The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structur...The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna grasslands.We analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral management.At two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near stockyards.Furthermore,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of GPI.The only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near stockyards.In summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations vary.Finally,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.展开更多
Remote sensing(RS)technologies are extensively exploited by scientists and a vast audience of local authorities,urban managers,and city planners.Coastal regions,geohazard-prone areas,and highly populated cities repres...Remote sensing(RS)technologies are extensively exploited by scientists and a vast audience of local authorities,urban managers,and city planners.Coastal regions,geohazard-prone areas,and highly populated cities represent natural laboratories to apply RS technologies and test new methods.Over the last decades,many efforts have been spent on improving Earth’s surface monitoring,including intensifying Earth Observation(EO)operations by the major national space agencies.They oversee to plan and make operational constellations of satellite sensors providing the scientific community with extensive research and development opportunities in the geoscience field.For instance,within this framework,the European Space Agency(ESA)and the Ministry of Science and Technology of China(MOST)have sponsored,since the early 2000s,the DRAGON initiative jointly carried out by the European and Chinese RS scientific communities.This manuscript aims to provide a synthetic overview of some research activities and new methods recently designed and applied and trace the route for further developments.The main findings are related to i)the analysis of flood risk in China,ii)the potential of new methods for the estimation and removal of ground displacement biases in small-baseline oriented interferometric Synthetic Aperture Radar(SAR)methods,iii)the analysis of the inundation risk in low-lying regions using coherent and incoherent SAR methods;and iv)the use of SAR-based technologies for marine applications.展开更多
This project is to evaluate the benefits of the MFN status and the consequences of non-MFN renewal on trades between China and the United States.This paper also reveals the effects of quota removal on clothing and tex...This project is to evaluate the benefits of the MFN status and the consequences of non-MFN renewal on trades between China and the United States.This paper also reveals the effects of quota removal on clothing and textile products on international trades between the United States,China,Hong Kong,Taiwan,and India.Data analyses,statistics,and charts,the changes in China’s number of exports to the United States,in particular,the apparel and textile sectors were selected to analyze from 1995 to 2005.展开更多
A 72-h high-resolution simulation of Supertyphoon Rammasun （2014） is performed using the Advanced Research Weather Research and Forecasting model. The model covers an initial 18-h spin-up, the 36-h rapid intensifica...A 72-h high-resolution simulation of Supertyphoon Rammasun （2014） is performed using the Advanced Research Weather Research and Forecasting model. The model covers an initial 18-h spin-up, the 36-h rapid intensification （RI） period in the northern South China Sea, and the 18-h period of weakening after landfall. The results show that the model reproduces the track, intensity, structure of the storm, and environmental circulations reasonably well. Analysis of the surface energetics under the storm indicates that the storm＇s intensification is closely related to the net energy gain rate （eg）, defined as the difference between the energy production （PD） due to surface entropy flux and the energy dissipation （Ds） due to surface friction near the radius of maximum wind （RMW）. Before and during the RI stage, the ~：g is high, indicating sufficient energy supply for the storm to intensify. However, the Sg decreases rapidly as the storm quickly intensifies, because the Ds increases more rapidly than the PD near the RMW. By the time the storm reaches its peak intensity, the Ds is about 20% larger than the PD near the RMW, leading to a local energetics deficit under the eyewall. During the mature stage, the PD and Ds can reach a balance within a radius of 86 km from the storm center （about 2.3 times the RMW）. This implies that the local PD under the eyewall is not large enough to balance the Ds, and the radially inward energy transport from outside the eyewall must play an important role in maintaining the storm＇s intensity, as well as its intensification.展开更多
