1,618 research outputs found
Source localization using a sparse representation framework to achieve superresolution
We present a source localization approach using resampling within a sparse representation framework. In particular, the amplitude and phase information of the sparse solution is considered holistically to estimate the direction-of-arrival (DOA), where a resampling technique is developed to determine which information will give a more precise estimation. The simulation results confirm the efficacy of our proposed method. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 01 Dec 201
An improved direction-of-arrival estimation via phase information of sparse solution
An improved direction-of-arrivals (DOAs) estimation via phase information of sparse solution is presented in this paper. Unlike the conventional sparse source localization approach using the amplitude of sparse solutions only, through a special partition of the receiving data of the sensors, the phase information of the available sparse solutions is also extracted to estimate DOAs. For the true DOAs exactly on the grids which are used to generate the over-complete dictionary, the performance of our method is close to the conventional sparse source localization method. For the true DOAs that are not on the grids, our method is far superior to the conventional method, as demonstrated by several simulation results. ©2009 IEEE.published_or_final_versio
Relationship between cognitive function and symptomology with self-stigma in patients with schizophrenia-spectrum disorders
E-PosterBACKGROUND: Self-stigma can be understood as a process of an individual gaining awareness of the associated stereotypes, agreeing with them and thus applying them to oneself [1]. This suggests the involvement of complex cognitive processes behind the development of self-stigma. Previous studies have also suggested that clinical symptoms are related to both cognitive function and self-stigma [2,3]. The current study examined the relationship of cognitive functions, clinical symptoms and self-stigma ...published_or_final_versio
Evolution of Landau Levels into Edge States at an Atomically Sharp Edge in Graphene
The quantum-Hall-effect (QHE) occurs in topologically-ordered states of
two-dimensional (2d) electron-systems in which an insulating bulk-state
coexists with protected 1d conducting edge-states. Owing to a unique
topologically imposed edge-bulk correspondence these edge-states are endowed
with universal properties such as fractionally-charged quasiparticles and
interference-patterns, which make them indispensable components for QH-based
quantum-computation and other applications. The precise edge-bulk
correspondence, conjectured theoretically in the limit of sharp edges, is
difficult to realize in conventional semiconductor-based electron systems where
soft boundaries lead to edge-state reconstruction. Using scanning-tunneling
microscopy and spectroscopy to follow the spatial evolution of bulk
Landau-levels towards a zigzag edge of graphene supported above a graphite
substrate we demonstrate that in this system it is possible to realize
atomically sharp edges with no edge-state reconstruction. Our results single
out graphene as a system where the edge-state structure can be controlled and
the universal properties directly probed.Comment: 16 pages, 4 figure
A 10-year outcome study of an early intervention program for psychosis in Hong Kong (EASY) compared with standard care service
Session - 9. Health Economics & Services Research: no. 1521946This journal suppl. contain Abstracts for the 14th International Congress on Schizophrenia ResearchBACKGROUND: Despite the service model of early intervention for first-episode psychosis being wildly adopted, evidence of long-term effects are limited. This study aimed to compare 10-year outcomes of patients with early intervention in first-episode psychosis and those received standard care in Hong Kong. METHODS: In this historical control study, 148 first-episode psychosis patients who received early intervention ...postprin
Pretreatment carcinoembryonic antigen level is a risk factor for para-aortic lymph node recurrence in addition to squamous cell carcinoma antigen following definitive concurrent chemoradiotherapy for squamous cell carcinoma of the uterine cervix
<p>Abstract</p> <p>Background</p> <p>To identify pretreatment carcinoembryonic antigen (CEA) levels as a risk factor for para-aortic lymph node (PALN) recurrence following concurrent chemoradiotherapy (CCRT) for cervical cancer.</p> <p>Methods</p> <p>From March 1995 to January 2008, 188 patients with squamous cell carcinoma (SCC) of the uterine cervix were analyzed retrospectively. No patient received PALN irradiation as the initial treatment. CEA and squamous cell carcinoma antigen (SCC-Ag) were measured before and after radiotherapy. PALN recurrence was detected by computer tomography (CT) scans. We analyzed the actuarial rates of PALN recurrence by using Kaplan-Meier curves. Multivariate analyses were carried out with Cox regression models. We stratified the risk groups based on the hazard ratios (HR).</p> <p>Results</p> <p>Both pretreatment CEA levels ≥ 10 ng/mL and SCC-Ag levels < 10 ng/mL (<it>p </it>< 0.001, HR = 8.838), SCC-Ag levels ≥ 40 ng/mL (<it>p </it>< 0.001, HR = 12.551), and SCC-Ag levels of 10-40 ng/mL (<it>p </it>< 0.001, HR = 4.2464) were significant factors for PALN recurrence. The corresponding 5-year PALN recurrence rates were 51.5%, 84.8%, and 27.5%, respectively. The 5-year PALN recurrence rate for patients with both low (< 10 ng/mL) SCC and CEA was only 9.6%. CEA levels ≥ 10 ng/mL or SCC-Ag levels ≥ 10 ng/mL at PALN recurrence were associated with overall survival after an isolated PALN recurrence. Pretreatment CEA levels ≥ 10 ng/mL were also associated with survival after an isolated PALN recurrence.</p> <p>Conclusions</p> <p>Pretreatment CEA ≥ 10 ng/mL is an additional risk factor of PALN relapse following definitive CCRT for SCC of the uterine cervix in patients with pretreatment SCC-Ag levels < 10 ng/mL. More comprehensive examinations before CCRT and intensive follow-up schedules are suggested for early detection and salvage in patients with SCC-Ag or CEA levels ≥ 10 ng/mL.</p
Optimism/pessimism and health-related quality of life during pregnancy across three continents: a matched cohort study in China, Ghana, and the United States
<p>Abstract</p> <p>Background</p> <p>Little is known about how optimism/pessimism and health-related quality of life compare across cultures.</p> <p>Methods</p> <p>Three samples of pregnant women in their final trimester were recruited from China, Ghana, and the United States (U.S.). Participants completed a survey that included the Life Orientation Test - Revised (LOT-R, an optimism/pessimism measure), the Short Form 12 (SF-12, a quality of life measure), and questions addressing health and demographic factors. A three-country set was created for analysis by matching women on age, gestational age at enrollment, and number of previous pregnancies. Anovas with post-hoc pairwise comparisons were used to compare results across the cohorts. Multivariate regression analysis was used to create a model to identify those variables most strongly associated with optimism/pessimism.</p> <p>Results</p> <p>LOT-R scores varied significantly across cultures in these samples, with Ghanaian pregnant women being the most optimistic and least pessimistic and Chinese pregnant women being the least optimistic overall and the least pessimistic in subscale analysis. Four key variables predicted approximately 20% of the variance in overall optimism scores: country of origin (p = .006), working for money (p = .05); level of education (p = .002), and ever being treated for emotional issues with medication (p < .001). Quality of life scores also varied by country in these samples, with the most pronounced difference occurring in the vitality measure. U.S. pregnant women reported far lower vitality scores than both Chinese and Ghanaian pregnant women in our sample.</p> <p>Conclusion</p> <p>This research raises important questions regarding what it is about country of origin that so strongly influences optimism/pessimism among pregnant women. Further research is warranted exploring underlying conceptualization of optimism/pessimism and health related quality of life across countries.</p
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