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Search Results: 1 - 10 of 469170 matches for " Matthew A. Steliga "
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Thoracic Anesthesia and Cross Field Ventilation for Tracheobronchial Injuries: A Challenge for Anesthesiologists
Sankalp Sehgal,Joshua C. Chance,Matthew A. Steliga
Case Reports in Anesthesiology , 2014, DOI: 10.1155/2014/972762
Abstract: Tracheobronchial injuries are rare but life threatening sequel of blunt chest trauma. Due to the difficult nature of these injuries and the demanding attributes of the involved surgery, the anesthesiologist faces tough challenges while securing the airway, controlling oxygenation, undertaking one-lung ventilation, maintaining anesthesia during tracheal reconstruction, and gaining adequate postoperative pain control. Amongst the few techniques that can be used with tracheobronchial injuries, cross field ventilation is a remotely described and rarely used technique, especially in injuries around the carina. We effectively applied cross field ventilation in both our cases and the outcome was excellent. 1. Introduction Tracheobronchial injuries (TBI) are life threatening complications encountered in blunt chest and neck trauma. Tracheal injuries should be suspected in all patients involved in high speed motor vehicle accidents. The first successful repair of a bronchial rupture caused by blunt chest trauma was reported in 1947 by Kinsella and Johnsrud [1]. They are found in 0.8% of blunt thoracic trauma victims presenting for emergency surgery [2]. Tragically, 30% to 80% of these patients die before reaching the hospital [3]. Surgical repair remains the treatment of choice for such injuries. Due to the difficult nature of these surgeries, the anesthesiologist faces tough challenges securing the airway, controlling oxygenation and ventilation, undertaking one-lung ventilation, maintaining anesthesia during tracheal reconstruction with loss of ventilation to the atmosphere, and gaining adequate postoperative pain control. For appropriate management of these injuries in the operating room, modified anesthetic techniques and effective communication with the thoracic surgeon are important. Key considerations are avoidance of excessive preoperative sedation, maintaining spontaneous ventilation during intubation, using bronchoscopy to visualize and secure the airway, avoiding blind instrumentation [4, 5], single-lumen tube endobronchial intubation, cross field ventilation, and adequate postoperative pain control. Using these techniques, the outcome of our cases was excellent. In the current case scenario, we shall discuss anesthetic management of two patients who presented to our level-1 trauma center, between years 2010 and 2012, with tracheobronchial injuries following severe blunt chest trauma in motor vehicle accidents. 2. Case Report Number 1 A 20-year-old male presented following a motor vehicle accident. His physical findings included a right-sided tension
Nonnegative Matrix Factorization with Zellner Penalty  [PDF]
Matthew A. Corsetti, Ernest Fokoué
Open Journal of Statistics (OJS) , 2015, DOI: 10.4236/ojs.2015.57077
Abstract:

Nonnegative matrix factorization (NMF) is a relatively new unsupervised learning algorithm that decomposes a nonnegative data matrix into a parts-based, lower dimensional, linear representation of the data. NMF has applications in image processing, text mining, recommendation systems and a variety of other fields. Since its inception, the NMF algorithm has been modified and explored by numerous authors. One such modification involves the addition of auxiliary constraints to the objective function of the factorization. The purpose of these auxiliary constraints is to impose task-specific penalties or restrictions on the objective function. Though many auxiliary constraints have been studied, none have made use of data-dependent penalties. In this paper, we propose Zellner nonnegative matrix factorization (ZNMF), which uses data-dependent auxiliary constraints. We assess the facial recognition performance of the ZNMF algorithm and several other well-known constrained NMF algorithms using the Cambridge ORL database.

Black-Scholes Option Pricing Model Modified to Admit a Miniscule Drift Can Reproduce the Volatility Smile  [PDF]
Matthew C. Modisett, James A. Powell
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.36093
Abstract: This paper develops a closed-form solution to an extended Black-Scholes (EBS) pricing formula which admits an implied drift parameter alongside the standard implied volatility. The market volatility smiles for vanilla call options on the S&P 500 index are recreated fitting the best volatility-drift combination in this new EBS. Using a likelihood ratio test, the implied drift parameter is seen to be quite significant in explaining volatility smiles. The implied drift parameter is sufficiently small to be undetectable via historical pricing analysis, suggesting that drift is best considered as an implied parameter rather than a historically-fit one. An overview of option-pricing models is provided as background.
Theta Rhythms Coordinate Hippocampal–Prefrontal Interactions in a Spatial Memory Task
Matthew W. Jones,Matthew A. Wilson
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.0030402
Abstract: Decision-making requires the coordinated activity of diverse brain structures. For example, in maze-based tasks, the prefrontal cortex must integrate spatial information encoded in the hippocampus with mnemonic information concerning route and task rules in order to direct behavior appropriately. Using simultaneous tetrode recordings from CA1 of the rat hippocampus and medial prefrontal cortex, we show that correlated firing in the two structures is selectively enhanced during behavior that recruits spatial working memory, allowing the integration of hippocampal spatial information into a broader, decision-making network. The increased correlations are paralleled by enhanced coupling of the two structures in the 4- to 12-Hz theta-frequency range. Thus the coordination of theta rhythms may constitute a general mechanism through which the relative timing of disparate neural activities can be controlled, allowing specialized brain structures to both encode information independently and to interact selectively according to current behavioral demands.
