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1.
Water Res ; 257: 121680, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38692261

RESUMEN

Diversion input lakes usually have a low catchment area/lake area ratio and pulsing pollution input. Various pollutants might accumulate in the lake continuously owing to the concentration effect under high evaporation but low precipitation over the entire area, typically for sedimentary cyclic elements such as phosphorus (P). However, the detailed transportation, sedimentation, and internal release mechanisms of P in the diversion input lakes remain unclear. This study conducted a year-long investigation of the littoral wetlands and open water areas of the shallow Lake Hengshui in the semi-humid region of North China. Results revealed that the average total P concentrations in the water and surficial sediment reached as high as 0.202 mg L-1 and 878.21 mg kg-1 in summer. The high water P levels in the lake were mainly regulated by the high internal P loading during summer and autumn, with the internal P loading being approximately nine times the external P loading. The littoral wetland area serves as a higher sedimentation sink and release source of P than the open water area. The concentrated P was continuously transported to the littoral wetland area through detritus burial, coprecipitation, and deposition of suspended particles. The release of P was mainly controlled by the dissolution of redox-sensitive Fe-P and Org-P at high temperatures and organic matter mineralization in the sediment, accompanied by the potential release capacity of apatite P (Ca-P). Future management of eutrophication and P levels in similar diversion input lakes should pay more attention to the high internal P loading in the sediment and the differentiated sedimentation and release processes in the littoral wetland and open water areas.

2.
BMC Prim Care ; 25(1): 119, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38641795

RESUMEN

BACKGROUND: Children and adolescents with complex medical issues need home care services; however, few studies have provided insight into the unmet home care needs of the families of patients with osteogenesis imperfecta (OI). In this study, we aimed to assess the home care needs of caregivers of children and adolescents with OI and the associated factors. METHODS: A self-administered questionnaire was administered online to 142 caregivers of patients with OI aged 3-17 years between May and October 2022 from 25 provinces in China. The questionnaire comprised 15 questions on demographic variables and 14 questions on home care needs. Chi-square analysis was used to compare group differences for categorical variables. Multivariate binary logistic regression analysis was conducted to examine predictors of caregivers' home care needs. RESULTS: The study findings indicated that 81.5% of caregivers had high home care needs. The three leading types of home care needs were helping the child carry out physical fitness recovery exercises at home (72.5%), understanding precautions regarding treatment drugs (72.5%), and relieving the child's pain (70.4%). OI patients' poor self-care ability (adjusted odds ratio = 5.9, 95% confidence interval = 1.8-19.0) was related to caregivers' high level of home care needs. CONCLUSIONS: The findings of this study suggest that future scientific research and nursing guidance should focus on OI patients' physical training, medication management, pain relief, fracture prevention, and treatment. In addition, caregivers of patients with poor self-care ability should receive special attention in the development of interventions. This study can help with addressing the unmet home care needs of caregivers of children and adolescents with OI. It is vital to develop a personalized intervention plan based on patients' self-care ability.


Asunto(s)
Servicios de Atención de Salud a Domicilio , Osteogénesis Imperfecta , Niño , Humanos , Adolescente , Cuidadores , Estudios Transversales , Osteogénesis Imperfecta/terapia , Evaluación de Necesidades , Encuestas y Cuestionarios , Dolor
3.
Sci Total Environ ; 914: 169924, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38199381

