A Note on Homoclinic Orbits for Second Order Hamiltonian Systems

In this paper, we study the existence for the homoclinic orbits for the second order Hamiltonian systems. Under suitable conditions on the potential $V$, we apply the direct method of variations and the Fourier analysis to prove the existence of homoclinc orbits

Ecosystem Carbon Stock Loss after Land Use Change in Subtropical Forests in China

Converting secondary natural forests (SFs) to Chinese fir plantations (CFPs) represents one of the most important (8.9 million ha) land use changes in subtropical China. This study estimated both biomass and soil C stocks in a SF and a CFP that was converted from a SF, to quantify the effects of land use change on ecosystem C stock. After the forest conversion, biomass C in the CFP (73 Mg¨ ha´1 ) was significantly lower than that of the SF (114 Mg¨ ha´1 ). Soil organic C content and stock decreased with increasing soil depth, and the soil C stock in the 0–10 cm layer accounted for more than one third of the total soil C stock over 0–50 cm, emphasizing the importance of management of the top soil to reduce the soil C loss. Total ecosystem C stock of the SF and the CFP was 318 and 200 Mg¨ ha´1 , respectively, 64% of which was soil C for both stands (205 Mg¨ ha´1 for the SF and 127 Mg¨ ha´1 for the CFP). This indicates that land use change from the SF to the CFP significantly decreased ecosystem C stock and highlights the importance of managing soil C

Ecosystem Carbon Stock Loss after Land Use Change in Subtropical Forests in China

Converting secondary natural forests (SFs) to Chinese fir plantations (CFPs) represents one of the most important (8.9 million ha) land use changes in subtropical China. This study estimated both biomass and soil C stocks in a SF and a CFP that was converted from a SF, to quantify the effects of land use change on ecosystem C stock. After the forest conversion, biomass C in the CFP (73 Mg¨ ha´1 ) was significantly lower than that of the SF (114 Mg¨ ha´1 ). Soil organic C content and stock decreased with increasing soil depth, and the soil C stock in the 0–10 cm layer accounted for more than one third of the total soil C stock over 0–50 cm, emphasizing the importance of management of the top soil to reduce the soil C loss. Total ecosystem C stock of the SF and the CFP was 318 and 200 Mg¨ ha´1 , respectively, 64% of which was soil C for both stands (205 Mg¨ ha´1 for the SF and 127 Mg¨ ha´1 for the CFP). This indicates that land use change from the SF to the CFP significantly decreased ecosystem C stock and highlights the importance of managing soil C

Identification and validation of a pyroptosis-related signature in identifying active tuberculosis via a deep learning algorithm

IntroductionActive tuberculosis (ATB), instigated by Mycobacterium tuberculosis (M.tb), rises as a primary instigator of morbidity and mortality within the realm of infectious illnesses. A significant portion of M.tb infections maintain an asymptomatic nature, recognizably termed as latent tuberculosis infections (LTBI). The complexities inherent to its diagnosis significantly hamper the initiatives aimed at its control and eventual eradication.MethodologyUtilizing the Gene Expression Omnibus (GEO), we procured two dedicated microarray datasets, labeled GSE39940 and GSE37250. The technique of weighted correlation network analysis was employed to discern the co-expression modules from the differentially expressed genes derived from the first dataset, GSE39940. Consequently, a pyroptosis-related module was garnered, facilitating the identification of a pyroptosis-related signature (PRS) diagnostic model through the application of a neural network algorithm. With the aid of Single Sample Gene Set Enrichment Analysis (ssGSEA), we further examined the immune cells engaged in the pyroptosis process in the context of active ATB. Lastly, dataset GSE37250 played a crucial role as a validating cohort, aimed at evaluating the diagnostic prowess of our model.ResultsIn executing the Weighted Gene Co-expression Network Analysis (WGCNA), a total of nine discrete co-expression modules were lucidly elucidated. Module 1 demonstrated a potent correlation with pyroptosis. A predictive diagnostic paradigm comprising three pyroptosis-related signatures, specifically AIM2, CASP8, and NAIP, was devised accordingly. The established PRS model exhibited outstanding accuracy across both cohorts, with the area under the curve (AUC) being respectively articulated as 0.946 and 0.787.ConclusionThe present research succeeded in identifying the pyroptosis-related signature within the pathogenetic framework of ATB. Furthermore, we developed a diagnostic model which exuded a remarkable potential for efficient and accurate diagnosis

