Cycle by Cycle Trapped Mass Estimation for Diagnosis and Control

The development of one cycle resolution control strategies and the research at HCCI engines demands an accurate estimation of the trapped mass. In contrast to current methods for determining the mass flow, which are only able to determine averaged values of the flow entering the cylinders, the present paper proposes a methodology based on the in-cylinder pressure resonance. The determination of such frequency allows inferring the cylinder mass with one cycle resolution. In addition, the method permits determining error metrics based on the mass conservation principle. Validation results for a reactivity controlled compression ignition (RCCI) engine equipped with electrohydraulic variable valve timing (VVT) are presented to illustrate the performance of the methodGuardiola, C.; Pla Moreno, B.; Blanco-Rodriguez, D.; Bares Moreno, P. (2014). Cycle by Cycle Trapped Mass Estimation for Diagnosis and Control. SAE International Journal of Engines. 7(3):1-9. doi:10.4271/2014-01-1702S197

A bias correction method for fast fuel-to-air ratio estimation in diesel engines

l probes in turbocharged diesel engines are usually located downstream of the turbine, exhibiting a good dynamic response but a significant delay because of the exhaust line transport and the hardware itself. With the introduction of after-treatment systems, new sensors that can measure the exhaust concentrations are required for optimal control and diagnosis. Zirconia-based potentiometric sensors permit the measurement of nitrogen oxides and oxygen with the same hardware. However, their dynamic response is slower and more filtered than that of traditional l probes and, in addition, the sensor location downstream of the after-treatment systems increases this problem. The paper uses a Kalman filter for online dynamic estimation of the relative fuel-to-air ratio l21 in a turbocharged diesel engine. The combination of a fast drifted fuel-to-air ratio model with a slow but accurate zirconia sensor permits the model bias to be corrected. This bias is modelled with a look-up table depending on the engine operating point and is integrated online on the basis of the Kalman filter output. The calculation burden is alleviated by using the converged gain of the steady-state Kalman filter, precalculated offline. Finally, robustness conditions for stopping the bias updating are included in order to account for the sensor and model uncertainties. The proposed algorithm and sensor layout are successfully proved in a turbocharged diesel engine. Experimental and simulation results are included to support validation of the algorithm.This work was partially supported through project HIREFIRE (grant number: IPT-370000-2010-022).Guardiola, C.; Plá Moreno, B.; Blanco-Rodriguez, D.; Mazer, A.; Hayat, O. (2013). A bias correction method for fast fuel-to-air ratio estimation in diesel engines. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. 227(8):1099-1111. https://doi.org/10.1177/0954407012473415S109911112278Lu, X., Han, D., & Huang, Z. (2011). Fuel design and management for the control of advanced compression-ignition combustion modes. Progress in Energy and Combustion Science, 37(6), 741-783. doi:10.1016/j.pecs.2011.03.003Chiang, C.-J., Stefanopoulou, A. G., & Jankovic, M. (2007). Nonlinear Observer-Based Control of Load Transitions in Homogeneous Charge Compression Ignition Engines. IEEE Transactions on Control Systems Technology, 15(3), 438-448. doi:10.1109/tcst.2007.894637Riegel, J. (2002). Exhaust gas sensors for automotive emission control. Solid State Ionics, 152-153, 783-800. doi:10.1016/s0167-2738(02)00329-6ZHUIYKOV, S., & MIURA, N. (2007). Development of zirconia-based potentiometric NOx sensors for automotive and energy industries in the early 21st century: What are the prospects for sensors? Sensors and Actuators B: Chemical, 121(2), 639-651. doi:10.1016/j.snb.2006.03.044Schilling, A., Amstutz, A., & Guzzella, L. (2008). Model-based detection and isolation of faults due to ageing in the air and fuel paths of common-rail direct injection diesel engines equipped with a λ and a nitrogen oxides sensor. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 222(1), 101-117. doi:10.1243/09544070jauto659Kalman, R. E. (1960). A New Approach to Linear Filtering and Prediction Problems. Journal of Basic Engineering, 82(1), 35-45. doi:10.1115/1.3662552Jones, V. K., Ault, B. A., Franklin, G. F., & Powell, J. D. (1995). Identification and air-fuel ratio control of a spark ignition engine. IEEE Transactions on Control Systems Technology, 3(1), 14-21. doi:10.1109/87.370705Chen-Fang Chang, Fekete, N. P., Amstutz, A., & Powell, J. D. (1995). Air-fuel ratio control in spark-ignition engines using estimation theory. IEEE Transactions on Control Systems Technology, 3(1), 22-31. doi:10.1109/87.370706Wagner, J. R., Dawson, D. M., & Liu Zeyu. (2003). Nonlinear air-to-fuel ratio and engine speed control for hybrid vehicles. IEEE Transactions on Vehicular Technology, 52(1), 184-195. doi:10.1109/tvt.2002.807156Muske, K. R., Jones, J. C. P., & Franceschi, E. M. (2008). Adaptive Analytical Model-Based Control for SI Engine Air–Fuel Ratio. IEEE Transactions on Control Systems Technology, 16(4), 763-768. doi:10.1109/tcst.2007.912243Regitz, S., & Collings, N. (2008). Fast response air-to-fuel ratio measurements using a novel device based on a wide band lambda sensor. Measurement Science and Technology, 19(7), 075201. doi:10.1088/0957-0233/19/7/075201Galindo, J., Serrano, J. R., Guardiola, C., Blanco-Rodriguez, D., & Cuadrado, I. G. (2011). An on-engine method for dynamic characterisation of NOx concentration sensors. Experimental Thermal and Fluid Science, 35(3), 470-476. doi:10.1016/j.expthermflusci.2010.11.010Ljung, L. (1979). Asymptotic behavior of the extended Kalman filter as a parameter estimator for linear systems. IEEE Transactions on Automatic Control, 24(1), 36-50. doi:10.1109/tac.1979.1101943Nyberg, M., & Stutte, T. (2004). Model based diagnosis of the air path of an automotive diesel engine. Control Engineering Practice, 12(5), 513-525. doi:10.1016/s0967-0661(03)00120-5Macian, V., Lujan, J. M., Guardiola, C., & Yuste, P. (2006). DFT-based controller for fuel injection unevenness correction in turbocharged diesel engines. IEEE Transactions on Control Systems Technology, 14(5), 819-827. doi:10.1109/tcst.2006.876924Macián, V., Luján, J. M., Guardiola, C., & Perles, A. (2006). A comparison of different methods for fuel delivery unevenness detection in Diesel engines. Mechanical Systems and Signal Processing, 20(8), 2219-2231. doi:10.1016/j.ymssp.2005.04.001Payri, F., Luján, J. M., Guardiola, C., & Rizzoni, G. (2006). Injection diagnosis through common-rail pressure measurement. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 220(3), 347-357. doi:10.1243/09544070jauto34Desantes, J. M., Galindo, J., Guardiola, C., & Dolz, V. (2010). Air mass flow estimation in turbocharged diesel engines from in-cylinder pressure measurement. Experimental Thermal and Fluid Science, 34(1), 37-47. doi:10.1016/j.expthermflusci.2009.08.009Galindo, J., Climent, H., Guardiola, C., & Doménech, J. (2009). Strategies for improving the mode transition in a sequential parallel turbocharged automotive diesel engine. International Journal of Automotive Technology, 10(2), 141-149. doi:10.1007/s12239-009-0017-1Kalman, R. E., & Bucy, R. S. (1961). New Results in Linear Filtering and Prediction Theory. Journal of Basic Engineering, 83(1), 95-108. doi:10.1115/1.3658902Rajamani, M. R., & Rawlings, J. B. (2009). Estimation of the disturbance structure from data using semidefinite programming and optimal weighting. Automatica, 45(1), 142-148. doi:10.1016/j.automatica.2008.05.032Höckerdal, E., Frisk, E., & Eriksson, L. (2011). EKF-based adaptation of look-up tables with an air mass-flow sensor application. Control Engineering Practice, 19(5), 442-453. doi:10.1016/j.conengprac.2011.01.006Peyton Jones, J. C., & Muske, K. R. (2009). Identification and adaptation of linear look-up table parameters using an efficient recursive least-squares technique. ISA Transactions, 48(4), 476-483. doi:10.1016/j.isatra.2009.04.00