RESUMEN

Nitrogen (N) and phosphorus (P) are common limiting elements for terrestrial ecosystem productivity. Understanding N-P nutrient limitations patterns is crucial for comprehending variations in productivity within terrestrial ecosystems. However, the global nutrient limitation patterns of woody plants, that dominate forests, especially across different functional types, remain unclear. Here, we compiled a global dataset of leaf N and P concentrations and resorption efficiency (NRE and PRE) to explore latitudinal nutrient limitation patterns in natural woody plants and their environmental drivers. Based on published fertilization experiments, we compiled another global woody plant nutrient database to validate such identified patterns. The results showed that with increasing latitude, the relative P vs N resorption efficiency (PRE minus NRE) and the N and P ratio decreased in woody plant leaves, suggesting that the nutrient status of woody plants shifts from P to N limitation as latitude increases, with a switching point of N-P balance occurring at mid-latitudes (42.9°-43.6°). Different functional types exhibited similar trends, but with different switching latitudes of N vs P limitation. Due to the lower N uptake capacity of broadleaves than conifers, broadleaves reached N-P balance at lower latitudes (39.6°-43.3°) than conifers (57.1°-59.1°) in both hemispheres. Data from fertilization experiments successfully identified 81 % of the N limitation cases and 91 % of the P limitation cases identified using the first database. N and P limitation cases for conifers and broadleaves were also well identified separately. The latitudinal nutrient limitations in global woody plants are primarily shaped by climate and soil. Our study demonstrates the switching latitudes of N vs P limitation which varies between broadleaves and conifers. These findings enhance our understanding of plant nutrient dynamics in global climate change and aid in refining forest management.


Asunto(s)
Tracheophyta , Árboles , Ecosistema , Nitrógeno/análisis , Fósforo , Plantas , Hojas de la Planta/química , Suelo
4.
New Phytol ; 241(3): 1088-1099, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37991013

RESUMEN

Stoichiometric rules may explain the allometric scaling among biological traits and body size, a fundamental law of nature. However, testing the scaling of elemental stoichiometry and growth to size over the course of plant ontogeny is challenging. Here, we used a fast-growing bamboo species to examine how the concentrations and contents of carbon (C), nitrogen (N) and phosphorus (P), relative growth rate (G), and nutrient productivity scale with whole-plant mass (M) at the culm elongation and maturation stages. The whole-plant C content vs M and N content vs P content scaled isometrically, and the N or P content vs M scaled as a general 3/4 power function across both growth stages. The scaling exponents of G vs M and N (and P) productivity in newly grown mass vs M relationships across the whole growth stages decreased as a -1 power function. These findings reveal the previously undocumented generality of stoichiometric allometries over the course of plant ontogeny and provide new insights for understanding the origin of ubiquitous quarter-power scaling laws in the biosphere.


Asunto(s)
Fósforo , Plantas , Desarrollo de la Planta , Tamaño Corporal , Nitrógeno
5.
Chemosphere ; 340: 139821, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37586490

RESUMEN

The long-term effects of oxytetracycline (OTC) with a high concentration on the anaerobic ammonium oxidation (Anammox) process were evaluated, and the role of static magnetic field (SMF) was further explored. The stress of OTC at 50 mg/L had little effect on the nitrogen removal of anammox process at the first 16 days. With the continuous addition of OTC and the increase of nitrogen loading, the OTC inhibited the nitrogen removal and anammox activity severely. During the 32 days of recovery period without OTC addition, the nitrogen removal was further deteriorated, indicating the inhibition of OTC on anammox activity was irreversible and persistent. The application of SMF alleviated the inhibition of OTC on anammox to some extent, and the specific anammox activity was enhanced by 47.1% compared to the system without SMF during the OTC stress stage. Antibiotic efflux was the major resistance mechanism in the anammox process, and tetA, tetG and rpsJ were the main functional antibiotic resistance genes. The addition of OTC weakened the metabolic interactions between the anammox bacteria and the symbiotic bacteria involved in the metabolism of cofactors and secondary metabolites, leading to the poor anammox activity. The adaptability of microbes to the OTC stress was improved by the application of SMF, which can enhance the metabolic pathways related to bacterial growth and resistance to environmental stress.