Clinical Evaluation of High-risk HR-HPV E6/E7 mRNA Detection during Pregnancy

BackgroundIt is necessary to differentiate high-risk human papillomavirus (HR-HPV) infection and cervical lesions during pregnancy using an effective measure, so as to guide personalized diagnosis and treatment and to reduce unnecessary invasive examinations during pregnancy.ObjectiveTo assess the value of HR-HPV E6/E7 mRNA detection in differentiating HR-HPV infection and cervical lesions during pregnancy by comparing efficacy between it and HR-HPV DNA testing.MethodsParticipants were healthy women with singleton pregnancy (20-45-years old) selected from Department of Obstetrics and Gynecology of Capital Medical University Xuanwu Hospital during January 2016 to January 2019. All had file creation and underwent regular prenatal examination, and those with abnormal liquid-based cytology and HR-HPV DNA testing results further underwent colposcopy with biopsy taken for pathological examination (serving as a gold standard) , and performed HR-HPV E6/E7 mRNA detection in cervical exfoliated cells collected as samples. Pathologically detected CIN Ⅱand Ⅲ were defined as high-grade cervical lesions.ResultsOf the 1 058 participants, 118 had cytological abnormalities and/or HPV 16 and 18 infections, and 84 of them consented to perform colposcopy with biopsy pathological results successfully obtained. The prevalence of HR-HPV E6/E7 mRNA positivity was lower than that of HR-HPV DNA positivity in women with CINⅠ, normal cervical epithelium or cervicitis detected by pathological examination (P<0.05) . In contrast, the prevalence of HR-HPV E6/E7 mRNA positivity was similar to that of HR-HPV DNA positivity in those with CINⅡ and Ⅲ detected by pathological examination without statistical difference (P>0.05) . In predicting CINⅡ and Ⅲ, the HR-HPV DNA testing had a sensitivity of 89.7% (26/29) , a specificity of 21.8% (12/55) , a positive predictive value of 37.1% (26/69) , and a negative predictive value of 75.0% (12/29) , and the HR-HPV E6/E7 mRNA detection had a sensitivity of 65.5% (19/29) , a specificity of 54.5% (25/55) , a positive predictive value of 43.0% (19/44) , and a negative predictive value 75.0% (25/40) . McNemar's test revealed that HR-HPV E6/E7 mRNA detection had a lower sensitivity but a higher specificity than HR-HPV DNA testing in diagnosing CINⅡ and Ⅲ (P<0.05) .ConclusionHR-HPV E6/E7 mRNA detection may have an increased specificity in diagnosing CINⅡandⅢ than HR-HPV DNA testing, so it may be used in HR-HPV positive cases for differentiating HR-HPV infections and cervical lesions to avoid unnecessary invasive examinations during pregnancy

Current climate overrides past climate change in explaining multi-site beta diversity of Lauraceae species in China

Background: We aimed to characterise the geographical distribution of Sorensen-based multi-site dissimilarity (beta(sor)) and its underlying true turnover (beta(sim)) and nestedness (beta(sne)) components for Chinese Lauraceae and to analyse their relationships to current climate and past climate change. Methods: We used ensembles of small models (ESMs) to map the current distributions of 353 Lauraceae species in China and calculated beta(sor) and its beta(sim) and beta(sne) components. We tested the relationship between beta(sor), beta s(ne) and beta(sim) with current climate and past climate change related predictors using a series of simultaneous autoregressive (SAR(err)) models. Results: Spatial distribution of beta(sor) of Lauraceae is positively correlated with latitude, showing an inverse relationship to the latitudinal alpha-diversity (species richness) gradient. High beta(sor) occurs at the boundaries of the warm temperate and subtropical zones and at the Qinghai-Tibet Plateau due to high beta(sne). The optimized SAR(err) model explains beta(sor) and beta(sne) well, but not beta(sim). Current mean annual temperature determines beta(sor) and beta(sne) of Lauraceae more than anomalies and velocities of temperature or precipitation since the Last Glacial Maximum. Conclusions: Current low temperatures and high climatic heterogeneity are the main factors explaining the high multi-site beta-diversity of Lauraceae. In contrast to analyses of the beta-diversity of entire species assemblages, studies of single plant families can provide complementary insights into the drivers of beta-diversity of evolutionarily more narrowly defined entities.Peer reviewe

cDNA Cloning and Expression Analysis of Gustavus Gene in the Oriental River Prawn Macrobrachium nipponense

The gustavus gene is required for localizing pole plasm and specifying germ cells. Research on gustavus gene expression will advance our understanding of the biological function of gustavus in animals. A cDNA encoding gustavus protein was identified and termed MnGus in the oriental river prawn Macrobrachium nipponense. Bioinformatic analyses showed that this gene encoded a protein of 262 amino acids and the protein belongs to the Spsb1 family. Real-time quantitative PCR analyses revealed that the expression level of MnGus in prawn embryos was slightly higher at the cleavage stage than at the blastula stage, and reached the maximum level during the zoea stage of embryos. The minimum level of MnGus expression occurred during the perinucleolus stage in the ovary, while the maximum was at the oil globule stage, and then the level of MnGus expression gradually decreased with the advancement of ovarian development. The expression level of MnGus in muscle was much higher than that in other tissues in mature prawn. The gustavus cDNA sequence was firstly cloned from the oriental river prawn and the pattern of gene expression was described during oocyte maturation, embryonic development, and in other tissues. The differential expression patterns of MnGus in the embryo, ovary and other somatic tissues suggest that the gustavus gene performs multiple physiological functions in the oriental river prawn