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A fundamental understanding of the underlying mechanisms involved in biological invasions is crucial to developing effective risk assessment and control measures against invasive species. The fall armyworm (FAW), Spodoptera frugiperda, is a highly invasive pest that has rapidly spread from its native Americas into much of the Eastern Hemisphere, with a highly homogeneous nuclear genetic background. However, the exact mechanism behind its rapid introduction and propagation remains unclear. Here, a systematic investigation is conducted into the population dynamics of FAW in China from 2019 to 2021 and found that FAW individuals carrying "rice" mitochondria (FAW-mR) are more prevalent (>98%) than that with "corn" mitochondria (FAW-mC) at the initial stage of the invasion and in newly-occupied non-overwintering areas. Further fitness experiments show that the two hybrid-strains of FAW exhibit different adaptions in the new environment in China, and this may have been facilitated by amino acid changes in mitochondrial-encoded proteins. FAW-mR used increases energy metabolism, faster wing-beat frequencies, and lower wing loadings to drive greater flight performance and subsequent rapid colonization of new habitats. In contrast, FAW-mC individuals adapt with more relaxed mitochondria and shuttle energetics into maternal investment, observed as faster development rate and higher fecundity. The presence of two different mitochondria types within FAW has the potential to significantly expand the range of damage and enhance competitive advantage. Overall, the study describes a novel invasion mechanism displayed by the FAW population that facilitates its expansion and establishment in new environments.
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We made separate experiments to examine life-history traits and activities of protective enzymes as affected by carbon dioxide (CO2) elevation to 780 µL/L as compared to 390 µL/L in imidacloprid- or buprofezin-resistant strains of the brown planthopper (BPH) Nilaparvata lugens. We found an interaction effect between resistance and the CO2 level on the nymphal survival and duration in both resistant strains. Nymphal durations in both resistant strains were much shorter in the resistant than susceptible BPH at 780 µL/L but similar between them or slightly shorter in the resistant than susceptible BPH at 390 µL/L. Nymphal survival was lower for imidacloprid-resistant than its susceptible BPH at 390 µL/L but higher at 780 µL/L; it stayed unaffected by the CO2 elevation in buprofezin-resistant BPH. We did not observe an interaction effect between resistance and the CO2 level on major reproductive parameters in both resistant strains. But the 2 strains were not consistent across CO2 levels in all parameters. Our measurements of protective enzyme activities of superoxide dismutase, catalase, and peroxidase showed an interaction between resistance and the CO2 level. Overall, these enzymes became similar in activity between resistant and susceptible BPH at 780 µL/L compared to 390 µL/L and the change was more distinct in the imidacloprid- than buprofezin-resistant BPH strains. Our findings suggest that CO2 elevation can affect life-history traits of insecticide-resistant BPH, while the effect may vary depending on the kind of insecticides it is resistant to.
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The fall armyworm (FAW), Spodoptera frugiperda, has colonized and caused consistent damage in the Eastern hemisphere. The identification of various FAW strains is essential for developing precise prevention and control measures. The triosephosphate isomerase (Tpi) gene is recognized as an effective marker closely linked to FAW subpopulations. However, most current studies primarily focus on the comparison of variations in specific gene sites of this gene. In this study, we conducted full-length sequencing of the Tpi genes from 5 representative FAW groups. Our findings revealed that the Tpi genes varied in length from 1220 to 1420 bp, with the primary variation occurring within 4 introns. Notably, the exon lengths remained consistent, at 747 bp, with 37 observed base variations; however, no amino acid variations were detected. Through sequence alignment, we identified 8 stable variation sites that can be used to distinguish FAW strains in the Eastern hemisphere. Additionally, we performed strain identification on 1569 FAW samples collected from 19 provinces in China between 2020 and 2021. The extensive analysis indicated the absence of the rice strain in the samples. Instead, we only detected the presence of the corn strain and the Zambia strain, with the Zambia strain being distributed in a very low proportion (3.44%). Furthermore, the corn strain could be further categorized into 2 subgroups. This comprehensive study provides a valuable reference for enhancing our understanding of FAW population differentiation and for improving monitoring and early warning efforts.
