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Find video protocols related to scientific articles indexed in Pubmed.
The Unforeseen Costs of Extraordinary Experience.
Psychol Sci
PUBLISHED: 10-03-2014
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People seek extraordinary experiences-from drinking rare wines and taking exotic vacations to jumping from airplanes and shaking hands with celebrities. But are such experiences worth having? We found that participants thoroughly enjoyed having experiences that were superior to those had by their peers, but that having had such experiences spoiled their subsequent social interactions and ultimately left them feeling worse than they would have felt if they had had an ordinary experience instead. Participants were able to predict the benefits of having an extraordinary experience but were unable to predict the costs. These studies suggest that people may pay a surprising price for the experiences they covet most.
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Social psychology. Just think: the challenges of the disengaged mind.
Science
PUBLISHED: 07-05-2014
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In 11 studies, we found that participants typically did not enjoy spending 6 to 15 minutes in a room by themselves with nothing to do but think, that they enjoyed doing mundane external activities much more, and that many preferred to administer electric shocks to themselves instead of being left alone with their thoughts. Most people seem to prefer to be doing something rather than nothing, even if that something is negative.
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Meta-review: adverse effects of inhaled corticosteroids relevant to older patients.
Drugs
PUBLISHED: 03-25-2014
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In recent years, clinical trials and observational studies have raised concerns about the potential adverse effects of inhaled corticosteroids (ICS) such as pneumonia, cataract, fractures and hyperglycaemia, which are of particular concern for older patients.
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Insertion sequence distribution bias in Archaea.
Mob Genet Elements
PUBLISHED: 01-11-2014
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Insertion sequences (IS) are common transposable elements in Archaea. Intergenic IS elements are usually less harmful than intragenic ISs, simply because they are less likely to disrupt host gene function. However, because regulatory sequences are intergenic and upstream of genes, we hypothesized that not all intergenic regions are selectively equivalent for IS insertion. We tested this hypothesis by analyzing the distributions of intergenic IS elements within 155 fully sequenced archaeal genomes. Of the 22 genomes with enough IS elements for statistical analysis, five have significantly fewer ISs between divergently oriented neighboring genes than expected by chance, and seven have significantly more ISs between convergently oriented genes. Furthermore, of the 85 genomes with at least one expected IS within each of the three possible neighboring gene orientations (i.e., divergent, convergent, and tandem), 73 genomes have fewer ISs between divergently oriented genes than expected, and 60 have more ISs between convergently oriented genes than expected (both values deviate significantly from binomial probabilities of random distribution). We suspect that these non-random IS distributions are molded by natural selection resulting from differential disruption of neighboring gene regulation, and that this selective pressure has affected transposable element distributions in prokaryotes for billions of years.
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Response of sphagnum peatland testate amoebae to a 1-year transplantation experiment along an artificial hydrological gradient.
Microb. Ecol.
PUBLISHED: 01-10-2014
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Peatland testate amoebae (TA) are well-established bioindicators for depth to water table (DWT), but effects of hydrological changes on TA communities have never been tested experimentally. We tested this in a field experiment by placing Sphagnum carpets (15 cm diameter) collected in hummock, lawn and pool microsites (origin) at three local conditions (dry, moist and wet) using trenches dug in a peatland. One series of samples was seeded with microorganism extract from all microsites. TA community were analysed at T0: 8-2008, T1: 5-2009 and T2: 8-2009. We analysed the data using conditional inference trees, principal response curves (PRC) and DWT inferred from TA communities using a transfer function used for paleoecological reconstruction. Density declined from T0 to T1 and then increased sharply by T2. Species richness, Simpson diversity and Simpson evenness were lower at T2 than at T0 and T1. Seeded communities had higher species richness in pool samples at T0. Pool samples tended to have higher density, lower species richness, Simpson diversity and Simpson Evenness than hummock and/or lawn samples until T1. In the PRC, the effect of origin was significant at T0 and T1, but the effect faded away by T2. Seeding effect was strongest at T1 and lowest vanished by T2. Local condition effect was strong but not in line with the wetness gradient at T1 but started to reflect it by T2. Likewise, TA-inferred DWT started to match the experimental conditions by T2, but more so in hummock and lawn samples than in pool samples. This study confirmed that TA responds to hydrological changes over a 1-year period. However, sensitivity of TA to hydrological fluctuations, and thus the accuracy of inferred DWT changes, was habitat specific, pool TA communities being least responsive to environmental changes. Lawns and hummocks may be thus better suited than pools for paleoecological reconstructions. This, however, contrasts with the higher prediction error and species' tolerance for DWT with increasing dryness observed in transfer function models.
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The impact bias is alive and well.
J Pers Soc Psychol
PUBLISHED: 11-14-2013
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A substantial body of research on affective forecasting has found that people often overestimate the affective impact of future events. Levine, Lench, Kaplan, and Safer (2012) argued that whereas people may overestimate the duration of their emotional responses, they do not overestimate the initial intensity of these responses as much as previous research has suggested. We suggest that Levine et al. (a) failed to review or include in their meta-analysis many studies that directly contradict their claim, (b) used a faulty classification scheme, (c) collapsed across conditions that were meant to (and did) produce opposing effects, and (d) miscoded some of the studies they did include. When these errors are corrected, their claim is clearly not supported. Levine et al. also reported the results of 4 studies, which are open to alternative explanations. The impact bias is alive and well.
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Robust RNAi enhancement via human Argonaute-2 overexpression from plasmids, viral vectors and cell lines.
Nucleic Acids Res.
