability. Moreover, differences in the left AF appeared to be dynamic. This study supports and expands recent insights into the neural basis of dyslexia, pointing towards pre-reading anomalies related to dyslexia, as well as underpinning the dynamic character of white matter.

  18. Early Spring Phytoplankton Dynamics in the Western Antarctic Peninsula

    Science.gov (United States)

    Arrigo, Kevin R.; van Dijken, Gert L.; Alderkamp, Anne-Carlijn; Erickson, Zachary K.; Lewis, Kate M.; Lowry, Kate E.; Joy-Warren, Hannah L.; Middag, Rob; Nash-Arrigo, Janice E.; Selz, Virginia; van de Poll, Willem

    2017-12-01

    The Palmer Long-Term Ecological Research program has sampled waters of the western Antarctic Peninsula (wAP) annually each summer since 1990. However, information about the wAP prior to the peak of the phytoplankton bloom in January is sparse. Here we present results from a spring process cruise that sampled the wAP in the early stages of phytoplankton bloom development in 2014. Sea ice concentrations were high on the shelf relative to nonshelf waters, especially toward the south. Macronutrients were high and nonlimiting to phytoplankton growth in both shelf and nonshelf waters, while dissolved iron concentrations were high only on the shelf. Phytoplankton were in good physiological condition throughout the wAP, although biomass on the shelf was uniformly low, presumably because of heavy sea ice cover. In contrast, an early stage phytoplankton bloom was observed beneath variable sea ice cover just seaward of the shelf break. Chlorophyll a concentrations in the bloom reached 2 mg m-3 within a 100-150 km band between the SBACC and SACCF. The location of the bloom appeared to be controlled by a balance between enhanced vertical mixing at the position of the two fronts and increased stratification due to melting sea ice between them. Unlike summer, when diatoms overwhelmingly dominate the phytoplankton population of the wAP, the haptophyte Phaeocystis antarctica dominated in spring, although diatoms were common. These results suggest that factors controlling phytoplankton abundance and composition change seasonally and may differentially affect phytoplankton populations as environmental conditions within the wAP region continue to change.

  19. Causal Cognition, Force Dynamics and Early Hunting Technologies

    Directory of Open Access Journals (Sweden)

    Peter Gärdenfors

    2018-02-01

    Full Text Available With this contribution we analyze ancient hunting technologies as one way to explore the development of causal cognition in the hominin lineage. Building on earlier work, we separate seven grades of causal thinking. By looking at variations in force dynamics as a central element in causal cognition, we analyze the thinking required for different hunting technologies such as stabbing spears, throwing spears, launching atlatl darts, shooting arrows with a bow, and the use of poisoned arrows. Our interpretation demonstrates that there is an interplay between the extension of human body through technology and expanding our cognitive abilities to reason about causes. It adds content and dimension to the trend of including embodied cognition in evolutionary studies and in the interpretation of the archeological record. Our method could explain variation in technology sets between archaic and modern human groups.

  20. Early dynamic ultrasound for neonatal hip instability: implications for rural Australia.

    Science.gov (United States)

    Charlton, Susan L; Schoo, Adrian; Walters, Lucie

    2017-03-21

    Neonatal instability of the hip (NIH), where the femoral head can move away from the acetabulum, in the first weeks of life, is an important risk factor for developmental dysplasia of the hip (DDH). In rural areas in Australia, there is a recent trend to increased late diagnosis of DDH. Clinical screening of infant hips, a common practice in Australia, is experience dependent. Best practice early screening techniques are still debated with different techniques and timing used internationally. This systematic review examines early dynamic ultrasound (eDUS) screening for hip instability in the first 6 weeks after birth, and the early interventions informed by these findings and considers the findings for the context of rural Australia. The Cochrane Library, Medline, CINAHL and PEDro were searched for original research or systematic reviews, and clinical studies 1998 to 2015 involving dynamic ultrasound. Critical Appraisal Skills Programme tools were used to appraise the studies. Nineteen studies were included. Early Dynamic Ultrasound (DUS) is consistently described as a reliable assessment of NIH. Early DUS is recommended for risk factors including geographical areas of high prevalence. Approaches to early intervention of hips with excessive movement are somewhat discipline-related and include: primary prevention (advice), secondary prevention (abduction supports), and conservative management (removable splints). In the context of increased prevalence of DDH in rural Australia, contemporary evidence suggests that introduction of early DUS could provide rural infants with more effective screening than clinical examination alone. Targeted early advice about posturing and simple removable supports to abduct infant hips could prevent some cases of DDH in rural Australia.

  1. Dynamic contrast-enhanced magnetic resonance imaging of the wrist in early arthritis

    Directory of Open Access Journals (Sweden)

    M.A. Cimmino

    2011-09-01

    Full Text Available Objectives: MRI has been proposed as the imaging method of choice to evaluate the long-term outcome in patients with early arthritis. The role of dynamic MRI, performed at presentation, in predicting the outcome of patients with early arthritis has been addressed in the present study. Methods: 39 patients with early arthritis, involving at least one wrist, were studied with clinical visits and laboratory investigations, every 3 months. Dynamic MRI was performed with a low-field (0.2T, extremity-dedicated machine (Artoscan, Esaote, Genova, Italy equipped with a permanent magnet and with a dedicated hand and wrist coil. During the intravenous injection of Gd-DTPA, twenty consecutive fast images of 3 slices of the wrist were acquired. The synovial contrast enhancement ratio was calculated both as rate of early enhancement (REE per second during the first 55” and as relative enhancement (RE at t seconds. Results: In our cohort of patients, REE and RE were significantly lower than those observed in a historical cohort of 36 patients with active rheumatoid arthritis. In univariate analysis, low RE predicted complete remission of arthritis. In multivariate analysis, fulfillment of RA criteria during follow-up was predicted by high RE. The need for immunosuppressive treatment at the end of follow-up was predicted by both low RE and high REE. Conclusions: Dynamic MRI may be used to predict several outcomes of early arthritis involving the wrist

  2. Dynamic expression patterns of differential proteins during early invasion of hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Rong-Xin Chen

    Full Text Available Tumor cell invasion into the surrounding matrix has been well documented as an early event of metastasis occurrence. However, the dynamic expression patterns of proteins during early invasion of hepatocellular carcinoma (HCC are largely unknown. Using a three-dimensional HCC invasion culture model established previously, we investigated the dynamic expression patterns of identified proteins during early invasion of HCC.Highly metastatic MHCC97H cells and a liver tissue fragment were long-term co-cultured in a rotating wall vessel (RWV bioreactor to simulate different pathological states of HCC invasion. The established spherical co-cultures were collected on days 0, 5, 10, and 15 for dynamic expression pattern analysis. Significantly different proteins among spheroids at different time points were screened and identified using quantitative proteomics of iTRAQ labeling coupled with LC-MS/MS. Dynamic expression patterns of differential proteins were further categorized by K-means clustering. The expression modes of several differentially expressed proteins were confirmed by Western blot and qRT-PCR.Time course analysis of invasion/metastasis gene expressions (MMP2, MMP7, MMP9, CD44, SPP1, CXCR4, CXCL12, and CDH1 showed remarkable, dynamic alterations during the invasion process of HCC. A total of 1,028 proteins were identified in spherical co-cultures collected at different time points by quantitative proteomics. Among these proteins, 529 common differential proteins related to HCC invasion were clustered into 25 types of expression patterns. Some proteins displayed significant dynamic alterations during the early invasion process of HCC, such as upregulation at the early invasion stage and downregulation at the late invasion stage (e.g., MAPRE1, PHB2, cathepsin D, etc. or continuous upregulation during the entire invasion process (e.g., vitronectin, Met, clusterin, ICAM1, GSN, etc..Dynamic expression patterns of candidate proteins during the

  3. Early Dynamics of Interleukin-6 in Cerebrospinal Fluid after Aneurysmal Subarachnoid Hemorrhage.

    Science.gov (United States)

    Ďuriš, Kamil; Neuman, Eduard; Vybíhal, Václav; Juráň, Vilém; Gottwaldová, Jana; Kýr, Michal; Vašků, Anna; Smrčka, Martin

    2018-03-01

     Subarachnoid hemorrhage (SAH) is a severe condition associated with high mortality. Early brain injury (EBI) plays an important role in the pathophysiology of SAH, and inflammation is a major contributor to EBI. Inflammation is a widely studied topic in both experimental and clinical conditions; however, just a few clinical studies have focused primarily on the early inflammatory response after SAH, and detailed information about the association between the dynamics of early inflammatory response with main clinical characteristics is lacking. This study analyzes the early dynamics of inflammatory response after SAH and evaluates the possible associations between the markers of early inflammatory response and main clinical characteristics.  A total of 47 patients with a diagnosis of aneurysmal SAH within the last 24 hours were enrolled in the study. All treatments, including treatment of aneurysm (surgery/coiling) and implantation of a drainage system (external ventricular drainage/lumbar catheter), were conducted in the same way as in other patients with this diagnosis. Blood and cerebrospinal fluid (CSF) samples were collected three times a day for 4 days. The dynamics of proinflammatory cytokines were assessed, and associations between levels of the proinflammatory cytokines interleukin (IL)-6, IL-1β, or tumor necrosis factor (TNF)α and main clinical characteristics were evaluated using linear mixed-effect models.  The CSF levels of IL-6 were massively increased initially after SAH (up to 72 hours) with an additional increase in later phases (after 72 hours), but there was high variability in IL-6 levels. A significant association was noted between the Glasgow Outcome Scale score and both overall levels of IL-6 ( p  = 0.0095) and their dynamics ( p  = 0.0208); the effect of the Hunt and Hess scale was borderline ( p  = 0.0887). No association was found between IL-6 levels and Fisher grade, modality of treatment (surgery, coiling, no treatment

  4. Does a dynamic test of phonological awareness predict early reading difficulties?

    DEFF Research Database (Denmark)

    Gellert, Anna Steenberg; Elbro, Carsten

    2017-01-01

    A few studies have indicated that dynamic measures of phonological awareness may contribute uniquely to the prediction of early reading development. However, standard control measures have been few and limited by floor effects, thus limiting their predictive value. The purpose of the present study...... was to examine the predictive value of a dynamic test of phonological awareness while controlling for both letter knowledge and standard phonological awareness using measures with no floor effect. We administered a dynamic test of phonological awareness along with traditional tests of phonological awareness...... and letter knowledge to 160 children in the fall of kindergarten. Reading outcomes were studied at three test points: at the end of kindergarten, in the first half of Grade 1, and at the end of Grade 1. The results indicated that the dynamic test of phonological awareness contributed significantly...

  5. Early circulating tumor DNA dynamics and clonal selection with palbociclib and fulvestrant for breast cancer.

    Science.gov (United States)

    O'Leary, Ben; Hrebien, Sarah; Morden, James P; Beaney, Matthew; Fribbens, Charlotte; Huang, Xin; Liu, Yuan; Bartlett, Cynthia Huang; Koehler, Maria; Cristofanilli, Massimo; Garcia-Murillas, Isaac; Bliss, Judith M; Turner, Nicholas C

    2018-03-01

    CDK4/6 inhibition substantially improves progression-free survival (PFS) for women with advanced estrogen receptor-positive breast cancer, although there are no predictive biomarkers. Early changes in circulating tumor DNA (ctDNA) level may provide early response prediction, but the impact of tumor heterogeneity is unknown. Here we use plasma samples from patients in the randomized phase III PALOMA-3 study of CDK4/6 inhibitor palbociclib and fulvestrant for women with advanced breast cancer and show that relative change in PIK3CA ctDNA level after 15 days treatment strongly predicts PFS on palbociclib and fulvestrant (hazard ratio 3.94, log-rank p = 0.0013). ESR1 mutations selected by prior hormone therapy are shown to be frequently sub clonal, with ESR1 ctDNA dynamics offering limited prediction of clinical outcome. These results suggest that early ctDNA dynamics may provide a robust biomarker for CDK4/6 inhibitors, with early ctDNA dynamics demonstrating divergent response of tumor sub clones to treatment.

  6. Artificial Neural Network-Based Early-Age Concrete Strength Monitoring Using Dynamic Response Signals

    Directory of Open Access Journals (Sweden)

    Junkyeong Kim

    2017-06-01

    Full Text Available Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process.

  7. Artificial Neural Network-Based Early-Age Concrete Strength Monitoring Using Dynamic Response Signals.

    Science.gov (United States)

    Kim, Junkyeong; Lee, Chaggil; Park, Seunghee

    2017-06-07

    Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process.

  8. Temporal dynamics of early visual word processing - Early versus late N1 sensitivity in children and adults.

    Science.gov (United States)

    Eberhard-Moscicka, Aleksandra K; Jost, Lea B; Fehlbaum, Lynn V; Pfenninger, Simone E; Maurer, Urs

    2016-10-01

    In the course of reading development children become familiar with letter strings and learn to distinguish between lexical and non-lexical items. In previous studies, the N1 component of the ERP was shown to reflect print tuning but also to be sensitive to lexical effects. It remains unclear, however, whether these two aspects of orthographic processing occur at the same time or in different time windows during the lengthy N1 component. Moreover, it is unclear whether these processes develop late or occur already at early stages of literacy acquisition and whether this is similar for native languages and languages acquired later in life. To address these questions, 27 children were tested longitudinally, i.e. before (mean: 7.6 years) and after one year of classroom-based English instruction. Additionally, 22 adult speakers of English as a foreign language (mean: 25.1 years) were investigated. A 128-channel EEG was recorded while participants performed a one-back task with native German words, English words, pseudowords and false-font strings. The event-related EEG analysis of early and late N1 phases revealed early effects related to print tuning and late effects related to lexical processing in the native, but not in the second language of adult readers. In the absence of lexicality effects in children, print tuning effects were found across both early and late N1 segments. The temporally distinct N1 sensitivities to print and lexicality reflect temporal dynamics of visual word processing, which seem to depend on reading expertise or maturation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Dynamic Pattern of HOXB9 Protein Localization during Oocyte Maturation and Early Embryonic Development in Mammals.

    Directory of Open Access Journals (Sweden)

    Caroline Sauvegarde

    Full Text Available We previously showed that the homeodomain transcription factor HOXB9 is expressed in mammalian oocytes and early embryos. However, a systematic and exhaustive study of the localization of the HOXB9 protein, and HOX proteins in general, during mammalian early embryonic development has so far never been performed.The distribution of HOXB9 proteins in oocytes and the early embryo was characterized by immunofluorescence from the immature oocyte stage to the peri-gastrulation period in both the mouse and the bovine. HOXB9 was detected at all studied stages with a dynamic expression pattern. Its distribution was well conserved between the two species until the blastocyst stage and was mainly nuclear. From that stage on, trophoblastic cells always showed a strong nuclear staining, while the inner cell mass and the derived cell lines showed important dynamic variations both in staining intensity and in intra-cellular localization. Indeed, HOXB9 appeared to be progressively downregulated in epiblast cells and only reappeared after gastrulation had well progressed. The protein was also detected in the primitive endoderm and its derivatives with a distinctive presence in apical vacuoles of mouse visceral endoderm cells.Together, these results could suggest the existence of unsuspected functions for HOXB9 during early embryonic development in mammals.

  10. Raman spectral dynamics of single cells in the early stages of growth factor stimulation.

    Science.gov (United States)

    Takanezawa, Sota; Morita, Shin-ichi; Ozaki, Yukihiro; Sako, Yasushi

    2015-05-05

    Cell fates change dynamically in response to various extracellular signals, including growth factors that stimulate differentiation and proliferation. The processes underlying cell-fate decisions are complex and often include large cell-to-cell variations, even within a clonal population in the same environment. To understand the origins of these cell-to-cell variations, we must detect the internal dynamics of single cells that reflect their changing chemical milieu. In this study, we used the Raman spectra of single cells to trace their internal dynamics during the early stages of growth factor stimulation. This method allows nondestructive and inclusive time-series analyses of chemical compositions of the same single cells. Applying a Gaussian mixture model to the major principal components of the single-cell Raman spectra, we detected the dynamics of the chemical states in MCF-7 cancer-derived cells in the absence and presence of differentiation and proliferation factors. The dynamics displayed characteristic variations according to the functions of the growth factors. In the differentiation pathway, the chemical composition changed directionally between multiple states, including both reversible and irreversible state transitions. In contrast, in the proliferation pathway, the chemical composition was homogenized into a single state. The differentiation factor also stimulated fluctuations in the chemical composition, whereas the proliferation factor did not. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. The influence of aspect on the early growth dynamics of hydroseeded species in coal reclamation areas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Alday, J.; Marrs, R.H.; Martinez-Ruiz, C. [University of Valladolid, Palencia (Spain)

    2008-08-15

    Question: Does aspect affect hydroseeding success and the development of vegetation during early vegetation establishment on the steep slopes of coal wastes during the reclamation process? Location: Open-pit coal mine near Villanueva de la Pena, northern Spain. Methods: In the first year after hydroseeding, we monitored the dynamics of hydroseeded species in three permanent plots of 20 m{sup 2} on north- and south-facing slopes every two months. Soil properties and weather conditions were also monitored. Aspect was related to total plant cover during early revegetation, and south-facing slopes had the lowest cover. Aspect also influenced the early dynamics of hydroseeded grasses and legumes establishing on these slopes. Grass cover was greater on the north slope throughout the study, but differences in plant cover between north and south slopes appeared later for the legumes. Aspect also affected the relative contribution of both of grasses and legumes to the total plant cover, with grasses dominant on both northern and southern slopes, except during the summer on the southern slope. The species with the greatest difference in cover between the north- and south-facing slopes were Festuca spp., Lolium perenne and Trifolium repens. In coal mine reclamation areas of Mediterranean climates, differences in the development of hydroseeded species depended on the slope of the coal mine reclamation areas, and this information is of importance to managers in selecting species for use in reclamation.

  12. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

    NARCIS (Netherlands)

    Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

    2016-01-01

    Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

  13. Characterizing the reproduction number of epidemics with early subexponential growth dynamics

    DEFF Research Database (Denmark)

    Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone

    2016-01-01

    mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results...... datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic......Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence...

  14. Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leach, M.O.; Orton, M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Morgan, B. [Univ. of Leicester, College of Medicine, Biological Sciences and Psychology, Leicester (United Kingdom); Tofts, P.S. [Brighton and Sussex Medical School, Univ. of Sussex, Clinical Imaging Sciences Centre, Sussex (United Kingdom); Buckley, D.L. [University of Leeds, Division of Medical Physics, Leeds (United Kingdom); Huang, W. [Oregon Health and Science Univ., Advanced Imaging Research Centre, Portland, OR (United States); Horsfield, M.A. [Medical Physics Section, Leicester Royal Infirmary, Dept. of Cardiovascular Sciences, Leicester (United Kingdom); Chenevert, T.L. [Univ. of Michigan Health System, Ann Arbor, MI (United States); Collins, D.J. [Royal Marsden Hospital NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Jackson, A. [Univ. of Manchester, Wolfson Molecular Imaging Centre, Withington, Manchester, M20 3LJ (United Kingdom); Lomas, D. [Univ. of Cambridge, Dept. of Radiology, Cambridge (United Kingdom); Whitcher, B. [Unit 2 Greenways Business Park, Mango Solutions, Chippenham (United Kingdom); Clarke, L. [Cancer Imaging Program, Imaging Technology Development Branch, Rockville, MD (United States); Plummer, R. [Univ. of Newcastle Upon Tyne, The Medical School, Medical Oncology, Northern Inst. for Cancer Research, Newcastle Upon Tyne (United Kingdom); Judson, I. [Royal Marsden Hospital, Sutton, Surrey (United Kingdom); Jones, R. [Beatson West of Scotland Cancer Centre, Glasgow (United Kingdom); Alonzi, R. [Mount Vernon Cancer Centre, Northwood (United Kingdom); Brunner, T. [Gray Inst. for Radiation, Oncology and Biology, Oxford (United Kingdom); Koh, D.M. [Royal Marsden NHS Foundation Trust, Diagnostic Radiology, Sutton, Surrey (United Kingdom)] [and others

    2012-07-15

    Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. (orig.)

  15. Design of a Dynamic Spinal Implant for the treatment of Early Onset Scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Alvarez, A.; Shepherd, D.; Dearn, K.

    2016-07-01

    GSDyn (Growing Spine Dynamic) is a novel implant that has been designed and manufactured to mechanically correct three dimensional spinal deformities in children with Early Onset Scoliosis (EOS). The innovative element of the implant is the lengthening mechanism that allows the elongation surgeries to be easier, faster and less invasive procedures than with other mechanical implants on the market, as they can be performed under local anaesthetics and with a surgical incision of less than one centimetre. It also includes a dynamic system to prevent implant breakage and anchor loosening, two of the most common complications occurring in this treatment. The development of the implant has been guided by spinal surgeons. Finite Element Analysis has been performed to evaluate the behaviour of the device under different loading conditions and two working prototypes have been successfully manufactured. (Author)

  16. Dynamic locomotor capabilities revealed by early dinosaur trackmakers from southern Africa.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Wilson

    Full Text Available BACKGROUND: A new investigation of the sedimentology and ichnology of the Early Jurassic Moyeni tracksite in Lesotho, southern Africa has yielded new insights into the behavior and locomotor dynamics of early dinosaurs. METHODOLOGY/PRINCIPAL FINDINGS: The tracksite is an ancient point bar preserving a heterogeneous substrate of varied consistency and inclination that includes a ripple-marked riverbed, a bar slope, and a stable algal-matted bar top surface. Several basal ornithischian dinosaurs and a single theropod dinosaur crossed its surface within days or perhaps weeks of one another, but responded to substrate heterogeneity differently. Whereas the theropod trackmaker accommodated sloping and slippery surfaces by gripping the substrate with its pedal claws, the basal ornithischian trackmakers adjusted to the terrain by changing between quadrupedal and bipedal stance, wide and narrow gauge limb support (abduction range = 31 degrees , and plantigrade and digitigrade foot posture. CONCLUSIONS/SIGNIFICANCE: The locomotor adjustments coincide with changes in substrate consistency along the trackway and appear to reflect 'real time' responses to a complex terrain. It is proposed that these responses foreshadow important locomotor transformations characterizing the later evolution of the two main dinosaur lineages. Ornithischians, which shifted from bipedal to quadrupedal posture at least three times in their evolutionary history, are shown to have been capable of adopting both postures early in their evolutionary history. The substrate-gripping behavior demonstrated by the early theropod, in turn, is consistent with the hypothesized function of pedal claws in bird ancestors.

  17. Dynamic Critical Rainfall-Based Flash Flood Early Warning and Forecasting for Medium-Small Rivers

    Science.gov (United States)

    Liu, Z.; Yang, D.; Hu, J.

    2012-04-01

    China is extremely frequent food disasters hit countries, annual flood season flash floods triggered by rainfall, mudslides, landslides have caused heavy casualties and property losses, not only serious threaten the lives of the masses, but the majority of seriously restricting the mountain hill areas of economic and social development and the people become rich, of building a moderately prosperous society goals. In the next few years, China will focus on prevention and control area in the flash flood disasters initially built "for the surveillance, communications, forecasting, early warning and other non-engineering measure based, non-engineering measures and the combinations of engineering measures," the mitigation system. The latest progresses on global torrential flood early warning and forecasting techniques are reviewed in this paper, and then an early warning and forecasting approach is proposed on the basis of a distributed hydrological model according to dynamic critical rainfall index. This approach has been applied in Suichuanjiang River basin in Jiangxi province, which is expected to provide valuable reference for building a national flash flood early warning and forecasting system as well as control of such flooding.

  18. Mediating Dynamic Supply Chain Formation by Collaborative Single Machine Earliness/Tardiness Agents in Supply Mesh

    Directory of Open Access Journals (Sweden)

    Hang Yang

    2014-01-01

    Full Text Available Nowadays, a trend of forming dynamic supply chains with different trading partners over different e-marketplaces has emerged. These supply chains, which are called “supply mesh,” generally refer to heterogeneous electronic marketplaces in which dynamic supply chains, as per project (often make-to-order, are formed across different parties. Conceptually, in a supply mesh a dynamic supply chain is formed vertically, mediating several companies for a project. Companies that are on the same level horizontally are either competitors or cohorts. A complex scenario such as this makes it challenging to find the right group of members for a dynamic supply chain. Earlier on, a multiagent model called the collaborative single machine earliness/tardiness (CSET model was proposed for the optimal formation of make-to-order supply chains. This paper contributes the particular agent designs, for enabling the mediation of CSET in a supply mesh, and the possibilities are discussed. It is demonstrated via a computer simulation, based on samples from the U.S. textile industry, that by using intelligent agents under the CSET model it is possible to automatically find an ideal group of trading partners from a supply mesh.

  19. Early sepsis detection in critical care patients using multiscale blood pressure and heart rate dynamics.

    Science.gov (United States)

    Shashikumar, Supreeth P; Stanley, Matthew D; Sadiq, Ismail; Li, Qiao; Holder, Andre; Clifford, Gari D; Nemati, Shamim

    Sepsis remains a leading cause of morbidity and mortality among intensive care unit (ICU) patients. For each hour treatment initiation is delayed after diagnosis, sepsis-related mortality increases by approximately 8%. Therefore, maximizing effective care requires early recognition and initiation of treatment protocols. Antecedent signs and symptoms of sepsis can be subtle and unrecognizable (e.g., loss of autonomic regulation of vital signs), causing treatment delays and harm to the patient. In this work we investigated the utility of high-resolution blood pressure (BP) and heart rate (HR) times series dynamics for the early prediction of sepsis in patients from an urban, academic hospital, meeting the third international consensus definition of sepsis (sepsis-III) during their ICU admission. Using a multivariate modeling approach we found that HR and BP dynamics at multiple time-scales are independent predictors of sepsis, even after adjusting for commonly measured clinical values and patient demographics and comorbidities. Earlier recognition and diagnosis of sepsis has the potential to decrease sepsis-related morbidity and mortality through earlier initiation of treatment protocols. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Early

    Directory of Open Access Journals (Sweden)

    Kamel Abd Elaziz Mohamed

    2014-04-01

    Conclusion: Early PDT is recommended for patients who require prolonged tracheal intubation in the ICU as outcomes like the duration of mechanical ventilation length of ICU stay and hospital stay were significantly shorter in early tracheostomy.

  1. Early Holocene to present landscape dynamics of the tectonic lakes of west-central Mexico

    Science.gov (United States)

    Castillo, Miguel; Muñoz-Salinas, Esperanza; Arce, José Luis; Roy, Priyadarsi

    2017-12-01

    Paleoclimatic reconstructions from lake sediments of central Mexico indicate that the environmental conditions in the Holocene have oscillated from cool-dry to warm-wet, thus, landscape erosion rates have been modified accordingly. The Cenozoic tectonics and volcanic activity of west-central Mexico have produced a set of lakes in warmer and drier conditions compared to lakes of central Mexico. Nevertheless, the Holocene landscape dynamics for this area remains understudied. Using age-depth models, OSL and multi-element chemistry analysis of sediments in the lakes of San Marcos and Sayula we explore the landscape dynamics from early Holocene present of west-central Mexico. Our results indicate that the sedimentation rates in San Marcos Lake notably increased from 240 yr BP to the present. Since AD 1950 the sedimentation rate in Sayula Lake rose fourfold the rates of the last 2000 years. Analysis of OSL and chemistry of major elements of sediments indicates that IRSL/BLSL strongly correlates with Ti/Al (R2 = 0.93) and with the mean monthly rainfall (R2 = 0.70). We propose that the IRSL/BLSL can be used as a proxy to infer past changes in landscape dynamics. Analysis of climatic data from the 1950s to present indicates that rainfall, and consequently water runoff, is enhanced in summers free of ENSO conditions. Extreme one-day rainfall can, however, exceed mean seasonal rainfall and occur in all phases of ENSO. Droughts are particularly severe in the phase of La Niña. Our results indicate that the erosion rate in San Marcos Lake was high from ∼8000 to ∼7000 yr BP in a period coinciding with the advance and recession of glaciers in Central Mexico, however, the erosion rates in the last 165 years have surpassed the rates of the early to mid-Holocene. By constraining the age of sediment and using environmental proxies such as the Ti/Al and IRSL/BLSL from lake sediments of Sayula and San Marcos we present the first model of landscape dynamics of this part of Mexico

  2. Cascading peer dynamics underlying the progression from problem behavior to violence in early to late adolescence.

    Science.gov (United States)

    Dishion, Thomas J; Véronneau, Marie-Hélène; Myers, Michael W

    2010-08-01

    This study examined the peer dynamics linking early adolescent problem behavior, school marginalization, and low academic performance to multiple indices of late adolescent violence (arrests, parent report, and youth report) in an ethnically diverse sample of 998 males and females. A cascade model was proposed in which early adolescent risk factors assessed at age 11 to 12 predict gang involvement at age 13 to 14, which in turn, predicts deviancy training with friends at age 16 to 17, which then predicts violence by age 18 to 19. Each construct in the model was assessed with multiple measures and methods. Structural equation modeling revealed that the cascade model fit the data well, with problem behavior, school marginalization, and low academic performance significantly predicting gang involvement 2 years later. Gang involvement, in turn, predicted deviancy training with a friend, which predicted violence. The best fitting model included an indirect and direct path between early adolescent gang involvement and later violence. These findings suggest the need to carefully consider peer clustering into gangs in efforts to prevent individual and aggregate levels of violence, especially in youths who may be disengaged, marginalized, or academically unsuccessful in the public school context.

  3. Transcriptional dynamics reveal critical roles for non-coding RNAs in the immediate-early response.

    Directory of Open Access Journals (Sweden)

    Stuart Aitken

    2015-04-01

    Full Text Available The immediate-early response mediates cell fate in response to a variety of extracellular stimuli and is dysregulated in many cancers. However, the specificity of the response across stimuli and cell types, and the roles of non-coding RNAs are not well understood. Using a large collection of densely-sampled time series expression data we have examined the induction of the immediate-early response in unparalleled detail, across cell types and stimuli. We exploit cap analysis of gene expression (CAGE time series datasets to directly measure promoter activities over time. Using a novel analysis method for time series data we identify transcripts with expression patterns that closely resemble the dynamics of known immediate-early genes (IEGs and this enables a comprehensive comparative study of these genes and their chromatin state. Surprisingly, these data suggest that the earliest transcriptional responses often involve promoters generating non-coding RNAs, many of which are produced in advance of canonical protein-coding IEGs. IEGs are known to be capable of induction without de novo protein synthesis. Consistent with this, we find that the response of both protein-coding and non-coding RNA IEGs can be explained by their transcriptionally poised, permissive chromatin state prior to stimulation. We also explore the function of non-coding RNAs in the attenuation of the immediate early response in a small RNA sequencing dataset matched to the CAGE data: We identify a novel set of microRNAs responsible for the attenuation of the IEG response in an estrogen receptor positive cancer cell line. Our computational statistical method is well suited to meta-analyses as there is no requirement for transcripts to pass thresholds for significant differential expression between time points, and it is agnostic to the number of time points per dataset.

  4. Predicting Reading Difficulty in First Grade Using Dynamic Assessment of Decoding in Early Kindergarten: A Large-Scale Longitudinal Study.

    Science.gov (United States)

    Petersen, Douglas B; Allen, Melissa M; Spencer, Trina D

    2016-01-01

    The purpose of this study was to examine and compare the classification accuracy of early static prereading measures and early dynamic assessment reading measures administered to 600 kindergarten students. At the beginning of kindergarten, all of the participants were administered two commonly used static prereading measures. The participants were then administered either a dynamic assessment featuring an onset-rime decoding strategy or a dynamic assessment featuring a sound-by-sound strategy. At the end of first grade, those same participants' reading ability was assessed using multiple reading measures. Results indicated that the dynamic assessments yielded significantly higher classification accuracy over the static measures, but that the classification accuracy of the two dynamic assessments did not differ significantly. Sensitivity for the static measures was less than 80%, and specificity ranged from 33% to 51%. The sensitivity and specificity for the dynamic assessments was greater than 80% for all children, with the exception of specificity for the Hispanic children, which was at or greater than 70%. Results also indicated that the combination of static and dynamic measures did not improve the classification accuracy over the dynamic assessments alone. Dynamic assessment appears to be a promising approach to classifying young children at risk for future reading difficulty. © Hammill Institute on Disabilities 2014.

  5. THE BASIC LAWS AND FEATURES OF CYTOKINE DYNAMICS IN PROCESS AND EARLY TERMS AFTER CARDIOPULMONARY BYPASS

    Directory of Open Access Journals (Sweden)

    S. I. Suskov

    2011-01-01

    Full Text Available The basic variants of cytokines reactions defining type of organ dysfunctions are revealed in the course of car- diopulmonary bypass and in the early postoperative period. Their character and expression, depends on gravity preoperative an immunodeficiency and initial degree of heart insufficiency. Diphasic dynamics of development of system inflammatory reaction is confirmed after cardiopulmonary bypass: increase of levels proinflammatory cytokines is in the first phase and anti-inflammatory cytokines with development immunodepression and cellular anergy in is the second phase. Also, key role IL-1Ra is revealed in restraint of hyperactivation of system inflam- matory reaction. Blood whey levels IL-6, IL-8, G-CSF, TNF-α and IL-1Ra should be defined to cardiopulmonary bypass, in 10–12 hours, 24 hours and 3 days after cardiopulmonary bypass and may be used as prognostic criteria of development of postoperative complications. 

  6. Molecular Dynamics of Channelrhodopsin at the Early Stages of Channel Opening.

    Science.gov (United States)

    Takemoto, Mizuki; Kato, Hideaki E; Koyama, Michio; Ito, Jumpei; Kamiya, Motoshi; Hayashi, Shigehiko; Maturana, Andrés D; Deisseroth, Karl; Ishitani, Ryuichiro; Nureki, Osamu

    2015-01-01

    Channelrhodopsin (ChR) is a light-gated cation channel that responds to blue light. Since ChR can be readily expressed in specific neurons to precisely control their activities by light, it has become a powerful tool in neuroscience. Although the recently solved crystal structure of a chimeric ChR, C1C2, provided the structural basis for ChR, our understanding of the molecular mechanism of ChR still remains limited. Here we performed electrophysiological analyses and all-atom molecular dynamics (MD) simulations, to investigate the importance of the intracellular and central constrictions of the ion conducting pore observed in the crystal structure of C1C2. Our electrophysiological analysis revealed that two glutamate residues, Glu122 and Glu129, in the intracellular and central constrictions, respectively, should be deprotonated in the photocycle. The simulation results suggested that the deprotonation of Glu129 in the central constriction leads to ion leakage in the ground state, and implied that the protonation of Glu129 is important for preventing ion leakage in the ground state. Moreover, we modeled the 13-cis retinal bound; i.e., activated C1C2, and performed MD simulations to investigate the conformational changes in the early stage of the photocycle. Our simulations suggested that retinal photoisomerization induces the conformational change toward channel opening, including the movements of TM6, TM7 and TM2. These insights into the dynamics of the ground states and the early photocycle stages enhance our understanding of the channel function of ChR.

  7. Molecular Dynamics of Channelrhodopsin at the Early Stages of Channel Opening.

    Directory of Open Access Journals (Sweden)

    Mizuki Takemoto

    Full Text Available Channelrhodopsin (ChR is a light-gated cation channel that responds to blue light. Since ChR can be readily expressed in specific neurons to precisely control their activities by light, it has become a powerful tool in neuroscience. Although the recently solved crystal structure of a chimeric ChR, C1C2, provided the structural basis for ChR, our understanding of the molecular mechanism of ChR still remains limited. Here we performed electrophysiological analyses and all-atom molecular dynamics (MD simulations, to investigate the importance of the intracellular and central constrictions of the ion conducting pore observed in the crystal structure of C1C2. Our electrophysiological analysis revealed that two glutamate residues, Glu122 and Glu129, in the intracellular and central constrictions, respectively, should be deprotonated in the photocycle. The simulation results suggested that the deprotonation of Glu129 in the central constriction leads to ion leakage in the ground state, and implied that the protonation of Glu129 is important for preventing ion leakage in the ground state. Moreover, we modeled the 13-cis retinal bound; i.e., activated C1C2, and performed MD simulations to investigate the conformational changes in the early stage of the photocycle. Our simulations suggested that retinal photoisomerization induces the conformational change toward channel opening, including the movements of TM6, TM7 and TM2. These insights into the dynamics of the ground states and the early photocycle stages enhance our understanding of the channel function of ChR.

  8. Dynamics, chemical properties and bioavailability of DOC in an early successional catchment

    Directory of Open Access Journals (Sweden)

    U. Risse-Buhl

    2013-07-01

    Full Text Available The dynamics of dissolved organic carbon (DOC have been intensively studied in mature ecosystems, but little is known about DOC dynamics and the significance of DOC as a substrate for microbial activity in early-successional catchments. We determined the concentration, chemical composition, source, radiocarbon age, and bioavailability of DOC along the hydrological flow path from soil solution to a downstream pond in a recently constructed catchment (Chicken Creek Catchment, Germany. Soil solution, upwelling ground water, stream water, subsurface water in an alluvial fan, and pond water all had high DOC concentrations (averages: 6.0–11.6 mg DOC L–1, despite small carbon stocks in both vegetation and soil of the catchment. Solid-state CPMAS 13C NMR of DOC in upwelling ground water revealed a higher proportion of aromatic compounds (32% and a lower proportion of carbohydrates (33% than in pond water (18% and 45%, respectively. The average 14C age of DOC in upwelling ground water was 2600 to 2900 yr, while organic matter of the Quaternary substrate of the catchment had a 14C age of 3000 to 16 000 yr. Both the 14C age data and 13C NMR spectra suggest that DOC partly derived from organic matter of the Quaternary substrate (about 40 to 90% of the C in the DOC, indicating that both recent and old C of the DOC can support microbial activity during early ecosystem succession. However, in a 70 day incubation experiment, only about 11% of the total DOC was found to be bioavailable. This proportion was irrespective of the water type. Origin of the microbial communities within the catchment (enriched from soil, stream sediment or pond water also had only a marginal effect on overall DOC utilization.

  9. Characterizing the reproduction number of epidemics with early subexponential growth dynamics.

    Science.gov (United States)

    Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M

    2016-10-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible-infectious-removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  10. Characterizing the reproduction number of epidemics with early subexponential growth dynamics

    Science.gov (United States)

    Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M.

    2016-01-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible–infectious–removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  11. Highly dynamic and sex-specific expression of microRNAs during early ES cell differentiation.

    Directory of Open Access Journals (Sweden)

    Constance Ciaudo

    2009-08-01

    Full Text Available Embryonic stem (ES cells are pluripotent cells derived from the inner cell mass of the mammalian blastocyst. Cellular differentiation entails loss of pluripotency and gain of lineage-specific characteristics. However, the molecular controls that govern the differentiation process remain poorly understood. We have characterized small RNA expression profiles in differentiating ES cells as a model for early mammalian development. High-throughput 454 pyro-sequencing was performed on 19-30 nt RNAs isolated from undifferentiated male and female ES cells, as well as day 2 and 5 differentiating derivatives. A discrete subset of microRNAs (miRNAs largely dominated the small RNA repertoire, and the dynamics of their accumulation could be readily used to discriminate pluripotency from early differentiation events. Unsupervised partitioning around meloids (PAM analysis revealed that differentiating ES cell miRNAs can be divided into three expression clusters with highly contrasted accumulation patterns. PAM analysis afforded an unprecedented level of definition in the temporal fluctuations of individual members of several miRNA genomic clusters. Notably, this unravelled highly complex post-transcriptional regulations of the key pluripotency miR-290 locus, and helped identify miR-293 as a clear outlier within this cluster. Accordingly, the miR-293 seed sequence and its predicted cellular targets differed drastically from those of the other abundant cluster members, suggesting that previous conclusions drawn from whole miR-290 over-expression need to be reconsidered. Our analysis in ES cells also uncovered a striking male-specific enrichment of the miR-302 family, which share the same seed sequence with most miR-290 family members. Accordingly, a miR-302 representative was strongly enriched in embryonic germ cells derived from primordial germ cells of male but not female mouse embryos. Identifying the chromatin remodelling and E2F-dependent transcription

  12. Pulmonary dynamics of radiolabelled erythrocytes and leucocytes in early gram-negative sepsis in pigs

    Energy Technology Data Exchange (ETDEWEB)

    Walther, Sten; Wenyao, Shi; Lennquist, Sten

    1999-07-01

    objective: to study the pulmonary dynamic of erythrocytes and leucocytes in vivo in early experimental sepsis. design: open, experimental study. setting: academic research laboratory, Sweden. material: 10 adolescent, domestic pigs. interventions: technetium (Tc 99) labelling of erythrocytes (n=5) and indium (In 111) labelling of autologous leucocytes (n=10). sepsis was induced by endotoxin (n=4) or live Escherichia Coli (n=3), given intravenously. major outcome measures: regional pulmonary scintigraphy, central haemodynamics and gas exchange followed for 180 minutes. results: septic animals developed arterial hypoxia, pulmonary hypertension and systemic hypotension. They also had an early increase in mean (SD) regional pulmonary erythrocyte and leucocyte counts (+10.3(7.7%) and + 12.0 (3.5%) respectively) with simultaneous maximum 27-32 minutes after the start of the septic insult. Conclusions: The immediate sepsis-induced pulmonary accumulation of leucocytes as detected by external scintigraphy can be ascribed at least in part, to a simultaneous sepsis-induced increase in pulmonary blood volume. 3 figs., 1 tab., 19 refs.

  13. Pulmonary dynamics of radiolabelled erythrocytes and leucocytes in early gram-negative sepsis in pigs

    International Nuclear Information System (INIS)

    Walther, Sten; Wenyao, Shi; Lennquist, Sten

    1999-01-01

    objective: to study the pulmonary dynamic of erythrocytes and leucocytes in vivo in early experimental sepsis. design: open, experimental study. setting: academic research laboratory, Sweden. material: 10 adolescent, domestic pigs. interventions: technetium (Tc 99) labelling of erythrocytes (n=5) and indium (In 111) labelling of autologous leucocytes (n=10). sepsis was induced by endotoxin (n=4) or live Escherichia Coli (n=3), given intravenously. major outcome measures: regional pulmonary scintigraphy, central haemodynamics and gas exchange followed for 180 minutes. results: septic animals developed arterial hypoxia, pulmonary hypertension and systemic hypotension. They also had an early increase in mean (SD) regional pulmonary erythrocyte and leucocyte counts (+10.3(7.7%) and + 12.0 (3.5%) respectively) with simultaneous maximum 27-32 minutes after the start of the septic insult. Conclusions: The immediate sepsis-induced pulmonary accumulation of leucocytes as detected by external scintigraphy can be ascribed at least in part, to a simultaneous sepsis-induced increase in pulmonary blood volume. 3 figs., 1 tab., 19 refs

  14. Dynamic changes in network activations characterize early learning of a natural language.

    Science.gov (United States)

    Plante, Elena; Patterson, Dianne; Dailey, Natalie S; Kyle, R Almyrde; Fridriksson, Julius

    2014-09-01

    Those who are initially exposed to an unfamiliar language have difficulty separating running speech into individual words, but over time will recognize both words and the grammatical structure of the language. Behavioral studies have used artificial languages to demonstrate that humans are sensitive to distributional information in language input, and can use this information to discover the structure of that language. This is done without direct instruction and learning occurs over the course of minutes rather than days or months. Moreover, learners may attend to different aspects of the language input as their own learning progresses. Here, we examine processing associated with the early stages of exposure to a natural language, using fMRI. Listeners were exposed to an unfamiliar language (Icelandic) while undergoing four consecutive fMRI scans. The Icelandic stimuli were constrained in ways known to produce rapid learning of aspects of language structure. After approximately 4 min of exposure to the Icelandic stimuli, participants began to differentiate between correct and incorrect sentences at above chance levels, with significant improvement between the first and last scan. An independent component analysis of the imaging data revealed four task-related components, two of which were associated with behavioral performance early in the experiment, and two with performance later in the experiment. This outcome suggests dynamic changes occur in the recruitment of neural resources even within the initial period of exposure to an unfamiliar natural language. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Simulations of the Solar System's Early Dynamical Evolution with a Self-gravitating Planetesimal Disk

    Science.gov (United States)

    Fan, Siteng; Batygin, Konstantin

    2017-12-01

    Over the course of the last decade, the Nice model has dramatically changed our view of the solar system’s formation and early evolution. Within the context of this model, a transient period of planet–planet scattering is triggered by gravitational interactions between the giant planets and a massive primordial planetesimal disk, leading to a successful reproduction of the solar system’s present-day architecture. In typical realizations of the Nice model, self-gravity of the planetesimal disk is routinely neglected, as it poses a computational bottleneck to the calculations. Recent analyses have shown, however, that a self-gravitating disk can exhibit behavior that is dynamically distinct, and this disparity may have significant implications for the solar system’s evolutionary path. In this work, we explore this discrepancy utilizing a large suite of Nice model simulations with and without a self-gravitating planetesimal disk, taking advantage of the inherently parallel nature of graphic processing units. Our simulations demonstrate that self-consistent modeling of particle interactions does not lead to significantly different final planetary orbits from those obtained within conventional simulations. Moreover, self-gravitating calculations show similar planetesimal evolution to non-self-gravitating numerical experiments after dynamical instability is triggered, suggesting that the orbital clustering observed in the distant Kuiper Belt is unlikely to have a self-gravitational origin.

  16. Analysis of the Cellular and Molecular Mechanisms Which Underlie Sensitivity to Bacterial Endotoxin and Early Tolerance

    Science.gov (United States)

    1992-06-24

    tachycardia, tachypnea, hypertriglyceridemia, thrombocytopenia, metabolic acidosis, acute renal failure, hepatic failure, acute respiratory distress...The symptomatology associated with endotoxemia was first noted in modem times in 1928 by Schwartzman, who first described the systemic disseminated...bilirubin, lactate (which indicates an ameliorating effect on metabolic acidosis), and to bring about an increase in the mean arterial pressure in balxxms

  17. Complex epithelial remodeling underlie the fusion event in early fetal development of the human penile urethra.

    Science.gov (United States)

    Shen, Joel; Overland, Maya; Sinclair, Adriane; Cao, Mei; Yue, Xuan; Cunha, Gerald; Baskin, Laurence

    We recently described a two-step process of urethral plate canalization and urethral fold fusion to form the human penile urethra. Canalization ("opening zipper") opens the solid urethral plate into a groove, and fusion ("closing zipper") closes the urethral groove to form the penile urethra. We hypothesize that failure of canalization and/or fusion during human urethral formation can lead to hypospadias. Herein, we use scanning electron microscopy (SEM) and analysis of transverse serial sections to better characterize development of the human fetal penile urethra as contrasted to the development of the human fetal clitoris. Eighteen 7-13 week human fetal external genitalia specimens were analyzed by SEM, and fifteen additional human fetal specimens were sectioned for histologic analysis. SEM images demonstrate canalization of the urethral/vestibular plate in the developing male and female external genitalia, respectively, followed by proximal to distal fusion of the urethral folds in males only. The fusion process during penile development occurs sequentially in multiple layers and through the interlacing of epidermal "cords". Complex epithelial organization is also noted at the site of active canalization. The demarcation between the epidermis of the shaft and the glans becomes distinct during development, and the epithelial tag at the distal tip of the penile and clitoral glans regresses as development progresses. In summary, SEM analysis of human fetal specimens supports the two-zipper hypothesis of formation of the penile urethra. The opening zipper progresses from proximal to distal along the shaft of the penis and clitoris into the glans in identical fashion in both sexes. The closing zipper mechanism is active only in males and is not a single process but rather a series of layered fusion events, uniquely different from the simple fusion of two epithelial surfaces as occurs in formation of the palate and neural tube. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  18. The Lenses Structure and Dynamics Survey: luminous and dark matter in high redshift early-type galaxies

    NARCIS (Netherlands)

    Treu, T.; Koopmans, L.

    2003-01-01

    I will present the latest results from the Lenses Structure and Dynamics (LSD) Survey. Using ESI on the Keck Telescope, we have measured spatially resolved stellar kinematics for a sample of 11 early-type galaxies (E/S0s) in the range z=0.1-1, selected as gravitational lenses. By combining lensing

  19. COMPARING X-RAY AND DYNAMICAL MASS PROFILES IN THE EARLY-TYPE GALAXY NGC 4636

    International Nuclear Information System (INIS)

    Johnson, Ria; Raychaudhury, Somak; Chakrabarty, Dalia; O'Sullivan, Ewan

    2009-01-01

    We present the results of an X-ray mass analysis of the early-type galaxy NGC 4636, using Chandra data. We have compared the X-ray mass density profile with that derived from a dynamical analysis of the system's globular clusters (GCs). Given the observed interaction between the central active galactic nucleus and the X-ray emitting gas in NGC 4636, we would expect to see a discrepancy in the masses recovered by the two methods. Such a discrepancy exists within the central ∼10 kpc, which we interpret as the result of non-thermal pressure support or a local inflow. However, over the radial range ∼10-30 kpc, the mass profiles agree within the 1σ errors, indicating that even in this highly disturbed system, agreement can be sought at an acceptable level of significance over intermediate radii, with both methods also indicating the need for a dark matter halo. However, at radii larger than 30 kpc, the X-ray mass exceeds the dynamical mass, by a factor of 4-5 at the largest disagreement. A Fully Bayesian Significance Test finds no statistical reason to reject our assumption of velocity isotropy, and an analysis of X-ray mass profiles in different directions from the galaxy center suggests that local disturbances at large radius are not the cause of the discrepancy. We instead attribute the discrepancy to the paucity of GC kinematics at large radius, coupled with not knowing the overall state of the gas at the radius where we are reaching the group regime (>30 kpc), or a combination of the two.

  20. Dynamic magnetic resonance imaging of the metacarpophalangeal joints in rheumatoid arthritis, early unclassified polyarthritis, and healthy controls

    DEFF Research Database (Denmark)

    Klarlund, Mette; Østergaard, Mikkel; Rostrup, Egill

    2000-01-01

    OBJECTIVE: To introduce dynamic magnetic resonance imaging (MRI) as an indicator of inflammatory activity in the metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA) or early unclassified polyarthritis, and to compare the results with a healthy control group. MATERIALS...... synovial membrane were compared: 1) outlining of enhancing synovial membrane on subtraction images and 2) automated recognition by principal component analysis (PCA). The early enhancement (EE) rate was calculated on the basis of the first method. RESULTS: Method 1) and 2) were closely associated (P... AND METHODS: We examined 42 RA and 23 early unclassified polyarthritis patients, and 12 healthy controls in a cross-sectional study. Dynamic MRI (repeated FLASH-MR images after injection of a contrast agent) was performed through the 2nd to the 5th MCP joint. Two methods for identification of the enhancing...

  1. Dynamic contrast enhanced ultrasound assessment of the vascular effects of novel therapeutics in early stage trials.

    Science.gov (United States)

    Leen, Edward; Averkiou, Michalakis; Arditi, Marcel; Burns, Peter; Bokor, Daniela; Gauthier, Thomas; Kono, Yuko; Lucidarme, Olivier

    2012-07-01

    Imaging is key in the accurate monitoring of response to cancer therapies targeting tumour vascularity to inhibit its growth and dissemination. Dynamic contrast enhanced ultrasound (DCE ultrasound) is a quantitative method with the advantage of being non-invasive, widely available, portable, cost effective, highly sensitive and reproducible using agents that are truly intravascular. Under the auspices of the initiative of the Experimental Cancer Medicine Centre Imaging Network, bringing together experts from the UK, Europe and North America for a 2-day workshop in May 2010, this consensus paper aims to provide guidance on the use of DCE ultrasound in the measurement of tumour vascular support in clinical trials. Key Points • DCE ultrasound can quantify and extract specific blood flow parameters, such as flow velocity, relative vascular volume and relative blood flow rate. • DCE ultrasound can be performed repeatedly and is therefore ideally suited for pharmacokinetic and pharmacodynamic studies evaluating vascular-targeted drugs. • DCE ultrasound provides a reproducible method of assessing the vascular effects of therapy in pre-clinical and early clinical trials, which is easily translatable into routine clinical practice.

  2. Meteorite Impact-Induced Rapid NH3 Production on Early Earth: Ab Initio Molecular Dynamics Simulation

    Science.gov (United States)

    Shimamura, Kohei; Shimojo, Fuyuki; Nakano, Aiichiro; Tanaka, Shigenori

    2016-12-01

    NH3 is an essential molecule as a nitrogen source for prebiotic amino acid syntheses such as the Strecker reaction. Previous shock experiments demonstrated that meteorite impacts on ancient oceans would have provided a considerable amount of NH3 from atmospheric N2 and oceanic H2O through reduction by meteoritic iron. However, specific production mechanisms remain unclear, and impact velocities employed in the experiments were substantially lower than typical impact velocities of meteorites on the early Earth. Here, to investigate the issues from the atomistic viewpoint, we performed multi-scale shock technique-based ab initio molecular dynamics simulations. The results revealed a rapid production of NH3 within several picoseconds after the shock, indicating that shocks with greater impact velocities would provide further increase in the yield of NH3. Meanwhile, the picosecond-order production makes one expect that the important nitrogen source precursors of amino acids were obtained immediately after the impact. It was also observed that the reduction of N2 proceeded according to an associative mechanism, rather than a dissociative mechanism as in the Haber-Bosch process.

  3. CENTRAL DARK MATTER TRENDS IN EARLY-TYPE GALAXIES FROM STRONG LENSING, DYNAMICS, AND STELLAR POPULATIONS

    International Nuclear Information System (INIS)

    Tortora, C.; Jetzer, P.; Napolitano, N. R.; Romanowsky, A. J.

    2010-01-01

    We analyze the correlations between central dark matter (DM) content of early-type galaxies and their sizes and ages, using a sample of intermediate-redshift (z ∼ 0.2) gravitational lenses from the SLACS survey, and by comparing them to a larger sample of z ∼ 0 galaxies. We decompose the deprojected galaxy masses into DM and stellar components using combinations of strong lensing, stellar dynamics, and stellar populations modeling. For a given stellar mass, we find that for galaxies with larger sizes, the DM fraction increases and the mean DM density decreases, consistently with the cuspy halos expected in cosmological formation scenarios. The DM fraction also decreases with stellar age, which can be partially explained by the inverse correlation between size and age. The residual trend may point to systematic dependencies on formation epoch of halo contraction or stellar initial mass functions. These results are in agreement with recent findings based on local galaxies by Napolitano et al. and suggest negligible evidence of galaxy evolution over the last ∼2.5 Gyr other than passive stellar aging.

  4. On the Causes and Dynamics of the Early Twentieth Century North American Pluvial

    Science.gov (United States)

    Cook, Benjamin I.; Seager, Richard; Miller, Ron L.

    2011-01-01

    The early twentieth century North American pluvial (1905-1917) was one of the most extreme wet periods of the last five hundred years and directly led to overly generous water allotments in the water-limited American West. Here we examine the causes and dynamics of the pluvial event using a combination of observation-based data sets and general circulation model (GCM) experiments. The character of the moisture surpluses during the pluvial differed by region, alternately driven by increased precipitation (the Southwest), low evaporation from cool temperatures (the Central Plains), or a combination of the two (the Pacific Northwest). Cool temperature anomalies covered much of the west and persisted through most months, part of a globally extensive period of cooler land and sea surface temperatures (SST). Circulation during boreal winter favored increased moisture import and precipitation in the southwest, while other regions and seasons were characterized by near normal or reduced precipitation. Anomalies in the mean circulation, precipitation, and SST fields are partially consistent with the relatively weak El Nino forcing during the pluvial, and also reflect the impact of positive departures in the Arctic Oscillation that occurred in ten of the thirteen pluvial winters. Differences between the reanalysis dataset, an independent statistical drought model, and GCM simulations highlight some of the remaining uncertainties in understanding the full extent of SST forcing of North American hydroclimatic variability.

  5. Clinical role of early dynamic FDG-PET/CT for the evaluation of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Reiko; Abe, Koichiro; Sakai, Shuji [Tokyo Women' s Medical University, Department of Diagnostic Imaging and Nuclear Medicine, Tokyo (Japan); Kondo, Tsunenori; Tanabe, Kazunari [Tokyo Women' s Medical University, Department of Urology, Tokyo (Japan)

    2016-06-15

    We studied the usefulness of early dynamic (ED) and whole-body (WB) FDG-PET/CT for the evaluation of renal cell carcinoma (RCC). One hundred patients with 107 tumours underwent kidney ED and WB FDG-PET/CT. We visually and semiquantitatively evaluated the FDG accumulation in RCCs in the ED and WB phases, and compared the accumulation values with regard to histological type (clear cell carcinoma [CCC] vs. non-clear cell carcinoma [N-CCC]), the TNM stage (high stage [3-4] vs. low stage [1-2]), the Fuhrman grade (high grade [3-4] vs. low grade [1-2]) and presence versus absence of venous (V) and lymphatic (Ly) invasion. In the ED phase, visual evaluation revealed no significant differences in FDG accumulation in terms of each item. However, the maximum standardized uptake value and tumour-to-normal tissue ratios were significantly higher in the CCCs compared to the N-CCCs (p < 0.001). In the WB phase, in contrast, significantly higher FDG accumulation (p < 0.001) was found in RCCs with a higher TNM stage, higher Furman grade, and the presence of V and Ly invasion in both the visual and the semiquantitative evaluations. ED and WB FDG-PET/CT is a useful tool for the evaluation of RCCs. (orig.)

  6. Developmental timing differences underlie armor loss across threespine stickleback populations.

    Science.gov (United States)

    Currey, Mark C; Bassham, Susan; Perry, Stephen; Cresko, William A

    2017-11-01

    Comparing ontogenetic patterns within a well-described evolutionary context aids in inferring mechanisms of change, including heterochronies or deletion of developmental pathways. Because selection acts on phenotypes throughout ontogeny, any within-taxon developmental variation has implications for evolvability. We compare ontogenetic order and timing of locomotion and defensive traits in three populations of threespine stickleback that have evolutionarily divergent adult forms. This analysis adds to the growing understanding of developmental genetic mechanisms of adaptive change in this evolutionary model species by delineating when chondrogenesis and osteogenesis in two derived populations begin to deviate from the developmental pattern in their immediate ancestors. We found that differences in adult defensive morphologies arise through abolished or delayed initiation of these traits rather than via an overall heterochronic shift, that intra-population ontogenetic variation is increased for some derived traits, and that altered armor developmental timing differentiates the derived populations from each other despite parallels in adult lateral plate armor phenotypes. We found that changes in ossified elements of the pelvic armor are linked to delayed and incomplete development of an early-forming pelvic cartilage, and that this disruption likely presages the variable pelvic vestiges documented in many derived populations. © 2017 Wiley Periodicals, Inc.

  7. Gait and Computerized Dynamic Posturography (CDP Aspects in Early Progressive Supranuclear Palsy (PSP - A Case Report

    Directory of Open Access Journals (Sweden)

    Douaa M. Mosalem

    2014-12-01

    CONCLUSIONS: Both CDP and gait analysis are important quantitative tools in the assessment of posture and gait instability as well as allow for early disclosure of the failure of the postural control system in early PSP.

  8. Early days in complex dynamics a history of complex dynamics in one variable during 1906-1942

    CERN Document Server

    Alexander, Daniel S; Rosa, Alessandro

    2011-01-01

    The theory of complex dynamics, whose roots lie in 19th-century studies of the iteration of complex function conducted by Kœnigs, Schröder, and others, flourished remarkably during the first half of the 20th century, when many of the central ideas and techniques of the subject developed. This book by Alexander, Iavernaro, and Rosa paints a robust picture of the field of complex dynamics between 1906 and 1942 through detailed discussions of the work of Fatou, Julia, Siegel, and several others. A recurrent theme of the authors' treatment is the center problem in complex dynamics. They present its complete history during this period and, in so doing, bring out analogies between complex dynamics and the study of differential equations, in particular, the problem of stability in Hamiltonian systems. Among these analogies are the use of iteration and problems involving small divisors which the authors examine in the work of Poincaré and others, linking them to complex dynamics, principally via the work of Samuel...

  9. Quantitative assessment of early experimental diabetes in rats using dynamic contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Kenya [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: murase@sahs.med.osaka-u.ac.jp; Kitamura, Akihiro; Tachibana, Atsushi; Kusakabe, Yoshinori; Matsuura, Risa; Miyazaki, Shohei [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2010-04-15

    Purpose: To quantitatively assess the time course of changes of the renal volume and function in the early phase of streptozotocin (STZ)-induced diabetes in rats using dynamic contrast-enhanced computed tomography (DCE-CT). Methods: The DCE-CT studies were performed in 24 male Sprague-Dawley rats (n = 6 for control and n = 18 for STZ-treated group) on days 0, 4, 7, 11, and 14 using a multi-detector row CT. The rats of an STZ-treated group were given intraperitoneally 65 mg/kg body weight of STZ on day 0, and were divided into two groups based on the blood glucose concentration on day 4 being less than 300 mg/dL [STZ-treated group (L), n = 8] or greater than 300 mg/dL [STZ-treated group (G), n = 10]. The contrast clearance per unit renal volume (K{sub 1}) was estimated from the DCE-CT data using the Patlak model. The renal volume (V{sub CT}) was calculated by manually delineating the kidney on the contrast-enhanced CT image. The contrast clearance of the entire kidney (K) was obtained by K{sub 1} x V{sub CT}. Results: V{sub CT} in the STZ-treated group was significantly enlarged on day 4 compared to that on day 0 and continued until day 14. Although there were no significant changes in the time course of K{sub 1} in all groups, K in the STZ-treated groups (L) and (G) significantly increased on days 7 and 4, respectively, and continued until day 14, suggesting that hyperfiltration occurs in parallel with renal volume enlargement. Conclusion: The present method appears useful for quantitatively evaluating the time course of STZ-induced diabetes in rats, because it allows repeated and simultaneous evaluation of renal morphology and function.

  10. Early Winter Sea Ice Dynamics in the Ross Sea from In Situ and Satellite Observations

    Science.gov (United States)

    Maksym, T.; Ackley, S. F.; Stammerjohn, S. E.; Tison, J. L.; Hoeppner, K.

    2017-12-01

    The Ross Sea sea ice cover is one of the few regions of the cryosphere that have been expanding in recent decades. However, 2017 saw a significantly delayed autumn ice advance and record low early winter sea ice extent. Understanding the causes and impacts of this variability has been hampered by a lack of in situ observations. A winter cruise into the Ross Sea in April-June 2017 provided some of the only in situ winter observations of sea ice processes in this region in almost 20 years. We present a first look at data from arrays of drifting buoys deployed in the ice pack and outflow from these polynyas, supplemented by a suite of high-resolution synthetic aperture radar (SAR) data. Additional observations included high-resolution sonar imagery of ice deformation features from an autonomous underwater vehicle, shipboard visual observations of sea ice properties, and in situ measurements of snow and thickness and structural properties. These data show that the delay in ice advance led to a thin, highly dynamic sea ice pack, with substantial ice production and export from the Ross Ice Shelf and Terra Nova Bay polynyas. Despite these high rates of ice production, the pack ice remained thin due to rapid export and northward drift. Compared to the only prior winter observations made in 1995 and 1998, the ice was thinner, with less ridging and snow cover, reflecting a younger ice cover. Granular ice was less prevalent than in these prior cruises, particularly in the outer pack, likely due to less snow ice formation and less pancake ice formation at the advancing ice edge. Despite rapid basal ice growth, the buoy data suggest that deformation may be the dominant mechanism for sea ice thickening in the pack once an initial ice cover forms.

