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1.
BMC Public Health ; 24(1): 1123, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654168

RESUMO

PURPOSE: This study aimed to investigate the risk factors for liver disease comorbidity among older adults in eastern, central, and western China, and explored binary, ternary and quaternary co-morbid co-causal patterns of liver disease within a health ecological model. METHOD: Basic information from 9,763 older adults was analyzed using data from the China Health and Retirement Longitudinal Study (CHARLS). LASSO regression was employed to identify significant predictors in eastern, central, and western China. Patterns of liver disease comorbidity were studied using association rules, and spatial distribution was analyzed using a geographic information system. Furthermore, binary, ternary, and quaternary network diagrams were constructed to illustrate the relationships between liver disease comorbidity and co-causes. RESULTS: Among the 9,763 elderly adults studied, 536 were found to have liver disease comorbidity, with binary or ternary comorbidity being the most prevalent. Provinces with a high prevalence of liver disease comorbidity were primarily concentrated in Inner Mongolia, Sichuan, and Henan. The most common comorbidity patterns identified were "liver-heart-metabolic", "liver-kidney", "liver-lung", and "liver-stomach-arthritic". In the eastern region, important combination patterns included "liver disease-metabolic disease", "liver disease-stomach disease", and "liver disease-arthritis", with the main influencing factors being sleep duration of less than 6 h, frequent drinking, female, and daily activity capability. In the central region, common combination patterns included "liver disease-heart disease", "liver disease-metabolic disease", and "liver disease-kidney disease", with the main influencing factors being an education level of primary school or below, marriage, having medical insurance, exercise, and no disabilities. In the western region, the main comorbidity patterns were "liver disease-chronic lung disease", "liver disease-stomach disease", "liver disease-heart disease", and "liver disease-arthritis", with the main influencing factors being general or poor health satisfaction, general or poor health condition, severe pain, and no disabilities. CONCLUSION: The comorbidities associated with liver disease exhibit specific clustering patterns at both the overall and local levels. By analyzing the comorbidity patterns of liver diseases in different regions and establishing co-morbid co-causal patterns, this study offers a new perspective and scientific basis for the prevention and treatment of liver diseases.


Assuntos
Comorbidade , Hepatopatias , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , China/epidemiologia , População do Leste Asiático , Disparidades nos Níveis de Saúde , Hepatopatias/epidemiologia , Estudos Longitudinais , Prevalência , Fatores de Risco
2.
Opt Express ; 30(18): 32010-32018, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242271

RESUMO

The parameter-tuning stochastic resonance (SR) method can convert part of the noise energy into the signal energy to suppress the noise and amplify the signal, comparing with traditional weak periodic signal detection methods (e.g., time average method, filtering method, and correlation analysis method). In this work, the numerical calculation is conducted to find the optimal resonance parameters for applying the SR method to the wavelength modulation spectroscopy (WMS). Under the stochastic resonance state, the peak value of 2f signal (a constant concentration of CH4∼20 ppm) is effectively amplified to ∼0.0863 V, which is 3.8 times as much as the peak value of 4000-time average signal (∼0.0231 V). Although the standard deviation also increases from ∼0.0015 V(1σ) to ∼0.003 V(1σ), the SNR can be improved by 1.83 times (from ∼25.9 to ∼15.8) correspondingly. A linear spectral response of SR 2f signal peak value to raw 2f signal peak value is obtained. It suggests that the SR method is effective for enhancing photoelectric signal under strong noise background.

3.
Glob Chang Biol ; 28(13): 4110-4123, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35429206

RESUMO

The dominance of vapor pressure deficit (VPD) and soil water content (SWC) for plant water stress is still under debate. These two variables are strongly coupled and influenced by climatic drivers. The impacts of climatic drivers on the relationships between gross primary production (GPP) and water stress from VPD/SWC and the interaction between VPD and SWC are not fully understood. Here, applying statistical methods and extreme gradient boosting models-Shapley additive explanations framework to eddy-covariance observations from the global FLUXNET2015 data set, we found that the VPD-GPP relationship was strongly influenced by climatic interactions and that VPD was more important for plant water stress than SWC across most plant functional types when we removed the effect of main climatic drivers, e.g. air temperature, incoming shortwave radiation and wind speed. However, we found no evidence for a significant influence of elevated CO2 on stress alleviation, possibly because of the short duration of the records (approximately one decade). Additionally, the interactive effect between VPD and SWC differed from their individual effect. When SWC was high, the SHAP interaction value of SWC and VPD on GPP was decreased with increasing VPD, but when SWC was low, the trend was the opposite. Additionally, we revealed a threshold effect for VPD stress on GPP loss; above the threshold value, the stress on GPP was flattened off. Our results have important implications for independently identifying VPD and SWC limitations on plant productivity, which is meaningful for capturing the magnitude of ecosystem responses to water stress in dynamic global vegetation models.