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Understanding the genetic basis of adaptive evolution following habitat expansion can have important implications for pest management. The pink rice borer (PRB), Sesamia inferens (Walker), is a destructive pest of rice that was historically restricted to regions south of 34° N latitude in China. However, with changes in global climate and farming practices, the distribution of this moth has progressively expanded, encompassing most regions in North China. Here, 3 highly differentiated subpopulations were discovered using high-quality single-nucleotide polymorphism and structural variant datasets across China, corresponding to northern, southern China regions, and the Yunnan-Guizhou Plateau, with significant patterns of isolation by geographic and environmental distances. Our estimates of evolutionary history indicate asymmetric migration with varying population sizes across the 3 subpopulations. Selective sweep analyses estimated strong selection at insect cuticle glycine-rich cuticular protein genes which are associated with enhanced desiccation adaptability in the northern group, and at the histone-lysine-N-methyltransferase gene associated with range expansion and local adaptation in the Shandong population. Our findings have significant implications for the development of effective strategies to control this pest.
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We attempt to determine the effect of the dietary switch from a native to non-native prey on the gut microbiota in the predaceous ladybird Harmonia axyridis larvae and adults and examine how the dietary effect may vary across generations. We fed H. axyridis with different diets, native aphid Megoura japonica (Matsumura) versus non-native mealybug Phenacoccus solenopsis (Tinsley), for 5 generations and sequenced microbes in the gut of the 3rd instar larvae and adults of the 1st, 3rd, and 5th generations. In addition, we identified microbes in M. japonica and P. solenopsis. The 2 prey species differed in microbial community as measured by abundances of prevalent microbial genera and diversity. In H. axyridis, abundances of some prevalent microbial genera differed between the 2 diets in the 1st and 3rd generations, but the difference disappeared in the 5th generation; this tendency is more obvious in adults than in larvae. Overall, gut microbial assemblages became gradually cohesive over generations. Microbial diversity differed between diets in the 1st and 3rd generations but became similar in the 5th generation. Major prevalent gut microbial genera are predicted to be associated with metabolic functions of H. axyridis and associated genera are more abundant for consuming the mealybug than the aphid. Our findings from this study suggest that the gut microbiota in H. axyridis is flexible in response to the dietary switch, but tends toward homogeneity in microbial composition over generations.
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The pink stem borer, Sesamia inferens (Walker), is a significant polyphagous pest historically restricted to regions south of N34° latitude. However, with changes in global climate and farming practices, the distribution of this moth has progressively exceeded its traditional limit of 34° N and encompassed most regions in North China. The genetic adaptations of S. inferens remain incompletely understood due to the lack of high-quality genome resources. Here, we sequenced the genome of S. inferens using PacBio and Hi-C technology, yielding a genome assembly of 865.04 Mb with contig N50 of 1.23 Mb. BUSCO analysis demonstrated this genome assembly has a high-level completeness of 96.1% gene coverage. In total, 459.72 Mb repeat sequences (53.14% of the assembled genome) and 20858 protein-coding genes were identified. We used the Hi-C technique to anchor 1135 contigs to 31 chromosomes, yielding a chromosome-level genome assembly with a scaffold N50 of 29.99 Mb. In conclusion, our high-quality genome assembly provided valuable resource that exploring the genetic characteristics of local adaptation and developing an efficient control strategy.
