Only a few cases of pedunculated hepatocellular carcinoma (P-HCC) have been reported in the literature. The common sites of extrahepatic metastases in patients with HCC are the lungs, regional lymph nodes, kidney, bon...Only a few cases of pedunculated hepatocellular carcinoma (P-HCC) have been reported in the literature. The common sites of extrahepatic metastases in patients with HCC are the lungs, regional lymph nodes, kidney, bone marrow and adrenals. Metastasis to spleen is mostly via hematogenous metastasis, direct metastasis to spleen was very rare. We report a case of P-HCC presenting as a left upper abdominal lesions which involved the spleen that was actually a P-HCC with splenic metastasis. This case is unique as P-HCC directly involved the spleen which is not via hematogenous metastasis.展开更多
Based upon a case study of Silver Beach coastal resort of Beihai, Guangxi Zhuang Autonomous Region, this article examines the rise and fall of Chinese coastal tourist resort development since the 1980s. It explores th...Based upon a case study of Silver Beach coastal resort of Beihai, Guangxi Zhuang Autonomous Region, this article examines the rise and fall of Chinese coastal tourist resort development since the 1980s. It explores the causes for and responses to the decline of Chinese coastal resorts. The data were collected through in-depth interviews with twelve local key information providers, and secondary information sources such as government archives, survey reports, and resort plans. It was found that the rise and fall of Chinese coastal resorts in the last three decades is closely linked to the transitional reform from a central planned economy to a market economy. Three stages of coastal tourism development were identified in a sequence of rapid growth, decline and redevelopment. It was government financial funds and high local government involvement that promoted the rapid expansion of coastal resorts during the 1980s. However, coastal resort decline occurred when transitional reform was intensified and deflationary policy executed af- ter 1992. Institutional failure is found to be the main reason of Chinese coastal resorts decline since the mid-1990s. The government-dominated pattern could not be sustained and should be restructured in forthcoming coastal tourism de- velopment in China. Revival strategies should emphasize enhancing market-oriented reform in the declining resorts on both suoolv and demand sides.展开更多
The influence of labor migration on rural household land transfer has been hotly debated in academic circles, which focuses on whether part-time employment leads to land transfer. Using survey data on rural households...The influence of labor migration on rural household land transfer has been hotly debated in academic circles, which focuses on whether part-time employment leads to land transfer. Using survey data on rural households in the Sichuan Province, and applying the theoretical framework of new economics of labor migration, this study explores the influences of labor migration on the direction and scale of land transfer from the perspective of rural household structure. The results indicate that: 1) the quantity of laborers has significant influence on the direction and scale of land transfer. The larger the on-farm labor variable(Labor), the lesser the possibility that land will be rented-out and the amount of land rented out will also be smaller. In addition, there is a greater probability that land will be rented-in and the amount of land rented-in will be greater. 2) The greater the ratio of off-farm laborers to rural household laborers(Off-farm) the greater the possibility that land will be rented-out. In addition the higher the ratio of on-farm laborers to the total household laborers(On-farm), the larger the possibility that land will be rented-in. Meanwhile, if the household has individuals at the age of 64 or older(Old) who are engaged in agriculture, there is a smaller possibility that land will be rentedout. 3) the ratio of part-time laborers to rural household laborers(Pluriactivity) have significant inverse U-shaped influences on the rent-in of land as well as the amount of land rented-in. The inflection points are 33.27% and 14.10%, respectively. Such findings confirm the significance of this study in better understanding the influence of labor migration on rural household land transfer.展开更多
In this paper,using the existence and comparison result for the quasi-monotone increasing system developed by C V Pao,the upper and lower solutions principle and an iterative method,we investigate the existence of the...In this paper,using the existence and comparison result for the quasi-monotone increasing system developed by C V Pao,the upper and lower solutions principle and an iterative method,we investigate the existence of the positive solutions of the Volterra-Lotka cooperating model.展开更多
In order to address spectrum resource scarcity in traditional cellular networks,television(TV)white space is considered as a potential solution to offload a portion of network traffic and enlarge network capacity.This...In order to address spectrum resource scarcity in traditional cellular networks,television(TV)white space is considered as a potential solution to offload a portion of network traffic and enlarge network capacity.This paper describes a cognitive cellular network which allocates low geometry users to the TV white space based on a proportional fair criterion.An uplink user allocation scheme is proposed and the validity of the proposed scheme is established by simulation of the cellular network usage in conjunction with the TV white space.The simulation results show clear improvements in both the user and the system performance with the cognitive coexistent cellular network compared with the traditional cellular network,and that the performance of the proposed user allocation scheme is superior to other user allocation schemes.展开更多
Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12,...Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12, DL/UL decouple access scheme has been proposed, which is especially suitable for heterogeneous networks(Het Nets). This paper is the pioneer to take the DL/UL decouple access scheme into consideration and develop a novel resource allocation algorithm in a two-tier Het Net to improve the total system throughput in the UL and ease the load imbalance between macro base stations(MBSs) and pico base stations(PBSs). A model is formulated as a nonlinear integer programming, and the proposed algorithm is a sub-optimal algorithm based on the graph theory. First, an undirected and weighted interference graph is obtained. Next, the users are grouped to let users with large mutual interferences to be assigned to different clusters. Then, the users in different clusters are allocated to different resource blocks(RBs) by using the Hungarian algorithm. Simulation results show that the proposed algorithm can provide great promotions for both the total system throughput and the average cell edge user throughput and successfully ease the load imbalance between MBSs and PBSs.展开更多
Whitecapping plays an important role in many air-sea exchange and upper ocean processes.Traditionally,whitecap coverage is parameterized as a function of wind speed only.At present,the relative speed of ocean current ...Whitecapping plays an important role in many air-sea exchange and upper ocean processes.Traditionally,whitecap coverage is parameterized as a function of wind speed only.At present,the relative speed of ocean current to wind is considered to be important in the air-sea exchange parameterization which is the function of wind speed only.In this paper,the effects of ocean surface velocity (current velocity and wave induced velocity) and the wave parameters on whitecap coverage through relative speeds are investigated,by applying a 2-parameter whitecap coverage model to the Atlantic Ocean.It is found that the impacts of both current and wave on whitecap coverage are considerable in the most part of the Atlantic Ocean.It is interesting that the effect of wave is more significant than that of current.展开更多
According to Kripke, traditional approaches to presupposition and anaphora do not work in some compound sentences because traditionally, they have been thought to assign presuppositions to each clause in isolation. I ...According to Kripke, traditional approaches to presupposition and anaphora do not work in some compound sentences because traditionally, they have been thought to assign presuppositions to each clause in isolation. I agree with this criticism, but also think that context is required in order to determine the presupposition included in a complex sentence. To show the context role in fixing the utterance truth-conditions in those cases, this paper introduces the Kripkean anaphoric account on presuppositions （section 2）, and then criticizes this approach because it is very restrictive （section 3）. The paper concludes that to solve those difficulties, one should appeal to a two-dimensional framework, including a new parameter that focuses on the sentence according to the concrete features of the context： the speaker＇s point of view （section 4）.展开更多
There is a discharge control feature of construction diversion system with the upstream operational reservoir. The risk evaluation model of construction diversion is established by taking into consideration the risk f...There is a discharge control feature of construction diversion system with the upstream operational reservoir. The risk evaluation model of construction diversion is established by taking into consideration the risk factors of construction diversion system with discharge control feature as well as their composition. And the risk factors include the upstream operational reservoir discharge control, the interval flood and branch flood and the diversion system itself. And then based on analyzing of the conversion relation between risk index and investment index of diversion scheme, the risk control and conversion principals of diversion system are put forward, and the feasible diversion scheme model is built. At last, the risk and economic evaluation and scheme economic feasibility analysis method of diversion scheme are shown by an example of construction diversion scheme optimization with the discharge control condition of upstream hydropower station. The study is valuable for establishment and optimization of construction diversion scheme with upstream reservoir discharge control.展开更多
AIM： To determine the and clinical features of prevalence, histologic types primary epithelial tumours of the vermiform appendix in a predominantly black population.METHODS： All cases of primary tumours of the appen...AIM： To determine the and clinical features of prevalence, histologic types primary epithelial tumours of the vermiform appendix in a predominantly black population.METHODS： All cases of primary tumours of the appendix identified by review of the histopathology records at the University of the West Indies between January 1987 and June 2007 were selected. Relevant pathologic and clinical data were extracted with supplementation from patient charts where available. Non-epithelial tumours were excluded. The total number of appendectomy specimens over the period was also ascertained.RESULTS： Forty-two primary epithelial tumours were identified out of 6 824 appendectomies yielding a prevalence rate of approximately 0.62%. Welldifferentiated neuroendocrine cell tumours （carcinoids, 47.6%） and benign non-endocrine cell tumours （adenomas, 45.2%） were most common with nearly equal frequency. The median age was 43 years, with no sex predilection. Carcinoid tumours occurred in younger patients （mean age 32 years）, with a male-to-female ratio of 1.2：1. A clinical diagnosis of acute appendicitis was the most common reason for appendectomy （57.1%） and was histologically confirmed in 75% （18 of 24） of cases. In total, 16.7% of cases were diagnosed after incidental appendectomy.CONCLUSION： Appendiceal epithelial tumours are rare in our experience, and are represented principally by carcinoid turnours and adenornas. Carcinoid tumours occurred in younger patients but were slightly more common in men than women. Tumours were not suspected clinically and were diagnosed incidentally in specimens submitted for acute appendicitis supporting the need for histological evaluation in all resection specimens.展开更多
文摘Only a few cases of pedunculated hepatocellular carcinoma (P-HCC) have been reported in the literature. The common sites of extrahepatic metastases in patients with HCC are the lungs, regional lymph nodes, kidney, bone marrow and adrenals. Metastasis to spleen is mostly via hematogenous metastasis, direct metastasis to spleen was very rare. We report a case of P-HCC presenting as a left upper abdominal lesions which involved the spleen that was actually a P-HCC with splenic metastasis. This case is unique as P-HCC directly involved the spleen which is not via hematogenous metastasis.
