Premixed flames exhibit different asymptotic regimes of interaction between heat release and turbulence depending on their respective length scales. At high Karlovitz number, the dilatation caused by ...heat release does not have any relevant effect on turbulent kinetic energy with respect to non-reacting flow, while at low Karlovitz number, the mean shear is a sink of turbulent kinetic energy, and counter-gradient transport is observed. This latter phenomenon is not well captured by closure models commonly used in Large Eddy Simulations that are based on gradient diffusion. The massive amount of data available from Direct Numerical Simulation (DNS) opens the possibility to develop data-driven models able to represent physical mechanisms and non-linear features present in both these regimes. In this work, the databases are formed by DNSs of two planar hydrogen/air flames at different Karlovitz numbers corresponding to the two asymptotic regimes. In this context, the Generative Adversarial Network (GAN) gives the possibility to successfully recognize and reconstruct both gradient and counter-gradient phenomena if trained with databases where both regimes are included. Two GAN models were first trained each for a specific Karlovitz number and tested using the same dataset in order to verify the capability of the models to learn the features of a single asymptotic regime and assess its accuracy. In both cases, the GAN models were able to reconstruct the Reynolds stress subfilter scales accurately. Later, the GAN was trained with a mixture of both datasets to create a model containing physical knowledge of both combustion regimes. This model was able to reconstruct the subfilter scales for both cases capturing the interaction between heat release and turbulence closely to the DNS as shown from the turbulent kinetic budget and barycentric maps.
In the past decades, Deep Learning (DL) frameworks have demonstrated excellent performance in modeling nonlinear interactions and are a promising technique to move beyond physics-based models. In ...this context, super-resolution techniques may present an accurate approach as subfilter-scale (SFS) closure model for Large Eddy Simulations (LES) in premixed combustion. However, DL models need to perform accurately in a variety of physical regimes and generalize well beyond their training conditions. In this work, a super-resolution Generative Adversarial Network (GAN) is proposed as closure model for the unresolved subfilter-stress and scalar-flux tensors of the filtered reactive Navier–Stokes equations solved in LES. The model trained on a premixed methane/air jet flame is evaluated a-priori on similar configurations at different Reynolds and Karlovitz numbers. The GAN generalizes well at both lower and higher Reynolds numbers and outperforms existing algebraic models when the ratio between the filter size and the Kolmogorov scale is preserved. Moreover, extrapolation at a higher Karlovitz number is investigated indicating that the ratio between the filter size and the thermal flame thickness may not need to be conserved in order to achieve high correlation in terms of SFS field. Generalization studies obtained on substantially different flame conditions indicate that successful predictive abilities are demonstrated if the generalization criterion is matched. Finally, the reconstruction of a scalar quantity, different from that used during the training, is evaluated, revealing that the model is able to reconstruct scalar fields with large gradients that have not been explicitly used in the training. The a-priori investigations carried out assess whether out-of-sample predictions are even feasible in the first place, providing insights into the quantities that need to be conserved for the model to perform well between different regimes, and represent a crucial step toward future embedding into LES numerical solvers.
A ginástica vai à escola Schiavon, Laurita; Vilma Nista Piccolo
Movimento (Porto Alegre, Brazil),
01/2007, Letnik:
13, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A partir de estudos que têm como foco de investigação as razões da ausência da Ginástica na escola, realizou-se uma pesquisa em instituições de ensino formal da Diretoria de ensino de Campinas (SP), ...para verificar até que ponto o quadro diagnóstico encontrado é o mesmo desenhado pelas conclusões apresentadas nesses estudos. O que se pretendeu foi levantar dados que fornecessem subsídios em relação às dificuldades da prática dos professores para posteriormente ser proposta a Ginástica como um tema da Educação Física escolar, de acordo com as possibilidades reais apresentadas pela maioria das escolas atualmente.
The present study investigates the ideas of the human body transmitted and grasped by the teachers of Physical Education in Basic Education classes. It was carried a research with Physical Education ...teachers using the following questions: What ideas about the human body are you transmitting in your Physical Education classes? Do you perceive the reactions of your students to these ideas? The analyses of the answers were methodologically followed in these moments: a) reading of the descriptions, b) elaboration of the units of meaning; c) ideographic analysis; d) nomothetic analysis. Results showed that teachers of Physical Education when transmitting ideas of restricted body in the physical dimension, they realized that the reactions of their students were directed to the concrete aspects of the body and to the aspects related to the behavior of the organisms; when they transmitted ideas of body focusing in the social dimension, they realized that their students demonstrated autonomy in social and cultural aspects. Finally, when they transmitted ideas of body in more including ways, they realized that their students related the physical activities to cognitive aspects. The results also showed that among the researched teachers, only one transmitted to the students the idea of the human body through inter-related physical, social and psychological knowledge.
