Earlier work by the authors in which active sound pressure signals and impulsive pressure disturbances were used to measure flow rates in gas solid systems was briefly reviewed. Work in progress with an emerging techn...Earlier work by the authors in which active sound pressure signals and impulsive pressure disturbances were used to measure flow rates in gas solid systems was briefly reviewed. Work in progress with an emerging technology in which Helmholtz resonance is applied to the measurement of volume is outlined.展开更多
Skeletal muscle has an extraordinary capacity to regenerate after injury and trauma. The muscle repair mechanism is a complex process orchestrated by multiple steps. In neuromuscular disorders such as Duchenne muscula...Skeletal muscle has an extraordinary capacity to regenerate after injury and trauma. The muscle repair mechanism is a complex process orchestrated by multiple steps. In neuromuscular disorders such as Duchenne muscular dystrophy (DMD), the pathological consequences of the lack of dystrophin and the loss of the dystrophin-associated protein complex are dramatic, with a progressive cascade of events, such as continual influx of inflammation, repeated cycles of degeneration and impaired regeneration. Thus, muscle regeneration is a hallmark of the disease and careful monitoring of regenerative processes with robust markers should provide useful information to the field. Since decades, several indices of regeneration such as centronucleation and fibre size have been commonly used. In the present review, we discuss the impaired regenerative process in DMD, the common and new indices of regeneration and their associated methodologies. We notably highlight the regenerative marker embryonic myosin as a robust indicator of muscle regeneration. We also describe new quantitative methodologies offering the possibility of using a panel of translational regenerative biomarkers to obtain a more complete view of the regeneration processes. Upregulation of utrophin, an autosomal and functional paralogue of dystrophin, is one of the most promising therapeutic strategies as it targets the primary cause of the disease and is applicable to all DMD patients regardless their genetic defects. As utrophin is a regeneration associated protein increased in dystrophic muscle, we discuss the correlation of utrophin levels after drug treatment with regeneration markers. The recent advances in technologies and complementary markers of muscle regeneration described in this review, provide an unprecedented opportunity to develop more robust utrophin DMD based strategies for all DMD patients.展开更多
A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, an...A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, and are considerably more stable than Cu–ZrO2 catalysts prepared by other co-precipitation methods for this reaction.Characterisation and further investigation of these catalysts by XRD, BET, SEM and XPS provided insight into the nature of the catalytic active site and the physicochemical properties that lead to catalyst stability.We consider the active site to be the interface between Cu/CuOxand ZrOx and that lattice Cu species assist with the dispersion of surface Cu through the promotion of a strong metal support interaction.This enhanced understanding of the active site and roles of lattice and surface Cu will assist with future catalyst design.As such, we conclude that the activity of Cu–ZrO2 catalysts in this reaction is dictated by the quantity of Cu–Zr interface sites.展开更多
The factors that determine fibrosis progression or normal tissue repair are largely unknown.We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition(EMT)in human alveolar epithel...The factors that determine fibrosis progression or normal tissue repair are largely unknown.We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition(EMT)in human alveolar epithelial type Il(ATIl)cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signaling.Here,we report that liver kinase B1(LKB1)inactivation in ATIl cells inhibits autophagy and induces EMT as a conse-quence.In IPF lungs,this is caused by the down-regulation of CAB39L,a key subunit within the LKB1 complex.3D co-cultures of ATIl cells and MRC5 lung fibroblasts coupled with RNA sequencing(RNA-seq)confirmed that paracrine signaling between LKB1-depleted ATIl cells and fibroblasts augmented myofibroblast differentiation.Together,these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATIl cells and contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.展开更多
A first search for the Ξ_(bc)^(+)J/ψΞ_(c)^(+) decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass...A first search for the Ξ_(bc)^(+)J/ψΞ_(c)^(+) decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of 4.3(2.8) and 4.1(2.4) standard deviations at masses of 6571 and 6694 MeV/c2, respectively. Upper limits are set on the Ξ+bc baryon production cross-section times the branching fraction relative to that of the B+c→J/ψD+s decay at centre-of-mass energies of 8 and 13 TeV, in the Ξ+bc and in the B+c rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to 20GeV/c, respectively. Upper limits are presented as a function of the Ξ+bc mass and lifetime.展开更多
