Information was obtained from the same questionnaire (23 risk factors listed) of cases and controls. We used a multivariate logistic model, which described variables significantly increased risk of birth defects....Information was obtained from the same questionnaire (23 risk factors listed) of cases and controls. We used a multivariate logistic model, which described variables significantly increased risk of birth defects. The risk factors included maternal educational levels, medicine taken during pregnancy and antenatal care. It was suggested to strengthen antenatal care was the main preventive measure against birth defects.展开更多
BACKGROUND: This study aimed to explore the risk factors associated with intensive care unitacquired weakness(ICU-AW) in critically ill patients at risk of malnutrition and to evaluate the efficacy of early enteral nu...BACKGROUND: This study aimed to explore the risk factors associated with intensive care unitacquired weakness(ICU-AW) in critically ill patients at risk of malnutrition and to evaluate the efficacy of early enteral nutrition(EEN) and the role of biomarkers in managing ICU-AW.METHODS: This retrospective, observational cohort study included 180 patients at risk of malnutrition admitted to the emergency intensive care unit of the First Affiliated Hospital of Xiamen University Hospital from January 2022 to December 2023. Patients were divided into ICU-AW group and non-ICU-AW group according to whether they developed ICU-AW, or categorized into EEN and parenteral nutrition(PN) groups according to nutritional support. ICU-AW was diagnosed using the Medical Research Council score. The primary outcome was the occurrence of ICU-AW.RESULTS: The significant factors associated with ICU-AW included age, sex, type of nutritional therapy, mechanical ventilation(MV), body mass index(BMI), blood urea nitrogen(BUN), and creatinine(Cr) levels(P<0.05). The PN group developed ICU-AW earlier than did the EEN group, with a significant difference observed(log-rank P<0.001). Among biomarkers for ICU-AW, the mean prealbumin(PAB)/C-reactive protein(CRP) ratio had the highest diagnostic accuracy(area under the curve [AUC] 0.928, 95% confidence interval [95% CI] 0.892–0.946), surpassing the mean Cr/BUN ratio(AUC 0.740, 95% CI 0.663–0.819) and mean transferrin levels(AUC 0.653, 95% CI 0.574–0.733).CONCLUSION: Independent risk factors for ICU-AW include female sex, advanced age, PN, MV, lower BMI, and elevated BUN and Cr levels. EEN may potentially delay ICU-AW onset, and the PAB/CRP ratio may be an effective diagnostic marker for this condition.展开更多
In this study we aimed to analyze the effects of water temperature and diet on the length-weight rela- tionship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The...In this study we aimed to analyze the effects of water temperature and diet on the length-weight rela- tionship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures （22, 26, 30, and 34 ℃） and two diets （commercial pellet and natural shrimp）. Fish were fed twice daily. L. malabancus exhibited negative allometric growth （b〈3） at the beginning of the experiment （Day 0） at all temperatures and both diets except for 22 ℃ fed with shrimp, which showed isometric growth （b=3）. Conversely, at the end of the experiment （Day 30） fish showed isometric growth （b=3） at 30 ℃ fed with the pellet diet, indicating that the shape of the fish did not change with increasing weight and length, and a positive allometric growth （b〉3） at 30 ℃ fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth （b〈3） on both diet, meaning that fish became lighter with increasing size. The condition factors in the initial and final measurements were greater than 1, indicating the state of health of the fish, except for those fed on a pellet diet at 34 ℃. However, the best condition was obtained at 30 ℃ on both diets. Nev- ertheless, diets did not have a significant effect on growth and condition of juvenile L. malabaricus. The data obtained from this study suggested culturing L. malabaricus at 30 ℃ and feeding on the pellet or shrimp diet, which will optimize the overall production and condition of this commercially important fish species.展开更多
Landslide susceptibility prediction(LSP)is significantly affected by the uncertainty issue of landslide related conditioning factor selection.However,most of literature only performs comparative studies on a certain c...Landslide susceptibility prediction(LSP)is significantly affected by the uncertainty issue of landslide related conditioning factor selection.However,most of literature only performs comparative studies on a certain conditioning factor selection method rather than systematically study this uncertainty issue.Targeted,this study aims to systematically explore the influence rules of various commonly used conditioning factor selection methods on LSP,and on this basis to innovatively propose a principle with universal application for optimal selection of conditioning factors.An'yuan County in southern China is taken as example considering 431 landslides and 29 types of conditioning factors.Five commonly used factor selection methods,namely,the correlation analysis(CA),linear regression(LR),principal component analysis(PCA),rough set(RS)and artificial neural network(ANN),are applied to select the optimal factor combinations from the original 29 conditioning factors.The factor selection results are then used as inputs of four types of common machine learning models to construct 20 types of combined models,such as CA-multilayer perceptron,CA-random forest.Additionally,multifactor-based multilayer perceptron random forest models that selecting conditioning factors based on the proposed principle of“accurate data,rich types,clear significance,feasible operation and avoiding duplication”are constructed for comparisons.Finally,the LSP uncertainties are evaluated by the accuracy,susceptibility index distribution,etc.Results show that:(1)multifactor-based models have generally higher LSP performance and lower uncertainties than those of factors selection-based models;(2)Influence degree of different machine learning on LSP accuracy is greater than that of different factor selection methods.Conclusively,the above commonly used conditioning factor selection methods are not ideal for improving LSP performance and may complicate the LSP processes.In contrast,a satisfied combination of conditioning factors can be constructed according to the proposed principle.展开更多
