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1.
Mol Biol Evol ; 41(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38401527

RESUMO

Following invasion, insects can become adapted to conditions experienced in their invasive range, but there are few studies on the speed of adaptation and its genomic basis. Here, we examine a small insect pest, Thrips palmi, following its contemporary range expansion across a sharp climate gradient from the subtropics to temperate areas. We first found a geographically associated population genetic structure and inferred a stepping-stone dispersal pattern in this pest from the open fields of southern China to greenhouse environments of northern regions, with limited gene flow after colonization. In common garden experiments, both the field and greenhouse groups exhibited clinal patterns in thermal tolerance as measured by critical thermal maximum (CTmax) closely linked with latitude and temperature variables. A selection experiment reinforced the evolutionary potential of CTmax with an estimated h2 of 6.8% for the trait. We identified 3 inversions in the genome that were closely associated with CTmax, accounting for 49.9%, 19.6%, and 8.6% of the variance in CTmax among populations. Other genomic variations in CTmax outside the inversion region were specific to certain populations but functionally conserved. These findings highlight rapid adaptation to CTmax in both open field and greenhouse populations and reiterate the importance of inversions behaving as large-effect alleles in climate adaptation.


Assuntos
Adaptação Fisiológica , Inversão Cromossômica , Animais , Adaptação Fisiológica/genética , Clima , Temperatura , Insetos
2.
Mol Ecol ; 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277936

RESUMO

Adaptive evolution following colonization can affect the impact of invasive species. The fall webworm (FWW) invaded China 40 years ago through a single introduction event involving a severe bottleneck and subsequently diverged into two genetic groups. The well-recorded invasion history of FWW, coupled with a clear pattern of genetic divergence, provides an opportunity to investigate whether there is any sign of adaptive evolution following the invasion. Based on genome-wide SNPs, we identified genetically separated western and eastern groups of FWW and correlated spatial variation in SNPs with geographical and climatic factors. Geographical factors explained a similar proportion of the genetic variation across all populations compared with climatic factors. However, when the two population groups were analysed separately, environmental factors explained more variation than geographical factors. SNP outliers in populations of the western group had relatively stronger response to precipitation than temperature-related variables. Functional annotation of SNP outliers identified genes associated with insect cuticle protein potentially related to desiccation adaptation in the western group and genes associated with lipase biosynthesis potentially related to temperature adaptation in the eastern group. Our study suggests that invasive species may maintain the evolutionary potential to adapt to heterogeneous environments despite a single invasion event. The molecular data suggest that quantitative trait comparisons across environments would be worthwhile.

3.
Phys Chem Chem Phys ; 25(44): 30636-30643, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37933412

RESUMO

Two-dimensional (2D) ferromagnetic materials with tunable magnetocrystalline anisotropy (MCA) provide unique opportunities for developing the next-generation data-storage and information devices. Herein we systematically investigate the electronic and magnetic properties of the 1T-MX2 (M = Cr, Mn, Fe, Co; X = As, Sb) monolayers, and identify the stable 2D ferromagnets as well as their MCA energies. Notably, the results demonstrate that the biaxial strain and carrier doping effects have a significant influence on their magnetic behaviors. In addition to the robust FM states, three FM monolayers yield tunable MCA depending on the applied strain type and carrier doping values. The dominant contributions to these complicated modifications in MCA are mainly attributed to the strain or carrier doping induced alterations of specific M-derived 3d states, which in turn lead to the changes of their spin-orbit coupling (SOC) energies. These findings show effective approaches to control 2D magnetism and suggest that these 2D FM materials may be promising candidates to design highly efficient memory devices.

