Objective: To develop and test a new classification system for stillbirths to help improve understanding of the main causes and conditions associated with fetal death. Design: Population based cohort study. Setting: W...Objective: To develop and test a new classification system for stillbirths to help improve understanding of the main causes and conditions associated with fetal death. Design: Population based cohort study. Setting: West Midlands region. Subjects: 2625 stillbirths from 1997 to 2003. Main outcome measures: Categories of death according to conventional classification methods and a newly developed system (ReCoDe, relevant condition at death). Results: By the conventional Wigglesworth classification, 66.2%of the stillbirths (1738 of 2625) were unexplained. The median gestational age of the unexplained group was 237 days, significantly higher than the stillbirths in the other categories (210 days; P < 0.001). The proportion of stillbirths that were unexplained was high regardless of whether a postmortem examination had been carried out or not (67%and 65%; P = 0.3). By the ReCoDe classification, the most common condition was fetal growth restriction (43.0%), and only 15.2%of stillbirths remained unexplained. ReCoDe identified 57.7%of the Wigglesworth unexplained stillbirths as growth restricted. The size of the category for intrapartum asphyxia was reduced from 11.7%(Wigglesworth) to 3.4%(ReCoDe). Conclusion: The new ReCoDe classification system reduces the predominance of stillbirths currently categorised as unexplained. Fetal growth restriction is a common antecedent of stillbirth, but its high prevalence is hidden by current classification systems. This finding has profound implications for maternity services, and raises the question whether some hitherto “unexplained”stillbirths may be avoidable.展开更多
While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drasti...While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)展开更多
In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we...In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.展开更多
This paper by analyzing the current situation and problems in China＇s current two-year vocational college English teaching system, employment-oriented focuses on developing students＇ professional competence jobs for...This paper by analyzing the current situation and problems in China＇s current two-year vocational college English teaching system, employment-oriented focuses on developing students＇ professional competence jobs for Reconstruction and innovative two-year vocational college English teaching system reform ideas, curriculum segments, curriculum construction, teaching design, teaching evalua-tion model and extracurricular teaching supplement five in-depth discussions, in order to make it more effective, science, flexibility and professional relevance, and lay a good foundation for English language students＇ future employment and real work.展开更多
文摘Objective: To develop and test a new classification system for stillbirths to help improve understanding of the main causes and conditions associated with fetal death. Design: Population based cohort study. Setting: West Midlands region. Subjects: 2625 stillbirths from 1997 to 2003. Main outcome measures: Categories of death according to conventional classification methods and a newly developed system (ReCoDe, relevant condition at death). Results: By the conventional Wigglesworth classification, 66.2%of the stillbirths (1738 of 2625) were unexplained. The median gestational age of the unexplained group was 237 days, significantly higher than the stillbirths in the other categories (210 days; P < 0.001). The proportion of stillbirths that were unexplained was high regardless of whether a postmortem examination had been carried out or not (67%and 65%; P = 0.3). By the ReCoDe classification, the most common condition was fetal growth restriction (43.0%), and only 15.2%of stillbirths remained unexplained. ReCoDe identified 57.7%of the Wigglesworth unexplained stillbirths as growth restricted. The size of the category for intrapartum asphyxia was reduced from 11.7%(Wigglesworth) to 3.4%(ReCoDe). Conclusion: The new ReCoDe classification system reduces the predominance of stillbirths currently categorised as unexplained. Fetal growth restriction is a common antecedent of stillbirth, but its high prevalence is hidden by current classification systems. This finding has profound implications for maternity services, and raises the question whether some hitherto “unexplained”stillbirths may be avoidable.
基金supported by the key project of the National Natural Science Foundation of China(No.61431001)the 863 project No.2014AA01A701+4 种基金Program for New Century Excellent Talents in University(NECT12-0774)the open research fund of National Mobile Communications Research Laboratory Southeast University(No.2013D12)Fundamental Research Funds for the Central Universities(FRF-BD-15-012A)the Research Foundation of China Mobilethe Foundation of Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services
文摘While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)
文摘In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.
文摘This paper by analyzing the current situation and problems in China＇s current two-year vocational college English teaching system, employment-oriented focuses on developing students＇ professional competence jobs for Reconstruction and innovative two-year vocational college English teaching system reform ideas, curriculum segments, curriculum construction, teaching design, teaching evalua-tion model and extracurricular teaching supplement five in-depth discussions, in order to make it more effective, science, flexibility and professional relevance, and lay a good foundation for English language students＇ future employment and real work.
