Background:Heat stress(HS)affects the ruminal microbiota and decreases the lactation performance of dairy cows.Because HS decreases feed intake,the results of previous studies were confounded by the effect of HS on fe...Background:Heat stress(HS)affects the ruminal microbiota and decreases the lactation performance of dairy cows.Because HS decreases feed intake,the results of previous studies were confounded by the effect of HS on feed intake.This study examined the direct effect of HS on the ruminal microbiota using lactating Holstein cows that were pair-fed and housed in environmental chambers in a 2×2 crossover design.The cows were pair-fed the same amount of identical total mixed ration to eliminate the effect of feed or feed intake.The composition and structure of the microbiota of prokaryotes,fungi,and protozoa were analyzed using metataxonomics and compared between two thermal conditions:pair-fed thermoneutrality(PFTN,thermal humidity index:65.5)and HS(87.2 for daytime and 81.8 for nighttime).Results:The HS conditions altered the structure of the prokaryotic microbiota and the protozoal microbiota,but not the fungal microbiota.Heat stress significantly increased the relative abundance of Bacteroidetes(primarily Gram-negative bacteria)while decreasing that of Firmicutes(primarily Gram-positive bacteria)and the Firmicutes-toBacteroidetes ratio.Some genera were exclusively found in the heat-stressed cows and thermal control cows.Some co-occurrence and mutual exclusion between some genera were also found exclusively for each thermal condition.Heat stress did not significantly affect the overall functional features predicted using the 16S rRNA gene sequences and ITS1 sequences,but some enzyme-coding genes altered their relative abundance in response to HS.Conclusions:Overall,HS affected the prokaryotes,fungi,and protozoa of the ruminal microbiota in lactating Holstein cows to a different extent,but the effect on the structure of ruminal microbiota and functional profiles was limited when not confounded by the effect on feed intake.However,some genera and co-occurrence were exclusively found in the rumen of heat-stressed cows.These effects should be attributed to the direct effect of heat stress on the host metabolism,physiology,and behavior.Some of the“heat-stress resistant”microbes may be useful as potential probiotics for cows under heat stress.展开更多
In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and th...In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and the weight profile function of the TC-AM,the bit error probability for both cases is evaluated in the sense of maximum likelihood decoding.The numerical result is given.展开更多
Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of w...Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of which bacteria, archaea, fungi, and protozoa may vary differently. However, few studies have examined all the four groups of rumen microbes. This study investigated the effect of both the level and source of dietary energy on rumen bacteria, archaea, fungi, and protozoa in the rumen of lactating dairy cows. A 2 × 2 factorial design resulted in four dietary treatments: low and high dietary energy levels(LE: 1.52–1.53;and HE: 1.71–1.72 Mcal/kg dry matter) and two dietary energy sources(GC: finely ground corn;and SFC: steam-flaked corn). We used a replicated 4 × 4 Latin square design using eight primiparous Chinese Holstein cows with each period lasting for 21 d. The rumen microbiota was analyzed using metataxonomics based on kingdom-specific phylogenetic markers [16 S r RNA gene for bacteria and archaea, 18 S r RNA gene for protozoa, and internally transcribed spacer 1(ITS1) for fungi] followed with subsequent functional prediction using PICRUSt2.Results: The GC resulted in a higher prokaryotic(bacterial and archaeal) species richness and Faith's phylogenetic diversity than SFC. For the eukaryotic(fungi and protozoa) microbiota, the LE diets led to significantly higher values of the above measurements than the HE diets. Among the major classified taxa, 23 genera across all the kingdoms differed in relative abundance between the two dietary energy levels, while only six genera(none being protozoal)were differentially abundant between the two energy sources. Based on prokaryotic amplicon sequence variants(ASVs) from all the samples, overall functional profiles predicted using PICRUSt2 differed significantly between LE and HE but not between the two energy sources. Fish Taco analysis identified Ruminococcus and Coprococcus as the taxa potentially contributing to the enriched KEGG pathways for biosynthesis of amino acids and to the metabolisms of pyruvate, glycerophospholipid, and nicotinate and nicotinamide in the rumen of HE-fed cows. The co-occurrence networks were also affected by the dietary treatments, especially the LE and GC diets, resulting in distinct co-occurrence networks. Several microbial genera appeared to be strongly correlated with one or more lactation traits.Conclusions: Dietary energy level affected the overall rumen multi-kingdom microbiota while little difference was noted between ground corn and steam-flaked corn. Some genera were also affected differently by the four dietary treatments, including genera that had been shown to be correlated with lactation performance or feed efficiency.The co-occurrence patterns among the genera exclusively found for each dietary treatment may suggest possible metabolic interactions specifically affected by the dietary treatment. Some of the major taxa were positively correlated to milk properties and may potentially serve as biomarkers of one or more lactation traits.展开更多