4.
Skin Res Technol ; 29(3): e13305, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36973985

RESUMO

BACKGROUND: Laser technology has been widely used in the treatment of hypertrophic scar (HPS). Due to the lack of effective quantitative relationship between laser doses and thermal effect of lesion tissue, the selection of laser doses in clinical laser treatment of HPS is blind, which cannot guarantee the best treatment effect. MATERIALS AND METHODS: The photothermal model of HPS was established by using finite element method. The effects of laser dose parameters such as laser energy density, pulse width, and spot diameter on the thermal effects of laser treatment were analyzed. According to tissue temperature threshold and thermal damage degree of the simulation results, the optimal laser doses of HPS were selected for the laser treatment experiments of rabbit ear HPSs to verify the rationality of the quantitative photothermal model. RESULTS: The temperature rise and thermal damage degree of HPS following laser treatment were directly correlated to the laser doses, which grew with the increase of energy density and laser pulse width. For the different spot diameters, the temperature rise decreased with the increase of spot diameter, whereas the thermal damage degree worsened with the increase of spot diameter. Both simulation and experimental results show that the optimal treatment parameters of HPS were as follows: The laser energy density was 7.5 J/cm3 , the pulse width was 4 ms, and the spot diameter was 7 mm. CONCLUSION: The laser dose parameters optimized by the photothermal model have achieved good therapeutic effects in the rabbit ear HPS, indicating that the model can be used for quantitative evaluation of laser doses before clinical treatment.


Assuntos
Cicatriz Hipertrófica , Terapia a Laser , Terapia Fototérmica , Animais , Coelhos , Cicatriz Hipertrófica/radioterapia , Cicatriz Hipertrófica/terapia , Terapia a Laser/métodos , Temperatura , Terapia Fototérmica/métodos , Temperatura Alta
5.
Phys Chem Chem Phys ; 24(35): 21470-21476, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36048558

RESUMO

The demand for ultra-compact spintronic devices with lower energy consumption and higher storage density requires two-dimensional (2D) magnetic materials with tunable magnetocrystalline anisotropy (MCA) energy. Employing first-principles calculations, we have investigated the influence of W atom adsorption and biaxial strain on the magnetic properties of layered Fe3GeTe2. We demonstrate that the adsorption mode and applied strain play a critical role in determining their MCA. The Fe3GeTe2 adsorbed with W atoms undergoes a change in spin reorientation from out-of-plane to in-plane magnetization, yielding a colossal MCA up to -13.112 erg cm-2. The dominant contribution to these unexpected changes mainly arises from the W atoms with emerged magnetism and large SOC. Moreover, our results reveal distinct strain-driven modulation behaviors of the MCA in different adsorption configurations. The underlying atomistic mechanism mainly involves the alteration of various W-derived 5d-orbital states under the strain effect, leading to competitive changes of the corresponding spin-orbit coupling energies between the spin-parallel and spin-flip channels. Our findings not only provide useful guidance in optimizing the MCA performance of 2D magnetic crystals but also highlight the potential of W-adsorbed Fe3GeTe2 in the applications of new-generation magnetic memory storage devices.

6.
Mol Ecol ; 30(17): 4204-4219, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34278603

RESUMO

Invasive species pose increasing threats to global biodiversity and ecosystems. While previous studies have characterized successful invaders based on ecological traits, characteristics related to evolutionary processes have rarely been investigated. Here we compared gene flow and local adaptation using demographic analyses and outlier tests in two co-occurring moth pests across their common native range of China, one of which (the peach fruit moth, Carposina sasakii) has maintained its native distribution, while the other (the oriental fruit moth, Grapholita molesta) has expanded its range globally during the past century. We found that both species showed a pattern of genetic differentiation and an evolutionary history consistent with a common southwestern origin and northward expansion in their native range. However, for the noninvasive species, genetic differentiation was closely aligned with the environment, and there was a relatively low level of gene flow, whereas in the invasive species, genetic differentiation was associated with geography. Genome scans indicated stronger patterns of climate-associated loci in the noninvasive species. While strong local adaptation and reduced gene flow across its native range may have decreased the invasiveness of C. sasakii, this requires further validation with additional comparisons of invasive and noninvasive species across their native range.


