18,304 results match your criteria [co gradient


Synergistic Effect of Surface Chemistry and Surface Topography Gradient on Osteogenic/Adipogenic Differentiation of hMSCs.

ACS Appl Mater Interfaces 2021 Jun 22. Epub 2021 Jun 22.

Unit of STEM, University of South Australia, Mawson Lakes 5095, Australia.

Much attention has been paid to understanding the individual effects of surface chemistry or topography on cell behavior. However, the synergistic influence of both surface chemistry and surface topography on differentiation of human mesenchymal stem cells (hMSCs) should also be addressed. Here, gold nanoparticles were immobilized in an increasing number density manner to achieve a surface topography gradient; a thin film rich in amine (-NH) or methyl (-CH) chemical groups was plasma-polymerized to adjust the surface chemistry of the outermost layer (ppAA and ppOD, respectively). Read More

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Evolution and expansion of Li concentration gradient during charge-discharge cycling.

Nat Commun 2021 Jun 21;12(1):3814. Epub 2021 Jun 21.

Analytical Engineering Group, Material Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Suwon, Republic of Korea.

To improve the performance of Li-ion batteries (LIBs), it is essential to understand the behaviour of Li ions during charge-discharge cycling. However, the analytical techniques for observing the Li ions are limited. Here, we present the complementary use of scanning transmission electron microscopy and atom probe tomography at identical locations to demonstrate that the evolution of the local Li composition and the corresponding structural changes at the atomic scale cause the capacity degradation of Li(NiCoMn)O (NCM), an LIB cathode. Read More

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Initial Thermal Decomposition Mechanism of (NH)C=C(NO)(ONO) Revealed by Double-Hybrid Density Functional Calculations.

ACS Omega 2021 Jun 3;6(23):15292-15299. Epub 2021 Jun 3.

School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials, Northwest University, Xi'an 710069, China.

This work employs double-hybrid density functionals to re-examine the CO-NO bond dissociation mechanism of nitrite isomer of 1,1-diamino-2,2-dinitro-ethylene (DADNE) into (NH)C=C(NO)O and nitric monoxide (NO). The calculated results confirm that an activated barrier is present in the CO-NO bond dissociation process of (NH)C=C(NO)(ONO). Furthermore, it is proposed that a radical-radical adduct is involved in the exit dissociation path with subsequent dissociation to separate (NH)C=C(NO)O and NO radicals. Read More

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MESMERISED: Super-accelerating T relaxometry and diffusion MRI with STEAM at 7 T for quantitative multi-contrast and diffusion imaging.

Neuroimage 2021 Jun 17:118285. Epub 2021 Jun 17.

Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands. Electronic address:

There is an increasing interest in quantitative imaging of T, T and diffusion contrast in the brain due to greater robustness against bias fields and artifacts, as well as better biophysical interpretability in terms of microstructure. However, acquisition time constraints are a challenge, particularly when multiple quantitative contrasts are desired and when extensive sampling of diffusion directions, high b-values or long diffusion times are needed for multi-compartment microstructure modeling. Although ultra-high fields of 7 T and above have desirable properties for many MR modalities, the shortening T and the high specific absorption rate (SAR) of inversion and refocusing pulses bring great challenges to quantitative T, T and diffusion imaging. Read More

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Diagnosis of central serous chorioretinopathy by deep learning analysis of en face images of choroidal vasculature: A pilot study.

PLoS One 2021 18;16(6):e0244469. Epub 2021 Jun 18.

Department of Ophthalmology, Tokyo Women's Medical University, Shinjuku, Tokyo, Japan.

Purpose: To diagnose central serous chorioretinopathy (CSC) by deep learning (DL) analyses of en face images of the choroidal vasculature obtained by optical coherence tomography (OCT) and to analyze the regions of interest for the DL from heatmaps.

Methods: One-hundred eyes were studied; 53 eyes with CSC and 47 normal eyes. Volume scans of 12×12 mm square were obtained at the same time as the OCT angiographic (OCTA) scans (Plex Elite 9000 Swept-Source OCT®, Zeiss). Read More

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Point Defect Engineering: Co-Doping Synergy Realizing Superior Performance in n-Type Bi Te Thermoelectric Materials.

Small 2021 Jun 17:e2101328. Epub 2021 Jun 17.

Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, and Guangdong Provincial Key Laboratory of Energy Materials for Electric Power, Southern University of Science and Technology, Shenzhen, 518055, China.

Bi Te has attracted great attention because of its excellent thermoelectric (TE) performance around room temperature. However, the TE property of the n-type Bi Te is still relatively low compared to the p-type counterpart, which seriously hinders its commercial application with a combination of the n-type and p-type materials. Herein, an effective process of Cl and W co-doping is employed into the n-type Bi Te materials to enhance its TE properties. Read More

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Consistent declines in aquatic biodiversity across diverse domains of life in rivers impacted by surface coal mining.

Ecol Appl 2021 Jun 17:e2389. Epub 2021 Jun 17.

Biology Department, Duke University, Durham, NC, USA.

The rivers of Appalachia (USA) are among the most biologically diverse freshwater ecosystems in the temperate zone and are home to numerous endemic aquatic organisms. Throughout the Central Appalachian ecoregion, extensive surface coal mines generate alkaline mine drainage that raises the pH, salinity and trace element concentrations in downstream waters. Previous regional assessments have found significant declines in stream macroinvertebrate and fish communities draining these mined areas. Read More

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Habitat heterogeneity, temperature, and primary productivity drive elevational gradients in avian species diversity.

Ecol Evol 2021 Jun 1;11(11):5985-5997. Epub 2021 May 1.

U. S. Geological Survey Idaho Cooperative Fish and Wildlife Research Unit Department of Fish and Wildlife Sciences, University of Idaho Moscow ID USA.

Aim: Anticipating and mitigating the impacts of climate change on species diversity in montane ecosystems requires a mechanistic understanding of drivers of current patterns of diversity. We documented the shape of elevational gradients in avian species richness in North America and tested a suite of a priori predictions for each of five mechanistic hypotheses to explain those patterns.

Location: United States. Read More

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A novel twin-column continuous chromatography approach for separation and enrichment of monoclonal antibody charge variants.

Eng Life Sci 2021 Jun 12;21(6):382-391. Epub 2021 May 12.

Key Laboratory of Biomass Chemical Engineering of Ministry of Education College of Chemical and Biological Engineering Zhejiang University Hangzhou P. R. China.

Downstream processing of mAb charge variants is difficult owing to their similar molecular structures and surface charge properties. This study aimed to apply a novel twin-column continuous chromatography (called N-rich mode) to separate and enrich acidic variants of an IgG1 mAb. Besides, a comparison study with traditional scaled-up batch-mode cation exchange (CEX) chromatography was conducted. Read More

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The effect of coarctation degrees on wall shear stress indices.

Sci Rep 2021 Jun 17;11(1):12757. Epub 2021 Jun 17.

Department of Mechanical Engineering, K. N. Toosi Univeristy of Technology, Tehran, Iran.

Coarctation of the aorta (CoA) is a congenital tightening of the proximal descending aorta. Flow quantification can be immensely valuable for an early and accurate diagnosis. However, there is a lack of appropriate diagnostic approaches for a variety of cardiovascular diseases, such as CoA. Read More

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The fine-tuning of NPQ in diatoms relies on the regulation of both xanthophyll cycle enzymes.

Sci Rep 2021 Jun 17;11(1):12750. Epub 2021 Jun 17.

Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de La Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Physico-Chimique, 75005, Paris, France.

Diatoms possess an efficient mechanism to dissipate photons as heat in conditions of excess light, which is visualized as the Non-Photochemical Quenching of chlorophyll a fluorescence (NPQ). In most diatom species, NPQ is proportional to the concentration of the xanthophyll cycle pigment diatoxanthin formed from diadinoxanthin by the diadinoxanthin de-epoxidase enzyme. The reverse reaction is performed by the diatoxanthin epoxidase. Read More

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Multispectral co-occurrence of wavelet coefficients for malignancy assessment of brain tumors.

PLoS One 2021 17;16(6):e0250964. Epub 2021 Jun 17.

Biomedical Imaging and Bioinformatics Lab, Machine Intelligence Unit, Indian Statistical Institute, Kolkata, West Bengal, India.

Brain tumor is not most common, but truculent type of cancer. Therefore, correct prediction of its aggressiveness nature at an early stage would influence the treatment strategy. Although several diagnostic methods based on different modalities exist, a pre-operative method for determining tumor malignancy state still remains as an active research area. Read More

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Dimensional Gradient Structure of [email protected] Anode Assisted by Ether for High-Capacity, Stable Sodium Storage.