A 2-km resolution simulation using the Weather Research and Forecasting model with Morrison microphysics was employed to investigate the rainwater microphysical properties during different stages of Typhoon Usagi(2013...A 2-km resolution simulation using the Weather Research and Forecasting model with Morrison microphysics was employed to investigate the rainwater microphysical properties during different stages of Typhoon Usagi(2013) in the inner-core and outer region. The model reproduced the track, intensity, and overall structure of Usagi(2013) reasonably. The simulated raindrop size distribution showed a rapid increase in small-size raindrop concentration but an oscillated decrease in large-size ones in the inner-core region, corresponding well with the upward motion. It was found that there existed two levels(1.25 and 5.25 km) of maximum number concentration of raindrops. The ice-related microphysics at high levels was stronger than the warm-rain processes at low levels. The larger raindrops formed by self-collection in the inner-core suffered from significant breakup, but the raindrops outside the eyewall did not experience evident breakup. Model results indicated that the dominant terms in the water vapor budget were the horizontal moisture flux convergence(HFC) and local condensation and deposition. The evaporation from the ocean surface(PBL) was ~10% of the HFC in the inner core, but up to 40% in the outer region as the air therein was far from saturation. Furthermore, water vapor in the outer region was obtained equally through evaporation from the cloud and inward transportation from the environment. An earlier start of cloud microphysical processes in the inner-core region was evident during the intensification stage, and the continuous decreasing of condensation in both the inner-core and outer regions might imply the beginning of the storm weakening.展开更多
AIM: To review the use of spectral domain optical coherence tomography(SD-OCT) for macular retinal ganglion cells(RGC) and ganglion cell complex(GCC) measurement in glaucoma assessment, specifically for early detectio...AIM: To review the use of spectral domain optical coherence tomography(SD-OCT) for macular retinal ganglion cells(RGC) and ganglion cell complex(GCC) measurement in glaucoma assessment, specifically for early detection and detection of disease progression. METHODS: A systematic review was performed by searching Pub Med, Medline, and Web of Science for articles published in English through July 2014 describing the various macular SD-OCT scanning strategies developed for glaucoma assessment. The review focused on papers evaluating the use of macular RGC/GCC SDOCT to detect early glaucoma and its progression. The search included keywords corresponding to the index test(macular ganglion cell/RGC/GCC/Spectral domain OCT), the target condition(glaucoma), and diagnostic performance. The RGC/GCC SD-OCT scanning strategies used to assess glaucoma of most commonly used SD-OCT instruments were described and compared. These included the Cirrus high definition-OCT(Carl Zeiss Meditec, Inc., Dublin, CA, United States), RTVue(Optovue, Inc., Fremont, CA, United States), Spectralis(Heidelberg Engineering, Heidelberg, Germany) and the 3D OCT 2000(Topcon Corporation, Tokyo, Japan). Studies focusing on the ability of RGC/GCC SD-OCT to detect early glaucomatous damage and on the correlation between glaucomatous progression and RGC/GCC measurement by SD-OCT were reviewed.RESULTS: According to the literature, macular RGC/GCC SD-OCT has high diagnostic power of preperimetric glaucoma, reliable discrimination ability to differentiate between healthy eyes and glaucomatous eyes, with good correlation with visual filed damage. The current data suggests that it may serve as a sensitive detection tool for glaucomatous structural progression even with mild functional progression as the rate of change of RGC/GCC thickness was found to be significantly higher in progressing than in stable eyes. Glaucoma assessment with RGC/GCC SD-OCT was comparable with and sometimes better than circumpapillary retinal nerve fiber layer thickness measurement.CONCLUSION: An increasing body of evidence supports using macular RGC/GCC thickness as an indicator for early glaucoma. This might be a useful tool for monitoring disease progression.展开更多