Assuntos
Desidratação , Ecossistema , Humanos , Solo , Temperatura , Pressão de Vapor
4.
Environ Monit Assess ; 193(6): 332, 2021 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-33966117

RESUMO

Methionine is one of the many amino acids in the soil. In order to study the role of methionine in acidic forest soil, the effect of methionine (Met) was compared with control together with addition of ammonium (Met + A), nitrite (Met + N), and glucose (Met + C) under 60% or 90% water holding capacity (WHC), because ammonium and nitrite are important factors in nitrification, and glucose affect the heterotrophic nitrification and nitrogen immobilization. We found that methionine addition significantly reduced NO3- concentration in acidic forest soil. Compared to Met, Met + A and Met + N treatments non-significantly enhanced nitrification; however, Met + C treatment decreased NH4+ concentration which suggested that soil autotrophic and heterotrophic nitrification were limited in the presence of methionine at 60% WHC. Further, our findings of 15N-labeled treatment showed the impact and priming effect of methionine was negative for NO3- concentration and positive for N2O emission, which were observed mainly from the soil N source rather than methionine. At 90% WHC, Met + C treatment significantly lessened concentrations of NH4+ and NO3-, nonetheless improved N2O compared to Met treatment. Therefore, besides the denitrification and dissimilatory NO3- reduction to ammonia, the immobilization might be the key factor to explain this decrease in NO3- concentration at 90% WHC, while these processes were induced with the C addition. This study indicated that the positive role of amino acids in soil N cycling might be overrated.


Assuntos
Compostos de Amônio , Solo , Desnitrificação , Monitoramento Ambiental , Glucose , Metionina , Nitrificação , Nitritos , Nitrogênio
5.
Educ Technol Res Dev ; 69(1): 393-396, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33469251

RESUMO

This paper is in response to the article entitled "Open educational resources and college textbook choices: a review of research on efficacy and perceptions" (Hilton, 2016). In the article, Hilton synthesized the results of 16 studies, and proposed a statement that the decision to employ and adopt open textbooks in higher education has appeared to have financial benefits to students without decrease in their learning outcomes. This finding would strengthen credibility of open textbooks use and encourage faculty to utilize high-quality open textbooks in a post-pandemic world. However, only if teachers are willing to develop and use open textbooks can millions be saved for students and higher performance be achieved by students. Furthermore, from integrative model of behavior prediction, future research needs to probe a variety of issues relating to how teachers could be intentionally and effectively use open textbooks to empower the digital learning in the 21st century.

6.
Opt Express ; 27(4): 4014-4023, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30876024

RESUMO

A continuous-wave mid-infrared radiation from difference frequency generation by mixing a continuous-wave Ti: sapphire laser and a continuous-wave YAG laser in a 15 mm long BaGa4Se7 crystal is demonstrated for the first time. The tunable range from 3.15 to 7.92 µm was achieved by rotating the crystal to fulfill the type I phase-matching condition. A maximum DFG power of 1.41 µW was obtained at 5 µm. Meanwhile the experimental DFG power conversion efficiency was 20.2 µW/W2, with a length-normalized slope efficiency of 15.5 µW/cmW2. The conversion efficiency decreases rapidly from 50 µW/cmW2 at 3.15 µm to 1 µW/cmW2 at 7.92 µm. The wavelength acceptance bandwidth and the angular acceptance bandwidth were measured to be 16.4 cm-1 and 44' for DFG at 5.1 µm, respectively.