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Cromossomos , Genoma de Inseto , Mariposas , Animais , Sequência de Bases , Mariposas/genética , Filogenia , Sequências Repetitivas de Ácido NucleicoRESUMO
Introduction: The development of insecticide resistance in Spodoptera frugiperda populations is a serious threat to the crop industry. Given the spread of invasive resistant populations, prospective monitoring should be accelerated, and the development of diagnostic tools for rapid and accurate assessments of insecticide resistance is essential. Methods: First, the discriminating dose and diagnostic time of the kit were determined by the glass vial method based on a susceptible strain. Then, pests that were collected from field populations were used to determine their susceptibility to seven insecticides by using the diagnostic kit. Finally, the accuracy of the kit was verified based on correlation analyses and the likelihood of insecticide control failure was assessed. Results: Here, we describe a diagnostic kit that enables the rapid detection of resistance to chlorpyrifos, bifenthrin, deltamethrin, lambda-cyhalothrin, phoxim, chlorantraniliprole and chlorfenapyr within 1-2 h in S. frugiperda at diagnostic doses of 0.98, 0.84, 0.38, 1.64, 0.0082, 1.75 and 0.65 µg/cm2, respectively. The linear equation between mortalities under diagnostic doses and actual resistance ratios measured by the diet-overlay bioassay was determined. The high correlation indicates that the insecticide resistance levels diagnosed by the kit were consistent with the results of the diet-overlay bioassay. Moreover, we found a significant negative correlation between diagnostic mortality and the likelihood of control failure for bifenthrin (r = -0.899, p = 0.001), deltamethrin (r = -0.737, p = 0.024) and lambda-cyhalothrin (r = -0.871, p = 0.002). Discussion: The insecticide resistance diagnostic kit for S. frugiperda is a user-friendly tool (portable, short detection time). Its excellent performance qualifies the kit as a reliable screening tool for identifying effective insecticides in sustainable resistance management.
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BACKGROUND: The gut microbiota has an intimate relationship with insect hosts and this relationship can become complicated with parasitic organisms being involved with the host. To date there has been limited evidence for the relevance of parasitism of the host by parasitoids to host gut microbiota, especially in host insect predators. Here, our study examined gut microbiotas in larvae of the predaceous lady beetle, Coccinella septempunctata, in response to their parasitism by Homalotylus eytelweinii regarding the development progress of offspring parasitoids. RESULTS: Overall 58.5% of gut bacterial operational taxonomic units (OTUs) in the parasitized lady beetle were different from those in the unparasitized host. The phylum Proteobacteria abundance increased while Firmicutes decreased in parasitized hosts compared to the unparasitized. The abundance of genus Aeribacillus decreased substantially in the parasitized lady beetle across all stages of the offspring development compared to the unparasitized host. The α-diversity of the gut microbiota in a parasitized lady beetle larva increased at the early stage of offspring parasitoids and then returned over the intermediate and later stages. Analyses of ß-diversity indicated that the gut microbial community in a parasitized lady beetle was distinct from that in an unparasitized one and different between early or middle and late stages of offspring parasitoids in parasitized hosts. CONCLUSION: Our results provide evidence for the relevance of the gut microbiota to interactions between a lady beetle host and its parasitoid. Our study provides a starting point for further investigations of the role the gut microbiota may play in host-parasitoid interactions. © 2023 Society of Chemical Industry.
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Besouros , Microbioma Gastrointestinal , Vespas , Humanos , Animais , Vespas/fisiologia , Interações Hospedeiro-Parasita , LarvaRESUMO
BACKGROUND: The harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae), native to Asia, has been introduced to other major continents where it has caused serious negative impacts on local biodiversity. Though notable advances to understand its invasion success have been made during the past decade, especially with then newer molecular tools, the conclusions reached remain to be confirmed with more advanced genomic analyses and especially using more samples from larger geographical regions across the native range. Furthermore, although H. axyridis is one of the best studied invasive insect species with respect to life history traits (often comparing invasive and native populations), the traits responsible for its colonization success in non-native areas warrant more research. RESULTS: Our analyses of genome-wide nuclear population structure indicated that an eastern Chinese population could be the source of all non-native populations and revealed several putatively adaptive candidate genomic loci involved in body color variation, visual perception, and hemolymph synthesis. Our estimates of evolutionary history indicate (1) asymmetric migration with varying population sizes across its native and non-native range, (2) a recent admixture between eastern Chinese and American populations in Europe, (3) signatures of a large progressive, historical bottleneck in the common ancestors of both populations and smaller effective sizes of the non-native population, and (4) the southwest origin and subsequent dispersal routes within its native range in China. In addition, we found that while two mitochondrial haplotypes-Hap1 and Hap2 were dominant in the native range, Hap1 was the only dominant haplotype in the non-native range. Our laboratory observations in both China and USA found statistical yet slight differences between Hap1 and Hap2 in some of life history traits. CONCLUSIONS: Our study on H. axyridis provides new insights into its invasion processes into other major continents from its native Asian range, reconstructs a geographic range evolution across its native region China, and tentatively suggests that its invasiveness may differ between mitochondrial haplotypes.