基金Under the auspices of National Natural Science Foundation of China (No. 70703012)Cutural and Social Foundation of National Education Ministry (No.11YJAZH059)
文摘Based upon a case study of Silver Beach coastal resort of Beihai, Guangxi Zhuang Autonomous Region, this article examines the rise and fall of Chinese coastal tourist resort development since the 1980s. It explores the causes for and responses to the decline of Chinese coastal resorts. The data were collected through in-depth interviews with twelve local key information providers, and secondary information sources such as government archives, survey reports, and resort plans. It was found that the rise and fall of Chinese coastal resorts in the last three decades is closely linked to the transitional reform from a central planned economy to a market economy. Three stages of coastal tourism development were identified in a sequence of rapid growth, decline and redevelopment. It was government financial funds and high local government involvement that promoted the rapid expansion of coastal resorts during the 1980s. However, coastal resort decline occurred when transitional reform was intensified and deflationary policy executed af- ter 1992. Institutional failure is found to be the main reason of Chinese coastal resorts decline since the mid-1990s. The government-dominated pattern could not be sustained and should be restructured in forthcoming coastal tourism de- velopment in China. Revival strategies should emphasize enhancing market-oriented reform in the declining resorts on both suoolv and demand sides.
基金financial supports from National Natural Science Foundation of China(Grant Nos.4157152741801221+3 种基金4160161441701622)Sichuan Center for Rural Development Research Project(Grant No.01781912)Ministry of education humanities and social science research youth fund project(No.17YJC630136)
文摘The influence of labor migration on rural household land transfer has been hotly debated in academic circles, which focuses on whether part-time employment leads to land transfer. Using survey data on rural households in the Sichuan Province, and applying the theoretical framework of new economics of labor migration, this study explores the influences of labor migration on the direction and scale of land transfer from the perspective of rural household structure. The results indicate that: 1) the quantity of laborers has significant influence on the direction and scale of land transfer. The larger the on-farm labor variable(Labor), the lesser the possibility that land will be rented-out and the amount of land rented out will also be smaller. In addition, there is a greater probability that land will be rented-in and the amount of land rented-in will be greater. 2) The greater the ratio of off-farm laborers to rural household laborers(Off-farm) the greater the possibility that land will be rented-out. In addition the higher the ratio of on-farm laborers to the total household laborers(On-farm), the larger the possibility that land will be rented-in. Meanwhile, if the household has individuals at the age of 64 or older(Old) who are engaged in agriculture, there is a smaller possibility that land will be rentedout. 3) the ratio of part-time laborers to rural household laborers(Pluriactivity) have significant inverse U-shaped influences on the rent-in of land as well as the amount of land rented-in. The inflection points are 33.27% and 14.10%, respectively. Such findings confirm the significance of this study in better understanding the influence of labor migration on rural household land transfer.
文摘In this paper,using the existence and comparison result for the quasi-monotone increasing system developed by C V Pao,the upper and lower solutions principle and an iterative method,we investigate the existence of the positive solutions of the Volterra-Lotka cooperating model.
基金Supported by the National Natural Science Foundation of China(No.61271230)the Starting Fund for Science Research of NJIT(No.YKJ201205)the Open Research Fund of National Mobile Communications Research Laboratory(No.2013D02)
文摘In order to address spectrum resource scarcity in traditional cellular networks,television(TV)white space is considered as a potential solution to offload a portion of network traffic and enlarge network capacity.This paper describes a cognitive cellular network which allocates low geometry users to the TV white space based on a proportional fair criterion.An uplink user allocation scheme is proposed and the validity of the proposed scheme is established by simulation of the cellular network usage in conjunction with the TV white space.The simulation results show clear improvements in both the user and the system performance with the cognitive coexistent cellular network compared with the traditional cellular network,and that the performance of the proposed user allocation scheme is superior to other user allocation schemes.
