Juzhi Hou | University of Washington (original) (raw)
Papers by Juzhi Hou
There is a great deal of controversy regarding the fate of glaciers and ice fields on the Tibetan... more There is a great deal of controversy regarding the fate of glaciers and ice fields on the Tibetan Plateau in the face of continued anthropogenic global warming. Paleoclimate reconstructions and spatial analyses aimed at mapping past climate changes are the key to understanding the climatic response of the Tibetan Plateau to changing conditions.
Abstract Climate proxy records and general circulation models suggest that Atlantic Meridional Ov... more Abstract Climate proxy records and general circulation models suggest that Atlantic Meridional Overturning Circulation (AMOC) plays a key role for global climate changes. Paleoceanographic data document multiple episodes of prominent AMOC weakening during the early Holocene. However, proxy records at adjacent continents have not been demonstrated to fully capture the climate responses to multiple AMOC variation due to temporal resolution and/or the proxy sensitivity.
Abstract Background: Bostrycin is a novel compound isolated from marine fungi that inhibits proli... more Abstract Background: Bostrycin is a novel compound isolated from marine fungi that inhibits proliferation of many cancer cells. However, the inhibitory effect of bostrycin on lung cancers has not been reported. This study is to investigate the inhibitory effects and mechanism of bostrycin on human lung cancer cells in vitro. Methods: We used MTT assay, flow cytometry, microarray, real time PCR, and Western blotting to detect the effect of bostrycin on A549 human pulmonary adenocarcinoma cells.
D/H ratios of leaf waxes (dD wax ) derived from terrestrial plants and preserved in lake sediment... more D/H ratios of leaf waxes (dD wax ) derived from terrestrial plants and preserved in lake sediments can provide important information on past continental hydrology. Ideally, dD wax can be used to reconstruct precipitation D/H ratios (dD P ) which is a well-established paleoclimate proxy. However, many other factors, such as vegetation and relative humidity (RH), also affect dD wax variation. How the combination of these factors affects sedimentary dD wax is unclear. Here, we use a transect of 32 lake surface sediments across large gradients of precipitation, relative humidity, and vegetation composition in the southwestern United States to study the natural factors affecting sedimentary dD wax . dD values of C 28 n-alkanoic acids show significant correlation with dD P values (R 2 = 0.76) with an apparent isotopic enrichment of $99 ± 8&, indicating that sedimentary dD wax values track overall dD P variation along the entire transect. Leaf waxes produced by plants grown under controlled conditions (RH = 80%, 60%, 40%) show a small increase in D/H ratios as RH decreases, consistent with prediction from the Craig-Gordon model. However, the isotopic effect of RH on dD wax along the natural transect is partially countered by the opposing influence of vegetation changes. The correlation between dD wax and dD P values is significantly higher (R 2 = 0.84) in the drier portions of the transect than in the wetter regions (R 2 = 0.64). This study suggests that D/H ratios of sedimentary leaf waxes can be used as a proxy for precipitation dD variations, with particularly high fidelity in dry regions, although more studies in other regions will be important to further test this proxy.
1] We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood ... more 1] We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood Pond, Massachusetts, USA, in order to reconstruct climate changes during the past 15 kyr. In addition to palmitic acid (C 16 n-acid), which has been shown to record lake water D/H ratios, our surface sediments and down core data indicate that behenic acid (C 22 n-acid), produced mainly by aquatic macrophytes, is also effective for capturing past environmental change. Calibration using surface sediments from two transects across eastern North America indicates that behenic acid records dD variation of lake water. Down core variations in dD values of behenic acid and pollen taxa are consistent with the known climate change history of New England. By evaluating the hypothesis that D/H fractionations of long chain even numbered fatty acids (C 24 -C 32 n-acids) relative to lake water provide independent estimates of relative humidity during the growing season, we find that differences between lake-level records and isotopically inferred humidity estimates may provide useful insight into seasonal aspects of the hydrologic cycle. Combined analyses of D/H of short and long chain fatty acids from lake sediment cores thus allow reconstructions of both past temperature and growing season relative humidity. Comparison of dD records from two lakes in New England provides critical information on regional climate variation and abrupt climate change, such as the 8.2 ka event.
Paleoclimatic interpretation of the hydrogen isotope ratios of plant leaf waxes extracted from se... more Paleoclimatic interpretation of the hydrogen isotope ratios of plant leaf waxes extracted from sediments requires a thorough understanding of the factors controlling the isotopic ratios. Existing studies have found relatively small variability in hydrogen isotope fractionation among plants of different photosynthetic pathways (C 3 , C 4 and CAM) and between gymnosperms and angiosperms. However, there has been no systematic study at a single site to determine how leaf wax hydrogen isotope (D/H) ratios differ in different plant types under the same precipitation and environmental regime. Such data are nevertheless crucial for understanding the impact of past vegetation changes on the sedimentary hydrogen isotope records of leaf waxes. Here, we present a study of D/H ratios of leaf waxes from 48 species in seven types of terrestrial and aquatic C 3 plants around Blood Pond, Dudley, Massachusetts, USA. The dD values of leaf waxes differ by as much as 70& for different plant types, with those from trees and ferns having the highest values and those from grasses having the lowest values. The large isotopic variation indicates that the apparent hydrogen isotopic fractionation between leaf waxes and precipitation is not constant for different plant types. Our results indicate that inferring precipitation D/H ratios on the basis of sedimentary leaf waxes is only viable when significant vegetation change is absent or can be accounted for isotopically.