Summary： Evidence-based medicine is advocated by WHO and adopted by developed countries for many years. In China, however, the selection of essential medicine and various medical insurance reimbursement schemes medic...Summary： Evidence-based medicine is advocated by WHO and adopted by developed countries for many years. In China, however, the selection of essential medicine and various medical insurance reimbursement schemes medicine is usually based on experts＇ experience of prescription practice which is under heavy critics resulting from the lack of related comparative efficacy and evidence-based research. The efficacy of Jian＇ganle in prevention of drug-induced liver injury （DILI） caused by antituberculotics was evaluated in this study by comparison with Hugan Pian, glucuronolactone and reduced glutathione. Evidence was provided for relevant sectors such as Ministry for Human Resources and Social Security of the People＇s Republic of China and National Health and Family Planning Commission of the Peo- ple＇s Republic of China to select and renew the Essential Medicine List （EML）, the new rural cooperative medical scheme in China （NRCMS） list or the reimbursement list of industrial injury insurance. A total of 189 patients with initial pulmonary tuberculosis were divided into four groups who took antituberculotics combined with Jian＇ganle, Hugan Pian, glucuronolactone and reduced glutathione respectively. Their liver function profile including alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, total bilirubin （TBIL）, direct bilirubin （DBIL）, total protein （TP）, albumin （A） and globulin （G） were detected at admission as baseline and after treatment. The Jian＇ganle group was compared with the three others by chi-square tests. In an aspect of maintaining bilirubin indexes normal, Jian＇ganle was more efficacious than glucuronolactone. And Jian＇ganle had a little more efficacy than reduced glutathione to maintain protein indexes normal as well. And the therapeutic regimen of antituberculotics combined with Jian＇ganle was the best in treating tuberculosis and preventing DILI at the same time. The study showed that among the four hepatinicas which demonstrated similar prevention of DILI caused by antituberculotics, Jian＇ganle has more advantages over the three others to some extent, which provides a reliable basis for health sectors to select and renew the EML, NRCMS List or the reimbursement list of industrial injury insurance.展开更多
We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon,...We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon, quark-quark, and gluon-quark interactions are included. Our results show that the QCD inspired model gives a perfect fit to experimental data of total cross section both for ^-pp and pp elastic scatterings at the whole energy region where experimental data existed at FNAL and CERN.展开更多
We use the QCD inspired model to analyze the ratio of the real to the imaginary for pp and pp elastic scatterings. A calculation for the ratio of the real to the imaginary is performed in which the contributions from ...We use the QCD inspired model to analyze the ratio of the real to the imaginary for pp and pp elastic scatterings. A calculation for the ratio of the real to the imaginary is performed in which the contributions from gluongluon interaction, quark-quark interaction, quark-gluon interaction, and odd eikonal profile function are included. Our results show that the QCD inspired model gives a good fit to the LHC experimental data.展开更多
Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and...Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and some confusing issues are clarified.展开更多
