Thermal cycling behavior of EBPVD TBC systems deposited on doped Pt-rich γ–γ′ bond coatings made by Spark Plasma Sintering (SPS)

In the last decade, an increasing interest was given to Pt-rich γ–γ′ alloys and coatings as they have shown good oxidation and corrosion properties. In our previous work, Spark Plasma Sintering (SPS) has been proved to be a fast and efficient tool to fabricate coatings on superalloys including entire thermal barrier coating systems (TBC). In the present study, this technique was used to fabricate doped Pt-rich γ–γ′ bond coatings on AM1® superalloy substrate. The doping elements were reactive elements such as Hf, Y or Zr, Si and metallic additions of Ag. These samples were then coated by electron beam physical vapour deposition (EBPVD) with an yttria partially stabilized zirconia (YPSZ) thermal barrier coating. Such TBC systems with SPS Pt rich γ–γ′ bond coatings were compared to conventional TBC system composed of a β-(Ni,Pt)Al bond coating. Thermal cycling tests were performed during 1000-1 h cycles at 1100 °C under laboratory air. Spalling areas were monitored during this oxidation test. Most of the Pt rich γ–γ′ samples exhibited a better adherence of the ceramic layer than the β-samples. After the whole cyclic oxidation test, cross sections were prepared to characterize the thickness and the composition of the oxide scales by using scanning-electron microscopy. In particular, the influence of the doping elements on the oxide scale formation, the metal/oxide roughness, the TBC adherence and the remaining Al and Pt under the oxide scale were monitored. It was shown that RE-doping did not improve the oxidation kinetics of the studied Pt rich γ–γ′ bond coatings, nevertheless most of the compositions were superior to “classic” β-(Ni,Pt)Al bond coatings in terms of ceramic top coat adherence, due to lower rumpling kinetics and better oxide scale adherence of the γ–γ′-based systems

The Zakharov-Shabat spectral problem on the semi-line: Hilbert formulation and applications

The inverse spectral transform for the Zakharov-Shabat equation on the semi-line is reconsidered as a Hilbert problem. The boundary data induce an essential singularity at large k to one of the basic solutions. Then solving the inverse problem means solving a Hilbert problem with particular prescribed behavior. It is demonstrated that the direct and inverse problems are solved in a consistent way as soon as the spectral transform vanishes with 1/k at infinity in the whole upper half plane (where it may possess single poles) and is continuous and bounded on the real k-axis. The method is applied to stimulated Raman scattering and sine-Gordon (light cone) for which it is demonstrated that time evolution conserves the properties of the spectral transform.Comment: LaTex file, 1 figure, submitted to J. Phys.

Characterization of the genomic region containing the Shadow of Prion Protein (SPRN) gene in sheep

<p>Abstract</p> <p>Background</p> <p>TSEs are a group of fatal neurodegenerative diseases occurring in man and animals. They are caused by prions, alternatively folded forms of the endogenous prion protein, encoded by <it>PRNP</it>. Since differences in the sequence of <it>PRNP </it>can not explain all variation in TSE susceptibility, there is growing interest in other genes that might have an influence on this susceptibility. One of these genes is <it>SPRN</it>, a gene coding for a protein showing remarkable similarities with the prion protein. Until now, <it>SPRN </it>has not been described in sheep, a highly relevant species in prion matters.</p> <p>Results</p> <p>In order to characterize the genomic region containing <it>SPRN </it>in sheep, a BAC mini-contig was built, covering approximately 200,000 bp and containing the genes <it>ECHS1</it>, <it>PAOX</it>, <it>MTG1</it>, <it>SPRN</it>, <it>LOC619207, CYP2E1 </it>and at least partially <it>SYCE1</it>. FISH mapping of the two most exterior BAC clones of the contig positioned this contig on Oari22q24. A fragment of 4,544 bp was also sequenced, covering the entire <it>SPRN </it>gene and 1206 bp of the promoter region. In addition, the transcription profile of <it>SPRN </it>in 21 tissues was determined by RT-PCR, showing high levels in cerebrum and cerebellum, and low levels in testis, lymph node, jejunum, ileum, colon and rectum.</p> <p>Conclusion</p> <p>Annotation of a mini-contig including <it>SPRN </it>suggests conserved linkage between Oari22q24 and Hsap10q26. The ovine <it>SPRN </it>sequence, described for the first time, shows a high level of homology with the bovine, and to a lesser extent with the human <it>SPRN </it>sequence. In addition, transcription profiling in sheep reveals main expression of <it>SPRN </it>in brain tissue, as in rat, cow, man and mouse.</p

A birational mapping with a strange attractor: Post critical set and covariant curves

We consider some two-dimensional birational transformations. One of them is a birational deformation of the H\'enon map. For some of these birational mappings, the post critical set (i.e. the iterates of the critical set) is infinite and we show that this gives straightforwardly the algebraic covariant curves of the transformation when they exist. These covariant curves are used to build the preserved meromorphic two-form. One may have also an infinite post critical set yielding a covariant curve which is not algebraic (transcendent). For two of the birational mappings considered, the post critical set is not infinite and we claim that there is no algebraic covariant curve and no preserved meromorphic two-form. For these two mappings with non infinite post critical sets, attracting sets occur and we show that they pass the usual tests (Lyapunov exponents and the fractal dimension) for being strange attractors. The strange attractor of one of these two mappings is unbounded.Comment: 26 pages, 11 figure

