Explore the vast range of titles available.

Plants live in biogeochemically diverse soils with diverse microbiota. Plant organs associate intimately with a subset of these microbes, and the structure of the microbial community can be altered by soil nutrient content. Plant-associated microbes can compete with the plant and with each other for nutrients, but may also carry traits that increase the productivity of the plant. It is unknown how the plant immune system coordinates microbial recognition with nutritional cues during microbiome assembly. Here we establish that a genetic network controlling the phosphate stress response influences the structure of the root microbiome community, even under non-stress phosphate conditions. We define a molecular mechanism regulating coordination between nutrition and defence in the presence of a synthetic bacterial community. We further demonstrate that the master transcriptional regulators of phosphate stress response in Arabidopsis thaliana also directly repress defence, consistent with plant prioritization of nutritional stress over defence. Our work will further efforts to define and deploy useful microbes to enhance plant performance. In Arabidopsis thaliana , a genetic network that controls the phosphate stress response also influences the structure of the root microbiome community, even under non-stress phosphate conditions. Root microbiota coordinate plant nutrition and immunity Plants live among a community of soil bacteria, the composition of which can be altered by changes in the soil nutrients. Therefore, even beneficial soil microbes can compete with plants for nutrients. Jeff Dangl and colleagues ask how, in the presence of a microbial community, plants coordinate their immune responses to nutrient shortages. They find that, even with sufficient phosphate present, the genetic network that regulates phosphate stress response affects the composition of the local microbial community. The mechanistic logic for this observation is that the transcriptional regulators of the phosphate stress response can directly repress plant defence. The findings also suggest that plants prioritize responses to nutrient shortages over defence.

Plants grow within a complex web of species that interact with each other and with the plant 1 – 10 . These interactions are governed by a wide repertoire of chemical signals, and the resulting chemical landscape of the rhizosphere can strongly affect root health and development 7 – 9 , 11 – 18 . Here, to understand how interactions between microorganisms influence root growth in Arabidopsis , we established a model system for interactions between plants, microorganisms and the environment. We inoculated seedlings with a 185-member bacterial synthetic community, manipulated the abiotic environment and measured bacterial colonization of the plant. This enabled us to classify the synthetic community into four modules of co-occurring strains. We deconstructed the synthetic community on the basis of these modules, and identified interactions between microorganisms that determine root phenotype. These interactions primarily involve a single bacterial genus ( Variovorax ), which completely reverses the severe inhibition of root growth that is induced by a wide diversity of bacterial strains as well as by the entire 185-member community. We demonstrate that Variovorax manipulates plant hormone levels to balance the effects of our ecologically realistic synthetic root community on root growth. We identify an auxin-degradation operon that is conserved in all available genomes of Variovorax and is necessary and sufficient for the reversion of root growth inhibition. Therefore, metabolic signal interference shapes bacteria–plant communication networks and is essential for maintaining the stereotypic developmental programme of the root. Optimizing the feedbacks that shape chemical interaction networks in the rhizosphere provides a promising ecological strategy for developing more resilient and productive crops. Experiments using an ecologically realistic 185-member bacterial synthetic community in the root system of Arabidopsis reveal that Variovorax bacteria can influence plant hormone levels to reverse the inhibitory effect of the community on root growth.

This study presents a column-switching solid-phase extraction online-coupled to a liquid chromatography/tandem mass spectrometry (SPE-LC-MS/MS) method for simultaneous analysis of 12 antibiotics (7 sulfonamides and 5 fluoroquinolones) and caffeine detected in the sewage and effluent of a pilot anaerobic reactor used in sewage treatment. After acidification and filtration, the samples were directly injected into a simple and conventional LC system. Backflush and foreflush modes were compared based on the theoretical plates and peak asymmetry observed. The method was tested in terms of detection (MDL) and quantification limit (MQL), linearity, relative recovery, and precision intra- and inter-day in lab-made sewage samples. The method presented suitable figures of merit in terms of detection, varying from 8.00 × 10⁻⁵ to 6.00 × 10⁻² ng (0.800 up to 600 ng L⁻¹; caffeine) with direct injection volume of only 100 μL and 13 min of total analysis time (sample preparation and chromatographic run). When the method was applied in the analysis of sewage and effluent of the anaerobic reactor (n = 15), six antibiotics and caffeine were detected in concentrations ranging from 0.018 to 1097 μg L⁻¹. To guarantee a reliable quantification, standard addition was used to overcome the matrix effect.