Complex perturbations in the profile and the sparsity of samples often limit the validity of rapid environmental assessment(REA)in the South China Sea(SCS).In this paper,the remote sensing data were used to estimate s...Complex perturbations in the profile and the sparsity of samples often limit the validity of rapid environmental assessment(REA)in the South China Sea(SCS).In this paper,the remote sensing data were used to estimate sound speed profile(SSP)with the self-organizing map(SOM)method in the SCS.First,the consistency of the empirical orthogonal functions was examined by using k-means clustering.The clustering results indicated that SSPs in the SCS have a similar perturbation nature,which means the inverted grid could be expanded to the entire SCS to deal with the problem of sparsity of the samples without statistical improbability.Second,a machine learning method was proposed that took advantage of the topological structure of SOM to significantly improve their accuracy.Validation revealed promising results,with a mean reconstruction error of 1.26 m/s,which is 1.16 m/s smaller than the traditional single empirical orthogonal function regression(sEOF-r)method.By violating the constraints of linear inversion,the topological structure of the SOM method showed a smaller error and better robustness in the SSP estimation.The improvements to enhance the accuracy and robustness of REA in the SCS were offered.These results suggested a potential utilization of REA in the SCS based on satellite data and provided a new approach for SSP estimation derived from sea surface data.展开更多
Fifty years ago, Hans A. Panofsky published a paper entitled Determination of stress from wind and temperature measurements. In his famous paper, he presented a new profile function for the mean horizontal wind speed ...Fifty years ago, Hans A. Panofsky published a paper entitled Determination of stress from wind and temperature measurements. In his famous paper, he presented a new profile function for the mean horizontal wind speed under the condition of diabatic stratification that includes his integral similarity function. With his integral similarity function, he opened the door for Monin-Obukhov scaling in a wide range of micrometeorological and microclimatological applications. In a historic survey ranging from the sixties of the past century down to the present days, we present integral similarity functions for momentum, sensible heat, and water vapor for both unstable and stable stratification, where on the one hand free convection condition and on the other hand strongly stable stratification are addressed.展开更多
Identification of all genes involved in the phytochrome （phy）-medieted responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth end developm...Identification of all genes involved in the phytochrome （phy）-medieted responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth end development. This article highlights end integrates the central findings of two recent comprehensive studies in Arabidopsis that have identified the genome-wide set of phy-reguleted genes that respond rapidly to red-light signals upon first exposure of dark-grown seedlings, and have tested the functional relevance to normal seedling photomorphogenesis of an Initial subset of these genes. The data： （a） reveal considerable complexity in the channeling of the light signals through the different phy-femily members （phyA to phyE） to responsive genes; （b） identify a diversity of transcription-factor-encoding genes as major early, if not primary, targets of phy signaling, end, therefore, as potentially important regulators in the transcriptional-network hierarchy; and （c） identify auxin-related genes as the dominant class among rapidly-regulated, hormone-related genes. However, reverse-genetic functional profiling of a selected subset of these genes reveals that only a limited fraction are necessary for optimal phy-induced seedling deetioletion.展开更多
Metagenomics is the study of microbial communities sampled directly from their natural environment, without prior culturing. By enabling an analysis of populations including many （so-far） unculturable and often unkn...Metagenomics is the study of microbial communities sampled directly from their natural environment, without prior culturing. By enabling an analysis of populations including many （so-far） unculturable and often unknown microbes, metagenomics is revolutionizing the field of microbiology, and has excited researchers in many disciplines that could benefit from the study of environmental microbes, including those in ecology, environmental sciences, and biomedicine. Specific computational and statistical tools have been developed for metagenomic data analysis and comparison. New studies, however, have revealed various kinds of artifacts present in metagenomics data caused by limitations in the experimental protocols and/or inadequate data analysis procedures, which often lead to incorrect conclusions about a microbial community. Here, we review some of the artifacts, such as overestimation of species diversity and incorrect estimation of gene family frequencies, and discuss emerging computational approaches to address them. We also review potential challenges that metagenomics may encounter with the extensive application of next-generation sequencing （NGS） techniques.展开更多