  11. Building performance simulation in the early design stage: An introduction to integrated dynamic models

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer

    2015-01-01

    Designing with building performance simulation feedback in the early design stage has existed since the early days of computational modeling. However, as a consequence of a fragmented building industry building performance simulations (BPSs) in the early design stage are closely related to who is...

  12. Altered Dynamic Postural Control during Step Turning in Persons with Early-Stage Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Jooeun Song

    2012-01-01

    Full Text Available Persons with early-stage Parkinson’s disease (EPD do not typically experience marked functional deficits but may have difficulty with turning tasks. Studies evaluating turning have focused on individuals in advanced stages of the disease. The purpose of this study was to compare postural control strategies adopted during turning in persons with EPD to those used by healthy control (HC subjects. Fifteen persons with EPD, diagnosed within 3 years, and 10 HC participated. Participants walked 4 meters and then turned 90°. Dynamic postural control was quantified as the distance between the center of pressure (COP and the extrapolated center of mass (eCOM. Individuals with EPD demonstrated significantly shorter COP-eCOM distances compared to HC. These findings suggest that dynamic postural control during turning is altered even in the early stages of PD.

  13. Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina.

    Science.gov (United States)

    Larkins, Christine E; Enriquez, Ana B; Cohn, Martin J

    2016-11-22

    Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development.

  14. Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina

    Science.gov (United States)

    Larkins, Christine E.; Enriquez, Ana B.; Cohn, Martin J.

    2016-01-01

    Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development. PMID:27821748

  15. Complex dynamics underlie the evolution of imperfect wing pattern convergence in butterflies.

    Science.gov (United States)

    Finkbeiner, Susan D; Briscoe, Adriana D; Mullen, Sean P

    2017-04-01

    Adaptive radiation is characterized by rapid diversification that is strongly associated with ecological specialization. However, understanding the evolutionary mechanisms fueling adaptive diversification requires a detailed knowledge of how natural selection acts at multiple life-history stages. Butterflies within the genus Adelpha represent one of the largest and most diverse butterfly lineages in the Neotropics. Although Adelpha species feed on an extraordinary diversity of larval hosts, convergent evolution is widespread in this group, suggesting that selection for mimicry may contribute to adaptive divergence among species. To investigate this hypothesis, we conducted predation studies in Costa Rica using artificial butterfly facsimiles. Specifically, we predicted that nontoxic, palatable Adelpha species that do not feed on host plants in the family Rubiaceae would benefit from sharing a locally convergent wing pattern with the presumably toxic Rubiaceae-feeding species via reduced predation. Contrary to expectations, we found that the presumed mimic was attacked significantly more than its locally convergent model at a frequency paralleling attack rates on both novel and palatable prey. Although these data reveal the first evidence for protection from avian predators by the supposed toxic, Rubiaceae-feeding Adelpha species, we conclude that imprecise mimetic patterns have high costs for Batesian mimics in the tropics. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  16. Dynamic 3D cell rearrangements guided by a fibronectin matrix underlie somitogenesis.

    Directory of Open Access Journals (Sweden)

    Gabriel G Martins

    Full Text Available Somites are transient segments formed in a rostro-caudal progression during vertebrate development. In chick embryos, segmentation of a new pair of somites occurs every 90 minutes and involves a mesenchyme-to-epithelium transition of cells from the presomitic mesoderm. Little is known about the cellular rearrangements involved, and, although it is known that the fibronectin extracellular matrix is required, its actual role remains elusive. Using 3D and 4D imaging of somite formation we discovered that somitogenesis consists of a complex choreography of individual cell movements. Epithelialization starts medially with the formation of a transient epithelium of cuboidal cells, followed by cell elongation and reorganization into a pseudostratified epithelium of spindle-shaped epitheloid cells. Mesenchymal cells are then recruited to this medial epithelium through accretion, a phenomenon that spreads to all sides, except the lateral side of the forming somite, which epithelializes by cell elongation and intercalation. Surprisingly, an important contribution to the somite epithelium also comes from the continuous egression of mesenchymal cells from the core into the epithelium via its apical side. Inhibition of fibronectin matrix assembly first slows down the rate, and then halts somite formation, without affecting pseudopodial activity or cell body movements. Rather, cell elongation, centripetal alignment, N-cadherin polarization and egression are impaired, showing that the fibronectin matrix plays a role in polarizing and guiding the exploratory behavior of somitic cells. To our knowledge, this is the first 4D in vivo recording of a full mesenchyme-to-epithelium transition. This approach brought new insights into this event and highlighted the importance of the extracellular matrix as a guiding cue during morphogenesis.

  17. Effects of stressor characteristics on early warning signs of critical transitions and "critical coupling" in complex dynamical systems

    Science.gov (United States)

    Blume, Steffen O. P.; Sansavini, Giovanni

    2017-12-01

    Complex dynamical systems face abrupt transitions into unstable and catastrophic regimes. These critical transitions are triggered by gradual modifications in stressors, which push the dynamical system towards unstable regimes. Bifurcation analysis can characterize such critical thresholds, beyond which systems become unstable. Moreover, the stochasticity of the external stressors causes small-scale fluctuations in the system response. In some systems, the decomposition of these signal fluctuations into precursor signals can reveal early warning signs prior to the critical transition. Here, we present a dynamical analysis of a power system subjected to an increasing load level and small-scale stochastic load perturbations. We show that the auto- and cross-correlations of bus voltage magnitudes increase, leading up to a Hopf bifurcation point, and further grow until the system collapses. This evidences a gradual transition into a state of "critical coupling," which is complementary to the established concept of "critical slowing down." Furthermore, we analyze the effects of the type of load perturbation and load characteristics on early warning signs and find that gradient changes in the autocorrelation provide early warning signs of the imminent critical transition under white-noise but not for auto-correlated load perturbations. Furthermore, the cross-correlation between all voltage magnitude pairs generally increases prior to and beyond the Hopf bifurcation point, indicating "critical coupling," but cannot provide early warning indications. Finally, we show that the established early warning indicators are oblivious to limit-induced bifurcations and, in the case of the power system model considered here, only react to an approaching Hopf bifurcation.

  18. Effects of stressor characteristics on early warning signs of critical transitions and "critical coupling" in complex dynamical systems.

    Science.gov (United States)

    Blume, Steffen O P; Sansavini, Giovanni

    2017-12-01

    Complex dynamical systems face abrupt transitions into unstable and catastrophic regimes. These critical transitions are triggered by gradual modifications in stressors, which push the dynamical system towards unstable regimes. Bifurcation analysis can characterize such critical thresholds, beyond which systems become unstable. Moreover, the stochasticity of the external stressors causes small-scale fluctuations in the system response. In some systems, the decomposition of these signal fluctuations into precursor signals can reveal early warning signs prior to the critical transition. Here, we present a dynamical analysis of a power system subjected to an increasing load level and small-scale stochastic load perturbations. We show that the auto- and cross-correlations of bus voltage magnitudes increase, leading up to a Hopf bifurcation point, and further grow until the system collapses. This evidences a gradual transition into a state of "critical coupling," which is complementary to the established concept of "critical slowing down." Furthermore, we analyze the effects of the type of load perturbation and load characteristics on early warning signs and find that gradient changes in the autocorrelation provide early warning signs of the imminent critical transition under white-noise but not for auto-correlated load perturbations. Furthermore, the cross-correlation between all voltage magnitude pairs generally increases prior to and beyond the Hopf bifurcation point, indicating "critical coupling," but cannot provide early warning indications. Finally, we show that the established early warning indicators are oblivious to limit-induced bifurcations and, in the case of the power system model considered here, only react to an approaching Hopf bifurcation.

  19. Dynamic FDG PET for assessing early effects of cerebral hypoxia and resuscitation in new-born pigs

    International Nuclear Information System (INIS)

    Lange, Charlotte de; Malinen, Eirik; Qu, Hong; Johnsrud, Kjersti; Skretting, Arne; Saugstad, Ola Didrik; Munkeby, Berit H.

    2012-01-01

    Changes in cerebral glucose metabolism may be an early prognostic indicator of perinatal hypoxic-ischaemic injury. In this study dynamic 18 F-FDG PET was used to evaluate cerebral glucose metabolism in piglets after global perinatal hypoxia and the impact of the resuscitation strategy using room air or hyperoxia. New-born piglets (n = 16) underwent 60 min of global hypoxia followed by 30 min of resuscitation with a fraction of inspired oxygen (FiO 2 ) of 0.21 or 1.0. Dynamic FDG PET, using a microPET system, was performed at baseline and repeated at the end of resuscitation under stabilized haemodynamic conditions. MRI at 3 T was performed for anatomic correlation. Global and regional cerebral metabolic rates of glucose (CMR gl ) were assessed by Patlak analysis for the two time-points and resuscitation groups. Global hypoxia was found to cause an immediate decrease in cerebral glucose metabolism from a baseline level (mean ± SD) of 21.2 ± 7.9 to 12.6 ± 4.7 μmol/min/100 g (p gl but no significant differences in global or regional CMR gl between the resuscitation groups were found. Dynamic FDG PET detected decreased cerebral glucose metabolism early after perinatal hypoxia in piglets. The decrease in CMR gl may indicate early changes of mild cerebral hypoxia-ischaemia. No significant effect of hyperoxic resuscitation on the degree of hypometabolism was found in this early phase after hypoxia. Cerebral FDG PET can provide new insights into mechanisms of perinatal hypoxic-ischaemic injury where early detection plays an important role in instituting therapy. (orig.)

  20. Dynamic MRI-based computer aided diagnostic systems for early detection of kidney transplant rejection: A survey

    Science.gov (United States)

    Mostapha, Mahmoud; Khalifa, Fahmi; Alansary, Amir; Soliman, Ahmed; Gimel'farb, Georgy; El-Baz, Ayman

    2013-10-01

    Early detection of renal transplant rejection is important to implement appropriate medical and immune therapy in patients with transplanted kidneys. In literature, a large number of computer-aided diagnostic (CAD) systems using different image modalities, such as ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), and radionuclide imaging, have been proposed for early detection of kidney diseases. A typical CAD system for kidney diagnosis consists of a set of processing steps including: motion correction, segmentation of the kidney and/or its internal structures (e.g., cortex, medulla), construction of agent kinetic curves, functional parameter estimation, diagnosis, and assessment of the kidney status. In this paper, we survey the current state-of-the-art CAD systems that have been developed for kidney disease diagnosis using dynamic MRI. In addition, the paper addresses several challenges that researchers face in developing efficient, fast and reliable CAD systems for the early detection of kidney diseases.

  1. Bone metabolism dynamics in the early post-transplant period following kidney and liver transplantation.

    Directory of Open Access Journals (Sweden)

    Peter W Schreiber

    Full Text Available Bone disease contributes to relevant morbidity after solid organ transplantation. Vitamin D has a crucial role for bone metabolism. Activation of vitamin D depends on the endocrine function of both, liver and kidney. Our study assessed key markers of bone metabolism at time of transplantation and 6 months after transplantation among 70 kidney and 70 liver recipients. In 70 kidney recipients 25-OH vitamin D levels did not differ significantly between peri-transplant (median 32.5nmol/l and 6 months post-transplant (median 41.9nmol/l; P = 0.272. Six months post-transplant median 1, 25-(OH2 vitamin D levels increased by >300% (from 9.1 to 36.5ng/l; P<0.001 and median intact parathyroid hormone levels decreased by 68.4% (from 208.7 to 66.0 ng/l; P<0.001. Median β-Crosslaps (CTx and total procollagen type 1 amino-terminal propeptide (P1NP decreased by 65.1% (from 1.32 to 0.46ng/ml; P<0.001 and 60.6% (from 158.2 to 62.3ng/ml; P<0.001, respectively. Kidney recipients with incident fractures had significantly lower levels of 1, 25-(OH2 vitamin D at time of transplantation and of intact parathyroid hormone 6 months post-transplant. Among 70 liver recipients, 25-OH vitamin D, 1, 25-(OH2 vitamin D and intact parathyroid hormone levels were not significantly altered between peri-transplant and 6 months post-transplant. Contrary to kidney recipients, median CTx increased by 60.0% (from 0.45 to 0.72 ng/ml; P = 0.002 and P1NP by 49.3% (from 84.0 to 125.4ng/ml; P = 0.001 in the longitudinal course. Assessed biomarkers didn't differ between liver recipients with and without fractures. To conclude, the assessed panel of biomarkers proved highly dynamic after liver as well as kidney transplantation in the early post-transplant period. After kidney transplantation a significant gain in 1, 25-(OH2 vitamin D combined with a decline in iPTH, CTx and P1NP, whereas after liver transplantation an increase in CTx and P1NP were characteristic.

  2. Switch of sensitivity dynamics revealed with DyGloSA toolbox for dynamical global sensitivity analysis as an early warning for system's critical transition.

    Science.gov (United States)

    Baumuratova, Tatiana; Dobre, Simona; Bastogne, Thierry; Sauter, Thomas

    2013-01-01

    Systems with bifurcations may experience abrupt irreversible and often unwanted shifts in their performance, called critical transitions. For many systems like climate, economy, ecosystems it is highly desirable to identify indicators serving as early warnings of such regime shifts. Several statistical measures were recently proposed as early warnings of critical transitions including increased variance, autocorrelation and skewness of experimental or model-generated data. The lack of automatized tool for model-based prediction of critical transitions led to designing DyGloSA - a MATLAB toolbox for dynamical global parameter sensitivity analysis (GPSA) of ordinary differential equations models. We suggest that the switch in dynamics of parameter sensitivities revealed by our toolbox is an early warning that a system is approaching a critical transition. We illustrate the efficiency of our toolbox by analyzing several models with bifurcations and predicting the time periods when systems can still avoid going to a critical transition by manipulating certain parameter values, which is not detectable with the existing SA techniques. DyGloSA is based on the SBToolbox2 and contains functions, which compute dynamically the global sensitivity indices of the system by applying four main GPSA methods: eFAST, Sobol's ANOVA, PRCC and WALS. It includes parallelized versions of the functions enabling significant reduction of the computational time (up to 12 times). DyGloSA is freely available as a set of MATLAB scripts at http://bio.uni.lu/systems_biology/software/dyglosa. It requires installation of MATLAB (versions R2008b or later) and the Systems Biology Toolbox2 available at www.sbtoolbox2.org. DyGloSA can be run on Windows and Linux systems, -32 and -64 bits.

  3. Switch of Sensitivity Dynamics Revealed with DyGloSA Toolbox for Dynamical Global Sensitivity Analysis as an Early Warning for System's Critical Transition

    Science.gov (United States)

    Baumuratova, Tatiana; Dobre, Simona; Bastogne, Thierry; Sauter, Thomas

    2013-01-01

    Systems with bifurcations may experience abrupt irreversible and often unwanted shifts in their performance, called critical transitions. For many systems like climate, economy, ecosystems it is highly desirable to identify indicators serving as early warnings of such regime shifts. Several statistical measures were recently proposed as early warnings of critical transitions including increased variance, autocorrelation and skewness of experimental or model-generated data. The lack of automatized tool for model-based prediction of critical transitions led to designing DyGloSA – a MATLAB toolbox for dynamical global parameter sensitivity analysis (GPSA) of ordinary differential equations models. We suggest that the switch in dynamics of parameter sensitivities revealed by our toolbox is an early warning that a system is approaching a critical transition. We illustrate the efficiency of our toolbox by analyzing several models with bifurcations and predicting the time periods when systems can still avoid going to a critical transition by manipulating certain parameter values, which is not detectable with the existing SA techniques. DyGloSA is based on the SBToolbox2 and contains functions, which compute dynamically the global sensitivity indices of the system by applying four main GPSA methods: eFAST, Sobol's ANOVA, PRCC and WALS. It includes parallelized versions of the functions enabling significant reduction of the computational time (up to 12 times). DyGloSA is freely available as a set of MATLAB scripts at http://bio.uni.lu/systems_biology/software/dyglosa. It requires installation of MATLAB (versions R2008b or later) and the Systems Biology Toolbox2 available at www.sbtoolbox2.org. DyGloSA can be run on Windows and Linux systems, -32 and -64 bits. PMID:24367574

  4. Piezo- and Flexoelectric Membrane Materials Underlie Fast Biological Motors in the Ear.

    Science.gov (United States)

    Breneman, Kathryn D; Rabbitt, Richard D

    2009-01-01

    The mammalian inner ear is remarkably sensitive to quiet sounds, exhibits over 100dB dynamic range, and has the exquisite ability to discriminate closely spaced tones even in the presence of noise. This performance is achieved, in part, through active mechanical amplification of vibrations by sensory hair cells within the inner ear. All hair cells are endowed with a bundle of motile microvilli, stereocilia, located at the apical end of the cell, and the more specialized outer hair cells (OHC's) are also endowed with somatic electromotility responsible for changes in cell length in response to perturbations in membrane potential. Both hair bundle and somatic motors are known to feed energy into the mechanical vibrations in the inner ear. The biophysical origin and relative significance of the motors remains a subject of intense research. Several biological motors have been identified in hair cells that might underlie the motor(s), including a cousin of the classical ATP driven actin-myosin motor found in skeletal muscle. Hydrolysis of ATP, however, is much too slow to be viable at audio frequencies on a cycle-by-cycle basis. Heuristically, the OHC somatic motor behaves as if the OHC lateral wall membrane were a piezoelectric material and the hair bundle motor behaves as if the plasma membrane were a flexoelectric material. We propose these observations from a continuum materials perspective are literally true. To examine this idea, we formulated mathematical models of the OHC lateral wall "piezoelectric" motor and the more ubiquitous "flexoelectric" hair bundle motor. Plausible biophysical mechanisms underlying piezo- and flexoelectricity were established. Model predictions were compared extensively to the available data. The models were then applied to study the power conversion efficiency of the motors. Results show that the material properties of the complex membranes in hair cells provide them with the ability to convert electrical power available in the inner

  5. Differences in early dynamics and effects of slope aspect between naturally regenerated and planted Pinus sylvestris woodland on inland dunes in Poland

    OpenAIRE

    Sewerniak P

    2016-01-01

    There is little knowledge of the effects of landform relief on early growth dynamics and competitive interactions of Pinus sylvestris (Scots pine) stands on inland dunes, which could potentially be substantial. The goal of this study was to examine and compare early dynamics (based on growth parameters and properties of the understorey vegetation) and the effects of slope aspect in naturally regenerated and pine-planted woodland on inland dunes in northern Poland. Growth parameters, tree dens...

  6. Dynamic range of Nef-mediated evasion of HLA class II-restricted immune responses in early HIV-1 infection.

    Science.gov (United States)

    Mahiti, Macdonald; Brumme, Zabrina L; Jessen, Heiko; Brockman, Mark A; Ueno, Takamasa

    2015-07-31

    HLA class II-restricted CD4(+) T lymphocytes play an important role in controlling HIV-1 replication, especially in the acute/early infection stage. But, HIV-1 Nef counteracts this immune response by down-regulating HLA-DR and up-regulating the invariant chain associated with immature HLA-II (Ii). Although functional heterogeneity of various Nef activities, including down-regulation of HLA class I (HLA-I), is well documented, our understanding of Nef-mediated evasion of HLA-II-restricted immune responses during acute/early infection remains limited. Here, we examined the ability of Nef clones from 47 subjects with acute/early progressive infection and 46 subjects with chronic progressive infection to up-regulate Ii and down-regulate HLA-DR and HLA-I from the surface of HIV-infected cells. HLA-I down-regulation function was preserved among acute/early Nef clones, whereas both HLA-DR down-regulation and Ii up-regulation functions displayed relatively broad dynamic ranges. Nef's ability to down-regulate HLA-DR and up-regulate Ii correlated positively at this stage, suggesting they are functionally linked in vivo. Acute/early Nef clones also exhibited higher HLA-DR down-regulation and lower Ii up-regulation functions compared to chronic Nef clones. Taken together, our results support enhanced Nef-mediated HLA class II immune evasion activities in acute/early compared to chronic infection, highlighting the potential importance of these functions following transmission. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Generation of a transgenic medaka (Oryzias latipes) strain for visualization of nuclear dynamics in early developmental stages.

    Science.gov (United States)

    Inoue, Takanobu; Iida, Atsuo; Maegawa, Shingo; Sehara-Fujisawa, Atsuko; Kinoshita, Masato

    2016-12-01

    In this study, we verified nuclear transport activity of an artificial nuclear localization signal (aNLS) in medaka fish (Oryzias latipes). We generated a transgenic medaka strain expresses the aNLS tagged enhanced green fluorescent protein (EGFP) driven by a medaka beta-actin promoter. The aNLS-EGFP was accumulated in the nuclei of somatic tissues and yolk nuclei of oocytes, but undetectable in the spermatozoa. The fluorescent signal was observed from immediately after fertilization by a maternal contribution. Furthermore, male and female pronuclei were visualized in fertilized eggs, and nuclear dynamics of pronuclear fusion and subsequent cleavage were captured by time-lapse imaging. In contrast, SV40NLS exhibited no activity of nuclear transport in early embryos. In conclusion, the aNLS possesses a strong nuclear localization activity and is a useful probe for fluorescent observation of the pronuclei and nuclei in early developmental stage of medaka. © 2016 Japanese Society of Developmental Biologists.

  8. Dynamically observing the value of the changes of serum sex hormone levels of early pregnancy after drug-induced abortion

    International Nuclear Information System (INIS)

    Zhao Honggang; Dong Hua; Gu Yan; Zhang Zuncheng

    2009-01-01

    Objective: To observe the value of the changes of serum β-human chorionic gonadotropin (β-HCG), estradiol (E), progesterone (P) Levels of early pregnancy after drug-induced abortion dynamically. Methods: Assessing 55 women proved pregnant by urine or blood HCG retrospecticly, who had terminated their pregnancy by mifepristonr and misoprostol. Meanwhile the serum levels of β-HCG, E, P were monitored dynamically. Results: Among the 55 patients, the levels of β-HCG, E and P had significant decreased (t β-HCG =4.845, t E =7.655, t P =11.390, P E =9.089, P P =2.910, P<0.05). Conclusion: Detectint the serum hormone's levels after drug-induced abortion by chemiluminescent immunoassay, we can assess indirectly the value of administration of mifepristone and misoprostol, predict the prolonged vaginal bleeding after drug-induced abortion, and the outcome of the treatment, which determine wether need another curestage. (authors)

  9. Interleukin-6 dynamics as a basis for an early-warning monitor for sepsis and inflammation in individual pigs.

    Science.gov (United States)

    Tambuyzer, Tim; De Waele, Tine; Chiers, Koen; Berckmans, Daniel; Goddeeris, Bruno M; Aerts, Jean-Marie

    2014-06-01

    Static interleukin-6 (IL-6) levels of pigs contain considerable individual differences, which obstruct the practical use of IL-6 for disease monitoring purposes. It was hypothesised that interleukin-6 (IL-6) dynamics could be used to quantify these individual differences and carries critical information of the individual pig infection status. Time series of IL-6 responses in 25 pigs were analysed before and after infection by Actinobacillus pleuropneumoniae. The results indicated that amplitude increases of IL-6 fluctuations of individual pigs rather than static IL-6 values should be used as indicator of the infection state. This study shows the added value for IL-6 time series analyses of individual pigs. These results are a first step towards the development of objective individualised methods for monitoring and early detection of sepsis and inflammation processes in pigs by integrating animal response dynamics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Dynamic Contrast-Enhanced Ultrasound of Colorectal Liver Metastases as an Imaging Modality for Early Response Prediction to Chemotherapy

    Directory of Open Access Journals (Sweden)

    Marie Benzon Mogensen

    2017-06-01

    Full Text Available Our aim was to investigate whether dynamic contrast-enhanced ultrasound (DCE-US can detect early changes in perfusion of colorectal liver metastases after initiation of chemotherapy. Newly diagnosed patients with colorectal cancer with liver metastases were enrolled in this explorative prospective study. Patients were treated with capecitabine or 5-fluorouracil-based chemotherapy with or without bevacizumab. DCE-US was performed before therapy (baseline and again 10 days after initiation of treatment. Change in contrast-enhancement in one liver metastasis (indicator lesion was measured. Treatment response was evaluated with a computed tomography (CT scan after three cycles of treatment and the initially observed DCE-US change of the indicator lesion was related to the observed CT response. Eighteen patients were included. Six did not complete three series of chemotherapy and the evaluation CT scan, leaving twelve patients for analysis. Early changes in perfusion parameters using DCE-US did not correlate well with subsequent CT changes. A subgroup analysis of eight patients receiving bevacizumab, however, demonstrated a statistically significant correlation (p = 0.045 between early changes in perfusion measures of peak enhancement at DCE-US and tumor shrinkage at CT scan. The study indicates that early changes in DCE-US perfusion measures may predict subsequent treatment response of colorectal liver metastases in patients receiving bevacizumab.

  11. Differentiation between early rheumatoid arthritis patients and healthy persons by conventional and dynamic contrast-enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Axelsen, Mette Bjørndal; Ejbjerg, B J; Hetland, M L

    2014-01-01

    OBJECTIVES: To identify the magnetic resonance imaging (MRI) parameter that best differentiates healthy persons and patients with early rheumatoid arthritis (RA), and to investigated responsiveness to treatment of various MRI parameters. METHOD: Conventional MRI and dynamic contrast-enhanced (DCE......), the initial rate of enhancement (IRE), the maximum enhancement (ME), ME×Nvoxel, and IRE×Nvoxel were calculated for wrist and 2nd-5th metacarpophalangeal (MCP) joints. Conventional MR images were evaluated using the RA MRI scoring system (RAMRIS) synovitis score. RESULTS: Using DCE-MRI, enhancement...

  12. Dancing to the rhythms of the Pleistocene? Early Middle Paleolithic population dynamics in NW Iberia (Duero Basin and Cantabrian Region)

    Science.gov (United States)

    Sánchez Yustos, Policarpo; Diez Martín, Fernando

    2015-08-01

    The Northwest of Iberia has yielded one of the most complete European Middle Paleolithic records. Despite this wealth of information, very little is known about population dynamics during this period. For that reason, the main concern of this paper is to provide socio-environmental models that may help explain Early Middle Paleolithic (EMP) population dynamics in NW Iberia, assessing to what extent they were shaped by climate forces. The archaeological record is analyzed on the basis of the heuristics of ecological models, already employed in the European Pleistocene record but never at a regional scale, in order to detect long-term changes in the composition of EMP populations, and the environmental, biological and sociocultural process influencing those changes. According to the models proposed, we have detected a long-term population dynamic between MIS 11 and MIS 6, characterized by low environmental stress, high biological productivity, interaction among populations and sociocultural complexity. Eventually, this population dynamic was broken due to an extreme climate phase in late MIS 6 that had a profound impact on populations and sociocultural structures. As a result, the Upper Pleistocene population of NW Iberia was concentrated in the Cantabrian region. This area became an isolated Neanderthal glacial refugium that hosted a population with different origins and fragile long-term demographic stability.

  13. Early Spring Post-Fire Snow Albedo Dynamics in High Latitude Boreal Forests Using Landsat-8 OLI Data

    Science.gov (United States)

    Wang, Zhuosen; Erb, Angela M.; Schaaf, Crystal B.; Sun, Qingsong; Liu, Yan; Yang, Yun; Shuai, Yanmin; Casey, Kimberly A.; Roman, Miguel O.

    2016-01-01

    Taking advantage of the improved radiometric resolution of Landsat-8 OLI which, unlike previous Landsat sensors, does not saturate over snow, the progress of fire recovery progress at the landscape scale (less than 100 m) is examined. High quality Landsat-8 albedo retrievals can now capture the true reflective and layered character of snow cover over a full range of land surface conditions and vegetation densities. This new capability particularly improves the assessment of post-fire vegetation dynamics across low- to high-burn severity gradients in Arctic and boreal regions in the early spring, when the albedos during recovery show the greatest variation. We use 30 m resolution Landsat-8 surface reflectances with concurrent coarser resolution (500 m) MODIS high quality full inversion surface Bidirectional Reflectance Distribution Functions (BRDF) products to produce higher resolution values of surface albedo. The high resolution full expression shortwave blue sky albedo product performs well with an overall RMSE of 0.0267 between tower and satellite measures under both snow-free and snow-covered conditions. While the importance of post-fire albedo recovery can be discerned from the MODIS albedo product at regional and global scales, our study addresses the particular importance of early spring post-fire albedo recovery at the landscape scale by considering the significant spatial heterogeneity of burn severity, and the impact of snow on the early spring albedo of various vegetation recovery types. We found that variations in early spring albedo within a single MODIS gridded pixel can be larger than 0.6. Since the frequency and severity of wildfires in Arctic and boreal systems is expected to increase in the coming decades, the dynamics of albedo in response to these rapid surface changes will increasingly impact the energy balance and contribute to other climate processes and physical feedback mechanisms. Surface radiation products derived from Landsat-8 data will

  14. Early mantle dynamics inferred from 142Nd variations in Archean rocks from southwest Greenland

    DEFF Research Database (Denmark)

    Rizo, Hanika; Boyet, Maud; Blichert-Toft, Janne

    2013-01-01

    of the Greenland samples from a source formed in the Hadean. This mantle source is the oldest yet identified on Earth and therefore provides key information about the nature and evolution of early-differentiated reservoirs. In contrast, modern mantle-derived rocks from around the world do not have Nd-142 anomalies...... Supracrustal Belt (ISB) in southwest Greenland has revealed ubiquitous Nd-142 excesses in these rocks compared to modern samples and terrestrial Nd standards. Because the parent isotope, Sm-146, was extant only during the first few hundred million years of Solar System history, this implies derivation......, suggesting that the primordial heterogeneities detected in Earth's early mantle have been erased over time. In order to better constrain the rate at which early mantle heterogeneities have been re-homogenized, we produced new Sm-146-Nd-142 data for both 3.8 and 3.3 Ga old mafic rocks from different tectonic...

  15. The ATLAS3D Project - XXVIII. Dynamically driven star formation suppression in early-type galaxies

    NARCIS (Netherlands)

    Davis, Timothy A.; Young, Lisa M.; Crocker, Alison F.; Bureau, Martin; Blitz, Leo; Alatalo, Katherine; Emsellem, Eric; Naab, Thorsten; Bayet, Estelle; Bois, Maxime; Bournaud, Frédéric; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. T.; Duc, Pierre-Alain; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Morganti, Raffaella; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie

    2014-01-01

    We present measurements of the star formation rate (SFR) in the early-type galaxies (ETGs) of the ATLAS3D sample, based on Wide-field Infrared Survey Explorer (WISE) 22 μm and Galaxy Evolution Explorer far-ultraviolet emission. We combine these with gas masses estimated from 12CO and H I data in

  16. Dynamic Tensions: Early Reflections from MDRC's Evaluation of the Innovative Professional Development Challenge

    Science.gov (United States)

    MDRC, 2015

    2015-01-01

    In the Innovative Professional Development (iPD) Challenge, the Bill & Melinda Gates Foundation has invested in helping school districts and networks redesign their instructional support systems to better support educators in increasing student success. This Issue Focus, the second in a series, presents early reflections from MDRC's evaluation…

  17. Promoting Alphabet Knowledge Using Peer-Mediated Intervention: A Dynamic Duo for Early Literacy Development

    Science.gov (United States)

    Harris, Kathleen I.; Kinley, Hannah L.; Cook, Angela

    2017-01-01

    One of early childhood teachers' first questions of parents with regard to school readiness is whether the child knows the ABCs (Hyson & Tomlinson, 2014). Crucial pre-reading and writing skills, such as oral language, phonological awareness, print awareness, and alphabet letter recognition, are important to children's cognitive development…

  18. Friendship selection and friends' influence : Dynamics of networks and actor attributes in early adolescence

    NARCIS (Netherlands)

    Knecht, Andrea Beate

    2008-01-01

    Adolescent friends are often found to be similar. Similarity can be caused by selection and influence processes. This book examines selection and influence processes for delinquency, school attitudes, and alcohol use in early adolescence. For selection processes, we hypothesize that adolescents

  19. Friendship selection and friends' influence. Dynamics of networks and actor attributes in early adolescence

    NARCIS (Netherlands)

    Knecht, A.B.

    2008-01-01

    Adolescent friends are often found to be similar. Similarity can be caused by selection and influence processes. This book examines selection and influence processes for delinquency, school attitudes, and alcohol use in early adolescence. For selection processes, we hypothesize that adolescents

  20. A Dynamic Learning Concept in Early Years' Education: A Possible Way to Prevent Schoolification

    Science.gov (United States)

    Broström, Stig

    2017-01-01

    In early childhood education and care, Nordic social pedagogy approach is challenged by a learning orientation that often results in unproductive "either/or" thinking. Therefore, based on the two approaches and by analysing several dimensions of Froebel's ideas and prevailing social-historical activity (play) theory, the author deduces…

  1. The Dynamics of Families Who Are Homeless: Implications for Early Childhood Educators

    Science.gov (United States)

    Swick, Kevin J.

    2004-01-01

    Family homelessness has emerged as a serious global problem (Stronge, 2000). Over the past 25 years in the United States, the makeup of the homeless population has changed significantly. As De Angelis (1994) reports: The landscape of homelessness has changed since the early 1980s, when nearly all homeless people were men. Today,…

  2. Early aberrations in chromatin dynamics in embryos produced under In vitro conditions

    DEFF Research Database (Denmark)

    Deshmukh, Rahul Shahaji; Østrup, Olga; Strejcek, Frantisek

    2012-01-01

    In vitro production of porcine embryos by means of in vitro fertilization (IVF) or somatic cell nuclear transfer (SCNT) is limited by great inefficienciy. The present study investigated chromatin and nucleolar dynamics in porcine embryos developed in vivo (IV) and compared this physiological...

  3. Caregivers' Gestures Direct Infant Attention during Early Word Learning: The Importance of Dynamic Synchrony

    Science.gov (United States)

    Rader, Nancy de Villiers; Zukow-Goldring, Patricia

    2012-01-01

    How do young infants discover word meanings? We have theorized that caregivers educate infants' attention (cf. Gibson, J.J., 1966) by synchronizing the saying of a word with a dynamic gesture displaying the object/referent (Zukow-Goldring, 1997). Detecting an amodal invariant across gesture and speech brackets the word and object within the…

  4. Early Triassic environmental dynamics and microbial development during the Smithian-Spathian transition (Lower Weber Canyon, Utah, USA)

    Science.gov (United States)

    Grosjean, Anne-Sabine; Vennin, Emmanuelle; Olivier, Nicolas; Caravaca, Gwénaël; Thomazo, Christophe; Fara, Emmanuel; Escarguel, Gilles; Bylund, Kevin G.; Jenks, James F.; Stephen, Daniel A.; Brayard, Arnaud

    2018-01-01

    The Early Triassic biotic recovery following the end-Permian mass extinction is well documented in the Smithian-Spathian Thaynes Group of the western USA basin. This sedimentary succession is commonly interpreted as recording harsh conditions of various shallow marine environments where microbial structures flourished. However, recent studies questioned the relevance of the classical view of long-lasting deleterious post-crisis conditions and suggested a rapid diversification of some marine ecosystems during the Early Triassic. Using field and microfacies analyses, we investigate a well-preserved Early Triassic marine sedimentary succession in Lower Weber Canyon (Utah, USA). The identification of microbial structures and their depositional settings provide insights on factors controlling their morphologies and distribution. The Lower Weber Canyon sediments record the vertical evolution of depositional environments from a middle Smithian microbial and dolosiliciclastic peritidal system to a late Smithian-early Spathian bioclastic, muddy mid ramp. The microbial deposits are interpreted as Microbially Induced Sedimentary Structures (MISS) that developed either (1) in a subtidal mid ramp where microbial wrinkles and chips are associated with megaripples characterizing hydrodynamic conditions of lower flow regime, or (2) in protected areas of inter- to subtidal inner ramp where they formed laminae and domal structures. Integrated with other published data, our investigations highlight that the distribution of these microbial structures was influenced by the combined effects of bathymetry, hydrodynamic conditions, lithology of the substrat physico-chemical characteristics of the depositional environment and by the regional relative sea-level fluctuations. Thus, we suggest that local environmental factors and basin dynamics primarily controlled the modalities of microbial development and preservation during the Early Triassic in the western USA basin.

  5. Distinct myocardial mechanisms underlie cardiac dysfunction in endotoxemic male and female mice

    OpenAIRE

    Hobai, Ion A.; Aziz, Kanwal; Buys, Emmanuel S.; Brouckaert, Peter; Siwik, Deborah A.; Colucci., Wilson S.

    2016-01-01

    In male mice, Sepsis-Induced Cardiomyopathy develops as a result of dysregulation of myocardial calcium (Ca2+) handling, leading to depressed cellular Ca2+ transients (ΔCai). ΔCai depression is partially due to inhibition of sarcoplasmic reticulum Ca2+ ATP-ase (SERCA) via oxidative modifications, which are partially opposed by cGMP generated by the enzyme soluble guanylyl cyclase (sGC). Whether similar mechanisms underlie Sepsis-Induced Cardiomyopathy in female mice is unknown.

  6. Assessment of the efficacy of early phase parameters by (123)I-MIBG dynamic imaging for distinguishing Lewy body-related diseases from Parkinson's syndrome.

    Science.gov (United States)

    Shiiba, Takuro; Nishii, Ryuichi; Sasaki, Masayuki; Kihara, Yasushi; Tsuruta, Kazuhito; Maeda, Masaji; Morishita, Junji

    2015-02-01

    The aim of this study was to assess the efficacy of early phase washout rate (early WR) and area under the time-activity curve (AUTAC) by (123)I-metaiodobenzylguanidine (MIBG) dynamic chest imaging for distinguishing Lewy body-related diseases (LBRD) from Parkinson's syndrome (PS) and reducing examination time. Sixty-two patients with suspected LBRD who underwent (123)I-MIBG dynamic imaging in early phase were retrospectively selected. The early WR and AUTAC were calculated from (123)I-MIBG dynamic data of the heart. We evaluated the relationships between proposed and conventional parameters by using Spearman's rank correlation coefficient. Differences in parameters between LBRD and PS groups were tested for statistical significance using the Mann-Whitney U test. The diagnostic performance of all parameters for distinguishing LBRD from PS was assessed in terms of receiver operating characteristic (ROC) analysis. Additionally, combination diagnostic performance and concordance rate between early phase parameters and late H/M ratio by kappa statistics were also assessed. The early WR and AUTAC showed a positive and negative correlation with conventional parameters. Both the early WR and AUTAC of LBRD group were significantly distinguishable from those of the PS group (p < 0.001). Area under the ROC curve of the early WR (0.98) was greater than that of AUTAC (0.91). The diagnostic performance of combination of the early phase parameters was 93 % sensitivity and 100 % specificity. Moreover, the early phase parameters showed excellent agreement with late H/M ratio (k = 0.93). The early WR and AUTAC showed high performance for distinguishing LBRD from PS, and the combination diagnosis with early H/M ratio and early WR contribute to improve the diagnostic performance. Thus, these parameters would be useful for reducing the examination time of myocardial (123)I-MIBG scintigraphy to diagnose LBRD.

  7. Monitoring early response to chemoradiotherapy with 18F-FMISO dynamic PET in head and neck cancer

    International Nuclear Information System (INIS)

    Grkovski, Milan; Beattie, Bradley J.; O'Donoghue, Joseph A.; Humm, John L.; Lee, Nancy Y.; Riaz, Nadeem; Leeman, Jonathan E.; Schoeder, Heiko; Carlin, Sean D.

    2017-01-01

    There is growing recognition that biologic features of the tumor microenvironment affect the response to cancer therapies and the outcome of cancer patients. In head and neck cancer (HNC) one such feature is hypoxia. We investigated the utility of 18 F-fluoromisonidazole (FMISO) dynamic positron emission tomography (dPET) for monitoring the early microenvironmental response to chemoradiotherapy in HNC. Seventy-two HNC patients underwent FMISO dPET scans in a customized immobilization mask (0-30 min dynamic acquisition, followed by 10 min static acquisitions starting at ∝95 min and ∝160 min post-injection) at baseline and early into treatment where patients have already received one cycle of chemotherapy and anywhere from five to ten fractions of 2 Gy per fraction radiation therapy. Voxelwise pharmacokinetic modeling was conducted using an irreversible one-plasma two-tissue compartment model to calculate surrogate biomarkers of tumor hypoxia (k 3 and Tumor-to-Blood Ratio (TBR)), perfusion (K 1 ) and FMISO distribution volume (DV). Additionally, Tumor-to-Muscle Ratios (TMR) were derived by visual inspection by an experienced nuclear medicine physician, with TMR > 1.2 defining hypoxia. One hundred and thirty-five lesions in total were analyzed. TBR, k 3 and DV decreased on early response scans, while no significant change was observed for K 1 . The k 3 -TBR correlation decreased substantially from baseline scans (Pearson's r = 0.72 and 0.76 for mean intratumor and pooled voxelwise values, respectively) to early response scans (Pearson's r = 0.39 and 0.40, respectively). Both concordant and discordant examples of changes in intratumor k 3 and TBR were identified; the latter partially mediated by the change in DV. In 13 normoxic patients according to visual analysis (all having lesions with TMR = 1.2), subvolumes were identified where k 3 indicated the presence of hypoxia. Pharmacokinetic modeling of FMISO dynamic PET reveals a more detailed

  8. Monitoring early response to chemoradiotherapy with {sup 18}F-FMISO dynamic PET in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Grkovski, Milan; Beattie, Bradley J.; O' Donoghue, Joseph A.; Humm, John L. [Memorial Sloan Kettering Cancer Center, Department of Medical Physics, New York, NY (United States); Lee, Nancy Y.; Riaz, Nadeem; Leeman, Jonathan E. [Memorial Sloan Kettering Cancer Center, Department of Radiation Oncology, New York, NY (United States); Schoeder, Heiko; Carlin, Sean D. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States)

    2017-09-15

    There is growing recognition that biologic features of the tumor microenvironment affect the response to cancer therapies and the outcome of cancer patients. In head and neck cancer (HNC) one such feature is hypoxia. We investigated the utility of {sup 18}F-fluoromisonidazole (FMISO) dynamic positron emission tomography (dPET) for monitoring the early microenvironmental response to chemoradiotherapy in HNC. Seventy-two HNC patients underwent FMISO dPET scans in a customized immobilization mask (0-30 min dynamic acquisition, followed by 10 min static acquisitions starting at ∝95 min and ∝160 min post-injection) at baseline and early into treatment where patients have already received one cycle of chemotherapy and anywhere from five to ten fractions of 2 Gy per fraction radiation therapy. Voxelwise pharmacokinetic modeling was conducted using an irreversible one-plasma two-tissue compartment model to calculate surrogate biomarkers of tumor hypoxia (k{sub 3} and Tumor-to-Blood Ratio (TBR)), perfusion (K{sub 1}) and FMISO distribution volume (DV). Additionally, Tumor-to-Muscle Ratios (TMR) were derived by visual inspection by an experienced nuclear medicine physician, with TMR > 1.2 defining hypoxia. One hundred and thirty-five lesions in total were analyzed. TBR, k{sub 3} and DV decreased on early response scans, while no significant change was observed for K{sub 1}. The k{sub 3} -TBR correlation decreased substantially from baseline scans (Pearson's r = 0.72 and 0.76 for mean intratumor and pooled voxelwise values, respectively) to early response scans (Pearson's r = 0.39 and 0.40, respectively). Both concordant and discordant examples of changes in intratumor k{sub 3} and TBR were identified; the latter partially mediated by the change in DV. In 13 normoxic patients according to visual analysis (all having lesions with TMR = 1.2), subvolumes were identified where k{sub 3} indicated the presence of hypoxia. Pharmacokinetic modeling of FMISO dynamic PET

  9. Dynamic Assembly of Brambleberry Mediates Nuclear Envelope Fusion during Early Development

    OpenAIRE

    Abrams, Elliott W.; Zhang, Hong; Marlow, Florence L.; Kapp, Lee; Lu, Sumei; Mullins, Mary C.

    2012-01-01

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, a mitotic intermediate wherein individual chromatin masses are surrounded by nuclear envelope, which then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion resulting in formation of multiple micronuclei. brambleberry is a previously unannotated gene homolo...

  10. Friendship selection and friends' influence. Dynamics of networks and actor attributes in early adolescence

    OpenAIRE

    Knecht, A.B.

    2008-01-01

    Adolescent friends are often found to be similar. Similarity can be caused by selection and influence processes. This book examines selection and influence processes for delinquency, school attitudes, and alcohol use in early adolescence. For selection processes, we hypothesize that adolescents whose attributes are positively associated tend to become and stay friends. For influence processes, we hypothesize that adolescents tend to adjust their attributes to their friends' attributes. We ana...

  11. Do early growth dynamics explain recruitment success in Japanese flounder Paralichthys olivaceus off the Pacific coast of northern Japan?

    Science.gov (United States)

    Oshima, Masakane; Robert, Dominique; Kurita, Yutaka; Yoneda, Michio; Tominaga, Osamu; Tomiyama, Takeshi; Yamashita, Yoh; Uehara, Shinji

    2010-07-01

    We examined the relative importance of growth-related processes operating during the larval and early juvenile stage in explaining variability in year class success of Japanese flounder off the Pacific coast of northern Japan. Early growth trajectory of larvae and juveniles sampled in 2005 (strong year class) and in 2006 (weak year class) was estimated from the analysis of the lapillar otolith. The larval pelagic stage was characterized by lower growth and developmental rates, as well as high selection for fast growth in the metamorphosis/settlement period, during the strong recruitment event of 2005 relative to 2006. Growth appeared higher in 2005 only after settlement despite high density in the nursery, which likely reflected superior productivity during that year combined with an increased probability of cannibalism from early settlers on late settlers. This implies that larval growth dynamics did not play an important role in determining recruitment strength in the two years considered. The decreasing distance from the nursery areas of pelagic larvae through ontogeny in 2005, combined with low age at settlement, suggest that larvae benefited from positive transport conditions during the dominant year class. To the contrary, unfavorable hydrographic conditions likely prevailed in 2006 as distance from the nurseries increased with ontogeny and settlement occurred later than in 2005 despite faster growth potential and developmental rate. We conclude that transport conditions to the nursery grounds, rather than larval growth potential, represented the most important determinant of year class success in the two years considered.

  12. Dynamical 3-Space Predicts Hotter Early Universe: Resolves CMB-BBN 7-Li and 4-He Abundance Anomalies

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2010-01-01

    Full Text Available The observed abundances of 7-Li and 4-He are significantly inconsistent with the predictions from Big Bang Nucleosynthesis (BBN when using the $Lambda$CDM cosmological model together with the value for $Omega_B h^2 = 0.0224pm0.0009$ from WMAP CMB fluctuations, with the value from BBN required to fit observed abundances being $0.009 < Omega_B h^2 < 0.013$. The dynamical 3-space theory is shown to predict a 20% hotter universe in the radiation-dominated epoch, which then results in a remarkable parameter-free agreement between the BBN and the WMAP value for $Omega_B h^2$. The dynamical 3-space also gives a parameter-free fit to the supernova redshift data, and predicts that the flawed $Lambda$CDM model would require $Omega_Lambda = 0.73$ and $Omega_M = 0.27$ to fit the 3-space dynamics Hubble expansion, and independently of the supernova data. These results amount to the discovery of new physics for the early universe that is matched by numerous other successful observational and experimental tests.

  13. Dynamic landscape of pancreatic carcinogenesis reveals early molecular networks of malignancy.

    Science.gov (United States)

    Kong, Bo; Bruns, Philipp; Behler, Nora A; Chang, Ligong; Schlitter, Anna Melissa; Cao, Jing; Gewies, Andreas; Ruland, Jürgen; Fritzsche, Sina; Valkovskaya, Nataliya; Jian, Ziying; Regel, Ivonne; Raulefs, Susanne; Irmler, Martin; Beckers, Johannes; Friess, Helmut; Erkan, Mert; Mueller, Nikola S; Roth, Susanne; Hackert, Thilo; Esposito, Irene; Theis, Fabian J; Kleeff, Jörg; Michalski, Christoph W

    2018-01-01

    The initial steps of pancreatic regeneration versus carcinogenesis are insufficiently understood. Although a combination of oncogenic Kras and inflammation has been shown to induce malignancy, molecular networks of early carcinogenesis remain poorly defined. We compared early events during inflammation, regeneration and carcinogenesis on histological and transcriptional levels with a high temporal resolution using a well-established mouse model of pancreatitis and of inflammation-accelerated Kras G12D -driven pancreatic ductal adenocarcinoma. Quantitative expression data were analysed and extensively modelled in silico. We defined three distinctive phases-termed inflammation, regeneration and refinement-following induction of moderate acute pancreatitis in wild-type mice. These corresponded to different waves of proliferation of mesenchymal, progenitor-like and acinar cells. Pancreas regeneration required a coordinated transition of proliferation between progenitor-like and acinar cells. In mice harbouring an oncogenic Kras mutation and challenged with pancreatitis, there was an extended inflammatory phase and a parallel, continuous proliferation of mesenchymal, progenitor-like and acinar cells. Analysis of high-resolution transcriptional data from wild-type animals revealed that organ regeneration relied on a complex interaction of a gene network that normally governs acinar cell homeostasis, exocrine specification and intercellular signalling. In mice with oncogenic Kras, a specific carcinogenic signature was found, which was preserved in full-blown mouse pancreas cancer. These data define a transcriptional signature of early pancreatic carcinogenesis and a molecular network driving formation of preneoplastic lesions, which allows for more targeted biomarker development in order to detect cancer earlier in patients with pancreatitis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  14. Influence of salinity on the early development and biochemical dynamics of a marine fish, Inimicus japonicus

    Science.gov (United States)

    Gong, Xu; Huang, Xuxiong; Wen, Wen

    2017-05-01

    Fertilised eggs of the devil stringer (Inimicus japonicus) were incubated at different salinity levels (21, 25, 29, 33, and 37), and then the hatching performances, morphological parameters, and biochemical composition (protein, lipid and carbohydrate) of the larvae were assayed to determine the influence of salinity on the early development of I. japonicus. The tested salinity levels did not affect the times of hatching or mouth opening for yolk-sac larvae. However, the salinity significantly influenced the hatching and survival rates of open-mouthed larvae, as well as the morphology of yolk-sac larvae. The data indicated that 30.5 to 37.3 and 24.4 to 29.8 were suitable salinity ranges for the survival of embryos and larvae of I. japonicus, respectively. Larvae incubated at a salinity level of 29 had the greatest full lengths, and decreasing yolk volume was positively correlated with the environmental salinity. With increasing salinity, the individual dry weights of newly hatched larvae or open-mouthed larvae decreased significantly. Newly hatched larvae incubated at a salinity level of 29 had the greatest metabolic substrate contents and gross energy levels, while the openmouthed larvae's greatest values occurred at a salinity level of 25. Larvae incubated in the salinity range of 33 to 37 had the lowest nutritional reserves and energy values. Thus, the I. japonicus yolk-sac larvae acclimated more readily to the lower salinity level than the embryos, and higher salinity levels negatively influenced larval growth and development. In conclusion, the environmental salinity level should be maintained at 29-33 during embryogenesis and at 25-29 during early larval development for this species. Our results can be used to provide optimum aquaculture conditions for the early larval development of I. japonicus.

  15. Coastal Marsh Longevity, Ecological Succession, and Organic Carbon Dynamics During Early Holocene Sea-Level Rise

    Science.gov (United States)

    Vetter, L.; Schreiner, K. M.; Rosenheim, B. E.; Tornqvist, T. E.

    2016-02-01

    Coastal marsh environments perform essential ecosystem services, including nutrient filtering, soil organic matter storage, and storm surge abatement, yet much is still unknown about their formation and fate under periods of sea-level change. During the early Holocene (7-10 ka), rapid sea-level rise in coastal Louisiana was one of the primary controls over marsh development and longevity. Here, we investigate plant community composition and succession and soil organic matter storage in early Holocene coastal marshes in Louisiana using bulk elemental ratios, lignin phenol biomarkers and stable isotopes from peat layers. Sediment cores were collected in southeastern Louisiana and contain a record of an early Holocene transgressive sea-level sequence 16-25 m below present sea-level. The sedimentary record consists of an immature paleosol overlain by basal peat that accumulated in an estuarine marsh, overlain by marine lagoonal muds. A re-established marsh peat is present 1-4 m above the initial transition to marine conditions, indicating a sequence of marsh development, sea-level rise and onset of marine conditions, and then further marsh development as the rate of relative sea-level rise decelerated. Plant community composition in coastal marshes was determined through cupric oxide oxidation and lignin-phenol and non-lignin-phenol biomarker abundances. The degradation state of soil organic matter and the specific source of stabilized organic matter within the sedimentary peats were determined through lignin-phenol biomarker ratios. Organic matter sources ranged from terrestrial to marine over the course of sea-level rise, and different sites showed different amounts of marine organic matter influence and different levels of terrestrial organic matter degradation. These results have important implications for reconstructing the response of coastal marshes and their plant communities to accelerated rates of sea-level rise projected through 2100.

  16. Time development in the early history of social networks: link stabilization, group dynamics, and segregation.

    Science.gov (United States)

    Bruun, Jesper; Bearden, Ian G

    2014-01-01

    Studies of the time development of empirical networks usually investigate late stages where lasting connections have already stabilized. Empirical data on early network history are rare but needed for a better understanding of how social network topology develops in real life. Studying students who are beginning their studies at a university with no or few prior connections to each other offers a unique opportunity to investigate the formation and early development of link patterns and community structure in social networks. During a nine week introductory physics course, first year physics students were asked to identify those with whom they communicated about problem solving in physics during the preceding week. We use these students' self reports to produce time dependent student interaction networks. We investigate these networks to elucidate possible effects of different student attributes in early network formation. Changes in the weekly number of links show that while roughly half of all links change from week to week, students also reestablish a growing number of links as they progress through their first weeks of study. Using the Infomap community detection algorithm, we show that the networks exhibit community structure, and we use non-network student attributes, such as gender and end-of-course grade to characterize communities during their formation. Specifically, we develop a segregation measure and show that students structure themselves according to gender and pre-organized sections (in which students engage in problem solving and laboratory work), but not according to end-of-coure grade. Alluvial diagrams of consecutive weeks' communities show that while student movement between groups are erratic in the beginning of their studies, they stabilize somewhat towards the end of the course. Taken together, the analyses imply that student interaction networks stabilize quickly and that students establish collaborations based on who is immediately

  17. Dynamic changes in antibody levels as an early warning of Salmonella Dublin in bovine dairy herds

    DEFF Research Database (Denmark)

    Stockmarr, Anders; Bødker, Rene; Nielsen, L. R.

    2013-01-01

    the herds being “likely infected” according to the existing classification system in the present quarter. The alarm herd concept can be used as a new early warning element in the existing surveillance program. Additionally, to improve accuracy of herd classification, the alarm herd concept could...... “likely free of infection” to “likely infected” in the following quarter of the year, thus warning the farmer 3mo earlier than the present system. The alarm herd concept was defined through aberrations from a stable development over time of antibody levels. For suitable parameter choices, alarm herd...

  18. Near-infrared hyperspectral imaging of water evaporation dynamics for early detection of incipient caries.

    Science.gov (United States)

    Usenik, Peter; Bürmen, Miran; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

    2014-10-01

    Incipient caries is characterized as demineralization of the tooth enamel reflecting in increased porosity of enamel structure. As a result, the demineralized enamel may contain increased amount of water, and exhibit different water evaporation dynamics than the sound enamel. The objective of this paper is to assess the applicability of water evaporation dynamics of sound and demineralized enamel for detection and quantification of incipient caries using near-infrared hyperspectral imaging. The time lapse of water evaporation from enamel samples with artificial and natural caries lesions of different stages was imaged by a near-infrared hyperspectral imaging system. Partial least squares regression was used to predict the water content from the acquired spectra. The water evaporation dynamics was characterized by a first order logarithmic drying model. The calculated time constants of the logarithmic drying model were used as the discriminative feature. The conducted measurements showed that demineralized enamel contains more water and exhibits significantly faster water evaporation than the sound enamel. By appropriate modelling of the water evaporation process from the enamel surface, the contrast between the sound and demineralized enamel observed in the individual near infrared spectral images can be substantially enhanced. The presented results indicate that near-infrared based prediction of water content combined with an appropriate drying model presents a strong foundation for development of novel diagnostic tools for incipient caries detection. The results of the study enhance the understanding of the water evaporation process from the sound and demineralized enamel and have significant implications for the detection of incipient caries by near-infrared hyperspectral imaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Changes in oscillatory dynamics in the cell cycle of early Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    Tony Y-C Tsai

    2014-02-01

    Full Text Available During the early development of Xenopus laevis embryos, the first mitotic cell cycle is long (∼85 min and the subsequent 11 cycles are short (∼30 min and clock-like. Here we address the question of how the Cdk1 cell cycle oscillator changes between these two modes of operation. We found that the change can be attributed to an alteration in the balance between Wee1/Myt1 and Cdc25. The change in balance converts a circuit that acts like a positive-plus-negative feedback oscillator, with spikes of Cdk1 activation, to one that acts like a negative-feedback-only oscillator, with a shorter period and smoothly varying Cdk1 activity. Shortening the first cycle, by treating embryos with the Wee1A/Myt1 inhibitor PD0166285, resulted in a dramatic reduction in embryo viability, and restoring the length of the first cycle in inhibitor-treated embryos with low doses of cycloheximide partially rescued viability. Computations with an experimentally parameterized mathematical model show that modest changes in the Wee1/Cdc25 ratio can account for the observed qualitative changes in the cell cycle. The high ratio in the first cycle allows the period to be long and tunable, and decreasing the ratio in the subsequent cycles allows the oscillator to run at a maximal speed. Thus, the embryo rewires its feedback regulation to meet two different developmental requirements during early development.

  20. Dynamic expression of calretinin in embryonic and early fetal human cortex

    Directory of Open Access Journals (Sweden)

    Miriam eGonzalez-Gomez

    2014-06-01

    Full Text Available Calretinin (CR is one of the earliest neurochemical markers in human corticogenesis. In embryos from Carnegie stages (CS 17 to 23, calbindin (CB and CR stain opposite poles of the incipient cortex suggesting early regionalization: CB marks the neuroepithelium of the medial boundary of the cortex with the choroid plexus (cortical hem. By contrast, CR is confined to the subventricular zone (SVZ of the lateral and caudal ganglionic eminences at the pallial-subpallial boundary (PSB, or antihem, from where CR+/Tbr1- neurons migrate toward piriform cortex and amygdala as a component of the lateral cortical stream. At CS 19, columns of CR+ cells arise in the rostral cortex, and contribute at CS 20 to the monolayer of horizontal Tbr1+/CR+ and GAD+ cells in the preplate. At CS 21, the pioneer cortical plate appears as a radial aggregation of CR+/Tbr1+ neurons, which cover the entire future neocortex and extend the first corticofugal axons. CR expression in early human corticogenesis is thus not restricted to interneurons, but is also present in the first excitatory projection neurons of the cortex. At CS 21/22, the cortical plate is established following a lateral to medial gradient, when Tbr1+/CR- neurons settle within the pioneer cortical plate, and thus separate superficial and deep pioneer neurons. CR+ pioneer neurons disappear shortly after the formation of the cortical plate. Reelin+ Cajal-Retzius cells begin to express CR around CS21 (7/8 PCW. At CS 21-23, the CR+ SVZ at the PSB is the source of CR+ interneurons migrating into the cortical SVZ. In turn, CB+ interneurons migrate from the subpallium into the intermediate zone following the fibers of the internal capsule. Early CR+ and CB+ interneurons thus have different origins and migratory routes. CR+ cell populations in the embryonic telencephalon take part in a complex sequence of events not analyzed so far in other mammalian species, which may represent a distinctive trait of the initial steps

  1. Implementation of Malaria Dynamic Models in Municipality Level Early Warning Systems in Colombia. Part I: Description of Study Sites

    Science.gov (United States)

    Ruiz, Daniel; Cerón, Viviana; Molina, Adriana M.; Quiñónes, Martha L.; Jiménez, Mónica M.; Ahumada, Martha; Gutiérrez, Patricia; Osorio, Salua; Mantilla, Gilma; Connor, Stephen J.; Thomson, Madeleine C.

    2014-01-01

    As part of the Integrated National Adaptation Pilot project and the Integrated Surveillance and Control System, the Colombian National Institute of Health is working on the design and implementation of a Malaria Early Warning System framework, supported by seasonal climate forecasting capabilities, weather and environmental monitoring, and malaria statistical and dynamic models. In this report, we provide an overview of the local ecoepidemiologic settings where four malaria process-based mathematical models are currently being implemented at a municipal level. The description includes general characteristics, malaria situation (predominant type of infection, malaria-positive cases data, malaria incidence, and seasonality), entomologic conditions (primary and secondary vectors, mosquito densities, and feeding frequencies), climatic conditions (climatology and long-term trends), key drivers of epidemic outbreaks, and non-climatic factors (populations at risk, control campaigns, and socioeconomic conditions). Selected pilot sites exhibit different ecoepidemiologic settings that must be taken into account in the development of the integrated surveillance and control system. PMID:24891460

  2. Dynamic assembly of brambleberry mediates nuclear envelope fusion during early development.

    Science.gov (United States)

    Abrams, Elliott W; Zhang, Hong; Marlow, Florence L; Kapp, Lee; Lu, Sumei; Mullins, Mary C

    2012-08-03

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Monomer Dynamics of Alzheimer Peptides and Kinetic Control of Early Aggregation in Alzheimer's Disease.

    Science.gov (United States)

    Acharya, Srabasti; Srivastava, Kinshuk R; Nagarajan, Sureshbabu; Lapidus, Lisa J

    2016-11-04

    The rate of reconfiguration-or intramolecular diffusion-of monomeric Alzheimer (Aβ) peptides is measured and, under conditions that aggregation is more likely, peptide diffusion slows down significantly, which allows bimolecular associations to be initiated. By using the method of Trp-Cys contact quenching, the rate of reconfiguration is observed to be about five times faster for Aβ 40 , which aggregates slowly, than that for Aβ 42 , which aggregates quickly. Furthermore, the rate of reconfiguration for Aβ 42 speeds up at higher pH, which slows aggregation, and in the presence of the aggregation inhibitor curcumin. The measured reconfiguration rates are able to predict the early aggregation behavior of the Aβ peptide and provide a kinetic basis for why Aβ 42 is more prone to aggregation than Aβ 40 , despite a difference of only two amino acids. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Dynamics and Predictors of Serum TSH and fT4 Reference Limits in Early Pregnancy

    DEFF Research Database (Denmark)

    Laurberg, Peter; Andersen, Stine Linding; Hindersson, Peter

    2016-01-01

    CONTEXT: Thyroid hormones are important developmental factors and levels should be adequate both in the pregnant woman and in the fetus. However, there is no consensus on maternal thyroid test reference limits in early pregnancy. OBJECTIVE: Estimation of week-to-week changes in and predictors...... of TSH and free T4 (fT4) reference limits in the first trimester of pregnancy. DESIGN: Measurement of TSH and fT4 in biobank sera collected in pregnancy weeks 5-19 from a random sample of the Danish National Birth Cohort that enrolled 101 032 pregnant in 1996-2002. SETTING: National cohort of pregnant...... women. PARTICIPANTS: Healthy participants (n = 6671) were identified and individual characteristics retrieved using interview data and data from Danish national health registers. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Reference limits for TSH and fT4 in each first trimester pregnancy week...