Reduction of adult hippocampal neurogenesis modifies brain functional connectivity and enhances cocaine-seeking in mice

Recently, adult hippocampal neurogenesis has been proposed as a putative neuroplastic mechanism involved in those behavioural processes. In this work, we studied the effect of the inhibition of adult hippocampal neurogenesis using the DNA alkylating agent temozolomide (TMZ), in cocaine-induced conditioned place preference (CPP) behaviour. In a first experiment, we investigated both CPP acquisition/expression and the functional brain circuits underlying CPP expression in control and neurogenesis-reduced conditions by analysing c-Fos immunoreactivity (c-Fos IR) in hippocampal and extrahippocampal addiction-related areas. A second experiment was designed to study the involvement of adult-born neurons in the extinction and cocaine-induced reinstatement of drug-seeking in the CPP model. We performed two independent studies where adult hippocampal neurogenesis was inhibited either before or after the CPP was acquired. Our results showed that TMZ treatment had no effect on the acquisition of the cocaine-induced CPP, but c-Fos IR associated to the test trial (CPP expression) revealed an increased activity in some of the analysed brain areas in the CPP-TMZ mice. Correlational and multivariate analysis revealed that, under normal conditions, the hippocampus showed widespread functional connectivity with other brain areas and strongly contributed to the functional brain network associated with CPP expression. However, mice with reduced neurogenesis showed an alternative brain circuit. The results of the second experiment revealed that mice acquiring the cocaine-induced CPP under neurogenesis-reduced conditions were delayed in extinguishing their drug seeking behaviour. However, when neurogenesis was inhibited after CPP acquisition, extinction was not affected but an enhanced long-term CPP retention was found, suggesting that the role of the adult-born neurons may differ depending on whether they are generated before or after drug-contextual associations are established. Importantly, cocaine-induced reinstatement of CPP behaviour was increased in the TMZ mice, regardless of the time of neurogenesis inhibition.Universidad de Málaga. Andalucía Tech, Campus de Excelencia Internacional. Spanish Ministry of Economy and Competitiveness (PSI2013-44901-P to L.J.S.; Subprograma RETICS Red de Trastornos Adictivos RD12/0028/0001, to F.R.F.). Author E.C-O. holds a ‘Sara Borrell’ research contract from the Spanish Carlos III Health Institute, Spanish Ministry of Economy and Competitiviness (grant number CD12/00455). Author D.L.G-M. holds a ‘FPU’ grant from the Spanish Ministry of Education, Culture and Sports (grant number FPU13/04819)

Stability of childhood anxiety disorder diagnoses: a follow-up naturalistic study in psychiatric care

Few studies have examined the stability of major psychiatric disorders in pediatric psychiatric clinical populations. The objective of this study was to examine the long-term stability of anxiety diagnoses starting with pre-school age children through adolescence evaluated at multiple time points. Prospective cohort study was conducted of all children and adolescents receiving psychiatric care at all pediatric psychiatric clinics belonging to two catchment areas in Madrid, Spain, between 1 January, 1992 and 30 April, 2006. Patients were selected from among 24,163 children and adolescents who received psychiatric care. Patients had to have a diagnosis of an ICD-10 anxiety disorder during at least one of the consultations and had to have received psychiatric care for the anxiety disorder. We grouped anxiety disorder diagnoses according to the following categories: phobic disorders, social anxiety disorders, obsessive–compulsive disorder (OCD), stress-related disorders, and "other" anxiety disorders which, among others, included generalized anxiety disorder, and panic disorder. Complementary indices of diagnostic stability were calculated. As much as 1,869 subjects were included and had 27,945 psychiatric/ psychological consultations. The stability of all ICD-10 anxiety disorder categories studied was high regardless of the measure of diagnostic stability used. Phobic and social anxiety disorders showed the highest diagnostic stability, whereas OCD and "other" anxiety disorders showed the lowest diagnostic stability. No significant sex differences were observed on the diagnostic stability of the anxiety disorder categories studied. Diagnostic stability measures for phobic, social anxiety, and "other" anxiety disorder diagnoses varied depending on the age at first evaluation. In this clinical pediatric outpatient sample it appears that phobic, social anxiety, and stress-related disorder diagnoses in children and adolescents treated in community outpatient services may have high diagnostic stability

