Biogenic volatile organic compound and respiratory CO₂ emissions after ¹³C-labeling: online tracing of C translocation dynamics in poplar plants

Background: Globally plants are the primary sink of atmospheric CO2, but are also the major contributor of a large spectrum of atmospheric reactive hydrocarbons such as terpenes (e.g. isoprene) and other biogenic volatile organic compounds (BVOC). The prediction of plant carbon (C) uptake and atmospheric oxidation capacity are crucial to define the trajectory and consequences of global environmental changes. To achieve this, the biosynthesis of BVOC and the dynamics of C allocation and translocation in both plants and ecosystems are important. Methodology: We combined tunable diode laser absorption spectrometry (TDLAS) and proton transfer reaction mass spectrometry (PTR-MS) for studying isoprene biosynthesis and following C fluxes within grey poplar (Populus x canescens) saplings. This was achieved by feeding either 13CO2 to leaves or 13C-glucose to shoots via xylem uptake. The translocation of 13CO2 from the source to other plant parts could be traced by 13C-labeled isoprene and respiratory 13CO2 emission. Principal Finding: In intact plants, assimilated 13CO2 was rapidly translocated via the phloem to the roots within 1 hour, with an average phloem transport velocity of 20.3±2.5 cm h21. 13C label was stored in the roots and partially reallocated to the plants’ apical part one day after labeling, particularly in the absence of photosynthesis. The daily C loss as BVOC ranged between 1.6% in mature leaves and 7.0% in young leaves. Non-isoprene BVOC accounted under light conditions for half of the BVOC C loss in young leaves and one-third in mature leaves. The C loss as isoprene originated mainly (76–78%) from recently fixed CO2, to a minor extent from xylem-transported sugars (7–11%) and from photosynthetic intermediates with slower turnover rates (8–11%). Conclusion: We quantified the plants’ C loss as respiratory CO2 and BVOC emissions, allowing in tandem with metabolic analysis to deepen our understanding of ecosystem C flux

The role of interpersonal influence in counterbalancing psychopathic personality trait facets at work

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordThe purpose of this study was to examine the relations of two facets of psychopathic personality (i.e., self-centered impulsivity and fearless dominance) with interpersonally directed counterproductive work behavior (CWB-I) and contextual performance (CP). Consistent with research on psychopathy, our hypothesis suggested that self-centered impulsivity (i.e., behavioral impulsivity characterized by disregard for rules and responsibilities) would be positively related to CWB-I and negatively related to CP. Using socioanalytic theory, we further suggested that fearless dominance (i.e., an egotistical personal style characterized by self-promotion and prioritization of one’s own needs before those of others) would be negatively associated with interpersonal performance (i.e., high CWB-I and low CP) only when individuals indicated low levels of interpersonal influence (i.e., a dimension of political skill reflecting an ability to adapt one’s behavior in subtle, sophisticated, and situationally effective ways). Results provided strong support for the differential relations of the psychopathic personality dimensions with the criteria of interest. Implications for theory, practice, and future research are provided in light of a number of notable strengths and limitations

Human SWI/SNF directs sequence-specific chromatin changes on promoter polynucleosomes

Studies in humans and other species have revealed that a surprisingly large fraction of nucleosomes adopt specific positions on promoters, and that these positions appear to be determined by nucleosome positioning DNA sequences (NPSs). Recent studies by our lab, using minicircles containing only one nucleosome, indicated that the human SWI/SNF complex (hSWI/SNF) prefers to relocate nucleosomes away from NPSs. We now make use of novel mapping techniques to examine the hSWI/SNF sequence preference for nucleosome movement in the context of polynucleosomal chromatin, where adjacent nucleosomes can limit movement and where hSWI/SNF forms altered dinucleosomal structures. Using two NPS templates (5S rDNA and 601) and two hSWI/SNF target promoter templates (c-myc and UGT1A1), we observed hSWI/SNF-driven depletion of normal mononucleosomes from almost all positions that were strongly favored by assembly. In some cases, these mononucleosomes were moved to hSWI/SNF-preferred sequences. In the majority of other cases, one repositioned mononucleosome appeared to combine with an unmoved mononucleosome forming a specifically localized altered or normal dinucleosome. These effects result in dramatic, template-specific changes in nucleosomal distribution. Taken together, these studies indicate hSWI/SNF is likely to activate or repress transcription of its target genes by generating promoter sequence-specific changes in chromatin configuration

Audition in vampire bats, Desmodus rotundus

1. Within the tonotopic organization of the inferior colliculus two frequency ranges are well represented: a frequency range within that of the echolocation signals from 50 to 100 kHz, and a frequency band below that of the echolocation sounds, from 10 to 35 kHz. The frequency range between these two bands, from about 40 to 50 kHz is distinctly underrepresented (Fig. 3B). 2. Units with BFs in the lower frequency range (10–25 kHz) were most sensitive with thresholds of -5 to -11 dB SPL, and units with BFs within the frequency range of the echolocation signals had minimal thresholds around 0 dB SPL (Fig. 1). 3. In the medial part of the rostral inferior colliculus units were encountered which preferentially or exclusively responded to noise stimuli. — Seven neurons were found which were only excited by human breathing noises and not by pure tones, frequency modulated signals or various noise bands. These neurons were considered as a subspeciality of the larger sample of noise-sensitive neurons. — The maximal auditory sensitivity in the frequency range below that of echolocation, and the conspicuous existence of noise and breathing-noise sensitive units in the inferior colliculus are discussed in context with the foraging behavior of vampire bats

Incorporação de extrato crioconcentrado de erva-mate em amido de milho.

A erva-mate possui propriedades farmacológicas relacionadas ao teor de compostos fenólicos, metilxantinas e saponinas. A crioconcentração é uma técnica empregada para concentrar estes compostos bioativos e preserválos. Este trabalho teve como objetivo crioconcentrar extrato aquoso de erva-mate e incorporar em amido de milho. A incorporação do extrato crioconcentrado em amido de milho proporciona maior aplicabilidade, pois o amido é excelente veículo para diversas formulações industriais. Através de análise de sólidos totais (ST) e cinzas, foi possível verificar que o processo de crioconcentração foi eficiente. E a análise térmica avaliou através das curvas de TG-DTA, a incorporação do extrato de erva-mate crioconcentrado no amido de milho. Os compostos bioativos incorporados no amido aumentaram o índice de oxigênio liberando maior energia em temperaturas mais altas (reação exotérmica). Deste modo a incorporação de extratos de erva-mate em amido de milho diminui a temperatura na decomposição térmica do amido

Cracking the code of oscillatory activity

Neural oscillations are ubiquitous measurements of cognitive processes and dynamic routing and gating of information. The fundamental and so far unresolved problem for neuroscience remains to understand how oscillatory activity in the brain codes information for human cognition. In a biologically relevant cognitive task, we instructed six human observers to categorize facial expressions of emotion while we measured the observers' EEG. We combined state-of-the-art stimulus control with statistical information theory analysis to quantify how the three parameters of oscillations (i.e., power, phase, and frequency) code the visual information relevant for behavior in a cognitive task. We make three points: First, we demonstrate that phase codes considerably more information (2.4 times) relating to the cognitive task than power. Second, we show that the conjunction of power and phase coding reflects detailed visual features relevant for behavioral response-that is, features of facial expressions predicted by behavior. Third, we demonstrate, in analogy to communication technology, that oscillatory frequencies in the brain multiplex the coding of visual features, increasing coding capacity. Together, our findings about the fundamental coding properties of neural oscillations will redirect the research agenda in neuroscience by establishing the differential role of frequency, phase, and amplitude in coding behaviorally relevant information in the brai