Theta rhythms coordinate hippocampal-prefrontal interactions in a spatial memory task.
Jones Matthew W,Wilson Matthew A
PLOS Biology , 2005,
Abstract: Decision-making requires the coordinated activity of diverse brain structures. For example, in maze-based tasks, the prefrontal cortex must integrate spatial information encoded in the hippocampus with mnemonic information concerning route and task rules in order to direct behavior appropriately. Using simultaneous tetrode recordings from CA1 of the rat hippocampus and medial prefrontal cortex, we show that correlated firing in the two structures is selectively enhanced during behavior that recruits spatial working memory, allowing the integration of hippocampal spatial information into a broader, decision-making network. The increased correlations are paralleled by enhanced coupling of the two structures in the 4- to 12-Hz theta-frequency range. Thus the coordination of theta rhythms may constitute a general mechanism through which the relative timing of disparate neural activities can be controlled, allowing specialized brain structures to both encode information independently and to interact selectively according to current behavioral demands.
Theta Rhythms Coordinate Hippocampal–Prefrontal Interactions in a Spatial Memory Task
Matthew W Jones,Matthew A Wilson
PLOS Biology , 2005, DOI: 10.1371/journal.pbio.0030402
Abstract: Decision-making requires the coordinated activity of diverse brain structures. For example, in maze-based tasks, the prefrontal cortex must integrate spatial information encoded in the hippocampus with mnemonic information concerning route and task rules in order to direct behavior appropriately. Using simultaneous tetrode recordings from CA1 of the rat hippocampus and medial prefrontal cortex, we show that correlated firing in the two structures is selectively enhanced during behavior that recruits spatial working memory, allowing the integration of hippocampal spatial information into a broader, decision-making network. The increased correlations are paralleled by enhanced coupling of the two structures in the 4- to 12-Hz theta-frequency range. Thus the coordination of theta rhythms may constitute a general mechanism through which the relative timing of disparate neural activities can be controlled, allowing specialized brain structures to both encode information independently and to interact selectively according to current behavioral demands.
Comparison of Methods to Remediate Compacted Soils for Infiltration and Vegetative Establishment  [PDF]
Matthew A. Haynes, Richard A. McLaughlin, Joshua L. Heitman
Open Journal of Soil Science (OJSS) , 2013, DOI: 10.4236/ojss.2013.35027
Abstract:

The process of constructing roads and buildings usually involves the removal of topsoil and grading of the subsoil followed by a variety of activities using heavy equipment. This presents multiple challenges in attempts to establish vegetation on these areas: low nutrient soils with little organic matter, high bulk densities, and low infiltration rates. The goals of this preliminary study were to quantify the impacts of soil compaction remediation methods on infiltration, runoff water quality, and vegetation establishment. The objectives were to measure: 1) steady state infiltration rate (IR); 2) quantity and quality of storm water runoff; and 3) ground cover, biomass production, and rooting depth of vegetation during early establishment. We evaluated four treatments: a compacted soil (C), a compacted soil with core aeration (A), a compacted soil with deep (20 - 30 cm) tillage (DT), and a compacted soil with deep tillage and incorporated compost (CT). Sites 1 and 2 received C, A and DT treatments and Site 3 received only DT and CT treatments. At Site 1, runoff from natural rainfall events was collected in plastic tubs at the bottom of each 2 × 1 m plot, and samples were measured for volume and sediment. Infiltration rates were determined using a Cornell Sprinkle Infiltrometer at all three sites. At Site 1, the A treatment had a higher erosion rate during two of four rain events and higher runoff volume during three of four rain events, when compared to C and DT. However, the aerator was only able to penetrate 1 - 2 cm due to the compacted soil. Average event runoff ranged from 0 to 22% (0 - 9.3 mm), 10 to 60% (1.9 - 26.2 mm), and 0 to 3.5% (0 - 1.1 mm) of the total rainfall for C, A, and DT, respectively. There was no difference between C and A for vegetative biomass and IR, but both biomass and IR were greater in the DT plots. Treatment DT had an average IR of 15 cm·hr-1, compared to 0.16 and 0.21 cm·hr-1 for C and A, respectively. Roots were much more abundant at the 20 - 50 cm depths with DT. At Site 2, there were no significant differences in IR, with many values too low to be measured with the infiltrometer. Vegetative cover also did not differ between the three treatments due to poor (16% - 22% cover)

Whole-Genome Pathway Analysis on 132,497 Individuals Identifies Novel Gene-Sets Associated with Body Mass Index
Matthew A. Simonson, Matthew B. McQueen, Matthew C. Keller
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0078546
Abstract: Whole genome pathway analysis is a powerful tool for the exploration of the combined effects of gene-sets within biological pathways. This study applied Interval Based Enrichment Analysis (INRICH) to perform whole-genome pathway analysis of body-mass index (BMI). We used a discovery set composed of summary statistics from a meta-analysis of 123,865 subjects performed by the GIANT Consortium, and an independent sample of 8,632 subjects to assess replication of significant pathways. We examined SNPs within nominally significant pathways using linear mixed models to estimate their contribution to overall BMI heritability. Six pathways replicated as having significant enrichment for association after correcting for multiple testing, including the previously unknown relationships between BMI and the Reactome regulation of ornithine decarboxylase pathway, the KEGG lysosome pathway, and the Reactome stabilization of P53 pathway. Two non-overlapping sets of genes emerged from the six significant pathways. The clustering of shared genes based on previously identified protein-protein interactions listed in PubMed and OMIM supported the relatively independent biological effects of these two gene-sets. We estimate that the SNPs located in examined pathways explain ~20% of the heritability for BMI that is tagged by common SNPs (3.35% of the 16.93% total).
