416 research outputs found
Multiple Imputation Ensembles (MIE) for dealing with missing data
Missing data is a significant issue in many real-world datasets, yet there are no robust methods for dealing with it appropriately. In this paper, we propose a robust approach to dealing with missing data in classification problems: Multiple Imputation Ensembles (MIE). Our method integrates two approaches: multiple imputation and ensemble methods and compares two types of ensembles: bagging and stacking. We also propose a robust experimental set-up using 20 benchmark datasets from the UCI machine learning repository. For each dataset, we introduce increasing amounts of data Missing Completely at Random. Firstly, we use a number of single/multiple imputation methods to recover the missing values and then ensemble a number of different classifiers built on the imputed data. We assess the quality of the imputation by using dissimilarity measures. We also evaluate the MIE performance by comparing classification accuracy on the complete and imputed data. Furthermore, we use the accuracy of simple imputation as a benchmark for comparison. We find that our proposed approach combining multiple imputation with ensemble techniques outperform others, particularly as missing data increases
A comparison of McGrath MAC, Pentax AWS, and Macintosh direct laryngoscopes for nasotracheal intubation: a randomized controlled trial
PURPOSE: Videolaryngoscopy in nasotracheal intubation has been reported to be better than direct laryngoscopy. The most suitable type of videolaryngoscope remains unknown. This study aimed to compare two videolaryngoscopes (McGrath MAC and Pentax AWS) with a Macintosh laryngoscope during nasotracheal intubation.
METHODS: Overall, 123 patients older than 18 with normal airways who needed nasotracheal intubation were randomly allocated into three groups: Macintosh (n=41), McGrath (n=41), and Pentax (n=41). Intubation time was the primary outcome and subdivided into three steps: nose to oropharynx, oropharynx to laryngeal inlet, and laryngeal inlet to trachea. Time required, ease of each step, glottic view grade, modified nasal intubation-difficulty score, and subjective difficulty were evaluated.
RESULTS: Intubation time among the three groups was not significantly different (Macintosh 34.6+/-8.1 seconds, McGrath 35.2+/-7.9 seconds, Pentax 36.2+/-9.7 seconds; p=0.727). While the glottal view was better with videolaryngoscopes (I/IIa/IIb/III 36.6%/36.6%/19.5%/7.3% vs 82.9%/9.8%/7.3%/0%, vs 63.4%/29.3%/4.9%/2.4%, p=0.000), modified nasal intubation-difficulty score and subjective difficulty and ease of each step were not significantly different. However, the Pentax took longest for the second step (11.8+/-6.3 vs 10.3+/-3.5 vs 15.1+/-7.6 seconds, p=0.001) but was shortest for the third step (2.9+/-2.6 vs 4.4+/-5.6 vs 1.7+/-0.7 seconds, p=0.001).