PUBLISHED: 09-17-2013
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As the only mammalian Argonaute protein capable of directly cleaving mRNAs in a small RNA-guided manner, Argonaute-2 (Ago2) is a keyplayer in RNA interference (RNAi) silencing via small interfering (si) or short hairpin (sh) RNAs. It is also a rate-limiting factor whose saturation by si/shRNAs limits RNAi efficiency and causes numerous adverse side effects. Here, we report a set of versatile tools and widely applicable strategies for transient or stable Ago2 co-expression, which overcome these concerns. Specifically, we engineered plasmids and viral vectors to co-encode a codon-optimized human Ago2 cDNA along with custom shRNAs. Furthermore, we stably integrated this Ago2 cDNA into a panel of standard human cell lines via plasmid transfection or lentiviral transduction. Using various endo- or exogenous targets, we demonstrate the potential of all three strategies to boost mRNA silencing efficiencies in cell culture by up to 10-fold, and to facilitate combinatorial knockdowns. Importantly, these robust improvements were reflected by augmented RNAi phenotypes and accompanied by reduced off-targeting effects. We moreover show that Ago2/shRNA-co-encoding vectors can enhance and prolong transgene silencing in livers of adult mice, while concurrently alleviating hepatotoxicity. Our customizable reagents and avenues should broadly improve future in vitro and in vivo RNAi experiments in mammalian systems.
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Evaluation of long noncoding RNA MALAT1 as a candidate blood-based biomarker for the diagnosis of non-small cell lung cancer.
BMC Res Notes
PUBLISHED: 08-22-2013
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The long noncoding RNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is described as a potential biomarker for NSCLC (non-small cell lung cancer). Diagnostic biomarkers need to be detectable in easily accessible body fluids, should be characterized by high specificity, sufficient sensitivity, and robustness against influencing factors. The aim of this study was to evaluate the performance of MALAT1 as a blood based biomarker for NSCLC.
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Exposure chambers for studying the partitioning of atmospheric PAHs in environmental compartments: validation and calibration using experimental and computational approaches.
Environ. Sci. Technol.
PUBLISHED: 07-17-2013
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The environmental partitioning of atmospheric polycyclic aromatic hydrocarbons (PAHs) conditions their entry into food chains and subsequent risks for human health. The need for new experimental exposure devices for elucidating the mechanisms governing ecosystemic PAH transfer motivated the elaboration of an original small-scale exposure chamber (EC). A dual approach pairing experimentation and computational fluid dynamics (CFD) was selected to provide comprehensive validation of this EC as a tool to study the transfer and biological effects of atmospheric PAH pollution in microsystems. Soil samples and passive air samplers (PASs) were exposed to atmospheric pollution by phenanthrene (PHE), a gaseous PAH, for 2 weeks in examples of the EC being tested, set up under different conditions. Dynamic concentrations of atmospheric PHE and its uptake by PASs were simulated with CFD, results showing homogeneous distribution and constant atmospheric PHE concentrations inside the ECs. This work provides insight into the setting of given concentrations and pollution levels when using such ECs. The combination of experimentation and CFD is a successful ECs calibration method that should be developed with other semivolatile organic pollutants, including those that tend to partition in the aerosol phase.
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"Show me the money": vulnerability to gambling moderates the attractiveness of money versus suspense.
Pers Soc Psychol Bull
PUBLISHED: 06-24-2013
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Do people take risks to obtain rewards or experience suspense? We hypothesized that people vulnerable to gambling are motivated more by the allure of winning money whereas people less vulnerable to gambling are motivated more by the allure of suspense. Consistent with this hypothesis, participants with high scores on a subscale of the Gambling Attitudes and Beliefs Survey--a measure of vulnerability to gambling--reported more of a motivation to earn money (pilot study), were more likely to accept a certain or near-certain amount of money than to gamble for that same amount (Studies 1-2), and worked harder to earn money (Study 3). People vulnerable to gambling also made more accurate predictions about how much they would gamble. People less vulnerable to gambling, in contrast, gambled more than people vulnerable to gambling, but did not know that they would.
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Sesterterpene glycinyl-lactams: a new class of glycine receptor modulator from Australian marine sponges of the genus Psammocinia.
Org. Biomol. Chem.
PUBLISHED: 06-11-2013
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Bioassay guided fractionation of three southern Australian marine sponges of the genus Psammocinia, selected for their ability to modulate glycine-gated chloride channel receptors (GlyRs), yielded the rare marine sesterterpenes (-)-ircinianin (1) and (-)-ircinianin sulfate (2), along with the new biosynthetically related metabolites (-)-ircinianin lactam A (3), (-)-ircinianin lactam A sulfate (4), (-)-oxoircinianin (5), (-)-oxoircinianin lactam A (6) and (-)-ircinianin lactone A (7). Acetylation of 1 returned (-)-ircinianin acetate (8). Whole cell patch-clamp electrophysiology on 1-8 established 3 as an exceptionally potent and selective ?3 GlyR potentiator, and 6 as a selective ?1 GlyR potentiator. The discovery and characterization of sesterterpenes 1-8, and in particular the glycinyl-lactams 3 and 6, provide valuable new insights into GlyR pharmacology. These insights have the potential to inform and inspire the development of new molecular tools to probe GlyR distribution and function, and therapeutics to treat a wide array of GlyR mediated diseases and disorders.
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To what extent do food preferences explain the trophic position of heterotrophic and mixotrophic microbial consumers in a Sphagnum peatland?
Microb. Ecol.
PUBLISHED: 04-09-2013
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Although microorganisms are the primary drivers of biogeochemical cycles, the structure and functioning of microbial food webs are poorly studied. This is the case in Sphagnum peatlands, where microbial communities play a key role in the global carbon cycle. Here, we explored the structure of the microbial food web from a Sphagnum peatland by analyzing (1) the density and biomass of different microbial functional groups, (2) the natural stable isotope (?(13)C and ?(15)N) signatures of key microbial consumers (testate amoebae), and (3) the digestive vacuole contents of Hyalosphenia papilio, the dominant testate amoeba species in our system. Our results showed that the feeding type of testate amoeba species (bacterivory, algivory, or both) translates into their trophic position as assessed by isotopic signatures. Our study further demonstrates, for H. papilio, the energetic benefits of mixotrophy when the density of its preferential prey is low. Overall, our results show that testate amoebae occupy different trophic levels within the microbial food web, depending on their feeding behavior, the density of their food resources, and their metabolism (i.e., mixotrophy vs. heterotrophy). Combined analyses of predation, community structure, and stable isotopes now allow the structure of microbial food webs to be more completely described, which should lead to improved models of microbial community function.