Assuntos
Mariposas , Animais , Ecossistema , Frutas , Fluxo Gênico , Geografia , Mariposas/genética
7.
Heredity (Edinb) ; 126(6): 942-954, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33686193

RESUMO

The fruit fly, Drosophila melanogaster, is a model species in evolutionary studies. However, population processes of this species in East Asia are poorly studied. Here we examined the population genetic structure of D. melanogaster across China. There were 14 mitochondrial haplotypes with 10 unique ones out of 23 known from around the globe. Pairwise FST values estimated from 15 novel microsatellites ranged from 0 to 0.11, with geographically isolated populations showing the highest level of genetic uniqueness. STRUCTURE analysis identified high levels of admixture at both the individual and population levels. Mantel tests indicated a strong association between genetic distance and geographical distance as well as environmental distance. Full redundancy analysis (RDA) showed that independent effects of environmental conditions and geography accounted for 62.10% and 31.58% of the total explained genetic variance, respectively. When geographic variables were constrained in a partial RDA analysis, the environmental variables bio2 (mean diurnal air temperature range), bio13 (precipitation of the wettest month), and bio15 (precipitation seasonality) were correlated with genetic distance. Our study suggests that demographic history, geographical isolation, and environmental factors have together shaped the population genetic structure of D. melanogaster after its introduction into China.


Assuntos
DNA Mitocondrial , Drosophila melanogaster , Animais , China , DNA Mitocondrial/genética , Drosophila melanogaster/genética , Variação Genética , Genética Populacional , Geografia , Haplótipos
8.
Exp Appl Acarol ; 77(4): 545-554, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30997606

RESUMO

The acaricide bifenazate acts as complex III inhibitor whereas cyenopyrafen and SYP-9625 act as complex II inhibitors. All these acaricides are commonly used to control two-spotted spider mite (TSSM), Tetranychus urticae Koch. We examined field-evolved and laboratory-selected resistance of TSSM to these three acaricides and determined cross-resistance among them. Six field populations of TSSM showed low levels of resistance to bifenazate with resistance ratios ranging from 2.20 to 10.65 compared to a susceptible strain. SYP-9625, structurally similar to cyenopyrafen, showed slightly higher activity to TSSMs but significant cross-resistance in both field populations and a laboratory-selected strain by SYP-9625. However, low levels of resistance to these two chemicals were found in field populations even when used for short time periods. Cross-resistance was not found between bifenazate and Complex II inhibitors, cyenopyrafen and SYP-9625, in both field populations and the laboratory-selected strain. Field-evolved resistance of TSSM to the tested acaricides is still low and should be delayed by the implementation of resistance management practices. Cross-resistance between cyenopyrafen and SYP-9625 is obvious, so they should not be used together in resistance management strategies based on mode of action rotation.


Assuntos
Acaricidas/farmacologia , Evolução Biológica , Resistência a Medicamentos , Tetranychidae/efeitos dos fármacos , Acrilonitrila/análogos & derivados , Acrilonitrila/farmacologia , Animais , Carbamatos/farmacologia , China , Hidrazinas/farmacologia , Pirazóis/farmacologia , Tetranychidae/fisiologia
9.
J Nat Prod ; 81(4): 768-777, 2018 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-29517238

RESUMO

Isoquinoline alkaloids possess a wide range of structural features and pharmaceutical activities and are promising drug candidates. Ten water-soluble catecholic isoquinolines were isolated from the medicinal plant Portulaca oleracea, including three new (1-3) and seven known compounds (4-10), along with the known catecholamines 11 and 12 and four other known compounds (13-16). A method of polyamide column chromatography using EtOAc-MeOH as the mobile phase was developed for the isolation of catecholic isoquinolines. Alkaloids 1-12 exhibited anti-inflammatory activities (EC50 = 18.0-497.7 µM) through inhibition of NO production in lipopolysaccharide-induced murine macrophage RAW 264.7 cells. Among these compounds, 11, 2, 5, 4, and 8 were more potent than was the positive control, 3,4-dihydroxybenzohydroxamic acid (EC50 = 82.4 µM), with EC50 values of 18.0, 18.1, 35.4, 36.3, and 58.7 µM, respectively. Additionally, at 100 µM, compounds 1-12 showed different degrees of ß2-adrenergic receptor (ß2-AR) agonist activity in the CHO-K1/GA15 cell line which stably expressed ß2-AR as detected by a calcium assay. The EC50 values of 2 and 10 were 5.1 µM and 87.9 nM, respectively.