  5. Dynamic associations among alcohol use and anxiety symptoms in early adolescence.

    Science.gov (United States)

    Pardee, Carolyn Speidel; Colder, Craig R; Bowker, Julie C

    2014-12-01

    The relationship between anxiety and alcohol use in adolescence remains unclear, with evidence for no association and for risk and protective effects of anxiety. Considering developmental trajectories may be important for understanding the association between anxiety and alcohol use and may help clarify prior mixed findings. The present study examined trajectories of alcohol use, social anxiety symptoms, and general anxiety symptoms in early to middle adolescence through the use of univariate and parallel process growth models. Social anxiety and general anxiety symptoms declined, while alcohol use increased with age. Parallel process growth models suggested that less rapid declines in social anxiety and general anxiety symptoms were associated with more rapid escalation in alcohol use. These results suggest that young adolescents who do not show normative declines in social anxiety or general anxiety symptoms may be at risk for more rapid increases in alcohol use.

  6. Nonstandard Work Schedules, Family Dynamics, and Mother-Child Interactions During Early Childhood.

    Science.gov (United States)

    Prickett, Kate C

    2018-03-01

    The rising number of parents who work nonstandard schedules has led to a growing body of research concerned with what this trend means for children. The negative outcomes for children of parents who work nonstandard schedules are thought to arise from the disruptions these schedules place on family life, and thus, the types of parenting that support their children's development, particularly when children are young. Using a nationally representative sample of two-parent families (Early Childhood Longitudinal Study-Birth cohort, n = 3,650), this study examined whether mothers' and their partners' nonstandard work schedules were associated with mothers' parenting when children were 2 and 4 years old. Structural equation models revealed that mothers' and their partners' nonstandard work schedules were associated with mothers' lower scores on measures of positive and involved parenting. These associations were mediated by fathers' lower levels of participation in cognitively supportive parenting and greater imbalance in cognitively supportive tasks conducted by mothers versus fathers.

  7. A short-time scale colloidal system reveals early bacterial adhesion dynamics.

    Directory of Open Access Journals (Sweden)

    Christophe Beloin

    2008-07-01

    Full Text Available The development of bacteria on abiotic surfaces has important public health and sanitary consequences. However, despite several decades of study of bacterial adhesion to inert surfaces, the biophysical mechanisms governing this process remain poorly understood, due, in particular, to the lack of methodologies covering the appropriate time scale. Using micrometric colloidal surface particles and flow cytometry analysis, we developed a rapid multiparametric approach to studying early events in adhesion of the bacterium Escherichia coli. This approach simultaneously describes the kinetics and amplitude of early steps in adhesion, changes in physicochemical surface properties within the first few seconds of adhesion, and the self-association state of attached and free-floating cells. Examination of the role of three well-characterized E. coli surface adhesion factors upon attachment to colloidal surfaces--curli fimbriae, F-conjugative pilus, and Ag43 adhesin--showed clear-cut differences in the very initial phases of surface colonization for cell-bearing surface structures, all known to promote biofilm development. Our multiparametric analysis revealed a correlation in the adhesion phase with cell-to-cell aggregation properties and demonstrated that this phenomenon amplified surface colonization once initial cell-surface attachment was achieved. Monitoring of real-time physico-chemical particle surface properties showed that surface-active molecules of bacterial origin quickly modified surface properties, providing new insight into the intricate relations connecting abiotic surface physicochemical properties and bacterial adhesion. Hence, the biophysical analytical method described here provides a new and relevant approach to quantitatively and kinetically investigating bacterial adhesion and biofilm development.

  8. Dynamics of friendship networks and alcohol use in early and mid-adolescence.

    Science.gov (United States)

    Mercken, Liesbeth; Steglich, Christian; Knibbe, Ronald; Vries, Hein de

    2012-01-01

    Similarity in alcohol consumption among adolescent friends could be caused by the influence of friends or by the selection of friends who consume similar levels of alcohol. This article aims to disentangle influence and selection processes while specifically examining changes over time in these processes and possible differences between reciprocal and nonreciprocal friendships. The design was longitudinal with four observations (Time 1-Time 4 [T1-T4]). Data consisted of a longitudinal sample of 1,204 Finnish adolescents in 10 junior high schools. The main measurements were adolescents' friendship networks and alcohol consumption. For three successive periods, T1-T2, T2-T3, and T3-T4, actor-based models for the co-evolution of networks and behavior were analyzed (Mage: T1 = 13.6 years, T2 = 14.6 years, T3 = 15.6 years, T4 = 16.1 years). Selection, as well as influence processes, played an important role in adolescent alcohol consumption. Influence was found during the first period (T1-T2), whereas support for selection was found during the last two periods (T2-T3 and T3-T4). The strength of influence and selection processes did not differ for reciprocal and nonreciprocal friendships. The impact of selection and influence processes changed over time such that influence was only present during early adolescence, whereas selection was present during mid-adolescence. During early adolescence, youngsters would benefit from learning to resist social influence. Alcohol-consumption prevention programs targeting mid-adolescence should consider peer selection processes. These findings stress the importance of considering changes over time in future practice and research.

  9. Dynamic Antarctic ice sheet during the early to mid-Miocene

    Science.gov (United States)

    Gasson, Edward; DeConto, Robert M.; Pollard, David; Levy, Richard H.

    2016-03-01

    Geological data indicate that there were major variations in Antarctic ice sheet volume and extent during the early to mid-Miocene. Simulating such large-scale changes is problematic because of a strong hysteresis effect, which results in stability once the ice sheets have reached continental size. A relatively narrow range of atmospheric CO2 concentrations indicated by proxy records exacerbates this problem. Here, we are able to simulate large-scale variability of the early to mid-Miocene Antarctic ice sheet because of three developments in our modeling approach. (i) We use a climate-ice sheet coupling method utilizing a high-resolution atmospheric component to account for ice sheet-climate feedbacks. (ii) The ice sheet model includes recently proposed mechanisms for retreat into deep subglacial basins caused by ice-cliff failure and ice-shelf hydrofracture. (iii) We account for changes in the oxygen isotopic composition of the ice sheet by using isotope-enabled climate and ice sheet models. We compare our modeling results with ice-proximal records emerging from a sedimentological drill core from the Ross Sea (Andrill-2A) that is presented in a companion article. The variability in Antarctic ice volume that we simulate is equivalent to a seawater oxygen isotope signal of 0.52-0.66‰, or a sea level equivalent change of 30-36 m, for a range of atmospheric CO2 between 280 and 500 ppm and a changing astronomical configuration. This result represents a substantial advance in resolving the long-standing model data conflict of Miocene Antarctic ice sheet and sea level variability.

  10. The Early Years of Molecular Dynamics and Computers at UCRL, LRL, LLL, and LLNL

    Science.gov (United States)

    Mansigh Karlsen, Mary Ann

    I'm the young woman in the picture shown in Fig. 12.1 that appeared with the invitation to the Symposium to celebrate Berni Alder's ninetieth birthday. I worked with Berni for over 25 years on the computer programs that provided the data he needed to write the fifteen papers published in scientific journals on Studies in Molecular Dynamics. My name appears at the end of each one thanking me for computer support. It has been interesting to look on the Internet to find my name in the middle of many foreign languages, including Japanese characters and Russian Cyrillic script. It shows how Berni's work has been of interest to many scientists all over the world from the earliest years. Figure 12.1 was also included with articles written when he received the National Medal of Science from President Obama in 2009…

  11. Fast neutron breeder reactor Rapsodie - situation of physics, hydraulic, thermal and dynamics studies and studies of stability early in 1963

    International Nuclear Information System (INIS)

    1964-01-01

    Early in 1963, it was necessary to make a choice among the two fuels examined for Rapsodie: the UPuMo alloy with double cladding, Nb and stainless steel, and the UO 2 -PuO 2 mix oxide. This report presents the results of the studies effected with the two types of fuel. We reconsider at first the different models which have been studied and we give a detailed description of the alloy and oxide cores as they are envisaged early in 1963. We give then the most important physics performances of the two cores: neutron flux and spectrum, reactivity of the compensation find safety rods, neutrons balance, specific power, effective fraction of delayed neutrons, lifetime of the prompt neutrons, reactivity coefficient. We describe the hydraulic studies and experiments which have been done concerning the two cores. We discuss the criteria adopted as basis for the flow calculations. We give the results of pressure drop and sub-assembly lifting, force measurements, and vibration and pin flow distribution experiments. We discuss the constants utilized for the thermal calculations and we give the temperatures of sodium and alloy or oxide fuel, the temperature increases due to the hot points, and the limitation of the oxide fuel burn-up, originated by the pressure of the fission gases. We treat the hypotheses having been utilized for the dynamics calculations and we describe the different accidents which have been studied. We give the results of the calculations for every accident and each fuel, and we show fuel melting or sodium boiling can be avoided, even in case of the most pessimistic hypotheses, by modifying reactor characteristics (shim-rod reactivity or power of the reactor with only one cooling circuit). The reactor stability has been evaluated with the hypotheses utilized for the dynamics calculations, except of the Doppler coefficient which was intentionally increased. We show that the alloy and oxide cores are stable for every envisaged reactor power. (authors) [fr

  12. Wisconsinan and early Holocene glacial dynamics of Cumberland Peninsula, Baffin Island, Arctic Canada

    Science.gov (United States)

    Margreth, Annina; Gosse, John C.; Dyke, Arthur S.

    2017-07-01

    Three glacier systems-an ice sheet with a large marine-based ice stream, an ice cap, and an alpine glacier complex-coalesced on Cumberland Peninsula during the Late Wisconsinan. We combine high-resolution mapping of glacial deposits with new cosmogenic nuclide and radiocarbon age determinations to constrain the history and dynamics of each system. During the Middle Wisconsinan (Oxygen Isotope Stage 3, OIS-3) the Cumberland Sound Ice Stream of the Laurentide Ice Sheet retreated well back into Cumberland Sound and the alpine ice retreated at least to fiord-head positions, a more significant recession than previously documented. The advance to maximal OIS-2 ice positions beyond the mouth of Cumberland Sound and beyond most stretches of coastline remains undated. Partial preservation of an over-ridden OIS-3 glaciomarine delta in a fiord-side position suggests that even fiord ice was weakly erosive in places. Moraines formed during deglaciation represent stillstands and re-advances during three major cold events: H-1 (14.6 ka), Younger Dryas (12.9-11.7 ka), and Cockburn (9.5 ka). Distinctly different responses of the three glacial systems are evident, with the alpine system responding most sensitively to Bølling-Allerød warming whereas the larger systems retreated mainly during Pre-Boreal warming. While the larger ice masses were mainly influenced by internal dynamics, the smaller alpine glacier system responded sensitively to local climate effects. Asymmetrical recession of the alpine glacier complex indicates topoclimatic control on deglaciation and perhaps migration of the accumulation area toward moisture source.

  13. What basal ganglia changes underlie the parkinsonian state? The significance of neuronal oscillatory activity

    Science.gov (United States)

    Quiroga-Varela, A.; Walters, J.R.; Brazhnik, E.; Marin, C.; Obeso, J.A.

    2014-01-01

    One well accepted functional feature of the parkinsonian state is the recording of enhanced beta oscillatory activity in the basal ganglia. This has been demonstrated in patients with Parkinson's disease (PD) and in animal models such as the rat with 6-hydroxydopamine (6-OHDA)-induced lesion and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys, all of which are associated with severe striatal dopamine depletion. Neuronal hyper-synchronization in the beta (or any other) band is not present despite the presence of bradykinetic features in the rat and monkey models, suggesting that increased beta band power may arise when nigro-striatal lesion is advanced and that it is not an essential feature of the early parkinsonian state. Similar observations and conclusions have been previously made for increased neuronal firing rate in the subthalamic and globus pallidus pars interna nuclei. Accordingly, it is suggested that early parkinsonism may be associated with dynamic changes in basal ganglia output activity leading to reduced movement facilitation that may be an earlier feature of the parkinsonian state. PMID:23727447

  14. Effects of early life stress on rodent hippocampal synaptic plasticity : a systematic review

    NARCIS (Netherlands)

    Derks, Nienke AV; Krugers, Harm J; Hoogenraad, Casper C.; Joëls, Marian; Sarabdjitsingh, R.A.

    2017-01-01

    Early life stress shapes brain development and animal behavior. Neurophysiological properties such as signal transmission and synaptic plasticity are thought to underlie the animal's behavioral performance. We carried out a systematic review to determine how early life stress relates to

  15. The attentional-relevance and temporal dynamics of visual-tactile crossmodal interactions differentially influence early stages of somatosensory processing.

    Science.gov (United States)

    Popovich, Christina; Staines, W Richard

    2014-03-01

    Crossmodal interactions between relevant visual and tactile inputs can enhance attentional modulation at early stages in somatosensory cortices to achieve goal-oriented behaviors. However, the specific contribution of each sensory system during attentional processing remains unclear. We used EEG to investigate the effects of visual priming and attentional relevance in modulating somatosensory cortical responses. Healthy adults performed a sensory integration task that required scaled motor responses dependent on the amplitudes of tactile and visual stimuli. Participants completed an attentional paradigm comprised of 5 conditions that presented sequential or concurrent pairs of discrete stimuli with random amplitude variations: 1) tactile-tactile (TT), 2) visual-visual (VV), 3) visual-tactile simultaneous (SIM), 4) tactile-visual delay (TVd), and 5) visual-tactile delay (VTd), each with a 100 ms temporal delay between stimulus onsets. Attention was directed to crossmodal conditions and graded motor responses representing the summation of the 2 stimulus amplitudes were made. Results of somatosensory ERPs showed that the modality-specific components (P50, P100) were sensitive to i) the temporal dynamics of crossmodal interactions, and ii) the relevance of these sensory signals for behaviour. Notably, the P50 amplitude was greatest in the VTd condition, suggesting that presentation of relevant visual information for upcoming movement modulates somatosensory processing in modality-specific cortical regions, as early as the primary somatosensory cortex (SI).

  16. The presence of nuclear cactus in the early Drosophila embryo may extend the dynamic range of the dorsal gradient.

    Directory of Open Access Journals (Sweden)

    Michael D O'Connell

    2015-04-01

    Full Text Available In a developing embryo, the spatial distribution of a signaling molecule, or a morphogen gradient, has been hypothesized to carry positional information to pattern tissues. Recent measurements of morphogen distribution have allowed us to subject this hypothesis to rigorous physical testing. In the early Drosophila embryo, measurements of the morphogen Dorsal, which is a transcription factor responsible for initiating the earliest zygotic patterns along the dorsal-ventral axis, have revealed a gradient that is too narrow to pattern the entire axis. In this study, we use a mathematical model of Dorsal dynamics, fit to experimental data, to determine the ability of the Dorsal gradient to regulate gene expression across the entire dorsal-ventral axis. We found that two assumptions are required for the model to match experimental data in both Dorsal distribution and gene expression patterns. First, we assume that Cactus, an inhibitor that binds to Dorsal and prevents it from entering the nuclei, must itself be present in the nuclei. And second, we assume that fluorescence measurements of Dorsal reflect both free Dorsal and Cactus-bound Dorsal. Our model explains the dynamic behavior of the Dorsal gradient at lateral and dorsal positions of the embryo, the ability of Dorsal to regulate gene expression across the entire dorsal-ventral axis, and the robustness of gene expression to stochastic effects. Our results have a general implication for interpreting fluorescence-based measurements of signaling molecules.

  17. Dynamical 3-Space Predicts Hotter Early Universe: Resolves CMB-BBN 7-Li and 4-He Abundance Anomalies

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2010-01-01

    Full Text Available The observed abundances of 7 Li and 4 He are significantly inconsistent with the pre- dictions from Big Bang Nucleosynthesis (BBN when using the CDM cosmolog- ical model together with the value for B h 2 = 0 : 0224 0 : 0009 from WMAP CMB fluctuations, with the value from BBN required to fit observed abundances being 0 : 009 < B h 2 < 0 : 013. The dynamical 3-space theory is shown to predict a 20% hot- ter universe in the radiation-dominated epoch, which then results in a remarkable parameter-free agreement between the BBN and the WMAP value for B h 2 . The dy- namical 3-space also gives a parameter-free fit to the supernova redshift data, and pre- dicts that the flawed CDM model would require = 0 : 73 and M = 0 : 27 to fit the 3-space dynamics Hubble expansion, and independently of the supernova data. These results amount to the discovery of new physics for the early universe that is matched by numerous other successful observational and experimental tests.

  18. [Dynamic concept of oral lichen planus. The diagnosis easy at early stages may become difficult in ancient lichen planus].

    Science.gov (United States)

    Lombardi, Tommaso; Küffer, Roger

    2016-02-01

    Dynamic concept of oral lichen planus. The diagnosis easy at early stages may become difficult in ancient lichen planus. Lichen planus is a chronic inflammatory dermatosis of the skin, skin appendages and mucous membranes, which frequently affects the oral mucosa. Its aetiology still remains unknown, and currently accepted pathogenesis is that of an autoimmune cell-mediated disease. To the contrary of skin lichen planus, oral lichen planus is a long-term chronic disease with dynamic evolution, in which progressive and profound changes of the clinical and histopathological aspects occur over time and under the influence of various exogenous factors. By convention, in the history of the oral lichen planus four successive stages can be distinguished without well-defined boundaries between them. These stages can be defined as an initial phase; a long intermediate phase with alternating periods of activity and quiescence, which has a gradually increasing risk of malignant transformation; a late stage which activity is traditionally diminished; and a post-lichen cicatricial stage with an absent or negligible and undetectable activity, often undiagnosed because clinically unrecognized; in this stage, the lesion does not respond to usual treatments, but retains the same risk of malignant transformation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Mental health and social networks in early adolescence: a dynamic study of objectively-measured social interaction behaviors.

    Science.gov (United States)

    Pachucki, Mark C; Ozer, Emily J; Barrat, Alain; Cattuto, Ciro

    2015-01-01

    How are social interaction dynamics associated with mental health during early stages of adolescence? The goal of this study is to objectively measure social interactions and evaluate the roles that multiple aspects of the social environment--such as physical activity and food choice--may jointly play in shaping the structure of children's relationships and their mental health. The data in this study are drawn from a longitudinal network-behavior study conducted in 2012 at a private K-8 school in an urban setting in California. We recruited a highly complete network sample of sixth-graders (n = 40, 91% of grade, mean age = 12.3), and examined how two measures of distressed mental health (self-esteem and depressive symptoms) are positionally distributed in an early adolescent interaction network. We ascertained how distressed mental health shapes the structure of relationships over a three-month period, adjusting for relevant dimensions of the social environment. Cross-sectional analyses of interaction networks revealed that self-esteem and depressive symptoms are differentially stratified by gender. Specifically, girls with more depressive symptoms have interactions consistent with social inhibition, while boys' interactions suggest robustness to depressive symptoms. Girls higher in self-esteem tended towards greater sociability. Longitudinal network behavior models indicate that gender similarity and perceived popularity are influential in the formation of social ties. Greater school connectedness predicts the development of self-esteem, though social ties contribute to more self-esteem improvement among students who identify as European-American. Cross-sectional evidence shows associations between distressed mental health and students' network peers. However, there is no evidence that connected students' mental health status becomes more similar in their over time because of their network interactions. These findings suggest that mental health during early

  20. Early pleural fluid dynamics following video-assisted thoracoscopic lobectomy has limited clinical value.

    Science.gov (United States)

    Holbek, Bo Laksáfoss; Petersen, René Horsleben; Kehlet, Henrik; Hansen, Henrik Jessen

    2017-07-01

    The objective of this study was to evaluate the potential of predicting the pleural fluid output in patients after video-assisted thoracoscopic lobectomy of the lung. Detailed measurements of continuous fluid output were obtained prospectively using an electronic thoracic drainage device (Thopaz+™, Medela AG, Switzerland). Patients were divided into high (≥500 mL) and low (fluid output, and detailed flow curves were plotted graphically to identify arithmetic patterns predicting fluid output in the early (≤24 hours) and later (24-48 hours) post-operative phase. Furthermore, multiple logistic regression analysis was used to predict high 24-hour fluid output using baseline data. Data were obtained from 50 patients, where 52% had a fluid output of fluid output 6 hours postoperatively. An output ≥200 mL/6 hours was predictive of 'high 24-hour fluid output' (Pfluid output'. Baseline data showed no predictive value of fluid production, and 24-hour fluid output had no predictive value of fluid output between 24 and 48 hours. Assessment of initial fluid production may predict high 24-hour fluid output (≥500 mL) but seems to lack clinical value in drain removal criteria.

  1. Dynamics and early post-tsunami evolution of floating marine debris near Fukushima Daiichi

    Science.gov (United States)

    Matthews, John Philip; Ostrovsky, Lev; Yoshikawa, Yutaka; Komori, Satoru; Tamura, Hitoshi

    2017-08-01

    The devastating tsunami triggered by the Tōhoku-Oki earthquake of 11 March 2011 caused a crisis at the Fukushima Daiichi nuclear power station where it overtopped the seawall defences. On retreating, the tsunami carried loose debris and wreckage seaward and marshalled buoyant material into extensive plumes. Widespread concern over the fate of these and numerous other Tōhoku tsunami depositions prompted attempts to simulate debris dispersion throughout the wider Pacific. However, the effects of locally perturbed wind and wave fields, active Langmuir circulation and current-induced attrition determine a complex and poorly understood morphology for large floating agglomerations. Here we show that the early post-tsunami evolution of marine-debris plumes near Fukushima Daiichi was also shaped by near-surface wind modifications that took place above relatively calm (lower surface roughness) waters covered by surface films derived from oil and other contaminants. High-spatial-resolution satellite tracking reveals faster-than-expected floating-debris motions and invigorated plume evolution within these regions, while numerical modelling of turbulent air flow over the low-drag, film-covered surface predicts typically metre-per-second wind strengthening at centimetric heights, sufficient to explain the observed debris-speed increases. Wind restructuring probably stimulates the dispersion of flotsam from both biological and anthropogenic sources throughout a global ocean of highly variable surface roughness.

  2. The temporal dynamics of early visual cortex involvement in behavioral priming.

    Directory of Open Access Journals (Sweden)

    Christianne Jacobs

    Full Text Available Transcranial magnetic stimulation (TMS allows for non-invasive interference with ongoing neural processing. Applied in a chronometric design over early visual cortex (EVC, TMS has proved valuable in indicating at which particular time point EVC must remain unperturbed for (conscious vision to be established. In the current study, we set out to examine the effect of EVC TMS across a broad range of time points, both before (pre-stimulus and after (post-stimulus the onset of symbolic visual stimuli. Behavioral priming studies have shown that the behavioral impact of a visual stimulus can be independent from its conscious perception, suggesting two independent neural signatures. To assess whether TMS-induced suppression of visual awareness can be dissociated from behavioral priming in the temporal domain, we thus implemented three different measures of visual processing, namely performance on a standard visual discrimination task, a subjective rating of stimulus visibility, and a visual priming task. To control for non-neural TMS effects, we performed electrooculographical recordings, placebo TMS (sham, and control site TMS (vertex. Our results suggest that, when considering the appropriate control data, the temporal pattern of EVC TMS disruption on visual discrimination, subjective awareness and behavioral priming are not dissociable. Instead, TMS to EVC disrupts visual perception holistically, both when applied before and after the onset of a visual stimulus. The current findings are discussed in light of their implications on models of visual awareness and (subliminal priming.

  3. The temporal dynamics of early visual cortex involvement in behavioral priming.

    Science.gov (United States)

    Jacobs, Christianne; de Graaf, Tom A; Goebel, Rainer; Sack, Alexander T

    2012-01-01

    Transcranial magnetic stimulation (TMS) allows for non-invasive interference with ongoing neural processing. Applied in a chronometric design over early visual cortex (EVC), TMS has proved valuable in indicating at which particular time point EVC must remain unperturbed for (conscious) vision to be established. In the current study, we set out to examine the effect of EVC TMS across a broad range of time points, both before (pre-stimulus) and after (post-stimulus) the onset of symbolic visual stimuli. Behavioral priming studies have shown that the behavioral impact of a visual stimulus can be independent from its conscious perception, suggesting two independent neural signatures. To assess whether TMS-induced suppression of visual awareness can be dissociated from behavioral priming in the temporal domain, we thus implemented three different measures of visual processing, namely performance on a standard visual discrimination task, a subjective rating of stimulus visibility, and a visual priming task. To control for non-neural TMS effects, we performed electrooculographical recordings, placebo TMS (sham), and control site TMS (vertex). Our results suggest that, when considering the appropriate control data, the temporal pattern of EVC TMS disruption on visual discrimination, subjective awareness and behavioral priming are not dissociable. Instead, TMS to EVC disrupts visual perception holistically, both when applied before and after the onset of a visual stimulus. The current findings are discussed in light of their implications on models of visual awareness and (subliminal) priming.

  4. Temporal dynamics of repetitions during the early stage of childhood stuttering: an acoustic study.

    Science.gov (United States)

    Throneburg, R N; Yairi, E

    1994-10-01

    The purpose of this study was to compare duration characteristics of single-syllable whole-word repetitions (with one and two repeated units) and part-word repetitions (with one repeated unit) in the speech of preschool children who stutter (N = 20) recorded near the onset of their stuttering to those of control nonstuttering children (N = 20). Disfluent episodes were identified in audiotape recordings of the subjects' conversational speech. The digitized signals were analyzed by means of the CSpeech computer software (Milenkovic, 1987). Using visual displays of sound spectrograms, the durations of the spoken repetition unit(s), the silent interval(s) between the units, and the total disfluency were measured. The stutters exhibited shorter silent intervals between spoken repetition units. The duration of the spoken repetition units was very similar for the two groups of children. The total duration of the stutterers' disfluencies was significantly shorter because of their shorter silent intervals when compared to disfluencies of equal repetition units produced by the control subjects. Statistical analysis revealed that silent interval duration was capable of differentiating stuttering from normally fluent children with 72-87% accuracy, dependent upon the disfluency type. To the degree that the groups of subjects represented random samples of the two specified populations from which they were drawn, there appears to be an overall tendency for repetitions during the early stage of stuttering to be produced at a faster rate than repetitions produced by nonstuttering children.

  5. Amino and fatty acid dynamics of octopus (Octopus vulgaris) early life stages under ocean warming.

    Science.gov (United States)

    Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui

    2016-01-01

    The oceans are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable early life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Temporal dynamics of immediate early gene expression during cellular consolidation of spatial memory.

    Science.gov (United States)

    Barry, Daniel N; Commins, Sean

    2017-06-01

    The consolidation of newly acquired memories on a cellular level is thought to take place in the first few hours following learning. This process is dependent on de novo protein synthesis during this time, which ultimately leads to long-term structural and functional neuronal changes and the stabilisation of a memory trace. Immediate early genes (IEGs) are rapidly expressed in neurons following learning, and previous research has suggested more than one wave of IEG expression facilitates consolidation in the hours following learning. We analysed the expression of Zif268, c-Fos and Arc protein in a number of brain regions involved in spatial learning either 90min, 4h or 8h following training in the Morris water maze task. Consistent with the role of IEGs in the earliest stages of consolidation, a single wave of expression was observed in most brain regions at 90min, however a subsequent wave of expression was not observed at 8h. In fact, Zif268 expression was observed to fall below the levels of naïve controls at this time-point in the medial prefrontal and perirhinal cortices. This may be indicative of synaptic downscaling in these regions in the hours following learning, and an important marker of the consolidation of spatial memory. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Temporal Genetic Dynamics of an Invasive Species, Frankliniella occidentalis (Pergande), in an Early Phase of Establishment.

    Science.gov (United States)

    Yang, Xian-Ming; Lou, Heng; Sun, Jing-Tao; Zhu, Yi-Ming; Xue, Xiao-Feng; Hong, Xiao-Yue

    2015-07-03

    Many species can successfully colonize new areas despite their propagules having low genetic variation. We assessed whether the decreased genetic diversity could result in temporal fluctuations of genetic parameters of the new populations of an invasive species, western flower thrips, Frankliniella occidentalis, using mitochondrial and microsatellite markers. This study was conducted in eight localities from four climate regions in China, where F. occidentalis was introduced in the year 2000 and had lower genetic diversity than its native populations. We also tested the level of genetic differentiation in these introduced populations. The genetic diversity of the samples at different years in the same locality was not significantly different from each other in most localities. FST and STRUCTURE analysis also showed that most temporal population comparisons from the same sites were not significantly differentiated. Our results showed that the invasive populations of F. occidentalis in China can maintain temporal stability in genetic composition at an early phase of establishment despite having lower genetic diversity than in their native range.

  8. Wavelet-based multifractal analysis of dynamic infrared thermograms to assist in early breast cancer diagnosis

    Directory of Open Access Journals (Sweden)

    Evgeniya eGerasimova

    2014-05-01

    Full Text Available Breast cancer is the most common type of cancer among women and despite recent advances in the medical field, there are still some inherent limitations in the currently used screening techniques. The radiological interpretation of screening X-ray mammograms often leads to over-diagnosis and, as a consequence, to unnecessary traumatic and painful biopsies. Here we propose a computer-aided multifractal analysis of dynamic infrared (IR imaging as an efficient method for identifying women with risk of breast cancer. Using a wavelet-based multi-scale method to analyze the temporal fluctuations of breast skin temperature collected from a panel of patients with diagnosed breast cancer and some female volunteers with healthy breasts, we show that the multifractal complexity of temperature fluctuations observed in healthy breasts is lost in mammary glands with malignant tumor. Besides potential clinical impact, these results open new perspectives in the investigation of physiological changes that may precede anatomical alterations in breast cancer development.

  9. Restricted Three-Body Dynamics and Morphologies of Early Novae Shells and their Spectral Signatures

    Science.gov (United States)

    Lynch, D. K.; Mazuk, S.; Campbell, E.; Venturini, C. C.

    2003-08-01

    The goal of this work is to calculate emission line profiles of classical novae systems for comparison to line profiles we observe in an attempt to deduce geometrical and dynamical properties of the system from the spectra. The material ejected by the thermonuclear runaway on the surface of the white dwarf (WD) is modeled as a large number of massless particles that are launched instantaneously and move ballistically thereafter. Each particle's position is propagated independently in three-dimensional space with a particle's track terminating if it impacts the WD or the secondary. Predicted line profiles, assuming an optically thin shell, are generated by computing a histogram of the number of particles in radial velocity space for a given observing projection. At high ejection velocities, a nearly spherical shell is produced. At ejection speeds near the WD's escape velocity, very complicated and ever changing geometries result and the material remains close to the system's barycenter. We present animations of computer simulations of novae shell development and the associated line profiles. This work supported by The Aerospace Corporation's Independent Research and Development program and by the US Air Force Space and Missile Systems Center through the Mission Oriented Investigation and Experimentation program, under contract F4701-00-C-0009 with the US Air Force.

  10. Sexually Dimorphic Faciometrics in Humans From Early Adulthood to Late Middle Age: Dynamic, Declining, and Differentiated.

    Science.gov (United States)

    Robertson, Julia M; Kingsley, Barbara E; Ford, Gina C

    2017-01-01

    Faciometrics have widely been used in contemporary studies on gender-related behavioral traits, for example, perceived and actual aggression, co-operation and trustworthiness, prejudicial beliefs, unethical behavior, and achievement drive, as well as, but to a lesser degree, in nonhuman primates. For the large part, these studies have focused primarily on "student-aged" populations with little empirical scrutiny regarding the efficacy of applying these measures with older participants. This study therefore investigated sexual dimorphism across four age-groups (20s, 30s, 40s, and 50s) in 444 participants (225 men). The expected sexual dimorphism was seen in the youngest age group in three of the four indices. The facial width to height ratio, however, although most commonly used empirically, was not found to be significantly different between men and women, consistent with more recent literature. Importantly, as age increased, sexual dimorphism decreased, but this was not consistent across all measures of it. Rather, it is evident that differing measures of sexual dimorphism follow distinct developmental trajectories. The only single marker which remained significantly different across all age-groups was cheekbone prominence. Sexual dimorphic faciometrics are therefore dynamic, declining, and differentiated through adulthood. Consequently, it is concluded that care should be taken in using faciometrics in studies involving older populations and that more research is needed to understand the impact of these distinct faciometric trajectories in gender- and masculinity-related studies.

  11. EARLY DYNAMICAL EVOLUTION OF THE SOLAR SYSTEM: PINNING DOWN THE INITIAL CONDITIONS OF THE NICE MODEL

    International Nuclear Information System (INIS)

    Batygin, Konstantin; Brown, Michael E.

    2010-01-01

    In the recent years, the 'Nice' model of solar system formation has attained an unprecedented level of success in reproducing much of the observed orbital architecture of the solar system by evolving the planets to their current locations from a more compact configuration. Within the context of this model, the formation of the classical Kuiper Belt requires a phase during which the ice giants have a high eccentricity. An outstanding question of this model is the initial configuration from which the solar system started out. Recent work has shown that multi-resonant initial conditions can serve as good candidates, as they naturally prevent vigorous type-II migration. In this paper, we use analytical arguments, as well as self-consistent numerical N-body simulations to identify fully resonant initial conditions, whose dynamical evolution is characterized by an eccentric phase of the ice giants, as well as planetary scattering. We find a total of eight such initial conditions. Four of these primordial states are compatible with the canonical 'Nice' model, while the others imply slightly different evolutions. The results presented here should prove useful in further development of a comprehensive model for solar system formation.

  12. Mechanical Strain Alters Cellular and Nuclear Dynamics at Early Stages of Oligodendrocyte Differentiation.

    Science.gov (United States)

    Makhija, Ekta; Jagielska, Anna; Zhu, Lena; Bost, Alexander C; Ong, William; Chew, Sing Y; Shivashankar, G V; Van Vliet, Krystyn J

    2018-01-01

    Mechanical and physical stimuli including material stiffness and topography or applied mechanical strain have been demonstrated to modulate differentiation of glial progenitor and neural stem cells. Recent studies probing such mechanotransduction in oligodendrocytes have focused chiefly on the biomolecular components. However, the cell-level biophysical changes associated with such responses remain largely unknown. Here, we explored mechanotransduction in oligodendrocyte progenitor cells (OPCs) during the first 48 h of differentiation induction by quantifying the biophysical state in terms of nuclear dynamics, cytoskeleton organization, and cell migration. We compared these mechanophenotypic changes in OPCs exposed to both chemical cues (differentiation factors) and mechanical cues (static tensile strain of 10%) with those exposed to only those chemical cues. We observed that mechanical strain significantly hastened the dampening of nuclear fluctuations and decreased OPC migration, consistent with the progression of differentiation. Those biophysical changes were accompanied by increased production of the intracellular microtubule network. These observations provide insights into mechanisms by which mechanical strain of physiological magnitude could promote differentiation of progenitor cells to oligodendrocytes via inducing intracellular biophysical responses over hours to days post induction.

  13. Early-time dynamics of gluon fields in high energy nuclear collisions

    Science.gov (United States)

    Chen, Guangyao; Fries, Rainer J.; Kapusta, Joseph I.; Li, Yang

    2015-12-01

    Nuclei colliding at very high energy create a strong, quasiclassical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromoelectric and chromomagnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. For example, we find that the ratio of longitudinal to transverse pressure very early in the system behaves as pL/pT=-[1 -3/2 a (Qτ ) 2] /[1 -1/a (Qτ ) 2] +O (Qτ ) 4 , where τ is the longitudinal proper time, Q is related to the saturation scales Qs of the two nuclei, and a =ln(Q2/m̂2) with m ̂ a scale to be defined later. Our results are generally applicable if τ ≲1 /Q . As already discussed in a previous paper, the transverse energy flow Si of the gluon field exhibits hydrodynamiclike contributions that follow transverse gradients of the energy density ∇iɛ . In addition, a rapidity-odd energy flow also emerges from the non-Abelian analog of Gauss' law and generates nonvanishing angular momentum of the field. We discuss the space-time picture that emerges from our analysis and its implications for observables in heavy-ion collisions.

  14. Integrated biostratigraphy and sealevel dynamics at the Santonian - early Campanian Schattau section - Northern Calcareous Alps, Austria

    Science.gov (United States)

    Wolfgring, Erik; Wagreich, Michael

    2016-04-01

    The Schattau section displays a Santonian to early Campanian transgressive sequence with a rich micro- and macro fossil fauna. A framework based on planktonic foraminifera, calcareous nannoplankton, ammonite, echinoid and crinoid biostratigraphy provides the foundation for a high resolution assessment of palaeoecologic changes in planktonic and benthic foraminiferal communities and local biostratigraphy (see Wagreich et al., 2009). The Santonian Hochmoos Formation (representing shallow water environments with the Sandkalkbank Member at the top of this unit) is overlain by the Santonian to Campanian Bibereck Formation (recording a distinct increase in water depth). The stratigraphically older subsections of the outcrop yield abundant miliolids and some rotaliid foraminiferal taxa (Quinqueloculina sp., Spiroloculina fassistomata, Hoeglundia spp., Gavellina spp.) and the larger benthic foraminifer Nummofallotia cretacea. A transgressive episode is recorded in the uppermost Hochmoos Formation's Sandkalkbank Member - consequently larger benthic foraminifera disappear and miliolids become a rare -, planktonic foraminifera an abundant element in deposits assigning to the stratigraphically youngest part of the Schattau section, the Bibereck Formation. Globotruncanids and marginotruncanids are frequently found. The planktonic/benthic foraminifera ratio rises from zero to ~50%. The benthic foraminiferal fauna is characterised by tubular and bi- and triserial agglutinated foraminifera (e.g. Ammobaculites spp., Dorothia spp., Gaudryina spp., Tritaxia spp.) as well as spiral calcareous benthic foraminifera (Gavellina spp., Lenticulina spp.). Accordingly, the younger deposits at the Schattau section record an outer neritic to upper slope environment. Planctonic foraminifera indicate the Dicarinella asymetrica and the lowest Globotruncanita elevata biozone: The top of the Schattau section records the last appearance of the planktonic foraminifera Dicarinella asymetrica and

  15. Climate-driven lacustrine dynamics from the Early Pleistocene Lorenyang Lake, Turkana Basin, Kenya

    Science.gov (United States)

    Joordens, Josephine; Beck, Catherine; Sier, Mark; Van der Lubbe, Jeroen; Dupont-Nivet, Guillaume; Langereis, Cor; Vonhof, Hubert; Cohen, Andy; Olago, Dan; Campisano, Chris; Feibel, Craig

    2016-04-01

    Two stratigraphic records from Kaitio in West Turkana, Kenya, span 1.87 - 1.34 Ma, and document environmental character and variability through a critical interval for human evolution and cultural development. The WTK13 core collected by the Hominin Sites and Paleolakes Drilling Project (HSPDP) recovered 216 m of sediment at 95% recovery. A parallel outcrop record of 180 m was investigated in exposures along the Kaitio laga close to the drill site. Six tephrostratigraphic markers, the Chari, Lokapetamoi, 22Q-3, Etirr, Ebei and KBS Tuffs are present in the outcrop and/or core. These were characterized by single-shard geochemical analysis, and provide links to the well-established tephrochronology of the Turkana Basin. Magnetic polarity stratigraphy of the two records documents the top of the Olduvai Subchron (C2N) at 1.78 Ma. The lithostratigraphic record, bolstered by magnetic susceptibility and sedimentary facies characterization, demonstrates a first-order transition from a deeper lacustrine system to a dynamic lake margin setting, followed by delta progradation. Facies analysis reveals repeated fluctuations of lake level at Milankovitch and sub-Milankovitch scales. Core-outcrop correlation allows detailed comparisons between diagenetically-prone outcrop samples and more pristine samples from the deep core. The excellent preservation of the core sediments makes it possible to obtain critical climate records of organic biomarkers, pollen, phytoliths and other proxies. This detailed archive of environmental variability is closely linked to the rich paleontological and archaeological discoveries from nearby sites and around the Turkana Basin.

  16. Regional hippocampal vulnerability in early multiple sclerosis: Dynamic pathological spreading from dentate gyrus to CA1.

    Science.gov (United States)

    Planche, Vincent; Koubiyr, Ismail; Romero, José E; Manjon, José V; Coupé, Pierrick; Deloire, Mathilde; Dousset, Vincent; Brochet, Bruno; Ruet, Aurélie; Tourdias, Thomas

    2018-04-01

    Whether hippocampal subfields are differentially vulnerable at the earliest stages of multiple sclerosis (MS) and how this impacts memory performance is a current topic of debate. We prospectively included 56 persons with clinically isolated syndrome (CIS) suggestive of MS in a 1-year longitudinal study, together with 55 matched healthy controls at baseline. Participants were tested for memory performance and scanned with 3 T MRI to assess the volume of 5 distinct hippocampal subfields using automatic segmentation techniques. At baseline, CA4/dentate gyrus was the only hippocampal subfield with a volume significantly smaller than controls (p < .01). After one year, CA4/dentate gyrus atrophy worsened (-6.4%, p < .0001) and significant CA1 atrophy appeared (both in the stratum-pyramidale and the stratum radiatum-lacunosum-moleculare, -5.6%, p < .001 and -6.2%, p < .01, respectively). CA4/dentate gyrus volume at baseline predicted CA1 volume one year after CIS (R 2  = 0.44 to 0.47, p < .001, with age, T2 lesion-load, and global brain atrophy as covariates). The volume of CA4/dentate gyrus at baseline was associated with MS diagnosis during follow-up, independently of T2-lesion load and demographic variables (p < .05). Whereas CA4/dentate gyrus volume was not correlated with memory scores at baseline, CA1 atrophy was an independent correlate of episodic verbal memory performance one year after CIS (ß = 0.87, p < .05). The hippocampal degenerative process spread from dentate gyrus to CA1 at the earliest stage of MS. This dynamic vulnerability is associated with MS diagnosis after CIS and will ultimately impact hippocampal-dependent memory performance. © 2018 Wiley Periodicals, Inc.

  17. Epigenetic dynamics of the Kcnq1 imprinted domain in the early embryo.

    Science.gov (United States)

    Lewis, Annabelle; Green, Kelly; Dawson, Claire; Redrup, Lisa; Huynh, Khanh D; Lee, Jeannie T; Hemberger, Myriam; Reik, Wolf

    2006-11-01

    The mouse Kcnq1 imprinted domain is located on distal chromosome 7 and contains several imprinted genes that are paternally repressed. Repression of these genes is regulated by a non-coding antisense transcript, Kcnq1ot1, which is paternally expressed. Maternal repression of Kcnq1ot1 is controlled by DNA methylation originating in the oocyte. Some genes in the region are imprinted only in the placenta, whereas others are imprinted in both extra-embryonic and embryonic lineages. Here, we show that Kcnq1ot1 is paternally expressed in preimplantation embryos from the two-cell stage, and that ubiquitously imprinted genes proximal to Kcnq1ot1 are already repressed in blastocysts, ES cells and TS cells. Repressive histone marks such as H3K27me3 are present on the paternal allele of these genes in both ES and TS cells. Placentally imprinted genes that are distal to Kcnq1ot1, by contrast, are not imprinted in blastocysts, ES or TS cells. In these genes, paternal silencing and differential histone marks arise during differentiation of the trophoblast lineage between E4.5 and E7.5. Our findings show that the dynamics during preimplantation development of gene inactivation and acquisition of repressive histone marks in ubiquitously imprinted genes of the Kcnq1 domain are very similar to those of imprinted X inactivation. By contrast, genes that are only imprinted in the placenta, while regulated by the same non-coding RNA transcript Kcnq1ot1, undergo epigenetic inactivation during differentiation of the trophoblast lineage. Our findings establish a model for how epigenetic gene silencing by non-coding RNA may depend on distance from the non-coding RNA and on lineage and differentiation specific factors.

  18. Recreational stimulants, herbal, and spice cannabis: The core psychobiological processes that underlie their damaging effects.

    Science.gov (United States)

    Parrott, Andrew C; Hayley, Amie C; Downey, Luke A

    2017-05-01

    Recreational drugs are taken for their positive mood effects, yet their regular usage damages well-being. The psychobiological mechanisms underlying these damaging effects will be debated. The empirical literature on recreational cannabinoids and stimulant drugs is reviewed. A theoretical explanation for how they cause similar types of damage is outlined. All psychoactive drugs cause moods and psychological states to fluctuate. The acute mood gains underlie their recreational usage, while the mood deficits on withdrawal explain their addictiveness. Cyclical mood changes are found with every central nervous system stimulant and also occur with cannabis. These mood state changes provide a surface index for more profound psychobiological fluctuations. Homeostatic balance is altered, with repetitive disturbances of the hypothalamic-pituitary-adrenal axis, and disrupted cortisol-neurohormonal secretions. Hence, these drugs cause increased stress, disturbed sleep, neurocognitive impairments, altered brain activity, and psychiatric vulnerability. Equivalent deficits occur with novel psychoactive stimulants such as mephedrone and artificial "spice" cannabinoids. These psychobiological fluctuations underlie drug dependency and make cessation difficult. Psychobiological stability and homeostatic balance are optimally restored by quitting psychoactive drugs. Recreational stimulants such as cocaine or MDMA (3.4-methylenedioxymethamphetamine) and sedative drugs such as cannabis damage human homeostasis and well-being through similar core psychobiological mechanisms. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Neural regions that underlie reinforcement learning are also active for social expectancy violations.

    Science.gov (United States)

    Harris, Lasana T; Fiske, Susan T

    2010-01-01

    Prediction error, the difference between an expected and an actual outcome, serves as a learning signal that interacts with reward and punishment value to direct future behavior during reinforcement learning. We hypothesized that similar learning and valuation signals may underlie social expectancy violations. Here, we explore the neural correlates of social expectancy violation signals along the universal person-perception dimensions trait warmth and competence. In this context, social learning may result from expectancy violations that occur when a target is inconsistent with an a priori schema. Expectancy violation may activate neural regions normally implicated in prediction error and valuation during appetitive and aversive conditioning. Using fMRI, we first gave perceivers high warmth or competence behavioral information that led to dispositional or situational attributions for the behavior. Participants then saw pictures of people responsible for the behavior; they represented social groups either inconsistent (rated low on either warmth or competence) or consistent (rated high on either warmth or competence) with the behavior information. Warmth and competence expectancy violations activate striatal regions that represent evaluative and prediction error signals. Social cognition regions underlie consistent expectations. These findings suggest that regions underlying reinforcement learning may work in concert with social cognition regions in warmth and competence social expectancy. This study illustrates the neural overlap between neuroeconomics and social neuroscience.

  20. Deficiency in the Heat Stress Response Could Underlie Susceptibility to Metabolic Disease.

    Science.gov (United States)

    Rogers, Robert S; Morris, E Matthew; Wheatley, Joshua L; Archer, Ashley E; McCoin, Colin S; White, Kathleen S; Wilson, David R; Meers, Grace M E; Koch, Lauren G; Britton, Steven L; Thyfault, John P; Geiger, Paige C

    2016-11-01

    Heat treatment (HT) effectively prevents insulin resistance and glucose intolerance in rats fed a high-fat diet (HFD). The positive metabolic actions of heat shock protein 72 (HSP72), which include increased oxidative capacity and enhanced mitochondrial function, underlie the protective effects of HT. The purpose of this study was to test the ability of HSP72 induction to mitigate the effects of consumption of a short-term 3-day HFD in rats selectively bred to be low-capacity runners (LCRs) and high-capacity runners (HCRs)-selective breeding that results in disparate differences in intrinsic aerobic capacity. HCR and LCR rats were fed a chow or HFD for 3 days and received a single in vivo HT (41°C, for 20 min) or sham treatment (ST). Blood, skeletal muscles, liver, and adipose tissues were harvested 24 h after HT/ST. HT decreased blood glucose levels, adipocyte size, and triglyceride accumulation in liver and muscle and restored insulin sensitivity in glycolytic muscles from LCR rats. As expected, HCR rats were protected from the HFD. Importantly, HSP72 induction was decreased in LCR rats after only 3 days of eating the HFD. Deficiency in the highly conserved stress response mediated by HSPs could underlie susceptibility to metabolic disease with low aerobic capacity. © 2016 by the American Diabetes Association.

  1. Language Use in Real-time Interactions during Early Elementary Science Lessons: The Bidirectional Dynamics of the Language Complexity of Teachers and Students

    Science.gov (United States)

    Menninga, Astrid; van Dijk, Marijn; Steenbeek, Henderien; van Geert, Paul

    2017-01-01

    This study used a dynamic approach to explore bidirectional sequential relations between the real-time language use of teachers and students in naturalistic early elementary science lessons. It also compared experienced teachers (n = 22) with novice teachers (n = 8) with respect to such relations. Verbal interactions were transcribed and coded at…

  2. Diagnostic and prognostic values of standard and dynamic ultrasound in early detection and treatment of developmental hip deformity

    Directory of Open Access Journals (Sweden)

    Pajić Miloš

    2007-01-01

    Full Text Available Introduction A clinical examination of a newborn infant is indispensable, but certainly insufficient for a diagnosis of developmental deformity of the hip (DDH to be made. The use of the ultrasound in the diagnostics of DDH, beside the visualization and making the respective clinical findings objective, made possible verification (still without a distinction of the tissues of the two basic categories of the primary condition of a newborn baby hips. Objective The purpose of this study was to find out the optimal methodological procedure for the early detection of DDH in newborn infants and suckling. Method During 2002 and 2003, at the Neonatal Department of the Clinic for Gynecology and Obstetrics, Novi Sad, as well as at the Institute for Orthopedic Surgery "Banjica" Belgrade, there were 4016 newborn infants examined, i.e. 8032 hips clinically and by ultrasound. The standard Graf’s methodological procedure was applied completely, supplemented by the dynamic examination by pushing back and stretching femora along, that is by the techniques of Couture and Harcke. Results In order to categorize the condition of the hip of a newborn infant, the sonographic classification of R. Graaf, Th. Harcke and D. Pajić was used. The ultrasound analysis demonstrated a frequency of the sonotype Ia in 552 (13.08% of the newborn infants, the sonotype Ib in 2934 (73.00%, the sonotype IIa+ in 481 (11.97% and the pathological cases with sonotypes IIg 42 (1.04%, IId 17 (0.42%, IIIa 15 (0.37% and IV 5 (0.12%. The total number of unstable critical, discentering and discentered cases of DDH was 79 (1.95%. The incidence of DDH was three times more frequent in girls, mostly bilateral; when unilateral, it was more frequent in the left one. The results of the early treatment were uniformly excellent, but in two cases there was established osteochondritis of the first degree (Pavlik’s harness 1, Von Rosen’s splint 1. Conclusion It has been proven that the clinical

  3. [Diagnostic and prognostic values of standard and dynamic ultrasound in early detection and treatment of developmental hip deformity].

    Science.gov (United States)

    Pajić, Milos; Vukasinović, Zoran

    2007-01-01

    A clinical examination of a newborn infant is indispensable, but certainly insufficient for a diagnosis of developmental deformity of the hip (DDH) to be made. The use of the ultrasound in the diagnostics of DDH, beside the visualization and making the respective clinical findings objective, made possible verification (still without a distinction of the tissues) of the two basic categories of the primary condition of a newborn baby hips. The purpose of this study was to find out the optimal methodological procedure for the early detection of DDH in newborn infants and sucklings. During 2002 and 2003, at the Neonatal Department of the Clinic for Gynaecology and Obstetrics, Novi Sad, as well as at the Institute for Orthopaedic Surgery "Banjica" Belgrade, there were 4016 newborn infants examined, i.e. 8032 hips clinically and by ultrasound. The standard Graf's methodological procedure was applied completely, supplemented by the dynamic examination by pushing back and streching femora along, that is by the techniques of Couture and Harcke. In order to categorize the condition of the hip of a newborn infant, the sonographic classification of R. Graaf, Th. Harcke and D. Pajidćwas used. The ultrasound analysis demonstrated a frequency of the sonotype lI in 552 (13.08%) of the newborn infants, the sonotype lI in 2934 (73.00%), the sonotype iII+ in 481 (11.97%) and the pathological cases with sonotypes IlIg+42 (1.04%), lIl 17 (0.42%), IlII 15 (0.37%) and IV5 (0.12%). The total number of unstable critical, discentering and discentered cases of DDH was 79 (1.95%). The incidence of DDH was three times more frequent in girls, mostly bilateral; when unilateral, it was more frequent in the left one.T he results of the early treatment were uniformly excellent, but in two cases there was established osteochondritis of the first degree (Pavlik's harness 1, Von Rosen's splint 1). iIt as been proven that the clinical examination was inevitable, but insufficient for diagnosis of DDH

  4. Molecular epidemiology of HIV-1 in Iceland: Early introductions, transmission dynamics and recent outbreaks among injection drug users.

    Science.gov (United States)

    Sallam, Malik; Esbjörnsson, Joakim; Baldvinsdóttir, Guðrún; Indriðason, Hlynur; Björnsdóttir, Thora Björg; Widell, Anders; Gottfreðsson, Magnús; Löve, Arthur; Medstrand, Patrik

    2017-04-01

    The molecular epidemiology of HIV-1 in Iceland has not been described so far. Detailed analyses of the dynamics of HIV-1 can give insights for prevention of virus spread. The objective of the current study was to characterize the genetic diversity and transmission dynamics of HIV-1 in Iceland. Partial HIV-1 pol (1020bp) sequences were generated from 230 Icelandic samples, representing 77% of all HIV-1 infected individuals reported in the country 1985-2012. Maximum likelihood phylogenies were reconstructed for subtype/CRF assignment and determination of transmission clusters. Timing and demographic growth patterns were determined in BEAST. HIV-1 infection in Iceland was dominated by subtype B (63%, n=145) followed by subtype C (10%, n=23), CRF01_AE (10%, n=22), sub-subtype A1 (7%, n=15) and CRF02_AG (7%, n=15). Trend analysis showed an increase in non-B subtypes/CRFs in Iceland over the study period (p=0.003). The highest proportion of phylogenetic clustering was found among injection drug users (IDUs; 89%), followed by heterosexuals (70%) and men who have sex with men (35%). The time to the most recent common ancestor of the oldest subtype B cluster dated back to 1978 (median estimate, 95% highest posterior density interval: 1974-1981) suggesting an early introduction of HIV-1 into Iceland. A previously reported increase in HIV-1 incidence among IDUs 2009-2011 was revealed to be due to two separate outbreaks. Our study showed that a variety of HIV-1 subtypes and CRFs were prevalent in Iceland 1985-2012, with subtype B being the dominant form both in terms of prevalence and domestic spread. The rapid increase of HIV-1 infections among IDUs following a major economic crisis in Iceland raises questions about casual associations between economic factors, drug use and public health. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Abnormal frontal theta oscillations underlie the cognitive flexibility deficits in children with high-functioning autism spectrum disorders.

    Science.gov (United States)

    Yeung, Michael K; Han, Yvonne M Y; Sze, Sophia L; Chan, Agnes S

    2016-03-01

    Deficits in cognitive flexibility have been suggested to underlie the repetitive and stereotyped behavior in individuals with autism spectrum disorders (ASD). Because cognitive flexibility is primarily mediated by the frontal lobe, where structural and functional abnormalities have been extensively found in these individuals, it is conceivable that their deficits in cognitive flexibility are related to abnormal activations of the frontal lobe. The present study investigates cognitive flexibility and its underlying neurophysiological activities as indicated by theta oscillations in children with ASD. Twenty-five children with high-functioning ASD and 25 IQ- and age-matched typically developing (TD) children were subjected to neuropsychological assessments on cognitive flexibility and electroencephalography recordings. The children with ASD performed significantly worse than the TD children across the tasks of cognitive flexibility, including the modified Wisconsin Card Sorting Test (WCST). These children also demonstrated a reduced increase of the theta power localized in multiple brain regions, including various sectors of the frontal lobe at the late stage (i.e., 600 ms-900 ms poststimulus interval) but not the early stage (i.e., 250 ms-550 ms poststimulus interval) of the performance of the modified WCST. The suppressed late frontal theta activities were further shown to be significantly correlated with a poorer performance on the cognitive flexibility measures. Our findings suggest that abnormal activations of multiple cortical regions, especially the frontal lobe, form the neural basis of the cognitive flexibility deficits in children with ASD. In addition, we found an EEG marker of cognitive flexibility which could be used to monitor treatment outcomes objectively. (c) 2016 APA, all rights reserved).

  6. Differing mechanisms underlie sexual size-dimorphism in two populations of a sex-changing fish.

    Directory of Open Access Journals (Sweden)

    Mark I McCormick

    Full Text Available Variability in the density of groups within a patchy environment lead to differences in interaction rates, growth dynamics and social organization. In protogynous hermaphrodites there are hypothesised trade-offs among sex-specific growth, reproductive output and mortality. When differences in density lead to changes to social organization the link between growth and the timing of sex-change is predicted to change. The present study explores this prediction by comparing the social organisation and sex-specific growth of two populations of a protogynous tropical wrasse, Halichoeres miniatus, which differ in density. At a low density population a strict harem structure was found, where males maintained a tight monopoly of access and spawning rights to females. In contrast, at a high density population a loosely organised system prevailed, where females could move throughout multiple male territories. Otolith microstructure revealed the species to be annual and deposit an otolith check associated with sex-change. Growth trajectories suggested that individuals that later became males in both populations underwent a growth acceleration at sex-change. Moreover, in the high density population, individuals that later became males were those individuals that had the largest otolith size at hatching and consistently deposited larger increments throughout early larval, juvenile and female life. This study demonstrates that previous growth history and growth rate changes associated with sex change can be responsible for the sexual dimorphism typically found in sex-changing species, and that the relative importance of these may be socially constrained.

  7. Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion.

    Science.gov (United States)

    Vegter, Riemer J K; Hartog, Johanneke; de Groot, Sonja; Lamoth, Claudine J; Bekker, Michel J; van der Scheer, Jan W; van der Woude, Lucas H V; Veeger, Dirkjan H E J

    2015-03-10

    To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is unclear in what way the propulsion technique impacts the load on the shoulder complex. The purpose of this study was to evaluate mechanical efficiency, propulsion technique and load on the shoulder complex during the initial stage of motor learning. 15 naive able-bodied participants received 12-minutes uninstructed wheelchair practice on a motor driven treadmill, consisting of three 4-minute blocks separated by two minutes rest. Practice was performed at a fixed belt speed (v = 1.1 m/s) and constant low-intensity power output (0.2 W/kg). Energy consumption, kinematics and kinetics of propulsion technique were continuously measured. The Delft Shoulder Model was used to calculate net joint moments, muscle activity and glenohumeral reaction force. With practice mechanical efficiency increased and propulsion technique changed, reflected by a reduced push frequency and increased work per push, performed over a larger contact angle, with more tangentially applied force and reduced power losses before and after each push. Contrary to our expectations, the above mentioned propulsion technique changes were found together with an increased load on the shoulder complex reflected by higher net moments, a higher total muscle power and higher peak and mean glenohumeral reaction forces. It appears that the early stages of motor learning in handrim wheelchair propulsion are indeed associated with improved technique and efficiency due to optimization of the kinematics and dynamics of the upper extremity. This process goes at the cost of an increased muscular effort and mechanical loading of the shoulder complex. This seems to be associated with an

  8. Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using Pharmacokinetic Modeling: Initial Experience in Patients With Early Arthritis.

    Science.gov (United States)

    Maijer, Karen I; van der Leij, Christiaan; de Hair, Maria J H; Tas, Sander W; Maas, Mario; Gerlag, Daniëlle M; Tak, Paul P; Lavini, Cristina

    2016-03-01

    Analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using pharmacokinetic modeling (PKM) provides quantitative measures that mirror microvessel integrity and can be used as an objective marker of the level of synovial inflammation. The aim of this study was to investigate the PKM parameters K(trans) , kep , and ve in a prospective cohort of disease-modifying antirheumatic drug (DMARD)-naive patients with early arthritis, and to validate the results by assessing their correlation with the number of synovial endothelial cells (ECs). Forty-seven patients with early arthritis (arthritis duration arthritis, 22 with unclassified arthritis, 6 with spondyloarthritis [SpA], and 5 with other arthritides) were included. At baseline, DCE-MRI was performed on an inflamed knee joint of each patient. These images were used to calculate the K(trans) (volume transfer constant between the plasma and extracellular extravascular space [EES]), the kep (transfer constant between the EES and plasma), and the ve (fractional volume of the EES). Second, markers of disease activity were collected. Finally, vascularity was evaluated by immunohistochemical analysis of synovial tissue samples obtained from the inflamed knee joints, using antibodies to detect von Willebrand factor (vWF), a marker of ECs. The 3 PKM parameters differed significantly between diagnostic groups at baseline, with the highest K(trans) value being observed in patients with SpA (median 0.050/minute, interquartile range [IQR] 0.041- 0.069). Furthermore, the K(trans) , kep , and ve values correlated significantly with markers of disease activity. Finally, the PKM parameters K(trans) and kep , but not ve , correlated significantly with synovial expression of vWF (r = 0.647, P = 0.004 for K(trans) ; r = 0.614, P = 0.007 for kep ; r = 0.398, P = 0.102 for ve ). These results suggest that the K(trans) , kep , and ve can be used to detect synovial inflammation in patients with

  9. Protecting the Innocence of Youth: Moral Sanctity Values Underlie Censorship From Young Children.

    Science.gov (United States)

    Anderson, Rajen A; Masicampo, E J

    2017-11-01

    Three studies examined the relationship between people's moral values (drawing on moral foundations theory) and their willingness to censor immoral acts from children. Results revealed that diverse moral values did not predict censorship judgments. It was not the case that participants who valued loyalty and authority, respectively, sought to censor depictions of disloyal and disobedient acts. Rather, censorship intentions were predicted by a single moral value-sanctity. The more people valued sanctity, the more willing they were to censor from children, regardless of the types of violations depicted (impurity, disloyalty, disobedience, etc.). Furthermore, people who valued sanctity objected to indecent exposure only to apparently innocent and pure children-those who were relatively young and who had not been previously exposed to immoral acts. These data suggest that sanctity, purity, and the preservation of innocence underlie intentions to censor from young children.

  10. Applications of multiscale waveform inversion to marine data using a flooding technique and dynamic early-arrival windows

    KAUST Repository

    Boonyasiriwat, Chaiwoot

    2010-11-01

    A recently developed time-domain multiscale waveform tomography (MWT) method is applied to synthetic and field marine data. Although the MWT method was already applied to synthetic data, the synthetic data application leads to a development of a hybrid method between waveform tomography and the salt flooding technique commonly use in subsalt imaging. This hybrid method can overcome a convergence problem encountered by inversion with a traveltime velocity tomogram and successfully provides an accurate and highly resolved velocity tomogram for the 2D SEG/EAGE salt model. In the application of MWT to the field data, the inversion process is carried out using a multiscale method with a dynamic early-arrival muting window to mitigate the local minima problem of waveform tomography and elastic effects. With the modified MWT method, reasonably accurate results as verified by comparison of migration images and common image gathers were obtained. The hybrid method with the salt flooding technique is not used in this field data example because there is no salt in the subsurface according to our interpretation. However, we believe it is applicable to field data applications. © 2010 Society of Exploration Geophysicists.

