32 research outputs found

    Estimating soot emission in diesel engines using gated recurrent unit networks

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    In this paper, a new data-driven modeling of a diesel engine soot emission formation using gated recurrent unit (GRU) networks is proposed. Different from the traditional time series prediction methods such as nonlinear autoregressive with exogenous input (NARX) approach, GRU structure does not require the determination of the pure time delay between the inputs and the output, and the number of regressors does not have to be chosen beforehand. Gates in a GRU network enable to capture such dependencies on the past input values without any prior knowledge. As a design of experiment, 30 different points in engine speed - injected fuel quantity plane are determined and the rest of the input channels, i.e., rail pressure, main start of injection, equivalence ratio, and intake oxygen concentration are excited with chirp signals in the intended regions of operation. Experimental results show that the prediction performances of GRU based soot models are quite satisfactory with 77% training and 57% validation fit accuracies and normalized root mean square error (NRMSE) values are less than 0.038 and 0.069, respectively. GRU soot models surpass the traditional NARX based soot models in both steady-state and transient cycles

    The association of functional mitral regurgitation and anemia in patients with non-ischemic dilated cardiomyopathy

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    Background: We investigated the association between anemia and functional mitral regurgitation (MR) in non-ischemic dilated cardiomyopathy (DCM) patients with sinus rhythm and normal renal function. Methods: Sixty non-ischemic DCM patients with sinus rhythm and left ventricular ejection fraction < 40% were recruited. Functional MR was quantified with the proximal isovelocity surface area method. MR was graded according to the mitral regurgitant volume (Reg Vol) or effective regurgitant orifice (ERO) area. The clinical, biochemical and echocardiographic correlates of functional MR severity were investigated in patients with DCM. Results: Hemoglobin degrees were significantly different between various MR levels (mild MR 13.9 &#177; 1.7 mg/dL, moderate MR 12.3 &#177; 1.5 mg/dL, moderate to severe MR 10.8 &#177; 0.9 mg/dL). Receiver operating characteristic (ROC) analysis was performed to assess the utility of hemoglobin levels to predict moderate or severe functional MR. A hemoglobin level less than 12.5 mg/dL predicted moderate or high MR with 80% sensitivity and 58% specificity (AUC: 0.789, 95% CI: 0.676&#8211;0.901, p < 0.0001). Logistic regression analysis was performed to determine the independent predictors of moderate or severe levels of MR. The left atrium diameter (OR: 19.3, 95% CI: 1.4-27.1, p = 0.028) and presence of anemia (OR: 11.9, 95% CI: 1.22-42.5, p = 0.0045) were independent predictors of moderate or severe functional MR. Conclusions: The presence of anemia and enlarged left atrium are independent predictors of moderate or severe functional MR in non-ischemic DCM patients with normal renal function. Hemoglobin levels less than 12.5 mg/dL should alert the physician for the presence of moderate or severe MR in patients with DCM. (Cardiol J 2010; 17, 3: 274-280

    Comparison of expression patterns of selected drought-responsive genes in barley (Hordeum vulgare L.) under shock-dehydration and slow drought treatments

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    WOS: 000385480800008Shock-like water stress using hydroponics and gradual water deficit in soil are the two widely used treatments to analyze transcriptional response of many crops to drought. In this study, we investigated the effects of shock drought (ShD) (0, 0.5, 1, 4, and 8 h) and slow drought (SDD) [soil water content (SWC) of 35 and 50 %] on the expression of well-known drought-responsive genes supplemented with physiological changes in barley. Two barley cultivars with contrasting leaf relative water content (RWC) and water loss rate (WLR) values were selected as Marti (MR; 60 % RWC and 0.046 gh(-1) g(-1) DW) and Erginel90 (ER; 38.3 % RWC and 0.350 gh(-1) g(-1) DW) under 38 % of SWC condition. According to the results, 0.5 h ShD was the critical time point for stress perception in leaves defined by the increase in WLR, ion leakage and H2O2 concentration. Expressions of antioxidant-related genes (Cu-Zn/SOD, HvCAT2, HvGST6, HvAPX) were rapidly induced in MR at 8 h shock, while only slightly upregulated in ER. We have also observed higher induction of expressions of HvBAS1, HvMT-2, HvABA7 and a photosynthesis-related gene HvLHCB during ShD compared to SDD. Contrarily, transcription factors (TFs), HvWRKY12 and HvDRF1 were expressed with lower values during shock-dehydration. Slow-drought treatments in both cultivars were characterized with high leaf RWCs and osmotic adjustment with low cell membrane damage, suggesting that barley maintains a basal tolerance to long-term water deficit. Our results confirmed that type of water stress treatment is crucial to measure gene expression, and a shock-like dehydration method should be the treatment of choice in evaluating barley plants with different physiological characteristics for water tolerance.Scientific Research Projects Coordination Unit of Istanbul University [BAP 4712]This work was supported by The Scientific Research Projects Coordination Unit of Istanbul University, Project Number BAP 4712. The authors thank to the staff of Dr. Maria von Korff's lab for experimental advice on stress applications and qRT-PCR

    Comparison of expression patterns of selected drought-responsive genes in barley (Hordeum vulgare L.) under shock-dehydration and slow drought treatments

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    Shock-like water stress using hydroponics and gradual water deficit in soil are the two widely used treatments to analyze transcriptional response of many crops to drought. In this study, we investigated the effects of shock drought (ShD) (0, 0.5, 1, 4, and 8 h) and slow drought (SDD) [soil water content (SWC) of 35 and 50 %] on the expression of well-known drought-responsive genes supplemented with physiological changes in barley. Two barley cultivars with contrasting leaf relative water content (RWC) and water loss rate (WLR) values were selected as Marti (MR; 60 % RWC and 0.046 gh(-1) g(-1) DW) and Erginel90 (ER; 38.3 % RWC and 0.350 gh(-1) g(-1) DW) under 38 % of SWC condition. According to the results, 0.5 h ShD was the critical time point for stress perception in leaves defined by the increase in WLR, ion leakage and H2O2 concentration. Expressions of antioxidant-related genes (Cu-Zn/SOD, HvCAT2, HvGST6, HvAPX) were rapidly induced in MR at 8 h shock, while only slightly upregulated in ER. We have also observed higher induction of expressions of HvBAS1, HvMT-2, HvABA7 and a photosynthesis-related gene HvLHCB during ShD compared to SDD. Contrarily, transcription factors (TFs), HvWRKY12 and HvDRF1 were expressed with lower values during shock-dehydration. Slow-drought treatments in both cultivars were characterized with high leaf RWCs and osmotic adjustment with low cell membrane damage, suggesting that barley maintains a basal tolerance to long-term water deficit. Our results confirmed that type of water stress treatment is crucial to measure gene expression, and a shock-like dehydration method should be the treatment of choice in evaluating barley plants with different physiological characteristics for water tolerance
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