A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity...A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit.展开更多
Progressive lung fibrosis is characterized by dysregulated extracellular matrix(ECM)homeostasis.Understand-ing of disease pathogenesis remains limited and has prevented the development of effective treatments.While an...Progressive lung fibrosis is characterized by dysregulated extracellular matrix(ECM)homeostasis.Understand-ing of disease pathogenesis remains limited and has prevented the development of effective treatments.While an abnormal wound-healing response is strongly implicated in lung fibrosis initiation,factors that determine why fi-brosis progresses rather than regular tissue repair occur are not fully explained.Within human lung fibrosis,there is evidence of altered epithelial and mesenchymal populations as well as cells undergoing epithelial-mesenchymal transition(EMT),a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell-cell adhesion to gain migratory properties.This review will focus on the role of EMT and dysregulated epithelial-mesenchymal crosstalk in progressive lung fibrosis.展开更多
Evidence for the '8.2 ka cold event' has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provid...Evidence for the '8.2 ka cold event' has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provide the evidence for the '8.2 ka cold event' from the Guliya ice core in the northwest Tibetan Plateau, and it was found that the peak cooling (-8.3-8.2 ka) in this ice core was about 7.8-10°C, which was larger than the cooling in the North Atlantic region. The primary causes for this episode were diminished solar activity and weakened thermohaline circulation. Moreover, another weak cold event, centered about 9.4 ka, was also recorded in the Guliya ice core record. These two cold events were concurrent with the ice-rafting episodes in the North Atlantic during the early Holocene, which implies that the millennial-scale climatic cyclicity might exist in the Tibetan Plateau as well as in the North Atlantic.展开更多
Background： Attention deficit hyperactivity disorder （ADHD） is a common childhood disorder that affects approximately 11% of children in the United States. Research supports that a single session of exercise benefi...Background： Attention deficit hyperactivity disorder （ADHD） is a common childhood disorder that affects approximately 11% of children in the United States. Research supports that a single session of exercise benefits cognitive performance by children, and a limited number of studies have demonstrated that these effects can also be realized by children with ADHD. The purpose of this study was to examine the effect of acute exercise on cognitive performance by children with and without ADHD. Methods： Children with and without ADHD were asked to perform cognitive tasks on 2 days following treatment conditions that were assigned in a random, counterbalanced order. The treatment conditions consisted of a 30-min control condition on 1 day and a moderate intensity exercise condition on the other day. Results： Exercise significantly benefited performance on all three conditions of the Stroop Task, but did not significantly affect performance on the Tower of London or the Trail Making Test. Conclusion： children with and without ADHD realize benefits in speed of processing and inhibitory control in response to a session of acute exercise, but do not experience benefits in planning or set shifting.展开更多
AIM:With successful surgical treatment of gastroesophageal reflux disease(GERD),there is interest in understanding the anti-reflux barrier and its mechanisms of failure.To date, the potential use of vector volumes to ...AIM:With successful surgical treatment of gastroesophageal reflux disease(GERD),there is interest in understanding the anti-reflux barrier and its mechanisms of failure.To date, the potential use of vector volumes to predict the DeMeester score has not been adequately explored. METHODS:627 patients in the referral database received esophageal manometry and ambulatory 24-hour pH monitoring.Study data included LES resting pressure(LESP), overall LES length(OL)and abdominal length(AL),total vector volume(TVV)and intrabdominal vector volume(IVV). RESULTS:In cases where LESP,TVV or IVV were all below normal,there was an 81.4%probability of a positive DeMeester score.In cases where all three were normal, there was an 86.9%probability that the DeMeester score would be negative.Receiver-operating characteristics(ROC) for LESP,TVV and IVV were nearly identical and indicated no useful cut-off values.Logistic regression demonstrated that LESP and IVV had the strongest association with a positive DeMeester score;however,the regression formula was only 76.1%accurate. CONCLUSION:While the indices based on TVV,IVV and LESP are more sensitive and specific,respectively,than any single measurement,the measurement of vector volumes does not add significantly to the diagnosis of GERD.展开更多
