A PHASE-PLANE TRAJECTORY VECTOR-BASED METHOD

Critical Machines (CMs) identification is the first and most important step of Equivalent-Single Machine Infinite Bus (E-SMIB) based methods such as EEAC and SMIE for transient stability assessment and control. This paper presents a novel real-time CMs identification method based on the Phase-plane Trajectory Vector (PTV) with PMU information support. The proposed method overcomes the drawbacks of conventional CMs identification methods and enables to track the change of CMs during the dynamic process. Only two sample points of all generators from PMUs are required to obtain the PTVs at each moment and the computation of feature matrix, as well as the k-means clustering, is fast and accurate. The application of the PTV based method is verified through cases study in IEEE 39 bus New England power system. Results are compared well with those obtained by conventional methods

Dynamic Coherency Real-time Identification for Controlled Islanding

Controlled islanding often acts as the last resort against a severe blackout. Generator coherency is the primary constraint to determine an effective controlled islanding strategy. This paper proposes a scheme to identify the dynamic coherency of generators for controlled islanding. The generator coherency is identified based on the Phase-plane Trajectory Vectors (PTVs) on the Phase Plane for Generators (PPG). Then a Phase Plane for Buses (PPB) is proposed to assign the non-generator buses to coherent generator groups following the minimum distance principle. The separated islands are formed by disconnecting certain transmission lines according to the identified coherent generators and areas. The case studies in IEEE 39-bus 10-machine power system show that the proposed scheme can not only adapt to different disturbances and changes of system conditions and network topology but also succeed in identifying the generator coherency at different times and developing proper islanding strategy according to current system states

A hybrid localization approach in 3D wireless sensor network

Location information acquisition is crucial for many wireless sensor network (WSN) applications. While existing localization approaches mainly focus on 2D plane, the emerging 3D localization brings WSNs closer to reality with much enhanced accuracy. Two types of 3D localization algorithms are mainly used in localization application: the range-based localization and the range-free localization. The range-based localization algorithm has strict requirements on hardware and therefore is costly to implement in practice. The range-free localization algorithm reduces the hardware cost but at the expense of low localization accuracy. On addressing the shortage of both algorithms, in this paper, we develop a novel hybrid localization scheme, which utilizes the range-based attribute RSSI and the range-free attribute hopsize, to achieve accurate yet low-cost 3D localization. As anchor node deployment strategy plays an important role in improving the localization accuracy, an anchor node configuration scheme is also developed in this work by utilizing the MIS (maximal independent set) of a network. With proper anchor node configuration and propagation model selection, using simulations, we show that our proposed algorithm improves the localization accuracy by 38.9% compared with 3D DV-HOP and 52.7% compared with 3D centroid

Correlations between IGF-IR Expression and Clinicopathological Factors and Prognosis in Patients with Lung Adenocarcinoma

Background and objective The incidence of lung adenocarcinoma increases rapidly, and IGF-IR is the key mediator of several growth factors signal transduction, therefore it plays an important role in the proliferation and differentiation of cancer cell. The aim of this study is to detect the expression of IGF-IR in lung adenocarcinoma and to evaluate its implication for the clinicopathological factors and prognosis of patients with this disease. Methods The IGF-IR expression was detected by immunohistochemical staining. Correlations between IGF-IR expression with clinicopathological factors were analyzed using the Chi-squared test. The Kaplan-Meier method was used to calculate the overall patient survival rate, and the difference in survival curves was evaluated using a Log-rank test. Univariate and multivariate analysis was carried out using the Cox proportional-hazard model. Results In 126 cases of tumor sections tested, IGF-IR were detected in 89 cases. Statistical analysis revealed that the IGF-IR expression was related to tumor size and T stage, while there were no relations between IGFIR expression and age, gender, smoking, pathological stages, and differentiation. Cox analysis indicated that metastasis and chemotherapy efficacy were the prognostic factors in these patients, while IGF-IR expression was not the independent prognostic factor. Conclusion The IGF-IR expression is related to tumor size and T stage, while there is no relation between IGF-IR expression and prognosis

Associations between palliative chemotherapy and adult cancer patients’ end of life care and place of death: prospective cohort study