Recreational waters contaminated with human fecal pollution are a public health concern, and ensuring the safety of recreational waters for public use is a priority of both the Environmental Protection Agency(EPA) and...Recreational waters contaminated with human fecal pollution are a public health concern, and ensuring the safety of recreational waters for public use is a priority of both the Environmental Protection Agency(EPA) and the Centers for Disease Control and Prevention(CDC). Current recreational water standards rely on fecal indicator bacteria(FIB) levels as indicators of human disease risk. However present evidence indicates that levels of FIB do not always correspond to the presence of other potentially harmful organisms, such as viruses. Thus, enteric viruses are currently tested as water quality indicators, but have yet to be successfully implemented in routine monitoring of water quality. This study utilized enteric viruses as possible alternative indicators of water quality to examine 18 different fresh and offshore recreational waters on O‘ahu, Hawai‘i, by using newly established laboratory techniques including highly optimized PCR, real time PCR, and viral infectivity assays. All sample sites were detected positive for human enteric viruses by PCR including enterovirus, norovirus genogroups I and II, and male specific FRNA coliphage. A six time-point seasonal study of enteric virus presence indicated significant variation in virus detection between the rainy and dry seasons. Quantitative PCR detected the presence of norovirus genogroup II at levels at which disease risk may occur, and there was no correlation found between enteric virus presence and FIB counts. Under the present laboratory conditions, no infectious viruses were detected from the samples PCR-positive for enteric viruses. These data emphasize both the need for additional indicators for improved monitoring of water quality, and the feasibility of using enteric viruses as these indicators.展开更多
This study represents a continuation of the Florida hotspot of tadpole abnormality found in the Southwest Florida suburban roadside drainage ditches in 2012 to determine if the adult frogs and toads frequenting the st...This study represents a continuation of the Florida hotspot of tadpole abnormality found in the Southwest Florida suburban roadside drainage ditches in 2012 to determine if the adult frogs and toads frequenting the study sites were anatomically abnormal.The gross examination of all organs included 397 adult anurans and 40 metamorphs representing five anuran species:Osteopilus septentrionalis(N=364),Rhinella marina(N=60),Lithobates sphenocephala(N=7),Anaxyrus terrestris(N=5)and Anaxyrus americanus(N=1).The gonads,liver,kidney and intestines were abnormal at a frequency of 87.4%.The few normal anurans(12.6%)were females and young male adults.We found a significant difference in organ abnormality type and f requency between sexes.Almost all f rog and toad males had testicular abnormality(92%)with only 6%with normal testes,whereas the female gonad abnormality was lower,at 41.6%.Hermaphroditism was found in both sexes at a frequency of 26.2%.The toads had a significantly higher frequency of hermaphroditism than the frogs.The toad hermaphroditism frequency was found to be 40%,whereas the frog hermaphroditism 23.3%.A hermaphrodite Cane toad male with a female phenotype coexisted with the normal male phenotype hermaphrodite.The fertility of 27 in situ pairs was assessed.The fertile testicular abnormal male and hermaphrodite pairs produced offspring with abnormal larval morphology.This information adds new evidence of the effect of chemicals on wild populations and the effect on non-target species which has always been underestimated.展开更多
In this study, the iterative harmonic balance method was used to develop analytical solutions of period-one rotations of a pendulum driven horizontally by harmonic excitations. The performance of the method was evalua...In this study, the iterative harmonic balance method was used to develop analytical solutions of period-one rotations of a pendulum driven horizontally by harmonic excitations. The performance of the method was evaluated by two criteria, one based on the system energy error and the other based on the global residual error. As a comparison, analytical solutions based on the multi-scale method were also considered. Numerical solutions obtained from the Dormand-Prince method (ODE45 in MATLAB©) were used as the baseline for evaluation. It was found that under lower-level excitations, the multi-scale method performed better than the iterative method. At higher-level excitations, however, the performance of the iterative method was noticeably more accurate.展开更多
Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusti...Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusting the abundance of CD34+LinNeg cells in human bone marrow we examined the relative significance of hematopoietic stem cells (HSC) in the recovery of cardiac function in a murine model of induced myocardial infarction. Enrichment of HSC by ~100-fold in WBM transplanted into mice significantly increased recovery of heart function and reduced scar size compared to transplantation of WBM depleted in HSC by ~10-fold (P P < 0.01 respectively). Peri-infarct capillary density was significantly increased in recipients of HSC-enriched samples (P < 0.01) or WBM samples (P < 0.01) compared to controls. These results strongly suggest?a critical role for HSC in the effective treatment of myocardial infarction with human bone marrow, and imply that enrichment of HSC may markedly benefit the clinical application of WBM treatments.展开更多
