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Sample records for accumulating evidence reveals

  1. Evidence accumulation for spatial reasoning

    NASA Technical Reports Server (NTRS)

    Matsuyama, T.; Hwang, V. S. S.; Davis, L. S.

    1984-01-01

    The evidence accumulation proces of an image understanding system is described enabling the system to perform top-down(goal-oriented) picture processing as well as bottom-up verification of consistent spatial relations among objects.

  2. Conservation of arthropod midline netrin accumulation revealed with a cross-reactive antibody provides evidence for midline cell homology

    PubMed Central

    Simanton, Wendy; Clark, Stephanie; Clemons, Anthony; Jacowski, Caitlin; Farrell-VanZomeren, Adrienne; Beach, Paul; Browne, William E.; Duman-Scheel, Molly

    2009-01-01

    SUMMARY Although many similarities in arthropod CNS development exist, differences in axonogenesis and the formation of midline cells, which regulate axon growth, have been observed. For example, axon growth patterns in the ventral nerve cord of Artemia franciscana differ from that of Drosophila melanogaster. Despite such differences, conserved molecular marker expression at the midline of several arthropod species indicates that midline cells may be homologous in distantly related arthropods. However, data from additional species are needed to test this hypothesis. In this investigation, nerve cord formation and the putative homology of midline cells were examined in distantly related arthropods, including: long- and short-germ insects (D. melanogaster, Aedes aeygypti, and Tribolium castaneum), branchiopod crustaceans (A. franciscana and Triops longicauditus), and malacostracan crustaceans (Porcellio laevis and Parhyale hawaiensis). These comparative analyses were aided by a cross-reactive antibody generated against the Netrin (Net) protein, a midline cell marker and regulator of axonogenesis. The mechanism of nerve cord formation observed in Artemia is found in Triops, another branchiopod, but is not found in the other arthropods examined. Despite divergent mechanisms of midline cell formation and nerve cord development, Net accumulation is detected in a well-conserved subset of midline cells in branchiopod crustaceans, malacostracan crustaceans, and insects. Notably, the Net accumulation pattern is also conserved at the midline of the amphipod P. hawaiensis, which undergoes split germ-band development. Conserved Net accumulation patterns indicate that arthropod midline cells are homologous, and that Nets function to regulate commissure formation during CNS development of Tetraconata. PMID:19469853

  3. Distinct relationships of parietal and prefrontal cortices to evidence accumulation

    PubMed Central

    Hanks, Timothy; Kopec, Charles D.; Brunton, Bingni W.; Duan, Chunyu A.; Erlich, Jeffrey C.; Brody, Carlos D.

    2014-01-01

    Gradual accumulation of evidence is thought to be fundamental for decision-making, and its neural correlates have been found in multiple brain regions1–8. Here we develop a generalizable method to measure tuning curves that specify the relationship between neural responses and mentally-accumulated evidence, and apply it to distinguish the encoding of decision variables in posterior parietal cortex (PPC) and prefrontal cortex (frontal orienting fields, FOF). We recorded the firing rates of neurons in PPC and FOF from rats performing a perceptual decision-making task. Classical analyses uncovered correlates of accumulating evidence, similar to previous observations in primates and also similar across the two regions. However, tuning curve assays revealed that while the PPC encodes a graded value of the accumulating evidence, the FOF has a more categorical encoding that indicates, throughout the trial, the decision provisionally favored by the evidence accumulated so far. Contrary to current views3,5,7–9, this suggests that premotor activity in frontal cortex does not play a role in the accumulation process, but instead has a more categorical function, such as transforming accumulated evidence into a discrete choice. To causally probe the role of FOF activity, we optogenetically silenced it during different timepoints of the trial. Consistent with a role in committing to a categorical choice at the end of the evidence accumulation process, but not consistent with a role during the accumulation itself, a behavioral effect was observed only when FOF silencing occurred at the end of the perceptual stimulus. Our results place important constraints on the circuit logic of brain regions involved in decision-making. PMID:25600270

  4. Normative evidence accumulation in unpredictable environments

    PubMed Central

    Glaze, Christopher M; Kable, Joseph W; Gold, Joshua I

    2015-01-01

    In our dynamic world, decisions about noisy stimuli can require temporal accumulation of evidence to identify steady signals, differentiation to detect unpredictable changes in those signals, or both. Normative models can account for learning in these environments but have not yet been applied to faster decision processes. We present a novel, normative formulation of adaptive learning models that forms decisions by acting as a leaky accumulator with non-absorbing bounds. These dynamics, derived for both discrete and continuous cases, depend on the expected rate of change of the statistics of the evidence and balance signal identification and change detection. We found that, for two different tasks, human subjects learned these expectations, albeit imperfectly, then used them to make decisions in accordance with the normative model. The results represent a unified, empirically supported account of decision-making in unpredictable environments that provides new insights into the expectation-driven dynamics of the underlying neural signals. DOI: http://dx.doi.org/10.7554/eLife.08825.001 PMID:26322383

  5. Evidence Accumulation and Choice Maintenance Are Dissociated in Human Perceptual Decision Making.

    PubMed

    Pedersen, Mads Lund; Endestad, Tor; Biele, Guido

    2015-01-01

    Perceptual decision making in monkeys relies on decision neurons, which accumulate evidence and maintain choices until a response is given. In humans, several brain regions have been proposed to accumulate evidence, but it is unknown if these regions also maintain choices. To test if accumulator regions in humans also maintain decisions we compared delayed and self-paced responses during a face/house discrimination decision making task. Computational modeling and fMRI results revealed dissociated processes of evidence accumulation and decision maintenance, with potential accumulator activations found in the dorsomedial prefrontal cortex, right inferior frontal gyrus and bilateral insula. Potential maintenance activation spanned the frontal pole, temporal gyri, precuneus and the lateral occipital and frontal orbital cortices. Results of a quantitative reverse inference meta-analysis performed to differentiate the functions associated with the identified regions did not narrow down potential accumulation regions, but suggested that response-maintenance might rely on a verbalization of the response. PMID:26510176

  6. Evidence of aluminium accumulation in aluminium welders.

    PubMed Central

    Elinder, C G; Ahrengart, L; Lidums, V; Pettersson, E; Sjögren, B

    1991-01-01

    Using atomic absorption spectrometry the aluminium concentrations in blood and urine and in two iliac bone biopsies obtained from welders with long term exposure to fumes containing aluminium were measured. The urinary excretion of two workers who had welded for 20 and 21 years varied between 107 and 351 micrograms Al/l, more than 10 times the concentration found in persons without occupational exposure. Urinary aluminium excretion remained high many years after stopping exposure. Blood and bone aluminium concentrations (4-53 micrograms Al/l and 18-29 micrograms Al/g respectively) were also raised but not to the same extent as urine excretion. It is concluded that long term exposure to aluminium by inhalation gives rise to accumulation of aluminium in the body and skeleton of health persons, and that the elimination of retained aluminium is very slow, in the order of several years. PMID:1954151

  7. Neural evidence accumulation persists after choice to inform metacognitive judgments

    PubMed Central

    Murphy, Peter R; Robertson, Ian H; Harty, Siobhán; O'Connell, Redmond G

    2015-01-01

    The ability to revise one’s certainty or confidence in a preceding choice is a critical feature of adaptive decision-making but the neural mechanisms underpinning this metacognitive process have yet to be characterized. In the present study, we demonstrate that the same build-to-threshold decision variable signal that triggers an initial choice continues to evolve after commitment, and determines the timing and accuracy of self-initiated error detection reports by selectively representing accumulated evidence that the preceding choice was incorrect. We also show that a peri-choice signal generated in medial frontal cortex provides a source of input to this post-decision accumulation process, indicating that metacognitive judgments are not solely based on the accumulation of feedforward sensory evidence. These findings impart novel insights into the generative mechanisms of metacognition. DOI: http://dx.doi.org/10.7554/eLife.11946.001 PMID:26687008

  8. Conscious and Nonconscious Processes:Distinct Forms of Evidence Accumulation?

    NASA Astrophysics Data System (ADS)

    Dehaene, Stanislas

    Among the many brain events evoked by a visual stimulus, which ones are associated specifically with conscious perception, and which merely reflect nonconscious processing? Understanding the neuronal mechanisms of consciousness is a major challenge for cognitive neuroscience. Recently, progress has been achieved by contrasting behavior and brain activation in minimally different experimental conditions, one of which leads to conscious perception whereas the other does not. This chapter reviews briefly this line of research and speculates on its theoretical interpretation. I propose to draw links between evidence accumulation models, which are highly successful in capturing elementary psychophysical decisions, and the conscious/nonconscious dichotomy. In this framework, conscious access would correspond to the crossing of a threshold in evidence accumulation within a distributed global workspace, a set of recurrently connected neurons with long axons that is able to integrate and broadcast back evidence from multiple brain processors. During nonconscious processing, evidence would be accumulated locally within specialized subcircuits, but would fail to reach the threshold needed for global ignition and, therefore, conscious reportability.

  9. Active inference, evidence accumulation and the urn task

    PubMed Central

    FitzGerald, Thomas HB; Schwartenbeck, Philipp; Moutoussis, Michael; Dolan, Raymond J; Friston, Karl

    2015-01-01

    Deciding how much evidence to accumulate before making a decision is a problem we and other animals often face, but one which is not completely understood. This issue is particularly important because a tendency to sample less information (often known as reflection impulsivity) is a feature in several psychopathologies, such as psychosis. A formal understanding information sampling may therefore clarify the computational anatomy of psychopathology. In this theoretical paper, we consider evidence accumulation in terms of active (Bayesian) inference using a generic model of Markov decision processes. Here, agents are equipped with beliefs about their own behaviour – in this case, that they will make informed decisions. Normative decision-making is then modelled using variational Bayes to minimise surprise about choice outcomes. Under this scheme, different facets of belief updating map naturally onto the functional anatomy of the brain (at least at a heuristic level). Of particular interest is the key role played by the expected precision of beliefs about control, which we have previously suggested may be encoded by dopaminergic neurons in the midbrain. We show that manipulating expected precision strongly affects how much information an agent characteristically samples, and thus provides a possible link between impulsivity and dopaminergic dysfunction. Our study therefore represents a step towards understanding evidence accumulation in terms of neurobiologically plausible Bayesian inference, and may cast light on why this process is disordered in psychopathology. PMID:25514108

  10. Auditory Streaming as an Online Classification Process with Evidence Accumulation

    PubMed Central

    Barniv, Dana; Nelken, Israel

    2015-01-01

    When human subjects hear a sequence of two alternating pure tones, they often perceive it in one of two ways: as one integrated sequence (a single "stream" consisting of the two tones), or as two segregated sequences, one sequence of low tones perceived separately from another sequence of high tones (two "streams"). Perception of this stimulus is thus bistable. Moreover, subjects report on-going switching between the two percepts: unless the frequency separation is large, initial perception tends to be of integration, followed by toggling between integration and segregation phases. The process of stream formation is loosely named “auditory streaming”. Auditory streaming is believed to be a manifestation of human ability to analyze an auditory scene, i.e. to attribute portions of the incoming sound sequence to distinct sound generating entities. Previous studies suggested that the durations of the successive integration and segregation phases are statistically independent. This independence plays an important role in current models of bistability. Contrary to this, we show here, by analyzing a large set of data, that subsequent phase durations are positively correlated. To account together for bistability and positive correlation between subsequent durations, we suggest that streaming is a consequence of an evidence accumulation process. Evidence for segregation is accumulated during the integration phase and vice versa; a switch to the opposite percept occurs stochastically based on this evidence. During a long phase, a large amount of evidence for the opposite percept is accumulated, resulting in a long subsequent phase. In contrast, a short phase is followed by another short phase. We implement these concepts using a probabilistic model that shows both bistability and correlations similar to those observed experimentally. PMID:26671774

  11. Is There Neural Evidence for an Evidence Accumulation Process in Memory Decisions?

    PubMed Central

    van Vugt, Marieke K.; Beulen, Marijke A.; Taatgen, Niels A.

    2016-01-01

    Models of evidence accumulation have been very successful at describing human decision making behavior. Recent years have also seen the first reports of neural correlates of this accumulation process. However, these studies have mostly focused on perceptual decision making tasks, ignoring the role of additional cognitive processes like memory retrieval that are crucial in real-world decisions. In this study, we tried to find a neural signature of evidence accumulation during a recognition memory task. To do this, we applied a method we have successfully used to localize evidence accumulation in scalp EEG during a perceptual decision making task. This time, however, we applied it to intracranial EEG recordings, which provide a much higher spatial resolution. We identified several brain areas where activity ramps up over time, but these neural patterns do not appear to be modulated by behavioral variables such as the amount of available evidence or response time. This casts doubt on the idea of evidence accumulation as a general decision-making mechanism underlying different types of decisions. PMID:27014024

  12. What is value—accumulated reward or evidence?

    PubMed Central

    Friston, Karl; Adams, Rick; Montague, Read

    2012-01-01

    Why are you reading this abstract? In some sense, your answer will cast the exercise as valuable—but what is value? In what follows, we suggest that value is evidence or, more exactly, log Bayesian evidence. This implies that a sufficient explanation for valuable behavior is the accumulation of evidence for internal models of our world. This contrasts with normative models of optimal control and reinforcement learning, which assume the existence of a value function that explains behavior, where (somewhat tautologically) behavior maximizes value. In this paper, we consider an alternative formulation—active inference—that replaces policies in normative models with prior beliefs about the (future) states agents should occupy. This enables optimal behavior to be cast purely in terms of inference: where agents sample their sensorium to maximize the evidence for their generative model of hidden states in the world, and minimize their uncertainty about those states. Crucially, this formulation resolves the tautology inherent in normative models and allows one to consider how prior beliefs are themselves optimized in a hierarchical setting. We illustrate these points by showing that any optimal policy can be specified with prior beliefs in the context of Bayesian inference. We then show how these prior beliefs are themselves prescribed by an imperative to minimize uncertainty. This formulation explains the saccadic eye movements required to read this text and defines the value of the visual sensations you are soliciting. PMID:23133414

  13. Loess is the accumulation of dust, not evidence for aridity

    NASA Astrophysics Data System (ADS)

    Zech, Roland

    2013-04-01

    Loess-paleosol sequences (LPS) are valuable terrestrial archives for Quaternary climate and environmental changes. The famous sections on the Chinese Loess Plateau, for example, document the alternation of warm and humid interglacials (paleosols) and cold and more arid glacials (loess). This, at least partly, reflects the weakening of the monsoonal circulation during glacials and has led to the notion that loess in general documents more arid conditions. Paleosols, on the other hand, are often interpreted to document more humid conditions. We studied the LPS Crvenka in the Carpathian Basin, southeast Europe, which spans the full last glacial cycle, and obtained results that do not fit the above concept: (i) The analysis of plant-derived long-chain n-alkanes indicates the presence of deciduous trees and shrubs during glacials, i.e. sufficient precipitation for tree growth, whereas tree-less grass steppes seem to have prevailed during the Eemian, the last interglacial. (ii) Compound-specific deuterium analyses on the alkanes show only little changes on glacial-interglacial timescale. When compared with the isotopic enrichment of the Mediterranean Sea during the last glacial, this likely documents a combination of increased rainfall, reduced evapo-transpiration and reduced temperatures. (iii) Novel lipid biomarkers derived from soil bacteria (GDGTs, glycerol dialkyl glycerol tetraethers) also indicate humid glacials (BIT index close to 1) and more arid interglacials (BIT<0.8). Our results are in good agreement with modelling studies suggesting a southward shift of the westerlies during glacials, and aridization in the Mediterranean area in response to man-made global warming. More importantly, they remind us of an important fact: Loess is the accumulation of dust, but not (necessarily) evidence for aridity. Pedogenesis may simply not have been able to keep pace with high glacial dust accumulation rates related to intense glacial, periglacial and fluvial activity

  14. Ultrastructural evidence for iron accumulation within the tube of Vestimentiferan Ridgeia piscesae.

    PubMed

    Peng, Xiaotong; Zhou, Huaiyang; Yao, Huiqiang; Li, Jiangtao; Wu, Zijun

    2009-10-01

    This study reports on the accumulation of iron within the tube wall of the deep sea vent macro invertebrate Vestimentiferan Ridgeia piscesae collected from Juan de Fuca ridge. Combining an array of approaches including environmental scanning electron microscope (ESEM), electron probe micro-analysis (EPMA), X-ray microanalysis (EDS) and transmission electron microscope (TEM), we provide evidences for the influence of prokaryotic organisms on the accumulation of metals on and within the tube wall. Two types of iron-rich minerals such as iron oxides and framboidal pyrites are identified within or on the tube wall. Our results reveal the presence of prokaryotic organism is apparently responsible for the early accumulation of iron-rich minerals in the tube wall. The implications of the biomineralisation of iron in tube wall at hydrothermal vents are discussed. PMID:19199091

  15. Oil Accumulation by the Oleaginous Diatom Fistulifera solaris as Revealed by the Genome and Transcriptome

    PubMed Central

    Veluchamy, Alaguraj; Tanaka, Michihiro; Abida, Heni; Maréchal, Eric; Bowler, Chris; Muto, Masaki; Sunaga, Yoshihiko; Tanaka, Masayoshi; Taniguchi, Takeaki; Fukuda, Yorikane; Nemoto, Michiko; Matsumoto, Mitsufumi; Wong, Pui Shan; Aburatani, Sachiyo; Fujibuchi, Wataru

    2015-01-01

    Oleaginous photosynthetic organisms such as microalgae are promising sources for biofuel production through the generation of carbon-neutral sustainable energy. However, the metabolic mechanisms driving high-rate lipid production in these oleaginous organisms remain unclear, thus impeding efforts to improve productivity through genetic modifications. We analyzed the genome and transcriptome of the oleaginous diatom Fistulifera solaris JPCC DA0580. Next-generation sequencing technology provided evidence of an allodiploid genome structure, suggesting unorthodox molecular evolutionary and genetic regulatory systems for reinforcing metabolic efficiencies. Although major metabolic pathways were shared with nonoleaginous diatoms, transcriptome analysis revealed unique expression patterns, such as concomitant upregulation of fatty acid/triacylglycerol biosynthesis and fatty acid degradation (β-oxidation) in concert with ATP production. This peculiar pattern of gene expression may account for the simultaneous growth and oil accumulation phenotype and may inspire novel biofuel production technology based on this oleaginous microalga. PMID:25634988

  16. The nitrogen legacy: emerging evidence of nitrogen accumulation in anthropogenic landscapes

    NASA Astrophysics Data System (ADS)

    Van Meter, K. J.; Basu, N. B.; Veenstra, J. J.; Burras, C. L.

    2016-03-01

    Watershed and global-scale nitrogen (N) budgets indicate that the majority of the N surplus in anthropogenic landscapes does not reach the coastal oceans. While there is general consensus that this ‘missing’ N either exits the landscape via denitrification or is retained within watersheds as nitrate or organic N, the relative magnitudes of these pools and fluxes are subject to considerable uncertainty. Our study, for the first time, provides direct, large-scale evidence of N accumulation in the root zones of agricultural soils that may account for much of the ‘missing N’ identified in mass balance studies. We analyzed long-term soil data (1957-2010) from 2069 sites throughout the Mississippi River Basin (MRB) to reveal N accumulation in cropland of 25-70 kg ha-1 yr-1, a total of 3.8 ± 1.8 Mt yr-1 at the watershed scale. We then developed a simple modeling framework to capture N depletion and accumulation dynamics under intensive agriculture. Using the model, we show that the observed accumulation of soil organic N (SON) in the MRB over a 30 year period (142 Tg N) would lead to a biogeochemical lag time of 35 years for 99% of legacy SON, even with complete cessation of fertilizer application. By demonstrating that agricultural soils can act as a net N sink, the present work makes a critical contribution towards the closing of watershed N budgets.

  17. Action Planning and the Timescale of Evidence Accumulation

    PubMed Central

    Donner, Tobias H.

    2015-01-01

    Perceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations, the decision-maker knows the required mapping between perceptual evidence and motor response (henceforth termed “sensory-motor contingency”) before decision formation. Here, the integrated evidence can be directly translated into a motor plan and, indeed, neural signatures of the integration process are evident as build-up activity in premotor brain regions. In other situations, however, the sensory-motor contingencies are unknown at the time of decision formation. We used behavioral psychophysics and computational modeling to test if knowledge about sensory-motor contingencies affects the timescale of perceptual evidence integration. We asked human observers to perform the same motion discrimination task, with or without trial-to-trial variations of the mapping between perceptual choice and motor response. When the mapping varied, it was either instructed before or after the stimulus presentation. We quantified the timescale of evidence integration under these different sensory-motor mapping conditions by means of two approaches. First, we analyzed subjects’ discrimination threshold as a function of stimulus duration. Second, we fitted a dynamical decision-making model to subjects’ choice behavior. The results from both approaches indicated that observers (i) integrated motion information for several hundred ms, (ii) used a shorter than optimal integration timescale, and (iii) used the same integration timescale under all sensory-motor mappings. We conclude that the mechanisms limiting the timescale of perceptual decisions are largely independent from long-term learning (under fixed mapping) or rapid acquisition (under variable mapping) of sensory

  18. Respirators versus medical masks: evidence accumulates but the jury remains out

    PubMed Central

    Killingley, Ben

    2011-01-01

    Please cite this paper as: Killingley (2011). Respiratory versus medical masks: evidence accumulates but the jury remains out. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2011.00237.x. PMID:21477131

  19. Perception as Evidence Accumulation and Bayesian Inference: Insights from Masked Priming

    ERIC Educational Resources Information Center

    Norris, Dennis; Kinoshita, Sachiko

    2008-01-01

    The authors argue that perception is Bayesian inference based on accumulation of noisy evidence and that, in masked priming, the perceptual system is tricked into treating the prime and the target as a single object. Of the 2 algorithms considered for formalizing how the evidence sampled from a prime and target is combined, only 1 was shown to be…

  20. Metabolic characteristics of a glycogen-accumulating organism in Defluviicoccus cluster II revealed by comparative genomics.

    PubMed

    Wang, Zhiping; Guo, Feng; Mao, Yanping; Xia, Yu; Zhang, Tong

    2014-11-01

    Glycogen-accumulating organisms (GAOs) may compete with phosphate-accumulating organisms (PAOs) for short-chain fatty acids (VFAs) in anaerobic polyhydroxyalkanoates (PHA) synthesis, but no consequently aerobic polyphosphate accumulation in enhanced biological phosphorus removal (EBPR) process, thus deteriorating the EBPR process. They are detected frequently in the deteriorated EBPR process, but their metabolisms are still far from our comprehensions for there is seldom pure culture. In this study, a nearly complete draft genome of a GAOs in Defluviicoccus cluster II, GAO-HK, is recruited from the metagenome of activated sludge in a full-scale industrial anoxic/aerobic wastewater plant. Comparative genomics reveal similar metabolisms of PHA and glycogen in GAOs of GAO-HK, Defluviicoccus tetraformis TFO71 (TFO71) and Competibacter phosphatis clade IIA (CPIIA), and PAOs of Accumulibacter clade IIA UW-1 (UW-1) and Tetrasphaera elongata Lp2 (Lp2). Although there are similar gene cassettes related with polyphosphate metabolism in these GAOs and PAOs, especially for Defluviicoccus-relative bacteria and UW-1, ppk1 in GAOs are diverse from those in the identified PAOs, implying the difference of polyphosphate metabolism in GAOs and PAOs. Additionally, genes related to the dissimilatory denitrification are absent in TFO71 and GAO-HK, implying that additional nitrate or nitrite may favor PAOs over Defluviicoccus-relative GAOs. Therefore, PAOs suffering from competition of Defluviicoccus-relative GAOs might be rescued with the additional nitrate/nitrite, which is important to improve the stability of EBPR processes. PMID:24889288

  1. Interference effects of choice on confidence: Quantum characteristics of evidence accumulation.

    PubMed

    Kvam, Peter D; Pleskac, Timothy J; Yu, Shuli; Busemeyer, Jerome R

    2015-08-25

    Decision-making relies on a process of evidence accumulation which generates support for possible hypotheses. Models of this process derived from classical stochastic theories assume that information accumulates by moving across definite levels of evidence, carving out a single trajectory across these levels over time. In contrast, quantum decision models assume that evidence develops over time in a superposition state analogous to a wavelike pattern and that judgments and decisions are constructed by a measurement process by which a definite state of evidence is created from this indefinite state. This constructive process implies that interference effects should arise when multiple responses (measurements) are elicited over time. We report such an interference effect during a motion direction discrimination task. Decisions during the task interfered with subsequent confidence judgments, resulting in less extreme and more accurate judgments than when no decision was elicited. These results provide qualitative and quantitative support for a quantum random walk model of evidence accumulation over the popular Markov random walk model. We discuss the cognitive and neural implications of modeling evidence accumulation as a quantum dynamic system. PMID:26261322

  2. Rhythmic fluctuations in evidence accumulation during decision making in the human brain

    PubMed Central

    Wyart, Valentin; de Gardelle, Vincent; Scholl, Jacqueline; Summerfield, Christopher

    2014-01-01

    Summary Categorical choices are preceded by the accumulation of sensory evidence in favour of one action or another. Current models describe evidence accumulation as a continuous process occurring at a constant rate, but this view is inconsistent with accounts of a psychological refractory period during sequential information processing. During multi-sample perceptual categorisation, we found that the neural encoding of momentary evidence in human electrical brain signals and its subsequent impact on choice fluctuated rhythmically according to the phase of ongoing parietal delta oscillations (1-3 Hz). By contrast, lateralised beta-band power (10-30 Hz) overlying human motor cortex encoded the integrated evidence as a response preparation signal. These findings draw a clear distinction between central and motor stages of perceptual decision making, with successive samples of sensory evidence competing to pass through a serial processing bottleneck before being mapped onto action. PMID:23177968

  3. Content-specific evidence accumulation in inferior temporal cortex during perceptual decision-making

    PubMed Central

    Tremel, Joshua J.; Wheeler, Mark E.

    2015-01-01

    During a perceptual decision, neuronal activity can change as a function of time-integrated evidence. Such neurons may serve as decision variables, signaling a choice when activity reaches a boundary. Because the signals occur on a millisecond timescale, translating to human decision-making using functional neuroimaging has been challenging. Previous neuroimaging work in humans has identified patterns of neural activity consistent with an accumulation account. However, the degree to which the accumulating neuroimaging signals reflect specific sources of perceptual evidence is unknown. Using an extended face/house discrimination task in conjunction with cognitive modeling, we tested whether accumulation signals, as measured using functional magnetic resonance imaging (fMRI), are stimulus-specific. Accumulation signals were defined as a change in the slope of the rising edge of activation corresponding with response time (RT), with higher slopes associated with faster RTs. Consistent with an accumulation account, fMRI activity in face- and house-selective regions in the inferior temporal cortex increased at a rate proportional to decision time in favor of the preferred stimulus. This finding indicates that stimulus-specific regions perform an evidence integrative function during goal-directed behavior and that different sources of evidence accumulate separately. We also assessed the decision-related function of other regions throughout the brain and found that several regions were consistent with classifications from prior work, suggesting a degree of domain generality in decision processing. Taken together, these results provide support for an integration-to-boundary decision mechanism and highlight possible roles of both domain-specific and domain-general regions in decision evidence evaluation. PMID:25562821

  4. Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula

    USGS Publications Warehouse

    Croteau, M.-N.; Luoma, S.N.; Topping, B.R.; Lopez, C.B.

    2004-01-01

    Characterization of uptake and loss dynamics is critical to understanding risks associated with contaminant exposure in aquatic animals. Dynamics are especially important in addressing questions such as why coexisting species in nature accumulate different levels of a contaminant. Here we manipulated copper (Cu) stable isotopic ratios (as an alternative to radioisotopes) to describe for the first time Cu dynamics in a freshwater invertebrate, the bivalve Corbicula fluminea. In the laboratory, Corbicula uptake and loss rate constants were determined from an environmentally realistic waterborne exposure to 65Cu (5.7 ??g L-1). That is, we spiked deionized water with Cu that was 99.4% 65Cu. Net tracer uptake was detectable after 1 day and strongly evident after 4 days. Thus, short-term exposures necessary to determine uptake dynamics are feasible with stable isotopes of Cu. In Corbicula, 65Cu depuration was biphasic. An unusually low rate constant of loss (0.0038 d-1) characterized the slow component of efflux, explaining why Corbicula strongly accumulates copper in nature. We incorporated our estimates of rate constants for dissolved 65Cu uptake and physiological efflux into a bioaccumulation model and showed that dietary exposure to Cu is likely an important bioaccumulation pathway for Corbicula.

  5. Sources of noise during accumulation of evidence in unrestrained and voluntarily head-restrained rats.

    PubMed

    Scott, Benjamin B; Constantinople, Christine M; Erlich, Jeffrey C; Tank, David W; Brody, Carlos D

    2015-01-01

    Decision-making behavior is often characterized by substantial variability, but its source remains unclear. We developed a visual accumulation of evidence task designed to quantify sources of noise and to be performed during voluntary head restraint, enabling cellular resolution imaging in future studies. Rats accumulated discrete numbers of flashes presented to the left and right visual hemifields and indicated the side that had the greater number of flashes. Using a signal-detection theory-based model, we found that the standard deviation in their internal estimate of flash number scaled linearly with the number of flashes. This indicates a major source of noise that, surprisingly, is not consistent with the widely used 'drift-diffusion modeling' (DDM) approach but is instead closely related to proposed models of numerical cognition and counting. We speculate that this form of noise could be important in accumulation of evidence tasks generally. PMID:26673896

  6. GWA Mapping of Anthocyanin Accumulation Reveals Balancing Selection of MYB90 in Arabidopsis thaliana

    PubMed Central

    Bac-Molenaar, Johanna A.; Fradin, Emilie F.; Rienstra, Juriaan A.; Vreugdenhil, Dick; Keurentjes, Joost J. B.

    2015-01-01

    Induction of anthocyanin accumulation by osmotic stress was assessed in 360 accessions of Arabidopsis thaliana. A wide range of natural variation, with phenotypes ranging from green to completely red/purple rosettes, was observed. A genome wide association (GWA) mapping approach revealed that sequence diversity in a small 15 kb region on chromosome 1 explained 40% of the variation observed. Sequence and expression analyses of alleles of the candidate gene MYB90 identified a causal polymorphism at amino acid (AA) position 210 of this transcription factor of the anthocyanin biosynthesis pathway. This amino acid discriminates the two most frequent alleles of MYB90. Both alleles are present in a substantial part of the population, suggesting balancing selection between these two alleles. Analysis of the geographical origin of the studied accessions suggests that the macro climate is not the driving force behind positive or negative selection for anthocyanin accumulation. An important role for local climatic conditions is, therefore, suggested. This study emphasizes that GWA mapping is a powerful approach to identify alleles that are under balancing selection pressure in nature. PMID:26588092

  7. Distinct effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat.

    PubMed

    Erlich, Jeffrey C; Brunton, Bingni W; Duan, Chunyu A; Hanks, Timothy D; Brody, Carlos D

    2015-01-01

    Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evidence have yet to be determined. Here, in rats performing an auditory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best described as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240 ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating auditory evidence, even while finding a strong role for PPC in internally-guided decisions. PMID:25869470

  8. Revealing Evidence of Spin in Galactic Black Holes

    NASA Astrophysics Data System (ADS)

    Miller, J. M.; Fabian, A. C.; Reynolds, C. S.; Nowak, M.; Wijnands, R.; Homan, J.; Belloni, T.; van der Klis, M.; Lewin, W. H. G.

    2002-12-01

    Our observations of Galactic black holes with Chandra and XMM-Newton have recently revealed broad, skewed Fe K-alpha emission lines similar to those seen in some AGN. If such lines are produced near the inner edge of the accretion disk, they can serve as an excellent spin diagnostic. Our analysis of the XMM-Newton spectrum of XTE J1650-500 reveals a strong, skewed Fe K-alpha emission line that requires near-maximal spin; with RXTE, we have discovered a 250 Hz QPO in this source which may also be produced near to the black hole. Although many Galactic black holes have been studied extensively, it is extremely rare that spectroscopic and timing studies both reveal features plausibly associated with the inner accretion disk. We will present the results of our XMM-Newton, Chandra, and RXTE observations of XTE J1650-500, as well as the results of our Chandra observations of Cygnus X-1 and preliminary results from our observations of GX 339-4 with XMM-Newton. We will discuss these results within the context of the relativistic Fe K lines reported by our group and others, and comment on the prospects for revealing evidence of spin in future observations. (JMM acknowledges support from the NSF through the Astronomy and Astrophysics Fellowship program.)

  9. Evidence accumulation in a complex task: Making choices about concurrent multiattribute stimuli under time pressure.

    PubMed

    Palada, Hector; Neal, Andrew; Vuckovic, Anita; Martin, Russell; Samuels, Kate; Heathcote, Andrew

    2016-03-01

    Evidence accumulation models transform observed choices and associated response times into psychologically meaningful constructs such as the strength of evidence and the degree of caution. Standard versions of these models were developed for rapid (∼1 s) choices about simple stimuli, and have recently been elaborated to some degree to address more complex stimuli and response methods. However, these elaborations can be difficult to use with designs and measurements typically encountered in complex applied settings. We test the applicability of 2 standard accumulation models-the diffusion (Ratcliff & McKoon, 2008) and the linear ballistic accumulation (LBA) (Brown & Heathcote, 2008)-to data from a task representative of many applied situations: the detection of heterogeneous multiattribute targets in a simulated unmanned aerial vehicle (UAV) operator task. Despite responses taking more than 2 s and complications added by realistic features, such as a complex target classification rule, interruptions from a simultaneous UAV navigation task, and time pressured choices about several concurrently present potential targets, these models performed well descriptively. They also provided a coherent psychological explanation of the effects of decision uncertainty and workload manipulations. Our results support the wider application of standard evidence accumulation models to applied decision-making settings. PMID:26844369

  10. Proteomic profiling of maize opaque endosperm mutants reveals selective accumulation of lysine-enriched proteins

    PubMed Central

    Morton, Kyla J.; Jia, Shangang; Zhang, Chi; Holding, David R.

    2016-01-01

    Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such as protein transport and folding, amino acid biosynthesis, and proteolysis. Principal component analysis and pathway enrichment suggested that the mutants partitioned into three groups: (i) Mc, DeB30, fl2 and o2; (ii) o1; and (iii) fl1. Indicator species analysis revealed mutant-specific proteins, and highlighted ER secretory pathway components that were enriched in selected groups of mutants. The most significantly changed proteins were related to stress or defense and zein partitioning into the soluble fraction for Mc, DeB30, o1, and fl1 specifically. In silico dissection of the most significantly changed proteins revealed novel qualitative changes in lysine abundance contributing to the overall lysine increase and the nutritional rebalancing of the o2 and fl2 endosperm. PMID:26712829

  11. Stover Composition in Maize and Sorghum Reveals Remarkable Genetic Variation and Plasticity for Carbohydrate Accumulation

    PubMed Central

    Sekhon, Rajandeep S.; Breitzman, Matthew W.; Silva, Renato R.; Santoro, Nicholas; Rooney, William L.; de Leon, Natalia; Kaeppler, Shawn M.

    2016-01-01

    Carbohydrates stored in vegetative organs, particularly stems, of grasses are a very important source of energy. We examined carbohydrate accumulation in adult sorghum and maize hybrids with distinct phenology and different end uses (grain, silage, sucrose or sweetness in stalk juice, and biomass). Remarkable variation was observed for non-structural carbohydrates and structural polysaccharides during three key developmental stages both between and within hybrids developed for distinct end use in both species. At the onset of the reproductive phase (average 65 days after planting, DAP), a wide range for accumulation of non-structural carbohydrates (free glucose and sucrose combined), was observed in internodes of maize (11–24%) and sorghum (7–36%) indicating substantial variation for transient storage of excess photosynthate during periods of low grain or vegetative sink strength. Remobilization of these reserves for supporting grain fill or vegetative growth was evident from lower amounts in maize (8–19%) and sorghum (9–27%) near the end of the reproductive period (average 95 DAP). At physiological maturity of grain hybrids (average 120 DAP), amounts of these carbohydrates were generally unchanged in maize (9–21%) and sorghum (16–27%) suggesting a loss of photosynthetic assimilation due to weakening sink demand. Nonetheless, high amounts of non-structural carbohydrates at maturity even in grain maize and sorghum (15–18%) highlight the potential for developing dual-purpose (grain/stover) crops. For both species, the amounts of structural polysaccharides in the cell wall, measured as monomeric components (glucose and pentose), decreased during grain fill but remained unchanged thereafter with maize biomass possessing slightly higher amounts than sorghum. Availability of carbohydrates in maize and sorghum highlights the potential for developing energy-rich dedicated biofuel or dual-purpose (grain/stover) crops. PMID:27375668

  12. Stover composition in maize and sorghum reveals remarkable genetic variation and plasticity for carbohydrate accumulation

    DOE PAGESBeta

    Sekhon, Rajandeep S.; Breitzman, Matthew W.; Silva, Renato R.; Santoro, Nicholas; Rooney, William L.; de Leon, Natalia; Kaeppler, Shawn M.

    2016-06-08

    Carbohydrates stored in vegetative organs, particularly stems, of grasses are a very important source of energy. We examined carbohydrate accumulation in adult sorghum and maize hybrids with distinct phenology and different end uses (grain, silage, sucrose or sweetness in stalk juice, and biomass). Remarkable variation was observed for nonstructural carbohydrates and structural polysaccharides during three key developmental stages both between and within hybrids developed for distinct end use in both species. At the onset of the reproductive phase (average 65 days after planting, DAP), a wide range for accumulation of non-structural carbohydrates (free glucose and sucrose combined), was observed inmore » internodes of maize (11-24%) and sorghum (7-36%) indicating substantial variation for transient storage of excess photosynthate during periods of low grain or vegetative sink strength. Remobilization of these reserves for supporting grain fill or vegetative growth was evident from lower amounts in maize (8-19%) and sorghum (9-27%) near the end of the reproductive period (average 95 DAP). At physiological maturity of grain hybrids (average 120 DAP), amounts of these carbohydrates were generally unchanged in maize (9-21%) and sorghum (16-27%) suggesting a loss of photosynthetic assimilation due to weakening sink demand. Nonetheless, high amounts of non-structural carbohydrates at maturity even in grain maize and sorghum (15-18%) highlight the potential for developing dual-purpose (grain/stover) crops. For both species, the amounts of structural polysaccharides in the cell wall, measured as monomeric components (glucose and pentose), decreased during grain fill but remained unchanged thereafter with maize biomass possessing slightly higher amounts than sorghum. In conclusion, availability of carbohydrates in maize and sorghum highlights the potential for developing energy-rich dedicated biofuel or dual-purpose (grain/stover) crops.« less

  13. Stover Composition in Maize and Sorghum Reveals Remarkable Genetic Variation and Plasticity for Carbohydrate Accumulation.

    PubMed

    Sekhon, Rajandeep S; Breitzman, Matthew W; Silva, Renato R; Santoro, Nicholas; Rooney, William L; de Leon, Natalia; Kaeppler, Shawn M

    2016-01-01

    Carbohydrates stored in vegetative organs, particularly stems, of grasses are a very important source of energy. We examined carbohydrate accumulation in adult sorghum and maize hybrids with distinct phenology and different end uses (grain, silage, sucrose or sweetness in stalk juice, and biomass). Remarkable variation was observed for non-structural carbohydrates and structural polysaccharides during three key developmental stages both between and within hybrids developed for distinct end use in both species. At the onset of the reproductive phase (average 65 days after planting, DAP), a wide range for accumulation of non-structural carbohydrates (free glucose and sucrose combined), was observed in internodes of maize (11-24%) and sorghum (7-36%) indicating substantial variation for transient storage of excess photosynthate during periods of low grain or vegetative sink strength. Remobilization of these reserves for supporting grain fill or vegetative growth was evident from lower amounts in maize (8-19%) and sorghum (9-27%) near the end of the reproductive period (average 95 DAP). At physiological maturity of grain hybrids (average 120 DAP), amounts of these carbohydrates were generally unchanged in maize (9-21%) and sorghum (16-27%) suggesting a loss of photosynthetic assimilation due to weakening sink demand. Nonetheless, high amounts of non-structural carbohydrates at maturity even in grain maize and sorghum (15-18%) highlight the potential for developing dual-purpose (grain/stover) crops. For both species, the amounts of structural polysaccharides in the cell wall, measured as monomeric components (glucose and pentose), decreased during grain fill but remained unchanged thereafter with maize biomass possessing slightly higher amounts than sorghum. Availability of carbohydrates in maize and sorghum highlights the potential for developing energy-rich dedicated biofuel or dual-purpose (grain/stover) crops. PMID:27375668

  14. Asymmetric Context-Dependent Mutation Patterns Revealed through Mutation–Accumulation Experiments

    PubMed Central

    Sung, Way; Ackerman, Matthew S.; Gout, Jean-François; Miller, Samuel F.; Williams, Emily; Foster, Patricia L.; Lynch, Michael

    2015-01-01

    Despite the general assumption that site-specific mutation rates are independent of the local sequence context, a growing body of evidence suggests otherwise. To further examine context-dependent patterns of mutation, we amassed 5,645 spontaneous mutations in wild- type (WT) and mismatch-repair deficient (MMR–) mutation–accumulation (MA) lines of the gram-positive model organism Bacillus subtilis. We then analyzed>7,500 spontaneous base-substitution mutations across B. subtilis, Escherichia coli, and Mesoplasma florum WT and MMR– MA lines, finding a context-dependent mutation pattern that is asymmetric around the origin of replication. Different neighboring nucleotides can alter site-specific mutation rates by as much as 75-fold, with sites neighboring G:C base pairs or dimers involving alternating pyrimidine–purine and purine–pyrimidine nucleotides having significantly elevated mutation rates. The influence of context-dependent mutation on genome architecture is strongest in M. florum, consistent with the reduced efficiency of selection in organisms with low effective population size. If not properly accounted for, the disparities arising from patterns of context-dependent mutation can significantly influence interpretations of positive and purifying selection. PMID:25750180

  15. Cadmium as a possible cause of bladder cancer: a review of accumulated evidence.

    PubMed

    Feki-Tounsi, Molka; Hamza-Chaffai, Amel

    2014-09-01

    Bladder cancer is a significant disease, the rates of which have increased over the few last years. However, its etiology remains as yet undefined. Cadmium, a widespread environmental carcinogen that has received considerable interest, presents evidence as a possible cause of bladder cancer. A literature review was conducted from the years 1984-2013 to study the accumulated evidence for cadmium as a possible cause of bladder cancer, including routes of cadmium exposure, accumulation, toxicity, carcinogenicity, and evidence from epidemiological and experimental studies. Special reference is devoted to cadmium nephrotoxicity, which illustrates how cadmium exerts its effects on the transitional epithelium of the urinary tract. Mechanisms of carcinogenesis are discussed. The effects of cadmium on gene expression in urothelial cells exposed to cadmium are also addressed. Despite different methodologies, several epidemiologic and nephrotoxicity studies of cadmium indicate that occupational exposure to cadmium is associated with increased risk of bladder cancer and provide additional evidence that cadmium is a potential toxic element in urothelial cells. In vitro studies provide further evidence that cadmium is involved in urothelial carcinogenesis. Animal studies encounter several problems such as morphology differences between species. Among the complex mechanisms of cadmium carcinogenesis, gene expression deregulation is the subject of recent studies on bladder cadmium-induced carcinogenesis. Further research, however, will be required to promise a better understanding of the mechanisms underlying cadmium carcinogenesis and to establish the precise role of cadmium in this important malignancy. PMID:24894749

  16. Metabolomic analysis reveals mechanism of antioxidant butylated hydroxyanisole on lipid accumulation in Crypthecodinium cohnii.

    PubMed

    Sui, Xiao; Niu, Xiangfeng; Shi, Mengliang; Pei, Guangsheng; Li, Jinghan; Chen, Lei; Wang, Jiangxin; Zhang, Weiwen

    2014-12-24

    The heterotrophic dinoflagellate alga Crypthecodinium cohnii is known to accumulate lipids with a high fraction of docosahexaenoic acid (DHA). In this study, we first evaluated two antioxidant compounds, butylated hydroxyanisole (BHA) and propyl gallate (PG), for their effects on lipid accumulation in C. cohnii. The results showed that antioxidant BHA could increase lipid accumulation in C. cohnii by 8.80% at a final concentration of 30 μM, while PG had no obvious effect on lipid accumulation at the tested concentrations. To decipher the molecular mechanism responsible for the increased lipid accumulation by BHA, we employed an integrated GC-MS and LC-MS metabolomic approach to determine the time-series metabolic profiles with or without BHA, and then subjected the metabolomic data to a principal component analysis (PCA) and a weighted gene coexpression network analysis (WGCNA) network analyses to identify the key metabolic modules and metabolites possibly relevant to the increased lipid accumulation. LC-MS analysis showed that several metabolites, including NADPH, could be important for the stimulation role of BHA on lipid accumulation. Meanwhile GC-MS and network analyses allowed identification of eight metabolic modules and nine hub metabolites possibly relevant to the stimulation role of BHA in C. cohnii. The study provided a metabolomics view of the BHA mode of action on lipid accumulation in C. cohnii, and the information could be valuable for a better understanding of antioxidant effects on lipid accumulation in other microalgae as well. PMID:25436856

  17. Sources of noise during accumulation of evidence in unrestrained and voluntarily head-restrained rats

    PubMed Central

    Scott, Benjamin B; Constantinople, Christine M; Erlich, Jeffrey C; Tank, David W; Brody, Carlos D

    2015-01-01

    Decision-making behavior is often characterized by substantial variability, but its source remains unclear. We developed a visual accumulation of evidence task designed to quantify sources of noise and to be performed during voluntary head restraint, enabling cellular resolution imaging in future studies. Rats accumulated discrete numbers of flashes presented to the left and right visual hemifields and indicated the side that had the greater number of flashes. Using a signal-detection theory-based model, we found that the standard deviation in their internal estimate of flash number scaled linearly with the number of flashes. This indicates a major source of noise that, surprisingly, is not consistent with the widely used 'drift-diffusion modeling' (DDM) approach but is instead closely related to proposed models of numerical cognition and counting. We speculate that this form of noise could be important in accumulation of evidence tasks generally. DOI: http://dx.doi.org/10.7554/eLife.11308.001 PMID:26673896

  18. Target Selection Signals Influence Perceptual Decisions by Modulating the Onset and Rate of Evidence Accumulation.

    PubMed

    Loughnane, Gerard M; Newman, Daniel P; Bellgrove, Mark A; Lalor, Edmund C; Kelly, Simon P; O'Connell, Redmond G

    2016-02-22

    Computational and neurophysiological research has highlighted neural processes that accumulate sensory evidence for perceptual decisions [1]. These processes have been studied in the context of highly simplified perceptual discrimination paradigms in which the physical evidence appears at times and locations that are either entirely predictable or exogenously cued (e.g., by the onset of the stimulus itself). Yet, we are rarely afforded such certainty in everyday life. For example, when driving along a busy motorway, we must continually monitor the movements of surrounding vehicles for events that call for a lane change. In such scenarios, it is unknown which of the continuously present information sources will become relevant or when. Although it is well established that evidence integration provides an effective mechanism for countering the impact of noise [2], the question of how this mechanism is implemented in the face of uncertain evidence onsets has yet to be answered. Here, we show that when monitoring two potential sources of information for evidence occurring unpredictably in both time and space, the human brain employs discrete, early target selection signals that significantly modulate the onset and rate of neural evidence accumulation, and thereby the timing and accuracy of perceptual reports. These selection signals share many of the key characteristics of the N2pc component highlighted in the literature on visual search [3, 4] yet are present even in the absence of distractors and under situations of low temporal and spatial uncertainty. These data provide novel insights into how target selection supports decision making in uncertain environments. PMID:26853360

  19. Evidence Accumulation in Obsessive-Compulsive Disorder: the Role of Uncertainty and Monetary Reward on Perceptual Decision-Making Thresholds

    PubMed Central

    Banca, Paula; Vestergaard, Martin D; Rankov, Vladan; Baek, Kwangyeol; Mitchell, Simon; Lapa, Tatyana; Castelo-Branco, Miguel; Voon, Valerie

    2015-01-01

    The compulsive behaviour underlying obsessive-compulsive disorder (OCD) may be related to abnormalities in decision-making. The inability to commit to ultimate decisions, for example, patients unable to decide whether their hands are sufficiently clean, may reflect failures in accumulating sufficient evidence before a decision. Here we investigate the process of evidence accumulation in OCD in perceptual discrimination, hypothesizing enhanced evidence accumulation relative to healthy volunteers. Twenty-eight OCD patients and thirty-five controls were tested with a low-level visual perceptual task (random-dot-motion task, RDMT) and two response conflict control tasks. Regression analysis across different motion coherence levels and Hierarchical Drift Diffusion Modelling (HDDM) were used to characterize response strategies between groups in the RDMT. Patients required more evidence under high uncertainty perceptual contexts, as indexed by longer response time and higher decision boundaries. HDDM, which defines a decision when accumulated noisy evidence reaches a decision boundary, further showed slower drift rate towards the decision boundary reflecting poorer quality of evidence entering the decision process in patients under low uncertainty. With monetary incentives emphasizing speed and penalty for slower responses, patients decreased the decision thresholds relative to controls, accumulating less evidence in low uncertainty. These findings were unrelated to visual perceptual deficits and response conflict. This study provides evidence for impaired decision-formation processes in OCD, with a differential influence of high and low uncertainty contexts on evidence accumulation (decision threshold) and on the quality of evidence gathered (drift rates). It further emphasizes that OCD patients are sensitive to monetary incentives heightening speed in the speed-accuracy tradeoff, improving evidence accumulation. PMID:25425323

  20. Evidence accumulation in obsessive-compulsive disorder: the role of uncertainty and monetary reward on perceptual decision-making thresholds.

    PubMed

    Banca, Paula; Vestergaard, Martin D; Rankov, Vladan; Baek, Kwangyeol; Mitchell, Simon; Lapa, Tatyana; Castelo-Branco, Miguel; Voon, Valerie

    2015-04-01

    The compulsive behaviour underlying obsessive-compulsive disorder (OCD) may be related to abnormalities in decision-making. The inability to commit to ultimate decisions, for example, patients unable to decide whether their hands are sufficiently clean, may reflect failures in accumulating sufficient evidence before a decision. Here we investigate the process of evidence accumulation in OCD in perceptual discrimination, hypothesizing enhanced evidence accumulation relative to healthy volunteers. Twenty-eight OCD patients and thirty-five controls were tested with a low-level visual perceptual task (random-dot-motion task, RDMT) and two response conflict control tasks. Regression analysis across different motion coherence levels and Hierarchical Drift Diffusion Modelling (HDDM) were used to characterize response strategies between groups in the RDMT. Patients required more evidence under high uncertainty perceptual contexts, as indexed by longer response time and higher decision boundaries. HDDM, which defines a decision when accumulated noisy evidence reaches a decision boundary, further showed slower drift rate towards the decision boundary reflecting poorer quality of evidence entering the decision process in patients under low uncertainty. With monetary incentives emphasizing speed and penalty for slower responses, patients decreased the decision thresholds relative to controls, accumulating less evidence in low uncertainty. These findings were unrelated to visual perceptual deficits and response conflict. This study provides evidence for impaired decision-formation processes in OCD, with a differential influence of high and low uncertainty contexts on evidence accumulation (decision threshold) and on the quality of evidence gathered (drift rates). It further emphasizes that OCD patients are sensitive to monetary incentives heightening speed in the speed-accuracy tradeoff, improving evidence accumulation. PMID:25425323

  1. Competing mechanisms for perfluoroalkyl acid accumulation in plants revealed using an Arabidopsis model system.

    PubMed

    Müller, Claudia E; LeFevre, Gregory H; Timofte, Anca E; Hussain, Fatima A; Sattely, Elizabeth S; Luthy, Richard G

    2016-05-01

    Perfluoroalkyl acids (PFAAs) bioaccumulate in plants, presenting a human exposure route if present in irrigation water. Curiously, accumulation of PFAAs in plant tissues is greatest for both the short-chain and long-chain PFAAs, generating a U-shaped relationship with chain length. In the present study, the authors decouple competing mechanisms of PFAA accumulation using a hydroponic model plant system (Arabidopsis thaliana) exposed to a suite of 10 PFAAs to determine uptake, depuration, and translocation kinetics. Rapid saturation of root concentrations occurred for all PFAAs except perfluorobutanoate, the least-sorptive (shortest-chain) PFAA. Shoot concentrations increased continuously, indicating that PFAAs are efficiently transported and accumulate in shoots. Tissue concentrations of PFAAs during depuration rapidly declined in roots but remained constant in shoots, demonstrating irreversibility of the translocation process. Root and shoot concentration factors followed the U-shaped trend with perfluoroalkyl chain length; however, when normalized to dead-tissue sorption, this relationship linearized. The authors therefore introduce a novel term, the "sorption normalized concentration factor," to describe PFAA accumulation in plants; because of their hydrophobicity, sorption is the determining factor for long-chain PFAAs, whereas the shortest-chain PFAAs are most effectively transported in the plant. The present study provides a mechanistic explanation for previously unexplained PFAA accumulation trends in plants and suggests that shorter-chained PFAAs may bioaccumulate more readily in edible portions. Environ Toxicol Chem 2016;35:1138-1147. © 2015 SETAC. PMID:26383989

  2. Demystifying "free will": the role of contextual information and evidence accumulation for predictive brain activity.

    PubMed

    Bode, Stefan; Murawski, Carsten; Soon, Chun Siong; Bode, Philipp; Stahl, Jutta; Smith, Philip L

    2014-11-01

    Novel multivariate pattern classification analyses have enabled the prediction of decision outcomes from brain activity prior to decision-makers' reported awareness. These findings are often discussed in relation to the philosophical concept of "free will". We argue that these studies demonstrate the role of unconscious processes in simple free choices, but they do not inform the philosophical debate. Moreover, these findings are difficult to relate to cognitive decision-making models, due to misleading assumptions about random choices. We review evidence suggesting that sequential-sampling models, which assume accumulation of evidence towards a decision threshold, can also be applied to free decisions. If external evidence is eliminated by the task instructions, decision-makers might use alternative, subtle contextual information as evidence, such as their choice history, that is not consciously monitored and usually concealed by the experimental design. We conclude that the investigation of neural activity patterns associated with free decisions should aim to investigate how decisions are jointly a function of internal and external contexts, rather than to resolve the philosophical "free will" debate. PMID:25452111

  3. Revealing basin and regional scale snow accumulation magnitude and variability on glaciers throughout Alaska

    NASA Astrophysics Data System (ADS)

    McGrath, D.; Oneel, S.; Sass, L. C., III; Gusmeroli, A.; Arendt, A. A.; Wolken, G. J.; Kienholz, C.; McNeil, C.

    2014-12-01

    Mass loss from Alaskan glaciers (-50 ± 17 Gt/a, 2003-2009) constitutes one of the largest contributions to global sea level rise outside of the Greenland and Antarctic ice sheets. The largest process-related uncertainties in this calculation arise from the difficulty in accurately measuring accumulation on glaciers and from the large variability of accumulation over a range of spatio-temporal scales. Further, the physical processes governing snow distribution in complex terrain elude model parameterization. Using ground-penetrating radar, constrained with probe and pit observations, we quantify the magnitude and variability of snow accumulation at six prominent glaciers throughout Alaska at the end of 2013 winter. We find that total SWE magnitude and variability are strongly controlled by the large-scale climate system (i.e. distance from the coastal moisture source along prevailing storm track). On average, total SWE decreases by 0.33 m per 100 km from the coast, while the SWE elevation gradient decreases by 0.06 m / 100 m per 100 km from the coast. SWE variability over small spatial scales (<200 m) is similar at most sites, although two glaciers exhibit notably low and high variability, likely related to their respective climatic provenance. On individual glaciers, strong elevation gradients, increasing from 0.07 m SWE / 100 m at the interior Gulkana Glacier to 0.30 m SWE / 100 m at the coastal Scott Glacier, exert the primary control on accumulation. Results from multi-variable linear regression models (based on topographic variables) find wind exposure/shelter is the most frequent secondary control on accumulation variability. Finally, we find strong agreement (<10% difference) between the radar derived and stake derived total SWE estimates at two glaciers in the USGS Benchmark Glacier Program.

  4. Distinct effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat

    PubMed Central

    Erlich, Jeffrey C; Brunton, Bingni W; Duan, Chunyu A; Hanks, Timothy D; Brody, Carlos D

    2015-01-01

    Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evidence have yet to be determined. Here, in rats performing an auditory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best described as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240 ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating auditory evidence, even while finding a strong role for PPC in internally-guided decisions. DOI: http://dx.doi.org/10.7554/eLife.05457.001 PMID:25869470

  5. Precision phenotyping of biomass accumulation in triticale reveals temporal genetic patterns of regulation

    NASA Astrophysics Data System (ADS)

    Busemeyer, Lucas; Ruckelshausen, Arno; Möller, Kim; Melchinger, Albrecht E.; Alheit, Katharina V.; Maurer, Hans Peter; Hahn, Volker; Weissmann, Elmar A.; Reif, Jochen C.; Würschum, Tobias

    2013-08-01

    To extend agricultural productivity by knowledge-based breeding and tailor varieties adapted to specific environmental conditions, it is imperative to improve our ability to assess the dynamic changes of the phenome of crops under field conditions. To this end, we have developed a precision phenotyping platform that combines various sensors for a non-invasive, high-throughput and high-dimensional phenotyping of small grain cereals. This platform yielded high prediction accuracies and heritabilities for biomass of triticale. Genetic variation for biomass accumulation was dissected with 647 doubled haploid lines derived from four families. Employing a genome-wide association mapping approach, two major quantitative trait loci (QTL) for biomass were identified and the genetic architecture of biomass accumulation was found to be characterized by dynamic temporal patterns. Our findings highlight the potential of precision phenotyping to assess the dynamic genetics of complex traits, especially those not amenable to traditional phenotyping.

  6. Precision phenotyping of biomass accumulation in triticale reveals temporal genetic patterns of regulation

    PubMed Central

    Busemeyer, Lucas; Ruckelshausen, Arno; Möller, Kim; Melchinger, Albrecht E.; Alheit, Katharina V.; Maurer, Hans Peter; Hahn, Volker; Weissmann, Elmar A.; Reif, Jochen C.; Würschum, Tobias

    2013-01-01

    To extend agricultural productivity by knowledge-based breeding and tailor varieties adapted to specific environmental conditions, it is imperative to improve our ability to assess the dynamic changes of the phenome of crops under field conditions. To this end, we have developed a precision phenotyping platform that combines various sensors for a non-invasive, high-throughput and high-dimensional phenotyping of small grain cereals. This platform yielded high prediction accuracies and heritabilities for biomass of triticale. Genetic variation for biomass accumulation was dissected with 647 doubled haploid lines derived from four families. Employing a genome-wide association mapping approach, two major quantitative trait loci (QTL) for biomass were identified and the genetic architecture of biomass accumulation was found to be characterized by dynamic temporal patterns. Our findings highlight the potential of precision phenotyping to assess the dynamic genetics of complex traits, especially those not amenable to traditional phenotyping. PMID:23942574

  7. Changes in vegetation, peat properties and peat accumulation in Swedish peatlands as revealed by archive data.

    NASA Astrophysics Data System (ADS)

    Schoning, Kristian; Sohlenius, Gustav

    2016-04-01

    In this investigation we have studied patterns in peat accumulation and changes in mire status since the early 1900s for two areas in Sweden. In the early 1900s the Geological Survey of Sweden collected a vast amount of peat and peatland data, including information on vegetation and land-use. We have used this archive data to evaluate changes in mire vegetation, mire wetness and surface peat properties, rates of peat accumulation, succession in young wetlands and the effects of cultivation on peatlands. In total 156 mires in an uplift area of eastern middle Sweden were included in the data-set, including both pristine mires and peatlands used for agricultural purposes. In this area new peatlands have continuously been formed during the past 7 000 years making it possible to evaluate changes in peat accumulation over time. The other study area is situated in the south Swedish Uplands where we have revisited some larger bogs. The results from our investigation show that many of the peatlands have underwent major changes since the early 1900s. In most of the small peatlands we have found important changes in vegetation where mire vegetation has been replaced by nutrient demanding and/or dry species flora while the tree stand on large mires in south Sweden have increased. In some mires humification has increased in the uppermost peat-layers and the mire surface have become drier compared to the early 1900s. In eastern middle Sweden there are indications that the peat accumulation is lower 0,5 mm/year in older peatlands compared with younger ones 1,2 mm/year, although the mire vegetation in the older peatlands is dominated by sphagnum. The peat depth of the cultivated mires in this area shows a mean decrease of 40 cm since the early 1900s.

  8. Rapid temporal accumulation in spider fear: Evidence from hierarchical drift diffusion modelling.

    PubMed

    Tipples, Jason

    2015-12-01

    Fear can distort sense of time--making time seem slow or even stand still. Here, I used hierarchical drift diffusion modeling (HDDM; Vandekerckhove, Tuerlinckx, & Lee, 2008, 2011; Wiecki, Sofer, & Frank, 2013) to test the idea that temporal accumulation speeds up during fear. Eighteen high fearful and 23 low fearful participants judged the duration of both feared stimuli (spiders) and nonfeared stimuli (birds) in a temporal bisection task. The drift diffusion modeling results support the main hypothesis. In high but not low fearful individuals, evidence accumulated more rapidly toward a long duration decision-drift rates were higher-for spiders compared with birds. This result and further insights into how fear affects time perception would not have been possible on the basis of analyses of choice proportion data alone. Further results were interpreted in the context of a recent 2-stage model of time perception (Balcı & Simen, 2014). The results highlight the usefulness of diffusion modeling to test process-based explanations of disordered cognition in emotional disorders. PMID:25938616

  9. The Nitrogen Legacy: Evidence of Soil Nitrogen Accumulation in Anthropogenic Landscapes

    NASA Astrophysics Data System (ADS)

    Van Meter, K. J.; Basu, N. B.

    2013-12-01

    Human modification of the nitrogen (N) cycle has resulted in increased flows of reactive N, with some suggesting that planetary boundaries for maintaining human and ecosystem health have been exceeded. Persistence of large hypoxic zones in inland and coastal waters created by elevated concentrations of nitrate is one of the most significant impacts of such increased flows. While the need to manage these flows and their associated ecological impacts is recognized, best management practices to reduce stream N concentrations have had only limited success. Some have attributed this lack of success to an accumulation of legacy N stores from decades of fertilizer application. Nitrogen mass balance studies seem to suggest an ongoing retention of N within anthropogenic landscapes, but the exact form and location of this legacy N and the associated retention rates are subject to question. Here we introduce an unprecedented analysis of long-term soil data from the Mississippi River Basin (MRB) revealing significant increases in total N (TN) content. We show that TN accumulation for the MRB accounts for 49% of net anthropogenic N inputs (NANI), which complements previous work indicating that approximately 25% of net inputs are lost as riverine output. These findings significantly reduce the uncertainty associated with basin-level N retention. Further, our results demonstrate that, despite conventional wisdom of intensive agriculture leading to a depletion of TN, an accumulation of N is occurring in the deeper subsurface (25 - 100 cm) that compensates for depletion in the plow layer (0-25 cm). These legacy N stores may lead to time lags between changes in management practices and decreasing N concentrations in stream waters, thus resulting in multidecadal effects on water quality in agricultural watersheds.

  10. Desiderata or Dogma: What the Evidence Reveals About Physician Attire

    PubMed Central

    2008-01-01

    Introduction Physician–patient interactions are complex and depend on multiple factors including common cultural definitions and evolving social norms. The once purely philosophical debate over what constitutes appropriate physician attire can benefit from a growing evidence base in the literature. Discussion Although this literature is commonly regarded as supporting traditional attire, the data actually represent a more balanced distribution of opinions held by patients and by physicians. Perhaps interpretations favoring a conservative approach are expected given the history and tradition of the physician–patient relationship. Conclusion Nevertheless, in the age of evidence-based medicine, it is difficult to argue against scrutiny of the available literature. Evidence that challenges the importance of traditional physician attire is reviewed. PMID:18286342

  11. Flavone synthases from Lonicera japonica and L. macranthoides reveal differential flavone accumulation

    NASA Astrophysics Data System (ADS)

    Wu, Jie; Wang, Xiao-Chen; Liu, Yang; Du, Hui; Shu, Qing-Yan; Su, Shang; Wang, Li-Jin; Li, Shan-Shan; Wang, Liang-Sheng

    2016-01-01

    Flavones are important secondary metabolites found in many plants. In Lonicera species, flavones contribute both physiological and pharmaceutical properties. However, flavone synthase (FNS), the key enzyme responsible for flavone biosynthesis, has not yet been characterized in Lonicera species. In this study, FNSII genes were identified from Lonicera japonica Thunb. and L. macranthoides Hand.-Mazz. In the presence of NADPH, the recombinant cytochrome P450 proteins encoded by LjFNSII-1.1, LjFNSII-2.1, and LmFNSII-1.1 converted eriodictyol, naringenin, and liquiritigenin to the corresponding flavones directly. The different catalytic properties between LjFNSII-2.1 and LjFNSII-1.1 were caused by a single amino acid substitution at position 242 (glutamic acid to lysine). A methionine at position 206 and a leucine at position 381 contributed considerably to the high catalytic activity of LjFNSII-1.1. In addition, LjFNSII-1.1&2.1 and LmFNSII-1.1 also biosynthesize flavones that were further modified by O-glycosylation in transgenic tobacco. The expression levels of the FNSII genes were consistent with flavone accumulation patterns in flower buds. Our findings suggested that the weak catalytic activity of LmFNSII-1.1 and the relatively low expression of LmFNSII-1.1 in flowers might be responsible for the low levels of flavone accumulation in flower buds of L. macranthoides.

  12. Flavone synthases from Lonicera japonica and L. macranthoides reveal differential flavone accumulation

    PubMed Central

    Wu, Jie; Wang, Xiao-Chen; Liu, Yang; Du, Hui; Shu, Qing-Yan; Su, Shang; Wang, Li-Jin; Li, Shan-Shan; Wang, Liang-Sheng

    2016-01-01

    Flavones are important secondary metabolites found in many plants. In Lonicera species, flavones contribute both physiological and pharmaceutical properties. However, flavone synthase (FNS), the key enzyme responsible for flavone biosynthesis, has not yet been characterized in Lonicera species. In this study, FNSII genes were identified from Lonicera japonica Thunb. and L. macranthoides Hand.-Mazz. In the presence of NADPH, the recombinant cytochrome P450 proteins encoded by LjFNSII-1.1, LjFNSII-2.1, and LmFNSII-1.1 converted eriodictyol, naringenin, and liquiritigenin to the corresponding flavones directly. The different catalytic properties between LjFNSII-2.1 and LjFNSII-1.1 were caused by a single amino acid substitution at position 242 (glutamic acid to lysine). A methionine at position 206 and a leucine at position 381 contributed considerably to the high catalytic activity of LjFNSII-1.1. In addition, LjFNSII-1.1&2.1 and LmFNSII-1.1 also biosynthesize flavones that were further modified by O-glycosylation in transgenic tobacco. The expression levels of the FNSII genes were consistent with flavone accumulation patterns in flower buds. Our findings suggested that the weak catalytic activity of LmFNSII-1.1 and the relatively low expression of LmFNSII-1.1 in flowers might be responsible for the low levels of flavone accumulation in flower buds of L. macranthoides. PMID:26754912

  13. Flavone synthases from Lonicera japonica and L. macranthoides reveal differential flavone accumulation.

    PubMed

    Wu, Jie; Wang, Xiao-Chen; Liu, Yang; Du, Hui; Shu, Qing-Yan; Su, Shang; Wang, Li-Jin; Li, Shan-Shan; Wang, Liang-Sheng

    2016-01-01

    Flavones are important secondary metabolites found in many plants. In Lonicera species, flavones contribute both physiological and pharmaceutical properties. However, flavone synthase (FNS), the key enzyme responsible for flavone biosynthesis, has not yet been characterized in Lonicera species. In this study, FNSII genes were identified from Lonicera japonica Thunb. and L. macranthoides Hand.-Mazz. In the presence of NADPH, the recombinant cytochrome P450 proteins encoded by LjFNSII-1.1, LjFNSII-2.1, and LmFNSII-1.1 converted eriodictyol, naringenin, and liquiritigenin to the corresponding flavones directly. The different catalytic properties between LjFNSII-2.1 and LjFNSII-1.1 were caused by a single amino acid substitution at position 242 (glutamic acid to lysine). A methionine at position 206 and a leucine at position 381 contributed considerably to the high catalytic activity of LjFNSII-1.1. In addition, LjFNSII-1.1&2.1 and LmFNSII-1.1 also biosynthesize flavones that were further modified by O-glycosylation in transgenic tobacco. The expression levels of the FNSII genes were consistent with flavone accumulation patterns in flower buds. Our findings suggested that the weak catalytic activity of LmFNSII-1.1 and the relatively low expression of LmFNSII-1.1 in flowers might be responsible for the low levels of flavone accumulation in flower buds of L. macranthoides. PMID:26754912

  14. Genome-Wide Transcriptional Profiling Reveals Connective Tissue Mast Cell Accumulation in Bronchopulmonary Dysplasia

    PubMed Central

    Bhattacharya, Soumyaroop; Go, Diana; Krenitsky, Daria L.; Huyck, Heidi L.; Solleti, Siva Kumar; Lunger, Valerie A.; Metlay, Leon; Srisuma, Sorachai; Wert, Susan E.; Pryhuber, Gloria S.

    2012-01-01

    Rationale: Bronchopulmonary dysplasia (BPD) is a major complication of premature birth. Risk factors for BPD are complex and include prenatal infection and O2 toxicity. BPD pathology is equally complex and characterized by inflammation and dysmorphic airspaces and vasculature. Due to the limited availability of clinical samples, an understanding of the molecular pathogenesis of this disease and its causal mechanisms and associated biomarkers is limited. Objectives: Apply genome-wide expression profiling to define pathways affected in BPD lungs. Methods: Lung tissue was obtained at autopsy from 11 BPD cases and 17 age-matched control subjects without BPD. RNA isolated from these tissue samples was interrogated using microarrays. Standard gene selection and pathway analysis methods were applied to the data set. Abnormal expression patterns were validated by quantitative reverse transcriptase–polymerase chain reaction and immunohistochemistry. Measurements and Main Results: We identified 159 genes differentially expressed in BPD tissues. Pathway analysis indicated previously appreciated (e.g., DNA damage regulation of cell cycle) as well as novel (e.g., B-cell development) biological functions were affected. Three of the five most highly induced genes were mast cell (MC)-specific markers. We confirmed an increased accumulation of connective tissue MCTC (chymase expressing) mast cells in BPD tissues. Increased expression of MCTC markers was also demonstrated in an animal model of BPD-like pathology. Conclusions: We present a unique genome-wide expression data set from human BPD lung tissue. Our data provide information on gene expression patterns associated with BPD and facilitated the discovery that MCTC accumulation is a prominent feature of this disease. These observations have significant clinical and mechanistic implications. PMID:22723293

  15. Evidence for gas accumulation associated with diapirism and gas hydrates at the head of the Cape Fear Slide

    NASA Astrophysics Data System (ADS)

    Schmuck, E. A.; Paull, C. K.

    1993-09-01

    Single-channel seismic reflection profiles show evidence for areas of significant gas accumulation at the head of the Cape Fear Slide on the continental rise off North Carolina. Gas accumulation appears to occur beneath a gas hydrate seal in landward-dipping strata and in domed strata associated with diapirism. In addition, gas venting may have occurred near diapirs located at the head of the slide.

  16. Evidence for gas accumulation associated with diapirism and gas hydrates at the head of the Cape Fear Slide

    USGS Publications Warehouse

    Schmuck, E.A.; Paull, C.K.

    1993-01-01

    Single-channel seismic reflection profiles show evidence for areas of significant gas accumulation at the head of the Cape Fear Slide on the continental rise off North Carolina. Gas accumulation appears to occur beneath a gas hydrate seal in landward-dipping strata and in domed strata associated with diapirism. In addition, gas venting may have occurred near diapirs located at the head of the slide. ?? 1993 Springer-Verlag.

  17. Proteomic analysis reveals dynamic regulation of fruit development and sugar and acid accumulation in apple.

    PubMed

    Li, Mingjun; Li, Dongxia; Feng, Fengjuan; Zhang, Sheng; Ma, Fengwang; Cheng, Lailiang

    2016-09-01

    Understanding the fruit developmental process is critical for fruit quality improvement. Here, we report a comprehensive proteomic analysis of apple fruit development over five growth stages, from young fruit to maturity, coupled with metabolomic profiling. A tandem mass tag (TMT)-based comparative proteomics approach led to the identification and quantification of 7098 and 6247 proteins, respectively. This large-scale proteomic dataset presents a global view of the critical pathways involved in fruit development and metabolism. When linked with metabolomics data, these results provide new insights into the modulation of fruit development, the metabolism and storage of sugars and organic acids (mainly malate), and events within the energy-related pathways for respiration and glycolysis. We suggest that the key steps identified here (e.g. those involving the FK2, TST, EDR6, SPS, mtME and mtMDH switches), can be further targeted to confirm their roles in accumulation and balance of fructose, sucrose and malate. Moreover, our findings imply that the primary reason for decreases in amino acid concentrations during fruit development is related to a reduction in substrate flux via glycolysis, which is mainly regulated by fructose-bisphosphate aldolase and bisphosphoglycerate mutase. PMID:27535992

  18. A Large Accumulation of Avian Eggs from the Late Cretaceous of Patagonia (Argentina) Reveals a Novel Nesting Strategy in Mesozoic Birds

    PubMed Central

    Fernández, Mariela S.; García, Rodolfo A.; Fiorelli, Lucas; Scolaro, Alejandro; Salvador, Rodrigo B.; Cotaro, Carlos N.; Kaiser, Gary W.; Dyke, Gareth J.