  11. The nuclear mitotic apparatus (NuMA) protein: localization and dynamics in human oocytes, fertilization and early embryos.

    Science.gov (United States)

    Alvarez Sedó, Cristian; Schatten, Heide; Combelles, Catherine M; Rawe, Vanesa Y

    2011-06-01

    The oocyte's meiotic spindle is a dynamic structure that relies on microtubule organization and regulation by centrosomes. Disorganization of centrosomal proteins, including the nuclear mitotic apparatus (NuMA) protein and the molecular motor complex dynein/dynactin, can lead to chromosomal instability and developmental abnormalities. The present study reports the distribution and function of these proteins in human oocytes, zygotes and early embryos. A total of 239 oocytes, 90 zygotes and discarded embryos were fixed and analyzed with confocal microscopy for NuMA and dynactin distribution together with microtubules and chromatin. Microtubule-associated dynein-dependent transport functions were explored by inhibiting phosphatase and ATPase activity with sodium-orthovanadate (SOV). At germinal vesicle (GV) stages, NuMA was dispersed across the nucleoplasm. After GV breaks down, NuMA became cytoplasmic before localizing at the spindle poles in metaphase I and II oocytes. Aberrant NuMA localization patterns were found during oocyte in vitro maturation. After fertilization, normal and abnormal pronuclear stage zygotes and embryos displayed translocation of NuMA to interphase nuclei. SOV treatment for up to 2 h induced lower maturation rates with chromosomal scattering and ectopic localization of NuMA. Accurate distribution of NuMA is important for oocyte maturation, zygote and embryo development in humans. Proper assembly of NuMA is likely necessary for bipolar spindle organization and human oocyte developmental competence.

  12. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  13. Early micronutrient supplementation protects against early stress-induced cognitive impairments

    NARCIS (Netherlands)

    Naninck, Eva F. G.; Oosterink, J. Efraim; Yam, Kit-Yi; de Vries, Lennart P.; Schierbeek, Henk; van Goudoever, Johannes B.; Verkaik-Schakel, Rikst Nynke; Plantinga, Josee; Plosch, Torsten; Lucassen, Paul J.; Korosi, Aniko

    Early-life stress (ES) impairs cognition later in life. Because ES prevention is problematic, intervention is needed, yet the mechanisms that underlie ES remain largely unknown. So far, the role of early nutrition in brain programming has been largely ignored. Here, we demonstrate that essential

  14. Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover.

    Science.gov (United States)

    Tennant, Jonathan P; Mannion, Philip D; Upchurch, Paul; Sutton, Mark D; Price, Gregory D

    2017-05-01

    The Late Jurassic to Early Cretaceous interval represents a time of environmental upheaval and cataclysmic events, combined with disruptions to terrestrial and marine ecosystems. Historically, the Jurassic/Cretaceous (J/K) boundary was classified as one of eight mass extinctions. However, more recent research has largely overturned this view, revealing a much more complex pattern of biotic and abiotic dynamics than has previously been appreciated. Here, we present a synthesis of our current knowledge of Late Jurassic-Early Cretaceous events, focusing particularly on events closest to the J/K boundary. We find evidence for a combination of short-term catastrophic events, large-scale tectonic processes and environmental perturbations, and major clade interactions that led to a seemingly dramatic faunal and ecological turnover in both the marine and terrestrial realms. This is coupled with a great reduction in global biodiversity which might in part be explained by poor sampling. Very few groups appear to have been entirely resilient to this J/K boundary 'event', which hints at a 'cascade model' of ecosystem changes driving faunal dynamics. Within terrestrial ecosystems, larger, more-specialised organisms, such as saurischian dinosaurs, appear to have suffered the most. Medium-sized tetanuran theropods declined, and were replaced by larger-bodied groups, and basal eusauropods were replaced by neosauropod faunas. The ascent of paravian theropods is emphasised by escalated competition with contemporary pterosaur groups, culminating in the explosive radiation of birds, although the timing of this is obfuscated by biases in sampling. Smaller, more ecologically diverse terrestrial non-archosaurs, such as lissamphibians and mammaliaforms, were comparatively resilient to extinctions, instead documenting the origination of many extant groups around the J/K boundary. In the marine realm, extinctions were focused on low-latitude, shallow marine shelf-dwelling faunas

  15. Single variant bottleneck in the early dynamics of H. influenzae bacteremia in neonatal rats questions the theory of independent action

    Science.gov (United States)

    Shao, Xinxian; Levin, Bruce; Nemenman, Ilya

    2017-08-01

    There is an abundance of information about the genetic basis, physiological and molecular mechanisms of bacterial pathogenesis. In contrast, relatively little is known about population dynamic processes, by which bacteria colonize hosts and invade tissues and cells and thereby cause disease. In an article published in 1978, Moxon and Murphy presented evidence that, when inoculated intranasally with a mixture streptomycin sensitive and resistant (Sm S and Sm R ) and otherwise isogenic strains of Haemophilus influenzae type b (Hib), neonatal rats develop a bacteremic infection that often is dominated by only one strain, Sm S or Sm R . After ruling out other possibilities through years of related experiments, the field seems to have settled on a plausible explanation for this phenomenon: the first bacterium to invade the host activates the host immune response that ‘shuts the door’ on the second invading strain. To explore this hypothesis in a necessarily quantitative way, we modeled this process with a set of mixed stochastic and deterministic differential equations. Our analysis of the properties of this model with realistic parameters suggests that this hypothesis cannot explain the experimental results of Moxon and Murphy, and in particular the observed relationship between the frequency of different types of blood infections (bacteremias) and the inoculum size. We propose modifications to the model that come closer to explaining these data. However, the modified and better fitting model contradicts the common theory of independent action of individual bacteria in establishing infections. We suggest possible experiments that would be able to confirm or reject our proposed modification of the early infection model.

  16. Psychoanalysis as cognitive remediation: Dynamic and Vygotskian perspectives in the analysis of an early adolescent dyslexic girl.

    Science.gov (United States)

    Weinstein, Lissa; Saul, Laurence

    2005-01-01

    The interface of neurocognitive problems and dynamic concerns are examined in the treatment of an early adolescent dyslexic girl. Despite previous intensive remediation, she had been unable to master reading and spelling, but made remarkable progress after a relatively brief period of psychoanalysis. Psychoanalytic and Vygotskian perspectives are integrated to provide a model of how play, within the analytic context, is mutative for learning disabled children. Through the process of reexteriorization in the transference, play allows for the interpretation and resolution of traumatic situations which have become associated with learning. As the act of learning becomes separate from the personal and affective context in which it took place, the child gains access to other, more normative, functions of play. These functions include the development of the capacity to separate meaning from action and the ability to understand words as generalized categories which represent objects, rather than being part of the specific object named. These two capacities, fundamental to the development of abstract thought, will support reflective awareness and help modulate affective states. The abilities furthered in play also act to remediate one component of dyslexia-the difficulty separating context from more abstract bits of knowledge. Finally, the child learns to "play at reality, " often trying on the new role of "student". As Vygotsky notes, play is essential in allowing the child to become aware of what she knows. For a dyslexic child, for whom reading may never become completely a part of procedural memory, becoming conscious of what he knows may also enhance mastery of the skills of phonological processing, albeit more slowly than normally developing readers. The pleasure in play and the repetition it generates aids the internalization of the task and the development of automaticity.

  17. Characterisation of the dynamic behaviour of lipid droplets in the early mouse embryo using adaptive harmonic generation microscopy

    Directory of Open Access Journals (Sweden)

    Wilson Tony

    2010-06-01

    Full Text Available Abstract Background Lipid droplets (LD are organelles with an important role in normal metabolism and disease. The lipid content of embryos has a major impact on viability and development. LD in Drosophila embryos and cultured cell lines have been shown to move and fuse in a microtubule dependent manner. Due to limitations in current imaging technology, little is known about the behaviour of LD in the mammalian embryo. Harmonic generation microscopy (HGM allows one to image LD without the use of exogenous labels. Adaptive optics can be used to correct aberrations that would otherwise degrade the quality and information content of images. Results We have built a harmonic generation microscope with adaptive optics to characterise early mouse embryogenesis. At fertilization, LD are small and uniformly distributed, but in the implanting blastocyst, LD are larger and enriched in the invading giant cells of the trophectoderm. Time-lapse studies reveal that LD move continuously and collide but do not fuse, instead forming aggregates that subsequently behave as single units. Using specific inhibitors, we show that the velocity and dynamic behaviour of LD is dependent not only on microtubules as in other systems, but also on microfilaments. We explore the limits within which HGM can be used to study living embryos without compromising viability and make the counterintuitive finding that 16 J of energy delivered continuously over a period of minutes can be less deleterious than an order of magnitude lower energy delivered dis-continuously over a period of hours. Conclusions LD in pre-implantation mouse embryos show a previously unappreciated complexity of behaviour that is dependent not only on microtubules, but also microfilaments. Unlike LD in other systems, LD in the mouse embryo do not fuse but form aggregates. This study establishes HGM with adaptive optics as a powerful tool for the study of LD biology and provides insights into the photo

  18. Real-time QCM-D monitoring of cancer cell death early events in a dynamic context.

    Science.gov (United States)

    Nowacki, Laetitia; Follet, Julie; Vayssade, Muriel; Vigneron, Pascale; Rotellini, Laura; Cambay, Florian; Egles, Christophe; Rossi, Claire

    2015-02-15

    Since a few years, the acoustic sensing of whole cell is the focus of increasing interest for monitoring the cytoskeletal cellular response to morphological modulators. We aimed at illustrating the potentialities of the quartz crystal microbalance with dissipation (QCM-D) technique for the real-time detection of the earliest morphological changes that occur at the cell-substrate interface during programmed cell death. Human breast cancer cells (MCF-7) grown on serum protein-coated gold sensors were placed in dynamic conditions under a continuous medium flow. The mass and viscoelasticity changes of the cells were tracked by monitoring the frequency and dissipation shifts during the first 4h of cell exposure to staurosporine, a well-known apoptosis inducer. We have identified a QCM-D signature characteristic of morphological modifications and cell detachment from the sensing surface that are related to the pro-apoptotic treatment. In particular, for low staurosporine doses below 1 µM, we showed that recording the dissipation shift allows to detect an early cell response which is undetectable after the same duration by the classical analytical techniques in cell biology. Furthermore, this sensing method allows quantifying the efficiency of the drug effect in less than 4h without requiring labeling and without interfering in the system, thus preventing any loss of information. In the actual context of targeted cancer therapy development, we believe that these results bring new insights in favor of the use of the non invasive QCM-D technique for quickly probing the cancer cell sensitivity to death inducer drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. All-trans retinol and retinol-binding protein from embryonic cerebrospinal fluid exhibit dynamic behaviour during early central nervous system development.

    Science.gov (United States)

    Parada, Carolina; Gato, Angel; Bueno, David

    2008-06-11

    Embryonic cerebrospinal fluid (E-CSF) is involved in the regulation of survival, proliferation and neurogenesis of neuroectodermal progenitor cells, as well as in the control of mesencephalic gene expression in collaboration with the isthmic organizer. Recently, we showed the presence of retinol-binding protein (RBP) within the E-CSF proteome. RBP is an all-trans retinol carrier, a molecule that can be metabolized into retinoic acid, a morphogen involved in central nervous system (CNS) morphogenesis and patterning. Here we demonstrate the presence of all-trans retinol within the E-CSF and analyse the dynamics of RBP and all-trans retinol within this fluid, as well as the expression of retinoic acid-synthesizing enzymes during early CNS development. Our results suggest a relationship between the dynamics of these molecules and the early events of CNS patterning.

  20. NbIT--a new information theory-based analysis of allosteric mechanisms reveals residues that underlie function in the leucine transporter LeuT.

    Science.gov (United States)

    LeVine, Michael V; Weinstein, Harel

    2014-05-01

    Complex networks of interacting residues and microdomains in the structures of biomolecular systems underlie the reliable propagation of information from an input signal, such as the concentration of a ligand, to sites that generate the appropriate output signal, such as enzymatic activity. This information transduction often carries the signal across relatively large distances at the molecular scale in a form of allostery that is essential for the physiological functions performed by biomolecules. While allosteric behaviors have been documented from experiments and computation, the mechanism of this form of allostery proved difficult to identify at the molecular level. Here, we introduce a novel analysis framework, called N-body Information Theory (NbIT) analysis, which is based on information theory and uses measures of configurational entropy in a biomolecular system to identify microdomains and individual residues that act as (i)-channels for long-distance information sharing between functional sites, and (ii)-coordinators that organize dynamics within functional sites. Application of the new method to molecular dynamics (MD) trajectories of the occluded state of the bacterial leucine transporter LeuT identifies a channel of allosteric coupling between the functionally important intracellular gate and the substrate binding sites known to modulate it. NbIT analysis is shown also to differentiate residues involved primarily in stabilizing the functional sites, from those that contribute to allosteric couplings between sites. NbIT analysis of MD data thus reveals rigorous mechanistic elements of allostery underlying the dynamics of biomolecular systems.

  1. Early dynamic imaging in {sup 68}Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

    Energy Technology Data Exchange (ETDEWEB)

    Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Fritz, Josef [Medical University Innsbruck, Department for Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Bektic, Jasmin; Horninger, Wolfgang [Medical University Innsbruck, Department of Urology, Innsbruck (Austria)

    2017-05-15

    PET/CT with {sup 68}Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic {sup 68}Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to {sup 68}Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV{sub max} of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic {sup 68}Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv{sub max} was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in {sup 68}Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic

  2. Rat hippocampal alterations could underlie behavioral abnormalities induced by exposure to moderate noise levels.

    Science.gov (United States)

    Uran, S L; Aon-Bertolino, M L; Caceres, L G; Capani, F; Guelman, L R

    2012-08-30

    Noise exposure is known to affect auditory structures in living organisms. However, it should not be ignored that many of the effects of noise are extra-auditory. Previous findings of our laboratory demonstrated that noise was able to induce behavioral alterations that are mainly related to the cerebellum (CE) and the hippocampus (HC). Therefore, the aim of this work was to reveal new data about the vulnerability of developing rat HC to moderate noise levels through the assessment of potential histological changes and hippocampal-related behavioral alterations. Male Wistar rats were exposed to noise (95-97 dB SPL, 2h daily) either for 1 day (acute noise exposure, ANE) or between postnatal days 15 and 30 (sub-acute noise exposure, SANE). Hippocampal histological evaluation as well as short (ST) and long term (LT) habituation and recognition memory assessments were performed. Results showed a mild disruption in the different hippocampal regions after ANE and SANE schemes, along with significant behavioral abnormalities. These data suggest that exposure of developing rats to noise levels of moderate intensity is able to trigger changes in the HC, an extra-auditory structure of the Central Nervous System (CNS), that could underlie the observed behavioral effects. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Chronic activation of the innate immune system may underlie the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Bruce Bartholow Duncan

    2001-05-01

    Full Text Available CONTEXTO: The metabolic syndrome is characterized by a clustering, in free-living populations, of cardiovascular and diabetes risk factors generally linked to insulin resistance, obesity and central obesity. Consonant with the well-established inflammatory pathogenesis of atherosclerotic disease, the metabolic syndrome is now being investigated in relation to its inflammatory nature. OBJETIVO: We present cross-sectional findings demonstrating that markers of inflammation correlate with components of the metabolic syndrome, and prospective findings of the ARIC Study indicating that markers of inflammation and endothelial dysfunction predict the development of diabetes mellitus and weight gain in adults. We present biological evidence to suggest that chronic activation of the innate immune system may underlie the metabolic syndrome, characterizing the common soil for the causality of type 2 diabetes mellitus and cardiovascular disease. CONCLUSIONS: Better understanding of the role of the innate immune system in these diseases may lead to important advances in the prediction and management of diabetes and cardiovascular disease.

  4. Low striatal glutamate levels underlie cognitive decline in the elderly: evidence from in vivo molecular spectroscopy.

    Science.gov (United States)

    Zahr, Natalie M; Mayer, Dirk; Pfefferbaum, Adolf; Sullivan, Edith V

    2008-10-01

    Glutamate (Glu), the principal excitatory neurotransmitter of prefrontal cortical efferents, potentially mediates higher order cognitive processes, and its altered availability may underlie mechanisms of age-related decline in frontally based functions. Although animal studies support a role for Glu in age-related cognitive deterioration, human studies, which require magnetic resonance spectroscopy for in vivo measurement of this neurotransmitter, have been impeded because of the similarity of Glu's spectroscopic signature to those of neighboring spectral brain metabolites. Here, we used a spectroscopic protocol, optimized for Glu detection, to examine the effect of age in 3 brain regions targeted by cortical efferents--the striatum, cerebellum, and pons--and to test whether performance on frontally based cognitive tests would be predicted by regional Glu levels. Healthy elderly men and women had lower Glu in the striatum but not pons or cerebellum than young adults. In the combined age groups, levels of striatal Glu (but no other proton metabolite also measured) correlated selectively with performance on cognitive tests showing age-related decline. The selective relations between performance and striatal Glu provide initial and novel, human in vivo support for age-related modification of Glu levels as contributing to cognitive decline in normal aging.

  5. Taxonomic diversity dynamics of early cretaceous brachiopods and gastropods in the Azerbaijanian domains of the Lesser Caucasus (Neo-Tethys Ocean

    Directory of Open Access Journals (Sweden)

    Ruban Dmitry A.

    2014-01-01

    Full Text Available Palaeontological data available from the Azerbaijanian domains (Somkhit-Agdam, Sevan-Karabakh, and Miskhan-Kafan tectonic zones of the Lesser Caucasus permit reconstruction of the regional taxonomic diversity dynamics of two groups of Early Cretaceous marine benthic invertebrates. Stratigraphical ranges of 31 species and 14 genera of brachiopods and 40 species and 31 genera of gastropods are considered. The total number of species and genera of brachiopods was low in the Berriasian-Valanginian and then rose to peak in the Barremian. Then, the diversity declined in the Aptian, and brachiopods are not known regionally from the Albian. Gastropods appeared in the Hauterivian and experienced a strong radiation in the Barremian. The diversity of species and genera declined in the Aptian (with a minor radiation in the Middle Aptian, and no gastropods are reported from the Albian. Globally, the number of brachiopod genera remained stable through the Early Cretaceous, and the number of gastropod genera increased stepwise with the maximum in the Albian. The regional and global patterns of the diversity dynamics differed for the both groups of marine benthic invertebrates. The Barremian maximum of the taxonomic diversity coincided with the regional flourishing of reefal ecosystems. The taxonomic diversity dynamics of brachiopods in the Azerbaijanian domains of the Lesser Caucasus is very similar to those of the Northern Caucasus, which is an evidence of proximity of these regions during the Early Cretaceous.

  6. Long-Term Synaptic Changes in Two Input Pathways into the Lateral Nucleus of the Amygdala Underlie Fear Extinction

    Science.gov (United States)

    Park, Junchol; Choi, June-Seek

    2010-01-01

    Plasticity in two input pathways into the lateral nucleus of the amygdala (LA), the medial prefrontal cortex (mPFC) and the sensory thalamus, have been suggested to underlie extinction, suppression of a previously acquired conditioned response (CR) following repeated presentations of the conditioned stimulus (CS). However, little is known about…

  7. Disease Stage-Dependent Changes in Cardiac Contractile Performance and Oxygen Utilization Underlie Reduced Myocardial Efficiency in Human Inherited Hypertrophic Cardiomyopathy.

    Science.gov (United States)

    Güçlü, Ahmet; Knaapen, Paul; Harms, Hendrik J; Parbhudayal, Rahana Y; Michels, Michelle; Lammertsma, Adriaan A; van Rossum, Albert C; Germans, Tjeerd; van der Velden, Jolanda

    2017-05-01

    Reduced myocardial efficiency represents a target for therapy in hypertrophic cardiomyopathy although therapeutic benefit may depend on disease stage. Here, we determined disease stage-dependent changes in myocardial efficiency and effects of myectomy surgery. Myocardial external efficiency (MEE) was determined in 27 asymptomatic mutation carriers (genotype positive/phenotype negative), 10 patients with hypertrophic obstructive cardiomyopathy (HOCM), 10 patients with aortic valve stenosis, and 14 healthy individuals using [ 11 C]-acetate positron emission tomography and cardiovascular magnetic resonance imaging. Follow-up measurements were performed in HOCM and aortic valve stenosis patients 4 months after surgery. External work did not differ in HOCM compared with controls, whereas myocardial oxygen consumption was lower in HOCM. Because of a higher cardiac mass, total cardiac oxygen consumption was significantly higher in HOCM than in controls and genotype positive/phenotype negative. MEE was significantly lower in genotype positive/phenotype negative than in controls (28±6% versus 42±6%) and was further decreased in HOCM (22±5%). In contrast to patients with aortic valve stenosis, MEE was not improved in patients with HOCM after surgery, which was explained by opposite changes in the septum (decrease) and lateral (increase) wall. Different mechanisms underlie reduced MEE at the early and advanced stage of hypertrophic cardiomyopathy. The initial increase and subsequent reduction in myocardial oxygen consumption during disease progression indicates that energy deficiency is a primary mutation-related event, whereas mechanisms secondary to disease remodeling underlie low MEE in HOCM. Our data highlight that the benefit of therapies to improve energetic status of the heart may vary depending on the disease stage and that treatment should be initiated before cardiac remodeling. © 2017 American Heart Association, Inc.

  8. Examination of early group dynamics and treatment outcome in a randomized controlled trial of group cognitive behavior therapy for binge eating disorder.

    Science.gov (United States)

    Pisetsky, Emily M; Durkin, Nora E; Crosby, Ross D; Berg, Kelly C; Mitchell, James E; Crow, Scott J; Wonderlich, Stephen A; Peterson, Carol B

    2015-10-01

    This study examined whether perceptions of group dynamics early in treatment predicted eating disorder outcomes in a sample of adults (N = 190) with binge eating disorder (BED) who participated in a 15-session group cognitive behavior therapy (gCBT) treatment with differing levels of therapist involvement (therapist led, therapist assisted, and self-help). The group dynamic variables included the Engaged subscale of the Group Climate Questionnaire--Short Form and the Group Attitude Scale, measured at session 2 and session 6. Treatment outcome was assessed in terms of global eating disorder severity and frequency of binge eating at end of treatment, 6-month, and 12-month follow-up. Session 2 engagement and group attitudes were associated with improved outcome at 12-month follow-up. No other group dynamic variables were significantly associated with treatment outcome. Group dynamic variables did not differ by levels of therapist involvement. Results indicate that early engagement and attitudes may be predictive of improved eating disorder psychopathology at 12 month follow-up. However, the pattern of mostly insignificant findings indicates that in gCBT, group process variables may be less influential on outcomes relative to other treatment components. Additionally, participants were able to engage in group treatment regardless of level of therapist involvement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Early evaluation of irradiated parotid glands with intravoxel incoherent motion MR imaging: correlation with dynamic contrast-enhanced MR imaging

    International Nuclear Information System (INIS)

    Zhou, Nan; Chu, Chen; Dou, Xin; Li, Ming; Liu, Song; Zhu, Lijing; Liu, Baorui; Guo, Tingting; Chen, Weibo; He, Jian; Yan, Jing; Zhou, Zhengyang; Yang, Xiaofeng; Liu, Tian

    2016-01-01

    Radiation-induced parotid damage is one of the most common complications in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy (RT). Intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging has been reported for evaluating irradiated parotid damage. However, the changes of IVIM perfusion-related parameters in irradiated parotid glands have not been confirmed by conventional perfusion measurements obtained from dynamic contrast-enhanced (DCE) MR imaging. The purposes of this study were to monitor radiation-induced parotid damage using IVIM and DCE MR imaging and to investigate the correlations between changes of these MR parameters. Eighteen NPC patients underwent bilateral parotid T1-weighted, IVIM and DCE MR imaging pre-RT (2 weeks before RT) and post-RT (4 weeks after RT). Parotid volume; IVIM MR parameters, including apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f); and DCE MR parameters, including maximum relative enhancement (MRE), time to peak (TTP), Wash in Rate, and the degree of xerostomia were recorded. Correlations of parotid MR parameters with mean radiation dose, atrophy rate and xerostomia degree, as well as the relationships between IVIM and DCE MR parameters, were investigated. From pre-RT to post-RT, all of the IVIM and DCE MR parameters increased significantly (p < 0.001 for ADC, D, f, MRE, Wash in Rate; p = 0.024 for D*; p = 0.037 for TTP). Change rates of ADC, f and MRE were negatively correlated with atrophy rate significantly (all p < 0.05). Significant correlations were observed between the change rates of D* and MRE (r = 0.371, p = 0.026) and between the change rates of D* and TTP (r = 0.396, p = 0.017). The intra- and interobserver reproducibility of IVIM and DCE MR parameters was good to excellent (intraclass correlation coefficient, 0.633–0.983). Early radiation-induced changes of parotid glands could be evaluated by IVIM and

  10. Does Animal Behavior Underlie Covariation Between Hosts' Exposure to Infectious Agents and Susceptibility to Infection? Implications for Disease Dynamics

    NARCIS (Netherlands)

    Hawley, Dana M.; Etienne, Rampal S.; Ezenwa, Vanessa O.; Jolles, Anna E.

    2011-01-01

    Animal behavior is unique in influencing both components of the process of transmission of disease: exposure to infectious agents, and susceptibility to infection once exposed. To date, the influence of behavior on exposure versus susceptibility has largely been considered separately. Here, we ask

  11. Different evolutionary pathways underlie the morphology of wrist bones in hominoids.

    Science.gov (United States)

    Kivell, Tracy L; Barros, Anna P; Smaers, Jeroen B

    2013-10-23

    The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context.We identify morphological features that principally characterize primate - and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones - the scaphoid, lunate, triquetrum, capitate and hamate - are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist

  12. Dynamic modeling in ovarian cancer: an original approach linking early changes in modeled longitudinal CA-125 kinetics and survival to help decisions in early drug development.

    Science.gov (United States)

    Wilbaux, Mélanie; Hénin, Emilie; Oza, Amit; Colomban, Olivier; Pujade-Lauraine, Eric; Freyer, Gilles; Tod, Michel; You, Benoit

    2014-06-01

    Early prediction of the expected benefit of treatment in recurrent ovarian cancer (ROC) patients may help in drug development decisions. The actual value of 50% CA-125 decrease is being reconsidered. The main objective of the present study was to quantify the links between longitudinal assessments of CA-125 kinetics and progression-free survival (PFS) in treated recurrent ovarian cancer (ROC) patients. The CALYPSO randomized phase III trial database comparing two platinum-based regimens in ROC patients was randomly split into a "learning dataset" and a "validation dataset". A parametric survival model was developed to associate longitudinal modeled CA-125 changes (ΔCA125), predictive factors, and PFS. The predictive performance of the model was evaluated with simulations. The PFS of 534 ROC patients were properly characterized by a parametric mathematical model. The modeled ΔCA125 from baseline to week 6 was a better predictor of PFS than the modeled fractional change in tumor size. Simulations confirmed the model's predictive performance. We present the first parametric survival model quantifying the relationship between PFS and longitudinal CA-125 kinetics in treated ROC patients. The model enabled calculation of the increase in ΔCA125 required to observe a predetermined benefit in PFS to compare therapeutic strategies in populations. Therefore, ΔCA125 may be a predictive marker of the expected gain in PFS and an early predictive tool in drug development decisions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Early dynamic imaging in 68Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions.

    Science.gov (United States)

    Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Fritz, Josef; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; von Guggenberg, Elisabeth; Bektic, Jasmin; Horninger, Wolfgang; Virgolini, Irene Johanna

    2017-05-01

    PET/CT with 68 Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic 68 Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to 68 Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV max of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic 68 Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv max was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p bladder accumulation. Performance of early dynamic imaging in addition to whole body imaging 60 min after tracer injection might improve the detection rate of local recurrence in PC patients with biochemical relapse referred for 68 Ga-PSMA-11 PET/CT.

  14. RNA-Seq reveals the dynamic and diverse features of digestive enzymes during early development of Pacific white shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Wei, Jiankai; Zhang, Xiaojun; Yu, Yang; Li, Fuhua; Xiang, Jianhai

    2014-09-01

    The Pacific white shrimp (Litopenaeus vannamei), with high commercial value, has a typical metamorphosis pattern by going through embryo, nauplius, zoea, mysis and postlarvae during early development. Its diets change continually in this period, and a high mortality of larvae also occurs in this period. Since there is a close relationship between diets and digestive enzymes, a comprehensive investigation about the types and expression patterns of all digestive enzyme genes during early development of L. vannamei is of considerable significance for shrimp diets and larvae culture. Using RNA-Seq data, the types and expression characteristics of the digestive enzyme genes were analyzed during five different development stages (embryo, nauplius, zoea, mysis and postlarvae) in L. vannamei. Among the obtained 66,815 unigenes, 296 were annotated as 16 different digestive enzymes including five types of carbohydrase, seven types of peptidase and four types of lipase. Such a diverse suite of enzymes illustrated the capacity of L. vannamei to exploit varied diets to fit their nutritional requirements. The analysis of their dynamic expression patterns during development also indicated the importance of transcriptional regulation to adapt to the diet transition. Our study revealed the diverse and dynamic features of digestive enzymes during early development of L. vannamei. These results would provide support to better understand the physiological changes during diet transition. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. A high-level dynamic analysis approach for studying global process plant availability and production time in the early stages of mining projects

    Directory of Open Access Journals (Sweden)

    Dennis Travagini Cremonese

    Full Text Available Abstract In the early stage of front-end studies of a Mining Project, the global availability (i.e. number of hours a plant is available for production and production (number of hours a plant is actually operated with material time of the process plant are normally assumed based on the experience of the study team. Understanding and defining the availability hours at the early stages of the project are important for the future stages of the project, as drastic changes in work hours will impact the economics of the project at that stage. An innovative high-level dynamic modeling approach has been developed to assist in the rapid evaluation of assumptions made by the study team. This model incorporates systems or equipment that are commonly used in mining projects from mine to product stockyard discharge after the processing plant. It includes subsystems that will simulate all the component handling, and major process plant systems required for a mining project. The output data provided by this high-level dynamic simulation approach will enhance the confidence level of engineering carried out during the early stage of the project. This study discusses the capabilities of the approach, and a test case compared with standard techniques used in mining project front-end studies.

  16. Distinct Myocardial Mechanisms Underlie Cardiac Dysfunction in Endotoxemic Male and Female Mice.

    Science.gov (United States)

    Hobai, Ion A; Aziz, Kanwal; Buys, Emmanuel S; Brouckaert, Peter; Siwik, Deborah A; Colucci, Wilson S

    2016-12-01

    In male mice, sepsis-induced cardiomyopathy develops as a result of dysregulation of myocardial calcium (Ca) handling, leading to depressed cellular Ca transients (ΔCai). ΔCai depression is partially due to inhibition of sarcoplasmic reticulum Ca ATP-ase (SERCA) via oxidative modifications, which are partially opposed by cGMP generated by the enzyme soluble guanylyl cyclase (sGC). Whether similar mechanisms underlie sepsis-induced cardiomyopathy in female mice is unknown.Male and female C57Bl/6J mice (WT), and mice deficient in the sGC α1 subunit activity (sGCα1), were challenged with lipopolysaccharide (LPS, ip). LPS induced mouse death and cardiomyopathy (manifested as the depression of left ventricular ejection fraction by echocardiography) to a similar degree in WT male, WT female, and sGCα1 male mice, but significantly less in sGCα1 female mice. We measured sarcomere shortening and ΔCai in isolated, externally paced cardiomyocytes, at 37°C. LPS depressed sarcomere shortening in both WT male and female mice. Consistent with previous findings, in male mice, LPS induced a decrease in ΔCai (to 30 ± 2% of baseline) and SERCA inhibition (manifested as the prolongation of the time constant of Ca decay, τCa, to 150 ± 5% of baseline). In contrast, in female mice, the depression of sarcomere shortening induced by LPS occurred in the absence of any change in ΔCai, or SERCA activity. This suggested that, in female mice, the causative mechanism lies downstream of the Ca transients, such as a decrease in myofilament sensitivity for Ca. The depression of sarcomere shortening shortening after LPS was less severe in female sGCα1 mice than in WT female mice, indicating that cGMP partially mediates cardiomyocyte dysfunction.These results suggest, therefore, that LPS-induced cardiomyopathy develops through distinct sex-specific myocardial mechanisms. While in males LPS induces sGC-independent decrease in ΔCai, in female mice LPS acts downstream of

  17. Incorporating regime metrics into latent variable dynamic models to detect early-warning signals of functional changes in fisheries ecology

    OpenAIRE

    Trifonova, N; Duplisea, D; Kenny, A; Maxwell, D; Tucker, A

    2014-01-01

    In this study, dynamic Bayesian networks have been applied to predict future biomass of geographically different but functionally equivalent fish species. A latent variable is incorporated to model functional collapse, where the underlying food web structure dramatically changes irrevocably (known as a regime shift). We examined if the use of a hidden variable can reflect changes in the trophic dynamics of the system and also whether the inclusion of recognised statistical metrics would impro...

  18. Long-term forest dynamics at Gribskov, eastern Denmark with early-Holocene evidence for thermophilous broadleaved tree species

    DEFF Research Database (Denmark)

    Overballe-Petersen, Mette V; Nielsen, Anne Birgitte; Hannon, Gina E.

    2012-01-01

    thermophilous broadleaved trees, including Quercus sp., Tilia sp. and Ulmus sp. The macrofossils contribute to the vegetation reconstruction with evidence for local presence of species with low pollen productivity or easily degraded pollen types such as Populus. The charcoal record shows frequent burning during...... two periods of the early Holocene and from c. 3000 cal. BP to present. The early-Holocene part of the record indicates a highly disturbed forest ecosystem with frequent fires and abundant macrofossils of particularly Betula sp. and Populus sp. The sediment stratigraphy and age–depth relationships give...

  19. Identification of Three Early Phases of Cell-Fate Determination during Osteogenic and Adipogenic Differentiation by Transcription Factor Dynamics

    NARCIS (Netherlands)

    van de Peppel, Jeroen; Strini, Tanja; Tilburg, Julia; Westerhoff, Hans; van Wijnen, Andre J.; van Leeuwen, Johannes P

    2017-01-01

    Age-related skeletal degeneration in patients with osteoporosis is characterized by decreased bone mass and occurs concomitant with an increase in bone marrow adipocytes. Using microarray expression profiling with high temporal resolution, we identified gene regulatory events in early stages of

  20. Group Dynamic Assessment in an Early Foreign Language Learning Program: Tracking Movement through the Zone of Proximal Development

    Science.gov (United States)

    Davin, Kristin Johnson

    2011-01-01

    Although researchers have begun to explore the implementation of dynamic assessment (DA) with foreign language learners, few of these studies have occurred in the language classroom. Whereas DA is typically implemented in dyads, promising research in the field of foreign language learning suggests that DA may promote development with groups of…

  1. Developmental Dynamics of Intergroup Contact and Intergroup Attitudes: Long-Term Effects in Adolescence and Early Adulthood

    NARCIS (Netherlands)

    Wölfer, R.; van Zalk, M.H.W.; Schmid, K.; Hewstone, M.

    2016-01-01

    Intergroup contact represents a powerful way to improve intergroup attitudes and to overcome prejudice and discrimination. However, long-term effects of intergroup contact that consider social network dynamics have rarely been studied at a young age. Study 1 validated an optimized social network

  2. Interdyad Differences in Early Mother-Infant Face-to-Face Communication: Real-Time Dynamics and Developmental Pathways

    Science.gov (United States)

    Lavelli, Manuela; Fogel, Alan

    2013-01-01

    A microgenetic research design with a multiple case study method and a combination of quantitative and qualitative analyses was used to investigate interdyad differences in real-time dynamics and developmental change processes in mother-infant face-to-face communication over the first 3 months of life. Weekly observations of 24 mother-infant dyads…

  3. Influence of ischemia before vein grafting on early hyperplasia of the graft and the dynamic changes of the intima after grafting

    Directory of Open Access Journals (Sweden)

    Zou RongJiang

    2012-09-01

    Full Text Available Abstract Background To investigate both the influence of ischemia before grafting on early hyperplasia of the vein grafts, and the dynamic changes of the intima after grafting in a rabbit model of vein graft disease. Methods We performed paired vein graft experiments under different ischemic conditions (15 vs. 60 min; 15 vs. 90 min in the neck of the rabbits and compared the differences between the grafts. Clopidogrel, an anti-platelet agent, was administered before and after surgery. Twenty-eight days after the grafting procedure, the veins were evaluated microscopically. The dynamic changes of the intima after grafting were evaluated by scanning electron microscopy over time. Results The vein grafts subjected to 60- or 90-min ischemia exhibited no differences compared to those subjected to 15-min ischemia in terms of the mean thickness of the intimal, medial, and adventitial layers of the graft. Similarly, there was no difference in the Ki-67 labeling index (proliferation marker between the vein grafts. Vein grafts with 15-min ischemia lost endothelial cells (ECs but healed by 3 days post graft, whereas vein grafts with 90-min ischemia suffered serious EC loss, which was restored with new ECs during days 2 to 14 post graft. Conclusions Ninety-minute ischemia before vein grafting can cause serious EC loss, but does not increase early intimal hyperplasia when clopidogrel is administered. Protecting the vein from ischemia and reperfusion injury preserves ECs.

  4. Early Tracking or Finally Leaving? Determinants of Early Study Success in First-Year University Students

    Science.gov (United States)

    Brouwer, Jasperina; Jansen, Ellen; Hofman, Adriaan; Flache, Andreas

    2016-01-01

    Two theoretical approaches underlie this investigation of the determinants of early study success among first-year university students. Specifically, to extend Walberg's educational productivity model, this study draws on the expectancy-value theory of achievement motivation in a contemporary university context. The survey data came from 407…

  5. Dynamic conduction and repolarisation changes in early arrhythmogenic right ventricular cardiomyopathy versus benign outflow tract ectopy demonstrated by high density mapping & paced surface ECG analysis.

    Science.gov (United States)

    Finlay, Malcolm C; Ahmed, Akbar K; Sugrue, Alan; Bhar-Amato, Justine; Quarta, Giovanni; Pantazis, Antonis; Ciaccio, Edward J; Syrris, Petros; Sen-Chowdhry, Srijita; Ben-Simon, Ron; Chow, Anthony W; Lowe, Martin D; Segal, Oliver R; McKenna, William J; Lambiase, Pier D

    2014-01-01

    The concealed phase of arrhythmogenic right ventricular cardiomyopathy (ARVC) may initially manifest electrophysiologically. No studies have examined dynamic conduction/repolarization kinetics to distinguish benign right ventricular outflow tract ectopy (RVOT ectopy) from ARVC's early phase. We investigated dynamic endocardial electrophysiological changes that differentiate early ARVC disease expression from RVOT ectopy. 22 ARVC (12 definite based upon family history and mutation carrier status, 10 probable) patients without right ventricular structural anomalies underwent high-density non-contact mapping of the right ventricle. These were compared to data from 14 RVOT ectopy and 12 patients with supraventricular tachycardias and normal hearts. Endocardial & surface ECG conduction and repolarization parameters were assessed during a standard S1-S2 restitution protocol. Definite ARVC without RV structural disease could not be clearly distinguished from RVOT ectopy during sinus rhythm or during steady state pacing. Delay in Activation Times at coupling intervals just above the ventricular effective refractory period (VERP) increased in definite ARVC (43 ± 20 ms) more than RVOT ectopy patients (36 ± 14 ms, p = 0.03) or Normals (25 ± 16 ms, p = 0.008) and a progressive separation of the repolarisation time curves between groups existed. Repolarization time increases in the RVOT were also greatest in ARVC (definite ARVC: 18 ± 20 ms; RVOT ectopy: 5 ± 14, Normal: 1 ± 18, pSurface ECG correlates of these intracardiac measurements demonstrated an increase of greater than 48 ms in stimulus to surface ECG J-point pre-ERP versus steady state, with an 88% specificity and 68% sensitivity in distinguishing definite ARVC from the other groups. This technique could not distinguish patients with genetic predisposition to ARVC only (probable ARVC) from controls. Significant changes in dynamic conduction and repolarization are apparent in early ARVC before detectable RV

  6. Piezo- and Flexoelectric Membrane Materials Underlie Fast Biological Motors in the Ear

    OpenAIRE

    Breneman, Kathryn D.; Rabbitt, Richard D.

    2009-01-01

    The mammalian inner ear is remarkably sensitive to quiet sounds, exhibits over 100dB dynamic range, and has the exquisite ability to discriminate closely spaced tones even in the presence of noise. This performance is achieved, in part, through active mechanical amplification of vibrations by sensory hair cells within the inner ear. All hair cells are endowed with a bundle of motile microvilli, stereocilia, located at the apical end of the cell, and the more specialized outer hair cells (OHC’...

  7. Dynamic Contrast-Enhanced Ultrasound of Colorectal Liver Metastases as an Imaging Modality for Early Response Prediction to Chemotherapy

    DEFF Research Database (Denmark)

    Mogensen, Marie Benzon; Hansen, Martin Lundsgaard; Henriksen, Birthe Merete

    2017-01-01

    study. Patients were treated with capecitabine or 5-fluorouracil-based chemotherapy with or without bevacizumab. DCE-US was performed before therapy (baseline) and again 10 days after initiation of treatment. Change in contrast-enhancement in one liver metastasis (indicator lesion) was measured....... Treatment response was evaluated with a computed tomography (CT) scan after three cycles of treatment and the initially observed DCE-US change of the indicator lesion was related to the observed CT response. Eighteen patients were included. Six did not complete three series of chemotherapy...... and the evaluation CT scan, leaving twelve patients for analysis. Early changes in perfusion parameters using DCE-US did not correlate well with subsequent CT changes. A subgroup analysis of eight patients receiving bevacizumab, however, demonstrated a statistically significant correlation (p = 0.045) between early...

  8. Mother-adolescent monitoring dynamics and the legitimacy of parental authority

    NARCIS (Netherlands)

    Keijsers, Loes; Laird, Robert D.

    2014-01-01

    This multi-informant longitudinal study aimed to understand whether the family dynamics that underlie adolescent voluntary disclosure regarding their leisure time behavior differs when adolescents strongly or weakly endorse the legitimacy of parental authority. Longitudinal linkages between parental

  9. The impact of global warming and anoxia on marine benthic community dynamics: an example from the Toarcian (Early Jurassic.

    Directory of Open Access Journals (Sweden)

    Silvia Danise

    Full Text Available The Pliensbachian-Toarcian (Early Jurassic fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK, and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed. Two main faunal turnover events occurred: (i at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0 and (ii in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II. The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of "dead zones" in modern oceans.

  10. The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

    Science.gov (United States)

    Danise, Silvia; Twitchett, Richard J.; Little, Crispin T. S.; Clémence, Marie-Emilie

    2013-01-01

    The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans. PMID:23457537

  11. Dynamics of Alloplastic Bone Grafts on an Early Stage of Corticotomy-Facilitated Orthodontic Tooth Movement in Beagle Dogs

    Science.gov (United States)

    Choi, Hyung-Joo; Kim, Tae-Woo

    2014-01-01

    Alveolar augmented corticotomy is effective in accelerating orthodontic tooth movement, but the effect only lasts for a relatively short time. Therefore, the purpose of this study was to investigate the underlying biology of the immediate periodontal response to orthodontic tooth movement after a corticotomy with alloplastic bone grafts. The results demonstrated that measurable tooth movement began as early as 3 days after the intervention in beagle dogs. Based on the results and histological findings, augmented corticotomy-facilitated orthodontic tooth movement might enhance the condition of the periodontal tissue and the stability of the outcomes of orthodontic treatment. PMID:25276787

  12. Dynamics of Alloplastic Bone Grafts on an Early Stage of Corticotomy-Facilitated Orthodontic Tooth Movement in Beagle Dogs

    Directory of Open Access Journals (Sweden)

    Hyung-Joo Choi

    2014-01-01

    Full Text Available Alveolar augmented corticotomy is effective in accelerating orthodontic tooth movement, but the effect only lasts for a relatively short time. Therefore, the purpose of this study was to investigate the underlying biology of the immediate periodontal response to orthodontic tooth movement after a corticotomy with alloplastic bone grafts. The results demonstrated that measurable tooth movement began as early as 3 days after the intervention in beagle dogs. Based on the results and histological findings, augmented corticotomy-facilitated orthodontic tooth movement might enhance the condition of the periodontal tissue and the stability of the outcomes of orthodontic treatment.

  13. Dynamical peculiarities of nucleo-genesis of light nuclei on the early stage of the Universe development

    International Nuclear Information System (INIS)

    Takibaev, N.Zh.; Spanova, G.A.

    2003-01-01

    The item of the L group chemical elements nuclei generation on the early stage of the Universe development has been studied. At this stage the thermodynamical equilibrium inside of nucleus, the electromagnetic and the neutrino component are passing at adiabatic matter expand condition. Description of hot hadron substance and light nuclei nucleo-genesis process are considered in the conditions of matter thermodynamical equilibrium. The approach of thermodynamical potential and state equation were used for analysis. The reactions balance in subsystems, including isotope group and neutron medium (for example, reactions in the hydrogen group) is studied. The assessments for disintegration channel influence are given

  14. Early changes in perfusion of glioblastoma during radio- and chemotherapy evaluated by T1-dynamic contrast enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møller, Søren; Lundemann, Michael; Law, Ian

    2015-01-01

    BACKGROUND: The survival times of patients with glioblastoma differ widely and biomarkers that would enable individualized treatment are needed. The objective of this study was to measure changes in the vascular physiology of tumor using T1-dynamic contrast enhanced magnetic resonance imaging (DCE...... months post-Tx. DCE-MRI at three Tesla generated maps of blood flow (BF), blood volume (BV), permeability (Ki) and volume of distribution (Vd) using a combination of model-free deconvolution and Patlak plots. Regions of interest in contrast enhancing tumor and in normal appearing white matter were...

  15. Dynamic CT in early stage of cerebral ischemia; Clinical usefulness of dynamic CT for rapid evaluation of patients considered for emergency cerebral revascularization

    Energy Technology Data Exchange (ETDEWEB)

    Aritake, Koichi; Sano, Keiji (Fuji Brain Inst. Hospital, Fujinomiya, Shizuoka (Japan))

    1990-12-01

    In the present study, we correlated collateral flow patterns derived from dynamic CT (DCT) and the evolution of cerebral infarction in patients with ischemic episodes and analyzed the efficacy of emergency cerebral revascularization (ECR) in preventing infarction. Forty-four patients, all of whom presented cerebral arterial occlusion without showing any hypodense areas on their initial CT scans, were examined. Eleven patients underwent ECR. Time-density curves (TDCs) within 239 different regions in territories of occluded arteries were derived from DCT. The degree of collateral flow and delay of circulation time were assessed, comparing peak values and peak times of TDCs on the occluded side with those in corresponding regions on the non-occluded side. Hemodynamic patterns of TDCs were classified into the following three types: Type 1 - the residual flow was considerably preserved with markedly delayed circulation time; Type 2 - the collateral flow was considerably preserved, but its circulation time was minimally or moderately delayed; and Type 3 - the residual flow was minimal or moderate with or without slowing of circulation time. In the medically-treated group, follow-up CT scans demonstrated infarction in 89% of Type 1, 6% of Type 2 and 97% of Type 3. In the surgically-treated group, infarction developed in 20% of Type 1, 0% of Type 2 and 95% of Type 3. The hemodynamic pattern map, demonstrated with the advent of the personal computer, was clinically useful in predicting the appearance and extent of infarction and judging the prognosis of patients, even immediately after the ischemic ictus. It would appear that patients whose preoperative DCT discloses a Type 1 perfusion pattern can be expected to benefit the most from ECR. (author).

  16. The effects of stellar dynamics on the X-ray emission of flat early-type galaxies

    Science.gov (United States)

    Negri, Andrea; Ciotti, Luca; Pellegrini, Silvia

    2014-03-01

    Past observational and numerical studies indicated that the hot gaseous haloes of early-type galaxies may be sensitive to the stellar kinematics. With high-resolution ZEUS 2D hydrosimulations, we study the hot gas evolution in flat early-type galaxies of fixed (stellar plus dark) mass distribution, but with variable amounts of azimuthal velocity dispersion and rotational support, including the possibility of a (counter) rotating inner disc. The hot gas is fed by stellar mass-losses, and heated by supernova explosions and thermalization of stellar motions. The simulations provide γth, the ratio between the heating due to the relative velocity between the stellar streaming and the interstellar medium bulk flow, and the heating attainable by complete thermalization of the stellar streaming. We find that (1) X-ray emission-weighted temperatures and luminosities match observed values and are larger in fully velocity dispersion supported systems; X-ray isophotes are boxy where rotation is significant; (2) γth ≃ 0.1-0.2 for isotropic rotators and (3) γth ≃ 1 for systems with an inner (counter) rotating disc. The lower X-ray luminosities of isotropic rotators are not explained just by their low γth but by a complicated flow structure and evolution, consequence of the angular momentum stored at large radii. Rotation is therefore important to explain the lower average X-ray emission and temperature observed in flat and more rotationally supported galaxies.

  17. Networks of Meaning and the Social Dynamics of Identity. An Example from Early Anglo-Saxon England

    Directory of Open Access Journals (Sweden)

    Kathrin Felder

    2015-02-01

    Full Text Available In the early Anglo-Saxon period, dressing and displaying the body in life and death played an important role in shaping and reinforcing identities and ruling social norms. Studies of the past decades have particularly highlighted the social significance of dressing and staging the body for the event of the funeral. This paper addresses how the production of dress items, the daily act of dressing, and the individuals involved in these practices helped shape the same identities that were enacted in the funeral. It argues that we must consider more explicitly how certain elements of dress became objects of identification through the social dialogue between groups of people who engaged with such objects at earlier stages of their lifecycle. This must include not only those who used dress items as grave goods but also those who produced and wore them. It works towards a framework that captures more fully the social communication and exchange of ideas that shaped and transformed notions of identity. Using data from the author’s research on early Anglo-Saxon girdle-hangers, this paper addresses how different forms of socio-material communication, and different actors involved, can be addressed through the material record of burials. Together these formed the mental networks in which meanings and values were created.

  18. Archean greenstone-tonalite duality: Thermochemical mantle convection models or plate tectonics in the early Earth global dynamics?

    Science.gov (United States)

    Kerrich, Robert; Polat, Ali

    2006-03-01

    Mantle convection and plate tectonics are one system, because oceanic plates are cold upper thermal boundary layers of the convection cells. As a corollary, Phanerozoic-style of plate tectonics or more likely a different version of it (i.e. a larger number of slowly moving plates, or similar number of faster plates) is expected to have operated in the hotter, vigorously convecting early Earth. Despite the recent advances in understanding the origin of Archean greenstone-granitoid terranes, the question regarding the operation of plate tectonics in the early Earth remains still controversial. Numerical model outputs for the Archean Earth range from predominantly shallow to flat subduction between 4.0 and 2.5 Ga and well-established steep subduction since 2.5 Ga [Abbott, D., Drury, R., Smith, W.H.F., 1994. Flat to steep transition in subduction style. Geology 22, 937-940], to no plate tectonics but rather foundering of 1000 km sectors of basaltic crust, then "resurfaced" by upper asthenospheric mantle basaltic melts that generate the observed duality of basalts and tonalities [van Thienen, P., van den Berg, A.P., Vlaar, N.J., 2004a. Production and recycling of oceanic crust in the early earth. Tectonophysics 386, 41-65; van Thienen, P., Van den Berg, A.P., Vlaar, N.J., 2004b. On the formation of continental silicic melts in thermochemical mantle convection models: implications for early Earth. Tectonophysics 394, 111-124]. These model outputs can be tested against the geological record. Greenstone belt volcanics are composites of komatiite-basalt plateau sequences erupted from deep mantle plumes and bimodal basalt-dacite sequences having the geochemical signatures of convergent margins; i.e. horizontally imbricated plateau and island arc crust. Greenstone belts from 3.8 to 2.5 Ga include volcanic types reported from Cenozoic convergent margins including: boninites; arc picrites; and the association of adakites-Mg andesites- and Nb-enriched basalts. Archean cratons

  19. Mitochondrial phenylalanyl-tRNA synthetase mutations underlie fatal infantile Alpers encephalopathy

    DEFF Research Database (Denmark)

    Elo, Jenni M; Yadavalli, Srujana S; Euro, Liliya

    2012-01-01

    the mitochondrial phenylalanyl transfer RNA (tRNA) synthetase (mtPheRS) in two patients with fatal epileptic mitochondrial encephalopathy. The mutations affected highly conserved amino acids, p.I329T and p.D391V. Recently, a homozygous FARS2 variant p.Y144C was reported in a Saudi girl with mitochondrial...... encephalopathy, but the pathogenic role of the variant remained open. Clinical features, including postnatal onset, catastrophic epilepsy, lactic acidemia, early lethality and neuroimaging findings of the patients with FARS2 variants, resembled each other closely, and neuropathology was consistent with Alpers...... was impaired. Our results imply that the three FARS2 mutations directly impair aminoacylation function and stability of mtPheRS, leading to a decrease in overall tRNA charging capacity. This study establishes a new genetic cause of infantile mitochondrial Alpers encephalopathy and reports a new mitochondrial...

  20. Deficits in Neurite Density Underlie White Matter Structure Abnormalities in First-Episode Psychosis.

    Science.gov (United States)

    Rae, Charlotte L; Davies, Geoff; Garfinkel, Sarah N; Gabel, Matt C; Dowell, Nicholas G; Cercignani, Mara; Seth, Anil K; Greenwood, Kathryn E; Medford, Nick; Critchley, Hugo D

    2017-11-15

    Structural abnormalities across multiple white matter tracts are recognized in people with early psychosis, consistent with dysconnectivity as a neuropathological account of symptom expression. We applied advanced neuroimaging techniques to characterize microstructural white matter abnormalities for a deeper understanding of the developmental etiology of psychosis. Thirty-five first-episode psychosis patients, and 19 healthy controls, participated in a quantitative neuroimaging study using neurite orientation dispersion and density imaging, a multishell diffusion-weighted magnetic resonance imaging technique that distinguishes white matter fiber arrangement and geometry from changes in neurite density. Fractional anisotropy (FA) and mean diffusivity images were also derived. Tract-based spatial statistics compared white matter structure between patients and control subjects and tested associations with age, symptom severity, and medication. Patients with first-episode psychosis had lower regional FA in multiple commissural, corticospinal, and association tracts. These abnormalities predominantly colocalized with regions of reduced neurite density, rather than aberrant fiber bundle arrangement (orientation dispersion index). There was no direct relationship with active symptoms. FA decreased and orientation dispersion index increased with age in patients, but not control subjects, suggesting accelerated effects of white matter geometry change. Deficits in neurite density appear fundamental to abnormalities in white matter integrity in early psychosis. In the first application of neurite orientation dispersion and density imaging in psychosis, we found that processes compromising axonal fiber number, density, and myelination, rather than processes leading to spatial disruption of fiber organization, are implicated in the etiology of psychosis. This accords with a neurodevelopmental origin of aberrant brain-wide structural connectivity predisposing individuals to

  1. Disruptions in the left frontoparietal network underlie resting state endophenotypic markers in schizophrenia.

    Science.gov (United States)

    Chahine, George; Richter, Anja; Wolter, Sarah; Goya-Maldonado, Roberto; Gruber, Oliver

    2017-04-01

    Advances in functional brain imaging have improved the search for potential endophenotypic markers in schizophrenia. Here, we employed independent component analysis (ICA) and dynamic causal modeling (DCM) in resting state fMRI on a sample of 35 schizophrenia patients, 20 first-degree relatives and 35 control subjects. Analysis on ICA-derived networks revealed increased functional connectivity between the left frontoparietal network (FPN) and left temporal and parietal regions in schizophrenia patients (P schizophrenia patients from all other nodes of the left FPN (P schizophrenia has been previously associated with a range of abnormalities, including formal thought disorder, working memory dysfunction and sensory hallucinations. Our analysis uncovered new potential endophenotypic markers of schizophrenia and shed light on the organization of the left FPN in patients and their first-degree relatives. Hum Brain Mapp 38:1741-1750, 2017. © 2017 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Transmission of single HIV-1 genomes and dynamics of early immune escape revealed by ultra-deep sequencing.

    Directory of Open Access Journals (Sweden)

    Will Fischer

    2010-08-01

    Full Text Available We used ultra-deep sequencing to obtain tens of thousands of HIV-1 sequences from regions targeted by CD8+ T lymphocytes from longitudinal samples from three acutely infected subjects, and modeled viral evolution during the critical first weeks of infection. Previous studies suggested that a single virus established productive infection, but these conclusions were tempered because of limited sampling; now, we have greatly increased our confidence in this observation through modeling the observed earliest sample diversity based on vastly more extensive sampling. Conventional sequencing of HIV-1 from acute/early infection has shown different patterns of escape at different epitopes; we investigated the earliest escapes in exquisite detail. Over 3-6 weeks, ultradeep sequencing revealed that the virus explored an extraordinary array of potential escape routes in the process of evading the earliest CD8 T-lymphocyte responses--using 454 sequencing, we identified over 50 variant forms of each targeted epitope during early immune escape, while only 2-7 variants were detected in the same samples via conventional sequencing. In contrast to the diversity seen within epitopes, non-epitope regions, including the Envelope V3 region, which was sequenced as a control in each subject, displayed very low levels of variation. In early infection, in the regions sequenced, the consensus forms did not have a fitness advantage large enough to trigger reversion to consensus amino acids in the absence of immune pressure. In one subject, a genetic bottleneck was observed, with extensive diversity at the second time point narrowing to two dominant escape forms by the third time point, all within two months of infection. Traces of immune escape were observed in the earliest samples, suggesting that immune pressure is present and effective earlier than previously reported; quantifying the loss rate of the founder virus suggests a direct role for CD8 T-lymphocyte responses

  3. Assessment of esophageal dynamics by radionuclide scintigraphy; a potential method for early diagnosis of aperistalsis in patients with Chagas disease

    Energy Technology Data Exchange (ETDEWEB)

    Marioni Filho, H.; Martins, L.R.F.; Thom, A.F. (Instituto Dante Pazzanese de Cardiologia. Setor de Medicina Nuclear); Boainain, E. (Instituto Dante Pazzanese de Cardiologia. Setor de Miocardiopatias; Goias Univ., Goiania (Brazil). Faculdade de Medicina)

    The esophageal transit time of a sup(99m) Tc labelled test drink (swallow to arrival at the cardia) - TTE - and the time elapsed from swallow to opening of the cardia - TDAC - were assessed by scintigraphy in 40 healthy volunteers (Group I) and in 106 patients with Chagas disease. Sequential images of tracer esophageal transit were obtained by scintigraphy chamber. A time/activity curve in the region of the cardia was obtained by a multichannel analyzer, from which the 2 parameters were calculated. The assessment of TTE and TDAC by scintigraphic technique is proposed as a screening test for early recognition of esophageal motor disorders as well as for follow-up studies after treatment.

  4. Assessment of esophageal dynamics by radionuclide scintigraphy a potential method for early diagnosis of aperistalsis in patients with Chagas disease

    International Nuclear Information System (INIS)

    Marioni Filho, H.; Martins, L.R.F.; Thom, A.F.; Boainain, E.; Goias Univ., Goiania

    1984-01-01

    The esophageal transit time of a sup(99m) Tc labelled test drink (swallow to arrival at the cardia) - TTE - and the time elapsed from swallow to opening of the cardia - TDAC - were assessed by scintigraphy in 40 healthy volunteers (Group I) and in 106 patients with Chagas disease. Sequential images of tracer esophageal transit were obtained by scintigraphy chamber. A time/activity curve in the region of the cardia was obtained by a multichannel analyzer, from which the 2 parameters were calculated. The assessment of TTE and TDAC by scintigraphic technique is proposed as a screening test for early recognition of esophageal motor disorders as well as for follow-up studies after treatment. (M.A.C.) [pt

  5. Development of a site specific dynamical tropical cyclone and other extreme weather early warning system for Kalpakkam

    International Nuclear Information System (INIS)

    Ramakrishna, S.S.V.S.; Bhaskar Rao, D.V.; Venkata Srinivas, C.; Venkatesan, R.; Srivastav, Rupa

    2014-01-01

    The project was to study the tropical cyclones over Bay of Bengal for the south east coast region in the neighbourhood of Kalpakkam, with the main objectives of developing a methodology for providing early warning of developing storms for Kalpakkam site region based on numerical methods. The main objectives of the project are to develop a numerical modeling system for the forecasting of cyclonic storms that form in the Bay of Bengal and cross the east coast of Kalpakkam. the model performance with respect to the intensity (extreme winds), rainfall and the movement of the storm will be assessed for a number of past cyclonic storms in the region and simulations will focus on the identification of proper model configuration in terms of horizontal/vertical resolutions and physics parameterizations for deriving best predictions and to implement the same for operations forecasting for the Kalpakkam site in Tamil Nadu

  6. Research on early warning of food security using a system dynamics model: evidence from Jiangsu province in China.

    Science.gov (United States)

    Xu, Jianling; Ding, Yi

    2015-01-01

    Analyzing the early warning of food security, this paper sets the self-sufficiency rate as the principal indicator in a standpoint of supplement. It is common to use the quantitative methods to forecast and warning the insecurity. However, this paper considers more about the probable outcome when the government intervenes. By constructing the causal feedbacks among grain supplement, demand, productive input, and the policy factors to simulate the future food security in Jiangsu province, conclusions can be drawn as the following: (1) The situation of food security is insecure if the self-sufficiency rate is under 68.3% according to the development of system inertia. (2) it is difficult to guarantee the food security in Jiangsu just depending on the increase of grain sown area. (3) The valid solution to ensure the food security in Jiangsu is to improve the productivity. © 2015 Institute of Food Technologists®

  7. A molecular dynamics simulation study decodes the early stage of the disassembly process abolishing the human SAMHD1 function

    Science.gov (United States)

    Cardamone, Francesca; Iacovelli, Federico; Chillemi, Giovanni; Falconi, Mattia; Desideri, Alessandro

    2017-05-01

    The human sterile alpha motif SAM and HD domain-containing protein 1 (SAMHD1) restricts in non-cycling cells type the infection of a large range of retroviruses including HIV-1, reducing the intracellular pool concentration of deoxynucleoside triphosphates (dNTPs) required for the reverse transcription of the viral genome. The enzyme is in equilibrium between different forms depending on bound cofactors and substrate. In this work, two SAMHD1 three-dimensional models have been investigated through classical molecular dynamics simulation, to define the role of cofactors and metal ions in the association of the tetrameric active form. A detailed analysis of the inter-subunit interactions, taking place at the level of helix 13, indicates that removal of metal ions and cofactors induces an asymmetric loosening of the monomer-monomer interface leading to the formation of a loose tetramer where the two dimeric interfaces are weakened in different way.

  8. The Validation of Macro and Micro Observations of Parent-Child Dynamics Using the Relationship Affect Coding System in Early Childhood.