A number of natural experiments have recently found that COVID-19 restrictions imposed in nations worldwide are correlated with short-term reductions—in some cases dramatic reductions—in mobile-source air pollutants...A number of natural experiments have recently found that COVID-19 restrictions imposed in nations worldwide are correlated with short-term reductions—in some cases dramatic reductions—in mobile-source air pollutants. Noticeably absent from these studies are estimates of the social net benefits associated with the changes in human behavior underlying the pandemic-induced effects. Using readily available data provided by the state of Utah and the U.S. Environmental Protection Agency’s Co-Benefits Risk Assessment Health Impacts Screening and Mapping Tool (COBRA), we find that daily social net benefit was positive during a pandemic-induced shutdown from March to April, 2020 in Utah’s Wasatch Front region solely when COBRA’s “high” health benefit estimate from combined reductions in PM<sub>2.5</sub> and NO<sub>x</sub> concentrations are weighed against the region’s “low” vehicle-trip cost estimate. All other scenarios correspond with negative net benefit estimates, <i>i.e.</i>, when high and low benefit estimates of reductions solely in PM<sub>2.5</sub> concentrations as well as for combined reductions in PM<sub>2.5</sub> and NO<sub>x</sub> concentrations are weighed against the region’s high vehicle-trip cost estimate. Generally speaking, social net benefits are higher for two of the Wasatch Front’s four counties.展开更多
The aim of this study is to identify and analyze ways to increase usage of destination website and motivate website visitors’intention to actually visit the destination.The sample population is South Koreans who visi...The aim of this study is to identify and analyze ways to increase usage of destination website and motivate website visitors’intention to actually visit the destination.The sample population is South Koreans who visit the VisitBritain website,the homepage of Britain’s national tourism agency.The data for this study were collected by a self-participated online survey on the blog of VisitBritain Korea,which is directly linked to the VisitBritain Korea website.Using structural equation modeling,six hypotheses were tested.The results show that the destination image on the destination marketing organization(DMO)website,quality of the destination website design including three dimensions(information quality,system quality,and service quality),and customers’satisfaction formed by high quality of the website design have a significant impact on website visitors’use intention and increase their visiting intention to the destination.Based upon the results of the analysis,managerial implications and areas for future research are proposed.展开更多
文摘The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna grasslands.We analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral management.At two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near stockyards.Furthermore,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of GPI.The only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near stockyards.In summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations vary.Finally,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.
基金supported by the DRAGON 5 ESA-MOST GREENISH project[grant number 58351].
文摘Remote sensing(RS)technologies are extensively exploited by scientists and a vast audience of local authorities,urban managers,and city planners.Coastal regions,geohazard-prone areas,and highly populated cities represent natural laboratories to apply RS technologies and test new methods.Over the last decades,many efforts have been spent on improving Earth’s surface monitoring,including intensifying Earth Observation(EO)operations by the major national space agencies.They oversee to plan and make operational constellations of satellite sensors providing the scientific community with extensive research and development opportunities in the geoscience field.For instance,within this framework,the European Space Agency(ESA)and the Ministry of Science and Technology of China(MOST)have sponsored,since the early 2000s,the DRAGON initiative jointly carried out by the European and Chinese RS scientific communities.This manuscript aims to provide a synthetic overview of some research activities and new methods recently designed and applied and trace the route for further developments.The main findings are related to i)the analysis of flood risk in China,ii)the potential of new methods for the estimation and removal of ground displacement biases in small-baseline oriented interferometric Synthetic Aperture Radar(SAR)methods,iii)the analysis of the inundation risk in low-lying regions using coherent and incoherent SAR methods;and iv)the use of SAR-based technologies for marine applications.