    2013-01-01

    We report the first evidence for a nesting colony of Mesozoic birds on Gondwana: a fossil accumulation in Late Cretaceous rocks mapped and collected from within the campus of the National University of Comahue, Neuquén City, Patagonia (Argentina). Here, Cretaceous ornithothoracine birds, almost certainly Enanthiornithes, nested in an arid, shallow basinal environment among sand dunes close to an ephemeral water-course. We mapped and collected 65 complete, near-complete, and broken eggs across an area of more than 55 m2. These eggs were laid either singly, or occasionally in pairs, onto a sandy substrate. All eggs were found apparently in, or close to, their original nest site; they all occur within the same bedding plane and may represent the product of a single nesting season or a short series of nesting attempts. Although there is no evidence for nesting structures, all but one of the Comahue eggs were half-buried upright in the sand with their pointed end downwards, a position that would have exposed the pole containing the air cell and precluded egg turning. This egg position is not seen in living birds, with the exception of the basal galliform megapodes who place their eggs within mounds of vegetation or burrows. This accumulation reveals a novel nesting behaviour in Mesozoic Aves that was perhaps shared with the non-avian and phylogenetically more basal troodontid theropods. PMID:23613776

  19. Silica uptake by Spartina—evidence of multiple modes of accumulation from salt marshes around the world

    PubMed Central

    Carey, Joanna C.; Fulweiler, Robinson W.

    2014-01-01

    Silicon (Si) plays a critical role in plant functional ecology, protecting plants from multiple environmental stressors. While all terrestrial plants contain some Si, wetland grasses are frequently found to have the highest concentrations, although the mechanisms driving Si accumulation in wetland grasses remain in large part uncertain. For example, active Si accumulation is often assumed to be responsible for elevated Si concentrations found in wetland grasses. However, life stage and differences in Si availability in the surrounding environment also appear to be important variables controlling the Si concentrations of wetland grasses. Here we used original data from five North American salt marshes, as well as all known published literature values, to examine the primary drivers of Si accumulation in Spartina, a genus of prolific salt marsh grasses found worldwide. We found evidence of multiple modes of Si accumulation in Spartina, with passive accumulation observed in non-degraded marshes where Spartina was native, while rejective accumulation was found in regions where Spartina was invasive. Evidence of active accumulation was found in only one marsh where Spartina was native, but was also subjected to nutrient over-enrichment. We developed a conceptual model which hypothesizes that the mode of Si uptake by Spartina is dependent on local environmental factors and genetic origin, supporting the idea that plant species should be placed along a spectrum of Si accumulation. We hypothesize that Spartina exhibits previously unrecognized phenotypic plasticity with regard to Si accumulation, allowing these plants to respond to changes in marsh condition. These results provide new insight regarding how salt marsh ecosystems regulate Si exchange at the land-sea interface. PMID:24904599

  20. Activity in Inferior Parietal and Medial Prefrontal Cortex Signals the Accumulation of Evidence in a Probability Learning Task

    PubMed Central

    d'Acremont, Mathieu; Fornari, Eleonora; Bossaerts, Peter

    2013-01-01

    In an uncertain environment, probabilities are key to predicting future events and making adaptive choices. However, little is known about how humans learn such probabilities and where and how they are encoded in the brain, especially when they concern more than two outcomes. During functional magnetic resonance imaging (fMRI), young adults learned the probabilities of uncertain stimuli through repetitive sampling. Stimuli represented payoffs and participants had to predict their occurrence to maximize their earnings. Choices indicated loss and risk aversion but unbiased estimation of probabilities. BOLD response in medial prefrontal cortex and angular gyri increased linearly with the probability of the currently observed stimulus, untainted by its value. Connectivity analyses during rest and task revealed that these regions belonged to the default mode network. The activation of past outcomes in memory is evoked as a possible mechanism to explain the engagement of the default mode network in probability learning. A BOLD response relating to value was detected only at decision time, mainly in striatum. It is concluded that activity in inferior parietal and medial prefrontal cortex reflects the amount of evidence accumulated in favor of competing and uncertain outcomes. PMID:23401673

  1. Transcriptomic analysis of the oleaginous microalga Neochloris oleoabundans reveals metabolic insights into triacylglyceride accumulation

    PubMed Central

    2012-01-01

    Background The lack of sequenced genomes for oleaginous microalgae limits our understanding of the mechanisms these organisms utilize to become enriched in triglycerides. Here we report the de novo transcriptome assembly and quantitative gene expression analysis of the oleaginous microalga Neochloris oleoabundans, with a focus on the complex interaction of pathways associated with the production of the triacylglycerol (TAG) biofuel precursor. Results After growth under nitrogen replete and nitrogen limiting conditions, we quantified the cellular content of major biomolecules including total lipids, triacylglycerides, starch, protein, and chlorophyll. Transcribed genes were sequenced, the transcriptome was assembled de novo, and the expression of major functional categories, relevant pathways, and important genes was quantified through the mapping of reads to the transcriptome. Over 87 million, 77 base pair high quality reads were produced on the Illumina HiSeq sequencing platform. Metabolite measurements supported by genes and pathway expression results indicated that under the nitrogen-limiting condition, carbon is partitioned toward triglyceride production, which increased fivefold over the nitrogen-replete control. In addition to the observed overexpression of the fatty acid synthesis pathway, TAG production during nitrogen limitation was bolstered by repression of the β-oxidation pathway, up-regulation of genes encoding for the pyruvate dehydrogenase complex which funnels acetyl-CoA to lipid biosynthesis, activation of the pentose phosphate pathway to supply reducing equivalents to inorganic nitrogen assimilation and fatty acid biosynthesis, and the up-regulation of lipases—presumably to reconstruct cell membranes in order to supply additional fatty acids for TAG biosynthesis. Conclusions Our quantitative transcriptome study reveals a broad overview of how nitrogen stress results in excess TAG production in N. oleoabundans, and provides a variety of genetic

  2. Ice core evidence for a recent increase in snow accumulation in coastal Dronning Maud Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Philippe, Morgane; Tison, Jean-Louis; Fjøsne, Karen; Hubbard, Bryn; Kjær, Helle Astrid; Lenaerts, Jan; Sheldon, Simon Geoffrey; De Bondt, Kevin; Claeys, Philippe; Pattyn, Frank

    2016-04-01

    Ice cores provide temporal records of snow accumulation, a crucial component of Antarctic mass balance. Coastal areas are particularly under-represented in such records, despite their relatively high and sensitive accumulation rates. Here we present records from a 120 m ice core drilled on Derwael Ice Rise, coastal Dronning Maud Land (DML), East Antarctica in 2012. We date the ice core bottom back to 1745 ± 2 AD. δ18O and δD stratigraphy is supplemented by discontinuous major ion profiles, and verified independently by electrical conductivity measurements (ECM) to detect volcanic horizons. The resulting annual layer history is combined with the core density profile to calculate accumulation history, corrected for the influence of ice deformation. The mean long-term accumulation is 0.425 ± 0.035 m water equivalent (w.e.) a‑1 (average corrected value). Reconstructed annual accumulation rates show an increase from 1955 onward to a mean value of 0.61 ± 0.02 m w.e. a‑1 between 1955 and 2012. This trend is compared to other reported accumulation data in Antarctica, generally showing a high spatial variability. Applying the Community Earth System Model demonstrated that sea ice and atmosphere patterns largely explain the accumulation variability. This is the first and longest record from a coastal ice core in East Antarctica showing a steady increase during the 20th and 21st centuries, thereby confirming modelling predictions.

  3. Crustal strain accumulation on Southern Basin and Range Province faults modulated by distant plate boundary earthquakes? Evidence from geodesy, seismic imaging, and paleoseismology

    NASA Astrophysics Data System (ADS)

    Bennett, R. A.; Shirzaei, M.; Broermann, J.; Spinler, J. C.; Holland, A. A.; Pearthree, P.

    2014-12-01

    GPS in Arizona reveals a change in the pattern of crustal strain accumulation in 2010 and based on viscoelastic modeling appears to be associated with the distant M7.2 El Mayor-Cucapah (EMC) earthquake in Baja California, Mexico. GPS data collected between 1999 and 2009 near the Santa Rita normal fault in SE Arizona reveal a narrow zone of crustal deformation coincident with the fault trace, delineated by W-NW facing Pleistocene fault scarps of heights 1 to 7 m. The apparent deformation zone is also seen in a preliminary InSAR interferogram. Total motion across the zone inferred using an elastic block model constrained by the pre-2010 GPS measurements is ~1 mm/yr in a sense consistent with normal fault motion. However, continuous GPS measurements throughout Arizona reveal pronounced changes in crustal velocity following the EMC earthquake, such that the relative motion across the Santa Rita fault post-2010 is negligible. Paleoseismic evidence indicates that mapped Santa Rita fault scarps were formed by two or more large magnitude (M6.7 to M7.6) surface rupturing normal-faulting earthquakes 60 to 100 kyrs ago. Seismic refraction and reflection data constrained by deep (~800 m) well log data provide evidence of progressive, possibly intermittent, displacement on the fault through time. The rate of strain accumulation observed geodetically prior to 2010, if constant over the past 60 to 100 kyrs, would imply an untenable minimum slip rate deficit of 60 to 100 m since the most recent earthquake. One explanation for the available geodetic, seismic, and paleoseismic evidence is that strain accumulation is modulated by viscoelastic relaxation associated with frequent large magnitude earthquakes in the Salton Trough region, episodically inhibiting the accumulation of elastic strain required to generate large earthquakes on the Santa Rita and possibly other faults in the Southern Basin and Range. An important question is thus for how long the postseismic velocity changes

  4. Metabolomics analysis reveals 6‐benzylaminopurine as a stimulator for improving lipid and DHA accumulation of Aurantiochytriumsp.

    PubMed Central

    Yu, Xin‐Jun; Sun, Jie; Zheng, Jian‐Yong; Sun, Ya‐Qi

    2016-01-01

    Abstract BACKGROUND Phytohormones are chemical messengers that have a positive effect on biodiesel production of microalgae at low concentrations. However, the effect of phytohormone 6‐benzylaminopurine on lipid and docosahexaenoic acid (DHA) production in marine DHA‐producer Aurantiochytrium has never been reported. In this study, a GC‐MS‐based metabolomics method combined with a multivariate analysis is applied to reveal the metabolic mechanism of 6‐benzylaminopurine enhancing production of lipid and DHA in Aurantiochytrium sp.YLH70. RESULTS In total, 71 metabolites were identified by GC‐MS. The PCA model revealed that 76.9% of metabolite variation was related to 6‐benzylaminopurine treatment, and overall metabolomics profiles between the 6‐benzylaminopurine and control groups were clearly discriminated. Forty‐six metabolites identified by the PLS‐DA model were responsible for responding to 6‐benzylaminopurine. Metabolic analysis showed that 6‐benzylaminopurine could accelerate the rate of utilization of glucose in Aurantiochytrium sp. YLH70, and the metabolic flux from glycolysis, TCA cycle and mevalonate pathway to fatty acids biosynthesis was promoted. Moreover, the anti‐stress mechanism in Aurantiochytrium sp.YLH70 might be induced by 6‐benzylaminopurine. CONCLUSION Metabolomics is a suitable tool to discover the metabolic mechanism for improving lipid and DHA accumulation in a microorganism. 6‐benzylaminopurine has the potential to stimulate lipid and DHA production of Aurantiochytrium sp.YLH70 for industrial purposes. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:27065509

  5. Demise of reef-flat carbonate accumulation with late Holocene sea-level fall: Evidence from Molokai, Hawaii

    USGS Publications Warehouse

    Engels, M.S.; Fletcher, C.H.; Field, M.; Conger, C.L.; Bochicchio, C.

    2008-01-01

    Twelve cores from the protected reef-flat of Molokai revealed that carbonate sediment accumulation, ranging from 3 mm year-1 to less than 1 mm year-1, ended on average 2,500 years ago. Modern sediment is present as a mobile surface veneer but is not trapped within the reef framework. This finding is consistent with the arrest of deposition at the end of the mid-Holocene highstand, known locally as the "Kapapa Stand of the Sea," ???2 m above the present datum ca. 3,500 years ago in the main Hawaiian Islands. Subsequent erosion, non-deposition, and/or a lack of rigid binding were probable factors leading to the lack of reef-flat accumulation during the late Holocene sea-level fall. Given anticipated climate changes, increased sedimentation of reef-flat environments is to be expected as a consequence of higher sea level. ?? 2008 Springer-Verlag.

  6. Evidence for the Accumulation of Peroxidized Lipids in Membranes of Senescing Cotyledons 1

    PubMed Central

    Pauls, K. Peter; Thompson, John E.

    1984-01-01

    Fluorescent products of lipid peroxidation accumulate with age in microsomal membranes from senescing cotyledons of Phaseolus vulgaris. The temporal pattern of accumulation is closely correlated with a rise in the lipid phase transition temperature reflecting the formation of gel phase lipid. Increased levels of fluorescent peroxidation products are also detectable in total lipid extracts of senescent cotyledons. Lipoxygenase activity increases with advancing age by about 3-fold on a fresh weight basis and 4-fold on a dry weight basis indicating that the tissue acquires elevated levels of lipid hydroperoxides. As well, levels of glutathione and superoxide dismutase activity decline on a dry weight basis as the cotyledons age, rendering the tissue more susceptible to oxidative damage. Catalase activity rises initially and then declines during senescence, but peroxidase activity rises steeply. Thus, apart from this increase in peroxidase, which would scavenge H2O2 only if appropriate cosubstrates were available, the defense mechanisms for coping with activated oxygen species (O2−, H2O2, OH) are less effective in the older tissue. The observations support the contention that formation of gel phase lipid in senescing membranes is attributable to lipid peroxidation and suggest that the reactions of lipid peroxidation are utilized by the cotyledons to mediate deteriorative changes accompanying the mobilization and transport of metabolites from the storage tissue to the developing embryo. Images Fig. 10 PMID:16663749

  7. Evidence for accumulation of Synechococcus elongatus (Cyanobacteria: Cyanophyceae) in the tissues of the oyster Crassostrea gigas (Mollusca: Bivalvia).

    PubMed

    Avila-Poveda, Omar Hernando; Torres-Ariño, Alejandra; Girón-Cruz, Diego Ademir; Cuevas-Aguirre, Angel

    2014-10-01

    Cyanobacteria appear to have direct relations with mollusks in several aspects. This is the first time, distinguishing Gram-negative cyanoprokaryotic Synechococcus elongatus as bright yellow-gold autofluorescence by Lillie's and Hiss' staining methods on paraffin-embedded tissues of Crassostrea gigas. Three diets: cyanoprokaryotes, cyanoprokaryotes with microalgae, and only microalgae were evaluated. Cyanoprokaryotes were intact, densely bundled, and immersed in the cytosol of the digestive gland, connective tissue, mantle, and gonad of C. gigas, revealing an accumulation systemic without tissue damage observed by histology. Unexpectedly, cyanoprokaryotes were slightly most accumulated with microalgae diet by each of the tissues of the C. gigas than with any other diets. Cyanoprokaryotes tend to be in mean slightly higher in the digestive gland than in any other tissues respectively for each diet, although these values are closely similar to connective tissue. A possible order of exposure of the oyster tissues to accumulation of cyanoprokaryotes was digestive gland, connective tissue, mantle, and gonad. Thereby, the digestive gland could be the major target tissue for the accumulation. Our observations provide a valuable insight regarding the ability of cyanoprokaryotes to penetrate, spread, and remain inside the oyster tissues, suggesting for S. elongatus: (1) a pre-accumulation in oyster tissues from the natural environment, (2) a phagocytosis and/or endocytosis process rather than ingestion and extracellular digestion, (3) an apparent cellular division in the cytosol of oyster tissues, (4) an apparent inter-tissue movement, and (5) a possible endosymbiosis between C. gigas and S. elongatus. Hereby, it is possible that S. elongatus have a well-developed host-endobiont relationship with oysters, and thereby support future work toward a description of the escape and spreading mechanisms of S. elongatus inside the tissues of mollusks, and put forward questions as

  8. Lifespan mercury accumulation pattern in Liza aurata : Evidence from two southern European estuaries

    NASA Astrophysics Data System (ADS)

    Tavares, S.; Oliveira, H.; Coelho, J. P.; Pereira, M. E.; Duarte, A. C.; Pardal, M. A.

    2011-10-01

    Mercury accumulation throughout the lifespan of Liza aurata (Risso, 1810) was analysed in four tissues (muscle, gills, liver and brain) in two southern European coastal ecosystems with distinct mercury contamination. Specimens from four to five age classes were captured in two sampling sites in the Ria de Aveiro (Laranjo bay and Mira), a system historically contaminated by industrial mercury, and in one site in the Mondego estuary, assumed as a mercury-free ecosystem. Mercury concentration in all tissues was found to be significantly higher in the Ria de Aveiro (Laranjo bay) compared to the Mondego, in accordance with the environmental contamination (water, sediments and suspended particulate matter). Significant differences inside the Ria de Aveiro (between the Mira and Laranjo bay) were only detected in the liver. This tissue registered the highest levels of mercury (ranging from 0.11 to 4.2 μg g -1 ) in all sampling sites, followed by muscle, brain, and gills. In all sampling sites and tissues was denoted a mercury dilution pattern along the lifecycle (except in liver at the Mondego, the reference area where the concentrations are always very low). An exponential trend was found in the metal age variation patterns in Laranjo (the most contaminated area) and a linear trend in the Mira and the Mondego (the least contaminated areas). Organic mercury concentration in muscle generally accounted for over 95% of total mercury concentration, and followed the same accumulation pattern of total mercury. This fish species is of lesser importance in mercury transfer to adjacent coastal areas and although the consumption of fish from Laranjo may present some risk for the humans, this risk decreases with fish age/size.

  9. Quantification of Maize Fine Streak Virus Genomic and Positive-sense RNAs in Infected Maize Reveals High Level Accumulation of ORF 3 and 4 MFSV Transcripts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantification of Maize fine streak virus genomic and positive-sense RNAs in infected maize reveals high level accumulation of ORF 3 and 4 MFSV transcripts. We improved methods to analyze RNA produced by Maize fine streak virus (MVSF) within infected maize tissue using real-time RT-qPCR. We designe...

  10. Error awareness revisited: accumulation of multimodal evidence from central and autonomic nervous systems.

    PubMed

    Wessel, Jan R; Danielmeier, Claudia; Ullsperger, Markus

    2011-10-01

    The differences between erroneous actions that are consciously perceived as errors and those that go unnoticed have recently become an issue in the field of performance monitoring. In EEG studies, error awareness has been suggested to influence the error positivity (Pe) of the response-locked event-related brain potential, a positive voltage deflection prominent approximately 300 msec after error commission, whereas the preceding error-related negativity (ERN) seemed to be unaffected by error awareness. Erroneous actions, in general, have been shown to promote several changes in ongoing autonomic nervous system (ANS) activity, yet such investigations have only rarely taken into account the question of subjective error awareness. In the first part of this study, heart rate, pupillometry, and EEG were recorded during an antisaccade task to measure autonomic arousal and activity of the CNS separately for perceived and unperceived errors. Contrary to our expectations, we observed differences in both Pe and ERN with respect to subjective error awareness. This was replicated in a second experiment, using a modified version of the same task. In line with our predictions, only perceived errors provoke the previously established post-error heart rate deceleration. Also, pupil size yields a more prominent dilatory effect after an erroneous saccade, which is also significantly larger for perceived than unperceived errors. On the basis of the ERP and ANS results as well as brain-behavior correlations, we suggest a novel interpretation of the implementation and emergence of error awareness in the brain. In our framework, several systems generate input signals (e.g., ERN, sensory input, proprioception) that influence the emergence of error awareness, which is then accumulated and presumably reflected in later potentials, such as the Pe. PMID:21268673

  11. Analysis of Strains Lacking Known Osmolyte Accumulation Mechanisms Reveals Contributions of Osmolytes and Transporters to Protection against Abiotic Stress

    PubMed Central

    Murdock, Lindsay; Burke, Tangi; Coumoundouros, Chelsea; Culham, Doreen E.; Deutch, Charles E.; Ellinger, James; Kerr, Craig H.; Plater, Samantha M.; To, Eric; Wright, Geordie

    2014-01-01

    Osmolyte accumulation and release can protect cells from abiotic stresses. In Escherichia coli, known mechanisms mediate osmotic stress-induced accumulation of K+ glutamate, trehalose, or zwitterions like glycine betaine. Previous observations suggested that additional osmolyte accumulation mechanisms (OAMs) exist and their impacts may be abiotic stress specific. Derivatives of the uropathogenic strain CFT073 and the laboratory strain MG1655 lacking known OAMs were created. CFT073 grew without osmoprotectants in minimal medium with up to 0.9 M NaCl. CFT073 and its OAM-deficient derivative grew equally well in high- and low-osmolality urine pools. Urine-grown bacteria did not accumulate large amounts of known or novel osmolytes. Thus, CFT073 showed unusual osmotolerance and did not require osmolyte accumulation to grow in urine. Yeast extract and brain heart infusion stimulated growth of the OAM-deficient MG1655 derivative at high salinity. Neither known nor putative osmoprotectants did so. Glutamate and glutamine accumulated after growth with either organic mixture, and no novel osmolytes were detected. MG1655 derivatives retaining individual OAMs were created. Their abilities to mediate osmoprotection were compared at 15°C, 37°C without or with urea, and 42°C. Stress protection was not OAM specific, and variations in osmoprotectant effectiveness were similar under all conditions. Glycine betaine and dimethylsulfoniopropionate (DMSP) were the most effective. Trimethylamine-N-oxide (TMAO) was a weak osmoprotectant and a particularly effective urea protectant. The effectiveness of glycine betaine, TMAO, and proline as osmoprotectants correlated with their preferential exclusion from protein surfaces, not with their propensity to prevent protein denaturation. Thus, their effectiveness as stress protectants correlated with their ability to rehydrate the cytoplasm. PMID:24951793

  12. Nitrogen starvation-induced accumulation of triacylglycerol in the green algae: evidence for a role for ROC40, a transcription factor involved in circadian rhythm.

    PubMed

    Goncalves, Elton C; Koh, Jin; Zhu, Ning; Yoo, Mi-Jeong; Chen, Sixue; Matsuo, Takuya; Johnson, Jodie V; Rathinasabapathi, Bala

    2016-03-01

    Microalgal triacylglycerol (TAG), a promising source of biofuel, is induced upon nitrogen starvation (-N), but the proteins and genes involved in this process are poorly known. We performed isobaric tagging for relative and absolute quantification (iTRAQ)-based quantitative proteomics to identify Chlorella proteins with modulated expression under short-term -N. Out of 1736 soluble proteins and 2187 membrane-associated proteins identified, 288 and 56, respectively, were differentially expressed under -N. Gene expression analysis on select genes confirmed the same direction of mRNA modulation for most proteins. The MYB-related transcription factor ROC40 was the most induced protein, with a 9.6-fold increase upon -N. In a previously generated Chlamydomonas mutant, gravimetric measurements of crude total lipids revealed that roc40 was impaired in its ability to increase the accumulation of TAG upon -N, and this phenotype was complemented when wild-type Roc40 was expressed. Results from radiotracer experiments were consistent with the roc40 mutant being comparable to the wild type in recycling membrane lipids to TAG but being impaired in additional de novo synthesis of TAG during -N stress. In this study we provide evidence to support the hypothesis that transcription factor ROC40 has a role in -N-induced lipid accumulation, and uncover multiple previously unknown proteins modulated by short-term -N in green algae. PMID:26920093

  13. Evidence for accumulated melt beneath the slow-spreading Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Sinha, M. C.; Navin, D. A.; MacGregor, L. M.; Constable, S.; Peirce, C.; White, A.; Heinson, G.; Inglis, M. A.

    The analysis of data from a multi-component geophysical experiment conducted on a segment of the slow-spreading (20 mm yr-1) Mid-Atlantic Ridge shows compelling evidence for a significant crustal magma body beneath the ridge axis. The role played by a crustal magma chamber beneath the axis in determining both the chemical and physical architecture of the newly formed crust is fundamental to our understanding of the accretion of oceanic lithosphere at spreading ridges, and over the last decade subsurface geophysical techniques have successfully imaged such magma chambers beneath a number of intermediate and fast spreading (60-140 mm yr-1 full rate) ridges. However, many similar geophysical studies of slow-spreading ridges have, to date, found little or no evidence for such a magma chamber beneath them. The experiment described here was carefully targeted on a magmatically active, axial volcanic ridge (AVR) segment of the Reykjanes Ridge, centred on 57 degrees 43 minutes North. It consisted of four major components: wide-angle seismic profiles using ocean bottom seismometers; seismic reflection profiles; controlled source electromagnetic sounding; and magneto-telluric sounding. Interpretation and modelling of the first three of these datasets shows that an anomalous body lies at a depth of between 2 and 3 km below the seafloor beneath the axis of the AVR. This body is characterized by anomalously low seismic P-wave velocity and electrical resistivity, and is associated with a seismic reflector. The geometry and extent of this melt body shows a number of similarities with the axial magma chambers observed beneath ridges spreading at much higher spreading rates. Magneto-telluric soundings confirm the existence of very low electrical resistivities in the crust beneath the AVR and also indicate a deeper zone of low resistivity within the upper mantle beneath the ridge.

  14. Target blood pressure in diabetes patients with hypertension--what is the accumulated evidence in 2011?

    PubMed

    Nilsson, Peter M

    2011-08-01

    There is overwhelming evidence that hypertension is an important risk factor for both macrovascular and microvascular complications in patients with diabetes, but the problem remains to identify appropriate goals for preventive therapies. A number of guidelines (the European Society of Cardiology (ESC)/European Association for the Study of Diabetes (EASD) 2007, the Joint National Committee (JNC)-VII 2003, the American Diabetes Association (ADA) 2011) have for example advocated a blood pressure goal of less than 130/80 mmHg, but this suggestion has been challenged by findings in recent trials and meta-analyses (2011). The European Society of Hypertension (ESH) therefore recommends a systolic blood pressure goal of "well below" 140 mmHg. Based on evidence from both randomized controlled trials (hypertension optimal treatment (HOT), action in diabetes and vascular disease: preterax and diamicron MR controlled evaluation (ADVANCE), action to control cardiovascular risk in diabetes (ACCORD)) and observational studies (ongoing telmisartan alone and in combination with ramipril global endpoint trial (ONTARGET), international verapamil-trandolapril study (INVEST), treat to new targets (TNT), and the National Diabetes Register (NDR)), it has been shown that the benefit for stroke reduction remains even at lower achieved blood pressure levels, but the risk of coronary events may be uninfluenced or even increased at lower systolic blood pressure levels. In a recent meta-analysis, it was therefore concluded that the new recommended goal should be 130-135 mmHg systolic blood pressure for most patients with type 2 diabetes. Other risk factors should also be controlled with a more ambitious strategy applied in the younger patients with shorter diabetes duration, but a more cautious approach in the elderly and frail patients with a number of vascular or non-vascular co-morbidities. In patients from East Asia, such as China, the stroke risk is relatively higher than the risk of

  15. Accumulating Evidence Supports a Taste Component for Free Fatty Acids in Humans

    PubMed Central

    Mattes, Richard D.

    2011-01-01

    The requisite criteria for what constitutes a taste primary have not been established. Recent advances in understanding of the mechanisms and functions of taste have prompted suggestions for an expanded list of unique taste sensations, including fat, or more specifically, free fatty acids (FFA). A set of criteria are proposed here and the data related to FFA are reviewed on each point. It is concluded that the data are moderate to strong that there are: A) adaptive advantages to FFA detection in the oral cavity; B) adequate concentrations of FFA to serve as taste stimuli; C) multiple complimentary putative FFA receptors on taste cells; D) signals generated by FFA that are conveyed by gustatory nerves; E) sensations generated by FFA that can be detected and scaled by psychophysical methods in humans when non-gustatory cues are masked; and F) physiological responses to oral fat/FFA exposure. On no point is there strong evidence challenging these observations. The reviewed findings are suggestive, albeit not definitive, that there is a taste component for FFA. PMID:21557960

  16. On the Dissociation of Word/Nonword Repetition Effects in Lexical Decision: An Evidence Accumulation Account

    PubMed Central

    Perea, Manuel; Marcet, Ana; Vergara-Martínez, Marta; Gomez, Pablo

    2016-01-01

    A number of models of visual-word recognition assume that the repetition of an item in a lexical decision experiment increases that item's familiarity/wordness. This would produce not only a facilitative repetition effect for words, but also an inhibitory effect for nonwords (i.e., more familiarity/wordness makes the negative decision slower). We conducted a two-block lexical decision experiment to examine word/nonword repetition effects in the framework of a leading “familiarity/wordness” model of the lexical decision task, namely, the diffusion model (Ratcliff et al., 2004). Results showed that while repeated words were responded to faster than the unrepeated words, repeated nonwords were responded to more slowly than the nonrepeated nonwords. Fits from the diffusion model revealed that the repetition effect for words/nonwords was mainly due to differences in the familiarity/wordness (drift rate) parameter. This word/nonword dissociation favors those accounts that posit that the previous presentation of an item increases its degree of familiarity/wordness. PMID:26925021

  17. On the Dissociation of Word/Nonword Repetition Effects in Lexical Decision: An Evidence Accumulation Account.

    PubMed

    Perea, Manuel; Marcet, Ana; Vergara-Martínez, Marta; Gomez, Pablo

    2016-01-01

    A number of models of visual-word recognition assume that the repetition of an item in a lexical decision experiment increases that item's familiarity/wordness. This would produce not only a facilitative repetition effect for words, but also an inhibitory effect for nonwords (i.e., more familiarity/wordness makes the negative decision slower). We conducted a two-block lexical decision experiment to examine word/nonword repetition effects in the framework of a leading "familiarity/wordness" model of the lexical decision task, namely, the diffusion model (Ratcliff et al., 2004). Results showed that while repeated words were responded to faster than the unrepeated words, repeated nonwords were responded to more slowly than the nonrepeated nonwords. Fits from the diffusion model revealed that the repetition effect for words/nonwords was mainly due to differences in the familiarity/wordness (drift rate) parameter. This word/nonword dissociation favors those accounts that posit that the previous presentation of an item increases its degree of familiarity/wordness. PMID:26925021

  18. Evolution of subgroup A respiratory syncytial virus: evidence for progressive accumulation of amino acid changes in the attachment protein.

    PubMed Central

    Cane, P A; Pringle, C R

    1995-01-01

    The variability of the attachment (G) proteins of 48 subgroup A isolates of respiratory syncytial virus (RSV) isolated over 38 years has been examined. Nucleotide sequences of two variable regions of the G protein genes were determined following amplification by PCR. The isolates showed temporal rather than geographical clustering, and there was evidence for progressive accumulation of amino acid changes at an average rate of approximately 0.25% per year estimated over the entire protein. The cocirculation of lineages of RSV at present appears to be the result of a process of evolution and survival of particular genotypes and the extinction of others. Analysis of reactivity of the isolates with monoclonal antibodies showed that their antigenic profiles closely paralleled their relatedness by nucleotide sequence, suggesting that antigenic drift due to immune selection may be occurring. PMID:7707517

  19. Evidence for the use of organic carbon as the sorbing matrix in the modeling of PCB accumulation in phytoplankton

    SciTech Connect

    Skoglung, R.S.; Swackhamer, D.L.

    1999-05-01

    This report presents empirical evidence for the use of organic carbon as the sorbing matrix in the kinetic modeling of PCB accumulation in phytoplankton. A kinetic-based model was used to predict congener-specific bioaccumulation factors of PCBs in phytoplankton samples collected from Green Bay, Lake Michigan. These values were compared to the measured bioaccumulation factors, and the sum of the residuals was used to evaluate the model`s predictive quality. The sorbing matrix fraction (F{sub M}) that minimized the sum of residuals of the model was then solved by iteration. The appropriateness of using dry weight, organic carbon fraction, or lipid fractions as the sorbing matrix fraction was determined by measuring their correlation to the optimum F{sub M}. It was determined that the F{sub M} correlated best with the organic carbon fraction, and this correlation appeared to be independent of both the spatial and seasonal differences of the field samples.

  20. Shallow Magma Accumulation at Halema'uma'u Crater, Kilauea Volcano, Revealed by Microgravity Measurements (1975-2008)

    NASA Astrophysics Data System (ADS)

    Battaglia, M.; Eggers, A.; Bagnardi, M.; Poland, M. P.; Miklius, A.

    2009-12-01

    We examined microgravity data collected during surveys of a dense network around the summit of Kilauea Volcano, Hawai'i, following the 1975 M7.2 earthquake and in 1981, 1998, 2003, and 2008. All gravity measurements are relative to a benchmark located 4 km northwest of the caldera. Gravity changes were adjusted for the free air effect by assuming a correction of -308.6 μGal/m and using leveling data (completed at approximately the same time as the gravity surveys) to determine elevation changes between successive gravity surveys. A several-year time series of water level measurements from a well within Kilauea’s caldera indicates that gravity variations due to groundwater fluctuations are negligible. Residual gravity data are characterized by a prominent positive residual gravity anomaly (an increase of 521 μGal during 1975-2008) along the east margin of Halema'uma'u Crater. The anomaly, which occurs in an area of relatively minor surface deformation, suggests subsurface magma accumulation in void space (probably a network of interconnected cracks) at shallow depths beneath Kilauea's caldera. The region beneath the southeast rim of Halema'uma'u Crater is a known volume of shallow magma storage on the basis of both geodetic and seismic data, and is near the site of several historical summit eruptive vents, including that of the 2008 explosion and subsequent eruption. Assuming a spherical source, we modeled the residual gravity changes measured at stations close to the Halema'uma'u source to estimate the source location, depth and mass change. The weighted least square inversion over the four time periods spanned by the daya gives a depth of 500-950 m (average is 725 m) with a total mass accumulation over 33 years of 6 x 1010 kg. Mass accumulation was variable over 1975-2008, with lower average rates during 1981-1998 and 1998-2003 and higher average rates during 1975-1981 and 2003-2008. The variable accumulation rates are consistent with changes in Kilauea

  1. Accumulation of Polyunsaturated Aldehydes in the Gonads of the Copepod Acartia tonsa Revealed by Tailored Fluorescent Probes

    PubMed Central

    Wolfram, Stefanie; Nejstgaard, Jens C.; Pohnert, Georg

    2014-01-01

    Polyunsaturated aldehydes (PUAs) are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies. PMID:25383890

  2. Single-particle imaging reveals intraflagellar transport–independent transport and accumulation of EB1 in Chlamydomonas flagella

    PubMed Central

    Harris, J. Aaron; Liu, Yi; Yang, Pinfen; Kner, Peter; Lechtreck, Karl F.

    2016-01-01

    The microtubule (MT) plus-end tracking protein EB1 is present at the tips of cilia and flagella; end-binding protein 1 (EB1) remains at the tip during flagellar shortening and in the absence of intraflagellar transport (IFT), the predominant protein transport system in flagella. To investigate how EB1 accumulates at the flagellar tip, we used in vivo imaging of fluorescent protein–tagged EB1 (EB1-FP) in Chlamydomonas reinhardtii. After photobleaching, the EB1 signal at the flagellar tip recovered within minutes, indicating an exchange with unbleached EB1 entering the flagella from the cell body. EB1 moved independent of IFT trains, and EB1-FP recovery did not require the IFT pathway. Single-particle imaging showed that EB1-FP is highly mobile along the flagellar shaft and displays a markedly reduced mobility near the flagellar tip. Individual EB1-FP particles dwelled for several seconds near the flagellar tip, suggesting the presence of stable EB1 binding sites. In simulations, the two distinct phases of EB1 mobility are sufficient to explain its accumulation at the tip. We propose that proteins uniformly distributed throughout the cytoplasm like EB1 accumulate locally by diffusion and capture; IFT, in contrast, might be required to transport proteins against cellular concentration gradients into or out of cilia. PMID:26631555

  3. Imaging Mass Spectrometry Revealed the Accumulation Characteristics of the 2-Nitroimidazole-Based Agent "Pimonidazole" in Hypoxia.

    PubMed

    Masaki, Yukiko; Shimizu, Yoichi; Yoshioka, Takeshi; Feng, Fei; Zhao, Songji; Higashino, Kenichi; Numata, Yoshito; Kuge, Yuji

    2016-01-01

    Hypoxia, or low oxygen concentration, is a key factor promoting tumor progression and angiogenesis and resistance of cancer to radiotherapy and chemotherapy. 2-Nitroimidazole-based agents have been widely used in pathological and nuclear medicine examinations to detect hypoxic regions in tumors; in particular, pimonidazole is used for histochemical staining of hypoxic regions. It is considered to accumulate in hypoxic cells via covalent binding with macromolecules or by forming reductive metabolites after reduction of its nitro group. However, the detailed mechanism of its accumulation remains unknown. In this study, we investigated the accumulation mechanism of pimonidazole in hypoxic tumor tissues in a mouse model by mass spectrometric analyses including imaging mass spectrometry (IMS). Pimonidazole and its reductive metabolites were observed in the tumor tissues. However, their locations in the tumor sections were not similar to the positively stained areas in pimonidazole-immunohistochemistry, an area considered hypoxic. The glutathione conjugate of reduced pimonidazole, a low-molecular-weight metabolite of pimonidazole, was found in tumor tissues by LC-MS analysis, and our IMS study determined that the intratumor localization of the glutathione conjugate was consistent with the area positively immunostained for pimonidazole. We also found complementary localization of the glutathione conjugate and reduced glutathione (GSH), implying that formation of the glutathione conjugate occurred in the tumor tissue. These results suggest that in hypoxic tumor cells, pimonidazole is reduced at its nitro group, followed by conjugation with GSH. PMID:27580239

  4. De Novo Assembly of the Peanut (Arachis hypogaea L.) Seed Transcriptome Revealed Candidate Unigenes for Oil Accumulation Pathways

    PubMed Central

    Yin, Dongmei; Wang, Yun; Zhang, Xingguo; Li, Hemin; Lu, Xiang; Zhang, Jinsong; Zhang, Wanke; Chen, Shouyi

    2013-01-01

    Peanuts are one of the most important edible oil crops in the world. In order to survey key genes controlling peanut oil accumulation, we analyzed the seed transcriptome in different developmental stages of high- and low-oil peanut varieties. About 54 million high quality clean reads were generated, which corresponded to 4.85 Gb total nucleotides. These reads were assembled into 59,236 unique sequences. Differential mRNA processing events were detected for most of the peanut Unigenes and found that 15.8% and 18.0% of the Unigenes were differentially expressed between high- and low-oil varieties at 30 DAF and 50 DAF, respectively. Over 1,500 Unigenes involved in lipid metabolism were identified, classified, and found to participate in FA synthesis and TAG assembly. There were seven possible metabolic pathways involved in the accumulation of oil during seed development. This dataset provides more sequence resource for peanut plant and will serve as the foundation to understand the mechanisms of oil accumulation in oil crops. PMID:24040062

  5. Single-particle imaging reveals intraflagellar transport-independent transport and accumulation of EB1 in Chlamydomonas flagella.

    PubMed

    Harris, J Aaron; Liu, Yi; Yang, Pinfen; Kner, Peter; Lechtreck, Karl F

    2016-01-15

    The microtubule (MT) plus-end tracking protein EB1 is present at the tips of cilia and flagella; end-binding protein 1 (EB1) remains at the tip during flagellar shortening and in the absence of intraflagellar transport (IFT), the predominant protein transport system in flagella. To investigate how EB1 accumulates at the flagellar tip, we used in vivo imaging of fluorescent protein-tagged EB1 (EB1-FP) in Chlamydomonas reinhardtii. After photobleaching, the EB1 signal at the flagellar tip recovered within minutes, indicating an exchange with unbleached EB1 entering the flagella from the cell body. EB1 moved independent of IFT trains, and EB1-FP recovery did not require the IFT pathway. Single-particle imaging showed that EB1-FP is highly mobile along the flagellar shaft and displays a markedly reduced mobility near the flagellar tip. Individual EB1-FP particles dwelled for several seconds near the flagellar tip, suggesting the presence of stable EB1 binding sites. In simulations, the two distinct phases of EB1 mobility are sufficient to explain its accumulation at the tip. We propose that proteins uniformly distributed throughout the cytoplasm like EB1 accumulate locally by diffusion and capture; IFT, in contrast, might be required to transport proteins against cellular concentration gradients into or out of cilia. PMID:26631555

  6. Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

    PubMed

    Wolfram, Stefanie; Nejstgaard, Jens C; Pohnert, Georg

    2014-01-01

    Polyunsaturated aldehydes (PUAs) are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies. PMID:25383890

  7. Ultrastructural Characterization of Turnip Mosaic Virus-Induced Cellular Rearrangements Reveals Membrane-Bound Viral Particles Accumulating in Vacuoles

    PubMed Central

    Wan, Juan; Basu, Kaustuv; Mui, Jeannie; Vali, Hojatollah; Zheng, Huanquan

    2015-01-01

    ABSTRACT Positive-strand RNA [(+) RNA] viruses remodel cellular membranes to facilitate virus replication and assembly. In the case of turnip mosaic virus (TuMV), the viral membrane protein 6K2 plays an essential role in endomembrane alterations. Although 6K2-induced membrane dynamics have been widely studied by confocal microscopy, the ultrastructure of this remodeling has not been extensively examined. In this study, we investigated the formation of TuMV-induced membrane changes by chemical fixation and high-pressure freezing/freeze substitution (HPF/FS) for transmission electron microscopy at different times of infection. We observed the formation of convoluted membranes connected to rough endoplasmic reticulum (rER) early in the infection process, followed by the production of single-membrane vesicle-like (SMVL) structures at the midstage of infection. Both SMVL and double-membrane vesicle-like structures with electron-dense cores, as well as electron-dense bodies, were found late in the infection process. Immunogold labeling results showed that the vesicle-like structures were 6K2 tagged and suggested that only the SMVL structures were viral RNA replication sites. Electron tomography (ET) was used to regenerate a three-dimensional model of these vesicle-like structures, which showed that they were, in fact, tubules. Late in infection, we observed filamentous particle bundles associated with electron-dense bodies, which suggests that these are sites for viral particle assembly. In addition, TuMV particles were observed to accumulate in the central vacuole as membrane-associated linear arrays. Our work thus unravels the sequential appearance of distinct TuMV-induced membrane structures for viral RNA replication, viral particle assembly, and accumulation. IMPORTANCE Positive-strand RNA viruses remodel cellular membranes for different stages of the infection process, such as protein translation and processing, viral RNA synthesis, particle assembly, and virus

  8. Global Transcriptome Analysis Reveals Distinct Aluminum-Tolerance Pathways in the Al-Accumulating Species Hydrangea macrophylla and Marker Identification

    PubMed Central

    Chen, Haixia; Lu, Changping; Jiang, Hui; Peng, Jinhui

    2015-01-01

    Hydrangea (Hydrangea macrophylla) is a well known Al-accumulating plant, showing a high level of aluminum (Al) tolerance and accumulation. Although the physiological mechanisms for detoxification of Al and the roles of Al in blue hydrangea sepals have been reported, the molecular mechanisms of Al tolerance and accumulation are poorly understood in hydrangea. In this study, we conducted a genome-wide transcriptome analysis of Al-response genes in the roots and leaves of hydrangea by RNA sequencing (RNA-seq). The assembly of hydrangea transcriptome provides a rich source for gene identification and mining molecular markers, including single nucleotide polymorphism (SNP) and simple sequence repeat (SSR). A total of 401,215 transcripts with an average length of 810.77bp were assembled, generating 256,127 unigenes. After annotation, 4,287 genes in the roots and 730 genes in the leaves were up-regulated by Al exposure, while 236 genes in the roots and 719 genes in the leaves were down-regulated, respectively. Many transporters, including MATE and ABC families, were involved in the process of Al-citrate complex transporting from the roots in hydrangea. A plasma membrane Al uptake transporter, Nramp aluminum transporter was up-regulated in roots and leaves under Al stress, indicating it may play an important role in Al tolerance by reducing the level of toxic Al. Although the exact roles of these candidate genes remain to be examined, these results provide a platform for further functional analysis of the process of detoxification of Al in hydrangea. PMID:26660093

  9. Quality of evidence revealing subtle gender biases in science is in the eye of the beholder.

    PubMed

    Handley, Ian M; Brown, Elizabeth R; Moss-Racusin, Corinne A; Smith, Jessi L

    2015-10-27

    Scientists are trained to evaluate and interpret evidence without bias or subjectivity. Thus, growing evidence revealing a gender bias against women-or favoring men-within science, technology, engineering, and mathematics (STEM) settings is provocative and raises questions about the extent to which gender bias may contribute to women's underrepresentation within STEM fields. To the extent that research illustrating gender bias in STEM is viewed as convincing, the culture of science can begin to address the bias. However, are men and women equally receptive to this type of experimental evidence? This question was tested with three randomized, double-blind experiments-two involving samples from the general public (n = 205 and 303, respectively) and one involving a sample of university STEM and non-STEM faculty (n = 205). In all experiments, participants read an actual journal abstract reporting gender bias in a STEM context (or an altered abstract reporting no gender bias in experiment 3) and evaluated the overall quality of the research. Results across experiments showed that men evaluate the gender-bias research less favorably than women, and, of concern, this gender difference was especially prominent among STEM faculty (experiment 2). These results suggest a relative reluctance among men, especially faculty men within STEM, to accept evidence of gender biases in STEM. This finding is problematic because broadening the participation of underrepresented people in STEM, including women, necessarily requires a widespread willingness (particularly by those in the majority) to acknowledge that bias exists before transformation is possible. PMID:26460001

  10. Quality of evidence revealing subtle gender biases in science is in the eye of the beholder

    PubMed Central

    Handley, Ian M.; Brown, Elizabeth R.; Moss-Racusin, Corinne A.; Smith, Jessi L.

    2015-01-01

    Scientists are trained to evaluate and interpret evidence without bias or subjectivity. Thus, growing evidence revealing a gender bias against women—or favoring men—within science, technology, engineering, and mathematics (STEM) settings is provocative and raises questions about the extent to which gender bias may contribute to women’s underrepresentation within STEM fields. To the extent that research illustrating gender bias in STEM is viewed as convincing, the culture of science can begin to address the bias. However, are men and women equally receptive to this type of experimental evidence? This question was tested with three randomized, double-blind experiments—two involving samples from the general public (n = 205 and 303, respectively) and one involving a sample of university STEM and non-STEM faculty (n = 205). In all experiments, participants read an actual journal abstract reporting gender bias in a STEM context (or an altered abstract reporting no gender bias in experiment 3) and evaluated the overall quality of the research. Results across experiments showed that men evaluate the gender-bias research less favorably than women, and, of concern, this gender difference was especially prominent among STEM faculty (experiment 2). These results suggest a relative reluctance among men, especially faculty men within STEM, to accept evidence of gender biases in STEM. This finding is problematic because broadening the participation of underrepresented people in STEM, including women, necessarily requires a widespread willingness (particularly by those in the majority) to acknowledge that bias exists before transformation is possible. PMID:26460001

  11. Integrated transcriptome sequencing and dynamic analysis reveal carbon source partitioning between terpenoid and oil accumulation in developing Lindera glauca fruits

    PubMed Central

    Niu, Jun; Chen, Yinlei; An, Jiyong; Hou, Xinyu; Cai, Jian; Wang, Jia; Zhang, Zhixiang; Lin, Shanzhi

    2015-01-01

    Lindera glauca fruits (LGF) with the abundance of terpenoid and oil has emerged as a novel specific material for industrial and medicinal application in China, but the complex regulatory mechanisms of carbon source partitioning into terpenoid biosynthetic pathway (TBP) and oil biosynthetic pathway (OBP) in developing LGF is still unknown. Here we perform the analysis of contents and compositions of terpenoid and oil from 7 stages of developing LGF to characterize a dramatic difference in temporal accumulative patterns. The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis. By Illumina sequencing, the obtained approximately 81 million reads are assembled into 69,160 unigenes, among which 174, 71, 81 and 155 unigenes are implicated in glycolysis, pentose phosphate pathway (PPP), TBP and OBP, respectively. Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF. These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca. PMID:26446413

  12. Proteomics to reveal metabolic network shifts towards lipid accumulation following nitrogen deprivation in the diatom Phaeodactylum tricornutum.

    PubMed

    Yang, Zhi-Kai; Ma, Yu-Han; Zheng, Jian-Wei; Yang, Wei-Dong; Liu, Jie-Sheng; Li, Hong-Ye

    2014-01-01

    The marine diatom Phaeodactylum tricornutum is attracting considerable interest as a candidate for biofuel production due to its fast growth and high lipid content. Nitrogen deficiency can increase the lipid content in certain microalgae species, including P. tricornutum. However, the molecular basis of such changes remains unclear without analyzing metabolism at the proteomic level. We attempted to systematically analyze protein expression level changes of P. tricornutum upon N deprivation. We observed translational level changes that could overall redirect the metabolic network from carbon flux towards lipid accumulation. N deprivation led to an increase in the expression of genes involved in nitrogen assimilation and fatty acid biosynthesis and a concomitant decrease in photosynthesis and lipid catabolism enzymes. These molecular level changes are consistent with the observed physiological changes, e.g., in photosynthesis rate and saturated lipid content. Our results provide information at the proteomic level of the key enzymes involved in carbon flux towards lipid accumulation in P. tricornutum and suggest candidates for genetic manipulation in microalgae breeding for biodiesel production. PMID:24600163

  13. Virus-induced gene silencing reveals control of reactive oxygen species accumulation and salt tolerance in tomato by γ-aminobutyric acid metabolic pathway.

    PubMed

    Bao, Hexigeduleng; Chen, Xianyang; Lv, Sulian; Jiang, Ping; Feng, Juanjuan; Fan, Pengxiang; Nie, Lingling; Li, Yinxin

    2015-03-01

    γ-Aminobutyric acid (GABA) accumulates in many plant species in response to environmental stress. However, the physiological function of GABA or its metabolic pathway (GABA shunt) in plants remains largely unclear. Here, the genes, including glutamate decarboxylases (SlGADs), GABA transaminases (SlGABA-Ts) and succinic semialdehyde dehydrogenase (SlSSADH), controlling three steps of the metabolic pathway of GABA, were studied through virus-induced gene silencing approach in tomato. Silencing of SlGADs (GABA biosynthetic genes) and SlGABA-Ts (GABA catabolic genes) led to increased accumulation of reactive oxygen species (ROS) as well as salt sensitivity under 200 mm NaCl treatment. Targeted quantitative analysis of metabolites revealed that GABA decreased and increased in the SlGADs- and SlGABA-Ts-silenced plants, respectively, whereas succinate (the final product of GABA metabolism) decreased in both silenced plants. Contrarily, SlSSADH-silenced plants, also defective in GABA degradation process, showed dwarf phenotype, curled leaves and enhanced accumulation of ROS in normal conditions, suggesting the involvement of a bypath for succinic semialdehyde catabolism to γ-hydroxybutyrate as reported previously in Arabidopsis, were less sensitive to salt stress. These results suggest that GABA shunt is involved in salt tolerance of tomato, probably by affecting the homeostasis of metabolites such as succinate and γ-hydroxybutyrate and subsequent ROS accumulation under salt stress. PMID:25074245

  14. Glomalin accumulated in seagrass sediments reveals past alterations in soil quality due to land-use change

    NASA Astrophysics Data System (ADS)

    López-Merino, Lourdes; Serrano, Oscar; Adame, María Fernanda; Mateo, Miguel Ángel; Martínez Cortizas, Antonio

    2015-10-01

    Arbuscular mycorrhizal fungi (AMF), symbionts with most terrestrial plants, produce glomalin-related soil protein (GRSP), which plays a major role in soil structure and quality. Both fungi hyphae and protein production in soils are affected by perturbations related to land-use changes, implying that GRSP is a sensitive indicator of soil quality. Unfortunately, GRSP degrades within years to decades in oxic environments, preventing its use as palaeoecological proxy. However, GRSP is transported to marine, near-shore anoxic sediments, where it accumulates and remains non-degraded, enabling the assessment of its potential as a palaeoecological proxy for soil ecosystem's health. Exploiting this fact, we have obtained for the first time a long-term record (c. 1250 years) of GRSP content using a Posidonia oceanica seagrass mat sediment core from the Western Mediterranean (Portlligat Bay, Spain). The trends in GRSP content matched well with land-use changes related to agrarian activities reconstructed by pollen analysis. In periods of cultivation, GRSP accumulation in the mat decreased. Given the role played by GRSP, the results suggest that agrarian intensification may have resulted in perturbations to soil quality. Thus, GRSP in seagrass mat sediments can be used to assess long-term trends in continental soil quality induced by human activities. These findings open new possibilities in long-term ecology research, as other anoxic environments could be potentially valid too. Testing them would open the possibility to identify long-term patterns in soil quality and other environmental stressors that could also affect AMF and GRSP production in soils.

  15. Tetrapyrrole profiling in Arabidopsis seedlings reveals that retrograde plastid nuclear signaling is not due to Mg-protoporphyrin IX accumulation

    PubMed Central

    Moulin, Michael; McCormac, Alex C.; Terry, Matthew J.; Smith, Alison G.

    2008-01-01

    Chloroplast biogenesis involves careful coordination of both plastid and nuclear gene expression, which is achieved in part by retrograde signaling from the chloroplast to the nucleus. This can be demonstrated by the fact that the herbicide, Norflurazon (NF), which causes bleaching of chloroplasts, prevents the light induction of photosynthesis-related genes in the nucleus. It has been proposed that the tetrapyrrole pathway intermediate Mg-protoporphyrin IX acts as the signaling molecule in this pathway and accumulates in the chloroplasts and cytosol of the cell after NF treatment. Here we present data that demonstrate that this model is too simplistic. We have developed a sensitive liquid chromatography-mass spectrometry (LC/MS) method to measure tetrapyrrole intermediates and have shown that no Mg-protoporphyrin IX, nor indeed any other chlorophyll-biosynthesis intermediate, can be detected in NF-treated plants under conditions in which nuclear gene expression is repressed. Conversely when endogenous Mg-protoporphyrin IX levels are artificially increased by supplementation with the tetrapyrrole precursor, 5-aminolevulinic acid, the expression of nuclear-encoded photosynthetic genes is induced, not repressed. We also demonstrate that NF-treatment leads to a strong down-regulation of tetrapyrrole biosynthesis genes, consistent with the absence of an accumulation of tetrapyrrole intermediates. Finally, there is no correlation between nuclear-gene expression and any of the chlorophyll biosynthetic intermediates over a range of growth conditions and treatments. Instead, it is possible that a perturbation of tetrapyrrole synthesis may lead to localized ROS production or an altered redox state of the plastid, which could mediate retrograde signaling. PMID:18818314

  16. Compositional characterization and imaging of "Wall-bound" acylesters of Populus trichocarpa Reveal Differential Accumulation of acyl Molecules in Normal and Reactive Woods

    SciTech Connect

    Guo, J.; Park, S; Yu, X; Liu, C

    2008-01-01

    Acylesterification is one of the common modifications of cell wall non-cellulosic polysaccharides and/or lignin primarily in monocot plants. We analyzed the cell-wall acylesters of black cottonwood (Populus trichocarpa Torr. & Gray) with liquid chromatography-mass spectrometry (LC-MS), Fourier transform-infrared (FT-IR) microspectroscopy, and synchrotron infrared (IR) imaging facility. The results revealed that the cell wall of dicotyledonous poplar, as the walls of many monocot grasses, contains a considerable amount of acylesters, primarily acetyl and p-hydroxycinnamoyl molecules. The 'wall-bound' acetate and phenolics display a distinct tissue specific-, bending stress responsible- and developmental-accumulation pattern. The 'wall-bound' p-coumarate predominantly accumulated in young leaves and decreased in mature leaves, whereas acetate and ferulate mostly amassed in the cell wall of stems. Along the development of stem, the level of the 'wall-bound' ferulate gradually increased, while the basal level of p-coumarate further decreased. Induction of tension wood decreased the accumulation of the 'wall-bound' phenolics while the level of acetate remained constant. Synchrotron IR-mediated chemical compositional imaging revealed a close spatial distribution of acylesters with cell wall polysaccharides in poplar stem. These results indicate that different 'wall-bound' acylesters play distinct roles in poplar cell wall structural construction and/or metabolism of cell wall matrix components.

  17. Genomewide analysis of Drosophila circular RNAs reveals their structural and sequence properties and age-dependent neural accumulation

    PubMed Central

    Westholm, Jakub O.; Miura, Pedro; Olson, Sara; Shenker, Sol; Joseph, Brian; Sanfilippo, Piero; Celniker, Susan E.; Graveley, Brenton R.; Lai, Eric C.

    2014-01-01

    Circularization was recently recognized to broadly expand transcriptome complexity. Here, we exploit massive Drosophila total RNA-sequencing data, >5 billion paired-end reads from >100 libraries covering diverse developmental stages, tissues and cultured cells, to rigorously annotate >2500 fruitfly circular RNAs. These mostly derive from back-splicing of protein-coding genes and lack poly(A) tails, and circularization of hundreds of genes is conserved across multiple Drosophila species. We elucidate structural and sequence properties of Drosophila circular RNAs, which exhibit commonalities and distinctions from mammalian circles. Notably, Drosophila circular RNAs harbor >1000 well-conserved canonical miRNA seed matches, especially within coding regions, and coding conserved miRNA sites reside preferentially within circularized exons. Finally, we analyze the developmental and tissue specificity of circular RNAs, and note their preferred derivation from neural genes and enhanced accumulation in neural tissues. Interestingly, circular isoforms increase dramatically relative to linear isoforms during CNS aging, and constitute a novel aging biomarker. PMID:25544350

  18. Aspartic Acid Racemization and Collagen Degradation Markers Reveal an Accumulation of Damage in Tendon Collagen That Is Enhanced with Aging*

    PubMed Central

    Thorpe, Chavaunne T.; Streeter, Ian; Pinchbeck, Gina L.; Goodship, Allen E.; Clegg, Peter D.; Birch, Helen L.

    2010-01-01

    Little is known about the rate at which protein turnover occurs in living tendon and whether the rate differs between tendons with different physiological roles. In this study, we have quantified the racemization of aspartic acid to calculate the age of the collagenous and non-collagenous components of the high strain injury-prone superficial digital flexor tendon (SDFT) and low strain rarely injured common digital extensor tendon (CDET) in a group of horses with a wide age range. In addition, the turnover of collagen was assessed indirectly by measuring the levels of collagen degradation markers (collagenase-generated neoepitope and cross-linked telopeptide of type I collagen). The fractional increase in d-Asp was similar (p = 0.7) in the SDFT (5.87 × 10−4/year) and CDET (5.82 × 10−4/year) tissue, and d/l-Asp ratios showed a good correlation with pentosidine levels. We calculated a mean (±S.E.) collagen half-life of 197.53 (±18.23) years for the SDFT, which increased significantly with horse age (p = 0.03) and was significantly (p < 0.001) higher than that for the CDET (34.03 (±3.39) years). Using similar calculations, the half-life of non-collagenous protein was 2.18 (±0.41) years in the SDFT and was significantly (p = 0.04) lower than the value of 3.51 (±0.51) years for the CDET. Collagen degradation markers were higher in the CDET and suggested an accumulation of partially degraded collagen within the matrix with aging in the SDFT. We propose that increased susceptibility to injury in older individuals results from an inability to remove partially degraded collagen from the matrix leading to reduced mechanical competence. PMID:20308077

  19. Flowery odor formation revealed by differential expression of monoterpene biosynthetic genes and monoterpene accumulation in rose (Rosa rugosa Thunb.).

    PubMed

    Feng, Liguo; Chen, Chen; Li, Tinglin; Wang, Meng; Tao, Jun; Zhao, Daqiu; Sheng, Lixia

    2014-02-01

    Rosa rugosa is an important ornamental and economical plant. In this paper, four genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), alcohol acyltransferase (AAT) and linalool synthase (LIS) involved in the monoterpene biosynthesis pathways were isolated from R. rugosa 'Tangzi', and the expression patterns of these genes in different flower development stages and different parts of floral organs were determined by real-time quantitative fluorescence PCR. Furthermore, a comprehensive analysis was carried out into the relationship between expression of four monoterpene synthesis genes and accumulation of main volatile monoterpenes and their acetic acid ester derivatives. The results showed that the genes RrDXS, RrDXR and RrLIS showed consistent expressions during the development process for R. rugosa flower from budding to withering stage, the overall expression levels of gene RrDXS and RrLIS were obviously lower as compared with those of gene RrDXR and RrAAT. Although the gene RrDXS, RrDXR, RrAAT and RrLIS were expressed in all parts of R. rugosa floral organs, the expression levels varied significantly. The variations in the constituent and content of volatile monoterpenes including citronellol, geraniol, nerol, linalool, citronellyl acetate, geranyl acetate and neryl acetate at different development stages and parts of floral organs were significantly different. On this basis, we concluded that the gene RrDXR and RrAAT might play a key role in the biosynthesis of volatile monoterpenes in R. rugosa flowers, and the two genes are important candidate genes for the regulation of secondary metabolism for rose aromatic components. PMID:24384414

  20. Properties of Modern Dust Accumulating in the Uinta Mountains, Utah, USA, and Soil Evidence of Long-Term Dust Deposition

    NASA Astrophysics Data System (ADS)

    Munroe, J. S.

    2013-12-01

    Modern eolian sediment was collected at four locations in the alpine zone of the Uinta Mountains (Utah, USA) between July 2011 and July 2012. Collectors were a passive design based on the classic marble dust trap, but modified for use in this high-precipitation environment. On average the collectors accumulated 1.5 gm of dust, corresponding to an annual flux of 4.4 g/m2. This result is similar to values measured from snowpack samples in the Wind River (Wyoming) and San Juan (Colorado) Mountains. Dust flux was 3 to 5x higher during the winter compared with summer at the two sites featuring continuous vegetation, but was consistent between the seasons at the two collectors surrounded by a greater area of exposed soil. XRD analysis reveals that dust samples are dominated by quartz, potassium feldspar, plagioclase, and illite. Some samples contain amphibole and chlorite. In contrast, samples of fine sediment collected from the surface of modern snowbanks are dominated by clay with no feldspar or quartz, suggesting that these minerals are derived from the surrounding soil surface, which is snow-covered in the winter. ICP-MS analysis reveals that the geochemistry of the coarse (>63-μm) fraction of the dust resembles that of the underlying bedrock, confirming a local origin for this sediment. In contrast, the fine (<63-μm) fraction of the dust closely matches the fine fraction of the soil A horizon, supporting an eolian origin for the ubiquitous layer of fines that mantles soil profiles throughout the Uinta Mountains. Grain size analysis with laser scattering reveals that modern dust is very well-sorted, with a median size of 8 μm (7.0 Φ). Using the annual dust flux and mean grain size, and taking into account the measured bulk density (0.95 gm/cm3), organic matter content (20%), and silt content (32%) of this loess cap, the extrapolated loess accretion rate is ~18 cm per 10,000 years. Given that prior studies (Bockheim et al., 2000 Catena; Munroe, 2007, Arctic

  1. Northern Bobwhite (Colinus virginianus) Mitochondrial Population Genomics Reveals Structure, Divergence, and Evidence for Heteroplasmy

    PubMed Central

    Halley, Yvette A.; Oldeschulte, David L.; Bhattarai, Eric K.; Hill, Joshua; Metz, Richard P.; Johnson, Charles D.; Presley, Steven M.; Ruzicka, Rebekah E.; Rollins, Dale; Peterson, Markus J.; Murphy, William J.; Seabury, Christopher M.

    2015-01-01

    Herein, we evaluated the concordance of population inferences and conclusions resulting from the analysis of short mitochondrial fragments (i.e., partial or complete D-Loop nucleotide sequences) versus complete mitogenome sequences for 53 bobwhites representing six ecoregions across TX and OK (USA). Median joining (MJ) haplotype networks demonstrated that analyses performed using small mitochondrial fragments were insufficient for estimating the true (i.e., complete) mitogenome haplotype structure, corresponding levels of divergence, and maternal population history of our samples. Notably, discordant demographic inferences were observed when mismatch distributions of partial (i.e., partial D-Loop) versus complete mitogenome sequences were compared, with the reduction in mitochondrial genomic information content observed to encourage spurious inferences in our samples. A probabilistic approach to variant prediction for the complete bobwhite mitogenomes revealed 344 segregating sites corresponding to 347 total mutations, including 49 putative nonsynonymous single nucleotide variants (SNVs) distributed across 12 protein coding genes. Evidence of gross heteroplasmy was observed for 13 bobwhites, with 10 of the 13 heteroplasmies involving one moderate to high frequency SNV. Haplotype network and phylogenetic analyses for the complete bobwhite mitogenome sequences revealed two divergent maternal lineages (dXY = 0.00731; FST = 0.849; P < 0.05), thereby supporting the potential for two putative subspecies. However, the diverged lineage (n = 103 variants) almost exclusively involved bobwhites geographically classified as Colinus virginianus texanus, which is discordant with the expectations of previous geographic subspecies designations. Tests of adaptive evolution for functional divergence (MKT), frequency distribution tests (D, FS) and phylogenetic analyses (RAxML) provide no evidence for positive selection or hybridization with the sympatric scaled quail (Callipepla

  2. Northern Bobwhite (Colinus virginianus) Mitochondrial Population Genomics Reveals Structure, Divergence, and Evidence for Heteroplasmy.

    PubMed

    Halley, Yvette A; Oldeschulte, David L; Bhattarai, Eric K; Hill, Joshua; Metz, Richard P; Johnson, Charles D; Presley, Steven M; Ruzicka, Rebekah E; Rollins, Dale; Peterson, Markus J; Murphy, William J; Seabury, Christopher M

    2015-01-01

    Herein, we evaluated the concordance of population inferences and conclusions resulting from the analysis of short mitochondrial fragments (i.e., partial or complete D-Loop nucleotide sequences) versus complete mitogenome sequences for 53 bobwhites representing six ecoregions across TX and OK (USA). Median joining (MJ) haplotype networks demonstrated that analyses performed using small mitochondrial fragments were insufficient for estimating the true (i.e., complete) mitogenome haplotype structure, corresponding levels of divergence, and maternal population history of our samples. Notably, discordant demographic inferences were observed when mismatch distributions of partial (i.e., partial D-Loop) versus complete mitogenome sequences were compared, with the reduction in mitochondrial genomic information content observed to encourage spurious inferences in our samples. A probabilistic approach to variant prediction for the complete bobwhite mitogenomes revealed 344 segregating sites corresponding to 347 total mutations, including 49 putative nonsynonymous single nucleotide variants (SNVs) distributed across 12 protein coding genes. Evidence of gross heteroplasmy was observed for 13 bobwhites, with 10 of the 13 heteroplasmies involving one moderate to high frequency SNV. Haplotype network and phylogenetic analyses for the complete bobwhite mitogenome sequences revealed two divergent maternal lineages (dXY = 0.00731; FST = 0.849; P < 0.05), thereby supporting the potential for two putative subspecies. However, the diverged lineage (n = 103 variants) almost exclusively involved bobwhites geographically classified as Colinus virginianus texanus, which is discordant with the expectations of previous geographic subspecies designations. Tests of adaptive evolution for functional divergence (MKT), frequency distribution tests (D, FS) and phylogenetic analyses (RAxML) provide no evidence for positive selection or hybridization with the sympatric scaled quail (Callipepla

  3. Aluminum inhibits neurofilament assembly, cytoskeletal incorporation, and axonal transport. Dynamic nature of aluminum-induced perikaryal neurofilament accumulations as revealed by subunit turnover.

    PubMed

    Shea, T B; Wheeler, E; Jung, C

    1997-01-01

    The mechanism by which aluminum induces formation of perikaryal neurofilament (NF) inclusions remains unclear. Aluminum treatment inhibits: 1. The incorporation of newly synthesized NF subunits into Triton-insoluble cytoskeleton of axonal neurites; 2. Their degradation and dephosphorylation; 3. Their translocation into axonal neurites. It also fosters the accumulation of phosphorylated NFs within perikarya. In the present study, we addressed the relationship among these effects. Aluminum reduced the assembly of newly synthesized NF subunits into NFs. During examination of those subunits that did assemble in the presence of aluminum, it was revealed that aluminum also interfered with transport of newly assembled NFs into axonal neurites. Similarly, a delay in axonal transport of microinjected biotinylated NF-H was observed in aluminum-treated cells. Aluminum also inhibited the incorporation of newly synthesized and microinjected subunits into the Triton-insoluble cytoskeleton within both perikarya and neurites. Once incorporated into Triton-insoluble cytoskeletons, however, biotinylated subunits were retained within perikarya of aluminum-treated cells to a greater extent than within untreated cells. Notably, these subunits were depleted in the presence and absence of aluminum within 48 h, despite the persistence of the aluminum-induced perikaryal accumulation itself, suggesting that individual NF subunits undergo turnover even within aluminum-induced perikaryal accumulations. These findings demonstrate that aluminum interferes with multiple aspects of neurofilament dynamics and furthermore leaves open the possibility that aluminum-induced perikaryal NF whorls may not represent permanent structures, but rather may require continued recruitment of cytoskeletal constituents. PMID:9437656

  4. Congener-specific accumulation and trophic transfer of polychlorinated biphenyls in spider crab food webs revealed by stable isotope analysis.

    PubMed

    Bodin, N; Le Loc'h, F; Caisey, X; Le Guellec, A-M; Abarnou, A; Loizeau, V; Latrouite, D

    2008-01-01

    Polychlorobiphenyls (PCB) and stable isotopes (delta15N and delta13C) were analyzed in the spider crab (Maja brachydactyla) food web from the Iroise Sea (Western Brittany) and the Seine Bay (Eastern English Channel). PCB concentrations were all significantly higher in organisms from the Seine Bay than those from the Iroise Sea. PCB patterns were strongly related to the feeding mode of the species, and increased influence of higher chlorinated congeners was highlighted with trophic position of the organisms. PCB concentrations (lipid normalized) were significantly related to the isotopically derived trophic level (TL) in spider crab food webs. The highest trophic magnification factors (TMFs) were calculated for the congeners with 2,4,5-substitution, and were lower in the Seine Bay compared to the Iroise Sea. The confrontation of PCB and TL data also revealed biotransformation capacity of decapod crustaceans for specific congeners based on structure-activity relations. PMID:17544187

  5. Quantitative dynamics of triacylglycerol accumulation in microalgae populations at single-cell resolution revealed by Raman microspectroscopy

    PubMed Central

    2014-01-01

    Background Rapid, real-time and label-free measurement of the cellular contents of biofuel molecules such as triacylglycerol (TAG) in populations at single-cell resolution are important for bioprocess control and understanding of the population heterogeneity. Raman microspectroscopy can directly detect the changes of metabolite profile in a cell and thus can potentially serve these purposes. Results Single-cell Raman spectra (SCRS) of the unicellular oleaginous microalgae Nannochloropsis oceanica from the cultures under nitrogen depletion (TAG-producing condition) and nitrogen repletion (non-TAG-producing condition) were sampled at eight time points during the first 96 hours upon the onset of nitrogen depletion. Single N. oceanica cells were captured by a 532-nm laser and the SCRS were acquired by the same laser within one second per cell. Using chemometric methods, the SCRS were able to discriminate cells between nitrogen-replete and nitrogen-depleted conditions at as early as 6 hours with >93.3% accuracy, and among the eight time points under nitrogen depletion with >90.4% accuracy. Quantitative prediction of TAG content in single cells was achieved and validated via SCRS and liquid chromatography-mass spectrometry (LC-MS) analysis at population level. SCRS revealed the dynamics of heterogeneity in TAG production among cells in each isogenic population. A significant negative correlation between TAG content and lipid unsaturation degree in individual microalgae cells was observed. Conclusions Our results show that SCRS can serve as a label-free and non-invasive proxy for quantitatively tracking and screening cellular TAG content in real-time at single-cell level. Phenotypic comparison of single cells via SCRS should also help investigating the mechanisms of functional heterogeneity within a cellular population. PMID:24716544

  6. Evidence of self organization in great Sumatra earthquake recurrence times: Implications for coupling of tidal forcing and tectonic stress accumulation

    NASA Astrophysics Data System (ADS)

    Tiwari, R. K.; Puli, K.

    2012-12-01

    We analyzed inter- event time series of earthquake activities (M≥ 5) of Sumatra region spanning over 1973 to 2009 using techniques of nonlinear dynamics. The earthquake data were taken from the USGS catalogue centered on latitude 3.240N and longitude 95.825E. As a first step, in our analyses we computed the rank order statistics which revealed mixed response of earthquake dynamics indicating distinct breaks in slope of the rank order. This suggests that earthquake dynamics in this region is partly unstable and partly "self-organized" with a random tail. Comparison of return maps of the earthquakes inter- event time series with those representing random, stochastic and chaotic processes shows a quasi-deterministic behavior of earthquake genesis in the region. We further assessed the dimensionality of earthquake-generating mechanisms using a nonlinear predictor technique on two dimensional phase portrait constructed by recurrence time series. The nonlinear forecasting analysis suggests that the earthquake processes in the Sumatra region evolve on a non-random low-dimensional chaotic plane. Further, "K2" Entropy revealed a coherent structure indicating the deterministic dynamical pattern. This analysis is consistent with "self-organized" processes which could be explained invoking earth's internal dynamics, where, impulsively derived interdependencies cascades through the stress generated by tectonic plate movement. Our results, however, do not preclude the role of coupling of the above self-organized system with tidal forcing. Evidence for such a coupling in this region exists as 'triggering force". Keywords: Sumatra Earthquakes, Quasi-deterministic, Stochastic, Chaotic, Self-organized, K2 entropy, Phase portrait.

  7. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus

    PubMed Central

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M.