On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ec...On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ecological traits concerning niche differentiation among sympatric animals on the Qinghai-Tibet Plateau,especially during winter when the environments are most severe.Here,we studied the seasonal variations in habitat occurrence,territorial behavior,and diet in two sympatric snow finches(the white-rumped snow finch,Onychostruthus taczanowskii,WRSF;and the rufous-necked snow finch,Pyrgilauda ruficollis,RNSF)to determine convergence and divergence of ecological traits in such severe climatic conditions.Our results showed that:(i)WRSF occupied rural areas as a dominant species throughout the annual cycle while RNSF occupied the rural areas in summer and then shifted to human-occupied areas in winter and spring;(ii)WRSFs exhibited robust aggressive behavior and territoriality during winter relative to RNSFs;(iii)the diets of both species varied with the season but did not vary between species except that WRSF ate significantly more seeds but RNSF consumed more starchy material derived from human food waste during winter.Therefore,the separations in the spatial niche and territoriality between WRSF and RNSF,especially in winter,may contribute to alleviating the pressure of interspecific competition,and promoting the coexistence of the two sympatric snow finches in the extreme environments on the Qinghai-Tibet Plateau.展开更多
Based on the data of temperature changes revealed by means of various palaeothermometric proxy indices,it is found that the magnitude of temperature decrease became large with altitude in the equatorial regions during...Based on the data of temperature changes revealed by means of various palaeothermometric proxy indices,it is found that the magnitude of temperature decrease became large with altitude in the equatorial regions during the Last Glacial Maximum. The direct cause of this phenomenon was the change in temperature lapse rate, which was about(0.1±0.05)℃/100 m larger in the equator during the Last Glacial Maximum than at present. Moreover, the analyses show that CLIMAP possibly underestimated the sea surface temperature decrease in the equatorial regions during the Last Glacial Maximum.展开更多
Trace analysis of volatile organic compounds(VOCs) during wildfires is imperative for environmental and health risk assessment. The use of gas sampling devices mounted on unmanned aerial vehicles(UAVs) to chemically s...Trace analysis of volatile organic compounds(VOCs) during wildfires is imperative for environmental and health risk assessment. The use of gas sampling devices mounted on unmanned aerial vehicles(UAVs) to chemically sample air during wildfires is of great interest because these devices move freely about their environment, allowing for more representative air samples and the ability to sample areas dangerous or unreachable by humans. This work presents chemical data from air samples obtained in Davis, CA during the most destructive wildfire in California's history-the 2018 Camp Fire – as well as the deployment of our sampling device during a controlled experimental fire while fixed to a UAV. The sampling mechanism was an in-house manufactured micro-gas preconcentrator(μPC) embedded onto a compact battery-operated sampler that was returned to the laboratory for chemical analysis. Compounds commonly observed in wildfires were detected during the Camp Fire using gas chromatography mass spectrometry(GC–MS), including BTEX(benzene, toluene, ethylbenzene, m + p-xylene, and o-xylene), benzaldehyde, 1,4-dichlorobenzene, naphthalene, 1,2,3-trimethylbenzene and 1-ethyl-3-methylbenzene. Concentrations of BTEX were calculated and we observed that benzene and toluene were highest with average concentrations of 4.7 and 15.1 μg/m^(3), respectively. Numerous fire-related compounds including BTEX and aldehydes such as octanal and nonanal were detected upon experimental fire ignition, even at a much smaller sampling time compared to samples taken during the Camp Fire. Analysis of the air samples taken both stationary during the Camp Fire and mobile during an experimental fire show the successful operation of our sampler in a fire environment.展开更多
文摘Earlier work by the authors in which active sound pressure signals and impulsive pressure disturbances were used to measure flow rates in gas solid systems was briefly reviewed. Work in progress with an emerging technology in which Helmholtz resonance is applied to the measurement of volume is outlined.