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Besouros , Animais , Besouros/genética , Haplótipos , Fenótipo , Genômica , Variação Biológica da PopulaçãoRESUMO
Understanding the genetic basis of pest adaptive evolution and the risk of adaptation in response to climate change is essential for the development of sustainable agricultural practices. However, the genetic basis of climatic adaptation for the Asian corn borer (ACB), Ostrinia furnacalis, the main pest of corn in Asia and Oceania, is poorly understood. Here, we revealed the genomic loci underlying the climatic adaptation and evolution in ACB by integrating population genomic and environmental factors. We assembled a 471-Mb chromosome-scale reference genome of ACB and resequenced 423 individuals covering 27 representative geographic areas. We inferred that the ACB effective population size changes tracked with the global temperature and followed by a recent decline. Based on an integrated analysis of whole-genome selection scans and genome-wide genotype-environment association studies, we revealed the genetic basis of ACB adaption to diverse climates. For diapause traits, we identified a major effect association locus containing a circadian clock gene (period) by analyzing a diapause-segregating population. Moreover, our predictions indicated that the northern populations were more ecologically resilient to climate change than the southern populations. Together, our results revealed the genomic basis for ACB environmental adaptation and provided potential candidate genes for future evolutionary studies and genetic adaptation to climate change, intending to maintain the efficacy and sustainability of novel control techniques.
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Mariposas , Zea mays , Animais , Zea mays/genética , Metagenômica , Biodiversidade , Temperatura , Mariposas/genética , ÁsiaRESUMO
Inherited bacterial symbionts are very common in arthropods, but infection frequency can vary widely among populations. Experiments and interpopulation comparisons suggest that host genetic background might be important in explaining this variation. Our extensive field investigation showed that the infection pattern of the facultative symbiont Cardinium was heterogeneous across geographical populations of the invasive whitefly Bemisia tabaci Mediterranean (MED) in China, with genetic nuclear differences evident in 2 of the populations: 1 with a low infection rate (SD line) and 1 with a high infection rate (HaN line). However, whether the heterogeneous frequency of Cardinium is associated with the host genetic background remains poorly understood. Here, we compared the fitness of the Cardinium-infected and uninfected sublines with similar nuclear genetic backgrounds from SD and HaN lines, respectively, and further determine whether host extranuclear or nuclear genotype influenced the Cardinium-host phenotype by performing 2 new introgression series of 6 generations between SD and HaN lines (i.e., Cardinium-infected females of SD were backcrossed with uninfected males of HaN, and vice versa). The results showed that Cardinium provides marginal fitness benefits in the SD line, whereas Cardinium provides strong fitness benefits in the HaN line. Further, both Cardinium and the Cardinium-host nuclear interaction influence the fecundity and pre-adult survival rate of B. tabaci, whereas the extranuclear genotype does not. In conclusion, our results provide evidence that Cardinium-mediated fitness effects were closely associated with the host genetic background, which provides a fundamental basis for understanding the mechanism underlying the heterogeneous distribution of Cardinium in B. tabaci MED populations across China.