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  8. Molecular chaperone accumulation as a function of stress evidences adaptation to high hydrostatic pressure in the piezophilic archaeon Thermococcus barophilus.

    PubMed

    Cario, Anaïs; Jebbar, Mohamed; Thiel, Axel; Kervarec, Nelly; Oger, Phil M

    2016-01-01

    The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. PMID:27378270

  9. Genomic signatures reveal new evidences for selection of important traits in domestic cattle.

    PubMed

    Xu, Lingyang; Bickhart, Derek M; Cole, John B; Schroeder, Steven G; Song, Jiuzhou; Tassell, Curtis P Van; Sonstegard, Tad S; Liu, George E

    2015-03-01

    We investigated diverse genomic selections using high-density single nucleotide polymorphism data of five distinct cattle breeds. Based on allele frequency differences, we detected hundreds of candidate regions under positive selection across Holstein, Angus, Charolais, Brahman, and N'Dama. In addition to well-known genes such as KIT, MC1R, ASIP, GHR, LCORL, NCAPG, WIF1, and ABCA12, we found evidence for a variety of novel and less-known genes under selection in cattle, such as LAP3, SAR1B, LRIG3, FGF5, and NUDCD3. Selective sweeps near LAP3 were then validated by next-generation sequencing. Genome-wide association analysis involving 26,362 Holsteins confirmed that LAP3 and SAR1B were related to milk production traits, suggesting that our candidate regions were likely functional. In addition, haplotype network analyses further revealed distinct selective pressures and evolution patterns across these five cattle breeds. Our results provided a glimpse into diverse genomic selection during cattle domestication, breed formation, and recent genetic improvement. These findings will facilitate genome-assisted breeding to improve animal production and health. PMID:25431480

  10. Genomic Signatures Reveal New Evidences for Selection of Important Traits in Domestic Cattle

    PubMed Central

    Xu, Lingyang; Bickhart, Derek M.; Cole, John B.; Schroeder, Steven G.; Song, Jiuzhou; Tassell, Curtis P. Van; Sonstegard, Tad S.; Liu, George E.

    2015-01-01

    We investigated diverse genomic selections using high-density single nucleotide polymorphism data of five distinct cattle breeds. Based on allele frequency differences, we detected hundreds of candidate regions under positive selection across Holstein, Angus, Charolais, Brahman, and N'Dama. In addition to well-known genes such as KIT, MC1R, ASIP, GHR, LCORL, NCAPG, WIF1, and ABCA12, we found evidence for a variety of novel and less-known genes under selection in cattle, such as LAP3, SAR1B, LRIG3, FGF5, and NUDCD3. Selective sweeps near LAP3 were then validated by next-generation sequencing. Genome-wide association analysis involving 26,362 Holsteins confirmed that LAP3 and SAR1B were related to milk production traits, suggesting that our candidate regions were likely functional. In addition, haplotype network analyses further revealed distinct selective pressures and evolution patterns across these five cattle breeds. Our results provided a glimpse into diverse genomic selection during cattle domestication, breed formation, and recent genetic improvement. These findings will facilitate genome-assisted breeding to improve animal production and health. PMID:25431480

  11. System level analysis of cacao seed ripening reveals a sequential interplay of primary and secondary metabolism leading to polyphenol accumulation and preparation of stress resistance.

    PubMed

    Wang, Lei; Nägele, Thomas; Doerfler, Hannes; Fragner, Lena; Chaturvedi, Palak; Nukarinen, Ella; Bellaire, Anke; Huber, Werner; Weiszmann, Jakob; Engelmeier, Doris; Ramsak, Ziva; Gruden, Kristina; Weckwerth, Wolfram

    2016-08-01

    Theobroma cacao and its popular product, chocolate, are attracting attention due to potential health benefits including antioxidative effects by polyphenols, anti-depressant effects by high serotonin levels, inhibition of platelet aggregation and prevention of obesity-dependent insulin resistance. The development of cacao seeds during fruit ripening is the most crucial process for the accumulation of these compounds. In this study, we analyzed the primary and the secondary metabolome as well as the proteome during Theobroma cacao cv. Forastero seed development by applying an integrative extraction protocol. The combination of multivariate statistics and mathematical modelling revealed a complex consecutive coordination of primary and secondary metabolism and corresponding pathways. Tricarboxylic acid (TCA) cycle and aromatic amino acid metabolism dominated during the early developmental stages (stages 1 and 2; cell division and expansion phase). This was accompanied with a significant shift of proteins from phenylpropanoid metabolism to flavonoid biosynthesis. At stage 3 (reserve accumulation phase), metabolism of sucrose switched from hydrolysis into raffinose synthesis. Lipids as well as proteins involved in lipid metabolism increased whereas amino acids and N-phenylpropenoyl amino acids decreased. Purine alkaloids, polyphenols, and raffinose as well as proteins involved in abiotic and biotic stress accumulated at stage 4 (maturation phase) endowing cacao seeds the characteristic astringent taste and resistance to stress. In summary, metabolic key points of cacao seed development comprise the sequential coordination of primary metabolites, phenylpropanoid, N-phenylpropenoyl amino acid, serotonin, lipid and polyphenol metabolism thereby covering the major compound classes involved in cacao aroma and health benefits. PMID:27136060

  12. Burkholderia phytofirmans Inoculation-Induced Changes on the Shoot Cell Anatomy and Iron Accumulation Reveal Novel Components of Arabidopsis-Endophyte Interaction that Can Benefit Downstream Biomass Deconstruction

    PubMed Central

    Zhao, Shuai; Wei, Hui; Lin, Chien-Yuan; Zeng, Yining; Tucker, Melvin P.; Himmel, Michael E.; Ding, Shi-You

    2016-01-01

    It is known that plant growth promoting bacteria (PGPB) elicit positive effects on plant growth and biomass yield. However, the actual mechanism behind the plant-PGPB interaction is poorly understood, and the literature is scarce regarding the thermochemical pretreatability and enzymatic degradability of biomass derived from PGPB-inoculated plants. Most recent transcriptional analyses of PGPB strain Burkholderia phytofirmans PsJN inoculating potato in literature and Arabidopsis in our present study have revealed the expression of genes for ferritin and the biosynthesis and transport of siderophores (i.e., the molecules with high affinity for iron), respectively. The expression of such genes in the shoots of PsJN-inoculated plants prompted us to propose that PsJN-inoculation can improve the host plant's iron uptake and accumulation, which facilitates the downstream plant biomass pretreatment and conversion to simple sugars. In this study, we employed B. phytofirmans PsJN to inoculate the Arabidopsis thaliana plants, and conducted the first investigation for its effects on the biomass yield, the anatomical organization of stems, the iron accumulation, and the pretreatment and enzymatic hydrolysis of harvested biomass. The results showed that the strain PsJN stimulated plant growth in the earlier period of plant development and enlarged the cell size of stem piths, and it also indeed enhanced the essential metals uptake and accumulation in host plants. Moreover, we found that the PsJN-inoculated plant biomass released more glucose and xylose after hot water pretreatment and subsequent co-saccharification, which provided a novel insight into development of lignocellulosic biofuels from renewable biomass resources. PMID:26858740

  13. Burkholderia phytofirmans inoculation-induced changes on the shoot cell anatomy and iron accumulation reveal novel components of Arabidopsis-endophyte interaction that can benefit downstream biomass deconstruction

    DOE PAGESBeta

    Zhao, Shuai; Wei, Hui; Lin, Chien -Yuan; Zeng, Yining; Tucker, Melvin P.; Himmel, Michael E.; Ding, Shi -You

    2016-01-29

    In this study, it is known that plant growth promoting bacteria (PGPB) elicit positive effects on plant growth and biomass yield. However, the actual mechanism behind the plant-PGPB interaction is poorly understood, and the literature is scarce regarding the thermochemical pretreatability and enzymatic degradability of biomass derived from PGPB-inoculated plants. Most recent transcriptional analyses of PGPB strain Burkholderia phytofirmans PsJN inoculating potato in literature and Arabidopsis in our present study have revealed the expression of genes for ferritin and the biosynthesis and transport of siderophores (i.e., the molecules with high affinity for iron), respectively. The expression of such genes inmore » the shoots of PsJN-inoculated plants prompted us to propose that PsJN-inoculation can improve the host plant's iron uptake and accumulation, which facilitates the downstream plant biomass pretreatment and conversion to simple sugars. In this study, we employed B. phytofirmans PsJN to inoculate the Arabidopsis thaliana plants, and conducted the first investigation for its effects on the biomass yield, the anatomical organization of stems, the iron accumulation, and the pretreatment and enzymatic hydrolysis of harvested biomass. The results showed that the strain PsJN stimulated plant growth in the earlier period of plant development and enlarged the cell size of stem piths, and it also indeed enhanced the essential metals uptake and accumulation in host plants. Moreover, we found that the PsJN-inoculated plant biomass released more glucose and xylose after hot water pretreatment and subsequent co-saccharification, which provided a novel insight into development of lignocellulosic biofuels from renewable biomass resources.« less

  14. Burkholderia phytofirmans Inoculation-Induced Changes on the Shoot Cell Anatomy and Iron Accumulation Reveal Novel Components of Arabidopsis-Endophyte Interaction that Can Benefit Downstream Biomass Deconstruction.

    PubMed

    Zhao, Shuai; Wei, Hui; Lin, Chien-Yuan; Zeng, Yining; Tucker, Melvin P; Himmel, Michael E; Ding, Shi-You

    2016-01-01

    It is known that plant growth promoting bacteria (PGPB) elicit positive effects on plant growth and biomass yield. However, the actual mechanism behind the plant-PGPB interaction is poorly understood, and the literature is scarce regarding the thermochemical pretreatability and enzymatic degradability of biomass derived from PGPB-inoculated plants. Most recent transcriptional analyses of PGPB strain Burkholderia phytofirmans PsJN inoculating potato in literature and Arabidopsis in our present study have revealed the expression of genes for ferritin and the biosynthesis and transport of siderophores (i.e., the molecules with high affinity for iron), respectively. The expression of such genes in the shoots of PsJN-inoculated plants prompted us to propose that PsJN-inoculation can improve the host plant's iron uptake and accumulation, which facilitates the downstream plant biomass pretreatment and conversion to simple sugars. In this study, we employed B. phytofirmans PsJN to inoculate the Arabidopsis thaliana plants, and conducted the first investigation for its effects on the biomass yield, the anatomical organization of stems, the iron accumulation, and the pretreatment and enzymatic hydrolysis of harvested biomass. The results showed that the strain PsJN stimulated plant growth in the earlier period of plant development and enlarged the cell size of stem piths, and it also indeed enhanced the essential metals uptake and accumulation in host plants. Moreover, we found that the PsJN-inoculated plant biomass released more glucose and xylose after hot water pretreatment and subsequent co-saccharification, which provided a novel insight into development of lignocellulosic biofuels from renewable biomass resources. PMID:26858740

  15. High Quality Maize Centromere 10 Sequence Reveals Evidence of Frequent Recombination Events

    PubMed Central

    Wolfgruber, Thomas K.; Nakashima, Megan M.; Schneider, Kevin L.; Sharma, Anupma; Xie, Zidian; Albert, Patrice S.; Xu, Ronghui; Bilinski, Paul; Dawe, R. Kelly; Ross-Ibarra, Jeffrey; Birchler, James A.; Presting, Gernot G.

    2016-01-01

    The ancestral centromeres of maize contain long stretches of the tandemly arranged CentC repeat. The abundance of tandem DNA repeats and centromeric retrotransposons (CR) has presented a significant challenge to completely assembling centromeres using traditional sequencing methods. Here, we report a nearly complete assembly of the 1.85 Mb maize centromere 10 from inbred B73 using PacBio technology and BACs from the reference genome project. The error rates estimated from overlapping BAC sequences are 7 × 10−6 and 5 × 10−5 for mismatches and indels, respectively. The number of gaps in the region covered by the reassembly was reduced from 140 in the reference genome to three. Three expressed genes are located between 92 and 477 kb from the inferred ancestral CentC cluster, which lies within the region of highest centromeric repeat density. The improved assembly increased the count of full-length CR from 5 to 55 and revealed a 22.7 kb segmental duplication that occurred approximately 121,000 years ago. Our analysis provides evidence of frequent recombination events in the form of partial retrotransposons, deletions within retrotransposons, chimeric retrotransposons, segmental duplications including higher order CentC repeats, a deleted CentC monomer, centromere-proximal inversions, and insertion of mitochondrial sequences. Double-strand DNA break (DSB) repair is the most plausible mechanism for these events and may be the major driver of centromere repeat evolution and diversity. In many cases examined here, DSB repair appears to be mediated by microhomology, suggesting that tandem repeats may have evolved to efficiently repair frequent DSBs in centromeres. PMID:27047500

  16. High Quality Maize Centromere 10 Sequence Reveals Evidence of Frequent Recombination Events.

    PubMed

    Wolfgruber, Thomas K; Nakashima, Megan M; Schneider, Kevin L; Sharma, Anupma; Xie, Zidian; Albert, Patrice S; Xu, Ronghui; Bilinski, Paul; Dawe, R Kelly; Ross-Ibarra, Jeffrey; Birchler, James A; Presting, Gernot G

    2016-01-01

    The ancestral centromeres of maize contain long stretches of the tandemly arranged CentC repeat. The abundance of tandem DNA repeats and centromeric retrotransposons (CR) has presented a significant challenge to completely assembling centromeres using traditional sequencing methods. Here, we report a nearly complete assembly of the 1.85 Mb maize centromere 10 from inbred B73 using PacBio technology and BACs from the reference genome project. The error rates estimated from overlapping BAC sequences are 7 × 10(-6) and 5 × 10(-5) for mismatches and indels, respectively. The number of gaps in the region covered by the reassembly was reduced from 140 in the reference genome to three. Three expressed genes are located between 92 and 477 kb from the inferred ancestral CentC cluster, which lies within the region of highest centromeric repeat density. The improved assembly increased the count of full-length CR from 5 to 55 and revealed a 22.7 kb segmental duplication that occurred approximately 121,000 years ago. Our analysis provides evidence of frequent recombination events in the form of partial retrotransposons, deletions within retrotransposons, chimeric retrotransposons, segmental duplications including higher order CentC repeats, a deleted CentC monomer, centromere-proximal inversions, and insertion of mitochondrial sequences. Double-strand DNA break (DSB) repair is the most plausible mechanism for these events and may be the major driver of centromere repeat evolution and diversity. In many cases examined here, DSB repair appears to be mediated by microhomology, suggesting that tandem repeats may have evolved to efficiently repair frequent DSBs in centromeres. PMID:27047500

  17. DNA Sequence Analyses Reveal Abundant Diversity, Endemism and Evidence for Asian Origin of the Porcini Mushrooms

    PubMed Central

    Feng, Bang; Xu, Jianping; Wu, Gang; Zeng, Nian-Kai; Li, Yan-Chun; Tolgor, Bau; Kost, Gerhard W.; Yang, Zhu L.

    2012-01-01

    The wild gourmet mushroom Boletus edulis and its close allies are of significant ecological and economic importance. They are found throughout the Northern Hemisphere, but despite their ubiquity there are still many unresolved issues with regard to the taxonomy, systematics and biogeography of this group of mushrooms. Most phylogenetic studies of Boletus so far have characterized samples from North America and Europe and little information is available on samples from other areas, including the ecologically and geographically diverse regions of China. Here we analyzed DNA sequence variation in three gene markers from samples of these mushrooms from across China and compared our findings with those from other representative regions. Our results revealed fifteen novel phylogenetic species (about one-third of the known species) and a newly identified lineage represented by Boletus sp. HKAS71346 from tropical Asia. The phylogenetic analyses support eastern Asia as the center of diversity for the porcini sensu stricto clade. Within this clade, B. edulis is the only known holarctic species. The majority of the other phylogenetic species are geographically restricted in their distributions. Furthermore, molecular dating and geological evidence suggest that this group of mushrooms originated during the Eocene in eastern Asia, followed by dispersal to and subsequent speciation in other parts of Asia, Europe, and the Americas from the middle Miocene through the early Pliocene. In contrast to the ancient dispersal of porcini in the strict sense in the Northern Hemisphere, the occurrence of B. reticulatus and B. edulis sensu lato in the Southern Hemisphere was probably due to recent human-mediated introductions. PMID:22629418

  18. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  19. AB-QTL analysis reveals new alleles associated to proline accumulation and leaf wilting under drought stress conditions in barley (Hordeum vulgare L.)

    PubMed Central

    2012-01-01

    Background Land plants have evolved several measures to maintain their life against abiotic stresses. The accumulation of proline is the most generalized response of plants under drought, heat or salt stress conditions. It is known as an osmoprotectant which also acts as an instant source of energy during drought recovery process. But, both its role and genetic inheritance are poorly understood in agriculture crops. In the present work, advanced backcross quantitative trait locus (AB-QTL) analysis was performed to elucidate genetic mechanisms controlling proline accumulation and leaf wilting in barley under drought stress conditions. Results The analysis revealed eight QTL associated to proline content (PC) and leaf wilting (WS). QTL for PC were localized on chromosome 3H, 4H, 5H and 6H. The strongest QTL effect QPC.S42.5H was detected on chromosome 5H where drought inducible exotic allele was associated to increase PC by 54%. QTL effects QPC.S42.3H, QPC.S42.4H and QPC.S42.6H were responsible to heighten PC due to the preeminence of elite alleles over the exotic alleles which ranged from 26% to 43%. For WS, QTL have been localized on chromosome 1H, 2H, 3H and 4H. Among these, QWS.S42.1H and QWS.S42.4H were associated to decrease in WS due to the introgression of exotic alleles. In addition, two digenic epistatic interaction effects were detected for WS where the additive effect of exotic alleles imparted a favorable increase in the trait value. Conclusions The present data represents a first report on whole-genome mapping of proline accumulation and leaf wilting in barley. The detected QTL are linked to new alleles from both cultivated and wild accessions which bring out an initial insight on the genetic inheritance of PC and WS. These QTL alleles are fixed in the isogenic background of Scarlett, which will allow for positional cloning of underlying genes and to develop drought resilient barley cultivars. PMID:22817330

  20. Character, paleoenvironment, rate of accumulation, and evidence for seismic triggering of Holocene turbidites, Canada Abyssal Plain, Arctic Ocean

    USGS Publications Warehouse

    Grantz, A.; Phillips, R.L.; Mullen, M.W.; Starratt, S.W.; Jones, Glenn A.; Naidu, A.S.; Finney, B.P.

    1996-01-01

    Four box cores and one piston core show that Holocene sedimentation on the southern Canada Abyssal Plain for the last 8010??120 yr has consisted of a continuing rain of pelagic organic and ice-rafted elastic sediment with a net accumulation rate during the late Holocene of ???10 mm/1000 yr, and episodically emplaced turbidites 1-5 m thick deposited at intervals of 830 to 3450 yr (average 2000 yr). The average net accumulation rate of the mixed sequence of turbidites and thin pelagite interbeds in the cores is about 1.2 m/1000 yr. Physiography suggests that the turbidites originated on the Mackenzie Delta or its clinoform, and ??13C values of -27 to - 25??? in the turbidites are compatible with a provenance on a delta. Extant displaced neritic and lower slope to basin plain calcareous benthic foraminifers coexist in the turbidite units. Their joint occurence indicates that the turbidites originated on the modern continental shelf and entrained sediment from the slope and rise enroute to their final resting place on the Canada Abyssal Plain. The presence of Middle Pleistocene diatoms in the turbidites suggests, in addition, that the turbidites may have originated in shallow submarine slides beneath the upper slope or outer shelf. Small but consistent differences in organic carbon content and ??13C values between the turbidite units suggest that they did not share an identical provenance, which is at least compatible with an origin in slope failures. The primary provenance of the ice-rafted component of the pelagic beds was the glaciated terrane of northwestern Canada; and the provenance of the turbidite units was Pleistocene and Holocene sedimentary deposits on the outer continental shelf and upper slope of the Mackenzie Delta. Largely local derivation of the sediment of the Canada Abyssal Plain indicates that sediment accumulation rates in the Arctic Ocean are valid only for regions with similar depositional sources and processes, and that these rates cannot be

  1. Excess 210Po in 2010 Eyjafjallajökull tephra (Iceland): Evidence for pre-eruptive gas accumulation

    NASA Astrophysics Data System (ADS)

    Sigmarsson, Olgeir; Condomines, Michel; Gauthier, Pierre-Jean

    2015-10-01

    Excess gas phase in magmas erupting explosively is well known worldwide. However, the origin of this gas phase, in excess of what can be dissolved in the erupting magma at depth, and the rate of gas accumulation is less well defined. The 2010 mildly explosive eruption at Eyjafjallajökull, Iceland, produced mingled tephra of benmoreitic and trachytic composition whereas alkali basalt was emitted during preceding flank eruption. Tephra of the first explosive phase are composed of three glass types, alkaline rhyolite, mixed benmoreite, and basalt, which suggests that the basaltic magma intruded a pre-existing rhyolitic magma chamber, and ultimately triggered the eruption. The mixed benmoreitic tephra (erupted on 15 and 17 April 2010) had large 210Po in excess of 210Pb [(210Po /210Pb) 0 = 1.88 ] at the time of eruption, and possibly a small 210Pb excess over its parent 226Ra. In contrast, the preceding flank eruption produced basalt with (210Po) 0 = 0, upon eruption, and the final trachyte had lost most of its 210Po during open-system degassing. The 210Po excess in the first erupted benmoreites is interpreted to result from 210Po degassing of basaltic magma and the accumulation of 210Po-enriched gas, either in the upper part of the basaltic intrusion, below the rhyolite-basalt interface, or in the pre-existing residual rhyolitic magma chamber. From a simple model of radon and polonium accumulation in the rhyolitic reservoir, the ratio of the mass of basalt magma degassing over the mass of magma accumulating the excess gas decreased from 20 to 15 over 2 days, implying zoned magma reservoir, with the uppermost and gas-richest part erupting first. The duration of pre-eruptive gas accumulation in this model is approximately one year. This corresponds closely to the initiation of a seismic swarm beneath Eyjafjallajökull, early June 2009, which was the first pre-eruptive signal detected. The coincidence between initiation of gas accumulation at relatively shallow depth and

  2. Accumulation of fructose 1,6-bisphosphate in mutant cells of mucoid Pseudomonas aeruginosa as an evidence of phosphofructokinase activity.

    PubMed

    Banerjee, P C

    1986-05-01

    Phosphoglucose isomerase negative mutant of mucoid Pseudomonas aeruginosa accumulated relatively higher concentration of fructose 1,6-bisphosphate (Fru-1,6-P2) when mannitol induced cells were incubated with this sugar alcohol. Also the toluene-treated cells of fructose 1,6-bisphosphate aldolase negative mutant of this organism produced Fru-1,6-P2 from fructose 6-phosphate in presence of ATP, but not from 6-phosphogluconate. The results together suggested the presence of an ATP-dependent fructose 6-phosphate kinase (EC 2.7.1.11) in mucoid P. aeruginosa. PMID:3017251

  3. Influence of Vegetation on Sediment Accumulation in Restored Tidal Saltmarshes: Field Evidence from the Blackwater Estuary, Essex, UK

    NASA Astrophysics Data System (ADS)

    Price, D.; French, J.; Burningham, H.

    2013-12-01

    Tidal saltmarshes in the UK, and especially in the estuaries of southeast England, have been subject to degradation and erosion over the last few decades, primarily caused by sea-level rise and coastal squeeze due to fixed coastal defences. This is of great concern to a range of coastal stakeholders due to the corresponding loss of functions and services associated with these systems. The coastal defence role that saltmarshes play is well established, and the importance of saltmarsh ecosystems as habitats for birds, fish, and other species is evidenced in the fact that a large proportion of saltmarsh in the southeast England is designated for its scientific and conservation significance. Sediment accumulation is critical for the maintenance of marsh elevation within the tidal frame and for delivery of the aforementioned functions and services. Although many studies have examined accumulation processes, key questions have yet to be fully tested through intensive field observations. One such question relates to the role of vegetation in mediating the retention of newly introduced sediment, as recent research has called into doubt the traditional view of halophytes significantly enhancing rates of sedimentation through wave dissipation. This study presents early results from a project designed to advance our understanding of the processes controlling sediment accumulation. The research focuses on the UK's first large-scale experimental managed flood defence realignment at Tollesbury, Blackwater estuary, Essex. The seawall protecting 21ha of reclaimed agricultural land was artificially breached in 1995 and saltmarsh has progressively developed as tidal exchange has introduced fine sediment into the site. Results from a 12 month monitoring campaign involving hierarchical two-week sediment trap deployments indicates that the role of vegetation in marsh development is less clear cut that previously thought. Gross sedimentation rates were generally higher in non

  4. First evidence for accumulation of protein-bound and protein-free pyrraline in human uremic plasma by mass spectrometry.

    PubMed

    Odani, H; Shinzato, T; Matsumoto, Y; Takai, I; Nakai, S; Miwa, M; Iwayama, N; Amano, I; Maeda, K

    1996-07-01

    Glucose-derived advanced glycation end products (AGEs) cross-link proteins and cause various biological tissue damage. One of them, pyrraline [epsilon-2-(formyl-5-hydroxymethyl-pyrrol-1-yl) -L-norleucine], has been demonstrated by utilizing antibody to accumulate in plasma and sclerosed matrix of diabetic individuals, suggesting responsibility for diabetic complications. To elucidate the involvement of pyrraline in uremia, we examined the pyrraline levels in patients with chronic renal failure by a mass spectrometric approach. Here we show that protein-free pyrraline as well as pyrraline with binding protein are significantly increased in non-diabetic uremic plasma compared to healthy subjects. Our results suggest that circulating pyrraline could be a substance contributing to complications in uremia. PMID:8694819

  5. Cosmic X-rays Reveal Evidence For New Form Of Matter

    NASA Astrophysics Data System (ADS)

    2002-04-01

    NASA's Chandra X-ray Observatory has found two stars -- one too small, one too cold -- that reveal cracks in our understanding of the structure of matter. These discoveries open a new window on nuclear physics, offering a link between the vast cosmos and its tiniest constituents. Chandra's observations of RX J1856.5-3754 and 3C58 suggest that the matter in these stars is even denser than nuclear matter found on Earth. This raises the possibility these stars are composed of pure quarks or contain crystals of sub-nuclear particles that normally have only a fleeting existence following high-energy collisions. By combining Chandra and Hubble Space Telescope data, astronomers found that RX J1856 radiates like a solid body with a temperature of 1.2 million degrees Fahrenheit (700,000 degrees Celsius) and has a diameter of about seven miles (11.3 kilometers). This size is too small to reconcile with standard models for neutron stars -- until now the most extreme form of matter known. "Taken at face value, the combined observational evidence points to a star composed not of neutrons, but of quarks in a form known as strange quark matter," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and lead author of a paper on RX J1856 to appear in the June 20, 2002, issue of The Astrophysical Journal. "Quarks, thought to be the fundamental constituents of nuclear particles, have never been seen outside a nucleus in Earth-bound laboratories." Observations by Chandra of 3C58 also yielded startling results. A team composed of Patrick Slane and Steven Murray, also of CfA, and David Helfand of Columbia University, New York, failed to detect the expected X-radiation from the hot surface of 3C58, a neutron star believed to have been created in an explosion witnessed by Chinese and Japanese astronomers in A.D. 1181. The team concluded that the star has a temperature of less than one million degrees Celsius, which is far below the predicted

  6. A label-free differential proteomics analysis reveals the effect of melatonin on promoting fruit ripening and anthocyanin accumulation upon postharvest in tomato.

    PubMed

    Sun, Qianqian; Zhang, Na; Wang, Jinfang; Cao, Yunyun; Li, Xingsheng; Zhang, Haijun; Zhang, Lei; Tan, Dun-Xian; Guo, Yang-Dong

    2016-09-01

    To better understand the function of melatonin in tomato fruit ripening and quality improvement, a label-free quantitation method was used to investigate the proteins that differ between the control (CK) and 50 μm melatonin treatment (M50) fruits. Proteomics data identified 241 proteins that were significantly influenced by melatonin. These proteins were involved in several ripening-related pathways, including cell wall metabolism, oxidative phosphorylation, carbohydrate, and fatty acid metabolism. Moreover, the application of exogenous melatonin increased eight proteins that are related to anthocyanin accumulation during fruit ripening. Additionally, the affected protein levels correlated with the corresponding gene transcript levels. Further, the total anthocyanin content from M50 increased by 52%, 48%, and 50% at 5, 8, and 13 DAT (day after melatonin treatment), respectively. The melatonin-mediated promotion of fruit ripening and quality might be due to the altered proteins involved in processes associated with ripening. In this work, we indicated that a senescence-related protein was downregulated in the M50 fruit, while a cell apoptosis inhibitor (API5) protein was upregulated. In addition, peroxidases (POD9, POD12, peroxidase p7-like) and catalase (CAT3) significantly increased in the M50 fruits. Based on the previous studies and our data, we inferred that melatonin might be positively related to fruit ripening but negatively related to fruit senescence. This research provides insights into the physiological and molecular mechanisms underlying melatonin-mediated fruit ripening as well as the anthocyanin formation process in tomato fruit at the protein concentration level, and we reveal possible candidates for regulation of anthocyanin formation during fruit ripening. PMID:26820691

  7. Footprints reveal direct evidence of group behavior and locomotion in Homo erectus.

    PubMed

    Hatala, Kevin G; Roach, Neil T; Ostrofsky, Kelly R; Wunderlich, Roshna E; Dingwall, Heather L; Villmoare, Brian A; Green, David J; Harris, John W K; Braun, David R; Richmond, Brian G

    2016-01-01

    Bipedalism is a defining feature of the human lineage. Despite evidence that walking on two feet dates back 6-7 Ma, reconstructing hominin gait evolution is complicated by a sparse fossil record and challenges in inferring biomechanical patterns from isolated and fragmentary bones. Similarly, patterns of social behavior that distinguish modern humans from other living primates likely played significant roles in our evolution, but it is exceedingly difficult to understand the social behaviors of fossil hominins directly from fossil data. Footprints preserve direct records of gait biomechanics and behavior but they have been rare in the early human fossil record. Here we present analyses of an unprecedented discovery of 1.5-million-year-old footprint assemblages, produced by 20+ Homo erectus individuals. These footprints provide the oldest direct evidence for modern human-like weight transfer and confirm the presence of an energy-saving longitudinally arched foot in H. erectus. Further, print size analyses suggest that these H. erectus individuals lived and moved in cooperative multi-male groups, offering direct evidence consistent with human-like social behaviors in H. erectus. PMID:27403790

  8. Footprints reveal direct evidence of group behavior and locomotion in Homo erectus

    PubMed Central

    Hatala, Kevin G.; Roach, Neil T.; Ostrofsky, Kelly R.; Wunderlich, Roshna E.; Dingwall, Heather L.; Villmoare, Brian A.; Green, David J.; Harris, John W. K.; Braun, David R.; Richmond, Brian G.

    2016-01-01

    Bipedalism is a defining feature of the human lineage. Despite evidence that walking on two feet dates back 6–7 Ma, reconstructing hominin gait evolution is complicated by a sparse fossil record and challenges in inferring biomechanical patterns from isolated and fragmentary bones. Similarly, patterns of social behavior that distinguish modern humans from other living primates likely played significant roles in our evolution, but it is exceedingly difficult to understand the social behaviors of fossil hominins directly from fossil data. Footprints preserve direct records of gait biomechanics and behavior but they have been rare in the early human fossil record. Here we present analyses of an unprecedented discovery of 1.5-million-year-old footprint assemblages, produced by 20+ Homo erectus individuals. These footprints provide the oldest direct evidence for modern human-like weight transfer and confirm the presence of an energy-saving longitudinally arched foot in H. erectus. Further, print size analyses suggest that these H. erectus individuals lived and moved in cooperative multi-male groups, offering direct evidence consistent with human-like social behaviors in H. erectus. PMID:27403790

  9. An Extraordinary Accumulation of (-)-Pinoresinol in Cell-Free Extracts of Forsythia intermedia: Evidence for Enantiospecific Reduction of (+)-Pinoresinol

    NASA Technical Reports Server (NTRS)

    Katayama, Takeshi; Davin, Laurence B.; Lewis, Norman G.

    1992-01-01

    Stereoselective and enantiospecific transformation mechanisms in lignan biogenesis are only now yielding to scientific inquiry: it has been shown that soluble cell-free preparations from Forsythia intermedia catalysis the formation of the enantiomerically pure lignan, (-)-secoisolariciresinol, when incubated with coniferyl alcohol in the presence of NAD(P)H and H2O2. Surprisingly, (-)-pinoresinol also accumulates in this soluble cell-free assay mixture in greater than 96% enantiomeric excess, even though it is not the naturally occurring antipode present in Forsythia sp. But these soluble cell-free preparations do not engender stereoselective coupling; instead, racemic pinoresinols are first formed, catalysed by an H2O2-dependent peroxidase reaction. An enantiospecific NAD(P)H reductase then converts (+)- pinoresinol, and not the (-)-antipode, into (-)-secoisolariciresinol. Stereoselective syntheis of(+)-pinoresinol from E-coniferyl alcohol is, however, catalysed by an insoluble enzyme preparation in F. suspensa, obtained following removal of readily soluble and ionically bound enzymes; no exogenously supplied cofactors were required other than oxygen, although the reaction was stimulated by NAD-malate addition. Thus, the overall biochemical pathway to enantiomerically pure (-)-secoisolariciresinol has been delineated.

  10. Temporal trends of triclosan contamination in dated sediment cores from four urbanized estuaries: evidence of preservation and accumulation.

    PubMed

    Cantwell, Mark G; Wilson, Brittan A; Zhu, Jun; Wallace, Gordon T; King, John W; Olsen, Curtis R; Burgess, Robert M; Smith, Joseph P

    2010-01-01

    Triclosan is an antimicrobial agent added to a wide array of consumer goods and personal care products. Through its use, it is introduced into municipal sewer systems where it is only partially removed during wastewater treatment. In this study, triclosan was measured in dated sediment cores from four urbanized estuaries in order to reconstruct temporal and spatial trends of accumulation. Measurable concentrations of triclosan first appeared in each of the sediment cores near 1964, which corresponds with the US patent issuance date of triclosan. The presence of triclosan at each of the study sites at or near the patent date indicates that long-term preservation is occurring in estuarine sediments. Temporal trends of triclosan at each location are unique, reflecting between site variability. Concentrations at one site climbed to as high as 400ngg(-1), due in part, to local commercial production of triclosan. At two locations, levels of triclosan rise towards the surface of each core, suggesting increasing usage in recent years. One location adjacent to a major combined sewer overflow had high sediment concentrations of triclosan, confirming their potential as a source of triclosan to estuaries. PMID:20006371

  11. Molecular evidence reveals a polyphyletic origin and chromosomal speciation of Lake Baikal's endemic asellid isopods.

    PubMed

    Hidding, B; Michel, E; Natyaganova, A V; Sherbakov, D Yu

    2003-06-01

    The six endemic isopod species of Lake Baikal have been regarded as a small species flock with uncertain affinities to related asellids. We provide evidence from 16S rRNA sequences for polyphyletic origins of Baikalian Asellidae. One clade of two species is related to the Eurasian genus Asellus. The other clade, Baicalasellus, shows affinities to North American asellids and may have a long evolutionary history within the lake basin. Some speciation events within Baicalasellus clearly have a chromosomal basis. In contrast with numerous taxa exhibiting monophyletic radiations in ancient lakes, the endemic Baikalian isopods arose by multiple invasions and chromosomal mechanisms. PMID:12755879

  12. Comparative phylogeography and population genetics within Buteo lineatus reveals evidence of distinct evolutionary lineages

    USGS Publications Warehouse

    Hull, J.M.; Strobel, Bradley N.; Boal, C.W.; Hull, A.C.; Dykstra, C.R.; Irish, A.M.; Fish, A.M.; Ernest, H.B.

    2008-01-01

    Traditional subspecies classifications may suggest phylogenetic relationships that are discordant with evolutionary history and mislead evolutionary inference. To more accurately describe evolutionary relationships and inform conservation efforts, we investigated the genetic relationships and demographic histories of Buteo lineatus subspecies in eastern and western North America using 21 nuclear microsatellite loci and 375-base pairs of mitochondrial control region sequence. Frequency based analyses of mitochondrial sequence data support significant population distinction between eastern (B. l. lineatus/alleni/texanus) and western (B. l. elegans) subspecies of B. lineatus. This distinction was further supported by frequency and Bayesian analyses of the microsatellite data. We found evidence of differing demographic histories between regions; among eastern sites, mitochondrial data suggested that rapid population expansion occurred following the end of the last glacial maximum, with B. l. texanus population expansion preceding that of B. l. lineatus/alleni. No evidence of post-glacial population expansion was detected among western samples (B. l. elegans). Rather, microsatellite data suggest that the western population has experienced a recent bottleneck, presumably associated with extensive anthropogenic habitat loss during the 19th and 20th centuries. Our data indicate that eastern and western populations of B. lineatus are genetically distinct lineages, have experienced very different demographic histories, and suggest management as separate conservation units may be warranted. ?? 2008 Elsevier Inc. All rights reserved.

  13. Analysis of a non-structural gene reveals evidence of possible hepatitis C virus (HCV) compartmentalization

    PubMed Central

    Blackard, Jason T.; Ma, Gang; Welge, Jeffrey A.; Martin, Christina M.; Sherman, Kenneth E.; Taylor, Lynn E.; Mayer, Kenneth H.; Jamieson, Denise J.

    2011-01-01

    Viral diversity is a hallmark of hepatitis C virus (HCV) infection; however, only limited data are available regarding HCV variability in extrahepatic sites, and none have systematically compared diversity in non-structural and structural genomic regions. Therefore, HCV diversity in the NS5B and envelope 1 (E1) hypervariable region 1 (HVR1) genes was evaluated in matched sera and peripheral blood mononuclear cells (PBMCs) obtained from 13 HCV-infected women. Multiple clonal sequences were compared to evaluate quasispecies diversity and viral compartmentalization in PBMCs. Genetic distances were higher for E1/HVR1 compared to NS5B in both the sera and PBMCs (p = 0.0511 and p = 0.0284). Genetic distances were higher in serum NS5B compared to PBMC NS5B (p = 0.0003); however, they were not different when comparing E1/HVR1 in sera to PBMCs. By phylogenetic analysis of NS5B, evidence of possible PBMC compartmentalization was observed for 1 woman, while statistical methods were consistent with PBMC compartmentalization for 6 women. Evidence of compartmentalization within a non-structural genomic region may suggest that viral adaptation to a unique extracellular microenvironment(s) may be required for efficient replication and could contribute to HCV persistence. PMID:22170544

  14. Evolutionary bet-hedging in the real world: empirical evidence and challenges revealed by plants

    PubMed Central

    Childs, Dylan Z.; Metcalf, C. J. E.; Rees, Mark

    2010-01-01

    Understanding the adaptations that allow species to live in temporally variable environments is essential for predicting how they may respond to future environmental change. Variation at the intergenerational scale can allow the evolution of bet-hedging strategies: a novel genotype may be favoured over an alternative with higher arithmetic mean fitness if the new genotype experiences a sufficiently large reduction in temporal fitness variation; the successful genotype is said to have traded off its mean and variance in fitness in order to ‘hedge its evolutionary bets’. We review the evidence for bet-hedging in a range of simple plant systems that have proved particularly tractable for studying bet-hedging under natural conditions. We begin by outlining the essential theory, reiterating the important distinction between conservative and diversified bet-hedging strategies. We then examine the theory and empirical evidence for the canonical example of bet-hedging: diversification via dormant seeds in annual plants. We discuss the complications that arise when moving beyond this simple case to consider more complex life-history traits, such as flowering size in semelparous perennial plants. Finally, we outline a framework for accommodating these complications, emphasizing the central role that model-based approaches can play. PMID:20573624

  15. Rapid and frequent turbidite accumulation in the bottom of Izu-Ogasawara Trench: Chemical and radiochemical evidence

    NASA Astrophysics Data System (ADS)

    Nozaki, Yoshiyuki; Ohta, Yoichi

    1993-12-01

    Two sediment cores (pilot gravity and piston) were obtained from the bottom of the Izu-Ogasawara Trench at 9750 m and analyzed for various elements and radioisotopes. The results showed a history of complex and frequent turbidite deposition: In the gravity core, eight layers rich in manganese were observed, of which five are enriched in Cu and Co as well. The other three are also enriched in Mo but no other heavy metals, suggesting the presence of at least two mechanisms of formation. Trapping of iron manganese micronodules can account for the enrichment of Mn, Cu and Co. The other three layers rich in Mn and Mo appear to be formed by a post-depositional diagenetic process of Mn mobilization and redeposition in the sediment column. A strong correlation between Ra-226 and Cu in the gravity core suggests that the Ra-226 was also carried into the bottom of the trench in turbidites in association with Mn micronodules. Little excess of Pb-210 over Ra-226 was found at the top but the excess was significant at mid-depths from 30 to 70 cm, indicating that those sediments were deposited within the last 200 y. In the piston core there is a sharp discontinuity of chemical and radiochemical composition around a depth of 250 cm. Below that depth the sediments appear to be dominated by materials derived from terrestrial sources, as compared with those in the upper layer which are of contemporary marine origin. Ra-226 is deficient relative to Th-230 throughout the sediment column down to about 6 m. This finding is consistent with the finding that the average rate of sediment accumulation is 1-2 orders of magnitude faster than that in the western North Pacific abyssal plain, suggesting the convergence of materials into the bottom of the trench.

  16. In vivo (/sup 3/H)spiperone binding: evidence for accumulation in corpus striatum by agonist-mediated receptor internalization

    SciTech Connect

    Chugani, D.C.; Ackermann, R.F.; Phelps, M.E.

    1988-06-01

    The processes of receptor internalization and recycling have been well-documented for receptors for hormones, growth factors, lysosomal enzymes, and cellular substrates. Evidence also exists that these processes also occur for beta-adrenergic, muscarinic cholinergic, and delta-opiate receptors in frog erythrocytes or cultured nervous tissue. In this study, evidence is presented that agonist-mediated receptor internalization and recycling occurs at the dopamine receptor in rat corpus striatum. First, the in vivo binding of the dopamine antagonist (3H)spiperone was increased by both electrical stimulation and pharmacologically induced increases of dopamine release. Conversely, depletion of dopamine with reserpine decreased in vivo (3H)spiperone binding, but the same reserpine treatment did not alter its in vitro binding. Second, the rate of dissociation of (3H)spiperone from microsomal membranes prepared from rat striatum following in vivo binding was fivefold slower than its dissociation following in vitro equilibrium binding. Mild detergent treatment, employed to disrupt endocytic vesicle membranes, increased the rate of dissociation of in vivo bound (3H)spiperone from microsomal membranes to values not significantly different from its in vitro bound dissociation rate. Third, treatment of rats with chloroquine, a drug that prevents receptor recycling but not internalization, prior to (3H)spiperone injection resulted in a selective increase of in vivo (3H)spiperone binding in the light microsome membranes. The existence of mechanisms that rapidly alter the number of neurotransmitter receptors at synapses provides dynamic regulation of receptors in response to varied acute stimulation states.

  17. Babesia canis: evidence for genetic diversity among isolates revealed by restriction fragment length polymorphism analysis.

    PubMed

    Citard, T; Mähl, P; Boulouis, H J; Chavigny, C; Druilhe, P

    1995-09-01

    The genetic diversity of B. canis was investigated by restriction fragment length polymorphism analysis. For this purpose, we identified a Babesia canis specific DNA probe named pS8. This 1.2 kbp probe can detect as low as 20 pg of B. canis DNA. Results suggest that the pS8 probe is distributed in multiple copies throughout the genome though is probably not itself internally repetitious, i.e. not structured into blocks of tandem units. This probe reveals discrete hybridizing fragments in B. canis enzyme-digested genomic DNA. RFLP patterns obtained with the pS8 probe revealed a large genetic diversity between various isolates and led us to distinguish several clones derived from a single isolate. Results suggest that for a single isolate, the fingerprints obtained reflect those of a few quantitatively dominant clones. This technique can now be routinely applied and provides a convenient tool for the characterization and the identification of B. canis isolates, strains and clones. PMID:8533020

  18. Inferential bridging relations reveal distinct neural mechanisms: evidence from event-related brain potentials.

    PubMed

    Burkhardt, Petra

    2006-08-01

    This study investigates the online comprehension of Determiner Phrases (DPs) as a function of the given-new distinction in two-sentence texts in German and further focuses on DPs whose interpretation depends on inferential information (so-called 'bridging relations'). Previous reaction time studies report an advantage of given over new information. In the present study, this difference is reflected in distinct neural mechanisms: event-related potentials reveal that previously introduced (i.e., given) DPs elicit a reduced N400, while new DPs show an enhanced N400 followed by a P600. Crucially, inferentially bridged DPs, which are hypothesized to share properties with new and given information, first pattern with given DPs (showing an attenuated N400) and then with new DPs (showing an enhanced P600). The data demonstrate that salience relations between DPs and prior context ease DP integration and that additional cost arises from the establishment of independent reference. They further reveal that processing cost associated with the interpretation of bridged DPs results from the anaphoric complexity of introducing an independent referent. PMID:16725188

  19. Hypertension and Dementia: Epidemiological and Experimental Evidence Revealing a Detrimental Relationship.

    PubMed

    Perrotta, Marialuisa; Lembo, Giuseppe; Carnevale, Daniela

    2016-01-01

    Hypertension and dementia represent two major public health challenges worldwide, notably in the elderly population. Although these two conditions have classically been recognized as two distinct diseases, mounting epidemiological, clinical and experimental evidence suggest that hypertension and dementia are strictly intertwined. Here, we briefly report how hypertension profoundly affects brain homeostasis, both at the structural and functional level. Chronic high blood pressure modifies the cerebral vasculature, increasing the risk of Aβ clearance impairment. The latter, excluding genetic etiologies, is considered one of the main causes of Aβ deposition in the brain. Studies have shown that hypertension induces cerebral arterial stiffening and microvascular dysfunction, thus contributing to dementia pathophysiology. This review examines the existing and the updated literature which has attempted to explain and clarify the relationship between hypertension and dementia at the pathophysiological level. PMID:27005613

  20. Hypertension and Dementia: Epidemiological and Experimental Evidence Revealing a Detrimental Relationship

    PubMed Central

    Perrotta, Marialuisa; Lembo, Giuseppe; Carnevale, Daniela

    2016-01-01

    Hypertension and dementia represent two major public health challenges worldwide, notably in the elderly population. Although these two conditions have classically been recognized as two distinct diseases, mounting epidemiological, clinical and experimental evidence suggest that hypertension and dementia are strictly intertwined. Here, we briefly report how hypertension profoundly affects brain homeostasis, both at the structural and functional level. Chronic high blood pressure modifies the cerebral vasculature, increasing the risk of Aβ clearance impairment. The latter, excluding genetic etiologies, is considered one of the main causes of Aβ deposition in the brain. Studies have shown that hypertension induces cerebral arterial stiffening and microvascular dysfunction, thus contributing to dementia pathophysiology. This review examines the existing and the updated literature which has attempted to explain and clarify the relationship between hypertension and dementia at the pathophysiological level. PMID:27005613

  1. Dengue in China: Comprehensive Phylogenetic Evaluation Reveals Evidence of Endemicity and Complex Genetic Diversity.

    PubMed

    Chen, Rubing; Han, Guan-Zhu

    2016-01-01

    Despite the increasing threat of dengue outbreaks in China, it is still considered as an imported disease and its introduction and/or circulation patterns remain obscure. On the basis of the most extensive phylogenetic analysis to date, we showed highly complex genetic diversity of dengue viruses (DENVs) in south China with up to 20 different clades/lineages from multiple serotypes co-circulating in the same year. Despite that most of these clades/lineages were resulted from imported cases, evidence of local persistence of DENV serotype 1 (DENV-1) was observed, indicating its potential endemicity in Guangdong province. This study, therefore, provided an overview of DENV genetic diversity and evolutionary dynamics in China, which will be useful for developing policies to prevent and control future dengue outbreaks in China. PMID:26458780

  2. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica

    PubMed Central

    Sugiyama, Nawa; Somerville, Andrew D.; Schoeninger, Margaret J.

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1–550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma’s zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29). PMID:26332042

  3. Revealing natural antisense transcripts from Plasmodium vivax isolates: evidence of genome regulation in complicated malaria.

    PubMed

    Boopathi, P A; Subudhi, Amit Kumar; Garg, Shilpi; Middha, Sheetal; Acharya, Jyoti; Pakalapati, Deepak; Saxena, Vishal; Aiyaz, Mohammed; Chand, Bipin; Mugasimangalam, Raja C; Kochar, Sanjay K; Sirohi, Parmendra; Kochar, Dhanpat K; Das, Ashis

    2013-12-01

    Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is less studied and poorly understood, in spite of these facts. Emerging evidence of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating the parasite directly from infected patients is the best way to study its biology and pathogenic mechanisms. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. The mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of Natural Antisense Transcripts (NATs) in Plasmodium falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed microarray with strand specific probes. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense (S) transcript. Our data also shows condition specific expression patterns of varying S and antisense (AS) transcript levels. Genes with AS transcripts enrich to various biological processes. To our knowledge this is the first report on the presence of NATs from P. vivax obtained from infected patients with different disease complications. The data suggests differential regulation of gene expression in diverse clinical conditions, as shown by differing sense/antisense ratios and would lead to future detailed investigations of gene regulation. PMID:24121022

  4. Bacterial diversity differences along an epigenic cave stream reveal evidence of community dynamics, succession, and stability

    PubMed Central

    Brannen-Donnelly, Kathleen; Engel, Annette S.

    2015-01-01

    Unchanging physicochemical conditions and nutrient sources over long periods of time in cave and karst subsurface habitats, particularly aquifers, can support stable ecosystems, termed autochthonous microbial endokarst communities (AMEC). AMEC existence is unknown for other karst settings, such as epigenic cave streams. Conceptually, AMEC should not form in streams due to faster turnover rates and seasonal disturbances that have the capacity to transport large quantities of water and sediment and to change allochthonous nutrient and organic matter sources. Our goal was to investigate whether AMEC could form and persist in hydrologically active, epigenic cave streams. We analyzed bacterial diversity from cave water, sediments, and artificial substrates (Bio-Traps®) placed in the cave at upstream and downstream locations. Distinct communities existed for the water, sediments, and Bio-Trap® samplers. Throughout the study period, a subset of community members persisted in the water, regardless of hydrological disturbances. Stable habitat conditions based on flow regimes resulted in more than one contemporaneous, stable community throughout the epigenic cave stream. However, evidence for AMEC was insufficient for the cave water or sediments. Community succession, specifically as predictable exogenous heterotrophic microbial community succession, was evident from decreases in community richness from the Bio-Traps®, a peak in Bio-Trap® community biomass, and from changes in the composition of Bio-Trap® communities. The planktonic community was compositionally similar to Bio-Trap® initial colonizers, but the downstream Bio-Trap® community became more similar to the sediment community at the same location. These results can help in understanding the diversity of planktonic and attached microbial communities from karst, as well as microbial community dynamics, stability, and succession during disturbance or contamination responses over time. PMID:26257715

  5. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica.

    PubMed

    Sugiyama, Nawa; Somerville, Andrew D; Schoeninger, Margaret J

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1-550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma's zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29). PMID:26332042

  6. Gene Profiling of Postnatal Mfrprd6 Mutant Eyes Reveals Differential Accumulation of Prss56, Visual Cycle and Phototransduction mRNAs

    PubMed Central

    Soundararajan, Ramani; Won, Jungyeon; Stearns, Timothy M.; Charette, Jeremy R.; Hicks, Wanda L.; Collin, Gayle B.; Naggert, Jürgen K.; Krebs, Mark P.; Nishina, Patsy M.

    2014-01-01

    Mutations in the membrane frizzled-related protein (MFRP/Mfrp) gene, specifically expressed in the retinal pigment epithelium (RPE) and ciliary body, cause nanophthalmia or posterior microphthalmia with retinitis pigmentosa in humans, and photoreceptor degeneration in mice. To better understand MFRP function, microarray analysis was performed on eyes of homozygous Mfrprd6 and C57BL/6J mice at postnatal days (P) 0 and P14, prior to photoreceptor loss. Data analysis revealed no changes at P0 but significant differences in RPE and retina-specific transcripts at P14, suggesting a postnatal influence of the Mfrprd6 allele. A subset of these transcripts was validated by quantitative real-time PCR (qRT-PCR). In Mfrprd6 eyes, a significant 1.5- to 2.0-fold decrease was observed among transcripts of genes linked to retinal degeneration, including those involved in visual cycle (Rpe65, Lrat, Rgr), phototransduction (Pde6a, Guca1b, Rgs9), and photoreceptor disc morphogenesis (Rpgrip1 and Fscn2). Levels of RPE65 were significantly decreased by 2.0-fold. Transcripts of Prss56, a gene associated with angle-closure glaucoma, posterior microphthalmia and myopia, were increased in Mfrprd6 eyes by 17-fold. Validation by qRT-PCR indicated a 3.5-, 14- and 70-fold accumulation of Prss56 transcripts relative to controls at P7, P14 and P21, respectively. This trend was not observed in other RPE or photoreceptor mutant mouse models with similar disease progression, suggesting that Prss56 upregulation is a specific attribute of the disruption of Mfrp. Prss56 and Glul in situ hybridization directly identified Müller glia in the inner nuclear layer as the cell type expressing Prss56. In summary, the Mfrprd6 allele causes significant postnatal changes in transcript and protein levels in the retina and RPE. The link between Mfrp deficiency and Prss56 up-regulation, together with the genetic association of human MFRP or PRSS56 variants and ocular size, raises the possibility that these genes

  7. Evidence of recent thrust faulting on the Moon revealed by the Lunar Reconnaissance Orbiter Camera.

    PubMed

    Watters, Thomas R; Robinson, Mark S; Beyer, Ross A; Banks, Maria E; Bell, James F; Pritchard, Matthew E; Hiesinger, Harald; van der Bogert, Carolyn H; Thomas, Peter C; Turtle, Elizabeth P; Williams, Nathan R

    2010-08-20

    Lunar Reconnaissance Orbiter Camera images reveal previously undetected lobate thrust-fault scarps and associated meter-scale secondary tectonic landforms that include narrow extensional troughs or graben, splay faults, and multiple low-relief terraces. Lobate scarps are among the youngest landforms on the Moon, based on their generally crisp appearance, lack of superposed large-diameter impact craters, and the existence of crosscut small-diameter impact craters. Identification of previously known scarps was limited to high-resolution Apollo Panoramic Camera images confined to the equatorial zone. Fourteen lobate scarps were identified, seven of which are at latitudes greater than +/-60 degrees, indicating that the thrust faults are globally distributed. This detection, coupled with the very young apparent age of the faults, suggests global late-stage contraction of the Moon. PMID:20724632

  8. What does children's spatial language reveal about spatial concepts? Evidence from the use of containment expressions.

    PubMed

    Johanson, Megan; Papafragou, Anna

    2014-06-01

    Children's overextensions of spatial language are often taken to reveal spatial biases. However, it is unclear whether extension patterns should be attributed to children's overly general spatial concepts or to a narrower notion of conceptual similarity allowing metaphor-like extensions. We describe a previously unnoticed extension of spatial expressions and use a novel method to determine its origins. English- and Greek-speaking 4- and 5-year-olds used containment expressions (e.g., English into, Greek mesa) for events where an object moved into another object but extended such expressions to events where the object moved behind or under another object. The pattern emerged in adult speakers of both languages and also in speakers of 10 additional languages. We conclude that learners do not have an overly general concept of Containment. Nevertheless, children (and adults) perceive similarities across Containment and other types of spatial scenes, even when these similarities are obscured by the conventional forms of the language. PMID:24641514

  9. Evidence of liquid phase during laser-induced periodic surface structures formation induced by accumulative ultraviolet picosecond laser beam

    SciTech Connect

    Huynh, T. T. D.; Petit, A.; Semmar, N.

    2015-11-09

    Laser-induced periodic surface structures (LIPSS) were formed on Cu/Si or Cu/glass thin films using Nd:YAG laser beam (40 ps, 10 Hz, and 30 mJ/cm{sup 2}). The study of ablation threshold is always achieved over melting when the variation of the number of pulses increases from 1 to 1000. But the incubation effect is leading to reduce the threshold of melting as increasing the number of laser pulse. Also, real time reflectivity signals exhibit typical behavior to stress the formation of a liquid phase during the laser-processing regime and helps to determine the threshold of soft ablation. Atomic Force Microscopy (AFM) analyses have shown the topology of the micro-crater containing regular spikes with different height. Transmission Electron Microscopy (TEM) allows finally to show three distinguished zones in the close region of isolated protrusions. The central zone is a typical crystallized area of few nanometers surrounded by a mixed poly-crystalline and amorphous area. Finally, in the region far from the protrusion zone, Cu film shows an amorphous structure. The real time reflectivity, AFM, and HR-TEM analyses evidence the formation of a liquid phase during the LIPSS formation in the picosecond regime.

  10. Synchrotron FTIR shows evidence of DNA damage and lipid accumulation in prostate adenocarcinoma PC-3 cells following proton irradiation

    NASA Astrophysics Data System (ADS)

    Lipiec, Ewelina; Bambery, Keith R.; Heraud, Phil; Hirschmugl, Carol; Lekki, Janusz; Kwiatek, Wojciech M.; Tobin, Mark J.; Vogel, Christian; Whelan, Donna; Wood, Bayden R.

    2014-09-01

    Synchrotron Radiation Fourier Transform Infrared (SR-FTIR) spectra of single human prostate adenocarcinoma PC-3 cells, irradiated with a defined number of 2 MeV protons generated by a proton microbeam along with non-irradiated control cells, were analysed using multivariate methods. A number of different Principal Component Analysis (PCA) models were tested and the spectral ranges associated with nucleic acids, proteins and lipids were analysed separately. The results show a dose dependent shift of the Osbnd Psbnd O asymmetric stretching mode from 1234 cm-1 to 1237 cm-1, consistent with local disorder in the B-DNA conformation along with a change in intensity of the Osbnd Psbnd O symmetric stretching band at 1083 cm-1 indicative of chromatin fragmentation - the natural consequence of a high number of DNA Double Strand Breaks (DSBs). 2D mapping of characteristic functional groups at the diffraction limit shows evidence of lipid deposition and chromatin condensation in cells exposed to protons indicative of cell apoptosis following irradiation. These studies lay the foundation for understanding the macromolecular changes that occur to cells in response to radiation therapy, which has important implications in the treatment of tumours.

  11. [Significance of Tc-99m pyrophosphate accumulation in unstable angina: clinical characteristics and evidence for myocardial stunning].

    PubMed

    Tange, S; Kondo, C; Ohta, Y; Kusakabe, K; Shigeta, A; Uchida, T; Sumiyoshi, T; Kaneko, N; Hosoda, S

    1993-01-01

    Tc-99m pyrophosphate (PYP) and Tl-201 simultaneous dual energy single photon emission computed tomography (SPECT) were performed for 33 patients with clinically diagnosed unstable angina. Twenty-two patients (76%) showed PYP accumulation in the myocardium (PYP+group). Clinical features, types of unstable angina, electrocardiographic changes during and after the anginal attack, and serial creatine kinase (CK) sampling data were reviewed and compared in the 2 groups. Selective coronary angiography was performed in all patients, and contrast left ventriculography was carried out in 29 patients both in unstable and stable states. In the study of left ventriculograms, the ejection fraction (EF) was calculated by the area-length method and the wall motion abnormality index was calculated by the centerline method. The PYP(+)group differed significantly from the PYP(-)group in several features as follows: 1) the "new angina at rest" type of unstable angina was more frequent in the PYP(+)group than in the PYP(-)group. The ratios of new angina at rest/effort angina (including new angina of effort and angina of effort with changing pattern) were 16/6; 2/9 for the PYP(+) and (-)groups, respectively (p < 0.05). 2) ST elevation during the heart attack was seen more in the PYP(+)group. The ratios of ST elevation/ST depression were 13/22 (59%); 5/22 (23%) for the PYP(+)group, and 2/11 (18%); 7/11 (64%) for the PYP(-)group, respectively (p < 0.05). 3) EF was improved in the PYP(+) group to the normal range. EF in the PYP(+)group changed from 57 +/- 12 in the unstable state to 62 +/- 11% in the stable state (p < 0.02), while that of the PYP(-)group showed no significant difference between the unstable state (59 +/- 9%) and the stable state (59 +/- 11%). 4) Wall motion abnormality index (WMI) in the PYP(+)group was poorer than in the PYP(-)group, but it improved markedly in one month to the same level as that of the PYP(-)group. WMI in the PYP(+)group in the unstable state (21

  12. Proton magnetic resonance spectroscopy and MRI reveal no evidence for brain mitochondrial dysfunction in children with autism spectrum disorder.

    PubMed

    Corrigan, Neva M; Shaw, Dennis W W; Richards, Todd L; Estes, Annette M; Friedman, Seth D; Petropoulos, Helen; Artru, Alan A; Dager, Stephen R

    2012-01-01

    Brain mitochondrial dysfunction has been proposed as an etiologic factor in autism spectrum disorder (ASD). Proton magnetic resonance spectroscopic imaging ((1)HMRS) and MRI were used to assess for evidence of brain mitochondrial dysfunction in longitudinal samples of children with ASD or developmental delay (DD), and cross-sectionally in typically developing (TD) children at 3-4, 6-7 and 9-10 years-of-age. A total of 239 studies from 130 unique participants (54ASD, 22DD, 54TD) were acquired. (1)HMRS and MRI revealed no evidence for brain mitochondrial dysfunction in the children with ASD. Findings do not support a substantive role for brain mitochondrial abnormalities in the etiology or symptom expression of ASD, nor the widespread use of hyperbaric oxygen treatment that has been advocated on the basis of this proposed relationship. PMID:21404085

  13. Mitochondrial genome evidence reveals successful Late Paleolithic settlement on the Tibetan Plateau

    PubMed Central

    Zhao, Mian; Kong, Qing-Peng; Wang, Hua-Wei; Peng, Min-Sheng; Xie, Xiao-Dong; Wang, Wen-Zhi; Jiayang; Duan, Jian-Guo; Cai, Ming-Cui; Zhao, Shi-Neng; Cidanpingcuo; Tu, Yuan-Quan; Wu, Shi-Fang; Yao, Yong-Gang; Bandelt, Hans-Jürgen; Zhang, Ya-Ping

    2009-01-01

    Due to its numerous environmental extremes, the Tibetan Plateau—the world's highest plateau—is one of the most challenging areas of modern human settlement. Archaeological evidence dates the earliest settlement on the plateau to the Late Paleolithic, while previous genetic studies have traced the colonization event(s) to no earlier than the Neolithic. To explore whether the genetic continuity on the plateau has an exclusively Neolithic time depth, we studied mitochondrial DNA (mtDNA) genome variation within 6 regional Tibetan populations sampled from Tibet and neighboring areas. Our results confirm that the vast majority of Tibetan matrilineal components can trace their ancestry to Epipaleolithic and Neolithic immigrants from northern China during the mid-Holocene. Significantly, we also identified an infrequent novel haplogroup, M16, that branched off directly from the Eurasian M founder type. Its nearly exclusive distribution in Tibetan populations and ancient age (>21 kya) suggest that M16 may represent the genetic relics of the Late Paleolithic inhabitants on the plateau. This partial genetic continuity between the Paleolithic inhabitants and the contemporary Tibetan populations bridges the results and inferences from archaeology, history, and genetics. PMID:19955425

  14. Population expansions shared among coexisting bacterial lineages are revealed by genetic evidence

    PubMed Central

    Avitia, Morena; Escalante, Ana E.; Rebollar, Eria A.; Moreno-Letelier, Alejandra; Eguiarte, Luis E.

    2014-01-01

    Comparative population studies can help elucidate the influence of historical events upon current patterns of biodiversity among taxa that coexist in a given geographic area. In particular, comparative assessments derived from population genetics and coalescent theory have been used to investigate population dynamics of bacterial pathogens in order to understand disease epidemics. In contrast, and despite the ecological relevance of non-host associated and naturally occurring bacteria, there is little understanding of the processes determining their diversity. Here we analyzed the patterns of genetic diversity in coexisting populations of three genera of bacteria (Bacillus, Exiguobacterium, and Pseudomonas) that are abundant in the aquatic systems of the Cuatro Cienegas Basin, Mexico. We tested the hypothesis that a common habitat leaves a signature upon the genetic variation present in bacterial populations, independent of phylogenetic relationships. We used multilocus markers to assess genetic diversity and (1) performed comparative phylogenetic analyses, (2) described the genetic structure of bacterial populations, (3) calculated descriptive parameters of genetic diversity, (4) performed neutrality tests, and (5) conducted coalescent-based historical reconstructions. Our results show a trend of synchronic expansions across most populations independent of both lineage and sampling site. Thus, we provide empirical evidence supporting the analysis of coexisting bacterial lineages in natural environments to advance our understanding of bacterial evolution beyond medical or health-related microbes. PMID:25548732

  15. Population expansions shared among coexisting bacterial lineages are revealed by genetic evidence.

    PubMed

    Avitia, Morena; Escalante, Ana E; Rebollar, Eria A; Moreno-Letelier, Alejandra; Eguiarte, Luis E; Souza, Valeria

    2014-01-01

    Comparative population studies can help elucidate the influence of historical events upon current patterns of biodiversity among taxa that coexist in a given geographic area. In particular, comparative assessments derived from population genetics and coalescent theory have been used to investigate population dynamics of bacterial pathogens in order to understand disease epidemics. In contrast, and despite the ecological relevance of non-host associated and naturally occurring bacteria, there is little understanding of the processes determining their diversity. Here we analyzed the patterns of genetic diversity in coexisting populations of three genera of bacteria (Bacillus, Exiguobacterium, and Pseudomonas) that are abundant in the aquatic systems of the Cuatro Cienegas Basin, Mexico. We tested the hypothesis that a common habitat leaves a signature upon the genetic variation present in bacterial populations, independent of phylogenetic relationships. We used multilocus markers to assess genetic diversity and (1) performed comparative phylogenetic analyses, (2) described the genetic structure of bacterial populations, (3) calculated descriptive parameters of genetic diversity, (4) performed neutrality tests, and (5) conducted coalescent-based historical reconstructions. Our results show a trend of synchronic expansions across most populations independent of both lineage and sampling site. Thus, we provide empirical evidence supporting the analysis of coexisting bacterial lineages in natural environments to advance our understanding of bacterial evolution beyond medical or health-related microbes. PMID:25548732

  16. Molecular Evidence for a Natural Primary Triple Hybrid in Plants Revealed from Direct Sequencing

    PubMed Central

    Kaplan, Zdenek; Fehrer, Judith

    2007-01-01

    Background and Aims Molecular evidence for natural primary hybrids composed of three different plant species is very rarely reported. An investigation was therefore carried out into the origin and a possible scenario for the rise of a sterile plant clone showing a combination of diagnostic morphological features of three separate, well-defined Potamogeton species. Methods The combination of sequences from maternally inherited cytoplasmic (rpl20-rps12) and biparentally inherited nuclear ribosomal DNA (ITS) was used to identify the exact identity of the putative triple hybrid. Key Results Direct sequencing showed ITS variants of three parental taxa, P. gramineus, P. lucens and P. perfoliatus, whereas chloroplast DNA identified P. perfoliatus as the female parent. A scenario for the rise of the triple hybrid through a fertile binary hybrid P. gramineus × P. lucens crossed with P. perfoliatus is described. Conclusions Even though the triple hybrid is sterile, it possesses an efficient strategy for its existence and became locally successful even in the parental environment, perhaps as a result of heterosis. The population investigated is the only one known of this hybrid, P. × torssanderi, worldwide. Isozyme analysis indicated the colony to be genetically uniform. The plants studied represented a single clone that seems to have persisted at this site for a long time. PMID:17478544

  17. Ultrastructural evidence for the accumulation of insulin in nuclei of intact 3T3-L1 adipocytes by an insulin-receptor mediated process

    SciTech Connect

    Smith, R.M.; Jarett, L.

    1987-01-01

    Monomeric ferritin-labeled insulin (F/sub m/-Ins), a biologically active, electron-dense marker of occupied insulin receptors, was used to characterize the internalization of insulin in 3T3-L1 adipocytes. F/sub m/-Ins bound specifically to insulin receptors and was internalized in a time- and temperature-dependent manner. In the nucleus, several F/sub m/-Ins particles usually were found in the same general location-near nuclear pores, associated with the periphery of the condensed chromatin. Addition of a 250-fold excess of unlabeled insulin or incubation at 15/sup 0/C reduced the number of F/sub m/-Ins particles found in nuclei after 90 min by 99% or 92%, respectively. Nuclear accumulation of unlabeled ferritin was only 2% of that found with F/sub m/-Ins after 90 min at 37/sup 0/C. Biochemical experiments utilizing /sup 125/I-labeled insulin and subcellular fractionation indicated that intact 3T3-L1 adipocytes internalized insulin rapidly and that approx. = 3% of the internalized ligand accumulated in nuclei after 1 hr. These data provide biochemical and high-resolution ultrastructural evidence that 3T3-L1 adipocytes accumulate potentially significant amounts of insulin in nuclei by an insulin receptor-mediated process. The transport of insulin or the insulin-receptor complex to nuclei in this cell or in others may be directly involved in the long-term biological effects of insulin - in particular, in the control of DNA and RNA synthesis.

  18. Interaction between carbon metabolism and phosphate accumulation is revealed by a mutation of a cellulose synthase-like protein, CSLF6

    PubMed Central

    Jin, Cheng; Fang, Chuanying; Yuan, Hui; Wang, Shouchuang; Wu, Yangyang; Liu, Xianqing; Zhang, Yuanyuan; Luo, Jie

    2015-01-01

    Phosphorus is an essential macronutrient for plant growth and development. However, the network that affects phosphate (Pi) accumulation in crops is not well established. It is reported here that OsCSLF6, a member of the cellulose synthase-like family (CSLF), which is found only in grasses, is involved in Pi accumulation. The oscslf6 mutants (oscslf6-1 and oscslf6-2) display Pi toxic symptoms and increased Pi accumulation in both roots and shoots under the Pi-sufficient condition, which correlate with the induced expression of Pi transporters in the knockout mutants. Consistent with the over-accumulation of Pi, a significant decrease in primary root length, adventitious root length, and adventitious root number were observed in the oscslf6 mutants when compared with the wild type (WT) under Pi-sufficient conditions. In addition, the sucrose (Suc) level was increased in the oscslf6 mutants and the expression of sucrose synthases (OsSUS4/5) and sucrose transporters (OsSUT1/2/4/OsSweet14) genes were also induced in the shoots of oscslf6 mutants, suggesting that OsCSLF6 may play a role in affecting Pi accumulation by affecting the level of carbon metabolism. PMID:25740927

  19. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  20. Evidence of Cholesterol Accumulated in High Curvature Regions: Implication to the Curvature Elastic Energy for Lipid Mixtures

    PubMed Central

    Wang, Wangchen; Yang, Lin; Huang, Huey W.

    2007-01-01

    Recent experiments suggested that cholesterol and other lipid components of high negative spontaneous curvature facilitate membrane fusion. This is taken as evidence supporting the stalk-pore model of membrane fusion in which the lipid bilayers go through intermediate structures of high curvature. How do the high-curvature lipid components lower the free energy of the curved structure? Do the high-curvature lipid components modify the average spontaneous curvature of the relevant monolayer, thereby facilitate its bending, or do the lipid components redistribute in the curved structure so as to lower the free energy? This question is fundamental to the curvature elastic energy for lipid mixtures. Here we investigate the lipid distribution in a monolayer of a binary lipid mixture before and after bending, or more precisely in the lamellar, hexagonal, and distorted hexagonal phases. The lipid mixture is composed of 2:1 ratio of brominated di18:0PC and cholesterol. Using a newly developed procedure for the multiwavelength anomalous diffraction method, we are able to isolate the bromine distribution and reconstruct the electron density distribution of the lipid mixture in the three phases. We found that the lipid distribution is homogenous and uniform in the lamellar and hexagonal phases. But in the distorted hexagonal phase, the lipid monolayer has nonuniform curvature, and cholesterol almost entirely concentrates in the high curvature region. This finding demonstrates that the association energies between lipid molecules vary with the curvature of membrane. Thus, lipid components in a mixture may redistribute under conditions of nonuniform curvature, such as in the stalk structure. In such cases, the spontaneous curvature depends on the local lipid composition and the free energy minimum is determined by lipid distribution as well as curvature. PMID:17259270

  1. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier

    PubMed Central

    Dreier, Jes; Sørensen, Jens A.; Brewer, Jonathan R.