文摘Skeletal muscle has an extraordinary capacity to regenerate after injury and trauma. The muscle repair mechanism is a complex process orchestrated by multiple steps. In neuromuscular disorders such as Duchenne muscular dystrophy (DMD), the pathological consequences of the lack of dystrophin and the loss of the dystrophin-associated protein complex are dramatic, with a progressive cascade of events, such as continual influx of inflammation, repeated cycles of degeneration and impaired regeneration. Thus, muscle regeneration is a hallmark of the disease and careful monitoring of regenerative processes with robust markers should provide useful information to the field. Since decades, several indices of regeneration such as centronucleation and fibre size have been commonly used. In the present review, we discuss the impaired regenerative process in DMD, the common and new indices of regeneration and their associated methodologies. We notably highlight the regenerative marker embryonic myosin as a robust indicator of muscle regeneration. We also describe new quantitative methodologies offering the possibility of using a panel of translational regenerative biomarkers to obtain a more complete view of the regeneration processes. Upregulation of utrophin, an autosomal and functional paralogue of dystrophin, is one of the most promising therapeutic strategies as it targets the primary cause of the disease and is applicable to all DMD patients regardless their genetic defects. As utrophin is a regeneration associated protein increased in dystrophic muscle, we discuss the correlation of utrophin levels after drug treatment with regeneration markers. The recent advances in technologies and complementary markers of muscle regeneration described in this review, provide an unprecedented opportunity to develop more robust utrophin DMD based strategies for all DMD patients.
基金financially supported by the European Union FP7 NMP project NOVACAM (Novel cheap and abundant EU-Japan604319)
文摘A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, and are considerably more stable than Cu–ZrO2 catalysts prepared by other co-precipitation methods for this reaction.Characterisation and further investigation of these catalysts by XRD, BET, SEM and XPS provided insight into the nature of the catalytic active site and the physicochemical properties that lead to catalyst stability.We consider the active site to be the interface between Cu/CuOxand ZrOx and that lattice Cu species assist with the dispersion of surface Cu through the promotion of a strong metal support interaction.This enhanced understanding of the active site and roles of lattice and surface Cu will assist with future catalyst design.As such, we conclude that the activity of Cu–ZrO2 catalysts in this reaction is dictated by the quantity of Cu–Zr interface sites.
基金supported by the UK Medical Research Council(MR/S025480/1)the UK Academy of Medical Sciences/the Wellcome Trust Springboard Award(SBF002/1038)+2 种基金AAIR Charity.ZX and LY were supported by China Scholarship Council.YZ was supported by an Institute for Life Sciences PhD Studentship.JD was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK(FC001070)the UK Medical Research Council(FC001070)the Wellcome Trust(FC001070).
文摘The factors that determine fibrosis progression or normal tissue repair are largely unknown.We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition(EMT)in human alveolar epithelial type Il(ATIl)cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signaling.Here,we report that liver kinase B1(LKB1)inactivation in ATIl cells inhibits autophagy and induces EMT as a conse-quence.In IPF lungs,this is caused by the down-regulation of CAB39L,a key subunit within the LKB1 complex.3D co-cultures of ATIl cells and MRC5 lung fibroblasts coupled with RNA sequencing(RNA-seq)confirmed that paracrine signaling between LKB1-depleted ATIl cells and fibroblasts augmented myofibroblast differentiation.Together,these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATIl cells and contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.
基金The project support from CERN and from the national agencies:CAPES,CNPq,FAPERJ and FINEP(Brazil)MOST and NSFC(China)+18 种基金CNRS/IN2P3(France)BMBF,DFG and MPG(Germany)INFN(Italy)NWO(Netherlands)MNiSW and NCN(Poland)MEN/IFA(Romania)MICINN(Spain)SNSF and SER(Switzerland)NASU(Ukraine)STFC(United Kingdom)DOE NP and NSF(USA).We acknowledge the computing resources that are provided by CERN,IN2P3(France),KIT and DESY(Germany),INFN(Italy),SURF(Netherlands),PIC(Spain),GridPP(United Kingdom),CSCS(Switzerland),IFIN-HH(Romania),CBPF(Brazil),Polish WLCG(Poland)and NERSC(USA).Individual groups or members have received support from ARC and ARDC(Australia)Minciencias(Colombia)AvH Foundation(Germany)EPLANET,Marie Sklodowska-Curie Actions and ERC(European Union)A*MIDEX,ANR,IPhU and Labex P2IO,and Région Auvergne-RhôneAlpes(France)Key Research Program of Frontier Sciences of CAS,CAS PIFI,CAS CCEPP,Fundamental Research Funds for the Central Universities,and Sci.&Tech.Program of Guangzhou(China)GVA,XuntaGal,GENCAT and Prog.Atracción Talento,CM(Spain)SRC(Sweden)the Leverhulme Trust,the Royal Society and UKRI(United Kingdom).