Assuntos
Agonistas Adrenérgicos/farmacologia , Agonistas de Receptores Adrenérgicos beta 2/metabolismo , Anti-Inflamatórios/farmacologia , Isoquinolinas/farmacologia , Portulaca/química , Agonistas Adrenérgicos/química , Animais , Anti-Inflamatórios/química , Células CHO , Linhagem Celular , Cricetulus , Isoquinolinas/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Células RAW 264.7
10.
Ecotoxicology ; 27(6): 742-751, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29951794

RESUMO

Chemical control is important in the management of the tobacco whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Susceptibility of B. tabaci to insecticides may vary among different developmental stages and geographical populations. In this study, we examined toxicity of seven commonly-used insecticides to B. tabaci MED in four field populations from China. Avermectin has high level of toxicity to all stages of B. tabaci MED in all four populations. Cyantraniliprole and sulfoxaflor have high toxicity to adults. Spirotetramat, cyantraniliprole and flonicamid have high toxicity to nymphs but not adults. Acetamiprid, cyantraniliprole and sulfoxaflor have high toxicity to eggs. However, the relative toxicity of B. tabaci MED to these chemicals varied across different populations, with little consistency in population differences across developmental stages. Our findings together with some instances where LC95 values were higher than field recommended dosages indicate field-evolved resistance to insecticides (such as thiamethoxam and sulfoxaflor) and stage-specific mechanisms that will influence effective control of B. tabaci MED by insecticides.


Assuntos
Hemípteros/efeitos dos fármacos , Inseticidas/farmacologia , Animais , China , Hemípteros/crescimento & desenvolvimento , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento
11.
Exp Appl Acarol ; 76(2): 185-196, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30251067

RESUMO

The two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most serious pests of strawberry worldwide. Understanding the preference of TSSM for particular cultivars of strawberry and performance on them helps identify host-plant resistance to this pest mite. In this study, we tested preference, developmental duration, fecundity and population levels of TSSM on 14 strawberry cultivars. TSSM showed strong preference for the Chinese cultivars of Yanxiang, Baixuegongzhu, and Jingtaoxiang. Development of TSSM on the cultivars varied from 32.32 to 36.82 days; it was longest on the cultivars Hongxiutianxiang and Baixuegongzhu, and shortest on Yanxiang, Jingzangxiang, and Darselect as well as on a wild variety (Wuye). TSSM had high fecundity on the cultivars Yanxiang, Taoxun, Hongxiutianxiang, Jingzangxiang, Albion and Baixuegongzhu as well as on Wuye, whereas egg production was lowest on Sweet Charlie, Portola, Akihime, and Benihoppe. After 28 days of plant infestation with 10 pairs of adults, the cultivars Yanxiang, Taoxun, Jingzangxiang, Jingtaoxiang, and Baixuegongzhu had the highest number of mites (> 1000 per plant), whereas mite numbers on Albion and Camarosa were low. The population size of TSSM was correlated with fecundity, but no correlation was found between other preference/performance measures. Our study suggests that a rapid increase of population size of TSSM on cultivars of strawberry is related to high fecundity, and also that there are substantial differences in preference and performance across cultivars.


Assuntos
Fertilidade , Fragaria/crescimento & desenvolvimento , Herbivoria , Tetranychidae/fisiologia , Animais , Feminino , Fragaria/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Densidade Demográfica , Tetranychidae/crescimento & desenvolvimento
12.
Exp Appl Acarol ; 75(2): 143-153, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29594845

RESUMO

To develop a new control method for the two-spotted spider mite (TSSM), Tetranychus urticae, we investigated the effect of controlled atmospheres of carbon dioxide (CO2) on TSSM mortality under different concentrations and treatment periods, and evaluated the impact of treatments on seedlings of five host plants of TSSM. Egg hatching rate of TSSM was reduced to 37.7, 5.4 or 0% after 24 h treatment involving concentrations of 16.7, 33.3 or 50%, respectively. Mobile stages (nymphs and adult) of TSSM were completely controlled after 24 h treatment at concentrations higher than 33.3%. After 4 h at concentrations of 33.3 or 50%, 1st-day survival rate for all mobile stages was 45.3 or 36.0%, respectively, whereas after 8 or 16 h treatments, all values were decreased to zero. Seedlings of four major host plants of TSSM (cucumber, eggplant, rape, green peppers) were damaged to varying degrees after 24 h at the three concentrations, but strawberry, another host plant, was not damaged. Cucumber suffered the most serious damage, resulting in wilting and death. In conclusion, controlled atmospheres of CO2 can kill TSSM, particularly at high concentrations and with long treatment times. It can be used to control TSSM on strawberry, but should be used cautiously on other host plants.