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Performance of scientific cameras with different sensor types in measuring dynamic processes in fluorescence microscopy.
Microsc. Res. Tech.
PUBLISHED: 03-19-2013
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The plethora of available scientific cameras of different types challenges the biologically oriented experimenter when picking the appropriate camera for his experiment. In this study, we chose to investigate camera performances in a typical nonsingle molecule situation in life sciences, that is, quantitative measurements of fluorescence intensity changes from video data with typically skewed intensity distributions. Here, intensity profile dynamics of pH-sensors upon triggered changes of pH-environments in living cells served as a model system. The following camera types were tested: sCMOS, CCD (scientific and nonscientific) and EM-CCD (back- and front-illuminated). We found that although the EM-CCD cameras achieved the best absolute spatial SNR (signal-to-noise ratio) values, the sCMOS was at least of equal performance when the spatial SNR was related to the effective dynamic range, and it was superior in terms of temporal SNR. In the measurements of triggered intensity changes, the sCMOS camera had the advantage that it used the smallest fraction of its dynamic range when depicting intensity changes, and thus featured the best SNR at full usage of its dynamic range.
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Australian marine sponge alkaloids as a new class of glycine-gated chloride channel receptor modulator.
Bioorg. Med. Chem.
PUBLISHED: 02-25-2013
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Chemical analysis of a specimen of the sponge Ianthella cf. flabelliformis returned two new sesquiterpene glycinyl lactams, ianthellalactams A (1) and B (2), the known sponge sesquiterpene dictyodendrillin (3) and its ethanolysis artifact ethyl dictyodendrillin (4), and five known sponge indole alkaloids, aplysinopsin (5), 8E-3-deimino-3-oxoaplysinopsin (6), 8Z-3-deimino-3-oxoaplysinopsin (7), dihydroaplysinopsin (8) and tubastrindole B (9). The equilibrated mixture 6/7 exhibited glycine-gated chloride channel receptor (GlyR) antagonist activity with a bias towards ?3 over ?1 GlyR, while tubastrindole B (9) exhibited a bias towards ?1 over ?3 GlyR. At low- to sub-micromolar concentrations, 9 was also a selective potentiator of ?1 GlyR, with no effect on ?3 GlyR-a pharmacology that could prove useful in the treatment of movement disorders such as spasticity and hyperekplexia. Our investigations into the GlyR modulatory properties of 1-9 were further supported by the synthesis of a number of structurally related indole alkaloids.
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The microtubule affinity regulating kinase MARK4 promotes axoneme extension during early ciliogenesis.
J. Cell Biol.
PUBLISHED: 02-11-2013
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Despite the critical contributions of cilia to embryonic development and human health, key regulators of cilia formation await identification. In this paper, a functional RNA interference-based screen linked 30 novel protein kinases with ciliogenesis. Of them, we have studied the role of the microtubule (MT)-associated protein/MT affinity regulating kinase 4 (MARK4) in depth. MARK4 associated with the basal body and ciliary axoneme in human and murine cell lines. Ultrastructural and functional analyses established that MARK4 kinase activity was required for initiation of axoneme extension. We identified the mother centriolar protein ODF2 as an interaction partner of MARK4 and showed that ODF2 localization to the centriole partially depended on MARK4. Our data indicated that, upon MARK4 or ODF2 knockdown, the ciliary program arrested before the complete removal of the CP110-Cep97 inhibitory complex from the mother centriole, suggesting that these proteins act at this level of axonemal extension. We propose that MARK4 is a critical positive regulator of early steps in ciliogenesis.
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Fluorescence-based high-throughput functional profiling of ligand-gated ion channels at the level of single cells.
PLoS ONE
PUBLISHED: 02-06-2013
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Ion channels are involved in many physiological processes and are attractive targets for therapeutic intervention. Their functional properties vary according to their subunit composition, which in turn varies in a developmental and tissue-specific manner and as a consequence of pathophysiological events. Understanding this diversity requires functional analysis of ion channel properties in large numbers of individual cells. Functional characterisation of ligand-gated channels involves quantitating agonist and drug dose-response relationships using electrophysiological or fluorescence-based techniques. Electrophysiology is limited by low throughput and high-throughput fluorescence-based functional evaluation generally does not enable the characterization of the functional properties of each individual cell. Here we describe a fluorescence-based assay that characterizes functional channel properties at single cell resolution in high throughput mode. It is based on progressive receptor activation and iterative fluorescence imaging and delivers >100 dose-responses in a single well of a 384-well plate, using ?1-3 homomeric and ?? heteromeric glycine receptor (GlyR) chloride channels as a model system. We applied this assay with transiently transfected HEK293 cells co-expressing halide-sensitive yellow fluorescent protein and different GlyR subunit combinations. Glycine EC50 values of different GlyR isoforms were highly correlated with published electrophysiological data and confirm previously reported pharmacological profiles for the GlyR inhibitors, picrotoxin, strychnine and lindane. We show that inter and intra well variability is low and that clustering of functional phenotypes permits identification of drugs with subunit-specific pharmacological profiles. As this method dramatically improves the efficiency with which ion channel populations can be characterized in the context of cellular heterogeneity, it should facilitate systems-level analysis of ion channel properties in health and disease and the discovery of therapeutics to reverse pathological alterations.
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The end of history illusion.
Science
PUBLISHED: 01-05-2013
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We measured the personalities, values, and preferences of more than 19,000 people who ranged in age from 18 to 68 and asked them to report how much they had changed in the past decade and/or to predict how much they would change in the next decade. Young people, middle-aged people, and older people all believed they had changed a lot in the past but would change relatively little in the future. People, it seems, regard the present as a watershed moment at which they have finally become the person they will be for the rest of their lives. This "end of history illusion" had practical consequences, leading people to overpay for future opportunities to indulge their current preferences.
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A novel multiplex cell viability assay for high-throughput RNAi screening.