7.
Perfusion ; 33(8): 663-666, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29963974

RESUMO

Deep hypothermia or circulation arrest is widely used during total aortic arch replacement. However, conventional procedures have high morbidity and mortality.1 We use the "branch-first" technique2,3 combined with clamping the distal aorta, incorporating a stented elephant trunk to avoid deep hypothermia and circulation arrest. This technique brings us closer to the goal of arch surgery without cerebral or visceral circulatory arrest and the morbidity of deep hypothermia. Early results are encouraging.


Assuntos
Aorta Torácica/cirurgia , Procedimentos Cirúrgicos Cardíacos/métodos , Parada Circulatória Induzida por Hipotermia Profunda/métodos , Adulto , Idoso , Procedimentos Cirúrgicos Cardíacos/instrumentação , Procedimentos Cirúrgicos Cardíacos/mortalidade , Parada Circulatória Induzida por Hipotermia Profunda/instrumentação , Parada Circulatória Induzida por Hipotermia Profunda/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Opt Lett ; 42(19): 4012-4015, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28957185

RESUMO

A new focusing structure is proposed, consisting of periodic array air holes in silicon and based on two-dimensional (2D) photonic crystal (PC) with negative refraction and subwavelength imaging characteristics. The light radiating from a point source can form a subwavelength imaging of which the half-width reaches 0.47λ through a wedge PC. Due to the influence of the aberration and evanescent field, the symmetry plane of the image is inside the structure rather than the boundary. In addition, moving the PC by 2 µm to the left horizontally, the image moves by 3.57 µm and the half-width of each image is less than the half-wavelength in this process.

9.
Opt Lett ; 41(16): 3833-5, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27519101

RESUMO

A new two-dimensional (2D) photonic crystal (PC) structure with effective refractive index approaching -1, consisting of periodic array air holes in silicon, is proposed. The light radiated from a point source can form an image through a single wedge PC. Numerical results show that the half-width of the image reaches 0.44λ, which is lower than half of the incident wavelength. In addition, the light through the combination of two of the same PCs can also form subwavelength imaging of which the half-width reaches 0.67λ, and the image almost flipped 180° compared with a point source.

10.
Zhongguo Zhong Yao Za Zhi ; 40(1): 48-52, 2015 Jan.
Artigo em Zh | MEDLINE | ID: mdl-25993786

RESUMO

The effect of low temperature storage on dormancy breaking, sprouting and growth after planting of Tulipa edulis was studied. The results showed that starch content and activity of amylases significantly decreased during 10 weeks of cold storage, soluble protein content raised at first then decreased, and the peak appeared at the 6th week. However, total soluble sugar content which in- creased slowly at first than rose sharply and reducing sugar content increased during the storage duration. The bulbs with cold storage treatment rooted in the 6th week, which was about 2 weeks earlier than room temperature storage, but there were less new roots in the late period of storage. After stored at a low temperature, bud lengths were longer than that with room temperature treatment. Cold storage treatment could promote earlier emergence, shorten germination time, prolong growth period and improve the yield of bulb, but rarely affect the emergence rate. It was not beneficial to flowering and fruiting. The results indicated that 6-8 weeks of cold storage was deemed to be the key period of dormancy breaking preliminary.


Assuntos
Dormência de Plantas , Raízes de Plantas/crescimento & desenvolvimento , Tulipa/crescimento & desenvolvimento , Temperatura Baixa , Raízes de Plantas/química , Raízes de Plantas/fisiologia , Tulipa/química , Tulipa/fisiologia
11.
Zhonghua Yi Xue Za Zhi ; 94(15): 1176-8, 2014 Apr 22.
Artigo em Zh | MEDLINE | ID: mdl-24924719

RESUMO

OBJECTIVE: To explore the effects of varus of knee osteoarthritis (OA) on patellar position. METHODS: A total of 19 patients (27 knees) underwent the examinations of anterior-posterior, lateral knee and axis of patellar X-ray at 30°, 45°, 60° and each X-ray was measured. RESULTS: The ratio between length of patellar tendon and length of patellar, vertical distance of lower edge of patellar to tibial plateau and height of patellar, distance of lower edge of medial facet of patellar to anterior angle of tibia and height of patellar were different from normal values. Patellar moved medially during the process of bending from 30°to 60°. CONCLUSION: The patellar of knee OA patients with varus moves down and medially.