Assuntos
Acaricidas , Dióxido de Carbono , Produtos Agrícolas , Tetranychidae , Controle de Ácaros e Carrapatos , Animais , Produtos Agrícolas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento
13.
Ecol Appl ; 26(4): 1211-22, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27509759

RESUMO

Accurately quantifying cropland gross primary production (GPP) is of great importance to monitor cropland status and carbon budgets. Satellite-based light-use efficiency (LUE) models and process-based terrestrial biosphere models (TBMs) have been widely used to quantify cropland GPP at different scales in past decades. However, model estimates of GPP are still subject to large uncertainties, especially for croplands. More recently, space-borne solar-induced chlorophyll fluorescence (SIF) has shown the ability to monitor photosynthesis from space, providing new insights into actual photosynthesis monitoring. In this study, we examined the potential of SIF data to describe maize phenology and evaluated three GPP modeling approaches (space-borne SIF retrievals, a LUE-based vegetation photosynthesis model [VPM], and a process-based soil canopy observation of photochemistry and energy flux [SCOPE] model constrained by SIF) at a maize (Zea mays L.) site in Mead, Nebraska, USA. The result shows that SIF captured the seasonal variations (particularly during the early and late growing season) of tower-derived GPP (GPP_EC) much better than did satellite-based vegetation indices (enhanced vegetation index [EVI] and land surface water index [LSWI]). Consequently, SIF was strongly correlated with GPP_EC than were EVI and LSWI. Evaluation of GPP estimates against GPP_EC during the growing season demonstrated that all three modeling approaches provided reasonable estimates of maize GPP, with Pearson's correlation coefficients (r) of 0.97, 0.94, and 0.93 for the SCOPE, VPM, and SIF models, respectively. The SCOPE model provided the best simulation of maize GPP when SIF observations were incorporated through optimizing the key parameter of maximum carboxylation capacity (Vcmax). Our results illustrate the potential of SIF data to offer an additional way to investigate the seasonality of photosynthetic activity, to constrain process-based models for improving GPP estimates, and to reasonably estimate GPP by integrating SIF and GPP_EC data without dependency on climate inputs and satellite-based vegetation indices.


Assuntos
Clorofila/fisiologia , Modelos Biológicos , Luz Solar , Zea mays/fisiologia , Zea mays/efeitos da radiação , Fluorescência , Estações do Ano , Fatores de Tempo
14.
Int J Appl Earth Obs Geoinf ; 46: 1-12, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27688742

RESUMO

Accurate and up-to-date information on the spatial distribution of paddy rice fields is necessary for the studies of trace gas emissions, water source management, and food security. The phenology-based paddy rice mapping algorithm, which identifies the unique flooding stage of paddy rice, has been widely used. However, identification and mapping of paddy rice in rice-wetland coexistent areas is still a challenging task. In this study, we found that the flooding/transplanting periods of paddy rice and natural wetlands were different. The natural wetlands flood earlier and have a shorter duration than paddy rice in the Panjin Plain, a temperate region in China. We used this asynchronous flooding stage to extract the paddy rice planting area from the rice-wetland coexistent area. MODIS Land Surface Temperature (LST) data was used to derive the temperature-defined plant growing season. Landsat 8 OLI imagery was used to detect the flooding signal and then paddy rice was extracted using the difference in flooding stages between paddy rice and natural wetlands. The resultant paddy rice map was evaluated with in-situ ground-truth data and Google Earth images. The estimated overall accuracy and Kappa coefficient were 95% and 0.90, respectively. The spatial pattern of OLI-derived paddy rice map agrees well with the paddy rice layer from the National Land Cover Dataset from 2010 (NLCD-2010). The differences between RiceLandsat and RiceNLCD are in the range of ±20% for most 1-km grid cell. The results of this study demonstrate the potential of the phenology-based paddy rice mapping algorithm, via integrating MODIS and Landsat 8 OLI images, to map paddy rice fields in complex landscapes of paddy rice and natural wetland in the temperate region.

