Plant Nutrient Resource Use Strategies Shape Active Rhizosphere Microbiota Through Root Exudation

Plant strategies for soil nutrient uptake have the potential to strongly influence plant-microbiota interactions, due to the competition between plants and microorganisms for soil nutrient acquisition and/or conservation. In the present study, we investigate whether these plant strategies could influence rhizosphere microbial activities via root exudation, and contribute to the microbiota diversification of active bacterial communities colonizing the root-adhering soil (RAS) and inhabiting the root tissues. We applied a DNA-based stable isotope probing (DNA-SIP) approach to six grass species distributed along a gradient of plant nutrient resource strategies, from conservative species, characterized by low nitrogen (N) uptake, a long lifespans and low root exudation level, to exploitative species, characterized by high rates of photosynthesis, rapid rates of N uptake and high root exudation level. We analyzed their (i) associated microbiota composition involved in root exudate assimilation and soil organic matter (SOM) degradation by 16S-rRNA-based metabarcoding. (ii) We determine the impact of root exudation level on microbial activities (denitrification and respiration) by gas chromatography. Measurement of microbial activities revealed an increase in denitrification and respiration activities for microbial communities colonizing the RAS of exploitative species. This increase of microbial activities results probably from a higher exudation rate and more diverse metabolites by exploitative plant species. Furthermore, our results demonstrate that plant nutrient resource strategies have a role in shaping active microbiota. We present evidence demonstrating that plant nutrient use strategies shape active microbiota involved in root exudate assimilation and SOM degradation via root exudation.

Anisotropic Magneto-Coulomb Properties of 2D-0D Heterostructure Single Electron Device

Fabrication and spintronics properties of 2D-0D heterostructures are reported. Devices based on graphene ("Gr")-aluminium nanoclusters heterostructures show robust and reproducible single-electron transport features, in addition to spin-dependent functionality when using a top magnetic electrode. The magnetic orientation of this single ferromagnetic electrode enables the modulation of the environmental charge experienced by the aluminium nanoclusters. This anisotropic magneto-Coulomb effect, originating from spin-orbit coupling within the ferromagnetic electrode, provides tunable spin valve-like magnetoresistance signatures without the requirement of spin coherent charge tunneling. These results extend the capability of Gr to act both as electrode and as a platform for the growth of 2D-0D mixed-dimensional van der Waals heterostructures, providing magnetic functionalities in the Coulomb blockade regime on scalable spintronic devices. These heterostructures pave the way towards novel device architectures at the crossroads of 2D material physics and spin electronics.

Knowledge on asthma, food allergies, and anaphylaxis: Assessment of elementary school teachers, parents/caregivers of asthmatic children, and university students in Uruguaiana, in the state of Rio Grande do Sul, Brazil

INTRODUCTION

Allergic diseases have become an increasingly common reality in the last years, extending beyond the family context.

OBJECTIVE

Assessing the level of knowledge on asthma, food allergies and anaphylaxis of asthmatic children's parents/caregivers (PC), elementary school teachers (EST) and university students (US) in Uruguaiana, RS, Brazil.

METHOD

577 individuals (PC - N=111; EST - N=177; US - N=299) took part in the study, answering the Newcastle Asthma Knowledge Questionnaire (validated for Portuguese) and another questionnaire on Food Allergy (FA) and anaphylaxis.

RESULTS

Although PC have asthmatic children, their asthma knowledge level was average, slightly above that of EST and EU. The lack of knowledge on passive smoking, use of medications and their side effects should be highlighted. US have shown to be better informed about FA and anaphylaxis. However, even though a significant proportion of respondents know the most common symptoms of FA and anaphylaxis, few named subcutaneous adrenaline as the drug of choice for treating anaphylaxis. Although a significant number of respondents know about the possibility of anaphylactic reactions happening at school or in activities outside the school, we were surprised by the absence of conditions in schools to provide emergency care to such students.

CONCLUSION

Despite the high prevalence of allergic diseases in childhood, asthmatic children's parents/caregivers, elementary school teachers and university students have inadequate levels of knowledge to monitor these patients.