文摘This project is to evaluate the benefits of the MFN status and the consequences of non-MFN renewal on trades between China and the United States.This paper also reveals the effects of quota removal on clothing and textile products on international trades between the United States,China,Hong Kong,Taiwan,and India.Data analyses,statistics,and charts,the changes in China’s number of exports to the United States,in particular,the apparel and textile sectors were selected to analyze from 1995 to 2005.
基金supported by the National Basic Research and Development Project (973 program) of China (Grant No. 2015CB452805)the National Natural Science Foundation of China (Grant No. 41375068)partly supported by the National Science Foundation (Grant No. AGS-1326524)
文摘A 72-h high-resolution simulation of Supertyphoon Rammasun （2014） is performed using the Advanced Research Weather Research and Forecasting model. The model covers an initial 18-h spin-up, the 36-h rapid intensification （RI） period in the northern South China Sea, and the 18-h period of weakening after landfall. The results show that the model reproduces the track, intensity, structure of the storm, and environmental circulations reasonably well. Analysis of the surface energetics under the storm indicates that the storm＇s intensification is closely related to the net energy gain rate （eg）, defined as the difference between the energy production （PD） due to surface entropy flux and the energy dissipation （Ds） due to surface friction near the radius of maximum wind （RMW）. Before and during the RI stage, the ~：g is high, indicating sufficient energy supply for the storm to intensify. However, the Sg decreases rapidly as the storm quickly intensifies, because the Ds increases more rapidly than the PD near the RMW. By the time the storm reaches its peak intensity, the Ds is about 20% larger than the PD near the RMW, leading to a local energetics deficit under the eyewall. During the mature stage, the PD and Ds can reach a balance within a radius of 86 km from the storm center （about 2.3 times the RMW）. This implies that the local PD under the eyewall is not large enough to balance the Ds, and the radially inward energy transport from outside the eyewall must play an important role in maintaining the storm＇s intensity, as well as its intensification.
基金sponsored by the National (Key) Basic Research and Development (973) Program of China under Contract No. 2015CB452805the National Natural Science Foundation of China under Grant Nos. 41775131, 91437101 and 41375068a Jiangsu Postgraduate Research and Innovation Program project (KYCX17 0868)
文摘A 2-km resolution simulation using the Weather Research and Forecasting model with Morrison microphysics was employed to investigate the rainwater microphysical properties during different stages of Typhoon Usagi(2013) in the inner-core and outer region. The model reproduced the track, intensity, and overall structure of Usagi(2013) reasonably. The simulated raindrop size distribution showed a rapid increase in small-size raindrop concentration but an oscillated decrease in large-size ones in the inner-core region, corresponding well with the upward motion. It was found that there existed two levels(1.25 and 5.25 km) of maximum number concentration of raindrops. The ice-related microphysics at high levels was stronger than the warm-rain processes at low levels. The larger raindrops formed by self-collection in the inner-core suffered from significant breakup, but the raindrops outside the eyewall did not experience evident breakup. Model results indicated that the dominant terms in the water vapor budget were the horizontal moisture flux convergence(HFC) and local condensation and deposition. The evaporation from the ocean surface(PBL) was ~10% of the HFC in the inner core, but up to 40% in the outer region as the air therein was far from saturation. Furthermore, water vapor in the outer region was obtained equally through evaporation from the cloud and inward transportation from the environment. An earlier start of cloud microphysical processes in the inner-core region was evident during the intensification stage, and the continuous decreasing of condensation in both the inner-core and outer regions might imply the beginning of the storm weakening.
