Publications by authors named "Henriksson N"

Although the separate effects of water and nitrogen (N) limitations on forest growth are well known, the question of how to predict their combined effects remains a challenge for modeling of climate change impacts on forests. Here, we address this challenge by developing a new eco-physiological model that accounts for plasticity in stomatal conductance and leaf N concentration. Based on optimality principle, our model determines stomatal conductance and leaf N concentration by balancing carbon uptake maximization, hydraulic risk and cost of maintaining photosynthetic capacity.

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Multilayered metal-dielectric nanostructures display both a strong plasmonic behavior and hyperbolic optical dispersion. The latter is responsible for the appearance of two separated radiative and nonradiative channels in the extinction spectrum of these structures. This unique property can open plenty of opportunities toward the development of multifunctional systems that simultaneously can behave as optimal scatterers and absorbers at different wavelengths, an important feature to achieve multiscale control of light-matter interactions in different spectral regions for different types of applications, such as optical computing or detection of thermal radiation.

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Isotopic pulse-labelling of photosynthate allows tracing of carbon (C) from tree canopies to belowground biota and calculations of its turnover in roots and recipient soil microorganisms. A high concentration of label is desirable, but is difficult to achieve in field studies of intact ecosystem patches with trees. Moreover, root systems of trees overlap considerably in most forests, which requires a large labelled area to minimize the impact of C allocated belowground by un-labelled trees.

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Article Synopsis
  • Most forest carbon measurements overlook the carbon loss from dead branches, which is an important part of tree physiology.
  • Analyzing data from over 184,000 trees across various forests revealed that considering branch turnover can raise aboveground wood production estimates by 16%, affecting global carbon sink calculations.
  • To improve carbon estimates, researchers suggest changing field measurement methods and models to properly account for branch turnover, as current methods significantly underestimate carbon loss.
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There are growing doubts about the true role of the common mycorrhizal networks (CMN or wood wide web) connecting the roots of trees in forests. We question the claims of a substantial carbon transfer from 'mother trees' to their offspring and nearby seedlings through the CMN. Recent reviews show that evidence for the 'mother tree concept' is inconclusive or absent.

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Article Synopsis
  • The concept that 'mother trees' share carbon with seedlings through mycorrhizal fungal networks has both captivated and polarized the scientific community, impacting our view of forest ecology.
  • Current studies indicate that the idea of beneficial carbon transfer is questionable, with findings suggesting insufficient evidence to support significant net carbon transfer among trees.
  • The relationship between fungi and trees in this context may not provide clear advantages for fungi, further complicating this hypothesis and raising doubts about its compatibility with observed forest regeneration patterns.
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  • Understanding the interaction between water uptake and nutrient acquisition, particularly nitrogen (N), is crucial for predicting how plants react to environmental changes, but existing models show conflicting results.
  • A new isotopic labelling method was used to study how trees in different soil N availability areas acquire water and N simultaneously, revealing that trees in high-N areas absorbed twice as much N compared to those in low-N areas, with water uptake being critical for N absorption.
  • In low-N environments, water uptake did not enhance N acquisition, indicating that trees adapt their nutrient acquisition strategies significantly based on the nitrogen availability in the soil.
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Trees receive growth-limiting nitrogen from their ectomycorrhizal symbionts, but supplying the fungi with carbon can also cause nitrogen immobilization, which hampers tree growth. We present results from field and greenhouse experiments combined with mathematical modelling, showing that these are not conflicting outcomes. Mycorrhizal networks connect multiple trees, and we modulated C provision by strangling subsets of Pinus sylvestris trees, assuming that carbon supply to fungi was reduced proportionally to the strangled fraction.

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  • The study investigates the latitudinal biodiversity gradient, which notes increased biodiversity from the poles to the tropics, in the context of marine microbes in the Pacific Ocean.
  • Researchers sampled microbial planktonic communities over a large area (15,400 km) using DNA sequencing techniques, yielding around 10.8 million sequences.
  • Findings indicated that while bacterial communities showed increasing richness from Arctic to Antarctic waters, Archaea and Eukarya did not exhibit clear latitudinal patterns, suggesting that traditional environmental factors impacting larger animals may not apply to microplankton diversity.
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Stem compression reduces or terminates the phloem-mediated transport of carbohydrates and other solutes in tree stems, without causing permanent damage to phloem functioning (Henriksson et al. Tree Physiol. 35:1075-1085, 2015).

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Cellular respiration via the alternative oxidase pathway (AOP) leads to a considerable loss in efficiency. Compared to the cytochrome pathway (COP), AOP produces 0-50% as much ATP per carbon (C) respired. Relative partitioning between the pathways can be measured in vivo based on their differing isotopic discriminations against O in O .