To perform landslide susceptibility prediction(LSP),it is important to select appropriate mapping unit and landslide-related conditioning factors.The efficient and automatic multi-scale segmentation(MSS)method propose...To perform landslide susceptibility prediction(LSP),it is important to select appropriate mapping unit and landslide-related conditioning factors.The efficient and automatic multi-scale segmentation(MSS)method proposed by the authors promotes the application of slope units.However,LSP modeling based on these slope units has not been performed.Moreover,the heterogeneity of conditioning factors in slope units is neglected,leading to incomplete input variables of LSP modeling.In this study,the slope units extracted by the MSS method are used to construct LSP modeling,and the heterogeneity of conditioning factors is represented by the internal variations of conditioning factors within slope unit using the descriptive statistics features of mean,standard deviation and range.Thus,slope units-based machine learning models considering internal variations of conditioning factors(variant slope-machine learning)are proposed.The Chongyi County is selected as the case study and is divided into 53,055 slope units.Fifteen original slope unit-based conditioning factors are expanded to 38 slope unit-based conditioning factors through considering their internal variations.Random forest(RF)and multi-layer perceptron(MLP)machine learning models are used to construct variant Slope-RF and Slope-MLP models.Meanwhile,the Slope-RF and Slope-MLP models without considering the internal variations of conditioning factors,and conventional grid units-based machine learning(Grid-RF and MLP)models are built for comparisons through the LSP performance assessments.Results show that the variant Slopemachine learning models have higher LSP performances than Slope-machine learning models;LSP results of variant Slope-machine learning models have stronger directivity and practical application than Grid-machine learning models.It is concluded that slope units extracted by MSS method can be appropriate for LSP modeling,and the heterogeneity of conditioning factors within slope units can more comprehensively reflect the relationships between conditioning factors and landslides.The research results have important reference significance for land use and landslide prevention.展开更多
Factoring quadratics over Z is a staple of introductory algebra and textbooks tend to create the impression that doable factorizations are fairly common. To the contrary, if coefficients of a general quadratic are sel...Factoring quadratics over Z is a staple of introductory algebra and textbooks tend to create the impression that doable factorizations are fairly common. To the contrary, if coefficients of a general quadratic are selected randomly without restriction, the probability that a factorization exists is zero. We achieve a specific quantification of the probability of factoring quadratics by taking a new approach that considers the absolute size of coefficients to be a parameter n. This restriction allows us to make relative likelihood estimates based on finite sample spaces. Our probability estimates are then conditioned on the size parameter n and the behavior of the conditional estimates may be studied as the parameter is varied. Specifically, we enumerate how many formal factored expressions could possibly correspond to a quadratic for a given size parameter. The conditional probability of factorization as a function of n is just the ratio of this enumeration to the total number of possible quadratics consistent with n. This approach is patterned after the well-known case where factorizations are carried out over a finite field. We review the finite field method as background for our method of dealing with Z [x]. The monic case is developed independently of the general case because it is simpler and the resulting probability estimating formula is more accurate. We conclude with a comparison of our theoretical probability estimates with exact data generated by a computer search for factorable quadratics corresponding to various parameter values.展开更多
Adequate,safe and affordable housing and basic services for all are the basis for sustainable development,livelihood security and basic housing rights.Shelter is a basic human rights guarantee and improvements in livi...Adequate,safe and affordable housing and basic services for all are the basis for sustainable development,livelihood security and basic housing rights.Shelter is a basic human rights guarantee and improvements in living conditions are of significant importance to the quality of life.The article uses data from China’s fifth,sixth and seventh population censuses to reveal the spatial and temporal differences in the improvement of housing conditions of households in 281 cities in China from 2000 to 2020.The study concludes the following:(i)The housing conditions score of urban households in China has improved significantly,and the living environment has been significantly improved.The center of gravity of the overall housing conditions score shifts from the western region to the eastern region and then to the central region.(ii)The housing facilities in China’s cities have become increasingly sophisticated during the study period.The overall variation in housing amenities tends to decrease overall,with higher intra-belt variation than inter-belt variation in the four main regions.(iii)Self-built housing,rented housing,purchased housing,other types of housing and inherited housing are the main sources of housing for urban househ olds in China.From 2000 to 2020,the housing structure is characterized by two increases and one decrease,namely an increase in the proportion of purchased and rented housing and a decrease in the proportion of self-built housing.(iv)The main factors influencing the improvement of housing conditions are historical factors,the forces of marketization,urbanization,and housing policy.展开更多