Asunto(s)
Compuestos de Amonio , Oxitetraciclina , Oxitetraciclina/farmacología , Oxidación Anaeróbica del Amoníaco , Oxidación-Reducción , Antibacterianos/farmacología , Bacterias/metabolismo , Anaerobiosis , Nitrógeno/metabolismo , Reactores Biológicos/microbiología
6.
J Neuroinflammation ; 20(1): 178, 2023 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-37516843

RESUMEN

BACKGROUND: Brain microglia and macrophages (Mi/MΦ) can shift to a harmful or advantageous phenotype following an ischemic stroke. Identification of key molecules that regulate the transformation of resting Mi/MΦ could aid in the development of innovative therapies for ischemic stroke. The transcription factor signal transducer and activator of transduction 1 (STAT1) has been found to contribute to acute neuronal death (in the first 24 h) following ischemic stroke, but its effects on Mi/MΦ and influence on long-term stroke outcomes have yet to be determined. METHODS: We generated mice with tamoxifen-induced, Mi/MΦ-specific knockout (mKO) of STAT1 driven by Cx3cr1CreER. Expression of STAT1 was examined in the brain by flow cytometry and RNA sequencing after ischemic stroke induced by transient middle cerebral artery occlusion (MCAO). The impact of STAT1 mKO on neuronal cell death, Mi/MΦ phenotype, and brain inflammation profiles were examined 3-5 days after MCAO. Neurological deficits and the integrity of gray and white matter were assessed for 5 weeks after MCAO by various neurobehavioral tests and immunohistochemistry. RESULTS: STAT1 was activated in Mi/MΦ at the subacute stage (3 days) after MCAO. Selective deletion of STAT1 in Mi/MΦ did not alter neuronal cell death or infarct size at 24 h after MCAO, but attenuated Mi/MΦ release of high mobility group box 1 and increased arginase 1-producing Mi/MΦ 3d after MCAO, suggesting boosted inflammation-resolving responses of Mi/MΦ. As a result, STAT1 mKO mice had mitigated brain inflammation at the subacute stage after MCAO and less white matter injury in the long term. Importantly, STAT1 mKO was sufficient to improve functional recovery for at least 5 weeks after MCAO in both male and female mice. CONCLUSIONS: Mi/MΦ-targeted STAT1 KO does not provide immediate neuroprotection but augments inflammation-resolving actions of Mi/MΦ, thereby facilitating long-term functional recovery after stroke. STAT1 is, therefore, a promising therapeutic target to harness beneficial Mi/MΦ responses and improve long-term outcomes after ischemic stroke.


Asunto(s)
Encefalitis , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Animales , Femenino , Masculino , Ratones , Inflamación , Macrófagos , Microglía
8.
J Plant Res ; 136(4): 515-525, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37055608

RESUMEN

Nutrient availability significantly regulates plant growth and metabolic functions, but whether and how the long-term exposure of ancestral plants to contrasting nutrient environments influences offspring phenotypic performance (i.e., transgenerational plasticity) remain poorly addressed. Here we conducted experimental manipulations using Arabidopsis thaliana with the ancestral plants grown in different nitrogen (N) and phosphorus (P) availabilities over eleven consecutive generations, and then examined the offspring phenotypic performance under the interactive effects of current and ancestral nutrient environments. We found that current rather than ancestral nutrient environments dominantly explained the variations in offspring plant traits (i.e., flowering time, aboveground biomass and biomass allocation fractions), suggesting the relatively weak transgenerational effects of ancestral N and P availabilities on offspring phenotypes. In contrast, increasing N and P availabilities in the offspring generation remarkably shortened the flowering time, increased the aboveground biomass, and altered biomass allocation fractions differentially among organs. Despite the overall weak transgenerational phenotypic plasticity, under the low nutrient environment, the offspring of ancestral plants from the low nutrient environment had a significantly higher fruit mass fraction than those from the suitable nutrient environment. Taken together, our findings suggest that A. thaliana exhibits a much stronger within- than trans-generational trait plasticity under contrasting nutrient availabilities, and may provide important insights into the understanding of plant adaptation and evolutionary processes under changing nutrient environments.