CONCLUSION: The McGrath MAC and Pentax AWS showed no benefits in intubation time or difficulty, despite better glottal views, compared to the Macintosh laryngoscope in nasotracheal intubation. Additionally, videolaryngoscopes had variable performance at different steps of nasotracheal intubation
Compression of the left subclavian artery caused by a transesophageal echocardiography probe in an infant with a right-sided aortic arch -A case report-
Intraoperative transesophageal echocardiography (TEE) has become an important monitoring device for patients undergoing cardiac or noncardiac surgery. Complications associated with TEE are unusual, but the potential for TEE probe compression of the posterior vascular structures has been reported in baby patients. We present here a case of compression of the left subclavian artery in an infant with a right-sided aortic arch after insertion of a TEE probe
Lightwand-Guided Insertion of Flexible Reinforced Laryngeal Mask Airway: Comparison with Standard Digital Manipulation Insertion
BACKGROUND The flexibility of the long flexometallic tube makes insertion of the flexible reinforced laryngeal mask airway (f-LMA) difficult. We compared the usefulness of rigid lightwand-guided f-LMA insertion with standard digital manipulation. MATERIAL AND METHODS Fifty-four patients (aged 19-70 years) were randomly divided into a control group (digital manipulation technique) or the lightwand group (lightwand-guided insertion technique). The insertion profiles, oropharyngeal leak pressure (OLP), peak inspiratory pressure (PIP), expiratory tidal volume, and ventilatory score were measured in patients with neutral, extension, rotation, flexion, and re-neutral head-neck positions in turn. RESULTS The success rate and ease of insertion did not differ between groups, but the insertion time was longer in the lightwand group. The fiberoptic laryngeal view was significantly better in the lightwand group than in the control group. However, the OLP, PIP, expiratory tidal volume, and ventilatory scores were not significantly different between groups according to head-neck positions. The extension posture was associated with a significant negative effect on ventilation, but ventilation returned to initial levels with the other postures. CONCLUSIONS Lightwand-guided f-LMA insertion showed a better fiberoptic laryngeal view than standard digital manipulation, but no improvement in the ventilatory state was observed due to position. Therefore, lightwand-guided insertion could facilitate correct placement of the f-LMA, but it has limited clinical usefulness
A secretome profile indicative of oleate-induced proliferation of HepG2 hepatocellular carcinoma cells
Increased fatty acid (FA) is often observed in highly proliferative tumors. FAs have been shown to modulate the secretion of proteins from tumor cells, contributing to tumor survival. However, the secreted factors affected by FA have not been systematically explored. Here, we found that treatment of oleate, a monounsaturated omega-9 FA, promoted the proliferation of HepG2 cells. To examine the secreted factors associated with oleate-induced cell proliferation, we performed a comprehensive secretome profiling of oleate-treated and untreated HepG2 cells. A comparison of the secretomes identified 349 differentially secreted proteins (DSPs; 145 upregulated and 192 downregulated) in oleate-treated samples, compared to untreated samples. The functional enrichment and network analyses of the DSPs revealed that the 145 upregulated secreted proteins by oleate treatment were mainly associated with cell proliferation-related processes, such as lipid metabolism, inflammatory response, and ER stress. Based on the network models of the DSPs, we selected six DSPs (MIF, THBS1, PDIA3, APOA1, FASN, and EEF2) that can represent such processes related to cell proliferation. Thus, our results provided a secretome profile indicative of an oleate-induced proliferation of HepG2 cell
Time to tracheal intubation over a fibreoptic bronchoscope using a silicone left double-lumen endobronchial tube versus polyvinyl chloride single-lumen tube with bronchial blocker: a randomized controlled non-inferiority trial
BACKGROUND: Direct insertion of a double-lumen endobronchial tube (DLT) over a fibreoptic bronchoscope (FOB) is considered more difficult and traumatic than that of a single-lumen tube (SLT). We hypothesized that time to intubation over an FOB using a silicone left DLT would be non-inferior to that using a polyvinyl chloride (PVC) SLT.
METHODS: Eighty patients were enrolled in this open-label, randomized controlled, non-inferiority trial. Patients were randomly allocated to fibreoptic tracheal intubation with either a silicone DLT or PVC SLT (DLT and SLT groups, respectively). Time to tracheal intubation [time to insertion of FOB plus railroading (advancement over the FOB) time]: total time for correct tube and bronchial blocker positioning: difficulty of railroading: and the incidence of sore throat, swallowing difficulty, and hoarseness were compared between groups.
RESULTS: The median time to intubation over the FOB was 20 s in the DLT group and 23 s in the SLT group. The upper limit of the confidence interval of this difference was below the non-inferiority margin of 10 s (median difference: -2 s: 95% confidence interval: -4 to 0 s). Railroading time was significantly shorter in the DLT group than in the SLT group (median time: 10 vs. 11 s: median difference: -1 s: 95% confidence interval: -3 to 0 s: P=0.03). Railroading over the FOB (rated on a four-point scale) was less difficult in the DLT group than in the SLT group (P<0.01).