Objectives: To determine whether the receipt of chemotherapy among terminally ill cancer patients months before death was associated with patients’ subsequent intensive medical care and place of death. Design: Secondary analysis of a prospective, multi-institution, longitudinal study of patients with advanced cancer. Setting: Eight outpatient oncology clinics in the United States. Participants: 386 adult patients with metastatic cancers refractory to at least one chemotherapy regimen, whom physicians identified as terminally ill at study enrollment and who subsequently died. Main outcome measures Primary outcomes: intensive medical care (cardiopulmonary resuscitation, mechanical ventilation, or both) in the last week of life and patients’ place of death (for example, intensive care unit). Secondary outcomes: survival, late hospice referrals (≤1 week before death), and dying in preferred place of death. Results: 216 (56%) of 386 terminally ill cancer patients were receiving palliative chemotherapy at study enrollment, a median of 4.0 months before death. After propensity score weighted adjustment, use of chemotherapy at enrollment was associated with higher rates of cardiopulmonary resuscitation, mechanical ventilation, or both in the last week of life (14% v 2%; adjusted risk difference 10.5%, 95% confidence interval 5.0% to 15.5%) and late hospice referrals (54% v 37%; 13.6%, 3.6% to 23.6%) but no difference in survival (hazard ratio 1.11, 95% confidence interval 0.90 to 1.38). Patients receiving palliative chemotherapy were more likely to die in an intensive care unit (11% v 2%; adjusted risk difference 6.1%, 1.1% to 11.1%) and less likely to die at home (47% v 66%; −10.8%, −1.0% to −20.6%), compared with those who were not. Patients receiving palliative chemotherapy were also less likely to die in their preferred place, compared with those who were not (65% v 80%; adjusted risk difference −9.4%, −0.8% to −18.1%). Conclusions: The use of chemotherapy in terminally ill cancer patients in the last months of life was associated with an increased risk of undergoing cardiopulmonary resuscitation, mechanical ventilation or both and of dying in an intensive care unit. Future research should determine the mechanisms by which palliative chemotherapy affects end of life outcomes and patients’ attainment of their goals

Dynamic stiffness method for free vibration analysis of variable diameter pipe conveying fluid

The governing equation of flow-induced vibration is deduced in terms of Hamilton’s principle for a variable diameter pipe conveying axial steady flow. Frobenius method is applied to analyze the governing equation. After the recursion formulas of coefficients are obtained, dynamic stiffness method is proposed for free vibration analysis of the variable diameter pipe conveying fluid. In the example, the natural frequencies of uniform pipes conveying fluid are computed and comparisons are made to validate the dynamic stiffness method. Then, the natural frequencies and modal shapes are obtained for the variable diameter pipe conveying fluid with different section variation coefficients and fluid velocities

Perspectives on the Application of Genome-Editing Technologies in Crop Breeding

Most conventional and modern crop-improvement methods exploit natural or artificially induced genetic variations and require laborious characterization of the progeny of multiple generations of time-consuming genetic crosses. Genome-editing systems, in contrast, provide the means to rapidly modify genomes in a precise and predictable way, making it possible to introduce improvements directly into elite varieties. Here, we describe the range of applications available to agricultural researchers using existing genome-editing tools. In addition to providing examples of genome-editing applications in crop breeding, we discuss the technical and social challenges faced by breeders using genome-editing tools for crop improvement

Endocytic sorting and recycling require membrane phosphatidylserine asymmetry maintained by TAT-1/CHAT-1. PLoS Genet

Endocytic sorting is achieved through the formation of morphologically and functionally distinct sub-domains within early endosomes. Cargoes destined for recycling are sorted to and transported through newly-formed tubular membranes, but the processes that regulate membrane tubulation are poorly understood. Here, we identified a novel Caenorhabditis elegans Cdc50 family protein, CHAT-1, which acts as the chaperone of the TAT-1 P4-ATPase to regulate membrane phosphatidylserine (PS) asymmetry and endocytic transport. In chat-1 and tat-1 mutants, the endocytic sorting process is disrupted, leading to defects in both cargo recycling and degradation. TAT-1 and CHAT-1 colocalize to the tubular domain of the early endosome, the tubular endocytic recycling compartment (ERC), and the recycling endosome where PS is enriched on the cytosolic surface. Loss of tat-1 and chat-1 function disrupts membrane PS asymmetry and abrogates the tubular membrane structure. Our data suggest that CHAT-1 and TAT-1 maintain membrane phosphatidylserine asymmetry, thus promoting membrane tubulation and regulating endocytic sorting and recycling