143 research outputs found

    Some estimates of Wang-Yau quasilocal energy

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    Given a spacelike 2-surface Σ\Sigma in a spacetime NN and a constant future timelike unit vector T0T_0 in R3,1\R^{3,1}, we derive upper and lower estimates of Wang-Yau quasilocal energy E(Σ,X,T0)E(\Sigma, X, T_0) for a given isometric embedding XX of Σ\Sigma into a flat 3-slice in R3,1\R^{3,1}. The quantity E(Σ,X,T0) E(\Sigma, X, T_0) itself depends on the choice of XX, however the infimum of E(Σ,X,T0) E(\Sigma, X, T_0) over T0 T_0 does not. In particular, when Σ\Sigma lies in a time symmetric 3-slice in NN and has nonnegative Brown-York quasilocal mass \mby(\Sigma), our estimates show that infT0E(Σ,X,T0)\inf\limits_{T_0}E(\Sigma, X, T_0) equals \mby (\Sigma). We also study the spatial limit of infT0E(Sr,Xr,T0) \inf\limits_{T_0}E(S_r,X_r,T_0), where SrS_r is a large coordinate sphere in a fixed end of an asymptotically flat initial data set (M,g,p)(M, g, p) and XrX_r is an isometric embeddings of SrS_r into R3R3,1\mathbb{R}^3 \subset \mathbb{R}^{3,1}. We show that if (M,g,p)(M, g, p) has future timelike ADM energy-momentum, then limrinfT0E(Sr,Xr,T0)\lim\limits_{r\to\infty}\inf\limits_{T_0}E(S_r,X_r,T_0) equals the ADM mass of (M,g,p)(M, g, p).Comment: 17 page

    Prognostic implications of residual disease tumor-infiltrating lymphocytes and residual cancer burden in triple-negative breast cancer patients after neoadjuvant chemotherapy

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    Abstract Background For primary triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), higher pretreatment tumor-infiltrating lymphocytes (TILs) correlates with increased pathologic complete response (pCR) rates, and improved survival. We evaluated the added prognostic value of residual disease (RD) TILs to residual cancer burden (RCB) in predicting survival post-NAC. Patients and methods We combined four TNBC NAC patient cohorts who did not achieve pCR. RD TILs were investigated for associations with recurrence-free survival (RFS), and overall survival (OS) using Cox models with stromal TILs as a continuous variable (per 10% increment). The likelihood ratio test was used to evaluate added prognostic value of RD TILs. Results A total of 375 RD TNBC samples were evaluable for TILs and RCB. The median age was 50 years, with 62% receiving anthracycline/taxane chemotherapy. The RCB class after NAC was 11%, 50%, and 39% for I, II, and III, respectively. The median RD TIL level was 20% (IQR 10–40). There was a positive correlation between RD TIL levels and CD8+ T-cell density (ρ = 0.41). TIL levels were significantly lower with increasing post-NAC tumor (P = 0.005), nodal stage (P = 0.032), but did not differ by RCB class (P = 0.84). Higher RD TILs were significantly associated with improved RFS (HR: 0.86; 95% CI 0.79–0.92; P  Conclusions TIL levels in TNBC RD are significantly associated with improved RFS and OS and add further prognostic information to RCB class, particularly in RCB class II

    Supervisory control using variable lookahead policies

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    This paper deals with the efficient on-line calculation of supervisory controls for discrete event systems (DES's) in the framework of limited lookahead control policies (or LLPs) that we introduced in previous papers. In the LLP scheme, the control action after a given trace of events has been executed is calculated on-line on the basis of an N -step ahead projection of the behavior of the DES. To compute these controls, one must calculate after the execution of each event the supremal controllable sublanguage of a finite language with respect to another finite larger language. In our previous work, we showed how the required supremal controllable sublanguage calculation can be performed by using a backward dynamic programming algorithm over the nodes of the tree representation of these two languages. In this paper, we pursue the same approach for the calculation of LLP controls, but instead we adopt a forward calculation procedure over the N -level tree of interest. This forward procedure improves upon previous work by avoiding the explicit consideration of all the nodes of the N -level tree, while still permitting tree-to-tree recursiveness as enabled events are executed by the system. The forward search ends whenever a control decision can be made unambiguously or whenever the boundary of the N -level tree is reached, whichever comes first. This motivates the name “Variable Lookahead Policy” (or VLP) for this implementation of the LLP supervisory control scheme. This paper presents a general VLP algorithm and studies the properties of several special cases of it. The paper also discusses the implementation of the VLP algorithms and presents computational results regarding the application of these algorithms to a “time-varying” DES.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45124/1/10626_2005_Article_BF01438709.pd

    Clinical features, acute complications, and outcome of Salmonella meningitis in children under one year of age in Taiwan