To the editor,The article by Vrancken Peeters and colleagues,1 showing updated five-year conditional relative survival(5-year CRS)for young breast cancer patients by relevant prognostic factors and longer follow-up th...To the editor,The article by Vrancken Peeters and colleagues,1 showing updated five-year conditional relative survival(5-year CRS)for young breast cancer patients by relevant prognostic factors and longer follow-up than previous European studies,2,3 has filled an important gap in knowledge for the most common cancer among young women.展开更多
In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius...In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.展开更多
Let G be a graph of order n, and let a and b be integers, such that 1 ≤ a b. Let H be a subgraph of G with m(≤b) edges, and δ(G) be the minimum degree. We prove that G has a [a,b]-factor containing all edges of H i...Let G be a graph of order n, and let a and b be integers, such that 1 ≤ a b. Let H be a subgraph of G with m(≤b) edges, and δ(G) be the minimum degree. We prove that G has a [a,b]-factor containing all edges of H if , , and when a ≤ 2, .展开更多
Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In th...Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In this study, we optimized the production of a recombinant ALF by expressing E. sinensis ALF genes in Eseherichia coli maintained in shake-flasks. In particular, we focused on optimization of both the medium composition and the culture condition. Various medium components were analyzed by the Plackett-Burman design, and two significant screened factors, （NH4）2SO4 and KH2PO4, were further optimized via the central composite design （CCD）. Based on the CCD analysis, we investigated the induction start-up time, the isopropylthio-D-galactoside （IPTG） concentration, the post-induction time, and the temperature by response surface methodology. We found that the highest level of ALF fusion protein was achieved in the medium containing 1.89 g/L （NH4）2SO4 and 3.18 g/L KH2PO4, with a cell optical density of 0.8 at 600 nm before induction, an IPTG concentration of 0.5 mmol/L, a post-induction temperature of 32.7~C, and a post-induction time of 4 h. Applying the whole optimization strategy using all optimal factors improved the target protein content from 6.1% （without optimization） to 13.2%. We further applied the optimized medium and conditions in high cell density cultivation, and determined that the soluble target protein constituted 105% of the total protein. Our identification of the economic medium composition, optimal culture conditions, and details of the fermentation process should facilitate the potential application of ALF for further research.展开更多
The hormone defined serum free conditioned medium (SFCM) of human nasopharyngeal carcinoma epithelioid cell line (CNE1) was assayed by both the 3H-thymidine incorporation test and the soft agar test. It was found that...The hormone defined serum free conditioned medium (SFCM) of human nasopharyngeal carcinoma epithelioid cell line (CNE1) was assayed by both the 3H-thymidine incorporation test and the soft agar test. It was found that the SFCM stimulated the growth of long-term serum-free cultured CNE4 cells in ac-cordence with the fact that the growth rate of long-term serum-free cultured CNE1 cells was directly proportional to the plating density. Alternatively 5% SFCM inhibited the growth of short-term serum-free cultured CNE4 cells by 51% in which the indicator cell remained the responsiveness state of growing in the serum-supplemented medium to the effector of interest. Furthermore, SFCM resulted in the inhibition of anchorage-independent growth of CNE4 cells and A431 cells. Also in soft agar test. SFCM reduced the colony formation of NRK(?),9F cells in the presence of EGF or EGF plus TGF-β. These finding suggested that CNE4 secreted autocrine growth stimulating factor(s) and growth inhibiting factor(s) in the serum-free medium, the latter strongly reverse malignant phenotypes of CNE4 and A431 cells in serum-supplemented surrounding.展开更多
Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fisherm...Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fishermen for a period of 24 months(between April 2012 and March 2014).699 specimens of the fish species were collected.The Length-weight relationship(LWR)of the fish was evaluated using the equation:W=a L^(b) while the condition factor of the fish was determined using the equation;K=100W L^(b).The standard length of sampled S.melanotheron ranged from 4.15 to 18.92 cm,total length 6.01 and 22.5 cm while the weight ranged from 7.85-286.71 g.The b value 2.1299 was less than 3 indicating that the growth pattern of the fish was allometric.The correlation co-efficient(r)value for S.melanotheron was 0.7528.The condition factor for the combined sexes fluctuated monthly.The length-weight relationships and condition factor of S.melanotheron in Forcados river estuary indicated that the fish were above average condition.展开更多