基金supported by the National Natural Science Foundation General Program of China under Grant No.61171110the National Basic Research Program of China under Grant No.2013CB329003
文摘Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12, DL/UL decouple access scheme has been proposed, which is especially suitable for heterogeneous networks(Het Nets). This paper is the pioneer to take the DL/UL decouple access scheme into consideration and develop a novel resource allocation algorithm in a two-tier Het Net to improve the total system throughput in the UL and ease the load imbalance between macro base stations(MBSs) and pico base stations(PBSs). A model is formulated as a nonlinear integer programming, and the proposed algorithm is a sub-optimal algorithm based on the graph theory. First, an undirected and weighted interference graph is obtained. Next, the users are grouped to let users with large mutual interferences to be assigned to different clusters. Then, the users in different clusters are allocated to different resource blocks(RBs) by using the Hungarian algorithm. Simulation results show that the proposed algorithm can provide great promotions for both the total system throughput and the average cell edge user throughput and successfully ease the load imbalance between MBSs and PBSs.
基金Supported by Ministry of Science and Technology of China (Nos.2005CB422307 and 2006BAC03B01)National Natural Science Foundation of China (No.40830959)
文摘Whitecapping plays an important role in many air-sea exchange and upper ocean processes.Traditionally,whitecap coverage is parameterized as a function of wind speed only.At present,the relative speed of ocean current to wind is considered to be important in the air-sea exchange parameterization which is the function of wind speed only.In this paper,the effects of ocean surface velocity (current velocity and wave induced velocity) and the wave parameters on whitecap coverage through relative speeds are investigated,by applying a 2-parameter whitecap coverage model to the Atlantic Ocean.It is found that the impacts of both current and wave on whitecap coverage are considerable in the most part of the Atlantic Ocean.It is interesting that the effect of wave is more significant than that of current.
文摘According to Kripke, traditional approaches to presupposition and anaphora do not work in some compound sentences because traditionally, they have been thought to assign presuppositions to each clause in isolation. I agree with this criticism, but also think that context is required in order to determine the presupposition included in a complex sentence. To show the context role in fixing the utterance truth-conditions in those cases, this paper introduces the Kripkean anaphoric account on presuppositions （section 2）, and then criticizes this approach because it is very restrictive （section 3）. The paper concludes that to solve those difficulties, one should appeal to a two-dimensional framework, including a new parameter that focuses on the sentence according to the concrete features of the context： the speaker＇s point of view （section 4）.
基金National Natural Science Foundation of China ( No. 10902078 and No. 51079115)
文摘There is a discharge control feature of construction diversion system with the upstream operational reservoir. The risk evaluation model of construction diversion is established by taking into consideration the risk factors of construction diversion system with discharge control feature as well as their composition. And the risk factors include the upstream operational reservoir discharge control, the interval flood and branch flood and the diversion system itself. And then based on analyzing of the conversion relation between risk index and investment index of diversion scheme, the risk control and conversion principals of diversion system are put forward, and the feasible diversion scheme model is built. At last, the risk and economic evaluation and scheme economic feasibility analysis method of diversion scheme are shown by an example of construction diversion scheme optimization with the discharge control condition of upstream hydropower station. The study is valuable for establishment and optimization of construction diversion scheme with upstream reservoir discharge control.
文摘AIM： To determine the and clinical features of prevalence, histologic types primary epithelial tumours of the vermiform appendix in a predominantly black population.METHODS： All cases of primary tumours of the appendix identified by review of the histopathology records at the University of the West Indies between January 1987 and June 2007 were selected. Relevant pathologic and clinical data were extracted with supplementation from patient charts where available. Non-epithelial tumours were excluded. The total number of appendectomy specimens over the period was also ascertained.RESULTS： Forty-two primary epithelial tumours were identified out of 6 824 appendectomies yielding a prevalence rate of approximately 0.62%. Welldifferentiated neuroendocrine cell tumours （carcinoids, 47.6%） and benign non-endocrine cell tumours （adenomas, 45.2%） were most common with nearly equal frequency. The median age was 43 years, with no sex predilection. Carcinoid tumours occurred in younger patients （mean age 32 years）, with a male-to-female ratio of 1.2：1. A clinical diagnosis of acute appendicitis was the most common reason for appendectomy （57.1%） and was histologically confirmed in 75% （18 of 24） of cases. In total, 16.7% of cases were diagnosed after incidental appendectomy.CONCLUSION： Appendiceal epithelial tumours are rare in our experience, and are represented principally by carcinoid turnours and adenornas. Carcinoid tumours occurred in younger patients but were slightly more common in men than women. Tumours were not suspected clinically and were diagnosed incidentally in specimens submitted for acute appendicitis supporting the need for histological evaluation in all resection specimens.