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    <p>Abstract</p> <p>Background</p> <p><it>Salmonella </it>meningitis remains a threat to children below two years of age in both developing and developed countries. However, information on such infections has not been well characterized. We analyzed data related to twelve years of experience in order to clarify the comprehensive features of <it>Salmonella </it>meningitis in our patients, including admission characteristics, acute complications, and long-term outcome.</p> <p>Methods</p> <p>The records of patients with spontaneous <it>Salmonella </it>meningitis from 1982 to 1994 were retrospectively reviewed. The long-term outcome was prospectively determined for survivors at school age by the developmental milestones reported by their parents and detailed neurological evaluation along with intelligence, hearing, visual, speech and language assessments.</p> <p>Results</p> <p>Of the twenty-four patients, seizures were noted in fifteen (63%) before admission and thirteen (54%) during hospitalization. Acute complications mainly included hydrocephalus (50%), subdural collection (42%), cerebral infarction (33%), ventriculitis (25%), empyema (13%), intracranial abscess (8%), and cranial nerve palsy (8%). Three patients (13%) died during the acute phase of <it>Salmonella </it>meningitis. The twenty-one survivors, on whom we followed up at school age, have sequelae consisting of language disorder (52%), motor disability (48%), intelligence quotient < 80 (43%), epilepsy (33%), sensorineural hearing loss (17%), visual deficits (10%), abducens nerve palsy (5%), microcephaly (5%), and hydrocephalus (5%). Overall, good outcome was noted in six (28.6%) of twenty-one survivors, mild sequelae in three (14.2%), moderate in six (28.6%), and severe in six (28.6%).</p> <p>Conclusion</p> <p><it>Salmonella </it>meningitis in neonates and infants had a wide spectrum of morbidity and acute complications, leading to a complicated hospital course and subsequently a high prevalence of permanent adverse outcome. Thus, early recognition of acute complications of <it>Salmonella </it>meningitis and a follow-up plan for early developmental assessment of survivors are vital.</p

    Application of a risk-management framework for integration of stromal tumor-infiltrating lymphocytes in clinical trials

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    Pitfalls in assessing stromal tumor infiltrating lymphocytes (sTILs) in breast cancer

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    The Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

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    This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic ‘secretomes’ that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to lignin-modification or depolymerization under anaerobic conditions

    Assessing trends and predictors of tuberculosis in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Variety of environmental and individual factors can cause tuberculosis (TB) incidence change. The purpose of this study was to assess the characteristics of TB trends in the period 2004 - 2008 in Taiwan by month, year, gender, age, temperature, seasonality, and aborigines.</p> <p>Methods</p> <p>The generalized regression models were used to examine the potential predictors for the monthly TB incidence in regional and national scales.</p> <p>Results</p> <p>We found that (<it>i</it>) in Taiwan the average TB incidence was 68 per 100,000 population with mortality rate of 0.036 person<sup>-1 </sup>yr<sup>-1</sup>, (<it>ii</it>) the highest TB incidence rate was found in eastern Taiwan (116 per 100,000 population) with the largest proportion of TB relapse cases (8.17%), (<it>iii</it>) seasonality, aborigines, gender, and age had a consistent and dominant role in constructing TB incidence patterns in Taiwan, and (<it>iv</it>) gender, time trend, and 2-month lag maximum temperature showed strong association with TB trends in aboriginal subpopulations.</p> <p>Conclusions</p> <p>The proposed Poisson regression model is capable of forecasting patterns of TB incidence at regional and national scales. This study suggested that assessment of TB trends in eastern Taiwan presents an important opportunity for understanding the time-series dynamics and control of TB infections, given that this is the typical host demography in regions where these infections remain major public health problems.</p

    Application of a risk-management framework for integration of stromal tumor-infiltrating lymphocytes in clinical trials

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    Stromal tumor-infiltrating lymphocytes (sTILs) are a potential predictive biomarker for immunotherapy response in metastatic triple-negative breast cancer (TNBC). To incorporate sTILs into clinical trials and diagnostics, reliable assessment is essential. In this review, we propose a new concept, namely the implementation of a risk-management framework that enables the use of sTILs as a stratification factor in clinical trials. We present the design of a biomarker risk-mitigation workflow that can be applied to any biomarker incorporation in clinical trials. We demonstrate the implementation of this concept using sTILs as an integral biomarker in a single-center phase II immunotherapy trial for metastatic TNBC (TONIC trial, NCT02499367), using this workflow to mitigate risks of suboptimal inclusion of sTILs in this specific trial. In this review, we demonstrate that a web-based scoring platform can mitigate potential risk factors when including sTILs in clinical trials, and we argue that this framework can be applied for any future biomarker-driven clinical trial setting

    Seven HCI Grand Challenges

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    This article aims to investigate the Grand Challenges which arise in the current and emerging landscape of rapid technological evolution towards more intelligent interactive technologies, coupled with increased and widened societal needs, as well as individual and collective expectations that HCI, as a discipline, is called upon to address. A perspective oriented to humane and social values is adopted, formulating the challenges in terms of the impact of emerging intelligent interactive technologies on human life both at the individual and societal levels. Seven Grand Challenges are identified and presented in this article: Human-Technology Symbiosis; Human-Environment Interactions; Ethics, Privacy and Security; Well-being, Health and Eudaimonia; Accessibility and Universal Access; Learning and Creativity; and Social Organization and Democracy. Although not exhaustive, they summarize the views and research priorities of an international interdisciplinary group of experts, reflecting different scientific perspectives, methodological approaches and application domains. Each identified Grand Challenge is analyzed in terms of: concept and problem definition; main research issues involved and state of the art; and associated emerging requirements
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