PLoS ONE
PUBLISHED: 10-13-2011
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Cell-based high-throughput RNAi screening has become a powerful research tool in addressing a variety of biological questions. In RNAi screening, one of the most commonly applied assay system is measuring the fitness of cells that is usually quantified using fluorescence, luminescence and absorption-based readouts. These methods, typically implemented and scaled to large-scale screening format, however often only yield limited information on the cell fitness phenotype due to evaluation of a single and indirect physiological indicator. To address this problem, we have established a cell fitness multiplexing assay which combines a biochemical approach and two fluorescence-based assaying methods. We applied this assay in a large-scale RNAi screening experiment with siRNA pools targeting the human kinome in different modified HEK293 cell lines. Subsequent analysis of ranked fitness phenotypes assessed by the different assaying methods revealed average phenotype intersections of 50.7±2.3%-58.7±14.4% when two indicators were combined and 40-48% when a third indicator was taken into account. From these observations we conclude that combination of multiple fitness measures may decrease false-positive rates and increases confidence for hit selection. Our robust experimental and analytical method improves the classical approach in terms of time, data comprehensiveness and cost.
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Store-operated calcium entry remains fully functional in aged mouse skeletal muscle despite a decline in STIM1 protein expression.
Aging Cell
PUBLISHED: 05-03-2011
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Store-operated Ca(2+) entry (SOCE) is a robust mechanism in skeletal muscle, supported by abundant STIM1 and Orai1 in the junctional membranes. The precise role of SOCE in skeletal muscle Ca(2+) homeostasis and excitation-contraction coupling remains to be defined. Regardless, it remains important to determine whether the function and capacity of SOCE changes in aged skeletal muscle. We identified an approximate 40% decline in the expression of the integral SOCE protein, stromal interacting molecule 1 (STIM1), but no such decline in its coupling partner, Orai1, in muscle fibers from aged mice. To determine whether this changed aspects of SOCE functionality in skeletal muscle in aged mice, Ca(2+) in the cytoplasm and t-system were continuously and simultaneously imaged on a confocal microscope during sarcoplasmic reticulum Ca(2+) release and compared to experiments under identical conditions using muscle fibers from young mice. Normal activation, deactivation, Ca(2+) influx, and spatiotemporal characteristics of SOCE were found to persist in skeletal muscle from aged mice. Thus, SOCE remains a robust mechanism in aged skeletal muscle despite the decline in STIM1 protein expression, suggesting STIM1 is in excess in young skeletal muscle.
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Characterizing the feeding habits of the testate amoebae Hyalosphenia papilio and Nebela tincta along a narrow "fen-bog" gradient using digestive vacuole content and 13C and 15N isotopic analyses.
Protist
PUBLISHED: 04-26-2011
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Population dynamics and feeding habits of the testate amoebae Nebela tincta and Hyalosphenia papilio were studied along a short "fen" to "bog" gradient in a Sphagnum-dominated mire (Jura, France). Samples were collected in living "top segments" (0-3 cm) and early declining "bottom segments" (3-6 cm) of Sphagnum fallax peat. Observations of digestive vacuole content and stable isotope analyses ((13)C and (15)N) were used to establish the feeding behavior of both testate amoeba species. Owing to their vertical distribution, the feeding habit of H. papilio was described from top segments, and that of N. tincta from bottom segments. Among identified food sources, those most frequently ingested by N. tincta were spores and mycelia of fungi (55%), microalgae (25%) and cyanobacteria (8.5%). For H. papilio, the most frequently ingested prey were ciliates (55%) and microalgae (35%). Nonmetric Multidimensional Scaling analysis clearly demonstrated that the two species did not have the same feeding habit along the "fen-bog" gradient, and furthermore that a significant spatial split exists in the feeding behavior of H. papilio. Additionally, isotope analyses suggested that H. papilio and N. tincta did not have the same trophic position in the microbial food web, probably resulting from their different feeding strategies.
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Winners love winning and losers love money.
Psychol Sci
PUBLISHED: 04-22-2011
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Salience and satisfaction are important factors in determining the comparisons that people make. We hypothesized that people make salient comparisons first, and then make satisfying comparisons only if salient comparisons leave them unsatisfied. This hypothesis suggests an asymmetry between winning and losing. For winners, comparison with a salient alternative (i.e., losing) brings satisfaction. Therefore, winners should be sensitive only to the relative value of their outcomes. For losers, comparison with a salient alternative (i.e., winning) brings little satisfaction. Therefore, losers should be drawn to compare outcomes with additional standards, which should make them sensitive to both relative and absolute values of their outcomes. In Experiment 1, participants won one of two cash prizes on a scratch-off ticket. Winners were sensitive to the relative value of their prizes, whereas losers were sensitive to both the relative and the absolute values of their prizes. In Experiment 2, losers were sensitive to the absolute value of their prize only when they had sufficient cognitive resources to engage in effortful comparison.
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Effect of a temperature gradient on Sphagnum fallax and its associated living microbial communities: a study under controlled conditions.
Can. J. Microbiol.
PUBLISHED: 03-02-2011
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Microbial communities living in Sphagnum are known to constitute early indicators of ecosystem disturbances, but little is known about their response (including their trophic relationships) to climate change. A microcosm experiment was designed to test the effects of a temperature gradient (15, 20, and 25°C) on microbial communities including different trophic groups (primary producers, decomposers, and unicellular predators) in Sphagnum segments (0-3 cm and 3-6 cm of the capitulum). Relationships between microbial communities and abiotic factors (pH, conductivity, temperature, and polyphenols) were also studied. The density and the biomass of testate amoebae in Sphagnum upper segments increased and their community structure changed in heated treatments. The biomass of testate amoebae was linked to the biomass of bacteria and to the total biomass of other groups added and, thus, suggests that indirect effects on the food web structure occurred. Redundancy analysis revealed that microbial assemblages differed strongly in Sphagnum upper segments along a temperature gradient in relation to abiotic factors. The sensitivity of these assemblages made them interesting indicators of climate change. Phenolic compounds represented an important explicative factor in microbial assemblages and outlined the potential direct and (or) indirect effects of phenolics on microbial communities.
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Atmospheric phenanthrene pollution modulates carbon allocation in red clover (Trifolium pratense L.).
Environ. Pollut.
