Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of l...Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of larger animals, but recent experiments have indicated that conspicuousness and contrast is important in eyespot function, and not eye mimicry. We undertake two further experiments to distinguish between the conspicuousness and mimicry hypotheses, by using artificial prey presented to wild avian predators in the field. In experiment 1, we test if eyespot effectiveness depends on the marking shape （bar or circle） and arrangement （eye-like and non-eye-like positions）. We find no difference between shapes or arrangement; all spots were equally effective in scaring birds. In experiment 2, we test if the often yellow and black colors of eyespots mimic the eyes of birds of prey. We find no effect of shape, and no advantage to yellow and black spots over non-eye-like but equally conspicuous colors. The consistent finding is that eyespot function lies in being a conspicuous signal to predators, and not necessarily due to eye mimicry [ Current Zoology 55 （5） ： 319 - 326, 2009].展开更多
The distance from an approaching threat at which animals initiate flight - flight-initiation distance （FID） -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessin...The distance from an approaching threat at which animals initiate flight - flight-initiation distance （FID） -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 （4）： 773-780, 2015].展开更多
Strengthening purchasing power,stimulating consumer confidence,and improving the structure and standards of consumption are essential for China's successful economic development.Human capital is linked to income,w...Strengthening purchasing power,stimulating consumer confidence,and improving the structure and standards of consumption are essential for China's successful economic development.Human capital is linked to income,wealth,social status,and cognitive preferences,and plays a long-term role in consumption growth.This study explored the impact of human capital on conspicuous consumption in China,using a novel individual-level measure-the visibility index-to capture conspicuous consumption.Drawing on data from the China Family Panel Studies(2012-2020),a comprehensive human capital index was constructed by combining cognitive and noncognitive abilities through the entropy weight method.To address potential endogeneity,the historical distribution of Confucian temples and ancient academies was used as an instrumental variable for human capital.The empirical results show that improvements in human capital can significantly increase conspicuous consumption,particularly among middle-income groups,rural residents,and nonagricultural workers.A key contribution of the study is the clear identification of social status signaling as the primary mechanism linking human capital to conspicuous consumption.These findings offer new insights into consumption behavior and human capital development in China's increasingly complex and rapidly evolving socioeconomic landscape.展开更多
BACKGROUND Three-phase dynamic computed tomography imaging is particularly useful in the liver region.However,dynamic imaging with contrast media has the disadvantage of increased radiation exposure due to multiple im...BACKGROUND Three-phase dynamic computed tomography imaging is particularly useful in the liver region.However,dynamic imaging with contrast media has the disadvantage of increased radiation exposure due to multiple imaging sessions.We hypothesized that the contrast enhancement boost(CE-boost)technique could be used to enhance the contrast in equilibrium phase(EP)images and produce enhancement similar to that of portal vein phase(PVP)images,and if this is possible,EP imaging could play the same role as PVP imaging.We also speculated that this might allow the conversion of three-phase dynamic imaging to biphasic dynamic imaging,reducing patients’radiation exposure.AIM To determine if the CE-boost of EP,CE-boost(EP)is useful compared to a conventional image.METHODS We retrospectively analyzed the cases of 52 patients who were diagnosed with liver cancer between January 2016 and October 2022 at our institution.From these computed tomography images,CE-boost images were generated from the EP and plane images.We compared the PVP,EP,and CE-boost(EP)for blood vessels and hepatic parenchyma based on the contrast-to-noise ratio(CNR),signal-to-noise ratio,and figure-of-merit(FOM).Visual assessments were also performed for vessel visualization,lesion conspicuity,and image noise.RESULTS The CE-boost(EP)images showed significant superiority compared to the PVP images in the CNR,signal-to-noise ratio,and FOM except regarding the hepatic parenchyma.No significant differences were detected in CNR or FOM comparisons within the hepatic parenchyma(P=0.62,0.67).The comparison of the EP and CE-boost(EP)images consistently favored CE-boost(EP).Regarding the visual assessment,the CE-boost(EP)images were significantly superior to the PVP images in lesion conspicuity,and the PVP in image noise.The CE-boost(EP)images were significantly better than the EP images in the vessel visualization of segmental branches of the portal vein and lesion conspicuity,and the EP in image noise.CONCLUSION The image quality of CE-boost(EP)images was comparable or superior to that of conventional PVP and EP.CEboost(EP)images might provide information comparable to the conventional PVP.展开更多
This year, I’m told, was a bit different:in the interest of not insulting millions of struggling Americans, Santa andhis reindeer touched down very lightly in the United States last month. New Year’sEve,
This article analyzes the confluence of economy and ritual,focusing on the pre-death ritual in Gling rgya village,Reb gong of Qinghai province,contemporary Amdo.Due to educational and economic developments,significant...This article analyzes the confluence of economy and ritual,focusing on the pre-death ritual in Gling rgya village,Reb gong of Qinghai province,contemporary Amdo.Due to educational and economic developments,significant changes have been taking place in the material circumstances of Tibetan households in Gling rgya and the surrounding villages in Reb gong since the 1980s,and these transformations have shaped their performance of the pre-death ritual(gson chos).Not only has the predeath ritual itself become a social obligation,the expenditure of the ritual has increased to such an extent that it has become a huge financial burden for most families.As some families compete to increase ritual expenses,the ritual has become a public display of wealth and social prestige,which is analyzed with the concept of"Conspicuous Consumption".展开更多
基金supported by a Research Fellowship from Girton College,Cambridge,and a Royal Society Research Grantby an Association for the Study of Animal Behaviour Undergraduate Project Scholarship+1 种基金by a Nuffield Undergraduate Science Bursaryby a Department of Zoology J Arthur Ramsay Trust Fund
文摘Many animals are marked with conspicuous circular features often called ＇eyespots＇, which intimidate predators, preventing or halting an attack. It has long been assumed that eyespots work by mimicking the eyes of larger animals, but recent experiments have indicated that conspicuousness and contrast is important in eyespot function, and not eye mimicry. We undertake two further experiments to distinguish between the conspicuousness and mimicry hypotheses, by using artificial prey presented to wild avian predators in the field. In experiment 1, we test if eyespot effectiveness depends on the marking shape （bar or circle） and arrangement （eye-like and non-eye-like positions）. We find no difference between shapes or arrangement; all spots were equally effective in scaring birds. In experiment 2, we test if the often yellow and black colors of eyespots mimic the eyes of birds of prey. We find no effect of shape, and no advantage to yellow and black spots over non-eye-like but equally conspicuous colors. The consistent finding is that eyespot function lies in being a conspicuous signal to predators, and not necessarily due to eye mimicry [ Current Zoology 55 （5） ： 319 - 326, 2009].