[Image-guided radiotherapy in lung cancer]

Image-guided radiotherapy takes place at every step of the treatment in lung cancer, from treatment planning, with fusion imaging, to daily in-room repositioning. Managing tumoral and surrounding thoracic structures motion has been allowed since the routine use of 4D computed tomography (4DCT). The integration of respiratory motion has been made with "passive" techniques based on reconstruction images from 4DCT planning, or "active" techniques adapted to the patient's breathing. Daily repositioning is based on regular images, weekly or daily, low (kV) or high (MV) energy. MRI and functional imaging also play an important part in lung cancer radiation and open the way for adaptative radiotherapy.

Root exudation rate as functional trait involved in plant nutrient-use strategy classification

Plants adopt a variety of life history strategies to succeed in the Earth's diverse environments. Using functional traits which are defined as "morphological, biochemical, physiological, or phonological" characteristics measurable at the individual level, plants are classified according to their species' adaptative strategies, more than their taxonomy, from fast growing plant species to slower-growing conservative species. These different strategies probably influence the input and output of carbon (C)-resources, from the assimilation of carbon by photosynthesis to its release in the rhizosphere soil via root exudation. However, while root exudation was known to mediate plant-microbe interactions in the rhizosphere, it was not used as functional trait until recently. Here, we assess whether root exudate levels are useful plant functional traits in the classification of plant nutrient-use strategies and classical trait syndromes? For this purpose, we conducted an experiment with six grass species representing along a gradient of plant resource-use strategies, from conservative species, characterized by low biomass nitrogen (N) concentrations and a long lifespans, to exploitative species, characterized by high rates of photosynthesis and rapid rates of N acquisition. Leaf and root traits were measured for each grass and root exudate rate for each planted soil sample. Classical trait syndromes in plant ecology were found for leaf and root traits, with negative relationships observed between specific leaf area and leaf dry matter content or between specific root length and root dry matter content. However, a new root trait syndrome was also found with root exudation levels correlating with plant resource-use strategy patterns, specifically, between root exudation rate and root dry matter content. We therefore propose root exudation rate can be used as a key functional trait in plant ecology studies and plant strategy classification.

Self-Interference of Exciton Emission in Organic Single Crystals Visualized by Energy-Momentum Spectroscopy

We employ energy-momentum spectroscopy on isolated organic single crystals with micrometer-sized dimensions. The single crystals are grown from a thiophene-based oligomer and are excellent low-loss active waveguides that support multiple guided modes. Excitation of the crystals with a diffraction-limited laser spot results in emission into guided modes as well as into quasi-discrete radiation modes. These radiation modes are mapped in energy-momentum space and give rise to dispersive interference patterns. On the basis of the known geometry of the crystals, especially the height, the characteristics of the interference maxima allow one to determine the energy dependence of two components of the anisotropic complex refractive index. Moreover, the method is suited to identify the orientation of molecules within (and around) a crystalline structure.

First endogenous fungal endophthalmitis due to Fusarium dimerum: A severe eye infection contracted during induction chemotherapy for acute leukemia

Endophthalmitis is a rare infection of the vitreous and/or aqueous. It can be bacterial or fungal. Exogenous endophthalmitis is the most common form and results from direct inoculation of a pathogen after eye surgery or penetrating trauma. Endophthalmitis can also be endogenous, secondary to disseminated infection. Fungal endophthalmitis is associated with poor prognosis and treatment is difficult given the low penetration of most of the antifungal agents available and the emergence of resistant filamentous fungi like Fusarium. To our knowledge, we describe the first endogenous fungal endophthalmitis due to Fusarium dimerum, a ubiquitous pathogen found in soil and plants. A 71-year-old woman, diagnosed with acute myeloid leukemia, was hospitalized for surveillance after induction chemotherapy. Prophylaxis by antibiotics and posaconazole was ongoing when she complained of pain and decreased vision in the left eye. A voluminous chorioretinal abscess developed and after multiple sterile aqueous humour samples, only vitrectomy allowed diagnosis with fungal hyphae seen on May-Grünwald Giemsa stained smear and positive cultures. The fungus was identified as Fusarium dimerum. The treatment, that included intravitreal injections of voriconazole and amphotericin B associated with systemic administration of voriconazole, allowed complete control of the infection. The source of this infection could not be confirmed despite the discovery of several possible infection sites including a periungual whitlow on the left hand and a lesion on a nail, from which samples were negative in microbiology laboratories. Unfortunately, damages of the retina were too important and the patient did not recover sight of her left eye.