D/H ratios of sedimentary leaf waxes can provide useful information about past climate change. Ho... more D/H ratios of sedimentary leaf waxes can provide useful information about past climate change. However, factors controlling dD values of higher plant leaf waxes (dD wax ) are poorly understood. Here we show that dD wax values are negatively correlated with d 13 C values of leaf waxes (d 13 C wax ), based on a study of 35 leaf samples of 11 tree species around Blood Pond, Massachusetts (USA). Our data suggest that plant water use efficiency exerts an important control on the dD wax variation among tree species.
Geophysical Research …, Jan 1, 2003
Geophysical Research Letters, Jan 1, 2004
... State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese... more ... State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi&amp;amp;amp;#x27;an, Shaanxi, China Juzhi Hou Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China ...
THE IMPACT OF SOIL EROSION ON …, Jan 1, 2005
H RATIO OF LAKE SEDIMENTS IN PALEOCLIMATIC …, Jan 1, 2010
Science in China Series D: Earth Sciences, Jan 1, 2002
Quaternary …, Jan 1, 2007
Geophys Res Lett, Jan 1, 2003
dsjyj.com.cn
Lowcomplexity and highperformance of diversity combing schemes always conflict. A new hybrid co... more Lowcomplexity and highperformance of diversity combing schemes always conflict. A new hybrid combining technique named SSCSC is proposed, which is composed of Selection Combining (SC) and SwitchandStay Combining (SSC). The SSCSC scheme with 2L branches ...
Analytical …, Jan 1, 2010
Geological Society of America Abstracts with Programs,, Jan 1, 2007
Extensive paleoecological studies indicate that northeastern North America experienced major clim... more Extensive paleoecological studies indicate that northeastern North America experienced major climate shifts during the Late Pleistocene - Early Holocene transition (LPEH). However, the uncertainties inherent to the modern analog technique increase the difficulty of using pollen and ...
… et Cosmochimica Acta, Jan 1, 2011
There is a great deal of controversy regarding the fate of glaciers and ice fields on the Tibetan... more There is a great deal of controversy regarding the fate of glaciers and ice fields on the Tibetan Plateau in the face of continued anthropogenic global warming. Paleoclimate reconstructions and spatial analyses aimed at mapping past climate changes are the key to understanding the climatic response of the Tibetan Plateau to changing conditions.
Abstract Climate proxy records and general circulation models suggest that Atlantic Meridional Ov... more Abstract Climate proxy records and general circulation models suggest that Atlantic Meridional Overturning Circulation (AMOC) plays a key role for global climate changes. Paleoceanographic data document multiple episodes of prominent AMOC weakening during the early Holocene. However, proxy records at adjacent continents have not been demonstrated to fully capture the climate responses to multiple AMOC variation due to temporal resolution and/or the proxy sensitivity.
Abstract Background: Bostrycin is a novel compound isolated from marine fungi that inhibits proli... more Abstract Background: Bostrycin is a novel compound isolated from marine fungi that inhibits proliferation of many cancer cells. However, the inhibitory effect of bostrycin on lung cancers has not been reported. This study is to investigate the inhibitory effects and mechanism of bostrycin on human lung cancer cells in vitro. Methods: We used MTT assay, flow cytometry, microarray, real time PCR, and Western blotting to detect the effect of bostrycin on A549 human pulmonary adenocarcinoma cells.
D/H ratios of leaf waxes (dD wax ) derived from terrestrial plants and preserved in lake sediment... more D/H ratios of leaf waxes (dD wax ) derived from terrestrial plants and preserved in lake sediments can provide important information on past continental hydrology. Ideally, dD wax can be used to reconstruct precipitation D/H ratios (dD P ) which is a well-established paleoclimate proxy. However, many other factors, such as vegetation and relative humidity (RH), also affect dD wax variation. How the combination of these factors affects sedimentary dD wax is unclear. Here, we use a transect of 32 lake surface sediments across large gradients of precipitation, relative humidity, and vegetation composition in the southwestern United States to study the natural factors affecting sedimentary dD wax . dD values of C 28 n-alkanoic acids show significant correlation with dD P values (R 2 = 0.76) with an apparent isotopic enrichment of $99 ± 8&, indicating that sedimentary dD wax values track overall dD P variation along the entire transect. Leaf waxes produced by plants grown under controlled conditions (RH = 80%, 60%, 40%) show a small increase in D/H ratios as RH decreases, consistent with prediction from the Craig-Gordon model. However, the isotopic effect of RH on dD wax along the natural transect is partially countered by the opposing influence of vegetation changes. The correlation between dD wax and dD P values is significantly higher (R 2 = 0.84) in the drier portions of the transect than in the wetter regions (R 2 = 0.64). This study suggests that D/H ratios of sedimentary leaf waxes can be used as a proxy for precipitation dD variations, with particularly high fidelity in dry regions, although more studies in other regions will be important to further test this proxy.