文摘A first search for the Ξ_(bc)^(+)J/ψΞ_(c)^(+) decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb−1 recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of 4.3(2.8) and 4.1(2.4) standard deviations at masses of 6571 and 6694 MeV/c2, respectively. Upper limits are set on the Ξ+bc baryon production cross-section times the branching fraction relative to that of the B+c→J/ψD+s decay at centre-of-mass energies of 8 and 13 TeV, in the Ξ+bc and in the B+c rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to 20GeV/c, respectively. Upper limits are presented as a function of the Ξ+bc mass and lifetime.
文摘A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit.
基金supported by the UK Medical Research Council(MR/S025480/1)the UK Academy of Medical Sciences/the Well-come Trust Springboard Award[SBF002\1038]LY and ZX were sup-ported by the China Scholarship Council.
文摘Progressive lung fibrosis is characterized by dysregulated extracellular matrix(ECM)homeostasis.Understand-ing of disease pathogenesis remains limited and has prevented the development of effective treatments.While an abnormal wound-healing response is strongly implicated in lung fibrosis initiation,factors that determine why fi-brosis progresses rather than regular tissue repair occur are not fully explained.Within human lung fibrosis,there is evidence of altered epithelial and mesenchymal populations as well as cells undergoing epithelial-mesenchymal transition(EMT),a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell-cell adhesion to gain migratory properties.This review will focus on the role of EMT and dysregulated epithelial-mesenchymal crosstalk in progressive lung fibrosis.
基金This work was supported by the Chinese National Committee of Science and Technology (Grant No. G1998040800)the Chinese Academy of Sciences (Grant No. KZCX1-10-02)+1 种基金 the National Natural Science Foundation of China (Grant No. 49801004) the US NSF-ESH
文摘Evidence for the '8.2 ka cold event' has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provide the evidence for the '8.2 ka cold event' from the Guliya ice core in the northwest Tibetan Plateau, and it was found that the peak cooling (-8.3-8.2 ka) in this ice core was about 7.8-10°C, which was larger than the cooling in the North Atlantic region. The primary causes for this episode were diminished solar activity and weakened thermohaline circulation. Moreover, another weak cold event, centered about 9.4 ka, was also recorded in the Guliya ice core record. These two cold events were concurrent with the ice-rafting episodes in the North Atlantic during the early Holocene, which implies that the millennial-scale climatic cyclicity might exist in the Tibetan Plateau as well as in the North Atlantic.
文摘Background： Attention deficit hyperactivity disorder （ADHD） is a common childhood disorder that affects approximately 11% of children in the United States. Research supports that a single session of exercise benefits cognitive performance by children, and a limited number of studies have demonstrated that these effects can also be realized by children with ADHD. The purpose of this study was to examine the effect of acute exercise on cognitive performance by children with and without ADHD. Methods： Children with and without ADHD were asked to perform cognitive tasks on 2 days following treatment conditions that were assigned in a random, counterbalanced order. The treatment conditions consisted of a 30-min control condition on 1 day and a moderate intensity exercise condition on the other day. Results： Exercise significantly benefited performance on all three conditions of the Stroop Task, but did not significantly affect performance on the Tower of London or the Trail Making Test. Conclusion： children with and without ADHD realize benefits in speed of processing and inhibitory control in response to a session of acute exercise, but do not experience benefits in planning or set shifting.
文摘AIM:With successful surgical treatment of gastroesophageal reflux disease(GERD),there is interest in understanding the anti-reflux barrier and its mechanisms of failure.To date, the potential use of vector volumes to predict the DeMeester score has not been adequately explored. METHODS:627 patients in the referral database received esophageal manometry and ambulatory 24-hour pH monitoring.Study data included LES resting pressure(LESP), overall LES length(OL)and abdominal length(AL),total vector volume(TVV)and intrabdominal vector volume(IVV). RESULTS:In cases where LESP,TVV or IVV were all below normal,there was an 81.4%probability of a positive DeMeester score.In cases where all three were normal, there was an 86.9%probability that the DeMeester score would be negative.Receiver-operating characteristics(ROC) for LESP,TVV and IVV were nearly identical and indicated no useful cut-off values.Logistic regression demonstrated that LESP and IVV had the strongest association with a positive DeMeester score;however,the regression formula was only 76.1%accurate. CONCLUSION:While the indices based on TVV,IVV and LESP are more sensitive and specific,respectively,than any single measurement,the measurement of vector volumes does not add significantly to the diagnosis of GERD.