On the Glucose SAT Solver

The set of novelties introduced with the SAT solver Glucose is now considered as a standard for practical SAT solving. In this paper, we review the different strategies and technologies added in Glucose over the years. We detail each technique and discuss its impact on the final performances reached by Glucose. We also come back on one of the main developments of the solver over the very last years: its efficient parallelization. We extensively tested different versions of Glucose and Syrup (its parallel version) on all the benchmarks since 2011. By including, as a reference, the SAT solver Lingeling (and its parallel version Plingeling), we show that Glucose and Syrup are significantly faster than other solvers, even if they can solve fewer instances.

Large-scale synthesis of fluorinated graphene by rapid thermal exfoliation of highly fluorinated graphite

Weakly fluorinated graphene nanosheets were efficiently prepared via fast thermal exfoliation of highly fluorinated graphite.

An effective time-constant algorithm for drug transport to capillaries and surrounding tissues

Expressions for a single time constant were developed in Maple (Waterloo Maple, Inc.) to calculate the rate at which a drug reaches steady-state levels in the blood capillaries and neighboring tissues. The solute concentration in the capillary region was represented by a one-dimensional convection-diffusion model. In a first case study, the plasma and the tissue reached equilibrium very quickly. Within the dynamic regime, the amount of drugs collected in both compartments increased with the Peclet number while the relaxation time to a steady-state value decreased. A similar conclusion was drawn, in a second case study, when axial and radial diffusive transports were considered important in the lungs or the skin. Also, as the mass transfer Biot number decreased, a larger amount of medication was delivered to the tissue at a given time during the transient period. Additional applications of the approach included the analysis of oxygen transport in peripheral nerves and the design of hollow fibre bioreactors.

Decreased myoblast differentiation in chronic binge alcohol-administered simian immunodeficiency virus-infected male macaques: role of decreased miR-206

Skeletal muscle stem cells play a critical role in regeneration of myofibers. We previously demonstrated that chronic binge alcohol (CBA) markedly attenuates myoblast differentiation potential and myogenic gene expression. Muscle-specific microRNAs (miRs) are implicated in regulation of myogenic genes. The aim of this study was to determine whether myoblasts isolated from asymptomatic CBA-administered simian immunodeficiency virus (SIV)-infected macaques treated with antiretroviral therapy (ART) showed similar impairments and, if so, to elucidate potential underlying mechanisms. Myoblasts were isolated from muscle at 11 mo after SIV infection from CBA/SIV macaques and from time-matched sucrose (SUC)-treated SIV-infected (SUC/SIV) animals and age-matched controls. Myoblast differentiation and myogenic gene expression were significantly decreased in myoblasts from SUC/SIV and CBA/SIV animals compared with controls. SIV and CBA decreased muscle-specific miR-206 in plasma and muscle and SIV decreased miR-206 expression in myoblasts, with no statistically significant changes in other muscle-specific miRs. These findings were associated with a significant increase in histone deacetylase 4 (HDAC4) and decrease in myogenic enhancer factor 2C (MEF2C) expression in CBA/SIV muscle. Transfection with miR-206 inhibitor decreased myotube differentiation, increased expression of HDAC4, and decreased MEF2C, suggesting a critical role of miR-206 in myogenesis. Moreover, HDAC4 was confirmed to be a direct miR-206 target. These results support a mechanistic role for decreased miR-206 in suppression of myoblast differentiation resulting from chronic alcohol and SIV infection. The parallel changes in skeletal muscle and circulating levels of miR-206 warrant studies to establish the possible use of plasma miR-206 as an indicator of impaired muscle function.