This paper presents an end-to-end learning framework for performing 6-DOF odometry by using only inertial data obtained from a low-cost IMU. The proposed inertial odometry method allows leveraging inertial sensors that are widely available on mobile platforms for estimating their 3D trajectories. For this purpose, neural networks based on convolutional layers combined with a two-layer stacked bidirectional LSTM are explored from the following three aspects. First, two 6-DOF relative pose representations are investigated: one based on a vector in the spherical coordinate system, and the other based on both a translation vector and an unit quaternion. Second, the loss function in the network is designed with the combination of several 6-DOF pose distance metrics: mean squared error, translation mean absolute error, quaternion multiplicative error and quaternion inner product. Third, a multi-task learning framework is integrated to automatically balance the weights of multiple metrics. In the evaluation, qualitative and quantitative analyses were conducted with publicly-available inertial odometry datasets. The best combination of the relative pose representation and the loss function was the translation and quaternion together with the translation mean absolute error and quaternion multiplicative error, which obtained more accurate results with respect to state-of-the-art inertial odometry techniques.

Intense exercise is a physiological stress capable of inducing the interaction of neutrophils with muscle endothelial cells and their transmigration into tissue. Mechanisms driving this physiological inflammatory response are not known. Here, we investigate whether production of reactive oxygen species is relevant for neutrophil interaction with endothelial cells and recruitment into the quadriceps muscle in mice subjected to the treadmill fatiguing exercise protocol. Mice exercised until fatigue by running for 56.3±6.8 min on an electric treadmill. Skeletal muscle was evaluated by intravital microscopy at different time points after exercise, and then removed to assess local oxidative stress and histopathological analysis. We observed an increase in plasma lactate and creatine kinase (CK) concentrations after exercise. The numbers of monocytes, neutrophils, and lymphocytes in blood increased 12 and 24 hours after the exercise. Numbers of rolling and adherent leukocytes increased 3, 6, 12, and 24 hours post-exercise, as assessed by intravital microscopy. Using LysM-eGFP mice and confocal intravital microscopy technology, we show that the number of transmigrating neutrophils increased 12 hours post-exercise. Mutant gp91phox-/- (non-functional NADPH oxidase) mice and mice treated with apocynin showed diminished neutrophil recruitment. SOD treatment promoted further adhesion and transmigration of leukocytes 12 hours after the exercise. These findings confirm our hypothesis that treadmill exercise increases the recruitment of leukocytes to the postcapillary venules, and NADPH oxidase-induced ROS plays an important role in this process.

The use of recycled aggregates (RA) for concrete production usually involves a reduction of the workability as measured by slump. This reduction is mainly due to higher absorption rates, rough-textured surfaces and particles with quite irregular shape from RA. Besides that, the slump test is a static test, whose result is influenced by its own weight and by internal friction between particles. Because of that, recycled concrete workability is not well explained by the slump test. Thus, the main goal of this study is to assess the workability of concrete by varying: (1) workability tests (slump test, flow test and VeBe test); (2) the amount of fine and coarse RAs (0, 50 and 100 %); and, (3) the compensation index of RA absorption rates (60, 70, 80 and 90 %). Concrete compressive strength, at 28 days of age was also evaluated. It was observed that the flow test is the most suitable method for measuring the workability of recycled concrete. The results show that increasing the compensation index of RA absorption rate, there is an improvement of the workability of concrete and a reduction of compressive strength, which is related to the increase of the initial water content in mixtures.

BackgroundMyasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction that can be exacerbated by many viral infections, including COVID-19. The management of MG exacerbations is challenging in this scenario. We report 8 cases of MG exacerbation or myasthenic crisis associated with COVID-19 and discuss prognosis and treatment based on a literature review.ResultsMost patients were female (7/8), with an average age of 47.1 years. Treatment was immunoglobulin (IVIG) in 3 patients, plasma exchange (PLEX) in 2 patients, and adjustment of baseline drugs in 3. In-hospital mortality was 25% and 37.5% in 2-month follow-up.DiscussionThis is the largest case series of MG exacerbation or myasthenic crisis due to COVID-19 to this date. Mortality was considerably higher than in myasthenic crisis of other etiologies. Previous treatment for MG or acute exacerbation treatment did not seem to interfere with prognosis, although sample size was too small to draw definitive conclusions. Further studies are needed to understand the safety and effectiveness of interventions in this setting, particularly of PLEX, IVIG, rituximab, and tocilizumab.