    2016-01-01

    In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS) to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED) images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers that transport their cargo directly through the skin barrier, but mainly burst and fuse with the outer lipid layers of the stratum corneum. It was also found that the flexible liposomes showed a greater delivery of the fluorophore into the stratum corneum, indicating that they functioned as chemical permeability enhancers. PMID:26751684

  2. Superresolution and Fluorescence Dynamics Evidence Reveal That Intact Liposomes Do Not Cross the Human Skin Barrier.

    PubMed

    Dreier, Jes; Sørensen, Jens A; Brewer, Jonathan R

    2016-01-01

    In this study we use the combination of super resolution optical microscopy and raster image correlation spectroscopy (RICS) to study the mechanism of action of liposomes as transdermal drug delivery systems in human skin. Two different compositions of liposomes were applied to newly excised human skin, a POPC liposome and a more flexible liposome containing the surfactant sodium cholate. Stimulated emission depletion microscopy (STED) images of intact skin and cryo-sections of skin treated with labeled liposomes were recorded displaying an optical resolution low enough to resolve the 100 nm liposomes in the skin. The images revealed that virtually none of the liposomes remained intact beneath the skin surface. RICS two color cross correlation diffusion measurements of double labeled liposomes confirmed these observations. Our results suggest that the liposomes do not act as carriers that transport their cargo directly through the skin barrier, but mainly burst and fuse with the outer lipid layers of the stratum corneum. It was also found that the flexible liposomes showed a greater delivery of the fluorophore into the stratum corneum, indicating that they functioned as chemical permeability enhancers. PMID:26751684

  3. Do Energy Efficiency Standards Improve Quality? Evidence from a Revealed Preference Approach

    SciTech Connect

    Houde, Sebastien; Spurlock, C. Anna

    2015-06-01

    Minimum energy efficiency standards have occupied a central role in U.S. energy policy for more than three decades, but little is known about their welfare effects. In this paper, we employ a revealed preference approach to quantify the impact of past revisions in energy efficiency standards on product quality. The micro-foundation of our approach is a discrete choice model that allows us to compute a price-adjusted index of vertical quality. Focusing on the appliance market, we show that several standard revisions during the period 2001-2011 have led to an increase in quality. We also show that these standards have had a modest effect on prices, and in some cases they even led to decreases in prices. For revision events where overall quality increases and prices decrease, the consumer welfare effect of tightening the standards is unambiguously positive. Finally, we show that after controlling for the effect of improvement in energy efficiency, standards have induced an expansion of quality in the non-energy dimension. We discuss how imperfect competition can rationalize these results.

  4. Mobile eye tracking reveals little evidence for age differences in attentional selection for mood regulation.

    PubMed

    Isaacowitz, Derek M; Livingstone, Kimberly M; Harris, Julia A; Marcotte, Stacy L

    2015-04-01

    Two studies are reported representing the first use of mobile eye tracking to study emotion regulation across adulthood. Past research on age differences in attentional deployment using stationary eye tracking has revealed older adults show relatively more positive looking and seem to benefit more moodwise from this looking pattern, compared with younger adults. However, these past studies have greatly constrained the stimuli participants can look at, despite real-world settings providing numerous possibilities for what we choose to look at. The authors therefore used mobile eye tracking to study age differences in attentional selection, as indicated by fixation patterns to stimuli of different valence freely chosen by the participant. In contrast to stationary eye-tracking studies of attentional deployment, Study 1 showed that younger and older individuals generally selected similar proportions of valenced stimuli, and attentional selection had similar effects on mood across age groups. Study 2 replicated this pattern with an adult life span sample including middle-aged individuals. Emotion regulation-relevant attention may thus differ depending on whether stimuli are freely chosen or not. (PsycINFO Database Record PMID:25527965

  5. Evidence of Viscoelastic Deformation following the 2011 Tohoku-oki Earthquake Revealed from Seafloor Geodetic Observation

    NASA Astrophysics Data System (ADS)

    Watanabe, S. I.; Sato, M.; Fujita, M.; Ishikawa, T.; Yokota, Y.; Ujihara, N.; Asada, A.

    2014-12-01

    The great Tohoku-oki earthquake (M9.0) occurred on 11th March, 2011 along the Japan Trench, off the Pacific coast of eastern Japan. The source region spreads over an area with a length of 500 km and a width of 200 km, almost all part of which is beneath the seafloor. We, the group of Japan Coast Guard (JCG), have continued repeated GPS-acoustic seafloor positioning after the Tohoku-oki earthquake at six seafloor sites in the offshore source region, the results of which are expected to provide information leading to better understandings of postseismic processes. In contrast to the coastal GNSS sites where trenchward-upward movements were reported, the offshore sites above the main rupture zone in the northern part of the source region exhibit landward displacements of tens of centimeters with significant subsidence from more than three years of repeated observations. At the sites above around the edge of the main rupture zone, smaller amount of trench-normal movements were found. Although the terrestrial movements were reasonably interpreted by afterslip beneath the coastal area, these offshore results are rather consistent with effects predicted from viscoelastic relaxation in the upper mantle, providing definitive evidence of its occurrence. On the other hand, a site in the southern part of the source region with relatively small coseismic slips shows not only trenchward movements with logarithmical decay with time but also significant subsidence, which imply superposition of effects from viscoelastic relaxation and afterslip. In this presentation, we report our latest observation results and discuss postseismic movements on the seafloor just above the source region for more than three years after the earthquake.

  6. Genomic Evidence Reveals Numerous Salmonella enterica Serovar Newport Reintroduction Events in Suwannee Watershed Irrigation Ponds

    PubMed Central

    Jackson, Scott A.; Gangiredla, Jayanthi; Wang, Weimin; Liu, Huanli; Tall, Ben D.; Beaubrun, Junia Jean-Gilles; Jay-Russell, Michele; Vellidis, George; Elkins, Christopher A.

    2015-01-01

    Our previous work indicated a predominance (56.8%) of Salmonella enterica serovar Newport among isolates recovered from irrigation ponds used in produce farms over a 2-year period (B. Li et al., Appl Environ Microbiol 80:6355–6365, http://dx.doi.org/10.1128/AEM.02063-14). This observation provided a valuable set of metrics to explore an underaddressed issue of environmental survival of Salmonella by DNA microarray. Microarray analysis correctly identified all the isolates (n = 53) and differentiated the S. Newport isolates into two phylogenetic lineages (S. Newport II and S. Newport III). Serovar distribution analysis showed no instances where the same serovar was recovered from a pond for more than a month. Furthermore, during the study, numerous isolates with an indistinguishable genotype were recovered from different ponds as far as 180 km apart for time intervals as long as 2 years. Although isolates within either lineage were phylogenetically related as determined by microarray analysis, subtle genotypic differences were detected within the lineages, suggesting that isolates in either lineage could have come from several unique hosts. For example, strains in four different subgroups (A, B, C, and D) possessed an indistinguishable genotype within their subgroups as measured by gene differences, suggesting that strains in each subgroup shared a common host. Based on this comparative genomic evidence and the spatial and temporal factors, we speculated that the presence of Salmonella in the ponds was likely due to numerous punctuated reintroduction events associated with several different but common hosts in the environment. These findings may have implications for the development of strategies for efficient and safe irrigation to minimize the risk of Salmonella outbreaks associated with fresh produce. PMID:26386063

  7. Genome-wide Evidence Reveals that African and Eurasian Golden Jackals Are Distinct Species.

    PubMed

    Koepfli, Klaus-Peter; Pollinger, John; Godinho, Raquel; Robinson, Jacqueline; Lea, Amanda; Hendricks, Sarah; Schweizer, Rena M; Thalmann, Olaf; Silva, Pedro; Fan, Zhenxin; Yurchenko, Andrey A; Dobrynin, Pavel; Makunin, Alexey; Cahill, James A; Shapiro, Beth; Álvares, Francisco; Brito, José C; Geffen, Eli; Leonard, Jennifer A; Helgen, Kristofer M; Johnson, Warren E; O'Brien, Stephen J; Van Valkenburgh, Blaire; Wayne, Robert K

    2015-08-17

    The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus), which is surprising given the absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than one million years, sufficient to merit formal recognition as different species: C. anthus (African golden wolf) and C. aureus (Eurasian golden jackal). Using morphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification. PMID:26234211

  8. Targeted Deep Sequencing Reveals No Definitive Evidence for Somatic Mosaicism in Atrial Fibrillation

    PubMed Central

    Roberts, Jason D.; Longoria, James; Poon, Annie; Gollob, Michael H.; Dewland, Thomas A.; Kwok, Pui-Yan; Olgin, Jeffrey E.; Deo, Rahul C.; Marcus, Gregory M.

    2015-01-01

    Background Studies of ≤15 atrial fibrillation (AF) patients have identified atrial-specific mutations within connexin genes, suggesting that somatic mutations may account for sporadic cases of the arrhythmia. We sought to identify atrial somatic mutations among patients with and without AF using targeted deep next-generation sequencing of 560 genes, including genetic culprits implicated in AF, the Mendelian cardiomyopathies and channelopathies, and all ion channels within the genome. Methods and Results Targeted gene capture and next generation sequencing were performed on DNA from lymphocytes and left atrial appendages of 34 patients (25 with AF). Twenty AF patients had undergone cardiac surgery exclusively for pulmonary vein isolation, and 17 had no structural heart disease. Sequence alignment and variant calling were performed for each atrial-lymphocyte pair using the Burrows-Wheeler Aligner, the Genome Analysis Toolkit, and MuTect packages. Next generation sequencing yielded a median 265-fold coverage depth (IQR 164–369). Comparison of the 3 million base pairs from each atrial-lymphocyte pair revealed a single potential somatic missense mutation in 3 AF patients and 2 in a single control (12 vs. 11%; p=1). All potential discordant variants had low allelic fractions (range: 2.3–7.3%) and none were detected with conventional sequencing. Conclusions Using high-depth next generation sequencing and state-of-the art somatic mutation calling approaches, no pathogenic atrial somatic mutations could be confirmed among 25 AF patients in a comprehensive cardiac arrhythmia genetic panel. These findings indicate that atrial specific mutations are rare and that somatic mosaicism is unlikely to exert a prominent role in AF pathogenesis. PMID:25406240

  9. Meteorological variation in daily travel behaviour: evidence from revealed preference data from the Netherlands

    NASA Astrophysics Data System (ADS)

    Creemers, Lieve; Wets, Geert; Cools, Mario

    2015-04-01

    This study investigates the meteorological variation in revealed preference travel data. The main objective of this study is to investigate the impact of weather conditions on daily activity participation (trip motives) and daily modal choices in the Netherlands. To this end, data from the Dutch National Travel Household Survey of 2008 were matched to hourly weather data provided by the Royal Dutch Meteorological Institute and were complemented with thermal indices to indicate the level of thermal comfort and additional variables to indicate the seasonality of the weather conditions. Two multinomial logit-generalised estimation equations (MNL-GEE) models were constructed, one to assess the impact of weather conditions on trip motives and one to assess the effect of weather conditions on modal choice. The modelling results indicate that, depending on the travel attribute of concern, other factors might play a role. Nonetheless, the thermal component, as well as the aesthetical component and the physical component of weather play a significant role. Moreover, the parameter estimates indicate significant differences in the impact of weather conditions when different time scales are considered (e.g. daily versus hourly based). The fact that snow does not play any role at all was unexpected. This finding can be explained by the relatively low occurrence of this weather type in the study area. It is important to consider the effects of weather in travel demand modelling frameworks because this will help to achieve higher accuracy and more realistic traffic forecasts. These will in turn allow policy makers to make better long-term and short-term decisions to achieve various political goals, such as progress towards a sustainable transportation system. Further research in this respect should emphasise the role of weather conditions and activity-scheduling attributes.

  10. Miiuy croaker transferrin gene and evidence for positive selection events reveal different evolutionary patterns.

    PubMed

    Sun, Yueyan; Zhu, Zhihuang; Wang, Rixin; Sun, Yuena; Xu, Tianjun

    2012-01-01

    Transferrin (TF) is a protein that plays a central role in iron metabolism. This protein is associated with the innate immune system, which is responsible for disease defense responses after bacterial infection. The clear link between TF and the immune defense mechanism has led researchers to consider TF as a candidate gene for disease resistance. In this study, the Miichthys miiuy (miiuy croaker) TF gene (MIMI-TF) was cloned and characterized. The gene structure consisted of a coding region of 2070 nucleotides divided into 17 exons, as well as a non-coding region that included 16 introns and spans 6757 nucleotides. The deduced MIMI-TF protein consisted of 689 amino acids that comprised a signal peptide and two lobes (N- and C-lobes). MIMI-TF expression was significantly up-regulated after infection with Vibrio anguillarum. A series of model tests implemented in the CODEML program showed that TF underwent a complex evolutionary process. Branch-site models revealed that vertebrate TF was vastly different from that of invertebrates, and that the TF of the ancestors of aquatic and terrestrial organisms underwent different selection pressures. The site models detected 10 positively selected sites in extant TF genes. One site was located in the cleft between the N1 and N2 domains and was expected to affect the capability of TF to bind to or release iron indirectly. In addition, eight sites were found near the TF exterior. Two of these sites, which could have evolved from the competition for iron between pathogenic bacteria and TF, were located in potential pathogen-binding domains. Our results could be used to further investigate the function of TF and the selective mechanisms involved. PMID:22957037

  11. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  12. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    PubMed

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  13. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization

    PubMed Central

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  14. Kinetic evidence that methionine sulfoxide reductase A can reveal its oxidase activity in the presence of thioredoxin.

    PubMed

    Kriznik, Alexandre; Boschi-Muller, Sandrine; Branlant, Guy

    2014-04-15

    The mouse methionine sulfoxide reductase A (MsrA) belongs to the subclass of MsrAs with one catalytic and two recycling Cys corresponding to Cys51, Cys198 and Cys206 in Escherichia coli MsrA, respectively. It was previously shown that in the absence of thioredoxin, the mouse and the E. coli MsrAs, which reduce two mol of methionine-O substrate per mol of enzyme, displays an in vitro S-stereospecific methionine oxidase activity. In the present study carried out with E. coli MsrA, kinetic evidence are presented which show that formation of the second mol of Ac-L-Met-NHMe is rate-limiting in the absence of thioredoxin. In the presence of thioredoxin, the overall rate-limiting step is associated with the thioredoxin-recycling process. Kinetic arguments are presented which support the accumulation of the E. coli MsrA under Cys51 sulfenic acid state in the presence of Trx. Thus, the methionine oxidase activity could be operative in vivo without the action of a regulatory protein in order to block the action of Trx as previously proposed. PMID:24632144

  15. Tissue-specific knockouts of ACAT2 reveal that intestinal depletion is sufficient to prevent diet-induced cholesterol accumulation in the liver and blood[S

    PubMed Central

    Zhang, Jun; Kelley, Kathryn L.; Marshall, Stephanie M.; Davis, Matthew A.; Wilson, Martha D.; Sawyer, Janet K.; Farese, Robert V.; Brown, J. Mark; Rudel, Lawrence L.

    2012-01-01

    Acyl-CoA:cholesterol acyltransferase 2 (ACAT2) generates cholesterol esters (CE) for packaging into newly synthesized lipoproteins and thus is a major determinant of blood cholesterol levels. ACAT2 is expressed exclusively in the small intestine and liver, but the relative contributions of ACAT2 expression in these tissues to systemic cholesterol metabolism is unknown. We investigated whether CE derived from the intestine or liver would differentially affect hepatic and plasma cholesterol homeostasis. We generated liver-specific (ACAT2L−/L−) and intestine-specific (ACAT2SI−/SI−) ACAT2 knockout mice and studied dietary cholesterol-induced hepatic lipid accumulation and hypercholesterolemia. ACAT2SI−/SI− mice, in contrast to ACAT2L−/L− mice, had blunted cholesterol absorption. However, specific deletion of ACAT2 in the intestine generated essentially a phenocopy of the conditional knockout of ACAT2 in the liver, with reduced levels of plasma very low-density lipoprotein and hepatic CE, yet hepatic-free cholesterol does not build up after high cholesterol intake. ACAT2L−/L− and ACAT2SI−/SI− mice were equally protected from diet-induced hepatic CE accumulation and hypercholesterolemia. These results suggest that inhibition of intestinal or hepatic ACAT2 improves atherogenic hyperlipidemia and limits hepatic CE accumulation in mice and that depletion of intestinal ACAT2 is sufficient for most of the beneficial effects on cholesterol metabolism. Inhibitors of ACAT2 targeting either tissue likely would be beneficial for atheroprotection. PMID:22460046

  16. Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory.

    PubMed

    Bigand, Emmanuel; Delbé, Charles; Poulin-Charronnat, Bénédicte; Leman, Marc; Tillmann, Barbara

    2014-01-01

    During the last decade, it has been argued that (1) music processing involves syntactic representations similar to those observed in language, and (2) that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing. To support this view, we simulated numerous empirical studies that investigated the processing of harmonic structures, using a model based on the accumulation of sensory information in auditory memory. The simulations revealed that most of the musical syntax manipulations used with behavioral and neurophysiological methods as well as with developmental and cross-cultural approaches can be accounted for by the auditory memory model. This led us to question whether current research on musical syntax can really be compared with linguistic processing. Our simulation also raises methodological and theoretical challenges to study musical syntax while disentangling the confounded low-level sensory influences. In order to investigate syntactic abilities in music comparable to language, research should preferentially use musical material with structures that circumvent the tonal effect exerted by psychoacoustic properties of sounds. PMID:24936174

  17. Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory

    PubMed Central

    Bigand, Emmanuel; Delbé, Charles; Poulin-Charronnat, Bénédicte; Leman, Marc; Tillmann, Barbara

    2014-01-01

    During the last decade, it has been argued that (1) music processing involves syntactic representations similar to those observed in language, and (2) that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing. To support this view, we simulated numerous empirical studies that investigated the processing of harmonic structures, using a model based on the accumulation of sensory information in auditory memory. The simulations revealed that most of the musical syntax manipulations used with behavioral and neurophysiological methods as well as with developmental and cross-cultural approaches can be accounted for by the auditory memory model. This led us to question whether current research on musical syntax can really be compared with linguistic processing. Our simulation also raises methodological and theoretical challenges to study musical syntax while disentangling the confounded low-level sensory influences. In order to investigate syntactic abilities in music comparable to language, research should preferentially use musical material with structures that circumvent the tonal effect exerted by psychoacoustic properties of sounds. PMID:24936174

  18. Affected-sib-pair analyses reveal support of prior evidence for a susceptibility locus for bipolar disorder, on 21q

    SciTech Connect

    Detera-Wadleigh, S.D.; Badner, J.A.; Goldin, L.R.

    1996-06-01

    In 22 multiplex pedigrees screened for linkage to bipolar disorder, by use of 18 markers on chromosome 21q, single-locus affected-sib-pair (ASP) analysis detected a high proportion (57%-62%) of alleles shared identical by descent (IBD), with P values of .049-.0008 on nine marker loci. Multilocus ASP analyses revealed locus trios in the distal region between D21S270 and D21S171, with excess allele sharing (nominal P values <.01) under two affection-status models, ASM I (bipolars and schizoaffectives) and ASM II (ASM I plus recurrent unipolars). In addition, under ASM I, the proximal interval spanned by D21S1436 and D21S65 showed locus trios with excess allele sharing (nominal P values of .03-.0003). These findings support prior evidence that a susceptibility locus for bipolar disorder is on 21q. 38 refs., 4 tabs.

  19. Metabolomics reveals novel biomarkers of illegal 5-nitromimidazole treatment in pigs. Further evidence of drug toxicity uncovered.

    PubMed

    Arias, M; Chevallier, O P; Graham, S F; Gasull-Gimenez, A; Fodey, T; Cooper, K M; Crooks, S R H; Danaher, M; Elliott, C T

    2016-05-15

    The aim of the study was to investigate the potential of a metabolomics platform to distinguish between pigs treated with ronidazole, dimetridazole and metronidazole and non-medicated animals (controls), at two withdrawal periods (day 0 and 5). Livers from each animal were biochemically profiled using UHPLC-QTof-MS in ESI+ mode of acquisition. Several Orthogonal Partial Least Squares-Discriminant Analysis models were generated from the acquired mass spectrometry data. The models classified the two groups control and treated animals. A total of 42 ions of interest explained the variation in ESI+. It was possible to find the identity of 3 of the ions and to positively classify 4 of the ionic features, which can be used as potential biomarkers of illicit 5-nitroimidazole abuse. Further evidence of the toxic mechanisms of 5-nitroimidazole drugs has been revealed, which may be of substantial importance as metronidazole is widely used in human medicine. PMID:26776047

  20. The Undernourished Neonatal Mouse Metabolome Reveals Evidence of Liver and Biliary Dysfunction, Inflammation, and Oxidative Stress123

    PubMed Central

    Preidis, Geoffrey A.; Keaton, Mignon A.; Campeau, Philippe M.; Bessard, Brooke C.; Conner, Margaret E.; Hotez, Peter J.

    2014-01-01

    Undernutrition contributes to half of all childhood deaths under the age of 5 y, and confers upon survivors a life-long predisposition to obesity, type 2 diabetes, and cardiovascular disease. Mechanisms underlying the link between early nutrient deprivation and noncommunicable diseases are unknown. Using outbred CD1 neonatal mice, we measured metabolic profile differences between conventionally reared mice given unrestricted access to nursing, the control group, and undernourished mice subjected to protein-calorie deprivation through timed separation from lactating mothers. After 11 d of undernutrition, urine, plasma, liver, ileal fluid, cecal fluid, and stool were harvested from 8 pools of 4 neonatal mice per group. The metabolome was identified using a multiplatform mass spectrometry-based approach, and random forest metrics were used to identify the most important metabolites that distinguished the undernourished from the control group. Our data reveal striking metabolic changes in undernourished mice consistent with the known mammalian response to starvation, including evidence of muscle and fat catabolism and increased reliance on the tricarboxylic acid cycle for energy. However, we also revealed evidence of liver and biliary injury, anomalies in bile acid metabolism, oxidative stress and inflammation, accelerated heme breakdown, and altered regulation of DNA methylation. Among the metabolites that most strongly distinguished the 2 groups were 2-hydroxyisobutyrate, increased 3-fold in plasma of undernourished mice (P = 2.19 × 10−11); urobilinogen, increased 11-fold in urine of undernourished mice (P = 4.22 × 10−7); deoxycholate, decreased 94% in stool of undernourished mice (P = 3.0 × 10−4); and 12 different products of the enzyme γ-glutamyltransferase, increased in all 6 compartments of undernourished mice. This model of the undernourished neonatal metabolome illustrates the wide range of pathways disrupted by undernutrition in early development

  1. In-Depth Investigation of Archival and Prospectively Collected Samples Reveals No Evidence for XMRV Infection in Prostate Cancer

    PubMed Central

    Lee, Deanna; Das Gupta, Jaydip; Gaughan, Christina; Steffen, Imke; Tang, Ning; Luk, Ka-Cheung; Qiu, Xiaoxing; Urisman, Anatoly; Fischer, Nicole; Molinaro, Ross; Broz, Miranda; Schochetman, Gerald; Klein, Eric A.; Ganem, Don; DeRisi, Joseph L.; Simmons, Graham; Hackett, John; Silverman, Robert H.; Chiu, Charles Y.

    2012-01-01

    XMRV, or xenotropic murine leukemia virus (MLV)-related virus, is a novel gammaretrovirus originally identified in studies that analyzed tissue from prostate cancer patients in 2006 and blood from patients with chronic fatigue syndrome (CFS) in 2009. However, a large number of subsequent studies failed to confirm a link between XMRV infection and CFS or prostate cancer. On the contrary, recent evidence indicates that XMRV is a contaminant originating from the recombination of two mouse endogenous retroviruses during passaging of a prostate tumor xenograft (CWR22) in mice, generating laboratory-derived cell lines that are XMRV-infected. To confirm or refute an association between XMRV and prostate cancer, we analyzed prostate cancer tissues and plasma from a prospectively collected cohort of 39 patients as well as archival RNA and prostate tissue from the original 2006 study. Despite comprehensive microarray, PCR, FISH, and serological testing, XMRV was not detected in any of the newly collected samples or in archival tissue, although archival RNA remained XMRV-positive. Notably, archival VP62 prostate tissue, from which the prototype XMRV strain was derived, tested negative for XMRV on re-analysis. Analysis of viral genomic and human mitochondrial sequences revealed that all previously characterized XMRV strains are identical and that the archival RNA had been contaminated by an XMRV-infected laboratory cell line. These findings reveal no association between XMRV and prostate cancer, and underscore the conclusion that XMRV is not a naturally acquired human infection. PMID:23028701

  2. 16S rRNA survey revealed complex bacterial communities and evidence of bacterial interference on human adenoids.

    PubMed

    Ren, Tiantian; Glatt, Dominique Ulrike; Nguyen, Tam Nhu; Allen, Emma Kaitlynn; Early, Stephen V; Sale, Michele; Winther, Birgit; Wu, Martin

    2013-02-01

    Adenoid microbiota plays an important role in the development of various infectious and non-infectious diseases of the upper airways, such as otitis media, adenotonsillitis, rhinosinusitis and adenoid hypertrophy. Studies have suggested that adenoids could act as a potential reservoir of opportunistic pathogens. However, previous bacterial surveys of adenoids were mainly culture based and therefore might only provide an incomplete and potentially biased assessment of the microbial diversity. To develop an in-depth and comprehensive understanding of the adenoid microbial communities and test the 'pathogen reservoir hypothesis', we carried out a 16S rRNA based, culture-independent survey of bacterial communities on 67 human adenoids removed by surgery. Our survey revealed highly diverse adenoid bacterial communities distinct from those of other body habitats. Despite large interpersonal variations, adenoid microbiota shared a core set of taxa and can be classified into at least five major types based on its bacterial species composition. Our results support the 'pathogen reservoir hypothesis' as we found common pathogens of otitis media to be both prevalent and abundant. Co-occurrence analyses revealed evidence consistent with the bacterial interference theory in that multiple common pathogens showed 'non-coexistence' relationships with non-pathogenic members of the commensal microflora. PMID:23113966

  3. Differential regulation of grain sucrose accumulation and metabolism in Coffea arabica (Arabica) and Coffea canephora (Robusta) revealed through gene expression and enzyme activity analysis.

    PubMed

    Privat, Isabelle; Foucrier, Séverine; Prins, Anneke; Epalle, Thibaut; Eychenne, Magali; Kandalaft, Laurianne; Caillet, Victoria; Lin, Chenwei; Tanksley, Steve; Foyer, Christine; McCarthy, James

    2008-01-01

    * Coffea arabica (Arabica) and Coffea canephora (Robusta) are the two main cultivated species used for coffee bean production. Arabica genotypes generally produce a higher coffee quality than Robusta genotypes. Understanding the genetic basis for sucrose accumulation during coffee grain maturation is an important goal because sucrose is an important coffee flavor precursor. * Nine new Coffea genes encoding sucrose metabolism enzymes have been identified: sucrose phosphate synthase (CcSPS1, CcSPS2), sucrose phosphate phosphatase (CcSP1), cytoplasmic (CaInv3) and cell wall (CcInv4) invertases and four invertase inhibitors (CcInvI1, 2, 3, 4). * Activities and mRNA abundance of the sucrose metabolism enzymes were compared at different developmental stages in Arabica and Robusta grains, characterized by different sucrose contents in mature grain. * It is concluded that Robusta accumulates less sucrose than Arabica for two reasons: Robusta has higher sucrose synthase and acid invertase activities early in grain development - the expression of CcSS1 and CcInv2 appears to be crucial at this stage and Robusta has a lower SPS activity and low CcSPS1 expression at the final stages of grain development and hence has less capacity for sucrose re-synthesis. Regulation of vacuolar invertase CcInv2 activity by invertase inhibitors CcInvI2 and/or CcInvI3 during Arabica grain development is considered. PMID:18384509

  4. Genetic evidence for a role of BiP/Kar2 that regulates Ire1 in response to accumulation of unfolded proteins.

    PubMed

    Kimata, Yukio; Kimata, Yuki I; Shimizu, Yusuke; Abe, Hiroshi; Farcasanu, Ileana C; Takeuchi, Masato; Rose, Mark D; Kohno, Kenji

    2003-06-01

    In the unfolded protein response (UPR) signaling pathway, accumulation of unfolded proteins in the endoplasmic reticulum (ER) activates a transmembrane kinase/ribonuclease Ire1, which causes the transcriptional induction of ER-resident chaperones, including BiP/Kar2. It was previously hypothesized that BiP/Kar2 plays a direct role in the signaling mechanism. In this model, association of BiP/Kar2 with Ire1 represses the UPR pathway while under conditions of ER stress, BiP/Kar2 dissociation leads to activation. To test this model, we analyzed five temperature-sensitive alleles of the yeast KAR2 gene. When cells carrying a mutation in the Kar2 substrate-binding domain were incubated at the restrictive temperature, association of Kar2 to Ire1 was disrupted, and the UPR pathway was activated even in the absence of extrinsic ER stress. Conversely, cells carrying a mutation in the Kar2 ATPase domain, in which Kar2 poorly dissociated from Ire1 even in the presence of tunicamycin, a potent inducer of ER stress, were unable to activate the pathway. Our findings provide strong evidence in support of BiP/Kar2-dependent Ire1 regulation model and suggest that Ire1 associates with Kar2 as a chaperone substrate. We speculate that recognition of unfolded proteins is based on their competition with Ire1 for binding with BiP/Kar2. PMID:12808051

  5. Genetic Evidence for a Role of BiP/Kar2 That Regulates Ire1 in Response to Accumulation of Unfolded Proteins

    PubMed Central

    Kimata, Yukio; Kimata, Yuki I.; Shimizu, Yusuke; Abe, Hiroshi; Farcasanu, Ileana C.; Takeuchi, Masato; Rose, Mark D.; Kohno, Kenji

    2003-01-01

    In the unfolded protein response (UPR) signaling pathway, accumulation of unfolded proteins in the endoplasmic reticulum (ER) activates a transmembrane kinase/ribonuclease Ire1, which causes the transcriptional induction of ER-resident chaperones, including BiP/Kar2. It was previously hypothesized that BiP/Kar2 plays a direct role in the signaling mechanism. In this model, association of BiP/Kar2 with Ire1 represses the UPR pathway while under conditions of ER stress, BiP/Kar2 dissociation leads to activation. To test this model, we analyzed five temperature-sensitive alleles of the yeast KAR2 gene. When cells carrying a mutation in the Kar2 substrate-binding domain were incubated at the restrictive temperature, association of Kar2 to Ire1 was disrupted, and the UPR pathway was activated even in the absence of extrinsic ER stress. Conversely, cells carrying a mutation in the Kar2 ATPase domain, in which Kar2 poorly dissociated from Ire1 even in the presence of tunicamycin, a potent inducer of ER stress, were unable to activate the pathway. Our findings provide strong evidence in support of BiP/Kar2-dependent Ire1 regulation model and suggest that Ire1 associates with Kar2 as a chaperone substrate. We speculate that recognition of unfolded proteins is based on their competition with Ire1 for binding with BiP/Kar2. PMID:12808051

  6. Uranium Bio-accumulation and Cycling as revealed by Uranium Isotopes in Naturally Reduced Sediments from the Upper Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Lefebvre, Pierre; Noël, Vincent; Jemison, Noah; Weaver, Karrie; Bargar, John; Maher, Kate

    2016-04-01

    Uranium (U) groundwater contamination following oxidized U(VI) releases from weathering of mine tailings is a major concern at numerous sites across the Upper Colorado River Basin (CRB), USA. Uranium(IV)-bearing solids accumulated within naturally reduced zones (NRZs) characterized by elevated organic carbon and iron sulfide compounds. Subsequent re-oxidation of U(IV)solid to U(VI)aqueous then controls the release to groundwater and surface water, resulting in plume persistence and raising public health concerns. Thus, understanding the extent of uranium oxidation and reduction within NRZs is critical for assessing the persistence of the groundwater contamination. In this study, we measured solid-phase uranium isotope fractionation (δ238/235U) of sedimentary core samples from four study sites (Shiprock, NM, Grand Junction, Rifle and Naturita, CO) using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). We observe a strong correlation between U accumulation and the extent of isotopic fractionation, with Δ238U up to +1.8 ‰ between uranium-enriched and low concentration zones. The enrichment in the heavy isotopes within the NRZs appears to be especially important in the vadose zone, which is subject to variations in water table depth. According to previous studies, this isotopic signature is consistent with biotic reduction processes associated with metal-reducing bacteria. Positive correlations between the amount of iron sulfides and the accumulation of reduced uranium underline the importance of sulfate-reducing conditions for U(IV) retention. Furthermore, the positive fractionation associated with U reduction observed across all sites despite some variations in magnitude due to site characteristics, shows a regional trend across the Colorado River Basin. The maximum extent of 238U enrichment observed in the NRZ proximal to the water table further suggests that the redox cycling of uranium, with net release of U(VI) to the groundwater by

  7. Chloride accumulation in the soil and groundwater under a downslope oak hedge reveals the impressive evapotranspiration of wooded linear structures below a temperate climate

    NASA Astrophysics Data System (ADS)

    Grimaldi, C.; Thomas, Z.; Merot, Ph.

    2009-04-01

    Although it is an essential element in plants, Cl- is excluded to a large extent by roots during absorption of water and nutrients, and its concentration rises as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for hedgerow trees. This article deals with the influence of a tree hedge on the soil and groundwater Cl- concentrations and with the possibility to use Cl- as an indicator of transpiration and water movements in the hedge vicinity. Cl- concentrations were measured over one year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge in the North-West of France, under an oceanic wet temperate climate. We observed a strong spatial variation of Cl- concentrations, with very high values up to 2 g L-1 in the unsaturated zone and 1.2 g L-1 in the upper part of the groundwater. These concentrations contrasted with the low values measured in the unsaturated zone far from the hedge (10 mg L-1) and in the deepest part of the groundwater (60-70 mg L-1). Cl- accumulation in the unsaturated zone at the end of the growing season allowed us to identify the active root zone extension of trees. The root zone begins at the surface under the hedge and widens out at depth at an increasing distance from the hedge, extending laterally on at least 10 m on both sides of the hedge. While the root zone is deeper at the upslope side of the hedge, it is nearer the ground surface downslope, where the development of roots is limited by the water-table close to the surface. Cl- concentrations varied along the year. In winter, upslope of the hedge, downwards leaching partly renewed the soil solution, while under the hedge or farther downslope the lack of any significant water movement resulted in Cl- accumulation. For a bottomland hedge, the proximity of the water-table probably increases the water availability of water for tree transpiration. The measurement of Cl

  8. A zebrafish model of PMM2-CDG reveals altered neurogenesis and a substrate-accumulation mechanism for N-linked glycosylation deficiency

    PubMed Central

    Cline, Abigail; Gao, Ningguo; Flanagan-Steet, Heather; Sharma, Vandana; Rosa, Sabrina; Sonon, Roberto; Azadi, Parastoo; Sadler, Kirsten C.; Freeze, Hudson H.; Lehrman, Mark A.; Steet, Richard

    2012-01-01

    Congenital disorder of glycosylation (PMM2-CDG) results from mutations in pmm2, which encodes the phosphomannomutase (Pmm) that converts mannose-6-phosphate (M6P) to mannose-1-phosphate (M1P). Patients have wide-spectrum clinical abnormalities associated with impaired protein N-glycosylation. Although it has been widely proposed that Pmm2 deficiency depletes M1P, a precursor of GDP-mannose, and consequently suppresses lipid-linked oligosaccharide (LLO) levels needed for N-glycosylation, these deficiencies have not been demonstrated in patients or any animal model. Here we report a morpholino-based PMM2-CDG model in zebrafish. Morphant embryos had developmental abnormalities consistent with PMM2-CDG patients, including craniofacial defects and impaired motility associated with altered motor neurogenesis within the spinal cord. Significantly, global N-linked glycosylation and LLO levels were reduced in pmm2 morphants. Although M1P and GDP-mannose were below reliable detection/quantification limits, Pmm2 depletion unexpectedly caused accumulation of M6P, shown earlier to promote LLO cleavage in vitro. In pmm2 morphants, the free glycan by-products of LLO cleavage increased nearly twofold. Suppression of the M6P-synthesizing enzyme mannose phosphate isomerase within the pmm2 background normalized M6P levels and certain aspects of the craniofacial phenotype and abrogated pmm2-dependent LLO cleavage. In summary, we report the first zebrafish model of PMM2-CDG and uncover novel cellular insights not possible with other systems, including an M6P accumulation mechanism for underglycosylation. PMID:22956764

  9. Comparative Analyses of Three Chlorella Species in Response to Light and Sugar Reveal Distinctive Lipid Accumulation Patterns in the Microalga C. sorokiniana

    PubMed Central

    Barnes, Austin; Noel, Eric A.; Betenbaugh, Michael J.; Oyler, George A.

    2014-01-01

    While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG) lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold's basal medium (BBM) and heterotrophy in BBM supplemented with glucose (10 g L−1). Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18∶1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18∶2 relative to 18∶1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L−1 d−1 to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L−1 d−1. This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis. PMID:24699196

  10. Comparative analyses of three Chlorella species in response to light and sugar reveal distinctive lipid accumulation patterns in the Microalga C. sorokiniana.

    PubMed

    Rosenberg, Julian N; Kobayashi, Naoko; Barnes, Austin; Noel, Eric A; Betenbaugh, Michael J; Oyler, George A

    2014-01-01

    While photosynthetic microalgae, such as Chlorella, serve as feedstocks for nutritional oils and biofuels, heterotrophic cultivation can augment growth rates, support high cell densities, and increase triacylglycerol (TAG) lipid content. However, these species differ significantly in their photoautotrophic and heterotrophic characteristics. In this study, the phylogeny of thirty Chlorella strains was determined in order to inform bioprospecting efforts and detailed physiological assessment of three species. The growth kinetics and lipid biochemistry of C. protothecoides UTEX 411, C. vulgaris UTEX 265, and C. sorokiniana UTEX 1230 were quantified during photoautotrophy in Bold's basal medium (BBM) and heterotrophy in BBM supplemented with glucose (10 g L-1). Heterotrophic growth rates of UTEX 411, 265, and 1230 were found to be 1.5-, 3.7-, and 5-fold higher than their respective autotrophic rates. With a rapid nine-hour heterotrophic doubling time, Chlorella sorokiniana UTEX 1230 maximally accumulated 39% total lipids by dry weight during heterotrophy compared to 18% autotrophically. Furthermore, the discrete fatty acid composition of each strain was examined in order to elucidate lipid accumulation patterns under the two trophic conditions. In both modes of growth, UTEX 411 and 265 produced 18:1 as the principal fatty acid while UTEX 1230 exhibited a 2.5-fold enrichment in 18:2 relative to 18:1. Although the total lipid content was highest in UTEX 411 during heterotrophy, UTEX 1230 demonstrated a two-fold increase in its heterotrophic TAG fraction at a rate of 28.9 mg L(-1) d(-1) to reach 22% of the biomass, corresponding to as much as 90% of its total lipids. Interestingly, UTEX 1230 growth was restricted during mixotrophy and its TAG production rate was suppressed to 18.2 mg L-1 d-1. This constraint on carbon flow raises intriguing questions about the impact of sugar and light on the metabolic regulation of microalgal lipid biosynthesis. PMID:24699196

  11. Geomodel constructs of the Earth's crust for water continuation of the Korotaikha depression from gravity and magnetic data for revealing promising areas of oil and gas accumulation

    NASA Astrophysics Data System (ADS)

    Litvinova, Tamara; Kudryavtsev, Ivan

    2016-04-01

    The paper considers the results of re-interpretation of geophysical data within the water continuation of the Korotaikha depression. To solve the issue of identifying promising areas of oil and gas accumulation in the region, magnetic and gravity materials were reprocessed: digital maps of potential fields at 1: 500 000 scale were compiled on a frame network of seismic lines (3 lines on land and 3 lines in water area) made by reflection-CDP, density models to a depth of 20 km by solving the direct problem of gravity prospecting in GM-SYS module (Geosoft) in 2D formulation were constructed. Deep reflection-CDP seismic sections specified according to the deep wells were used as starting models. Correctness of the selected density models was controlled by comparing the theoretical curve with the values interpolated on the profile line from the digital model of gravity anomaly (Bouguer, density of the intermediate layer of 2.67 g/cm3). Magnetic modeling was performed using geometry of blocks from the obtained density models to a depth of 20 km and is based on selection of local anomaly sources in the upper section (in the Triassic strata). Blocks of the Precambrian basement were used as sources of regional magnetic anomalies in the considered models. Modeling constructs show the defining role of the topography of terrigenous and carbonate complex boundary within the Paleozoic section as a source of gravity anomalies for the region under study. These findings are confirmed by comparison of gravity and seismic data (maps of local gravity anomalies and structural maps of reflecting horizons) and additionally substantiated by analysis of the nature of local magnetic anomalies distribution. The latter are associated with the Triassic basalt horizons at the top of the terrigenous complex and thus also reflect structures of the sedimentary cover, which are registered independently by gravity data.

  12. Experimental and observational evidence reveals that predators in natural environments do not regulate their prey: They are passengers, not drivers

    NASA Astrophysics Data System (ADS)

    White, T. C. R.

    2013-11-01

    Among both ecologists and the wider community there is a tacit assumption that predators regulate populations of their prey. But there is evidence from a wide taxonomic and geographic range of studies that predators that are adapted to co-evolved prey generally do not regulate their prey. This is because predators either cannot reproduce as fast as their prey and/or are inefficient hunters unable to catch enough prey to sustain maximum reproduction. The greater capacity of herbivores to breed successfully is, however, normally restricted by a lack of enough food of sufficient quality to support reproduction. But whenever this shortage is alleviated by a large pulse of food, herbivores increase their numbers to outbreak levels. Their predators are unable to contain this increase, but their numbers, too, surge in response to this increase in food. Eventually both their populations will crash once the food supply runs out, first for the herbivores and then for the predators. Then an “over-run” of predators will further depress the already declining prey population, appearing to be controlling its abundance. This latter phenomenon has led many ecologists to conclude that predators are regulating the numbers of their prey. However, it is the same process that is revealed during outbreaks that limits populations of both predator and prey in “normal” times, although this is usually not readily apparent. Nevertheless, as all the diverse cases discussed here attest, the abundance of predators and their co-evolved prey are both limited by their food: the predators are passengers, not drivers.

  13. Argon, oxygen, and boron isotopic evidence documenting 40ArE accumulation in phengite during water-rich high-pressure subduction metasomatism of continental crust

    NASA Astrophysics Data System (ADS)

    Menold, Carrie A.; Grove, Marty; Sievers, Natalie E.; Manning, Craig E.; Yin, An; Young, Edward D.; Ziegler, Karen

    2016-07-01

    The Luliang Shan area of the North Qaidam high pressure (HP) to ultrahigh pressure (UHP) metamorphic terrane in northwestern China features thick, garnet- and phengite-rich metasomatic selvages that formed around gneiss-hosted mafic eclogite blocks during HP conditions. Here we present new 40Ar/39Ar, δ18 O, and δ11 B results from a previously studied 30 m, 18 sample traverse that extends from the host gneiss into a representative eclogite block. Previous thermobarometry and new mica-quartz oxygen isotope thermometry from the traverse reveal that the phengite-rich selvage formed at temperatures similar to those recorded by the eclogites at peak pressure. Quartz and white mica δ18 O data from the selvage cannot be explained by simple mixing of gneiss and eclogite, and indicate a fluid/rock ratio >1 during regional-scale infiltration of high δ18 O (ca. 14‰) fluids. Heavy δ18 O overgrowths of metamorphic zircon over lighter δ18 O detrital grains indicate that the gneiss was similarly affected. Starkly contrasting boron content and δ11 B compositions for the host gneiss and the selvage also cannot be explained by local-scale devolatilization of the gneiss to form the selvage. Instead, the boron systematics are best attributed to two distinct phases of fluid infiltration: (1) low-boron selvage phengite with δ11 B from -10 to -30‰ grew under HP conditions; and (2) tourmaline and boron-rich muscovite with generally positive δ11 B crystallized in the host gneiss under subsequent lower pressure epidote-amphibolite facies conditions as the Luliang Shan gneiss terrane was exhumed past shallower portions of the subduction channel. Consistent with observations made worldwide, we were able to identify uptake of excess argon (40ArE) in phengite as a high pressure phenomenon. Phengite 40Ar/39Ar ages from massive eclogite exceed the ca. 490 Ma zircon U-Pb age of eclogite metamorphism by a factor of 1.5. However, phengite ages from the more permeable schistose selvage

  14. Genetic evidence for gonochoristic reproduction in gynogenetic silver crucian carp (Carassius auratus gibelio bloch) as revealed by RAPD assays.

    PubMed

    Zhou, L; Wang, Y; Gui, J F

    2000-11-01

    Sex evolution has been a debating focus in evolutionary genetics. In lower vertebrates of reptiles, amphibians, and fish, a species or a bioform reproduces either sexually or asexually but never both. A few species were found to consist of all females in fish. These all-female species can propagate by asexual reproduction modes, such as gynogenesis and hybridogenesis. However, the coexistence of sexuality and asexuality in a single species was recently noted only in a cyprinid fish silver crucian carp, Carassius auratus gibelio. This fish had been demonstrated to be capable of gynogenesis stimulated by sperm from other related species. Surprisingly, natural populations of this fish consist of a minor but significant portion (approx. 20%) of males. As different clones with specific phenotypic and genetic characteristics have been found, and RAPD markers specific to each clone have recently been identified, this fish offers many advantages for analyzing whether or not genetic recombination occurs between different clones. In this study, artificial propagation was performed in clone F and clone D. Ovulated eggs from clone F were divided into two parts and respectively inseminated with sperm from a clone D male and from a red common carp (Cyprinus carpio) male. The control clone D individuals were selected from gynogenetic offspring of clone D activated by sperm of red common carp. The phenotype and sex ratio in the experimental groups were also observed. Using RAPD molecular markers, which allow for reliable discrimination and genetic analysis of different clones, we have revealed direct molecular evidence for gonochoristic reproduction in the gynogenetic silver crucian carp and confirmed a previous hypothesis that the silver crucian carp might reproduce both gynogenetically and gonochoristically. Therefore, we conclude that the silver crucian carp possesses two reproductive modes, i.e., gynogenetic and gonochoristic reproduction. The response mechanism of two

  15. Deep-sea ash layers reveal evidence of large Pleistocene and Holocene volcanic eruptions from Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Salisbury, M. J.; Kent, A.; Patton, J. R.; Goldfinger, C.; Surachman, Y.; Udrekh, U.

    2010-12-01

    At least six undocumented, latest Pleistocene to Holocene volcanic eruptions have been identified through geochemical and textural analysis of glass shards from twenty volcanic tephra layers sampled from deep-sea cores collected along the Sunda trench and accretionary prism piggy-back slope basins, ~ 200 - 300 km west of the Sumatran volcanic arc. The tephra layers were sampled from depths ranging from 15 to 486 cm within 12 deep-sea cores collected from 3.3°N to 4.6°S at water depths between 1.8 and 5.5 km. The tephra layers range from a few mm to 8 cm and are variably distorted by bioturbation. Glass shards within the tephra are relatively small (<150 µm), commonly pumiceous, and show little evidence for significant chemical, post-depositional alteration. Major and trace element compositions of glass shards, analyzed using electron microprobe and LA-ICP-MS at Oregon State University, reveal six unique geochemical signatures. We interpret these as distinct volcanic eruptive units, with compositions ranging from andesite to rhyolite. The most widespread unit is rhyodacitic and correlates among six cores from 0.8 to 1.7°S along the Sunda trench, at a distance of ~300-340 km due west of the active Marapi volcano. The unit is at least 8 cm thick in the most near-shore core, and 1 to 4 cm in the more distal cores. Radiocarbon age determinations of foraminifera constrain the deposition of this unit to ~4,800 cal yrs BP. Ages for thinner units are constrained at ~1,900, ~5,600, ~13,600, and ~24,000 cal yrs BP. Although limited data points preclude the creation of accurate isopach maps, layer thickness and distances to the nearest volcanoes suggest minimum eruptive volumes in excess of 1 km3 (VEI = 5). We have yet to find a close geochemical match with any on-land volcanic deposits, although due to proximity and high productivity, the little-studied Sumatran arc is the most likely source of these tephra layers. This study highlights the potential hazards of explosive

  16. Decolonizing the Evidence-Based Education and Policy Movement: Revealing the Colonial Vestiges in Educational Policy, Research, and Neoliberal Reform

    ERIC Educational Resources Information Center

    Shahjahan, Riyad Ahmed

    2011-01-01

    There is a growing body of literature discussing evidence-based education, practice, policy, and decision-making from a critical perspective. In this article, drawing on the literature and policy documents related to evidence-based education in the USA, Britain, and Canada, I join this critique and offer an anticolonial perspective. I argue that…

  17. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  18. 3D Visualization of the Temporal and Spatial Spread of Tau Pathology Reveals Extensive Sites of Tau Accumulation Associated with Neuronal Loss and Recognition Memory Deficit in Aged Tau Transgenic Mice

    PubMed Central

    Fu, Hongjun; Hussaini, S. Abid; Wegmann, Susanne; Profaci, Caterina; Daniels, Jacob D.; Herman, Mathieu; Emrani, Sheina; Figueroa, Helen Y.; Hyman, Bradley T.; Davies, Peter; Duff, Karen E.

    2016-01-01

    3D volume imaging using iDISCO+ was applied to observe the spatial and temporal progression of tau pathology in deep structures of the brain of a mouse model that recapitulates the earliest stages of Alzheimer’s disease (AD). Tau pathology was compared at four timepoints, up to 34 months as it spread through the hippocampal formation and out into the neocortex along an anatomically connected route. Tau pathology was associated with significant gliosis. No evidence for uptake and accumulation of tau by glia was observed. Neuronal cells did appear to have internalized tau, including in extrahippocampal areas as a small proportion of cells that had accumulated human tau protein did not express detectible levels of human tau mRNA. At the oldest timepoint, mature tau pathology in the entorhinal cortex (EC) was associated with significant cell loss. As in human AD, mature tau pathology in the EC and the presence of tau pathology in the neocortex correlated with cognitive impairment. 3D volume imaging is an ideal technique to easily monitor the spread of pathology over time in models of disease progression. PMID:27466814

  19. 3D Visualization of the Temporal and Spatial Spread of Tau Pathology Reveals Extensive Sites of Tau Accumulation Associated with Neuronal Loss and Recognition Memory Deficit in Aged Tau Transgenic Mice.

    PubMed

    Fu, Hongjun; Hussaini, S Abid; Wegmann, Susanne; Profaci, Caterina; Daniels, Jacob D; Herman, Mathieu; Emrani, Sheina; Figueroa, Helen Y; Hyman, Bradley T; Davies, Peter; Duff, Karen E

    2016-01-01

    3D volume imaging using iDISCO+ was applied to observe the spatial and temporal progression of tau pathology in deep structures of the brain of a mouse model that recapitulates the earliest stages of Alzheimer's disease (AD). Tau pathology was compared at four timepoints, up to 34 months as it spread through the hippocampal formation and out into the neocortex along an anatomically connected route. Tau pathology was associated with significant gliosis. No evidence for uptake and accumulation of tau by glia was observed. Neuronal cells did appear to have internalized tau, including in extrahippocampal areas as a small proportion of cells that had accumulated human tau protein did not express detectible levels of human tau mRNA. At the oldest timepoint, mature tau pathology in the entorhinal cortex (EC) was associated with significant cell loss. As in human AD, mature tau pathology in the EC and the presence of tau pathology in the neocortex correlated with cognitive impairment. 3D volume imaging is an ideal technique to easily monitor the spread of pathology over time in models of disease progression. PMID:27466814

  20. The RAMESSES experiment-II. Evidence for accumulated melt beneath a slow spreading ridge from wide-angle refraction and multichannel reflection seismic profiles

    NASA Astrophysics Data System (ADS)

    Navin, D. A.; Peirce, C.; Sinha, M. C.

    1998-12-01

    The RAMESSES study (Reykjanes Axial Melt Experiment: Structural Synthesis from Electromagnetics and Seismics) targeted an apparently magmatically active axial volcanic ridge (AVR), centred on 57°45'N at the Reykjanes Ridge, with the aim of investigating the processes of crustal accretion at a slow spreading mid-ocean ridge. As part of this multicomponent experiment, airgun and explosive wide-angle seismic data were recorded by 10 digital ocean-bottom seismometers (OBSs) along profiles oriented both across- and along-axis. Coincident normal-incidence seismic, bathymetry and underway gravity and magnetic data were also collected. Forward modelling of the seismic and gravity data has revealed layer thicknesses, velocities and densities similar to those observed elsewhere within the oceanic crust near mid-ocean ridges. At 57°45'N, the Reykjanes Ridge has a crustal thickness of approximately 7.5 km on-axis. However, the crust is modelled to decrease in thickness slightly off-axis (i.e. with age), which implies that full crustal thickness is achieved on-axis and that it is subsequently thinned, most likely, by off-axis extension. Modelling also indicates that the AVR is underlain by a thin (~100 m), narrow (~4 km) melt lens some 2.5 km beneath the seafloor, which overlies a broader zone of partial melt approximately 8 km in width. Thus the results of this study provide the first clear evidence for a crustal magma chamber beneath any slow spreading ridge. The size and depth of this magma chamber (the melt lens and underlying zone of partial melt) are similar to those observed beneath fast and intermediate spreading ridges, which implies that the processes of crustal accretion are similar at all spreading rates. Hence the lack of previous observations of magma chambers beneath slow spreading ridges is probably temporally related to the periods of magmatic activity being considerably shorter and more widely spaced in time than at fast and intermediate spreading ridges.

  1. Acceleration of large active earthflows triggered by massive snow accumulation events: evidences from monitoring the Corvara landslide in early 2014 (Dolomites, Italy)

    NASA Astrophysics Data System (ADS)

    Corsini, Alessandro; Mulas, Marco; Marcato, Gianluca; Chinellato, Giulia; Mair, Volkmar

    2015-04-01

    In the Dolomites of Italy, snowfall during winter 2013/2014 was exceptionally abundant. Major snowfall events occurred from late December 2013 to mid-March 2014. Snow accumulation in Badia Valley peaked in early February: from 2 to 4 meters with a positive gradient respect to altimetry and accordingly to wind accumulation zones. Below 2000 m asl, due to the mild temperatures recorded before the onset of snowfall, the relatively dry snow cover was mostly deposited on top of unfrozen soils. The Corvara landslide is a large active earthflow located close to Corvara in Badia, at an elevation from 2000 to 1600 m. It's displacement rate before, during and after the exceptional snowfall period was monitored at high temporal frequency. Surface displacement was measured bi-weekly by differential GPS in several benchmarks in the source, track and accumulation zone. Deep displacement was monitored semi-continuously by two in-place inclinometers at 48 m depth in the accumulation zone, across the main deep-seated sliding surface. Results show an acceleration of movements, both at surface and at depth, soon after the massive snow accumulation event of 31st January to 2nd February 2014, which suddenly increased snow thickness from 1 to more than 2 metres. Short time lags between the onset of the acceleration of movements in the source, the track and the accumulation zones were also recorded. The landslide then maintained a relatively constant velocity during the high snow cover period extended to earlyApril and underwent a progressive deceleration during the snowmelt period that lasted until mid-June. The fact that the acceleration of the Corvara earthflow was triggered by a massive and rapid snow accumulation event, provides a quite different perspective from the generally adopted one that considers the destabilizing effect of snow only in relation to the increase of groundwater level during rapid snowmelt. A full explanation of the processes associated to the dynamics observed

  2. Do Child Development Accounts Promote Account Holding, Saving, and Asset Accumulation for Children's Future? Evidence from a Statewide Randomized Experiment

    ERIC Educational Resources Information Center

    Nam, Yunju; Kim, Youngmi; Clancy, Margaret; Zager, Robert; Sherraden, Michael

    2013-01-01

    This study examines the impacts of Child Development Accounts (CDAs) on account holding, saving, and asset accumulation for children, using data from the SEED for Oklahoma Kids experiment (SEED OK). SEED OK, a policy test of universal and progressive CDAs, provides a 529 college savings plan account to every infant in the treatment group with…

  3. Ground penetrating radar (GPR) evidence for variations in free phase carbon gas accumulation as a function of peatland landforms: a comparison between near-crest bogs and mid-slope lawns

    NASA Astrophysics Data System (ADS)

    Parsekian, A.; Slater, L.; Comas, X.; Nolan, J.; Glaser, P.

    2009-05-01

    Northern peatlands serve as atmospheric sources of biogenic free-phase gas (FPG) produced under anaerobic conditions below the water table (mostly methane and carbon dioxide). Recent evidence suggest that FPG accumulates in the subsurface under confining layers and is released during sudden ebullition events, often triggered by sudden drops in atmospheric pressure. Accurate quantification of the impact of FPG releases on the global carbon budget is needed given recent observations of increasing atmospheric methane concentrations. One important step towards understanding the dynamics of FPG in peatlands is to investigate whether certain peatland landforms (i.e. areas with significantly different vegetation patterns) may be more conducive to FPG accumulation and/or release. Additionally, it is important to determine the vertical distribution of FPG within the peat soil and the potential role of peat stratigraphy on gas accumulation and release. In this study, we used common mid-point (CMP) velocity surveys to predict vertical profiles of FPG accumulations by comparing two different peatland landforms: historically forested near-crest bogs and non- forested mid-slope lawns in the Glacial Lake Agassiz Peatland of Minnesota, USA. We show that there is a statistically significant difference in electromagnetic (EM) wave velocities calculated over gas-rich intervals in the peat strata compared to gas-poor intervals. Common-offset radar profiles identified laterally continuous woody confining layers responsible for FPG accumulation. Chaotic GPR facies containing diffraction hyperbolae at the forested near-crest sites are interpreted as deformation of the peat matrix due to FPG accumulation and/or peat fabric disturbance during FPG release events. In contrast, non-forested mid-slope lawn sites, are characterized by planar GPR facies with no evidence of peat fabric disturbance and small relative changes in interpreted EM velocity distribution along the peat column. Using the

  4. Regulation of myofibrillar accumulation in chick muscle cultures - Evidence for the involvement of calcium and lysosomes in non-uniform turnover of contractile proteins

    NASA Technical Reports Server (NTRS)

    Silver, Geri; Etlinger, Joseph D.

    1985-01-01

    The effects of calcium on the synthesis and the degradation of individual myofibrillar proteins were investigated using primary chick-leg skeletal muscle cultures labeled with S-35-methionine (for protein accumulation experiments) or Ca(2+)-45 (for calcium efflux experiments). It was found that the turnover of individual contractile proteins is regulated nonuniformly by a calcium-dependent mechanism involving lysosomes. The results also indicate that contractile proteins are released from the myofibril before their breakdown to amino acids.

  5. Proton Magnetic Resonance Spectroscopy and MRI Reveal No Evidence for Brain Mitochondrial Dysfunction in Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Corrigan, Neva M.; Shaw, Dennis. W. W.; Richards, Todd L.; Estes, Annette M.; Friedman, Seth D.; Petropoulos, Helen; Artru, Alan A.; Dager, Stephen R.

    2012-01-01

    Brain mitochondrial dysfunction has been proposed as an etiologic factor in autism spectrum disorder (ASD). Proton magnetic resonance spectroscopic imaging ([superscript 1]HMRS) and MRI were used to assess for evidence of brain mitochondrial dysfunction in longitudinal samples of children with ASD or developmental delay (DD), and cross-sectionally…

  6. What Does Children's Spatial Language Reveal about Spatial Concepts? Evidence from the Use of Containment Expressions

    ERIC Educational Resources Information Center

    Johanson, Megan; Papafragou, Anna

    2014-01-01

    Children's overextensions of spatial language are often taken to reveal spatial biases. However, it is unclear whether extension patterns should be attributed to children's overly general spatial concepts or to a narrower notion of conceptual similarity allowing metaphor-like extensions. We describe a previously unnoticed extension of…

  7. Revealing the face of an ancient Egyptian: synthesis of current and traditional approaches to evidence-based facial approximation.

    PubMed

    Lindsay, Kaitlin E; Rühli, Frank J; Deleon, Valerie Burke

    2015-06-01

    The technique of forensic facial approximation, or reconstruction, is one of many facets of the field of mummy studies. Although far from a rigorous scientific technique, evidence-based visualization of antemortem appearance may supplement radiological, chemical, histological, and epidemiological studies of ancient remains. Published guidelines exist for creating facial approximations, but few approximations are published with documentation of the specific process and references used. Additionally, significant new research has taken place in recent years which helps define best practices in the field. This case study records the facial approximation of a 3,000-year-old ancient Egyptian woman using medical imaging data and the digital sculpting program, ZBrush. It represents a synthesis of current published techniques based on the most solid anatomical and/or statistical evidence. Through this study, it was found that although certain improvements have been made in developing repeatable, evidence-based guidelines for facial approximation, there are many proposed methods still awaiting confirmation from comprehensive studies. This study attempts to assist artists, anthropologists, and forensic investigators working in facial approximation by presenting the recommended methods in a chronological and usable format. PMID:25998648

  8. Mercury accumulation in sediment cores from three Washington state lakes: evidence for local deposition from a coal-fired power plant.

    PubMed

    Furl, Chad V; Meredith, Callie A

    2011-01-01

    Mercury accumulation rates measured in age-dated sediment cores were compared at three Washington state lakes. Offutt Lake and Lake St. Clair are located immediately downwind (18 and 28 km, respectively) of a coal-fired power plant and Lake Sammamish is located outside of the immediate area of the plant (110 km). The sites immediately downwind of the power plant were expected to receive increased mercury deposition from particulate and reactive mercury not deposited at Lake Sammamish. Mercury accumulation in cores was corrected for variable sedimentation, background, and sediment focusing to estimate the anthropogenic contribution (Hg(A,F)). Results indicated lakes immediately downwind of the power plant contained elevated Hg(A,F) levels with respect to the reference lake. Estimated fluxes to Lake Sammamish were compared to measured values from a nearby mercury wet deposition collector to gauge the efficacy of the core deconstruction techniques. Total deposition calculated through the sediment core (20.7 μg/m²/year) fell just outside of the upper estimate (18.9 μg/m²/year) of total deposition approximated from the wet deposition collector. PMID:20437040

  9. Evidence of various mechanisms of Cd sequestration in the hyperaccumulator Arabidopsis halleri, the non-accumulator Arabidopsis lyrata, and their progenies by combined synchrotron-based techniques.

    PubMed

    Isaure, Marie-Pierre; Huguet, Stéphanie; Meyer, Claire-Lise; Castillo-Michel, Hiram; Testemale, Denis; Vantelon, Delphine; Saumitou-Laprade, Pierre; Verbruggen, Nathalie; Sarret, Géraldine

    2015-06-01

    Arabidopsis halleri is a model plant for Zn and Cd hyperaccumulation. The objective of this study was to determine the relationship between the chemical forms of Cd, its distribution in leaves, and Cd accumulation and tolerance. An interspecific cross was carried out between A. halleri and the non-tolerant and non-hyperaccumulating relative A. lyrata providing progenies segregating for Cd tolerance and accumulation. Cd speciation and distribution were investigated using X-ray absorption spectroscopy and microfocused X-ray fluorescence. In A. lyrata and non-tolerant progenies, Cd was coordinated by S atoms only or with a small contribution of O groups. Interestingly, the proportion of O ligands increased in A. halleri and tolerant progenies, and they were predominant in most of them, while S ligands were still present. Therefore, the binding of Cd with O ligands was associated with Cd tolerance. In A. halleri, Cd was mainly located in the xylem, phloem, and mesophyll tissue, suggesting a reallocation process for Cd within the plant. The distribution of the metal at the cell level was further discussed. In A. lyrata, the vascular bundles were also Cd enriched, but the epidermis was richer in Cd as compared with the mesophyll. Cd was identified in trichomes of both species. This work demonstrated that both Cd speciation and localization were related to the tolerance character of the plant. PMID:25873676

  10. Partial sequencing reveals the transposable element composition of Coffea genomes and provides evidence for distinct evolutionary stories.

    PubMed

    Guyot, Romain; Darré, Thibaud; Dupeyron, Mathilde; de Kochko, Alexandre; Hamon, Serge; Couturon, Emmanuel; Crouzillat, Dominique; Rigoreau, Michel; Rakotomalala, Jean-Jacques; Raharimalala, Nathalie E; Akaffou, Sélastique Doffou; Hamon, Perla

    2016-10-01

    The Coffea genus, 124 described species, has a natural distribution spreading from inter-tropical Africa, to Western Indian Ocean Islands, India, Asia and up to Australasia. Two cultivated species, C. arabica and C. canephora, are intensively studied while, the breeding potential and the genome composition of all the wild species remained poorly uncharacterized. Here, we report the characterization and comparison of the highly repeated transposable elements content of 11 Coffea species representatives of the natural biogeographic distribution. A total of 994 Mb from 454 reads were produced with a genome coverage ranging between 3.2 and 15.7 %. The analyses showed that highly repeated transposable elements, mainly LTR retrotransposons (LTR-RT), represent between 32 and 53 % of Coffea genomes depending on their biogeographic location and genome size. Species from West and Central Africa (Eucoffea) contained the highest LTR-RT content but with no strong variation relative to their genome size. At the opposite, for the insular species (Mascarocoffea), a strong variation of LTR-RT was observed suggesting differential dynamics of these elements in this group. Two LTR-RT lineages, SIRE and Del were clearly differentially accumulated between African and insular species, suggesting these lineages were associated to the genome divergence of Coffea species in Africa. Altogether, the information obtained in this study improves our knowledge and brings new data on the composition, the evolution and the divergence of wild Coffea genomes. PMID:27469896

  11. Structural Variant Detection by Large-scale Sequencing Reveals New Evolutionary Evidence on Breed Divergence between Chinese and European Pigs

    PubMed Central

    Zhao, Pengju; Li, Junhui; Kang, Huimin; Wang, Haifei; Fan, Ziyao; Yin, Zongjun; Wang, Jiafu; Zhang, Qin; Wang, Zhiquan; Liu, Jian-Feng

    2016-01-01

    In this study, we performed a genome-wide SV detection among the genomes of thirteen pigs from diverse Chinese and European originated breeds by next genetation sequencing, and constrcuted a single-nucleotide resolution map involving 56,930 putative SVs. We firstly identified a SV hotspot spanning 35 Mb region on the X chromosome specifically in the genomes of Chinese originated individuals. Further scrutinizing this region by large-scale sequencing data of extra 111 individuals, we obtained the confirmatory evidence on our initial finding. Moreover, thirty five SV-related genes within the hotspot region, being of importance for reproduction ability, rendered significant different evolution rates between Chinese and European originated breeds. The SV hotspot identified herein offers a novel evidence for assessing phylogenetic relationships, as well as likely explains the genetic difference of corresponding phenotypes and features, among Chinese and European pig breeds. Furthermore, we employed various SVs to infer genetic structure of individuls surveyed. We found SVs can clearly detect the difference of genetic background among individuals. This clues us that genome-wide SVs can capture majority of geneic variation and be applied into cladistic analyses. Characterizing whole genome SVs demonstrated that SVs are significantly enriched/depleted with various genomic features. PMID:26729041

  12. Fine-Scale Genetic Structure and Cryptic Associations Reveal Evidence of Kin-Based Sociality in the African Forest Elephant

    PubMed Central

    Schuttler, Stephanie G.; Philbrick, Jessica A.; Jeffery, Kathryn J.; Eggert, Lori S.

    2014-01-01

    Spatial patterns of relatedness within animal populations are important in the evolution of mating and social systems, and have the potential to reveal information on species that are difficult to observe in the wild. This study examines the fine-scale genetic structure and connectivity of groups within African forest elephants, Loxodonta cyclotis, which are often difficult to observe due to forest habitat. We tested the hypothesis that genetic similarity will decline with increasing geographic distance, as we expect kin to be in closer proximity, using spatial autocorrelation analyses and Tau Kr tests. Associations between individuals were investigated through a non-invasive genetic capture-recapture approach using network models, and were predicted to be more extensive than the small groups found in observational studies, similar to fission-fusion sociality found in African savanna (Loxodonta africana) and Asian (Elephas maximus) species. Dung samples were collected in Lopé National Park, Gabon in 2008 and 2010 and genotyped at 10 microsatellite loci, genetically sexed, and sequenced at the mitochondrial DNA control region. We conducted analyses on samples collected at three different temporal scales: a day, within six-day sampling sessions, and within each year. Spatial autocorrelation and Tau Kr tests revealed genetic structure, but results were weak and inconsistent between sampling sessions. Positive spatial autocorrelation was found in distance classes of 0–5 km, and was strongest for the single day session. Despite weak genetic structure, individuals within groups were significantly more related to each other than to individuals between groups. Social networks revealed some components to have large, extensive groups of up to 22 individuals, and most groups were composed of individuals of the same matriline. Although fine-scale population genetic structure was weak, forest elephants are typically found in groups consisting of kin and based on matrilines

  13. Direct evidence of "damage accumulation" in cement mantles surrounding femoral hip stems retrieved at autopsy: cement damage correlates with duration of use and BMI.

    PubMed

    Race, A; Miller, M A; Izant, T H; Mann, K A

    2011-09-01

    The "damage accumulation" phenomenon has not been quantitatively demonstrated in clinical cement mantles surrounding femoral hip stems. We stained transverse sections of 11 postmortem retrieved femoral hip components fixed with cement using fluorescent dye-penetrant and quantified cement damage, voids, and cement-bone interface gaps in epifluorescence and white light micrographs. Crack density (Cr.Dn), crack length-density (Cr.Ln.Dn), porosity, and cement-bone interface gap fraction (c/b-gap%) were calculated, normalized by mantle area. Multiple regression tests showed that cement damage (Cr.Ln.Dn. & Cr.Dn.) was significantly positively correlated (r(2)=0.98, p<0.001) with "duration of use" and body mass index ("BMI") but not cement mantle "porosity". There were significant interactions: "duration of use"*"BMI" was strongly predictive (p<0.005) of Cr.Dn.; and "duration of use"*"porosity" was predictive (p=0.04) of Cr.Ln.Dn. Stem related cracks accounted for approximately one fifth of Cr.Dn and one third of Cr.Ln.Dn. The mean c/b-gap% was 13.8% but it did not correlate (r(2)=0.01, p=0.8) with duration of use. We concluded that duration-dependent fatigue damage accumulation occurred during in vivo use. BMI strongly influenced cement crack length and the rate of new crack formation over time. Voids did not increase the rate of crack initiation but appeared to have promoted crack growth over time. Although not progressive, substantial bone resorption at the cement-bone interface appeared to be common. PMID:21802085

  14. Mid-latency auditory evoked potential response revealed as an evidence of neural plasticity in blinnd individuals.

    PubMed

    Muthusamy, Anbarasi; Gajendran, Rajkumar; Rao B, Vishwanatha

    2014-01-01

    There is a general impression that visually blind individuals show an exceptionally better perception of other sensory modalities such as hearing, touch and smell sensations. In this study, we intended to compare the mid-latency auditory evoked potential response (MLAEP) or Middle latency Response (MLR) to get an idea of the activity pattern of auditory thalamus and cortex between 30 visually handicapped subjects and 30 normal sighted subjects. The results showed a decrease in many of the MLR wave latencies, but highly significant for the wave Pa (P value <0.002). This fact can be reflected as an evidence of existence of cross-modal neuroplasticity. We also inferred that there are significant gender differences with latencies shorter in males than females (P value <0.02) in the blind subjects group which could be attributed to their rehabilitation training. PMID:25509959

  15. Comparative proteomic analysis using 2DE-LC-MS/MS reveals the mechanism of Fuzhuan brick tea extract against hepatic fat accumulation in rats with nonalcoholic fatty liver disease.

    PubMed

    Liu, Zhonghua; Lin, Yong; Zhang, Sheng; Wang, Die; Liang, Qionglin; Luo, Guoan

    2015-09-01

    Fuzhuan brick tea has received increasing attention in recent years owing to its benefits for nonalcoholic fatty liver disease (NAFLD) and associated metabolic syndrome. For exploring the ameliorative mechanism, the liver proteomes from three groups of rats fed either a normal control diet (NCD), a high fat diet (HFD), or a HFD supplemented with high-dose Fuzhuan brick tea extract (FTE) (HFD + HFTE) were comprehensively compared by quantitative proteomics using 2DE-LC-MS/MS. This is the first study of the effects of tea aqueous extract on the liver proteome of rats suffering from metabolic syndrome. The results showed that 57 proteins displayed more than 1.5-fold differences in at least one of two comparisons of HFD versus NCD and HFD versus HFD + HFTE due to HFD feeding and FTE treatment, respectively. Of them, over 75% of proteins exhibited a similar tendency of expression in the two comparisons, meaning FTE was able to correct HFD effects on rat livers. By function analyses, an extensive list of proteins was involved in sugar and lipid metabolism. Compared with HFD-fed rats, the reduced lipogenesis and enhanced β-oxidation, tricarboxylic acid cycle and respiratory chain in HFD + HFTE-fed rats, which mainly contributed to ameliorate hepatic fat accumulation and associated NAFLD. Additionally, some putative drug targets were also revealed such as COX2, PGAM1, ACACB, FAS, and ECHS1. PMID:26036873

  16. Genomic characterization of emergent pseudorabies virus in China reveals marked sequence divergence: Evidence for the existence of two major genotypes.