Nanomicro Lett 2021 Jan 4;13(1):40. Epub 2021 Jan 4.

School of Materials Science and Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China.

Recently, abundant resources, low-cost sodium-ion batteries are deemed to the new-generation battery in the field of large-scale energy storage. Nevertheless, poor active reaction dynamics, dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved. Herein, dimensional gradient structure of sheet-tube-dots is constructed with [email protected] Read More

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January 2021

The Allegra transcatheter heart valve: Short term results from a multicenter registry.

Catheter Cardiovasc Interv 2021 Jun 17. Epub 2021 Jun 17.

Heart Center Lucerne, Luzerner Kantonsspital, Lucerne, Switzerland.

Objectives: We aimed to determine the safety and efficacy of the Allegra transcatheter heart valve (THV) for the treatment of severe aortic valve stenosis in a large patient population treated under real-world conditions.

Background: The Allegra is a novel self-expanding THV with supra-annular bovine leaflets. The valve is available in three different sizes (23, 27, and 31 mm), all are delivered through an 18F sheath. Read More

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Improvement of symptoms and coronary perfusion gradient with mechanical left ventricular unloading in flow-limiting complex spontaneous coronary artery dissection, without revascularization.

Catheter Cardiovasc Interv 2021 Jun 15. Epub 2021 Jun 15.

Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Padova, Italy.

Spontaneous coronary artery dissection (SCAD) can lead to acute coronary syndrome and sudden cardiac death, particularly in young women. Observational data show that, in SCAD patients, both percutaneous coronary intervention and coronary artery bypass grafting seem to be hampered by higher technical complexity, lower success rates, and worse outcomes. As spontaneous healing is a common occurrence, expert consensus advices medical management of the acute phase, when feasible. Read More

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Exploring the ecological and evolutionary relationships between Rickettsia and hard ticks in the Neotropical region.

Ticks Tick Borne Dis 2021 Jun 4;12(5):101754. Epub 2021 Jun 4.

Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva, 87, Cidade Universitária. São Paulo, SP, 05508-270, Brazil.

This study addresses a meta-analysis of the distribution of Rickettsia spp. in the Neotropical region, as well as their associations with ticks and vertebrates. A total of 219 published reports on Rickettsia in ticks in the target region were compiled, providing 599 records of 31 species of Rickettsia recorded in 50 species of Ixodidae. Read More

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Polish Multicenter Registry (Pol-LAS-SE registry). Stress echocardiography in low-gradient aortic stenosis in Poland: numbers, settings, results, complications and clinical practice.

Kardiol Pol 2021 ;79(5):517-524

Department of Cardiology, Wroclaw Medical University, Wrocław, Poland.

Background: The diagnostic workup of low-gradient aortic stenosis (LG AS) is a challenge in clinical practice.

Aims: Our goal was to assess the diagnostic value of stress echocardiography (SE) performed in patients with undefined LG AS with low and preserved ejection fraction (EF) and the impact of its result on therapeutic decisions in Polish third level of reference.

Methods: All the patients with LG AS and with SE performed were recruited in 16 Polish cardiology departments between 2016 and 2019. Read More

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Novel use of intravascular lithotripsy for coral reef aorta: a case report.

Eur Heart J Case Rep 2021 Apr 14;5(4):ytab102. Epub 2021 Apr 14.

Smt. NHL Municipal Medical College, Ahmedabad 380006, India.

Background: The coral reef aorta (CRA) is a rare disease of extreme calcification in the juxtarenal aorta. These heavily calcified exophytic plaques grow into the lumen and can cause significant stenoses, leading to visceral ischaemia, renovascular hypertension, and claudication. Surgery or percutaneous intervention with stenting carries a high risk of complications and mortality. Read More

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Research on an Identification Method for Gas Disaster Risk Based on the Selective Ensemble Classification Model.

ACS Omega 2021 Jun 25;6(22):14059-14067. Epub 2021 May 25.

Department of Computer Science and Technology, Xi'an University of Science and Technology, Yanta Road, Xi'an 710054, China.