The present study investigates the ideas of the human body transmitted and grasped by the teachers of Physical Education in Basic Education classes. It was carried a research with Physical Education ...teachers using the following questions: What ideas about the human body are you transmitting in your Physical Education classes? Do you perceive the reactions of your students to these ideas? The analyses of the answers were methodologically followed in these moments: a) reading of the descriptions, b) elaboration of the units of meaning; c) ideographic analysis; d) nomothetic analysis. Results showed that teachers of Physical Education when transmitting ideas of restricted body in the physical dimension, they realized that the reactions of their students were directed to the concrete aspects of the body and to the aspects related to the behavior of the organisms; when they transmitted ideas of body focusing in the social dimension, they realized that their students demonstrated autonomy in social and cultural aspects. Finally, when they transmitted ideas of body in more including ways, they realized that their students related the physical activities to cognitive aspects. The results also showed that among the researched teachers, only one transmitted to the students the idea of the human body through inter-related physical, social and psychological knowledge. PUBLICATION ABSTRACT
Three molecular protocols using qPCR TaqMan probe, SYBR Green, and loop-mediated isothermal amplification (LAMP) methods were set up for the identification of larvae and adults of an African invasive ...moth, Thaumatotibia leucotreta (Meyrick, 1913) (Lepidoptera: Tortricidae). The DNA extracts from larval and adult samples of T. leucotreta were perfectly amplified with an average Ct value of 19.47 ± 2.63. All assays were demonstrated to be inclusive for T. leucotreta and exclusive for the nontarget species tested; the absence of false positives for nontarget species showed a 100% of diagnostic specificity and diagnostic sensitivity for all assays. With the SYBR Green protocol, the Cq values were only considered for values less than 22 (cutoff value) to prevent false-positive results caused by the late amplification of nonspecific amplicons.The limit of detection (LoD) for the qPCR probe protocol was equal to 0.02 pg/µl while a value equal to 0.128 pg/µl for the qPCR SYBR Green assay and LAMP method were established, respectively.The intrarun variabilities of reproducibility and repeatability in all the assays evaluated as CV%, ranged between 0.21 and 6.14, and between 0.33 and 9.52, respectively; the LAMP values were slightly higher than other assays, indicating a very low interrun variability. In order for an operator to choose the most desirable method, several parameters were considered and discussed. For future development of these assays, it is possible to hypothesize the setup of a diagnostic kit including all the three methods combined, to empower the test reliability and robustness.
Summary
Background
Aminosalicylates are the mainstay of therapy to prevent relapse of quiescent ulcerative colitis. The rationale for using probiotics is based on the evidence implicating intestinal ...bacteria in the pathogenesis of this disorder.
Aim
To evaluate the efficacy of Lactobacillus GG alone or in combination with mesalazine vs. mesalazine as maintenance treatment in ulcerative colitis.
Patients and methods
187 ulcerative colitis patients with quiescent disease were randomized to receive Lactobacillus GG 18 × 109 viable bacteria/day (65 patients), mesalazine 2400 mg/day (60 patients) or Lactobacillus GG + mesalazine (62 patients). Disease activity index, endoscopic and histological scores were determined at 0, 6 and 12 months and in case of relapse. The primary end point was to evaluate sustained remission.
Results
Overall analysis showed no difference in relapse rate at 6 (P = 0.44) and 12 months (P = 0.77) among the three treatment groups. However, the treatment with Lactobacillus GG seems to be more effective than standard treatment with mesalazine in prolonging the relapse‐free time (P < 0.05).
Conclusions
Lactobacillus GG seems to be effective and safe for maintaining remission in patients with ulcerative colitis, and it could represent a good therapeutic option for preventing relapse in this group of patients.
Summary
Background : Helicobacter pylori infection may persist after both first‐ and second‐line current treatments.
Aim : To assess the efficacy of a third‐line, culture‐guided treatment approach ...for the eradication of H. pylori.
Methods : Patterns of resistance were analysed in H. pylori isolates from 94 consecutive patients in whom H. pylori infection had persisted after two eradication attempts. Using the epsilometer test, susceptibility analysis was performed for amoxicillin, clarithromycin, metronidazole, tetracycline and levofloxacin. Patients were then treated with a culture‐guided, third‐line regimen: 89 patients with a 1‐week quadruple regimen including omeprazole, bismuth, doxycycline and amoxicillin, and five patients with a 1‐week triple regimen containing omeprazole, amoxicillin and levofloxacin or clarithromycin.
Results : Ninety‐four subjects (100%) were resistant to metronidazole, 89 (95%) to clarithromycin, 29 (31%) to levofloxacin and five (5%) to tetracycline. No resistance to amoxicillin was found in any patient. Overall, H. pylori eradication was obtained in 90% of subjects. The quadruple regimen was effective in 81 patients (92% by per protocol and 91% by intention‐to‐treat analysis). Four patients (80%, both per protocol and intention‐to‐treat analysis) were H. pylori‐negative after the triple regimen.
Conclusions : A culture‐guided, third‐line therapeutic approach is effective for the eradication of H. pylori. Furthermore, the 1‐week doxycycline‐ and amoxicillin‐based quadruple regimen is a good third‐line ‘rescue’ treatment option.
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