Objective To observe the effect of electroacupuncture （EA） on egg quality of polycystic ovarian syndrome （PCOS） patients, and to explore its mechanism. Methods Two hundred patients who received in vitro fertilizat...Objective To observe the effect of electroacupuncture （EA） on egg quality of polycystic ovarian syndrome （PCOS） patients, and to explore its mechanism. Methods Two hundred patients who received in vitro fertilization-embryo transfer （IVF-ET） were divided into an EA group （102 cases） and a control group （98 cases） according to random number table. All the patients in the two groups were given Diane-35 and gonadotropin-releasing hormone agonist （GnRH-α） for ovarian hyperstimulation. Besides, EA intervention was applied to Shenshu （肾俞 BL 23）, Qihai （气海 GV 6）, Zusanli （足三里ST 36）, Sanyinjiao （三阴交 SP 6）, Neiguan （内关 PC 6） and Zigong （子宫 EX-CA1）, etc. in the EA group. Then egg quality, final outcome of pregnancy and levels of tumor necrosis factor-α （TNF-α） were compared between the two groups. Results （1） EA intervention significantly improved high quality embryo rate of PCOS patients （P〈0.05）, and clinical pregnancy rate was increased by 8.36%; （2） EA intervention significantly reduced the TNF-α levels of follicular fluid （13.61±15.46 vs 34.09±93.53, P〈0.05）; （3） TNF-α levels of serum and follicular fluid in the pregnancy group were lower than those of non-pregnancy group [pregnancy group： （53.91±63.32） pg/mL, （14.93±25.37） pg/mL, nonpregnancy group： （76.82 ± 82.96） pg/mL, （25.04 ± 35.79） pg/mL], and the differences were significant （both P〈0.05）. Conclusion EA improves egg quality of PCOS patients and increases the clinical pregnancy rate of IVF-ET, the mechanism may be related to TNF-α levels.展开更多
[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A st...[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A strain ZY-19-2 with strong inhibitory effect against P. parasitica were isolated and screened from tobacco rhizosphere soil samples, and identified according to its morphological characteristics. The chitinase production activity of the strain under different culture conditions was also studied. [Result] For stain ZY-19-2 Paecilomyces lilacinus, the optimal fermentation conditions were as follows： 1.2% colloidal chitin as carbon source, 1% peptone as nitrogen source, 0.1% Tween 80 as surfactant, initial pH of fermentation broth at 6.0, the fermentation time of 60 h, inoculum amount at 1%, shaker speed at 120 r/min. The highest enzyme activity reached 0.216 U/ml. [Conclusion]The optimization of fermentation condition of strain ZY-19-2 lay foundation for large-scale production of cheap and efficient chitinase and chitin oligosaccharides, as well as application of the strain for control of tobacco black shank.展开更多
Most gear fault diagnosis(GFD)approaches su er from ine ciency when facing with multiple varying working conditions at the same time.In this paper,a non-negative matrix factorization(NMF)-theoretic co-clustering strat...Most gear fault diagnosis(GFD)approaches su er from ine ciency when facing with multiple varying working conditions at the same time.In this paper,a non-negative matrix factorization(NMF)-theoretic co-clustering strategy is proposed specially to classify more than one task at the same time using the high dimension matrix,aiming to o er a fast multi-tasking solution.The short-time Fourier transform(STFT)is first used to obtain the time-frequency features from the gear vibration signal.Then,the optimal clustering numbers are estimated using the Bayesian information criterion(BIC)theory,which possesses the simultaneous assessment capability,compared with traditional validity indexes.Subsequently,the classical/modified NMF-based co-clustering methods are carried out to obtain the classification results in both row and column tasks.Finally,the parameters involved in BIC and NMF algorithms are determined using the gradient ascent(GA)strategy in order to achieve reliable diagnostic results.The Spectra Quest’s Drivetrain Dynamics Simulator gear data sets were analyzed to verify the e ectiveness of the proposed approach.展开更多
The stability of the anchorage slope on the Baiyang Yangtze River Highway Bridge in Yichang,China,was investigated under different rainfall conditions using model test,numerical simulation,and factor analysis.The resu...The stability of the anchorage slope on the Baiyang Yangtze River Highway Bridge in Yichang,China,was investigated under different rainfall conditions using model test,numerical simulation,and factor analysis.The results of the study are as follows:(1)with the increase of rainfall intensity,the change of earth pressure can be divided into three stages.However,when the rainfall intensity was larger than a certain value,the change of earth pressure of cut slope became two stages;with the increase of rainfall intensity,pore water pressure increased with the increase of rainfall time,while at a certain stage after the rainfall,the pore water pressure in the cut slope did not decrease immediately,but increased for a period of time.(2)When the rainfall stopped,the stability coefficient of the anchorage slope continued to decrease,then slowly increased,and finally tended to be gentle.Meanwhile,when the rainstorm reached a certain intensity,the main factor that restricted the rainfall infiltration rate became the geotechnical permeability coefficient of the cut slope,which was no longer the rainfall intensity.(3)Factor analysis shows that the rainfall intensity and rainfall duration were the most important factors for anchorage slope stability,while earth pressure,pore water pressure and slope displacement were much less significant.展开更多
Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water...Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water-soluble polysaccharide were investigated, which contained liquid-solid ratio, temperature, time and pH. The results showed that pH was the most important factor of polysaccharide extraction, followed by temperature. The optimized extraction technology conditions were obtained. The liquid-solid ratio was 1:40, temperature was 90?C, time was 2.0 h, and pH was 2. The highest extraction rate of crude polysaccharide was 8.30%.展开更多
文摘Information was obtained from the same questionnaire (23 risk factors listed) of cases and controls. We used a multivariate logistic model, which described variables significantly increased risk of birth defects. The risk factors included maternal educational levels, medicine taken during pregnancy and antenatal care. It was suggested to strengthen antenatal care was the main preventive measure against birth defects.