Asunto(s)
Arabidopsis , Fósforo , Fósforo/metabolismo , Nitrógeno/metabolismo , Fenotipo , Biomasa
9.
Brain Sci ; 13(2)2023 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-36831854

RESUMEN

For social animals, a moderate group size is greatly important to maintain their reproductive success. However, the underlying neurobiological mechanism of group size on behavior and reproduction has rarely been investigated. In this study, we examined the effects of group size (1, 2, 4 pairs of adult male and female voles raised per cage) on behavior and reproduction. Meanwhile, the mRNA expression of stress and reproduction response-related genes in male brains was detected. We found that Brandt's voles (Lasiopodomys brandtii) in the large-sized group fight more severely than those in the small-sized group. Meanwhile, male voles were more anxious than females. The average number of embryos and litters per female in the medium-sized group was significantly higher than that of large-sized group. In male voles, stress- or reproduction-response mRNA expressions were more related to final group size or final density due to death caused by fighting. Our results indicated that a moderate group size was beneficial to the reproductive output of Brandt's voles. Our study highlights the combined effects of stress- or reproduction-related gene expression or behavior in regulating the fitness of voles with different group sizes.

10.
Neurobiol Dis ; 178: 106029, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36736599

RESUMEN

Brain edema is one of the most devastating consequences of ischemic stroke. Malignant cerebral edema is the main reason accounting for the high mortality rate of large hemispheric strokes. Despite decades of tremendous efforts to elucidate mechanisms underlying the formation of ischemic brain edema and search for therapeutic targets, current treatments for ischemic brain edema remain largely symptom-relieving rather than aiming to stop the formation and progression of edema. Recent preclinical research reveals novel cellular mechanisms underlying edema formation after brain ischemia and reperfusion. Advancement in neuroimaging techniques also offers opportunities for early diagnosis and prediction of malignant brain edema in stroke patients to rapidly adopt life-saving surgical interventions. As reperfusion therapies become increasingly used in clinical practice, understanding how therapeutic reperfusion influences the formation of cerebral edema after ischemic stroke is critical for decision-making and post-reperfusion management. In this review, we summarize these research advances in the past decade on the cellular mechanisms, and evaluation, prediction, and intervention of ischemic brain edema in clinical settings, aiming to provide insight into future preclinical and clinical research on the diagnosis and treatment of brain edema after stroke.


Asunto(s)
Edema Encefálico , Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Edema Encefálico/etiología , Edema Encefálico/terapia , Encéfalo/diagnóstico por imagen , Isquemia Encefálica/terapia , Isquemia Encefálica/tratamiento farmacológico , Edema
11.
Chemosphere ; 313: 137555, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36526137

RESUMEN

Anthropogenic input of nutrient has profoundly influenced water quality and aquatic organisms, however, large and unbalanced nitrogen (N) and phosphorus (P) inputs (decoupling) can lead to a range of ecological health problems such as eutrophication. Whether and how the decoupling varies along the aquatic food chain remains poorly addressed. Here we chose an urban river ecosystem in the cosmopolis region of Beijing, with reclaimed water as the entire replenishment water source over 20 years, to demonstrate the decoupling pattern of N vs P across trophic levels. Results showed that organism C, N and P concentration increased, but N:P ratio decreased upward along the food chains, suggesting that this decoupling of N and P increased as trophic level ascends. Compared with natural freshwater ecosystem, the decoupling of N and P was aggravated in the reclaimed water river. Moreover, the homeostasis of N and P were higher at higher relative to lower trophic levels, and higher in macro-food chain relative to planktonic food chain. This study, for the first time, revealed the increasing decoupling of N vs P upward along the major food chains in an urban aquatic ecosystem, and could improve the understanding of nutrient cycling at the food chain level under human disturbance, and provide useful information for ecological restoration and eutrophication control of urban wetlands replenished with reclaimed water.