Assuntos
Genu Varum , Osteoartrite do Joelho , Patela , Idoso , Feminino , Genu Varum/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico por imagem , Patela/diagnóstico por imagem , Radiografia
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(11): 2881-6, 2014 Nov.
Artigo em Zh | MEDLINE | ID: mdl-25752024

RESUMO

The accuracy of absorption spectral parameters is very important for the trace gas measurement based on absorption spectroscopy techniques, especially for the isotopic abundance measurement of gas molecules. For some of the applications, spectral parameters listed in HITRAN database were used to retrieve the trace gas concentration. However, these parameters have uncertainty, in order to validate spectroscopic parameters near 2.0 µm of CO2 lines, which are to be used in detecting the CO2 concentration and isotopic abundance, spectra of those lines were recorded at room temperature using a distributed feed-back (DFB) diode laser. The recorded absorption spectra were fitted to Voigt profile. Line position, intensity, self-broadening coefficient and N2-broadening coefficient were deduced from those data. The results show a good consistency in comparison with those listed in HITRAN2012 database. The discrepancy of most line intensities and self-broadening coefficients are less than 2%. The CO2 concentration and Δ(13 CO2 ) in real atmosphere inside laboratory are 440 ppm and -9 per hundred respectively. These results provide a reliable basis for real time and on line detecting the CO2 concentration and Δ(13 CO2) in the wavelength range.

13.
Zhongguo Zhong Yao Za Zhi ; 39(11): 2016-8, 2014 Jun.
Artigo em Zh | MEDLINE | ID: mdl-25272833

RESUMO

The study was conducted to explore the response of growth and yield of Tulipa edulis to flower bud removal and artificial pollination. And flower bud removal and artificial pollination were carried out in the squaring period and bloom stage respectively. The morphological index and biomass indicators were determined and the yield was counted in harvest time. Result showed that flower bud removal was beneficial to the growth of T. edulis, resulting in increasing growth index, biomass as well as the yield of bulb. The diameter and dry weight of T. edulis fruit by artificial pollination were increased significantly compared with the control. Seed setting percentage increased to 100%, and the number of seed as well as the single grain weight increased by 69.03% and 16.48%, respectively, which did not significantly affect the bulb production. In conclusion, Flower bud removal treatment accelerates bulb biomass increase, so as to improve its yield. Artificial pollination raised significantly seed setting percentage, seed number as well as the single grain weight.


Assuntos
Botânica/métodos , Tulipa/crescimento & desenvolvimento , Biomassa , Flores/crescimento & desenvolvimento , Flores/fisiologia , Pólen/crescimento & desenvolvimento , Pólen/fisiologia , Polinização , Tulipa/fisiologia
14.
Biochim Biophys Acta Gen Subj ; 1868(4): 130560, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38211821

RESUMO

BACKGROUND: Polymerase chain reaction (PCR) technology and quantitative real-time PCR (qPCR) technology are widely used in clinical diagnosis and research, but amplification efficiency and sensitivity are still key problems for researchers. An increasing number of reports show that gold nanoparticles (AuNPs) can be used to improve the sensitivity and amplification efficiency of PCR. Here, we found that 60 nm gold nanoparticles with a positive charge (60 nm- Au+) can enhance the amplification efficiency of qPCR. METHODS: Mouse DNA was extracted by the alkaline lysis method. Primer 5.0 software was used to design primers and mutation primers, and the DNA fragments were obtained by the method of synthesizing plasmids. The qPCR was applied to amplify target gene fragments. RESULTS: The amplification efficiency of qPCR was improved by about 1.828 times in the experimental group with 60 nm- Au+ compared with the control group without 60 nm- Au+. The primer pair contains a specific palindromic sequence (GGATCC or ACCGGT). And 60 nm Au+ did not enhance the amplification efficiency of qPCR when the above primer was mutated. CONCLUSIONS: The primers contain special palindrome sequences (GGATCC or ACCGGT) with 60 nm- Au+ can enhance the amplification efficiency of qPCR. Therefore, it suggests a more in-depth understanding of the mechanism and function of gold nanoparticles and primer sequences. This study has presented some implications for gold nanoparticles application in the development of qPCR technology.


