4,159 research outputs found
Estimation of colorectal adenoma recurrence with dependent censoring
<p>Abstract</p> <p>Background</p> <p>Due to early colonoscopy for some participants, interval-censored observations can be introduced into the data of a colorectal polyp prevention trial. The censoring could be dependent of risk of recurrence if the reasons of having early colonoscopy are associated with recurrence. This can complicate estimation of the recurrence rate.</p> <p>Methods</p> <p>We propose to use midpoint imputation to convert interval-censored data problems to right censored data problems. To adjust for potential dependent censoring, we use information from auxiliary variables to define risk groups to perform the weighted Kaplan-Meier estimation to the midpoint imputed data. The risk groups are defined using two risk scores derived from two working proportional hazards models with the auxiliary variables as the covariates. One is for the recurrence time and the other is for the censoring time. The method described here is explored by simulation and illustrated with an example from a colorectal polyp prevention trial.</p> <p>Results</p> <p>We first show that midpoint imputation under an assumption of independent censoring will produce an unbiased estimate of recurrence rate at the end of the trial, which is often the main interest of a colorectal polyp prevention trial, and then show in simulations that the weighted Kaplan-Meier method using the information from auxiliary variables based on the midpoint imputed data can improve efficiency in a situation with independent censoring and reduce bias in a situation with dependent censoring compared to the conventional methods, while estimating the recurrence rate at the end of the trial.</p> <p>Conclusion</p> <p>The research in this paper uses midpoint imputation to handle interval-censored observations and then uses the information from auxiliary variables to adjust for dependent censoring by incorporating them into the weighted Kaplan-Meier estimation. This approach can handle a situation with multiple auxiliary variables by deriving two risk scores from two working PH models. Although the idea of this approach might appear simple, the results do show that the weighted Kaplan-Meier approach can gain efficiency and reduce bias due to dependent censoring.</p
The effect of glutamine supplement on small intestinal morphology and xylose absorptive ability of weaned piglets
The purpose of this study is to demonstrate the effects of glutamine (Gln) supplement on small intestinal morphology, xylose absorptive and growth performance of weaned piglets. Forty eight piglets weaned at 28 ± 2 days of age were randomly allotted to three treatment groups. A basal corn-soybean diet was formulated to contain 20.3% protein and 3450 kcal DE/kg diet. Glutamine was supplemented to the basal diet at 0% (control), 1% (Gln 1%) and 2% (Gln 2%). Pigs were fed experimental diets for three weeks. The results showed that the villous height of the Gln groups tended higher than the control group in duodenum and jejunum (P < 0.1). Glutamine supplementation increased plasma net xylose absorptive concentration from 0.78 to 1.20 and 0.95 to 1.23 in Gln 1% and Gln 2% group, respectively, which were better than the control group (0.86 to 0.97) in day 7 to 14 after weaning. Growth performance was not significantly affected by Gln supplement; however, average daily gain was approximately improved from 21 to 28% by Gln supplement compared to the control group during 21 days of experimental period. In summary, the results suggested that dietary supplementation of Gln could be beneficial in small intestinal villous morphology and xylose absorptive capacity, and could have a slight contribution to the average daily gain of weaned piglets.Key words: Glutamine, growth performance, intestinal morphology, weaned piglets
Auditing program evaluation audits: Executive training exercise for assessing management thinking, planning, and actions
[[abstract]]The present article is an application of Schank's (Schank, Roger C. (2005), Lessons in Learning, New York: Wiley.) "principle #1: just-in-time information delivery makes information useful....OR, don't tell people things that they cannot immediately make use of." The article describes five activities that always occurring implicitly and sometimes explicitly in managing a product, brand, or service: scanning, planning, implementing, assessing, and administering. Management and financial audits of actions and outcomes of programs are sometimes required by firms and government legislative bodies. Similar to the use of written checklist by pilots of the multiple steps involved before plane take-offs, management audit templates are useful for insuring complete and in-depth assessments of management actions and outcomes. This article provides such a management audit template and illustrates its use. The article includes an invitation to the reader to use the template immediately in evaluating both an audit report and a marketing program that the audit report details. (C) 2008 Published by Elsevier Inc