Profile likelihood function is introduced to analyze the uncertainty of hydrometeorological extreme inference and the theory of estimating confidence intervals of the key parameters and quantiles of extreme value dist...Profile likelihood function is introduced to analyze the uncertainty of hydrometeorological extreme inference and the theory of estimating confidence intervals of the key parameters and quantiles of extreme value distribution by profile likelihood function is described.GEV(generalized extreme value)distribution and GP(generalized Pareto)distribution are used respectively to fit the annual maximum daily flood discharge sample of the Yichang station in the Yangtze River and the daily rainfall sample in10 big cities including Guangzhou.The parameters of the models are estimated by maximum likelihood method and the fitting results are tested by probability plot,quantile plot,return level plot and density plot.The return levels and confidence intervals of flood and rainstorm in different return periods are calculated by profile likelihood function.The results show that the asymmetry of the profile likelihood function curve increases with the return period,which can reflect the effect of the length of sample series and return periods on confidence interval.As an effective tool for estimating confidence interval of the key parameters and quantiles of extreme value distribution,profile likelihood function can lead to a more accurate result and help to analyze the uncertainty of extreme values of hydrometeorology.展开更多
In order to evaluate the reliability and applicability of the Empirical Orthogonal Functions（EOFs）in the acoustic inversion of sound speed profile（SSP）and reduce EOF＇s dependence on the sample data,a methodology ...In order to evaluate the reliability and applicability of the Empirical Orthogonal Functions（EOFs）in the acoustic inversion of sound speed profile（SSP）and reduce EOF＇s dependence on the sample data,a methodology is proposed for the achievement of the basis functions for SSP＇s expansion.By analyzing the oceanographic dynamics which is the main cause of the SSP＇s variation,the basis functions are obtained naming the Hydrodynamic Normal Modes（HNMs）.The HNM basis functions are almost the same as those derived from the EOF method,while HNMs has less dependence on the amount of the sample data.HNMs method has a physically meaningful interpretation,and it could give out the physical parameters which determine the basis functions for the expansion of SSP,and this makes it possible to analyze and evaluate the trustiness and applicability of EOFs.展开更多
基金funded by the National Natural Science Foundation of China(award number:31872383)the Scientific Research Project for Major Achievements of The Agricultural Science and Technology Innovation Program(award number:ASTIP-IAS07-1)the Beijing Dairy Industry Innovation Team(Award number:BAIC06-2021).
文摘Background:Heat stress(HS)affects the ruminal microbiota and decreases the lactation performance of dairy cows.Because HS decreases feed intake,the results of previous studies were confounded by the effect of HS on feed intake.This study examined the direct effect of HS on the ruminal microbiota using lactating Holstein cows that were pair-fed and housed in environmental chambers in a 2×2 crossover design.The cows were pair-fed the same amount of identical total mixed ration to eliminate the effect of feed or feed intake.The composition and structure of the microbiota of prokaryotes,fungi,and protozoa were analyzed using metataxonomics and compared between two thermal conditions:pair-fed thermoneutrality(PFTN,thermal humidity index:65.5)and HS(87.2 for daytime and 81.8 for nighttime).Results:The HS conditions altered the structure of the prokaryotic microbiota and the protozoal microbiota,but not the fungal microbiota.Heat stress significantly increased the relative abundance of Bacteroidetes(primarily Gram-negative bacteria)while decreasing that of Firmicutes(primarily Gram-positive bacteria)and the Firmicutes-toBacteroidetes ratio.Some genera were exclusively found in the heat-stressed cows and thermal control cows.Some co-occurrence and mutual exclusion between some genera were also found exclusively for each thermal condition.Heat stress did not significantly affect the overall functional features predicted using the 16S rRNA gene sequences and ITS1 sequences,but some enzyme-coding genes altered their relative abundance in response to HS.Conclusions:Overall,HS affected the prokaryotes,fungi,and protozoa of the ruminal microbiota in lactating Holstein cows to a different extent,but the effect on the structure of ruminal microbiota and functional profiles was limited when not confounded by the effect on feed intake.However,some genera and co-occurrence were exclusively found in the rumen of heat-stressed cows.These effects should be attributed to the direct effect of heat stress on the host metabolism,physiology,and behavior.Some of the“heat-stress resistant”microbes may be useful as potential probiotics for cows under heat stress.
文摘In this paper we use trellis coded amplitude modulation (TC-AM) as models to analyze the receivers with intersymbol interference (ISI) under BPSK and π/4-QPSK modulations.Using the modified generating function and the weight profile function of the TC-AM,the bit error probability for both cases is evaluated in the sense of maximum likelihood decoding.The numerical result is given.