    Science.gov (United States)

    Dishion, Thomas J; Mun, Chung Jung; Tein, Jenn-Yun; Kim, Hanjoe; Shaw, Daniel S; Gardner, Frances; Wilson, Melvin N; Peterson, Jenene

    2017-04-01

    This study examined the validity of micro social observations and macro ratings of parent-child interaction in early to middle childhood. Seven hundred and thirty-one families representing multiple ethnic groups were recruited and screened as at risk in the context of Women, Infant, and Children (WIC) Nutritional Supplement service settings. Families were randomly assigned to the Family Checkup (FCU) intervention or the control condition at age 2 and videotaped in structured interactions in the home at ages 2, 3, 4, and 5. Parent-child interaction videotapes were micro-coded using the Relationship Affect Coding System (RACS) that captures the duration of two mutual dyadic states: positive engagement and coercion. Macro ratings of parenting skills were collected after coding the videotapes to assess parent use of positive behavior support and limit setting skills (or lack thereof). Confirmatory factor analyses revealed that the measurement model of macro ratings of limit setting and positive behavior support was not supported by the data, and thus, were excluded from further analyses. However, there was moderate stability in the families' micro social dynamics across early childhood and it showed significant improvements as a function of random assignment to the FCU. Moreover, parent-child dynamics were predictive of chronic behavior problems as rated by parents in middle childhood, but not emotional problems. We conclude with a discussion of the validity of the RACS and on methodological advantages of micro social coding over the statistical limitations of macro rating observations. Future directions are discussed for observation research in prevention science.

  9. Two case studies on the interaction of large-scale transport, mesoscale photochemistry, and boundary-layer processes on the lower tropospheric ozone dynamics in early spring

    Directory of Open Access Journals (Sweden)

    S. Brönnimann

    Full Text Available The vertical distribution of ozone in the lower troposphere over the Swiss Plateau is investigated in detail for two episodes in early spring (February 1998 and March 1999. Profile measurements of boundary-layer ozone performed during two field campaigns with a tethered balloon sounding system and a kite are investigated using regular aerological and ozone soundings from a nearby site, measurements from monitoring stations at various altitudes, backward trajectories, and synoptic analyses of meteorological fields. Additionally, the effect of in situ photochemistry was estimated for one of the episodes employing the Metphomod Eulerian photochemical model. Although the meteorological situations were completely different, both cases had elevated layers with high ozone concentrations, which is not untypical for late winter and early spring. In the February episode, the highest ozone concentrations of 55 to 60 ppb, which were found at around 1100 m asl, were partly advected from Southern France, but a considerable contribution of in situ photochemistry is also predicted by the model. Below that elevation, the local chemical sinks and surface deposition probably overcompensated chemical production, and the vertical ozone distribution was governed by boundary-layer dynamics. In the March episode, the results suggest that ozone-rich air parcels, probably of stratospheric or upper tropospheric origin, were advected aloft the boundary layer on the Swiss Plateau.

    Key words. Atmospheric composition and structure (pollution – urban and regional; troposphere – composition and  chemistry – Meteorology and atmospheric dynamics (mesoscale meteorology

  10. Early-stage changes in natural (13)C and (15)N abundance and nutrient dynamics during different litter decomposition.

    Science.gov (United States)

    Gautam, Mukesh Kumar; Lee, Kwang-Sik; Song, Byeong-Yeol; Lee, Dongho; Bong, Yeon-Sik

    2016-05-01

    Decomposition, nutrient, and isotopic (δ(13)C and δ(15)N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ(13)C (0.32-6.70 ‰) and δ(15)N (0.74-3.90 ‰) values of residual litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.

  11. [Influence chronopharmacology therapy methionine (melaxen) on the dynamics of sleep disturbance, cognitive and emotional disorders, brain-derived neurotrophic factor (BDNF) in patients with cerebral stroke in the early and late recovery periods].

    Science.gov (United States)

    Kostenko, E V

    To study the efficacy of melaxen on the dynamics of sleep disturbance, cognitive and emotional disorders, BDNF and the level of secretion of melatonin (6-SOMT) in patients with stroke in the early and late recovery phase. One hundred and ten patients in the rehabilitation period of stroke (mean age of 58.4±6.4 years), including 60 patients in the early recovery phase (group 1) and 50 patients in the late phase (group 2), were studied. Patients received melaxen in dose of 3 mg/day for 3 months along with standard treatment. The efficacy of therapy was assessed by the dynamics of sleep disorders, emotional status, dynamics of serum BDNF levels, 6-SOMT concentration in the urine. The study has demonstrated the high efficacy of melaxen in the rehabilitation of patients in early and late recovery phase of stroke. The drug significantly increased the BDNF level that correlated with improved sleep, emotional status, quality of life of patients.

  12. Distinct Circuits Underlie the Effects of 5-HT1B Receptors on Aggression and Impulsivity.

    Science.gov (United States)

    Nautiyal, Katherine M; Tanaka, Kenji F; Barr, Mary M; Tritschler, Laurent; Le Dantec, Yannick; David, Denis J; Gardier, Alain M; Blanco, Carlos; Hen, René; Ahmari, Susanne E

    2015-05-06

    Impulsive and aggressive behaviors are both modulated by serotonergic signaling, specifically through the serotonin 1B receptor (5-HT1BR). 5-HT1BR knockout mice show increased aggression and impulsivity, and 5-HT1BR polymorphisms are associated with aggression and drug addiction in humans. To dissect the mechanisms by which the 5-HT1BR affects these phenotypes, we developed a mouse model to spatially and temporally regulate 5-HT1BR expression. Our results demonstrate that forebrain 5-HT1B heteroreceptors expressed during an early postnatal period contribute to the development of the neural systems underlying adult aggression. However, distinct heteroreceptors acting during adulthood are involved in mediating impulsivity. Correlating with the impulsivity, dopamine in the nucleus accumbens is elevated in the absence of 5-HT1BRs and normalized following adult rescue of the receptor. Overall, these data show that while adolescent expression of 5-HT1BRs influences aggressive behavior, a distinct set of 5-HT1B receptors modulates impulsive behavior during adulthood. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Novelties of the flowering plant pollen tube underlie diversification of a key life history stage

    Science.gov (United States)

    Williams, Joseph H.

    2008-01-01

    The origin and rapid diversification of flowering plants has puzzled evolutionary biologists, dating back to Charles Darwin. Since that time a number of key life history and morphological traits have been proposed as developmental correlates of the extraordinary diversity and ecological success of angiosperms. Here, I identify several innovations that were fundamental to the evolutionary lability of angiosperm reproduction, and hence to their diversification. In gymnosperms pollen reception must be near the egg largely because sperm swim or are transported by pollen tubes that grow at very slow rates (pollen tube growth rates of taxa in ancient angiosperm lineages (Amborella, Nuphar, and Austrobaileya) range from ≈80 to 600 μm/h. Comparative analyses point to accelerated pollen tube growth rate as a critical innovation that preceded the origin of the true closed carpel, long styles, multiseeded ovaries, and, in monocots and eudicots, much faster pollen tube growth rates. Ancient angiosperm pollen tubes all have callosic walls and callose plugs (in contrast, no gymnosperms have these features). The early association of the callose-walled growth pattern with accelerated pollen tube growth rate underlies a striking repeated pattern of faster and longer-distance pollen tube growth often within solid pathways in phylogenetically derived angiosperms. Pollen tube innovations are a key component of the spectacular diversification of carpel (flower and fruit) form and reproductive cycles in flowering plants. PMID:18678915

  14. Recessive mutations in LEPREL1 underlie a recognizable lens subluxation phenotype.

    Science.gov (United States)

    Khan, Arif O; Aldahmesh, Mohammed A; Alsharif, Hadeel; Alkuraya, Fowzan S

    2015-03-01

    To uncover the homozygous recessive gene mutation underlying familial lens subluxation and/or juvenile lens opacities in four sisters from a consanguineous family. Prospective family study (clinical phenotyping; homozygosity-analysis-guided candidate gene testing). The proband was a 14-year-old girl with long-standing poor vision, bilateral temporal lens subluxation, lens opacities, and axial high myopia. There were no syndromic findings, and fibrillin-1 sequencing was normal. Three sisters, also non-syndromic, had undergone bilateral juvenile lens surgery (two for juvenile cataract, 1 for lens subluxation) within the first two decades of life. Both sisters who had cataract surgery developed bilateral post-operative retinal detachments and one had documented lens instability during cataract surgery. Genetic analysis revealed the phenotype to segregate with a novel homozygous recessive mutation in LEPREL1 (c.292delC; p.Gly100Alafs*104). Recessive mutations in this gene were recently highlighted as a cause for axial myopia and early-onset cataract in two families for whom some affected members also had ectopia lentis and/or post-operative retinal detachments. Recessive LEPREL1 mutations should be recognized as part of the differential diagnosis of lens subluxation. The associated phenotype is non-syndromic and distinguishable from other causes of ectopia lentis in the context of its additional features: juvenile lens opacities, axial myopia, and a predisposition to retinal tears/detachment following intraocular surgery.

  15. Early perfusion changes within 1 week of systemic treatment measured by dynamic contrast-enhanced MRI may predict survival in patients with advanced hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bang-Bin; Yu, Chih-Wei; Liang, Po-Chin [National Taiwan University College of Medicine and Hospital, Department of Medical Imaging and Radiology, Taipei City (China); Hsu, Chao-Yu [National Taiwan University College of Medicine and Hospital, Department of Medical Imaging and Radiology, Taipei City (China); Taipei Hospital, Ministry of Health and Welfare, Department of Radiology, New Taipei City (China); Hsu, Chiun; Hsu, Chih-Hung; Cheng, Ann-Lii [National Taiwan University College of Medicine and Hospital, Department of Oncology, Taipei City (China); Shih, Tiffany Ting-Fang [National Taiwan University College of Medicine and Hospital, Department of Medical Imaging and Radiology, Taipei City (China); Taipei City Hospital, Department of Medical Imaging, Taipei City (China); National Taiwan University Hospital, Department of Medical Imaging, Taipei (China)

    2017-07-15

    To correlate early changes in the parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) within 1 week of systemic therapy with overall survival (OS) in patients with advanced hepatocellular carcinoma (HCC). Eighty-nine patients with advanced HCC underwent DCE-MRI before and within 1 week following systemic therapy. The relative changes of six DCE-MRI parameters (Peak, Slope, AUC, Ktrans, Kep and Ve) of the tumours were correlated with OS using the Kaplan-Meier model and the double-sided log-rank test. All patients died and the median survival was 174 days. Among the six DCE-MRI parameters, reductions in Peak, AUC, and Ktrans, were significantly correlated with one another. In addition, patients with a high Peak reduction following treatment had longer OS (P = 0.023) compared with those with a low Peak reduction. In multivariate analysis, a high Peak reduction was an independent favourable prognostic factor in all patients [hazard ratio (HR), 0.622; P = 0.038] after controlling for age, sex, treatment methods, tumour size and stage, and Eastern Cooperative Oncology Group performance status. Early perfusion changes within 1 week following systemic therapy measured by DCE-MRI may aid in the prediction of the clinical outcome in patients with advanced HCC. (orig.)

  16. Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Saha, Sujoy; Purath, Ahammed Shabeer Thekkum; Jadhav, Manjusha R; Loganathan, M; Banerjee, Kaushik; Rai, A B

    2014-01-01

    This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

  17. Myosin-1 inhibition by PClP affects membrane shape, cortical actin distribution and lipid droplet dynamics in early Zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Prabuddha Gupta

    Full Text Available Myosin-1 (Myo1 represents a mechanical link between the membrane and actin-cytoskeleton in animal cells. We have studied the effect of Myo1 inhibitor PClP in 1-8 cell Zebrafish embryos. Our results indicate a unique involvement of Myo1 in early development of Zebrafish embryos. Inhibition of Myo1 (by PClP and Myo2 (by Blebbistatin lead to arrest in cell division. While Myo1 isoforms appears to be important for both the formation and the maintenance of cleavage furrows, Myo2 is required only for the formation of furrows. We found that the blastodisc of the embryo, which contains a thick actin cortex (~13 μm, is loaded with cortical Myo1. Myo1 appears to be crucial for maintaining the blastodisc morphology and the actin cortex thickness. In addition to cell division and furrow formation, inhibition of Myo1 has a drastic effect on the dynamics and distribution of lipid droplets (LDs in the blastodisc near the cleavage furrow. All these results above are effects of Myo1 inhibition exclusively; Myo2 inhibition by blebbistatin does not show such phenotypes. Therefore, our results demonstrate a potential role for Myo1 in the maintenance and formation of furrow, blastodisc morphology, cell-division and LD organization within the blastodisc during early embryogenesis.

  18. Dynamic metabolic reprogramming of steroidal glycol-alkaloid and phenylpropanoid biosynthesis may impart early blight resistance in wild tomato (Solanum arcanum Peralta).

    Science.gov (United States)

    Shinde, Balkrishna A; Dholakia, Bhushan B; Hussain, Khalid; Panda, Sayantan; Meir, Sagit; Rogachev, Ilana; Aharoni, Asaph; Giri, Ashok P; Kamble, Avinash C

    2017-11-01

    Exploration with high throughput leaf metabolomics along with functional genomics in wild tomato unreveal potential role of steroidal glyco-alkaloids and phenylpropanoids during early blight resistance. Alternaria solani severely affects tomato (Solanum lycopersicum L.) yield causing early blight (EB) disease in tropical environment. Wild relative, Solanum arcanum Peralta could be a potential source of EB resistance; however, its underlying molecular mechanism largely remains unexplored. Hence, non-targeted metabolomics was applied on resistant and susceptible S. arcanum accessions upon A. solani inoculation to unravel metabolic dynamics during different stages of disease progression. Total 2047 potential metabolite peaks (mass signals) were detected of which 681 and 684 metabolites revealed significant modulation and clear differentiation in resistant and susceptible accessions, respectively. Majority of the EB-triggered metabolic changes were active from steroidal glycol-alkaloid (SGA), lignin and flavonoid biosynthetic pathways. Further, biochemical and gene expression analyses of key enzymes from these pathways positively correlated with phenotypic variation in the S. arcanum accessions indicating their potential role in EB. Additionally, transcription factors regulating lignin biosynthesis were also up-regulated in resistant plants and electrophoretic mobility shift assay revealed sequence-specific binding of rSaWRKY1 with MYB20 promoter. Moreover, transcript accumulation of key genes from phenylpropanoid and SGA pathways along with WRKY and MYB in WRKY1 transgenic tomato lines supported above findings. Overall, this study highlights vital roles of SGAs as phytoalexins and phenylpropanoids along with lignin accumulation unrevealing possible mechanistic basis of EB resistance in wild tomato.

  19. Characterization of intracellular dynamics of inoculated PrP-res and newly generated PrPSc during early stage prion infection in Neuro2a cells

    Science.gov (United States)

    Yamasaki, Takeshi; Baron, Gerald S; Suzuki, Akio; Hasebe, Rie; Horiuchi, Motohiro

    2014-01-01

    Summary To clarify the cellular mechanisms for the establishment of prion infection, we analyzed the intracellular dynamics of inoculated and newly generated abnormal isoform of prion protein (PrPSc) in Neuro2a cells. Within 24 h after inoculation, the newly generated PrPSc was evident at the plasma membrane, in early endosomes, and in late endosomes, but this PrPSc was barely evident in lysosomes; in contrast, the majority of the inoculated PrPSc was evident in late endosomes and lysosomes. However, during the subsequent 48 h, the newly generated PrPSc increased remarkably in early endosomes and recycling endosomes. Overexpression of wild-type and mutant Rab proteins showed that membrane trafficking along not only the endocytic-recycling pathway but also the endo-lysosomal pathway is involved in de novo PrPSc generation. These results suggest that the trafficking of exogenously introduced PrPSc from the endo-lysosomal pathway to the endocytic-recycling pathway is important for the establishment of prion infection. PMID:24503096

  20. Connected Gene Communities Underlie Transcriptional Changes in Cornelia de Lange Syndrome.

    Science.gov (United States)

    Boudaoud, Imène; Fournier, Éric; Baguette, Audrey; Vallée, Maxime; Lamaze, Fabien C; Droit, Arnaud; Bilodeau, Steve

    2017-09-01

    Cornelia de Lange syndrome (CdLS) is a complex multisystem developmental disorder caused by mutations in cohesin subunits and regulators. While its precise molecular mechanisms are not well defined, they point toward a global deregulation of the transcriptional gene expression program. Cohesin is associated with the boundaries of chromosome domains and with enhancer and promoter regions connecting the three-dimensional genome organization with transcriptional regulation. Here, we show that connected gene communities, structures emerging from the interactions of noncoding regulatory elements and genes in the three-dimensional chromosomal space, provide a molecular explanation for the pathoetiology of CdLS associated with mutations in the cohesin-loading factor NIPBL and the cohesin subunit SMC1A NIPBL and cohesin are important constituents of connected gene communities that are centrally positioned at noncoding regulatory elements. Accordingly, genes deregulated in CdLS are positioned within reach of NIPBL- and cohesin-occupied regions through promoter-promoter interactions. Our findings suggest a dynamic model where NIPBL loads cohesin to connect genes in communities, offering an explanation for the gene expression deregulation in the CdLS. Copyright © 2017 by the Genetics Society of America.

  1. The dynamics of germination and morphometrics properties of Austrian pine (Pinus nigra Arnold saplings in terms of early indicators of tolerance toward the drought

    Directory of Open Access Journals (Sweden)

    Mataruga Milan

    2011-01-01

    Full Text Available Genetic markers, from morphological to molecular, in function with early indicators of tolerance toward drought, have been an object of research and scientific papers for many years. It starts with the hypothesis that seedlings produced from seeds that were collected from population of extremely different site conditions, on the level of open pollinated families, will have different results concerning drought tolerance. By tracking the dynamics of germination and morphological parameters of saplings, we are researching the interdependence of these parameters with the survival and growth of two-year-old seedlings in conditions where there is a lack of water. Austrian Pine seeds were collected from forty trees, distributed over five provenances on the Balkan Peninsula. Within each provenance a group is assigned to an extremely harsh and dry habitat, while also another group is assigned to prosperous (the most productive habitat. The analysis of the twenty-one-day-old seedlings (saplings is performed in the laboratory, while the tolerance test of the two-year-old seedlings is performed in the field. Seedlings that are exposed to conditions in which there is lack of water, have the coefficient of water formation evaluation 22.59 times bigger than sandy-clay soil with fraction of sand bigger than 60 percent. The results show significant and positive correlation between some parameters of saplings and the dynamics of growth (high increments of the seedlings in drought, but no correlation with the survival of the seedlings.

  2. Dynamics of CD4 and CD8 T-Cell Subsets and Inflammatory Biomarkers during Early and Chronic HIV Infection in Mozambican Adults

    Directory of Open Access Journals (Sweden)

    Lucía Pastor

    2018-01-01

    Full Text Available During primary HIV infection (PHI, there is a striking cascade response of inflammatory cytokines and many cells of the immune system show altered frequencies and signs of extensive activation. These changes have been shown to have a relevant role in predicting disease progression; however, the challenges of identifying PHI have resulted in a lack of critical information about the dynamics of early pathogenic events. We studied soluble inflammatory biomarkers and changes in T-cell subsets in individuals at PHI (n = 40, chronic HIV infection (CHI, n = 56, and HIV-uninfected (n = 58 recruited at the Manhiça District Hospital in Mozambique. Plasma levels of 49 biomarkers were determined by Luminex and ELISA. T-cell immunophenotyping was performed by multicolor flow cytometry. Plasma HIV viremia, CD4, and CD8 T cell counts underwent rapid stabilization after PHI. However, several immunological parameters, including Th1-Th17 CD4 T cells and activation or exhaustion of CD8 T cells continued decreasing until more than 9 months postinfection. Importantly, no sign of immunosenescence was observed over the first year of HIV infection. Levels of IP-10, MCP-1, BAFF, sCD14, tumor necrosis factor receptor-2, and TRAIL were significantly overexpressed at the first month of infection and underwent a prompt decrease in the subsequent months while, MIG and CD27 levels began to increase 1 month after infection and remained overexpressed for almost 1 year postinfection. Early levels of soluble biomarkers were significantly associated with subsequently exhausted CD4 T-cells or with CD8 T-cell activation. Despite rapid immune control of virus replication, the stabilization of the T-cell subsets occurs months after viremia and CD4 count plateau, suggesting persistent immune dysfunction and highlighting the potential benefit of early treatment initiation that could limit immunological damage.

  3. Early quantification of the therapeutic efficacy of the vascular disrupting agent, CKD-516, using dynamic contrast-enhanced ultrasonography in rabbit VX2 liver tumors

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Ijin; Kim, Jung Hoon; Lee, Jeong Min; Choi, Jin Woo; Han, Joon Koo; Choi, Byung Ihn [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-03-15

    To evaluate the usefulness of dynamic contrast-enhanced ultrasonography (DCE-US) in the early quantification of hemodynamic change following administration of the vascular disrupting agent (VDA) CKD-516 using a rabbit VX2 liver tumor model. This study was approved by our institutional animal care and use committee. Eight VX2 liver-tumor-bearing rabbits were treated with intravenous CKD-516, and all underwent DCE-US using SonoVue before and again 2, 4, 6, and 24 hours following their treatment. The tumor perfusion parameters were obtained from the time-intensity curve of the DCE-US data. Repeated measures analysis of variance was performed to assess any significant change in tumor perfusion over time. Relative changes in the DCE-US parameters between the baseline and follow-up assessments were correlated with the relative changes in tumor size over the course of seven days using Pearson correlation. CKD-516 treatment resulted in significant changes in the DCE-US parameters, including the peak intensity, total area under the time-intensity curve (AUCtotal), and AUC during wash-out (AUCout) over time (P<0.05). Pairwise comparison tests revealed that the AUCtotal and AUC during wash-in (AUCin) seen on the two-hour follow-up were significantly lower than the baseline values (P<0.05). However, none of early changes in the DCE-US parameters until 24-hour follow-up showed a significant correlation with the relative changes in tumor size during seven days after CKD-516 treatment. Our results suggest that a novel VDA (CKD-516) can cause disruption of tumor perfusion as early as two hours after treatment and that the therapeutic effect of CKD-516 treatment can be effectively quantified using DCE-US.

  4. Quantification of synovitis in the cranio-cervical region: Dynamic contrast enhanced and diffusion weighted magnetic resonance imaging in early rheumatoid arthritis-A feasibility follow up study

    Energy Technology Data Exchange (ETDEWEB)

    Jeromel, M., E-mail: miran.jeromel@gmail.com [Institute of Radiology, Department for Neuroradiology, University Medical Centre Ljubljana, Zaloska cesta 2, 1000 Ljubljana (Slovenia); Jevtic, V., E-mail: vladimir.jevtic@mf.uni-lj.si [Medical Faculty Ljubljana, Vrazov trg 2, 1104 Ljubljana (Slovenia); Sersa, I., E-mail: igor.sersa@ijs.si [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Ambrozic, A., E-mail: ales.ambrozic@mf.uni-lj.si [Department of Rheumatology, University Medical Centre Ljubljana, Vodnikova 62, 1000 Ljubljana (Slovenia); Tomsic, M., E-mail: matija.tomsic@kclj.si [Department of Rheumatology, University Medical Centre Ljubljana, Vodnikova 62, 1000 Ljubljana (Slovenia)

    2012-11-15

    Objective: To test the feasibility of dynamic contrast enhanced (DCEI) and diffusion weighted (DWI) magnetic resonance imaging (MRI) for quantifying synovitis of the cranio-cervical (C-C) region in patients with early rheumatoid arthritis (RA) and neck pain at the beginning and at a six month follow up. Methods: 27 patients with duration of RA of less than 24 months and neck pain were studied with standard qualitative MRI evaluation and two quantitative MRI methods (DCEI and DWI) at the level of atlantoaxial joints. Rate of early enhancement (REE), enhancement gradient (Genh) and apparent diffusion coefficient (ADC) were extracted from DCEI and DWI data. MRI was coupled with clinical assessment and radiographic imaging. Results: Using standard qualitative MRI evaluation, unequivocal active synovitis (grade 2 or 3 contrast enhancement) was proved in 16 (59%) patients at baseline and 14 (54%) at follow up. DCEI and DWI measurements confirmed active synovitis in 25 (93%) patients at baseline and 24 (92%) at follow up. Average REE, Genh and ADC values decreased during follow up, however the difference was not statistically significant (p > 0.05). Both qualitative and quantitative MRI methods confirmed active inflammatory disease in the C-C region following therapy although all clinical criteria showed signs of improvement of the peripheral disease. Conclusions: The study proved the feasibility of DCEI and DWI MRI for quantifying synovitis of the C-C region in patients with early RA and neck pain. Both techniques can be used as additional method for evaluation of synovitis of the C-C region in RA.

  5. Quantification of synovitis in the cranio-cervical region: Dynamic contrast enhanced and diffusion weighted magnetic resonance imaging in early rheumatoid arthritis—A feasibility follow up study

    International Nuclear Information System (INIS)

    Jeromel, M.; Jevtič, V.; Serša, I.; Ambrožič, A.; Tomšič, M.

    2012-01-01

    Objective: To test the feasibility of dynamic contrast enhanced (DCEI) and diffusion weighted (DWI) magnetic resonance imaging (MRI) for quantifying synovitis of the cranio-cervical (C-C) region in patients with early rheumatoid arthritis (RA) and neck pain at the beginning and at a six month follow up. Methods: 27 patients with duration of RA of less than 24 months and neck pain were studied with standard qualitative MRI evaluation and two quantitative MRI methods (DCEI and DWI) at the level of atlantoaxial joints. Rate of early enhancement (REE), enhancement gradient (Genh) and apparent diffusion coefficient (ADC) were extracted from DCEI and DWI data. MRI was coupled with clinical assessment and radiographic imaging. Results: Using standard qualitative MRI evaluation, unequivocal active synovitis (grade 2 or 3 contrast enhancement) was proved in 16 (59%) patients at baseline and 14 (54%) at follow up. DCEI and DWI measurements confirmed active synovitis in 25 (93%) patients at baseline and 24 (92%) at follow up. Average REE, Genh and ADC values decreased during follow up, however the difference was not statistically significant (p > 0.05). Both qualitative and quantitative MRI methods confirmed active inflammatory disease in the C-C region following therapy although all clinical criteria showed signs of improvement of the peripheral disease. Conclusions: The study proved the feasibility of DCEI and DWI MRI for quantifying synovitis of the C-C region in patients with early RA and neck pain. Both techniques can be used as additional method for evaluation of synovitis of the C-C region in RA.

  6. Quantifying early 17th century changes in Chesapeake Bay estuarine carbon dynamics from James River, VA oyster geochemistry

    Science.gov (United States)

    Grimm, B. L.; Spero, H. J.; Harding, J. M.

    2012-12-01

    The first successful European colonization of North America occurred in 1607 following the arrival of English settlers at Jamestown, Virginia. Within a few decades, land use changes and clear-cutting farming practices dramatically altered the terrestrial landscape and removed the overlying canopy and stabilizing root network of the previously-dominant hardwood forests. The Eastern oyster, Crassostrea virginica, has inhabited the Chesapeake Bay since the end of the last deglaciation. During the start of the Jamestown Colony, an extensive drought (1606-1612) shifted James River salinity zones upriver, expanding the available oyster habitat to the vicinity of Jamestown. This allowed the colonists to collect and eat oysters from areas near the colony down to the river's entry into the bay, and later discard the shells in wells and trash pits that have recently been excavated. The oysters' calcium carbonate shells discovered in these deposits act as multi-year stationary recorders preserving the local environmental chemistry throughout their life until collection. Here we present δ13C, δ18O, and radiocarbon data from historical oyster shell hinge transects that encompass the time period between ~1609 and the early 1700s. Samples include shells from the 1609 Jamestown freshwater well and five additional sites, as well as modern shells collected in 2006. Because shell δ13C and radiocarbon (14C) reflect James River δ13CDIC, it is possible to document carbon source changes during this period of land use change. Our preliminary data suggest a decrease in ambient δ13CDIC of approximately 2‰ between just prior to 1609 conditions and the modern estuary. This is most likely due to an increase in isotopically light organic carbon loading into the river as water moves more rapidly through the terrestrial system. Radiocarbon reservoir ages will also be presented to better constrain carbon flow through the system during this period of disturbance. δ18O measurements from the

  7. Early smoking-induced lung lesions in asymptomatic subjects. Correlations between high resolution dynamic CT and pulmonary function testing

    International Nuclear Information System (INIS)

    Spaggiari, Enrica; Zompadori, Maurizio; Bna', Claudio; Ormitti, Francesca; Svaerzellati, Nicola; Rabaiotti, Enrico; Verduri, Alessia; Chetta, Alfredo

    2005-01-01

    Purpose: To evaluate the prevalence and significance of the pathological effects of cigarette smoking on the lung and the sensitivity of high-resolution CT (HRCT) in the recognition of early smoking-induced lesions in asymptomatic former of current smokers. Materials and methods: We performed a prospective and consecutive analysis of 36 volunteers (16 males, 20 females), 10 non-smokers (3 males, 7 females) and 26 smokers (13 males, 13 females / 17 current smokers; 9 former smokers), all asymptomatic and with normal respiratory flows. These subjects underwent lung function testing and HRCT, after providing written informed consent for the study. The HRCT scans were obtained at three pre-selected levels (aortic arch, tracheal carina and venous hilum). The same scans were obtained in post-expiration phase. At the level of the apical segmental bronchus of the right upper lobe, we measured on the monitor wall thickening, and the total and internal diameters using the techniques reported in literature. Each study was independently evaluated by two radiologists that were blinded to all clinical and functional data: they also evaluated the presence, prevalence and type of emphysema, areas of patchy hyperlucency and oligoemia in the inspiration phase and areas of expiratory air trapping. The extension was evaluated with the visual score method. The data obtained were analysed with the Windows SPSS package for statistical analysis. Results: The two groups (non smokers and smokers) showed significant differences in some functional tests such as FEV1 (p [it

  8. Nonlinear dynamics of early atherosclerotic plaque formation may determine the efficacy of high density lipoproteins (HDL in plaque regression.

    Directory of Open Access Journals (Sweden)

    Alexander D Chalmers

    Full Text Available We use a computational model to explore the effect of foam cell accumulation on plaque regression following an increase in high density lipoprotein (HDL influx into the plaque. Atherosclerotic plaque formation is the outcome of cellular and cytokine responses to low density lipoproteins (LDL that penetrate the artery wall following an injury to the endothelium and become modified. We modelled the cells and cytokines that are most important in plaque formation using partial differential equations. The model includes monocytes and macrophages, foam cells, macrophage chemoattractants, endothelium-stimulating cytokines, modified low density lipoproteins (mod LDL and HDL. We included interactions both at the endothelium surface and inside the artery wall. The model predicts that when HDL influx into a well-established plaque with large numbers of foam cells is increased, the plaque may not regress but may continue to grow at a slower rate. If HDL influx is increased when a model plaque is recently established and has fewer foam cells, then the plaque does regress. If modLDL influx into the plaque is lowered at the same time that HDL influx increased or the capacity of the HDL to remove cholesterol from foam cells is increased, then the plaque is more likely to regress. The predictions of the model are in qualitative agreement with experimental studies in mice and rabbits. The results suggest that the intrinsic dynamics of reverse cholesterol transport by HDL are important in determining the success of HDL raising in promoting plaque regression.

  9. Protein instability, haploinsufficiency, and cortical hyper-excitability underlie STXBP1 encephalopathy.

    Science.gov (United States)

    Kovacevic, Jovana; Maroteaux, Gregoire; Schut, Desiree; Loos, Maarten; Dubey, Mohit; Pitsch, Julika; Remmelink, Esther; Koopmans, Bastijn; Crowley, James; Cornelisse, L Niels; Sullivan, Patrick F; Schoch, Susanne; Toonen, Ruud F; Stiedl, Oliver; Verhage, Matthijs

    2018-03-12

    De novo heterozygous mutations in STXBP1/Munc18-1 cause early infantile epileptic encephalopathies (EIEE4, OMIM #612164) characterized by infantile epilepsy, developmental delay, intellectual disability, and can include autistic features. We characterized the cellular deficits for an allelic series of seven STXBP1 mutations and developed four mouse models that recapitulate the abnormal EEG activity and cognitive aspects of human STXBP1-encephalopathy. Disease-causing STXBP1 variants supported synaptic transmission to a variable extent on a null background, but had no effect when overexpressed on a heterozygous background. All disease variants had severely decreased protein levels. Together, these cellular studies suggest that impaired protein stability and STXBP1 haploinsufficiency explain STXBP1-encephalopathy and that, therefore, Stxbp1+/- mice provide a valid mouse model. Simultaneous video and EEG recordings revealed that Stxbp1+/- mice with different genomic backgrounds recapitulate the seizure/spasm phenotype observed in humans, characterized by myoclonic jerks and spike-wave discharges that were suppressed by the antiepileptic drug levetiracetam. Mice heterozygous for Stxbp1 in GABAergic neurons only, showed impaired viability, 50% died within 2-3 weeks, and the rest showed stronger epileptic activity. c-Fos staining implicated neocortical areas, but not other brain regions, as the seizure foci. Stxbp1+/- mice showed impaired cognitive performance, hyperactivity and anxiety-like behaviour, without altered social behaviour. Taken together, these data demonstrate the construct, face and predictive validity of Stxbp1+/- mice and point to protein instability, haploinsufficiency and imbalanced excitation in neocortex, as the underlying mechanism of STXBP1-encephalopathy. The mouse models reported here are valid models for development of therapeutic interventions targeting STXBP1-encephalopathy.

  10. Asymmetric cultural effects on perceptual expertise underlie an own-race bias for voices.

    Science.gov (United States)

    Perrachione, Tyler K; Chiao, Joan Y; Wong, Patrick C M

    2010-01-01

    The own-race bias in memory for faces has been a rich source of empirical work on the mechanisms of person perception. This effect is thought to arise because the face-perception system differentially encodes the relevant structural dimensions of features and their configuration based on experiences with different groups of faces. However, the effects of sociocultural experiences on person perception abilities in other identity-conveying modalities like audition have not been explored. Investigating an own-race bias in the auditory domain provides a unique opportunity for studying whether person identification is a modality-independent construct and how it is sensitive to asymmetric cultural experiences. Here we show that an own-race bias in talker identification arises from asymmetric experience with different spoken dialects. When listeners categorized voices by race (White or Black), a subset of the Black voices were categorized as sounding White, while the opposite case was unattested. Acoustic analyses indicated listeners' perceptions about race were consistent with differences in specific phonetic and phonological features. In a subsequent person-identification experiment, the Black voices initially categorized as sounding White elicited an own-race bias from White listeners, but not from Black listeners. These effects are inconsistent with person-perception models that strictly analogize faces and voices based on recognition from only structural features. Our results demonstrate that asymmetric exposure to spoken dialect, independent from talkers' physical characteristics, affects auditory perceptual expertise for talker identification. Person perception thus additionally relies on socioculturally-acquired dynamic information, which may be represented by different mechanisms in different sensory modalities.

  11. Statistical Learning and Adaptive Decision-Making Underlie Human Response Time Variability in Inhibitory Control

    Directory of Open Access Journals (Sweden)

    Ning eMa

    2015-08-01

    Full Text Available Response time (RT is an oft-reported behavioral measure in psychological and neurocognitive experiments, but the high level of observed trial-to-trial variability in this measure has often limited its usefulness. Here, we combine computational modeling and psychophysics to examine the hypothesis that fluctuations in this noisy measure reflect dynamic computations in human statistical learning and corresponding cognitive adjustments. We present data from the stop-signal task, in which subjects respond to a go stimulus on each trial, unless instructed not to by a subsequent, infrequently presented stop signal. We model across-trial learning of stop signal frequency, P(stop, and stop-signal onset time, SSD (stop-signal delay, with a Bayesian hidden Markov model, and within-trial decision-making with an optimal stochastic control model. The combined model predicts that RT should increase with both expected P(stop and SSD. The human behavioral data (n=20 bear out this prediction, showing P(stop and SSD both to be significant, independent predictors of RT, with P(stop being a more prominent predictor in 75% of the subjects, and SSD being more prominent in the remaining 25%. The results demonstrate that humans indeed readily internalize environmental statistics and adjust their cognitive/behavioral strategy accordingly, and that subtle patterns in RT variability can serve as a valuable tool for validating models of statistical learning and decision-making. More broadly, the modeling tools presented in this work can be generalized to a large body of behavioral paradigms, in order to extract insights about cognitive and neural processing from apparently quite noisy behavioral measures. We also discuss how this behaviorally validated model can then be used to conduct model-based analysis of neural data, in order to help identify specific brain areas for representing and encoding key computational quantities in learning and decision-making.

  12. Disrupted sensorimotor and social–cognitive networks underlie symptoms in childhood-onset schizophrenia

    Science.gov (United States)

    Gotts, Stephen J.; McAdams, Harrison M.; Greenstein, Dede; Lalonde, Francois; Clasen, Liv; Watsky, Rebecca E.; Shora, Lorie; Ordonez, Anna E.; Raznahan, Armin; Martin, Alex; Gogtay, Nitin; Rapoport, Judith

    2016-01-01

    See Lancaster and Hall (doi:10.1093/awv330) for a scientific commentary on this article. Schizophrenia is increasingly recognized as a neurodevelopmental disorder with altered connectivity among brain networks. In the current study we examined large-scale network interactions in childhood-onset schizophrenia, a severe form of the disease with salient genetic and neurobiological abnormalities. Using a data-driven analysis of resting-state functional magnetic resonance imaging fluctuations, we characterized data from 19 patients with schizophrenia and 26 typically developing controls, group matched for age, sex, handedness, and magnitude of head motion during scanning. This approach identified 26 regions with decreased functional correlations in schizophrenia compared to controls. These regions were found to organize into two function-related networks, the first with regions associated with social and higher-level cognitive processing, and the second with regions involved in somatosensory and motor processing. Analyses of across- and within-network regional interactions revealed pronounced across-network decreases in functional connectivity in the schizophrenia group, as well as a set of across-network relationships with overall negative coupling indicating competitive or opponent network dynamics. Critically, across-network decreases in functional connectivity in schizophrenia predicted the severity of positive symptoms in the disorder, such as hallucinations and delusions. By contrast, decreases in functional connectivity within the social-cognitive network of regions predicted the severity of negative symptoms, such as impoverished speech and flattened affect. These results point toward the role that abnormal integration of sensorimotor and social-cognitive processing may play in the pathophysiology and symptomatology of schizophrenia. PMID:26493637

  13. Early Endothelial Progenitor Cells (eEPCs) in systemic sclerosis (SSc) - dynamics of cellular regeneration and mesenchymal transdifferentiation.

    Science.gov (United States)

    Patschan, S; Tampe, D; Müller, C; Seitz, C; Herink, C; Müller, G A; Zeisberg, E; Zeisberg, M; Henze, E; Patschan, D

    2016-08-12

    Patients with systemic sclerosis (SSc) are endagered by tissue fibrosis and by microvasculopathy, with the latter caused by endothelial cell expansion/proliferation. SSc-associated fibrosis potentially results from mesenchymal transdifferentiation of endothelial cells. Early Endothelial Progenitor Cells (eEPCs) act proangiogenic under diverse conditions. Aim of the study was to analyze eEPC regeneration and mesenchymal transdifferentiation in patients with limited and diffuse SSs (lSSc and dSSc). Patients with both, lSSc and dSSc were included into the study. The following parameters were evaluated: eEPC numbers and regeneration, concentrations of vasomodulatory mediators, mesenchymal properties of blood-derived eEPC. Serum samples of healthy subjects and SS patients were used for stimulation of cultured human eEPC, subsequently followed by analysis of mesenchymal cell characteristics and mobility. Twenty-nine patients were included into the study. Regenerative activity of blood-derived eEPCs did not differ between Controls and patients. Circulating eEPC were significantly lower in all patients with SSc, and in limited and diffuse SSc (lSSc/dSSc). Serum concentrations of promesenchymal TGF-b was elevated in all patients with SSc. Cultured mononuclear cells from SS patients displayed higher abundances of CD31 and of CD31 and aSMA combined. Finally, serum from SSc patients inhibited migration of cultured eEPCs and the cells showed lower sensitivity towards the endothelin antagonist Bosentan. The eEPC system, which represents an essential element of the endogenous vascular repair machinery is affected in SSc. The increased appearance of mesenchymal properties in eEPC may indicate that alterations of the cells potentially contribute to the accumulation of connective tissue and to vascular malfunction.

  14. Maize Domestication and Anti-Herbivore Defences: Leaf-Specific Dynamics during Early Ontogeny of Maize and Its Wild Ancestors

    Science.gov (United States)

    Maag, Daniel; Erb, Matthias; Bernal, Julio S.; Wolfender, Jean-Luc; Turlings, Ted C. J.; Glauser, Gaétan

    2015-01-01

    As a consequence of artificial selection for specific traits, crop plants underwent considerable genotypic and phenotypic changes during the process of domestication. These changes may have led to reduced resistance in the cultivated plant due to shifts in resource allocation from defensive traits to increased growth rates and yield. Modern maize (Zea mays ssp. mays) was domesticated from its ancestor Balsas teosinte (Z. mays ssp. parviglumis) approximately 9000 years ago. Although maize displays a high genetic overlap with its direct ancestor and other annual teosintes, several studies show that maize and its ancestors differ in their resistance phenotypes with teosintes being less susceptible to herbivore damage. However, the underlying mechanisms are poorly understood. Here we addressed the question to what extent maize domestication has affected two crucial chemical and one physical defence traits and whether differences in their expression may explain the differences in herbivore resistance levels. The ontogenetic trajectories of 1,4-benzoxazin-3-ones, maysin and leaf toughness were monitored for different leaf types across several maize cultivars and teosinte accessions during early vegetative growth stages. We found significant quantitative and qualitative differences in 1,4-benzoxazin-3-one accumulation in an initial pairwise comparison, but we did not find consistent differences between wild and cultivated genotypes during a more thorough examination employing several cultivars/accessions. Yet, 1,4-benzoxazin-3-one levels tended to decline more rapidly with plant age in the modern maize cultivars. Foliar maysin levels and leaf toughness increased with plant age in a leaf-specific manner, but were also unaffected by domestication. Based on our findings we suggest that defence traits other than the ones that were investigated are responsible for the observed differences in herbivore resistance between teosinte and maize. Furthermore, our results indicate

  15. Hypolyminetic Oxygen Depletion And Dynamics of P Binding Forms: Insights From Modeling Sediment Early Diagenesis Coupled With Automatic Parameter Estimation

    Science.gov (United States)

    Shafei, Babak; Schmid, Martin; Müller, Beat; Chwalek, Thomas

    2014-05-01

    Sediment diagenesis can significantly impact on lake water quality through depleting hypolimnion oxygen and acting as a sink or source of nutrients and contaminants. In this study, we apply MATsedLAB, a sediment diagenesis module developed in MATLAB [1, 2] to quantify benthic oxygen consumption and biogeochemical cycling of phosphate (P) in lacustrine sediments of Lake Baldegg, located in central Switzerland. MATsedLAB provides an access to the advanced computational and visualization capabilities of the interactive programming environment of MATLAB. It allows for a flexible definition of non steady-state boundary conditions at the sediment-water interface (SWI), the model parameters as well as transport and biogeochemical reactions. The model has been extended to facilitate the model-independent parameter estimation and uncertainty analysis using the software package, PEST. Lake Baldegg represents an interesting case where sediment-water interactions control P loading in an eutrophic lake. It is of 5.2 km2 surface area and has been artificially aerated since 1982. Between 1960 and 1980, low oxygen concentrations and meromictic condition were established as a result of high productivity. Here, we use the cores for the measurements of anions and cations which were collected in April and June 2012 respectively from the deepest location (66 m), by Torres et al. (2013) to calibrate the developed model [3]. Depth profiles of thirty three species were simulated by including thirty mixed kinetic-equilibrium biogeochemical processes as well as imposing the fluxes of organic and inorganic matters along with solute concentrations at the SWI as dynamic boundary conditions. The diffusive transport in the boundary layer (DBL) above the SWI was included as the supply of O2 to the sediment surface can be diffusion-limited, and applying a constant O2 concentration at the sediment surface may overestimate O2 consumption. Benthic oxygen consumption was calculated as a function of

  16. Regional deficiencies in chaperone-mediated autophagy underlie α-synuclein aggregation and neurodegeneration

    Science.gov (United States)

    Malkus, Kristen A.; Ischiropoulos, Harry

    2012-01-01

    In neurodegenerative diseases, it remains unclear why certain brain regions are selectively vulnerable to protein aggregation. In transgenic mice expressing human A53T α-synuclein, the brainstem and spinal cord develop the most prominent α-synuclein inclusions which correlate with age-dependent motor dysfunction. Herein we present the novel finding that this selective aggregation is in part dependent on the inability of chaperone-mediated autophagy (CMA) to effectively degrade α-synuclein in these brain regions. Lysosomal assays revealed that CMA activity was significantly decreased in aggregation-prone regions compared to the remainder of the brain. Previously, CMA activity has been shown to be proportional to levels of the CMA receptor Lamp-2a. Using antibodies, brain tissue from Lamp-2a null mice, enzymatic deglycosylation, and mass spectrometry, we identified Lamp2a as a novel 72 kDa glycoprotein in the mouse brain. Examination of Lamp-2a levels revealed differences in expression across brain regions. The brainstem and the spinal cord had a more than three-fold greater levels of Lamp-2a as compared to regions less vulnerable to aggregation and exhibited a selective upregulation of Lamp-2a during development of α-synuclein inclusions. Despite this dynamic response of Lamp-2a, the levels of substrates bound to the brain lysosomes as well as the rates of substrate uptake and degradation were not proportional to the levels of Lamp-2a. These regional differences in CMA activity and Lamp-2a expression were found in both non-transgenic mice as well as A53T α-syn mice. Therefore, these are inherent variations and not a transgene-specific effect. However, differences in CMA activity may render select brain regions vulnerable to homeostatic dysfunction in the presence of stressors such as overexpression of human A53T α-syn. Collectively, the data provide a potential mechanism to explain the dichotomy of vulnerability or resistance that underlies brain regions

  17. Alternative Earths: The Diverse Chapters of Sustained Habitability on a Dynamic Early Earth and Their Astrobiological Significance

    Science.gov (United States)

    Lyons, T. W.

    2015-12-01

    The oldest signs of animal life appear in the geologic record 600 to 700 million years ago. For the four billion years prior, our planet experienced dramatic changes that paved the way for this milestone. Beyond the establishment of Earth's earliest oceans 4.3 billion years ago (Ga), the single most important environmental transformation in history may have been the first permanent rise of atmospheric oxygen around 2.3 Ga. Before this Great Oxidation Event (GOE), Earth's atmosphere and oceans were virtually devoid of this gas, which forms the basis for all macroscopic life. Yet full oxygenation was a long, drawn out process. This talk will lay out the state-of-the-art in our understanding of Earth's early oxygenation, with an emphasis on the delay between the first biological oxygen production, tentatively placed at 3 Ga, and the appearance of animals almost 2.5 billion years later. Recent work suggests transient oxygenation episodes occurred prior to the GOE. Once permanently present in the atmosphere, oxygen may have risen to very high levels and then nose-dived. Then, at least a billion years of dominantly oxygen-free conditions in the deep ocean followed, beneath an atmosphere and shallow oceans much leaner in oxygen than previous estimates indicated. Deficiencies in oxygen and associated nutrients may have, in turn, set a challenging course for many of the oceans' inhabitants, explaining persistently low populations and diversities of eukaryotes. The latest data suggest these billion-plus years of intermediate oxygen were followed by increases in both ocean and atmosphere oxygen contents and eukaryotic diversity 750 to 800 million years ago. Novel, rock-bound proxies and complementary numerical models are now steering our views of co-evolving life and marine and atmospheric chemistry, including greenhouse gas controls on climate. New findings are revealing various states of planetary habitability that differ greatly from the Earth we know today. These

  18. An experimental investigation of the early dynamic impact behaviour of textile armour systems: Decoupling material from system response

    Science.gov (United States)

    Cepus, Elvis

    This work focuses on the early impact response of textile armour systems. A relatively new data acquisition system, the Enhanced Laser Velocity Sensor (ELVS), was refined and used to generate a large database of results for a 5.57 mm diameter, 3 gram, non-deforming projectile impacting single-ply configurations of Ballistic Nylon, two weaves of Kevlar 129, and Zylon (PBO) over a range of velocities from 61 m/s to 248 m/s. In addition, one Kevlar 129 material was tested in configurations of 2, 3, 4, 8 and 16 plies over a range of strike velocities from 90 m/s to 481 m/s. ELVS results consisted of high-resolution timehistories of displacement, velocity and energy for each system tested. The strain wave velocity and ballistic performance of each system was also determined. Results taken from during the impact event were analysed up to just prior to the strain-wave rebounding from the boundary and returning to the impact point---effectively removing boundary influences. Regardless of system type, a constant rate of energy absorption within the pre-rebound timeframe was found to exist, which scales with the strike velocity to approximately the 8/3-power. Well-established single fibre theory was modified and applied to woven materials. It was assumed that three primary energy absorption mechanisms exist; elastic strain, in-plane kinetic and out-of-plane kinetic. This simple model yields the experimentally observed 8/3 exponent and parametrically predicts the difference between the different single-ply material systems, but underpredicts the observed behaviour by a factor of 2 and cannot address the performance reduction with increasing ply count. This combined experimental and analytical work confirms the long-held assumption that single fibre wave physics is applicable to multi-ply woven systems. More significantly, for the first time, it decouples material response from overall system response and provides the experimental tools and methodology required to analyse

  19. Does insulin resistance, visceral adiposity, or a sex hormone alteration underlie the metabolic syndrome? Studies in women.

    Science.gov (United States)

    Phillips, Gerald B; Jing, Tianyi; Heymsfield, Steven B

    2008-06-01

    Insulin resistance, obesity, and a sex hormone alteration have each been suggested as the underlying link for the constellation of risk factors for myocardial infarction (MI) commonly referred to as the metabolic syndrome or the insulin resistance syndrome. In an attempt to identify in women which of these variables is the most likely link, insulin, adiposity variables, sex hormones, and risk factors for MI were measured and their relationships analyzed statistically in 58 premenopausal and 20 postmenopausal healthy women. On controlling for age, visceral adipose tissue (VAT) correlated more strongly with risk factors for MI, insulin, and free testosterone (FT) than did total adipose tissue or subcutaneous adipose tissue. VAT, therefore, was used as the adiposity variable for further data analysis. Waist circumference was a better surrogate of VAT than was waist-hip ratio, which was a poor surrogate of VAT. VAT correlated positively with insulin, FT, triglyceride, and glucose, and negatively with high-density lipoprotein and sex hormone-binding globulin. On controlling for age, FT and insulin correlated with risk factors for MI and with each other, but on controlling for age and VAT, all of their correlations lost statistical significance except for FT-triglyceride and FT-insulin in the postmenopausal women. In conclusion, VAT accumulation in women, independently of other measures of adiposity, may largely explain the correlations of insulin, obesity, and sex hormones with risk factors for MI and may be the immediate underlying factor that links risk factors for MI to form the metabolic syndrome. Insulin resistance, which has been generally accepted to be the underlying factor, may be a component of the syndrome rather than its underlying link. We hypothesize that in women FT may effect preferential VAT accumulation and induce insulin resistance directly, as well as via VAT accumulation, so that a sex hormone alteration may underlie VAT accumulation and thus

  20. The general dynamic model

    DEFF Research Database (Denmark)

    Borregaard, Michael K.; Matthews, Thomas J.; Whittaker, Robert James

    2016-01-01

    Aim: Island biogeography focuses on understanding the processes that underlie a set of well-described patterns on islands, but it lacks a unified theoretical framework for integrating these processes. The recently proposed general dynamic model (GDM) of oceanic island biogeography offers a step...... towards this goal. Here, we present an analysis of causality within the GDM and investigate its potential for the further development of island biogeographical theory. Further, we extend the GDM to include subduction-based island arcs and continental fragment islands. Location: A conceptual analysis...... dynamics of distinct island types are predicted to lead to markedly different evolutionary dynamics. This sets the stage for a more predictive theory incorporating the processes governing temporal dynamics of species diversity on islands....

  1. Early biomarkers from dynamic contrast-enhanced magnetic resonance imaging to predict the response to antiangiogenic therapy in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Piludu, Francesca; Vidiri, Antonello [Regina Elena National Cancer Institute, Radiology and Diagnostic Imaging Department, Rome (Italy); Marzi, Simona [Regina Elena National Cancer Institute, Medical Physics Laboratory, Rome (Italy); Pace, Andrea; Villani, Veronica [Regina Elena National Cancer Institute, Neurology Division, Rome (Italy); Fabi, Alessandra [Regina Elena National Cancer Institute, Oncology Department, Rome (Italy); Carapella, Carmine Maria [Regina Elena National Cancer Institute, Oncologic Surgery Department, Rome (Italy); Terrenato, Irene [Regina Elena National Cancer Institute, Biostatistics-Scientific Direction, Rome (Italy); Antenucci, Anna [Regina Elena National Cancer Institute, Clinical Pathology, Rome (Italy)

    2015-12-15

    The aim of this study is to investigate whether early changes in tumor volume and perfusion measurements derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) may predict response to antiangiogenic therapy in recurrent high-grade gliomas. Twenty-seven patients who received bevacizumab every 3 weeks were enrolled in the study. For each patient, three MRI scans were performed: at baseline, after the first dose, and after the fourth dose of bevacizumab. The entire tumor volume (V{sub tot}), as well as contrast-enhanced and noncontrast-enhanced tumor subvolumes (V{sub CE-T1} and V{sub NON-CE-T1}, respectively) were outlined using post-contrast T1-weighted images as a guide for the tumor location. Histogram analysis of normalized IAUGC (nIAUGC) and transfer constant K{sup trans} maps were performed. Each patient was classified as a responder patient if he/she had a partial response or a stable disease or as a nonresponder patient if he/she had progressive disease. Responding patients showed a larger reduction in V{sub NON-CE-T1} after a single dose, compared to nonresponding patients. Tumor subvolumes with increased values of nIAUGC and K{sup trans}, after a single dose, significantly differed between responders and nonresponders. The radiological response was found to be significantly associated to the clinical outcome. After a single dose, V{sub tot} was predictive of overall survival (OS), while V{sub CE-T1} showed a tendency of correlation with OS. Tumor subvolumes with increased nIAUGC and K{sup trans} showed the potential for improving the diagnostic accuracy of DCE. Early assessments of the entire tumor volume, including necrotic areas, may provide complementary information of tumor behavior in response to anti-VEGF therapies and is worth further investigation. (orig.)

  2. [Novel method for dynamic monitoring and early-warning on wild resources of traditional Chinese medicines based on price ratio between drug and foodstuff].

    Science.gov (United States)

    Wang, Jiabo; Xiao, Xiaohe; Huang, Luqi; Chen, Shilin; Wang, Wenquan; Zhao, Runhuai; Long, Xingchao; Zhang, Xueru; Xiao, Peigen

    2011-02-01

    To probe into the new idea along with establishment of a novel method for dynamic monitoring and early-warning on the wild resources of traditional Chinese medicines (TCMs). The alterations of wild traditional Chinese medicinal resources were assessed through the price ratio between drug and foodstuff (PRDF) indicating the balance between supply and demand of the specific TCMs, referred to the price ration between pork to foodstuff which is used in national monitoring to the balance between pork supply and demand. Since the price of rice was tightly controlled by government, it was selected as a relatively stable reference to build the PRDF in order to take away the non-marketing influence to TCMs price such as CPI and inflation rate. The modified relative alteration trend of TCMs price had been researched through comparing different formulae to build PRDF, including absolute average month price of TCMs, month average price ratio of TCMs to foodstuff (rice) , month-on-month change of TCMs to rice, year-on-year change of TCMs to rice, and difference in value of period-on-period change (DVPPC). In the research, Cordyceps, Glycyrrhiza and totally five herbs were selected as model drugs and the price data were collected from 2002 to 2008. The results showed that DVPPC calculated of relative long time window was more sensitive and stable to reflect the relative alteration trend of TCMs price. For instance, the DVPPC of Ligustici showed continuously increase trend in recent years. This suggested appearance of unbalance between supply and demand of Ligustici, and forced policy intervention to maintain reasonable and continuable utilization of Ligustici resource. The proposed method and the formula of DVPPC revealed some useful guidance for dynamic monitoring the wild resources of TCMs.

  3. Large Blooms ofBacillales(Firmicutes) Underlie the Response to Wetting of Cyanobacterial Biocrusts at Various Stages of Maturity.

    Science.gov (United States)

    Karaoz, Ulas; Couradeau, Estelle; da Rocha, Ulisses Nunes; Lim, Hsiao-Chien; Northen, Trent; Garcia-Pichel, Ferran; Brodie, Eoin L

    2018-03-06

    Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from "light" to "dark." We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throughput 16S rRNA and rRNA gene sequencing to monitor the dynamics of microbial response. Overall, shorter-term changes in phylogenetic beta diversity attributable to periodic wetting were as large as those attributable to biocrust successional stage. Notably, more mature crusts showed significantly higher resistance to precipitation disturbance. A large bloom of a few taxa within the Firmicutes , primarily in the order Bacillales , emerged 18 h after wetting, while filamentous crust-forming cyanobacteria showed variable responses to wet-up across the successional gradient, with populations collapsing in less-developed light crusts but increasing in later-successional-stage dark crusts. Overall, the consistent Bacillales bloom accompanied by the variable collapse of pioneer cyanobacteria of the Oscillatoriales order across the successional gradient suggests that the strong response of few organisms to a hydration pulse with the mortality of the autotroph might have important implications for carbon (C) balance in semiarid ecosystems. IMPORTANCE Desert biological soil crusts are terrestrial topsoil microbial communities common to arid regions that comprise 40% of Earth's terrestrial surface. They successionally develop over years to decades to deliver a suite of ecosystem services of local

  4. (18)F-alfatide II and (18)F-FDG dual-tracer dynamic PET for parametric, early prediction of tumor response to therapy.

    Science.gov (United States)

    Guo, Jinxia; Guo, Ning; Lang, Lixin; Kiesewetter, Dale O; Xie, Qingguo; Li, Quanzheng; Eden, Henry S; Niu, Gang; Chen, Xiaoyuan

    2014-01-01

    or (18)F-FDG were observed, both (18)F-alfatide II Bp and (18)F-FDG influx from kinetic analysis in tumors showed significant decreases. For therapy of MDA-MB-435 tumors with paclitaxel protein-bound particles, a significant decrease was observed only with (18)F-alfatide II Bp value from kinetic analysis but not (18)F-FDG influx. The parameters fitted with compartmental modeling from the dual-tracer dynamic imaging are consistent with those from single-tracer imaging, substantiating the feasibility of this methodology. Even though no significant differences in tumor size were found until 5 d after doxorubicin treatment started, at day 3 there were already substantial differences in (18)F-alfatide II Bp and (18)F-FDG influx rate. Dual-tracer imaging can measure (18)F-alfatide II Bp value and (18)F-FDG influx simultaneously to evaluate tumor angiogenesis and metabolism. Such changes are known to precede anatomic changes, and thus parametric imaging may offer the promise of early prediction of therapy response.

  5. 18F-Alfatide II and 18F-FDG Dual Tracer Dynamic PET for Parametric, Early Prediction of Tumor Response to Therapy

    Science.gov (United States)

    Guo, Jinxia; Guo, Ning; Lang, Lixin; Kiesewetter, Dale O.; Xie, Qingguo; Li, Quanzheng; Eden, Henry S.; Niu, Gang; Chen, Xiaoyuan

    2014-01-01

    analysis in tumors showed significant decreases. For Abraxane therapy of MDA-MB-435 tumors, significant decrease was only observed with 18F-Alfatide II Bp value from kinetic analysis but not 18F-FDG influx. Conclusion The parameters fitted with compartmental modeling from the dual tracer dynamic imaging are consistent with those from single tracer imaging, substantiating the feasibility of this methodology. Even though no significant differences in tumor size were found until 5 days after doxorubicin treatment started, at day 3 there were already substantial differences in 18F-Alfatide II Bp and 18F-FDG influx rate. Dual tracer imaging can measure 18F-Alfatide II Bp value and 18F-FDG influx simultaneously to evaluate tumor angiogenesis and metabolism. Such changes are known to precede anatomical changes, and thus parametric imaging may offer the promise of early prediction of therapy response. PMID:24232871

  6. Changing dynamics in problematic personality: a multiwave longitudinal study of the relationship between shyness and aggressiveness from childhood to early adulthood.

    Science.gov (United States)

    Hutteman, Roos; Denissen, Jaap J A; Asendorpf, Jens B; van Aken, Marcel A G

    2009-01-01

    The present longitudinal study investigated cascade effects linking the longitudinal trajectories of shyness and aggressiveness between age 4 and 23 and individual differences in this longitudinal relationship. Results demonstrated that there were cascade effects from shyness to adjacent measures of aggressiveness at three moments in time, and that the dynamics of these relationships changed over time. Children who were shy at age 6 became less aggressive at age 7 and the same effect was found between age 8 and age 10. From adolescence to early adulthood, the direction of the relationship changed and shy adolescents at age 17 became increasingly aggressive 5 years later. Interindividual differences were found in the latter cascade effect in that shyness at age 17 only predicted an increase in aggressiveness at age 23 for adolescents receiving low levels of support from their parents and for adolescents spending little time in part-time work. Together, findings suggest the importance of examining the development of normal variations in personality and personality disorders from a developmental perspective and taking into account person-environment interactions.

  7. A real-time, dynamic early-warning model based on uncertainty analysis and risk assessment for sudden water pollution accidents.

    Science.gov (United States)

    Hou, Dibo; Ge, Xiaofan; Huang, Pingjie; Zhang, Guangxin; Loáiciga, Hugo

    2014-01-01

    A real-time, dynamic, early-warning model (EP-risk model) is proposed to cope with sudden water quality pollution accidents affecting downstream areas with raw-water intakes (denoted as EPs). The EP-risk model outputs the risk level of water pollution at the EP by calculating the likelihood of pollution and evaluating the impact of pollution. A generalized form of the EP-risk model for river pollution accidents based on Monte Carlo simulation, the analytic hierarchy process (AHP) method, and the risk matrix method is proposed. The likelihood of water pollution at the EP is calculated by the Monte Carlo method, which is used for uncertainty analysis of pollutants' transport in rivers. The impact of water pollution at the EP is evaluated by expert knowledge and the results of Monte Carlo simulation based on the analytic hierarchy process. The final risk level of water pollution at the EP is determined by the risk matrix method. A case study of the proposed method is illustrated with a phenol spill accident in China.

  8. Early transcriptional and epigenetic regulation of CD8+ T cell differentiation revealed by single-cell RNA-seq

    Science.gov (United States)

    Kakaradov, Boyko; Arsenio, Janilyn; Widjaja, Christella E.; He, Zhaoren; Aigner, Stefan; Metz, Patrick J.; Yu, Bingfei; Wehrens, Ellen J.; Lopez, Justine; Kim, Stephanie H.; Zuniga, Elina I.; Goldrath, Ananda W.; Chang, John T.; Yeo, Gene W.