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Manipulating tree belowground carbon (C) transport enables investigation of the ecological and physiological roles of tree roots and their associated mycorrhizal fungi, as well as a range of other soil organisms and processes. Girdling remains the most reliable method for manipulating this flux and it has been used in numerous studies. However, girdling is destructive and irreversible.

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Genomic characterization of pediatric acute lymphoblastic leukemia (ALL) has identified distinct patterns of genes and pathways altered in patients with well-defined genetic aberrations. To extend the spectrum of known somatic variants in ALL, we performed whole genome and transcriptome sequencing of three B-cell precursor patients, of which one carried the t(12;21)ETV6-RUNX1 translocation and two lacked a known primary genetic aberration, and one T-ALL patient. We found that each patient had a unique genome, with a combination of well-known and previously undetected genomic aberrations.

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Background: Target enrichment and resequencing is a widely used approach for identification of cancer genes and genetic variants associated with diseases. Although cost effective compared to whole genome sequencing, analysis of many samples constitutes a significant cost, which could be reduced by pooling samples before capture. Another limitation to the number of cancer samples that can be analyzed is often the amount of available tumor DNA.

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Deadenylation of eukaryotic mRNA is a mechanism critical for mRNA function by influencing mRNA turnover and efficiency of protein synthesis. Here, we review poly(A)-specific ribonuclease (PARN), which is one of the biochemically best characterized deadenylases. PARN is unique among the currently known eukaryotic poly(A) degrading nucleases, being the only deadenylase that has the capacity to directly interact during poly(A) hydrolysis with both the m(7)G-cap structure and the poly(A) tail of the mRNA.

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Poly(A)-specific ribonuclease (PARN) is a mammalian 3'-exoribonuclease that degrades poly(A) with high specificity. To reveal mechanisms by which poly(A) is recognized by the active site of PARN, we have performed a kinetic analysis using a large repertoire of trinucleotide substrates. Our analysis demonstrated that PARN harbors specificity for adenosine recognition in its active site and that the nucleotides surrounding the scissile bond are critical for adenosine recognition.

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Poly(A)-specific ribonuclease (PARN) is a homodimeric, processive, and cap-interacting 3' exoribonuclease that efficiently degrades eukaryotic mRNA poly(A) tails. The crystal structure of a C-terminally truncated PARN in complex with m(7)GpppG reveals that, in one subunit, m(7)GpppG binds to a cavity formed by the RRM domain and the nuclease domain, whereas in the other subunit, it binds almost exclusively to the RRM domain. Importantly, our structural and competition data show that the cap-binding site overlaps with the active site in the nuclease domain.

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Poly(A)-specific ribonuclease (PARN) is an oligomeric, processive and cap-interacting 3' exoribonuclease that efficiently degrades mRNA poly(A) tails. Here we show that the RNA recognition motif (RRM) of PARN harbors both poly(A) and cap binding properties, suggesting that the RRM plays an important role for the two critical and unique properties that are tightly associated with PARN activity, i.e.

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During recent decades a vast amount of literature concerning horizontal optokinetic nystagmus has emerged, regarding which--and especially as regards our own work--this report is intended to consider the clinical value of optokinetic nystagmus.

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The eye tracking test is today a well established part of clinical otoneurological examination. In the present paper some applications of the test in evaluating of the level of lesion within the vestibular system are reviewed.

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Optokinetic nystagmus (OKN) was studied in ten patients with vestibular neuritis, and in seventeen patients with unilateral and thirteen patients with bilateral infratentorial lesions and compared with OKN in fifty healthy subjects. Mean and maximum slow phase velocity of OKN was calculated as well as the asymmetry of responses. The efficiency of the different variables in OKN, in discriminating between different lesion sites, was tested in a linear discriminant function analysis.

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The effects of TTS-scopolamine, dimenhydrinate, lidocaine, and tocainide on motion sickness and vertigo and on caloric and postrotatory nystagmus were evaluated in healthy volunteers. TTS-scopolamine was administered transdermally (delivering approximately 10 micrograms X h-1 scopolamine base) and 100 mg dimenhydrinate orally. Lidocaine and tocainide were administered intravenously (average plasma concentration of lidocaine 6 mol X L-1 and of tocainide 20 mol X L-1).

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Postrotatory responses of nystagmus were analysed in an exponential model by utilizing linear regression analysis. Four nystagmus qualities (velocity and duration of slow and fast phases) were studied in 10 patients with vestibular peripheral lesions, 10 patients with frontal lobe lesions and 10 patients with brain-stem lesions, together with 10 control subjects. In addition, pauses during the responses were quantified.

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Mean peak velocity and accuracy of vertical saccades were measured in 15 patients with disorders in the brain stem and in 12 normal subjects. (1) In the normal group up-directed saccades were faster than down-directed and the velocity of the saccade was not dependent on the age of the subject. Up-saccades were faster whether electro-oculography or photo-electro-oculography were used.

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