    PubMed

    Ye, Chao; Zhang, Qing-Zhan; Tian, Zhi-Jun; Zheng, Hao; Zhao, Kuan; Liu, Fei; Guo, Jin-Chao; Tong, Wu; Jiang, Cheng-Gang; Wang, Shu-Jie; Shi, Mang; Chang, Xiao-Bo; Jiang, Yi-Feng; Peng, Jin-Mei; Zhou, Yan-Jun; Tang, Yan-Dong; Sun, Ming-Xia; Cai, Xue-Hui; An, Tong-Qing; Tong, Guang-Zhi

    2015-09-01

    Recently pseudorabies outbreaks have occurred in many vaccinated farms in China. To identify genetic characteristics of pseudorabies virus (PRV) strains, we obtained the genomic sequences of PRV strains HeN1 and JS, which were compared to 4 PRV genomes and 729 partial gene sequences. PRV strains isolated in China showed marked sequence divergence compared to European and American strains. Phylogenetic analysis revealed that for the first time PRV can be divided into 2 distinct clusters, with Chinese strains being genotype II and PRVs isolated from other countries being genotype I. Restriction fragment length polymorphism analysis confirmed differences between HeN1 and Bartha strains, as did the presence of unique insertion/deletion polymorphisms and microsatellites. This divergence between the two genotypes may have been generated from long-term, independent evolution, which could also explain the low efficacy of the Bartha vaccine in protecting pigs infected with genotype II PRV. PMID:25965793

  17. Early Pleistocene glaciations of the North Sea basin revealed by geomorphic evidence from 3D seismic datasets

    NASA Astrophysics Data System (ADS)

    Stewart, Margaret A.; Graham, Alastair G. C.; Lonergan, Lidia

    2013-04-01

    The record of the last major glaciation across northwest Europe is increasingly well understood, but the extent, timing, and palaeoenvironmental significance of earlier Pleistocene glaciations is still poorly known. Here, two sets of iceberg ploughmarks and a buried tunnel valley, all well-imaged within 3D seismic data, provide direct geomorphic evidence for glacial conditions in the central North Sea during periods of the Early to Middle Pleistocene. Each set of geomorphic features is mapped within separate stratigraphic intervals and constrained using seismic-borehole ties to the Bruhnes-Matuyama [B-M] palaeomagnetic reversal, dated in NW Europe at approximately 0.79 Ma B.P (Funnell, 1995). The first set of iceberg ploughmarks mapped within the Witch Ground Basin at approximately 0°30'W, 58°10N comprises 423 scours within a package of relatively disturbed seismic reflectors approximately 130-170m below seabed. Scours are sub-parallel, cross-cutting, and occasionally sinuous, with widths of 40-60m and lengths between 1km and 10km+. The ploughmarked surface is extensively incised by multiple generations of younger tunnel valleys imaged within the same 3D seismic data, and lies above the older B-M horizon. A second set of ploughmarks are buried approximately 250-430m beneath seabed at 2 °40'E 56 °30'N approximately180km SE of the Witch Ground Basin scours. More than 1800 individual scours are observed with widths between 50m and 100m, and lengths from 1km to 17km. The buried scours are observed within three horizons, and their stratigraphic position indicates they pre-date the B-M reversal, lying within a unit traditionally associated with times of non-glacial deposition. A single buried tunnel valley, c.60km in length, is observed towards the NW of the study area at approximately 0°30'W and 58°30'N. The main channel of the tunnel valley is curvilinear and trends approximately NE-SW with two significant tributary channels trending NW-SE. The tunnel valley

  18. Stable Isotopic Signatures in the Isolated Brine Cyroecosystem of Lake Vida Reveal Evidence of both Abiotic and Biotic Processes

    NASA Astrophysics Data System (ADS)

    Murray, A. E.; Ostrom, N. E.; Glazer, B. T.; McKay, C.; Kenig, F.; Loeffler, F. E.; Fritsen, C. H.; Doran, P. T.

    2011-12-01

    Lake Vida in the Victoria Valley of East Antarctica harbors ice-entrained brine that has been isolated from surface processes for several thousand years. The brine conditions (permanently dark, temperature of -13.4 °C, lack of oxygen, and pH of 6.2) and geochemistry are highly unusual. As an example, the brine contains excessive quantities of both reduced and oxidized nitrogen in nearly all forms, which in several cases are the highest levels found among natural ecosystems on Earth. Though this cryoecosystem appears to be relatively inhospitable, we have evidence that microbial life persists in abundance (cell levels over 107 cells per mL), is capable of protein production at in situ temperatures, and harbors a unique, but not necessarily novel, assemblage of bacterial phylotypes spanning at least eight phyla. In order to assess in situ microbial activities occurring today and in the past, and test hypotheses concerning energy generation in the brine cryoecosystem, the stable isotope signatures of nitrogen, oxygen, and hydrogen have been characterized in liquid and dissolved gas phases of the brine. The data provide evidence for both biotic and potentially abiotic formation of different fractions. The site preference of 15N-nitrous oxide (-3.64) suggests that the primary source of this dissolved gas, which is found at levels as high as 86 μM, is biologically produced by denitrification pathways. This appears to be consistent with detection of Marinobacter and Psychrobacter-related bacterial rRNA gene sequences and isolates in the brine microbial community. On the other hand, dissolved hydrogen present in the brine harbors an δH-H2 isotope signature suggesting that abiotic (potentially via serpentinization) or biotic production is equivocal based on the significant levels of fractionation observed. We postulate however, that a serpentinization production route is more favorable in this system that lies in a basin comprised of Ferrar dolerite sills and granite

  19. Approximate Bayesian Inference Reveals Evidence for a Recent, Severe Bottleneck in a Netherlands Population of Drosophila melanogaster

    PubMed Central

    Thornton, Kevin; Andolfatto, Peter

    2006-01-01

    Genome-wide nucleotide variation in non-African populations of Drosophila melanogaster is a subset of variation found in East sub-Saharan African populations, suggesting a bottleneck in the history of the former. We implement an approximate Bayesian approach to infer the timing, duration, and severity of this putative bottleneck and ask whether this inferred model is sufficient to account for patterns of variability observed at 115 loci scattered across the X chromosome. We estimate a recent bottleneck 0.006Ne generations ago, somewhat further in the past than suggested by biogeographical evidence. Using various proposed statistical tests, we find that this bottleneck model is able to predict the majority of observed features of diversity and linkage disequilibrium in the data. Thus, while precise estimates of bottleneck parameters (like inferences of selection) are sensitive to model assumptions, our results imply that it may be unnecessary to invoke frequent selective sweeps associated with the dispersal of D. melanogaster from Africa to explain patterns of variability in non-African populations. PMID:16299396

  20. Looking at the evidence in visual world: eye-movements reveal how bilingual and monolingual Turkish speakers process grammatical evidentiality.

    PubMed

    Arslan, Seçkin; Bastiaanse, Roelien; Felser, Claudia

    2015-01-01

    This study presents pioneering data on how adult early bilinguals (heritage speakers) and late bilingual speakers of Turkish and German process grammatical evidentiality in a visual world setting in comparison to monolingual speakers of Turkish. Turkish marks evidentiality, the linguistic reference to information source, through inflectional affixes signaling either direct (-DI) or indirect (-mIş) evidentiality. We conducted an eye-tracking-during-listening experiment where participants were given access to visual 'evidence' supporting the use of either a direct or indirect evidential form. The behavioral results indicate that the monolingual Turkish speakers comprehended direct and indirect evidential scenarios equally well. In contrast, both late and early bilinguals were less accurate and slower to respond to direct than to indirect evidentials. The behavioral results were also reflected in the proportions of looks data. That is, both late and early bilinguals fixated less frequently on the target picture in the direct than in the indirect evidential condition while the monolinguals showed no difference between these conditions. Taken together, our results indicate reduced sensitivity to the semantic and pragmatic function of direct evidential forms in both late and early bilingual speakers, suggesting a simplification of the Turkish evidentiality system in Turkish heritage grammars. We discuss our findings with regard to theories of incomplete acquisition and first language attrition. PMID:26441762

  1. Empirical Evidence Reveals Seasonally Dependent Reduction in Nitrification in Coastal Sediments Subjected to Near Future Ocean Acidification

    PubMed Central

    Braeckman, Ulrike; Van Colen, Carl; Guilini, Katja; Van Gansbeke, Dirk; Soetaert, Karline; Vincx, Magda; Vanaverbeke, Jan

    2014-01-01

    Research so far has provided little evidence that benthic biogeochemical cycling is affected by ocean acidification under realistic climate change scenarios. We measured nutrient exchange and sediment community oxygen consumption (SCOC) rates to estimate nitrification in natural coastal permeable and fine sandy sediments under pre-phytoplankton bloom and bloom conditions. Ocean acidification, as mimicked in the laboratory by a realistic pH decrease of 0.3, significantly reduced SCOC on average by 60% and benthic nitrification rates on average by 94% in both sediment types in February (pre-bloom period), but not in April (bloom period). No changes in macrofauna functional community (density, structural and functional diversity) were observed between ambient and acidified conditions, suggesting that changes in benthic biogeochemical cycling were predominantly mediated by changes in the activity of the microbial community during the short-term incubations (14 days), rather than by changes in engineering effects of bioturbating and bio-irrigating macrofauna. As benthic nitrification makes up the gross of ocean nitrification, a slowdown of this nitrogen cycling pathway in both permeable and fine sediments in winter, could therefore have global impacts on coupled nitrification-denitrification and hence eventually on pelagic nutrient availability. PMID:25329898

  2. The Effects of Revealed Information on Catastrophe Loss Projection Models' Characterization of Risk: Damage Vulnerability Evidence from Florida.

    PubMed

    Karl, J Bradley; Medders, Lorilee A; Maroney, Patrick F

    2016-06-01

    We examine whether the risk characterization estimated by catastrophic loss projection models is sensitive to the revelation of new information regarding risk type. We use commercial loss projection models from two widely employed modeling firms to estimate the expected hurricane losses of Florida Atlantic University's building stock, both including and excluding secondary information regarding hurricane mitigation features that influence damage vulnerability. We then compare the results of the models without and with this revealed information and find that the revelation of additional, secondary information influences modeled losses for the windstorm-exposed university building stock, primarily evidenced by meaningful percent differences in the loss exceedance output indicated after secondary modifiers are incorporated in the analysis. Secondary risk characteristics for the data set studied appear to have substantially greater impact on probable maximum loss estimates than on average annual loss estimates. While it may be intuitively expected for catastrophe models to indicate that secondary risk characteristics hold value for reducing modeled losses, the finding that the primary value of secondary risk characteristics is in reduction of losses in the "tail" (low probability, high severity) events is less intuitive, and therefore especially interesting. Further, we address the benefit-cost tradeoffs that commercial entities must consider when deciding whether to undergo the data collection necessary to include secondary information in modeling. Although we assert the long-term benefit-cost tradeoff is positive for virtually every entity, we acknowledge short-term disincentives to such an effort. PMID:26720056

  3. A 10-year study reveals clinical and laboratory evidence for the 'semi-invasive' properties of chronic pulmonary aspergillosis.

    PubMed

    Chan, Jasper Fuk-Woo; Lau, Susanna Kar-Pui; Wong, Sally Cheuk-Ying; To, Kelvin Kai-Wang; So, Simon Yung-Chun; Leung, Sally Sau-Man; Chan, Siu-Mang; Pang, Chiu-Mei; Xiao, Chenlu; Hung, Ivan Fan-Ngai; Cheng, Vincent Chi-Chung; Yuen, Kwok-Yung; Woo, Patrick Chiu-Yat

    2016-01-01

    In recent years, infections caused by Aspergillus sp. have become an emerging focus of clinical microbiology and infectious disease, as the number of patients infected with Aspergillus sp. has increased markedly. Although chronic pulmonary aspergillosis (CPA) is considered a 'semi-invasive' or 'intermediate' disease, little data are available for the direct comparison of CPA with invasive pulmonary aspergillosis (IPA) and pulmonary aspergilloma (PA) to quantify invasiveness. In this study, we compared the characteristics of CPA with those of IPA and PA among hospitalized patients over a 10-year period. A total of 29, 51 and 31 cases of CPA, IPA and PA, respectively, were included. An increasing trend in galactomannan antigen seropositivity rate from PA (24.1%) to CPA (35.7%) to IPA (54.9%) and an opposite trend for anti-Aspergillus antibody (PA (71.0%) to CPA (45.8%) to IPA (7.1%)) were observed. Eight percent of CPA patients were infected with more than one Aspergillus sp. The survival rate of the CPA group also fell between the survival rate of PA and IPA, confirming the intermediate severity of CPA. The survival rate of the CPA group became significantly higher than that of the IPA group from day 180 onwards until 2 years after admission (P<0.05). The survival rate of the CPA group remained lower than that of the PA group from day 30 onwards until 2 years after admission. Poor prognostic factors for CPA included older age (P=0.019), higher total leukocyte count (P=0.011) and higher neutrophil count (P=0.012) on admission. This study provided clinical and laboratory evidence for the semi-invasive properties of CPA. PMID:27094904

  4. A 10-year study reveals clinical and laboratory evidence for the ‘semi-invasive' properties of chronic pulmonary aspergillosis

    PubMed Central

    Chan, Jasper Fuk-Woo; Lau, Susanna Kar-Pui; Wong, Sally Cheuk-Ying; To, Kelvin Kai-Wang; So, Simon Yung-Chun; Leung, Sally Sau-Man; Chan, Siu-Mang; Pang, Chiu-Mei; Xiao, Chenlu; Hung, Ivan Fan-Ngai; Cheng, Vincent Chi-Chung; Yuen, Kwok-Yung; Woo, Patrick Chiu-Yat

    2016-01-01

    In recent years, infections caused by Aspergillus sp. have become an emerging focus of clinical microbiology and infectious disease, as the number of patients infected with Aspergillus sp. has increased markedly. Although chronic pulmonary aspergillosis (CPA) is considered a ‘semi-invasive' or ‘intermediate' disease, little data are available for the direct comparison of CPA with invasive pulmonary aspergillosis (IPA) and pulmonary aspergilloma (PA) to quantify invasiveness. In this study, we compared the characteristics of CPA with those of IPA and PA among hospitalized patients over a 10-year period. A total of 29, 51 and 31 cases of CPA, IPA and PA, respectively, were included. An increasing trend in galactomannan antigen seropositivity rate from PA (24.1%) to CPA (35.7%) to IPA (54.9%) and an opposite trend for anti-Aspergillus antibody (PA (71.0%) to CPA (45.8%) to IPA (7.1%)) were observed. Eight percent of CPA patients were infected with more than one Aspergillus sp. The survival rate of the CPA group also fell between the survival rate of PA and IPA, confirming the intermediate severity of CPA. The survival rate of the CPA group became significantly higher than that of the IPA group from day 180 onwards until 2 years after admission (P<0.05). The survival rate of the CPA group remained lower than that of the PA group from day 30 onwards until 2 years after admission. Poor prognostic factors for CPA included older age (P=0.019), higher total leukocyte count (P=0.011) and higher neutrophil count (P=0.012) on admission. This study provided clinical and laboratory evidence for the semi-invasive properties of CPA. PMID:27094904

  5. Strong evidence for the influence of solar cycles on a Late Miocene lake system revealed by biotic and abiotic proxies

    PubMed Central

    Kern, A.K.; Harzhauser, M.; Piller, W.E.; Mandic, O.; Soliman, A.

    2012-01-01

    The Late Miocene paleogeography of central Europe and its climatic history are well studied with a resolution of c. 106 years. Small-scale climatic variations are yet unresolved. Observing past climatic change of short periods, however, would encourage the understanding of the modern climatic system. Therefore, past climate archives require a resolution on a decadal to millennial scale. To detect such a short-term evolution, a continuous 6-m-core of the Paleo-Lake Pannon was analyzed in 1-cm-sample distance to provide information as precise and regular as possible. Measurements of the natural gamma radiation and magnetic susceptibility combined with the total abundance of ostracod shells were used as proxies to estimate millennial- to centennial scale environmental changes during the mid-Tortonian warm period. Patterns emerged, but no indisputable age model can be provided for the core, due to the lack of paleomagnetic reversals and the lack of minerals suitable for absolute dating. Therefore, herein we propose another method to determine a hypothetic time frame for these deposits. Based on statistical processes, including Lomb–Scargle and REDFIT periodograms along with Wavelet spectra, several distinct cyclicities could be detected. Calculations considering established off-shore sedimentation rates of the Tortonian Vienna Basin revealed patterns resembling Holocene solar-cycle-records well. The comparison of filtered data of Miocene and Holocene records displays highly similar patterns and comparable modulations. A best-fit adjustment of sedimentation rate results in signals which fit to the lower and upper Gleissberg cycle, the de Vries cycle, the unnamed 500-year- and 1000-year-cycles, as well as the Hallstatt cycle. Each of these cycles has a distinct and unique expression in the investigated environmental proxies, reflecting a complex forcing-system. Hence, a single-proxy-analysis, as often performed on Holocene records, should be considered cautiously as

  6. Strong evidence for the influence of solar cycles on a Late Miocene lake system revealed by biotic and abiotic proxies.

    PubMed

    Kern, A K; Harzhauser, M; Piller, W E; Mandic, O; Soliman, A

    2012-04-15

    The Late Miocene paleogeography of central Europe and its climatic history are well studied with a resolution of c. 10(6) years. Small-scale climatic variations are yet unresolved. Observing past climatic change of short periods, however, would encourage the understanding of the modern climatic system. Therefore, past climate archives require a resolution on a decadal to millennial scale. To detect such a short-term evolution, a continuous 6-m-core of the Paleo-Lake Pannon was analyzed in 1-cm-sample distance to provide information as precise and regular as possible. Measurements of the natural gamma radiation and magnetic susceptibility combined with the total abundance of ostracod shells were used as proxies to estimate millennial- to centennial scale environmental changes during the mid-Tortonian warm period. Patterns emerged, but no indisputable age model can be provided for the core, due to the lack of paleomagnetic reversals and the lack of minerals suitable for absolute dating. Therefore, herein we propose another method to determine a hypothetic time frame for these deposits. Based on statistical processes, including Lomb-Scargle and REDFIT periodograms along with Wavelet spectra, several distinct cyclicities could be detected. Calculations considering established off-shore sedimentation rates of the Tortonian Vienna Basin revealed patterns resembling Holocene solar-cycle-records well. The comparison of filtered data of Miocene and Holocene records displays highly similar patterns and comparable modulations. A best-fit adjustment of sedimentation rate results in signals which fit to the lower and upper Gleissberg cycle, the de Vries cycle, the unnamed 500-year- and 1000-year-cycles, as well as the Hallstatt cycle. Each of these cycles has a distinct and unique expression in the investigated environmental proxies, reflecting a complex forcing-system. Hence, a single-proxy-analysis, as often performed on Holocene records, should be considered cautiously as

  7. Deep Sequencing Reveals Novel Genetic Variants in Children with Acute Liver Failure and Tissue Evidence of Impaired Energy Metabolism

    PubMed Central

    Valencia, C. Alexander; Wang, Xinjian; Wang, Jin; Peters, Anna; Simmons, Julia R.; Moran, Molly C.; Mathur, Abhinav; Husami, Ammar; Qian, Yaping; Sheridan, Rachel; Bove, Kevin E.; Witte, David; Huang, Taosheng; Miethke, Alexander G.

    2016-01-01

    Background & Aims The etiology of acute liver failure (ALF) remains elusive in almost half of affected children. We hypothesized that inherited mitochondrial and fatty acid oxidation disorders were occult etiological factors in patients with idiopathic ALF and impaired energy metabolism. Methods Twelve patients with elevated blood molar lactate/pyruvate ratio and indeterminate etiology were selected from a retrospective cohort of 74 subjects with ALF because their fixed and frozen liver samples were available for histological, ultrastructural, molecular and biochemical analysis. Results A customized next-generation sequencing panel for 26 genes associated with mitochondrial and fatty acid oxidation defects revealed mutations and sequence variants in five subjects. Variants involved the genes ACAD9, POLG, POLG2, DGUOK, and RRM2B; the latter not previously reported in subjects with ALF. The explanted livers of the patients with heterozygous, truncating insertion mutations in RRM2B showed patchy micro- and macrovesicular steatosis, decreased mitochondrial DNA (mtDNA) content <30% of controls, and reduced respiratory chain complex activity; both patients had good post-transplant outcome. One infant with severe lactic acidosis was found to carry two heterozygous variants in ACAD9, which was associated with isolated complex I deficiency and diffuse hypergranular hepatocytes. The two subjects with heterozygous variants of unknown clinical significance in POLG and DGUOK developed ALF following drug exposure. Their hepatocytes displayed abnormal mitochondria by electron microscopy. Conclusion Targeted next generation sequencing and correlation with histological, ultrastructural and functional studies on liver tissue in children with elevated lactate/pyruvate ratio expand the spectrum of genes associated with pediatric ALF. PMID:27483465

  8. Evidence of Carbon Fixation Pathway in a Bacterium from Candidate Phylum SBR1093 Revealed with Genomic Analysis

    PubMed Central

    Wang, Zhiping; Guo, Feng; Liu, Lili; Zhang, Tong

    2014-01-01

    Autotrophic CO2 fixation is the most important biotransformation process in the biosphere. Research focusing on the diversity and distribution of relevant autotrophs is significant to our comprehension of the biosphere. In this study, a draft genome of a bacterium from candidate phylum SBR1093 was reconstructed with the metagenome of an industrial activated sludge. Based on comparative genomics, this autotrophy may occur via a newly discovered carbon fixation path, the hydroxypropionate-hydroxybutyrate (HPHB) cycle, which was demonstrated in a previous work to be uniquely possessed by some genera from Archaea. This bacterium possesses all of the thirteen enzymes required for the HPHB cycle; these enzymes share 30∼50% identity with those in the autotrophic species of Archaea that undergo the HPHB cycle and 30∼80% identity with the corresponding enzymes of the mixotrophic species within Bradyrhizobiaceae. Thus, this bacterium might have an autotrophic growth mode in certain conditions. A phylogenetic analysis based on the 16S rRNA gene reveals that the phylotypes within candidate phylum SBR1093 are primarily clustered into 5 clades with a shallow branching pattern. This bacterium is clustered with phylotypes from organically contaminated environments, implying a demand for organics in heterotrophic metabolism. Considering the types of regulators, such as FnR, Fur, and ArsR, this bacterium might be a facultative aerobic mixotroph with potential multi-antibiotic and heavy metal resistances. This is the first report on Bacteria that may perform potential carbon fixation via the HPHB cycle, thus may expand our knowledge of the distribution and importance of the HPHB cycle in the biosphere. PMID:25310003

  9. Absolute pitch: evidence for early cognitive facilitation during passive listening as revealed by reduced P3a amplitudes.

    PubMed

    Rogenmoser, Lars; Elmer, Stefan; Jäncke, Lutz

    2015-03-01

    Absolute pitch (AP) is the rare ability to identify or produce different pitches without using reference tones. At least two sequential processing stages are assumed to contribute to this phenomenon. The first recruits a pitch memory mechanism at an early stage of auditory processing, whereas the second is driven by a later cognitive mechanism (pitch labeling). Several investigations have used active tasks, but it is unclear how these two mechanisms contribute to AP during passive listening. The present work investigated the temporal dynamics of tone processing in AP and non-AP (NAP) participants by using EEG. We applied a passive oddball paradigm with between- and within-tone category manipulations and analyzed the MMN reflecting the early stage of auditory processing and the P3a response reflecting the later cognitive mechanism during the second processing stage. Results did not reveal between-group differences in MMN waveforms. By contrast, the P3a response was specifically associated with AP and sensitive to the processing of different pitch types. Specifically, AP participants exhibited smaller P3a amplitudes, especially in between-tone category conditions, and P3a responses correlated significantly with the age of commencement of musical training, suggesting an influence of early musical exposure on AP. Our results reinforce the current opinion that the representation of pitches at the processing level of the auditory-related cortex is comparable among AP and NAP participants, whereas the later processing stage is critical for AP. Results are interpreted as reflecting cognitive facilitation in AP participants, possibly driven by the availability of multiple codes for tones. PMID:25170790

  10. Evidence for early intracellular accumulation of volatile compounds during spadix development in Arum italicum L. and preliminary data on some tropical Aroids

    NASA Astrophysics Data System (ADS)

    Leguet, Aurélia; Gibernau, Marc; Shintu, Laetitia; Caldarelli, Stefano; Moja, Sandrine; Baudino, Sylvie; Caissard, Jean-Claude

    2014-08-01

    Staining and histochemistry of volatile organic compounds (VOCs) were performed at different inflorescence developmental stages on nine aroid species; one temperate, Arum italicum and eight tropical from the genera Caladium, Dieffenbachia and Philodendron. Moreover, a qualitative and quantitative analysis of VOCs constituting the scent of A. italicum, depending on the stage of development of inflorescences was also conducted. In all nine species, vesicles were observed in the conical cells of either the appendix or the stamens (thecae) and the staminodes. VOCs were localised in intracellular vesicles from the early stages of inflorescence development until their release during receptivity of gynoecium. This localisation was observed by the increase of both number and diameter of the vesicles during 1 week before receptivity. Afterwards, vesicles were fewer and smaller but rarely absent. In A. italicum, staining and gas chromatography analyses confirmed that the vesicles contained terpenes. The quantitatively most important ones were the sesquiterpenes, but monoterpenes were not negligible. Indeed, the quantities of terpenes matched the vesicles' size evolution during 1 week. Furthermore, VOCs from different biosynthetic pathways (sesquiterpenes and alkanes) were at their maximum quantity 2 days before gynoecium receptivity (sesquiterpenes and alkanes) or during receptivity (isobutylamine, monoterpenes, skatole and p-cresol). VOCs seemed to be emitted during gynoecium receptivity and/or during thermogenesis, and FADs are accumulated after thermogenesis in the spadix. These complex dynamics of the different VOCs could indicate specialisation of some VOCs and cell machinery to attract pollinators on the one hand and to repulse/protect against phytophagous organisms and pathogens after pollination on the other hand.

  11. Evidence for early intracellular accumulation of volatile compounds during spadix development in Arum italicum L. and preliminary data on some tropical Aroids.

    PubMed

    Leguet, Aurélia; Gibernau, Marc; Shintu, Laetitia; Caldarelli, Stefano; Moja, Sandrine; Baudino, Sylvie; Caissard, Jean-Claude

    2014-08-01

    Staining and histochemistry of volatile organic compounds (VOCs) were performed at different inflorescence developmental stages on nine aroid species; one temperate, Arum italicum and eight tropical from the genera Caladium, Dieffenbachia and Philodendron. Moreover, a qualitative and quantitative analysis of VOCs constituting the scent of A. italicum, depending on the stage of development of inflorescences was also conducted. In all nine species, vesicles were observed in the conical cells of either the appendix or the stamens (thecae) and the staminodes. VOCs were localised in intracellular vesicles from the early stages of inflorescence development until their release during receptivity of gynoecium. This localisation was observed by the increase of both number and diameter of the vesicles during 1 week before receptivity. Afterwards, vesicles were fewer and smaller but rarely absent. In A. italicum, staining and gas chromatography analyses confirmed that the vesicles contained terpenes. The quantitatively most important ones were the sesquiterpenes, but monoterpenes were not negligible. Indeed, the quantities of terpenes matched the vesicles' size evolution during 1 week. Furthermore, VOCs from different biosynthetic pathways (sesquiterpenes and alkanes) were at their maximum quantity 2 days before gynoecium receptivity (sesquiterpenes and alkanes) or during receptivity (isobutylamine, monoterpenes, skatole and p-cresol). VOCs seemed to be emitted during gynoecium receptivity and/or during thermogenesis, and FADs are accumulated after thermogenesis in the spadix. These complex dynamics of the different VOCs could indicate specialisation of some VOCs and cell machinery to attract pollinators on the one hand and to repulse/protect against phytophagous organisms and pathogens after pollination on the other hand. PMID:24925357

  12. A Draft De Novo Genome Assembly for the Northern Bobwhite (Colinus virginianus) Reveals Evidence for a Rapid Decline in Effective Population Size Beginning in the Late Pleistocene

    PubMed Central

    Halley, Yvette A.; Dowd, Scot E.; Decker, Jared E.; Seabury, Paul M.; Bhattarai, Eric; Johnson, Charles D.; Rollins, Dale; Tizard, Ian R.; Brightsmith, Donald J.; Peterson, Markus J.; Taylor, Jeremy F.; Seabury, Christopher M.

    2014-01-01

    Wild populations of northern bobwhites (Colinus virginianus; hereafter bobwhite) have declined across nearly all of their U.S. range, and despite their importance as an experimental wildlife model for ecotoxicology studies, no bobwhite draft genome assembly currently exists. Herein, we present a bobwhite draft de novo genome assembly with annotation, comparative analyses including genome-wide analyses of divergence with the chicken (Gallus gallus) and zebra finch (Taeniopygia guttata) genomes, and coalescent modeling to reconstruct the demographic history of the bobwhite for comparison to other birds currently in decline (i.e., scarlet macaw; Ara macao). More than 90% of the assembled bobwhite genome was captured within <40,000 final scaffolds (N50 = 45.4 Kb) despite evidence for approximately 3.22 heterozygous polymorphisms per Kb, and three annotation analyses produced evidence for >14,000 unique genes and proteins. Bobwhite analyses of divergence with the chicken and zebra finch genomes revealed many extremely conserved gene sequences, and evidence for lineage-specific divergence of noncoding regions. Coalescent models for reconstructing the demographic history of the bobwhite and the scarlet macaw provided evidence for population bottlenecks which were temporally coincident with human colonization of the New World, the late Pleistocene collapse of the megafauna, and the last glacial maximum. Demographic trends predicted for the bobwhite and the scarlet macaw also were concordant with how opposing natural selection strategies (i.e., skewness in the r-/K-selection continuum) would be expected to shape genome diversity and the effective population sizes in these species, which is directly relevant to future conservation efforts. PMID:24621616

  13. Evidence for an anterior-posterior differentiation in the human hippocampal formation revealed by meta-analytic parcellation of fMRI coordinate maps: Focus on the subiculum

    PubMed Central

    Chase, Henry W.; Clos, Mareike; Dibble, Sofia; Fox, Peter; Grace, Anthony A.; Phillips, Mary L.; Eickhoff, Simon B.

    2015-01-01

    Previous studies, predominantly in experimental animals, have suggested the presence of a differentiation of function across the hippocampal formation. In rodents, ventral regions are thought to be involved in emotional behavior while dorsal regions mediate cognitive or spatial processes. Using a combination of modeling the co-occurrence of significant activations across thousands of neuroimaging experiments and subsequent data-driven clustering of these data we were able to provide evidence of distinct subregions within a region corresponding to the human subiculum, a critical hub within the hippocampal formation. This connectivity-based model consists of a bilateral anterior region, as well as separate posterior and intermediate regions on each hemisphere. Functional connectivity assessed both by meta-analytic and resting fMRI approaches revealed that more anterior regions were more strongly connected to the default mode network, and more posterior regions were more strongly connected to ‘task positive’ regions. In addition, our analysis revealed that the anterior subregion was functionally connected to the ventral striatum, midbrain and amygdala, a circuit that is central to models of stress and motivated behavior. Analysis of a behavioral taxonomy provided evidence for a role for each subregion in mnemonic processing, as well as implication of the anterior subregion in emotional and visual processing and the right posterior subregion in reward processing. These findings lend support to models which posit anterior-posterior differentiation of function within the human hippocampal formation and complement other early steps toward a comparative (cross-species) model of the region. PMID:25776219

  14. Deep sequencing reveals the complete genome and evidence for transcriptional activity of the first virus-like sequences identified in Aristotelia chilensis (Maqui Berry).

    PubMed

    Villacreses, Javier; Rojas-Herrera, Marcelo; Sánchez, Carolina; Hewstone, Nicole; Undurraga, Soledad F; Alzate, Juan F; Manque, Patricio; Maracaja-Coutinho, Vinicius; Polanco, Victor

    2015-04-01

    Here, we report the genome sequence and evidence for transcriptional activity of a virus-like element in the native Chilean berry tree Aristotelia chilensis. We propose to name the endogenous sequence as Aristotelia chilensis Virus 1 (AcV1). High-throughput sequencing of the genome of this tree uncovered an endogenous viral element, with a size of 7122 bp, corresponding to the complete genome of AcV1. Its sequence contains three open reading frames (ORFs): ORFs 1 and 2 shares 66%-73% amino acid similarity with members of the Caulimoviridae virus family, especially the Petunia vein clearing virus (PVCV), Petuvirus genus. ORF1 encodes a movement protein (MP); ORF2 a Reverse Transcriptase (RT) and a Ribonuclease H (RNase H) domain; and ORF3 showed no amino acid sequence similarity with any other known virus proteins. Analogous to other known endogenous pararetrovirus sequences (EPRVs), AcV1 is integrated in the genome of Maqui Berry and showed low viral transcriptional activity, which was detected by deep sequencing technology (DNA and RNA-seq). Phylogenetic analysis of AcV1 and other pararetroviruses revealed a closer resemblance with Petuvirus. Overall, our data suggests that AcV1 could be a new member of Caulimoviridae family, genus Petuvirus, and the first evidence of this kind of virus in a fruit plant. PMID:25855242

  15. Deep Sequencing Reveals the Complete Genome and Evidence for Transcriptional Activity of the First Virus-Like Sequences Identified in Aristotelia chilensis (Maqui Berry)

    PubMed Central

    Villacreses, Javier; Rojas-Herrera, Marcelo; Sánchez, Carolina; Hewstone, Nicole; Undurraga, Soledad F.; Alzate, Juan F.; Manque, Patricio; Maracaja-Coutinho, Vinicius; Polanco, Victor

    2015-01-01

    Here, we report the genome sequence and evidence for transcriptional activity of a virus-like element in the native Chilean berry tree Aristotelia chilensis. We propose to name the endogenous sequence as Aristotelia chilensis Virus 1 (AcV1). High-throughput sequencing of the genome of this tree uncovered an endogenous viral element, with a size of 7122 bp, corresponding to the complete genome of AcV1. Its sequence contains three open reading frames (ORFs): ORFs 1 and 2 shares 66%–73% amino acid similarity with members of the Caulimoviridae virus family, especially the Petunia vein clearing virus (PVCV), Petuvirus genus. ORF1 encodes a movement protein (MP); ORF2 a Reverse Transcriptase (RT) and a Ribonuclease H (RNase H) domain; and ORF3 showed no amino acid sequence similarity with any other known virus proteins. Analogous to other known endogenous pararetrovirus sequences (EPRVs), AcV1 is integrated in the genome of Maqui Berry and showed low viral transcriptional activity, which was detected by deep sequencing technology (DNA and RNA-seq). Phylogenetic analysis of AcV1 and other pararetroviruses revealed a closer resemblance with Petuvirus. Overall, our data suggests that AcV1 could be a new member of Caulimoviridae family, genus Petuvirus, and the first evidence of this kind of virus in a fruit plant. PMID:25855242

  16. Phylogeography of postglacial range expansion in Juglans mandshurica (Juglandaceae) reveals no evidence of bottleneck, loss of genetic diversity, or isolation by distance in the leading-edge populations.

    PubMed

    Wang, Wen-Ting; Xu, Bing; Zhang, Da-Yong; Bai, Wei-Ning

    2016-09-01

    The past studies of postglacial recolonization patterns in high latitude regions have revealed a significant role of dispersal capacity in shaping the genetic diversity and population structure of temperate trees. However, most of these studies have focused on species with long-distance dispersal followed by exponential population growth and were therefore unable to reveal the patterns in the case of a gradual expansion. Here we studied the impacts of postglacial range expansions on the distribution of genetic diversity in the Manchurian walnut (Juglans mandshurica), a common tree of East Asian cool-temperate deciduous forests that apparently lacks long-distance seed dispersal ability. The genetic diversity and structure of 19 natural walnut populations in Northeast China and the Korean Peninsula were examined using 17 nuclear simple sequence repeat (SSR) loci. Potential habitats under current and past climatic conditions were predicted using the ecological niche modelling (ENM) method. Bayesian clustering analysis revealed three groups, which were inferred to have diverged through multiple glacial-interglacial cycles in multiple refugia during the Quaternary Period. ENM estimated a southward range shift at the LGM, but high suitability scores still occurred in the western parts of the Changbai Mountains (Northeast China), the Korean peninsula and the exposed seafloor of the Yellow Sea. In contrast to most other cool-temperate trees co-occurring in the same region, the Manchurian walnut did not show any evidence of a population bottleneck, loss of genetic diversity or isolation by distance during the postglacial expansion. Our study clearly indicates that current northern populations originated from one glacial lineage and recolonization via a gradually advancing front due to the lack of a long-distance seed dispersal mechanism led to no latitudinal decrease in genetic diversity. PMID:27346642

  17. Combined transcriptome, genetic diversity and metabolite profiling in tomato fruit reveals the ethylene response factor SlERF6 to play an important role in ripening and carotenoid accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato (Solanum lycopersicum) and its wild relatives harbor genetic diversity that yields heritable variation in fruit chemistry that could be exploited to identify genes regulating their synthesis and accumulation. Carotenoids, for example, are essential in plant and animal nutrition and are the vi...

  18. Genome-wide set of SNPs reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate.

    PubMed

    Sim, Zijian; Hall, Jocelyn C; Jex, Bill; Hegel, Troy M; Coltman, David W

    2016-08-01

    Past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in North America. The advancement of glaciers can isolate populations in ice-free refugia, where they can survive until the recession of ice sheets. The major Beringian refugium is thought to have held thinhorn sheep (Ovis dalli) populations during times of glacial advance. While isolation in the major refugium can account for much of the genetic and morphological diversity seen in extant thinhorn sheep populations, mounting evidence suggests the persistence of populations in smaller minor refugia. We investigated the refugial origins of thinhorn sheep using ~10 000 SNPs obtained via a cross-species application of the domestic sheep ovine HD BeadChip to genotype 52 thinhorn sheep and five bighorn sheep (O. canadensis) samples. Phylogenetic inference revealed a distinct lineage of thinhorn sheep inhabiting British Columbia, which is consistent with the survival of a group of thinhorn sheep in a minor refugium separate from the Beringian refugium. Isolation in separate glacial refugia probably mediated the evolution of the two thinhorn sheep subspecies, the white Dall's sheep (O. d. dalli), which persisted in Beringia, and the dark Stone's sheep (O. d. stonei), which utilized the minor refugium. We also found the first genetic evidence for admixture between sheep from different glacial refugia in south-central Yukon as a consequence of post glacial expansion and recolonization. These results show that glaciation events can have a major role in the evolution of species inhabiting previously glaciated habitats and the need to look beyond established refugia when examining the evolutionary history of such species. PMID:27272944

  19. Low-coverage exome sequencing screen in formalin-fixed paraffin-embedded tumors reveals evidence of exposure to carcinogenic aristolochic acid

    PubMed Central

    Castells, Xavier; Karanović, Sandra; Ardin, Maude; Tomić, Karla; Xylinas, Evanguelos; Durand, Geoffroy; Villar, Stephanie; Forey, Nathalie; Le Calvez-Kelm, Florence; Voegele, Catherine; Karlović, Krešimir; Mišić, Maja; Dittrich, Damir; Dolgalev, Igor; McKay, James; Shariat, Shahrokh F.; Sidorenko, Viktoria S.; Fernandes, Andrea; Heguy, Adriana; Dickman, Kathleen G.; Olivier, Magali; Grollman, Arthur P.; Jelaković, Bojan; Zavadil, Jiri

    2015-01-01

    Background Dietary exposure to cytotoxic and carcinogenic aristolochic acid (AA) causes severe nephropathy typically associated with urological cancers. Monitoring of AA exposure uses biomarkers such as aristolactam-DNA adducts, detected by mass spectrometry in the kidney cortex, or the somatic A>T transversion pattern characteristic of exposure to AA, as revealed by previous DNA sequencing studies using fresh frozen tumors. Methods Here we report a low-coverage whole-exome sequencing method (LC-WES) optimized for multi-sample detection of the AA mutational signature, and demonstrate its utility in 17 formalin-fixed paraffin-embedded urothelial tumors obtained from 15 patients with endemic nephropathy, an environmental form of aristolochic acid nephropathy. Results LC-WES identified the AA signature, alongside signatures of age and APOBEC enzyme activity, in 15 samples sequenced at the average per-base coverage of ~10x. Analysis at 3–9x coverage revealed the signature in 91% of the positive samples. The exome-wide distribution of the predominant A>T transversions exhibited a stochastic pattern whereas 83 cancer driver genes were enriched for recurrent non-synonymous A>T mutations. In two patients, pairs of tumors from different parts of the urinary tract, including the bladder, harbored overlapping mutation patterns, suggesting tumor dissemination via cell seeding. Conclusion LC-WES analysis of archived tumor tissues is a reliable method applicable to investigations of both the exposure to AA and its biologic effects in human carcinomas. Impact By detecting cancers associated with AA exposure in high-risk populations, LC-WES can support future molecular epidemiology studies and provide evidence-base for relevant preventive measures. PMID:26383547

  20. Proteomic analysis reveals differential accumulation of small heat shock proteins and late embryogenesis abundant proteins between ABA-deficient mutant vp5 seeds and wild-type Vp5 seeds in maize.

    PubMed

    Wu, Xiaolin; Gong, Fangping; Yang, Le; Hu, Xiuli; Tai, Fuju; Wang, Wei

    2014-01-01

    ABA is a major plant hormone that plays important roles during many phases of plant life cycle, including seed development, maturity and dormancy, and especially the acquisition of desiccation tolerance. Understanding of the molecular basis of ABA-mediated plant response to stress is of interest not only in basic research on plant adaptation but also in applied research on plant productivity. Maize mutant viviparous-5 (vp5), deficient in ABA biosynthesis in seeds, is a useful material for studying ABA-mediated response in maize. Due to carotenoid deficiency, vp5 endosperm is white, compared to yellow Vp5 endosperm. However, the background difference at proteome level between vp5 and Vp5 seeds is unclear. This study aimed to characterize proteome alterations of maize vp5 seeds and to identify ABA-dependent proteins during seed maturation. We compared the embryo and endosperm proteomes of vp5 and Vp5 seeds by gel-based proteomics. Up to 46 protein spots, most in embryos, were found to be differentially accumulated between vp5 and Vp5. The identified proteins included small heat shock proteins (sHSPs), late embryogenesis abundant (LEA) proteins, stress proteins, storage proteins and enzymes among others. However, EMB564, the most abundant LEA protein in maize embryo, accumulated in comparable levels between vp5 and Vp5 embryos, which contrasted to previously characterized, greatly lowered expression of emb564 mRNA in vp5 embryos. Moreover, LEA proteins and sHSPs displayed differential accumulations in vp5 embryos: six out of eight identified LEA proteins decreased while nine sHSPs increased in abundance. Finally, we discussed the possible causes of global proteome alterations, especially the observed differential accumulation of identified LEA proteins and sHSPs in vp5 embryos. The data derived from this study provides new insight into ABA-dependent proteins and ABA-mediated response during maize seed maturation. PMID:25653661

  1. Epoch-based likelihood models reveal no evidence for accelerated evolution of viviparity in squamate reptiles in response to cenozoic climate change.

    PubMed

    King, Benedict; Lee, Michael S Y

    2015-09-01

    A broad scale analysis of the evolution of viviparity across nearly 4,000 species of squamates revealed that origins increase in frequency toward the present, raising the question of whether rates of change have accelerated. We here use simulations to show that the increased frequency is within the range expected given that the number of squamate lineages also increases with time. Novel, epoch-based methods implemented in BEAST (which allow rates of discrete character evolution to vary across time-slices) also give congruent results, with recent epochs having very similar rates to older epochs. Thus, contrary to expectations, there was no accelerated burst of origins of viviparity in response to global cooling during the Cenozoic or glacial cycles during the Plio-Pleistocene. However, if one accepts the conventional view that viviparity is more likely to evolve than to be lost, and also the evidence here that viviparity has evolved with similar regularity throughout the last 200 Ma, then the absence of large, ancient clades of viviparous squamates (analogs to therian mammals) requires explanation. Viviparous squamate lineages might be more prone to extinction than are oviparous lineages, due to their prevalance at high elevations and latitudes and thus greater susceptibility to climate fluctuations. If so, the directional bias in character evolution would be offset by the bias in extinction rates. PMID:25851129

  2. Mitochondrial coding genome analysis of tropical root-knot nematodes (Meloidogyne) supports haplotype based diagnostics and reveals evidence of recent reticulate evolution

    PubMed Central

    Janssen, Toon; Karssen, Gerrit; Verhaeven, Myrtle; Coyne, Danny; Bert, Wim

    2016-01-01

    The polyphagous parthenogenetic root-knot nematodes of the genus Meloidogyne are considered to be the most significant nematode pest in sub-tropical and tropical agriculture. Despite the crucial need for correct diagnosis, identification of these pathogens remains problematic. The traditionally used diagnostic strategies, including morphometrics, host-range tests, biochemical and molecular techniques, now appear to be unreliable due to the recently-suggested hybrid origin of root-knot nematodes. In order to determine a suitable barcode region for these pathogens nine quickly-evolving mitochondrial coding genes were screened. Resulting haplotype networks revealed closely related lineages indicating a recent speciation, an anthropogenic-aided distribution through agricultural practices, and evidence for reticulate evolution within M. arenaria. Nonetheless, nucleotide polymorphisms harbor enough variation to distinguish these closely-related lineages. Furthermore, completeness of lineage sorting was verified by screening 80 populations from widespread geographical origins and variable hosts. Importantly, our results indicate that mitochondrial haplotypes are strongly linked and consistent with traditional esterase isozyme patterns, suggesting that different parthenogenetic lineages can be reliably identified using mitochondrial haplotypes. The study indicates that the barcode region Nad5 can reliably identify the major lineages of tropical root-knot nematodes. PMID:26940543

  3. Next generation sequencing of stage IV squamous cell lung cancers reveals an association of PI3K aberrations and evidence of clonal heterogeneity in patients with brain metastases

    PubMed Central

    Paik, Paul K.; Shen, Ronglai; Won, Helen; Rekhtman, Natasha; Wang, Lu; Sima, Camelia S.; Arora, Arshi; Seshan, Venkatraman; Ladanyi, Marc; Berger, Michael F.; Kris, Mark G.

    2015-01-01

    Large-scale genomic characterization of squamous cell lung cancers (SQCLC) has revealed several putative oncogenic drivers. There are, however, little data to suggest that these alterations have clinical relevance. We performed comprehensive genomic profiling of 79 stage IV SQCLCs (including next-generation sequencing) and analyzed differences in the clinical characteristics of two major SQCLC subtypes: FGFR1 amplified and PI3K aberrant. Patients with PI3K aberrant tumors had aggressive disease marked by worse survival (median OS 8.6 vs. 19.1 mo, p<0.001), higher metastatic burden (>3 organs 18% vs. 3%, p=0.025), and greater incidence of brain metastases (27% vs. 0% in others, p<0.001). We performed whole-exome and RNA sequencing on paired brain metastases and primary lung cancers to elucidate the metastatic process to brain. SQCLC primaries that gave rise to brain metastases exhibited truncal PTEN loss. SQCLC brain metastases exhibited a high degree of genetic heterogeneity and evidence of clonal differences between their primary sites. PMID:25929848

  4. Intra-species variation in transient accumulation of leaf anthocyanins in Cistus creticus during winter: evidence that anthocyanins may compensate for an inherent photosynthetic and photoprotective inferiority of the red-leaf phenotype.

    PubMed

    Kytridis, Velissarios-Phaedon; Karageorgou, Panagiota; Levizou, Efi; Manetas, Yiannis

    2008-06-16

    Leaf color in some individuals of Cistus creticus turns transiently to red during winter, while neighboring individuals occupying the same site remain green. We have examined whether anthocyanin accumulation can be associated with variations in photosynthetic and/or photoprotective characteristics between the two phenotypes, rendering the red phenotype more vulnerable to photoinhibition and, accordingly, needing additional protection in the form of anthocyanins. Towards this aim, maximum (pre-dawn) and effective (mid-day) PSII photochemical efficiencies, xanthophyll cycle pool sizes and leaf nitrogen contents were seasonably followed, encompassing both the green (spring, summer, autumn) and the red (winter) period of the year. Moreover, the distribution of the two phenotypes in exposed and shaded sites was assessed. The frequency of red individuals was considerably higher in fully exposed sites, pointing to a photoprotective function of leaf anthocyanins. Yet, the assumption was not corroborated by pre-dawn PSII yield measurements, since both phenotypes displayed similar high values throughout the year and a similar drop during winter. However, the red phenotype was characterized by lower light-saturated PSII yields, xanthophyll cycle pool sizes and leaf nitrogen, during both the green and the red period of the year. Based on this correlative evidence, we suggest that winter redness in C. creticus may compensate for an inherent photosynthetic and photoprotective inferiority, possibly through a light screen and/or an antioxidant function of leaf anthocyanins. PMID:17923168

  5. Carbonate Fluxes to the Eastern Equatorial Pacific during the Eocene: using the GENIE Earth System Model to investigate carbonate accumulation event mechanisms and dynamics revealed by the Pacific Equatorial Age Transect (PEAT)

    NASA Astrophysics Data System (ADS)

    Pälike, H.; Lyle, M. W.; Ridgwell, A. J.; Edgar, K. M.; Science Party, I.; Iodp Expeditions 320/321 Science Party

    2010-12-01

    The Pacific Equatorial Age Transect (PEAT) recovered sediments and data from a set of Sites that form a palaeo-depth transect for most of Cenozoic time. We are using the data from IODP Expedition 320 and ODP Leg 199 sites to refine the dynamics of the carbonate compensation depth (CCD) during the Eocene. We are able to use the PEAT depth transect approach to determine the intensity of carbonate fluxes at the seafloor for the previously identified carbonate accumulation events (CAEs) of Lyle et al (ODP Leg 199 SR, 2005). Using the reconstructed depths for the drilled sites we are able to determine the amplitude of the CCD fluctuations to be about 500m in depth, and carbonate accumulation rates fluctuate between near zero and ~1.5 g/cm2/kyr. Each event lasts for a time period of around 1 Myr, with sharp transitions into and out of these cycles of enhanced carbonate accumulation. To investigate the potential mechanisms for these events we use an Earth System Model of Intermediate complexity (GENIE), as previously employed to study the carbon cycle during the PETM (Panchuk et al., Geology 2008). Using estimated values for ocean water Ca and Mg concentrations, we ran ensemble simulations for different pCO2 concentrations, different Alkalinity and different CaCO3:POC scenarios. We find that different CaCO3:POC ratios are able to explain many of the observed dissolution/preservation events, and are able to use these to constrain other parameters in the Earth System.

  6. Mobility of water ice on Callisto - Evidence and implications

    NASA Technical Reports Server (NTRS)

    Spencer, J. R.; Maloney, P. R.

    1984-01-01

    Voyager images of Callisto reveal evidence for the accumulation of a bright volatile, presumably water ice, on north-facing slopes in the north polar region. The geometry of these accumulations suggests that ice migration in Callistoan high latitudes is dominated by thermal sublimation, controlled by insolation-dependent surface temperature contrasts. Such sublimation-dominated migration may result in the cold-trapping of most of the surface ice in discrete high-albedo regions.

  7. Re-analysis of protein data reveals the germination pathway and up accumulation mechanism of cell wall hydrolases during the radicle protrusion step of seed germination in Podophyllum hexandrum- a high altitude plant

    PubMed Central

    Dogra, Vivek; Bagler, Ganesh; Sreenivasulu, Yelam

    2015-01-01

    Podophyllum hexandrum Royle is an important high-altitude plant of Himalayas with immense medicinal value. Earlier, it was reported that the cell wall hydrolases were up accumulated during radicle protrusion step of Podophyllum seed germination. In the present study, Podophyllum seed Germination protein interaction Network (PGN) was constructed by using the differentially accumulated protein (DAP) data set of Podophyllum during the radicle protrusion step of seed germination, with reference to Arabidopsis protein–protein interaction network (AtPIN). The developed PGN is comprised of a giant cluster with 1028 proteins having 10,519 interactions and a few small clusters with relevant gene ontological signatures. In this analysis, a germination pathway related cluster which is also central to the topology and information dynamics of PGN was obtained with a set of 60 key proteins. Among these, eight proteins which are known to be involved in signaling, metabolism, protein modification, cell wall modification, and cell cycle regulation processes were found commonly highlighted in both the proteomic and interactome analysis. The systems-level analysis of PGN identified the key proteins involved in radicle protrusion step of seed germination in Podophyllum. PMID:26579141

  8. Electromobility Shift Assay Reveals Evidence in Favor of Allele-Specific Binding of RUNX1 to the 5' Hypersensitive Site 4-Locus Control Region.

    PubMed

    Dehghani, Hossein; Ghobakhloo, Sepideh; Neishabury, Maryam

    2016-08-01

    In our previous studies on the Iranian β-thalassemia (β-thal) patients, we identified an association between the severity of the β-thal phenotype and the polymorphic palindromic site at the 5' hypersensitive site 4-locus control region (5'HS4-LCR) of the β-globin gene cluster. Furthermore, a linkage disequilibrium was observed between this region and XmnI-HBG2 in the patient population. Based on this data, it was suggested that the well-recognized phenotype-ameliorating role assigned to positive XmnI could be associated with its linked elements in the LCR. To investigate the functional significance of polymorphisms at the 5'HS4-LCR, we studied its influence on binding of transcription factors. Web-based predictions of transcription factor binding revealed a binding site for runt-related transcription factor 1 (RUNX1), when the allele at the center of the palindrome (TGGGG(A/G)CCCCA) was A but not when it was G. Furthermore, electromobility shift assay (EMSA) presented evidence in support of allele-specific binding of RUNX1 to 5'HS4. Considering that RUNX1 is a well-known regulator of hematopoiesis, these preliminary data suggest the importance of further studies to confirm this interaction and consequently investigate its functional and phenotypical relevance. These studies could help us to understand the molecular mechanism behind the phenotype modifying role of the 5'HS4-LCR polymorphic palindromic region (rs16912979), which has been observed in previous studies. PMID:27492765

  9. In vivo experimental evidence that the major metabolites accumulating in 3-hydroxy-3-methylglutaryl-CoA lyase deficiency induce oxidative stress in striatum of developing rats: a potential pathophysiological mechanism of striatal damage in this disorder.

    PubMed

    Fernandes, Carolina Gonçalves; da Rosa, Mateus Struecker; Seminotti, Bianca; Pierozan, Paula; Martell, Rafael Wolter; Lagranha, Valeska Lizzi; Busanello, Estela Natacha Brandt; Leipnitz, Guilhian; Wajner, Moacir

    2013-06-01

    3-Hydroxy-3-methylglutaryl-CoA lyase (HL) deficiency is a genetic disorder biochemically characterized by predominant accumulation of 3-hydroxy-3-methylglutaric (HMG) and 3-methylglutaric (MGA) acids in tissues and biological fluids of affected individuals. Clinically, the patients present neurological symptoms and basal ganglia injury, whose pathomechanisms are partially understood. In the present study, we investigated the ex vivo effects of intrastriatal administration of HMG and MGA on important parameters of oxidative stress in striatum of developing rats. Our results demonstrate that HMG and MGA induce lipid and protein oxidative damage. HMG and MGA also increased 2',7'-dichlorofluorescein oxidation, whereas only HMG elicited nitric oxide production, indicating a role for reactive oxygen (HMG and MGA) and nitrogen (HMG) species in these effects. Regarding the enzymatic antioxidant defenses, both organic acids decreased reduced glutathione concentrations and the activities of superoxide dismutase and glutathione reductase and increased glutathione peroxidase activity. HMG also provoked an increase of catalase activity and a diminution of glucose-6-phosphate dehydrogenase activity. We finally observed that antioxidants fully prevented or attenuated HMG-induced alterations of the oxidative stress parameters, further indicating the participation of reactive species in these effects. We also observed that MK-801, a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, prevented some of these effects, indicating the involvement of the NMDA receptor in HMG effects. The present data provide solid evidence that oxidative stress is induced in vivo by HMG and MGA in rat striatum and it is presumed that this pathomechanism may explain, at least in part, the cerebral alterations observed in HL deficiency. PMID:23611578

  10. Investigation of a miRNA-Induced Gene Silencing Technique in Petunia Reveals Alterations in miR173 Precursor Processing and the Accumulation of Secondary siRNAs from Endogenous Genes

    PubMed Central

    Han, Yao; Zhang, Bin; Qin, Xiaoting; Li, Mingyang; Guo, Yulong

    2015-01-01

    MIGS (miRNA-induced gene silencing) is a straightforward and efficient gene silencing technique in Arabidopsis. It works by exploiting miR173 to trigger the production of phasiRNAs (phased small interfering RNAs). MIGS can be used in plant species other than Arabidopsis by co-expression of miR173 and target gene fragments fused to an upstream miR173 target site. However, the efficiency and technical mechanisms have not been thoroughly investigated in other plants. In this work, two vectors, pMIGS-chs and pMIGS-pds, were constructed and transformed into petunia plants. The transgenic plants showed CHS (chalcone synthase) and PDS (phytoene desaturase) gene-silencing phenotypes respectively, indicating that MIGS functions in petunia. MIGS-chs plants were used to investigate the mechanisms of this technique in petunia. Results of 5′- RACE showed that the miR173 target site was cleaved at the expected position and that endogenous CHS genes were cut at multiple positions. Small RNA deep sequencing analysis showed that the processing of Arabidopsis miR173 precursors in MIGS-chs transgenic petunia plants did not occur in exactly the same way as in Arabidopsis, suggesting differences in the machinery of miRNA processing between plant species. Small RNAs in-phase with the miR173 cleavage register were produced immediately downstream from the cleavage site and out-of-phase small RNAs were accumulated at relatively high levels from processing cycle 5 onwards. Secondary siRNAs were generated from multiple sites of endogenous CHS-A and CHS-J genes, indicating that miR173 cleavage induced siRNAs have the same ability to initiate siRNA transitivity as the siRNAs functioning in co-suppression and hpRNA silencing. On account of the simplicity of vector construction and the transitive amplification of signals from endogenous transcripts, MIGS is a good alternative gene silencing method for plants, especially for silencing a cluster of homologous genes with redundant functions. PMID

  11. Fast carry accumulator design

    NASA Technical Reports Server (NTRS)

    Mastin, W. C.

    1971-01-01

    Simple iterative accumulator combined with gated-carry, carry-completion detection, and skip-carry circuits produces three accumulators with decreased carry propagation times. Devices are used in machine control, measurement equipment, and computer applications to increase speed of binary addition. NAND gates are used in combining network.

  12. Adipocyte differentiation-related protein promotes lipid accumulation in goat mammary epithelial cells.

    PubMed

    Shi, H B; Yu, K; Luo, J; Li, J; Tian, H B; Zhu, J J; Sun, Y T; Yao, D W; Xu, H F; Shi, H P; Loor, J J

    2015-10-01

    Milk fat originates from the secretion of cytosolic lipid droplets (CLD) synthesized within mammary epithelial cells. Adipocyte differentiation-related protein (ADRP; gene symbol PLIN2) is a CLD-binding protein that is crucial for synthesis of mature CLD. Our hypothesis was that ADRP regulates CLD production and metabolism in goat mammary epithelial cells (GMEC) and thus plays a role in determining milk fat content. To understand the role of ADRP in ruminant milk fat metabolism, ADRP (PLIN2) was overexpressed or knocked down in GMEC using an adenovirus system. Immunocytochemical staining revealed that ADRP localized to the surface of CLD. Supplementation with oleic acid (OA) enhanced its colocalization with CLD surface and enhanced lipid accumulation. Overexpression of ADRP increased lipid accumulation and the concentration of triacylglycerol in GMEC. In contrast, morphological examination revealed that knockdown of ADRP decreased lipid accumulation even when OA was supplemented. This response was confirmed by the reduction in mass of cellular TG when ADRP was knocked down. The fact that knockdown of ADRP did not completely eliminate lipid accumulation at a morphological level in GMEC without OA suggests that some other compensatory factors may also aid in the process of CLD formation. The ADRP reversed the decrease of CLD accumulation induced by adipose triglyceride lipase. This is highly suggestive of ADRP promoting triacylglycerol stability within CLD by preventing access to adipose triglyceride lipase. Collectively, these data provide direct in vitro evidence that ADRP plays a key role in CLD formation and stability in GMEC. PMID:26298750

  13. How awareness changes the relative weights of evidence during human decision-making.

    PubMed

    de Lange, Floris P; van Gaal, Simon; Lamme, Victor A F; Dehaene, Stanislas

    2011-11-01

    Human decisions are based on accumulating evidence over time for different options. Here we ask a simple question: How is the accumulation of evidence affected by the level of awareness of the information? We examined the influence of awareness on decision-making using combined behavioral methods and magneto-encephalography (MEG). Participants were required to make decisions by accumulating evidence over a series of visually presented arrow stimuli whose visibility was modulated by masking. Behavioral results showed that participants could accumulate evidence under both high and low visibility. However, a top-down strategic modulation of the flow of incoming evidence was only present for stimuli with high visibility: once enough evidence had been accrued, participants strategically reduced the impact of new incoming stimuli. Also, decision-making speed and confidence were strongly modulated by the strength of the evidence for high-visible but not low-visible evidence, even though direct priming effects were identical for both types of stimuli. Neural recordings revealed that, while initial perceptual processing was independent of visibility, there was stronger top-down amplification for stimuli with high visibility than low visibility. Furthermore, neural markers of evidence accumulation over occipito-parietal cortex showed a strategic bias only for highly visible sensory information, speeding up processing and reducing neural computations related to the decision process. Our results indicate that the level of awareness of information changes decision-making: while accumulation of evidence already exists under low visibility conditions, high visibility allows evidence to be accumulated up to a higher level, leading to important strategical top-down changes in decision-making. Our results therefore suggest a potential role of awareness in deploying flexible strategies for biasing information acquisition in line with one's expectations and goals. PMID:22131904

  14. Revealing Rembrandt

    PubMed Central

    Parker, Andrew J.

    2014-01-01

    The power and significance of artwork in shaping human cognition is self-evident. The starting point for our empirical investigations is the view that the task of neuroscience is to integrate itself with other forms of knowledge, rather than to seek to supplant them. In our recent work, we examined a particular aspect of the appreciation of artwork using present-day functional magnetic resonance imaging (fMRI). Our results emphasized the continuity between viewing artwork and other human cognitive activities. We also showed that appreciation of a particular aspect of artwork, namely authenticity, depends upon the co-ordinated activity between the brain regions involved in multiple decision making and those responsible for processing visual information. The findings about brain function probably have no specific consequences for understanding how people respond to the art of Rembrandt in comparison with their response to other artworks. However, the use of images of Rembrandt's portraits, his most intimate and personal works, clearly had a significant impact upon our viewers, even though they have been spatially confined to the interior of an MRI scanner at the time of viewing. Neuroscientific studies of humans viewing artwork have the capacity to reveal the diversity of human cognitive responses that may be induced by external advice or context as people view artwork in a variety of frameworks and settings. PMID:24795552

  15. The accumulation and structure of comets

    NASA Technical Reports Server (NTRS)

    Donn, Bertram

    1991-01-01

    The paper reviews evidence for the accumulation of the terrestrial planets and comets from solid grains, with emphasis on the various proposals for the formation of cometary nuclei. With three exceptions, all hypotheses conclude or imply that a single compact object forms. Several hypotheses start with Goldreich-Ward-type gravitational instabilities. The collapse for this case also occurs at low velocities in the cm/s to m/s range. Experiment and theory show that under these conditions, low-density, filamentary clusters form that are fractal aggregates with a fractal dimension approximately equal to 2. In order to form cometary nuclei, the initial temperature must be about 50 K and not undergo a significant temperature rise during the accumulation process. The calculations show that accumulation will occur at low temperatures. Models of cometary nuclei are reviewed, and a simple model of the structure that results fom the accumulation of fluffy aggregates is described.

  16. Revealing Mercury

    NASA Astrophysics Data System (ADS)

    Prockter, L. M.; Solomon, S. C.; Head, J. W.; Watters, T. R.; Murchie, S. L.; Robinson, M. S.; Chapman, C. R.; McNutt, R. L.

    2009-04-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, developed under NASA's Discovery Program, launched in August 2004. En route to insertion into orbit about Mercury in 2011, MESSENGER flies by Mercury three times. The first and second of these encounters were accomplished in January and October of 2008. These flybys viewed portions of Mercury's surface that were not observed by Mariner 10 during its reconnaissance of somewhat less than half of the planet in 1974-1975. All MESSENGER instruments operated during each flyby and returned a wealth of new data. Many of the new observations were focused on the planet's geology, including monochrome imaging at resolutions as high as 100 m/pixel, multispectral imaging in 11 filters at resolutions as high as 500 m/pixel, laser altimetry tracks extending over several thousands of kilometers, and high-resolution spectral measurements of several types of terrain. Here we present an overview of the first inferences on the global geology of Mercury from the MESSENGER observations. Whereas evidence for volcanism was equivocal from Mariner 10 data, the new MESSENGER images and altimetry provide compelling evidence that volcanism was widespread and protracted on Mercury. Color imaging reveals three common spectral units on the surface: a higher-reflectance, relatively red material occurring as a distinct class of smooth plains, typically with distinct embayment relationships interpreted to indicate volcanic emplacement; a lower-reflectance, relatively blue material typically excavated by impact craters and therefore inferred to be more common at depth; and a spectrally intermediate terrain that constitutes much of the uppermost crust. Three more minor spectral units are also seen: fresh crater ejecta, reddish material associated with rimless depressions interpreted to be volcanic centers, and high-reflectance deposits seen in some crater floors. Preliminary measurements of crater size

  17. [Glial cells are involved in iron accumulation and degeneration of dopamine neurons in Parkinson's disease].

    PubMed

    Xu, Hua-Min; Wang, Jun; Song, Ning; Jiang, Hong; Xie, Jun-Xia

    2016-08-25

    A growing body of evidence suggests that glial cells play an important role in neural development, neural survival, nerve repair and regeneration, synaptic transmission and immune inflammation. As the highest number of cells in the central nervous system, the role of glial cells in Parkinson's disease (PD) has attracted more and more attention. It has been confirmed that nigral iron accumulation contributes to the death of dopamine (DA) neurons in PD. Until now, most researches on nigral iron deposition in PD are focusing on DA neurons, but in fact glial cells in the central nervous system also play an important role in the regulation of iron homeostasis. Therefore, this review describes the role of iron metabolism of glial cells in death of DA neurons in PD, which could provide evidence to reveal the mechanisms underlying nigral iron accumulation of DA neurons in PD and provide the basis for discovering new potential therapeutic targets for PD. PMID:27546505

  18. Copper accumulation in the crayfish (Orconectes rusticus)

    SciTech Connect

    Evans, M.L.

    1980-06-01

    The purpose of this study was to determine whether or not the crayfish, O. rusticus could fulfill Nehring's (1976) criteria for a good biological monitor of heavy metal pollution. Since there is some evidence that the cupric ion is the most toxic form of aqueous copper, crayfish-accumulated copper was compared to both total and cupric copper in the culture water.

  19. 3D morphology of the human hepatic ferritin mineral core: New evidence for a subunit structure revealed by single particle analysis of HAADF-STEM images

    PubMed Central

    Pan, Ying-Hsi; Sader, Kasim; Powell, Jonathan J.; Bleloch, Andrew; Gass, Mhairi; Trinick, John; Warley, Alice; Li, Andy; Brydson, Rik; Brown, Andy

    2009-01-01

    Ferritin, the major iron storage protein, has dual functions; it sequesters redox activity of intracellular iron and facilitates iron turn-over. Here we present high angle annular dark field (HAADF) images from individual hepatic ferritin cores within tissue sections, these images were obtained using spherical aberration corrected scanning transmission electron microscopy (STEM) under controlled electron fluence. HAADF images of the cores suggest a cubic morphology and a polycrystalline (ferrihydrite) subunit structure that is not evident in equivalent bright field images. By calibrating contrast levels in the HAADF images using quantitative electron energy loss spectroscopy, we have estimated the absolute iron content in any one core, and produced a three dimensional reconstruction of the average core morphology. The core is composed of up to eight subunits, consistent with the eight channels in the protein shell that deliver iron to the central cavity. We find no evidence of a crystallographic orientation relationship between core subunits. Our results confirm that the ferritin protein shell acts as a template for core morphology and within the core, small (∼2 nm), surface-disordered ferrihydrite subunits connect to leave a low density centre and a high surface area that would allow rapid turn-over of iron in biological systems. PMID:19116170

  20. Mechanistic evidence of Passiflora edulis (Passifloraceae) anxiolytic activity in relation to its metabolite fingerprint as revealed via LC-MS and chemometrics.

    PubMed

    Otify, Asmaa; George, Camilia; Elsayed, Aly; Farag, Mohamed A

    2015-12-01

    Passiflora edulis Sims F. flavicarpa along with several other plants belonging to the genus Passiflora have been reported as sedatives and for treatment or prevention of central disorders. This study evaluated the anxiolytic effect of P. edulis ethanol extract and its fractions (viz. chloroform, ethyl acetate and butanol) using the elevated plus-maze model of anxiety and assessment of γ-aminobutyric acid levels. The results revealed that butanol and chloroform extracts exhibit the strongest effect followed by ethyl acetate suggesting that a combination of different classes of metabolites is likely to mediate for P. edulis anxiolytic effect in these fractions. To further pinpoint bioactive agents in fractions, ultra-performance liquid chromatography (UPLC) coupled to high resolution qTOF-MS was used for secondary metabolite profiling. A total of 65 metabolites were characterized including O-flavonoids, C-flavonoids, cyanogenic glycosides and fatty acids. Harman type alkaloids found in P. incarnata were not detected in P. edulis ethanol extract or any of its fractions suggesting that they do not mediate for its CNS modulating effects. Multivariate data analysis (PCA) was further applied to identify metabolite markers for fractions and revealed that enrichment of C-glycoside type flavonoids in chloroform/ethyl acetate fractions versus the exclusive presence of cyanogenic glycosides in its butanol fraction. PMID:26437270

  1. Neurodegeneration with Brain Iron Accumulation

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Neurodegeneration with Brain Iron Accumulation Information Page Synonym(s): Hallervorden-Spatz Disease, ... done? Clinical Trials Organizations What is Neurodegeneration with Brain Iron Accumulation? Neurodegeneration with brain iron accumulation (NBIA) ...

  2. Plastids and Carotenoid Accumulation.

    PubMed

    Li, Li; Yuan, Hui; Zeng, Yunliu; Xu, Qiang

    2016-01-01

    Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants. PMID:27485226

  3. Evidences for high gas content beneath the Gorely volcano in Kamchatka (Russia) based on very low Vp/Vs ratio revealed from local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Koulakov, Ivan; Kuznetsov, Pavel; Ilyich Gordeev, Evgeny; Nikolaevich Chebrov, Viktor

    2015-04-01

    The Gorely volcano, which is located at distance of 70 km from Petropavlovsk-Kamchatsky, is one of the most active volcanoes in Kamchatka. Nowadays, a large fumarole inside the volcano crater ejects approximately 11,000 tons of gases daily. During the last thousands years, eruptions in Gorely were mostly basaltic that determined the shield type of the volcano. However, a large caldera of ~20 km diameter dated at approximately 30,000 years indicates that the volcano has high explosive potential. To identify the feeding mechanisms and to assess the possibility of future large eruptions, scientists from IPGG, Novosibirsk, have deployed the first temporary seismic network on the Gorely volcano. This network consisted of 21 uniformly distributed seismic stations that operated for one year from August 2013 to July 2014. Most of the time during the observation period, dozens to hundreds events per day and frequent tremors were recorded which indicated significant activity inside the volcano. As a result of preliminary processing, almost 300 events were identified during only several weeks of recording. The available distributions of events and stations enables fairly high resolution in the derived seismic velocity models, as demonstrated by a number of synthetic tests. A striking feature of the tomographic inversion is an average ratio of Vp/Vs=1.53, which is an exceptionally low compared to other volcanic areas. We propose that this low Vp/Vs ratio is a signature of high content of gases beneath the volcano. Higher values of Vp/Vs beneath the crater below ~2 km depth might indicate some presence of liquid water, which comes from deeper sources and is transformed to the steam at shallower levels due to the decompression. It appears that Gorely is a kind of a huge steam boiler covered with a solid cover consisting of previously erupted basaltic layers. The fumarole inside the crater plays the role of safety valve which prevents the accumulation of excessive pressure inside

  4. Live/Dead Comparisons of Ostracodes in Temperate Lakes Reveal Evidence of Human Impact and Provides a Tool to Measure the Progress of Remediation Efforts

    NASA Astrophysics Data System (ADS)

    Spergel, J.; Kimball, K. C.; Fitzpatrick, S. A.; Michelson, A. V.; Leonard-Pingel, J.

    2015-12-01

    the progress of remediation efforts already underway. Further work will focus on dating the upper centimeter of sediment in these lakes to provide an estimate of how long it takes for death assemblages to accumulate and thus how long it will take to regain high live/dead fidelity in impacted lakes undergoing remediation.

  5. Molecular and morphological evidence supports the species status of the Mahachai fighter Betta sp. Mahachai and reveals new species of Betta from Thailand.

    PubMed

    Sriwattanarothai, N; Steinke, D; Ruenwongsa, P; Hanner, R; Panijpan, B

    2010-08-01

    Two regions of mitochondrial (mt) DNA, cytochrome c oxidase subunit 1 (COI) and 16S rRNA, were sequenced in nine species of Betta from Thailand and Indonesia. Most species showed little intraspecific COI variation (adjusted mean = 0.48%) including the putative species Betta sp. Mahachai, but one species (Betta smaragdina) included three lineages showing much greater divergence (7.03-13.48%) that probably represent overlooked species. These findings were confirmed by maximum likelihood analysis and Bayesian inference, which revealed well-supported corresponding monophyletic clades. Based on these results and morphological differences, the putative species Betta sp. Mahachai from central Thailand is a species distinct from other members of the B. splendens group and represents a new and hitherto undescribed species. Furthermore, this study also demonstrated the probable existence of two overlooked Betta species found in the Khorat plateau basin, illustrating the utility of mitochondrial genetic markers in the revelation of overlooked diversity. PMID:20646165

  6. Chimpanzee accumulative stone throwing.

    PubMed

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  7. Chimpanzee accumulative stone throwing

    PubMed Central

    Kühl, Hjalmar S.; Kalan, Ammie K.; Arandjelovic, Mimi; Aubert, Floris; D’Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E.; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J.; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M.; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  8. Accumulation of the planets

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.

    1987-01-01

    In modeling the accumulation of planetesimals into planets, it is appropriate to distinguish between two stages: an early stage, during which approximately 10 km diameter planetesimals accumulate locally to form bodies approximate 10 to the 25th g in mass; and a later stage in which the approximately 10 to the 25th g planetesimals accumulate into the final planets. In the terrestrial planet region, an initial planetesimal swarm corresponding to the critical mass of dust layer gravitational instabilities is considered. In order to better understand the accumulation history of Mercury-sized bodies, 19 Monte-Carlo simulations of terrestrial planet growth were calculated. A Monte Carlo technique was used to investigate the orbital evolution of asteroidal collision debris produced interior to 2.6 AU. It was found that there are two regions primarily responsible for production of Earth-crossing meteoritic material and Apollo objects. The same techniques were extended to include the origin of Earth-approaching asteroidal bodies. It is found that these same two resonant mechanisms predict a steady-state number of Apollo-Amor about 1/2 that estimated based on astronomical observations.