15.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 38(1): 55-61, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26956857

RESUMO

OBJECTIVE: To investigate the permeation-enhancing effect of dl-linalool, d-linalool, and l-linalool on model drugs across excised rat skin and the effect of linalool on the ceramides in stratum corneum lipids. METHODS: In vitro skin permeation studies were performed with Valia-Chien diffusion cells, and the permeation samples were analyzed by high performance liquid chromatography with chiral stationary phase. Infrared spectroscopy was used to investigate the effect of linalool on stratum corneum lipids. RESULTS: When the donor vehicles added with 1% dl-linalool, 1% d-linalool, or 1% l-linalool, the steady-state skin permeation rate of naproxen was (2.47±0.63), (1.53±0.54), (1.73±0.48) µg·cm(-2)·h(-1), respectively, which is 2.49, 1.55, and 1.75 times (all P<0.05) compared with control group [(0.99±0.42)µg·cm(-2)·h(-1)], and the differences were statistically significant (all P<0.05). The permeation-enhancing effect of dl-linalool on naproxen was found significantly greater than that of d-linalool and l-linalool (both P<0.05). Compared with the control group, the stratum corneum treated with dl-linalool shifted to higher wave number on 2.09 cm(-1) of asymmetric CH2 stretching vibrations in attenuated total reflection-fourier transform infrared spectroscopy analysis. However, stratum corneum treated with d-linalool and l-linalool did not display this phenomenon. CONCLUSION: The disturbing degree of dl-linalool on stratum corneum lipids (ceramides) is different from that of linalool enantiomers, suggesting their different enhancing effect on the same drug.


Assuntos
Absorção Cutânea , Monoterpenos Acíclicos , Animais , Lipídeos , Monoterpenos , Naproxeno , Ratos , Pele , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
16.
ISPRS J Photogramm Remote Sens ; 106: 157-171, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27667901

RESUMO

Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, and estimation of greenhouse gas (methane) emissions. Paddy rice agriculture has expanded rapidly in northeastern China in the last decade, but there are no updated maps of paddy rice fields in the region. Existing algorithms for identifying paddy rice fields are based on the unique physical features of paddy rice during the flooding and transplanting phases and use vegetation indices that are sensitive to the dynamics of the canopy and surface water content. However, the flooding phenomena in high latitude area could also be from spring snowmelt flooding. We used land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to determine the temporal window of flooding and rice transplantation over a year to improve the existing phenology-based approach. Other land cover types (e.g., evergreen vegetation, permanent water bodies, and sparse vegetation) with potential influences on paddy rice identification were removed (masked out) due to their different temporal profiles. The accuracy assessment using high-resolution images showed that the resultant MODIS-derived paddy rice map of northeastern China in 2010 had a high accuracy (producer and user accuracies of 92% and 96%, respectively). The MODIS-based map also had a comparable accuracy to the 2010 Landsat-based National Land Cover Dataset (NLCD) of China in terms of both area and spatial pattern. This study demonstrated that our improved algorithm by using both thermal and optical MODIS data, provides a robust, simple and automated approach to identify and map paddy rice fields in temperate and cold temperate zones, the northern frontier of rice planting.

17.
ISPRS J Photogramm Remote Sens ; 105: 220-233, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27695195

RESUMO

Accurate and timely rice paddy field maps with a fine spatial resolution would greatly improve our understanding of the effects of paddy rice agriculture on greenhouse gases emissions, food and water security, and human health. Rice paddy field maps were developed using optical images with high temporal resolution and coarse spatial resolution (e.g., Moderate Resolution Imaging Spectroradiometer (MODIS)) or low temporal resolution and high spatial resolution (e.g., Landsat TM/ETM+). In the past, the accuracy and efficiency for rice paddy field mapping at fine spatial resolutions were limited by the poor data availability and image-based algorithms. In this paper, time series MODIS and Landsat ETM+/OLI images, and the pixel- and phenology-based algorithm are used to map paddy rice planting area. The unique physical features of rice paddy fields during the flooding/open-canopy period are captured with the dynamics of vegetation indices, which are then used to identify rice paddy fields. The algorithm is tested in the Sanjiang Plain (path/row 114/27) in China in 2013. The overall accuracy of the resulted map of paddy rice planting area generated by both Landsat ETM+ and OLI is 97.3%, when evaluated with areas of interest (AOIs) derived from geo-referenced field photos. The paddy rice planting area map also agrees reasonably well with the official statistics at the level of state farms (R2 = 0.94). These results demonstrate that the combination of fine spatial resolution images and the phenology-based algorithm can provide a simple, robust, and automated approach to map the distribution of paddy rice agriculture in a year.