PUBLISHED: 02-07-2011
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The influence of atmospheric phenanthrene (PHE) exposure (160 ?g m(-3)) during one month on carbon allocation in clover was investigated by integrative (plant growth analysis) and instantaneous (13)CO(2) pulse-labelling approaches. PHE exposure diminished plant growth parameters (relative growth rate and net assimilation rate) and disturbed photosynthesis (carbon assimilation rate and chlorophyll content), leading to a 25% decrease in clover biomass. The root-shoot ratio was significantly enhanced (from 0.32 to 0.44). Photosynthates were identically allocated to leaves while less allocated to stems and roots. PHE exposure had a significant overall effect on the (13)C partitioning among clover organs as more carbon was retained in leaves at the expense of roots and stems. The findings indicate that PHE decreases root exudation or transfer to symbionts and in leaves, retains carbon in a non-structural form diverting photosynthates away from growth and respiration (emergence of an additional C loss process).
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"He loves me, he loves me not . . . ": uncertainty can increase romantic attraction.
Psychol Sci
PUBLISHED: 12-17-2010
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This research qualifies a social psychological truism: that people like others who like them (the reciprocity principle). College women viewed the Facebook profiles of four male students who had previously seen their profiles. They were told that the men (a) liked them a lot, (b) liked them only an average amount, or (c) liked them either a lot or an average amount (uncertain condition). Comparison of the first two conditions yielded results consistent with the reciprocity principle. Participants were more attracted to men who liked them a lot than to men who liked them an average amount. Results for the uncertain condition, however, were consistent with research on the pleasures of uncertainty. Participants in the uncertain condition were most attracted to the men-even more attracted than were participants who were told that the men liked them a lot. Uncertain participants reported thinking about the men the most, and this increased their attraction toward the men.
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A wandering mind is an unhappy mind.
Science
PUBLISHED: 11-13-2010
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We developed a smartphone technology to sample peoples ongoing thoughts, feelings, and actions and found (i) that people are thinking about what is not happening almost as often as they are thinking about what is and (ii) found that doing so typically makes them unhappy.
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Assessment of mRNA and microRNA Stabilization in Peripheral Human Blood for Multicenter Studies and Biobanks.
Biomark Insights
PUBLISHED: 09-22-2010
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In this study we evaluate the suitability of two methods of RNA conservation in blood samples, PAXgene and RNAlater, in combination with variable shipping conditions for their application in multicenter studies and biobanking. RNA yield, integrity, and purity as well as levels of selected mRNA and microRNA species were analyzed in peripheral human blood samples stabilized by PAXgene or RNAlater and shipped on dry ice or at ambient temperatures from the study centers to the central analysis laboratory. Both examined systems were clearly appropriate for RNA stabilization in human blood independently of the shipping conditions. The isolated RNA is characterized by good quantity and quality and well suited for downstream applications like quantitative RT-PCR analysis of mRNA and microRNA. Superior yield and integrity values were received using RNAlater. It would be reasonable to consider the production and approval of blood collection tubes prefilled with RNAlater to facilitate the use of this excellent RNA stabilization system in large studies.
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Exon-skipping splice variants of excitatory amino acid transporter-2 (EAAT2) form heteromeric complexes with full-length EAAT2.
J. Biol. Chem.
PUBLISHED: 08-05-2010
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The glial transporter excitatory amino acid transporter-2 (EAAT2) is the main mediator of glutamate clearance in brain. The wild-type transporter (EAAT2wt) forms trimeric membrane complexes in which each protomer functions autonomously. Several EAAT2 variants are found in control and Alzheimer-diseased human brains; their expression increases with pathological severity. These variants might alter EAAT2wt-mediated transport by abrogating membrane trafficking, or by changing the configuration or functionality of the assembled transporter complex. HEK293 cells were transfected with EAAT2wt; EAAT2b, a C-terminal variant; or either of two exon-skipping variants: alone or in combination. Surface biotinylation studies showed that only the exon-7 deletion variant was not trafficked to the membrane when transfected alone, and that all variants could reach the membrane when co-transfected with EAAT2wt. Fluorescence resonance energy transfer (FRET) studies showed that co-transfected EAAT2wt and EAAT2 splice variants were expressed in close proximity. Glutamate transporter function was measured using a whole cell patch clamp technique, or by changes in membrane potential indexed by a voltage-sensitive fluorescent dye (FMP assay): the two methods gave comparable results. Cells transfected with EAAT2wt or EAAT2b showed glutamate-dependent membrane potential changes consistent with functional expression. Cells transfected with EAAT2 exon-skipping variants alone gave no response to glutamate. Co-transfection of EAAT2wt (or EAAT2b) and splice variants in various ratios significantly raised glutamate EC(50) and decreased Hill coefficients. We conclude that exon-skipping variants form heteromeric complexes with EAAT2wt or EAAT2b that traffic to the membrane but show reduced glutamate-dependent activity. This could allow glutamate to accumulate extracellularly and promote excitotoxicity.
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Pathophysiological mechanisms of dominant and recessive GLRA1 mutations in hyperekplexia.
J. Neurosci.
PUBLISHED: 07-16-2010
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Hyperekplexia is a rare, but potentially fatal, neuromotor disorder characterized by exaggerated startle reflexes and hypertonia in response to sudden, unexpected auditory or tactile stimuli. This disorder is primarily caused by inherited mutations in the genes encoding the glycine receptor (GlyR) alpha1 subunit (GLRA1) and the presynaptic glycine transporter GlyT2 (SLC6A5). In this study, systematic DNA sequencing of GLRA1 in 88 new unrelated human hyperekplexia patients revealed 19 sequence variants in 30 index cases, of which 21 cases were inherited in recessive or compound heterozygote modes. This indicates that recessive hyperekplexia is far more prevalent than previous estimates. From the 19 GLRA1 sequence variants, we have investigated the functional effects of 11 novel and 2 recurrent mutations. The expression levels and functional properties of these hyperekplexia mutants were analyzed using a high-content imaging system and patch-clamp electrophysiology. When expressed in HEK293 cells, either as homomeric alpha1 or heteromeric alpha1beta GlyRs, subcellular localization defects were the major mechanism underlying recessive mutations. However, mutants without trafficking defects typically showed alterations in the glycine sensitivity suggestive of disrupted receptor function. This study also reports the first hyperekplexia mutation associated with a GlyR leak conductance, suggesting tonic channel opening as a new mechanism in neuronal ligand-gated ion channels.