CONCLUSIONS: Tracheal intubation using an FOB can be achieved at least as fast using the silicone DLT as using the PVC SLT. The silicone DLT exhibited superior railroading performance to the PVC SLT
The effect of cuff pressure on postoperative sore throat after Cobra perilaryngeal airway
PURPOSE: The cuff volume of the Cobra perilaryngeal airway (CobraPLA) is larger than that of other alternative airway devices and makes it difficult to predict the effect of cuff pressure on the perilaryngeal mucosa. We tested the hypothesis that adjustment of the cuff pressure of the CobraPLA could reduce the incidence of postoperative sore throat (POST).
METHODS: After induction of general anesthesia and insertion of the CobraPLA by standardized method, the cuff pressure was set to 60 cmH(2)O (group C, n = 87) or adjusted to minimal seal-up pressure +5 cmH(2)O (group A, n = 87). The frequency and severity (0, none; 1, mild; 2, moderate; 3, severe) of throat soreness, pain, discomfort, and adverse effects were evaluated 1 and 24 h after removal of the CobraPLA.
RESULTS: Incidence of moderate POST in group C was higher than that in group A (11% vs. 2%, P = 0.021) whereas the overall POST incidence was not different between the two groups (31% vs. 20%, P = 0.092). The inflated air volume of group A was different from that of group C (41 vs. 50 ml, P = 0.009).
CONCLUSIONS: Adjustment of cuff pressure reduces the incidence of moderate POST after use of the CobraPLA
Use of twitter data for waste minimisation in beef supply chain
Approximately one third of the food produced is discarded or lost, which accounts for 1.3 billion tons per annum. The waste is being generated throughout the supply chain viz. farmers, wholesalers/processors, logistics, retailers and consumers. The majority of waste occurs at the interface of retailers and consumers. Many global retailers are making efforts to extract intelligence from customer’s complaints left at retail store to backtrack their supply chain to mitigate the waste. However, majority of the customers don’t leave the complaints in the store because of various reasons like inconvenience, lack of time, distance, ignorance etc. In current digital world, consumers are active on social media and express their sentiments, thoughts, and opinions about a particular product freely. For example, on an average, 45,000 tweets are tweeted daily related to beef products to express their likes and dislikes. These tweets are large in volume, scattered and unstructured in nature. In this study, twitter data is utilised to develop waste minimization strategies by backtracking the supply chain. The execution process of proposed framework is demonstrated for beef supply chain. The proposed model is generic enough and can be applied to other domains as well
Protein misfolding and dysregulated protein homeostasis in autoinflammatory diseases and beyond.
Cells have a number of mechanisms to maintain protein homeostasis, including proteasome-mediated degradation of ubiquitinated proteins and autophagy, a regulated process of ‘self-eating’ where the contents of entire organelles can be recycled for other uses. The unfolded protein response prevents protein overload in the secretory pathway. In the past decade, it has become clear that these fundamental cellular processes also help contain inflammation though degrading pro-inflammatory protein complexes such as the NLRP3 inflammasome. Signaling pathways such as the UPR can also be co-opted by toll-like receptor and mitochondrial reactive oxygen species signaling to induce inflammatory responses. Mutations that alter key inflammatory proteins, such as NLRP3 or TNFR1, can overcome normal protein homeostasis mechanisms, resulting in autoinflammatory diseases. Conversely, Mendelian defects in the proteasome cause protein accumulation, which can trigger interferon-dependent autoinflammatory disease. In non-Mendelian inflammatory diseases, polymorphisms in genes affecting the UPR or autophagy pathways can contribute to disease, and in diseases not formerly considered inflammatory such as neurodegenerative conditions and type 2 diabetes, there is increasing evidence that cell intrinsic or environmental alterations in protein homeostasis may contribute to pathogenesis
Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders
Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively
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