Assuntos
Ouro , Nanopartículas Metálicas , Animais , Camundongos , DNA , Reação em Cadeia da Polimerase em Tempo Real/métodos , Plasmídeos
15.
J Intell ; 12(6)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38921690

RESUMO

This study was to investigate the relationship between metacognition and the mathematical modeling skills of high school students, as well as the mediating role of computational thinking. A cluster sampling method was adopted to investigate 661 high school students, using the metacognition scale, computational thinking scale, and mathematical modeling skill test questions. The results showed that metacognitive knowledge and metacognitive monitoring had a direct and positive correlation with high school students' mathematical modeling skills. Additionally, the critical thinking dimension of computational thinking mediated the relationship between metacognitive knowledge, experience, monitoring, and mathematical modeling skills. These findings indicated that sufficient metacognition could improve the critical thinking of high school students' computational thinking and enhance their mathematical modeling skills.

16.
Food Chem ; 441: 138392, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38211475

RESUMO

Although wheat (Triticum aestivum L.) grain protein content is increased by shade stress, the relationship between the baking quality of wheat flour and protein composition and structure remains unclear. Here, we investigated the effects of shade stress on wheat flour protein composition and structure. The contents of the flour protein, α/ß-gliadins and disulfide and hydrogen bonds were significantly increased by shade stress. Glutenins, UPP%, and ß-sheet contents also increased, whereas that of α-helices decreased. Spearman correlations revealed that the flour protein content, Glu:Gli ratio, and disulfide, hydrogen, and ionic bonds can predict the specific volume and number of crumb cells in bread, whereas α/ß-gliadins content can predict the crumb cell wall thickness and diameter of bread. Under shade stress, variations in protein composition and structure help increase the specific volume and crumb cells number and decrease crumb cell wall thickness and diameter of bread, ultimately leading to improved baking quality.


Assuntos
Proteínas de Grãos , Triticum , Triticum/química , Farinha , Gliadina , Dissulfetos , Pão
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 315: 124273, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38615417

RESUMO

Rosmarinic acid (RA), Tanshinone IIA (Tan IIA), and Salvianolic acid B (Sal B) are crucial compounds found in Salvia miltiorrhiza. Quickly predicting these components can aid in ensuring the quality of S. miltiorrhiza. Spectral preprocessing and variable selection are essential processes in quantitative analysis using near infrared spectroscopy (NIR). A novel hybrid variable selection approach utilizing iVISSA was employed in this study to enhance the quantitative measurement of RA, Tan IIA, and Sal B contents in S. miltiorrhiza. The spectra underwent 108 preprocessing approaches, with the optimal method being determined as orthogonal signal correction (OSC). iVISSA was utilized to identify the intervals (feature bands) that were most pertinent to the target chemical. Various methods such as bootstrapping soft shrinkage (BOSS), competitive adaptive reweighted sampling (CARS), genetic algorithm (GA), variable combination population analysis (VCPA), successive projections algorithm (SPA), iteratively variable subset optimization (IVSO), and iteratively retained informative variables (IRIV) were used to identify significant feature variables. PLSR models were created for comparison using the given variables. The results fully demonstrated that iVISSA-SPA calibration model had the best comprehensive performance for Tan IIA, and iVISSA-BOSS had the best comprehensive performance for RA and Sal B, and correlation coefficients of cross-validation (R2cv), root mean square errors of cross-validation (RMSECV), correlation coefficients of prediction (R2p), and root mean square errors of prediction (RMSEP) were 0.9970, 0.0054, 0.9990 and 0.0033, 0.9992, 0.0016, 0.9961 and 0.0034, 0.9998, 0.0138, 0.9875 and 0.1090, respectively. The results suggest that NIR spectroscopy, along with PLSR and a hybrid variable selection method using iVISSA, can be a valuable tool for quickly quantifying RA, Sal B, and Tan IIA in S. miltiorrhiza.