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Fine-scale horizontal and vertical micro-distribution patterns of testate amoebae along a narrow Fen/Bog gradient.
Microb. Ecol.
PUBLISHED: 06-15-2010
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The ecology of peatland testate amoebae is well studied along broad gradient from very wet (pool) to dry (hummock) micro-sites where testate amoebae are often found to respond primarily to the depth to water table (DWT). Much less is known on their responses to finer-scale gradients, and nothing is known of their possible response to phenolic compounds, which play a key role in carbon storage in peatlands. We studied the vertical (0-3, 3-6, and 6-9 cm sampling depths) micro-distribution patterns of testate amoebae in the same microhabitat (Sphagnum fallax lawn) along a narrow ecological gradient between a poor fen with an almost flat and homogeneous Sphagnum carpet (fen) and a "young bog" (bog) with more marked micro-topography and mosaic of poor fen and bog vegetation. We analyzed the relationships between the testate amoeba data and three sets of variables (1) "chemical" (pH, Eh potential, and conductivity), (2) "physical" (water temperature, altitude, i.e., Sphagnum mat micro-topography, and DWT), and (3) phenolic compounds in/from Sphagnum (water-soluble and primarily bound phenolics) as well as the habitat (fen/bog) and the sampling depth. Testate amoeba Shannon H diversity, equitability J of communities, and total density peaked in lower parts of Sphagnum, but the patterns differed between the fen and bog micro-sites. Redundancy analyses revealed that testate amoeba communities differed significantly in relation to Eh, conductivity, water temperature, altitude, water-soluble phenolics, habitat, and sampling depth, but not to DWT, pH, or primarily bound phenolics. The sensitivity of testate amoebae to weak environmental gradients makes them particularly good integrators of micro-environmental variations and has implications for their use in paleoecology and environmental monitoring. The correlation between testate amoeba communities and the concentration of water-soluble phenolic suggests direct (e.g., physiological) and/or indirect (e.g., through impact on prey organisms) effects on testate amoebae, which requires further research.
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Medial prefrontal cortex predicts intertemporal choice.
J Cogn Neurosci
PUBLISHED: 03-29-2010
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People often make shortsighted decisions to receive small benefits in the present rather than large benefits in the future, that is, to favor their current selves over their future selves. In two studies using fMRI, we demonstrated that people make such decisions in part because they fail to engage in the same degree of self-referential processing when thinking about their future selves. When participants predicted how much they would enjoy an event in the future, they showed less activity in brain regions associated with introspective self-reference--such as the ventromedial pFC (vMPFC)--than when they predicted how much they would enjoy events in the present. Moreover, the magnitude of vMPFC reduction predicted the extent to which participants made shortsighted monetary decisions several weeks later. In light of recent findings that the vMPFC contributes to the ability to simulate future events from a first-person perspective, these data suggest that shortsighted decisions result in part from a failure to fully imagine the subjective experience of ones future self.
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Ircinialactams: subunit-selective glycine receptor modulators from Australian sponges of the family Irciniidae.
Bioorg. Med. Chem.
PUBLISHED: 02-08-2010
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Screening an extract library of >2500 southern Australian and Antarctic marine invertebrates and algae for modulators of glycine receptor (GlyR) chloride channels identified three Irciniidae sponges that yielded new examples of a rare class of glycinyl lactam sesterterpene, ircinialactam A, 8-hydroxyircinialactam A, 8-hydroxyircinialactam B, ircinialactam C, ent-ircinialactam C and ircinialactam D. Structure-activity relationship (SAR) investigations revealed a new pharmacophore with potent and subunit selective modulatory properties against alpha1 and alpha3 GlyR isoforms. Such GlyR modulators have potential application as pharmacological tools, and as leads for the development of GlyR targeting therapeutics to treat chronic inflammatory pain, epilepsy, spasticity and hyperekplexia.
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Assessment of Confounding Factors Affecting the Tumor Markers SMRP, CA125, and CYFRA21-1 in Serum.
Biomark Insights
PUBLISHED: 01-28-2010
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The purpose of this analysis was to evaluate if serum levels of potential tumor markers for the diagnosis of malignant mesothelioma and lung cancer are affected by confounding factors in a surveillance cohort of workers formerly exposed to asbestos. SMRP, CA125, and CYFRA21-1 concentrations were determined in about 1,700 serum samples from 627 workers formerly exposed to asbestos. The impact of factors that could modify the concentrations of the tumor markers was examined with linear mixed models. SMRP values increased with age 1.02-fold (95% CI 1.01-1.03) and serum creatinine concentration 1.32-fold (95% CI 1.20-1.45). Levels differed by study centers and were higher after 40 years of asbestos exposure. CA125 levels increased with longer storage of the samples. CYFRA21-1 values correlated with age 1.02-fold (95% CI 1.01-1.02), serum creatinine 1.21-fold (95% CI 1.14-1.30) and varied by study centers due to differences in sample handling. Tumor marker concentrations are influenced by subject-related factors, sample handling, and storage. These factors need to be taken into account in screening routine.
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Relationship of atmospheric pollution characterized by gas (NO2) and particles (PM10) to microbial communities living in bryophytes at three differently polluted sites (rural, urban, and industrial).
Microb. Ecol.