基金partially funded by grants from the National Key Research and Development Program of China (2018YFD0501600)the Scientific Research Project for Major Achievements of The Agricultural Science and Technology Innovation Program (ASTIP)(No. CAAS-ZDXT2019004+3 种基金CAASXTCX2016011–01ASTIP-IAS07)Beijing Dairy Industry Innovation Team(BAIC06–2019)the USDA National Institute of Food and Agriculture(award number:2019–67030-29003)。
文摘Background: Dietary energy source and level in lactation diets can profoundly affect milk yield and composition.Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of which bacteria, archaea, fungi, and protozoa may vary differently. However, few studies have examined all the four groups of rumen microbes. This study investigated the effect of both the level and source of dietary energy on rumen bacteria, archaea, fungi, and protozoa in the rumen of lactating dairy cows. A 2 × 2 factorial design resulted in four dietary treatments: low and high dietary energy levels(LE: 1.52–1.53;and HE: 1.71–1.72 Mcal/kg dry matter) and two dietary energy sources(GC: finely ground corn;and SFC: steam-flaked corn). We used a replicated 4 × 4 Latin square design using eight primiparous Chinese Holstein cows with each period lasting for 21 d. The rumen microbiota was analyzed using metataxonomics based on kingdom-specific phylogenetic markers [16 S r RNA gene for bacteria and archaea, 18 S r RNA gene for protozoa, and internally transcribed spacer 1(ITS1) for fungi] followed with subsequent functional prediction using PICRUSt2.Results: The GC resulted in a higher prokaryotic(bacterial and archaeal) species richness and Faith's phylogenetic diversity than SFC. For the eukaryotic(fungi and protozoa) microbiota, the LE diets led to significantly higher values of the above measurements than the HE diets. Among the major classified taxa, 23 genera across all the kingdoms differed in relative abundance between the two dietary energy levels, while only six genera(none being protozoal)were differentially abundant between the two energy sources. Based on prokaryotic amplicon sequence variants(ASVs) from all the samples, overall functional profiles predicted using PICRUSt2 differed significantly between LE and HE but not between the two energy sources. Fish Taco analysis identified Ruminococcus and Coprococcus as the taxa potentially contributing to the enriched KEGG pathways for biosynthesis of amino acids and to the metabolisms of pyruvate, glycerophospholipid, and nicotinate and nicotinamide in the rumen of HE-fed cows. The co-occurrence networks were also affected by the dietary treatments, especially the LE and GC diets, resulting in distinct co-occurrence networks. Several microbial genera appeared to be strongly correlated with one or more lactation traits.Conclusions: Dietary energy level affected the overall rumen multi-kingdom microbiota while little difference was noted between ground corn and steam-flaked corn. Some genera were also affected differently by the four dietary treatments, including genera that had been shown to be correlated with lactation performance or feed efficiency.The co-occurrence patterns among the genera exclusively found for each dietary treatment may suggest possible metabolic interactions specifically affected by the dietary treatment. Some of the major taxa were positively correlated to milk properties and may potentially serve as biomarkers of one or more lactation traits.
基金supported by Health and Family Planning Commission of Hubei Province(No.02-16-516052)
文摘Summary： Evidence-based medicine is advocated by WHO and adopted by developed countries for many years. In China, however, the selection of essential medicine and various medical insurance reimbursement schemes medicine is usually based on experts＇ experience of prescription practice which is under heavy critics resulting from the lack of related comparative efficacy and evidence-based research. The efficacy of Jian＇ganle in prevention of drug-induced liver injury （DILI） caused by antituberculotics was evaluated in this study by comparison with Hugan Pian, glucuronolactone and reduced glutathione. Evidence was provided for relevant sectors such as Ministry for Human Resources and Social Security of the People＇s Republic of China and National Health and Family Planning Commission of the Peo- ple＇s Republic of China to select and renew the Essential Medicine List （EML）, the new rural cooperative medical scheme in China （NRCMS） list or the reimbursement list of industrial injury insurance. A total of 189 patients with initial pulmonary tuberculosis were divided into four groups who took antituberculotics combined with Jian＇ganle, Hugan Pian, glucuronolactone and reduced glutathione respectively. Their liver function profile including alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, total bilirubin （TBIL）, direct bilirubin （DBIL）, total protein （TP）, albumin （A） and globulin （G） were detected at admission as baseline and after treatment. The Jian＇ganle group was compared with the three others by chi-square tests. In an aspect of maintaining bilirubin indexes normal, Jian＇ganle was more efficacious than glucuronolactone. And Jian＇ganle had a little more efficacy than reduced glutathione to maintain protein indexes normal as well. And the therapeutic regimen of antituberculotics combined with Jian＇ganle was the best in treating tuberculosis and preventing DILI at the same time. The study showed that among the four hepatinicas which demonstrated similar prevention of DILI caused by antituberculotics, Jian＇ganle has more advantages over the three others to some extent, which provides a reliable basis for health sectors to select and renew the EML, NRCMS List or the reimbursement list of industrial injury insurance.