Asunto(s)
Ecosistema , Cadena Alimentaria , Humanos , Ríos , Agua Dulce , Fósforo , Nitrógeno
12.
J Hum Nutr Diet ; 36(3): 742-753, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36448617

RESUMEN

BACKGROUND: This scoping review presents existing research evidence regarding diet therapy in patients with rare diseases (RDs). METHODS: Using the five-stage scoping review framework proposed by Arksey, O'Malley and Levac, we searched the published literature in PubMed, Web of Science, Royal Society of Chemistry, China National Knowledge Infrastructure, VIP Database and Wan Fang Database from January 2010 to November 2022. We selected diet therapy studies on 121 RDs, as categorised by the National Health Commission of China in 2018. Charts for research analysis were developed and used to categorise the data. RESULTS: We ultimately included 34 diet therapy studies from 19 countries and territories for 10 RDs and 3 RD groups. RD diet therapy studies have mainly focused on inborn errors of metabolism (92.3%) and are common in Western countries. Most studies focused on diet therapy methods for RDs (44%). In addition, 29% of studies included diet therapy management, 15% included guidelines for diet therapy and 12% included the impact of diet therapy on patients. CONCLUSIONS: Current diet therapies for RDs lack specificity and present with limited characteristics. Therefore, it is necessary to expand the scope and depth of future research and explore evidence-based recommendations and new diet therapies focused on patient needs and family support to provide a reference for improving the efficacy and safety of diet therapies for RDs.


Asunto(s)
Enfermedades Raras , Proyectos de Investigación , Humanos , Enfermedades Raras/terapia , China
13.
J Integr Neurosci ; 22(6): 165, 2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38176918

RESUMEN

BACKGROUND: Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a severe complication that can arise from acute carbon monoxide poisoning (ACOP). This study aims to identify the independent risk factors associated with DEACMP and to develop a nomogram to predict the probability of developing DEACMP. METHODS: The data of patients diagnosed with ACOP between September 2015 and June 2021 were analyzed retrospectively. The patients were divided into the two groups: the DEACMP group and the non-DEACMP group. Univariate analysis and multivariate logistic regression analysis were conducted to identify the independent risk factors for DEACMP. Subsequently, a nomogram was constructed to predict the probability of DEACMP. RESULTS: The study included 122 patients, out of whom 30 (24.6%) developed DEACMP. The multivariate logistic regression analysis revealed that acute high-signal lesions on diffusion-weighted imaging (DWI), duration of carbon monoxide (CO) exposure, and Glasgow Coma Scale (GCS) score were independent risk factors for DEACMP (Odds Ratio = 6.230, 1.323, 0.714, p < 0.05). Based on these indicators, a predictive nomogram was constructed. CONCLUSIONS: This study constructed a nomogram for predicting DEACMP using high-signal lesions on DWI and clinical indicators. The nomogram may serve as a dependable tool to differentiate high-risk patients and enable the provision of personalized treatment to lower the incidence of DEACMP.


Asunto(s)
Encefalopatías , Intoxicación por Monóxido de Carbono , Humanos , Intoxicación por Monóxido de Carbono/complicaciones , Intoxicación por Monóxido de Carbono/diagnóstico por imagen , Intoxicación por Monóxido de Carbono/terapia , Estudios Retrospectivos , Nomogramas , Encefalopatías/diagnóstico por imagen , Encefalopatías/etiología , Imagen de Difusión por Resonancia Magnética
14.
Front Neurosci ; 16: 1050240, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36523433

RESUMEN

Background: Previous neuroimaging studies have mostly focused on changes in static functional connectivity in patients with chronic insomnia (CI) . Features of dynamic brain activity in patients with CI have rarely been described in detail. The present study investigated changes in dynamic intrinsic brain activity in patients with CI by dynamic fractional amplitude of low-frequency fluctuation (dfALFF) analysis. Materials and methods: A total of 30 patients with CI and 27 healthy controls (HCs) were enrolled. We compared dfALFF between these two groups, and examined the correlation between changes in dfALFF and clinical symptoms of CI. Multivariate pattern analysis was performed to differentiate patients with CI from HCs. Results: Compared with HC subjects, patients with CI showed significantly increased dfALFF in the left insula, right superior temporal gyrus, left parahippocampal gyrus, right amygdala, and bilateral posterior lobes of the cerebellum. Moreover, dfALFF values in the left insula and left parahippocampal gyrus showed a positive correlation with Pittsburgh Sleep Quality Index scores. A logistic regression model was constructed that had 96.7% sensitivity, 80.0% specificity, and 83.0% overall accuracy for distinguishing patients with CI from HCs. Conclusion: Dynamic local brain activity showed increased instability in patients with CI. The variability in dfALFF in the limbic system and brain areas related to sleep/wakefulness was associated with insomnia symptoms. These findings may provide insight into the neuropathologic basis of CI.