    2017-01-01

    SUMMARY During microbial infection, responding CD8+ T lymphocytes differentiate into heterogeneous subsets that together provide immediate and durable protection. To elucidate the dynamic transcriptional changes that underlie this process, we applied a single-cell RNA sequencing approach and analyzed individual CD8+ T lymphocytes sequentially throughout the course of a viral infection in vivo. Our analyses revealed a striking transcriptional divergence among cells that had undergone their first division and identified previously unknown molecular determinants controlling CD8+ T lymphocyte fate specification. These findings suggest a model of terminal effector cell differentiation initiated by an early burst of transcriptional activity and subsequently refined by epigenetic silencing of transcripts associated with memory lymphocytes, highlighting the power and necessity of single-cell approaches. PMID:28218746

  9. Natural Variation in SER1 and ENA6 Underlie Condition-Specific Growth Defects in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Amy Sirr

    2018-01-01

    Full Text Available Despite their ubiquitous use in laboratory strains, naturally occurring loss-of-function mutations in genes encoding core metabolic enzymes are relatively rare in wild isolates of Saccharomyces cerevisiae. Here, we identify a naturally occurring serine auxotrophy in a sake brewing strain from Japan. Through a cross with a honey wine (white tecc brewing strain from Ethiopia, we map the minimal medium growth defect to SER1, which encodes 3-phosphoserine aminotransferase and is orthologous to the human disease gene, PSAT1. To investigate the impact of this polymorphism under conditions of abundant external nutrients, we examine growth in rich medium alone or with additional stresses, including the drugs caffeine and rapamycin and relatively high concentrations of copper, salt, and ethanol. Consistent with studies that found widespread effects of different auxotrophies on RNA expression patterns in rich media, we find that the SER1 loss-of-function allele dominates the quantitative trait locus (QTL landscape under many of these conditions, with a notable exacerbation of the effect in the presence of rapamycin and caffeine. We also identify a major-effect QTL associated with growth on salt that maps to the gene encoding the sodium exporter, ENA6. We demonstrate that the salt phenotype is largely driven by variation in the ENA6 promoter, which harbors a deletion that removes binding sites for the Mig1 and Nrg1 transcriptional repressors. Thus, our results identify natural variation associated with both coding and regulatory regions of the genome that underlie strong growth phenotypes.

  10. Does Growth in the Executive System of Working Memory Underlie Growth in Literacy for Bilingual Children with and without Reading Disabilities?

    Science.gov (United States)

    Swanson, H. Lee; Orosco, Michael J.; Kudo, Milagros

    2017-01-01

    This cohort-sequential study explored the components of working memory (WM) that underlie second language (L2) reading growth in 450 children at risk and not at risk for reading disabilities (RD) whose first language is Spanish. English language learners designated as balanced and nonbalanced bilinguals with and without risk for RD in Grades 1, 2,…

  11. Dynamic Contrast Enhanced MRI Can Monitor the Very Early Inflammatory Treatment Response upon Intra-Articular Steroid Injection in the Knee Joint: A Case Report with Review of the Literature

    DEFF Research Database (Denmark)

    Boesen, Mikael; Kubassova, Olga; Cimmino, Marco A

    2011-01-01

    Dynamic contrast-enhanced MRI in inflammatory arthritis, especially in conjunction with computer-aided analysis using appropriate dedicated software, seems to be a highly sensitive tool for monitoring the early inflammatory treatment response in patients with rheumatoid arthritis. This paper gives...... a review of the current knowledge of the emerging technique. The potential of the technique is demonstrated and discussed in the context of a case report following the early effect of an intra-articular steroid injection in a patient with rheumatoid arthritis flare in the knee....

  12. Kv4 channels underlie the subthreshold-operating A-type K+-current in nociceptive dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Thanawath R Na Phuket

    2009-07-01

    Full Text Available The dorsal root ganglion (DRG contains heterogeneous populations of sensory neurons including primary nociceptive neurons and C-fibers implicated in pain signaling.  Recent studies have demonstrated DRG hyperexcitability associated with downregulation of A-type K+ channels; however, the molecular correlate of the corresponding A-type K+ current (IA has remained hypothetical.  Kv4 channels may underlie the IA in DRG neurons.  We combined electrophysiology, molecular biology (whole-tissue and single-cell RT-PCR and immunohistochemistry to investigate the molecular basis of the IA in acutely dissociated DRG neurons from 7-8 day-old rats.  Whole-cell recordings demonstrate a robust tetraethylammonium-resistant (20 mM and 4-aminopyridine-sensitive (5 mM IA.  Matching Kv4 channel properties, activation and inactivation of this IA occur in the subthreshold range of membrane potentials and the rate of recovery from inactivation is rapid and voltage-dependent.  Among Kv4 transcripts, the DRG expresses significant levels of Kv4.1 and Kv4.3 mRNAs.  Also, single small-medium diameter DRG neurons (~30 mm exhibit correlated frequent expression of mRNAs encoding Kv4.1 and Nav1.8, a known nociceptor marker.  In contrast, the expressions of Kv1.4 and Kv4.2 mRNAs at the whole-tissue and single-cell levels are relatively low and infrequent.  Kv4 protein expression in nociceptive DRG neurons was confirmed by immunohistochemistry, which demonstrates colocalization of Kv4.3 and Nav1.8, and negligible expression of Kv4.2.  Furthermore, specific dominant-negative suppression and overexpression strategies confirmed the contribution of Kv4 channels to IA in DRG neurons.  Contrasting the expression patterns of Kv4 channels in the central and peripheral nervous systems, we discuss possible functional roles of these channels in primary sensory neurons.

  13. A Theoretical Analysis of How Segmentation of Dynamic Visualizations Optimizes Students' Learning

    Science.gov (United States)

    Spanjers, Ingrid A. E.; van Gog, Tamara; van Merrienboer, Jeroen J. G.

    2010-01-01

    This article reviews studies investigating segmentation of dynamic visualizations (i.e., showing dynamic visualizations in pieces with pauses in between) and discusses two not mutually exclusive processes that might underlie the effectiveness of segmentation. First, cognitive activities needed for dealing with the transience of dynamic…

  14. Using the Dynamic Indicators of Basic Early Literacy Skills with Students Who Are Deaf or Hard of Hearing: Perspectives of a Panel of Experts

    Science.gov (United States)

    Luckner, John L.

    2013-01-01

    Early literacy skills serve as the foundation for the development of subsequent reading skills and strategies. Increasingly, educators are administering early literacy assessments to identify young students who are at risk for reading failure and providing them with additional evidence based interventions. The most widely used assessments for…

  15. Brain mechanisms in early language acquisition.

    Science.gov (United States)

    Kuhl, Patricia K

    2010-09-09

    The last decade has produced an explosion in neuroscience research examining young children's early processing of language. Noninvasive, safe functional brain measurements have now been proven feasible for use with children starting at birth. The phonetic level of language is especially accessible to experimental studies that document the innate state and the effect of learning on the brain. The neural signatures of learning at the phonetic level can be documented at a remarkably early point in development. Continuity in linguistic development from infants' earliest brain responses to phonetic stimuli is reflected in their language and prereading abilities in the second, third, and fifth year of life, a finding with theoretical and clinical impact. There is evidence that early mastery of the phonetic units of language requires learning in a social context. Neuroscience on early language learning is beginning to reveal the multiple brain systems that underlie the human language faculty. 2010 Elsevier Inc. All rights reserved.

  16. Proinsulin-producing, hyperglycemia-induced adipose tissue macrophages underlie insulin resistance in high fat-fed diabetic mice

    Science.gov (United States)

    Adipose tissue macrophages play an important role in the pathogenesis of obese type 2 diabetes. High-fat diet-induced obesity has been shown to lead to adipose tissue macrophages accumulation in rodents;however, the impact of hyperglycemia on adipose tissue macrophages dynamics in high-fat diet-fed ...

  17. Qualitative and quantitative analyses of the morphological-dynamics of early cardiac pump action using video densidometry and optical coherence tomography (OCT)

    DEFF Research Database (Denmark)

    Männer, Jörg; Thrane, Lars; Thommes, Jan

    2010-01-01

    During the initial phase of its pump action, vertebrate embryonic hearts are seen as valveless tubular pumps. It was traditionally thought that these tubular hearts generate unidirectional blood flow via peristalsis. Recently, however, the pumping mechanism of early embryonic hearts has become a ...... embryonic chick hearts in frontal views, which provide a much better understanding of early cardiac pump action than the traditional right or left lateral views....

  18. HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals

    Czech Academy of Sciences Publication Activity Database

    Veceřa, J.; Bártová, Eva; Krejčí, Jana; Legartová, Soňa; Komůrková, Denisa; Rudá-Kučerová, J.; Štark, T.; Dražanová, Eva; Kašpárek, T.; Šulcová, A.; Dekker, F.J.; Szymanski, W.; Seiser, C.; Weitzer, G.; Mechoulam, R.; Micale, V.; Kozubek, Stanislav

    2018-01-01

    Roč. 233, č. 1 (2018), s. 530-548 ISSN 0021-9541 R&D Projects: GA ČR GBP302/12/G157 Institutional support: RVO:68081707 ; RVO:68081731 Keywords : cell-adhesion molecule * histone deacetylase inhibitors * neuronal differentiation Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 4.080, year: 2016

  19. HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals

    Czech Academy of Sciences Publication Activity Database

    Večeřa, J.; Bártová, Eva; Krejčí, Jana; Legartová, Soňa; Komůrková, Denisa; Rudá-Kučerová, J.; Štark, T.; Dražanová, Eva; Kašpárek, T.; Šulcová, A.; Dekker, F.J.; Szymanski, W.; Seiser, C.; Weitzer, G.; Mechoulam, R.; Micale, V.; Kozubek, Stanislav

    2018-01-01

    Roč. 233, č. 1 (2018), s. 530-548 ISSN 0021-9541 R&D Projects: GA ČR(CZ) GBP302-12-G157; GA MŠk 7F14369 Institutional support: RVO:68081707 Keywords : cell-adhesion molecule * histone deacetylase inhibitors * neuronal differentiation OBOR OECD: Cell biology Impact factor: 4.080, year: 2016

  20. HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals

    NARCIS (Netherlands)

    Večeřa, Josef; Bártová, Eva; Krejčí, Jana; Legartová, Soňa; Komůrková, Denisa; Rudá-Kučerová, Jana; Štark, Tibor; Dražanová, Eva; Kašpárek, Tomáš; Šulcová, Alexandra; Dekker, Frank J; Szymanski, Wiktor; Seiser, Christian; Weitzer, Georg; Mechoulam, Raphael; Micale, Vincenzo; Kozubek, Stanislav

    Although histone acetylation is one of the most widely studied epigenetic modifications, there is still a lack of information regarding how the acetylome is regulated during brain development and pathophysiological processes. We demonstrate that the embryonic brain (E15) is characterized by an

  1. Assessing Component Language Deficits in the Early Detection of Reading Difficulty Risk

    Science.gov (United States)

    van der Lely, Heather K. J.; Marshall, Chloe R.

    2010-01-01

    This article focuses on some of the linguistic components that underlie letter-sound decoding skills and reading comprehension: specifically phonology, morphology, and syntax. Many children who have reading difficulties had language deficits that were detectable before they began reading. Early identification of language difficulties will…

  2. Adaptation and inhibition underlie responses to time-varying interaural phase cues in a model of inferior colliculus neurons.

    Science.gov (United States)

    Borisyuk, Alla; Semple, Malcolm N; Rinzel, John

    2002-10-01

    A mathematical model was developed for exploring the sensitivity of low-frequency inferior colliculus (IC) neurons to interaural phase disparity (IPD). The formulation involves a firing-rate-type model that does not include spikes per se. The model IC neuron receives IPD-tuned excitatory and inhibitory inputs (viewed as the output of a collection of cells in the medial superior olive). The model cell possesses cellular properties of firing rate adaptation and postinhibitory rebound (PIR). The descriptions of these mechanisms are biophysically reasonable, but only semi-quantitative. We seek to explain within a minimal model the experimentally observed mismatch between responses to IPD stimuli delivered dynamically and those delivered statically (McAlpine et al. 2000; Spitzer and Semple 1993). The model reproduces many features of the responses to static IPD presentations, binaural beat, and partial range sweep stimuli. These features include differences in responses to a stimulus presented in static or dynamic context: sharper tuning and phase shifts in response to binaural beats, and hysteresis and "rise-from-nowhere" in response to partial range sweeps. Our results suggest that dynamic response features are due to the structure of inputs and the presence of firing rate adaptation and PIR mechanism in IC cells, but do not depend on a specific biophysical mechanism. We demonstrate how the model's various components contribute to shaping the observed phenomena. For example, adaptation, PIR, and transmission delay shape phase advances and delays in responses to binaural beats, adaptation and PIR shape hysteresis in different ranges of IPD, and tuned inhibition underlies asymmetry in dynamic tuning properties. We also suggest experiments to test our modeling predictions: in vitro simulation of the binaural beat (phase advance at low beat frequencies, its dependence on firing rate), in vivo partial range sweep experiments (dependence of the hysteresis curve on

  3. Emergence in Dynamical Systems

    Directory of Open Access Journals (Sweden)

    John Collier

    2013-12-01

    Full Text Available Emergence is a term used in many contexts in current science; it has become fashionable. It has a traditional usage in philosophy that started in 1875 and was expanded by J. S. Mill (earlier, under a different term and C. D. Broad. It is this form of emergence that I am concerned with here. I distinguish it from uses like ‘computational emergence,’ which can be reduced to combinations of program steps, or its application to merely surprising new features that appear in complex combinations of parts. I will be concerned specifically with ontological emergence that has the logical properties required by Mill and Broad (though there might be some quibbling about the details of their views. I restrict myself to dynamical systems that are embodied in processes. Everything that we can interact with through sensation or action is either dynamical or can be understood in dynamical terms, so this covers all comprehensible forms of emergence in the strong (nonreducible sense I use. I will give general dynamical conditions that underlie the logical conditions traditionally assigned to emergence in nature.The advantage of this is that, though we cannot test logical conditions directly, we can test dynamical conditions. This gives us an empirical and realistic form of emergence, contrary those who say it is a matter of perspective.

  4. Islands of spatially discordant APD alternans underlie arrhythmogenesis by promoting electrotonic dyssynchrony in models of fibrotic rat ventricular myocardium

    Science.gov (United States)

    Majumder, Rupamanjari; Engels, Marc C.; de Vries, Antoine A. F.; Panfilov, Alexander V.; Pijnappels, Daniël A.

    2016-04-01

    Fibrosis and altered gap junctional coupling are key features of ventricular remodelling and are associated with abnormal electrical impulse generation and propagation. Such abnormalities predispose to reentrant electrical activity in the heart. In the absence of tissue heterogeneity, high-frequency impulse generation can also induce dynamic electrical instabilities leading to reentrant arrhythmias. However, because of the complexity and stochastic nature of such arrhythmias, the combined effects of tissue heterogeneity and dynamical instabilities in these arrhythmias have not been explored in detail. Here, arrhythmogenesis was studied using in vitro and in silico monolayer models of neonatal rat ventricular tissue with 30% randomly distributed cardiac myofibroblasts and systematically lowered intercellular coupling achieved in vitro through graded knockdown of connexin43 expression. Arrhythmia incidence and complexity increased with decreasing intercellular coupling efficiency. This coincided with the onset of a specialized type of spatially discordant action potential duration alternans characterized by island-like areas of opposite alternans phase, which positively correlated with the degree of connexinx43 knockdown and arrhythmia complexity. At higher myofibroblast densities, more of these islands were formed and reentrant arrhythmias were more easily induced. This is the first study exploring the combinatorial effects of myocardial fibrosis and dynamic electrical instabilities on reentrant arrhythmia initiation and complexity.

  5. Phase Transitions: In the Brain, Socio-­Dramatic Play and Meaningful Early Learning

    Science.gov (United States)

    Fromberg, Doris Pronin

    2017-01-01

    There are similar, non-linear complex dynamical systems that underlie the epigenetic development of young children. This paper discusses the confluence of research on brain functions; a body or research that informs the characteristics of young children's play and imagination; and the ways in which young children acquire fresh perceptions and…

  6. A Framework for Evaluating R&D Impacts and Supply Chain Dynamics Early in a Product Life Cycle. Looking inside the black box of innovation

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Gretchen [360 Innovation LLC (United States); Mote, Jonathan [George Washington Univ., Washington, DC (United States); Ruegg, Rosalie [TIA Consulting Inc. (United States); Choi, Thomas [Arizona State Univ., Tempe, AZ (United States); Becker-Dippmann, Angela [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    This report provides a framework for evaluation of R&D investments aimed at speeding up the pace of innovation and strengthening domestic manufacturing and supply chains, which make up a portion of the investments of the U.S. Department of Energy's (DOEs) Office of Energy Efficiency and Renewable Energy (EERE). These investments focus on early phases of the product life cycle, characterized as extending from pre-product, late stage R&D, to initial product introduction and through to early market growth. The investments aim to provide support for additional technology, supply-chain, manufacturing, and early market development to enhance or create markets for clean energy technologies and strengthen the U.S. industry base.

  7. Linking Cellular Mechanisms to Behavior: Entorhinal Persistent Spiking and Membrane Potential Oscillations May Underlie Path Integration, Grid Cell Firing, and Episodic Memory

    Directory of Open Access Journals (Sweden)

    Michael E. Hasselmo

    2008-01-01

    Full Text Available The entorhinal cortex plays an important role in spatial memory and episodic memory functions. These functions may result from cellular mechanisms for integration of the afferent input to entorhinal cortex. This article reviews physiological data on persistent spiking and membrane potential oscillations in entorhinal cortex then presents models showing how both these cellular mechanisms could contribute to properties observed during unit recording, including grid cell firing, and how they could underlie behavioural functions including path integration. The interaction of oscillations and persistent firing could contribute to encoding and retrieval of trajectories through space and time as a mechanism relevant to episodic memory.

  8. The Relationship between Attending a Pennsylvania Pre-K Counts Prekindergarten Program and Future Dynamic Indicators of Basic Early Literacy Skills (DIBELS) in Kindergarten

    Science.gov (United States)

    Zegarski, Cassandra Marie

    2017-01-01

    The benefits of involvement in early childhood education have been researched from many different perspectives to show how children achieve social, emotional, and academic gains when they participate in a pre-kindergarten program. The purpose of this non-experimental quantitative study was to assess how attending a pre-kindergarten program in a…

  9. The endocrine and follicular growth dynamics throughout the menstrual cycle in women with consistently or variably elevated early follicular phase FSH compared with controls

    NARCIS (Netherlands)

    C.H. de Koning; J. McDonnell (Joseph); A.P.N. Themmen (Axel); F.H. de Jong (Frank); R. Homburg; C.B. Lambalk (Cornelius)

    2008-01-01

    textabstractBACKGROUND: Elevated early follicular phase (EFP) FSH is frequently observed in subfertile patients. In these women, temporary normalization of FSH concentrations is known to occur. We studied the complete endocrine cycle profile of subfertile young women with elevated basal FSH compared

  10. Social inequality in dynamic balance performance in an early old age Spanish population: The role of health and life style associated factors

    DEFF Research Database (Denmark)

    Rodriguez Lopez, Santiago; Nilsson, Charlotte Juul; Lund, Rikke

    2012-01-01

    of poor balance, also after adjustment for age, gender, obesity and physical activity. In addition, obesity and sedentary physical activity were related to poor dynamic balance. The findings suggest an independent effect of both SES and behavioral factors on poor balance performance in the older Spanish...

  11. Language use in real-time interactions during early elementary science lessons : The bidirectional dynamics of the language complexity of teachers and students

    NARCIS (Netherlands)

    Menninga, Astrid; van Dijk, Marijn; Steenbeek, Henderien; van Geert, Paul

    2017-01-01

    This study explored bidirectional sequential relations between the real-time language use of teachers and pupils in naturalistic science lessons from a dynamic approach. It also compared experienced teachers (N = 22) with relative starters (student teachers, N = 8) when it comes to such relations.

  12. Polo-Like Kinase 2 is Dynamically Regulated to Coordinate Proliferation and Early Lineage Specification Downstream of Yes-Associated Protein 1 in Cardiac Progenitor Cells.

    Science.gov (United States)

    Mochizuki, Michika; Lorenz, Vera; Ivanek, Robert; Della Verde, Giacomo; Gaudiello, Emanuele; Marsano, Anna; Pfister, Otmar; Kuster, Gabriela M

    2017-10-24

    Recent studies suggest that adult cardiac progenitor cells (CPCs) can produce new cardiac cells. Such cell formation requires an intricate coordination of progenitor cell proliferation and commitment, but the molecular cues responsible for this regulation in CPCs are ill defined. Extracellular matrix components are important instructors of cell fate. Using laminin and fibronectin, we induced two slightly distinct CPC phenotypes differing in proliferation rate and commitment status and analyzed the early transcriptomic response to CPC adhesion (<2 hours). Ninety-four genes were differentially regulated on laminin versus fibronectin, consisting of mostly downregulated genes that were enriched for Yes-associated protein (YAP) conserved signature and TEA domain family member 1 (TEAD1)-related genes. This early gene regulation was preceded by the rapid cytosolic sequestration and degradation of YAP on laminin. Among the most strongly regulated genes was polo-like kinase 2 ( Plk2 ). Plk2 expression depended on YAP stability and was enhanced in CPCs transfected with a nuclear-targeted mutant YAP. Phenotypically, the early downregulation of Plk2 on laminin was succeeded by lower cell proliferation, enhanced lineage gene expression (24 hours), and facilitated differentiation (3 weeks) compared with fibronectin. Finally, overexpression of Plk2 enhanced CPC proliferation and knockdown of Plk2 induced the expression of lineage genes. Plk2 acts as coordinator of cell proliferation and early lineage commitment in CPCs. The rapid downregulation of Plk2 on YAP inactivation marks a switch towards enhanced commitment and facilitated differentiation. These findings link early gene regulation to cell fate and provide novel insights into how CPC proliferation and differentiation are orchestrated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  13. A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

    Science.gov (United States)

    Jerath, Ravinder; Crawford, Molly W.; Barnes, Vernon A.

    2015-01-01

    The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system. PMID:26379573

  14. A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

    Directory of Open Access Journals (Sweden)

    Ravinder eJerath

    2015-08-01

    Full Text Available The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information is filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

  15. A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience.

    Science.gov (United States)

    Jerath, Ravinder; Crawford, Molly W; Barnes, Vernon A

    2015-01-01

    The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

  16. Serotonin-dependent kinetics of feeding bursts underlie a graded response to food availability in C. elegans.

    Science.gov (United States)

    Lee, Kyung Suk; Iwanir, Shachar; Kopito, Ronen B; Scholz, Monika; Calarco, John A; Biron, David; Levine, Erel

    2017-02-01

    Animals integrate physiological and environmental signals to modulate their food uptake. The nematode C. elegans, whose food uptake consists of pumping bacteria from the environment into the gut, provides excellent opportunities for discovering principles of conserved regulatory mechanisms. Here we show that worms implement a graded feeding response to the concentration of environmental bacteria by modulating a commitment to bursts of fast pumping. Using long-term, high-resolution, longitudinal recordings of feeding dynamics under defined conditions, we find that the frequency and duration of pumping bursts increase and the duration of long pauses diminishes in environments richer in bacteria. The bioamine serotonin is required for food-dependent induction of bursts as well as for maintaining their high rate of pumping through two distinct mechanisms. We identify the differential roles of distinct families of serotonin receptors in this process and propose that regulation of bursts is a conserved mechanism of behaviour and motor control.

  17. Non-equilibrium reactivation of Na+ current drives early afterdepolarizations in mouse ventricle

    Science.gov (United States)

    Edwards, Andrew G.; Grandi, Eleonora; Hake, Johan E.; Patel, Sonia; Li, Pan; Miyamoto, Shigeki; Omens, Jeffrey H.; Brown, Joan Heller; Bers, Donald M.; McCulloch, Andrew D.

    2015-01-01

    Background Early-afterdepolarizations (EADs) are triggers of cardiac arrhythmia driven by L-type Ca2+ current (ICaL) reactivation or sarcoplasmic reticulum (SR) Ca2+ release and Na+/Ca2+ exchange. In large mammals the positive action potential (AP) plateau promotes ICaL reactivation, and the current paradigm holds that cardiac EAD dynamics are dominated by interaction between ICaL and the repolarizing K+ currents. However, EADs are also frequent in the rapidly repolarizing mouse AP, which should not readily permit ICaL reactivation. This suggests that murine EADs exhibit unique dynamics, which are key for interpreting arrhythmia mechanisms in this ubiquitous model organism. We investigated these dynamics in myocytes from arrhythmia-susceptible CaMKIIδC-overexpressing mice (Tg), and via computational simulations. Methods and Results In Tg myocytes, β-adrenergic challenge slowed late repolarization, potentiated SR Ca2+ release, and initiated EADs below the ICaL activation range (−47±0.7 mV). These EADs were abolished by caffeine and tetrodotoxin (but not Ranolazine), suggesting that SR Ca2+ release and Na+ current (INa), but not late INa, are required for EAD initiation. Simulations suggest that potentiated SR Ca2+ release and Na+/Ca2+ exchange triangulate late AP repolarization, which permits non-equilibrium reactivation of INa, and thereby drives the EAD upstroke. AP clamp experiments suggest that lidocaine eliminates virtually all inward current elicited by EADs, and that this effect occurs at concentrations (40-60 μM) for which lidocaine remains specific for inactivated Na+ channels. This strongly suggests that previously inactive channels are recruited during the EAD upstroke, and that non-equilibrium INa dynamics underlie murine EADs. Conclusions Non-equilibrium reactivation of INa drives murine EADs. PMID:25236710

  18. Dynamic Path Analysis in Life-Course Epidemiology

    DEFF Research Database (Denmark)

    Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.

    2011-01-01

    it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie...

  19. Teaching polymorphism early

    DEFF Research Database (Denmark)

    2005-01-01

    Is it possible to teach dynamic polymorphism early? What techniques could facilitate teaching it in Java. This panel will bring together people who have considered this question and attempted to implement it in various ways, some more completely than others. It will also give participants...

  20. Four USH2A founder mutations underlie the majority of Usher syndrome type 2 cases among non-Ashkenazi Jews.

    Science.gov (United States)

    Auslender, Noa; Bandah, Dikla; Rizel, Leah; Behar, Doron M; Shohat, Mordechai; Banin, Eyal; Allon-Shalev, Stavit; Sharony, Reuven; Sharon, Dror; Ben-Yosef, Tamar

    2008-06-01

    Type 2 Usher syndrome (USH2) is a recessively inherited disorder, characterized by the combination of early onset, moderate-to-severe, sensorineural hearing loss, and vision impairment due to retinitis pigmentosa. From 74% to 90% of USH2 cases are caused by mutations of the USH2A gene. USH2A is composed of 72 exons, encoding for usherin, an extracellular matrix protein, which plays an important role in the development and maintenance of neurosensory cells in both retina and cochlea. To date, over 70 pathogenic mutations of USH2A have been reported in individuals of various ethnicities. Many of these mutations are rare private mutations segregating in single families. The aim of the current work was to investigate the genetic basis for USH2 among Jews of various origins. We found that four USH2A mutations (c.239-240insGTAC, c.1000C>T, c.2209C>T, and c.12067-2A>G) account for 64% of mutant alleles underlying USH2 in Jewish families of non-Ashkenazi descent. Considering the very large size of the USH2A gene and the high number of mutations detected in USH2 patients worldwide, our findings have significant implications for genetic counseling and carrier screening in various Jewish populations.

  1. Gravity-dependent estimates of object mass underlie the generation of motor commands for horizontal limb movements.

    Science.gov (United States)

    Crevecoeur, F; McIntyre, J; Thonnard, J-L; Lefèvre, P

    2014-07-15

    Moving requires handling gravitational and inertial constraints pulling on our body and on the objects that we manipulate. Although previous work emphasized that the brain uses internal models of each type of mechanical load, little is known about their interaction during motor planning and execution. In this report, we examine visually guided reaching movements in the horizontal plane performed by naive participants exposed to changes in gravity during parabolic flight. This approach allowed us to isolate the effect of gravity because the environmental dynamics along the horizontal axis remained unchanged. We show that gravity has a direct effect on movement kinematics, with faster movements observed after transitions from normal gravity to hypergravity (1.8g), followed by significant movement slowing after the transition from hypergravity to zero gravity. We recorded finger forces applied on an object held in precision grip and found that the coupling between grip force and inertial loads displayed a similar effect, with an increase in grip force modulation gain under hypergravity followed by a reduction of modulation gain after entering the zero-gravity environment. We present a computational model to illustrate that these effects are compatible with the hypothesis that participants partially attribute changes in weight to changes in mass and scale incorrectly their motor commands with changes in gravity. These results highlight a rather direct internal mapping between the force generated during stationary holding against gravity and the estimation of inertial loads that limb and hand motor commands must overcome. Copyright © 2014 the American Physiological Society.

  2. Dynamics of interstellar matter

    International Nuclear Information System (INIS)

    Kahn, F.D.

    1975-01-01

    A review of the dynamics of interstellar matter is presented, considering the basic equations of fluid flow, plane waves, shock waves, spiral structure, thermal instabilities and early star cocoons. (B.R.H.)

  3. Towards global understanding of plant defence against aphids--timing and dynamics of early Arabidopsis defence responses to cabbage aphid (Brevicoryne brassicae) attack.

    Science.gov (United States)

    Kuśnierczyk, Anna; Winge, Per; Jørstad, Tommy S; Troczyńska, Joanna; Rossiter, John T; Bones, Atle M

    2008-08-01

    Insect feeding on plants causes a complex series of coordinated defence responses. Little is known, however, about the time-dependent aspect of induced changes. Here we present a time series-based investigation of Arabidopsis thaliana Ler subjected to attack by a specialist pest of Brassicaceae species, Brevicoryne brassicae. Transcriptome and metabolome changes were studied at 6, 12, 24 and 48 h after infestation to monitor the progress of early induced responses. The use of full-genome oligonucleotide microarrays revealed the initiation of extensive gene expression changes already during the first 6 h of infestation. Data indicated the involvement of reactive oxygen species (ROS) and calcium in early signalling, and salicylic acid (SA) and jasmonic acid (JA) in the regulation of defence responses. Transcripts related to senescence, biosynthesis of anti-insect proteins, indolyl glucosinolates (GS) and camalexin, as well as several uncharacterized to date WRKY transcription factors, were induced. Follow-up studies of defence-involved secondary metabolites revealed depositions of callose at the insects' feeding sites, a decrease in the total level of aliphatic GS, particularly 3-hydroxypropyl glucosinolate, and accumulation of 4-methoxyindol-3-ylmethyl glucosinolate 48 h after the attack. The novel role of camalexin, induced as a part of defence against aphids, was verified in fitness experiments. Fecundity of B. brassicae was reduced on camalexin-accumulating wild-type (WT) plants as compared with camalexin-deficient pad3-1 mutants. Based on experimental data, a model of plant-aphid interactions at the early phase of infestation was proposed.

  4. Increased Laforin and Laforin Binding to Glycogen Underlie Lafora Body Formation in Malin-deficient Lafora Disease*

    Science.gov (United States)

    Tiberia, Erica; Turnbull, Julie; Wang, Tony; Ruggieri, Alessandra; Zhao, Xiao-Chu; Pencea, Nela; Israelian, Johan; Wang, Yin; Ackerley, Cameron A.; Wang, Peixiang; Liu, Yan; Minassian, Berge A.

    2012-01-01

    The solubility of glycogen, essential to its metabolism, is a property of its shape, a sphere generated through extensive branching during synthesis. Lafora disease (LD) is a severe teenage-onset neurodegenerative epilepsy and results from multiorgan accumulations, termed Lafora bodies (LB), of abnormally structured aggregation-prone and digestion-resistant glycogen. LD is caused by loss-of-function mutations in the EPM2A or EPM2B gene, encoding the interacting laforin phosphatase and malin E3 ubiquitin ligase enzymes, respectively. The substrate and function of malin are unknown; an early counterintuitive observation in cell culture experiments that it targets laforin to proteasomal degradation was not pursued until now. The substrate and function of laforin have recently been elucidated. Laforin dephosphorylates glycogen during synthesis, without which phosphate ions interfere with and distort glycogen construction, leading to LB. We hypothesized that laforin in excess or not removed following its action on glycogen also interferes with glycogen formation. We show in malin-deficient mice that the absence of malin results in massively increased laforin preceding the appearance of LB and that laforin gradually accumulates in glycogen, which corresponds to progressive LB generation. We show that increasing the amounts of laforin in cell culture causes LB formation and that this occurs only with glycogen binding-competent laforin. In summary, malin deficiency causes increased laforin, increased laforin binding to glycogen, and LB formation. Furthermore, increased levels of laforin, when it can bind glycogen, causes LB. We conclude that malin functions to regulate laforin and that malin deficiency at least in part causes LB and LD through increased laforin binding to glycogen. PMID:22669944

  5. Bacterial community dynamics during the early stages of biofilm formation in a chlorinated experimental drinking water distribution system: implications for drinking water discolouration

    Science.gov (United States)

    Douterelo, I; Sharpe, R; Boxall, J

    2014-01-01

    Aims To characterize bacterial communities during the early stages of biofilm formation and their role in water discolouration in a fully representative, chlorinated, experimental drinking water distribution systems (DWDS). Methods and Results Biofilm development was monitored in an experimental DWDS over 28 days; subsequently the system was disturbed by raising hydraulic conditions to simulate pipe burst, cleaning or other system conditions. Biofilm cell cover was monitored by fluorescent microscopy and a fingerprinting technique used to assess changes in bacterial community. Selected samples were analysed by cloning and sequencing of the 16S rRNA gene. Fingerprinting analysis revealed significant changes in the bacterial community structure over time (P < 0·05). Cell coverage increased over time accompanied by an increase in bacterial richness and diversity. Conclusions Shifts in the bacterial community structure were observed along with an increase in cell coverage, bacterial richness and diversity. Species related to Pseudomonas spp. and Janthinobacterium spp. dominated the process of initial attachment. Based on fingerprinting results, the hydraulic regimes did not affect the bacteriological composition of biofilms, but they did influence their mechanical stability. Significance and Importance of the Study This study gives a better insight into the early stages of biofilm formation in DWDS and will contribute to the improvement of management strategies to control the formation of biofilms and the risk of discolouration. PMID:24712449

  6. The lifelong effects of early childhood adversity and toxic stress.

    Science.gov (United States)

    Boyce, W Thomas

    2014-01-01

    A rapidly expanding body of research indicates that early social environments characterized by adversity, subordination and stress, along with individual differences in susceptibility to such environments, create risks for lifelong chronic diseases, including declines in oral health. Emerging findings suggest that gene-environment interplay, resulting in epigenetically regulated differences in gene expression, underlie many such declines in health. The origins of these processes in early life reveal how many of the chronic morbidities of adulthood should be viewed as developmental disorders, with etiologic roots in childhood.

  7. Early-Onset Severe Encephalopathy with Epilepsy: The BRAT1 Gene Should Be Added to the List of Causes

    NARCIS (Netherlands)

    van de Pol, Laura A.; Wolf, Nicole I.; van Weissenbruch, Mirjam M.; Stam, Cornelie J.; Weiss, Janneke M.; Waisfisz, Quinten; Kevelam, Sietske H.; Bugiani, Mariana; van de Kamp, Jiddeke M.; van der Knaap, Marjo S.

    2015-01-01

    A variety of pathologies can underlie early-onset severe encephalopathy with epilepsy. To aid the diagnostic process in such patients we present an overview of causes, including the rapidly expanding list of genes involved. When no explanation is found, whole-exome sequencing (WES) can be used in an

  8. Heterogeneity of trans-callosal structural connectivity and effects on resting state subnetwork integrity may underlie both wanted and unwanted effects of therapeutic corpus callostomy

    Directory of Open Access Journals (Sweden)

    Peter Neal Taylor

    2016-01-01

    Conclusion: Consideration of the selective vulnerability of resting state sub-networks, and of between-individual variability in connectivity patterns, sheds new light on the occurrence of both wanted and unwanted effects of callosotomy. We propose that beneficial effects (seizure reduction relate to disruption of the default mode network, with unwanted “disconnection syndrome” effects due to disruption particularly of the somatomotor and frontoparietal RSNs. Our results may also explain why disconnection syndromes primary reflect lateralised sensory-motor problems (e.g. of limb movement rather than midline function (e.g. tongue movement. Marked between-subject variation in callosal connectivity may underlie the poor predictability of effects of callosotomy. High resolution structural connectivity studies of this nature may be useful in pre-surgical planning of therapeutic callosotomy for intractable epilepsy.

  9. What factors underlie children's susceptibility to semantic and phonological false memories? investigating the roles of language skills and auditory short-term memory.

    Science.gov (United States)

    McGeown, Sarah P; Gray, Eleanor A; Robinson, Jamey L; Dewhurst, Stephen A

    2014-06-01

    Two experiments investigated the cognitive skills that underlie children's susceptibility to semantic and phonological false memories in the Deese/Roediger-McDermott procedure (Deese, 1959; Roediger & McDermott, 1995). In Experiment 1, performance on the Verbal Similarities subtest of the British Ability Scales (BAS) II (Elliott, Smith, & McCulloch, 1997) predicted correct and false recall of semantic lures. In Experiment 2, performance on the Yopp-Singer Test of Phonemic Segmentation (Yopp, 1988) did not predict correct recall, but inversely predicted the false recall of phonological lures. Auditory short-term memory was a negative predictor of false recall in Experiment 1, but not in Experiment 2. The findings are discussed in terms of the formation of gist and verbatim traces as proposed by fuzzy trace theory (Reyna & Brainerd, 1998) and the increasing automaticity of associations as proposed by associative activation theory (Howe, Wimmer, Gagnon, & Plumpton, 2009). Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    International Nuclear Information System (INIS)

    Knobloch, Gesine; Hamm, Bernd; Jost, Gregor; Pietsch, Hubertus; Huppertz, Alexander

    2014-01-01

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

  11. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

    2014-08-15

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF. DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT. circle Regorafenib treatment response was evaluated by CT in a rat tumour model. (orig.)

  12. Spatial and dynamic organization of molecular structures in the cell nucleus

    NARCIS (Netherlands)

    Brouwer, Anne-Kee

    2010-01-01

    In this thesis we attempt to provide a better understanding of the principles that underlie the spatial dynamic organization of the cell nucleus. Chapter 1 reviews the current status of knowledge about the structural and functional organization of the cell nucleus. In chapter 2, the development of a

  13. μCT-based, in vivo dynamic bone histomorphometry allows 3D evaluation of the early responses of bone resorption and formation to PTH and alendronate combination therapy.

    Science.gov (United States)

    de Bakker, Chantal M J; Altman, Allison R; Tseng, Wei-Ju; Tribble, Mary Beth; Li, Connie; Chandra, Abhishek; Qin, Ling; Liu, X Sherry

    2015-04-01

    Current osteoporosis treatments improve bone mass by increasing net bone formation: anti-resorptive drugs such as bisphosphonates block osteoclast activity, while anabolic agents such as parathyroid hormone (PTH) increase bone remodeling, with a greater effect on formation. Although these drugs are widely used, their role in modulating formation and resorption is not fully understood, due in part to technical limitations in the ability to longitudinally assess bone remodeling. Importantly, it is not known whether or not PTH-induced bone formation is independent of resorption, resulting in controversy over the effectiveness of combination therapies that use both PTH and an anti-resorptive. In this study, we developed a μCT-based, in vivo dynamic bone histomorphometry technique for rat tibiae, and applied this method to longitudinally track changes in bone resorption and formation as a result of treatment with alendronate (ALN), PTH, or combination therapy of both PTH and ALN (PTH+ALN). Correlations between our μCT-based measures of bone formation and measures of bone formation based on calcein-labeled histology (r=0.72-0.83) confirm the accuracy of this method. Bone remodeling parameters measured through μCT-based in vivo dynamic bone histomorphometry indicate an increased rate of bone formation in rats treated with PTH and PTH+ALN, together with a decrease in bone resorption measures in rats treated with ALN and PTH+ALN. These results were further supported by traditional histology-based measurements, suggesting that PTH was able to induce bone formation while bone resorption was suppressed. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. CDKN2A/B Deletion and Double-hit Mutations of the MAPK Pathway Underlie the Aggressive Behavior of Langerhans Cell Tumors.

    Science.gov (United States)

    Xerri, Luc; Adélaïde, José; Popovici, Cornel; Garnier, Séverine; Guille, Arnaud; Mescam-Mancini, Lenaïg; Laurent, Camille; Brousset, Pierre; Coze, Carole; Michel, Gérard; Chaffanet, Max; Bouabdallah, Reda; Coso, Diane; Bertucci, François; Birnbaum, Daniel

    2018-02-01

    Langerhans cell histiocytosis (LCH) has a mostly favorable outcome, whereas Langerhans cell sarcoma (LCS) is an aggressive tumor. It is still unclear whether any specific molecular alterations could underlie the aggressive behavior of Langerhans cell proliferations. We used targeted next-generation sequencing and array-comparative genomic hybridization to profile 22 LCH samples from different patients together with 3 LCS samples corresponding to different relapses from the same patient. The third LCS relapse was a composite tumor including both B-cell chronic lymphocytic leukemia and LCS components. The 22 LCH samples were mostly of bone origin and showed classic histophenotypical features. Array-comparative genomic hybridization showed in all 3 LCS samples a similar homozygous somatic loss affecting the CDKN2A/B locus, whereas the 17 informative LCH samples did not show any detectable abnormality. In the 3 LCS samples, targeted next-generation sequencing of 495 cancer genes detected common mutations in KMT2D/MLL2 and in both MAP2K1 and NRAS genes, whereas BRAF was not mutated. A NOTCH1 mutation was acquired in 2 LCS samples. The composite LCS/B-cell chronic lymphocytic leukemia tumor showed the same genetic profile in its 2 components. LCH samples showed mutually exclusive mutations of BRAF (8/20) and MAP2K1 (4/19), but no mutation of KMT2D, NRAS nor NOTCH1. These results suggest that CDKN2A/B deletion and/or simultaneous mutations of MAP2K1 and NRAS may underlie the aggressive behavior of Langerhans cell tumors, and thus could be useful for the diagnosis of malignancy in histiocytic neoplasms. The MAPK pathway "double hit" profile provides a basis for targeted therapy in LCS patients.

  15. Independent channels for miRNA biosynthesis ensure efficient static and dynamic control in the regulation of the early stages of myogenesis.

    Science.gov (United States)

    Fiorentino, Jonathan; De Martino, Andrea

    2017-10-07

    Motivated by recent experimental work, we define and study a deterministic model of the complex miRNA-based regulatory circuit that putatively controls the early stage of myogenesis in human. We aim in particular at a quantitative understanding of (i) the roles played by the separate and independent miRNA biosynthesis channels (one involving a miRNA-decoy system regulated by an exogenous controller, the other given by transcription from a distinct genomic locus) that appear to be crucial for the differentiation program, and of (ii) how competition to bind miRNAs can efficiently control molecular levels in such an interconnected architecture. We show that optimal static control via the miRNA-decoy system constrains kinetic parameters in narrow ranges where the channels are tightly cross-linked. On the other hand, the alternative locus for miRNA transcription can ensure that the fast concentration shifts required by the differentiation program are achieved, specifically via non-linear response of the target to even modest surges in the miRNA transcription rate. While static, competition-mediated regulation can be achieved by the miRNA-decoy system alone, both channels are essential for the circuit's overall functionality, suggesting that that this type of joint control may represent a minimal optimal architecture in different contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Analysis of the influence of respiratory disorders observed in preoperative spirometry on the dynamics of early inflammatory response in patients undergoing isolated coronary artery bypass grafting.

    Science.gov (United States)

    Szylińska, Aleksandra; Listewnik, Mariusz J; Rotter, Iwona; Rył, Aleksandra; Biskupski, Andrzej; Brykczyński, Mirosław

    2017-01-01

    Preoperative spirometry provides measurable information about the occurrence of respiratory disorders. The aim of this study was to assess the association between preoperative spirometry abnormalities and the intensification of early inflammatory responses in patients following coronary artery bypass graft in extracorporeal circulation. The study involved 810 patients (625 men and 185 women) aged 65.4±7.9 years who were awaiting isolated coronary artery bypass surgery. On the basis of spirometry performed on the day of admittance to the hospital, the patients were divided into three groups. Patients without respiratory problems constituted 78.8% of the entire group. Restricted breathing was revealed by spirometry in 14.9% and obstructive breathing in 6.3% of patients. Inter-group analysis showed statistically significant differences in C-reactive protein (CRP) between patients with restrictive spirometry abnormalities and patients without any pulmonary dysfunction. CRP concentrations differed before surgery ( P =0.006) and on the second ( P spirometry results from restrictive respiratory disorders have an elevated level of generalized inflammatory response both before and after the isolated coronary artery bypass surgery. Therefore, this group of patients should be given special postoperative monitoring and, in particular, intensive respiratory rehabilitation immediately after reconstitution.

  17. Eigentumors for prediction of treatment failure in patients with early-stage breast cancer using dynamic contrast-enhanced MRI: a feasibility study

    Science.gov (United States)

    Chan, H. M.; van der Velden, B. H. M.; E Loo, C.; Gilhuijs, K. G. A.

    2017-08-01

    We present a radiomics model to discriminate between patients at low risk and those at high risk of treatment failure at long-term follow-up based on eigentumors: principal components computed from volumes encompassing tumors in washin and washout images of pre-treatment dynamic contrast-enhanced (DCE-) MR images. Eigentumors were computed from the images of 563 patients from the MARGINS study. Subsequently, a least absolute shrinkage selection operator (LASSO) selected candidates from the components that contained 90% of the variance of the data. The model for prediction of survival after treatment (median follow-up time 86 months) was based on logistic regression. Receiver operating characteristic (ROC) analysis was applied and area-under-the-curve (AUC) values were computed as measures of training and cross-validated performances. The discriminating potential of the model was confirmed using Kaplan-Meier survival curves and log-rank tests. From the 322 principal components that explained 90% of the variance of the data, the LASSO selected 28 components. The ROC curves of the model yielded AUC values of 0.88, 0.77 and 0.73, for the training, leave-one-out cross-validated and bootstrapped performances, respectively. The bootstrapped Kaplan-Meier survival curves confirmed significant separation for all tumors (P  treatment eigentumors for use in prediction of treatment failure of breast cancer.

  18. Population dynamics of Euglossinae bees (Hymenoptera, Apidae in an early second-growth forest of Cajual Island, in the State of Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    SILVA F. S.

    2002-01-01

    Full Text Available A study was conducted in an early second-growth forest aiming at knowing the richness, relative abundance, seasonal distribution, and hourly frequency of euglossine bees, and their association with scent baits. Male bees were attracted to cineole, vanillin, methyl salicylate, and eugenol. The baits were hooked 1.5 m high and 6 m from one another. The specimens were collected from December 1997 to November 1998, once a month, from 7:00 to 17:00 h. A total of 339 male euglossine bees were caughts, accounting for 19 species and four genera. The most common species was E. cordata, making up 69.9% of the individuals, followed by E. truncata (2.3%, E. violaceifrons, and E. smaragdina (2.1%. The most attractive scent was cineole, which baited 87% of the specimens and 73.7% of the species. Vanillin, the second most visited bait, eured 7.6% of the specimens and 26.3% of the species. E. surinamensis was only collected with this bait. Methyl salicylate and eugenol baited combined 2.6% of the specimens. However, by species numbers Methyl salicylate attracted 21% whereas eugenol was attractive for 15.8% of them. In general, the species were more abundantly found in the rainy season (January-June. The hourly activity data showed that the euglossine bees were attracted to the baits all day long, but at a higher frequency in the morning period, peaking between 8:00 and 10:00 h.

  19. Population dynamics of Euglossinae bees (Hymenoptera, Apidae in an early second-growth forest of Cajual Island, in the State of Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    F. S. SILVA

    Full Text Available A study was conducted in an early second-growth forest aiming at knowing the richness, relative abundance, seasonal distribution, and hourly frequency of euglossine bees, and their association with scent baits. Male bees were attracted to cineole, vanillin, methyl salicylate, and eugenol. The baits were hooked 1.5 m high and 6 m from one another. The specimens were collected from December 1997 to November 1998, once a month, from 7:00 to 17:00 h. A total of 339 male euglossine bees were caughts, accounting for 19 species and four genera. The most common species was E. cordata, making up 69.9% of the individuals, followed by E. truncata (2.3%, E. violaceifrons, and E. smaragdina (2.1%. The most attractive scent was cineole, which baited 87% of the specimens and 73.7% of the species. Vanillin, the second most visited bait, eured 7.6% of the specimens and 26.3% of the species. E. surinamensis was only collected with this bait. Methyl salicylate and eugenol baited combined 2.6% of the specimens. However, by species numbers Methyl salicylate attracted 21% whereas eugenol was attractive for 15.8% of them. In general, the species were more abundantly found in the rainy season (January-June. The hourly activity data showed that the euglossine bees were attracted to the baits all day long, but at a higher frequency in the morning period, peaking between 8:00 and 10:00 h.

  20. Early functional postoperative therapy of distal radius fracture with a dynamic orthosis: results of a prospective randomized cross-over comparative study.

    Directory of Open Access Journals (Sweden)

    Fabian M Stuby

    Full Text Available This study was conducted according to GCP criteria as a prospective randomized cross-over study. The primary goal of the study was to determine clinical findings and patient satisfaction with postoperative treatment. 29 patients with a distal radius fracture that was surgically stabilized from volar and who met the inclusion criteria were enrolled over a 12-month period. Each patient randomly received either a dorsal plaster splint or a vacuum-fit flexible but blocked orthosis applied postoperatively in the operating theatre to achieve postoperative immobilization. After one week all patients were crossed over to the complementary device maintaining the immobilization until end of week 2. After week 2 both groups were allowed to exercise wrist mobility with a physiotherapist, in the orthosis group the device was deblocked, thus allowing limited wrist mobility. After week 4 the devices were removed in both groups. Follow-up exams were performed after postoperative weeks 1, 2, 4 and 12.Results were determined after week 1 and 2 using SF 36 and a personally compiled questionnaire; after weeks 4 and 12 with a clinical check-up, calculation of ROM and the DASH Score. Comparison of the two groups showed a significant difference in ROM for volar flexion after 4 weeks, but no significant differences in DASH Score, duration of disability or x-ray findings. With regard to satisfaction with comfort and hygiene, patients were significantly more satisfied with the dynamic orthosis, and 23 of the 29 patients would prefer the flexible vacuum orthosis in future.German Clinical Trials Register (DRKS DRKS00006097.

  1. Transcript dynamics at early stages of molecular interactions of MYMIV with resistant and susceptible genotypes of the leguminous host, Vigna mungo.

    Science.gov (United States)

    Kundu, Anirban; Patel, Anju; Paul, Sujay; Pal, Amita

    2015-01-01

    Initial phases of the MYMIV-Vigna mungo interaction is crucial in determining the infection phenotype upon challenging with the virus. During incompatible interaction, the plant deploys multiple stratagems that include extensive transcriptional alterations defying the virulence factors of the pathogen. Such molecular events are not frequently addressed by genomic tools. In order to obtain a critical insight to unravel how V. mungo respond to Mungbean yellow mosaic India virus (MYMIV), we have employed the PCR based suppression subtractive hybridization technique to identify genes that exhibit altered expressions. Dynamics of 345 candidate genes are illustrated that differentially expressed either in compatible or incompatible reactions and their possible biological and cellular functions are predicted. The MYMIV-induced physiological aspects of the resistant host include reactive oxygen species generation, induction of Ca2+ mediated signaling, enhanced expression of transcripts involved in phenylpropanoid and ubiquitin-proteasomal pathways; all these together confer resistance against the invader. Elicitation of genes implicated in salicylic acid (SA) pathway suggests that immune response is under the regulation of SA signaling. A significant fraction of modulated transcripts are of unknown function indicating participation of novel candidate genes in restricting this viral pathogen. Susceptibility on the other hand, as exhibited by V. mungo Cv. T9 is perhaps due to the poor execution of these transcript modulation exhibiting remarkable repression of photosynthesis related genes resulting in chlorosis of leaves followed by penalty in crop yield. Thus, the present findings revealed an insight on the molecular warfare during host-virus interaction suggesting plausible signaling mechanisms and key biochemical pathways overriding MYMIV invasion in resistant genotype of V. mungo. In addition to inflate the existing knowledge base, the genomic resources identified in

  2. Contributions of dynamic environmental signals during life-cycle transitions to early life-history traits in lodgepole pine (Pinus contorta Dougl.)

    Science.gov (United States)

    Liu, Yang; Wang, Tongli; El-Kassaby, Yousry A.

    2016-05-01

    Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961-1990) and future (2041-2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavorable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span. These findings provide useful information to studies related to assessments of seed transfer and tree adaptation.

  3. Dynamic contrast enhanced MRI detects early response to adoptive NK cellular immunotherapy targeting the NG2 proteoglycan in a rat model of glioblastoma.

    Directory of Open Access Journals (Sweden)

    Cecilie Brekke Rygh

    Full Text Available There are currently no established radiological parameters that predict response to immunotherapy. We hypothesised that multiparametric, longitudinal magnetic resonance imaging (MRI of physiological parameters and pharmacokinetic models might detect early biological responses to immunotherapy for glioblastoma targeting NG2/CSPG4 with mAb9.2.27 combined with natural killer (NK cells. Contrast enhanced conventional T1-weighted MRI at 7±1 and 17±2 days post-treatment failed to detect differences in tumour size between the treatment groups, whereas, follow-up scans at 3 months demonstrated diminished signal intensity and tumour volume in the surviving NK+mAb9.2.27 treated animals. Notably, interstitial volume fraction (ve, was significantly increased in the NK+mAb9.2.27 combination therapy group compared mAb9.2.27 and NK cell monotherapy groups (p = 0.002 and p = 0.017 respectively in cohort 1 animals treated with 1 million NK cells. ve was reproducibly increased in the combination NK+mAb9.2.27 compared to NK cell monotherapy in cohort 2 treated with increased dose of 2 million NK cells (p<0.0001, indicating greater cell death induced by NK+mAb9.2.27 treatment. The interstitial volume fraction in the NK monotherapy group was significantly reduced compared to mAb9.2.27 monotherapy (p<0.0001 and untreated controls (p = 0.014 in the cohort 2 animals. NK cells in monotherapy were unable to kill the U87MG cells that highly expressed class I human leucocyte antigens, and diminished stress ligands for activating receptors. A significant association between apparent diffusion coefficient (ADC of water and ve in combination NK+mAb9.2.27 and NK monotherapy treated tumours was evident, where increased ADC corresponded to reduced ve in both cases. Collectively, these data support histological measures at end-stage demonstrating diminished tumour cell proliferation and pronounced apoptosis in the NK+mAb9.2.27 treated tumours compared to the other

  4. Neuro-, Cardio-, and Immunoplasticity: Effects of Early Adversity.

    Science.gov (United States)

    Pakulak, Eric; Stevens, Courtney; Neville, Helen

    2018-01-04

    The relationship between early adversity and outcomes across the lifespan is apparent in a striking range of measures. Evidence suggests that many of these outcomes can be traced to the impacts of early adversity on multiple and integrated biological systems mediated by the brain. In this review, we integrate empirical and theoretical advances in the understanding of relationships among the brain and the functions of the endocrine, autonomic, and immune systems. We emphasize the effects of environmental experiences related to caregiver relationships because it is these experiences, in particular, that shape regulatory and threat response systems in ways that increase vulnerability and may underlie the wide range of poor outcomes associated with early adversity. Thus, we metaphorically extend the concept of plasticity to highlight our goal of a broader consideration of these interconnected mechanisms. We conclude by discussing implications for neurobiologically informed interventions that can potentially ameliorate the broad and costly effects of early adversity.

  5. Epigenetic Mechanisms Underlie Genome Development

    Science.gov (United States)

    Lamm, Ehud

    2013-01-01

    Technological and methodological advances, in particular next-generation sequencing and chromatin profiling, has led to a deluge of data on epigenetic mechanisms and processes. Epigenetic regulation in the brain is no exception. In this commentary, Ehud Lamm writes that extending existing frameworks for thinking about psychological development to…

  6. Poster — Thur Eve — 03: Application of the non-negative matrix factorization technique to [{sup 11}C]-DTBZ dynamic PET data for the early detection of Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Chang [CancerCare Manitoba, Winnipeg, MB (Canada); Jans, Hans; McEwan, Sandy; Riauka, Terence [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Cross Cancer Institute, Alberta Health Services, Edmonton, AB (Canada); Martin, Wayne; Wieler, Marguerite [Division of Neurology, University of Alberta, Edmonton, AB (Canada)

    2014-08-15

    In this work, a class of non-negative matrix factorization (NMF) technique known as alternating non-negative least squares, combined with the projected gradient method, is used to analyze twenty-five [{sup 11}C]-DTBZ dynamic PET/CT brain data. For each subject, a two-factor model is assumed and two factors representing the striatum (factor 1) and the non-striatum (factor 2) tissues are extracted using the proposed NMF technique and commercially available factor analysis software “Pixies”. The extracted factor 1 and 2 curves represent the binding site of the radiotracer and describe the uptake and clearance of the radiotracer by soft tissues in the brain, respectively. The proposed NMF technique uses prior information about the dynamic data to obtain sample time-activity curves representing the striatum and the non-striatum tissues. These curves are then used for “warm” starting the optimization. Factor solutions from the two methods are compared graphically and quantitatively. In healthy subjects, radiotracer uptake by factors 1 and 2 are approximately 35–40% and 60–65%, respectively. The solutions are also used to develop a factor-based metric for the detection of early, untreated Parkinson's disease. The metric stratifies healthy subjects from suspected Parkinson's patients (based on the graphical method). The analysis shows that both techniques produce comparable results with similar computational time. The “semi-automatic” approach used by the NMF technique allows clinicians to manually set a starting condition for “warm” starting the optimization in order to facilitate control and efficient interaction with the data.

  7. Does Growth in the Executive System of Working Memory Underlie Growth in Literacy for Bilingual Children With and Without Reading Disabilities?

    Science.gov (United States)

    Swanson, H Lee; Orosco, Michael J; Kudo, Milagros

    This cohort-sequential study explored the components of working memory (WM) that underlie second language (L2) reading growth in 450 children at risk and not at risk for reading disabilities (RD) whose first language is Spanish. English language learners designated as balanced and nonbalanced bilinguals with and without risk for RD in Grades 1, 2, and 3 at Wave 1 were administered a battery of cognitive (short-term memory, WM, naming speed, and inhibition), vocabulary, and reading measures in Spanish and English. These same measures were administered 1 and 2 years later. Two important findings occurred: First, growth in the WM executive component was significantly related to growth in English word identification and passage comprehension when competing measures (phonological processing, naming speed, inhibition, and fluid intelligence) were entered into the multilevel growth model. Second, children defined as at risk for RD in Wave 1 had lower intercepts than children not at risk at Wave 3 across several measures of cognition, language, and achievement. However, except on measures of the executive component of WM, no significant group differences in linear growth emerged. These findings suggest that growth in L2 reading was tied to growth in the executive system of WM.

  8. Neurons That Underlie Drosophila melanogaster Reproductive Behaviors: Detection of a Large Male-Bias in Gene Expression in fruitless-Expressing Neurons

    Directory of Open Access Journals (Sweden)

    Nicole R. Newell

    2016-08-01

    Full Text Available Male and female reproductive behaviors in Drosophila melanogaster are vastly different, but neurons that express sex-specifically spliced fruitless transcripts (fru P1 underlie these behaviors in both sexes. How this set of neurons can generate such different behaviors between the two sexes is an unresolved question. A particular challenge is that fru P1-expressing neurons comprise only 2–5% of the adult nervous system, and so studies of adult head tissue or whole brain may not reveal crucial differences. Translating Ribosome Affinity Purification (TRAP identifies the actively translated pool of mRNAs from fru P1-expressing neurons, allowing a sensitive, cell-type-specific assay. We find four times more male-biased than female-biased genes in TRAP mRNAs from fru P1-expressing neurons. This suggests a potential mechanism to generate dimorphism in behavior. The male-biased genes may direct male behaviors by establishing cell fate in a similar context of gene expression observed in females. These results suggest a possible global mechanism for how distinct behaviors can arise from a shared set of neurons.

  9. Bariatric Surgery in Obese Women of Reproductive Age Improves Conditions That Underlie Fertility and Pregnancy Outcomes: Retrospective Cohort Study of UK National Bariatric Surgery Registry (NBSR).

    Science.gov (United States)

    Edison, Eric; Whyte, Martin; van Vlymen, Jeremy; Jones, Simon; Gatenby, Piers; de Lusignan, Simon; Shawe, Jill

    2016-12-01

    The aims of this study are the following: to describe the female population of reproductive age having bariatric surgery in the UK, to assess the age and ethnicity of women accessing surgery, and to assess the effect of bariatric surgery on factors that underlie fertility and pregnancy outcomes. Demographic details, comorbidities, and operative type of women aged 18-45 years were extracted from the National Bariatric Surgery Registry (NBSR). A comparison was made with non-operative cases (aged 18-45 and BMI ≥40 kg/m 2 ) from the Health Survey for England (HSE, 2007-2013). Analyses were performed using "R" software. Data were extracted on 15,222 women from NBSR and 1073 from HSE. Women aged 18-45 comprised 53 % of operations. Non-Caucasians were under-represented in NBSR compared to HSE (10 vs 16 % respectively, p fertility and pregnancy outcomes. A prospective study is required to verify these effects.

  10. Early anaerobic metabolisms

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity......Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were...... of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent...

  11. Suppression of Wnt1-induced mammary tumor growth and lower serum insulin in offspring exposed to maternal blueberry diet suggest early dietary influence on developmental programming

    Science.gov (United States)

    Despite the well-accepted notion that early maternal influences persist beyond fetal life and may underlie many adult diseases, the risks imposed by the maternal environment on breast cancer development and underlying biological mechanisms remain poorly understood. Here, we investigated whether earl...

  12. Early literacy

    DEFF Research Database (Denmark)

    Jensen, Anders Skriver

    2012-01-01

    This paper discusses findings from the Danish contribution to the EASE project, a European research project running from 2008 to 2010 on early literacy in relation to the transition from childcare to school. It explores a holistic, inclusive approach to early literacy that resists a narrow...... and schools. The paper also draws on Gee’s (2001, 2003, 2004, 2008) sociocultural approach to literacy, and Honneth’s (2003, 2006) concept of recognition. Emphasizing participation and recognition as key elements, it claims that stakeholders in early liter- acy must pay attention to how diverse early literacy...... opportunities empower children, especially when these opportunities are employed in a project-based learning environ- ment in which each child is able to contribute to the shared literacy events....

  13. Selective attention to phonology dynamically modulates initial encoding of auditory words within the left hemisphere.

