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Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystems 2024年第1期11卷 110-119页

作者： J.Touche C.Calvaruso p.De Donato M.-p.Turpault INRAE BEFF-54000NancyFrance UMR 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly *** experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim was to identify potential nutritional consequences of droughts for *** nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(p)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree *** calcium(Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

Wind energy feasibility and wind turbine selection studies for the city Surat,India

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Clean Energy 2024年第3期8卷 166-173页

作者： Arshi Banu p S Maanat Bhadani Hindustan Institute of Technology and Science ChennaiIndia The Doon School UttarakhandDehradunIndia

Wind energy represents a clean,abundant and cost-effective power source,fostering job growth and environmental *** wind energy harnesses several gigawatts today,its availability hinges on diverse factors,with geographical location standing *** turbines,with varying capacity ranges,saturate the *** site-specific suitability and matching the appropriate turbine to meet specific requirements are of paramount *** study aims to assess the feasibility of wind energy in Surat,Gujarat,India and select an optimal small commercial turbine for residential *** research involves Rayleigh and Weibull probability distribution functions based on yearlong velocity *** distributions are fitted with actual data,revealing the most probable velocity(v_(mf)=3 m/s)and velocity at maximum power(v_(pmax)=5 m/s).The power availability of the site has been assessed as 42.6 W/m^(2)using both graphical and analytical *** commercial turbines have been shortlisted based on on-site power criteria and their specifications are evaluated against site power availability.A comparative analysis culminates in identifying the most suitable turbine for the *** best suitable turbine for the site with an annual energy yield of 8 MW has been suggested amongst selected turbines for small-scale residential applications.

关键词： site feasibility wind energy commercial wind turbine probability distribution function rated power

Stress granules: friend or foe in neurodegenerative disorders?

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Neural Regeneration Research 2024年第2期19卷 403-404页

作者： Shanshan Xu Nico p.Dantuma Department of Cell and Molecular Biology(CMB) Karolinska InstitutetSolnavägen 9S-17165 StockholmSweden

Neurodegenerative diseases,such as Alzheimer’s disease,parkinson’s disease,and amyotrophic lateral sclerosis,despite the diversity in clinical symptoms,share a striking feature at the cellular level:the accumulation of insoluble aggregates of misfolded proteins that are sequestered in intraneuronal inclusion *** mutations in disease-associated proteins that render them aggregation-prone,the decline of protein homeostasis(***)with aging is also believed to be a contributing factor to the accumulation of protein aggregates.

关键词： degenerative homeostasis clinical

Unveiling the culprit:the fusobacterium lineage that populates colorectal cancer

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Signal Transduction and Targeted Therapy 2024年第6期9卷 2349-2350页

作者： Johannes Betge Matthias p.Ebert Department of Medicine Ⅱ Medical Faculty MannheimHeidelberg UniversityMannheimGermany Junior Clinical Cooperation Unit Translational Gastrointestinal Oncology and preclinical Models German Cancer Research Center(DKFZ)HeidelbergGermany DKFZ Hector Cancer Institute at University Medical Center MannheimGermany MMpU Microbiota Drug Metabolism and Cancer Therapy European Molecular Biology LaboratoryHeidelbergGermany

In a recent study published in Nature,Zepeda-Rivera et al.1 discovered that one distinct clade of Fusobacterium nucleatum animalis(Fna)dominates the colorectal cancer(CRC)tumor *** work unravels a more precise understanding of a major bacterial species associated with CRC progression,thereby establishing a new focus for future studies,which may aid to develop improved microbiome-based diagnostics and treatments(Fig.1).

关键词： colorectal al. cancer

proteins as nanomagnets and magnetoreceptors

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Zoological Research 2024年第4期45卷 831-832页

作者： p.J.Hore Department of Chemistry University of OxfordUK

It is an appealing notion that a protein molecule could act as a nanomagnet.A genetically encodable biomolecule with a permanent magnetic moment at room temperature could have a range of applications:a magnetogenetic actuator,a magnetic tag for purifying and immobilizing enzymes,a contrast agent for magnetic resonance imaging,and a basis for a biomimetic magnetic sensing device,to name just a few.A magnetic protein could perhaps also function as the sensor in the magnetic compass that enables small songbirds to navigate the huge distances between their breeding and wintering *** though such possibilities may be,how realistic are they?