Characterization of the ovine ribosomal protein SA gene and its pseudogenes

Background: The ribosomal protein SA (RPSA), previously named 37-kDa laminin receptor precursor/67-kDa laminin receptor (LRP/LR) is a multifunctional protein that plays a role in a number of pathological processes, such as cancer and prion diseases. In all investigated species, RPSA is a member of a multicopy gene family consisting of one full length functional gene and several pseudogenes. Therefore, for studies on RPSA related pathways/pathologies, it is important to characterize the whole family and to address the possible function of the other RPSA family members. The present work aims at deciphering the RPSA family in sheep. Results: In addition to the full length functional ovine RPSA gene, 11 other members of this multicopy gene family, all processed pseudogenes, were identified. Comparison between the RPSA transcript and these pseudogenes shows a large variety in sequence identities ranging from 99% to 74%. Only one of the 11 pseudogenes, i.e. RPSAP7, shares the same open reading frame (ORF) of 295 amino acids with the RPSA gene, differing in only one amino acid. All members of the RPSA family were annotated by comparative mapping and fluorescence in situ hybridization (FISH) localization. Transcription was investigated in the cerebrum, cerebellum, spleen, muscle, lymph node, duodenum and blood, and transcripts were detected for 6 of the 11 pseudogenes in some of these tissues. Conclusions: In the present work we have characterized the ovine RPSA family. Our results have revealed the existence of 11 ovine RPSA pseudogenes and provide new data on their structure and sequence. Such information will facilitate molecular studies of the functional RPSA gene taking into account the existence of these pseudogenes in the design of experiments. It remains to be investigated if the transcribed members are functional as regulatory non-coding RNA or as functional proteins

Comparative performances of machine learning methods for classifying Crohn Disease patients using genome-wide genotyping data

© 2019, The Author(s). Crohn Disease (CD) is a complex genetic disorder for which more than 140 genes have been identified using genome wide association studies (GWAS). However, the genetic architecture of the trait remains largely unknown. The recent development of machine learning (ML) approaches incited us to apply them to classify healthy and diseased people according to their genomic information. The Immunochip dataset containing 18,227 CD patients and 34,050 healthy controls enrolled and genotyped by the international Inflammatory Bowel Disease genetic consortium (IIBDGC) has been re-analyzed using a set of ML methods: penalized logistic regression (LR), gradient boosted trees (GBT) and artificial neural networks (NN). The main score used to compare the methods was the Area Under the ROC Curve (AUC) statistics. The impact of quality control (QC), imputing and coding methods on LR results showed that QC methods and imputation of missing genotypes may artificially increase the scores. At the opposite, neither the patient/control ratio nor marker preselection or coding strategies significantly affected the results. LR methods, including Lasso, Ridge and ElasticNet provided similar results with a maximum AUC of 0.80. GBT methods like XGBoost, LightGBM and CatBoost, together with dense NN with one or more hidden layers, provided similar AUC values, suggesting limited epistatic effects in the genetic architecture of the trait. ML methods detected near all the genetic variants previously identified by GWAS among the best predictors plus additional predictors with lower effects. The robustness and complementarity of the different methods are also studied. Compared to LR, non-linear models such as GBT or NN may provide robust complementary approaches to identify and classify genetic markers

Secukinumab shows significant efficacy in palmoplantar psoriasis: Results from GESTURE, a randomized controlled trial

Background: Plaque psoriasis affecting palms and soles is disabling and often resistant to treatment. Objective: Evaluate the efficacy and safety of secukinumab, an anti-interleukin 17A antibody, in subjects with palmoplantar psoriasis. Methods: In this double-blinded, randomized controlled trial, 205 subjects were randomized 1:1:1 to secukinumab 300 mg, 150 mg, or placebo. The primary endpoint was Palmoplantar Investigator's Global Assessment (ppIGA) 0 (clear) or 1 (almost clear/minimal) response at week 16. Results: At week 16, the percentage of subjects who achieved clear or almost clear palms and soles (or ppIGA 0/1) with secukinumab 300 mg (33.3%) and 150 mg (22.1%) was superior to the percentage achieved with placebo (1.5%, . P < .001). Palmoplantar Psoriasis Area and Severity Index (ppPASI) was significantly reduced with secukinumab 300 mg (-54.5%) and 150 mg (-35.3%) compared with placebo (-4.0%, . P < .001). Dermatology Life Quality Index (DLQI) 0/1 responses from subjects in the secukinumab groups were also significantly higher compared with placebo at week 16 (P < .01) and pain and function of palms and soles was markedly improved with secukinumab as measured by the palmoplantar Quality-of-Life Instrument. Secukinumab 300 mg consistently showed the best outcomes. The safety profile was favorable and similar to previous studies. Limitations: Lack of active comparator. Conclusion: In GESTURE, the largest randomized controlled trial in palmoplantar psoriasis, secukinumab demonstrated the greatest efficacy to date for treating difficult-to-treat psoriasis

Nonlinear energy transmission in the gap

Numerical simulations of the scattering of a linear plane wave incoming onto a nonlinear medium (sine-Gordon) reveals that: i) nonlinearity allows energy transmission in the forbidden band, ii) this nonlinear transmission occurs beyond an energy threshold of the incoming wave, iii) the process begins (at the threshold) with large amplitude breathers, and then energy is generically transmitted both by kink-antikink pairs and breathers.Comment: Latex file, 6 figures, 9 pages, to appear in Physics Letters