  9. Evidence for Niche Partitioning Revealed by the Distribution of Sulfur Oxidation Genes Collected from Areas of a Terrestrial Sulfidic Spring with Differing Geochemical Conditions

    PubMed Central

    Engel, Annette Summers

    2013-01-01

    The diversity and phylogenetic significance of bacterial genes in the environment has been well studied, but comparatively little attention has been devoted to understanding the functional significance of different variations of the same metabolic gene that occur in the same environment. We analyzed the geographic distribution of 16S rRNA pyrosequences and soxB genes along a geochemical gradient in a terrestrial sulfidic spring to identify how different taxonomic variations of the soxB gene were naturally distributed within the spring outflow channel and to identify possible evidence for altered SoxB enzyme function in nature. Distinct compositional differences between bacteria that utilize their SoxB enzyme in the Paracoccus sulfide oxidation pathway (e.g., Bradyrhizobium, Paracoccus, and Rhodovulum) and bacteria that utilize their SoxB enzyme in the branched pathway (e.g., Chlorobium, Thiothrix, Thiobacillus, Halothiobacillus, and Thiomonas) were identified. Different variations of the soxB genes were present at different locations within the spring outflow channel in a manner that significantly corresponded to geochemical conditions. The distribution of the different soxB gene sequence variations suggests that the enzymes encoded by these genes are functionally different and could be optimized to specific geochemical conditions that define niche space for bacteria capable of oxidizing reduced sulfur compounds. PMID:23220955

  10. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic–Jurassic transition

    PubMed Central

    Kürschner, Wolfram M.; Batenburg, Sietske J.; Mander, Luke

    2013-01-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic–Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  11. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic-Jurassic transition.

    PubMed

    Kürschner, Wolfram M; Batenburg, Sietske J; Mander, Luke

    2013-10-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic-Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  12. Disparity between dorsal and ventral networks in patients with obsessive-compulsive disorder: evidence revealed by graph theoretical analysis based on cortical thickness from MRI

    PubMed Central

    Kim, Seung-Goo; Jung, Wi Hoon; Kim, Sung Nyun; Jang, Joon Hwan; Kwon, Jun Soo

    2013-01-01

    As one of the most widely accepted neuroanatomical models on obsessive-compulsive disorder (OCD), it has been hypothesized that imbalance between an excitatory direct (ventral) pathway and an inhibitory indirect (dorsal) pathway in cortico-striato-thalamic circuit underlies the emergence of OCD. Here we examine the structural network in drug-free patients with OCD in terms of graph theoretical measures for the first time. We used a measure called efficiency which quantifies how a node transfers information efficiently. To construct brain networks, cortical thickness was automatically estimated using T1-weighted magnetic resonance imaging. We found that the network of the OCD patients was as efficient as that of healthy controls so that the both networks were in the small-world regime. More importantly, however, disparity between the dorsal and the ventral networks in the OCD patients was found in terms of graph theoretical measures, suggesting a positive evidence to the imbalance theory on the underlying pathophysiology of OCD. PMID:23840184

  13. Sequencing and characterisation of rearrangements in three S. pastorianus strains reveals the presence of chimeric genes and gives evidence of breakpoint reuse.

    PubMed

    Hewitt, Sarah K; Donaldson, Ian J; Lovell, Simon C; Delneri, Daniela

    2014-01-01

    Gross chromosomal rearrangements have the potential to be evolutionarily advantageous to an adapting organism. The generation of a hybrid species increases opportunity for recombination by bringing together two homologous genomes. We sought to define the location of genomic rearrangements in three strains of Saccharomyces pastorianus, a natural lager-brewing yeast hybrid of Saccharomyces cerevisiae and Saccharomyces eubayanus, using whole genome shotgun sequencing. Each strain of S. pastorianus has lost species-specific portions of its genome and has undergone extensive recombination, producing chimeric chromosomes. We predicted 30 breakpoints that we confirmed at the single nucleotide level by designing species-specific primers that flank each breakpoint, and then sequencing the PCR product. These rearrangements are the result of recombination between areas of homology between the two subgenomes, rather than repetitive elements such as transposons or tRNAs. Interestingly, 28/30 S. cerevisiae-S. eubayanus recombination breakpoints are located within genic regions, generating chimeric genes. Furthermore we show evidence for the reuse of two breakpoints, located in HSP82 and KEM1, in strains of proposed independent origin. PMID:24643015

  14. Sequencing and Characterisation of Rearrangements in Three S. pastorianus Strains Reveals the Presence of Chimeric Genes and Gives Evidence of Breakpoint Reuse

    PubMed Central

    Hewitt, Sarah K.; Donaldson, Ian J.; Lovell, Simon C.; Delneri, Daniela

    2014-01-01

    Gross chromosomal rearrangements have the potential to be evolutionarily advantageous to an adapting organism. The generation of a hybrid species increases opportunity for recombination by bringing together two homologous genomes. We sought to define the location of genomic rearrangements in three strains of Saccharomyces pastorianus, a natural lager-brewing yeast hybrid of Saccharomyces cerevisiae and Saccharomyces eubayanus, using whole genome shotgun sequencing. Each strain of S. pastorianus has lost species-specific portions of its genome and has undergone extensive recombination, producing chimeric chromosomes. We predicted 30 breakpoints that we confirmed at the single nucleotide level by designing species-specific primers that flank each breakpoint, and then sequencing the PCR product. These rearrangements are the result of recombination between areas of homology between the two subgenomes, rather than repetitive elements such as transposons or tRNAs. Interestingly, 28/30 S. cerevisiae- S. eubayanus recombination breakpoints are located within genic regions, generating chimeric genes. Furthermore we show evidence for the reuse of two breakpoints, located in HSP82 and KEM1, in strains of proposed independent origin. PMID:24643015

  15. RADIO STACKING REVEALS EVIDENCE FOR STAR FORMATION IN THE HOST GALAXIES OF X-RAY-SELECTED ACTIVE GALACTIC NUCLEI AT z < 1

    SciTech Connect

    Pierce, C. M.; Ballantyne, D. R.; Ivison, R. J.

    2011-11-20

    Nuclear starbursts may contribute to the obscuration of active galactic nuclei (AGNs). The predicted star formation rates (SFRs) are modest, and, for the obscured AGNs that form the X-ray background at z < 1, the associated faint radio emission lies just beyond the sensitivity limits of the deepest surveys. Here, we search for this level of star formation by studying a sample of 359 X-ray-selected AGNs at z < 1 from the Cosmic Evolution Survey field that are not detected by current radio surveys. The AGNs are separated into bins based on redshift, X-ray luminosity, obscuration, and mid-infrared characteristics. An estimate of the AGN contribution to the radio flux density is subtracted from each radio image, and the images are then stacked to uncover any residual faint radio flux density. All of the bins containing 24 {mu}m detected AGNs are detected with a signal-to-noise >3{sigma} in the stacked radio images. In contrast, AGNs not detected at 24 {mu}m are not detected in the resulting stacked radio images. This result provides strong evidence that the stacked radio signals are likely associated with star formation. The estimated SFRs derived from the radio stacks range from 3 M{sub Sun} yr{sup -1} to 29 M{sub Sun} yr{sup -1}. Although it is not possible to associate the radio emission with a specific region of the host galaxies, these results are consistent with the predictions of nuclear starburst disks in AGN host galaxies.

  16. Evidence for anthropophily in five species of phlebotomine sand flies (Diptera: Psychodidae) from northern Colombia, revealed by molecular identification of bloodmeals.

    PubMed

    Paternina, Luís E; Verbel-Vergara, Daniel; Romero-Ricardo, Luís; Pérez-Doria, Alveiro; Paternina-Gómez, Margaret; Martínez, Lily; Bejarano, Eduar E

    2016-01-01

    Identification of the bloodmeal sources of phlebotomine sand flies is fundamental to determining which species are anthropophilic and understanding the transmission of Leishmania parasites in natural epidemiological settings. The objective of this study was to identify sand fly bloodmeals in the mixed leishmaniasis focus of the department of Sucre, northern Colombia. In all 141 engorged female sand flies were analyzed, after being captured in intradomiciliary, peridomiciliary and extradomiciliary habitats with Shannon and CDC traps and by active searching in diurnal resting sites. Bloodmeals were identified by sequencing and analysis of a 358bp fragment of the mitochondrial gene Cytochrome b (CYB) and a 330bp fragment of the nuclear gene prepronociceptin (PNOC). Using both genes 105 vertebrate bloodmeals were identified, with an efficiency of 72% for CYB but only 7% for PNOC. Ten species of vertebrates were identified as providing bloodmeal sources for 8 sand fly species: Homo sapiens (Lutzomyia evansi, Lutzomyia panamensis, Lutzomyia micropyga, Lutzomyia shannoni and Lutzomyia atroclavata), Equus caballus (L. evansi, L. panamensis and Lutzomyia cayennensis cayennensis), Equus asinus (L. evansi and L. panamensis), Bos taurus (L. evansi, L. panamensis and L. c. cayennensis), Tamandua mexicana (L. shannoni and Lutzomyia trinidadensis), Proechimys guyanensis (L. evansi, L. panamensis and L. c. cayennensis), Mabuya sp. (Lutzomyia micropyga), Anolissp. (L. micropyga), Sus scrofa (L. evansi and Lutzomyia gomezi) and Gallus gallus (L. evansi). Cattle, donkeys, humans and pigs were significantly more important than other animals (P=0.0001) as hosts of L. evansi, this being the most abundant sand fly species. The five Lutzomyia species in which blood samples of human origin were detected included L. micropyga and L. atroclavata, constituting the first evidence of anthropophily in both species. PMID:26464046

  17. High-throughput sequencing of partially edited trypanosome mRNAs reveals barriers to editing progression and evidence for alternative editing.

    PubMed

    Simpson, Rachel M; Bruno, Andrew E; Bard, Jonathan E; Buck, Michael J; Read, Laurie K

    2016-05-01

    Uridine insertion/deletion RNA editing in kinetoplastids entails the addition and deletion of uridine residues throughout the length of mitochondrial transcripts to generate translatable mRNAs. This complex process requires the coordinated use of several multiprotein complexes as well as the sequential use of noncoding template RNAs called guide RNAs. The majority of steady-state mitochondrial mRNAs are partially edited and often contain regions of mis-editing, termed junctions, whose role is unclear. Here, we report a novel method for sequencing entire populations of pre-edited partially edited, and fully edited RNAs and analyzing editing characteristics across populations using a new bioinformatics tool, the Trypanosome RNA Editing Alignment Tool (TREAT). Using TREAT, we examined populations of two transcripts, RPS12 and ND7-5', in wild-typeTrypanosoma brucei We provide evidence that the majority of partially edited sequences contain junctions, that intrinsic pause sites arise during the progression of editing, and that the mechanisms that mediate pausing in the generation of canonical fully edited sequences are distinct from those that mediate the ends of junction regions. Furthermore, we identify alternatively edited sequences that constitute plausible alternative open reading frames and identify substantial variability in the 5' UTRs of both canonical and alternatively edited sequences. This work is the first to use high-throughput sequencing to examine full-length sequences of whole populations of partially edited transcripts. Our method is highly applicable to current questions in the RNA editing field, including defining mechanisms of action for editing factors and identifying potential alternatively edited sequences. PMID:26908922

  18. Hepatogenous photosensitization associated with liver copper accumulation in buffalos.

    PubMed

    Minervino, Antonio H H; Júnior, Raimundo A Barrêto; Rodrigues, Frederico A M L; Ferreira, Rodrigo N F; Reis, Leonardo F; Headley, Selwyn A; Ortolani, Enrico L

    2010-06-01

    Four 1.5-year-old, male, Murrah buffalos were maintained during eight months without direct solar exposure during a study of copper toxicosis. Four days after solar exposure, all buffalos presented clinical manifestations consistent with acute photosensitization, including anorexia, apathy, loss of body weight, and generalized cutaneous lesions. Gross lesions were characterized by severe erythema, localized edema, fissures, tissue necrosis, gangrene and crust formation with serous exudation. Liver copper concentration was evaluated, and cutaneous biopsies were taken when clinical signs were evident. The liver copper concentration before solar exposure was increased in all animals. Histopathologic examination of the skin revealed hepatogenous photosensitization characterized by parakeratotic hyperkeratosis, acantholysis, degeneration of squamous epithelial cells, epidermal necrosis with atrophy of sweat glands, and multifocal superficial and deep dermal edema. These findings suggest that asymptomatic accumulation of copper within the liver might have induced hepatic insufficiency thereby resulting in secondary photosensitization when these buffalos were exposed to sunlight. PMID:20064649

  19. Site-directed tryptophan fluorescence reveals the solution structure of tear lipocalin: evidence for features that confer promiscuity in ligand binding.

    PubMed

    Gasymov, O K; Abduragimov, A R; Yusifov, T N; Glasgow, B J

    2001-12-11

    The solution structure of human TL was deduced from the position of the emission peaks after site-directed tryptophan fluorescence (SDTF). The fluorescent amino acid tryptophan was sequentially substituted for each native amino acid in the sequence. Characteristic periodicities for eight beta-strands that comprise the beta-barrel and three alpha-helices were identified. The putative beta-strand I was relatively exposed to solvent, suggesting it does not participate in the formation of the beta-barrel. The beta-strands A and F contain beta-bulges. The average lambda(max) of emission maxima reveals that strand D is at the edge of the barrel and beta-strand H interacts with the main alpha-helical domain. On the basis of the SDTF data, a 3D homology model was constructed for TL and compared to the known crystallographic structures of RBP and beta-lactoglobulin. The small size and splayed open configuration of the E-F hairpin facilitate access of ligands into the cavity mouth of TL as compared to that of RBP with a long overhanging loop that restricts access. In the model of TL, four alanine residues are positioned in the binding site as compared to bulkier residues in the corresponding positions of beta-lactoglobulin. Substitution of A51, A66, A86 to Trp results in a 3-4-fold decrease in binding affinity. The data suggest that the smaller side chains of Ala provide more capacity in the cavity of TL than the bulkier side chains (I56, I71, V92) in the cavity of beta-lactoglobulin. The structural features provide an explanation for the promiscuous binding characteristics exhibited by TL. SDTF provides a general approach for determining the solution structure of many proteins and enhances homology modeling in the absence of high sequence identity. PMID:11732894

  20. 150,000 years of loess accumulation in central Alaska

    NASA Astrophysics Data System (ADS)

    Jensen, Britta J. L.; Evans, Michael E.; Froese, Duane G.; Kravchinsky, Vadim A.

    2016-03-01

    The Halfway House site in interior Alaska is arguably the most studied loess deposit in northwestern North America. The site contains a complex paleomagnetic and paleoenvironmental record, but has lacked the robust chronologic control that would allow its full potential to be exploited. Detailed reexamination of stratigraphy, paleomagnetics and tephrostratigraphy reveals a relatively complete marine isotope stage (MIS) 6 to Holocene record constrained by the Old Crow (124 ± 10 ka), VT (106 ± 10 ka), Sheep Creek-Klondike (ca. 80 ka), Dominion Creek (77 ± 8 ka) and Dawson (ca. 30.2 cal ka BP) tephras. We show two well-developed paleosols formed during Marine Isotope Stages (MIS) 5e and 5a, while MIS 5c and 5b are either poorly represented or absent. The new tephrostratigraphy presented here is the most complete one to date for the late Pleistocene and indicates MIS 5 sediments are more common than previously recognized. A magnetic excursion within the sediments is identified as the post-Blake excursion (94.1 ± 7.8 ka), providing independent age control and adding to the increasing body of evidence that Alaskan loess is a detailed recorder of variations of the Earth's magnetic field over time. A high-resolution magnetic susceptibility profile placed into this new chronostratigraphic framework supports the hypothesis that wind-intensity is the main variable controlling fluctuations in susceptibility. Correlation of the susceptibility record to global marine δ18O records is complicated by highly variable accumulation rates. We find the lowest rates of accumulation during peak warm and cold stages, while abrupt increases are associated with periods of transition between marine isotope (sub)stages. Building on previous accumulation models for Alaska, surface roughness is likely a leading variable controlling loess accumulation rates during transitions and peak cold periods, but the negligible accumulation during MIS 5e and 5a suggests that loess production was

  1. Eruptive History of Volcán Tepetiltic, Mexico: Evidence for Remelting of Silicic Ashflows Revealed by 40Ar/39Ar Geochronology

    NASA Astrophysics Data System (ADS)

    Frey, H. M.; Lange, R. A.; Hall, C. M.; Nelson, S. A.; Granados, H. D.

    2004-12-01

    andesite dated from the caldera rim. The minimum age of the eruption is constrained by the occurrence of airfall from VT found underneath lava flows from the Amado Nervo shield volcano (220 ± 30 ka). Given these results, the Plinian eruption likely occurred ˜225 ± 40 kyrs ago. The two rhyolite obsidian domes on the eastern flanks of VT were dated at 307 ± 34 ka and 274 ± 52 ka and are thus similar in age or slightly older than the Plinian eruption. The >200 kyr hiatus between the construction of the andesite/dacite stratocone and the rhyolitic activity argues against crystal fractionation of the andesite to form the rhyolite. The upper crustal magma chamber feeding the main edifice ˜524 kyrs ago was likely short-lived (tens of kyrs), and may have crystallized to a granitoid. We suggest that the rhyolites formed ˜230 kyrs ago by partial melting of older shallow basement rhyolitic ashflows prevalent in the area. Evidence for this process is found in an unconsolidated pyroclastic flow from VT with pumiceous rhyolitic blocks and andesitic lithic fragments. Anorthoclase crystals in this deposit yield ages of 4.5 ± 0.34 Ma and 25.9 ± 0.24 Ma. Thus the rhyolites were likely produced by refusing of 4-5 Ma silicic ashflows and ashflows from the Sierra Madre Occidental province (20-35 Ma) and not crystal fractionation.

  2. Heat exchanger-accumulator

    DOEpatents

    Ecker, Amir L.

    1980-01-01

    What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

  3. How Are Preferences Revealed?

    PubMed Central

    Beshears, John; Choi, James J.; Laibson, David; Madrian, Brigitte C.

    2009-01-01

    Revealed preferences are tastes that rationalize an economic agent’s observed actions. Normative preferences represent the agent’s actual interests. It sometimes makes sense to assume that revealed preferences are identical to normative preferences. But there are many cases where this assumption is violated. We identify five factors that increase the likelihood of a disparity between revealed preferences and normative preferences: passive choice, complexity, limited personal experience, third-party marketing, and intertemporal choice. We then discuss six approaches that jointly contribute to the identification of normative preferences: structural estimation, active decisions, asymptotic choice, aggregated revealed preferences, reported preferences, and informed preferences. Each of these approaches uses consumer behavior to infer some property of normative preferences without equating revealed and normative preferences. We illustrate these issues with evidence from savings and investment outcomes. PMID:24761048

  4. Solids Accumulation Scouting Studies

    SciTech Connect

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  5. ITER helium ash accumulation

    SciTech Connect

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  6. Uptake, accumulation and metabolization of the antidepressant fluoxetine by Mytilus galloprovincialis.

    PubMed

    Silva, Liliana J G; Martins, Margarida C; Pereira, André M P T; Meisel, Leonor M; Gonzalez-Rey, Maria; Bebianno, Maria João; Lino, Celeste M; Pena, Angelina

    2016-06-01

    Fluoxetine, a selective serotonin re-uptake inhibitor (SSRI) antidepressant, is among the most prescribed pharmaceutical active substances worldwide. This study aimed to assess its accumulation and metabolization in the mussel Mytillus galloprovincialis, considered an excellent sentinel species for traditional and emerging pollutants. Mussels were collected from Ria Formosa Lagoon, Portugal, and exposed to a nominal concentration of fluoxetine (75 ng L(-1)) for 15 days. Approximately 1 g of whole mussel soft tissues was extracted with acetonitrile:formic acid, loaded into an Oasis MCX cartridge, and fluoxetine analysed by liquid chromatography with tandem mass spectrometry (LC-MSn). After 3 days of exposure, fluoxetine was accumulated in 70% of the samples, with a mean of 2.53 ng g(-1) dry weight (d.w.) and norfluoxetine was only detected in one sample (10%), at 3.06 ng g(-1) d.w. After 7 days of exposure, the accumulation of fluoxetine and norfluoxetine increased up to 80 and 50% respectively, and their mean accumulated levels in mussel tissues were up to 4.43 and 2.85 ng g(-1) d.w., respectively. By the end of the exposure period (15 days), both compounds were detected in 100% of the samples (mean of 9.31 and 11.65 ng g(-1) d.w., respectively). Statistical analysis revealed significant accumulation differences between the 3rd and 15th day of exposure for fluoxetine, and between the 3rd and 7th against the 15th day of exposure for norfluoxetine. These results suggest that the fluoxetine accumulated in mussel tissues is likely to be metabolised into norfluoxetine with the increase of the time of exposure, giving evidence that at these realistic environmental concentrations, toxic effects of fluoxetine in mussel tissues may occur. PMID:26946178

  7. Role of taurine accumulation in keratinocyte hydration.

    PubMed

    Janeke, Guido; Siefken, Wilfried; Carstensen, Stefanie; Springmann, Gunja; Bleck, Oliver; Steinhart, Hans; Höger, Peter; Wittern, Klaus-Peter; Wenck, Horst; Stäb, Franz; Sauermann, Gerhard; Schreiner, Volker; Doering, Thomas

    2003-08-01

    Epidermal keratinocytes are exposed to a low water concentration at the stratum corneum-stratum granulosum interface. When epithelial tissues are osmotically perturbed, cellular protection and cell volume regulation is mediated by accumulation of organic osmolytes such as taurine. Previous studies reported the presence of taurine in the epidermis of several animal species. Therefore, we analyzed human skin for the presence of the taurine transporter (TAUT) and studied the accumulation of taurine as one potential mechanism protecting epidermal keratinocytes from dehydration. According to our results, TAUT is expressed as a 69 kDa protein in human epidermis but not in the dermis. For the epidermis a gradient was evident with maximal levels of TAUT in the outermost granular keratinocyte layer and lower levels in the stratum spinosum. No TAUT was found in the basal layer or in the stratum corneum. Keratinocyte accumulation of taurine was induced by experimental induction of skin dryness via application of silica gel to human skin. Cultured human keratinocytes accumulated taurine in a concentration- and osmolarity-dependent manner. TAUT mRNA levels were increased after exposure of human keratinocytes to hyperosmotic culture medium, indicating osmosensitive TAUT mRNA expression as part of the adaptation of keratinocytes to hyperosmotic stress. Keratinocyte uptake of taurine was inhibited by beta-alanine but not by other osmolytes such as betaine, inositol, or sorbitol. Accumulation of taurine protected cultured human keratinocytes from both osmotically induced and ultraviolet-induced apoptosis. Our data indicate that taurine is an important epidermal osmolyte required to maintain keratinocyte hydration in a dry environment. PMID:12880428

  8. Genome-wide localization analysis of a complete set of Tafs reveals a specific effect of the taf1 mutation on Taf2 occupancy and provides indirect evidence for different TFIID conformations at different promoters.

    PubMed

    Ohtsuki, Kazushige; Kasahara, Koji; Shirahige, Katsuhiko; Kokubo, Tetsuro

    2010-04-01

    In Saccharomyces cerevisiae, TFIID and SAGA principally mediate transcription of constitutive housekeeping genes and stress-inducible genes, respectively, by delivering TBP to the core promoter. Both are multi-protein complexes composed of 15 and 20 subunits, respectively, five of which are common and which may constitute a core sub-module in each complex. Although genome-wide gene expression studies have been conducted extensively in several TFIID and/or SAGA mutants, there are only a limited number of studies investigating genome-wide localization of the components of these two complexes. Specifically, there are no previous reports on localization of a complete set of Tafs and the effects of taf mutations on localization. Here, we examine the localization profiles of a complete set of Tafs, Gcn5, Bur6/Ncb2, Sua7, Tfa2, Tfg1, Tfb3 and Rpb1, on chromosomes III, IV and V by chromatin immunoprecipitation (ChIP)-chip analysis in wild-type and taf1-T657K mutant strains. In addition, we conducted conventional and sequential ChIP analysis of several ribosomal protein genes (RPGs) and non-RPGs. Intriguingly, the results revealed a novel relationship between TFIIB and NC2, simultaneous co-localization of SAGA and TFIID on RPG promoters, specific effects of taf1 mutation on Taf2 occupancy, and an indirect evidence for the existence of different TFIID conformations. PMID:20026583

  9. Noise Reduction by Signal Accumulation

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2006-01-01

    The aim of this paper is to show how the noise reduction by signal accumulation can be accomplished with a data acquisition system. This topic can be used for student projects. In many cases, the noise reduction is an unavoidable part of experimentation. Several techniques are known for this purpose, and among them the signal accumulation is the…

  10. Heat accumulation during pulsed laser materials processing.

    PubMed

    Weber, Rudolf; Graf, Thomas; Berger, Peter; Onuseit, Volkher; Wiedenmann, Margit; Freitag, Christian; Feuer, Anne

    2014-05-01

    Laser materials processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed laser materials processing for a given pulse repetition rate is derived. PMID:24921828

  11. Accumulative Tritium Transfer from Water into Biosystems

    SciTech Connect

    Baumgaertner, Franz

    2005-07-15

    The energy balance of hydrogen isotopes in H bonds of water and biomolecules results in accumulative tritium transfer from water into biomolecules. Tests of DNA dissolved in tritiated water and of maize or barley hydroponically grown in tritiated water confirm the increase. The primary hydration shell of DNA shows an accumulation factor of {approx}1.4, and the exchangeable hydrogens inside DNA show {approx}2. Logistic growth analyses of maize and barley reveal the intrinsic growth rates of tritium 1.3 and 1.2 times larger than that of hydrogen. The higher rate of tritium than hydrogen incorporation in solid biomatter is caused by the hydration shells, which constitute an intrinsic component of biomolecules.

  12. Revealing Roosevelt

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This image mosaic from the microscopic imager aboard NASA's Mars Exploration Rover Opportunity shows detailed structure of a small fin-like structure dubbed 'Roosevelt,' which sticks out from the outcrop pavement at the edge of 'Erebus Crater.'

    Roosevelt lines a fracture in the local pavement and scientists hypothesize that it is a fracture fill, formed by water that percolated through the fracture. This would mean the feature is younger than surrounding rocks and, therefore, might provide evidence of water that was present some time after the formation of Meridiani Planum sedimentary rocks.

    The image shows fine laminations (layers about 1 millimeter or .04 inch thick) that run parallel to the axis of the fin. Some of the textures visible in the image likely indicate that minerals precipitated from the outcrop rocks, but sediment grains are also apparent.

    The three frames combined into this mosaic were taken during Opportunity's 727th Martian day, or sol (Feb. 8, 2006). In subsequent days, the rover completed textural and chemical inspection of Roosevelt to help the science team understand this structure's significance for Martian history.

  13. Antagonism of eosinophil accumulation in asthma.

    PubMed

    Walsh, Garry M

    2010-11-01

    There is considerable evidence that implicates eosinophils as important effector cells and immunomodulators in the inflammation characteristic of asthma. Numerous in vitro and animal studies have demonstrated essential roles for cell adhesion molecules in eosinophil adhesion and transendothelial migration including the selectins, ICAM-1, VCAM-1 together with many of the 1 and β2 integrins. A large body of evidence has also implicated several cytokines and chemokines in the selective recruitment of eosinophils to sites of asthmatic inflammation. Biopharmaceutical approaches have been used to identify inhibitory molecules that target key elements in the processes controlling eosinophil accumulation in asthma. This review will summarise, the problems and successes regarding recent patents and developments in adhesion-based therapeutic strategies aimed at reducing eosinophil-mediated inflammation in the asthmatic lung. PMID:20804449

  14. Gypsum accumulation on carbonate stone

    USGS Publications Warehouse

    McGee, E.S.; Mossotti, V.G.

    1992-01-01

    The accumulation of gypsum on carbonate stone has been investigated through exposure of fresh samples of limestone and marble at monitored sites, through examination of alteration crusts from old buildings and through laboratory experiments. Several factors contribute to gypsum accumulation on carbonate stone. Marble or limestone that is sheltered from direct washing by rain in an urban environment with elevated pollution levels is likely to accumulate a gypsum crust. Crust development may be enhanced if the stone is porous or has an irregular surface area. Gypsum crusts are a surficial alteration feature; gypsum crystals form at the pore opening-air interface, where evaporation is greatest.

  15. Anthocyanins facilitate tungsten accumulation in Brassica

    SciTech Connect

    Hale, K.L.

    2002-11-01

    Accumulation of molybdenum in Brassica was recently found to be correlated with anthocyanin content, involving the formation of a blue complex. Here the role of anthocyanins in tungsten sequestration was investigated using three species of Brassica: B. rapa (cv. Fast plants), B. juncea (Indian mustard) and B. oleracea (red cabbage). Seedlings of B. rapa and B. juncea turned blue when supplied with colourless tungstate. The blue compound co-localized with anthocyanins in the peripheral cell layers, and the degree of blueness was correlated with anthocyanin content. The direct involvement of anthocyanins in the blue coloration was evident when purified anthocyanins showed a colour change from pink to blue in vitro upon addition of tungstate, over a wide pH range. Anthocyanin production was upregulated 3-fold by W in B. juncea, possibly reflecting a function for anthocyanins in W tolerance or sequestration. The presence of anthocyanins facilitated W accumulation in B. rapa: anthocyanin-containing seedlings accumulated 3-fold more W than an anthocyaninless mutant. There was no correlation between anthocyanin content and W tolerance under these conditions. The nature of the interaction between anthocyanins and tungstate was investigated. X-ray absorption spectroscopy showed no change in the local chemical environment of Wupon uptake of tungstate by the plant; HPLC analysis of purified anthocyanin with or without tungstate showed no peak shift after metal treatment.

  16. How Financial Literacy Affects Household Wealth Accumulation

    PubMed Central

    Behrman, Jere R.; Mitchell, Olivia S.; Soo, Cindy K.; Bravo, David

    2012-01-01

    This study isolates the causal effects of financial literacy and schooling on wealth accumulation using a new household dataset and an instrumental variables (IV) approach. Financial literacy and schooling attainment are both strongly positively associated with wealth outcomes in linear regression models, whereas the IV estimates reveal even more potent effects of financial literacy. They also indicate that the schooling effect only becomes positive when interacted with financial literacy. Estimated impacts are substantial enough to imply that investments in financial literacy could have large wealth payoffs. PMID:23355747

  17. Frailty: Scaling from Cellular Deficit Accumulation?

    PubMed

    Rockwood, Kenneth; Mitnitski, Arnold; Howlett, Susan E

    2015-01-01

    Cells age in association with deficit accumulation via mechanisms that are far from fully defined. Even so, how deficits might scale up from the subcellular level to give rise to clinically evident age-related changes can be investigated. This 'scaling problem' can be viewed either as a series of little-related events that reflect discrete processes--such as the development of particular diseases--or as a stochastic process with orderly progression at the systems level, regardless of which diseases are present. Some recent evidence favors the latter hypothesis, but determining the best approach to study how deficits scale remains a key goal for understanding aging. In consequence, approaching the problem of frailty as one of the scaling of subcellular deficits has implications for understanding aging. Considering the cumulative effects of many small deficits appears to allow for the observation of important aspects of the behavior of systems that are close to failure. Mathematical modeling offers useful possibilities in clarifying the extent to which different clinical scales measure different phenomena. Even so, to be useful, mathematical modelling must be clinically coherent in addition to mathematically sound. In this regard, queuing appears to offer some potential for investigating how deficits originate and accumulate. PMID:26301975

  18. Manganese As a Metal Accumulator

    EPA Science Inventory

    Manganese deposits in water distribution systems accumulate metals, radionuclides and oxyanions by a combination of surface complexation, adsorption and solid substitution, as well as a combination of oxidation followed by manganese reduction and sorption of the oxidized constitu...

  19. Flavonols Accumulate Asymmetrically and Affect Auxin Transport in Arabidopsis1[C][W][OA

    PubMed Central

    Kuhn, Benjamin M.; Geisler, Markus; Bigler, Laurent; Ringli, Christoph

    2011-01-01

    Flavonoids represent a class of secondary metabolites with diverse functions in plants including ultraviolet protection, pathogen defense, and interspecies communication. They are also known as modulators of signaling processes in plant and animal systems and therefore are considered to have beneficial effects as nutraceuticals. The rol1-2 (for repressor of lrx1) mutation of Arabidopsis (Arabidopsis thaliana) induces aberrant accumulation of flavonols and a cell-growth phenotype in the shoot. The hyponastic cotyledons, aberrant shape of pavement cells, and deformed trichomes in rol1-2 mutants are suppressed by blocking flavonoid biosynthesis, suggesting that the altered flavonol accumulation in these plants induces the shoot phenotype. Indeed, the identification of several transparent testa, myb, and fls1 (for flavonol synthase1) alleles in a rol1-2 suppressor screen provides genetic evidence that flavonols interfere with shoot development in rol1-2 seedlings. The increased accumulation of auxin in rol1-2 seedlings appears to be caused by a flavonol-induced modification of auxin transport. Quantification of auxin export from mesophyll protoplasts revealed that naphthalene-1-acetic acid but not indole-3-acetic acid transport is affected by the rol1-2 mutation. Inhibition of flavonol biosynthesis in rol1-2 fls1-3 restores naphthalene-1-acetic acid transport to wild-type levels, indicating a very specific mode of action of flavonols on the auxin transport machinery. PMID:21502189

  20. Anion channels and the stimulation of anthocyanin accumulation by blue light in Arabidopsis seedlings

    NASA Technical Reports Server (NTRS)

    Noh, B.; Spalding, E. P.; Evans, M. H. (Principal Investigator)

    1998-01-01

    Activation of anion channels by blue light begins within seconds of irradiation in seedlings and is related to the ensuing growth inhibition. 5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) is a potent, selective, and reversible blocker of these anion channels in Arabidopsis thaliana. Here we show that 20 microM NPPB blocked 72% of the blue-light-induced accumulation of anthocyanin pigments in seedlings. Feeding biosynthetic intermediates to wild-type and tt5 seedlings provided evidence that NPPB prevented blue light from up-regulating one or more steps between and including phenylalanine ammonia lyase and chalcone isomerase. NPPB was found to have no significant effect on the blue-light-induced increase in transcript levels of PAL1, CHS, CHI, or DFR, which are genes that encode anthocyanin-biosynthetic enzymes. Immunoblots revealed that NPPB also did not inhibit the accumulation of the chalcone synthase, chalcone isomerase, or flavanone-3-hydroxylase proteins. This is in contrast to the reduced anthocyanin accumulation displayed by a mutant lacking the HY4 blue-light receptor, as hy4 displayed reduced expression of the above enzymes. Taken together, the data indicate that blue light acting through HY4 leads to an increase in the amount of biosynthetic enzymes but blue light must also act through a separate, anion-channel-dependent system to create a fully functional biosynthetic pathway.

  1. The Kallisti Limnes, carbon dioxide-accumulating subsea pools

    NASA Astrophysics Data System (ADS)

    2015-07-01

    Natural CO2 releases from shallow marine hydrothermal vents are assumed to mix into the water column, and not accumulate into stratified seafloor pools. We present newly discovered shallow subsea pools located within the Santorini volcanic caldera of the Southern Aegean Sea, Greece, that accumulate CO2 emissions from geologic reservoirs. This type of hydrothermal seafloor pool, containing highly concentrated CO2, provides direct evidence of shallow benthic CO2 accumulations originating from sub-seafloor releases. Samples taken from within these acidic pools are devoid of calcifying organisms, and channel structures among the pools indicate gravity driven flow, suggesting that seafloor release of CO2 at this site may preferentially impact benthic ecosystems. These naturally occurring seafloor pools may provide a diagnostic indicator of incipient volcanic activity and can serve as an analog for studying CO2 leakage and benthic accumulations from subsea carbon capture and storage sites.

  2. The Kallisti Limnes, carbon dioxide-accumulating subsea pools.

    PubMed

    Camilli, Richard; Nomikou, Paraskevi; Escartín, Javier; Ridao, Pere; Mallios, Angelos; Kilias, Stephanos P; Argyraki, Ariadne

    2015-01-01

    Natural CO2 releases from shallow marine hydrothermal vents are assumed to mix into the water column, and not accumulate into stratified seafloor pools. We present newly discovered shallow subsea pools located within the Santorini volcanic caldera of the Southern Aegean Sea, Greece, that accumulate CO2 emissions from geologic reservoirs. This type of hydrothermal seafloor pool, containing highly concentrated CO2, provides direct evidence of shallow benthic CO2 accumulations originating from sub-seafloor releases. Samples taken from within these acidic pools are devoid of calcifying organisms, and channel structures among the pools indicate gravity driven flow, suggesting that seafloor release of CO2 at this site may preferentially impact benthic ecosystems. These naturally occurring seafloor pools may provide a diagnostic indicator of incipient volcanic activity and can serve as an analog for studying CO2 leakage and benthic accumulations from subsea carbon capture and storage sites. PMID:26179858

  3. The Kallisti Limnes, carbon dioxide-accumulating subsea pools

    PubMed Central

    Camilli, Richard; Nomikou, Paraskevi; Escartín, Javier; Ridao, Pere; Mallios, Angelos; Kilias, Stephanos P.; Argyraki, Ariadne; Andreani, Muriel; Ballu, Valerie; Campos, Ricard; Deplus, Christine; Gabsi, Taoufic; Garcia, Rafael; Gracias, Nuno; Hurtós, Natàlia; Magí, Lluis; Mével, Catherine; Moreira, Manuel; Palomeras, Narcís; Pot, Olivier; Ribas, David; Ruzié, Lorraine; Sakellariou, Dimitris

    2015-01-01

    Natural CO2 releases from shallow marine hydrothermal vents are assumed to mix into the water column, and not accumulate into stratified seafloor pools. We present newly discovered shallow subsea pools located within the Santorini volcanic caldera of the Southern Aegean Sea, Greece, that accumulate CO2 emissions from geologic reservoirs. This type of hydrothermal seafloor pool, containing highly concentrated CO2, provides direct evidence of shallow benthic CO2 accumulations originating from sub-seafloor releases. Samples taken from within these acidic pools are devoid of calcifying organisms, and channel structures among the pools indicate gravity driven flow, suggesting that seafloor release of CO2 at this site may preferentially impact benthic ecosystems. These naturally occurring seafloor pools may provide a diagnostic indicator of incipient volcanic activity and can serve as an analog for studying CO2 leakage and benthic accumulations from subsea carbon capture and storage sites. PMID:26179858

  4. Metal accumulation capacity of five species of Sphagnum moss

    SciTech Connect

    Aulio, K.

    1985-10-01

    The present paper describes the first experimental evidence of the species-specific differences in the cation accumulation properties in Sphagnum mosses. Manganese was chosen for the object of the experiments because this element appears to show the greatest variability under natural conditions.

  5. A lee-side eddy and its influence on snow accumulation

    NASA Astrophysics Data System (ADS)

    Gerber, Franziska; Mott, Rebecca; Hoch, Sebastian W.; Lehning, Michael

    2016-04-01

    Knowledge of changes in seasonal mountain snow water resources is essential for e.g. hydropower companies. To successfully predict these changes a fundamental understanding of precipitation patterns and their changes in mountainous terrain is needed. Both, snow accumulation and ablation need to be investigated to make precise predictions of the amount of water stored in seasonal snow cover. Only if the processes governing snow accumulation and ablation are understood with sufficient quantitative accuracy, the evolution of snow water resources under a changing climate can be addressed. Additionally, knowledge of detailed snow accumulation patterns is essential to assess avalanche danger. In alpine terrain, snow accumulation is strongly dependent on the local wind field. Based on the concept of preferential deposition, reduced snow accumulation is expected on the upper windward slope of a mountain due to updrafts, while enhanced snow accumulation should occur through blocking at the windward foot or due to flow separation on the leeward side. However, the understanding of these processes is mainly based on numerical simulations, as they are hard to measure. A LiDAR (Light Detection And Ranging) campaign was conducted in October 2015 in the Dischma valley (Davos, CH) to investigate the local flow field in the lee of the Sattelhorn during a one-day snowfall event. The flow field was monitored using a plane position indicator (PPI) scan at 25/28° and a range height indicator (RHI) scan across the Sattelhorn. Additionally, snow height change measurements on the leeward side of the Sattelhorn were performed by terrestrial laser scanning (TLS). Analyses of the flow field in the framework of preferential deposition are in agreement with the concept of flow separation and preferred snow deposition on leeward slopes. A very persistent eddy that formed over the leeward slope of the Sattelhorn detached from the main flow became evident from the retrievals of the RHI scans. An

  6. HPLC-MS/MS Analyses Show That the Near-Starchless aps1 and pgm Leaves Accumulate Wild Type Levels of ADPglucose: Further Evidence for the Occurrence of Important ADPglucose Biosynthetic Pathway(s) Alternative to the pPGI-pPGM-AGP Pathway

    PubMed Central

    Muñoz, Francisco José; Li, Jun; Almagro, Goizeder; Montero, Manuel; Pujol, Pablo; Galarza, Regina; Kaneko, Kentaro; Oikawa, Kazusato; Wada, Kaede; Mitsui, Toshiaki; Pozueta-Romero, Javier

    2014-01-01

    In leaves, it is widely assumed that starch is the end-product of a metabolic pathway exclusively taking place in the chloroplast that (a) involves plastidic phosphoglucomutase (pPGM), ADPglucose (ADPG) pyrophosphorylase (AGP) and starch synthase (SS), and (b) is linked to the Calvin-Benson cycle by means of the plastidic phosphoglucose isomerase (pPGI). This view also implies that AGP is the sole enzyme producing the starch precursor molecule, ADPG. However, mounting evidence has been compiled pointing to the occurrence of important sources, other than the pPGI-pPGM-AGP pathway, of ADPG. To further explore this possibility, in this work two independent laboratories have carried out HPLC-MS/MS analyses of ADPG content in leaves of the near-starchless pgm and aps1 mutants impaired in pPGM and AGP, respectively, and in leaves of double aps1/pgm mutants grown under two different culture conditions. We also measured the ADPG content in wild type (WT) and aps1 leaves expressing in the plastid two different ADPG cleaving enzymes, and in aps1 leaves expressing in the plastid GlgC, a bacterial AGP. Furthermore, we measured the ADPG content in ss3/ss4/aps1 mutants impaired in starch granule initiation and chloroplastic ADPG synthesis. We found that, irrespective of their starch contents, pgm and aps1 leaves, WT and aps1 leaves expressing in the plastid ADPG cleaving enzymes, and aps1 leaves expressing in the plastid GlgC accumulate WT ADPG content. In clear contrast, ss3/ss4/aps1 leaves accumulated ca. 300 fold-more ADPG than WT leaves. The overall data showed that, in Arabidopsis leaves, (a) there are important ADPG biosynthetic pathways, other than the pPGI-pPGM-AGP pathway, (b) pPGM and AGP are not major determinants of intracellular ADPG content, and (c) the contribution of the chloroplastic ADPG pool to the total ADPG pool is low. PMID:25133777

  7. Comparative functional characterization of eugenol synthase from four different Ocimum species: Implications on eugenol accumulation.

    PubMed

    Anand, Atul; Jayaramaiah, Ramesha H; Beedkar, Supriya D; Singh, Priyanka A; Joshi, Rakesh S; Mulani, Fayaj A; Dholakia, Bhushan B; Punekar, Sachin A; Gade, Wasudeo N; Thulasiram, Hirekodathakallu V; Giri, Ashok P

    2016-11-01

    Isoprenoids and phenylpropanoids are the major secondary metabolite constituents in Ocimum genus. Though enzymes from phenylpropanoid pathway have been characterized from few plants, limited information exists on how they modulate levels of secondary metabolites. Here, we performed phenylpropanoid profiling in different tissues from five Ocimum species, which revealed significant variations in secondary metabolites including eugenol, eugenol methyl ether, estragole and methyl cinnamate levels. Expression analysis of eugenol synthase (EGS) gene showed higher transcript levels especially in young leaves and inflorescence; and were positively correlated with eugenol contents. Additionally, transcript levels of coniferyl alcohol acyl transferase, a key enzyme diverting pool of substrate to phenylpropanoids, were in accordance with their abundance in respective species. In particular, eugenol methyl transferase expression positively correlated with higher levels of eugenol methyl ether in Ocimum tenuiflorum. Further, EGSs were functionally characterized from four Ocimum species varying in their eugenol contents. Kinetic and expression analyses indicated, higher enzyme turnover and transcripts levels, in species accumulating more eugenol. Moreover, biochemical and bioinformatics studies demonstrated that coniferyl acetate was the preferred substrate over coumaryl acetate when used, individually or together, in the enzyme assay. Overall, this study revealed the preliminary evidence for varied accumulation of eugenol and its abundance over chavicol in these Ocimum species. Current findings could potentially provide novel insights for metabolic modulations in medicinal and aromatic plants. PMID:27519164

  8. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  9. Cholesterol Accumulation Is Associated with Lysosomal Dysfunction and Autophagic Stress in Npc1−/− Mouse Brain

    PubMed Central

    Liao, Guanghong; Yao, Yueqin; Liu, Jihua; Yu, Zhang; Cheung, Simon; Xie, Ang; Liang, Xiaoli; Bi, Xiaoning

    2007-01-01

    Niemann-Pick type C (NPC) disease is an autosomal recessive disorder caused by mutations of NPC1 and NPC2 genes. Progressive neurodegeneration that accompanies NPC is fatal, but the underlying mechanisms are still poorly understood. In the present study, we characterized the association of autophagic-lysosomal dysfunction with cholesterol accumulation in Npc1−/− mice during postnatal development. Brain levels of lysosomal cathepsin D were significantly higher in mutant than in wild-type mice. Increases in cathepsin D occurred first in neurons and later in astrocytes and microglia and were both spatially and temporally associated with intracellular cholesterol accumulation and neurodegeneration. Furthermore, levels of ubiquitinated proteins were higher in endosomal/lysosomal fractions of brains from Npc1−/− mice than from wild-type mice. Immunoblotting results showed that levels of LC3-II were significantly higher in brains of mutant than wild-type mice. Combined LC3 immunofluorescence and filipin staining showed that LC3 accumulated within filipin-labeled cholesterol clusters inside Purkinje cells. Electron microscopic examination revealed the existence of autophagic vacuole-like structures and multivesicles in brains from Npc1−/− mice. These results provide strong evidence that cholesterol accumulation-induced changes in autophagy-lysosome function are closely associated with neurodegeneration in NPC. PMID:17631520

  10. Proline accumulation is a general response to abiotic stress in the date palm tree (Phoenix dactylifera L.).

    PubMed

    Yaish, M W

    2015-01-01

    Plants exposed to certain abiotic stress conditions tend to produce the amino acid proline, which acts as an active osmolyte, a metal chelator, an antioxidant, and a signaling molecule. There is increasing evidence that proline accumulates in plants due to a wide range of abiotic stress, in particular high soil salinity and drought. Therefore, proline content is often used as a marker-assisted breeding tool aimed at improving drought and salinity tolerance. In this study, it was investigated whether proline accumulation in date palm (Phoenix dactylifera L.) seedlings occurs solely due to high salinity and drought stresses or due to other unspecified abiotic stresses, including salinity and salinity shock, drought, extreme temperatures, and abscisic acid. The free proline assays revealed that this amino acid over-accumulated in the roots and leaves of each stress-treated plant, and was remarkably high when leaves were exposed to suboptimum temperatures and salinity stress. These results indicate that the production of proline is a common response to various abiotic stresses and its differential accumulation cannot be used as a molecular marker in date palm breeding programs aimed at improving drought or salinity tolerance traits in date palms. This conclusion is consistent with the theory that the molecular outcomes of abiotic stresses are often non-specific. PMID:26345930

  11. Intracellular accumulation and dissolution of silver nanoparticles in L-929 fibroblast cells using live cell time-lapse microscopy.

    PubMed

    Wildt, Bridget E; Celedon, Alfredo; Maurer, Elizabeth I; Casey, Brendan J; Nagy, Amber M; Hussain, Saber M; Goering, Peter L

    2016-08-01

    Cytotoxicity assessments of nanomaterials, such as silver nanoparticles, are challenging due to interferences with test reagents and indicators as well uncertainties in dosing as a result of the complex nature of nanoparticle intracellular accumulation. Furthermore, current theories suggest that silver nanoparticle cytotoxicity is a result of silver nanoparticle dissolution and subsequent ion release. This study introduces a novel technique, nanoparticle associated cytotoxicity microscopy analysis (NACMA), which combines fluorescence microscopy detection using ethidium homodimer-1, a cell permeability marker that binds to DNA after a cell membrane is compromised (a classical dead-cell indicator dye), with live cell time-lapse microscopy and image analysis to simultaneously investigate silver nanoparticle accumulation and cytotoxicity in L-929 fibroblast cells. Results of this method are consistent with traditional methods of assessing cytotoxicity and nanoparticle accumulation. Studies conducted on 10, 50, 100 and 200 nm silver nanoparticles reveal size dependent cytotoxicity with particularly high cytotoxicity from 10 nm particles. In addition, NACMA results, when combined with transmission electron microscopy imaging, reveal direct evidence of intracellular silver ion dissolution and possible nanoparticle reformation within cells for all silver nanoparticle sizes. PMID:26643278

  12. Ecology: accumulating threats to life

    SciTech Connect

    Peterson, R.W.

    1980-04-01

    The accumulating impacts of toxic materials like polychloridnated bephenyls (PCBs), acid rain, deforestation in the Amazon River Basin, and nuclear energy are examined as life-threatening actions that the public must recognize. Immediate action is needed to abandon destructive human activities and search out those life-supporting choices which will replace immediate gratification with long-range benefits. (DCK)

  13. Pensions and Household Wealth Accumulation

    ERIC Educational Resources Information Center

    Engelhardt, Gary V.; Kumar, Anil

    2011-01-01

    Economists have long suggested that higher private pension benefits "crowd out" other sources of household wealth accumulation. We exploit detailed information on pensions and lifetime earnings for older workers in the 1992 wave of the Health and Retirement Study and employ an instrumental-variable (IV) identification strategy to estimate…

  14. Enhanced lipid accumulation of photoautotrophic microalgae by high-dose CO2 mimics a heterotrophic characterization.

    PubMed

    Sun, Zhilan; Dou, Xiao; Wu, Jun; He, Bing; Wang, Yuancong; Chen, Yi-Feng

    2016-01-01

    Microalgae possess higher photosynthetic efficiency and accumulate more neutral lipids when supplied with high-dose CO2. However, the nature of lipid accumulation under conditions of elevated CO2 has not been fully elucidated so far. We now revealed that the enhanced lipid accumulation of Chlorella in high-dose CO2 was as efficient as under heterotrophic conditions and this may be attributed to the driving of enlarged carbon source. Both photoautotrophic and heterotrophic cultures were established by using Chlorella sorokiniana CS-1. A series of changes in the carbon fixation, lipid accumulation, energy conversion, and carbon-lipid conversion under high-dose CO2 (1-10%) treatment were characterized subsequently. The daily carbon fixation rate of C. sorokiniana LS-2 in 10% CO2 aeration was significantly increased compared with air CO2. Correspondingly, double oil content (28%) was observed in 10% CO2 aeration, close to 32.3% produced under heterotrophic conditions. In addition, with 10% CO2 aeration, the overall energy yield (Ψ) in Chlorella reached 12.4 from 7.3% (with air aeration) because of the enhanced daily carbon fixation rates. This treatment also improved the energetic lipid yield (Ylipid/Es) with 4.7-fold, tending to the heterotrophic parameters. More significantly, 2.2 times of carbon-lipid conversion efficiency (ηClipid/Ctotal, 42.4%) was observed in 10% CO2 aeration, towards to 53.7% in heterotrophic cultures, suggesting that more fixed carbon might flow into lipid synthesis under both 10% CO2 aeration and heterotrophic conditions. Taken together, all our evidence showed that 10% CO2 may push photoautotrophic Chlorella to display heterotrophic-like efficiency at least in lipid production. It might bring us an efficient model of lipid production based on microalgal cells with high-dose CO2, which is essential to sustain biodiesel production at large scales. PMID:26712624

  15. Accumulation of artificial radionuclides in agricultural plants in the area used for surface nuclear tests.

    PubMed

    Kozhakhanov, T E; Lukashenko, S N; Larionova, N V

    2014-11-01

    The paper reports on the study of artificial radionuclide accumulation in agricultural crops grown at the territory with high concentration of radionuclides, and first of all - with high concentration of transuranium elements. As a result of this work, peculiarities of accumulation and distribution of artificial radionuclides in the vegetative and generative organs of the studied plants have been revealed. Basic accumulation factors have been found for (137)Cs, (90)Sr, (239+240)Pu, and (241)Am in agricultural products. Accumulation factor dependence on type of planting was found for the investigated types of plants. It has been found that the vegetative organs accumulate radionuclides most of all. PMID:25128979

  16. Pulmonary alveolar microlithiasis with low fluorodeoxyglucose accumulation in PET/computed tomography

    PubMed Central

    Günay, Ersin; Özcan, Aysenaz; Günay, Sibel; Tatci, Ebru; Keyf, Atila Ihsan; Simsek, Cebrail

    2011-01-01

    Pulmonary alveolar microlithiasis (PAM) is an uncommon lung disease characterized by accumulation of intraalveolar calcifications. The disease can be diagnosed based on the radiological findings. We present a 27-year-old women with five-year history of shortness of breath. She was diagnosed with PAM due to the presence of the characteristic chest X-ray and thorax computed tomography (CT) findings. We performed 18F-fluorodeoxyglucose (FDG)-PET/CT imaging in order to detect any evidence of inflamation in the lung before deciding an anti-inflammatory treatment. The lung regions with dense calcifications revealed low FDG uptakes (SUVmax: 2.7) and the lung regions without calcifications showed lower FDG uptakes. No further treatment modality was planned besides inhaler salbutamol. Herein, we discuss this rare entity with literature search. PMID:21977072

  17. Sevoflurane Contamination: Water Accumulation in Sevoflurane Vaporizers Can Allow Bacterial Growth in the Vaporizer.

    PubMed

    Wallace, Arthur W

    2016-06-15

    Sevoflurane vaporizers (GE Tec 7) were difficult to fill with "slow flow" and a need to "burp." Evaluation of the bottle of sevoflurane (AbbVie Ultane) demonstrated a contaminant. Four of the facilities' 13 sevoflurane vaporizers had the contaminant. Unopened sevoflurane bottles did not have evidence of contamination. The contaminant was found to be water at pH 6.0 growing Staphylococcus epidermidis. Gas chromatography revealed the production of multiple metabolites of sevoflurane, including primarily urea and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione (83% and 9.6% of volatiles) in addition to multiple other organic molecules. Sevoflurane contains water that can accumulate in vaporizers allowing bacterial growth. PMID:27301057

  18. Different approaches for improving skin accumulation of topical corticosteroids.

    PubMed

    Senyiğit, Taner; Padula, Cristina; Ozer, Ozgen; Santi, Patrizia

    2009-10-01

    The aim of this paper was to evaluate the effect of vehicle, chemical enhancer and iontophoresis on the skin accumulation of clobetasol propionate (CP) and mometasone furoate (MF). In vitro permeation experiments were performed using pig ear skin as barrier and HPLC as quantification method. The formulations tested were chitosan gels, sodium-deoxycholate gels and commercial creams of CP and MF. The results obtained indicate that Na-DOC gel had an enhancing effect on the skin accumulation of both active agents. This effect was more evident with CP especially in the stratum corneum and epidermis which are the target sites of topical steroidal treatment. Two terpene derivatives (D-limonene and nerolidol) and Transcutol P were evaluated as chemical penetration enhancers. Nerolidol produced considerable increase in the amount of CP and MF accumulated without any permeation across the skin. The application of electric current (anodal iontophoresis) to the gels improved the accumulation of MF while it did not effect the accumulation of CP. Due to the best accumulation results of nerolidol, the enhancement effect in combination with iontophoresis was also investigated. It was shown that, the combination of anodal iontophoresis and chemical enhancer (nerolidol) produced no further enhancement for both active agents. PMID:19635541

  19. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  20. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  1. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  2. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  3. Metal accumulating plants: Medium's role

    NASA Astrophysics Data System (ADS)

    Rabier, J.; Prudent, P.; Szymanska, B.; Mevy, J.-P.

    2003-05-01

    To evaluate phytoremediation potentialities by metal accumulation in tolerant plants, trials are carried out using in vitro cultures. Organie compounds influence on metal accumulation is studied with metals supplemented media. The tested compounds on zinc and lead absorption by Brassica juncea, are chelating agents (EDTA, citric acid) and soluble organic fractions of compost. EDTA seems to enhance the transfer of lead in plant but it is the opposite in the case of zinc. Citric acid stimulates root absorption for both zinc and lead. For the aqueous extracts of compost, variable effects are obtained according to the origin of compost (green wastes and food wastes). In'all tested conditions of cultures, zinc is mainly exported towards shoot while lead is stored in root.

  4. Phophatidylinositol-3 kinase/mammalian target of rapamycin/p70S6K regulates contractile protein accumulation in airway myocyte differentiation.

    PubMed

    Halayko, Andrew J; Kartha, Sreedharan; Stelmack, Gerald L; McConville, John; Tam, John; Camoretti-Mercado, Blanca; Forsythe, Sean M; Hershenson, Marc B; Solway, Julian

    2004-09-01

    Increased airway smooth muscle in airway remodeling results from myocyte proliferation and hypertrophy. Skeletal and vascular smooth muscle hypertrophy is induced by phosphatidylinositide-3 kinase (PI(3) kinase) via mammalian target of rapamycin (mTOR) and p70S6 kinase (p70S6K). We tested the hypothesis that this pathway regulates contractile protein accumulation in cultured canine airway myocytes acquiring an elongated contractile phenotype in serum-free culture. In vitro assays revealed a sustained activation of PI(3) kinase and p70S6K during serum deprivation up to 12 d, with concomitant accumulation of SM22 and smooth muscle myosin heavy chain (smMHC) proteins. Immunocytochemistry revealed that activation of PI3K/mTOR/p70S6K occurred almost exclusively in myocytes that acquire the contractile phenotype. Inhibition of PI(3) kinase or mTOR with LY294002 or rapamycin blocked p70S6K activation, prevented formation of large elongated contractile phenotype myocytes, and blocked accumulation of SM22 and smMHC. Inhibition of MEK had no effect. Steady-state mRNA abundance for SM22 and smMHC was unaffected by blocking p70S6K activation. These studies provide primary evidence that PI(3) kinase and mTOR activate p70S6K in airway myocytes leading to the accumulation of contractile apparatus proteins, differentiation, and growth of large, elongated contractile phenotype airway smooth muscle cells. PMID:15105162

  5. Strain accumulation and rotation in the Eastern California Shear Zone

    NASA Astrophysics Data System (ADS)

    Savage, J. C.; Gan, Weijun; Svarc, J. L.

    2001-10-01

    Although the Eastern California Shear Zone (ECSZ) (strike ˜N25°W) does not quite coincide with a small circle drawn about the Pacific-North America pole of rotation, trilateration and GPS measurements demonstrate that the motion within the zone corresponds to right-lateral simple shear across a vertical plane (strike N33°W±5°) roughly parallel to the tangent to that local small circle (strike ˜N40°W). If the simple shear is released by slip on faults subparallel to the shear zone, the accumulated rotation is also released, leaving no secular rotation. South of the Garlock fault the principal faults (e.g., Calico-Blackwater fault) strike ˜N40°W, close enough to the strike of the vertical plane across which maximum right-lateral shear accumulates to almost wholly accommodate that accumulation of both strain and rotation by right-lateral slip. North of the Garlock fault dip slip as well as strike slip on the principal faults (strike ˜N20°W) is required to accommodate the simple shear accumulation. In both cases the accumulated rotation is released with the shear strain. The Garlock fault, which transects the ECSZ, is not offset by north-northwest striking faults nor, despite geological evidence for long-term left-lateral slip, does it appear at the present time to be accumulating left-lateral simple shear strain across the fault due to slip at depth. Rather the motion is explained by right-lateral simple shear across the orthogonal ECSZ. Left-lateral slip on the Garlock fault will release the shear strain accumulating there but would augment the accumulating rotation, resulting in a secular clockwise rotation rate ˜80 nrad yr-1 (4.6° Myr-1).

  6. Strain accumulation and rotation in the Eastern California Shear Zone

    USGS Publications Warehouse

    Savage, J.C.; Gan, Weijun; Svarc, J.L.

    2001-01-01

    Although the Eastern California Shear Zone (ECSZ) (strike ???N25??W) does not quite coincide with a small circle drawn about the Pacific-North America pole of rotation, trilateration and GPS measurements demonstrate that the motion within the zone corresponds to right-lateral simple shear across a vertical plane (strike N33??W??5??) roughly parallel to the tangent to that local small circle (strike ???N40??W). If the simple shear is released by slip on faults subparallel to the shear zone, the accumulated rotation is also released, leaving no secular rotation. South of the Garlock fault the principal faults (e.g., Calico-Blackwater fault) strike ???N40??W, close enough to the strike of the vertical plane across which maximum right-lateral shear accumulates to almost wholly accommodate that accumulation of both strain and rotation by right-lateral slip. North of the Garlock fault dip slip as well as strike slip on the principal faults (strike ???N20??W) is required to accommodate the simple shear accumulation. In both cases the accumulated rotation is released with the shear strain. The Garlock fault, which transects the ECSZ, is not offset by north-northwest striking faults nor, despite geological evidence for long-term left-lateral slip, does it appear at the present time to be accumulating left-lateral simple shear strain across the fault due to slip at depth. Rather the motion is explained by right-lateral simple shear across the orthogonal ECSZ. Left-lateral slip on the Garlock fault will release the shear strain accumulating there but would augment the accumulating rotation, resulting in a secular clockwise rotation rate ???80 nrad yr-1 (4.6?? Myr-1).

  7. Mechanisms of intrahepatic triglyceride accumulation

    PubMed Central

    Ress, Claudia; Kaser, Susanne

    2016-01-01

    Hepatic steatosis defined as lipid accumulation in hepatocytes is very frequently found in adults and obese adolescents in the Western World. Etiologically, obesity and associated insulin resistance or excess alcohol intake are the most frequent causes of hepatic steatosis. However, steatosis also often occurs with chronic hepatitis C virus (HCV) infection and is also found in rare but potentially life-threatening liver diseases of pregnancy. Clinical significance and outcome of hepatic triglyceride accumulation are highly dependent on etiology and histological pattern of steatosis. This review summarizes current concepts of pathophysiology of common causes of hepatic steatosis, including non-alcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease, chronic HCV infections, drug-induced forms of hepatic steatosis, and acute fatty liver of pregnancy. Regarding the pathophysiology of NAFLD, this work focuses on the close correlation between insulin resistance and hepatic triglyceride accumulation, highlighting the potential harmful effects of systemic insulin resistance on hepatic metabolism of fatty acids on the one side and the role of lipid intermediates on insulin signalling on the other side. Current studies on lipid droplet morphogenesis have identified novel candidate proteins and enzymes in NAFLD. PMID:26819531

  8. Reducing synuclein accumulation improves neuronal survival after spinal cord injury.

    PubMed

    Fogerson, Stephanie M; van Brummen, Alexandra J; Busch, David J; Allen, Scott R; Roychaudhuri, Robin; Banks, Susan M L; Klärner, Frank-Gerrit; Schrader, Thomas; Bitan, Gal; Morgan, Jennifer R

    2016-04-01

    Spinal cord injury causes neuronal death, limiting subsequent regeneration and recovery. Thus, there is a need to develop strategies for improving neuronal survival after injury. Relative to our understanding of axon regeneration, comparatively little is known about the mechanisms that promote the survival of damaged neurons. To address this, we took advantage of lamprey giant reticulospinal neurons whose large size permits detailed examination of post-injury molecular responses at the level of individual, identified cells. We report here that spinal cord injury caused a select subset of giant reticulospinal neurons to accumulate synuclein, a synaptic vesicle-associated protein best known for its atypical aggregation and causal role in neurodegeneration in Parkinson's and other diseases. Post-injury synuclein accumulation took the form of punctate aggregates throughout the somata and occurred selectively in dying neurons, but not in those that survived. In contrast, another synaptic vesicle protein, synaptotagmin, did not accumulate in response to injury. We further show that the post-injury synuclein accumulation was greatly attenuated after single dose application of either the "molecular tweezer" inhibitor, CLR01, or a translation-blocking synuclein morpholino. Consequently, reduction of synuclein accumulation not only improved neuronal survival, but also increased the number of axons in the spinal cord proximal and distal to the lesion. This study is the first to reveal that reducing synuclein accumulation is a novel strategy for improving neuronal survival after spinal cord injury. PMID:26854933

  9. Regulation of starch and lipid accumulation in a microalga Chlorella sorokiniana.

    PubMed

    Li, Tingting; Gargouri, Mahmoud; Feng, Jie; Park, Jeong-Jin; Gao, Difeng; Miao, Chao; Dong, Tao; Gang, David R; Chen, Shulin

    2015-03-01

    Microalgae have attracted growing attention due to their potential in biofuel feedstock production. However, current understanding of the regulatory mechanisms for lipid biosynthesis and storage in microalgae is still limited. This study revealed that the microalga Chlorella sorokiniana showed sequential accumulation of starch and lipids. When nitrogen was replete and/or depleted over a short period, starch was the predominant carbon storage form with basal levels of lipid accumulation. After prolonged nitrogen depletion, lipid accumulation increased considerably, which was partially due to starch degradation, as well as the turnover of primary metabolites. Lipid accumulation is also strongly dependent on the linear electron flow of photosynthesis, peaking at lower light intensities. Collectively, this study reveals a relatively clear regulation pattern of starch and lipid accumulation that is basically controlled by nitrogen levels. The mixotrophic growth of C. sorokiniana shows promise for biofuel production in terms of lipid accumulation in the final biomass. PMID:25616239

  10. Rapid intraplate strain accumulation in the New Madrid seismic zone

    USGS Publications Warehouse

    Liu, L.; Zoback, M.D.; Segall, P.

    1992-01-01

    Remeasurement of a triangulation network in the southern part of the New Madrid seismic zone with the Global Positioning System has revealed rapid crustal strain accumulation since the 1950s. This area experienced three large (moment magnitudes >8) earthquakes in 1811 to 1812. The orientation and sense of shear is consistent with right-lateral strike slip motion along a northeast-trending fault zone (as indicated by current seismicity). Detection of crustal strain accumulation may be a useful discriminant for identifying areas where potentially damaging intraplate earthquakes may occur despite the absence of large earthquakes during historic time.

  11. The neural basis of value accumulation in intertemporal choice.

    PubMed

    Rodriguez, Christian A; Turner, Brandon M; Van Zandt, Trisha; McClure, Samuel M

    2015-09-01

    Making intertemporal choices (choosing between rewards available at different points in time) requires determining and comparing the subjective values of available rewards. Several studies have found converging evidence identifying the neural systems that encode subjective value in intertemporal choice. However, the neural mechanisms responsible for the process that produces intertemporal decisions on the basis of subjective values have not been investigated. Using model-based and connectivity analyses of functional magnetic resonance imaging data, we investigated the neural mechanisms underlying the value-accumulation process by which subjective value guides intertemporal decisions. Our results show that the dorsomedial frontal cortex, bilateral posterior parietal cortex, and bilateral lateral prefrontal cortex are all involved in the accumulation of subjective value for the purpose of action selection. Our findings establish a mechanistic framework for understanding frontoparietal contributions to intertemporal choice and suggest that value-accumulation processes in the frontoparietal cortex may be a general mechanism for value-based choice. PMID:26179826

  12. A New Dynamic Accumulator for Batch Updates

    NASA Astrophysics Data System (ADS)

    Wang, Peishun; Wang, Huaxiong; Pieprzyk, Josef

    A dynamic accumulator is an algorithm, which gathers together a large set of elements into a constant-size value such that for a given element accumulated, there is a witness confirming that the element was indeed included into the value, with a property that accumulated elements can be dynamically added and deleted into/from the original set such that the cost of an addition or deletion operation is independent of the number of accumulated elements. Although the first accumulator was presented ten years ago, there is still no standard formal definition of accumulators. In this paper, we generalize formal definitions for accumulators, formulate a security game for dynamic accumulators so-called Chosen Element Attack (CEA), and propose a new dynamic accumulator for batch updates based on the Paillier cryptosystem. Our construction makes a batch of update operations at unit cost. We prove its security under the extended strong RSA (es-RSA) assumption.

  13. Poly-beta-hydroxybutyrate-accumulating bacteria protect gnotobiotic Artemia franciscana from pathogenic Vibrio campbellii.

    PubMed

    Halet, Dirk; Defoirdt, Tom; Van Damme, Petra; Vervaeren, Han; Forrez, Ilse; Van de Wiele, Tom; Boon, Nico; Sorgeloos, Patrick; Bossier, Peter; Verstraete, Willy

    2007-06-01

    A poly-beta-hydroxybutyrate (PHB)-accumulating enrichment culture was obtained using activated sludge from a polyphosphate-accumulating reactor as inoculum. PHB accumulated by the enrichment culture significantly enhanced the survival of Artemia nauplii, infected with the virulent pathogen Vibrio campbellii LMG 21363. A strain was isolated from the enrichment culture, based on its ability to accumulate PHB, and 16S rRNA gene sequencing of the isolate revealed 99% sequence similarity to Brachymonas denitrificans AS-P1. The isolate, named PHB2, showed good PHB-accumulating activity (up to 32% of the cell dry weight). PHB accumulated by isolate PHB2 was able to protect Artemia completely from the V. campbellii strain. Our data indicate that PHB-accumulating bacteria, such as B. denitrificans PHB2, could be used as an an effective and economically interesting alternative strategy to control infections in aquaculture. PMID:17391334

  14. Annual accumulation over the Greenland ice sheet interpolated from historical and newly compiled observation data

    USGS Publications Warehouse

    Shen, Dayong; Liu, Yuling; Huang, Shengli

    2012-01-01

    The estimation of ice/snow accumulation is of great significance in quantifying the mass balance of ice sheets and variation in water resources. Improving the accuracy and reducing uncertainty has been a challenge for the estimation of annual accumulation over the Greenland ice sheet. In this study, we kriged and analyzed the spatial pattern of accumulation based on an observation data series including 315 points used in a recent research, plus 101 ice cores and snow pits and newly compiled 23 coastal weather station data. The estimated annual accumulation over the Greenland ice sheet is 31.2 g cm−2 yr−1, with a standard error of 0.9 g cm−2 yr−1. The main differences between the improved map developed in this study and the recently published accumulation maps are in the coastal areas, especially southeast and southwest regions. The analysis of accumulations versus elevation reveals the distribution patterns of accumulation over the Greenland ice sheet.

  15. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth

    PubMed Central

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL – mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  16. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth.

    PubMed

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL - mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  17. An ice core record of net snow accumulation and seasonal snow chemistry at Mt. Waddington, southwest British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Neff, P. D.; Steig, E. J.; Clark, D. H.; McConnell, J. R.; Pettit, E. C.; Menounos, B.

    2011-12-01

    We recovered a 141 m ice core from Combatant Col (51.39°N, 125.22°W, 3000 m asl) on the flank of Mt. Waddington, southern Coast Mountains, British Columbia, Canada. Aerosols and other impurities in the ice show unambiguous seasonal variations, allowing for annual dating of the core. Clustered melt layers, originating from summer surface heating, also aid in the dating of the core. Seasonality in water stable isotopes is preserved throughout the record, showing little evidence of diffusion at depth, and serves as an independent verification of the timescale. The annual signal of deuterium excess is especially well preserved. The record of lead deposition in the core agrees with those of ice cores from Mt. Logan and from Greenland, with a sharp drop-off in concentration in the 1970s and early 1980s, further validating the timescales. Despite significant summertime melt at this mid-latitude site, these data collectively reveal a continuous and annually resolved 36-year record of snow accumulation. We derived an accumulation time series from the Mt. Waddington ice core, after correcting for ice flow. Years of anomalously high or low snow accumulation in the core correspond with extremes in precipitation data and geopotential height anomalies from reanalysis data that make physical sense. Specifically, anomalously high accumulation years at Mt. Waddington correlate with years where "Pineapple Express" atmospheric river events bring large amounts of moisture from the tropical Pacific to western North America. The Mt. Waddington accumulation record thus reflects regional-scale climate. These results demonstrate the potential of ice core records from temperate glaciers to provide meaningful paleoclimate information. A longer core to bedrock (250-300 m) at the Mt. Waddington site could yield ice with an age of several hundred to 1000 years.

  18. Investigation of factors affecting the accumulation of vinyl chloride in polyvinyl chloride piping used in drinking water distribution systems.

    PubMed

    Walter, Ryan K; Lin, Po-Hsun; Edwards, Marc; Richardson, Ruth E

    2011-04-01

    Plastic piping made of polyvinyl chloride (PVC), and chlorinated PVC (CPVC), is being increasingly used for drinking water distribution lines. Given the formulation of the material from vinyl chloride (VC), there has been concern that the VC (a confirmed human carcinogen) can leach from the plastic piping into drinking water. PVC/CPVC pipe reactors in the laboratory and tap samples collected from consumers homes (n = 15) revealed vinyl chloride accumulation in the tens of ng/L range after a few days and hundreds of ng/L after two years. While these levels did not exceed the EPA's maximum contaminant level (MCL) of 2 μg/L, many readings that simulated stagnation times in homes (overnight) exceeded the MCL-Goal of 0 μg/L. Considerable differences in VC levels were seen across different manufacturers, while aging and biofilm effects were generally small. Preliminary evidence suggests that VC may accumulate not only via chemical leaching from the plastic piping, but also as a disinfection byproduct (DBP) via a chlorine-dependent reaction. This is supported from studies with CPVC pipe reactors where chlorinated reactors accumulated more VC than dechlorinated reactors, copper pipe reactors that accumulated VC in chlorinated reactors and not in dechlorinated reactors, and field samples where VC levels were the same before and after flushing the lines where PVC/CPVC fittings were contributing. Free chlorine residual tests suggest that VC may be formed as a secondary, rather than primary, DBP. Further research and additional studies need to be conducted in order to elucidate reaction mechanisms and tease apart relative contributions of VC accumulation from PVC/CPVC piping and chlorine-dependent reactions. PMID:21420710

  19. Accumulation of Zn, Cu and Cd by crabs and barnacles

    NASA Astrophysics Data System (ADS)

    Rainbow, P. S.