18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(6): 1474-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26601350

RESUMO

Combining the spectra of could-to-ground lightning discharge processes obtained by a slit-less spectrograph with synchronous electric field information, the temperature, the conductivity, the current peak, electromagnetic power peak and the luminance of the discharge channel are calculated. The values are in a normal range reported by references. The correlation among cut-off time before a subsequent return stroke, the luminance and electromagnetic power peak of the channel is discussed. The change trends of the conductivity, the current peak and electromagnetic power peak are also investigated. The results show when cut-off time is long, neutralized charges will grow, the current will rise and electromagnetic power radiated from the channel will increase. When the conductivity and the peak of the electric field change increase simultaneously, the current in the channel will rise and electromagnetic power radiated from the channel will be greater. This work will provide some references for calculating optical and electromagnetic energy radiated by lightning discharge processes.

19.
Yao Xue Xue Bao ; 49(8): 1175-80, 2014 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-25322561

RESUMO

The purpose of this study is to investigate the enantioselectivity of norgestrel (NG) transdermal permeation and the potential influence of linalool and lipids on the enantioselectivity. In vitro skin permeation studies of NG across the excised rat skins were performed with Valia-Chien diffusion cells, and the permeation samples were analyzed by enantioselective HPLC. The possible enantioselective permeation of NG across intact rat back skin and lipids extracted rat back skin and the influence of linalool were evaluated. The skin permeation rate of dl-NG was two times higher than that of l-NG when donor solutions (EtOH/H2O 2 : 8, v/v) containing l-NG or dl-NG. It may be mainly attributed to the solubility discrepancy between enantiomer and racemate. The enantioselective permeation of dl-NG across intact rat skin was observed when the donor solutions containing dl-linalool. The permeation flux of l-NG was 22% higher than that of d-NG. But interestingly, the enantioselective permeation of dl-NG disappeared under the same experimental condition except that the lipid extracted rat skin was used. Attenuated total reflection-fourier transform infrared spectroscopy analysis of stratum corneum showed that the wave number for asymmetric CH2 stretching vibrations of lipids treated with dl-linalool was greater than that of the control. The results indicated that the enantioselective permeation of NG may be contributed by the interaction between dl-linalool and lipids. More than half of lipids were composed of ceramides. The stereospecific interaction maybe existed among chiral enhancer (linalool), lipids (ceramides) and/or chiral drugs (NG).


Assuntos
Monoterpenos/farmacologia , Norgestrel/farmacocinética , Absorção Cutânea/efeitos dos fármacos , Monoterpenos Acíclicos , Administração Cutânea , Animais , Lipídeos/farmacologia , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
20.
J Phys Chem Lett ; 15(10): 2650-2657, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38422484

RESUMO

Magnetoelectric coupling represents a significant breakthrough for next-generation electronics, offering the ability to achieve nonvolatile magnetic control via electrical means. In this comprehensive investigation, leveraging first-principles calculations, we unveil a robust magnetoelectric coupling within multiferroic heterostructures (HSs) by ingeniously integrating a non-van der Waals (non-vdW) magnetic FeTiO3 monolayer with the ferroelectric (FE) Ga2O3. Diverging from conventional van der Waals (vdW) multiferroic HSs, the magnetic states of the FeTiO3 monolayer can be efficiently toggled between ferromagnetic (FM) and antiferromagnetic (AFM) configurations by reversing the polarization of the Ga2O3 monolayer. This intriguing phenomenon arises from polarization-dependent substantial interlayer electron transfers and the interplay between superexchange and direct-exchange magnetic couplings of the iron atoms. The carrier-mediated interfacial interactions induce crucial shifts in Fermi level positions, decisively imparting distinct electronic characteristics near the Fermi level of composite systems. These novel findings offer exciting prospects for the future of magnetoelectric technology.

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