To improve the accuracy of gas disaster risk identification, a selective ensemble classification model is proposed based on clustering selection and a new degree of combination fitness (CS-NDCF). First, nine base classifiers for gas disasters are constructed on the training data set, including the backpropagation (BP) neural network classifier, naive Bayes (NB) classifier, -nearest neighbor (KNN) classifier, logistic regression (LR) classifier, decision tree (DT) classifier, support vector machine (SVM) classifier, SVM classifier with cross-validation (SVMCV), random forest (RF) classifier, and gradient boosting DT (GBDT) classifier. Second, the -means clustering algorithm is used to cluster the base classifiers according to their classification performance. Read More

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Zoantharian Endosymbiont Community Dynamics During a Stress Event.

Front Microbiol 2021 28;12:674026. Epub 2021 May 28.

Molecular Invertebrate Systematics and Ecology Laboratory, Department of Chemistry, Biology, and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Japan.

Coral reefs are complex ecosystems composed of many interacting species. One ecologically important group consists of zoantharians, which are closely related to reef-building corals. Like corals, zoantharians form mutualistic symbioses with dinoflagellate micro-algae (family Symbiodiniaceae), but their associations remain underexplored. Read More

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Differential Impacts of Water Table and Temperature on Bacterial Communities in Pore Water From a Subalpine Peatland, Central China.

Front Microbiol 2021 28;12:649981. Epub 2021 May 28.

State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.

The level of water table and temperature are two environmental variables shaping soil bacterial communities, particularly in peatland ecosystems. However, discerning the specific impact of these two factors on bacterial communities in natural ecosystems is challenging. To address this issue, we collected pore water samples across different months (August and November in 2017 and May 2018) with a gradient of water table changes and temperatures at the Dajiuhu peatland, Central China. Read More

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Edge-enhancing gradient echo with multi-image co-registration and averaging (EDGE-MICRA) for targeting thalamic centromedian and parafascicular nuclei.

Neuroradiol J 2021 Jun 13:19714009211021781. Epub 2021 Jun 13.

Department of Neurosurgery, Mayo Clinic, Florida, USA.

Background And Purpose: Deep brain stimulation of the thalamus is an effective treatment for multiple neurological disorders. The centromedian and parafascicular nuclei are recently emerging targets for multiple conditions, such as epilepsy and Tourette syndrome; however, their limited visibility on conventional magnetic resonance imaging sequences has been a major obstacle. The goal of this study was to demonstrate the feasibility of a high-resolution and high-contrast targeting sequence for centromedian-parafascicular deep brain stimulation using a recently described magnetic resonance imaging sequence, three-dimensional edge-enhancing gradient echo. Read More

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Evaluation of DNA damage and stress in wildlife chronically exposed to low-dose, low-dose rate radiation from the Fukushima Dai-ichi Nuclear Power Plant accident.

Environ Int 2021 Jun 10;155:106675. Epub 2021 Jun 10.

Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1618, USA.

The health effects associated with chronic low-dose, low-dose rate (LD-LDR) exposures to environmental radiation are uncertain. All dose-effect studies conducted outside controlled laboratory conditions are challenged by inherent complexities of ecological systems and difficulties quantifying dose to free-ranging organisms in natural environments. Consequently, the effects of chronic LD-LDR radiation exposures on wildlife health remain poorly understood and much debated. Read More

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Core-Peripheral Temperature Gradient and Skin Temperature as Predictors of Major Adverse Events Among Postoperative Pediatric Cardiac Patients.

J Cardiothorac Vasc Anesth 2021 May 18. Epub 2021 May 18.

Department of Pediatric Intensive Care Unit, The Royal Children's Hospital, Melbourne, Victoria, Australia.; Department of Pediatrics, University of Melbourne, Melbourne, Victoria, Australia.; Murdoch Children's Research Institute, Melbourne, Victoria, Australia.

Objective: During episodes of low cardiac output, sympathetic neurohumoral responses with peripheral vasoconstriction result in an increase in the core-peripheral temperature gradient (CPTG). However, assessment of CPTG as a surrogate of low cardiac output and a predictor of outcomes in pediatric cardiac patients rarely has been performed. In this retrospective study, the authors assessed the prognostic abilities of CPTG, skin temperature, and serum lactate level for predicting clinical outcomes. Read More

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Quantitative Susceptibility Mapping for Staging Acute Cerebral Hemorrhages: Comparing the Conventional and Multiecho Complex Total Field Inversion magnetic resonance imaging MR Methods.