关键词： magnetic magnets enable

Non-participation of asymptomatic candidates in screening protocols reduces early diagnosis and worsens prognosis of colorectal cancer

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World Journal of Gastroenterology 2024年第26期30卷 3198-3200页

作者： Sergio pérez-Holanda Office of Regional Viceministry of Health Regional Viceministry of HealthOviedo 33005AsturiasSpain

The Agatsuma et al’s study shows that despite the evidence of the benefits of an early colorectal cancer(CRC)diagnosis,through screening in asymptomatic subjects,up to 50%of candidates reject this option and many of those affected are diagnosed later,in advanced *** efficacy of screening programs has been well-established for several years,which reduces the risk of CRC morbidity and mortality,without taking into account the test used for screening,or other ***,a significant proportion of patients remain unscreened,so understanding the factors involved,as well as the barriers of the population to adherence is the first step to possibly modify the participation *** barriers could include a full range of social and political aspects,especially the type of financial provision of each health *** Japan,health services are universal,and this advantageous situation makes it easier for citizens to access to these services,contributing to the detection of various diseases,including ***,the symptomatic CRC group had a lower early-stage diagnosis rate than the patients detected during follow-up for other comorbidities,and symptomatic and cancer screening groups showed similar early-stage diagnosis.

关键词： Colorectal neoplasms Cancer registry Diagnostic route Cancer screening Stage at diagnosis

The great catastrophe: causes of the permo-Triassic marine mass extinction

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National Science Review 2024年第1期11卷 37-50页

作者： paul B.Wignall David p.G.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(pid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Experimental investigation of radiative heat propagation in a simplified generic packed bed

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particuology 2024年第5期88卷 149-160页

作者： Matthias Tyslik Lukas pörtner Siegmar Wirtz Martin Schiemann Institute of Energy plant Technology Ruhr-University Bochum44780 BochumGermany

A novel test rig for the investigation of radiative heat transfer in packed beds has been developed and is introduced with representative experimental *** individual components and the calibration are *** generic packed bed is realized in a simplified way by an arrangement of parallel rods,which represent particles in *** this arrangement,electrically heated rods provide the radiation propagating through the rod array to heat the passive counterparts.A sophisticated temperature-control scheme with a large number of thermocouples and infrared-imaging provides in-depth information about heat transfer in the *** radiation intensities are determined with a Fourier-transform infrared spectroscopy,which has been modified and validated for this specific *** order to compare the influence of different surface properties of particles on the heat propagation and surface reflections,rod samples made of stainless steel and magnesium oxide are *** influence of material properties becomes clearly visible by comparing the high radiation intensities resulting from a stainless steel rod array to the same geometry built from magnesium oxide *** addition,the influence of the surface properties is particularly evident in the infrared images since the reflections are significantly higher for the stainless steel samples than for the magnesium oxide *** experimental results in the current work demonstrate the ability of the test rig to provide data with a well-defined accuracy as a validation base for numerical radiation simulations in packed beds.

关键词： Thermal radiation Spectral reflections Fourier-transform infrared spectroscopy

Constraining the variable generalized Chaplygin gas model in matter creation cosmology

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Communications in Theoretical physics 2024年第10期76卷 121-136页

作者： Yogesh Bhardwaj C p Singh Department of Applied Mathematics Delhi Technological University

We explore the variable generalized Chaplygin gas（VGCG） model in the theory of matter creation cosmology within the framework of a spatially homogeneous and isotropic flat Friedmann—Lemai tre—Robertson—Walker space-time. Matter creation cosmology is based on reinterpretation of the energy–momentum tensor in Einstein's field equations. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. The variable Chaplygin gas（VCG） is also studied as a particular solution. We use the Markov chain Monte Carlo method to constrain the free parameters of three models, namely,Lambda-Cold-Dark matter（ΛCDM）, VGCG and VCG models with and without matter creation from the latest observational data from baryon acoustic oscillations, cosmic chronometer, type Ia supernovae（pantheon） including gamma-ray bursts, quasars and the local measurement of H0from R21 data. Two different combinations of dataset provide a fairly tight constraint on the parameters of the ΛCDM, VGCG and VCG models. The present values of various cosmological parameters are obtained, which are very close to the ΛCDM model. Furthermore, we perform stability analysis, Bayesian evidence analysis and information criteria analysis for these models through studying the sound speed, Bayes factor, and Akaike information criteria（AIC） and Bayesian information criteria（BIC） selection criteria. The values of sound speed for VGCG and VCG models shows that both the models are stable. According to AIC, it is observed that VGCG and VCG models with matter creation are supported considerably less by current observations,while BIC shows that these models are not favoured by observational data.

关键词： Chaplygin gas model cosmological model dark energy matter creation