Unique Features of HLA-Mediated HIV Evolution in a Mexican Cohort: A Comparative Study

Background: Mounting evidence indicates that HLA-mediated HIV evolution follows highlystereotypic pathways that result in HLA-associated footprints in HIV at the population level.However, it is not known whether characteristic HLA frequency distributions in differentpopulations have resulted in additional unique footprints. Methods: The phylogenetic dependency network model was applied to assess HLA-mediatedevolution in datasets of HIV pol sequences from free plasma viruses and peripheral bloodmononuclear cell (PBMC)-integrated proviruses in an immunogenetically unique cohort of Mexicanindividuals. Our data were compared with data from the IHAC cohort, a large multi-center cohortof individuals from Canada, Australia and the USA.Results: Forty three different HLA-HIV codon associations representing 30 HLA-HIV codon pairswere observed in the Mexican cohort (q < 0.2). Strikingly, 23 (53%) of these associations differedfrom those observed in the well-powered IHAC cohort, strongly suggesting the existence of uniquecharacteristics in HLA-mediated HIV evolution in the Mexican cohort. Furthermore, 17 of the 23novel associations involved HLA alleles whose frequencies were not significantly different fromthose in IHAC, suggesting that their detection was not due to increased statistical power but todifferences in patterns of epitope targeting. Interestingly, the consensus differed in four positionsbetween the two cohorts and three of these positions could be explained by HLA-associated selection. Additionally, different HLA-HIV codon associations were seen when comparing HLAmediatedselection in plasma viruses and PBMC archived proviruses at the population level, with asignificantly lower number of associations in the proviral dataset. Conclusion: Our data support universal HLA-mediated HIV evolution at the population level,resulting in detectable HLA-associated footprints in the circulating virus. However, it also stronglysuggests that unique genetic backgrounds in different HIV-infected populations may influence HIVevolution in a particular direction as particular HLA-HIV codon associations are determined byspecific HLA frequency distributions. Our analysis also suggests a dynamic HLA-associatedevolution in HIV with fewer HLA-HIV codon associations observed in the proviral compartment,which is likely enriched in early archived HIV sequences, compared to the plasma viruscompartment. These results highlight the importance of comparative HIV evolutionary studies inimmunologically different populations worldwide

Identification of Importin 8 (IPO8) as the most accurate reference gene for the clinicopathological analysis of lung specimens

<p>Abstract</p> <p>Background</p> <p>The accurate normalization of differentially expressed genes in lung cancer is essential for the identification of novel therapeutic targets and biomarkers by real time RT-PCR and microarrays. Although classical "housekeeping" genes, such as GAPDH, HPRT1, and beta-actin have been widely used in the past, their accuracy as reference genes for lung tissues has not been proven.</p> <p>Results</p> <p>We have conducted a thorough analysis of a panel of 16 candidate reference genes for lung specimens and lung cell lines. Gene expression was measured by quantitative real time RT-PCR and expression stability was analyzed with the softwares <it>GeNorm </it>and <it>NormFinder</it>, mean of |ΔCt| (= |Ct Normal-Ct tumor|) ± SEM, and correlation coefficients among genes. Systematic comparison between candidates led us to the identification of a subset of suitable reference genes for clinical samples: IPO8, ACTB, POLR2A, 18S, and PPIA. Further analysis showed that IPO8 had a very low mean of |ΔCt| (0.70 ± 0.09), with no statistically significant differences between normal and malignant samples and with excellent expression stability.</p> <p>Conclusion</p> <p>Our data show that IPO8 is the most accurate reference gene for clinical lung specimens. In addition, we demonstrate that the commonly used genes GAPDH and HPRT1 are inappropriate to normalize data derived from lung biopsies, although they are suitable as reference genes for lung cell lines. We thus propose IPO8 as a novel reference gene for lung cancer samples.</p