Assuntos
Abietanos , Algoritmos , Benzofuranos , Cinamatos , Depsídeos , Ácido Rosmarínico , Salvia miltiorrhiza , Espectroscopia de Luz Próxima ao Infravermelho , Salvia miltiorrhiza/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Depsídeos/análise , Abietanos/análise , Benzofuranos/análise , Cinamatos/análise , Análise dos Mínimos Quadrados
18.
Front Plant Sci ; 15: 1344972, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38425798

RESUMO

Over the past several decades, a decreasing trend in solar radiation has been observed during the wheat growing season. The effects of shade stress on grain yield formation have been extensively studied. However, little information on shade stress's effects on protein formation warrants further investigation. Two wheat cultivars were grown under three treatments, no shade as the control group (CK), shading from the joint to the anthesis stage (S1), and shading from the joint to the mature stage (S2), to investigate the effects of shade stress on the free amino acids of the caryopsis and endosperm and protein accumulation during grain filling. The dry mass of caryopsis and endosperm was significantly decreased under shade stress, whereas Glu, Ser, Ala, and Asp and protein relative content increased during grain filling. The observed increases in total protein in S1 and S2 were attributed to the increases in the SDS-isoluble and SDS-soluble protein extracts, respectively. S1 improved polymer protein formation, but S2 delayed the conversion of albumins and globulins into monomeric and polymeric proteins. Moreover, shade stress increased the proportion of SDS-unextractable polymeric protein, which represented an increase in the degree of protein polymerization. The polymerization of protein interrelations between protein components and accumulation in caryopsis and endosperm provided novel insights into wheat quality formation under shade stress.

19.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1293-1300, 2024 May.
Artigo em Zh | MEDLINE | ID: mdl-38886428

RESUMO

Reductive soil disinfestation (RSD) is an effective method for remediating degraded facility vegetable soils. However, the effectiveness of RSD using green manure as a carbon source in the field has not yet been clarified. We investigated the effects of RSD and organic fertilizer application on soil microbial community composition, diversity, and stability in a degraded facility vegetable soil. There were six treatments, including no fertilization (CK), no fertilization and soil flooded and mulched with plastic film (FF), soil amended with chicken manure (OM), soil amended with chicken manure and flooded and mulched with plastic film (OMR), soil amended with Sesbania cannabina (TF), and soil amended with S. cannabina and flooded and mulched with plastic film (TR). The results showed that the OMR and TR treatments significantly decreased bacterial Chao1 index, altered bacterial and fungal community structure, and increased the relative abundances of Bacillus, Rhodococcus, Clostridium, and Penicillium. The TR treatment significantly reduced the relative abundance of Fusarium. Results of redundancy analysis and Mantel test analysis suggested that soil ammonium nitrogen and dissolved organic carbon contents were the key factors influencing bacterial community composition, and soil pH was the key factor affecting fungal community composition. Results of cohesion analysis showed that the OMR and TR treatments significantly improved bacterial community stability, and that there was no difference between OMR and TR treatments. The TR treatment enhanced fungal community stability, which was significantly higher than the OMR treatment. Therefore, the RSD with green manure as carbon source could be effective remediation practice to improve soil health.


Assuntos
Fertilizantes , Esterco , Microbiologia do Solo , Solo , Verduras , Solo/química , Verduras/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Bactérias/classificação , Bactérias/metabolismo , Microbiota , Compostos Orgânicos/análise , Fungos/crescimento & desenvolvimento
20.
Nat Commun ; 15(1): 4826, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844502

RESUMO

During extensive periods without rain, known as dry-downs, decreasing soil moisture (SM) induces plant water stress at the point when it limits evapotranspiration, defining a critical SM threshold (θcrit). Better quantification of θcrit is needed for improving future projections of climate and water resources, food production, and ecosystem vulnerability. Here, we combine systematic satellite observations of the diurnal amplitude of land surface temperature (dLST) and SM during dry-downs, corroborated by in-situ data from flux towers, to generate the observation-based global map of θcrit. We find an average global θcrit of 0.19 m3/m3, varying from 0.12 m3/m3 in arid ecosystems to 0.26 m3/m3 in humid ecosystems. θcrit simulated by Earth System Models is overestimated in dry areas and underestimated in wet areas. The global observed pattern of θcrit reflects plant adaptation to soil available water and atmospheric demand. Using explainable machine learning, we show that aridity index, leaf area and soil texture are the most influential drivers. Moreover, we show that the annual fraction of days with water stress, when SM stays below θcrit, has increased in the past four decades. Our results have important implications for understanding the inception of water stress in models and identifying SM tipping points.


Assuntos
Ecossistema , Solo , Água , Solo/química , Água/metabolismo , Temperatura , Transpiração Vegetal/fisiologia , Plantas/metabolismo , Desidratação , Folhas de Planta/fisiologia , Clima , Chuva , Aprendizado de Máquina
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