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10647002 and 10565001 and the Science Foundation of Guangxi Province of China under Grant Nos. 0481030, 0542042, and 0575020
文摘We propose QCD inspired model to calculate ^-pp and pp elastic scatterings at high energies in this paper. A calculation for total cross section of ^-pp and pp is performed in which the contributions from gluon-gluon, quark-quark, and gluon-quark interactions are included. Our results show that the QCD inspired model gives a perfect fit to experimental data of total cross section both for ^-pp and pp elastic scatterings at the whole energy region where experimental data existed at FNAL and CERN.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10647002 and 10565001 and the Science Foundation of Guangxi Province of China under Grant Nos. 0481030, 0542042, and 0575020
文摘We use the QCD inspired model to analyze the ratio of the real to the imaginary for pp and pp elastic scatterings. A calculation for the ratio of the real to the imaginary is performed in which the contributions from gluongluon interaction, quark-quark interaction, quark-gluon interaction, and odd eikonal profile function are included. Our results show that the QCD inspired model gives a good fit to the LHC experimental data.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51172236,51272254,51102239,61205173,and 61405206)
文摘Profile function properties with different variables are discussed, the formulae of stimulated absorption, spontaneous and stimulated emission, absorption and emission coefficients, and cross sections are deduced, and some confusing issues are clarified.
基金The Natural Science Foundation of Guangdong Province under contract No.2022A1515011519the National Natural Science Foundation of China under contract No.11904290.
文摘Complex perturbations in the profile and the sparsity of samples often limit the validity of rapid environmental assessment(REA)in the South China Sea(SCS).In this paper,the remote sensing data were used to estimate sound speed profile(SSP)with the self-organizing map(SOM)method in the SCS.First,the consistency of the empirical orthogonal functions was examined by using k-means clustering.The clustering results indicated that SSPs in the SCS have a similar perturbation nature,which means the inverted grid could be expanded to the entire SCS to deal with the problem of sparsity of the samples without statistical improbability.Second,a machine learning method was proposed that took advantage of the topological structure of SOM to significantly improve their accuracy.Validation revealed promising results,with a mean reconstruction error of 1.26 m/s,which is 1.16 m/s smaller than the traditional single empirical orthogonal function regression(sEOF-r)method.By violating the constraints of linear inversion,the topological structure of the SOM method showed a smaller error and better robustness in the SSP estimation.The improvements to enhance the accuracy and robustness of REA in the SCS were offered.These results suggested a potential utilization of REA in the SCS based on satellite data and provided a new approach for SSP estimation derived from sea surface data.
基金the National Science Foundation for funding Dillon Amaya’s project work in summer 2012 through the Research Experience for Undergraduates(REU)Program,grant AGS1005265
文摘Fifty years ago, Hans A. Panofsky published a paper entitled Determination of stress from wind and temperature measurements. In his famous paper, he presented a new profile function for the mean horizontal wind speed under the condition of diabatic stratification that includes his integral similarity function. With his integral similarity function, he opened the door for Monin-Obukhov scaling in a wide range of micrometeorological and microclimatological applications. In a historic survey ranging from the sixties of the past century down to the present days, we present integral similarity functions for momentum, sensible heat, and water vapor for both unstable and stable stratification, where on the one hand free convection condition and on the other hand strongly stable stratification are addressed.
基金Supported by National Institute of Health Grant GM47475, Department of Energy Grant DE-FG03-87ER13742, and U.S. Department of Agriculture Grant 5335-21000-010-00D. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.Acknowledgements Thank the coauthors of the original research publications used as the basis for this article, and Jim Tepperman for figure preparation and help with the manuscript.