    1985-11-01

    The crab Carcinus maenas (L.) and the barnacle Elminius modestus Darwin were exposed to a range of dissolved concentrations of Zn, Cu and Cd for 21 days in artificial seawater. Accumulation of Zn and Cu by crabs has been interpreted in terms of the presence of a regulation mechanism to maintain constant body concentrations (83·2 ± 19·4 μg Zn g -1 dry wt.; 39·8 ± 9·8 μg Cu g -1 dry wt.) under varying external dissolved metal levels, until a threshold dissolved metal concentration ( c. 400 μg Zn l -1; c. 170 μg Cu l -1) beyond which net accumulation of metal begins. Cadium appears to be accumulated by C. maenas at all exposures with no evidence for regulation of body cadmium concentrations. Exposure of E. modestus to Zn, Cu or Cd caused net accumulation of the respective metal in the bodies of the barnacles, with no evidence for regulation of body metal concentrations.

  20. Comparison of accumulation of four metalloids in Allium sativum.

    PubMed

    Ogra, Yasumitsu; Awaya, Yumi; Anan, Yasumi

    2015-05-01

    In this study, we evaluated the accumulation and metabolism of four metalloids: arsenic (As), selenium (Se), antimony (Sb), and tellurium (Te) in garlic to determine whether garlic can be used for the phytoremediation of those metalloids. Garlic was able to efficiently accumulate As and Se, the two-fourth-period metalloids. However, it was not able to accumulate Sb and Te, the two-fifth-period metalloids, because their bioaccumulation factors were below one. Speciation analyses revealed that four metalloids could be metabolized in garlic, although their metabolites could not be identified yet. Results also suggested that garlic was able to distinguish the metalloids in groups 15 and 16 and the fourth and fifth periods, i.e., As, Se, Sb, and Te. Therefore, garlic is one of the potential plants for the phytoremediation of the fourth-period metalloids. PMID:25733447

  1. Developmental accumulation of inorganic polyphosphate affects germination and energetic metabolism in Dictyostelium discoideum.

    PubMed

    Livermore, Thomas Miles; Chubb, Jonathan Robert; Saiardi, Adolfo

    2016-01-26

    Inorganic polyphosphate (polyP) is composed of linear chains of phosphate groups linked by high-energy phosphoanhydride bonds. However, this simple, ubiquitous molecule remains poorly understood. The use of nonstandardized analytical methods has contributed to this lack of clarity. By using improved polyacrylamide gel electrophoresis we were able to visualize polyP extracted from Dictyostelium discoideum. We established that polyP is undetectable in cells lacking the polyphosphate kinase (DdPpk1). Generation of this ppk1 null strain revealed that polyP is important for the general fitness of the amoebae with the mutant strain displaying a substantial growth defect. We discovered an unprecedented accumulation of polyP during the developmental program, with polyP increasing more than 100-fold. The failure of ppk1 spores to accumulate polyP results in a germination defect. These phenotypes are underpinned by the ability of polyP to regulate basic energetic metabolism, demonstrated by a 2.5-fold decrease in the level of ATP in vegetative ppk1. Finally, the lack of polyP during the development of ppk1 mutant cells is partially offset by an increase of both ATP and inositol pyrophosphates, evidence for a model in which there is a functional interplay between inositol pyrophosphates, ATP, and polyP. PMID:26755590

  2. A redox-regulated chloroplast protein phosphatase binds to starch diurnally and functions in its accumulation.

    PubMed

    Sokolov, Lubomir N; Dominguez-Solis, Jose R; Allary, Anne-Laure; Buchanan, Bob B; Luan, Sheng

    2006-06-20

    Starch is the ultimate storage molecule formed in the photosynthetic fixation of carbon dioxide by chloroplasts. Starch accumulates during the day and is degraded at night to intermediates that are exported to heterotrophic organs. The mechanism by which diurnal cycles control the transitory biosynthesis and degradation of chloroplast starch has long remained a mystery. We now report evidence that a dual-specificity protein phosphatase, DSP4, binds to starch granules during the day and dissociates at night. Disruption of the DSP4 gene resulted in a dramatic increase in the level of starch in mutant Arabidopsis plants. Moreover, although composition was apparently unchanged, the morphology of the starch granule was significantly altered compared to the wild type counterpart. Two regulatory factors linked to light (i.e., pH and redox status) changed both the activity and the starch-binding capacity of DSP4. The results further revealed that DSP4 represents a major fraction of granule-bound phosphatase activity during the day but not at night. Our study suggests that DSP4 acts as a bridge between light-induced redox changes and protein phosphorylation in the regulation of starch accumulation. PMID:16772378

  3. Iron Overload Coordinately Promotes Ferritin Expression and Fat Accumulation in Caenorhabditis elegans.

    PubMed

    Wang, Haizhen; Jiang, Xue; Wu, Jieyu; Zhang, Linqiang; Huang, Jingfei; Zhang, Yuru; Zou, Xiaoju; Liang, Bin

    2016-05-01

    The trace element iron is crucial for living organisms, since it plays essential roles in numerous cellular functions. Systemic iron overload and the elevated level of ferritin, a ubiquitous intracellular protein that stores and releases iron to maintain the iron homeostasis in cells, has long been epidemiologically associated with obesity and obesity-related diseases. However, the underlying mechanisms of this association remain unclear. Here, using Caenorhabditis elegans, we show that iron overload induces the expression of sgk-1, encoding the serum and glucocorticoid-inducible kinase, to promote the level of ferritin and fat accumulation. Mutation of cyp-23A1, encoding a homolog of human cytochrome P450 CYP7B1 that is related to neonatal hemochromatosis, further enhances the elevated expression of ftn-1, sgk-1, and fat accumulation. sgk-1 positively regulates the expression of acs-20 and vit-2, genes encoding homologs of the mammalian FATP1/4 fatty acid transport proteins and yolk lipoproteins, respectively, to facilitate lipid uptake and translocation for storage under iron overload. This study reveals a completely novel pathway in which sgk-1 plays a central role to synergistically regulate iron and lipid homeostasis, offering not only experimental evidence supporting a previously unverified link between iron and obesity, but also novel insights into the pathogenesis of iron and obesity-related human metabolic diseases. PMID:27017620

  4. Functional UQCRC1 polymorphisms affect promoter activity and body lipid accumulation.

    PubMed

    Kunej, Tanja; Wang, Zeping; Michal, Jennifer J; Daniels, Tyler F; Magnuson, Nancy S; Jiang, Zhihua

    2007-12-01

    Obesity and type 2 diabetes constitute leading public health problems worldwide. Studies have shown that insulin resistance affiliated with these conditions is associated with skeletal muscle lipid accumulation, while the latter is associated with mitochondrial dysfunctions. However, the initiation and regulation of mitochondrial biogenesis rely heavily on approximately 1000 nuclear-encoded mitochondrial regulatory proteins. In this study, we targeted the ubiquinol-cytochrome c reductase core protein I gene, a nuclear-encoded component of mitochondrial complex III, for its association with subcutaneous fat depth (SFD) and skeletal muscle lipid accumulation (SMLA) using cattle as a model. Four promoter polymorphisms were identified and genotyped on approximately 250 Wagyu x Limousin F2 progeny. Statistical analysis revealed that two completely linked polymorphic sites, g.13487C>T and g.13709G>C (r2 = 1), were significantly associated with both SFD (p < 0.01) and SMLA (p < 0.0001). The difference between TTCC and CCGG haplotypes was 0.178 cm for SFD and 0.624 scores for SMLA. Interestingly, the former haplotype produced higher promoter activities than the latter by 43% to 49% in three cell lines (p < 0.05). In addition to Rett syndrome and breast/ovarian cancer observed in other studies, we report evidence for the first time, to our knowledge, that overexpression of ubiquinol-cytochrome c reductase core protein I might affect mitochondrial morphology and/or physiology and lead to development of obesity and related conditions. PMID:18198295

  5. A new framework for modeling decisions about changing information: The Piecewise Linear Ballistic Accumulator model.

    PubMed

    Holmes, William R; Trueblood, Jennifer S; Heathcote, Andrew

    2016-03-01

    In the real world, decision making processes must be able to integrate non-stationary information that changes systematically while the decision is in progress. Although theories of decision making have traditionally been applied to paradigms with stationary information, non-stationary stimuli are now of increasing theoretical interest. We use a random-dot motion paradigm along with cognitive modeling to investigate how the decision process is updated when a stimulus changes. Participants viewed a cloud of moving dots, where the motion switched directions midway through some trials, and were asked to determine the direction of motion. Behavioral results revealed a strong delay effect: after presentation of the initial motion direction there is a substantial time delay before the changed motion information is integrated into the decision process. To further investigate the underlying changes in the decision process, we developed a Piecewise Linear Ballistic Accumulator model (PLBA). The PLBA is efficient to simulate, enabling it to be fit to participant choice and response-time distribution data in a hierarchal modeling framework using a non-parametric approximate Bayesian algorithm. Consistent with behavioral results, PLBA fits confirmed the presence of a long delay between presentation and integration of new stimulus information, but did not support increased response caution in reaction to the change. We also found the decision process was not veridical, as symmetric stimulus change had an asymmetric effect on the rate of evidence accumulation. Thus, the perceptual decision process was slow to react to, and underestimated, new contrary motion information. PMID:26760448

  6. Developmental accumulation of inorganic polyphosphate affects germination and energetic metabolism in Dictyostelium discoideum

    PubMed Central

    Livermore, Thomas Miles; Chubb, Jonathan Robert; Saiardi, Adolfo

    2016-01-01

    Inorganic polyphosphate (polyP) is composed of linear chains of phosphate groups linked by high-energy phosphoanhydride bonds. However, this simple, ubiquitous molecule remains poorly understood. The use of nonstandardized analytical methods has contributed to this lack of clarity. By using improved polyacrylamide gel electrophoresis we were able to visualize polyP extracted from Dictyostelium discoideum. We established that polyP is undetectable in cells lacking the polyphosphate kinase (DdPpk1). Generation of this ppk1 null strain revealed that polyP is important for the general fitness of the amoebae with the mutant strain displaying a substantial growth defect. We discovered an unprecedented accumulation of polyP during the developmental program, with polyP increasing more than 100-fold. The failure of ppk1 spores to accumulate polyP results in a germination defect. These phenotypes are underpinned by the ability of polyP to regulate basic energetic metabolism, demonstrated by a 2.5-fold decrease in the level of ATP in vegetative ppk1. Finally, the lack of polyP during the development of ppk1 mutant cells is partially offset by an increase of both ATP and inositol pyrophosphates, evidence for a model in which there is a functional interplay between inositol pyrophosphates, ATP, and polyP. PMID:26755590

  7. Intraneuronal Amyloid β Accumulation and Oxidative Damage to Nucleic Acids in Alzheimer Disease

    PubMed Central

    Nunomura, Akihiko; Tamaoki, Toshio; Tanaka, Koich; Motohashi, Nobutaka; Nakamura, Masao; Hayashi, Takaaki; Yamaguchi, Haruyasu; Shimohama, Shun; Lee, Hyoung-gon; Zhu, Xiongwei; Smith, Mark A.; Perry, George

    2010-01-01

    An in situ approach was used to identify amyloid-β (Aβ) accumulation and oxidative damage to nucleic acids in postmortem brain tissue of the hippocampal formation from subjects with Alzheimer disease. When carboxyl-terminal specific antibodies directed against Aβ40 and Aβ42 were used for immunocytochemical analyses, Aβ42 was especially apparent within the neuronal cytoplasm, at sites not detected by the antibody specific to Aβ-oligomer. In comparison to the Aβ42-positive neurons, neurons bearing oxidative damage to nucleic acids were more widely distributed in the hippocampus. Comparative density measurements of the immunoreactivity revealed that levels of intraneuronal Aβ42 were inversely correlated with levels of intraneuronal 8-hydroxyguanosine, an oxidized nucleoside (r = − 0.61, p < 0.02). Together with recent evidence that the Aβ peptide can act as an antioxidant, these results suggest that intraneuronal accumulation of non-oligomeric Aβ may be a compensatory response in neurons to oxidative stress in Alzheimer disease. PMID:20034567

  8. Renal accumulation and effects of intraperitoneal injection of extracted microcystins in omnivorous crucian carp (Carassius auratus).

    PubMed

    Li, Li; Xie, Ping; Lei, Hehua; Zhang, Xuezhen

    2013-08-01

    An acute toxicological experiment was designed to characterize the sequence of renal ultrastructural changes with accumulated MCs in crucian carp injected intraperitoneally (i.p.) with extracted microcystins (mainly MC-RR and -LR) at two doses, 50 and 200 μg MC-LReq. kg⁻¹ body weight. Quantitative and qualitative determinations of MCs in the kidney were conducted by HPLC and LC-MS, respectively. MC-RR content in kidney of crucian carp showed a time dose-dependent increase within 48 h post-injection, followed by a sharp decline afterward, while no MC-LR in kidney was detectable throughout the experiment. Ultrastructural changes in the kidney of crucian carp progressed with increasing accumulated MCs and exposure times within 48 h post-injection, whereas renal ultrastructural recovery of crucian carp in the 50 μg MC-LReq. kg⁻¹ dose group was evident at 168 h post-injection. Our ultrastructural observation suggests that the membranous structure is the main action site of MCs in the kidney, among which mitochondria damage in the tubules is clearly an early, and presumably a critically important effect of MCs. The increases in blood urea nitrogen (BUN) and creatinine (CR) in both dose groups further revealed severe impairment occurred in the kidney of crucian carp. PMID:23608020

  9. Active transport and accumulation of bicarbonate by a unicellular cyanobacterium.

    PubMed

    Miller, A G; Colman, B

    1980-09-01

    The rates of inorganic carbon accumulation and carbon fixation in light by the unicellular cyanobacterim Coccohloris peniocystis have been determined. Cells incubated in the light in medium containing H14CO3- were rapidly separated from the medium by centrifugation through silicone oil into a strongly basic terminating solution. Samples of these inactivated cells were assayed to determine total 14C accumulation, and acid-treated samples were assayed to determine 14C fixation. The rate of transport of inorganic into illuminated cells was faster than the rate of CO2 production in the medium from HCO3- dehydration. This evidence for HCO3- transport in these cells is in agreement with our previous results based upon measurements of photosynthetic O2 evolution. A substantial pool of inorganic carbon was bulit up within the cells presumably as HCO3- before the onset of the maximum rate of photosynthesis. Large accumulation ratios were observed, greater than 1,000 times the external HCO3- concentration. Accumulation did not occur in the dark and was greatly suppressed by the photosynthesis inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethyl urea and 3-chloro-carbonylcyanide phenylhydrazone. These results indicate that the accumulation of inorganic carbon in these cells involves a light-dependent active transport process. PMID:6773925

  10. Racial Differences in Patterns of Wealth Accumulation

    ERIC Educational Resources Information Center

    Gittleman, Maury; Wolff, Edward N.

    2004-01-01

    The race differences in patterns of asset accumulations were examined using PSD data for 1984, 1989 and 1994. The results indicate that inheritances led to wealth accumulations among whites as compared to the African Americans.

  11. Neurodegeneration with brain iron accumulation (NBIA)

    MedlinePlus

    ... gov/ency/article/001225.htm Neurodegeneration with brain iron accumulation (NBIA) To use the sharing features on this page, please enable JavaScript. Neurodegeneration with brain iron accumulation (formerly known as Hallervorden-Spatz disease) is ...

  12. Spatial and Temporal Characteristics of Insulator Contaminations Revealed by Daily Observations of Equivalent Salt Deposit Density

    PubMed Central

    Ruan, Ling; Han, Ge; Zhu, Zhongmin; Zhang, Miao; Gong, Wei

    2015-01-01

    The accurate estimation of deposits adhering on insulators is of great significance to prevent pollution flashovers which cause huge costs worldwide. Researchers have developed sensors using different technologies to monitor insulator contamination on a fine time scale. However, there is lack of analysis of these data to reveal spatial and temporal characteristics of insulator contamination, and as a result the scheduling of periodical maintenance of power facilities is highly dependent on personal experience. Owing to the deployment of novel sensors, daily Equivalent Salt Deposit Density (ESDD) observations of over two years were collected and analyzed for the first time. Results from 16 sites distributed in four regions of Hubei demonstrated that spatial heterogeneity can be seen at both the fine and coarse geographical scales, suggesting that current polluted area maps are necessary but are not sufficient conditions to guide the maintenance of power facilities. Both the local emission and the regional air pollution condition exert evident influences on deposit accumulation. A relationship between ESDD and PM10 was revealed by using regression analysis, proving that air pollution exerts influence on pollution accumulations on insulators. Moreover, the seasonality of ESDD was discovered for the first time by means of time series analysis, which could help engineers select appropriate times to clean the contamination. Besides, the trend component shows that the ESDD increases in a negative exponential fashion with the accumulation date (ESDD = a − b × exp(−time)) at a long time scale in real environments. PMID:25643058

  13. Accumulation of an acidic dehydrin in the vicinity of the plasma membrane during cold acclimation of wheat

    PubMed Central

    Danyluk, J; Perron, A; Houde, M; Limin, A; Fowler, B; Benhamou, N; Sarhan, F

    1998-01-01

    Expression of the acidic dehydrin gene wcor410 was found to be associated with the development of freezing tolerance in several Gramineae species. This gene is part of a family of three homologous members, wcor410, wcor410b, and wcor410c, that have been mapped to the long arms of the homologous group 6 chromosomes of hexaploid wheat. To gain insight into the function of this gene family, antibodies were raised against the WCOR410 protein and affinity purified to eliminate cross-reactivity with the WCS120 dehydrin-like protein of wheat. Protein gel blot analyses showed that the accumulation of WCOR410 proteins correlates well with the capacity of each cultivar to cold acclimate and develop freezing tolerance. Immunoelectron microscope analyses revealed that these proteins accumulate in the vicinity of the plasma membrane of cells in the sensitive vascular transition area where freeze-induced dehydration is likely to be more severe. Biochemical fractionation experiments indicated that WCOR410 is a peripheral protein and not an integral membrane protein. These results provide direct evidence that a subtype of the dehydrin family accumulates near the plasma membrane. The properties, abundance, and localization of these proteins suggest that they are involved in the cryoprotection of the plasma membrane against freezing or dehydration stress. We propose that WCOR410 plays a role in preventing the destabilization of the plasma membrane that occurs during dehydrative conditions. PMID:9548987

  14. 47 CFR 32.3100 - Accumulated depreciation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Accumulated depreciation. 32.3100 Section 32... Accumulated depreciation. (a) This account shall include the accumulated depreciation associated with the... with depreciation amounts concurrently charged to Account 6561, Depreciation...

  15. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Accumulators. 58.30-25 Section 58.30-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired pressure vessel in which energy is...

  16. Sub-lethal plasma ammonia accumulation and the exercise performance of salmonids.

    PubMed

    McKenzie, D J; Shingles, A; Taylor, E W

    2003-08-01

    The proposal that plasma ammonia accumulation might impair the swimming performance of fish was first made over a decade ago, and has now proven to be the case for a number of salmonid species. The first experimental evidence was indirect, when a negative linear relationship between plasma ammonia concentrations and maximum sustainable swimming speed (U(crit)) was found following the exposure of brown trout (Salmo trutta) to sub-lethal concentrations of copper in soft acidic water. Since then, negative linear relationships between plasma ammonia concentration and U(crit) have been demonstrated following exposure of brown trout, rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch) to elevated water ammonia. For brown trout, the relationships between plasma ammonia and U(crit) were remarkably similar following either exposure to elevated water ammonia or to sub-lethal copper. This indicates that the impairment of swimming performance resulting from exposure to sub-lethal concentrations of heavy metals may be attributable in large part to an accumulation of endogenous ammonia. The negative relationship between plasma ammonia concentration and U(crit) was similar in size-matched rainbow and brown trout but, under similar regimes of ammonia exposure, rainbow trout were able to maintain a significantly lower plasma ammonia concentration, revealing inter-specific differences in ammonia permeability and/or transport. One primary mechanism by which ammonia accumulation may impair exercise performance is a partial depolarisation of membrane potential in tissues such as the brain and white muscle. This may prejudice the co-ordination of swimming movements and reduce or abolish the development of muscle tension, thus, compromising swimming efficiency and performance at the top end of the range. PMID:12890542

  17. Chip integrated fuel cell accumulator

    NASA Astrophysics Data System (ADS)

    Frank, M.; Erdler, G.; Frerichs, H.-P.; Müller, C.; Reinecke, H.

    A unique new design of a chip integrated fuel cell accumulator is presented. The system combines an electrolyser and a self-breathing polymer electrolyte membrane (PEM) fuel cell with integrated palladium hydrogen storage on a silicon substrate. Outstanding advantages of this assembly are the fuel cell with integrated hydrogen storage, the possibility of refuelling it by electrolysis and the opportunity of simply refilling the electrolyte by adding water. By applying an electrical current, wiring the palladium hydrogen storage as cathode and the counter-electrode as anode, the electrolyser produces hydrogen at the palladium surface and oxygen at the electrolyser cell anode. The generated hydrogen is absorbed by the palladium electrode and the hydrogen storage is refilled consequently enabling the fuel cell to function.

  18. Guidelines for Waste Accumulation Areas (WAAs)

    SciTech Connect

    Not Available

    1991-07-01

    The purpose of this document is to set conditions for establishing and maintaining areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes in quantities greater than 100 kg (220 lb) per month of solid waste or 55 gallons per month of liquid waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs; constructing a WAA; storing waste in a WAA; operating and maintaining a WAA, and responding to spills in a WAA. 4 figs.

  19. Nutrient-contaminant (Pu) plant accumulation model

    SciTech Connect

    Cowan, C.E.; Jenne, E.A.; Simpson, J.C.; Cataldo, D.A.

    1981-12-01

    A model was developed which simulates the movement and daily accumulation of nutrients and contaminants in crop plants resulting from known physiological processes in the plant. In the model, the daily contaminant accumulation is governed by daily increase in plant biomass derived from photosynthesis and by the specified thermodynamic activity of the bioavailable contaminant species in soil or hydroponic solutin. Total accumulation and resulting concentration in the plant's root, stem and branch, leaf, and reproductive compartments can be simulated any time during the growing season. Parameters were estimated from data on plutonium accumulation in soybeans and the model was calibrated against this same data set. The plutonium distribution in the plant was found to be most sensitive to parameters related to leaf accumulation. Contamination at different times during the growing season resulted in a large change in predicted leaf accumulation but very little change in predicted accumulation in other plant parts except when contamination occurred very late in the growing season.

  20. Accumulated damage process of thermal sprayed coating under rolling contact by acoustic emission technique

    NASA Astrophysics Data System (ADS)

    Xu, Jia; Zhou, Zhen-yu; Piao, Zhong-yu

    2016-07-01

    The accumulated damage process of rolling contact fatigue (RCF) of plasma-sprayed coatings was investigated. The influences of surface roughness, loading condition, and stress cycle frequency on the accumulated damage status of the coatings were discussed. A ball-ondisc machine was employed to conduct RCF experiments. Acoustic emission (AE) technique was introduced to monitor the RCF process of the coatings. AE signal characteristics were investigated to reveal the accumulated damage process. Result showed that the polished coating would resist the asperity contact and remit accumulated damage. The RCF lifetime would then extend. Heavy load would aggravate the accumulated damage status and induce surface fracture. Wear became the main failure mode that reduced the RCF lifetime. Frequent stress cycle would aggravate the accumulated damage status and induce interface fracture. Fatigue then became the main failure mode that also reduced the RCF lifetime.

  1. Synoptic controls on precipitation pathways and snow delivery to high-accumulation ice core sites in the Ross Sea region, Antarctica

    NASA Astrophysics Data System (ADS)

    Sinclair, K. E.; Bertler, N. A. N.; Trompetter, W. J.

    2010-11-01

    Dominant storm tracks to two ice core sites on the western margin of the Ross Sea, Antarctica (Skinner Saddle (SKS) and Evans Piedmont Glacier), are investigated to establish key synoptic controls on snow accumulation. This is critical in terms of understanding the seasonality, source regions, and transport pathways of precipitation delivered to these sites. In situ snow depth and meteorological observations are used to identify major accumulation events in 2007-2008, which differ considerably between sites in terms of their magnitude and seasonal distribution. While snowfall at Evans Piedmont Glacier occurs almost exclusively during summer and spring, Skinner Saddle receives precipitation year round with a lull during the months of April and May. Cluster analysis of daily back trajectories reveals that the highest-accumulation days at both sites result from fast-moving air masses, associated with synoptic-scale low-pressure systems. There is evidence that short-duration pulses of snowfall at SKS also originate from mesocyclone development over the Ross Ice Shelf and local moisture sources. Changes in the frequency and seasonal distribution of these mechanisms of precipitation delivery will have a marked impact on annual accumulation over time and will therefore need careful consideration during the interpretation of stable isotope and geochemical records from these ice cores.

  2. The effects of 13 wk of liraglutide treatment on endocrine and exocrine pancreas in male and female ZDF rats: a quantitative and qualitative analysis revealing no evidence of drug-induced pancreatitis.

    PubMed

    Vrang, Niels; Jelsing, Jacob; Simonsen, Lotte; Jensen, Andres Eskjær; Thorup, Inger; Søeborg, Henrik; Knudsen, Lotte Bjerre

    2012-07-15

    A possible association between glucagon-like peptide-1 (GLP-1) analogs and incidences of pancreatitis has been suggested based on clinical studies. In male and female diabetic Zucker diabetic fatty (ZDF) rats, we investigated the effects of continuous administration of liraglutide and exenatide on biochemical [lipase, pancreatic amylase (P-amylase)] and histopathological markers of pancreatitis. Male and female ZDF rats were dosed for 13 wk with liraglutide (0.4 or 1.0 mg·kg(-1)·day(-1) sc once daily) or exenatide (0.25 mg·kg(-1)·day(-1) sc, Alzet osmotic minipumps). P-amylase and lipase plasma activity were measured, and an extended histopathological and stereological (specific cell mass and proliferation rate) evaluation of the exocrine and the endocrine pancreas was performed. Expectedly, liraglutide and exenatide lowered blood glucose and Hb A(1c) in male and female ZDF rats, whereas β-cell mass and proliferation rate were increased with greatly improved blood glucose control. Whereas neither analog affected lipase activity, small increases in P-amylase activity were observed in animals treated with liraglutide and exenatide. However, concurrent or permanent increases in lipase and P-amylase activity were never observed. Triglycerides were lowered by both GLP-1 analogs. The qualitative histopathological findings did not reveal adverse effects of liraglutide. The findings were mainly minimal in severity and focal in distribution. Similarly, the quantitative stereological analyses revealed no effects of liraglutide or exenatide on overall pancreas weight or exocrine and duct cell mass or proliferation. The present study demonstrates that, in overtly diabetic male and female ZDF rats, prolonged exposure to GLP-1 receptor agonists does not affect biochemical or histopathological markers of pancreatitis, and whereas both exenatide and liraglutide increase β-cell mass, they have no effect on the exocrine pancreas. However, clinical outcome studies and studies

  3. Natural radionuclide accumulation by raindrops

    NASA Astrophysics Data System (ADS)

    Gusev, Anatoly; Martin, Inacio; Shkevov, Rumen; Alves, Mauro

    2016-07-01

    The laboratory of environmental radiation of ITA (São José dos Campos, 23°11'11″S, 45°52'43″W, 650 MAMSL) performs simultaneous monitoring of a natural radiation background and meteorological parameters. A time resolution of up to 1 minute allows a detailed comparison of changes in meteorological parameters with those of a concentration of ambient radon progenies in the atmosphere. Results of a study of variation of a fallout of radon progenies ^{214}Pb and ^{214}Bi concomitanting rainfalls are present. The radionuclide fallout rate is reconstructed from the observed gamma rate through a simulation of the first kind Volterra integral equation with difference kernel, determined by ratio of precipitating rates of 214Pb and 214Bi and their decay half times. An original straightforward step-by-step procedure was used for the numerical solution of the equation. The radionuclide concentration in the rainwater is calculated as a ratio of the reconstructed fallout to the measured rainfall. It was observed that the radionuclide fallout rate increases as the rainfall one in approximately power 0.6, i.e. the same as the mean raindrop volume. The concentration thereafter decreases as the rainfall rate in power 0.4. A numerical simulation of the process of accumulation of the radionuclides during diffusion and coalescence drop growth and aerosol scavenging during a passage from a cloud to the ground was performed. The results of the simulations agree with the experimental data.

  4. Topically applied ceramide accumulates in skin glyphs.

    PubMed

    Zhang, Qihong; Flach, Carol R; Mendelsohn, Richard; Mao, Guangru; Pappas, Apostolos; Mack, M Catherine; Walters, Russel M; Southall, Michael D

    2015-01-01

    Ceramides (CERs), structural components of the stratum corneum (SC), impart essential barrier properties to this thin outer layer of the epidermis. Variations in CER species within this layer have been linked to several skin diseases. A recent proliferation of CER-containing topical skin-care products warrants the elucidation of CER penetration profiles in both healthy and diseased skin. In the current study, the spatial distributions of CER concentration profiles, following topical application of two species of CER, were tracked using infrared imaging. Suspensions of single-chain perdeuterated sphingosine and phytosphingosine CER in oleic acid were applied, in separate experiments, to the surface of healthy intact ex vivo human skin using Franz diffusion cells. Following either a 24- or 48-hour incubation period at 34°C, infrared images were acquired from microtomed skin sections. Both CER species accumulated in glyph regions of the skin and penetrated into the SC, to a limited extent, only in these regions. The concentration profiles observed herein were independent of the CER species and incubation time utilized in the study. As a result, a very heterogeneous, sparse, spatial distribution of CERs in the SC was revealed. In contrast, oleic acid was found to be fairly homogeneously distributed throughout the SC and viable epidermis, albeit at lower concentrations in the latter. A more uniform, lateral distribution of CERs in the SC would likely be important for barrier efficacy or enhancement. PMID:26170709

  5. Vinpocetine attenuates lipid accumulation and atherosclerosis formation

    SciTech Connect

    Cai, Yujun; Li, Jian-Dong; Yan, Chen

    2013-05-10

    Highlights: •Vinpocetine attenuates hyperlipidemia-induced atherosclerosis in a mouse model. •Vinpocetine antagonizes ox-LDL uptake and accumulation in macrophages. •Vinpocetine blocks the induction of ox-LDL receptor LOX-1 in vitro and in vivo. -- Abstract: Atherosclerosis, the major cause of myocardial infarction and stroke, is a chronic arterial disease characterized by lipid deposition and inflammation in the vessel wall. Cholesterol, in low-density lipoprotein (LDL), plays a critical role in the pathogenesis of atherosclerosis. Vinpocetine, a derivative of the alkaloid vincamine, has long been used as a cerebral blood flow enhancer for treating cognitive impairment. Recent study indicated that vinpocetine is a potent anti-inflammatory agent. However, its role in the pathogenesis of atherosclerosis remains unexplored. In the present study, we show that vinpocetine significantly reduced atherosclerotic lesion formation in ApoE knockout mice fed with a high-fat diet. In cultured murine macrophage RAW264.7 cells, vinpocetine markedly attenuated oxidized LDL (ox-LDL) uptake and foam cell formation. Moreover, vinpocetine greatly blocked the induction of ox-LDL receptor 1 (LOX-1) in cultured macrophages as well as in the LOX-1 level in atherosclerotic lesions. Taken together, our data reveal a novel role of vinpocetine in reduction of pathogenesis of atherosclerosis, at least partially through suppressing LOX-1 signaling pathway. Given the excellent safety profile of vinpocetine, this study suggests vinpocetine may be a therapeutic candidate for treating atherosclerosis.

  6. Evaluation of Simultaneous Nutrient and COD Removal with Polyhydroxybutyrate (PHB) Accumulation Using Mixed Microbial Consortia under Anoxic Condition and Their Bioinformatics Analysis

    PubMed Central

    Jena, Jyotsnarani; Kumar, Ravindra; Dixit, Anshuman; Pandey, Sony; Das, Trupti

    2015-01-01

    Simultaneous nitrate-N, phosphate and COD removal was evaluated from synthetic waste water using mixed microbial consortia in an anoxic environment under various initial carbon load (ICL) in a batch scale reactor system. Within 6 hours of incubation, enriched DNPAOs (Denitrifying Polyphosphate Accumulating Microorganisms) were able to remove maximum COD (87%) at 2g/L of ICL whereas maximum nitrate-N (97%) and phosphate (87%) removal along with PHB accumulation (49 mg/L) was achieved at 8 g/L of ICL. Exhaustion of nitrate-N, beyond 6 hours of incubation, had a detrimental effect on COD and phosphate removal rate. Fresh supply of nitrate-N to the reaction medium, beyond 6 hours, helped revive the removal rates of both COD and phosphate. Therefore, it was apparent that in spite of a high carbon load, maximum COD and nutrient removal can be maintained, with adequate nitrate-N availability. Denitrifying condition in the medium was evident from an increasing pH trend. PHB accumulation by the mixed culture was directly proportional to ICL; however the time taken for accumulation at higher ICL was more. Unlike conventional EBPR, PHB depletion did not support phosphate accumulation in this case. The unique aspect of all the batch studies were PHB accumulation was observed along with phosphate uptake and nitrate reduction under anoxic conditions. Bioinformatics analysis followed by pyrosequencing of the mixed culture DNA from the seed sludge revealed the dominance of denitrifying population, such as Corynebacterium, Rhodocyclus and Paraccocus (Alphaproteobacteria and Betaproteobacteria). Rarefaction curve indicated complete bacterial population and corresponding number of OTUs through sequence analysis. Chao1 and Shannon index (H’) was used to study the diversity of sampling. “UCI95” and “LCI95” indicated 95% confidence level of upper and lower values of Chao1 for each distance. Values of Chao1 index supported the results of rarefaction curve. PMID:25689047

  7. Phytochelatin Synthesis Is Essential for the Detoxification of Excess Zinc and Contributes Significantly to the Accumulation of Zinc1[W][OA

    PubMed Central

    Tennstedt, Pierre; Peisker, Daniel; Böttcher, Christoph; Trampczynska, Aleksandra; Clemens, Stephan

    2009-01-01

    The synthesis of phytochelatins (PCs) is essential for the detoxification of nonessential metals and metalloids such as cadmium and arsenic in plants and a variety of other organisms. To our knowledge, no direct evidence for a role of PCs in essential metal homeostasis has been reported to date. Prompted by observations in Schizosaccharomyces pombe and Saccharomyces cerevisiae indicating a contribution of PC synthase expression to Zn2+ sequestration, we investigated a known PC-deficient Arabidopsis (Arabidopsis thaliana) mutant, cad1-3, and a newly isolated second strong allele, cad1-6, with respect to zinc (Zn) homeostasis. We found that in a medium with low cation content PC-deficient mutants show pronounced Zn2+ hypersensitivity. This phenotype is of comparable strength to the well-documented Cd2+ hypersensitivity of cad1 mutants. PC deficiency also results in significant reduction in root Zn accumulation. To be able to sensitively measure PC accumulation, we established an assay using capillary liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry of derivatized extracts. Plants grown under control conditions consistently showed PC2 accumulation. Analysis of plants treated with same-effect concentrations revealed that Zn2+-elicited PC2 accumulation in roots reached about 30% of the level of Cd2+-elicited PC2 accumulation. We conclude from these data that PC formation is essential for Zn2+ tolerance and provides driving force for the accumulation of Zn. This function might also help explain the mysterious occurrence of PC synthase genes throughout the plant kingdom and in a wide range of other organisms. PMID:19074629

  8. [Job crisis and transformations in the new model of accumulation].

    PubMed

    Zerda-Sarmiento, Alvaro

    2012-06-01

    The general and structural crisis capitalism is going through is the token of the difficulties accumulation model has been dealing with since 70's in developed countries. This model has been trying to settle down again on the basis of neoliberal principle and a new technical-economical paradigm. The new accumulation pattern has had a effect in employment sphere which have been made evident at all the elements that constitute work relationships. In Colombia, this model implementation has been partial and segmented. However, its consequences (and the long-term current crisis) have been evident in unemployment, precarious work, segmentation, informal work and restricted and private health insurance. Besides, financial accumulation makes labour profits flow at different levels. The economic model current government has aimed to implement leads to strengthening exports, so making population life conditions more difficult. In order to overcome the current state of affairs, the work sphere needs to become more creative. This creative approach should look for new schemes for expression and mobilization of work sphere's claims. This is supposed to be done by establishing a different economic model aimed to build a more inclusive future, with social justice. PMID:23258748

  9. Influence of cadmium on PCB congener accumulation in quail

    SciTech Connect

    Leonzio, C.; Marsili, L.; Focardi, S. )

    1992-11-01

    Technological development this century has led to an environmental input of synthetic chemical compounds totally extraneous to natural ecosystems such as Polychlorobiphenyls (PCBs), extensively used in agriculture and industry. These xenobiotics have a high fat/water repartition coefficient, making them easily accumulated by living organisms. Their persistence and low degradability means that they are now present throughout the global ecosystem. Ubiquitous environmental contaminants also include heavy metals like Hg, As, Pb, Cd and Cr, of which Cd, an element causing functional damage to the kidney and liver in which it preferentially accumulates, is of special ecotoxicological importance. The WHO has defined an accumulation of 60 mg/kg (fresh weight), beyond which damage occurs. Cd occurs [open quotes]naturally[close quotes] in high concentrations in certain animal species including molluscs. Birds and marine mammals feeding largely on cephalopods show high levels of this metal. Many monitoring studies have also revealed high concentrations of PCBs in the same animals. The vast majority of studies on contaminants in experimental animals consider the short-, medium- and long-term effects of a single pollutant. However, the presence of synergisms and antagonisms between compounds makes it necessary to adopt a more holistic approach to the problem of environmental pollution. In order to understand if the effect of xenobiotic compounds like PCBs may be potentiated by the natural presence of cadmium in bird population, we sought preliminary information on how the presence of cadmium in the diet may influence the accumulation and metabolization of PCB congeners. The influence of Cd on PCB accumulation was investigated in Japanese quail treated experimentally with Cd and PCBs. Particular attention was paid to final congener accumulation and qualitative differences in congener composition between controls and treated birds. 15 refs., 3 figs., 1 tab.

  10. Indole Glucosinolate Biosynthesis Limits Phenylpropanoid Accumulation in Arabidopsis thaliana

    PubMed Central

    2015-01-01

    Plants produce an array of metabolites (including lignin monomers and soluble UV-protective metabolites) from phenylalanine through the phenylpropanoid biosynthetic pathway. A subset of plants, including many related to Arabidopsis thaliana, synthesizes glucosinolates, nitrogen- and sulfur-containing secondary metabolites that serve as components of a plant defense system that deters herbivores and pathogens. Here, we report that the Arabidopsis thaliana reduced epidermal fluorescence5 (ref5-1) mutant, identified in a screen for plants with defects in soluble phenylpropanoid accumulation, has a missense mutation in CYP83B1 and displays defects in glucosinolate biosynthesis and in phenylpropanoid accumulation. CYP79B2 and CYP79B3 are responsible for the production of the CYP83B1 substrate indole-3-acetaldoxime (IAOx), and we found that the phenylpropanoid content of cyp79b2 cyp79b3 and ref5-1 cyp79b2 cyp79b3 plants is increased compared with the wild type. These data suggest that levels of IAOx or a subsequent metabolite negatively influence phenylpropanoid accumulation in ref5 and more importantly that this crosstalk is relevant in the wild type. Additional biochemical and genetic evidence indicates that this inhibition impacts the early steps of the phenylpropanoid biosynthetic pathway and restoration of phenylpropanoid accumulation in a ref5-1 med5a/b triple mutant suggests that the function of the Mediator complex is required for the crosstalk. PMID:25944103

  11. Microbiological screening of Irish patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy reveals persistence of Candida albicans strains, gradual reduction in susceptibility to azoles, and incidences of clinical signs of oral candidiasis without culture evidence.

    PubMed

    McManus, Brenda A; McGovern, Eleanor; Moran, Gary P; Healy, Claire M; Nunn, June; Fleming, Pádraig; Costigan, Colm; Sullivan, Derek J; Coleman, David C

    2011-05-01

    Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are prone to chronic mucocutaneous candidiasis, which is often treated with azoles. The purpose of this study was to characterize the oral Candida populations from 16 Irish APECED patients, who comprise approximately half the total number identified in Ireland, and to examine the effect of intermittent antifungal therapy on the azole susceptibility patterns of Candida isolates. Patients attended between one and four clinical evaluations over a 5-year period, providing oral rinses and/or oral swab samples each time. Candida was recovered from 14/16 patients, and Candida albicans was the only Candida species identified. Interestingly, clinical diagnosis of candidiasis did not correlate with microbiological evidence of Candida infection at 7/22 (32%) clinical assessments. Multilocus sequence typing analysis of C. albicans isolates recovered from the same patients on separate occasions identified the same sequence type each time. Fluconazole resistance was detected in isolates from one patient, and isolates exhibiting a progressive reduction in itraconazole and/or fluconazole susceptibility were identified in a further 3/16 patients, in each case correlating with the upregulation of CDR- and MDR-encoded efflux pumps. Mutations were also identified in the ERG11 and the TAC1 genes of isolates from these four patients; some of these mutations have previously been associated with azole resistance. The findings suggest that alternative Candida treatment options, other than azoles such as chlorhexidine, should be considered in APECED patients and that clinical diagnosis of oral candidiasis should be confirmed by culture prior to the commencement of anti-Candida therapy. PMID:21367996

  12. A Whole-Genome Scan and Fine-Mapping Linkage Study of Auditory-Visual Synesthesia Reveals Evidence of Linkage to Chromosomes 2q24, 5q33, 6p12, and 12p12

    PubMed Central

    Asher, Julian E.; Lamb, Janine A.; Brocklebank, Denise; Cazier, Jean-Baptiste; Maestrini, Elena; Addis, Laura; Sen, Mallika; Baron-Cohen, Simon; Monaco, Anthony P.

    2009-01-01

    Synesthesia, a neurological condition affecting between 0.05%–1% of the population, is characterized by anomalous sensory perception and associated alterations in cognitive function due to interference from synesthetic percepts. A stimulus in one sensory modality triggers an automatic, consistent response in either another modality or a different aspect of the same modality. Familiality studies show evidence of a strong genetic predisposition; whereas initial pedigree analyses supported a single-gene X-linked dominant mode of inheritance with a skewed F:M ratio and a notable absence of male-to-male transmission, subsequent analyses in larger samples indicated that the mode of inheritance was likely to be more complex. Here, we report the results of a whole-genome linkage scan for auditory-visual synesthesia with 410 microsatellite markers at 9.05 cM density in 43 multiplex families (n = 196) with potential candidate regions fine-mapped at 5 cM density. Using NPL and HLOD analysis, we identified four candidate regions. Significant linkage at the genome-wide level was detected to chromosome 2q24 (HLOD = 3.025, empirical genome-wide p = 0.047). Suggestive linkage was found to chromosomes 5q33, 6p12, and 12p12. No support was found for linkage to the X chromosome; furthermore, we have identified two confirmed cases of male-to-male transmission of synesthesia. Our results demonstrate that auditory-visual synesthesia is likely to be an oligogenic disorder subject to multiple modes of inheritance and locus heterogeneity. This study comprises a significant step toward identifying the genetic substrates underlying synesthesia, with important implications for our understanding of the role of genes in human cognition and perception. PMID:19200526

  13. Evidence for the conformational rigidity of triplex d(C +T) 8-d(AG) 8·d(CT) 8 on silver electrode revealed by Fourier transform Raman scattering studies

    NASA Astrophysics Data System (ADS)

    Fang, Ye; Bai, Chunli; Wang, Ting; Zhong, Faping; Tang, Youqi; Lin, S. B.; Kan, Lou-sing

    1996-03-01

    Fourier transform surface enhanced Raman scattering spectroscopy (FT-SERS) has been first applied to characterize the triple stranded helix d(C +T) 8-d(AG) 8·d(CT) 8 (pH 4.5) (triplex) and its corresponding double-stranded helix d(AG) 8·d(CT) 8 (pH 7.0) (duplex) at an ex situ roughened silver electrode polarized at between 0.0 and -1.0 V vs. {Ag}/{AgCl}. The triplex adsorbed on the silver electrode yields five intense and one weak SERS bands located at 241, 839, 1189, 1293, 1643, and 1530 cm -1, respectively. These bands are not seen in the FT-SERS spectrum of the duplex, which showed a pattern similar to that of an oligo-DNA duplex observed by Koglin and Sequaries (Top. Curr. Chem., 134 (1989) 1). In the case of the triplex, the occurrence of the 839 cm -1 band with concomitant disappearance of the adsorbed adenine ring-breathing band at 734 cm -1 of the duplex indicates that the helical structure of the triplex near the surface of the silver electrode is well preserved and exhibits conformational rigidity. We observed a desorption process of the triplex from the silver electrode when the electrode approached -0.9 V (potential of zero charge of the triplex) vs. {Ag}/{AgCl}. This indicates that the highly negatively charged triplex shows a more favorable absorption on a highly positively charged silver surface. The structure of the triplex has also been studied by Fourier transform infrared (FTIR) and Raman spectroscopy. The vibrational spectra obtained clearly revealed that the conformation of the sugar moiety of the purine strand and one pyrimidine strand in the triplex is C 2'-endo/anti, whereas that of the other pyrimidine strand is C 3'-endo/anti.

  14. Spatial and temporal variability of snow chemical composition and accumulation rate at Talos Dome site (East Antarctica).

    PubMed

    Caiazzo, Laura; Becagli, Silvia; Frosini, Daniele; Giardi, Fabio; Severi, Mirko; Traversi, Rita; Udisti, Roberto

    2016-04-15

    Five snow pits and five firn cores were sampled during the 2003-2004 Italian Antarctic Campaign at Talos Dome (East Antarctica), where a deep ice core (TALDICE, TALos Dome Ice CorE, 1650m depth) was drilled in 2005-2008 and analyzed for ionic content. Particular attention is spent in applying decontamination procedures to the firn cores, as core sections were stored for approximately 10years before analysis. By considering the snow pit samples to be unperturbed, the comparison with firn core samples from the same location shows that ammonium, nitrate and MSA are affected by storage post-depositional losses. All the other measured ions are confirmed to be irreversibly deposited in the snow layer. The removal of the most external layers (few centimeters) from the firn core sections is proved to be an effective decontamination procedure. High-resolution profiles of seasonal markers (nitrate, sulfate and MSA) allow a reliable stratigraphic dating and a seasonal characterization of the samples. The calculated mean accumulation-rate values range from 70 to 85mmw.e.year(-1), in the period 2003-1973 with small differences between two sectors: 70-74mmw.e.year(-1) in the NNE sector (spanning 2003-1996years) and 81-92mmw.e.year(-1) in the SSW sector (spanning 2003-1980years). This evidence is interpreted as a coupled effect of wind-driven redistribution processes in accumulation/ablation areas. Statistical treatment applied to the concentration values of the snow pits and firn cores samples collected in different points reveals a larger temporal variability than spatial one both in terms of concentration of chemical markers and annual accumulation. The low spatial variability of the accumulation rate and chemical composition measured in the five sites demonstrates that the TALDICE ice core paleo-environmental and paleo-climatic stratigraphies can be considered as reliably representative for the Talos Dome area. PMID:26849319

  15. Refeeding-induced brown adipose tissue glycogen hyper-accumulation in mice is mediated by insulin and catecholamines.

    PubMed

    Carmean, Christopher M; Bobe, Alexandria M; Yu, Justin C; Volden, Paul A; Brady, Matthew J

    2013-01-01

    Brown adipose tissue (BAT) generates heat during adaptive thermogenesis through a combination of oxidative metabolism and uncoupling protein 1-mediated electron transport chain uncoupling, using both free-fatty acids and glucose as substrate. Previous rat-based work in 1942 showed that prolonged partial fasting followed by refeeding led to a dramatic, transient increase in glycogen stores in multiple fat depots. In the present study, the protocol was replicated in male CD1 mice, resulting in a 2000-fold increase in interscapular BAT (IBAT) glycogen levels within 4-12 hours (hr) of refeeding, with IBAT glycogen stores reaching levels comparable to fed liver glycogen. Lesser effects occurred in white adipose tissues (WAT). Over the next 36 hr, glycogen levels dissipated and histological analysis revealed an over-accumulation of lipid droplets, suggesting a potential metabolic connection between glycogenolysis and lipid synthesis. 24 hr of total starvation followed by refeeding induced a robust and consistent glycogen over-accumulation similar in magnitude and time course to the prolonged partial fast. Experimentation demonstrated that hyperglycemia was not sufficient to drive glycogen accumulation in IBAT, but that elevated circulating insulin was sufficient. Additionally, pharmacological inhibition of catecholamine production reduced refeeding-induced IBAT glycogen storage, providing evidence of a contribution from the central nervous system. These findings highlight IBAT as a tissue that integrates both canonically-anabolic and catabolic stimulation for the promotion of glycogen storage during recovery from caloric deficit. The preservation of this robust response through many generations of animals not subjected to food deprivation suggests that the over-accumulation phenomenon plays a critical role in IBAT physiology. PMID:23861810

  16. The enigmatic nature of the circumstellar envelope and bow shock surrounding Betelgeuse as revealed by Herschel. I. Evidence of clumps, multiple arcs, and a linear bar-like structure

    NASA Astrophysics Data System (ADS)

    Decin, L.; Cox, N. L. J.; Royer, P.; Van Marle, A. J.; Vandenbussche, B.; Ladjal, D.; Kerschbaum, F.; Ottensamer, R.; Barlow, M. J.; Blommaert, J. A. D. L.; Gomez, H. L.; Groenewegen, M. A. T.; Lim, T.; Swinyard, B. M.; Waelkens, C.; Tielens, A. G. G. M.

    2012-12-01

    Context. The interaction between stellar winds and the interstellar medium (ISM) can create complex bow shocks. The photometers on board the Herschel Space Observatory are ideally suited to studying the morphologies of these bow shocks. Aims: We aim to study the circumstellar environment and wind-ISM interaction of the nearest red supergiant, Betelgeuse. Methods.Herschel PACS images at 70, 100, and 160 μm and SPIRE images at 250, 350, and 500 μm were obtained by scanning the region around Betelgeuse. These data were complemented with ultraviolet GALEX data, near-infrared WISE data, and radio 21 cm GALFA-HI data. The observational properties of the bow shock structure were deduced from the data and compared with hydrodynamical simulations. Results: The infrared Herschel images of the environment around Betelgeuse are spectacular, showing the occurrence of multiple arcs at ~6-7' from the central target and the presence of a linear bar at ~9'. Remarkably, no large-scale instabilities are seen in the outer arcs and linear bar. The dust temperature in the outer arcs varies between 40 and 140 K, with the linear bar having the same colour temperature as the arcs. The inner envelope shows clear evidence of a non-homogeneous clumpy structure (beyond 15''), probably related to the giant convection cells of the outer atmosphere. The non-homogeneous distribution of the material even persists until the collision with the ISM. A strong variation in brightness of the inner clumps at a radius of ~2' suggests a drastic change in mean gas and dust density ~32 000 yr ago. Using hydrodynamical simulations, we try to explain the observed morphology of the bow shock around Betelgeuse. Conclusions: Different hypotheses, based on observational and theoretical constraints, are formulated to explain the origin of the multiple arcs and the linear bar and the fact that no large-scale instabilities are visible in the bow shock region. We infer that the two main ingredients for explaining

  17. Comment on "Single-trial spike trains in parietal cortex reveal discrete steps during decision-making".

    PubMed

    Shadlen, Michael N; Kiani, Roozbeh; Newsome, William T; Gold, Joshua I; Wolpert, Daniel M; Zylberberg, Ariel; Ditterich, Jochen; de Lafuente, Victor; Yang, Tianming; Roitman, Jamie

    2016-03-25

    Latimeret al (Reports, 10 July 2015, p. 184) claim that during perceptual decision formation, parietal neurons undergo one-time, discrete steps in firing rate instead of gradual changes that represent the accumulation of evidence. However, that conclusion rests on unsubstantiated assumptions about the time window of evidence accumulation, and their stepping model cannot explain existing data as effectively as evidence-accumulation models. PMID:27013723

  18. Iron Accumulation Is Not Homogenous among Patients with Parkinson's Disease

    PubMed Central

    Dashtipour, Khashayar; Liu, Manju; Kani, Camellia; Dalaie, Pejman; Obenaus, Andre; Simmons, Daniel; Gatto, Nicole M.; Zarifi, Mehran

    2015-01-01

    Background. Iron is considered to lead to neurodegeneration and has been hypothesized as a possible cause of Parkinson's disease (PD). Susceptibility-weighted imaging (SWI) is a powerful tool to measure phase related iron content of brain. Methods. Twelve de novo patients with PD were recruited from the Movement Disorders Clinic, Department of Neurology, Loma Linda University. Twelve age- and sex-matched non-PD subjects were recruited from neurology clinic as controls. Using SWI, the phase related iron content was estimated from different brain regions of interest (ROIs). Results. There was a trend between increasing age and iron accumulation in the globus pallidus and putamen in all subjects. Iron accumulation was not significant in different ROIs in PD patients compared to controls after adjustment for age. Our data revealed heterogeneity of phase values in different brain ROIs among all subjects with an exaggerated trend at SN in PD patients. Conclusions. Our data suggest a nonhomogeneous pattern of iron accumulation in different brain regions among PD patients. Further studies are needed to explore whether this may correlate to the progression of PD. To our knowledge, this is the first study demonstrating the heterogeneity of iron accumulation in the brain, among patients with PD. PMID:25945281

  19. Sludge accumulation pattern inside oxidation ditch case study.

    PubMed

    Fouad, Moharram; El-Morsy, Ahmed

    2014-01-01

    The sludge accumulation pattern of an oxidation ditch (OD) plant treating municipal wastewater was observed under dry and wet weather conditions, during 3 years of operation. The accumulation patterns along the ditches and their rates were revealed. In addition, the composition of the accumulation was investigated. Finally, the ratio of sand and volatile particles, mixed liquor suspended solids (MLSS), and mixed liquor volatile suspended solids, as well as the removal efficiency were also observed against the accumulated sludge. Further, a laboratory-scale channel was used to investigate the settleability of grit after mixing with variable values of MLSS. The observed results indicated that the economical design and operation of ODs using a velocity value between 0.3-0.35 m/s is not recommended, to avoid the settling of all solids. High values of MLSS and sludge age need high horizontal velocity (more than 0.35 m/s) and more power to avoid settling problems and system failure. The influence of flow velocity on the sludge settleability was studied, enabling better planning of future ditch design and operation. PMID:24960009

  20. Local proliferation initiates macrophage accumulation in adipose tissue during obesity

    PubMed Central

    Zheng, C; Yang, Q; Cao, J; Xie, N; Liu, K; Shou, P; Qian, F; Wang, Y; Shi, Y

    2016-01-01

    Obesity-associated chronic inflammation is characterized by an accumulation of adipose tissue macrophages (ATMs). It is generally believed that those macrophages are derived from peripheral blood monocytes. However, recent studies suggest that local proliferation of macrophages is responsible for ATM accumulation. In the present study, we revealed that both migration and proliferation contribute to ATM accumulation during obesity development. We show that there is a significant increase in ATMs at the early stage of obesity, which is largely due to an enhanced in situ macrophage proliferation. This result was obtained by employing fat-shielded irradiation and bone marrow reconstitution. Additionally, the production of CCL2, a pivotal chemoattractant of monocytes, was not found to be increased at this stage, corroborating with a critical role of proliferation. Nonetheless, as obesity proceeds, the role of monocyte migration into adipose tissue becomes more significant and those new immigrants further proliferate locally. These proliferating ATMs mainly reside in crown-like structures formed by macrophages surrounding dead adipocytes. We further showed that IL-4/STAT6 is a driving force for ATM proliferation. Therefore, we demonstrated that local proliferation of resident macrophages contributes to ATM accumulation during obesity development and has a key role in obesity-associated inflammation. PMID:27031964

  1. Local proliferation initiates macrophage accumulation in adipose tissue during obesity.

    PubMed

    Zheng, C; Yang, Q; Cao, J; Xie, N; Liu, K; Shou, P; Qian, F; Wang, Y; Shi, Y

    2016-01-01

    Obesity-associated chronic inflammation is characterized by an accumulation of adipose tissue macrophages (ATMs). It is generally believed that those macrophages are derived from peripheral blood monocytes. However, recent studies suggest that local proliferation of macrophages is responsible for ATM accumulation. In the present study, we revealed that both migration and proliferation contribute to ATM accumulation during obesity development. We show that there is a significant increase in ATMs at the early stage of obesity, which is largely due to an enhanced in situ macrophage proliferation. This result was obtained by employing fat-shielded irradiation and bone marrow reconstitution. Additionally, the production of CCL2, a pivotal chemoattractant of monocytes, was not found to be increased at this stage, corroborating with a critical role of proliferation. Nonetheless, as obesity proceeds, the role of monocyte migration into adipose tissue becomes more significant and those new immigrants further proliferate locally. These proliferating ATMs mainly reside in crown-like structures formed by macrophages surrounding dead adipocytes. We further showed that IL-4/STAT6 is a driving force for ATM proliferation. Therefore, we demonstrated that local proliferation of resident macrophages contributes to ATM accumulation during obesity development and has a key role in obesity-associated inflammation. PMID:27031964

  2. Ultrastructural and flow cytometric analyses of lipid accumulation in microalgae

    SciTech Connect

    Solomon, J.A.; Hand, R.E. Jr.; Mann, R.C.

    1986-12-01

    Lipid accumulation in three species of microalgae was investigated with flow cytometry (FCM) and transmission electron microscopy (TEM). Previous studies using batch cultures of a algae have led to the assumption that lipid accumulation in microalgae is a gradual process requiring at least several days for completion. However, FCM reveals, through changes in the chlorophyll:lipid ratio, that the time span required for individual cells to change metabolic state is short. Simultaneous FCM measurements of chlorophyll and nile red (neutral lipid) fluorescence in individual cells of nitrogen-deficient Isochrysis populations revealed a bimodal population distribution as one stage in the lipid accumulation process. The fact that two discrete populations exist, with few cells in an intermediate stage, suggests rapid response to a liqid trigger. Interpretations of light and electron microscopic observations are consistent with this hypothesis. The time required for an entire population to achieve maximum lipid content is considerably longer than that required for a single cell, due to the variation in response time among cells. In this study high lipid cultures were sometimes obtained by using FCM to separate high lipid cells from the remainder of the population. FCM holds much promise for strain enhancement but considerable developmental work, directed at providing more consistent results, remains to be done. 8 refs., 35 figs.

  3. Metal accumulation in wild-caught opossum.

    PubMed

    Lockhart, J Mitchell; Siddiqui, Samreen; Loughry, W J; Bielmyer-Fraser, Gretchen K

    2016-06-01

    The Virginia opossum (Didelphis virginiana) is widespread in the USA, ranging south through Latin America. The ecology of opossums is such that they are in frequent contact with soils, suggesting that they may function as a valuable bioindicator for chemical contamination in terrestrial environments. Surprisingly, there have been virtually no toxicology studies on opossums. Here, we provide the first analysis of metal contaminants in opossum liver tissues. Liver samples were obtained from 471 opossums, collected from 2003 to 2006, at four sites in North Florida and South Georgia, USA, and concentrations of copper, lead, nickel, selenium, and zinc were measured. We found little evidence of age differences in the concentration of any of the metals. However, there were at least some significant differences between years, males and females, and between sites for each metal, although the pattern of these differences was not always consistent across metals. Concentrations of metals in liver tissue were positively correlated with one another, primarily of each metal (except Pb) with zinc. Reference levels of metal contaminants are not available for opossums, but concentrations of Cu, Ni, Pb, and Zn in our samples were for the most part significantly higher than those reported from liver tissues of nine-banded armadillos (Dasypus novemcinctus) collected at the same sites and in the same years. Data from other small mammals studied elsewhere further indicate that metal concentrations in opossums were high, but at this time, it is not possible to determine if these elevated levels generated toxicity. The substantial temporal and spatial variation we found in metal concentrations suggests that determination of baseline levels for opossums may not be straightforward. Nonetheless, this is the first study quantifying metal accumulation in the livers of Didelphis virginiana and, as such, provides an important starting point for future research. PMID:27138002

  4. Monoclonal Antibodies against Accumulation-Associated Protein Affect EPS Biosynthesis and Enhance Bacterial Accumulation of Staphylococcus epidermidis

    PubMed Central

    Hu, Jian; Xu, Tao; Zhu, Tao; Lou, Qiang; Wang, Xueqin; Wu, Yang; Huang, Renzheng; Liu, Jingran; Liu, Huayong; Yu, Fangyou; Ding, Baixing; Huang, Yalin; Tong, Wenyan; Qu, Di

    2011-01-01

    Because there is no effective antibiotic to eradicate Staphylococcus epidermidis biofilm infections that lead to the failure of medical device implantations, the development of anti-biofilm vaccines is necessary. Biofilm formation by S. epidermidis requires accumulation-associated protein (Aap) that contains sequence repeats known as G5 domains, which are responsible for the Zn2+-dependent dimerization of Aap to mediate intercellular adhesion. Antibodies against Aap have been reported to inhibit biofilm accumulation. In the present study, three monoclonal antibodies (MAbs) against the Aap C-terminal single B-repeat construct followed by the 79-aa half repeat (AapBrpt1.5) were generated. MAb18B6 inhibited biofilm formation by S. epidermidis RP62A to 60% of the maximum, while MAb25C11 and MAb20B9 enhanced biofilm accumulation. All three MAbs aggregated the planktonic bacteria to form visible cell clusters. Epitope mapping revealed that the epitope of MAb18B6, which recognizes an identical area within AapBrpt constructs from S. epidermidis RP62A, was not shared by MAb25C11 and MAb20B9. Furthermore, all three MAbs were found to affect both Aap expression and extracellular polymeric substance (EPS, including extracellular DNA and PIA) biosynthesis in S. epidermidis and enhance the cell accumulation. These findings contribute to a better understanding of staphylococcal biofilm formation and will help to develop epitope-peptide vaccines against staphylococcal infections. PMID:21687690

  5. Evidence for compartmentalization of mammalian carotenoid metabolism

    PubMed Central

    Palczewski, Grzegorz; Amengual, Jaume; Hoppel, Charles L.; von Lintig, Johannes

    2014-01-01

    The critical role of retinoids (vitamin A and its derivatives) for vision, reproduction, and survival has been well established. Vitamin A is produced from dietary carotenoids such as β-carotene by centric cleavage via the enzyme BCO1. The biochemical and molecular identification of a second structurally related β-carotene metabolizing enzyme, BCO2, has led to a prolonged debate about its relevance in vitamin A biology. While BCO1 cleaves provitamin A carotenoids, BCO2 is more promiscuous and also metabolizes nonprovitamin A carotenoids such as zeaxanthin into long-chain apo-carotenoids. Herein we demonstrate, in cell lines, that human BCO2 is associated with the inner mitochondrial membrane. Different human BCO2 isoforms possess cleavable N-terminal leader sequences critical for mitochondrial import. Subfractionation of murine hepatic mitochondria confirmed the localization of BCO2 to the inner mitochondrial membrane. Studies in BCO2-knockout mice revealed that zeaxanthin accumulates in the inner mitochondrial membrane; in contrast, β-carotene is retained predominantly in the cytoplasm. Thus, we provide evidence for a compartmentalization of carotenoid metabolism that prevents competition between BCO1 and BCO2 for the provitamin and the production of noncanonical β-carotene metabolites.—Palczewski, G., Amengual, J., Hoppel, C. L., von Lintig, J. Evidence for compartmentalization of mammalian carotenoid metabolism. PMID:25002123

  6. 40 CFR 262.34 - Accumulation time.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Accumulation time. 262.34 Section 262.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS APPLICABLE TO GENERATORS OF HAZARDOUS WASTE Pre-Transport Requirements § 262.34 Accumulation time. (a) Except as provided in paragraphs (d),...

  7. Challenging the spin accumulation interpretation of local ``3T'' measurements

    NASA Astrophysics Data System (ADS)

    Tinkey, Holly; Appelbaum, Ian; Li, Pengke

    2015-03-01

    The recent observation of magnetoresistance in local ``three-terminal'' (3T) measurements on ferromagnet/ insulator/ semiconductor junctions have spawned many claims of direct bulk spin injection or ``accumulation''. We present a self-consistent model to rigorously calculate expected voltage changes due to electrochemical potential splitting from spin accumulation driven by pure elastic tunnel injection in such junctions, and find that the experimentally observed magnetoresistance vastly exceeds theoretical predictions in all doping, temperature, and bias voltage regimes. Our own experimental measurements using inelastic electron tunneling spectroscopy reveal that extrinsic impurities and defects within the junctions are responsible for the observed magnetoresistance signals, which cannot possibly be attributed to spin dephasing of polarized bulk electrons from elastic injection as claimed by proponents of the method. Supported by the Maryland Nanocenter, the Office of Naval Research Contract N000141110637, the National Science Foundation contracts ECCS-0901941 and ECCS-1231855 and Graduate Fellowship DGE13221, and the Defense Threat Reduction Agency contract HDTRA1.

  8. Elevation changes in Antarctica mainly determined by accumulation variability.

    PubMed

    Helsen, Michiel M; van den Broeke, Michiel R; van de Wal, Roderik S W; van de Berg, Willem Jan; van Meijgaard, Erik; Davis, Curt H; Li, Yonghong; Goodwin, Ian

    2008-06-20

    Antarctic Ice Sheet elevation changes, which are used to estimate changes in the mass of the interior regions, are caused by variations in the depth of the firn layer. We quantified the effects of temperature and accumulation variability on firn layer thickness by simulating the 1980-2004 Antarctic firn depth variability. For most of Antarctica, the magnitudes of firn depth changes were comparable to those of observed ice sheet elevation changes. The current satellite observational period ( approximately 15 years) is too short to neglect these fluctuations in firn depth when computing recent ice sheet mass changes. The amount of surface lowering in the Amundsen Sea Embayment revealed by satellite radar altimetry (1995-2003) was increased by including firn depth fluctuations, while a large area of the East Antarctic Ice Sheet slowly grew as a result of increased accumulation. PMID:18511656

  9. Revealing ontological commitments by magic.

    PubMed

    Griffiths, Thomas L

    2015-03-01

    Considering the appeal of different magical transformations exposes some systematic asymmetries. For example, it is more interesting to transform a vase into a rose than a rose into a vase. An experiment in which people judged how interesting they found different magic tricks showed that these asymmetries reflect the direction a transformation moves in an ontological hierarchy: transformations in the direction of animacy and intelligence are favored over the opposite. A second and third experiment demonstrated that judgments of the plausibility of machines that perform the same transformations do not show the same asymmetries, but judgments of the interestingness of such machines do. A formal argument relates this sense of interestingness to evidence for an alternative to our current physical theory, with magic tricks being a particularly pure source of such evidence. These results suggest that people's intuitions about magic tricks can reveal the ontological commitments that underlie human cognition. PMID:25490128

  10. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS.

    PubMed

    Chouchani, Edward T; Pell, Victoria R; Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y; Robb, Ellen L; Logan, Angela; Nadtochiy, Sergiy M; Ord, Emily N J; Smith, Anthony C; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J; James, Andrew M; Rogatti, Sebastian; Hartley, Richard C; Eaton, Simon; Costa, Ana S H; Brookes, Paul S; Davidson, Sean M; Duchen, Michael R; Saeb-Parsy, Kourosh; Shattock, Michael J; Robinson, Alan J; Work, Lorraine M; Frezza, Christian; Krieg, Thomas; Murphy, Michael P

    2014-11-20

    Ischaemia-reperfusion injury occurs when the blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death and aberrant immune responses through the generation of mitochondrial reactive oxygen species (ROS). Although mitochondrial ROS production in ischaemia reperfusion is established, it has generally been considered a nonspecific response to reperfusion. Here we develop a comparative in vivo metabolomic analysis, and unexpectedly identify widely conserved metabolic pathways responsible for mitochondrial ROS production during ischaemia reperfusion. We show that selective accumulation of the citric acid cycle intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase, which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. After reperfusion, the accumulated succinate is rapidly re-oxidized by succinate dehydrogenase, driving extensive ROS generation by reverse electron transport at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo ischaemia-reperfusion injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of ischaemia-reperfusion injury. Furthermore, these findings reveal a new pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation after subsequent reperfusion is a potential therapeutic target to decrease ischaemia

  11. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS

    PubMed Central

    Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y.; Robb, Ellen L.; Logan, Angela; Nadtochiy, Sergiy M.; Ord, Emily N. J.; Smith, Anthony C.; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J.; James, Andrew M.; Rogatti, Sebastian; Hartley, Richard C.; Eaton, Simon; Costa, Ana S.H.; Brookes, Paul S.; Davidson, Sean M.; Duchen, Michael R.; Saeb-Parsy, Kourosh; Shattock, Michael J.; Robinson, Alan J.; Work, Lorraine M.; Frezza, Christian; Krieg, Thomas; Murphy, Michael P.

    2014-01-01

    Ischaemia-reperfusion (IR) injury occurs when blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death, and aberrant immune responses through generation of mitochondrial reactive oxygen species (ROS)1-5. Although mitochondrial ROS production in IR is established, it has generally been considered a non-specific response to reperfusion1,3. Here, we developed a comparative in vivo metabolomic analysis and unexpectedly identified widely conserved metabolic pathways responsible for mitochondrial ROS production during IR. We showed that selective accumulation of the citric acid cycle (CAC) intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase (SDH), which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. Upon reperfusion, the accumulated succinate is rapidly re-oxidised by SDH, driving extensive ROS generation by reverse electron transport (RET) at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo IR injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of IR injury. Furthermore, these findings reveal a novel pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation upon subsequent reperfusion is a potential therapeutic target to decrease IR injury in a range of pathologies. PMID:25383517

  12. Transient Expression of WNT2 Promotes Somatic Cell Reprogramming by Inducing β-Catenin Nuclear Accumulation.

    PubMed

    Kimura, Mizuki; Nakajima-Koyama, May; Lee, Joonseong; Nishida, Eisuke

    2016-06-14

    Treatment with several Wnt/β-catenin signaling pathway regulators can change the cellular reprogramming efficiency; however, the dynamics and role of endogenous Wnt/β-catenin signaling in reprogramming remain largely unanswered. Here we identify the upregulation of WNT2 and subsequent β-catenin nuclear accumulation as key events in reprogramming. Transient nuclear accumulation of β-catenin occurs early in MEF reprogramming. Wnt2 is strongly expressed in the early stage of reprogramming. Wnt2 knockdown suppresses the nuclear accumulation of β-catenin and reduces the reprogramming efficiency. WNT2 overexpression promotes β-catenin nuclear accumulation and enhances the reprogramming efficiency. WNT2 contributes to the promotion of cell proliferation. Experiments with several drugs that control the Wnt pathway also indicate the importance of β-catenin nuclear accumulation in reprogramming. Our findings reveal the role of WNT2/β-catenin signaling in reprogramming. PMID:27211212

  13. Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

    PubMed

    Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

    2014-09-01

    Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. PMID:24446756

  14. Sulfur-accumulating plants convert sulfate salts from soils into environmentally resilient biominerals

    NASA Astrophysics Data System (ADS)

    Robson, Thomas; Reid, Nathan; Stevens, Jason; Dixon, Kingsley

    2016-04-01

    Sulfur-accumulator plants (thiophores), which accumulate atypically high sulfur and calcium concentrations in their aerial biomass, may be suitable for revegetating and phytostabilising reactive sulfur-enriched substrates such as mine tailings, acid-sulfate soils and polluted soils. We present biogeochemical insights on thiophores from the Australian Great Sandy Desert, which accumulate up to 40 times as much sulfur (2-5 %S) versus comparator species. X-ray microanalyses revealed this accumulation relates to peculiar gypsum-like mineralisation throughout their foliage, illustrating a mechanism for sulfate removal from soils and sequestration as sparingly soluble biominerals. However, we did not know whether these species treat the excess Ca/S as a waste to be shed with senescent litter and, if so, how resilient these 'biominerals' are to photo-biodegradation once shed and so to what extent the accumulated elements are recycled back into the reactive/bioavailable sulfate reservoir. To address these questions, we sampled four foliage (phyllode) fractions from ten individuals of the thiophore, Acacia bivenosa: healthy mature phyllodes, senescent phyllodes on the branch, recently shed and older, more degraded ground litter. We selected two thiophores (A. bivenosa and A. robeorum) and a non-thiophore (A. ancistrocarpa) for detailed soil/regolith studies. Samples were collected from trenches bisected by each tree, taken from varying depth (20-500 mm) and distance from the stem (0.1-5 m). Dried foliage was cleaned, sectioned for SEM-EDXS examination and elemental compositions of foliage and soils were determined (microwave-assisted acid digestion + ICP-OES/MS). Each species generated a 'halo' of elevated S/Ca in the soil immediately beneath their crowns, although that of A. ancistrocarpa was of minor magnitude. These anomalies were confined to shallow soil (20-50 mm i.e. influenced by litter), suggesting limited S/Ca re-mobilisation from the litter. Foliar elemental

  15. Lysosomal cholesterol accumulation in macrophages leading to coronary atherosclerosis in CD38(-/-) mice.

    PubMed

    Xu, Xiaoyang; Yuan, Xinxu; Li, Ningjun; Dewey, William L; Li, Pin-Lan; Zhang, Fan

    2016-06-01

    The disruption in transportation of oxLDL-derived cholesterol and the subsequent lipid accumulation in macrophages are the hallmark events in atherogenesis. Our recent studies demonstrated that lysosomal Ca(2+) messenger of nicotinic acid adenine dinucleotide phosphate (NAADP), an enzymatic product of CD38 ADP-ribosylcyclase (CD38), promoted lipid endocytic trafficking in human fibroblast cells. The current studies are designed to examine the functional role of CD38/NAADP pathway in the regulation of lysosomal cholesterol efflux in atherosclerosis. Oil red O staining showed that oxLDL concentration-dependently increased lipid buildup in bone marrow-derived macrophages from both wild type and CD38(-/-) , but to a significant higher extent with CD38 gene deletion. Bodipy 493/503 fluorescence staining found that the deposited lipid in macrophages was mainly enclosed in lysosomal organelles and largely enhanced with the blockade of CD38/NAADP pathway. Filipin staining and direct measurement of lysosome fraction further revealed that the free cholesterol constituted a major portion of the total cholesterol segregated in lysosomes. Moreover, in situ assay disclosed that both lysosomal lumen acidity and the acid lipase activity were reduced upon cholesterol buildup in lysosomes. In CD38(-/-) mice, treatment with Western diet (12 weeks) produced atherosclerotic damage in coronary artery with striking lysosomal cholesterol sequestration in macrophages. These data provide the first experimental evidence that the proper function of CD38/NAADP pathway plays an essential role in promoting free cholesterol efflux from lysosomes and that a defection of this signalling leads to lysosomal cholesterol accumulation in macrophages and results in coronary atherosclerosis in CD38(-/-) mice. PMID:26818887

  16. Variations in xanthophyll composition in etiolated seedlings of Arabidopsis thaliana correlate with protochlorophyllide accumulation.