Changing diagnostics and therapeutics forever with cDNA arrays
Matthew A Roberts
Genome Biology , 2000, DOI: 10.1186/gb-2000-1-6-reports4026
Abstract: It has been predicted in numerous reviews that over the next few years there will be an explosion of gene-expression profiling data coming from a number of new technologies that promise 'global' analysis of cellular transcripts. Although complemented by flow-based techniques, the principal technology that is currently generating such data, and which has captured the thinking of many biologists, is the DNA array. Whether it be constructed by spotting cDNA onto immobilized solid supports or through the surface assembly of oligonucleotide probes, it is fundamentally an immobilized array of hundreds to thousands of transcript probes that is being used to explore biological regulation at the level of gene expression.This conference session brought home the message that this technology is not only changing the pace of discovery but may also be fundamentally altering the paradigms upon which biological experimentation is based. An alternative experimental paradigm to the historical hypothesis-driven research model is the systematic analysis of sets of biological interactions measured against broad comprehensive sets of end-points: gene expression arrays, proteomics, metabolomics, and so on. After initial experimentation, questions are asked in silico and then new hypotheses are generated for focused follow-up testing.The talk by John Weinstein (National Cancer Institute (NCI), National Institutes of Health, Bethesda, USA) discussed gene expression profiling for cancer drug discovery, in particular the current state of the art at NCI. They have constructed cDNA arrays consisting of approximately 8,000 unique genetic elements and used them in a systematic way to investigate the relationship between candidate therapeutic compounds, cancer tissue type and gene expression regulation. The program currently uses a panel of 60 cultured human cancer cell types which had been characterized pharmacologically against more than 70,000 chemical entities as of March 2000.Weinstein's grou
Progress in spondylarthritis. Progress in studies of the genetics of ankylosing spondylitis
Matthew A Brown
Arthritis Research & Therapy , 2009, DOI: 10.1186/ar2692
Abstract: Genetic factors are the primary determinants not only of the risk of developing ankylosing spondylitis (AS) but also of its severity [1], as assessed by radiographic measures or by self-administered questionnaires such as the widely used Bath Ankylosing Spondylitis Disease Activity Index and Bath Ankylosing Spondylitis Functional Index [2,3]. The disease has long been known to be highly familial, with siblings of a case with the disease having >50 times risk of developing the condition themselves compared with individuals in the general population [4].The main disease-causative gene in AS, HLA-B27, was the first gene identified to be associated with any common human arthropathy, and the discovery proved that the familiality of the condition was, to a significant degree, genetically determined. The disease is strongly associated with the gene HLA-B27; however, only 1 to 5% of B27-positive individuals develop AS, and there is increasing evidence to suggest that other genes must also be involved. B27-positive relatives of AS patients have a recurrence risk of the disease 5.6 to 16 times greater than B27-positive individuals in the general population, implying the presence of non-B27 shared familial risk factors [5,6]. A major non-B27 contribution to susceptibility to AS is suggested by the greater concordance rate of monozygotic twins (63%) than of B27-positive dizygotic twin pairs (23%) [7].Recurrence risk modeling indicates that the observed pattern of disease recurrence in families best fits an oligogenic disease model [8]. Extensive efforts to identify genes by linkage mapping in families has proven relatively unproductive, with linkage demonstrated at genomewide significant levels to only one region (chromosome 16q (LOD score 4.7)) [9]. No genomewide association study in AS has yet been reported, although a screen of 14,500 common nonsynonymous SNPs has been reported, identifying the association of the genes ERAP1 (formerly known as ARTS-1) and IL23R with AS [10].
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