基金We thank Kate Rose for help managing data, the survey participants for judging vividness, C. East- wood for his intellectual contributions, and Bill Cooper and one anonymous reviewer for their constructive comments on a previous version of this MS. NMH was supported by the UC Regents Special Fellowship. JPD was supported by a National Science Foundation （NSF） Graduate Research Fellowship and a fellowship from the UCLA Graduate Division during the course of this study. DTB is supported by NSF-DEB-1119660.
文摘The distance from an approaching threat at which animals initiate flight - flight-initiation distance （FID） -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 （4）： 773-780, 2015].
文摘Strengthening purchasing power,stimulating consumer confidence,and improving the structure and standards of consumption are essential for China's successful economic development.Human capital is linked to income,wealth,social status,and cognitive preferences,and plays a long-term role in consumption growth.This study explored the impact of human capital on conspicuous consumption in China,using a novel individual-level measure-the visibility index-to capture conspicuous consumption.Drawing on data from the China Family Panel Studies(2012-2020),a comprehensive human capital index was constructed by combining cognitive and noncognitive abilities through the entropy weight method.To address potential endogeneity,the historical distribution of Confucian temples and ancient academies was used as an instrumental variable for human capital.The empirical results show that improvements in human capital can significantly increase conspicuous consumption,particularly among middle-income groups,rural residents,and nonagricultural workers.A key contribution of the study is the clear identification of social status signaling as the primary mechanism linking human capital to conspicuous consumption.These findings offer new insights into consumption behavior and human capital development in China's increasingly complex and rapidly evolving socioeconomic landscape.
文摘BACKGROUND Three-phase dynamic computed tomography imaging is particularly useful in the liver region.However,dynamic imaging with contrast media has the disadvantage of increased radiation exposure due to multiple imaging sessions.We hypothesized that the contrast enhancement boost(CE-boost)technique could be used to enhance the contrast in equilibrium phase(EP)images and produce enhancement similar to that of portal vein phase(PVP)images,and if this is possible,EP imaging could play the same role as PVP imaging.We also speculated that this might allow the conversion of three-phase dynamic imaging to biphasic dynamic imaging,reducing patients’radiation exposure.AIM To determine if the CE-boost of EP,CE-boost(EP)is useful compared to a conventional image.METHODS We retrospectively analyzed the cases of 52 patients who were diagnosed with liver cancer between January 2016 and October 2022 at our institution.From these computed tomography images,CE-boost images were generated from the EP and plane images.We compared the PVP,EP,and CE-boost(EP)for blood vessels and hepatic parenchyma based on the contrast-to-noise ratio(CNR),signal-to-noise ratio,and figure-of-merit(FOM).Visual assessments were also performed for vessel visualization,lesion conspicuity,and image noise.RESULTS The CE-boost(EP)images showed significant superiority compared to the PVP images in the CNR,signal-to-noise ratio,and FOM except regarding the hepatic parenchyma.No significant differences were detected in CNR or FOM comparisons within the hepatic parenchyma(P=0.62,0.67).The comparison of the EP and CE-boost(EP)images consistently favored CE-boost(EP).Regarding the visual assessment,the CE-boost(EP)images were significantly superior to the PVP images in lesion conspicuity,and the PVP in image noise.The CE-boost(EP)images were significantly better than the EP images in the vessel visualization of segmental branches of the portal vein and lesion conspicuity,and the EP in image noise.CONCLUSION The image quality of CE-boost(EP)images was comparable or superior to that of conventional PVP and EP.CEboost(EP)images might provide information comparable to the conventional PVP.
文摘This year, I’m told, was a bit different:in the interest of not insulting millions of struggling Americans, Santa andhis reindeer touched down very lightly in the United States last month. New Year’sEve,
文摘This article analyzes the confluence of economy and ritual,focusing on the pre-death ritual in Gling rgya village,Reb gong of Qinghai province,contemporary Amdo.Due to educational and economic developments,significant changes have been taking place in the material circumstances of Tibetan households in Gling rgya and the surrounding villages in Reb gong since the 1980s,and these transformations have shaped their performance of the pre-death ritual(gson chos).Not only has the predeath ritual itself become a social obligation,the expenditure of the ritual has increased to such an extent that it has become a huge financial burden for most families.As some families compete to increase ritual expenses,the ritual has become a public display of wealth and social prestige,which is analyzed with the concept of"Conspicuous Consumption".