15.
Sci Total Environ ; 846: 157369, 2022 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-35842147

RESUMEN

Proliferation of blaNDM-1 in water and wastewater is particularly concerning because of multidrug-resistance and horizontal transfer of the gene. In the present study, a pathogenic NDM-1-positive Escherichia coli strain (named E. coli NDM-1) and the blaNDM-1 gene were treated with titanium dioxide (TiO2)/ultraviolet A (UVA) photocatalysis. Effects of catalyst dose, UVA intensity, and phosphate on bacteria and intracellular and extracellular blaNDM-1 genes were determined. With increases in TiO2 dose and UVA intensity, the inactivation rate of E. coli NDM-1 increased greatly in saline solution. However, phosphate in water hindered adsorption of bacteria to TiO2 and partly changed the TiO2 photocatalytic pathway, resulting in low degradation efficiency. Although inactivation of E. coli NDM-1 was highly efficient, TiO2/UVA photocatalysis had little effect on removal of the blaNDM-1 gene. During the 2-h photocatalytic experiments, E. coli cells decreased by 4.7-log, while the blaNDM-1 gene decreased by 0.7- ~ 1.5-log. Moreover, the degradation rate of extracellular blaNDM-1 was ~2.7 times higher than that of intracellular genes. Abundance and transformation frequency of residual blaNDM-1 genes remained high, even when bacteria were completely inactivated, indicating potential health risks. Increases in treatment time and UVA irradiation intensity are needed to remove the blaNDM-1 gene to sufficiently low levels.


Asunto(s)
Escherichia coli , beta-Lactamasas , Antibacterianos/farmacología , Bacterias , Escherichia coli/genética , Fosfatos , Titanio/farmacología , Rayos Ultravioleta , Agua , beta-Lactamasas/genética
16.
Front Zool ; 18(1): 56, 2021 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-34717666

RESUMEN

Density-dependent change in aggressive behavior contributes to the population regulation of many small rodents, but the underlying neurological mechanisms have not been examined in field conditions. We hypothesized that crowding stress and aggression-associated oxytocin (OT) and arginine vasopressin (AVP) in specific regions of the brain may be closely related to aggressive behaviors and population changes of small rodents. We analyzed the association of OT and AVP expression, aggressive behavior, and population density of Brandt's voles in 24 large semi-natural enclosures (0.48 ha each) in Inner Mongolia grassland. We tested the effects of population density on the OT/AVP system and aggressive behavior by experimentally manipulating populations of Brandt's voles in the grassland enclosures. High density was positively and significantly associated with more aggressive behavior, and increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of the voles. Our study suggests that changes in OT/AVP expression are likely a result of the increased psychosocial stress that these voles experience during overcrowding, and thus the OT/AVP system can be used as indicators of density-dependent stressors in Brandt's voles.

17.
New Phytol ; 232(4): 1648-1660, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34418102

RESUMEN

Leaf functional traits and their covariation underlie plant ecological adaptations along environmental gradients, but there is limited information on the global covariation patterns of key leaf construction traits. To explore how leaf construction traits co-vary across diverse climate and soil environmental conditions, we compiled a global dataset including cell wall mass per unit leaf mass (CWmass ), leaf carbon (C) and calcium (Ca) concentrations, and specific leaf area (SLA) for 2348 angiosperm species from 340 sites world-wide. Our results demonstrated negative correlations between leaf C and Ca concentrations and between leaf C and SLA across diverse nongraminoid angiosperms. Leaf C concentration increased with increasing mean annual temperature (MAT) and mean annual precipitation (MAP) and with decreasing soil pH and calcium carbonate (CaCO3 ) concentration, whereas leaf Ca concentration and SLA exhibited the opposite responses to these environmental variables. The covariations of leaf Ca-C and of leaf SLA-C were stronger in habitats with lower MAT and MAP, and/or higher soil CaCO3 content. This global-scale analysis demonstrates that the leaf C and Ca concentrations and SLA together govern the C and biomass investment strategies in leaves of nongraminoids. We conclude that environmental conditions strongly shape leaf construction traits and their covariation patterns.