PUBLISHED: 08-10-2009
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Atmospheric pollution has become a major problem for modern societies owing to its fatal effects on both human health and ecosystems. We studied the relationships of nitrogen dioxide atmospheric pollution and metal trace elements contained in atmospheric particles which were accumulated in bryophytes to microbial communities of bryophytes at three differently polluted sites in France (rural, urban, and industrial) over an 8-month period. The analysis of bryophytes showed an accumulation of Cr and Fe at the rural site; Cr, Fe, Zn, Cu, Al, and Pb at the urban site; and Fe, Cr, Pb, Al, Sr, Cu, and Zn at the industrial site. During this study, the structure of the microbial communities which is characterized by biomasses of microbial groups evolved differently according to the site. Microalgae, bacteria, rotifers, and testate amoebae biomasses were significantly higher in the rural site. Cyanobacteria biomass was significantly higher at the industrial site. Fungal and ciliate biomasses were significantly higher at the urban and industrial sites for the winter period and higher at the rural site for the spring period. The redundancy analysis showed that the physico-chemical variables ([NO(2)], relative humidity, temperature, and site) and the trace elements which were accumulated in bryophytes ([Cu], [Sr], [Pb]) explained 69.3% of the variance in the microbial community data. Moreover, our results suggest that microbial communities are potential biomonitors of atmospheric pollution. Further research is needed to understand the causal relationship underlined by the observed patterns.
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DetecTiff: a novel image analysis routine for high-content screening microscopy.
J Biomol Screen
PUBLISHED: 07-29-2009
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In this article, the authors describe the image analysis software DetecTiff, which allows fully automated object recognition and quantification from digital images. The core module of the LabView-based routine is an algorithm for structure recognition that employs intensity thresholding and size-dependent particle filtering from microscopic images in an iterative manner. Detected structures are converted into templates, which are used for quantitative image analysis. DetecTiff enables processing of multiple detection channels and provides functions for template organization and fast interpretation of acquired data. The authors demonstrate the applicability of DetecTiff for automated analysis of cellular uptake of fluorescence-labeled low-density lipoproteins as well as diverse other image data sets from a variety of biomedical applications. Moreover, the performance of DetecTiff is compared with preexisting image analysis tools. The results show that DetecTiff can be applied with high consistency for automated quantitative analysis of image data (e.g., from large-scale functional RNAi screening projects).
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High Throughput Techniques for Discovering New Glycine Receptor Modulators and their Binding Sites.
Front Mol Neurosci
PUBLISHED: 07-23-2009
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The inhibitory glycine receptor (GlyR) is a member of the Cys-loop receptor family that mediates inhibitory neurotransmission in the central nervous system. These receptors are emerging as potential drug targets for inflammatory pain, immunomodulation, spasticity and epilepsy. Antagonists that specifically inhibit particular GlyR isoforms are also required as pharmacological probes for elucidating the roles of particular GlyR isoforms in health and disease. Although a substantial number of both positive and negative GlyR modulators have been identified, very few of these are specific for the GlyR over other receptor types. Thus, the potential of known compounds as either therapeutic leads or pharmacological probes is limited. It is therefore surprising that there have been few published studies describing attempts to discover novel GlyR isoform-specific modulators. The first aim of this review is to consider various methods for efficiently screening compounds against these receptors. We conclude that an anion sensitive yellow fluorescent protein is optimal for primary screening and that automated electrophysiology of cells stably expressing GlyRs is useful for confirming hits and quantitating the actions of identified compounds. The second aim of this review is to demonstrate how these techniques are used in our laboratory for the purpose of both discovering novel GlyR-active compounds and characterizing their binding sites. We also describe a reliable, cost effective method for transfecting HEK293 cells in single wells of a 384-well plate using nanogram quantities of plasmid DNA.
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Why the brain talks to itself: sources of error in emotional prediction.
Philos. Trans. R. Soc. Lond., B, Biol. Sci.
PUBLISHED: 06-17-2009
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People typically choose pleasure over pain. But how do they know which of these their choices will entail? The brain generates mental simulations (previews) of future events, which produce affective reactions (premotions), which are then used as a basis for forecasts (predictions) about the future events emotional consequences. Research shows that this process leads to systematic errors of prediction. We review evidence indicating that these errors can be traced to five sources.
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Atmospheric heavy metal deposition in Northern Vietnam: Hanoi and Thainguyen case study using the moss biomonitoring technique, INAA and AAS.
Environ Sci Pollut Res Int
PUBLISHED: 05-19-2009
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The moss technique is widely used to monitor atmospheric deposition of heavy metals in many countries in Europe, whereas this technique is scarcely used in Asia. To implement this international reliable and cheap methodology in the Asian countries, it is necessary to find proper moss types typical for the Asian environment and suitable for the biomonitoring purposes. Such a case study was undertaken in Vietnam for assessing the environmental situation in strongly contaminated areas using local species of moss Barbula indica.
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Anticipating ones troubles: the costs and benefits of negative expectations.
Emotion
PUBLISHED: 04-08-2009
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Although negative expectations may have the benefit of softening the blow when a negative event occurs, they also have the cost of making people feel worse while they are waiting for that event to happen. Three studies suggest that the cost of negative expectations is greater than the benefit. In 2 laboratory experiments and a field study, people felt worse when they were expecting a negative than a positive event; but once the event occurred, their prior expectations had no measurable influence on how they felt. These results suggest that anticipating ones troubles may be a poor strategy for maximizing positive affect.
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Identification of cholesterol-regulating genes by targeted RNAi screening.
Cell Metab.
PUBLISHED: 04-07-2009
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Elevated plasma cholesterol levels are considered responsible for excess cardiovascular morbidity and mortality. Cholesterol in plasma is tightly controlled by cholesterol within cells. Here, we developed and applied an integrative functional genomics strategy that allows systematic identification of regulators of cellular cholesterol levels. Candidate genes were identified by genome-wide gene-expression profiling of sterol-depleted cells and systematic literature queries. The role of these genes in cholesterol regulation was then tested by targeted siRNA knockdown experiments quantifying cellular cholesterol levels and the efficiency of low-density lipoprotein (LDL) uptake. With this strategy, 20 genes were identified as functional regulators of cellular cholesterol homeostasis. Of these, we describe TMEM97 as SREBP target gene that under sterol-depleted conditions localizes to endo-/lysosomal compartments and binds to LDL cholesterol transport-regulating protein Niemann-Pick C1 (NPC1). Taken together, TMEM97 and other factors described here are promising to yield further insights into how cells control cholesterol levels.
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The surprising power of neighborly advice.