文摘On the Qinghai-Tibet Plateau,extreme environmental conditions have imposed intense selective pressure on the evolution of phenotypic traits of wild animals.To date,limited information is available on behavioral and ecological traits concerning niche differentiation among sympatric animals on the Qinghai-Tibet Plateau,especially during winter when the environments are most severe.Here,we studied the seasonal variations in habitat occurrence,territorial behavior,and diet in two sympatric snow finches(the white-rumped snow finch,Onychostruthus taczanowskii,WRSF;and the rufous-necked snow finch,Pyrgilauda ruficollis,RNSF)to determine convergence and divergence of ecological traits in such severe climatic conditions.Our results showed that:(i)WRSF occupied rural areas as a dominant species throughout the annual cycle while RNSF occupied the rural areas in summer and then shifted to human-occupied areas in winter and spring;(ii)WRSFs exhibited robust aggressive behavior and territoriality during winter relative to RNSFs;(iii)the diets of both species varied with the season but did not vary between species except that WRSF ate significantly more seeds but RNSF consumed more starchy material derived from human food waste during winter.Therefore,the separations in the spatial niche and territoriality between WRSF and RNSF,especially in winter,may contribute to alleviating the pressure of interspecific competition,and promoting the coexistence of the two sympatric snow finches in the extreme environments on the Qinghai-Tibet Plateau.
基金Project supported by the Chinese National and CAS' Qinghai-Tibet Project (Grant No. KZ951-A1-204-02).
文摘Based on the data of temperature changes revealed by means of various palaeothermometric proxy indices,it is found that the magnitude of temperature decrease became large with altitude in the equatorial regions during the Last Glacial Maximum. The direct cause of this phenomenon was the change in temperature lapse rate, which was about(0.1±0.05)℃/100 m larger in the equator during the Last Glacial Maximum than at present. Moreover, the analyses show that CLIMAP possibly underestimated the sea surface temperature decrease in the equatorial regions during the Last Glacial Maximum.
基金supported by NIH award U01 EB0220003-01[CED,NJK]the NIH National Center for Advancing Translational Sciences(NCATS)through grant UL1 TR000002[CED,NJK]+1 种基金NIH award 1P30ES023513-01A1[CED,NJK]NIH award UG3-OD023365[CED,NJK]。
文摘Trace analysis of volatile organic compounds(VOCs) during wildfires is imperative for environmental and health risk assessment. The use of gas sampling devices mounted on unmanned aerial vehicles(UAVs) to chemically sample air during wildfires is of great interest because these devices move freely about their environment, allowing for more representative air samples and the ability to sample areas dangerous or unreachable by humans. This work presents chemical data from air samples obtained in Davis, CA during the most destructive wildfire in California's history-the 2018 Camp Fire – as well as the deployment of our sampling device during a controlled experimental fire while fixed to a UAV. The sampling mechanism was an in-house manufactured micro-gas preconcentrator(μPC) embedded onto a compact battery-operated sampler that was returned to the laboratory for chemical analysis. Compounds commonly observed in wildfires were detected during the Camp Fire using gas chromatography mass spectrometry(GC–MS), including BTEX(benzene, toluene, ethylbenzene, m + p-xylene, and o-xylene), benzaldehyde, 1,4-dichlorobenzene, naphthalene, 1,2,3-trimethylbenzene and 1-ethyl-3-methylbenzene. Concentrations of BTEX were calculated and we observed that benzene and toluene were highest with average concentrations of 4.7 and 15.1 μg/m^(3), respectively. Numerous fire-related compounds including BTEX and aldehydes such as octanal and nonanal were detected upon experimental fire ignition, even at a much smaller sampling time compared to samples taken during the Camp Fire. Analysis of the air samples taken both stationary during the Camp Fire and mobile during an experimental fire show the successful operation of our sampler in a fire environment.