文摘BACKGROUND: This study aimed to explore the risk factors associated with intensive care unitacquired weakness(ICU-AW) in critically ill patients at risk of malnutrition and to evaluate the efficacy of early enteral nutrition(EEN) and the role of biomarkers in managing ICU-AW.METHODS: This retrospective, observational cohort study included 180 patients at risk of malnutrition admitted to the emergency intensive care unit of the First Affiliated Hospital of Xiamen University Hospital from January 2022 to December 2023. Patients were divided into ICU-AW group and non-ICU-AW group according to whether they developed ICU-AW, or categorized into EEN and parenteral nutrition(PN) groups according to nutritional support. ICU-AW was diagnosed using the Medical Research Council score. The primary outcome was the occurrence of ICU-AW.RESULTS: The significant factors associated with ICU-AW included age, sex, type of nutritional therapy, mechanical ventilation(MV), body mass index(BMI), blood urea nitrogen(BUN), and creatinine(Cr) levels(P<0.05). The PN group developed ICU-AW earlier than did the EEN group, with a significant difference observed(log-rank P<0.001). Among biomarkers for ICU-AW, the mean prealbumin(PAB)/C-reactive protein(CRP) ratio had the highest diagnostic accuracy(area under the curve [AUC] 0.928, 95% confidence interval [95% CI] 0.892–0.946), surpassing the mean Cr/BUN ratio(AUC 0.740, 95% CI 0.663–0.819) and mean transferrin levels(AUC 0.653, 95% CI 0.574–0.733).CONCLUSION: Independent risk factors for ICU-AW include female sex, advanced age, PN, MV, lower BMI, and elevated BUN and Cr levels. EEN may potentially delay ICU-AW onset, and the PAB/CRP ratio may be an effective diagnostic marker for this condition.
基金supported by the Ministry of Science Technology and Innovation Malaysia(MOSTI)(No.04-01-02-SF1208)
文摘In this study we aimed to analyze the effects of water temperature and diet on the length-weight rela- tionship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures （22, 26, 30, and 34 ℃） and two diets （commercial pellet and natural shrimp）. Fish were fed twice daily. L. malabancus exhibited negative allometric growth （b〈3） at the beginning of the experiment （Day 0） at all temperatures and both diets except for 22 ℃ fed with shrimp, which showed isometric growth （b=3）. Conversely, at the end of the experiment （Day 30） fish showed isometric growth （b=3） at 30 ℃ fed with the pellet diet, indicating that the shape of the fish did not change with increasing weight and length, and a positive allometric growth （b〉3） at 30 ℃ fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth （b〈3） on both diet, meaning that fish became lighter with increasing size. The condition factors in the initial and final measurements were greater than 1, indicating the state of health of the fish, except for those fed on a pellet diet at 34 ℃. However, the best condition was obtained at 30 ℃ on both diets. Nev- ertheless, diets did not have a significant effect on growth and condition of juvenile L. malabaricus. The data obtained from this study suggested culturing L. malabaricus at 30 ℃ and feeding on the pellet or shrimp diet, which will optimize the overall production and condition of this commercially important fish species.
基金funded by the Natural Science Foundation of China(Grant Nos.42377164 and 41972280)the Badong National Observation and Research Station of Geohazards(Grant No.BNORSG-202305).
文摘Landslide susceptibility prediction(LSP)is significantly affected by the uncertainty issue of landslide related conditioning factor selection.However,most of literature only performs comparative studies on a certain conditioning factor selection method rather than systematically study this uncertainty issue.Targeted,this study aims to systematically explore the influence rules of various commonly used conditioning factor selection methods on LSP,and on this basis to innovatively propose a principle with universal application for optimal selection of conditioning factors.An'yuan County in southern China is taken as example considering 431 landslides and 29 types of conditioning factors.Five commonly used factor selection methods,namely,the correlation analysis(CA),linear regression(LR),principal component analysis(PCA),rough set(RS)and artificial neural network(ANN),are applied to select the optimal factor combinations from the original 29 conditioning factors.The factor selection results are then used as inputs of four types of common machine learning models to construct 20 types of combined models,such as CA-multilayer perceptron,CA-random forest.Additionally,multifactor-based multilayer perceptron random forest models that selecting conditioning factors based on the proposed principle of“accurate data,rich types,clear significance,feasible operation and avoiding duplication”are constructed for comparisons.Finally,the LSP uncertainties are evaluated by the accuracy,susceptibility index distribution,etc.Results show that:(1)multifactor-based models have generally higher LSP performance and lower uncertainties than those of factors selection-based models;(2)Influence degree of different machine learning on LSP accuracy is greater than that of different factor selection methods.Conclusively,the above commonly used conditioning factor selection methods are not ideal for improving LSP performance and may complicate the LSP processes.In contrast,a satisfied combination of conditioning factors can be constructed according to the proposed principle.