J Magn Reson Imaging 2021 Jun 11. Epub 2021 Jun 11.

Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.

Background: The perceived acuity of intracerebral hemorrhage (ICH) impacts the management of patients, both within emergent and outpatient/urgent settings. Morphology enabled dipole inversion (MEDI) quantitative susceptibility imaging (QSM) has improved characterization of ICH acuity, despite outstanding limitations in distinguishing blood products.

Purpose/hypothesis: Using improved susceptibility quantification, novel postprocessing QSM method from multiecho complex total field inversion (mcTFI) may better discriminate between acute and subacute ICH, compared to MEDI. Read More

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Engineering of stealth (maghemite/PLGA)/chitosan (core/shell)/shell nanocomposites with potential applications for combined MRI and hyperthermia against cancer.

J Mater Chem B 2021 Jun 11. Epub 2021 Jun 11.

Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Granada, Granada, Spain. and Institute of Biopathology and Regenerative Medicine (IBIMER), Center of Biomedical Research (CIBM), University of Granada, Granada, Spain and Biosanitary Research Institute of Granada (ibs.GRANADA), Andalusian Health Service (SAS), University of Granada, Granada, Spain.

(Maghemite/poly(d,l-lactide-co-glycolide))/chitosan (core/shell)/shell nanoparticles have been prepared reproducibly by nanoprecipitation solvent evaporation plus coacervation (production performance ≈ 45%, average size ≈ 325 nm). Transmission electron microscopy, energy dispersive X-ray spectroscopy, electrophoretic determinations, and X-ray diffraction patterns demonstrated the satisfactory embedment of iron oxide nanocores within the solid polymer matrix and the formation of an external shell of chitosan in the nanostructure. The adequate magnetic responsiveness of the nanocomposites was characterized in vitro by hysteresis cycle determinations and by visualization of the nanosystem under the influence of a 0. Read More

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Maturation of the Na,K-ATPase in the Endoplasmic Reticulum in Health and Disease.

J Membr Biol 2021 Jun 10. Epub 2021 Jun 10.

Department of Internal Medicine, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus Liebig University, Klinikstrasse 33, 35392, Giessen, Germany.

The Na,K-ATPase establishes the electrochemical gradient of cells by driving an active exchange of Na and K ions while consuming ATP. The minimal functional transporter consists of a catalytic α-subunit and a β-subunit with chaperon activity. The Na,K-ATPase also functions as a cell adhesion molecule and participates in various intracellular signaling pathways. Read More

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Extensive cone-dependent spectral opponency within a discrete zone of the lateral geniculate nucleus supporting mouse color vision.

Curr Biol 2021 Jun 2. Epub 2021 Jun 2.

Centre for Biological Timing, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK. Electronic address:

Color vision, originating with opponent processing of spectrally distinct photoreceptor signals, plays important roles in animal behavior. Surprisingly, however, comparatively little is understood about color processing in the brain, including in widely used laboratory mammals such as mice. The retinal gradient in S- and M-cone opsin (co-)expression has traditionally been considered an impediment to mouse color vision. Read More

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Development of a Web-Based Ensemble Machine Learning Application to Select the Optimal Size of Posterior Chamber Phakic Intraocular Lens.

Transl Vis Sci Technol 2021 May;10(6)

B&VIIT Eye Center, Seoul, South Korea.

Purpose: Selecting the optimal lens size by predicting the postoperative vault can reduce complications after implantation of an implantable collamer lens with a central-hole (ICL with KS-aquaport). We built a web-based machine learning application that incorporated clinical measurements to predict the postoperative ICL vault and select the optimal ICL size.

Methods: We applied the stacking ensemble technique based on eXtreme Gradient Boosting (XGBoost) and a light gradient boosting machine to pre-operative ocular data from two eye centers to predict the postoperative vault. Read More

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Plant-plant co-occurrences under a complex land-use gradient in a temperate forest.

Oecologia 2021 Jun 10. Epub 2021 Jun 10.

Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba and CONICET, Córdoba, Argentina.

Land-use generates multiple stress factors, and we need to understand their effects on plant-plant interactions to predict the consequences of land-use intensification. The stress-gradient hypothesis predicts that the relative strength of positive and negative interactions changes inversely under increasing environmental stress. However, the outcome of interactions also depends on stress factor's complexity, the scale of analysis, and the role of functional traits in structuring the community. Read More

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