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Hemípteros , Rickettsia , Masculino , Feminino , Animais , Hemípteros/genética , Hemípteros/microbiologia , Simbiose , Bacteroidetes , Fertilidade/genéticaRESUMO
The sweetpotato whitefly, Bemisia tabaci species complex, comprises at least 44 morphologically indistinguishable cryptic species, whose endosymbiont infection patterns often varied at the spatial and temporal dimension. However, the effects of ecological factors (e.g., climatic or geographical factors) on the distribution of whitefly and the infection frequencies of their endosymbionts have not been fully elucidated. We, here, analyzed the associations between ecological factors and the distribution of whitefly and their three facultative endosymbionts (Candidatus Cardinium hertigii, Candidatus Hamiltonella defensa, and Rickettsia sp.) by screening 665 individuals collected from 29 geographical localities across China. The study identified eight B. tabaci species via mitochondrial cytochrome oxidase I (mtCOI) gene sequence alignment: two invasive species, MED (66.9%) and MEAM1 (12.2%), and six native cryptic species (20.9%), which differed in distribution patterns, ecological niches, and high suitability areas. The infection frequencies of the three endosymbionts in different cryptic species were distinct and multiple infections were relatively common in B. tabaci MED populations. Furthermore, the annual mean temperature positively affected Cardinium sp. and Rickettsia sp. infection frequencies in B. tabaci MED but negatively affected the quantitative distribution of B. tabaci MED, which indicates that Cardinium sp. and Rickettsia sp. maybe play a crucial role in the thermotolerance of B. tabaci MED, although the host whitefly per se exhibits no resistance to high temperature. Our findings revealed the complex effects of ecological factors on the expansion of the invasive whitefly.
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Land use in uplands is an important factor affecting water quality in its respective catchment, and its influences at the different spatial scales and configurations warrant further investigation. Here, we selected 26 catchments in the upper Han River (China) and sampled the surface water at the outlet of each catchment in four seasons during 2019. Multivariate statistics were used to identify the relationships between land use characteristics in uplands and water quality in river system. The results indicated that chemical oxygen demand (CODMn); pH; dissolved oxygen; electrical conductivity; nutrient, i.e., NH4+-N, NO3--N; and dissolved phosphorus (DP) in rivers displayed significant seasonal variations. Stepwise regression revealed that landscape metrics such as patch density, landscape shape index, and splitting index were important factors influencing water quality in rivers regardless of their spatiality and seasonality. Urban was the most frequently chosen land-use type in the best prediction models, and forest area showed a negative correlation with water quality parameters in most cases for example, DP. Overall, the influence of land use on river water quality was slightly stronger at reach scale than at catchment and riparian scales. Also, nutrients (i.e., NH4+-N, NO3--N, and DP) in rivers were primarily impacted by the land use characteristic at catchment and riparian scales. Our results suggested that multi-scale explorations would help to achieve a fully understanding on the impacts of land use on river water quality.
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Poluentes Químicos da Água , Qualidade da Água , Florestas , China , Análise da Demanda Biológica de Oxigênio , Rios/química , Fósforo/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análiseRESUMO
Sediment particle size and heterogeneity play an important role in sediment denitrification through direct and indirect effects on, for example, the material exchange rate, environmental gradients, microbial biomass, and grazing pressure. However, these effects have mostly been observed in impermeable sediments. On the other hand, the material exchange of permeable sediments is dominated by advection instead of diffusion, with the exchange or transport rates exceeding those of diffusion by two orders of magnitude relative to impermeable sediments. The impact of permeable sediment particle size and heterogeneity on denitrification remains poorly understood, especially at the millimeter scale. Here, we conducted an in situ control experiment in which we sorted sand sediment into four homogeneous-particle-sizes treatments and four heterogeneous treatments. Each treatment was deployed, in replicate, within the riffle in three different river reaches with contrasting physicochemical characteristics. After incubating for three months, sediment denitrifier communities (nirS, nirK, nosZ), denitrification gene abundances (nirS, nirK, nosZ), and denitrification rates in all treatments were measured. We found that most of the denitrifying microbes in permeable sediments were unclassified denitrifying microbes, and particle size and heterogeneity were not significantly correlated with the functional gene abundances or denitrification rates. Water chemistry was the key controlling factor for the denitrification of permeable sediments. Water NO3--N directly regulated the denitrification rate of permeable sediments, instead of indirectly regulating the denitrification rate of sediments by affecting the chemical characteristics of the sediments. Our study fills a knowledge gap of denitrification in permeable sediment in a headwater river and highlights that particle size and heterogeneity are less important for permeable sediment denitrification.