    Science.gov (United States)

    Yoncheva, Yuliya; Maurer, Urs; Zevin, Jason D; McCandliss, Bruce D

    2014-08-15

    Selective attention to phonology, i.e., the ability to attend to sub-syllabic units within spoken words, is a critical precursor to literacy acquisition. Recent functional magnetic resonance imaging evidence has demonstrated that a left-lateralized network of frontal, temporal, and posterior language regions, including the visual word form area, supports this skill. The current event-related potential (ERP) study investigated the temporal dynamics of selective attention to phonology during spoken word perception. We tested the hypothesis that selective attention to phonology dynamically modulates stimulus encoding by recruiting left-lateralized processes specifically while the information critical for performance is unfolding. Selective attention to phonology was captured by manipulating listening goals: skilled adult readers attended to either rhyme or melody within auditory stimulus pairs. Each pair superimposed rhyming and melodic information ensuring identical sensory stimulation. Selective attention to phonology produced distinct early and late topographic ERP effects during stimulus encoding. Data-driven source localization analyses revealed that selective attention to phonology led to significantly greater recruitment of left-lateralized posterior and extensive temporal regions, which was notably concurrent with the rhyme-relevant information within the word. Furthermore, selective attention effects were specific to auditory stimulus encoding and not observed in response to cues, arguing against the notion that they reflect sustained task setting. Collectively, these results demonstrate that selective attention to phonology dynamically engages a left-lateralized network during the critical time-period of perception for achieving phonological analysis goals. These findings suggest a key role for selective attention in on-line phonological computations. Furthermore, these findings motivate future research on the role that neural mechanisms of attention may

  14. Long-term and seasonal dynamics of dengue in Iquitos, Peru.

    Directory of Open Access Journals (Sweden)

    Steven T Stoddard

    2014-07-01

    Full Text Available Long-term disease surveillance data provide a basis for studying drivers of pathogen transmission dynamics. Dengue is a mosquito-borne disease caused by four distinct, but related, viruses (DENV-1-4 that potentially affect over half the world's population. Dengue incidence varies seasonally and on longer time scales, presumably driven by the interaction of climate and host susceptibility. Precise understanding of dengue dynamics is constrained, however, by the relative paucity of laboratory-confirmed longitudinal data.We studied 10 years (2000-2010 of laboratory-confirmed, clinic-based surveillance data collected in Iquitos, Peru. We characterized inter and intra-annual patterns of dengue dynamics on a weekly time scale using wavelet analysis. We explored the relationships of case counts to climatic variables with cross-correlation maps on annual and trimester bases.Transmission was dominated by single serotypes, first DENV-3 (2001-2007 then DENV-4 (2008-2010. After 2003, incidence fluctuated inter-annually with outbreaks usually occurring between October and April. We detected a strong positive autocorrelation in case counts at a lag of ∼ 70 weeks, indicating a shift in the timing of peak incidence year-to-year. All climatic variables showed modest seasonality and correlated weakly with the number of reported dengue cases across a range of time lags. Cases were reduced after citywide insecticide fumigation if conducted early in the transmission season.Dengue case counts peaked seasonally despite limited intra-annual variation in climate conditions. Contrary to expectations for this mosquito-borne disease, no climatic variable considered exhibited a strong relationship with transmission. Vector control operations did, however, appear to have a significant impact on transmission some years. Our results indicate that a complicated interplay of factors underlie DENV transmission in contexts such as Iquitos.

  15. Early and sustained dynamic intervention in schizophrenia

    DEFF Research Database (Denmark)

    Rosenbaum, Bent; Rosenbaum, Bent

    2009-01-01

    This paper is based on the Danish National Schizophrenia Project manual for psychodynamic individual psychotherapy with persons in states of schizophrenia. The methods for engaging with and treating a patient with schizophrenia in a supportive, psychodynamic way are described....

  16. Early dynamics of stereoscopic surface slant perception.

    Science.gov (United States)

    Caziot, Baptiste; Backus, Benjamin T; Lin, Esther

    2017-12-01

    Surface orientation is an important visual primitive that can be estimated from monocular or binocular (stereoscopic) signals. Changes in motor planning occur within about 200 ms after either type of signal is perturbed, but the time it takes for apparent (perceived) slant to develop from stereoscopic cues is not known. Apparent slant sometimes develops very slowly (Gillam, Chambers, & Russo, 1988; van Ee & Erkelens, 1996). However, these long durations could reflect the time it takes for the visual system to resolve conflicts between slant cues that inevitably specify different slants in laboratory displays (Allison & Howard, 2000). We used a speed-accuracy tradeoff analysis to measure the time it takes to discriminate slant, allowing us to report psychometric functions as a function of response time. Observers reported which side of a slanted surface was farther, with a temporal deadline for responding that varied block-to-block. Stereoscopic slant discrimination rose above chance starting at 200 ms after stimulus onset. Unexpectedly, observers discriminated slant from binocular disparity faster than texture, and for stereoscopic whole-field stimuli faster than stereoscopic slant contrast stimuli. However, performance after the initial deviation from chance increased more rapidly for slant-contrast stimuli than whole-field stimuli. Discrimination latencies were similar for slants about the horizontal and vertical axes, but performance increased faster for slants about the vertical axis. Finally, slant from vertical disparity was somewhat slower than slant from horizontal disparity, which may reflect cue conflict. These results demonstrate, in contradiction with the previous literature, that the perception of slant from disparity happens very quickly-in fact, more quickly than the perception of slant from texture-and in comparable time to the simple perception of brightness from luminance.

  17. Structure-based control of complex networks with nonlinear dynamics

    Science.gov (United States)

    Zanudo, Jorge G. T.; Yang, Gang; Albert, Reka

    What can we learn about controlling a system solely from its underlying network structure? Here we use a framework for control of networks governed by a broad class of nonlinear dynamics that includes the major dynamic models of biological, technological, and social processes. This feedback-based framework provides realizable node overrides that steer a system towards any of its natural long term dynamic behaviors, regardless of the dynamic details and system parameters. We use this framework on several real networks, identify the topological characteristics that underlie the predicted node overrides, and compare its predictions to those of classical structural control theory. Finally, we demonstrate this framework's applicability in dynamic models of gene regulatory networks and identify nodes whose override is necessary for control in the general case, but not in specific model instances. This work was supported by NSF Grants PHY 1205840 and IIS 1160995. JGTZ is a recipient of a Stand Up To Cancer - The V Foundation Convergence Scholar Award.

  18. Cooperation and Competition: The Comparative Assessment of Tribal Dynamics in the Marginal Landscapes of the Wadi el-Hasa, in west-central Jordan in the Early Bronze and Iron ages

    Directory of Open Access Journals (Sweden)

    Bulent Arikan

    2011-12-01

    Full Text Available The issue of emergent social complexity has long been debated in the anthropological literature. In the eastern Mediterranean context, the archaeological discussions of social complexity focused largely on societies that showed centralized administration, hierarchic social formations, and large urban centers in temperate parts of the region. For the marginal landscapes in the eastern Mediterranean, such as semi-desert regions, scholars have long denied social complexity on the basis of lack of attributes listed in traditional frameworks of complexity. Recently however, alternate models of complexity have been developed for tribal societies following heterarchy and corporate mode of complexity. In these models, the concepts of group fusion (i.e., cooperation and fission (i.e., competition have significant roles and they need to be examined in more detail, especially about how we can identify these group dynamics in the archaeological record, specifically in the settlement systems. This article focuses on the Early Bronze I-III (ca. 3,500-2,400 BC and the Iron Age (ca. 1,200-500 BC of the Wadi el-Hasa, in west-central Jordan, for the evolution of settlement systems as a result of tribal cooperation/competition strategies and the emergence of long-distance trade, which allowed tribes not only to thrive economically but also gain political significance in a marginal landscape in the southern Levant. The use of relatively new analytical methods in archaeology, such as the geographical information systems, for assessing temporal changes in spatial distribution of sites, identifying trade routes, determining the impacts of long-distance trade and other socio-political events in the region on the settlement systems of the Hasa has been discussed.

  19. Angiogenic imbalance and diminished matrix metalloproteinase-2 and -9 underlie regional decreases in uteroplacental vascularization and feto-placental growth in hypertensive pregnancy.

    Science.gov (United States)

    Dias-Junior, Carlos A; Chen, Juanjuan; Cui, Ning; Chiang, Charles L; Zhu, Minglin; Ren, Zongli; Possomato-Vieira, Jose S; Khalil, Raouf A

    2017-12-15

    Preeclampsia is a form of hypertension-in-pregnancy (HTN-Preg) with unclear mechanism. Generalized reduction of uterine perfusion pressure (RUPP) could be an initiating event leading to uteroplacental ischemia, angiogenic imbalance, and HTN-Preg. Additional regional differences in uteroplacental blood flow could further affect the pregnancy outcome and increase the risk of preeclampsia in twin or multiple pregnancy, but the mechanisms involved are unclear. To test the hypothesis that regional differences in angiogenic balance and matrix metalloproteinases (MMPs) underlie regional uteroplacental vascularization and feto-placental development, we compared fetal and placental growth, and placental and myoendometrial vascularization in the proximal, middle and distal regions of the uterus (in relation to the iliac bifurcation) in normal pregnant (Preg) and RUPP rats. Maternal blood pressure and plasma anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt-1)/placenta growth factor (PIGF) ratio were higher, and average placentae number, placenta weight, litter size, and pup weight were less in RUPP than Preg rats. The placenta and pup number and weight were reduced, while the number and diameter of placental and adjacent myoendometrial arteries, and MMP-2 and MMP-9 levels/activity were increased, and sFlt-1/PlGF ratio was decreased in distal vs proximal uterus of Preg rats. In RUPP rats, the placenta and pup number and weight, the number and diameter of placental and myoendometrial arteries, and MMP-2 and -9 levels/activity were decreased, and sFlt-1/PlGF ratio was increased in distal vs proximal uterus. Treatment with sFlt-1 or RUPP placenta extract decreased MMP-2 and MMP-9 in distal segments of Preg uterus, and treatment with PIGF or Preg placenta extract restored MMP levels in distal segments of RUPP uterus. Thus, in addition to the general reduction in placental and fetal growth during uteroplacental ischemia, localized angiogenic imbalance and diminished MMP-2

  20. Microhomology-mediated mechanisms underlie non-recurrent disease-causing microdeletions of the FOXL2 gene or its regulatory domain.

    Directory of Open Access Journals (Sweden)

    Hannah Verdin

    Full Text Available Genomic disorders are often caused by recurrent copy number variations (CNVs, with nonallelic homologous recombination (NAHR as the underlying mechanism. Recently, several microhomology-mediated repair mechanisms--such as microhomology-mediated end-joining (MMEJ, fork stalling and template switching (FoSTeS, microhomology-mediated break-induced replication (MMBIR, serial replication slippage (SRS, and break-induced SRS (BISRS--were described in the etiology of non-recurrent CNVs in human disease. In addition, their formation may be stimulated by genomic architectural features. It is, however, largely unexplored to what extent these mechanisms contribute to rare, locus-specific pathogenic CNVs. Here, fine-mapping of 42 microdeletions of the FOXL2 locus, encompassing FOXL2 (32 or its regulatory domain (10, serves as a model for rare, locus-specific CNVs implicated in genetic disease. These deletions lead to blepharophimosis syndrome (BPES, a developmental condition affecting the eyelids and the ovary. For breakpoint mapping we used targeted array-based comparative genomic hybridization (aCGH, quantitative PCR (qPCR, long-range PCR, and Sanger sequencing of the junction products. Microhomology, ranging from 1 bp to 66 bp, was found in 91.7% of 24 characterized breakpoint junctions, being significantly enriched in comparison with a random control sample. Our results show that microhomology-mediated repair mechanisms underlie at least 50% of these microdeletions. Moreover, genomic architectural features, like sequence motifs, non-B DNA conformations, and repetitive elements, were found in all breakpoint regions. In conclusion, the majority of these microdeletions result from microhomology-mediated mechanisms like MMEJ, FoSTeS, MMBIR, SRS, or BISRS. Moreover, we hypothesize that the genomic architecture might drive their formation by increasing the susceptibility for DNA breakage or promote replication fork stalling. Finally, our locus-centered study

  1. Early Atomism

    Indian Academy of Sciences (India)

    was yet no experimental method for counting the num- ber of molecules in a given volume of gas which would allow direct verification of Avogadro's hypothesis. 6. Periodic Properties of Elements. By the early 19th century, about fifty elements had been discovered and their properties investigated. Based on these studies ...

  2. Early intervention

    African Journals Online (AJOL)

    family conflict.12 We also know that the effects of violence exposure are likely magnified in unstable ... and how chronic 'toxic stress' may lead to difficulties in self-regulation, poor control of emotions, and ... High levels of violence affect every family in South Africa. Exposure to violence starts early, in both the home.

  3. Quantum ChromoDynamics

    CERN Document Server

    Seymour, Michael H

    2010-01-01

    These lectures on QCD stress the theoretical elements that underlie a wide range of phenomenological studies, particularly gauge invariance, renormalization, factorization and infrared safety. The three parts cover the basics of QCD, QCD at tree level and higher order corrections.

  4. Early discontinuation

    DEFF Research Database (Denmark)

    Hansen, Dorte Gilså; Felde, Lina; Gichangi, Anthony

    2007-01-01

    Introduction Discontinuation of medical drug treatment is a serious problem in primary care. The need for a better understanding of the processes, including physician-specific mechanisms, is apparent. The aim of this study was to analyse the association between general practitioners' prescribing....... There was a positive association between the prevalence of prescribing for the specific drugs studied (antidepressants, antidiabetics, drugs against osteoporosis and lipid-lowering drugs) and early discontinuation (r = 0.29 -0.44), but not for anti-hypertensive drugs. The analysis of the association between prevalence...... of all drugs and drug-specific early discontinuation showed some degree of positive association - strongest for anti-hypertensive drugs (r = 0.62) and antidepressants (r = 0.43). Conclusion This study confirmed our hypothesis that general practitioners with high levels of prescribing attain higher rates...

  5. TU-F-CAMPUS-J-02: Evaluation of Textural Feature Extraction for Radiotherapy Response Assessment of Early Stage Breast Cancer Patients Using Diffusion Weighted MRI and Dynamic Contrast Enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y; Wang, C; Horton, J; Chang, Z [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: To investigate the feasibility of using classic textural feature extraction in radiotherapy response assessment, we studied a unique cohort of early stage breast cancer patients with paired pre - and post-radiation Diffusion Weighted MRI (DWI-MRI) and Dynamic Contrast Enhanced MRI (DCE-MRI). Methods: 15 female patients from our prospective phase I trial evaluating preoperative radiotherapy were included in this retrospective study. Each patient received a single-fraction radiation treatment, and DWI and DCE scans were conducted before and after the radiotherapy. DWI scans were acquired using a spin-echo EPI sequence with diffusion weighting factors of b = 0 and b = 500 mm{sup 2} /s, and the apparent diffusion coefficient (ADC) maps were calculated. DCE-MRI scans were acquired using a T{sub 1}-weighted 3D SPGR sequence with a temporal resolution of about 1 minute. The contrast agent (CA) was intravenously injected with a 0.1 mmol/kg bodyweight dose at 2 ml/s. Two parameters, volume transfer constant (K{sup trans} ) and k{sub ep} were analyzed using the two-compartment Tofts kinetic model. For DCE parametric maps and ADC maps, 33 textural features were generated from the clinical target volume (CTV) in a 3D fashion using the classic gray level co-occurrence matrix (GLCOM) and gray level run length matrix (GLRLM). Wilcoxon signed-rank test was used to determine the significance of each texture feature’s change after the radiotherapy. The significance was set to 0.05 with Bonferroni correction. Results: For ADC maps calculated from DWI-MRI, 24 out of 33 CTV features changed significantly after the radiotherapy. For DCE-MRI pharmacokinetic parameters, all 33 CTV features of K{sup trans} and 33 features of k{sub ep} changed significantly. Conclusion: Initial results indicate that those significantly changed classic texture features are sensitive to radiation-induced changes and can be used for assessment of radiotherapy response in breast cancer.

  6. Structure-based control of complex networks with nonlinear dynamics

    Science.gov (United States)

    Zañudo, Jorge Gomez Tejeda; Yang, Gang; Albert, Réka

    2017-01-01

    What can we learn about controlling a system solely from its underlying network structure? Here we adapt a recently developed framework for control of networks governed by a broad class of nonlinear dynamics that includes the major dynamic models of biological, technological, and social processes. This feedback-based framework provides realizable node overrides that steer a system toward any of its natural long-term dynamic behaviors, regardless of the specific functional forms and system parameters. We use this framework on several real networks, identify the topological characteristics that underlie the predicted node overrides, and compare its predictions to those of structural controllability in control theory. Finally, we demonstrate this framework’s applicability in dynamic models of gene regulatory networks and identify nodes whose override is necessary for control in the general case but not in specific model instances. PMID:28655847

  7. Early Maladaptive Schemas in Substance Use Patients and their Intimate Partners: A Preliminary Investigation

    Science.gov (United States)

    Shorey, Ryan C.; Anderson, Scott; Stuart, Gregory L.

    2012-01-01

    Recent research has documented that substance users have a number of early maladaptive schemas that may underlie their substance use and that treatment that addresses these schemas may result in improved outcomes. Research has also shown that intimate partners of substance users have a number of mental and physical health problems, although no known research has examined the early maladaptive schemas of these relationship partners. The current study examined the early maladaptive schemas of substance use treatment patients and their intimate partners (N = 80). Findings showed that both patients and intimate partners had a number of problematic early maladaptive schemas; that patients scored significantly higher than their intimate partners on a few early maladaptive schemas; and that patient and intimate partner schemas may be interrelated. Implications of these findings for treatment and future research are discussed. PMID:22745593

  8. From cytoskeletal dynamics to organ asymmetry: a nonlinear, regulative pathway underlies left–right patterning

    OpenAIRE

    McDowell, Gary; Rajadurai, Suvithan; Levin, Michael

    2016-01-01

    Consistent left–right (LR) asymmetry is a fundamental aspect of the bodyplan across phyla, and errors of laterality form an important class of human birth defects. Its molecular underpinning was first discovered as a sequential pathway of left- and right-sided gene expression that controlled positioning of the heart and visceral organs. Recent data have revised this picture in two important ways. First, the physical origin of chirality has been identified; cytoskeletal dynamics underlie the a...

  9. Early micronutrient supplementation protects against early stress-induced cognitive impairments.

    Science.gov (United States)

    Naninck, Eva F G; Oosterink, J Efraim; Yam, Kit-Yi; de Vries, Lennart P; Schierbeek, Henk; van Goudoever, Johannes B; Verkaik-Schakel, Rikst-Nynke; Plantinga, Josèe A; Plosch, Torsten; Lucassen, Paul J; Korosi, Aniko

    2017-02-01

    Early-life stress (ES) impairs cognition later in life. Because ES prevention is problematic, intervention is needed, yet the mechanisms that underlie ES remain largely unknown. So far, the role of early nutrition in brain programming has been largely ignored. Here, we demonstrate that essential 1-carbon metabolism-associated micronutrients (1-CMAMs; i.e., methionine and B vitamins) early in life are crucial in programming later cognition by ES. ES was induced in male C57Bl/6 mice from postnatal d (P)2-9. 1-CMAM levels were measured centrally and peripherally by using liquid chromatography-mass spectroscopy. Next, we supplemented the maternal diet with 1-CMAM only during the ES period and studied cognitive, neuroendocrine, neurogenic, transcriptional, and epigenetic changes in adult offspring. We demonstrate that ES specifically reduces methionine in offspring plasma and brain. Of note, dietary 1-CMAM enrichment during P2-9 restored methionine levels and rescued ES-induced adult cognitive impairments. Beneficial effects of this early dietary enrichment were associated with prevention of the ES-induced rise in corticosterone and adrenal gland hypertrophy did not involve changes in maternal care, hippocampal volume, neurogenesis, or global/Nr3c1-specific DNA methylation. In summary, nutrition is important in brain programming by ES. A short, early supplementation with essential micronutrients can already prevent lasting effects of ES. This concept opens new avenues for nutritional intervention.-Naninck, E. F. G., Oosterink, J. E., Yam, K.-Y., de Vries, L. P., Schierbeek, H., van Goudoever, J. B., Verkaik-Schakel, R.-N., Plantinga, J. A., Plosch, T., Lucassen, P. J., Korosi, A. Early micronutrient supplementation protects against early stress-induced cognitive impairments. © FASEB.

  10. Early anaerobic metabolisms

    Science.gov (United States)

    Canfield, Don E; Rosing, Minik T; Bjerrum, Christian

    2006-01-01

    Before the advent of oxygenic photosynthesis, the biosphere was driven by anaerobic metabolisms. We catalogue and quantify the source strengths of the most probable electron donors and electron acceptors that would have been available to fuel early-Earth ecosystems. The most active ecosystems were probably driven by the cycling of H2 and Fe2+ through primary production conducted by anoxygenic phototrophs. Interesting and dynamic ecosystems would have also been driven by the microbial cycling of sulphur and nitrogen species, but their activity levels were probably not so great. Despite the diversity of potential early ecosystems, rates of primary production in the early-Earth anaerobic biosphere were probably well below those rates observed in the marine environment. We shift our attention to the Earth environment at 3.8 Gyr ago, where the earliest marine sediments are preserved. We calculate, consistent with the carbon isotope record and other considerations of the carbon cycle, that marine rates of primary production at this time were probably an order of magnitude (or more) less than today. We conclude that the flux of reduced species to the Earth surface at this time may have been sufficient to drive anaerobic ecosystems of sufficient activity to be consistent with the carbon isotope record. Conversely, an ecosystem based on oxygenic photosynthesis was also possible with complete removal of the oxygen by reaction with reduced species from the mantle. PMID:17008221

  11. Future Directions for Research on School Shootings: Commentary on: "Bullying, Romantic Rejection, and Conflicts with Teachers: The Crucial Role of Social Dynamics in the Development of School Shootings--A Systematic Review"

    Science.gov (United States)

    Cornell, Dewey

    2014-01-01

    Sommer, Leuschner, and Scheithauer ("International Journal of Developmental Science," v8, n1-2, p 3-24, 2014.) make an excellent contribution to the field in bringing attention to the social dynamics that underlie many homicidal attacks that have occurred in schools. By drawing on 126 cases reported in 35 studies, the authors are able to…

  12. Semiclassical dynamics

    International Nuclear Information System (INIS)

    Balazs, N.L.

    1979-01-01

    It is pointed out that in semiclassical dynamics one is encouraged to study the evolution of those curves in phase space which classically represent ensembles corresponding to wave functions. It is shown that the fixed points generate new time scales so that for times longer than the critical times, quantum dynamics will profoundly differ from classical dynamics. (P.L.)

  13. Dynamical Languages

    Science.gov (United States)

    Xie, Huimin

    The following sections are included: * Definition of Dynamical Languages * Distinct Excluded Blocks * Definition and Properties * L and L″ in Chomsky Hierarchy * A Natural Equivalence Relation * Symbolic Flows * Symbolic Flows and Dynamical Languages * Subshifts of Finite Type * Sofic Systems * Graphs and Dynamical Languages * Graphs and Shannon-Graphs * Transitive Languages * Topological Entropy

  14. Improving early seizure detection.

    Science.gov (United States)

    Jouny, Christophe C; Franaszczuk, Piotr J; Bergey, Gregory K

    2011-12-01

    Over the last decade, the search for a method able to reliably predict seizures hours in advance has been largely replaced by the more realistic goal of very early detection of seizure onset, which would allow therapeutic or warning devices to be triggered prior to the onset of disabling clinical symptoms. We explore in this article the steps along the pathway from data acquisition to closed-loop applications that can and should be considered to design the most efficient early seizure detection. Microelectrodes, high-frequency oscillations, high sampling rate, high-density arrays, and modern analysis techniques are all elements of the recording and detection process that in combination with modeling studies can provide new insights into the dynamics of seizure onsets. Each of these steps needs to be considered if detection devices that will favorably impact the quality of life of patients are to be implemented. This article is part of a Supplemental Special Issue entitled The Future of Automated Seizure Detection and Prediction. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. The relation between antisocial and borderline personality symptoms and early maladaptive schemas in a treatment seeking sample of male substance users.

    Science.gov (United States)

    Shorey, Ryan C; Anderson, Scott; Stuart, Gregory L

    2014-01-01

    Individuals with substance use disorders are more likely to have antisocial and borderline personality disorder than non-substance abusers. Recently, research has examined the relations between early maladaptive schemas and personality disorders, as early maladaptive schemas are believed to underlie personality disorders. However, there is a dearth of research on the relations between early maladaptive schemas and personality disorders among individuals seeking treatment for substance abuse. The current study examined the relations among early maladaptive schemas and antisocial and borderline personality within in a sample of men seeking substance abuse treatment (n = 98). Results demonstrated that early maladaptive schema domains were associated with antisocial and borderline personality symptoms. Implications of these findings for substance use treatment and research are discussed. Antisocial (ASPD) and Borderline (BPD) personality disorder symptoms are prevalence among individuals seeking substance abuse treatment. Early maladaptive schemas are believed to underlie the development of ASPD and BPD symptoms, and are also prevalence among individuals seeking substance use treatment. Findings from the current study suggest that specific early maladaptive schema domains predict ASPD and BPD symptoms in a substance abuse treatment seeking sample of adult males. The treatment of ASPD and BPD among men seeking substance use treatment may want to focus on early maladaptive schemas. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Dynamic bifurcations on financial markets

    International Nuclear Information System (INIS)

    Kozłowska, M.; Denys, M.; Wiliński, M.; Link, G.; Gubiec, T.; Werner, T.R.; Kutner, R.; Struzik, Z.R.

    2016-01-01

    We provide evidence that catastrophic bifurcation breakdowns or transitions, preceded by early warning signs such as flickering phenomena, are present on notoriously unpredictable financial markets. For this we construct robust indicators of catastrophic dynamical slowing down and apply these to identify hallmarks of dynamical catastrophic bifurcation transitions. This is done using daily closing index records for the representative examples of financial markets of small and mid to large capitalisations experiencing a speculative bubble induced by the worldwide financial crisis of 2007-08.

  17. Evolutionary dynamics of diploid populations

    Science.gov (United States)

    Desimone, Ralph; Newman, Timothy

    2003-10-01

    There has been much recent interest in constructing computer models of evolutionary dynamics. Typically these models focus on asexual population dynamics, which are appropriate for haploid organsims such as bacteria. Using a recently developed ``genome template'' model, we extend the algorithm to a sexual population of diploid organisms. We will present some early results showing the temporal evolution of mean fitness and genetic variation, and compare this to typical results from haploid populations.

  18. Mechanisms Involving Ang II and MAPK/ERK1/2 Signaling Pathways Underlie Cardiac and Renal Alterations during Chronic Undernutrition

    Science.gov (United States)

    Pereira-Acácio, Amaury; Luzardo, Ricardo; Sampaio, Luzia S.; Luna-Leite, Marcia A.; Lara, Lucienne S.; Einicker-Lamas, Marcelo; Panizzutti, Rogério; Madeira, Caroline; Vieira-Filho, Leucio D.; Castro-Chaves, Carmen; Ribeiro, Valdilene S.; Paixão, Ana D. O.; Medei, Emiliano; Vieyra, Adalberto

    2014-01-01

    Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood. PMID:24983243

  19. Assessing component language deficits in the early detection of reading difficulty risk.

    Science.gov (United States)

    van der Lely, Heather K J; Marshall, Chloë R

    2010-01-01

    This article focuses on some of the linguistic components that underlie letter-sound decoding skills and reading comprehension: specifically phonology, morphology, and syntax. Many children who have reading difficulties had language deficits that were detectable before they began reading. Early identification of language difficulties will therefore help identify children at risk of reading failure. Using a developmental psycholinguistic framework, the authors provide a model of how syntax, morphology, and phonology break down in children with language impairments. The article reports on a screening test of these language abilities for preschool or young school-aged children that identifies those at risk for literacy problems and in need of further assessment.

  20. Noninvasive measurement of dynamic correlation functions

    CSIR Research Space (South Africa)

    Uhrich, P

    2017-08-01

    Full Text Available )spin systems and arbitrary equilibrium or nonequilibrium initial states. Different choices of the coupling operator give access to the real and imaginary parts of the dynamic correlation function. This protocol reduces disturbances due to the early...

  1. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new pa...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  2. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  3. Dynamics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Dynamics Lab replicates vibration environments for every Navy platform. Testing performed includes: Flight Clearance, Component Improvement, Qualification, Life...

  4. Early or Premature Menopause

    Science.gov (United States)

    ... email updates Enter email Submit Early or premature menopause Menopause that happens before age 40 is called ... What is the difference between early and premature menopause? Early or premature menopause happens when ovaries stop ...

  5. Early marriage and early motherhood in Nepal.

    Science.gov (United States)

    Choe, Minja Kim; Thapa, Shyam; Mishra, Vinod

    2005-03-01

    This paper examines age patterns of first marriage and motherhood and covariates of early marriage, delayed consummation of marriage and early motherhood in Nepal using data from the 2000 Nepal Adolescent and Young Adult Survey (NAYA). Both unmarried and married male and female youths (age 14-22) were included in the survey. The analysis is based on 2800 urban youths and 5075 rural youths with complete information on the variables examined. Proportional hazard models are used to estimate covariates of early marriage and early motherhood, and logistic regression models are used to estimate covariates of delayed consummation of marriage. The results show that early marriage and early motherhood are quite common among Nepalese women, especially in rural areas. Early marriage is much less common among men. Delayed consummation of marriage is common among very young brides, especially in rural areas. The main covariates associated with early marriage and early motherhood are respondent's education, region of residence and ethnicity. The main covariates of delayed consummation of marriage are age at first marriage, region of residence and ethnicity. The study highlights the need to focus on less educated female youths in the Terai region in order to reduce the reproductive and child health risks associated with early marriage and early childbearing.

  6. Early hospital discharge and early puerperal complications.

    Science.gov (United States)

    Ramírez-Villalobos, Dolores; Hernández-Garduño, Adolfo; Salinas, Aarón; González, Dolores; Walker, Dilys; Rojo-Herrera, Guadalupe; Hernández-Prado, Bernardo

    2009-01-01

    To evaluate the association between time of postpartum discharge and symptoms indicative of complications during the first postpartum week. Women with vaginal delivery at a Mexico City public hospital, without complications before the hospital discharge, were interviewed seven days after delivery. Time of postpartum discharge was classified as early (25 hours). The dependent variable was defined as the occurrence and severity of puerperal complication symptoms. Out of 303 women, 208 (68%) were discharged early. However, women with early discharge and satisfactory prenatal care had lower odds of presenting symptoms in early puerperium than women without early discharge and inadequate prenatal care (OR 0.36; 95% confidence intervals = 0.17-0.76). There was no association between early discharge and symptoms of complications during the first postpartum week; the odds of complications were lower for mothers with early discharge and satisfactory prenatal care.

  7. Classical dynamics a modern perspective

    CERN Document Server

    Sudarshan, Ennackal Chandy George

    2016-01-01

    Classical dynamics is traditionally treated as an early stage in the development of physics, a stage that has long been superseded by more ambitious theories. Here, in this book, classical dynamics is treated as a subject on its own as well as a research frontier. Incorporating insights gained over the past several decades, the essential principles of classical dynamics are presented, while demonstrating that a number of key results originally considered only in the context of quantum theory and particle physics, have their foundations in classical dynamics.Graduate students in physics and practicing physicists will welcome the present approach to classical dynamics that encompasses systems of particles, free and interacting fields, and coupled systems. Lie groups and Lie algebras are incorporated at a basic level and are used in describing space-time symmetry groups. There is an extensive discussion on constrained systems, Dirac brackets and their geometrical interpretation. The Lie-algebraic description of ...

  8. Computation in Dynamically Bounded Asymmetric Systems

    Science.gov (United States)

    Rutishauser, Ueli; Slotine, Jean-Jacques; Douglas, Rodney

    2015-01-01

    Previous explanations of computations performed by recurrent networks have focused on symmetrically connected saturating neurons and their convergence toward attractors. Here we analyze the behavior of asymmetrical connected networks of linear threshold neurons, whose positive response is unbounded. We show that, for a wide range of parameters, this asymmetry brings interesting and computationally useful dynamical properties. When driven by input, the network explores potential solutions through highly unstable ‘expansion’ dynamics. This expansion is steered and constrained by negative divergence of the dynamics, which ensures that the dimensionality of the solution space continues to reduce until an acceptable solution manifold is reached. Then the system contracts stably on this manifold towards its final solution trajectory. The unstable positive feedback and cross inhibition that underlie expansion and divergence are common motifs in molecular and neuronal networks. Therefore we propose that very simple organizational constraints that combine these motifs can lead to spontaneous computation and so to the spontaneous modification of entropy that is characteristic of living systems. PMID:25617645

  9. Fluid Dynamics

    DEFF Research Database (Denmark)

    Brorsen, Michael

    These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University.......These lecture notes are intended mainly for the 7th semester course "Fluid Dynamics" offered by the Study Committee on Civil Engineering, Aalborg University....

  10. Molecular dynamics

    NARCIS (Netherlands)

    Bergstra, J.A.; Bethke, I.

    2002-01-01

    Molecular dynamics is a model for the structure and meaning of object based programming systems. In molecular dynamics the memory state of a system is modeled as a fluid consisting of a collection of molecules. Each molecule is a collection of atoms with bindings between them. A computation is

  11. Full Day Early Learning Kindergarten Program Team: Perspectives from the Principal

    Science.gov (United States)

    Shahbazi, Sara; Salinitri, Geri

    2016-01-01

    The Full Day Early Learning Kindergarten (FDK) Program has expanded the role of the principal and has altered the teaching dynamics of the classroom with the introduction of an early years team. The early years team consists of a certified teacher with the Ontario College of Teachers and a registered early childhood educator from the College of…

  12. Early cannabis use and schizotypal personality disorder symptoms from adolescence to middle adulthood.

    Science.gov (United States)

    Anglin, Deidre M; Corcoran, Cheryl M; Brown, Alan S; Chen, Henian; Lighty, Quenesha; Brook, Judith S; Cohen, Patricia R

    2012-05-01

    While increasing evidence suggests that cannabis use may play a role in the development of schizophrenia in some young people, less is known about the strength and specificity of its relationship to latent schizophrenia liability, i.e., schizotypal personality disorder traits. Determine the predictive value of cannabis use during childhood and early adolescence on schizotypal personality disorder (SPD) symptoms projecting into adulthood, using a community-based longitudinal cohort from upstate New York. Prospective data from 804 participants was used to determine associations between early cannabis use and later schizotypal symptoms, accounting for important potential confounds (e.g., adolescent schizotypal symptoms). Cannabis use with onset prior to age 14 strongly predicted SPD symptoms in adulthood, independent of early adolescent SPD symptoms, major depression, anxiety disorder, other drug use, and cigarette use. There was no interaction effect of early cannabis use and early adolescent SPD symptoms on SPD symptoms into adulthood. Our data provide further support for a strong association of early cannabis use with the development of symptoms characteristic of schizophrenia spectrum disorders. As with studies in schizophrenia, early SPD symptoms could not fully explain the association of early cannabis use with later schizotypal symptoms. The mechanisms that underlie the association of cannabis use and schizotypal symptoms in a developmental context deserve further exploration. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Discrete dynamics versus analytic dynamics

    DEFF Research Database (Denmark)

    Toxværd, Søren

    2014-01-01

    For discrete classical Molecular dynamics obtained by the “Verlet” algorithm (VA) with the time increment h there exists a shadow Hamiltonian H˜ with energy E˜(h) , for which the discrete particle positions lie on the analytic trajectories for H˜ . Here, we proof that there, independent of such a......For discrete classical Molecular dynamics obtained by the “Verlet” algorithm (VA) with the time increment h there exists a shadow Hamiltonian H˜ with energy E˜(h) , for which the discrete particle positions lie on the analytic trajectories for H˜ . Here, we proof that there, independent...... of such an analytic analogy, exists an exact hidden energy invariance E * for VA dynamics. The fact that the discrete VA dynamics has the same invariances as Newtonian dynamics raises the question, which of the formulations that are correct, or alternatively, the most appropriate formulation of classical dynamics....... In this context the relation between the discrete VA dynamics and the (general) discrete dynamics investigated by Lee [Phys. Lett. B122, 217 (1983)] is presented and discussed....

  14. Early History of Titan

    Science.gov (United States)

    Castillo-Rogez, J. C.; Matson, D. L.; Johnson, T. V.; Atreya, S.; Lunine, J. I.

    2007-05-01

    We revisit models for the early history of Titan. Our models start a few My after the production of calcium- aluminum inclusions (CAIs), consistent with the dates required by our thermophysical-dynamical modeling of Saturn's medium-sized satellites. Depending on the time of formation with respect to CAIs, the accretion time scale, and the available accretional energy, models of Titan's interior after accretion are partially to fully differentiated. At one extreme of the models, Titan accretes incorporating a minimal amount of heat. This results in a relatively cold core that, over the long term, heats up and overturns, consistent with previous models of Titan. At the other extreme, accretional heat and heat fom the decay of short-lived radiogenic isotopes results in quick and complete differentiation. In this model there is no core overturn, and conditions soon develop for silicate serpentinization, and hydrothermal activity starts. We identify the periods during which conditions are suitable for hydrothermal geochemistry leading to the production of molecular nitrogen from ammonia decomposition and methane from the Fischer-Tropsch reaction. Key questions include the availability of suitable metal catalysts and/or clay minerals, storage of the reactants and products in the interior of Titan, and mechanisms by which they are released to the atmosphere. Acknowledgements: This work was carried out at the Jet Propulsion Laboratory-California Institute of Technology, under contract to NASA.

  15. Record dynamics

    DEFF Research Database (Denmark)

    Robe, Dominic M.; Boettcher, Stefan; Sibani, Paolo

    2016-01-01

    When quenched rapidly beyond their glass transition, colloidal suspensions fall out of equilibrium. The pace of their dynamics then slows down with the system age, i.e., with the time elapsed after the quench. This breaking of time translational invariance is associated with dynamical observables......-facto irreversible and become increasingly harder to achieve. Thus, a progression of record-sized dynamical barriers are traversed in the approach to equilibration. Accordingly, the statistics of the events is closely described by a log-Poisson process. Originally developed for relaxation in spin glasses...

  16. Galactic dynamics

    CERN Document Server

    Binney, James

    2008-01-01

    Since it was first published in 1987, Galactic Dynamics has become the most widely used advanced textbook on the structure and dynamics of galaxies and one of the most cited references in astrophysics. Now, in this extensively revised and updated edition, James Binney and Scott Tremaine describe the dramatic recent advances in this subject, making Galactic Dynamics the most authoritative introduction to galactic astrophysics available to advanced undergraduate students, graduate students, and researchers. Every part of the book has been thoroughly overhauled, and many section

  17. The Emerging Role of the Cytoskeleton in Chromosome Dynamics

    Directory of Open Access Journals (Sweden)

    Maya Spichal

    2017-05-01

    Full Text Available Chromosomes underlie a dynamic organization that fulfills functional roles in processes like transcription, DNA repair, nuclear envelope stability, and cell division. Chromosome dynamics depend on chromosome structure and cannot freely diffuse. Furthermore, chromosomes interact closely with their surrounding nuclear environment, which further constrains chromosome dynamics. Recently, several studies enlighten that cytoskeletal proteins regulate dynamic chromosome organization. Cytoskeletal polymers that include actin filaments, microtubules and intermediate filaments can connect to the nuclear envelope via Linker of the Nucleoskeleton and Cytoskeleton (LINC complexes and transfer forces onto chromosomes inside the nucleus. Monomers of these cytoplasmic polymers and related proteins can also enter the nucleus and play different roles in the interior of the nucleus than they do in the cytoplasm. Nuclear cytoskeletal proteins can act as chromatin remodelers alone or in complexes with other nuclear proteins. They can also act as transcription factors. Many of these mechanisms have been conserved during evolution, indicating that the cytoskeletal regulation of chromosome dynamics is an essential process. In this review, we discuss the different influences of cytoskeletal proteins on chromosome dynamics by focusing on the well-studied model organism budding yeast.

  18. Structural Dynamics

    International Nuclear Information System (INIS)

    Kim, Du Gi

    2005-08-01

    This book introduces summary of structural dynamics, the reason of learning of structural dynamics, single-degree of freedom system, simple harmonic vibration and application, numerical analysis method, such as time domain and frequency domain and nonlinear system, multi-degree of freedom system random vibration over discrete distribution, continuous distribution and extreme value distribution, circumstance vibration, earth quake vibration, including input earthquake, and earthquake-resistant design and capacity spectrum method, wind oscillation wave vibration, vibration control and maintenance control.

  19. Early Changes in Tumor Perfusion from T1-Weighted Dynamic Contrast-Enhanced MRI following Neural Stem Cell-Mediated Therapy of Recurrent High-Grade Glioma Correlate with Overall Survival

    Directory of Open Access Journals (Sweden)

    Prativa Sahoo

    2018-01-01

    Full Text Available Background. The aim of this study was to correlate T1-weighted dynamic contrast-enhanced MRI- (DCE-MRI- derived perfusion parameters with overall survival of recurrent high-grade glioma patients who received neural stem cell- (NSC- mediated enzyme/prodrug gene therapy. Methods. A total of 12 patients were included in this retrospective study. All patients were enrolled in a first-in-human study (NCT01172964 of NSC-mediated therapy for recurrent high-grade glioma. DCE-MRI data from all patients were collected and analyzed at three time points: MRI#1—day 1 postsurgery/treatment, MRI#2— day 7 ± 3 posttreatment, and MRI#3—one-month follow-up. Plasma volume (Vp, permeability (Ktr, and leakage (λtr perfusion parameters were calculated by fitting a pharmacokinetic model to the DCE-MRI data. The contrast-enhancing (CE volume was measured from the last dynamic phase acquired in the DCE sequence. Perfusion parameters and CE at each MRI time point were recorded along with their relative change between MRI#2 and MRI#3 (Δ32. Cox regression was used to analyze patient survival. Results. At MRI#1 and at MRI#3, none of the parameters showed a significant correlation with overall survival (OS. However, at MRI#2, CE and λtr were significantly associated with OS (p<0.05. The relative λtr and Vp from timepoint 2 to timepoint 3 (Δ32λtr and Δ32Vp were each associated with a higher hazard ratio (p<0.05. All parameters were highly correlated, resulting in a multivariate model for OS including only CE at MRI#2 and Δ32Vp, with an R2 of 0.89. Conclusion. The change in perfusion parameter values from 1 week to 1 month following NSC-mediated therapy combined with contrast-enhancing volume may be a useful biomarker to predict overall survival in patients with recurrent high-grade glioma.

  20. Functional neural circuits that underlie developmental stuttering

    Science.gov (United States)

    Zhao, Guihu; Huo, Yuankai; Herder, Carl L.; Sikora, Chamonix O.; Peterson, Bradley S.

    2017-01-01

    The aim of this study was to identify differences in functional and effective brain connectivity between persons who stutter (PWS) and typically developing (TD) fluent speakers, and to assess whether those differences can serve as biomarkers to distinguish PWS from TD controls. We acquired resting-state functional magnetic resonance imaging data in 44 PWS and 50 TD controls. We then used Independent Component Analysis (ICA) together with Hierarchical Partner Matching (HPM) to identify networks of robust, functionally connected brain regions that were highly reproducible across participants, and we assessed whether connectivity differed significantly across diagnostic groups. We then used Granger Causality (GC) to study the causal interactions (effective connectivity) between the regions that ICA and HPM identified. Finally, we used a kernel support vector machine to assess how well these measures of functional connectivity and granger causality discriminate PWS from TD controls. Functional connectivity was stronger in PWS compared with TD controls in the supplementary motor area (SMA) and primary motor cortices, but weaker in inferior frontal cortex (IFG, Broca’s area), caudate, putamen, and thalamus. Additionally, causal influences were significantly weaker in PWS from the IFG to SMA, and from the basal ganglia to IFG through the thalamus, compared to TD controls. ICA and GC indices together yielded an accuracy of 92.7% in classifying PWS from TD controls. Our findings suggest the presence of dysfunctional circuits that support speech planning and timing cues for the initiation and execution of motor sequences in PWS. Our high accuracy of classification further suggests that these aberrant brain features may serve as robust biomarkers for PWS. PMID:28759567

  1. Functional neural circuits that underlie developmental stuttering.

    Directory of Open Access Journals (Sweden)

    Jianping Qiao

    Full Text Available The aim of this study was to identify differences in functional and effective brain connectivity between persons who stutter (PWS and typically developing (TD fluent speakers, and to assess whether those differences can serve as biomarkers to distinguish PWS from TD controls. We acquired resting-state functional magnetic resonance imaging data in 44 PWS and 50 TD controls. We then used Independent Component Analysis (ICA together with Hierarchical Partner Matching (HPM to identify networks of robust, functionally connected brain regions that were highly reproducible across participants, and we assessed whether connectivity differed significantly across diagnostic groups. We then used Granger Causality (GC to study the causal interactions (effective connectivity between the regions that ICA and HPM identified. Finally, we used a kernel support vector machine to assess how well these measures of functional connectivity and granger causality discriminate PWS from TD controls. Functional connectivity was stronger in PWS compared with TD controls in the supplementary motor area (SMA and primary motor cortices, but weaker in inferior frontal cortex (IFG, Broca's area, caudate, putamen, and thalamus. Additionally, causal influences were significantly weaker in PWS from the IFG to SMA, and from the basal ganglia to IFG through the thalamus, compared to TD controls. ICA and GC indices together yielded an accuracy of 92.7% in classifying PWS from TD controls. Our findings suggest the presence of dysfunctional circuits that support speech planning and timing cues for the initiation and execution of motor sequences in PWS. Our high accuracy of classification further suggests that these aberrant brain features may serve as robust biomarkers for PWS.

  2. Shared genetic factors underlie chronic pain syndromes

    NARCIS (Netherlands)

    Vehof, Jelle; Zavos, Helena M. S.; Lachance, Genevieve; Hammond, Christopher J.; Williams, Frances M. K.

    Chronic pain syndromes (CPS) are highly prevalent in the general population, and increasingly the evidence points to a common etiological pathway. Using a large cohort of twins (n = 8564) characterized for chronic widespread musculoskeletal pain (CWP), chronic pelvic pain (PP), migraine (MIG), dry

  3. Structural hemispheric asymmetries underlie verbal Stroop performance.

    Science.gov (United States)

    Vallesi, Antonino; Mazzonetto, Ilaria; Ambrosini, Ettore; Babcock, Laura; Capizzi, Mariagrazia; Arbula, Sandra; Tarantino, Vincenza; Semenza, Carlo; Bertoldo, Alessandra

    2017-09-29

    Performance on tasks involving cognitive control such as the Stroop task is often associated with left lateralized brain activations. Based on this neuro-functional evidence, we tested whether leftward structural grey matter asymmetries would also predict inter-individual differences in combatting Stroop interference. To check for the specificity of the results, both a verbal Stroop task and a spatial one were administered to a total of 111 healthy young individuals, for whom T1-weighted magnetic resonance imaging (MRI) images were also acquired. Surface thickness and area estimations were calculated using FreeSurfer. Participants' hemispheres were registered to a symmetric template and Laterality Indices (LI) for the surface thickness and for the area at each vertex in each participant were computed. The correlation of these surface LI measures with the verbal and spatial Stroop effects (incongruent-congruent difference in trial performance) was assessed at each vertex by means of general linear models at the whole-brain level. We found a significant correlation between performance and surface area LI in an inferior posterior temporal cluster (overlapping with the so-called visual word form area, VWFA), with a more left-lateralized area in this region associated with a smaller Stroop effect only in the verbal task. These results point to an involvement of the VWFA for higher-level processes based on word reading, including the suppression of this process when required by the task, and could be interpreted in the context of cross-hemispheric rivalry. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Do convergent developmental mechanisms underlie convergent phenotypes?

    Science.gov (United States)

    Wray, Gregory A.

    2002-01-01

    Convergence is a pervasive evolutionary process, affecting many aspects of phenotype and even genotype. Relatively little is known about convergence in developmental processes, however, nor about the degree to which convergence in development underlies convergence in anatomy. A switch in the ecology of sea urchins from feeding to nonfeeding larvae illustrates how convergence in development can be associated with convergence in anatomy. Comparisons to more distantly related taxa, however, suggest that this association may be limited to relatively close phylogenetic comparisons. Similarities in gene expression during development provide another window into the association between convergence in developmental processes and convergence in anatomy. Several well-studied transcription factors exhibit likely cases of convergent gene expression in distantly related animal phyla. Convergence in regulatory gene expression domains is probably more common than generally acknowledged, and can arise for several different reasons. Copyright 2002 S. Karger AG, Basel.

  5. Perceived social isolation moderates the relationship between early childhood trauma and pulse pressure in older adults.

    Science.gov (United States)

    Norman, Greg J; Hawkley, Louise; Ball, Aaron; Berntson, Gary G; Cacioppo, John T

    2013-06-01

    Over a million children are subjected to some form of trauma in the United States every year. Early trauma has been shown to have deleterious effects on cardiovascular health in adulthood. However, the presence of strong social relationships as an adult can buffer an individual against many of the harmful effects of early trauma. Furthermore, the perception of social isolation has been shown to be a significant risk factor for the development of cardiovascular disease and is a strong predictor of all cause mortality. One likely mechanism thought to underlie the influence of perceived isolation on health is changes in arterial stiffness. One of the more widely used measures of arterial stiffness in older individuals is pulse pressure. The goal of the present study was to determine whether early childhood trauma is associated with elevations on pulse pressure. Furthermore, this study sought to determine whether perceived social isolation moderates the relationship between early trauma and pulse pressure. Results revealed that individuals with low perceived social isolation displayed no significant relationship between early trauma and pulse pressure. However, individuals who reported higher levels of perceived isolation showed a significant positive association between early trauma and pulse pressure. Therefore, the detrimental effects of early trauma may be partially dependent upon the quality of social relationships as an adult. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. A «titulus pictus» with an imperial mention in «Carthago Nova» and some considerations concerning the urban dynamics of the city in the early 3rd century ad

    Directory of Open Access Journals (Sweden)

    José Miguel NOGUERA CELDRÁN

    2017-06-01

    Full Text Available The archaeological and epigraphic record in Carthago Nova suggests that the colony underwent a period of instability and urban retreat during the second half of the 2nd and the 3rd century ad. This was probably triggered by the slowing down of economic activity, a shrinking population and collapse of local institutions and the crisis of evergetism. The process caused a substantial transformation of urban landscapes and a reduction of the size of the inhabited areas; the interruption of the epigraphic habit, the abandonment, looting and reoccupation of public areas and buildings; the pulling down of domestic buildings; and the insufficient maintenance of the urban road network. This has led some specialists to suggest that the city lost importance, and even that it could have been totally abandoned during the second half of the 2nd and, especially, the 3rd century ad. The recent discovery of the substantial transformation of the Atrium Building (Insula i Molinete in the early 3rd century ad, and of a titulus pictus which mentions the consuls for the year, Heliogabalus and the prefect of the praetorium Adventus, which dates the final date for the refectio in 218 ad, resituates the debate around the retreat of the urban centre in the 2nd and 3rd centuries ad.

  7. Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

    International Nuclear Information System (INIS)

    Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; Luijk, Peter van

    2016-01-01

    Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed the dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late

  8. Motor and extra-motor gray matter integrity may underlie neurophysiologic parameters of motor function in amyotrophic lateral sclerosis: a combined voxel-based morphometry and transcranial stimulation study.

    Science.gov (United States)

    Christidi, Foteini; Karavasilis, Efstratios; Velonakis, Georgios; Rentzos, Michail; Zambelis, Thomas; Zouvelou, Vasiliki; Xirou, Sophia; Ferentinos, Panagiotis; Efstathopoulos, Efstathios; Kelekis, Nikolaos; Evdokimidis, Ioannis; Karandreas, Nikolaos

    2018-02-07

    The association between gray matter (GM) density and neurophysiologic changes is still unclear in amyotrophic lateral sclerosis (ALS). We evaluated the relationship between GM density and motor system integrity combining voxel-based morphometry (VBM) and transcranial magnetic stimulation (TMS) in ALS. We included 17 ALS patients and 22 healthy controls (HC) who underwent 3D-T1-weighted imaging. Among the ALS group, we applied left motor cortex single-pulse TMS. We used whole-brain VBM comparing ALS and HC in GM density. We also conducted regression analysis to examine correlations between GM density and the following TMS parameters: motor evoked potential (MEP)/M ratio and central motor conduction time (CMCT). We found significantly decreased GM density in ALS patients in several frontal, temporal, parietal/occipital and cerebellar regions (p motor area (negative association). CMCT was associated with GM density in (a) inferior frontal gyrus and middle cingulated gyrus (positive association) and (b) superior parietal lobule; cuneus and cerebellum (negative association). Our findings support a significant interaction between motor and extra-motor structural and functional changes and highlight that motor and extra-motor GM integrity may underlie TMS parameters of motor function in ALS patients.

  9. Dynamic Bifurcations

    CERN Document Server

    1991-01-01

    Dynamical Bifurcation Theory is concerned with the phenomena that occur in one parameter families of dynamical systems (usually ordinary differential equations), when the parameter is a slowly varying function of time. During the last decade these phenomena were observed and studied by many mathematicians, both pure and applied, from eastern and western countries, using classical and nonstandard analysis. It is the purpose of this book to give an account of these developments. The first paper, by C. Lobry, is an introduction: the reader will find here an explanation of the problems and some easy examples; this paper also explains the role of each of the other paper within the volume and their relationship to one another. CONTENTS: C. Lobry: Dynamic Bifurcations.- T. Erneux, E.L. Reiss, L.J. Holden, M. Georgiou: Slow Passage through Bifurcation and Limit Points. Asymptotic Theory and Applications.- M. Canalis-Durand: Formal Expansion of van der Pol Equation Canard Solutions are Gevrey.- V. Gautheron, E. Isambe...

  10. Dynamical Groups

    Science.gov (United States)

    Paldus, Josef

    The well known symmetry (invariance, degeneracy) dynamical groups or algebras of quantum mechanical Hamiltonians provide quantum numbers (conservation laws, integrals of motion) for state labeling and the associated selection rules. In addition, it is often advantageous to employ much larger groups, referred to as the dynamical groups (noninvariance groups, dynamical algebras, spectrum generating algebras), which may or may not be the invariance groups of the studied system [4.1,2,3,4,5,6,7]. In all known cases, they are Lie groups (LGs), or rather corresponding Lie algebras (LAs), and one usually requires that all states of interest of a system be contained in a single irreducible representation (irrep). Likewise, one may require that the Hamiltonian be expressible in terms of the Casimir operators of the corresponding universal enveloping algebra [4.8,9]. In a weaker sense, one regards any group (or corresponding algebra) as a dynamical group if the Hamiltonian can be expressed in terms of its generators [4.10,11,12]. In nuclear physics, one sometimes distinguishes exact (baryon number preserving), almost exact (e.g., total isospin), approximate (e.g., SU(3) of the "eightfold way") and model (e.g., nuclear shell model) dynamical symmetries [4.13]. The dynamical groups of interest in atomic and molecular physics can be conveniently classified by their topological characteristic of compactness. Noncompact LGs (LAs) generally arise in simple problems involving an infinite number of bound states, while those involving a finite number of bound states (e.g., molecular vibrations or ab initio models of electronic structure) exploit compact LG's.

  11. Task-dependent recurrent dynamics in visual cortex

    Science.gov (United States)

    Tajima, Satohiro; Koida, Kowa; Tajima, Chihiro I; Suzuki, Hideyuki; Aihara, Kazuyuki; Komatsu, Hidehiko

    2017-01-01

    The capacity for flexible sensory-action association in animals has been related to context-dependent attractor dynamics outside the sensory cortices. Here, we report a line of evidence that flexibly modulated attractor dynamics during task switching are already present in the higher visual cortex in macaque monkeys. With a nonlinear decoding approach, we can extract the particular aspect of the neural population response that reflects the task-induced emergence of bistable attractor dynamics in a neural population, which could be obscured by standard unsupervised dimensionality reductions such as PCA. The dynamical modulation selectively increases the information relevant to task demands, indicating that such modulation is beneficial for perceptual decisions. A computational model that features nonlinear recurrent interaction among neurons with a task-dependent background input replicates the key properties observed in the experimental data. These results suggest that the context-dependent attractor dynamics involving the sensory cortex can underlie flexible perceptual abilities. DOI: http://dx.doi.org/10.7554/eLife.26868.001 PMID:28737487

  12. Dynamical systems

    CERN Document Server

    Birkhoff, George D

    1927-01-01

    His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o

  13. Glassy Dynamics

    DEFF Research Database (Denmark)

    Jensen, Henrik J.; Sibani, Paolo

    2007-01-01

    The term glassy dynamics is often used to refer to the extremely slow relaxation observed in several types of many component systems. The time span needed to reach a steady, time independent, state will typically be far beyond experimentally accessible time scales. When melted alloys are cooled...... down they typically do not enter a crystalline ordered state. Instead the atoms retain the amorphous arrangement characteristic of the liquid high temperature phase while the mobility of the molecules decreases very many orders of magnitude. This colossal change in the characteristic dynamical time...

  14. Forest dynamics.

    Science.gov (United States)

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  15. Growth factors and early mesoderm morphogenesis: insights from the sea urchin embryo.

    Science.gov (United States)

    Adomako-Ankomah, Ashrifia; Ettensohn, Charles A

    2014-03-01

    The early morphogenesis of the mesoderm is critically important in establishing the body plan of the embryo. Recent research has led to a better understanding of the mechanisms that underlie this process, and growth factor signaling pathways have emerged as key regulators of the directional movements of mesoderm cells during gastrulation. In this review, we undertake a comparative analysis of the various essential functions of growth factor signaling pathways in regulating early mesoderm morphogenesis, with an emphasis on recent advances in the sea urchin embryo. We focus on the roles of the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) pathways in the migration of primary mesenchyme cells and the formation of the embryonic endoskeleton. We compare the functions of VEGF and FGF in sea urchins with the roles that these and other growth factors play in regulating mesoderm migration during gastrulation in Drosophila and vertebrates. Copyright © 2014 Wiley Periodicals, Inc.

  16. Dynamic effective connectivity in resting state fMRI.

    Science.gov (United States)

    Park, Hae-Jeong; Friston, Karl J; Pae, Chongwon; Park, Bumhee; Razi, Adeel

    2017-11-20

    Context-sensitive and activity-dependent fluctuations in connectivity underlie functional integration in the brain and have been studied widely in terms of synaptic plasticity, learning and condition-specific (e.g., attentional) modulations of synaptic efficacy. This dynamic aspect of brain connectivity has recently attracted a lot of attention in the resting state fMRI community. To explain dynamic functional connectivity in terms of directed effective connectivity among brain regions, we introduce a novel method to identify dynamic effective connectivity using spectral dynamic causal modelling (spDCM). We used parametric empirical Bayes (PEB) to model fluctuations in directed coupling over consecutive windows of resting state fMRI time series. Hierarchical PEB can model random effects on connectivity parameters at the second (between-window) level given connectivity estimates from the first (within-window) level. In this work, we used a discrete cosine transform basis set or eigenvariates (i.e., expression of principal components) to model fluctuations in effective connectivity over windows. We evaluated the ensuing dynamic effective connectivity in terms of the consistency of baseline connectivity within default mode network (DMN), using the resting state fMRI from Human Connectome Project (HCP). To model group-level baseline and dynamic effective connectivity for DMN, we extended the PEB approach by conducting a multilevel PEB analysis of between-session and between-subject group effects. Model comparison clearly spoke to dynamic fluctuations in effective connectivity - and the dynamic functional connectivity these changes explain. Furthermore, baseline effective connectivity was consistent across independent sessions - and notably more consistent than estimates based upon conventional models. This work illustrates the advantage of hierarchical modelling with spDCM, in characterizing the dynamics of effective connectivity. Copyright © 2017 The Authors

  17. The perceptual dimensions of natural dynamic flow.

    Science.gov (United States)

    Morgenstern, Yaniv; Kersten, Daniel J

    2017-10-01

    We measured perceptual judgments of category, material attributes, affordances, and similarity to investigate the perceptual dimensions underlying the visual representation of a broad class of natural dynamic flows (sea waves, smoke, and windblown foliage). The dynamic flows were looped 3-s movies windowed with circular apertures of two sizes to manipulate the level of spatial context. In low levels of spatial context (smaller apertures), human observers' judgments of material attributes and affordances were inaccurate, with estimates biased toward assumptions that the flows resulted from objects that were rigid, "pick-up-able," and not penetrable. The similarity arrangements showed dynamic flow clusters based partly on material, but dominated by color appearance. In high levels of spatial context (large apertures), observers reliably estimated material categories and their attributes. The similarity arrangements were based primarily on categories related to external, physical causes. Representational similarity analysis suggests that while shallow dimensions like color sometimes account for inferences of physical causes in the low-context condition, shallow dimensions cannot fully account for these inferences in the high-context condition. For the current broad data set of dynamic flows, the perceptual dimensions that best account for the similarity arrangements in the high-context condition are related to the intermolecular bond strength of a material's underlying physical structure. These arrangements are also best related to affordances that underlie common motor activities. Thus, the visual system appears to use an efficient strategy to resolve flow ambiguity; vision will sometimes rely on local, image-based, statistical properties that can support reliable inference of external physical causes, and other times it uses deeper causal knowledge to interpret and use flow information to the extent that it is useful for everyday action decisions.

  18. Participatory System Dynamics Modeling: Increasing Stakeholder Engagement and Precision to Improve Implementation Planning in Systems.

    Science.gov (United States)

    Zimmerman, Lindsey; Lounsbury, David W; Rosen, Craig S; Kimerling, Rachel; Trafton, Jodie A; Lindley, Steven E

    2016-11-01

    Implementation planning typically incorporates stakeholder input. Quality improvement efforts provide data-based feedback regarding progress. Participatory system dynamics modeling (PSD) triangulates stakeholder expertise, data and simulation of implementation plans prior to attempting change. Frontline staff in one VA outpatient mental health system used PSD to examine policy and procedural "mechanisms" they believe underlie local capacity to implement evidence-based psychotherapies (EBPs) for PTSD and depression. We piloted the PSD process, simulating implementation plans to improve EBP reach. Findings indicate PSD is a feasible, useful strategy for building stakeholder consensus, and may save time and effort as compared to trial-and-error EBP implementation planning.

  19. Early Cambrian oxygen minimum zone-like conditions at Chengjiang

    DEFF Research Database (Denmark)

    Hammarlund, Emma U.; Gaines, Robert R.; Prokopenko, Maria G.

    2017-01-01

    in early Cambrian marine settings and the relationship of those conditions to early metazoan ecosystems is still emerging. Here, we report multi-proxy geochemical data from two drill cores through the early Cambrian (Series 2) Yu’anshan Formation of Yunnan, China. Results reveal dynamic water...... oxygen-minimum zones. The oxygenated benthic environments in which the Chengjiang biota thrived were proximal to, but sharply separated from, the open ocean by a persistent anoxic water mass that occupied a portion of the outer shelf. Oxygen depletion in the lower water column developed dynamically...