基金funded by the Natural Science Foundation of China(Grant Nos.41807285,41972280 and 52179103).
文摘To perform landslide susceptibility prediction(LSP),it is important to select appropriate mapping unit and landslide-related conditioning factors.The efficient and automatic multi-scale segmentation(MSS)method proposed by the authors promotes the application of slope units.However,LSP modeling based on these slope units has not been performed.Moreover,the heterogeneity of conditioning factors in slope units is neglected,leading to incomplete input variables of LSP modeling.In this study,the slope units extracted by the MSS method are used to construct LSP modeling,and the heterogeneity of conditioning factors is represented by the internal variations of conditioning factors within slope unit using the descriptive statistics features of mean,standard deviation and range.Thus,slope units-based machine learning models considering internal variations of conditioning factors(variant slope-machine learning)are proposed.The Chongyi County is selected as the case study and is divided into 53,055 slope units.Fifteen original slope unit-based conditioning factors are expanded to 38 slope unit-based conditioning factors through considering their internal variations.Random forest(RF)and multi-layer perceptron(MLP)machine learning models are used to construct variant Slope-RF and Slope-MLP models.Meanwhile,the Slope-RF and Slope-MLP models without considering the internal variations of conditioning factors,and conventional grid units-based machine learning(Grid-RF and MLP)models are built for comparisons through the LSP performance assessments.Results show that the variant Slopemachine learning models have higher LSP performances than Slope-machine learning models;LSP results of variant Slope-machine learning models have stronger directivity and practical application than Grid-machine learning models.It is concluded that slope units extracted by MSS method can be appropriate for LSP modeling,and the heterogeneity of conditioning factors within slope units can more comprehensively reflect the relationships between conditioning factors and landslides.The research results have important reference significance for land use and landslide prevention.
文摘Factoring quadratics over Z is a staple of introductory algebra and textbooks tend to create the impression that doable factorizations are fairly common. To the contrary, if coefficients of a general quadratic are selected randomly without restriction, the probability that a factorization exists is zero. We achieve a specific quantification of the probability of factoring quadratics by taking a new approach that considers the absolute size of coefficients to be a parameter n. This restriction allows us to make relative likelihood estimates based on finite sample spaces. Our probability estimates are then conditioned on the size parameter n and the behavior of the conditional estimates may be studied as the parameter is varied. Specifically, we enumerate how many formal factored expressions could possibly correspond to a quadratic for a given size parameter. The conditional probability of factorization as a function of n is just the ratio of this enumeration to the total number of possible quadratics consistent with n. This approach is patterned after the well-known case where factorizations are carried out over a finite field. We review the finite field method as background for our method of dealing with Z [x]. The monic case is developed independently of the general case because it is simpler and the resulting probability estimating formula is more accurate. We conclude with a comparison of our theoretical probability estimates with exact data generated by a computer search for factorable quadratics corresponding to various parameter values.
基金Project of Philosophy and Social Science of Shanghai“Study on the Role of Population Ageing on Economic Growth in the Yangtze River Delta Urban Agglomeration”(2023ZSH002).
文摘Adequate,safe and affordable housing and basic services for all are the basis for sustainable development,livelihood security and basic housing rights.Shelter is a basic human rights guarantee and improvements in living conditions are of significant importance to the quality of life.The article uses data from China’s fifth,sixth and seventh population censuses to reveal the spatial and temporal differences in the improvement of housing conditions of households in 281 cities in China from 2000 to 2020.The study concludes the following:(i)The housing conditions score of urban households in China has improved significantly,and the living environment has been significantly improved.The center of gravity of the overall housing conditions score shifts from the western region to the eastern region and then to the central region.(ii)The housing facilities in China’s cities have become increasingly sophisticated during the study period.The overall variation in housing amenities tends to decrease overall,with higher intra-belt variation than inter-belt variation in the four main regions.(iii)Self-built housing,rented housing,purchased housing,other types of housing and inherited housing are the main sources of housing for urban househ olds in China.From 2000 to 2020,the housing structure is characterized by two increases and one decrease,namely an increase in the proportion of purchased and rented housing and a decrease in the proportion of self-built housing.(iv)The main factors influencing the improvement of housing conditions are historical factors,the forces of marketization,urbanization,and housing policy.
基金supported by the Italian Association for Cancer Re-search(AIRC)(grant number:28893)the Italian Ministry of Health(Ricerca Corrente)(no grant number).
文摘To the editor,The article by Vrancken Peeters and colleagues,1 showing updated five-year conditional relative survival(5-year CRS)for young breast cancer patients by relevant prognostic factors and longer follow-up than previous European studies,2,3 has filled an important gap in knowledge for the most common cancer among young women.