文摘AIM: To review the use of spectral domain optical coherence tomography(SD-OCT) for macular retinal ganglion cells(RGC) and ganglion cell complex(GCC) measurement in glaucoma assessment, specifically for early detection and detection of disease progression. METHODS: A systematic review was performed by searching Pub Med, Medline, and Web of Science for articles published in English through July 2014 describing the various macular SD-OCT scanning strategies developed for glaucoma assessment. The review focused on papers evaluating the use of macular RGC/GCC SDOCT to detect early glaucoma and its progression. The search included keywords corresponding to the index test(macular ganglion cell/RGC/GCC/Spectral domain OCT), the target condition(glaucoma), and diagnostic performance. The RGC/GCC SD-OCT scanning strategies used to assess glaucoma of most commonly used SD-OCT instruments were described and compared. These included the Cirrus high definition-OCT(Carl Zeiss Meditec, Inc., Dublin, CA, United States), RTVue(Optovue, Inc., Fremont, CA, United States), Spectralis(Heidelberg Engineering, Heidelberg, Germany) and the 3D OCT 2000(Topcon Corporation, Tokyo, Japan). Studies focusing on the ability of RGC/GCC SD-OCT to detect early glaucomatous damage and on the correlation between glaucomatous progression and RGC/GCC measurement by SD-OCT were reviewed.RESULTS: According to the literature, macular RGC/GCC SD-OCT has high diagnostic power of preperimetric glaucoma, reliable discrimination ability to differentiate between healthy eyes and glaucomatous eyes, with good correlation with visual filed damage. The current data suggests that it may serve as a sensitive detection tool for glaucomatous structural progression even with mild functional progression as the rate of change of RGC/GCC thickness was found to be significantly higher in progressing than in stable eyes. Glaucoma assessment with RGC/GCC SD-OCT was comparable with and sometimes better than circumpapillary retinal nerve fiber layer thickness measurement.CONCLUSION: An increasing body of evidence supports using macular RGC/GCC thickness as an indicator for early glaucoma. This might be a useful tool for monitoring disease progression.
基金supported in part by grants from the Centers for Oceans and Human Health (COHH) programthe National Institutes of Environmental Health Sciences (P50ES012740)+1 种基金the National Science Foundation (OCE04-32479 and OCE09-11000)the Hawai‘i Community Foundation (11ADVC-49702)
文摘Recreational waters contaminated with human fecal pollution are a public health concern, and ensuring the safety of recreational waters for public use is a priority of both the Environmental Protection Agency(EPA) and the Centers for Disease Control and Prevention(CDC). Current recreational water standards rely on fecal indicator bacteria(FIB) levels as indicators of human disease risk. However present evidence indicates that levels of FIB do not always correspond to the presence of other potentially harmful organisms, such as viruses. Thus, enteric viruses are currently tested as water quality indicators, but have yet to be successfully implemented in routine monitoring of water quality. This study utilized enteric viruses as possible alternative indicators of water quality to examine 18 different fresh and offshore recreational waters on O‘ahu, Hawai‘i, by using newly established laboratory techniques including highly optimized PCR, real time PCR, and viral infectivity assays. All sample sites were detected positive for human enteric viruses by PCR including enterovirus, norovirus genogroups I and II, and male specific FRNA coliphage. A six time-point seasonal study of enteric virus presence indicated significant variation in virus detection between the rainy and dry seasons. Quantitative PCR detected the presence of norovirus genogroup II at levels at which disease risk may occur, and there was no correlation found between enteric virus presence and FIB counts. Under the present laboratory conditions, no infectious viruses were detected from the samples PCR-positive for enteric viruses. These data emphasize both the need for additional indicators for improved monitoring of water quality, and the feasibility of using enteric viruses as these indicators.
文摘This study represents a continuation of the Florida hotspot of tadpole abnormality found in the Southwest Florida suburban roadside drainage ditches in 2012 to determine if the adult frogs and toads frequenting the study sites were anatomically abnormal.The gross examination of all organs included 397 adult anurans and 40 metamorphs representing five anuran species:Osteopilus septentrionalis(N=364),Rhinella marina(N=60),Lithobates sphenocephala(N=7),Anaxyrus terrestris(N=5)and Anaxyrus americanus(N=1).The gonads,liver,kidney and intestines were abnormal at a frequency of 87.4%.The few normal anurans(12.6%)were females and young male adults.We found a significant difference in organ abnormality type and f requency between sexes.Almost all f rog and toad males had testicular abnormality(92%)with only 6%with normal testes,whereas the female gonad abnormality was lower,at 41.6%.Hermaphroditism was found in both sexes at a frequency of 26.2%.The toads had a significantly higher frequency of hermaphroditism than the frogs.The toad hermaphroditism frequency was found to be 40%,whereas the frog hermaphroditism 23.3%.A hermaphrodite Cane toad male with a female phenotype coexisted with the normal male phenotype hermaphrodite.The fertility of 27 in situ pairs was assessed.The fertile testicular abnormal male and hermaphrodite pairs produced offspring with abnormal larval morphology.This information adds new evidence of the effect of chemicals on wild populations and the effect on non-target species which has always been underestimated.