    PubMed

    Myśliwa-Kurdziel, Beata; Jemioła-Rzemińska, Małgorzata; Turek, Elżbieta; Strzałka, Kazimierz; Malec, Przemysław

    2012-01-01

    Protochlorophyllide (Pchlide) accumulation and xantophyll composition were studied in 5-day old etiolated seedlings of three ecotypes of Arabidopsis thaliana: Columbia (Col-0), Landsberg erecta (Ler) and Wassiliewska (Ws). The total Pchlide level as measured by fluorescence spectroscopy varied significantly between ecotypes. A rapid HPLC method revealed quantitative differences in carotenoid composition. It was found that in the Ler ecotype any enhanced accumulation of Pchlide correlates with an increased level of lutein, suggesting the role of enzymes involved in lutein synthesis in cross-regulation between chlorophyll and carotenoid biosynthetic pathways. The function of the dark-accumulated carotenoid pool in seedling de-etiolation is discussed. PMID:22428143

  17. Induction and Accumulation of Heat Shock-Specific Poly(A+) RNAs and Proteins in Soybean Seedlings during Arsenite and Cadmium Treatments 1

    PubMed Central

    Edelman, Leonard; Czarnecka, Eva; Key, Joe L.

    1988-01-01

    Northern blot hybridization analyzes revealed that poly(A+) RNAs homologous to eight heat shock (HS)-specific cDNA clones were induced by arsenite (As) or Cd treatments. The mRNAs accumulated slower, and maximum accumulations were consistently lower than HS-induced levels. Prolonged treatment with low concentrations (50-100 micromolar) of As for 6 hours, or Cd for 12 hours, resulted in decreased accumulations of HS-specific mRNAs. This response resembled the `autoregulation' observed during continuous 40°C HS. However, no autoregulation was evident when soybean seedlings were exposed to high concentrations of As (250 micromolar) or Cd (1 millimolar) for 12 hours. The cDNA probe pCE54 detected a second higher molecular weight poly(A+) RNA following As or Cd treatments which accumulated concomitantly with the lower molecular weight HS-specific poly(A+) RNA. The patterns of low molecular weight HS polypeptides from in vitro translations induced by HS, As, and Cd, and analyzed by one-dimensional and two-dimensional SDS-PAGE, were similar but temporal differences were apparent. In addition to HS proteins, many control proteins were also detected in both in vitro and in vivo labeling patterns from As and, to a lesser extent, Cd treatments. The chemical agents used in this study apparently induced the accumulation and translation of HS messages in vivo but not in the selective manner as observed during HS treatment. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:16666030

  18. THE KINETICS OF PENETRATION : VIII. TEMPORARY ACCUMULATION.

    PubMed

    Osterhout, W J; Kamerling, S E

    1934-03-20

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  19. Geochemistry Model Validation Report: External Accumulation Model

    SciTech Connect

    K. Zarrabi

    2001-09-27

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  20. Microbial accumulation of uranium, radium, and cesium

    SciTech Connect

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; North, S.E.

    1981-05-01

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested.

  1. No Accumulation of Transposable Elements in Asexual Arthropods.

    PubMed

    Bast, Jens; Schaefer, Ina; Schwander, Tanja; Maraun, Mark; Scheu, Stefan; Kraaijeveld, Ken

    2016-03-01

    Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads. PMID:26560353

  2. No Accumulation of Transposable Elements in Asexual Arthropods

    PubMed Central

    Bast, Jens; Schaefer, Ina; Schwander, Tanja; Maraun, Mark; Scheu, Stefan; Kraaijeveld, Ken

    2016-01-01

    Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads. PMID:26560353

  3. Saccharomyces cerevisiae does not accumulate ethanol against a concentration gradient.

    PubMed Central

    Guijarro, J M; Lagunas, R

    1984-01-01

    It has been reported that yeast cells accumulate ethanol against a concentration gradient. We initiated a study of the mechanism involved in this phenomenon. However, we found that this accumulation does not occur and that ethanol permeates the yeast cell plasma membrane by simple diffusion. The following evidence supports this conclusion. (i) Uptake and outflow of ethanol in yeast cells followed first-order kinetics and were insensitive to the presence of structural analogs of ethanol, to drastic pH changes, and to the action of reagents of amino and thiol groups. These results strongly suggest that ethanol permeates the yeast cell plasma membrane without involvement of any carrier. (ii) The outflow rate of ethanol seems greater than the ability of this organism to produce ethanol, indicating that intracellular accumulation of ethanol is not possible. (iii) The intracellular concentration of ethanol found was similar to the concentration in culture media in all tested conditions. With the available information, it is difficult to ascertain the reasons for the discrepancy between our results and those previously reported by other authors. However, the inadequacy of the cell-sampling procedure and of the chromatographic conditions used by those authors suggests that the discrepancy may be due to artifacts in the measurements of ethanol. PMID:6389514

  4. Biogeographical Evidences Help Revealing the Origin of Hainan Island

    PubMed Central

    Zhu, Hua

    2016-01-01

    Both the continental or island origin of Hainan, and the Indo-Malaysian or East Asian affinity of its flora, are debatable. In this study, 196 families, 1283 genera and 3894 species of Hainan plants were recognized. Patterns of seed plant distribution were quantified at the generic and the family levels. The floras of Vietnam, and the adjacent Guangxi and Guangdong provinces of mainland China, were compared with Hainan. The results showed that the flora of Hainan Island is dominated by families and genera with tropical distributions. Among its floristic elements, tropical Asian distributions make up 23.85% of the total flora, while East Asian distributions contribute only 3.74%. There are only 7 genera and c. 10% of species endemic to Hainan Island. The Hainan flora has strong similarities to the flora of Vietnam at the family and the generic levels, and also to the flora of Guangxi, but less with the adjacent Guangdong province. The main conclusions are: Hainan’s flora is tropical in nature with a strongly tropical Asian affinity, and it has very low endemism at the generic and species levels, which implies a continental origin. We conjecture that Hainan Island could have been adjacent to northern Vietnam and the Guangxi at least in Eocene. This suggestion is supported by palaeobotanical, palaeomagnetic and volcanism studies. PMID:27055236

  5. Metabolomic analysis revealed glycylglycine accumulation in astrocytes after methionine enkephalin administration exhibiting neuron protective effects.

    PubMed

    Zhao, Chungang; Du, Huijie; Xu, Li; Wang, Jiao; Tang, Ling; Cao, Yunfeng; Li, Chen; Wang, Qingjun; Liu, Yang; Shan, Fengping; Feng, Juan; Xu, Fang; Gao, Peng

    2015-11-10

    Owing to its unrevealed etiology, multiple sclerosis lacks specific therapies up to now. Experiential administration of methionine enkephalin (MENK) on mouse model improved disease manifestations to some extent. In order to gain more insight on the significance of MENK application, a capillary electrophoresis-mass spectrometry (CE-MS) technique was employed to profile intracellular metabolite fluctuation in 5 astrocytoma cell lines challenged by MENK. The processed data were first evaluated through a bioinformatic process to ensure their compatibility with the study aims and then subjected to multivariate analysis. The results indicated that MENK administration increased intracellular tyrosine, phenylalanine, methionine and glycylglycine. Exemplified by U87 cells, glycylglycine inhibited cell proliferation as well as MENK but it also decreased cell nitric oxide excretion which could not be evoked by MENK. The neuron protective effects were also mirrored by the increased expression of some genes related to remyelination. This study demonstrated CE-MS to be a promising tool for cell metabolomic analysis and benefited the therapeutic exploring of multiple sclerosis with respect to metabolism intervention. PMID:26163404

  6. Kre6 Protein Essential for Yeast Cell Wall β-1,6-Glucan Synthesis Accumulates at Sites of Polarized Growth*

    PubMed Central

    Kurita, Tomokazu; Noda, Yoichi; Takagi, Tomoko; Osumi, Masako; Yoda, Koji

    2011-01-01

    Saccharomyces cerevisiae Kre6 is a type II membrane protein with amino acid sequence homology with glycoside hydrolase and is essential for β-1,6-glucan synthesis as revealed by the mutant phenotype, but its biochemical function is still unknown. The localization of Kre6, determined by epitope tagging, is a matter of debate. We raised anti-Kre6 rabbit antiserum and examined the localization of Kre6 and its tagged protein by immunofluorescence microscopy, subcellular fractionation in sucrose density gradients, and immunoelectron microscopy. Integration of the results indicates that the majority of Kre6 is in the endoplasmic reticulum; however, a small but significant portion is also present in the secretory vesicle-like compartments and plasma membrane. Kre6 in the latter compartments is observed as strong signals that accumulate at the sites of polarized growth by immunofluorescence. The truncated Kre6 without the N-terminal 230-amino acid cytoplasmic region did not show this polarized accumulation and had a severe defect in β-1,6-glucan synthesis. This is the first evidence of a β-1,6-glucan-related protein showing the polarized membrane localization that correlates with its biological function. PMID:21193403

  7. Accumulation of nickel in transgenic tobacco

    NASA Astrophysics Data System (ADS)

    Sidik, Nik Marzuki; Othman, Noor Farhan

    2013-11-01

    The accumulation of heavy metal Ni in the roots and leaves of four T1 transgenic lines of tobacco (T(1)20E, T(1)24C, T(1)18B1 and T(1)20B) expressing eiMT1 from E.indica was assessed. The aim of the study was to investigate the level of Ni accumulation in the leaves and roots of each transgenic lines and to evaluate the eligibility of the plants to be classified as a phytoremediation agent. All of the transgenic lines showed different ability in accumulating different metals and has translocation factor (TF) less than 1 (TF<1) at all levels of metal treatment. Among the 4 transgenic lines, transgenic line T(1)24C showed the highest accumulation of Ni (251.9 ± 0.014 mg/kg) and the lowest TF value (TFT(1)24C=0.0875) at 60 ppm Ni.

  8. Evaluating the Role of Microbial Internal Storage Turnover on Nitrous Oxide Accumulation During Denitrification

    PubMed Central

    Liu, Yiwen; Peng, Lai; Guo, Jianhua; Chen, Xueming; Yuan, Zhiguo; Ni, Bing-Jie

    2015-01-01

    Biological wastewater treatment processes under a dynamic regime with respect to carbon substrate can result in microbial storage of internal polymers (e.g., polyhydroxybutyrate (PHB)) and their subsequent utilizations. These storage turnovers play important roles in nitrous oxide (N2O) accumulation during heterotrophic denitrification in biological wastewater treatment. In this work, a mathematical model is developed to evaluate the key role of PHB storage turnovers on N2O accumulation during denitrification for the first time, aiming to establish the key relationship between N2O accumulation and PHB storage production. The model is successfully calibrated and validated using N2O data from two independent experimental systems with PHB storage turnovers. The model satisfactorily describes nitrogen reductions, PHB storage/utilization, and N2O accumulation from both systems. The results reveal a linear relationship between N2O accumulation and PHB production, suggesting a substantial effect of PHB storage on N2O accumulation during denitrification. Application of the model to simulate long-term operations of a denitrifying sequencing batch reactor and a denitrifying continuous system indicates the feeding pattern and sludge retention time would alter PHB turnovers and thus affect N2O accumulation. Increasing PHB utilization could substantially raise N2O accumulation due to the relatively low N2O reduction rate when using PHB as carbon source. PMID:26463891

  9. Biosynthesis and accumulation of osmoprotective compounds by halophytic plants of the genus Limonium

    SciTech Connect

    Hanson, A.D.; Rathinasabapathi, B. ); Gage, D.A. )

    1991-05-01

    Analyses of quaternary ammonium compounds in leaf and root tissues of halophytic Limonium spp. using fast atom bombardment mass spectrometry revealed that only 3 out of 21 spp. accumulated glycine betaine, the common angiosperm osmolyte. The 18 other spp. accumulated {beta}-alanine betaine instead. However, all the Limonium spp. studied accumulated choline-O-sulfate and their leaf disks metabolized ({sup 14}C) choline to choline-O-sulfate. Only the glycine betaine accumulators oxidized ({sup 14}C) choline to glycine betaine and only {beta}-alanine betaine accumulators converted {beta}-({sup 14}C)alanine to {beta}-alanine betaine. When {beta}-alanine betaine and glycine betaine accumulators were salinized with NaCl, the levels of their respective betaines and of choline sulfate were closely correlated with solute potential. Glycine betaine accumulators had less choline-O-sulfate than {beta}-alanine betaine accumulators and increasing the SO{sub 4}{sup 2}/Cl ratio in the medium increased choline-O-sulfate and caused a matching decrease in glycine betaine. Thus, it appears that {beta}-alanine betaine has replaced glycine betaine in most members of this genus, eliminating a possible competition between glycine betaine and choline-O-sulfate for choline.

  10. Evaluating the Role of Microbial Internal Storage Turnover on Nitrous Oxide Accumulation During Denitrification.

    PubMed

    Liu, Yiwen; Peng, Lai; Guo, Jianhua; Chen, Xueming; Yuan, Zhiguo; Ni, Bing-Jie

    2015-01-01

    Biological wastewater treatment processes under a dynamic regime with respect to carbon substrate can result in microbial storage of internal polymers (e.g., polyhydroxybutyrate (PHB)) and their subsequent utilizations. These storage turnovers play important roles in nitrous oxide (N2O) accumulation during heterotrophic denitrification in biological wastewater treatment. In this work, a mathematical model is developed to evaluate the key role of PHB storage turnovers on N2O accumulation during denitrification for the first time, aiming to establish the key relationship between N2O accumulation and PHB storage production. The model is successfully calibrated and validated using N2O data from two independent experimental systems with PHB storage turnovers. The model satisfactorily describes nitrogen reductions, PHB storage/utilization, and N2O accumulation from both systems. The results reveal a linear relationship between N2O accumulation and PHB production, suggesting a substantial effect of PHB storage on N2O accumulation during denitrification. Application of the model to simulate long-term operations of a denitrifying sequencing batch reactor and a denitrifying continuous system indicates the feeding pattern and sludge retention time would alter PHB turnovers and thus affect N2O accumulation. Increasing PHB utilization could substantially raise N2O accumulation due to the relatively low N2O reduction rate when using PHB as carbon source. PMID:26463891

  11. Primitive red alga Cyanidioschyzon merolae accumulates storage glucan and triacylglycerol under nitrogen depletion.

    PubMed

    Takusagawa, Mari; Nakajima, Yohei; Saito, Takafumi; Misumi, Osami

    2016-07-14

    Most microalgae accumulate neutral lipids, including triacylglycerol (TAG), into spherical structures called lipid bodies (LBs) under environmental stress conditions such as nutrient depletion. In green algae, starch accumulation precedes TAG accumulation, and the starch is thought to be a substrate for TAG synthesis. However, the relationship between TAG synthesis and the starch content in red algae, as well as how TAG accumulation is regulated, is unclear. In this study, we cultured the primitive red alga Cyanidioschyzon merolae under nitrogen-depleted conditions, and monitored the formation of starch granules (SGs) and LBs using microscopy. SGs stained with potassium iodide were observed at 24 h; however, LBs stained specifically with BODIPY 493/503 were observed after 48 h. Quantitative analysis of neutral sugar and cytomorphological semi-quantitative analysis of TAG accumulation also supported these results. Thus, the accumulation of starch occurred and preceded the accumulation of TAG in cells of C. merolae. However, TAG accumulation was not accompanied by a decrease in the starch content, suggesting that the starch is a major carbon storage sink, at least under nitrogen-depleted conditions. Quantitative real-time PCR revealed that the mRNA levels of genes involved in starch and TAG synthesis rarely changed during the culture period, suggesting that starch and TAG synthesis in C. merolae are not controlled through gene transcription but at other stages, such as translation and/or enzymatic activity. PMID:27181396

  12. Accumulation of atmospheric sulfur in some Costa Rican soils

    USGS Publications Warehouse

    Bern, Carleton R.; Townsend, Alan R.

    2013-01-01

    Sulfur is one of the macronutrient elements whose sources to terrestrial ecosystems should shift from dominance by rock-weathering to atmospheric deposition as soils and underlying substrate undergo progressive weathering and leaching. However, the nature and timing of this transition is not well known. We investigated sources of sulfur to tropical rain forests growing on basalt-derived soils in the Osa Peninsula region of Costa Rica. Sulfur sources were examined using stable isotope ratios (δ34S) and compared to chemical indices of soil development. The most weathered soils, and the forests they supported, are dominated by atmospheric sulfur, while a less weathered soil type contains both rock-derived and atmospheric sulfur. Patterns of increasing δ34S with increasing soil sulfur concentration across the landscape suggest atmospheric sulfur is accumulating, and little rock-derived sulfur has been retained. Soil sulfur, minus adsorbed sulfate, is correlated with carbon and nitrogen, implying that sulfur accumulation occurs as plants and microbes incorporate sulfur into organic matter. Only the lower depth increments of the more weathered soils contained significant adsorbed sulfate. The evidence suggests a pattern of soil development in which sulfur-bearing minerals in rock, such as sulfides, weather early relative to other minerals, and the released sulfate is leached away. Sulfur added via atmospheric deposition is retained as organic matter accumulates in the soil profile. Adsorbed sulfate accumulates later, driven by changes in soil chemistry and mineralogy. These aspects of sulfur behavior during pedogenesis in this environment may hasten the transition to dominance by atmospheric sources.

  13. Persistent vascular collagen accumulation alters hemodynamic recovery from chronic hypoxia

    PubMed Central

    Tabima, Diana M.; Roldan-Alzate, Alejandro; Wang, Zhijie; Hacker, Timothy A.; Molthen, Robert C.; Chesler, Naomi C.

    2011-01-01

    Pulmonary arterial hypertension (PAH) is caused by narrowing and stiffening of the pulmonary arteries that increase pulmonary vascular impedance (PVZ). In particular, small arteries narrow and large arteries stiffen. Large pulmonary artery (PA) stiffness is the best current predictor of mortality from PAH. We have previously shown that collagen accumulation leads to extralobar PA stiffening at high strain (Ooi, Wang et al. 2010). We hypothesized that collagen accumulation would increase PVZ, including total pulmonary vascular resistance (Z0), characteristic impedance (ZC), pulse wave velocity (PWV), and index of global wave reflections (Pb/Pf), which contribute to increased right ventricular afterload. We tested this hypothesis by exposing mice unable to degrade type I collagen (Col1a1R/R) to 21 days of hypoxia (hypoxia), some of which were allowed to recover for 42 days (recovery). Littermate wild-type mice (Col1a1+/+) were used as controls. In response to hypoxia, mean PA pressure (mPAP) increased in both mouse genotypes with no changes in cardiac output (CO) or PA inner diameter (ID); as a consequence, Z0 (mPAP/CO) increased by ~100% in both genotypes (p<0.05). Contrary to our expectations, ZC, PWV and Pb/Pf did not change. However, with recovery, ZC and PWV decreased in the Col1a1+/+ mice and remained unchanged in the Col1a1R/R mice. Z0 decreased with recovery in both genotypes. Microcomputed tomography measurements of large PAs did not show evidence of stiffness changes as a function of hypoxia exposure or genotype. We conclude that hypoxia-induced PA collagen accumulation does not affect the pulsatile components of pulmonary hemodynamics but that excessive collagen accumulation does prevent normal hemodynamic recovery, which may have important consequences for right ventricular function. PMID:22183202

  14. Naturally Ocurring Polyphosphate-accumulating Bacteria in Benthic Biofilms

    NASA Astrophysics Data System (ADS)

    Locke, N. A.; Saia, S. M.; Walter, M. T.; Carrick, H. J.; Buda, A. R.; Regan, J. M.

    2014-12-01

    Polyphosphate accumulating organisms (PAOs), known to store excess phosphorus (P) as polyphosphate (poly-P), influence P transport in the environment. Enhanced biological phosphorus removal (EBPR) from wastewater has long served as a basis to study bacterial PAOs, yet little research has genetically identified similar organisms in natural settings. Aerobic/anaerobic cycles, used to select for PAOs in EBPR, can result from changing environmental conditions such as night/day cycles for benthic biofilms. Benthic biofilms from eight Pennsylvanian streams were studied for naturally-occurring bacterial PAOs similar to those typically found in EBPR systems. PAOs were confirmed in the benthic biofilms by a characteristic yellow fluorescent emission from DAPI staining. Cells containing yellow fluorescence were separated from the rest of the sample using a flow cytometer, resulting in a physically enriched culture of PAOs from the benthic biofilms. Amplicon-based metagenomic sequencing will reveal the phylogeny of bacteria responsible for poly-P accumulation in these benthic biofilms. Sequencing data will be used to develop fluorescent in-situ hybridization (FISH) probes, and hybridizations will be performed on DAPI-stained cells to confirm poly-P accumulation by targeted phylotypes. Identifying PAOs in natural settings is a critical step towards studying environments that support high concentrations of PAOs, serving as significant factors in the P cycle. PAOs can then be connected to P transport models to help understand and mitigate P pollution in agricultural watersheds.

  15. Significance of Bacillus subtilis strain SJ-101 as a bioinoculant for concurrent plant growth promotion and nickel accumulation in Brassica juncea.

    PubMed

    Zaidi, Sabina; Usmani, Saima; Singh, Braj Raj; Musarrat, Javed

    2006-08-01

    In this study, a nickel (Ni)-tolerant Bacillus subtilis strain SJ-101 was characterized based on the 16SrDNA homology and phylogenetic analysis. The role of this strain ascertained in facilitating Ni accumulation in the Indian mustard plant (Brassica juncea [L]. Czern and Coss) var. Pusa Bold (DIR-50), to elucidate the potential of Ni phytoremediation in combination with metal-tolerant rhizobacteria. The data revealed that the plants exposed to NiCl2 (1750 mg kg(-1)) in soil bioaugmented with strain SJ-101 have accumulated 0.147% Ni vis-à-vis 0.094% accumulation in dry biomass of the plants grown in uninoculated soil. The strain SJ-101 has also exhibited the capability of producing indole acetic acid (IAA) (55 microg ml(-1)), and solubilizing inorganic phosphate (90 microg ml(-1)) in specific culture media. The pot culture experiments clearly demonstrated the beneficial effects of bioinoculant strain SJ-101 with significant increase (p<0.05) in the plant growth attributes in untreated control soil. Furthermore, the protective effect of the strain SJ-101 against Ni phytotoxicity was evident in plants grown in soil treated with NiCl2 in concentration range of 250-1750 mg kg(-1). Thus, it is suggested that the strain SJ-101 owing to its intrinsic abilities of plant growth promotion, and attenuation of soil Ni by biosorption and bioaccumulation, could be exploited for bacteria-assisted phytoaccumulation of this toxic heavy metal from contaminated sites. PMID:16487570

  16. Mutant SOD1 accumulation in sensory neurons does not associate with endoplasmic reticulum stress features: Implications for differential vulnerability of sensory and motor neurons to SOD1 toxicity.

    PubMed

    Taiana, Michela; Sassone, Jenny; Lauria, Giuseppe

    2016-08-01

    Mutations in Cu/Zn-superoxide dismutase (SOD1) cause familial amyotrophic lateral sclerosis (ALS). Previous papers showed that mutant SOD1 accumulates and undergoes misfolding in motor neurons and that the specific interaction of mutant SOD1 with derlin-1 leads to endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). Because evidence shows that mutant SOD1 expression also damages sensory neurons, we hypothesized that, similarly to motor neurons, the sensory neurons of ALS mouse model SOD1(G93A) accumulate mutant/misfolded SOD1 and suffer from ER stress and UPR activation. Our results reveal that SOD1(G93A) sensory neurons accumulate mutant/misfolded SOD1 but, surprisingly, do not suffer from ER stress and UPR activation. Moreover, the sensory neurons do not express detectable levels of the SOD1 interactor derlin-1. These results suggest a potential molecular mechanism underlying the differential vulnerability of motor and sensory neurons to mutant SOD1 toxicity. PMID:27241719

  17. Diffusion versus linear ballistic accumulation: different models for response time with different conclusions about psychological mechanisms?

    PubMed

    Heathcote, Andrew; Hayes, Brett

    2012-06-01

    Two similar classes of evidence-accumulation model have dominated theorizing about rapid binary choice: diffusion models and racing accumulator pairs. Donkin, Brown, Heathcote, and Wagenmakers (2011) examined mimicry between the Ratcliff diffusion (RD; Ratcliff & Smith, 2004) and the linear ballistic accumulator (LBA; Brown & Heathcote, 2008), the 2 least similar models from each class that provide a comprehensive account of a set benchmark phenomena in rapid binary choice. Where conditions differed only in the rate of evidence accumulation (the most common case in past research), simulations showed the models supported equivalent psychological inferences. In contrast, differences in 2 other parameters of key psychological interest, response caution (the amount of information required for a decision), and nondecision time, traded-off when fitting 1 model to data simulated from the other, implying the potential for divergent inferences about latent cognitive processes. However, Donkin, Brown, Heathcote, and Wagenmakers did not find such inconsistencies between fits of the RD and LBA models in a survey of data sets from paradigms using a range of experimental manipulations. We examined a further data set, collected by Dutilh, Vandekerckhove, Tuerlinckx, and Wagenmakers (2009), which used a manipulation not surveyed by Donkin, Brown, Heathcote, and Wagenmakers's practice. Dutilh et al.'s RD model fits indicated that practice had large effects on all three types of parameters. We show that in this case the LBA provides a different and simpler account of practice effects. Implications for evidence accumulation modelling are discussed. PMID:22686161

  18. Evidence of deregulated cholesterol efflux in abdominal aortic aneurysm.

    PubMed

    Mourmoura, Evanthia; Vasilaki, Anna; Giannoukas, Athanasios; Michalodimitrakis, Emmanouel; Pavlidis, Pavlos; Tsezou, Aspasia

    2016-03-01

    Previous studies indicated that lipids may be associated with abdominal aortic aneurysm (AAA); however the molecular mechanism involved is unclear. Our study aimed to investigate the expression pattern of cholesterol efflux related proteins in AAA. Liver X receptors (LXRα and LXRβ), ATP-binding-cassette transporter A1 (ABCA1), Apolipoprotein AI (ApoAI), smooth muscle α-actin (α-SM) and vimentin expression levels were evaluated in human AAA, atherosclerotic (ATH) and normal abdominal aortic tissues. We found significant differences in LXRα, LXRβ and ABCA1 mRNA expression levels between AAA, ATH and normal whole aortic tissues and also within the AAA, ATH and normal "intima-media" layers. Specifically, LXRα, LXRβ and ABCA1 mRNA levels were decreased in AAA compared to ATH-whole tissues, as well as in AAA "intima-media" compared to ATH and normal "intima-media" layers. Moreover, immunohistochemical evaluation revealed that LXRα and ABCA1 immunoreactivities (IR) were reduced in the AAA media compared to the normal and ATH media layers and that they were also reduced in the intima layer of AAA and ATH tissues, whereas ApoAI-IR was increased in the AAA and ATH aortic walls compared to normal pointing to possible deregulation of the cholesterol efflux mechanism in AAA. Furthermore, double staining for vimentin and α-SM showed vimentin expression in the intima and inner media layer of AAA with sparse vimentin positive SMCs designating possible SMCs phenotype switch from contractile to synthetic form. In addition, histochemical analysis showed excessive lipid accumulation in the AAA wall, while co-staining using Oil Red O with α-SM or CD68 revealed lipid accumulation in SMCs and macrophages, respectively. Our study provides novel evidence for impaired cholesterol efflux in AAA associated with lipid accumulation in SMCs and macrophages, as well as switch of SMCs phenotype from contractile to synthetic form. PMID:26725543

  19. Accumulation, Speciation And Cellular Localization of Copper in 'Sesbania Drummondii'

    SciTech Connect

    Sahi, S.V.; Israr, M.; Srivastava, A.K.; Gardea-Torresdey, J.L.; Parsons, J.G.; /Western Kentucky U. /Texas U., El Paso

    2007-07-12

    Growth, accumulation and intracellular speciation and distribution of copper (Cu) in Sesbania drummondii was studied using scanning-electron microscopy (SEM), X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The growth of seedlings was assessed in terms of biomass accumulation. The growth of the seedling was enhanced by 73.5% at a low Cu concentration (50 mg l{sup -1}) compared to the control treatment. Additionally, seedling growth was inhibited by 18% at 300 mg l{sup -1} Cu with respect to the control. Copper concentration in roots and shoots was increased with increasing Cu concentration in the growth solution. The accumulation of Cu was found to be higher in roots than in the shoots. At a concentration of 300 mg l{sup -1} Cu, the roots accumulated 27,440 mg Cu kg{sup -1} dry weight (dw) while shoots accumulated 1282 mg Cu kg{sup -1} dw. Seedlings were assessed for photosynthetic activity by measuring chlorophyll a fluorescence parameters: Fv/Fm and Fv/F0 values. Photosynthetic integrity was not affected by any of the Cu treatments. The X-ray absorption spectroscopic (XAS) studies showed that Cu was predominantly present as Cu(II) in Sesbania tissue. In addition, from the XAS studies it was shown that the Cu exists in a mixture of different coordination states consisting of Cu bound to sugars and small organic acids with some possible precipitated copper oxide. From the EXAFS studies, the coordination of Cu was determined to have four equatorial oxygen(nitrogen) ligands at 1.96 angstroms and two axial oxygen ligands at 2.31 angstroms. Scanning-electron microscopy studies revealed the distribution of Cu within the seedlings tissues, predominantly accumulated in the cortical and vascular (xylem) regions of root tissues. In the stem, most of the Cu was found within the xylem tissue. However, the deposition of Cu within the leaf tissues was in the parenchyma. The present study demonstrates the mechanisms employed by

  20. Accumulation of arachidonic acid-containing phosphatidylinositol at the outer edge of colorectal cancer

    PubMed Central

    Hiraide, Takanori; Ikegami, Koji; Sakaguchi, Takanori; Morita, Yoshifumi; Hayasaka, Takahiro; Masaki, Noritaka; Waki, Michihiko; Sugiyama, Eiji; Shinriki, Satoru; Takeda, Makoto; Shibasaki, Yasushi; Miyazaki, Shinichiro; Kikuchi, Hirotoshi; Okuyama, Hiroaki; Inoue, Masahiro; Setou, Mitsutoshi; Konno, Hiroyuki

    2016-01-01

    Accumulating evidence indicates that cancer cells show specific alterations in phospholipid metabolism that contribute to tumour progression in several types of cancer, including colorectal cancer. Questions still remain as to what lipids characterize the outer edge of cancer tissues and whether those cancer outer edge-specific lipid compositions emerge autonomously in cancer cells. Cancer tissue-originated spheroids (CTOSs) that are composed of pure primary cancer cells have been developed. In this study, we aimed to seek out the cancer cell-autonomous acquisition of cancer outer edge-characterizing lipids in colorectal cancer by analysing phospholipids in CTOSs derived from colorectal cancer patients with matrix-assisted laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS). A signal at m/z 885.5 in negative ion mode was detected specifically at the surface regions. The signal was identified as an arachidonic acid (AA)-containing phosphatidylinositol (PI), PI(18:0/20:4), by tandem mass spectrometry analysis. Quantitative analysis revealed that the amount of PI(18:0/20:4) in the surface region of CTOSs was two-fold higher than that in the medial region. Finally, PI(18:0/20:4) was enriched at the cancer cells/stromal interface in colorectal cancer patients. These data imply a possible importance of AA-containing PI for colorectal cancer progression, and suggest cells expressing AA-containing PI as potential targets for anti-cancer therapy. PMID:27435310

  1. Transient strain accumulation and fault interaction in the Eastern California shear zone

    NASA Astrophysics Data System (ADS)

    Peltzer, Gilles; Crampé, Fréderic; Hensley, Scott; Rosen, Paul

    2001-11-01

    Satellite synthetic aperture radar interferometry reveals transient strain accumulation along the Blackwater Little Lake fault system within the Eastern California shear zone. The surface strain map obtained by averaging eight years (1992 2000) of Earth Resource Satellite (ERS) radar data shows a 120-km-long, 20-km- wide zone of concentrated shear between the southern end of the 1872 Owens Valley earthquake surface break and the northern end of the 1992 Landers earthquake surface break. The observed shear zone is continuous through the Garlock fault, which does not show any evidence of left-lateral slip during the same time period. A dislocation model of the observed shear indicates right-lateral slip at 7 ± 3 mm/yr on a vertical fault below ˜5 km depth, a rate that is two to three times greater than the geologic rates estimated on northwest-trending faults in the eastern Mojave area. This transient slip rate and the absence of resolvable slip on the Garlock fault may be the manifestation of an oscillatory strain pattern between interacting, conjugate fault systems.

  2. PCNA-dependent accumulation of CDKN1A into nuclear foci after ionizing irradiation

    SciTech Connect

    Wiese, Claudia; Rudolph, Jeanette Heede; Jakob, Burkhard; Fink, Daniela; Tobias, Frank; Blattner, Christine; Taucher-Scholz, Gisela

    2012-03-26

    The cyclin-dependent kinase inhibitor CDKN1A/p21 confers cell-cycle arrest in response to DNA damage and inhibits DNA replication through its direct interaction with the proliferating cell nuclear antigen (PCNA) and cyclin/cyclin-dependent kinase complexes. Previously, we reported that in response to densely ionizing radiation CDKN1A rapidly is recruited to the sites of particle traversal, and that CDKN1A foci formation in response to heavy ions is independent of its transactivation by TP53. In this paper, we show that exposure of normal human fibroblasts to X-rays or to H2O2 also induces nuclear accumulations of CDKN1A. We find that CDKN1A foci formation in response to radiation damage is dependent on its dephosphorylation and on its direct physical interaction with PCNA. Live cell imaging analyses of ectopically expressed EGFP-CDKN1A and dsRed-PCNA show rapid recruitment of both proteins into foci after radiation damage. Detailed dynamic measurements reveal a slightly delayed recruitment of CDKN1A compared to PCNA, which is best described by bi-exponential curve fitting, taking the preceding binding of PCNA to DNA into account. Finally, we propose a regulatory role for CDKN1A in mediating PCNA function after radiation damage, and provide evidence that this role is distinct from its involvement in nucleotide excision repair and unrelated to double-strand break repair.

  3. Accumulation of arachidonic acid-containing phosphatidylinositol at the outer edge of colorectal cancer.

    PubMed

    Hiraide, Takanori; Ikegami, Koji; Sakaguchi, Takanori; Morita, Yoshifumi; Hayasaka, Takahiro; Masaki, Noritaka; Waki, Michihiko; Sugiyama, Eiji; Shinriki, Satoru; Takeda, Makoto; Shibasaki, Yasushi; Miyazaki, Shinichiro; Kikuchi, Hirotoshi; Okuyama, Hiroaki; Inoue, Masahiro; Setou, Mitsutoshi; Konno, Hiroyuki

    2016-01-01

    Accumulating evidence indicates that cancer cells show specific alterations in phospholipid metabolism that contribute to tumour progression in several types of cancer, including colorectal cancer. Questions still remain as to what lipids characterize the outer edge of cancer tissues and whether those cancer outer edge-specific lipid compositions emerge autonomously in cancer cells. Cancer tissue-originated spheroids (CTOSs) that are composed of pure primary cancer cells have been developed. In this study, we aimed to seek out the cancer cell-autonomous acquisition of cancer outer edge-characterizing lipids in colorectal cancer by analysing phospholipids in CTOSs derived from colorectal cancer patients with matrix-assisted laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS). A signal at m/z 885.5 in negative ion mode was detected specifically at the surface regions. The signal was identified as an arachidonic acid (AA)-containing phosphatidylinositol (PI), PI(18:0/20:4), by tandem mass spectrometry analysis. Quantitative analysis revealed that the amount of PI(18:0/20:4) in the surface region of CTOSs was two-fold higher than that in the medial region. Finally, PI(18:0/20:4) was enriched at the cancer cells/stromal interface in colorectal cancer patients. These data imply a possible importance of AA-containing PI for colorectal cancer progression, and suggest cells expressing AA-containing PI as potential targets for anti-cancer therapy. PMID:27435310

  4. Altered accumulation and subcellular disposition of testicular cadmium in inbred mice resistant to cadmium-induced testicular necrosis

    SciTech Connect

    Chellman, G.J.

    1985-01-01

    Rodent testis is one of the most sensitive mammalian tissues to the toxic effects of acutely administered Cd. However, numerous inbred mouse strains are resistant to Cd-induced testicular damage, even at lethal Cd doses; the mechanism of this resistance has not been determined. Therefore, testes of mice susceptible (129/J) or resistant (A/J) to Cd-induced damage were examined for possible differences in the accumulation and subcellular disposition of Cd. Twenty-four hours after subcutaneous injection of mice with 30 ..mu..moles CdCl/sub 2//kg, 129/J testes showed extensive interstitial hemorrhage and seminiferous tubule necrosis, while A/J testes appeared histologically normal. Testicular Cd accumulation was 5-6 times less in A/J mice than in 129/J mice at all time points examined. Chromatography of testicular cytosol on Sephadex G-75 Superfine revealed four Cd-binding peaks. Both 15 min and 6 hr after dosing, A/J testes had 14% more of the total tissue Cd bound to the 14,500 MW protein (Cd-BP III), compared to 129/J testes, Cd-BP III behaved like metallothionein during gel filtration and ion exchange chromatography. Additional mice were injected i.v. with 10 (129/J) or 45 (A/J) ..mu..moles CdCl/sub 2//kg to achieve equal testicular Cd concentrations (approx. 4 nmoles Cd/g testis). Twenty-four hours later, 129/J testes were necrotic while A/J testes showed no microscopic evidence of damage. Therefore, resistance of A/J testes to Cd is not determined solely by decreased Cd accumulation, but is associated with increased binding of testicular Cd to Cd-BP III.

  5. Accumulation of heavy metals in the earthworm Eisenia foetida

    SciTech Connect

    Hartenstein, R.; Neuhauser, E.F.; Collier, J.

    1980-01-01

    Conversion of waste-activated sludge into egesta by the earthworm Eisenia foetida resulted in neither an increase nor decrease of 0.1 N HCl-extractable cadmium, copper, nickel, lead, or zinc. The addition of 2500 ppM copper as copper sulfate to activated sludge caused 100% mortality whthin 1 week, though feeding upon nonamended activated sludges with up to 1500 ppM copper over several months was innocuous. Amendment of sludge with 10, 50, and 100 ppM Cd as CdSO/sub 4/ resulted in 3.90-, 2.04-, and 1.44-fold concentrations in the earthworm over the quantities present in the sludge, with a range of 118 to 170 ppM being found on exposure to the highest level for periods of 1 to 5 weeks at 25/sup 0/C. In field trials with nonamended sludge, however, containing 12 to 27 ppM Cd, biweekly sampling for 28 weeks revealed accumulations in E. foetida ranging from 8 to 46 ppM; control earthworms not exposed to culture media with easily measurable Cd levels contained 0.3 to 2 ppM Cd. Upwards to about 50 ppM Ni, 325 ppM Pb, and 250 ppM Zn accumulated from sludges amended with ionic soluble forms of these metals. In the field, where these metals ranged from 2 to 46, 1 to 53, and 68 to 210 ppM, respectively, an upper concentration of about 50 ppM Ni, 55 ppM Pb, and 250 ppM Zn were found in the earthworm. Distinctions were made between accumulable and concentratable and a discussion is provided to show that each of the most problematic heavy metals, Cd, Zn, Ni, Pb, and Cu, may accumulate or concentrate in the earthworm.

  6. Accumulated destructive effect of nanosecond repetitive voltage pulses on the insulated coatings of Fe-based nanocrystalline ribbon

    SciTech Connect

    Zhang, Yu; Liu, Jinliang

    2013-03-11

    Fe-based nanocrystalline ribbon is widely employed in pulsed power devices and accelerators. A temperature accumulation model is put forward to explain the accumulated destructive effect of discharge plasma bombardment on the TiO{sub 2} coatings of nanocrystalline ribbon under 50 Hz/100 ns voltage pulses. Experimental results revealed that the plasma channel expansion caused by air breakdown in the coating crack heated the coating repetitively, and the coating temperature was increased and accumulated around the crack. The fact that repetitive voltage pulses were more destructive than a single pulse with the same amplitude was caused by the intensified coating ablation under the temperature accumulation effect.

  7. Metabolomics reveals insect metabolic responses associated with fungal infection.

    PubMed

    Xu, Yong-Jiang; Luo, Feifei; Gao, Qiang; Shang, Yanfang; Wang, Chengshu

    2015-06-01

    The interactions between insects and pathogenic fungi are complex. We employed metabolomic techniques to profile insect metabolic dynamics upon infection by the pathogenic fungus Beauveria bassiana. Silkworm larvae were infected with fungal spores and microscopic observations demonstrated that the exhaustion of insect hemocytes was coupled with fungal propagation in the insect body cavity. Metabolomic analyses revealed that fungal infection could significantly alter insect energy and nutrient metabolisms as well as the immune defense responses, including the upregulation of carbohydrates, amino acids, fatty acids, and lipids, but the downregulation of eicosanoids and amines. The insect antifeedant effect of the fungal infection was evident with the reduced level of maclurin (a component of mulberry leaves) in infected insects but elevated accumulations in control insects. Insecticidal and cytotoxic mycotoxins like oosporein and beauveriolides were also detected in insects at the later stages of infection. Taken together, the metabolomics data suggest that insect immune responses are energy-cost reactions and the strategies of nutrient deprivation, inhibition of host immune responses, and toxin production would be jointly employed by the fungus to kill insects. The data obtained in this study will facilitate future functional studies of genes and pathways associated with insect-fungus interactions. PMID:25895944

  8. How to Say "No" to a Nonword: A Leaky Competing Accumulator Model of Lexical Decision

    ERIC Educational Resources Information Center

    Dufau, Stephane; Grainger, Jonathan; Ziegler, Johannes C.

    2012-01-01

    We describe a leaky competing accumulator (LCA) model of the lexical decision task that can be used as a response/decision module for any computational model of word recognition. The LCA model uses evidence for a word, operationalized as some measure of lexical activity, as input to the "YES" decision node. Input to the "NO" decision node is…

  9. 26 CFR 1.1551-1 - Disallowance of surtax exemption and accumulated earnings credit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... both, was not a major factor in relationship to the other consideration or considerations which... preponderance of the evidence that the securing of such exemption or credit was not a major purpose of the... section 11(d) or the accumulated earnings credit provided in section 535, or both, was not a major...

  10. Civil Conflict and Human Capital Accumulation: The Long-Term Effects of Political Violence in Peru

    ERIC Educational Resources Information Center

    Leon, Gianmarco

    2012-01-01

    This paper provides empirical evidence of the persistent effect of exposure to political violence on human capital accumulation. I exploit the variation in conflict location and birth cohorts to identify the long- and short-term effects of the civil war on educational attainment. Conditional on being exposed to violence, the average person…

  11. Regulatory effects of curcumin on lipid accumulation in monocytes/macrophages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent evidence suggests potential benefits from phytochemicals and micronutrients in protecting against oxidative and lipid-mediated damage, but the molecular mechanisms of these actions are still unclear. Here we investigated whether the dietary polyphenol curcumin can modulate the accumulation of...

  12. Record of the accumulation of sediment and trace metals in a Connecticut salt marsh

    SciTech Connect

    McCaffrey, R.J.; Thomson, J.

    1980-12-01

    The possibility that a useful, historical record of deposition might be found in a salt marsh is investigated by considering a record of the accumulation of sediment and trace metals in a Connecticut salt marsh. Evidence of salt-marsh deposition dominated by riverine runoff is presented.

  13. Interpreting Evidence.

    ERIC Educational Resources Information Center

    Munsart, Craig A.

    1993-01-01

    Presents an activity that allows students to experience the type of discovery process that paleontologists necessarily followed during the early dinosaur explorations. Students are read parts of a story taken from the "American Journal of Science" and interpret the evidence leading to the discovery of Triceratops and Stegosaurus. (PR)

  14. Preferential Osmolyte Accumulation: a Mechanism of Osmotic Stress Adaptation in Diazotrophic Bacteria

    PubMed Central

    Madkour, Magdy A.; Smith, Linda Tombras; Smith, Gary M.

    1990-01-01

    A common cellular mechanism of osmotic-stress adaptation is the intracellular accumulation of organic solutes (osmolytes). We investigated the mechanism of osmotic adaptation in the diazotrophic bacteria Azotobacter chroococcum, Azospirillum brasilense, and Klebsiella pneumoniae, which are adversely affected by high osmotic strength (i.e., soil salinity and/or drought). We used natural-abundance 13C nuclear magnetic resonance spectroscopy to identify all the osmolytes accumulating in these strains during osmotic stress generated by 0.5 M NaCl. Evidence is presented for the accumulation of trehalose and glutamate in Azotobacter chroococcum ZSM4, proline and glutamate in Azospirillum brasilense SHS6, and trehalose and proline in K. pneumoniae. Glycine betaine was accumulated in all strains grown in culture media containing yeast extract as the sole nitrogen source. Alternative nitrogen sources (e.g., NH4Cl or casamino acids) in the culture medium did not result in measurable glycine betaine accumulation. We suggest that the mechanism of osmotic adaptation in these organisms entails the accumulation of osmolytes in hyperosmotically stressed cells resulting from either enhanced uptake from the medium (of glycine betaine, proline, and glutamate) or increased net biosynthesis (of trehalose, proline, and glutamate) or both. The preferred osmolyte in Azotobacter chroococcum ZSM4 shifted from glutamate to trehalose as a consequence of a prolonged osmotic stress. Also, the dominant osmolyte in Azospirillum brasilense SHS6 shifted from glutamate to proline accumulation as the osmotic strength of the medium increased. PMID:16348295

  15. Approach to distribution and accumulation of dibutyl phthalate in rats by immunoassay.

    PubMed

    Zeng, Qiang; Wei, Chenxi; Wu, Yang; Li, Ke; Ding, Shumao; Yuan, Junlin; Yang, Xu; Chen, Mingqing

    2013-06-01

    Dibutyl phthalate (DBP) is mainly taken up by the general population from food intake. To estimate intake of phthalates, determining distribution and accumulation of DBP in biological materials was a critical need. In this work, we set up two novel approaches with a monoclonal antibody specific to DBP to determine the distribution and accumulation of DBP in vivo. The contents of DBP in liver, kidney, stomach and testes were detected by immunofluorescence assays and indirect competitive ELISA. This data give directly evidence that indicates the distribution and accumulation of DBP in vivo. Double-label immunofluorescence assay provides with a visual approach to determination of the distribution and accumulation of DBP. It indicated that DBP accumulated in subcutaneous tissue such as sweat gland, hair follicle. Both of immunofluorescence assay and ELISA can be used to detect the content of DBP in biological materials. Our assays showed that DBP accumulated in viscera being rich in fat, such as liver, kidney and could overcome physiological barriers to penetrate testes. The date suggested that the accumulations of DBP exposed through dermal route were less than that of oral route and most of DBP was metabolized in 2 or 3 days. PMID:23419389

  16. Geomorphic control of landscape carbon accumulation

    USGS Publications Warehouse

    Rosenbloom, N.A.; Harden, J.W.; Neff, J.C.; Schimel, D.S.

    2006-01-01

    We use the CREEP process-response model to simulate soil organic carbon accumulation in an undisturbed prairie site in Iowa. Our primary objectives are to identify spatial patterns of carbon accumulation, and explore the effect of erosion on basin-scale C accumulation. Our results point to two general findings. First, redistribution of soil carbon by erosion results in a net increase in basin-wide carbon storage relative to a noneroding environment. Landscape-average mean residence times are increased in an eroding landscape owing to the burial/preservation of otherwise labile C. Second, field observations taken along a slope transect may overlook significant intraslope variations in carbon accumulation. Spatial patterns of modeled deep C accumulation are complex. While surface carbon with its relatively short equilibration time is predictable from surface properties, deep carbon is strongly influenced by the landscape's geomorphic and climatic history, resulting in wide spatial variability. Convergence and divergence associated with upland swales and interfluves result in bimodal carbon distributions in upper and mid slopes; variability in carbon storage within modeled mid slopes was as high as simulated differences between erosional shoulders and depositional valley bottoms. The bimodality of mid-slope C variability in the model suggests that a three-dimensional sampling strategy is preferable over the traditional two-dimensional analog or "catena" approach. Copyright 2006 by the American Geophysical Union.

  17. Assessing the Impacts of Herbivory on Plant Silica Accumulation across a Global Network of Grasslands

    NASA Astrophysics Data System (ADS)

    Quigley, K.

    2015-12-01

    Plants, especially grasses, have a profound impact on the biogeochemical cycling of silicon. Silicic acid (Si(OH)4) in soil water is absorbed by plant roots, transported via the transpiration stream, and deposited as solid silica (SiO2) phytoliths in leaf tissue. Evidence indicates that plant phytolith accumulation may have evolved as an anti-herbivore strategy, and modern studies reveal that these silica particles are abrasive to animal mouthparts and can interfere with digestion. Furthermore, several studies have shown that grasses have the ability to respond to insect and mammal herbivory by modifying the amount of silicon they absorb from soil, a property known as inducible defense. However, herbivory studies remain largely limited to a laboratory setting, and research in natural systems has only been conducted at a regional spatial scale. To address whether these localized patterns persist at the global scale, we utilized data from a network of 40 grassland sites occurring on six continents. Vegetation samples including grasses, forbs, and litter, were collected in and out of 6m x 6m herbivore exclosures by a team of collaborating scientists for an on-going research effort known as the Nutrient Network (NutNet). We utilized near infrared spectroscopy (NIRS) to create a calibration for plant silica which allowed for the rapid analysis of more than 1000 samples. Preliminary analyses indicate that silica content of grasses was higher outside of exclosures, where herbivores had access to vegetation. Our data reveal that herbivores play a significant role in modifying plant silicon uptake, and hence, the rates of silicon cycling in grasslands across the globe.

  18. Landscape Evolution and Carbon Accumulation: Uniformitarianism Revisited

    NASA Astrophysics Data System (ADS)

    Rosenbloom, N. A.; Harden, J. W.; Neff, J. C.; Schimel, D. S.

    2003-12-01

    What is the role of hillslope transport in long-term carbon accumulation in soils? How do parent material, climate, and landform interact to produce the landscapes we observe today and to what extent can we use present day conditions to infer the dominant processes of the past? We use the CREEP [Rosenbloom, N.A. et al., 2001] process-response model to ask these questions, exploring the time-evolution of landscape form, soil distribution, and carbon accumulation in an undisturbed prairie site in western Iowa [Harden, J.W. et al., 2002]. The CREEP model simulates differential transport of soil particles, blanket deposition of atmospheric 10Be with eolian dust, and passive advection of soil carbon and 10Be, enabling the preferential enrichment and burial of rapidly moving soil constituents. By comparing landscape-wide average accumulations of 10Be to borehole observations at three hillslope positions, we conclude that the distribution of clay-adsorbed 10Be cannot be explained by co-transport with clay particles alone. Rather, 10Be appears to behave as a more complex tracer than originally assumed, requiring an explicit, independent parameterization of wet deposition and transport. By comparison, model carbon accumulation strongly reflects patterns of clay redistribution indicating that in situ carbon turnover is faster than redistribution. Observed vertical distributions of soil properties, including 10Be, could only be explained by assuming variations in deposition and erosion rates, specifically periods of accumulation, followed by periods of transport. This effect might not be apparent if only landform shape, geometry, and soil depth were considered and vertical distributions of soil properties were not explicitly simulated. The current landscape reflects a history of strong shifts in erosion and accumulation rates that cannot be simulated using a uniform parameterization of long-term landscape-evolution processes.

  19. Update on the Argonne positron accumulator ring

    SciTech Connect

    Borland, M.

    1993-07-01

    The injector for the Advanced Photon Source incorporates a 450-MeV positron accumulator ring (PAR) to decrease the filling time with the 2-Hz synchrotron. In addition to accumulating positrons from the linac, the PAR damps the beam and reduces the bunch length. The PAR lattice has been redesigned to use zero-gradient dipoles, while retaining essentially the same damping partition. Extensive simulations have been performed to set tolerances that will give high capture efficiency, in spite of the large momentum spread of the incoming positron beam.

  20. Assessing the Capacity of Plant Species to Accumulate Particulate Matter in Beijing, China

    PubMed Central

    Mo, Li; Ma, Zeyu; Xu, Yansen; Sun, Fengbin; Lun, Xiaoxiu; Liu, Xuhui; Chen, Jungang; Yu, Xinxiao

    2015-01-01

    Air pollution causes serious problems in spring in northern China; therefore, studying the ability of different plants to accumulate particulate matter (PM) at the beginning of the growing season may benefit urban planners in their attempts to control air pollution. This study evaluated deposits of PM on the leaves and in the wax layer of 35 species (11 shrubs, 24 trees) in Beijing, China. Differences in the accumulation of PM were observed between species. Cephalotaxus sinensis, Euonymus japonicus, Broussonetia papyriferar, Koelreuteria paniculata and Quercus variabilis were all efficient in capturing small particles. The plants exhibiting high amounts of total PM accumulation (on leaf surfaces and/or in the wax layer), also showed comparatively high levels of PM accumulation across all particle sizes. A comparison of shrubs and trees did not reveal obvious differences in their ability to accumulate particles based on growth form; a combination of plantings with different growth forms can efficiently reduce airborne PM concentrations near the ground. To test the relationships between leaf traits and PM accumulation, leaf samples of selected species were observed using a scanning electron microscope. Growth forms with greater amounts of pubescence and increased roughness supported PM accumulation; the adaxial leaf surfaces collected more particles than the abaxial surfaces. The results of this study may inform the selection of species for urban green areas where the goal is to capture air pollutants and mitigate the adverse effects of air pollution on human health. PMID:26506104

  1. Protozoal ciliate promotes bacterial autoinducer-2 accumulation in mixed culture with Escherichia coli.

    PubMed

    Oguri, Satoshi; Hanawa, Tomoko; Matsuo, Junji; Ishida, Kasumi; Yamazaki, Tomohiro; Nakamura, Shinji; Okubo, Torahiko; Fukumoto, Tatsuya; Akizawa, Kouzi; Shimizu, Chikara; Kamiya, Shigeru; Yamaguchi, Hiroyuki

    2015-01-01

    We have previously demonstrated conjugation of Escherichia coli into vacuoles of the protozoal ciliate (Tetrahymena thermophila). This indicated a possible role of ciliates in evoking bacterial quorum sensing, directly connecting bacterial survival via accumulation in the ciliate vacuoles. We therefore assessed if ciliates promoted bacterial autoinducer (AI)-2 accumulation with vacuole formation, which controls quorum sensing. E. coli AI-2 accumulation was significantly enhanced in the supernatants of a mixed culture of ciliates and bacteria, likely depending on ciliate density rather than bacterial concentration. As expected, AI-2 production was significantly correlated with vacuole formation. The experiment with E. coli luxS mutants showed that ciliates failed to enhance bacterial AI-2 accumulation, denying a nonspecific phenomenon. Fluorescence microscopy revealed accumulation of fragmented bacteria in ciliate vacuoles, and, more importantly, expulsion of the vacuoles containing disrupted bacteria into the culture supernatant. There was no increase in the expression of luxS (encoding AI-2) or ydgG (a transporter for controlling bacterial export of AI-2). We conclude that ciliates promote bacterial AI-2 accumulation in a mixed culture, via accumulation of disrupted bacteria in ciliate vacuoles followed by expulsion of the vacuoles, independently of luxS or ydgG gene induction. This is believed to be the first demonstration of a relationship between E. coli AI-2 dynamics and ciliates. In the natural environment, ciliate biotopes may provide a survival advantage to bacteria inhabiting such biotopes, via evoking quorum sensing. PMID:26582290

  2. Comparative study of radiation damage accumulation in Cu and Fe

    NASA Astrophysics Data System (ADS)

    Caturla, M. J.; Soneda, N.; Alonso, E.; Wirth, B. D.; Díaz de la Rubia, T.; Perlado, J. M.

    2000-01-01

    Bcc and fcc metals exhibit significant differences in behavior when exposed to neutron or heavy ion irradiation. Transmission electron microscopy (TEM) observations reveal that damage in the form of stacking fault tetrahedra (SFT) is visible in copper irradiated to very low doses, but that no damage is visible in iron irradiated to the same total dose. In order to understand and quantify this difference in behavior, we have simulated damage production and accumulation in fcc Cu and bcc Fe. We use 20 keV primary knock-on atoms (PKAs) at a homologous temperature of 0.25 of the melting point. The primary damage state was calculated using molecular dynamics (MD) with empirical, embedded-atom interatomic potentials. Damage accumulation was modeled using a kinetic Monte Carlo (kMC) algorithm to follow the evolution of all defects produced in the cascades. The diffusivities and binding energies of defects are input data for this simulation and were either extracted from experiments, the literature, or calculated using MD. MD simulations reveal that vacancy clusters are produced within the cascade core in the case of copper. In iron, most of the vacancies do not cluster during cooling of the cascade core and are available for diffusion. In addition, self-interstitial atom (SIA) clusters are produced in copper cascades but those observed in iron are smaller in number and size. The combined MD/kMC simulations reveal that the visible cluster densities obtained as a function of dose are at least one order of magnitude lower in Fe than in Cu. We compare the results with experimental measurements of cluster density and find excellent agreement between the simulations and experiments when small interstitial clusters are considered to be mobile as suggested by recent MD simulations.

  3. Surface Roughness and Snow Accumulation in East Antarctica

    NASA Astrophysics Data System (ADS)

    Scambos, T. A.; Vornberger, P. L.; Bohlander, J. A.; Das, I.; Klinger, M.; Pope, A.; Lenaerts, J.; Fahnestock, M. A.

    2015-12-01

    A complex relationship exists between snow accumulation (e.g., net surface mass balance) and meter-scale surface roughness as represented by sastrugi and erosional structures over the East Antarctic Ice Sheet (EAIS). The morphology of the ice sheet at this scale is a result of a complex interaction between katabatic winds, synoptic storms, and the slope of the surface, all driving local patterns of snow accretion and sublimation. In megadune regions, the accumulation, surface slope, and surface roughness are highly correlated with slope. Smooth glazed surfaces are present on the steeper leeward wind-faces, and much rougher snow-accreting megadunes are present on the windward (depositional) slope. However, the highest elevation areas near the ridge crest of the EAIS (above ~3200 m) have a converse relationship between roughness and accumulation. Here, very low wind ridge crest areas are smooth and have higher accumulation than adjacent, slightly steeper regions that exhibit a slight increase in roughness. Below the main regions of megadunes (<~2000 m) wind glaze areas gradually become rougher as wind scouring and erosion dominate locally steeper regions. In coastal areas (<~1000), roughness is highly variable, and is tied to frequent synoptic storm deposition. We compare roughness data derived from MISR (Multi-angle Imaging SpectroRadiometer) and Landsat 8 acquisitions with available wind and accumulation data from climate model results and field measurements. Roughness is determined by sunlight scattering relative to viewing geometry (MISR) or from the amplitude of textural characteristics tied to surface sastrugi (Landsat 8). Both are validated by comparison with meter-scale images (WorldView-1) and field observations. MISR roughness mapping shows persistent qualitative patterns of surface roughness across the EAIS, but an absolute roughness scale mapping is difficult to generate because of complex viewing, illumination, and bi-directional reflectance variations

  4. Phenylcoumaran Benzylic Ether Reductase Prevents Accumulation of Compounds Formed under Oxidative Conditions in Poplar Xylem[W

    PubMed Central

    Niculaes, Claudiu; Morreel, Kris; Kim, Hoon; Lu, Fachuang; McKee, Lauren S.; Ivens, Bart; Haustraete, Jurgen; Vanholme, Bartel; Rycke, Riet De; Hertzberg, Magnus; Fromm, Jorg; Bulone, Vincent; Polle, Andrea; Ralph, John; Boerjan, Wout

    2014-01-01

    Phenylcoumaran benzylic ether reductase (PCBER) is one of the most abundant proteins in poplar (Populus spp) xylem, but its biological role has remained obscure. In this work, metabolite profiling of transgenic poplar trees downregulated in PCBER revealed both the in vivo substrate and product of PCBER. Based on mass spectrometry and NMR data, the substrate was identified as a hexosylated 8–5-coupling product between sinapyl alcohol and guaiacylglycerol, and the product was identified as its benzyl-reduced form. This activity was confirmed in vitro using a purified recombinant PCBER expressed in Escherichia coli. Assays performed on 20 synthetic substrate analogs revealed the enzyme specificity. In addition, the xylem of PCBER-downregulated trees accumulated over 2000-fold higher levels of cysteine adducts of monolignol dimers. These compounds could be generated in vitro by simple oxidative coupling assays involving monolignols and cysteine. Altogether, our data suggest that the function of PCBER is to reduce phenylpropanoid dimers in planta to form antioxidants that protect the plant against oxidative damage. In addition to describing the catalytic activity of one of the most abundant enzymes in wood, we provide experimental evidence for the antioxidant role of a phenylpropanoid coupling product in planta. PMID:25238751

  5. Hydrogeological influences on petroleum accumulations in the Arabian Gulf

    SciTech Connect

    Vizgirda, J.; Burke, L.

    1995-08-01

    The stratigraphic and topographic conditions in the Arabian Gulf are appropriate for the instigation and maintenance of an active hydrodynamic regime. The setting is that of a gentle basin surrounded by topographic highs. The central Arabian highlands to the west-southwest, the Tarus-Zagros mountains to the north, and the Oman mountains to the east rim the structural low occupied by the Gulf. Elevations in these areas reach maximum values of approximately 1000 meters. Paleozoic through Cenozoic strata stretch continuously across the basin, are relatively unfaulted, and outcrop in the topographic highs. Such a setting is propitious for a regional hydrodynamic system with meteoric recharge in the topographic highs and discharge in the middle of the Gulf. The prolific oil and gas accumulations of this region would be subject to influence by these hydrodynamic processes. The existence of such a hydrodynamic regime is documented by a variety of evidence, including potentiometric data, water salinity measurements, and observed tilts in oil-water contacts. Potentiometric data for several Tertiary and Cretaceous units on the Arabian platform, in the Gulf, and in Iraq show a pattern of consistently decreasing potential from topographic highs to lows. Water salinities show a consistent, but inverse, variation with the potentiometric data. Tilted oil-water contacts in Cretaceous and Jurassic reservoirs are observed in several fields of the Gulf region. The direction and magnitude of the observed tilts are consistent with the water potential and salinity data, and suggest that petroleum accumulations are being influenced by a regional hydrodynamic drive. Basin modelling is used to simulate petroleum generation and migration scenarios, and to integrate these histories with the structural evolution of the Gulf. The integrated modelling study illustrates the influence of hydrodynamic processes on the distribution of petroleum accumulations.

  6. 19 CFR 10.772 - Accumulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Accumulation. 10.772 Section 10.772 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  7. 19 CFR 10.772 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accumulation. 10.772 Section 10.772 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  8. 19 CFR 10.772 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Accumulation. 10.772 Section 10.772 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  9. 19 CFR 10.772 - Accumulation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Accumulation. 10.772 Section 10.772 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  10. 19 CFR 10.772 - Accumulation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Accumulation. 10.772 Section 10.772 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade...

  11. Hippocampal Networks Habituate as Novelty Accumulates

    ERIC Educational Resources Information Center

    Murty, Vishnu P.; Ballard, Ian C.; Macduffie, Katherine E.; Krebs, Ruth M.; Adcock, R. Alison

    2013-01-01

    Novelty detection, a critical computation within the medial temporal lobe (MTL) memory system, necessarily depends on prior experience. The current study used functional magnetic resonance imaging (fMRI) in humans to investigate dynamic changes in MTL activation and functional connectivity as experience with novelty accumulates. fMRI data were…

  12. RF SYSTEM FOR THE SNS ACCUMULATOR RING.

    SciTech Connect

    BLASKIEWICZ, M.; BRENNAN, J.M.; BRODOWSKI, J.; DELONG, J.; METH, M.; SMITH, K.; ZALTSMAN, A.

    2001-06-18

    During accumulation the RF beam current in the spallation neutron source ring rises from 0 to 50 amperes. A clean, 250 nanosecond gap is needed for the extraction kicker risetime. Large momentum spread and small peak current are needed to prevent instabilities and stopband related losses. A robust RF system meeting these requirements has been designed.

  13. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Accumulation. 10.597 Section 10.597 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. Dominican Republic-Central...

  14. ACCUMULATION FACTORS FOR ELEVEN POLYCHLORINATED BIPHENYL CONGENERS

    EPA Science Inventory

    According to the fugacity approach (Mackay 1979), pollutant uptake by an organism is determined by the chemical fugacity differential between the organism and its environment. he Accumulation Factor [AF - (concentration of pollutant in animal tissue, Ct (ng/g dry wt)/animal lipid...

  15. Plastic Accumulation in the Mediterranean Sea

    PubMed Central

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  16. 19 CFR 10.917 - Accumulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Accumulation. 10.917 Section 10.917 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade Promotion...

  17. 19 CFR 10.917 - Accumulation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Accumulation. 10.917 Section 10.917 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Peru Trade Promotion...

  18. 19 CFR 10.458 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free Trade Agreement Rules of Origin § 10.458 Accumulation. (a) Originating goods or materials of Chile or the United States... of Chile, the United States, or both, by one or more producers, will be considered as an...

  19. 19 CFR 10.534 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accumulation. 10.534 Section 10.534 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free Trade...

  20. 19 CFR 10.458 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accumulation. 10.458 Section 10.458 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free Trade Agreement...

  1. Organic carbon accumulation in Brazilian mangal sediments

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Smoak, Joseph M.; Sanders, Luciana M.; Sathy Naidu, A.; Patchineelam, Sambasiva R.

    2010-12-01

    This study reviews the organic carbon (OC) accumulation rates in mangrove forests, margins and intertidal mudflats in geographically distinct areas along the Brazilian coastline (Northeastern to Southern). Our initial results indicate that the mangrove forests in the Northeastern region of Brazil are accumulating more OC (353 g/m 2/y) than in the Southeastern areas (192 g/m 2/y) being that the sediment accumulation rates, 2.8 and 2.5 mm/y, and OC content ˜7.1% and ˜5.8% (dry sediment weight) were contributing factors to the discrepancies between the forests. The intertidal mudflats on the other hand showed substantially greater OC accumulation rates, sedimentation rates and content 1129 g/m 2/y and 234 g/m 2/y; 7.3 and 3.4 mm/y; 10.3% and ˜2.7% (OC of dry sediment weight content), respectively, in the Northeastern compared to the Southeastern region. Mangrove forests in the South-Southeastern regions of Brazil may be more susceptible to the rising sea level, as they are geographically constricted by the vast mountain ranges along the coastline.

  2. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  3. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  4. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  5. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  6. 19 CFR 10.3017 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Accumulation. 10.3017 Section 10.3017 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia Trade...

  7. 19 CFR 10.3017 - Accumulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Accumulation. 10.3017 Section 10.3017 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Colombia Trade...

  8. Plastic accumulation in the Mediterranean sea.

    PubMed

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  9. 19 CFR 10.534 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Accumulation. 10.534 Section 10.534 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free Trade...

  10. 19 CFR 10.812 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Accumulation. 10.812 Section 10.812 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Bahrain Free Trade...

  11. Brain responses in humans reveal ideal observer-like sensitivity to complex acoustic patterns.

    PubMed

    Barascud, Nicolas; Pearce, Marcus T; Griffiths, Timothy D; Friston, Karl J; Chait, Maria

    2016-02-01

    We use behavioral methods, magnetoencephalography, and functional MRI to investigate how human listeners discover temporal patterns and statistical regularities in complex sound sequences. Sensitivity to patterns is fundamental to sensory processing, in particular in the auditory system, because most auditory signals only have meaning as successions over time. Previous evidence suggests that the brain is tuned to the statistics of sensory stimulation. However, the process through which this arises has been elusive. We demonstrate that listeners are remarkably sensitive to the emergence of complex patterns within rapidly evolving sound sequences, performing on par with an ideal observer model. Brain responses reveal online processes of evidence accumulation--dynamic changes in tonic activity precisely correlate with the expected precision or predictability of ongoing auditory input--both in terms of deterministic (first-order) structure and the entropy of random sequences. Source analysis demonstrates an interaction between primary auditory cortex, hippocampus, and inferior frontal gyrus in the process of discovering the regularity within the ongoing sound sequence. The results are consistent with precision based predictive coding accounts of perceptual inference and provide compelling neurophysiological evidence of the brain's capacity to encode high-order temporal structure in sensory signals. PMID:26787854

  12. Dynamics of Free Amino Acid Accumulations in Cotton Leaves Measured on Different Timelines After Irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accumulations of 16 free amino acids (FAAs) in cotton, Gossypium hirsutum L., leaves in potted greenhouse plants were recorded across three time scales following irrigation. The time scales, 15-minute, 12-hours, and daily sampling intervals, revealed the dynamic response of each FAA, and showed dif...

  13. Evidence-based dentistry.

    PubMed

    Chambers, David W

    2010-01-01

    choose to wait for collective professional standards to reveal acceptable practice or follow a strategy of punctuated equilibrium, only switching out established practice habits when very conspicuous advantages are identified. Integration in medicine appears to follow the statistically sophisticated practice of updating estimates of clinical parameters (probabilities) for diagnoses, treatments, prognoses, and side-effects. This approach is likely beyond the skill or interest of clinical dentists and it fails to incorporate values in the integration. The use of decision trees to integrate both research and experiential parameters and values is illustrated and it is shown that such a technique identifies why there are very few cases in dentistry where evidence needs to be consulted and indicates what such cases are. PMID:21485345

  14. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci

    PubMed Central

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A.; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R.; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  15. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci.

    PubMed

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  16. Therapeutic Targeting of Eosinophil Adhesion and Accumulation in Allergic Conjunctivitis

    PubMed Central

    Baiula, Monica; Bedini, Andrea; Carbonari, Gioia; Dattoli, Samantha Deianira; Spampinato, Santi

    2012-01-01

    Considerable evidence indicates that eosinophils are important effectors of ocular allergy. Increased worldwide prevalence of allergic eye pathologies has stimulated the identification of novel drug targets, including eosinophils and adhesion molecules. Accumulation of eosinophils in the eye is a key event in the onset and maintenance of allergic inflammation and is mediated by different adhesion molecules. Antihistamines with multiple mechanisms of action can be effective during the early and late phases of allergic conjunctivitis by blocking the interaction between β1 integrins and vascular cell adhesion molecule (VCAM)-1. Small molecule antagonists that target key elements in the process of eosinophil recruitment have been identified and reinforce the validity of α4β1 integrin as a therapeutic target. Glucocorticoids are among the most effective drugs for ocular allergy, but their use is limited by adverse effects. Novel dissociated glucocorticoids can prevent eosinophil accumulation and induce apoptosis of eosinophils, making them promising candidates for ophthalmic drugs. This article reviews recent understanding of the role of adhesion molecules in eosinophil recruitment in the inflamed conjunctiva along with effective treatments for allergic conjunctivitis. PMID:23271999

  17. Nodularia spumigena Peptides—Accumulation and Effect on Aquatic Invertebrates

    PubMed Central

    Mazur-Marzec, Hanna; Sutryk, Katarzyna; Hebel, Agnieszka; Hohlfeld, Natalia; Pietrasik, Anna; Błaszczyk, Agata

    2015-01-01

    Thus far, the negative effects of Nodularia spumigena blooms on aquatic organisms have been mainly attributed to the production of the hepatotoxic nodularin (NOD). In the current work, the accumulation of other N. spumigena metabolites in blue mussels and crustaceans, and their effect on Thamnocephalus platyurus and Artemia franciscana, were examined. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses provided evidence that both blue mussels collected after a cyanobacterial bloom in the Baltic Sea and the crustaceans exposed under laboratory conditions to N. spumigena extract accumulated the cyclic anabaenopeptins (APs). In the crustaceans, the linear peptides, spumigins (SPUs) an