1] We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood ... more 1] We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood Pond, Massachusetts, USA, in order to reconstruct climate changes during the past 15 kyr. In addition to palmitic acid (C 16 n-acid), which has been shown to record lake water D/H ratios, our surface sediments and down core data indicate that behenic acid (C 22 n-acid), produced mainly by aquatic macrophytes, is also effective for capturing past environmental change. Calibration using surface sediments from two transects across eastern North America indicates that behenic acid records dD variation of lake water. Down core variations in dD values of behenic acid and pollen taxa are consistent with the known climate change history of New England. By evaluating the hypothesis that D/H fractionations of long chain even numbered fatty acids (C 24 -C 32 n-acids) relative to lake water provide independent estimates of relative humidity during the growing season, we find that differences between lake-level records and isotopically inferred humidity estimates may provide useful insight into seasonal aspects of the hydrologic cycle. Combined analyses of D/H of short and long chain fatty acids from lake sediment cores thus allow reconstructions of both past temperature and growing season relative humidity. Comparison of dD records from two lakes in New England provides critical information on regional climate variation and abrupt climate change, such as the 8.2 ka event.
Paleoclimatic interpretation of the hydrogen isotope ratios of plant leaf waxes extracted from se... more Paleoclimatic interpretation of the hydrogen isotope ratios of plant leaf waxes extracted from sediments requires a thorough understanding of the factors controlling the isotopic ratios. Existing studies have found relatively small variability in hydrogen isotope fractionation among plants of different photosynthetic pathways (C 3 , C 4 and CAM) and between gymnosperms and angiosperms. However, there has been no systematic study at a single site to determine how leaf wax hydrogen isotope (D/H) ratios differ in different plant types under the same precipitation and environmental regime. Such data are nevertheless crucial for understanding the impact of past vegetation changes on the sedimentary hydrogen isotope records of leaf waxes. Here, we present a study of D/H ratios of leaf waxes from 48 species in seven types of terrestrial and aquatic C 3 plants around Blood Pond, Dudley, Massachusetts, USA. The dD values of leaf waxes differ by as much as 70& for different plant types, with those from trees and ferns having the highest values and those from grasses having the lowest values. The large isotopic variation indicates that the apparent hydrogen isotopic fractionation between leaf waxes and precipitation is not constant for different plant types. Our results indicate that inferring precipitation D/H ratios on the basis of sedimentary leaf waxes is only viable when significant vegetation change is absent or can be accounted for isotopically.
D/H ratios of sedimentary leaf waxes can provide useful information about past climate change. Ho... more D/H ratios of sedimentary leaf waxes can provide useful information about past climate change. However, factors controlling dD values of higher plant leaf waxes (dD wax ) are poorly understood. Here we show that dD wax values are negatively correlated with d 13 C values of leaf waxes (d 13 C wax ), based on a study of 35 leaf samples of 11 tree species around Blood Pond, Massachusetts (USA). Our data suggest that plant water use efficiency exerts an important control on the dD wax variation among tree species.
Geophysical Research …, Jan 1, 2003
Geophysical Research Letters, Jan 1, 2004
... State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese... more ... State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi&amp;amp;amp;#x27;an, Shaanxi, China Juzhi Hou Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China ...
THE IMPACT OF SOIL EROSION ON …, Jan 1, 2005
H RATIO OF LAKE SEDIMENTS IN PALEOCLIMATIC …, Jan 1, 2010
Science in China Series D: Earth Sciences, Jan 1, 2002
Quaternary …, Jan 1, 2007
Geophys Res Lett, Jan 1, 2003
dsjyj.com.cn
Lowcomplexity and highperformance of diversity combing schemes always conflict. A new hybrid co... more Lowcomplexity and highperformance of diversity combing schemes always conflict. A new hybrid combining technique named SSCSC is proposed, which is composed of Selection Combining (SC) and SwitchandStay Combining (SSC). The SSCSC scheme with 2L branches ...
Analytical …, Jan 1, 2010
Geological Society of America Abstracts with Programs,, Jan 1, 2007
Extensive paleoecological studies indicate that northeastern North America experienced major clim... more Extensive paleoecological studies indicate that northeastern North America experienced major climate shifts during the Late Pleistocene - Early Holocene transition (LPEH). However, the uncertainties inherent to the modern analog technique increase the difficulty of using pollen and ...
… et Cosmochimica Acta, Jan 1, 2011