2,181 research outputs found
Correlated Binary Regression Using Orthogonalized Residuals
This paper focuses on marginal regression models for correlated binary responses when estimation of the association structure is of primary interest. A new estimating function approach based on orthogonalized residuals is proposed. This procedure allows a new representation and addresses some of the difficulties of the conditional-residual formulation of alternating logistic regressions of Carey, Zeger & Diggle (1993). The new method is illustrated with an analysis of data on impaired pulmonary function
MAPPING THE SURROUNDINGS AS A REQUIREMENT FOR AUTONOMOUS DRIVING
Motivated by the hype around driverless cars and the challenges of the sensor integration and data processing, this paper presents a model for using a XBox One Microsoft Kinect stereo camera as sensor for mapping the surroundings. Today, the recognition of the environment of the car is mostly done by a mix of sensors like LiDAR, RADAR and cameras. In the case of the outdoor delivery challenge Robotour 2016 with model cars in scale 1:5, it is our goal to solve the task with one camera only. To this end, a three-stage approach was developed. The test results show that our approach can detect and locate objects at a range of up to eight meters in order to incorporate them as barriers in the navigation process
Guidelines for the Management of Severe Head Injury: Are Emergency Physicians Following Them?
The Brain Trauma Foundation published “Guidelines for the Management of Severe Head Injury” in 1995. These evidence-based clinical guidelines (CGs) recommended against prophylactic hyperventilation and glucocorticoid use and advocated for aggressive blood pressure (BP) resuscitation, and the careful use of mannitol. Objective: To survey Michigan emergency physicians (MEPs) to test their adherence to these guidelines. Methods: An anonymous mail survey was sent to all 566 MEPs who are members of the American College of Emergency Physicians. Three clinical scenarios involving severe head injury were presented, all with Glasgow Coma Scale (GCS) scores of 8 or less. The physicians were asked to choose from 15 diagnostic and treatment options, which included: intubation and hyperventilation, BP resuscitation, intravenous (IV) mannitol administration, and IV glucocorticoid administration. Results: Three hundred nineteen (56%) surveys were returned. Forty-six percent [95% confidence interval (95% CI) = 40% to 51%] of the MEPs elected to use prophylactic hyperventilation; very few administered IV glucocorticoids. Seventy-eight percent (95% CI = 75% to 81%) corrected hypotension with systolic BP < 90 mm Hg; 83% (95% CI = 80% to 86%) also administered mannitol appropriately. Conclusions: A majority of MEPs are managing severe head injury patients in accordance with the “Guidelines for the Management of Severe Head Injury,” with the exception of avoiding prophylactic hyperventilation. More education and/or exposure to the evidence regarding prophylactic hyperventilation of severely head injured patients may improve adherence to the guidelines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74731/1/aemj.9.8.806.pd
Coloring Mixed and Directional Interval Graphs
A mixed graph has a set of vertices, a set of undirected egdes, and a set ofdirected arcs. A proper coloring of a mixed graph is a function thatassigns to each vertex in a positive integer such that, for each edge in , and, for each arc in , G\chi(G)G$. A directional interval graph is a mixedgraph whose vertices correspond to intervals on the real line. Such a graph hasan edge between every two intervals where one is contained in the other and anarc between every two overlapping intervals, directed towards the interval thatstarts and ends to the right. Coloring such graphs has applications in routing edges in layered orthogonalgraph drawing according to the Sugiyama framework; the colors correspond to thetracks for routing the edges. We show how to recognize directional intervalgraphs, and how to compute their chromatic number efficiently. On the otherhand, for mixed interval graphs, i.e., graphs where two intersecting intervalscan be connected by an edge or by an arc in either direction arbitrarily, weprove that computing the chromatic number is NP-hard.<br
Comparative CRISPR type III-based knockdown of essential genes in hyperthermophilic Sulfolobales and the evasion of lethal gene silencing
CRISPR type III systems, which are abundantly found in archaea, recognize and degrade RNA in their specific response to invading nucleic acids. Therefore, these systems can be harnessed for gene knockdown technologies even in hyperthermophilic archaea to study essential genes. We show here the broader usability of this posttranscriptional silencing technology by expanding the application to further essential genes and systematically analysing and comparing silencing thresholds and escape mutants. Synthetic guide RNAs expressed from miniCRISPR cassettes were used to silence genes involved in cell division (cdvA), transcription (rpo8), and RNA metabolism (smAP2) of the two crenarchaeal model organisms Saccharolobus solfataricus and Sulfolobus acidocaldarius. Results were systematically analysed together with those obtained from earlier experiments of cell wall biogenesis (slaB) and translation (aif5A). Comparison of over 100 individual transformants revealed gene-specific silencing maxima ranging between 40 and 75%, which induced specific knockdown phenotypes leading to growth retardation. Exceedance of this threshold by strong miniCRISPR constructs was not tolerated and led to specific mutation of the silencing miniCRISPR array and phenotypical reversion of cultures. In two thirds of sequenced reverted cultures, the targeting spacers were found to be precisely excised from the miniCRISPR array, indicating a still hypothetical, but highly active recombination system acting on the dynamics of CRISPR spacer arrays. Our results indicate that CRISPR type III - based silencing is a broadly applicable tool to study in vivo functions of essential genes in Sulfolobales which underlies a specific mechanism to avoid malignant silencing overdose
Applying case based reasoning for prioritizing areas of business management
Determining the importance of different management areas in a company provides guidance about the
needs of increasing the analysis and actions focuses in particular topic. To do it, it is necessary to decompose
the management in a coherent set of specific management areas and provide a way that allows the
company to determine the importance of these areas for them. This paper presents a novel system that
guides companies to obtain a classification of important management areas for them. It is focused on the
use of a case based reasoning system because the variability and the evolution of companies as time
passes requires using techniques with learning capabilities. The proposed system provides an automatic
self-assessment system that provides companies an ordered list of their most important management
areas. This system was implemented a year ago for the evaluation of Spanish companies. Currently, it
is in production providing relevant information about the management areas of these companies
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