基金supported by the National Natural Science Foundation of China(Grant Nos.11875122,12175025,and 12147102)Tongling University Talent Program(Grant No.R23100)。
文摘In this paper,we study the ρ-meson electromagnetic form factors(EMFFs)within the framework of the light-front quark model.The physical form factors G_(C,M,Q)(Q^(2))of the ρ-meson,as well as the charged square radius<r^(2)>,the magnetic moment μ,and the quadrupole moment Q,are calculated,which describe the behaviors of EMFFs at zero momentum transfer.Using the type-Ⅱ replacement,we find that the zero-mode does contribute zero to the matrix element S_(00)^(+).It is found that the“M→M_(0)”replacement improves the angular condition remarkably,which permits different prescriptions of ρ-meson EMFFs to give the consistent results.The residual tiny violation of angular condition needs other explanations beyond the zero-mode contributions.Our results indicate that the relativistic effects or interaction internal structure are weaken in the zero-binding limit.This work is also applicable to other spin-1 particles.
文摘Let G be a graph of order n, and let a and b be integers, such that 1 ≤ a b. Let H be a subgraph of G with m(≤b) edges, and δ(G) be the minimum degree. We prove that G has a [a,b]-factor containing all edges of H if , , and when a ≤ 2, .
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2006AA100311)
文摘Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In this study, we optimized the production of a recombinant ALF by expressing E. sinensis ALF genes in Eseherichia coli maintained in shake-flasks. In particular, we focused on optimization of both the medium composition and the culture condition. Various medium components were analyzed by the Plackett-Burman design, and two significant screened factors, （NH4）2SO4 and KH2PO4, were further optimized via the central composite design （CCD）. Based on the CCD analysis, we investigated the induction start-up time, the isopropylthio-D-galactoside （IPTG） concentration, the post-induction time, and the temperature by response surface methodology. We found that the highest level of ALF fusion protein was achieved in the medium containing 1.89 g/L （NH4）2SO4 and 3.18 g/L KH2PO4, with a cell optical density of 0.8 at 600 nm before induction, an IPTG concentration of 0.5 mmol/L, a post-induction temperature of 32.7~C, and a post-induction time of 4 h. Applying the whole optimization strategy using all optimal factors improved the target protein content from 6.1% （without optimization） to 13.2%. We further applied the optimized medium and conditions in high cell density cultivation, and determined that the soluble target protein constituted 105% of the total protein. Our identification of the economic medium composition, optimal culture conditions, and details of the fermentation process should facilitate the potential application of ALF for further research.
文摘The hormone defined serum free conditioned medium (SFCM) of human nasopharyngeal carcinoma epithelioid cell line (CNE1) was assayed by both the 3H-thymidine incorporation test and the soft agar test. It was found that the SFCM stimulated the growth of long-term serum-free cultured CNE4 cells in ac-cordence with the fact that the growth rate of long-term serum-free cultured CNE1 cells was directly proportional to the plating density. Alternatively 5% SFCM inhibited the growth of short-term serum-free cultured CNE4 cells by 51% in which the indicator cell remained the responsiveness state of growing in the serum-supplemented medium to the effector of interest. Furthermore, SFCM resulted in the inhibition of anchorage-independent growth of CNE4 cells and A431 cells. Also in soft agar test. SFCM reduced the colony formation of NRK(?),9F cells in the presence of EGF or EGF plus TGF-β. These finding suggested that CNE4 secreted autocrine growth stimulating factor(s) and growth inhibiting factor(s) in the serum-free medium, the latter strongly reverse malignant phenotypes of CNE4 and A431 cells in serum-supplemented surrounding.
文摘Length-weight relationship(LWR),condition factor(k)of the black chin tilapia,Sarotherodon melanotheron(Rüppel,1852)from Forcados River estuary Nigeria was investigated.The fish were collected monthly from fishermen for a period of 24 months(between April 2012 and March 2014).699 specimens of the fish species were collected.The Length-weight relationship(LWR)of the fish was evaluated using the equation:W=a L^(b) while the condition factor of the fish was determined using the equation;K=100W L^(b).The standard length of sampled S.melanotheron ranged from 4.15 to 18.92 cm,total length 6.01 and 22.5 cm while the weight ranged from 7.85-286.71 g.The b value 2.1299 was less than 3 indicating that the growth pattern of the fish was allometric.The correlation co-efficient(r)value for S.melanotheron was 0.7528.The condition factor for the combined sexes fluctuated monthly.The length-weight relationships and condition factor of S.melanotheron in Forcados river estuary indicated that the fish were above average condition.