文摘In this study, the iterative harmonic balance method was used to develop analytical solutions of period-one rotations of a pendulum driven horizontally by harmonic excitations. The performance of the method was evaluated by two criteria, one based on the system energy error and the other based on the global residual error. As a comparison, analytical solutions based on the multi-scale method were also considered. Numerical solutions obtained from the Dormand-Prince method (ODE45 in MATLAB©) were used as the baseline for evaluation. It was found that under lower-level excitations, the multi-scale method performed better than the iterative method. At higher-level excitations, however, the performance of the iterative method was noticeably more accurate.
文摘Recent studies suggest that whole bone marrow (WBM) derived stem cells may facilitate recovery following myocardial infarction. However, the sub-population of WBM responsible for recovery remains uncertain. By adjusting the abundance of CD34+LinNeg cells in human bone marrow we examined the relative significance of hematopoietic stem cells (HSC) in the recovery of cardiac function in a murine model of induced myocardial infarction. Enrichment of HSC by ~100-fold in WBM transplanted into mice significantly increased recovery of heart function and reduced scar size compared to transplantation of WBM depleted in HSC by ~10-fold (P P < 0.01 respectively). Peri-infarct capillary density was significantly increased in recipients of HSC-enriched samples (P < 0.01) or WBM samples (P < 0.01) compared to controls. These results strongly suggest?a critical role for HSC in the effective treatment of myocardial infarction with human bone marrow, and imply that enrichment of HSC may markedly benefit the clinical application of WBM treatments.
文摘A number of natural experiments have recently found that COVID-19 restrictions imposed in nations worldwide are correlated with short-term reductions—in some cases dramatic reductions—in mobile-source air pollutants. Noticeably absent from these studies are estimates of the social net benefits associated with the changes in human behavior underlying the pandemic-induced effects. Using readily available data provided by the state of Utah and the U.S. Environmental Protection Agency’s Co-Benefits Risk Assessment Health Impacts Screening and Mapping Tool (COBRA), we find that daily social net benefit was positive during a pandemic-induced shutdown from March to April, 2020 in Utah’s Wasatch Front region solely when COBRA’s “high” health benefit estimate from combined reductions in PM<sub>2.5</sub> and NO<sub>x</sub> concentrations are weighed against the region’s “low” vehicle-trip cost estimate. All other scenarios correspond with negative net benefit estimates, <i>i.e.</i>, when high and low benefit estimates of reductions solely in PM<sub>2.5</sub> concentrations as well as for combined reductions in PM<sub>2.5</sub> and NO<sub>x</sub> concentrations are weighed against the region’s high vehicle-trip cost estimate. Generally speaking, social net benefits are higher for two of the Wasatch Front’s four counties.
文摘The aim of this study is to identify and analyze ways to increase usage of destination website and motivate website visitors’intention to actually visit the destination.The sample population is South Koreans who visit the VisitBritain website,the homepage of Britain’s national tourism agency.The data for this study were collected by a self-participated online survey on the blog of VisitBritain Korea,which is directly linked to the VisitBritain Korea website.Using structural equation modeling,six hypotheses were tested.The results show that the destination image on the destination marketing organization(DMO)website,quality of the destination website design including three dimensions(information quality,system quality,and service quality),and customers’satisfaction formed by high quality of the website design have a significant impact on website visitors’use intention and increase their visiting intention to the destination.Based upon the results of the analysis,managerial implications and areas for future research are proposed.