To assess the influence of physical training on neuronal activation and hypothalamic expression of vasopressin and oxytocin in spontaneously hypertensive rats (SHR), untrained and trained normotensive rats and SHR were submitted to running until fatigue while internal body and tail temperatures were recorded. Hypothalamic c-Fos expression was evaluated in thermoregulatory centers such as the median preoptic nucleus (MnPO), medial preoptic nucleus (mPOA), paraventricular nucleus of the hypothalamus (PVN), and supraoptic nucleus (SON). The PVN and the SON were also investigated for vasopressin and oxytocin expressions. Although exercise training improved the workload performed by the animals, it was reduced in SHR and followed by increased internal body temperature due to tail vasodilation deficit. Physical training enhanced c-Fos expression in the MnPO, mPOA, and PVN of both strains, and these responses were attenuated in SHR. Vasopressin immunoreactivity in the PVN was also increased by physical training to a lesser extent in SHR. The already-reduced oxytocin expression in the PVN of SHR was increased in response to physical training. Within the SON, neuronal activation and the expressions of vasopressin and oxytocin were reduced by hypertension and unaffected by physical training. The data indicate that physical training counterbalances in part the negative effect of hypertension on hypothalamic neuronal activation elicited by exercise, as well as on the expression of vasopressin and oxytocin. These hypertension features seem to negatively influence the workload performed by SHR due to the hyperthermia derived from the inability of physical training to improve heat dissipation through skin vasodilation.

The flow around two neighboring, circular, vegetation patches of equal diameter ( D ) was investigated using computational fluid dynamics. Depending on the patches’ transverse and longitudinal center-to-center spacing ( T and L , respectively), several distinct flow patterns were observed. The patterns are compared to flow near an isolated patch. The key flow patterns were interpreted in terms of implications for deposition. Deposition maps were calculated for two different threshold velocities: 0.5 U 0 and 0.7 U 0 , where U 0 is the free stream velocity. When the two patches were far away from each other, the interaction of their wakes was weak, and the flow and deposition pattern around each patch resembled that of a single, isolated patch. When the patches were very close, wake interaction took place, resulting in additional deposition along the centerline between the two patches, but further downstream than the deposition in line with each patch. For some intermediate patch spacings, the wake of the upstream patch was dramatically shortened, relative to an isolated patch, and the wake of the downstream patch was lengthened. The results show that flow distribution is influenced by interaction between neighboring vegetation patches and suggest that this may create feedbacks that influence the evolution of vegetated landscapes.

Abstract The text presents the knowledge system of the Indigenous peoples of the northwestern Amazon, based on orality and its own social institutions, distinct from Western science. Their origin narratives describe the construction of the terrestrial world by the demiurges Yepa- oãku and Yepalio, who created habitable spaces through ritual techniques. In this cosmology, (humans) mahsã and the invisible humans waimahsã, who inhabit domains of water, forest/land, and air, emerge, acting as guardians and responsible for the maintenance of spaces and beings. The land is symbolically conceived as a womb, where natural cycles, such as fish spawning and fruiting, represent the “birth of the earth.” This worldview understands the terrestrial world as an integrated organism, in constant movement and transformation, whose balance depends on the interaction between humans and waimahsã. Indigenous specialists, such as the kumu and yai, mediate these relationships, preserving knowledge, ritual practices, and the socio-environmental harmony of the region. Resumo O texto apresenta o sistema de conhecimento dos povos indígenas do noroeste amazônico, fundamentado na oralidade e em instituições sociais próprias, distintas da ciência ocidental. Suas narrativas de origem descrevem a construção do mundo terrestre pelos demiurgos Yepa-oãku e Yepalio, que criaram espaços habitáveis por meio de técnicas rituais. Nessa cosmologia, surgem os mahsã (humanos) e os waimahsã, humanos invisíveis que habitam domínios da água, floresta/terra e ar, atuando como guardiões e responsáveis pela manutenção dos espaços e seres. A terra é concebida simbolicamente como útero, onde ciclos naturais, como a piracema e a frutificação, representam o “parto da terra”. Essa cosmovisão entende o mundo terrestre como um organismo integrado, em constante movimento e transformação, cujo equilíbrio depende da interação entre humanos e waimahsã. Especialistas indígenas, como os kumu e yai, mediam essas relações, preservando saberes, práticas rituais e a harmonia socioambiental da região. Resumen El texto presenta el sistema de conocimiento de los pueblos indígenas del noroeste amazónico, fundamentado en la oralidad y en instituciones sociales propias, distintas de la ciencia occidental. Sus narrativas de origen describen la construcción del mundo terrestre por los demiurgos Yepa-oãku y Yepalio, quienes crearon espacios habitables a través de técnicas rituales. En esta cosmología, surgen los mahsã (humanos) y los waimahsã, humanos invisibles que habitan dominios del agua, de la selva/tierra y del aire, actuando como guardianes y responsables del mantenimiento de los espacios y seres. La tierra se concibe simbólicamente como un útero, donde ciclos naturales, como la piracema y la fructificación, representan el “parto de la tierra”. Esta cosmovisión entiende el mundo terrestre como un organismo integrado, en constante movimiento y transformación, cuyo equilibrio depende de la interacción entre humanos y waimahsã. Especialistas indígenas, como los kumu y yai, median estas relaciones, preservando saberes, prácticas rituales y la armonía socioambiental de región.