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In response to the outbreak of COVID-19, in accordance with the principles of 'unified command, early involvement, prompt review and scientific approval' as well as the requirements of ensuring product safety, effectiveness and controllable quality, the Center for Medical Device Evaluation (CMDE) has issued Key Points of Technical Review for the Registration of SARS-CoV-2 Nucleic Acid Tests (Key Points) to provide the requirements of tests. Because of the sustainability of the pandemic, more efforts and attempts are needed for SARS-CoV-2 detection and control. This article interprets the Key Points issued by the CMDE and provides certain refinements to wider audiences.
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Teste de Ácido Nucleico para COVID-19/métodos , China , Humanos , SARS-CoV-2RESUMO
Dissimilatory nitrate reduction processes, including denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA), are important pathways of nitrate transformation in the aquatic environments. In this study, we investigated potential rates of denitrification, anammox, and DNRA in the sediments of two subtropical rivers, Jinshui River and Qi River, with different intensities of human activities in their respective catchment, China. Our objectives were to assess the seasonality of dissimilatory nitrate reduction rates, quantify their respective contributions to nitrate reduction, and reveal the relationship between dissimilatory nitrate reduction rates, functional gene abundances, and physicochemicals in the river ecosystems. Our results showed higher rates of denitrification and anammox in the intensively disturbed areas in autumn and spring, and higher potential DNRA in the slightly disturbed areas in summer. Generally, denitrification, anammox, and DNRA were higher in summer, autumn, and spring, respectively. Relative contributions of nitrate reduction from denitrification, anammox, and DNRA were quite different in different seasons. Dissimilatory nitrate reduction rates and gene abundances correlated significantly with water temperature, dissolved organic carbon (DOC), sediment total organic carbon (SOC), NO3-, NH4+, DOC/NO3-, iron ions, and sulfide. Understanding dissimilatory nitrate reduction is essential for restoring nitrate reduction capacity and improving and sustaining ecohealth of the river ecosystems.
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Compostos de Amônio , Nitratos , Oxidação Anaeróbia da Amônia , Desnitrificação , Matéria Orgânica Dissolvida , Ecossistema , Humanos , Nitratos/análise , Nitrogênio/análise , Oxirredução , RiosRESUMO
In order to explore the characteristics and driving factors of the epilithic algae community in the middle and lower reaches of the Lhasa River, epilithic algae was collected and identified in September 2019, the species composition and spatial distribution were analyzed, and the key environmental factors affecting the epilithic algae community were identified through redundancy analysis. The results indicated that 31 genera of epilithic algae belonging to six phyla were identified, and the average cell density of the epilithic algae was 1.92×106 cells·m-2. The number of species and cell density of the diatom phylum were the largest at each sampling point. The species number and cell density of the epilithic algae were significantly different between the main stream and tributaries. The main stream and tributaries contained relatively small differences in the dominant algae genera, which were Gomphonema, Fragilaria, Cymbella, and Planktolyngbya in the main stream and Gomphonema, Fragilaria, Cymbella, and Oscillatoria in the tributaries. The redundancy analysis revealed that temperature, pH, and dissolved oxygen were the main driving factors affecting the community structure of the dominant genus in the main stream, while HCO3- and flow velocity controlled the community structure of the dominant genus in the tributaries. This study provides basic data and the theoretical basis for the conservation of aquatic ecosystems and water quality management in the middle and lower reaches of the Lhasa River.