Science
PUBLISHED: 03-21-2009
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Two experiments revealed that (i) people can more accurately predict their affective reactions to a future event when they know how a neighbor in their social network reacted to the event than when they know about the event itself and (ii) people do not believe this. Undergraduates made more accurate predictions about their affective reactions to a 5-minute speed date (n = 25) and to a peer evaluation (n = 88) when they knew only how another undergraduate had reacted to these events than when they had information about the events themselves. Both participants and independent judges mistakenly believed that predictions based on information about the event would be more accurate than predictions based on information about how another person had reacted to it.
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The feeling of uncertainty intensifies affective reactions.
Emotion
PUBLISHED: 02-04-2009
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Uncertainty has been defined as a lack of information about an event and has been characterized as an aversive state that people are motivated to reduce. The authors propose an uncertainty intensification hypothesis, whereby uncertainty during an emotional event makes unpleasant events more unpleasant and pleasant events more pleasant. The authors hypothesized that this would happen even when uncertainty is limited to the feeling of "not knowing," separable from a lack of information. In 4 studies, the authors held information about positive and negative film clips constant while varying the feeling of not knowing by having people repeat phrases connoting certainty or uncertainty while watching the films. As predicted, the subjective feeling of uncertainty intensified peoples affective reactions to the film clips.
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Multiplexed labeling of viable cells for high-throughput analysis of glycine receptor function using flow cytometry.
Cytometry A
PUBLISHED: 02-03-2009
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Flow cytometry is an important drug discovery tool because it permits high-content multiparameter analysis of individual cells. A new method dramatically enhanced screening throughput by multiplexing many discrete fixed cell populations; however, this method is not suited to assays requiring functional cellular responses. HEK293 cells were transfected with unique mutant glycine receptors. Mutant receptor expression was confirmed by coexpression of yellow fluorescent protein (YFP). Commercially available cell-permeant dyes were used to label each glycine receptor expressing mutant with a unique optical code. All encoded cell lines were combined in a single tube and analyzed on a flow cytometer simultaneously before and after the addition of glycine receptor agonist. We decoded multiplexed cells that expressed functionally distinct glycine receptor chloride channels and analyzed responses to glycine in terms of chloride-sensitive YFP expression. Here, data provided by flow cytometry can be used to discriminate between functional and nonfunctional mutations in the glycine receptor, a process accelerated by the use of multiplexing. Further, this data correlates to data generated using a microscopy-based technique. The present study demonstrates multiplexed labeling of live cells, to enable cell populations to be subject to further cell culture and experimentation, and compares the results with those obtained using live cell microscopy.
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Optimizing the expression of recombinant alphabetagamma GABAA receptors in HEK293 cells for high-throughput screening.
J Biomol Screen
PUBLISHED: 01-28-2009
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Despite being important clinical targets, it is not straightforward to reliably express recombinant trimeric alphabetagamma GABA-A receptors (GABA(A)Rs) for high-throughput screening. This study therefore sought to devise a simple and reliable means of transiently expressing alpha1beta1gamma1 and alpha1beta1gamma2 GABA(A)Rs in HEK293 cells. Expression efficiencies resulting from 5 different transfection strategies were assessed by flow cytometry and pharmacological analysis using an anion-sensitive yellow fluorescent protein-based assay. PolyFect and Effectene, employed according to the manufacturers instructions, conferred the strongest and most reliable expression of trimeric alphabetagamma GABA(A)Rs. Functional analysis via the yellow fluorescent protein assay revealed dramatic differences in the pharmacological properties of gamma1- and gamma2-containing receptors, consistent with previous electrophysiological characterizations. The authors conclude that this method of expressing and screening recombinant GABA(A)Rs provides an effective means of discovering novel GABA(A)R modulators for use as therapeutic lead compounds and pharmacological probes.
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Above- and belowground linkages in Sphagnum peatland: climate warming affects plant-microbial interactions.
Glob Chang Biol
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Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above- and belowground linkages that regulate soil organic carbon dynamics and C-balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top-predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum-polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above- and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands.
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Using testate amoeba as potential biointegrators of atmospheric deposition of phenanthrene (polycyclic aromatic hydrocarbon) on "moss/soil interface-testate amoeba community" microecosystems.
Ecotoxicology
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Microecosystem models could allow understanding of the impacts of pollutants such as polycyclic aromatic hydrocarbons on ecosystem functioning. We studied the effects of atmospheric phenanthrene (PHE) deposition on the microecosystem "moss/soil interface-testate amoebae (TA) community" over a 1-month period under controlled conditions. We found that PHE had an impact on the microecosystem. PHE was accumulated by the moss/soil interface and was significantly negatively correlated (0.4 < r(2) < 0.7) with total TA abundance and the abundance of five species of TA (Arcella sp., Centropyxis sp., Nebela lageniformis, Nebela tincta and Phryganella sp.). Among sensitive species, species with a superior trophic level (determined by the test aperture size) were more sensitive than other TA species. This result suggests that links between microbial groups in the microecosystems are disrupted by PHE and that this pollutant had effects both direct (ingestion of the pollutant or direct contact with cell) and/or indirect (decrease of prey) on the TA community. The TA community seems to offer a potential integrative tool to understand mechanisms and processes by which the atmospheric PHE deposition affects the links between microbial communities.
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The science behind the smile. Interview by Gardiner Morse.
Harv Bus Rev
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Only recently have we been able to apply science to one of the worlds oldest questions: "What is the nature of happiness?" In this edited interview, the author of the 2006 best seller Stumbling on Happiness surveys the field. Gilbert explores the sudden emergence of happiness as a discipline, reviews the major findings (including the mistakes we all make in predicting how happy or miserable well be), and examines the role of happiness in productivity on the job. He describes what makes us truly happy-its not a promotion or a new house-and sketches out a "happiness diet" that emphasizes small, routine efforts. Looking forward, Gilbert discusses the breakthrough work of his colleague Matthew Killingsworth, whose iPhoneenabled real-time surveys of peoples moods are providing an ultra-high-resolution picture of how our emotional states shift from minute to minute. A sidebar by Killingsworth offers a preliminary look at his findings and their implications for our personal and workplace lives.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.