Asunto(s)
Clima , Suelo , Carbono , Ecosistema , Hojas de la Planta
18.
Appl Opt ; 60(4): A234-A242, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690374

RESUMEN

Deep learning has recently shown great potential in computational imaging. Here, we propose a deep-learning-based reconstruction method to realize the sparse-view imaging of a fiber internal structure in holographic diffraction tomography. By taking the sparse-view sinogram as the input and the cross-section image obtained by the dense-view sinogram as the ground truth, the neural network can reconstruct the cross-section image from the sparse-view sinogram. It performs better than the corresponding filtered back-projection algorithm with a sparse-view sinogram, both in the case of simulated data and real experimental data.

19.
Integr Zool ; 16(2): 149-159, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32652776

RESUMEN

It is known that social stress could alter oxytocin (OT) and arginine-vasopressin (AVP) expression in specific regions of brains which regulate the aggressive behavior of small rodents, but the effects of density-induced social stress are still unknown. Brandt's voles (Lasiopodomys brandtii) are small herbivores in the grassland of China, but the underlying neurological mechanism of population regulation is still unknown. We tested the effects of housing density of Brandt's voles on OT/AVP system with physical contact (allowing aggression) and without physical contact (not allowing aggression) under laboratory conditions. Then, we tested the effects of paired-aggression (no density effect) of Brandt's voles on OT/AVP system under laboratory conditions. We hypothesized that high density would increase aggression among animals which would then increase AVP but reduce OT in brains of animals. Our results showed that high housing density induced more aggressive behavior. We found high-density-induced social stress (with or without physical contact) and direct aggression significantly increased expression of mRNA and protein of AVP and its receptor, but decreased expression of mRNA and protein of OT and its receptor in specific brain regions of voles. The results suggest that density-dependent change of OT/AVP systems may play a significant role in the population regulation of small rodents by altering density-dependent aggressive behavior.


Asunto(s)
Arginina Vasopresina/metabolismo , Arvicolinae/fisiología , Encéfalo/metabolismo , Aglomeración , Oxitocina/metabolismo , Agresión/fisiología , Animales , Densidad de Población , Conducta Social , Estrés Psicológico
20.
Sci Total Environ ; 744: 140888, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-32712420

RESUMEN

Global warming has exerted profound effects on terrestrial ecosystems. Soil metallic nutrients, an integrated part of soil nutrient fertility, play a significant role in the maintenance of ecosystem functions. However, how soil metallic nutrients respond to global warming remains poorly understood. Spatial observations across a temperature gradient provide a solid evidence in clarifying the long-term responses of soil metallic nutrients to global warming. But due to the collinearity between temperature and precipitation in the geographical patterns, the influence of temperature on soil metallic nutrients might be interfered by the precipitation effect. To minimize the precipitation effect, this study conducted a soil sampling over broad geographical scale along the 400 mm isohyet in China, which extends about 6000 km. Variations in soil potassium (K), calcium (Ca), magnesium (Mg) and iron (Fe) concentrations across the temperature transect were investigated. These four elements all increased until mean annual temperature (MAT) increased to about 2 °C and then decreased with increasing MAT. Temperature, soil property and vegetation type were responsible for the changes of soil metallic nutrients at MAT below 2 °C; altitude, soil property, vegetation type and soil parent material were dominant influential factors of soil metallic nutrients at MAT above 2 °C. Temperature exerted an indirect influence on soil metallic nutrients through its effects on soil property, vegetation type, rock weathering, microbial decomposition and plant growth. It could be expected based on our results that the effects of global warming on soil K, Ca, Mg and Fe might depend on local MAT. Different regions with different climates should adopt different strategies to cope with the effect of global warming on soil metallic nutrients so that ecosystems maintain stable.

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