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Ecossistema , Rios , Monitoramento Ambiental , Tibet , Qualidade da ÁguaRESUMO
Over the past 30 yr, multiple species of predatory Coccinellidae, prominently Coccinella septempunctata L. and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) have spread to new continents, influencing biodiversity and biological control. Here we review the mechanisms underlying these ecological interactions, focusing on multi-year field studies of native and non-native coccinellids and those using molecular and quantitative ecological methods. Field data from Asia show that H. axyridis, C. septempunctata, and Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) are regularly among the most abundant predatory species but their rank varies by habitat. Studies of these species in their native Asian range, primarily related to their range in mainland China, document different patterns of seasonal abundance, species specific associations with prey, and habitat separation. Intraguild predation is well documented both in Asia and in newly invaded areas, and H. axyridis benefits most from this interaction. Harmonia axyridis also seems to rely more on cannibalism in times of prey scarcity than other species, and relatively sparse data indicate a lower predation pressure on it from natural enemies of coccinellids. Declines in the abundance of native coccinellids following the spread and increase of non-native species, documented in several multi-year studies on several continents, is a major concern for native biodiversity and the persistence of native coccinellid species. We suggest that future studies focus more attention on the community ecology of these invasive species in their native habitats.
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Coronavirus disease-2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally since its first report and become a worldwide pandemic. In response to the outbreak of COVID-19, Center for Medical Device Evaluation, NMPA (CMDE) initiated emergency review and approval procedures to accelerate the process of reviewing emergent medical products and issued the Key Points of Technical Review for the Registration of SARS-CoV-2 Antigen/Antibody Tests (Key Points) to provide the requirements on the technical review of the tests. With uncontrolled spread and evolution of COVID-19 in the world, continuous prevention and measurements are necessary for fighting this pandemic and SARS-CoV-2 antigen/antibody tests are still urgently needed. This article is an attempt to expand clarification of the Key Points to wider audiences based on current understanding of SARS-CoV-2 to facilitate the development and application of SARS-CoV-2 antigen/antibody tests.
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Anticorpos Antivirais/análise , Antígenos Virais/análise , Teste para COVID-19 , COVID-19/diagnóstico , Reações Antígeno-Anticorpo , Teste para COVID-19/instrumentação , China , Ensaios Clínicos como Assunto , Reações Cruzadas , Humanos , Imunoglobulina M/análise , Limite de Detecção , Pandemias , Padrões de Referência , Reprodutibilidade dos TestesRESUMO
Objective: To develop and validate a prediction model for identifying pregnant women at risk of developing pregnancy-induced hypertension (PIH) to guide treatment decision and classification of management. Methods: This study retrospectively enrolled 907 consecutive pregnant women with de novo hypertension from the Antenatal Care Center of Henan Provincial People's Hospital between June 1, 2018 and May 31, 2019. The cohort was randomly divided into two subgroups: the development cohort (n = 635) and validation cohort (n = 272). Univariate analysis and backward elimination of multivariate logistic regression analyses were utilized to identify predictive factors, and a nomogram was established. The performance was assessed using the area under the curve (AUC), the mean AUC of k-fold cross-validation, and calibration plots. Based on the classification and regression tree model, risk classification was performed. Results: The score included five commonly available predictors: body mass index, proteinuria, age, uric acid, and mean arterial pressure (BPAUM score). When applied to internal validation, the score revealed good discrimination with stratified fivefold cross-validation in the development cohort (AUC = 0.91) and validation cohort (AUC: 0.89) at fixed 10% false-positive rates, and the calibration plots showed good calibration. The total score point was divided into three risk classifications: low risk (0 - 179 points), medium risk (179 - 204 points), and high risk (>204 points). Conclusions: This study established a prediction model for predicting PIH, which could be used in clinical decision-making to improve maternal health and birth outcomes.