文摘Identification of all genes involved in the phytochrome （phy）-medieted responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth end development. This article highlights end integrates the central findings of two recent comprehensive studies in Arabidopsis that have identified the genome-wide set of phy-reguleted genes that respond rapidly to red-light signals upon first exposure of dark-grown seedlings, and have tested the functional relevance to normal seedling photomorphogenesis of an Initial subset of these genes. The data： （a） reveal considerable complexity in the channeling of the light signals through the different phy-femily members （phyA to phyE） to responsive genes; （b） identify a diversity of transcription-factor-encoding genes as major early, if not primary, targets of phy signaling, end, therefore, as potentially important regulators in the transcriptional-network hierarchy; and （c） identify auxin-related genes as the dominant class among rapidly-regulated, hormone-related genes. However, reverse-genetic functional profiling of a selected subset of these genes reveals that only a limited fraction are necessary for optimal phy-induced seedling deetioletion.
基金supported by NIH under Grant No. 1R01HG004908-01NSF of USA under Grant No. DBI-0845685 (YY)the Gordon and Betty Moore Foundation for the Community Cyberinfrastructure for Marine Microbial Ecological Research and Analysis (CAMERA) Project (JW)
文摘Metagenomics is the study of microbial communities sampled directly from their natural environment, without prior culturing. By enabling an analysis of populations including many （so-far） unculturable and often unknown microbes, metagenomics is revolutionizing the field of microbiology, and has excited researchers in many disciplines that could benefit from the study of environmental microbes, including those in ecology, environmental sciences, and biomedicine. Specific computational and statistical tools have been developed for metagenomic data analysis and comparison. New studies, however, have revealed various kinds of artifacts present in metagenomics data caused by limitations in the experimental protocols and/or inadequate data analysis procedures, which often lead to incorrect conclusions about a microbial community. Here, we review some of the artifacts, such as overestimation of species diversity and incorrect estimation of gene family frequencies, and discuss emerging computational approaches to address them. We also review potential challenges that metagenomics may encounter with the extensive application of next-generation sequencing （NGS） techniques.
基金supported by the National Basic Research Program of China("973" Program)(Grant Nos.2013CB036406,2010CB951102)the National Natural Science Foundation of China(Grant No.51109224)
文摘Profile likelihood function is introduced to analyze the uncertainty of hydrometeorological extreme inference and the theory of estimating confidence intervals of the key parameters and quantiles of extreme value distribution by profile likelihood function is described.GEV(generalized extreme value)distribution and GP(generalized Pareto)distribution are used respectively to fit the annual maximum daily flood discharge sample of the Yichang station in the Yangtze River and the daily rainfall sample in10 big cities including Guangzhou.The parameters of the models are estimated by maximum likelihood method and the fitting results are tested by probability plot,quantile plot,return level plot and density plot.The return levels and confidence intervals of flood and rainstorm in different return periods are calculated by profile likelihood function.The results show that the asymmetry of the profile likelihood function curve increases with the return period,which can reflect the effect of the length of sample series and return periods on confidence interval.As an effective tool for estimating confidence interval of the key parameters and quantiles of extreme value distribution,profile likelihood function can lead to a more accurate result and help to analyze the uncertainty of extreme values of hydrometeorology.
基金supported by the National Natural Science Foundation of China(11004214,11274338)the National Defense Foundation of China(9140A03050312ZK0201)
文摘In order to evaluate the reliability and applicability of the Empirical Orthogonal Functions（EOFs）in the acoustic inversion of sound speed profile（SSP）and reduce EOF＇s dependence on the sample data,a methodology is proposed for the achievement of the basis functions for SSP＇s expansion.By analyzing the oceanographic dynamics which is the main cause of the SSP＇s variation,the basis functions are obtained naming the Hydrodynamic Normal Modes（HNMs）.The HNM basis functions are almost the same as those derived from the EOF method,while HNMs has less dependence on the amount of the sample data.HNMs method has a physically meaningful interpretation,and it could give out the physical parameters which determine the basis functions for the expansion of SSP,and this makes it possible to analyze and evaluate the trustiness and applicability of EOFs.