A genetic approach reveals different modes of action of prefoldins

[EN] The prefoldin complex (PFDc) was identified in humans as a co-chaperone of the cytosolic chaperonin T-COMPLEX PROTEIN RING COMPLEX (TRiC)/CHAPERONIN CONTAINING TCP-1 (CCT). PFDc is conserved in eukaryotes and is composed of subunits PFD1-6, and PFDc-TRiC/CCT folds actin and tubulins. PFDs also participate in a wide range of cellular processes, both in the cytoplasm and in the nucleus, and their malfunction causes developmental alterations and disease in animals and altered growth and environmental responses in yeast and plants. Genetic analyses in yeast indicate that not all of their functions require the canonical complex. The lack of systematic genetic analyses in plants and animals, however, makes it difficult to discern whether PFDs participate in a process as the canonical complex or in alternative configurations, which is necessary to understand their mode of action. To tackle this question, and on the premise that the canonical complex cannot be formed if one subunit is missing, we generated an Arabidopsis (Arabidopsis thaliana) mutant deficient in the six PFDs and compared various growth and environmental responses with those of the individual mutants. In this way, we demonstrate that the PFDc is required for seed germination, to delay flowering, or to respond to high salt stress or low temperature, whereas at least two PFDs redundantly attenuate the response to osmotic stress. A coexpression analysis of differentially expressed genes in the sextuple mutant identified several transcription factors, including ABA INSENSITIVE 5 (ABI5) and PHYTOCHROME-INTERACTING FACTOR 4, acting downstream of PFDs. Furthermore, the transcriptomic analysis allowed assigning additional roles for PFDs, for instance, in response to higher temperature.This work was supported by grants from the Spanish Ministry of Economy and Competitiveness and "Agencia Estatal de Investigacion"/FEDER/European Union (BIO2013-43184-P to D.A. and M.A.B., and BIO2016-79133-P and PID2019-109925GB-I00 to D.A.). N.B.-T., A.S.-M., and A.P.-A. were recipient of Ministerio de Economia y Competitividad (BES-2014-068868), EU MSCA-IF (H2020-MSCA-IF-2016746396) and Ministerio de Educacion (FPU17/05186) fellowships, respectively.Esteve-Bruna, D.; Blanco-Touriñán, N.; Serrano-Mislata, A.; Esquinas-Ariza, RM.; Resentini, F.; Forment Millet, JJ.; Carrasco-López, C.... (2021). A genetic approach reveals different modes of action of prefoldins. Plant Physiology. 187(3):1534-1550. https://doi.org/10.1093/plphys/kiab348S15341550187

Physical and Numerical Modeling of an Innovative Vertical Breakwater for Sustainable Power Generation in Ports: SE@PORTS Project

This work has been supported by the OCEANERA-NET project, SE@PORTS (Sustainable Energy at Sea Ports); reference OCEANERA/0003/2016, under the frame of Sociedad para el Desarrollo Regional de Cantabria S.A. (SODERCAN)

Formate induces a metabolic switch in nucleotide and energy metabolism

Formate is a precursor for the de novo synthesis of purine and deoxythymidine nucleotides. Formate also interacts with energy metabolism by promoting the synthesis of adenine nucleotides. Here we use theoretical modelling together with metabolomics analysis to investigate the link between formate, nucleotide and energy metabolism. We uncover that endogenous or exogenous formate induces a metabolic switch from low to high adenine nucleotide levels, increasing the rate of glycolysis and repressing the AMPK activity. Formate also induces an increase in the pyrimidine precursor orotate and the urea cycle intermediate argininosuccinate, in agreement with the ATP-dependent activities of carbamoyl-phosphate and argininosuccinate synthetase. In vivo data for mouse and human cancers confirms the association between increased formate production, nucleotide and energy metabolism. Finally, the in vitro observations are recapitulated in mice following and intraperitoneal injection of formate. We conclude that formate is a potent regulator of purine, pyrimidine and energy metabolism