基金Supported by the National Natural Science Foundation of China:30973790
文摘Objective To observe the effect of electroacupuncture （EA） on egg quality of polycystic ovarian syndrome （PCOS） patients, and to explore its mechanism. Methods Two hundred patients who received in vitro fertilization-embryo transfer （IVF-ET） were divided into an EA group （102 cases） and a control group （98 cases） according to random number table. All the patients in the two groups were given Diane-35 and gonadotropin-releasing hormone agonist （GnRH-α） for ovarian hyperstimulation. Besides, EA intervention was applied to Shenshu （肾俞 BL 23）, Qihai （气海 GV 6）, Zusanli （足三里ST 36）, Sanyinjiao （三阴交 SP 6）, Neiguan （内关 PC 6） and Zigong （子宫 EX-CA1）, etc. in the EA group. Then egg quality, final outcome of pregnancy and levels of tumor necrosis factor-α （TNF-α） were compared between the two groups. Results （1） EA intervention significantly improved high quality embryo rate of PCOS patients （P〈0.05）, and clinical pregnancy rate was increased by 8.36%; （2） EA intervention significantly reduced the TNF-α levels of follicular fluid （13.61±15.46 vs 34.09±93.53, P〈0.05）; （3） TNF-α levels of serum and follicular fluid in the pregnancy group were lower than those of non-pregnancy group [pregnancy group： （53.91±63.32） pg/mL, （14.93±25.37） pg/mL, nonpregnancy group： （76.82 ± 82.96） pg/mL, （25.04 ± 35.79） pg/mL], and the differences were significant （both P〈0.05）. Conclusion EA improves egg quality of PCOS patients and increases the clinical pregnancy rate of IVF-ET, the mechanism may be related to TNF-α levels.
基金Supported by Technology Development Project of Zhengzhou Tobacco Research Institute of CNTC"Isolation,Application and Research of Disease-resistant Endophyte"(122009CZ0420)~~
文摘[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A strain ZY-19-2 with strong inhibitory effect against P. parasitica were isolated and screened from tobacco rhizosphere soil samples, and identified according to its morphological characteristics. The chitinase production activity of the strain under different culture conditions was also studied. [Result] For stain ZY-19-2 Paecilomyces lilacinus, the optimal fermentation conditions were as follows： 1.2% colloidal chitin as carbon source, 1% peptone as nitrogen source, 0.1% Tween 80 as surfactant, initial pH of fermentation broth at 6.0, the fermentation time of 60 h, inoculum amount at 1%, shaker speed at 120 r/min. The highest enzyme activity reached 0.216 U/ml. [Conclusion]The optimization of fermentation condition of strain ZY-19-2 lay foundation for large-scale production of cheap and efficient chitinase and chitin oligosaccharides, as well as application of the strain for control of tobacco black shank.
基金Supported by National Natural Science Foundation of China(Grant No.51575102)Jiangsu Postgraduate Research Innovation Program(Grant No.KYCX18_0075).
文摘Most gear fault diagnosis(GFD)approaches su er from ine ciency when facing with multiple varying working conditions at the same time.In this paper,a non-negative matrix factorization(NMF)-theoretic co-clustering strategy is proposed specially to classify more than one task at the same time using the high dimension matrix,aiming to o er a fast multi-tasking solution.The short-time Fourier transform(STFT)is first used to obtain the time-frequency features from the gear vibration signal.Then,the optimal clustering numbers are estimated using the Bayesian information criterion(BIC)theory,which possesses the simultaneous assessment capability,compared with traditional validity indexes.Subsequently,the classical/modified NMF-based co-clustering methods are carried out to obtain the classification results in both row and column tasks.Finally,the parameters involved in BIC and NMF algorithms are determined using the gradient ascent(GA)strategy in order to achieve reliable diagnostic results.The Spectra Quest’s Drivetrain Dynamics Simulator gear data sets were analyzed to verify the e ectiveness of the proposed approach.
基金the National Natural Science Foundation of China(Nos.41807265,41972286)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGQY1931)。
文摘The stability of the anchorage slope on the Baiyang Yangtze River Highway Bridge in Yichang,China,was investigated under different rainfall conditions using model test,numerical simulation,and factor analysis.The results of the study are as follows:(1)with the increase of rainfall intensity,the change of earth pressure can be divided into three stages.However,when the rainfall intensity was larger than a certain value,the change of earth pressure of cut slope became two stages;with the increase of rainfall intensity,pore water pressure increased with the increase of rainfall time,while at a certain stage after the rainfall,the pore water pressure in the cut slope did not decrease immediately,but increased for a period of time.(2)When the rainfall stopped,the stability coefficient of the anchorage slope continued to decrease,then slowly increased,and finally tended to be gentle.Meanwhile,when the rainstorm reached a certain intensity,the main factor that restricted the rainfall infiltration rate became the geotechnical permeability coefficient of the cut slope,which was no longer the rainfall intensity.(3)Factor analysis shows that the rainfall intensity and rainfall duration were the most important factors for anchorage slope stability,while earth pressure,pore water pressure and slope displacement were much less significant.
文摘Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water-soluble polysaccharide were investigated, which contained liquid-solid ratio, temperature, time and pH. The results showed that pH was the most important factor of polysaccharide extraction, followed by temperature. The optimized extraction technology conditions were obtained. The liquid-solid ratio was 1:40, temperature was 90?C, time was 2.0 h, and pH was 2. The highest extraction rate of crude polysaccharide was 8.30%.