  20. DNA methylation dynamics in neurogenesis

    Science.gov (United States)

    Wang, Zhiqin; Tang, Beisha; He, Yuquan; Jin, Peng

    2016-01-01

    Neurogenesis is not limited to the embryonic stage, but continually proceeds in the adult brain throughout life. Epigenetic mechanisms, including DNA methylation, histone modification and noncoding RNA, play important roles in neurogenesis. For decades, DNA methylation was thought to be a stable modification, except for demethylation in the early embryo. In recent years, DNA methylation has proved to be dynamic during development. In this review, we summarize the latest understanding about DNA methylation dynamics in neurogenesis, including the roles of different methylation forms (5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine), as well as their ‘writers’, ‘readers’ and interactions with histone modifications. PMID:26950681

  1. EARLY ENTRANCE COPRODUCTION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    John Anderson; Mark Anselmo; Earl Berry; Mark Bohn; Roko Bujas; Ming He; Ken Kwik; Charles H. Schrader; Lalit Shah; Dennis Slater; Donald Todd; Don Wall

    2003-08-21

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC (TES), a subsidiary of ChevronTexaco, General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, Inc. GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems were assessed for technical risks and barriers. A plan was identified to mitigate the identified risks (Phase II RD&T Plan, October 2000). The RD&T Plan identified catalyst/wax separation as a potential technical and economic risk. To mitigate risks to the proposed EECP, Phase II RD&T included tests of an alternative (to Rentech's Dynamic Settler) primary catalyst

  2. Climate, vegetation and lake development at Sokli (northern Finland) during early MIS 3 at ∼50 kyr: Revising earlier concepts on climate, glacial and vegetation dynamics in Fennoscandia during the Weichselian

    International Nuclear Information System (INIS)

    Helmens, Karin F.

    2009-08-01

    Long sediment records that register environmental changes in formerly glaciated regions such as Fennoscandia in the period preceding the Last Glacial Maximum (LGM) at ∼ 20 kyr are rare. The Weichselian history of Fennoscandia is based on the long-distance correlation of poorly dated stratigraphic fragmentary evidence and studies on glacial geomorphology. Environmental conditions during ice-free intervals have been mostly reconstructed based on low resolution palynological analysis only. Here we present the results of a detailed study of a for Fennoscandia unusually long and continuous sediment sequence that has been recovered from the Sokli basin in northern Finland. The Sokli sequence consists of tills, glacio-fluvial beds, and fluvial beds, interlayered with fossil-rich lacustrine sediments that according to multiple accelerator mass spectrometer (AMS) 14 C and optically stimulated luminescence (OSL) datings extend from the present into the Penultimate Glacial representing the last ∼130 kyr. This report focuses on the youngest Weichselian interstadial interval with ice-free conditions at Sokli dated to ∼50 kyr in the early part of Marine Isotope Stage (MIS) 3. A comprehensive environmental reconstruction is made based on multi-proxy analysis on a two meter thick laminated, lacustrine clay-silt sequence, including lithological characteristics; organic content (loss-on-ignition, LOI); plant microfossils (pollen, spores, algal and fungal remains); macrofossils of plants (e.g. seeds, moss remains) and of aquatic animals (e.g. statoblasts of Bryozoa); head-capsules of chironomids (i.e. aquatic insects); and diatoms and other siliceous microfossils (e.g. phytolits, chrysophyte stomatocysts). Additionally, geomorphic evidence and analysis of Digital Elevation Model (DEM) data are employed in the environmental reconstruction. Mean July temperatures are reconstructed by applying transfer functions to the pollen, chironomid and diatom records. The results have been

  3. Climate, vegetation and lake development at Sokli (northern Finland) during early MIS 3 at approx50 kyr: Revising earlier concepts on climate, glacial and vegetation dynamics in Fennoscandia during the Weichselian

    Energy Technology Data Exchange (ETDEWEB)

    Helmens, Karin F. (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))

    2009-08-15

    Long sediment records that register environmental changes in formerly glaciated regions such as Fennoscandia in the period preceding the Last Glacial Maximum (LGM) at approx 20 kyr are rare. The Weichselian history of Fennoscandia is based on the long-distance correlation of poorly dated stratigraphic fragmentary evidence and studies on glacial geomorphology. Environmental conditions during ice-free intervals have been mostly reconstructed based on low resolution palynological analysis only. Here we present the results of a detailed study of a for Fennoscandia unusually long and continuous sediment sequence that has been recovered from the Sokli basin in northern Finland. The Sokli sequence consists of tills, glacio-fluvial beds, and fluvial beds, interlayered with fossil-rich lacustrine sediments that according to multiple accelerator mass spectrometer (AMS) 14C and optically stimulated luminescence (OSL) datings extend from the present into the Penultimate Glacial representing the last approx130 kyr. This report focuses on the youngest Weichselian interstadial interval with ice-free conditions at Sokli dated to approx50 kyr in the early part of Marine Isotope Stage (MIS) 3. A comprehensive environmental reconstruction is made based on multi-proxy analysis on a two meter thick laminated, lacustrine clay-silt sequence, including lithological characteristics; organic content (loss-on-ignition, LOI); plant microfossils (pollen, spores, algal and fungal remains); macrofossils of plants (e.g. seeds, moss remains) and of aquatic animals (e.g. statoblasts of Bryozoa); head-capsules of chironomids (i.e. aquatic insects); and diatoms and other siliceous microfossils (e.g. phytolits, chrysophyte stomatocysts). Additionally, geomorphic evidence and analysis of Digital Elevation Model (DEM) data are employed in the environmental reconstruction. Mean July temperatures are reconstructed by applying transfer functions to the pollen, chironomid and diatom records. The results

  4. Structural dynamics

    CERN Document Server

    Strømmen, Einar N

    2014-01-01

    This book introduces to the theory of structural dynamics, with focus on civil engineering structures that may be described by line-like beam or beam-column type of systems, or by a system of rectangular plates. Throughout this book the mathematical presentation contains a classical analytical description as well as a description in a discrete finite element format, covering the mathematical development from basic assumptions to the final equations ready for practical dynamic response predictions. Solutions are presented in time domain as well as in frequency domain. Structural Dynamics starts off at a basic level and step by step brings the reader up to a level where the necessary safety considerations to wind or horizontal ground motion induced dynamic design problems can be performed. The special theory of the tuned mass damper has been given a comprehensive treatment, as this is a theory not fully covered elsewhere. For the same reason a chapter on the problem of moving loads on beams has been included.

  5. Coastal Dynamics

    NARCIS (Netherlands)

    Roelvink, J.A.; Steetzel, H.J.; Bliek, A.; Rakhorst, H.D.; Roelse, P.; Bakker, W.T.

    1998-01-01

    This book deals on "Coastal Dynamics", which will be defined in a narrow sense as a mathematical theory, which starts from given equations of motion for the sediment, which leads with the continuity equation and given boundary conditions to a calculated (eventually schematized) coastal topography,

  6. Random dynamics

    International Nuclear Information System (INIS)

    Bennett, D.L.; Brene, N.; Nielsen, H.B.

    1986-06-01

    The goal of random dynamics is the derivation of the laws of Nature as we know them (standard model) from inessential assumptions. The inessential assumptions made here are expressed as sets of general models at extremely high energies: gauge glass and spacetime foam. Both sets of models lead tentatively to the standard model. (orig.)

  7. Dynamic Pricing

    DEFF Research Database (Denmark)

    Sharifi, Reza; Anvari-Moghaddam, Amjad; Fathi, S. Hamid

    2017-01-01

    Dynamic pricing scheme, also known as real-time pricing (RTP), can be more efficient and technically beneficial than the other price-based schemes (such as flat-rate or time-of-use (TOU) pricing) for enabling demand response (DR) actions. Over the past few years, advantages of RTP-based schemes h...

  8. Classical dynamics

    CERN Document Server

    Greenwood, Donald T

    1997-01-01

    Graduate-level text for science and technology students provides strong background in the more abstract and intellectually satisfying areas of dynamical theory. Topics include d'Alembert's principle and the idea of virtual work, Hamilton's equations, Hamilton-Jacobi theory, canonical transformations, more. Problems and references at chapter ends.

  9. Cybersecurity Dynamics

    Science.gov (United States)

    2014-08-20

    Vision: Cybersecurity Dynamics Foundation for the Science of Cybersecurity Cryptography Intrusion & Malware Detection Access Control TPM MTD...Science of Cybersecurity Cryptography Intrusion & Malware Detection Access Control TPM MTD Security Policy Security Architecture Attack...for the Science of Cybersecurity Cryptography Intrusion & Malware Detection Access Control TPM MTD Security Policy Security Architecture

  10. Expansion dynamics

    International Nuclear Information System (INIS)

    Knoll, J.

    1985-10-01

    A quantum dynamical model is suggested which describes the expansion and disassembly phase of highly excited compounds formed in energetic heavy-ion collisions. First applications in two space and one time dimensional model world are discussed and qualitatively compared to standard freeze-out concepts. (orig.)

  11. Dynamic Assessment.

    Science.gov (United States)

    Schoel, Jim

    1998-01-01

    Adventure therapists are often asked to assess clients in a manner that differs from their therapeutic approach, resulting in assessment being perceived as burdensome. Project Adventure's Decision Tree combines assessment with activity selection to create a dynamic tool that is responsive to group, individual, and leader needs. Example focuses on…

  12. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...

  13. Differences in Early Maladaptive Schemas in a Sample of Alcohol and Opioid Dependent Women: Do Schemas Vary Across Disorders?

    Science.gov (United States)

    Shorey, Ryan C.; Stuart, Gregory L.; Anderson, Scott

    2012-01-01

    Research suggests that there may be differences between individuals diagnosed with alcohol dependence and individuals diagnosed with opioid dependence on co-morbid mental health problems (e.g., personality disorders, mood disorders, etc.). The current study examined whether there were differences in early maladaptive schemas, which are theorized to underlie mental health problems, among women diagnosed with alcohol dependence or opioid dependence who were seeking treatment for their substance use (N = 420). Results showed that opioid dependent women scored higher on 2 of the 18 early maladaptive schemas, particularly the schemas of dependence and punitiveness. Overall, these findings suggest that early maladaptive schemas may be largely consistent across women diagnosed with alcohol or opioid dependence. Implications of these findings for future research and treatment are discussed. PMID:23494129

  14. How nonlinear systems inform meaning and early education.

    Science.gov (United States)

    Fromberg, Doris Pronin

    2010-01-01

    This paper contends that educators need to prepare young learners to function with the predictable unpredictability of life in this century by participating in the kind of education that is transformational and adaptive to the ways in which children acquire meaning. When teachers implement a dynamic-themes theory of early education they can help children younger than nine years of age to integrate meaning. The isomorphic relationships apparent within each of several theories--script theory, Theory of Mind as metacognition, and chaos and complexity theory--together can provide evidence for the nature of meaning and its relationship to the nonlinear early education of children. The transformational-generative characteristics of these theories, that include constructed learning, inform dynamic early educational practice. Play, as one condition for meaningful early learning, also has particular significance in early education by affording an environment for assessing learning.

  15. Applied dynamics

    CERN Document Server

    Schiehlen, Werner

    2014-01-01

    Applied Dynamics is an important branch of engineering mechanics widely applied to mechanical and automotive engineering, aerospace and biomechanics as well as control engineering and mechatronics. The computational methods presented are based on common fundamentals. For this purpose analytical mechanics turns out to be very useful where D’Alembert’s principle in the Lagrangian formulation proves to be most efficient. The method of multibody systems, finite element systems and continuous systems are treated consistently. Thus, students get a much better understanding of dynamical phenomena, and engineers in design and development departments using computer codes may check the results more easily by choosing models of different complexity for vibration and stress analysis.

  16. Delta Dynamics

    DEFF Research Database (Denmark)

    Bendixen, Mette

    A warming climate affects the entire planet, but the Arctic experience a warming that is faster than elsewhere in the world. This influences several processes affecting the evolution of the Arctic coast, and increasing erosion rates are detected throughout large parts of these high-latitude coasts...... to sandy beaches, marshes and deltas. This PhD thesis investigates coastal evolution with a special focus on changes in deltaic environments both during the Holocene and in a modern changing climate. The first part of the thesis (Paper 1 and 2) focus on detailed processes affecting delta evolution...... of a fjord and the second type is a wider fan-shaped open delta. Most deltas are directly coupled to the Greenland Ice Sheet or local icecaps and are highly influenced by the dynamics in the catchments. It is demonstrated how a modern changing climate directly affects delta dynamics, and that Greenlandic...

  17. Guideline for Early Interventions

    Science.gov (United States)

    2006-04-01

    RTO-MP-HFM-134 6 - 1 Guideline for Early Interventions Maaike de Vries Impact Foundation, Dutch Knowledge & Advice Centre for Post...assistance, also referred to as ‘ early interventions ’ or ‘debriefing’, is offered following shocking events. These may be large scale disasters or...calamities, but also military deployment and individual incidents. During the last years, the demand for early interventions has been increasing

  18. Education of dance skills in early adolescence

    OpenAIRE

    Banevičiūtė Ališauskienė , Birutė

    2010-01-01

    The dissertation deals with the problem of dance skills education in early adolescence. The analyses of educational, professional, psychological and philosophical sources substantiated the structure of dance skills which is grounded by principles of cognitive arts education theory and based on expression of dance elements (movement, spac, rhythm, tempo, energy, dynamics, metaphore) and communication trough it. Communicative course in dance skills education, kinesthetic aspect of dance skill...

  19. Early intervention in psychosis

    DEFF Research Database (Denmark)

    Csillag, Claudio; Nordentoft, Merete; Mizuno, Masafumi

    2017-01-01

    AIM: Early intervention in psychosis (EIP) is a well-established approach with the intention of early detection and treatment of psychotic disorders. Its clinical and economic benefits are well documented. This paper presents basic aspects of EIP services, discusses challenges to their implementa......AIM: Early intervention in psychosis (EIP) is a well-established approach with the intention of early detection and treatment of psychotic disorders. Its clinical and economic benefits are well documented. This paper presents basic aspects of EIP services, discusses challenges...

  20. Hamiltonian dynamics

    CERN Document Server

    Vilasi, Gaetano

    2001-01-01

    This is both a textbook and a monograph. It is partially based on a two-semester course, held by the author for third-year students in physics and mathematics at the University of Salerno, on analytical mechanics, differential geometry, symplectic manifolds and integrable systems. As a textbook, it provides a systematic and self-consistent formulation of Hamiltonian dynamics both in a rigorous coordinate language and in the modern language of differential geometry. It also presents powerful mathematical methods of theoretical physics, especially in gauge theories and general relativity. As a m

  1. Understanding the cognitive underpinnings of functional impairments in early dementia: a review.

    Science.gov (United States)

    Giebel, Clarissa M; Challis, David; Montaldi, Daniela

    2015-01-01

    Early dementia is marked by cognitive and functional impairments, and although studies indicate an association between these, detailed analyses exploring this relationship are rare. It is crucial to understand how specific cognitive deficits underlie functional deficits to develop successful cognitive interventions. This paper reviews the evidence of impairment in everyday functioning and in working, long-term and prospective memory in early dementia. Findings are evaluated with respect to the relationship between cognitive and functional impairments. From the literature searches, 17 studies on everyday functioning and 40 studies on memory were obtained. Studies were only included if patients had an official diagnosis and were in the early stages of dementia. Complex instrumental activities of daily living were subject to greater impairment than basic activities of daily living. In particular, early dementia patients struggle with finance tasks; a deficit linked to impaired working memory. Regarding cognition, long-term memory is the earliest form of memory to decline as is well recognised. Evidence also indicates deficits in working and prospective memory, with inconsistent evidence about impairments of the former. A major limitation of the literature is a lack of studies assessing individual everyday activities and the associated error patterns that might occur. This review critically assesses the status of translational research for everyday activities in early dementia, an area with critical implications for cognitive-based rehabilitation. Further research is required into the detailed assessment of individual everyday activity and specific memory deficits, in order to effectively map cognitive functions onto functional performance.

  2. Diastolic and autonomic dysfunction in early cirrhosis

    DEFF Research Database (Denmark)

    Dahl, Emilie Kristine; Møller, Søren; Kjær, Andreas

    2014-01-01

    cirrhosis during maximal β-adrenergic drive. MATERIAL AND METHODS. Nineteen patients with Child A (n = 12) and Child B cirrhosis (n = 7) and seven matched controls were studied during cardiac stress induced by increasing dosages of dobutamine and atropine. RESULTS. Pharmacological responsiveness was similar...... fraction was similar in patients and controls. Peak filling rate was longer in cirrhosis compared to controls (1.8 ± 0.4 and 1.4 ± 0.2 end-diastolic volume/s, p stress by 13% compared to 0% in controls, p ... indicate that patients with early stage cirrhosis exhibit early diastolic and autonomic dysfunction as well as elevated pro-ANP. However, the cardiac chronotropic and inotropic responses to dobutamine stress were normal. The dynamics of ventricular repolarization appears normal in patients with early stage...

  3. Interstellar matter in early-type galaxies

    International Nuclear Information System (INIS)

    Kim, D.W.

    1988-01-01

    Multi-wavelength observations were performed in order to investigate various phases of interstellar matter in early type galaxies. The IRAS coadding procedure for a large sample of galaxies, the author found that about half of early type galaxies contain detectable amounts of cold interstellar dust. Selecting galaxies with strong far infrared fluxes, he undertook optical imaging and spectroscopy, HI λ21 cm line observations and CO J = 1-0 line observations. He successfully detected cold dust, HI gas, ionized gas and molecular material; proving that the far infrared flux is indeed a good indicator for the presence of interstellar matter. The infrared emission mechanism and origin and fate of interstellar matter are discussed using the data obtained from various phases of interstellar matter. The interstellar matter is also used as a probe of dynamical structure, nuclear activity and star formation in early type galaxies

  4. Maternal early warning systems.

    Science.gov (United States)

    Friedman, Alexander M

    2015-06-01

    This article reviews evidence and recommendations for maternal early warning systems designed to reduce severe maternal morbidity and mortality. The clinical rationale for these systems is discussed as is research literature on early warning systems from other fields. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Early College High Schools

    Science.gov (United States)

    Dessoff, Alan

    2011-01-01

    For at-risk students who stand little chance of going to college, or even finishing high school, a growing number of districts have found a solution: Give them an early start in college while they still are in high school. The early college high school (ECHS) movement that began with funding from the Bill and Melinda Gates Foundation 10 years ago…

  6. Early rehabilitation after stroke.

    Science.gov (United States)

    Bernhardt, Julie; Godecke, Erin; Johnson, Liam; Langhorne, Peter

    2017-02-01

    Early rehabilitation is recommended in many guidelines, with limited evidence to guide practice. Brain neurobiology suggests that early training, at the right dose, will aid recovery. In this review, we highlight recent trials of early mobilization, aphasia, dysphagia and upper limb treatment in which intervention is commenced within 7 days of stroke and discuss future research directions. Trials in this early time window are few. Although the seminal AVERT trial suggests that a cautious approach is necessary immediately (stroke, early mobility training and mobilization appear well tolerated, with few reasons to delay initiating some rehabilitation within the first week. The results of large clinical trials of early aphasia therapy are on the horizon, and examples of targeted upper limb treatments with better patient selection are emerging. Early rehabilitation trials are complex, particularly those that intervene across acute and rehabilitation care settings, but these trials are important if we are to optimize recovery potential in the critical window for repair. Concerted efforts to standardize 'early' recruitment, appropriately stratify participants and implement longer term follow-up is needed. Trial standards are improving. New recommendations from a recent Stroke Recovery and Rehabilitation Roundtable will help drive new research.

  7. Holocene fire dynamics in Fennoscandia

    Science.gov (United States)

    Clear, Jennifer; Seppa, Heikki; Kuosmanen, Niina; Molinari, Chiara; Lehsten, Veiko; Allen, Katherine; Bradshaw, Richard

    2015-04-01

    Prescribed burning is advocated in Fennoscandia to promote regeneration and to encourage biodiversity. This method of forest management is based on the perception that fire was much more frequent in the recent past and over a century of active fire suppression has created a boreal forest ecosystem almost free of natural fire. The absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce) with the successive spruce dominated forest further reducing fire ignition potential. However, humans have altered the natural fire dynamics of Fennoscandia since the early- to mid-Holocene and disentangling the anthropogenic driven fire dynamics from the natural fire dynamics is challenging. Through palaeoecology and sedimentary charcoal deposits we are able to explore the Holocene spatial and temporal variability and changing drivers of fire and vegetation dynamics in Fennoscandia. At the local-scale, two forest hollow environments (history are compared to identify unique and mutual changes in disturbance history. Pollen derived quantitative reconstruction of vegetation at both the local- and regional-scale identifies local-scale disturbance dynamics and large-scale ecosystem response. Spatio-temporal heterogeneity and variability in biomass burning is explored throughout Fennoscandia and Denmark to identify the changing drives of fire dynamics throughout the Holocene. Palaeo-vegetation reconstructions are compared to process-based, climate driven dynamic vegetation model output to test the significance of fire frequency as a driver of vegetation composition and dynamics. Early-Holocene fire regimes in Fennoscandia are driven by natural climate variations and fuel availability. The establishment and spread of Norway spruce is driven by an increase in continentality of climate, but local natural and anthropogenic ecosystem disturbance may have aided this spread. The expansion of spruce led to a step-wise reduction in regional biomass

  8. Complex dynamics

    CERN Document Server

    Carleson, Lennart

    1993-01-01

    Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...

  9. Premelting Dynamics

    Science.gov (United States)

    Wettlaufer, J. S.; Grae Worster, M.

    2006-01-01

    When the free surfaces of most solids approach their bulk melting temperatures from below, the molecular structure of the material gives way to a disordered structure with some attributes of both the solid and liquid phases. When the temperature is sufficiently close to that of bulk transition, the surface melts and literally flows as a viscous fluid. This phenomenon, called interfacial premelting, lies at the heart of the microscopic theory of melting of solid matter, and captures the interest of condensed matter physicists and physical chemists alike. The process is ubiquitous and responsible for a wide range of consequences in materials with biological, geophysical, and technological significance. Because such systems are often exposed to spatial or temporal variations in thermodynamic forcing, there are a host of fluid mechanical phenomena that result from this underlying melting behavior. The fluid dynamics of unfrozen surfaces holds clues for understanding the bulk behavior of polycrystalline materials, from Earth's mantle to the stratosphere and beyond. In this review we focus on the fluid dynamical consequences of the premelting of solids.

  10. Mitochondrial dynamics and the cell cycle

    Directory of Open Access Journals (Sweden)

    Penny M.A. Kianian

    2014-05-01

    Full Text Available Nuclear-mitochondrial (NM communication impacts many aspects of plant development including vigor, sterility and viability. Dynamic changes in mitochondrial number, shape, size, and cellular location takes place during the cell cycle possibly impacting the process itself and leading to distribution of this organelle into daughter cells. The genes that underlie these changes are beginning to be identified in model plants such as Arabidopsis. In animals disruption of the drp1 gene, a homolog to the plant drp3A and drp3B, delays mitochondrial division. This mutation results in increased aneuploidy due to chromosome mis-segregation. It remains to be discovered if a similar outcome is observed in plants. Alloplasmic lines provide an opportunity to understand the communication between the cytoplasmic organelles and the nucleus. Examples of studies in these lines, especially from the extensive collection in wheat, point to the role of mitochondria in chromosome movement, pollen fertility and other aspects of development. Genes involved in NM interaction also are believed to play a critical role in evolution of species and interspecific cross incompatibilities.

  11. Population dynamics

    Directory of Open Access Journals (Sweden)

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

  12. Dynamics of thymus organogenesis and colonization in early human development

    Science.gov (United States)

    Farley, Alison M.; Morris, Lucy X.; Vroegindeweij, Eric; Depreter, Marianne L. G.; Vaidya, Harsh; Stenhouse, Frances H.; Tomlinson, Simon R.; Anderson, Richard A.; Cupedo, Tom; Cornelissen, Jan J.; Blackburn, C. Clare

    2013-01-01

    The thymus is the central site of T-cell development and thus is of fundamental importance to the immune system, but little information exists regarding molecular regulation of thymus development in humans. Here we demonstrate, via spatial and temporal expression analyses, that the genetic mechanisms known to regulate mouse thymus organogenesis are conserved in humans. In addition, we provide molecular evidence that the human thymic epithelium derives solely from the third pharyngeal pouch, as in the mouse, in contrast to previous suggestions. Finally, we define the timing of onset of hematopoietic cell colonization and epithelial cell differentiation in the human thymic primordium, showing, unexpectedly, that the first colonizing hematopoietic cells are CD45+CD34int/-. Collectively, our data provide essential information for translation of principles established in the mouse to the human, and are of particular relevance to development of improved strategies for enhancing immune reconstitution in patients. PMID:23571219

  13. Phosphorylation dynamics during early differentiation of human embryonic stem cells

    NARCIS (Netherlands)

    van Hoof, D.; Munoz, J.; Braam, S.R.; Pinkse, M.W.H.; Linding, R.; Heck, A.J.R.; Mummery, C.L.; Krijgsveld, J.

    2009-01-01

    Pluripotent stem cells self-renew indefinitely and possess characteristic protein-protein networks that remodel during differentiation. How this occurs is poorly understood. Using quantitative mass spectrometry, we analyzed the (phospho)proteome of human embryonic stem cells (hESCs) during

  14. Stochastic Modeling of the Persistence of HIV: Early Population Dynamics

    Science.gov (United States)

    2013-05-10

    move about. Mathematically, this process was described first by Norbert Wiener , after whom the process is named. We abbreviate the Wiener process W...stochastic process is Brownian motion, which is also known as the Wiener process. Originally used to describe the motion of particles suspended within a

  15. Dynamic Data Driven Operator Error Early Warning System

    Science.gov (United States)

    2015-08-13

    mental states in a mathematical fashion, thus enabling the possibility of prediction. 15. SUBJECT TERMS human performance sensor controll decision-making...results show that this algorithm has the potential to capture mental states in a mathematical fashion, thus enabling the possibility of prediction...calibrations, participants started to do the experiment with a 3-minute baselining session. They were rested and listened to the music Bachs Harpsichord

  16. Early signatures of regime shifts in complex dynamical systems

    Indian Academy of Sciences (India)

    2015-02-05

    Feb 5, 2015 ... such as asthma attacks [10] or epileptic seizures [11] are also representative of sudden regime shifts. There are evidences to suggest that the progression of complex diseases may not be smooth but marked by an abrupt deterioration at a threshold point [12]. Pat- terns of oceanic circulation and the climate ...

  17. No Way Back? The Dynamics of Early School Leaving

    OpenAIRE

    SMYTH, EMER

    2010-01-01

    PUBLISHED Education is a key determinant of adult life chances across Western societies and is especially so in Ireland. Young people with higher levels of educational qualifications are more likely to access high quality employment and receive higher pay levels in the immediate period after leaving school, and these advantages persist into adult life. Furthermore, more highly educated adults have broader social advantages, including improved health status (Smyth and McCo...

  18. 31st IMAC Conference on Structural Dynamics

    CERN Document Server

    Adams, Douglas; Carrella, Alex; Mayes, Randy; Rixen, Daniel; Allen, Matt; Cunha, Alvaro; Catbas, Fikret; Pakzad, Shamim; Racic, Vitomir; Pavic, Aleksandar; Reynolds, Paul; Simmermacher, Todd; Cogan, Scott; Moaveni, Babak; Papadimitriou, Costas; Allemang, Randall; Clerck, James; Niezrecki, Christopher; Wicks, Alfred

    2013-01-01

    Topics in Nonlinear Dynamics, Volume 1: Proceedings of the 31st IMAC, A Conference and Exposition on Structural Dynamics, 2013, the first volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Structural Dynamics, including papers on:   Nonlinear Oscillations Nonlinearities In Practice Nonlinear System Identification: Methods Nonlinear System Identification: Friction & Contact Nonlinear Modal Analysis Nonlinear Modeling & Simulation Nonlinear Vibration Absorbers Constructive Utilization of Nonlinearity.

  19. Transition dynamics in two-photon ionisation

    Science.gov (United States)

    Vacher, Morgane; Gaillac, Romain; Maquet, Alfred; Taïeb, Richard; Caillat, Jérémie

    2017-11-01

    We review various aspects of photoemission dynamics in the case of two-photon ionisation. We first recall the definition of a transition phase specific to two-photon transitions. Numerical experiments on model atoms are used to show how the group delay associated with the transition phase is actually representative of the early dynamics of the detected photoelectron wave packets. Then we address the question of measuring these transition delays using a standard interferometric technique of experimental attosecond physics, so-called rabbit. Finally, we outline different reinterpretations of rabbit giving access to the more fundamental scattering dynamics affecting any photoemission processes.

  20. Superconductor Dynamics

    CERN Document Server

    Gömöry, F.

    2014-07-17

    Superconductors used in magnet technology could carry extreme currents because of their ability to keep the magnetic flux motionless. The dynamics of the magnetic flux interaction with superconductors is controlled by this property. The cases of electrical transport in a round wire and the magnetization of wires of various shapes (circular, elliptical, plate) in an external magnetic field are analysed. Resistance to the magnetic field penetration means that the field produced by the superconducting magnet is no longer proportional to the supplied current. It also leads to a dissipation of electromagnetic energy. In conductors with unequal transverse dimensions, such as flat cables, the orientation with respect to the magnetic field plays an essential role. A reduction of magnetization currents can be achieved by splitting the core of a superconducting wire into fine filaments; however, new kinds of electrical currents that couple the filaments consequently appear. Basic formulas allowing qualitative analyses ...

  1. Early discharge following birth

    DEFF Research Database (Denmark)

    Nilsson, Ingrid M. S.; Kronborg, Hanne; Knight, Christopher H.

    2017-01-01

    of discharge after birth. Results In total 34% mothers were discharged within 12 hours (very early) and 25% between 13 and 50 hours (early), respectively. Vaginal birth and multiparity were the most influential predictors, as Caesarean section compared to vaginal birth had an OR of 0.35 (CI 0....... Smoking, favourable social support and breastfeeding knowledge were significantly associated with discharge within 12 hours. Finally time of discharge varied significantly according to region and time of day of birth. Conclusions Parity and birth related factors were the strongest predictors of early...

  2. Early Option Exercise

    DEFF Research Database (Denmark)

    Heje Pedersen, Lasse; Jensen, Mads Vestergaard

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  3. Early Option Exercise

    DEFF Research Database (Denmark)

    Jensen, Mads Vestergaard; Heje Pedersen, Lasse

    2016-01-01

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  4. The Ecological Dynamics of Natural Selection: Traits and the Coevolution of Community Structure.

    Science.gov (United States)

    McPeek, Mark A

    2017-05-01

    Natural selection has both genetic and ecological dynamics. The fitnesses of individuals change with their ecological context, and so the form and strength of selective agents change with abiotic factors and the phenotypes and abundances of interacting species. I use standard models of consumer-resource interactions to explore the ecological dynamics of natural selection and how various trait types influence these dynamics and the resulting structure of a community of coevolving species. Evolutionary optima favored by natural selection depend critically on the abundances of interacting species, and the traits of species can undergo dynamic cycling in limited areas of parameter space. The ecological dynamics of natural selection can also drive shifts from one adaptive peak to another, and these ecologically driven adaptive peak shifts are fundamental to the dynamics of niche differentiation. Moreover, this ecological differentiation is fostered in more productive and more benign environments where species interactions are stronger and where the selection gradients generated by species interactions are stronger. Finally, community structure resulting from coevolution depends fundamentally on the types of traits that underlie species interactions. The ecological dynamics of the process cannot be simplified, neglected, or ignored if we are to build a predictive theory of natural selection.

  5. The Impact of Early-Life Exposure to Air-borne Environmental Insults on the Function of the Airway Epithelium in Asthma.

    Science.gov (United States)

    Spann, Kirsten; Snape, Natale; Baturcam, Engin; Fantino, Emmanuelle

    2016-01-01

    The airway epithelium is both a physical barrier protecting the airways from environmental insults and a significant component of the innate immune response. There is growing evidence that exposure of the airway epithelium to environmental insults in early life may lead to permanent changes in structure and function that underlie the development of asthma. Here we review the current published evidence concerning the link between asthma and epithelial damage within the airways and identify gaps in knowledge for future studies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Early Head Start Evaluation

    Data.gov (United States)

    U.S. Department of Health & Human Services — Longitudinal information from an evaluation where children were randomly assigned to Early Head Start or community services as usual;direct assessments and...

  7. Earth's early biosphere

    Science.gov (United States)

    Des Marais, D. J.

    1998-01-01

    Understanding our own early biosphere is essential to our search for life elsewhere, because life arose on Earth very early and rocky planets shared similar early histories. The biosphere arose before 3.8 Ga ago, was exclusively unicellular and was dominated by hyperthermophiles that utilized chemical sources of energy and employed a range of metabolic pathways for CO2 assimilation. Photosynthesis also arose very early. Oxygenic photosynthesis arose later but still prior to 2.7 Ga. The transition toward the modern global environment was paced by a decline in volcanic and hydrothermal activity. These developments allowed atmospheric O2 levels to increase. The O2 increase created new niches for aerobic life, most notably the more advanced Eukarya that eventually spawned the megascopic fauna and flora of our modern biosphere.

  8. Guideline for Early Interventions

    National Research Council Canada - National Science Library

    Vries, de, Maaike

    2006-01-01

    .... During the last years, the demand for early interventions has been increasing. International literature has shown that the psychosocial effects of disaster and military deployment may last for years...

  9. Cancer treatment - early menopause

    Science.gov (United States)

    Premature menopause; Ovarian insufficiency - cancer ... Cancer treatments that can cause early menopause include: Surgery. Having both ovaries removed causes menopause to happen right away. If you are age 50 or younger, your provider may ...

  10. Q fever - early

    Science.gov (United States)

    ... spread by domestic and wild animals and ticks. Causes Q fever is caused by the bacteria Coxiella burnetii , which ... Prevention Pasteurization of milk destroys the bacteria that cause early Q fever. Domestic animals should be inspected for signs of ...

  11. Early Life Stages

    Science.gov (United States)

    Childhood should be viewed as a sequence of lifestages, from birth through infancy and adolescence. When assessing early life risks, consideration is given to risks resulting from fetal exposure via the pregnant mother, as well as postnatal exposures.

  12. The Nonrandom Brain: Efficiency, Economy, and Complex Dynamics

    Directory of Open Access Journals (Sweden)

    Olaf eSporns

    2011-02-01

    Full Text Available Modern anatomical tracing and imaging techniques are beginning to reveal the structural anatomy of neural circuits at small and large scales in unprecedented detail. When examined with analytic tools from graph theory and network science, neural connectivity exhibits highly nonrandom features, including high clustering and short path length, as well as modules and highly central hub nodes. These characteristic topological features of neural connections shape nonrandom dynamic interactions that occur during spontaneous activity or in response to external stimulation. Disturbances of connectivity and thus of neural dynamics are thought to underlie a number of disease states of the brain, and some evidence suggests that degraded functional performance of brain networks may be the outcome of a process of randomization affecting their nodes and edges. This article provides a survey of the nonrandom structure of neural connectivity, primarily at the large-scale of regions and pathways in the mammalian cerebral cortex. In addition, we will discuss how nonrandom connections can give rise to differentiated and complex patterns of dynamics and information flow. Finally, we will explore the idea that at least some disorders of the nervous system are associated with increased randomness of neural connections.

  13. Dynamic structure of joint-action stimulus-response activity.

    Directory of Open Access Journals (Sweden)

    MaryLauren Malone

    Full Text Available The mere presence of a co-actor can influence an individual's response behavior. For instance, a social Simon effect has been observed when two individuals perform a Go/No-Go response to one of two stimuli in the presence of each other, but not when they perform the same task alone. Such effects are argued to provide evidence that individuals co-represent the task goals and the to-be-performed actions of a co-actor. Motivated by the complex-systems approach, the present study was designed to investigate an alternative hypothesis--that such joint-action effects are due to a dynamical (time-evolving interpersonal coupling that operates to perturb the behavior of socially situated actors. To investigate this possibility, participants performed a standard Go/No-Go Simon task in joint and individual conditions. The dynamic structure of recorded reaction times was examined using fractal statistics and instantaneous cross-correlation. Consistent with our hypothesis that participants responding in a shared space would become behaviorally coupled, the analyses revealed that reaction times in the joint condition displayed decreased fractal structure (indicative of interpersonal perturbation processes modulating ongoing participant behavior compared to the individual condition, and were more correlated across a range of time-scales compared to the reaction times of pseudo-pair controls. Collectively, the findings imply that dynamic processes might underlie social stimulus-response compatibility effects and shape joint cognitive processes in general.

  14. The Dynamics of Democracy, Development and Cultural Values

    Science.gov (United States)

    Spaiser, Viktoria; Ranganathan, Shyam; Mann, Richard P.; Sumpter, David J. T.

    2014-01-01

    Over the past decades many countries have experienced rapid changes in their economies, their democratic institutions and the values of their citizens. Comprehensive data measuring these changes across very different countries has recently become openly available. Between country similarities suggest common underlying dynamics in how countries develop in terms of economy, democracy and cultural values. We apply a novel Bayesian dynamical systems approach to identify the model which best captures the complex, mainly non-linear dynamics that underlie these changes. We show that the level of Human Development Index (HDI) in a country drives first democracy and then higher emancipation of citizens. This change occurs once the countries pass a certain threshold in HDI. The data also suggests that there is a limit to the growth of wealth, set by higher emancipation. Having reached a high level of democracy and emancipation, societies tend towards equilibrium that does not support further economic growth. Our findings give strong empirical evidence against a popular political science theory, known as the Human Development Sequence. Contrary to this theory, we find that implementation of human-rights and democratisation precede increases in emancipative values. PMID:24905920

  15. The dynamics of democracy, development and cultural values.

    Science.gov (United States)

    Spaiser, Viktoria; Ranganathan, Shyam; Mann, Richard P; Sumpter, David J T

    2014-01-01

    Over the past decades many countries have experienced rapid changes in their economies, their democratic institutions and the values of their citizens. Comprehensive data measuring these changes across very different countries has recently become openly available. Between country similarities suggest common underlying dynamics in how countries develop in terms of economy, democracy and cultural values. We apply a novel Bayesian dynamical systems approach to identify the model which best captures the complex, mainly non-linear dynamics that underlie these changes. We show that the level of Human Development Index (HDI) in a country drives first democracy and then higher emancipation of citizens. This change occurs once the countries pass a certain threshold in HDI. The data also suggests that there is a limit to the growth of wealth, set by higher emancipation. Having reached a high level of democracy and emancipation, societies tend towards equilibrium that does not support further economic growth. Our findings give strong empirical evidence against a popular political science theory, known as the Human Development Sequence. Contrary to this theory, we find that implementation of human-rights and democratisation precede increases in emancipative values.

  16. Sub-nanometer glass surface dynamics induced by illumination

    International Nuclear Information System (INIS)

    Nguyen, Duc; Nienhaus, Lea; Haasch, Richard T.; Lyding, Joseph; Gruebele, Martin

    2015-01-01

    Illumination is known to induce stress and morphology changes in opaque glasses. Amorphous silicon carbide (a-SiC) has a smaller bandgap than the crystal. Thus, we were able to excite with 532 nm light a 1 μm amorphous surface layer on a SiC crystal while recording time-lapse movies of glass surface dynamics by scanning tunneling microscopy (STM). Photoexcitation of the a-SiC surface layer through the transparent crystal avoids heating the STM tip. Up to 6 × 10 4 s, long movies of surface dynamics with 40 s time resolution and sub-nanometer spatial resolution were obtained. Clusters of ca. 3-5 glass forming units diameter are seen to cooperatively hop between two states at the surface. Photoexcitation with green laser light recruits immobile clusters to hop, rather than increasing the rate at which already mobile clusters hop. No significant laser heating was observed. Thus, we favor an athermal mechanism whereby electronic excitation of a-SiC directly controls glassy surface dynamics. This mechanism is supported by an exciton migration-relaxation-thermal diffusion model. Individual clusters take ∼1 h to populate states differently after the light intensity has changed. We believe the surrounding matrix rearranges slowly when it is stressed by a change in laser intensity, and clusters serve as a diagnostic. Such cluster hopping and matrix rearrangement could underlie the microscopic mechanism of photoinduced aging of opaque glasses

  17. Dynamic reorganization of open chromatin underlies diverse transcriptomes during spermatogenesis

    Science.gov (United States)

    Maezawa, So; Yukawa, Masashi; Alavattam, Kris G; Barski, Artem

    2018-01-01

    Abstract During spermatogenesis, germ cells undergo massive cellular reconstruction and dynamic chromatin remodeling to facilitate highly diverse transcriptomes, which are required for the production of functional sperm. However, it remains unknown how germline chromatin is organized to promote the dynamic, complex transcriptomes of spermatogenesis. Here, using ATAC-seq, we establish the varied landscape of open chromatin during spermatogenesis. We identify the reorganization of accessible chromatin in intergenic and intronic regions during the mitosis-to-meiosis transition. During the transition, mitotic-type open chromatin is closed while the de novo formation of meiotic-type open chromatin takes place. Contrastingly, differentiation processes such as spermatogonial differentiation and the meiosis-to-postmeiosis transition involve chromatin closure without the de novo formation of accessible chromatin. In spermiogenesis, the germline-specific Polycomb protein SCML2 promotes the closure of open chromatin at autosomes for gene suppression. Paradoxically, we identify the massive de novo formation of accessible chromatin when the sex chromosomes undergo meiotic sex chromosome inactivation, and this is also mediated by SCML2. These results reveal meiotic sex chromosome inactivation as an active process for chromatin organization. Together, our results unravel the genome-wide, dynamic reorganization of open chromatin and reveal mechanisms that underlie diverse transcriptomes during spermatogenesis. PMID:29126117

  18. Early Prediction of Preeclampsia

    Directory of Open Access Journals (Sweden)

    Leona C. Poon

    2014-01-01

    Full Text Available Effective screening for the development of early onset preeclampsia (PE can be provided in the first-trimester of pregnancy. Screening by a combination of maternal risk factors, uterine artery Doppler, mean arterial pressure, maternal serum pregnancy-associated plasma protein-A, and placental growth factor can identify about 95% of cases of early onset PE for a false-positive rate of 10%.

  19. Embracing early literacy indicators

    DEFF Research Database (Denmark)

    Broström, Stig; Hansen, Ole Henrik; Jensen, Anders Skriver

    2010-01-01

    Abstract til paper om early literacy indikatorer. Det paper abstractet er knyttet til var en del af et inviteret, selvorganiseret symposium som afrapporterede EASE-projektet (www.ease-eu.com) på OMEP's 26. verdenskongres.......Abstract til paper om early literacy indikatorer. Det paper abstractet er knyttet til var en del af et inviteret, selvorganiseret symposium som afrapporterede EASE-projektet (www.ease-eu.com) på OMEP's 26. verdenskongres....

  20. Who Gets Early Tracheostomy?

    Science.gov (United States)

    Shaw, Joshua J.

    2015-01-01

    BACKGROUND: Although the benefits of early tracheostomy in patients dependent on ventilators are well established, the reasons for variation in time from intubation to tracheostomy remain unclear. We identified clinical and demographic disparities in time to tracheostomy. METHODS: We performed a level 3 retrospective prognostic study by querying the University HealthSystem Consortium (2007-2010) for adult patients receiving a tracheostomy after initial intubation. Time to tracheostomy was designated early ( 10 days). Cohorts were stratified by time to tracheostomy and compared using univariate tests of association and multivariable adjusted models. RESULTS: A total of 49,191 patients underwent tracheostomy after initial intubation: 42% early (n = 21,029) and 58% late (n = 28,162). On both univariate and multivariable analyses, women, blacks, Hispanics, and patients receiving Medicaid were less likely to receive an early tracheostomy. Patients in the early group also experienced lower rates of mortality (OR, 0.84; 95% CI, 0.79-0.88). CONCLUSIONS: Early tracheostomy was associated with increased survival. Yet, there were still significant disparities in time to tracheostomy according to sex, race, and type of insurance. Application of evidence-based algorithms for tracheostomy may reduce unequal treatment and improve overall mortality rates. Additional research into this apparent bias in referral/rendering of tracheostomy is needed. PMID:26313324

  1. Internet dynamics

    Science.gov (United States)

    Lukose, Rajan Mathew

    The World Wide Web and the Internet are rapidly expanding spaces, of great economic and social significance, which offer an opportunity to study many phenomena, often previously inaccessible, on an unprecedented scale and resolution with relative ease. These phenomena are measurable on the scale of tens of millions of users and hundreds of millions of pages. By virtue of nearly complete electronic mediation, it is possible in principle to observe the time and ``spatial'' evolution of nearly all choices and interactions. This cyber-space therefore provides a view into a number of traditional research questions (from many academic disciplines) and creates its own new phenomena accessible for study. Despite its largely self-organized and dynamic nature, a number of robust quantitative regularities are found in the aggregate statistics of interesting and useful quantities. These regularities can be understood with the help of models that draw on ideas from statistical physics as well as other fields such as economics, psychology and decision theory. This thesis develops models that can account for regularities found in the statistics of Internet congestion and user surfing patterns and discusses some practical consequences. practical consequences.

  2. Fluid dynamics

    CERN Document Server

    Ruban, Anatoly I

    This is the first book in a four-part series designed to give a comprehensive and coherent description of Fluid Dynamics, starting with chapters on classical theory suitable for an introductory undergraduate lecture course, and then progressing through more advanced material up to the level of modern research in the field. The present Part 1 consists of four chapters. Chapter 1 begins with a discussion of Continuum Hypothesis, which is followed by an introduction to macroscopic functions, the velocity vector, pressure, density, and enthalpy. We then analyse the forces acting inside a fluid, and deduce the Navier-Stokes equations for incompressible and compressible fluids in Cartesian and curvilinear coordinates. In Chapter 2 we study the properties of a number of flows that are presented by the so-called exact solutions of the Navier-Stokes equations, including the Couette flow between two parallel plates, Hagen-Poiseuille flow through a pipe, and Karman flow above an infinite rotating disk. Chapter 3 is d...

  3. Early life factors and type 2 diabetes mellitus.

    Science.gov (United States)

    Jiang, Xinli; Ma, Huijie; Wang, Yan; Liu, Yan

    2013-01-01

    Type 2 diabetes mellitus (T2DM) is a multifactorial disease, and its aetiology involves a complex interplay between genetic, epigenetic, and environmental factors. In recent years, evidences from both human and animal experiments have correlated early life factors with programming diabetes risk in adult life. Fetal and neonatal period is crucial for organ development. Many maternal factors during pregnancy may increase the risk of diabetes of offsprings in later life, which include malnutrition, healthy (hyperglycemia and obesity), behavior (smoking, drinking, and junk food diet), hormone administration, and even stress. In neonates, catch-up growth, lactation, glucocorticoids administration, and stress have all been found to increase the risk of insulin resistance or T2DM. Unfavorable environments (socioeconomic situation and famine) or obesity also has long-term negative effects on children by causing increased susceptibility to T2DM in adults. We also address the potential mechanisms that may underlie the developmental programming of T2DM. Therefore, it might be possible to prevent or delay the risk for T2DM by improving pre- and/or postnatal factors.

  4. Early Life Factors and Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Xinli Jiang

    2013-01-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a multifactorial disease, and its aetiology involves a complex interplay between genetic, epigenetic, and environmental factors. In recent years, evidences from both human and animal experiments have correlated early life factors with programming diabetes risk in adult life. Fetal and neonatal period is crucial for organ development. Many maternal factors during pregnancy may increase the risk of diabetes of offsprings in later life, which include malnutrition, healthy (hyperglycemia and obesity, behavior (smoking, drinking, and junk food diet, hormone administration, and even stress. In neonates, catch-up growth, lactation, glucocorticoids administration, and stress have all been found to increase the risk of insulin resistance or T2DM. Unfavorable environments (socioeconomic situation and famine or obesity also has long-term negative effects on children by causing increased susceptibility to T2DM in adults. We also address the potential mechanisms that may underlie the developmental programming of T2DM. Therefore, it might be possible to prevent or delay the risk for T2DM by improving pre- and/or postnatal factors.

  5. Triassic origin and early radiation of multicellular volvocine algae.

    Science.gov (United States)

    Herron, Matthew D; Hackett, Jeremiah D; Aylward, Frank O; Michod, Richard E

    2009-03-03

    Evolutionary transitions in individuality (ETIs) underlie the watershed events in the history of life on Earth, including the origins of cells, eukaryotes, plants, animals, and fungi. Each of these events constitutes an increase in the level of complexity, as groups of individuals become individuals in their own right. Among the best-studied ETIs is the origin of multicellularity in the green alga Volvox, a model system for the evolution of multicellularity and cellular differentiation. Since its divergence from unicellular ancestors, Volvox has evolved into a highly integrated multicellular organism with cellular specialization, a complex developmental program, and a high degree of coordination among cells. Remarkably, all of these changes were previously thought to have occurred in the last 50-75 million years. Here we estimate divergence times using a multigene data set with multiple fossil calibrations and use these estimates to infer the times of developmental changes relevant to the evolution of multicellularity. Our results show that Volvox diverged from unicellular ancestors at least 200 million years ago. Two key innovations resulting from an early cycle of cooperation, conflict and conflict mediation led to a rapid integration and radiation of multicellular forms in this group. This is the only ETI for which a detailed timeline has been established, but multilevel selection theory predicts that similar changes must have occurred during other ETIs.

  6. Dynamics of Gestalt psychology (invited review of Perceptual Dynamics: Theoretical foundations and philosophical implications of Gestalt psychology by F. Sundqvist)

    NARCIS (Netherlands)

    Helm, P.A. van der

    2006-01-01

    In Perceptual Dynamics, Sundqvist argues that the early 20th-century Gestaltist ideas gain fresh relevance by recent developments in cognitive science, particularly by approaches that start from either dynamic systems theory or connectionism. In this review, it is argued that Sundqvist's book is a

  7. Early cosmology constrained

    Energy Technology Data Exchange (ETDEWEB)

    Verde, Licia; Jimenez, Raul [Institute of Cosmos Sciences, University of Barcelona, IEEC-UB, Martí Franquès, 1, E08028 Barcelona (Spain); Bellini, Emilio [University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Pigozzo, Cassio [Instituto de Física, Universidade Federal da Bahia, Salvador, BA (Brazil); Heavens, Alan F., E-mail: liciaverde@icc.ub.edu, E-mail: emilio.bellini@physics.ox.ac.uk, E-mail: cpigozzo@ufba.br, E-mail: a.heavens@imperial.ac.uk, E-mail: raul.jimenez@icc.ub.edu [Imperial Centre for Inference and Cosmology (ICIC), Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2017-04-01

    We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the ΛCDM model. To do this we use a method to separate early- and late-universe information enclosed in observational data, thus markedly reducing the model-dependency of the conclusions. We find that the 95% credibility regions for extra energy components of the early universe at recombination are: non-accelerating additional fluid density parameter Ω{sub MR} < 0.006 and extra radiation parameterised as extra effective neutrino species 2.3 < N {sub eff} < 3.2 when imposing flatness. Our constraints thus show that even when analyzing the data in this largely model-independent way, the possibility of hiding extra energy components beyond ΛCDM in the early universe is seriously constrained by current observations. We also find that the standard ruler, the sound horizon at radiation drag, can be well determined in a way that does not depend on late-time Universe assumptions, but depends strongly on early-time physics and in particular on additional components that behave like radiation. We find that the standard ruler length determined in this way is r {sub s} = 147.4 ± 0.7 Mpc if the radiation and neutrino components are standard, but the uncertainty increases by an order of magnitude when non-standard dark radiation components are allowed, to r {sub s} = 150 ± 5 Mpc.

  8. Early knee osteoarthritis.

    Science.gov (United States)

    Favero, Marta; Ramonda, Roberta; Goldring, Mary B; Goldring, Steven R; Punzi, Leonardo

    2015-01-01

    Concepts regarding osteoarthritis, the most common joint disease, have dramatically changed in the past decade thanks to the development of new imaging techniques and the widespread use of arthroscopy that permits direct visualisation of intra-articular tissues and structure. MRI and ultrasound allow the early detection of pre-radiographic structural changes not only in the peri-articular bone but also in the cartilage, menisci, synovial membrane, ligaments and fat pad. The significance of MRI findings such as cartilage defects, bone marrow lesions, synovial inflammation/effusions and meniscal tears in patients without radiographic signs of osteoarthritis is not fully understood. Nevertheless, early joint tissue changes are associated with symptoms and, in some cases, with progression of disease. In this short review, we discuss the emerging concept of early osteoarthritis localised to the knee based on recently updated knowledge. We highlight the need for a new definition of early osteoarthritis that will permit the identification of patients at high risk of osteoarthritis progression and to initiate early treatment interventions.

  9. Early Dementia Screening

    Directory of Open Access Journals (Sweden)

    Peter K. Panegyres

    2016-01-01

    Full Text Available As the population of the world increases, there will be larger numbers of people with dementia and an emerging need for prompt diagnosis and treatment. Early dementia screening is the process by which a patient who might be in the prodromal phases of a dementing illness is determined as having, or not having, the hallmarks of a neurodegenerative condition. The concepts of mild cognitive impairment, or mild neurocognitive disorder, are useful in analyzing the patient in the prodromal phase of a dementing disease; however, the transformation to dementia may be as low as 10% per annum. The search for early dementia requires a comprehensive clinical evaluation, cognitive assessment, determination of functional status, corroborative history and imaging (including MRI, FDG-PET and maybe amyloid PET, cerebrospinal fluid (CSF examination assaying Aβ1–42, T-τ and P-τ might also be helpful. Primary care physicians are fundamental in the screening process and are vital in initiating specialist investigation and treatment. Early dementia screening is especially important in an age where there is a search for disease modifying therapies, where there is mounting evidence that treatment, if given early, might influence the natural history—hence the need for cost-effective screening measures for early dementia.

  10. Using physiology and behaviour to understand the responses of fish early life stages to toxicants.

    Science.gov (United States)

    Sloman, K A; McNeil, P L

    2012-12-01

    The use of early life stages of fishes (embryos and larvae) in toxicity testing has been in existence for a long time, generally utilizing endpoints such as morphological defects and mortality. Behavioural endpoints, however, may represent a more insightful evaluation of the ecological effects of toxicants. Indeed, recent years have seen a considerable increase in the use of behavioural measurements in early life stages reflecting a substantial rise in zebrafish Danio rerio early life-stage toxicity testing and the development of automated behavioural monitoring systems. Current behavioural endpoints identified for early life stages in response to toxicant exposure include spontaneous activity, predator avoidance, capture of live food, shoaling ability and interaction with other individuals. Less frequently used endpoints include measurement of anxiogenic behaviours and cognitive ability, both of which are suggested here as future indicators of toxicant disruption. For many simple behavioural endpoints, there is still a need to link behavioural effects with ecological relevance; currently, only a limited number of studies have addressed this issue. Understanding the physiological mechanisms that underlie toxicant effects on behaviour so early in life has received far less attention, perhaps because physiological measurements can be difficult to carry out on individuals of this size. The most commonly established physiological links with behavioural disruption in early life stages are similar to those seen in juveniles and adults including sensory deprivation (olfaction, lateral line and vision), altered neurogenesis and neurotransmitter concentrations. This review highlights the importance of understanding the integrated behavioural and physiological response of early life stages to toxicants and identifies knowledge gaps which present exciting areas for future research. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  11. Replicator dynamics in value chains

    DEFF Research Database (Denmark)

    Cantner, Uwe; Savin, Ivan; Vannuccini, Simone

    2016-01-01

    The pure model of replicator dynamics though providing important insights in the evolution of markets has not found much of empirical support. This paper extends the model to the case of firms vertically integrated in value chains. We show that i) by taking value chains into account, the replicator...... dynamics may revert its effect. In these regressive developments of market selection, firms with low fitness expand because of being integrated with highly fit partners, and the other way around; ii) allowing partner's switching within a value chain illustrates that periods of instability in the early...... stage of industry life-cycle may be the result of an 'optimization' of partners within a value chain providing a novel and simple explanation to the evidence discussed by Mazzucato (1998); iii) there are distinct differences in the contribution to market selection between the layers of a value chain...

  12. Early diagnosis of early stage lung cancer

    Directory of Open Access Journals (Sweden)

    Andrej Debeljak

    2005-11-01

    Full Text Available Background: For the detection of premalignant changes of bronchial mucosa and early stages of lung cancer frequent chest X-ray, spiral low dose computed tomography, fluorescence bronchoscopy, sputum cytology (also with automated systems with genetic and molecular changes in the sputum cells and bronchial mucosa were used. These screening methods of the high-risk groups for lung cancer achieved: earlier diagnosis of lung cancer in lower stage, higher operability, longer 5-year survival, but without mortality reduction.Conclusions: In the clinical practice we can examine higher risk groups for lung cancer in randomised control trials with multimodality approach: frequent chest low-dose fast spiral computed tomography, sputum cytology with genetic and molecular examinations and fluorescence bronchoscopy. Smoking cessation remains the best means to achieve mortality reduction from lung cancer.

  13. Dynamic Instability of Barlike Modes

    Science.gov (United States)

    Durisen, Richard H.; Pickett, Brian K.; Bate, Matthew R.; Imamura, James N.; Brandl, Andreas; Sterzik, Michael F.

    Numerical simulations during the 1980's established that prompt binary formation (or ``fission'') through dynamic growth of barlike modes is aborted by gravitational torques. Because these instabilities may occur during star formation and because their outcome over long times is still uncertain, we have combined various linear analyses with simulations by hydrodynamics codes to refine our understanding. We show that it is in fact the torques which cause nonlinear saturation of the mode amplitude. Excellent agreement for the early nonlinear phase is obtained using radically different hydrodynamics codes. However, the ultimate outcome is sensitive to assumptions about dissipative heating and is also somewhat code-dependent.

  14. Approaches to Modelling the Dynamical Activity of Brain Function Based on the Electroencephalogram

    Science.gov (United States)

    Liley, David T. J.; Frascoli, Federico

    The brain is arguably the quintessential complex system as indicated by the patterns of behaviour it produces. Despite many decades of concentrated research efforts, we remain largely ignorant regarding the essential processes that regulate and define its function. While advances in functional neuroimaging have provided welcome windows into the coarse organisation of the neuronal networks that underlie a range of cognitive functions, they have largely ignored the fact that behaviour, and by inference brain function, unfolds dynamically. Modelling the brain's dynamics is therefore a critical step towards understanding the underlying mechanisms of its functioning. To date, models have concentrated on describing the sequential organisation of either abstract mental states (functionalism, hard AI) or the objectively measurable manifestations of the brain's ongoing activity (rCBF, EEG, MEG). While the former types of modelling approach may seem to better characterise brain function, they do so at the expense of not making a definite connection with the actual physical brain. Of the latter, only models of the EEG (or MEG) offer a temporal resolution well matched to the anticipated temporal scales of brain (mental processes) function. This chapter will outline the most pertinent of these modelling approaches, and illustrate, using the electrocortical model of Liley et al, how the detailed application of the methods of nonlinear dynamics and bifurcation theory is central to exploring and characterising their various dynamical features. The rich repertoire of dynamics revealed by such dynamical systems approaches arguably represents a critical step towards an understanding of the complexity of brain function.

  15. Impaired social brain network for processing dynamic facial expressions in autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Sato Wataru

    2012-08-01

    Full Text Available Abstract Background Impairment of social interaction via facial expressions represents a core clinical feature of autism spectrum disorders (ASD. However, the neural correlates of this dysfunction remain unidentified. Because this dysfunction is manifested in real-life situations, we hypothesized that the observation of dynamic, compared with static, facial expressions would reveal abnormal brain functioning in individuals with ASD. We presented dynamic and static facial expressions of fear and happiness to individuals with high-functioning ASD and to age- and sex-matched typically developing controls and recorded their brain activities using functional magnetic resonance imaging (fMRI. Result Regional analysis revealed reduced activation of several brain regions in the ASD group compared with controls in response to dynamic versus static facial expressions, including the middle temporal gyrus (MTG, fusiform gyrus, amygdala, medial prefrontal cortex, and inferior frontal gyrus (IFG. Dynamic causal modeling analyses revealed that bi-directional effective connectivity involving the primary visual cortex–MTG–IFG circuit was enhanced in response to dynamic as compared with static facial expressions in the control group. Group comparisons revealed that all these modulatory effects were weaker in the ASD group than in the control group. Conclusions These results suggest that weak activity and connectivity of the social brain network underlie the impairment in social interaction involving dynamic facial expressions in individuals with ASD.

  16. Early intervention as a catalyst for effective early childhood ...

    African Journals Online (AJOL)

    Early childhood intervention is an essential contributor and catalyst for the development of a culture of positive attitudes towards children with disabilities in a country like Ghana. Intervention could begin at the early years or early childhood education level. Does early intervention make a difference in the lives of children ...

  17. Early Islamic Syria

    DEFF Research Database (Denmark)

    Walmsley, Alan

    After more than a century of neglect, a profound revolution is occurring in the way archaeology addresses and interprets developments in the social history of early Islamic Syria-Palestine. This concise book offers an innovative assessment of social and economic developments in Syria......-Palestine shortly before, and in the two centuries after, the Islamic expansion (the later sixth to the early ninth century AD), drawing on a wide range of new evidence from recent archaeological work. Alan Walmsley challenges conventional explanations for social change with the arrival of Islam, arguing...... for considerable cultural and economic continuity rather than devastation and unrelenting decline. Much new, and increasingly non-elite, architectural evidence and an ever-growing corpus of material culture indicate that Syria-Palestine entered a new age of social richness in the early Islamic period, even...

  18. Early detection of psychosis

    DEFF Research Database (Denmark)

    Larsen, T. K.; Melle, I.; Auestad, B.

    2011-01-01

    Background During the last decades we have seen a new focus on early treatment of psychosis. Several reviews have shown that duration of untreated psychosis (DUP) is correlated to better outcome. However, it is still unknown whether early treatment will lead to a better long-term outcome....... This study reports the effects of reducing DUP on 5-year course and outcome.Method During 1997â€"2000 a total of 281 consecutive patients aged >17 years with first episode non-affective psychosis were recruited, of which 192 participated in the 5-year follow-up. A comprehensive early detection (ED) programme...... with public information campaigns and low-threshold psychosis detection teams was established in one healthcare area (ED-area), but not in a comparable area (no-ED area). Both areas ran equivalent treatment programmes during the first 2 years and need-adapted treatment thereafter.Results At the start...

  19. Early life vaccination

    DEFF Research Database (Denmark)

    Nazerai, Loulieta; Bassi, Maria Rosaria; Uddbäck, Ida Elin Maria

    2016-01-01

    Intracellular pathogens represent a serious threat during early life. Importantly, even though the immune system of newborns may be characterized as developmentally immature, with a propensity to develop Th2 immunity, significant CD8+ T-cell responses may still be elicited in the context of optimal...... the first period of life and provide a pertinent alternative in infant vaccinology. To address this, infant mice were vaccinated with three different adenoviral vectors and the CD8+ T-cell response after early life vaccination was explored. We assessed the frequency, polyfunctionality and in vivo...... cytotoxicity of the elicited memory CD8+ T cells, as well as the potential of these cells to respond to secondary infections and confer protection. We further tested the impact of maternal immunity against our replication-deficient adenoviral vector during early life vaccination. Overall, our results indicate...

  20. [Early orthodontic treatment].

    Science.gov (United States)

    Boute, S; Kleutghen, J

    1989-01-01

    Several preventive procedures are recommended for the interception of early malocclusion. Therefore some important characteristics of normal dental development are mentioned. This preventive approach is focused around selected topics as forced bite, midline diastema and retarded eruption. This influence of functional disturbances on dentofacial morphology is discussed. An overview of possible therapy by the general dentist is presented for problems, aroused by thumb- and fingersucking, agenesis of upper lateral and mandibular second premolars as well as early loss of deciduous molars. Finally, the possible indications for serial extractions are examined.