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Clouds + Games: A multifaceted approach
The computer game landscape is changing: people play games on multiple computing devices with heterogeneous form-factors, capability, and connectivity. Providing high playability on such devices concurrently is difficult. To enhance the gaming experience, designers could leverage abundant and elastic cloud resources, but current cloud platforms aren't optimized for highly interactive games. Existing studies focus on streaming-based cloud gaming, which is a special case for the more general cloud game architecture. The authors explain how to integrate techniques from the cloud and game research communities into a complete architecture for enhanced online gaming quality. They examine several open issues that appear only when clouds and games are put together. © 2014 IEEE
Flood impact assessment under climate change scenarios in central Taipei area, Taiwan
Providing effective information regarding flood control for responding climate change is essential to
future flood risk management for cities. This study simulated and assessed the impacts of flooding for
future climate change scenarios in Taipei city, Taiwan. We modelled rainfall events, generated by
general circulation models, with different return periods. The flood extents and damage in the Central
Taipei Area for the A1B climate change scenarios were compared to the ones, caused by the rainfall
events with same return periods, without climate change (baseline scenario). The proposed approach
provides potential flooding maps and flood damage assessment for climate change scenarios as
useful information for flood risk management in urban areas.The work is supported by the National Science Council, Taiwan (NSC 99-2915-I-002-120) and the
CORFU project, funded by the European Commission through Framework Programme 7, Grant
Number 244047
High-efficiency Urban-traffic Management in Context-aware Computing and 5G Communication
With the increasing number of vehicle and traffic jams, urban-traffic management is becoming a serious issue. In this article, we propose novel four-tier architecture for urban-traffic management with the convergence of vehicle ad hoc networks (VANETs), 5G wireless network, software-defined network (SDN), and mobile-edge computing (MEC) technologies. The proposed architecture provides better communication and rapider responsive speed in a more distributed and dynamic manner. The practical case of rapid accident rescue can significantly cut down the time for rescue. Key technologies with respect to vehicle localization, data pre-fetching, traffic lights control, and traffic prediction are also discussed. Obviously, the novel architecture shows noteworthy potential for alleviating the traffic congestion and improving the efficiency of urban-traffic management
A novel approach to sonographic examination in a patient with a calf muscle tear: a case report
© 2009 Chen et al; licensee Cases Network Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
A new mib allele with a chromosomal deletion covering foxc1a exhibits anterior somite specification defect
mibnn2002, found from an allele screen, showed early segmentation defect and severe cell death phenotypes, which are different from previously known mib mutants. Despite distinct morphological phenotypes, the typical mib molecular phenotypes: her4 down-regulation, neurogenic phenotype and cold sensitive dlc expression pattern, still remained. The linkage analysis also indicated that mibnn2002 is a new mib allele. Failure of specification in anterior 7-10 somites is likely due to lack of foxc1a expression in mibnn2002 homozygotes. Somites and somite markers gradually appeared after 7-10 somite stage, suggesting that foxc1a is only essential for the formation of anterior 7-10 somites. Apoptosis began around 16-somite stage with p53 up-regulation. To find the possible links of mib, foxc1a and apoptosis, transcriptome analysis was employed. About 140 genes, including wnt3a, foxc1a and mib, were not detected in the homozygotes. Overexpression of foxc1a mRNA in mibnn2002 homozygotes partially rescued the anterior somite specification. In the process of characterizing mibnn2002 mutation, we integrated the scaffolds containing mib locus into chromosome 2 (or linkage group 2, LG2) based on synteny comparison and transcriptome results. Genomic PCR analysis further supported the conclusion and showed that mibnn2002 has a chromosomal deletion with the size of about 9.6 Mbp.published_or_final_versio
Observation of Magnetic Moments in the Superconducting State of YBaCuO
Neutron Scattering measurements for YBaCuO have identified
small magnetic moments that increase in strength as the temperature is reduced
below and further increase below . An analysis of the data shows
the moments are antiferromagnetic between the Cu-O planes with a correlation
length of longer than 195 \AA in the - plane and about 35 \AA along the
c-axis. The origin of the moments is unknown, and their properties are
discusssed both in terms of Cu spin magnetism and orbital bond currents.Comment: 9 pages, and 4 figure
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